DESERT~FICATION AND ITS CONTROL

Released on the occasion oi THE UN CONFERENCE ON DESERTIFICATION, NAIROBI 29 August -9 September, 1977

!CAR

INDIAN COUNCIL OF AGRICULTURAL RESEARCH NEW DELHI PRINTED AUGUST 1977

Chief Editor: P. L. JAISWAL Associates: RAJINDER SINGH N. N. CHHABRA KRISHNA SUNDARARAMAN

Chief ofProduction: KRISHAN KUMAR Production Assistant: J. B. MEHRA

Dy. Chief Artist: M. K. BARDHAN Senior Artist: RAJENDRA MOHAN

Printed in India by Megh Raj at Model Press (P) Ltd., 6-E, Rani Jhansi Road, New Delhi-llOOS5, and published by S. S. Grewal, Under-Secretary, for the Indian Council of Agricultural Researcb New Delhi-l10001. FOREWORD

I am happy that the Indian Council of Research Institute was established at Agricultural Research is bringing out a Jodhpur in 1959 to conduct basic and publication on "Desertification and Its applied researches on the problems of arid Control" on the occasion of the United areas. As a result of the intensive work Nations Conference on Desertification. I carried out at this Institute, considerable would like to congratulate the United experience has been gained on different Nations and its specialized agencies for aspects of the problem. The scientific and focusing attention on this important technical basis for dryland agriculture and problem. horticulture, grassland management, live­ About one-third of the world's land stock farming, afforestation and water surface today is in the grip of deserts. The harvesting have been explored with a fair man-made deserts alone, total about 9.1 degree of success. Operational research million sq km in area. In India, the projects have also been initiated in the arid zone occupies nearly 12 per cent of arid areas of Rajasthan to expedite effec­ the total area sustaining a human popula­ tive transfer of technology. tion of over 19 millions and livestock of However, despite useful contributions over 23 millions. According to a recent and efforts by research organisations, we study on Desertification completed at the have not been able to achieve a significant Central Arid Zone Research Institute, it breakthrough on the development front. has been found that 4.35 per cent of A major reason for this is the lack of an western Rajasthan has already been affec­ integrated approach. The available scien­ ted by the processes of desertification and tific information on the rational use of that another 76 per cent area is modera­ eco-system resources are yet to be conver­ tely vulnerable to desertification. ted into action programmes. The develop­ An important factor in the accentuation ment of the desert area, thus, is a major of desert condition is the escalation of task which covers programmes under human and livestock population. The many disciplines and consequently several human population in the Rajasthan desert departments. In view of its magnitude itself has increased from 3.42 millions in and complexity, it is important to have 1901 to 8.84 millions in 1971. In fact, the comprehensive time-phased plans of de­ Indian desert is one of the most thickly velopment with a clear knowledge of re­ populated among the desert areas of the lative priorities. world. The ultimate success of all our pro­ During the past few years, several grammes will depend on the extent of in­ studies on the problems of arid zone volvement of the desert people themselves have been promoted by international who have been fighting for survival bra­ organisations such as the UNESCO and ving the sun, wind and lack of water over F AO. In India, the Central Arid Zone the centuries. Backed by science and

iii FOREWORD technology they can bring about the re­ control. The message of the papers is quired transformation. clear, namely, "Given the will and appro­ I hope the papers contained in the book priate action, the desert can bloom": It will be found useful by all interested in is now up to everyone concerned to take the problems of desertification and its action to convert the potential into reality.

New Delhi SURJIT SINGH BARNA LA 26 July, 1977 Union Minister for Agriculture and Irrigation PREFACE

THE arid zone of India occupies an area fit only for forestry or range management, of 3.2 lakh sq km of hot desert, mostly land is increasingly being brought under in Rajasthan, Gujarat, Haryana and cropping. The areas cropped rose from Karnataka and 0.7 lakh sq km of cold 26 per cent in 1960 to 38 per cent in 1970, desert in Ladakh. In Ladakh, extreme thus extending cultivation even to sub­ aridity combined with low temperature marginal areas. Thirdly, the area under limits the possibility of growing crops to forests is only 2 per cent although the ex­ about 5 months in a year. Hence, the tent of land classified under barren un­ strategy for agricultural development in cultivable waste is 28 per cent and cultu­ Ladakh has to depend largely on the cul­ ral waste is 18 per cent, all of which could tivation of qUick-growing cereals, oil seeds be planted with tree species like Acacia and fodder crops and the rearing of goats, tortilis, Prosopis juliflora and Eucalyptus giving Pashmina wool. The hot desert sp. Fruit trees like ber (Zizyphus mauritiana) regions, in contrast, have an abundance of and pomegranate can also be grown. sunshine, land and soils capable of respon­ Afforestation has to be the focal point ding to management, well-adapted grasses for reclaiming the desert. Techniques for and trees, excellent breeds of sheep, goat soil and water conservation and for sand­ and cattle, and considerable reserves of dune stabiliza ion are fortunately avail­ ground-water. Water and not land, is able today. Large scale planting of shel­ the principal limiting factor and hence all ter-belts could help to minimise wind attempts have to be focused on maximi­ erosion and decrease the dust over the sing income per litre of water This will dese:t. Scope for the establishment of ~e possible only if the ecological balance pastures and grazing lands is great and ]s not further disturbed and a proper land­ strip cropping involving the setting up of use pattern is adopted. permanent grass strips to prevent wind Let me cite three examples to illustrate damage will help to increase the yield of the trends which are aggravating the un­ crops like bajra (Pennisetum typhoides) and favourable consequences of aridity. First, moong (Vigna radiata) substantially. If the area used exclusively for grazing in steps of this kind can be taken, it may be Western. ~ajasthan has dropped from possible for the nomadic tribes to start 13.09 millIOn hectares to I 1.04 million leading a more settled life. he?tares during 1951-61, while the popu­ Rajasthan has many fine breeds of latIOn of grazing animals increased during sheep and research has shown that appro­ the same period from 9.4 millions to 14.4 priate cross-breeding procedures can help milli.ons. The same trend of diminishing to improve the yield and quality of wool wazmg area and rapidly expanding graz­ a,d of mutton. Fortunately, techniques mg. population is persisting. Secondly, for arti ficial insemination have been de­ whlle most of the land in the arid zone is veloped and hence more widespread gene-

v PREFACE

tic improvement programmes are possible. bad season or to derive maximum ad­ An important need in the desert areas vantage from a good season. For example, is the preservation of organic matter for 1977, because of the good monsoon, pro­ the soil. Unfortunately, due to deficiency vides a unique opportunity for planting of fuel, the available organic wastes are in the desert a large number of trees and generally used for burning and trees are for seeding large areas with grasses. In cut in an unplanned manner. It is here spite of the shallow nature of the soils and that more extensive research and extension the calcium carbonate pans which occur efforts on the utilization of solar energy in the subsoil, thereby increasing run-off for purposes like heating. cooking, light­ and reducing infiltration, abundant mois­ ing and distilling water will be of grea t ture will be available to facilitate the es­ value. Often in the desert areas, the tablishment of trees, shrubs and grasses. water is saline and people have to walk The present publication brought out on several miles every day to fetch sweet the occasion of the United Nations Con­ water. Solar stills to produce water for ference on Desertification provides a drinking in such area will be a great boon synoptic account of the work done in to the villagers. India on problems relating to the Rajas­ Sophisticated techniques for raising than desert. I am grateful to Dr H.S. crops in desert a'reas with very limited Mann, Director, Central Arid Zone Re­ quantities of water are now becoming search Institute, Jodhpur and his band of available. These involve cultivation of devoted scientists of CAZRI as well as to vegetables and high-value crops under air­ the other contributors to this volume for inflated polyethylene houses using econo­ the trouble they have taken to prepare the mic methods of water supply like drip or material. Besides the editorial and pro­ sprinkler irrigation. Since the Lathi duction staff of ICAR whose names are aquifers of the Thar desert are rich, it listed in this volume, Dr K.S. Bedi served may be possible to develop efficient water­ as Honorary Editor and paid detailed use systems at least for raising community attention to the language aspect of the nurseries of different crops so that trans­ presentation. My sincere thanks are also planting can be done if there is a delayed due to him. I hope this volume will be onset of monsoon and for purposes like found to be of some value by all interes­ the cultivation of vegetables and seed pro­ ted in the problems of the desert and the duction. challenge they pose to the scientists, and Unfortunately, we have no arrangements to those involved in the development and now either to mitigate the rigours of a proper utilization of resources.

M. S. SWAMINATHAN New Delhi Director-General 27 July, 1977 Indian Council of Agricultural Research CONTENTS

Foreword iii Preface v 1. Introduction - H. S. Mann 1 2. Origin and history of the Rajasthan desert-Palaeobotanical 6 evidence - Vishnu-Mittre 3. Evolution of the pattern of human settlement in the arid and 10 semi-arid regions - V. N. Misra

CLIMATE 4. Climatic changes in the Indian desert - Gurdip Singh 25 5. Palynological evidence on climatic changes in Jaisalmer Basin, 31 Rajasthan - N. G. Lukose 6. A climatic analysis of the arid zone of north-western India 42 - A. Krishnan

LAND 7. Geological history of the north-western arid zone of India 58 - P. C. Chatterji 8. Geomorphology of the Rajastlian desert - Bimal Ghose, 69 S. Singh and Amal Kar 9. The methodology of mapping land resources for rational utilization 77 - K. A. Shankarnarayan and Amal Kumar Sen 10. The extent, resources and prospects of the coastal desert of north- 81 western India - Amal Kumar Sen and K. A. Shankarnarayan

vii CONTENTS

11. Land and resource utilization in the arid zone - H. S. Mann, 89 S.P. Malhotra and K. A. Slzankamarayan

12. Western Rajasthan soils : their characteristics and properties 102 -R.P. Dhir

13. Geomorphology, soil and land use in desert regions of Gujarat, 116 Punjab and Haryana - R. S. Murthy and S. Pandey

WATER RESOURCES

14. The Rajasthan canal project - A. S. Kapoor and B. S. Rajvanshi , 121

15. Saline waters-their potentiality as a source of irrigation 130 -R. P. Dllir

16. Desalination techniques for conversion of brackish water into 149 potable water for small communities - A. V. Rao' and D.J. Mehta

17. Ground-water resources of the arid zone Of India - T. N. Mehra 156 and Amal Kumar Sen

VEGETATION

18. The arid zones of India : Bioclimatic and vegetational aspects 160 - V. M. Meher-Homji

19. Vegetation and its succession in the Indian desert - S. K. Saxena 176

20. Measuring desertification through plant-indicators 193 - Vinod Shankar 21.. Forest-tree planting in arid zones-R. N. Kalil and Gyan Chand 196

22. Improving rangeland productivity - L. D. Ahuja 203

AGRICULTURE

23. Crop production in the Indian arid zone - H. S. Mann and 215 R. P. Singh

24. Plants in relation to soil moisture conditions of the arid areas 225 - A. N. Lahiri

25. Optimum utilization of limited water supply - S. D. Singh 237

26. Arid horticulture - O. P. Pareek 256

viii CONTENTS

RODENTS AND INSECT PESTS

27. Desert rodents and their management - Ishwar Prakash 263 28. Insect pests and their control - K. S. Kushwaha and S. K. Pal 269

LIVESTOCK

29. Livestock production-Problems and prospects-R. M.Acharya, 275 B. C. Patnayak and L. D. Ahuja

OTHER NATURAL RESOURCES

30. Salt and by-product resources of Gujarat and Rajasthan 281 - M. P. Bhatt, G. T. Gadre and D. J. Mehta 3l. The utilization of wind energy and wind regimes of arid areas 291 in India - S. K. Tewari 32. The utilization of solar energy in the arid and semi-arid zoneS 301 of India - H. P. Garg

DEMOGRAPHY AND SOCIOLOGY

33. Socio-demographic factors and nomadism in the arid zone 310 - S. P. Malhotra ,_ 34. Asset-liability imbalances in agricultural sector of the Indian 324 arid zone - H. S. Mann and Jagdeesh C. Kalla 35. Land-tenure problems and policies in the arid region of 335 Rajasthan - N. S. Jodha

COLD DESERT 36. Geothermal energy and its possible application in agriculture in 348 Ladakh region - Mohan L. Gupta

EXTENSION 37. An operational research project for arid-land management 354 - S. P. Malhotra

ix CONTRIBUTORS

R. M. ACHARYA J. C. KALLA Central Sheep & Wool Research Institute Central Arid Zone Research Institute Avikanagar (Rajasthan) Jodhpur L. D. AHu1A A. S. KAPOOR Central Arid Zone Research Institute Rajasthan Canal Project Jodhpur Bikaner M. P. BHA'IT AMAL KAR Central Salt & Marine Chemicals Central Arid Zone Research Institute Research Institute Jodhpur Bhavnagar (Gujarat) R.N.KAUL GYAN CHAND Department of Agriculture (Soil Conservation) Central Arid Zone Research Institute Government of India Jodbpur New Delhi 'P. C. CHATTERJI A. KRISHNAN Central Arid Zone Research Institute Central Arid Zone Research Institute Jodhpur Jodhpur R.P. DHIR K. S. KUSHWA.'fA Central Arid Zone Research Institute Udaipur University Jodhpur Udaipur G. T. GADRE A. N.J.,AHlRI Central Salt & Marine Che1llicals Central Arid Zone Research Institu te Research Institute Jodhpur Bhavnagar H. P. GARG N. G. LUKOSE Oil & Natural Gas Commission Central Arid Zone Research Institute Jodhpur Jodhpur BlMAL GHOSE S. P. MALHOTRA Central Arid Zone Research Institute Central Arid Zone Research Institute Jodhpur Jodhpur M. L. GUPTA H. S. MANN National Geophysical Research Institute Central Arid Zone Research Institute Hyderabad Jodhpur N. S. JODHA v. M. MEHER-HoM1I ICRISAT Institute Francais Hyderabad Pondicherry

x CONTRIBUTORS

T. N. MEHRA A. V. RAO Rajasthan Underground Water Board Central Salt & Marine Chemicals Jodhpur :Research Institute Bhavnagar

D. J. MEHTA S. K. SAXENA Central Salt & Marine Chemicals Research Institute Centra] Arid Zone Research Institute Bhavnagar Jodhpur

A. K. SEN V. N. MISRA Department of Archaeology Central Arid Zone Research Institute Poona University Jodhpur Poona K. A. SHANKARNARAYAN R.S.MURTHY Central Arid Zone Research Institute National Bureau of Soil Survey & Land Use Jodbpur Planning IARI Campus VINOD SHANKAR New Delhi Central Arid Zone Research Institute Jodbpur S. D. PAL ICRISAT GURDIP SINGH Hyderabad Research School of Pacific Studies Australian National University S. PANDEY Canberra (Australia) National Bureau of Soil Survey & Land Use Planning R. P. SINGH IARI Campus Central Arid Zone Research Institute New Delhi Jodhpur

O.P. PAREEK S. SINGH Central Arid Zone Research Institute Central Arid Zone Research Institute Jodhpur Jodhpur

B. C. PA1NAYAK S. D. SINGH Central Sheep & Wool Research Institute Central Arid Zone 'Research Institute Avikanagar Jodhpur

ISHWAR PRAKASH S. K. TEWARI Central Arid Zone Research Institute National Aeronautical LaboratorY Jodhpur Bangalore

B. S. RAJVANSHI VISHNU-MuTRE Rajasthan Canal Project Birbal Sahni Institute of Palaeobotany Bikaner Lucknow

XI 1

INTRODUCTION

H.S.MANN

THE Indian desert, a hot-season rainfall quartzite have been found from Jaipur region, situated in the north-west covers and Indargarh. These tools must be at about 28,600 km". The western scarp of least 2,00,000 years old (Sankalia, 1952). the Aravalli Range, running in a NE-SW Misra and Rajaguru (1975) consider that direction, is the geomorphic as well as the the Middle Palaeolithic culture of the climatic (500 m isohyte) boundary of the Luni Valley of the Rajasthan desert is of desert in the east, whereas in the west it late Pleistocene age. There is considera­ merges into the Pakistan desert. In the ble evidence that Rajasthan was inhabited north, the desert extends into the Punjab by man early in Holocene times, though and Haryana States and in the south into it is not certain whether there was cultural the Gujarat State. continuity from Palaeolithic to this Mesoli­ Archaeological evidences suggest that the thic period (c.f. Tilwara, 70°5'E, 25°52'N) onset of aridity was the major cause of the estimated roughly to 5000 B.C. The extinction of the Riparian and Harappa­ Harappan culture has been traced at Kali­ Kalibangan civilization. A well-knit river bangan, situated on the bank of the 'lost' system existed in the desert until recent Saraswati river. Radio-carbon dating times. The deterioration of climate, the indicates that this culture flourished around rise of the Himalayas, the lowering of the 2700 B.C. (Satya Prakash, 1964); Harappan Aravallis, important changes in the river culture is generally placed at 2300-1750 sysfems, e.g. the diversion and disappea­ B.C. More than a hundred sites of this cul­ rance of three classical rivers (the Yamuna, ture have been discovered in the Ghaggar the Saraswati and the Ghaggar), and the bed in the northern desert. It is thus lowering of the underground water-table clear that the roots of man in the Rajas­ caused increased aridity in the area than desert are fairly old. (Wadia, 1960). Krishnan (1952) observed The notion that the Rajasthan desert that arid conditions might have set in has been advancing at the rate of 1/2 a between 4000 B.C. and 1000 B.C. Palyno­ mile per year for the last 50 years, as logical evidences indicate that the deserti­ claimed by the Planning Commission in its fication process set in during the late Creta­ First Five-Year Plan Report, is fairly ceous (Lukose, 1972; Gurdip Singh, pers. widespread, but lacks scientific unanimity, comm.). Biotic interference of the natural' mostly because of terminological con­ resources further accentuated the xeric troversies. The increase and decrease in conditions at a later stage. There is clearly wind-blown surfaces have been illustrated much SCope for further work. by a comparison of old and recent survey There are archaeological evidences to maps which indicated an extension of the sug~est that Rajasthan, Punjab and desert towards the east (Singh, 1952). GUJarat Were inhabited by man during the However, the fact that in some. areas sand Palaeolithic period. Hand-axes made of formations have developed, whereas in DESERTIFICATION AND ITS CONTROL

others they have diminished or vanished, under the plough and this trend is con­ is no conclusive proof of the movement tinuing. of the desert. Recently, a study based The increasing human population is a on socio-economic parameters has also serious stress, particularly on the vegetal yielded evidence that there may not be resources of the desert. The trees and any scientific basis of the view that the shrubs and even their roots are indiscri­ Rajasthan desert has been spreading in minately cut by the rural population for the north-easterly direction (Mann, Mal­ fuel, top feed, thorn fencing and the con­ hotra and Kalla, 1974). Scientists are, struction of thatched hutments. It has however, unanimous with regard to the been estimated that the requirement of the accentuation of xeric conditions within the people in the desert in respect of the woody desert owing to over exploitation of the biomass has increased from 1.85 million vegetation and land resources. The dearth tonnes' in 1951 to 3.33 million tonnes in of sufficient climatic data do preclude the 1971. The desert people have developed establishment of definite climatic shifts, peculiar food habits. All the available although indications of some climatic air-dried seeds and pods of the trees are fluctuations in the past have been noti­ used as delicacies. The seeds of Acacia ced. senegal (kwnat), the fruits of Capparis The major factors of desertification decidua (karir) and the pods of Prosopis (accentuation of the desert conditions) cineraria are harvested. Almost all the within the desert are the escalation of fruits of Zizyphus nummularia (ber, jhad­ human and livestock population and their beri) growing in accessible parts of the activities, besides the climatic and geo­ desert are harvested for human consump­ morphological factors. The human popu­ tion. The seeds of grasses, e.g. Panicum lation within the Rajasthan desert has turgidum, P. anlidolale, Cenchrus biflorus increased from 3.42 millions in 1901 to and Echil1ochloa co/anum, are mixed with 8.84 millions in 1971-a growth rate of millet for making c/zapatis (unleavened 158 per cent, and this rate is much more cakes) especially during drought years. (125 per cent) in comparison with the whole The grass seeds are supposed to add to the of the Rajasthan State. The density of nutritive value of the food. The intensity popUlation in various desert districts vary with which seed collection is made for from 4 in Iaisalmer to 157 persons per direct human consumption throughout the km2 in the Ihunjhunu district. The desert region seriously affects the natural human popUlation in the desert is largely process of regeneration of the desirable rural; the ratio of urban to rural popu­ plant species in the inhospitable terrain. lation came to 3.90, 4.50 and 4.33 res­ Along with efforts to evolve technology for pectively in 1951, 1961 and 1971: About- increasing vegetable production locally. 79 per cent of the popUlation is engaged the problem has to be tackled also by in agriculture. One of the crucial bottle­ formulating a suitable educational pro­ necks is that we are un'able to find occu­ gramme for the masses. pations for the ever-increasing human Livestock population far exceeds human population. The occupations do not population in arid western Rajasthan. It require the use of water, land or domestic increased from 9. 4 millions in 1951 to 15.5 animals, e.g. large-scale mining, oil and millions in 1972. The goat and sheep natural gas, tourism, etc. which could earn populations ranged from 57. 1 to 69. 3 % a livelihood for the people without becom­ during this period. Owing to continued ing a denuding stress on the land. Agri­ droughts during 1967-71, with the con­ culture and animal husbandry remain the sequent migration and mortality, the major sources of income of the people in number of cattle fell heavily (10.8% the Rajasthan desert. Owing to the in­ decrease), but the number of hardy creasing population and related economic animals, e.g. the goat, increased substan­ facto~s, marginal lands have been brought tially (34 % increase). The data thus not

2 INTRODUCTION

only reveal a preponderance of the goat pensity is InJunous to soil conservation. and sheep populations in the arid Rajas­ Out of 17 species of rodents found, 10 are than but also point to their increase during of economic importance. In various the years of drought. The goats are the desert habitats, their number fluctuates desert-makers par excellence, eating every from 7.4 to 523 per hectare and their bit of green or dry vegetation. biomass from 435 to 2,641 g/ha. Their Because of cultivation of marginal lands. dietary demands (1,044 kg/ha) are so overgrazing, and the depredations of field insatiable that a resident population of rodents, the compact, stabilized sand over Meriones liurrianae during the monsoon the inter-dunal and dune lands is loose­ can consume the total forage production ned to be carried away by the strong desert of an area (1,100 kg/ha), thus virtually winds. It has been estimated that dust leaving nothing for the livestock. Rodents blowing from the surface to a height of also ravage the germinating and growing 3 metres on a dust storm day varies from vegetation, feed on seeds, thus lowering 0.58 to 4.20 quintals per hectare at Jodh­ the regeneration potential of the vegetation pur and 5.11 quintals at Jaisalmer during and even debark 20-30 per cent of 1-8- the normal years. In exceptionally dry year-old saplings planted for reforesta­ years, as in 1970, the germinated khari/ tion of the dunes. The merion gerbils crop was buried under shifting sands over alone are estimated to excavate 61,500 kg vast areas in Jaisalmer, Bikaner and Barmer of soil per day per km' in cultivated fields districts. As recommended by the National during summer and 10,43,800 kg/day/km" Commission on Agriculture, it is impor­ in uncultivated areas. tant to work out a policy whether arid The locust menace, though under control lands receiving rainfall lower than 300 mm during the last decade, is known to cause per annum or so should be cultivated or havoc in the desert and its adjoining areas. used as rangelands for livestock. In the past, locust swarms entered the Another important consequence of Rajasthan desert in the hot months of overgrazing is the interference in natural May and June and devoured whatever regeneration and succession of vegetation, green vegetation that might still be fight­ especially the grass species. The lush ing for survival, leaving the sandy desert monsoon vegetation in the desert may seem to the mercy of the strong summer winds. an inexhaustible source of foraging mate­ As it is well-known, even large trees are rial for the very large number of domestic totally defoliated by locusts and they livestock. Most of the species, e.g. Tep­ sometimes collapse owing to the sheer hrosia purpurea, Indigo/era cordi/olia, weight of the tiny marauders. Thus, Tribulus terrestris, erotalaria burhia, Lype­ historically, the desert locust has been one rlls spp., are not only inedible or unpalat­ of the major agents of accentuation of xeric able to livestock, but compete severely with conditions. the perennial species of nutritive grasses The scientific exploitation of ground­ and, consequently, the landscape is in­ water in the Indian desert is another fested by low-ranking unpalatable annuals, important matter. The occurrence and thus ~ecreasing vegetation production and the quality of the ground-water at a parti­ a~ordmg poor coverage for soil conserva­ cular site are mainly dependent on the tIon. mode of formation and nature of the . Pests join man and his livestock in deple­ . aquifer and its relation to the overlying tIng the vegetative resources of a region. beds. The water-bearing rock formations Rod~nts are an important factor in deserti­ of the Rajasthan desert are the Aravalli ficatIOn. Besides maintaining a perpetual slates, schists, quartzite, phyllite, Malani pressure on the natural vegetation for their rhyolite and granite, Jodhpur and Lathi food, bec~us: of their burrowing habits, sandstones, and Bilara limestone. In rodents slgmficantly induce soil erosion a major part of the desert, ground-water (Prakash, 1976). Their fossorial pro- generally occurs in small, isolated pockets

3 DESERTIFICATION AND ITS CONTROL

and not as a continuous body. Only a few completed at the Central Arid Zone Re­ areas have been recognized for moderate search Institute on behalf of the UNESCO, to large-scale ground-water development, it has been found that about 9,290 km' e.g. the Jawai-Sukri river alluvium of or 4.35 per cent of the western Rajasthan Jalore, the alluvial sediments of Doli­ has already been affected by the proces­ Jhanwar-Pal area, the Lathi sandstone ses of desertification. 1,62,900 km" or of Jaisalmer, the Borunda limestone and 76. 15 per cent of the area has been cate­ the Jodhpur sandstone in the Jodhpur­ gorized as highly and moderately vulnera­ Phalodi region. ble and 41,692 km" or 19.5 per cent of the area is moderately to slightly vulnerable Utilization of ground-water to the various processes of desertification. It has been estimated that 47.78 per The shifting of sand and soil erosion by cent of the total exploitable ground-water winds are the major causative factors. potential is tapped in various desert dis­ In the study area, the Luni Development tricts (Das Gupta et al., 1973). Jalore, Block, it was observed that during the last Jodhpur, Pali and Sikar are the only 18 years, sand movement leading to a districts where more than 50 per cent of the further accentuation of undulations has total exploitable water potential is utili­ taken place over 166 kmS. The recent zed. About 7 per cent of the total exploit­ sand-shifting has led to an increase in the able water is utilized for irrigation thickness of the 'soil on the previously and 13 per cent for human and live­ created fence-line hummocks by 15 to 30 m stock consumption. Considering the needs and have enhanced their width by 1-2 m. for irrigation and human and livestock The process of desertification is rather consumption, it appears that in a few years revealing in the vegetal component of the the exploitation of ground-water will exceed ecosystem. The productive climax plant the annual recharge. There is, therefore, associations have changed to degraded an immediate need to evolve a sound vegetation types with the increase of un­ ground-water exploitation policy. palatable species. Certain areas of the The water-scarcity problem is compound­ desert, belonging to the slight-vulnerabi­ ed by its quality aspects. Saline ground­ lity category, are also associated with waters up to and over a salinity level water erosion. of 10,000 micromhos (about 6-7 grammes The knowledge of various disciplines of soluble salts/litre) are being used in the have been gained and the technologies d\!sert for growing barley and 'Kharchia' for the development of the arid regions wheat and it is estimated that the area have been evolved by research institutions covered by saline-water irrigation is nearly and they are reflected in the formulation 0.4 million ha. The continued use of of policies for development. A recent these waters renders the soil saline or report of the National Commission on saline/sodic. Loamy ~oils tend to accu­ Agriculture on Desert Development, and mulate a higher concentration of salts and the initiation of the Drought-Prone Area also show a high SAR. The soils which Programme in collaboration with the accumulate salts up to 10-16 millimhos World Bank are important landmarks in ECe, however, attain a salinity level of this field. 2-6 millimhos ECe after one or two rainy This publication has been prepared for seasons, depending on the' soil texture, the UN Conference on Desertification and become fit again for cultivation. to be held at Nairobi in August-September However, the salts leach to deeper depths 1977. The contributions reflect the and continue to accumulate there and scientific work done and the available . after several decades of cultivation, areas technologies. While scientific research is with loamy and heavier-textured soils in­ being intensified for discovering methods variably become unfit for cultivation. of harnessing the resources of the arid In, a recent study on desertification, and semi-arid areas, operational research

4 INTRODUCTION

projects that have been initiated by the Zone 13 (2); 103-113. MISRA, V. M. and RAJAGURU, S. N. 1975. Some Indian Council of Agricultural Research aspects of Quaternary environment and early in the region are likely to pave the way man in western India. Workshop on the for the down-to-earth application of the , problems of desert in India, Jaipur. available knowledge for the good of the PRAKASH, I. 1976. Rodent Pest Management­ Principles and Practices. Central Arid Zone desert people. Research Institute, Jodhpur, Monograph No: 4, 1-28. REFERENCES PRAKASH SATYA, 1964. Archaeology. Recent Deve­ DAS GUPTA, K., KHILNANJ, V.B. and BHANDARI. lopment in Rojasthan. Souvenir vo!. CAZRI, U.M. 1973. An approximate assessment of Jodhpur, India, 134-148. exploitable groundwater potential of Rajas­ Roy, B.B. and PANDEY, S. 1970. Expansion or than. Proc. Winter School. Dev. Raj. Desert. contraction of Great Indian Desert. Proc. Indian natn. Sci. Acad. India, Jodhpur, Feb. Indian natn. Sci. Acad. 36 (6) ; 331-343. 1973. KRISHNAN, M. S. 1952. Geological history of SANKALIA, H.D. ]952. The condition of Rajputana Rajasthan and to present day conditions. in the past as deducted from archaeological Bull. natn. Inst. India 1 : 19-31. evidence. Proc. Symp. Rajputana Desert. LUKOSE, N.C. ]972. Palynology of the sub-surface Bull. natn. Inst. Sci. India, 43-49. sediment of Manfera Tibba structure, Jai­ SINGH, GAMBHm, 1952. The Rajputana Desert, salmer, Western Rajasthan. The Palaeobo­ Geography. Proc. Rajputana Desert. Bull. tanist 21 (3) ; 285-297. natn. Sci. India, 151-152. MANN, H. S., MALHOTRA, S. P. and KALLA, J. C. WADIA, D.N. 1960. The past glacial desiccation of 1974. Desert Spread. A quantitative analysis Central Asia. Jl.fonogr. naln. Inst. Sci. India in the arid zone of Rajasthan. Ann. Arid 10 ; 1-25.

5 2

ORIGIN AND HISTORY OF THE RAJASTHAN DESERT­ PALAEOBOTANICAL EVIDENCE

VISHNU-MITIRE

THE origin and history of the Rajasthan Mediterranean element (40-42 %) in wes­ desert cannot be divorced from the origin tern Rajasthan and Kutch, a gradual dec­ and history of aridity in the vast geo­ reases of which is noticeable in the floristics graphical expanse, not only in the western of the Aravallis (25 %), Madhya Pradesh part of the Indo-Pakistan subcontinent (4%), northern Gujarat (19%), the Deccan but also in a large part of the central and (13 %) and the Coromandel coast (2. 5 %). the peninsular region almost down to the The Mediterranean clement is non-existent tip of Cape Comorin where the tropical in the peninsular region, though the tropi­ dry deciduous and thorn forests occur. cal African element does occur. On the In this vast area, the summer tempera­ other hand, the Indo-Malayan element tures are high and the precipitation is low, with concentration in the ever green, semi­ but the western part of the subcontinent evergreen forests of north-east India and has, in addition, lower winter temperatures of the west coast exhibits a proportional accompanied with precipitation in winter, decrease in the arid, semi-arid regions autumn and spring. In the latter part, with pronounced reduction in the western the influence of Mediterranean climate part of the subcontinent (Meher-Homji, (a mild winter rains during the cool sea­ 1973). sons of the year and a hot dry summer), The present position of floristics and which tends to inhibit or slow down the climate in western India has either re­ growth of the woody species and prevents mained static over the geological history or the growth of the non-woody plants, has is reminiscent of the once-exclusive occur­ been recognized. But for the typical rence of the Indo-Malayan floristics with Mediterranean climate in some parts of its characteristic climate in the entire Baluchista,n (Nok Kundi) in the extreme - subcontinent. It began to recede as a west of the subcontinent, moderate and result of change in climate sometime in attenuated Mediterraneity occurs in the the geological history resulting in the rest of the western region of the sub­ invasion of the Saharo-Sudanian-Medi­ continent (Meher-Homji, 1973). Along terrane an element. The reconstruction of side this, the influence of the temperate the past plant life from palaeobotanical climate owing to the proximity of the discoveries indeed reveals that both the region to the Himalayas in the north im­ present-day floristics and climatic pattern parts a distinctive feature to the climate have not been static during the geological of the western region from the climate in past (Vishnu-Mittre, 1969). the arid, semi-arid region in the south of the subcontinent. RAJASTHAN DESERT DURING The present vegetation in the western THE GEOLOGICAL AGES part of the subcontinent has a substantial The discovery of fossils of Mesua, Gar­ proportion of the Saharo-Sudanian- cinia and Calophyllum (Lakhanpal and

6 ORIGIN AND HISTORY OF THE RAJASTHAN DESERT

Bose 1951) from the Fuller's earth in the India. The palaeobotanical evidence be­ Bar~er District and Cocos from Kapurdi ginning from the end of the last glaciation in the Jodhpur District (Kaul, 1951) in about 10,000 years ago reveals that th~ western Rajasthan and dated back to 60 desert with arid and semi-arid plant com­ million years (Eocene Age) is of signifi­ munities had already established itself cant interest. The first three are impor­ as known through pollen analysis of the tant members of evergreen, semi-ever­ salt lakes, Lunkaransar, Didwana and green forests in the Western Ghats and Sambhar, in northern Rajasthan and of north-east Assam under an annual rainfall subsequent date from the Pushkar Lake in regime of about or above 2,000 mm, with central Rajasthan (Singh et al., 1974; a very short dry period or without it. A Vishnu-Mittre, 1974a,b,c; Vishnu-Mittre, species of Calophyllum also occurs in 1976). lagoons. Cocos is highly reminiscent The analysis of the palynological data of the marine environment not very far in the light of vegetational survey of from Jodhpur. An equable, warm to Rajasthan by Gaussen et al. (1972) moist tropical climate is suggested by the reveals that the vegetational development plant fossils to have occurred in the pre­ in the vicinity of Lunkaransar largely sent Rajasthan desert about 60 million comprised members of the Calligol1um years ago (Vishnu-Mittre, 1969). series on active and stabilized sand-dunes In spite of the absence of any palaeo­ and of Prosopis-Capparis-Zizyphus series botanical evidence thereafter, particularly on the sandy alluvium in the vicinities of during the mid- and late-Tertiary and a Didwana and Sambhar lakes. Today, large part of the Quaternary of Rajasthan, both occur under annual precipitation of the mid-Miocene to Pliocene evidence 150-400 mm, with the dry period extend­ from north-western India of the floristics ing over 9-11 months a year, with mean of semi-evergreen elements, such as Dip­ temperature of the coldest month between terocarpus, Cyanometra, M illetia, Fissis­ 15 and 20°C or less than 15°C. The rocky tigma wallichi and of Anisoptera which ground with shallow soil had May tell us occur today in Assam, Bengal, the Anda­ growing over it and the saline/alkaline mans Islands and along the west coast and areas were overgrown with Tamarix, the the Pliocene evidence of Dipterocarpus, members of the Chenopodiaceae and some Podocatpus, palms, Lycopodium, Selaginella grasses and sedges. The overall aspect in Kutch (Ghosh and Ghosh, 1958; was of a desert Savannah. Mathur and Mathur, 1969; Lakhanpal The intensity in the sand-dune forma­ et al., 1975) are highly suggestive of the tion as a result of the renewed violent ~ontinuation of the semi-evergreen forests aolian activity about 5,000 years ago In north-west and western India until the caused the invasion of Calligonum series b~gi!1ning of the Quaternary, about 2-3 in the Didwana area, but this series did mIllIon years ago (Vishnu-Mittre, 1969, not invade the area of the Sambhar Lake. 19~6). The region now occupied by A comparative study of the three pollen Rajasthan, too, had a similar vegetation diagrams suggests that the moisture gra­ and climate as in the north-west and Kutch. dient, more or less as at present, had During this period, the immigration of the already been established in western Rajas­ temperate flora had also commenced in than. the emerging Himalayan mountains. The central Rajasthan area in the vici­ The period from the end of Pliocene nity of Ajmer was a meeting-ground for the to t~e e~d of the last glaciation, the shortest Calligol1um series, the Prosopis-Capparis pe~lOd In geological history and charac­ series, and the Anogeissus series. The ~er~zed by repeated fluctuations in £limate, last-mentioned has in recent times repla­ IS. Indeed most important for the floristic ced the Calligol1um series, thus suggest­ hIstory, but unfortunately without any ing a slight change in precipitation (from palaeobotanical evidence from western 400 mm to the present level), and with a

7 DESERTIFICATION AND ITS CONTRCL

slight reduction in the dry period but the and circumstances which led to the origin temperature of the coldest month remain­ of the desert. The history outlined above ing the same. amply suggests that it must have origina­ The palaeobotanical work in the ad­ ted sometime between the end of the joining Gujarat State, particularly from Pliocene and before the end of the last the Nal Lake near Ahmedabad (Vishnu­ glaciation. It is during this period that Mittre and Sharma, 1975) and from northern India had experienced repeated Malvan (Vishnu-Mittre and Sharma, fluctuations, both in temperature and pre­ 1975) has brought out a grassland Savan­ cipitation, the impact of which upon nah of semi-arid type since the end of the western Rajasthan cannot be overlooked, last glaciation. In the absence of palaeobotanical evidence From the above account it appears that this point cannot be stretched any further. the desert had already established itself However increasing trend in aridity wit­ before the biotic factor had become effec­ nessed since the Eocene times which had tively operative. The Palaeolithic man caused an increase in the deciduous element did exist here and the Mesolithic man had in the evergreen, semi-evergreen forests settled on the sand-dunes or the sandy and the sudden emergence of desert alluvium about 6,000 years ago (Misra, conditions in the Rajasthan desert at the 1971). The urbanization in the desert end of the last glaci

8 ORIGIN AND HISTORY OF THE RAJASTHAN DESERT

desert has continued and the palaeo­ botany with remarks on socio-economy and environment of Indian protohistoric botanical evidence has been found of such cultures. Ph.D. Thesis, Lucknow University. an activity as recent as 5,000 years ago. SINGH, G., JOSHI, R. D., CHOPRA, S.K. and SINGH A.B. 1974. Late Quaternary history of REFERENCES vegetation and climate of the Rajasthan GAUSSEN, B., MEHER-HoMJI, V.M., LEGRIS, P .. Desert, India. Phil. Trans. Roy. Soc. London BLASCO, F., DELAcouRT. A., GUPTA, R.K. B. 267 (889), 467-501. and TROY, J.P. 1972. Notice de la Feuille VISHNU-MITTRE 1969. Some evolutionary as­ Rajasthan. Trav. Sect. Sci. Tech. Inst. pects of Indian flora. J. Sen. Mem. vol. Francais de Pondicherry, Hors Ser. No. 12 : Bot. Soc. Bengal, Calcutta, 385-394. 1-154. VISHNu-MITTRE 1974a. Plant remains and cli­ GHOSH, S.A. and GHOSH, A.K. 1958. Anisop­ mate from the late Harappan and other teroxylon jawalamukhi sp. nov. a new fossil Chalcolithic cultures in India-A study in record from the Siwalik. Sci. & Cult. 24 : interrelationships. Geophyt. 4 (1): 46-53. 238-24l. VISHNU-MITTRE 1974b. Late Quaternary Palae­ KAUL, KN. 1951. A palm fruit from Kapurdi obotany and Palynology in India­ (Jodhpur, Rajasthan desert), Cocos sahnii An Appraisement. In Late Quaternary sp. nov. Curro Sci. 20: 138. Vegetational Developments in extra­ LAKHANPAL, R.N. and BosE, M. N. 1951. Some European areas Ed. Vishnu-Mittre. Birbal Tertiary leaves and fruits of the Guttiferae Sahni Inst.' of Palaeobotany Special Pub!. from Rajasthan. J. Indian bot. Soc. 30 No.5: 16-51. (1-4): 132-136. VISHNU-MITTRE 1974c. Environmental changes LAKHANPAL. R. N., GULARIA, J. S. and AWASTHI, during the Quarternary in India. As­ N. 1975. Podocarpaceous woods from the pects and Appraisal of Indian Palaeobotany, Pliocene of Kutch. Geophyt. 5(2): 172- (ed. K.R. Surange et al.) Lucknow. 179. VISHNu-MITTRE 1975a. Problems and prospects MATHUR, Y. K and MATHUR, KEWAL (Mrs) of palaeobotanical approach towards the 1969. Studies on the fossil flora of Kutch investigation of the history of the Rajasthan (India). On the palaeoflora in the Pliocene desert. Problems of the Desert of India, sediments of Naera-Baraia area, Kutch. Geo!. Surv. India (in press). Bull. Geol. Min. Alet. Soc., India 42 : 1-12. VISHNU-MITTRE 1975b. Environment of early man MEHER-HoMJI, V. M. 1973. A phytoclimatic in India-Palaeobotanical evidence. Early approach to the problem of mediterraneity Man in India, (ed. Professor S.R.K Chopra), in the Indo-Pakistan Subcontinent. Fed. Chandigarh (in press) . Rep. 83 (9, 10): 757-788. MEHER-HoMJI, V. M. and MISRA, K C. 1973. VISHNu-MITTRE 1976. Palaeoecology of the Phytogeography of the Indian Subcontinent. Rajasthan desert during the last 10,000 years. In: Progress of Plant Ecology ill India Palaeobot. (in press). by R. Misra and B. Gopal, New Delhi, VISHNU-MITTRE and SHARMA, CHHAYA (Mrs) 9-88. 1975. Pollen analysis of Malvan, Gujarat. MISRA, V. N. 1971. Two late Mesolithic settle­ Palaeobot. 22(2) : 118-123. ments in Rajasthan-a brief review of in­ VISHNu-MITTRE and SHARMA, CHHAYA (Mrs) vestigation. J. Poona Univ. 35: 39-77. 1975. Pollen analysis of Nal lake, Gujarat. SAVITHRI, R. 1976. Studies in Indian Archaeo- Geophyt. (in press).

9 3

EVOLUTION OF THE PATTERN OF HUMAN SETTLEMENT IN THE ARID AND SEMI-ARID REGIONS

V.N.MISRA

As a result of relatively recent research 1965). Here, a small number of pebble done in Rajasthan, Gujarat and Haryana, tools, hand-axes and flakes were found in a we now have a fairly good picture of the gravel deposit. The region to the west evolution of human cultures and of the of the Aravallis seems to have been coloni­ pattern of human colonization in the arid zed by man only towards the end of the and semi-arid regions of western India Lower Palaeolithic. On the eastern side during pre-historic times. of the Aravallis, the cultural remains There is no true Neolithic period in of this period are plentiful. In Mewar, western India, because by the time the rich Lower Palaeolithic assemblages have food-producing way of life was introduced been found at Chittor and Nagari on the into this region, man had already learnt Gambhiri and the Berach, respectively, and the use of copper and bronze. So the at Kota on the Chambal. Numerous Mesolithic period in this entire region is other sites are known on the Chambal, the succeeded directly by Chalco lithic Age Banas and their tributaries. In fact, and in some cases by the Bronze Age. Mewar is one of the richest areas in the coun!ry for Lower Palaeolithic cultural Lower Palaeolithic period remams. The Lower Palaeolithic occupation in the The Acheulian industry is found in the arid and semi-arid zone is known from pebbly gravel and where the gravel has Gujarat and eastern Rajasthan. In Guja­ been eroded in the river-bed. At Chittor rat, Foote (1916) had discovered Palaeo- and Nagari, Acheulian implements can be , lithic implements at Pedhamli in the allu­ s:ollected from the river-bed in almost un­ vium, of the Sabarmati river in the last limited numbers. The concentration of decade of the nineteenth century. In Acheulian tools has been found up to Tonk the Sabarmati, the Lower Palaeolithic on the Banas. Perhaps, the country near implements have been found at several the foothills of the Aravallis was too den­ sites in its upper reaches near the sely forested to attract the Acheulian Aravallis. hunters. The available evidence shows that human The Acheulian assemblages are in­ occupation in Gujarat during the Lower variably made on quartzite and include Palaeolithic period was confined only hand-axes, cleavers, discoids, choppers, to a few areas, and the population was chopping-tools, Levallois and plain flakes, meagre. blades and cores. The Acheulian industry North of Gujarat, western Rajasthan is of this area represents a fairly developed poor in the Lower Palaeolithic cultural stage. remains. The only true Lower Palaeoli­ It is difficult to know the precise climate thic site known is Govindgarh on the conditions during this period. But cul­ Sabarmati in the Ajmer district (Misra, tural evidence would imply that rainfall

10 EVOLunON OF THE PATTERN OF HUMAN SETTLEMENT

was adequate and vegetation and game and quartzite. The presence of evolved were plentiful to support the large Acheu­ han-daxes and cleavers in small numbers lian populations. The transport of large suggests that human occupation in this pebbles and boulders over lo.ng distances area commenced towards the close of the in the river-beds would also Imply ample Lower Palaeolithic period. rainfall. Upper Palaeolithic period Middle Palaeolithic period The evidence for the Upper Palaeolithic There is no reliable evidence of Middle period is as yet very meagre in the whole Palaeolithic period in Gujarat outside of the arid and semi-arid belt, although Saurashtra. A few Middle Palaeolithic some Upper Palaeolithic quartz implements tools have been found in the central part have been reported from the Panch­ of Kutch. mahals district of Gujarat and at Budha In eastern Rajasthan too, the evidence Pushkar near Ajmer (Allchin and Goudie, of Middle Palaeolithic culture is as yet 1971, 1974). It is believed that these tools meagre. Such tools have been found were originally incorporated into the body mostly at Rajiakheri and other sites on of the dune and have subsequently slid the Wagan river, and in very small num­ down to the weathered surface. ber at Nimbahera on the Gambhiri river The reason for the paucity of the Upper and at Chittor on the Berach river, all in Palaeolithic cultural material in the arid the Chittorgarh district, and at Kota on and semi-arid zone probably lies in the the Chambal river in the Kota district. extremely arid climate that prevailed dur­ The implements are found in the sandy ing the terminal upper Pleistocene in this gravel which overlies the second white zone. Recent scientific studies of the dune clayey deposit. They are made on quart­ fields in Rajasthan and Gujarat by scien­ zite and chert. The tools are made mainly tists of the Central Arid Zone Research of flakes and are much smaller and thinner Institute, Jodhpur, the Geological Survey than the Lower Palaeolithic tools and are of India and the universities CAllchin and also less rolled, suggesting that they were Goudie, 1971, ]974) amply show that manufactured and used near the places at one time the arid climate prevailed over of their present discovery. The paucity the whole of north-western India and that of Middle Palaeolithic remains in the dunes were formed extensively from Pava­ Mewar region will indicate unfavourable garh near Baroda in the south to Hissar environmental conditions during this in Haryana in the- north. period in this region. In western Rajasthan, the cultural Mesolithic period remains of Middle Palaeolithic period are This last phase of the Stone Age is best plentiful. Tools of this period have been known in the arid and semi-arid zone. found at a number of sites in the Luni Far more sites of this period are known and its tributaries in the Pali and Jodhpur than of the earlier Stone Age cultures, districts (Misra, 1968). certainly because of the considerable ex­ ~t Luni itself and at several other sites, pansion of human populations. These MIddle Palaeolithic tools have been found sites, being of a comparatively recent age, in situ in the cemented gravel. But they are also much better preserved. Several are more commonly found in the eroded human settlements of this period have been g_ravel in river-beds. At Sojat, there are . excavated, and have given us information nch factory sites in the limestone hills of the living patterns during this period. where a_plentiful supply of cherty material Evidence for Mesolithic period is known was avaIlable. from Gujarat and Rajasthan. No Stone The raw material used for tools in this Age remains of any period are known from r~¥i?n is quite varied. It includes chert, Haryana primarily because in the alluvial sIhcIfied wood, rhyolite, felspar, porphyry plains the basic raw material-~tone-for

11 DESERTIFICATION AND ITS CONTROL

the manufacture of stone tools was absent. practice of cannibalism, Kennedy thought And if any evidence existed in the past, it that the cracks and fractures noticed on must be buried under the alluvium. these crania and other bones could have In Gujarat, nearly a hundred micro li­ been easily produced by the pressure of thic sites are known and they are distribu­ the debris over the bones and by natural ted all over the alluvial plain. In nor­ agencies affecting bones. According to thern and central Gujarat, microlithic Ehrhardt, the skeletons share Mediterranid sites are invariably located on the top of and Veddid racial features in a mixed sand-dunes with enclosed basins. These form, and this racial mixing must have dunes, where they have not come under taken place at a very early stage, Kennedy cultivation, are covered by thorny scrub agreed with this assessment, but he thinks jungle and are well-stabilized. that the Langhnaj people shared some of Although microliths on dunes were first their genetic features with the Chalcolithic described by Foote as early as 1893, it was populations of the Indus Valley and the Sankalia and his co-workers who made Deccan and with the Iron Age people of the most significant discoyeries in this field. southern India. The maximum information about the Only one radio-carbon date,! TF-744, Mesolithic culture has come from the 2040± 110 B,C, is available from Langhnaj. Sankalia group's work at Langhnaj This determination is obtained from mixed (Sankalia, 1965). samples of uncharred bones derived from The cultural materials at Langhnaj and phases I and II, and as only the inorganic at other sites occur all through in the dune fraction was dated, the possibility of con­ sand, and the habitation deposit varies tamination is considered very high, How­ from 1.75 to 2 m. Though the culture ever, since there is no evidence of domesti­ revealed by the excavation is essentially cation and, in the earlier levels, of any homogeneous, three phases can be dis­ contact with the Harappa culture that flou­ cerned within it. rished in the neighbouring Saurashtra and A considerable amount of animal Kutch, the phase I of the site can be safely remains has been found at Langhnaj. dated to a period before 2000 B,C. The Bovines bones are the commonest. The presence of a copper knife in phase II sug­ bones may belong to cattle (Bos indicus) gests contact with the Harappa culture, or to Indian buffalo (Bubalus bubalis) or to and this phase may, therefore, belong to both. Many of the bones were charred, and the first half of the second millennium B.C. it is probable that most of the animals Phase III, if the iron arrowhead and wheel­ were kIlled for food. made pottery are not .intrusive, will have Fourteen human skeletons found at the to be dated to the latter half of the first site all come from intentional burials. millennium B,C., but it could also be much ,Except one which was laid in a'n extended later. position, all the skeletons were placed in To the north of Langhnaj, microlithic a tightly flexed posture with feet brought sites extend into the hilly country of the well below the pelvic bones. None of the Aravallis. At Dhek Vadlo in the Sabar­ skeletons is complete, and some are very kantha district, for which alone data are fragmentary, the bones often being disarti­ available, most of the microliths occurred culated, The burial was, therefore, partial in the top 60-cm deposit, and no other and secondary, Ehrha'rdt, and Kennedy materials were found. Geometric types (1965) believed that breaks noticed on some were absent in the industry. The evi- skulls represent blows suffered by persons in life with sharp as well as with blunt lSingle radiocarbon dates mentioned in the text. weapons, and, therefore, the persons had are based on the half-life of 5,568±30 years. been slain in battle. While Ehrhardt In the case of double dates from the same sample, the first date is based on the half-life of 5,568± thought that some blows were struck post 30 years, whereas the second date, given in paren­ mortem, and, therefore, suggested the theses is based on the half-life of 5,730±40 years,

12 EVOLUJION OF THE PATTERN OF HUMAN SETTLEMENT

dence from these outlying si_tes supports spotted deer (Axis axis Erxleben), hog­ the inference drawn from Langhnaj, deer (Axis porcinus Zimmermann), jackal namely that ,in the earlier phase of the or dog (Canis aureus Linn. or Canis familia­ Gujarat Mesolithic culture, pottery was ris Linn.), and mongoose (Herpestes auro­ unknown. In the south-east, microli­ punctatus Hodgson). Among these, bones thic sites extend into the hilly country of of cattle are the commonest. The fauna the Panchmahals district. is a mixture of wild and domesticated spe­ In Rajasthan, Mesolithic cultures are cies. The economy was therefore pro­ known from two regions. In Marwar, bably based on a combination of hunting microliths have been collected from many and stock-raising. It, however, is not sites, mainly in the Luni basin, but the clear whether this position existed from the most important site is Tilwara (72°50' beginning or developed at a later stage. E : 25°52'N) in the Barmer district on the Carefully made spherical stone-balls are edge of the Great Indian Desert (Misra, likely to have been used as missiles in I971a, I971b). This site lies on a low hunting. No radio-carbon date is availa­ sand-dune in the old flood plain of the Luni ble from the site, and in the absence of any river. The habitation deposit here is only other datable material, it is not possible about 50 cm deep. Here, two phases of to estimate the antiquity of the site. occupation can be made out. Phase I A few kilometres north of Tilwara, mic­ between I5-cm and 50-cm depths from the roliths of the same tradition have been surface, is characterized by an abundance collected from the shores of the Pachpadra of microliths and stray potsherds, whereas salt basin by Gurdip Singh (personal com­ in phase II, between the surface and I5-cm munication). In view of the fact that depth, the microlithic industry declines and saline lakes of western Rajasthan were the wheel-made pottery is plentiful. initially freshwater lakes, there is a strong Stray glass and stone beads also occur in possibility of Mesolithic habitation sites this phase. It is possible that the pot­ being discovered on the shores of the tery and glass beads actually belong to a Pachpadra and other salt basins. East­ later and post-Mesolithic phase and have ward, microliths occur on the surface at got mixed up with the microliths because Kanawas and Jadan midway between Pali of the prolonged and constant movement and Sojat towns and in the limestone hills at of cattle and men on the dune. The stone Sojat (Misra, 1973), all in the Pali district. industry is made of quartzite, chert and Further north-east microliths have been rhyolite, and is geometric in character. found on sand-dunes surrounding fresh­ The size of many chert and rhyolite blades water lakes at Budha Pushkar (Allchin, exceeds 5 cm and is in sharp contrast to Hegde and Goudie, 1972) and Hokhra the very small size of the blades and blade­ (Allchin and Goudie, 1974) not far from lets at most microlithic sites. The blades the town of Ajmer. and bladelets were produced by the pres­ In eastern Rajasthan, the Mesolithic sure flaking technique and show a very high phase is even better known, especially in st~ndard of craftsmanship. Circular stone the Mewar region. In the districts of alIgnments with 2.25 to 3 m diameter Udaipur, Chitorgarh, Bhilwara, Tonk suggest outlines of huts or windbreaks. and Ajmer, some sixty microlithic sites The presence of hearths with charred have been discovered, largely on elevated animal bones in them further testifies rocky surfaces where suitable raw mate­ t? the habitational character of the rials, like chert and chalcedony, were ~lte. Animal bones from the site found available as nodules in limestone outcrops. 10 a limited quantity and in a' poorly On these sites, artifactual material mostly preser~ed condition, belong t;) the consists of waste products with only rare ~oll?WlTIg. species: humped cattle (Bos blades and microliths. It is clear that here In.dICUS LI?n.), goat (Capra hircus aegagrus we are dealing with workshop sites where Lllln.), pIg (Sus scrofa cristatus Wagner), prehistoric hunters manufactured their

13 DESERTIFICATION AND ITS CONTROL

tools probably during intervals of hunting lithic occupation of the site. It must, expeditions, taking advantage of the easily therefore, have been the source of water available raw materials. They took the for the inhabitants and a major attraction finished tools to their camp sites and left for establishing the settlement. the waste products behind. Sites on river The habitation deposit at Bagor is 1, 50 banks, such as Nimbahera on the Kadmali, m thick and consists throughout of wind­ south of Chittorgarh, show a higher pro­ borne sand. Three phases of occupation portion of finished tools and were, there­ can be recognized. Phase I represented fore, probably used as temporary camps by a deposit of 50 to 80 cm is purelr Meso­ (Misra, 1967). lithic. Here, the microlithic industry and A few camp sites of a more permanent animal remains are most profuse. Struc­ nature have also been discovered. The tural remains consist of extensive stone­ best known of these sites is Bagor (74 0 paved floors and occasionally circular 23' E: 25°21'N) in the Bhilwara district alignments of stones with diameters of 3 (Misra, 1973). The site is located on a to 5 m, the latter probably representing prominent sand-dune overlooking the outlines of huts or windbreaks. Animal Kothari river. Horizontal excavations bones, mostly broken, split open and during three seasons between 1968 and 1970 charred, and microliths and their debris have yielded extensive living-floors and lay thickly scattered on these floors. Small have yielded a variety of cultural materials. areas-40 to 70 em across-tightly packed Estimates made on the basis of the location with pebbles and full of bones probably of trenches on the mound suggest that represent butchering-places. Numerous about 6,000 sq.m must have been occu­ ,stone hammers with tell-tale marks of pied during the Mesolithic period. Radio­ bruising were presumably used for break­ carbon dates suggest a duration of nearly ing and splitting open animal bones and for 3,000 years for the settlement. The eco­ manufacturing stone implements. Occa­ logical setting of the site probably helps sional shallow querns and rubbers must to explain the unusually large size and have been used for the preparation of plant duration of the settlement. Bagor is foods. The dead were disposed of during located in the midst of an extensive un­ this time as well as during phase II within dulating rocky plain. Cultivation is con­ the habitation areas. A single burial from fined to narrow alluvial strips, and the this phase belongs to an adult person. rocky tracts are covered with grass, shrubs The body was laid in an extended position and a Savannah type vegetation of khejri with head to the west, and no grave goods (Prosopis cineraria), palas (Butea frondosa) were provided. and khajur (Phoenix sylvestris) trees. Wild In phase II, the essential elements of animals., like blackbuck (Anti/ope cervicapra phase I including the microlithic industry, Linn.), nilgai (Boselaplzus tragocamelus animal bones and stone-paved floors per­ Pallas), fox, jackal, rabbit and a variety of sist, but there is a slow decline in the quan­ game birds are still available in the area. tity of stone tools and animal bones. Several millennia ago, when both human Instead, new elements, such as pottery, and animal demands on vegetation were copper tools and stone beads, make their far less, the vegetation cover must have appearance, suggesting contact between been denser and wild-life more plentiful. Bagor hunter-gatherers and farming settle­ Close to the site is a large depression, ments in the region (Misra, 1970). Pot­ now partially strengthened by an artificial tery from this phase is handmade and ill­ embankment which retains water for the baked though the shapes are quite sophis­ greater part of the year and is a source of ticated. Decoration on it consists of in­ ,irrigation. There is ample geomorphological cised and applique designs (Misra, 1973). evidence to show that this depression is Copper objects, all found in association a remnant of the old bed of the Kothari with burials, include three triangular bar­ river, and that it existed before the Meso- bed arrowheads with two holes near the

14 EVOLUTION OF THE PATTERN OF HUMAN SETTLEMENT

base for fastening the arrowhead to the identified bones, 72.29 per cent come from shaft, one spearhead and one awl-like phase I, 19. 06 % from phase II, and only rod (Misra, 1970). Arrow-heads show 2.65 per cent from phase III. The follow­ close similarity to specimens of the same ing animals are represented: sheep/goat class from many Harappan sites and to (Ovis orientalis vignei/Capra hircus aegagrus later examples from the Minoan Bronze Linn.), humped cattle (Bos indicus Linn.), Age (Misra, 1970). The only example of pig (Sus scrofa cristatus Wagner), buffalo this class of arrow-head from a non­ (Bubalus bubalis Linn.), blackbuck (Anti/ope Harappan Chalcolithic site in India comes cervicapra Linn.), chinkara (Gazella gazella from the recent excavation in Indore in Pallas), chital (Axis axis Erxleben), sambar Madhya Pradesh (Dr V.S. Wakankar (Cervus ullicolor Kerr), hare (Lepus nigricois personal communication). Three human F. Cuvier), fox (Vulpes sp.) and mongoose burials from this phase were all laid in a (Herpestes sp.). In all phases, sheep or flexed position and were richly provided goat bones account for between 60 and with grave goods in the form of clay pots 80 % of the bone material. It must, how­ loriginally no doubt containing food and ever, be pointed out that the trochlear water), copper tools (probably belonging bones from which most of the identifica­ to the deceased), pieces of meat (now tions have been made cannot always be surviving as bare bones) and in one case a separated with certainty in the case of sheep terracotta spindle whorl and a necklace or goat on the one hand and blackbuck of thirty-six stones and bone-beads (Misra, on the other. The Bagor economy appears 1972). to have been based from the outset, on a In phase III, microliths and animal combination of hunting-gathering and bones further decline in quantity. Be­ stock-raising. In phase II, the appearance sides, this phase has also given plentiful of new material traits, such as copper tools, wheel-made plain pottery, two iron arrow­ pottery, ornaments of stone-beads and heads and stray pieces of iron, glass beads richly furnished graves and also the dec­ and floors paved with brickbats and oc­ line in the quantity of microliths and ani­ casionally dressed stone. It appears that mal bones all indicate an increased eco­ the site was reoccupied in early historical nomic stability and prosperity, and by in­ times and in this process later materials ference imply a greater reliance on stock­ got mixed up with microliths and animal raising. The presence of som;: perforated bones of the earlier two phases. circular stones, ethnographically docu­ The most characteristic and abundant mented for their use as weights of digging­ cultural material at the site is the stone sticks, might suggest a practice of rudi­ industry. This is exceptionally rich, com­ mentary agriculture. The presence of prising several hundred thousand worked tortoise and fish bones in all phases shows pieces. It is richest in phase I and gra­ the exploitation of aquatic resources as dually declines in later phases. The well. industry is made up of quartz, ched Five radiocarbon determinations, all and chalcedony and consists essen­ obtained from charred bone, are known tially of microliths, the flake and core from the site. Three of them come from ~ools being very scarce. The microlithic phase I and two from phase II. These Industry is essentially of a geometric are as follows: phase I : TF-786. 6,245 character comprising blunted back and ± 200 (6430 ± 200) = 4480 B.C.; TF- obliquely truncated blades, crescents, 1107. 5,620 ± 125 (5,785 ± 130) = 3,835 isosceles and scalene triangles, trapezes B.C.; TF-IOI2. 5090 ± 85 (5,235 ± 90) = and petit tranchets, the last more typical 3285 B.C., phase II: TF-I009. 4,585± than at any other Indian site. 105 (4,715±105) = 2765 B.C.; TF-1005 The main evidence for the subsistence and TF-1009. 4,585 ± 105 (4,060 ± 90)= pattern of the settlement comes from ani­ 2110 B.C. mal bones (Thomas, 1975). Of the 2,266 Since no dates are available from the

15 DESERTIFICATION AND ITS CONTROL lowermost levels of phase I, it may not be mena indicate scrub-burning at the hands unreasonable to put the beginning of this of man and this practice in turn, was con­ phase around 5000 B.C. The beginning of nected with the emergency of primitive phase II can be put around the middle of slash-and-burn agriculture. the second millennium B.C., because ar­ Phase IV: Pollen zone C: circa 3000 chaeological evidence does not justify ex­ B.C. -circa 1000 B.C. This phase can be divi­ pecting copper tools and pottery before ded into three sub-phases IVa (c. 3000 B.C.­ that date in this area. The end of this -c. 1800 B.C.), IVb (c. 1800 B.C.-C. 1500 phase cannot be dated in the absence of B.C.); 'IVc (c. 1503 B.C.-C. 1000 B.C.). radiocarbon determinations. Phase III, Phase IVa is characterized by a considera­ as has been pointed out earlier, may be a ble increase in rainfall, as depicted in the post-Mesolithic occupation, and may be pollen record. According to Singh, the as late as the first half of the first miI1en­ annual average rainfall during this phase nium of the Christian Era. may have been in excess by at least 50 cm of the present-day rainfall in the arid belt. PROBLEMS OF PALAEO-ECOLOGY This period coincides with the emergence AND PALAEO-CLIMATE and flourishing of pre-Harappan and In recent years~ there has been consider­ Harappan cultures in north-west India, able effort at reconstructing the palaeo-eco­ and the increase in rainfall may have been logy and palaeo-climate of western India one of the causative f;.tctors in the expan­ during the late Quaternary, and the evidence sion of these cultures. up to the beginning of 1972 was critically Though the dating of the Mesolithic reviewed by Misra (1973). The most cultures of north-west India (except eastern significant evidence has come from the Rajasthan) is at present uncertain, there palynological work of Singh (197i) in seems little doubt that most of these cul­ the salt lakes of Sambhar, Didwana and tures must have flourished during the Lunkaransar in western Rajasthan. The period covered by the palynological se­ climatic sequence worked out by Singh is quence in the lakes. During this long briefly as follows: period, namely, 7500 B.C. to 1000 B.C. Phase I : BlIfore 8000 B.C. This phase, except for two relatively short intervals, represented b_)i.._ wind-borne sand deposits viz., 8000 B.C. to 7500 B.C. and 3000 B.C. at the base of lake sediments, was charac­ to 1800 B.C., rainfall appears to have been terized by an arid climate. only marginally higher than at present. Phase II : Pollen zone A: circa 8000 B.C. In recent years archaeological and geo­ -circa 7500 B.C. This phase is represen­ morphological studies by Allchin, Hegde ted by the first sedimentation in lakes. and Goudie in Gujarat and western Rajas­ On the basis of vegetation, as deduced from than have produced evidence of climatic the pollen record, Singh believes that rain­ change in the past. According to these fall at this time was at least 2.'5 cm more investigators, the active dunes in western than the present annual precipitation in India are now confined to the west of the western Rajasthan. 275 mm isohyet, whereas the fossil dunes Phase III : Pollen zone B : circa 7500 extend several hundred kilometres towards B.c.-circa 3000 B.C. A slight decline in the east where the annual rainfall ranges rainfall is indicated at the beginning of this from around 900 mm at Baroda in the phase, but it was not severe enough to south, through 600 mm at Jaipur in the substantially alter the ecological pattern centre to 430 mm at Hissar in the north. established in phase II. A noteworthy From this distribution it follows that the f~atu~e of this phase is the extraordinary annual rainfall in the zone of fossil dunes flse In carbonized vegetable remains at has increased by two to four times since al~· the sites. This rise is accompanied the cessation of the dune-building activity. wIth the appearance of Cerealia type pol­ At some six sites in Gujarat and western len. Si~gh believes that these two pheno- Rajasthan where digging has been done,

16 EVOLUTION OF THE PATTERN OF HUMAN SETTLEMENT microliths and other cultural materials Surat and Broach districts. Further south are invariably found to occur within the on the Tapti, two chalcolithic settlements, body of the dunes at varying depths. namely Malvan and Jokha, have been This evidence shows that microlithic man excavated. The pottery industries of lived in Gujarat and Rajasthan when the Ma:lvan show influences from Malwa, dune-building processes were active. And Deccan and Saurashtra. The settlers at these sites, there is little evidence to here had also dug a ditch 1.10 m deep and show any interruption in the dune-build­ 1 . 50 m wide perhaps for irrigation (All­ ing activity during the Mesolithic occupa­ chin and Joshi, 1972). tion. In Kutch, some 17 Harappan settle­ ments have been found. Of them, two, Chalcclithic and Bronze ages namely Desalpur and Surkotada, have The emergence of settled community way been excavated. The settlement at Sur­ of life based on a food-producing economy kotada was fortified with mud-bricks and in the arid and semi-arid zones of north­ included a citadel and a residential area. west India is geographically very uneven Three phases of occupation, namely lA, and not easily explicable. Whereas IB, IC, are distinguished. The earliest Singh's (1971) palynological evidence from occupation was Harappan in character, salt lakes of western Rajasthan suggests but certain ceramics show the influence of the beginning of cereal agriculture of slash­ earlier cultures from Baluchistan and Iran. and-burn type as early as the seventh mil­ Besides the typical Harappan features, this lennium B.C., there is no archaeological phase also gave bone tools, potsherds bear­ evidence at all at present to support this ing the Harappan script, linga-like ob­ hypothesis. This is not all. Whereas jects of unbaked clay and four pot burials. regular pre-Harappan or Harappan towns In phase IB, the width of the citadel ram­ and villages or both are known from part was reduced from 7 to 6 m and a mud­ Saurashtra, Kutch, southernmost Gujarat, brick reinforcement was provided for the the Ghaggar Valley in northern Rajasthan, inner face on the eastern side. Phase IC and Haryana, not a single pre-Iron Age shows considerable changes. Stone rubble agricultural settlement is known from the as well as dressed stones were used on a whole of western Rajasthan outside the large scale in the construction of the forti­ Ghaggar Valley and in the Gujarat plain. fication as well as in that of residential Whereas Singh's palynological evidence units. Though writing on potsherds shows a considerably wet climate between disappears, ·new ceramic elements appear. 3000 B.C. and 1500 B.C., this climatic ame­ Chief among these are the White-painted lioration did not lead to the appearance black-and-red wares showing affinities of the agricultural way of life in much of with phase IC of Ahar in Mewar. Eight the arid and semi-arid zone. Also at the C 14 dates show the duration of this settle­ moment, there is no archaeological evi­ ment from 2000 B.C. to 1600 B.C. (Joshi, dence to suggest that the food-producing 1972). The sequence at Desalpur is broadly way of life emerged independently in this similar to that at Surkotada. ~on~; on the contrary, all available evidence The large number and the large size mdIcates that it was introduced from the of the Harappan settlements in Kutch west, i.e. Sind and Baluchistan. clearly show that climatic and environ­ In Gujarat, a large number of Harappan mental conditions in this area from the settlements-both towns and villages­ end of the third millennium B.C. to the are known from Saurashtra. The most ·middle of the second millennium B.C. famous of these is the port town of Lothal, were far more favourable to human occu­ located about 90 km south of Ahmedabad pation than they are today. It is also clear (Rao, 1973). Smaller Harappan settle­ that the Harappan colonization of this area ments are known from the estuaries of took place from Sind by a land route. the Narmada and its tributaries in the In northern Rajasthan, the valley of the ....-::;:. ta1tE RI(JI~M ~ ,,-~ . ~'+ r "\ ~ DESERTIFICATION A1'.'D ITS CONTROL

now dried-up Ghaggar river was the scene hed field. It had a grid pattern of furrows; of the emergence of earliest rural and one set running east-west, had a spacings urban centres in the area. Stein (1942) of 3) cm between adjacent furrows, • had discovered a string of such settlements whereas the second running north-south, on the Ghaggar in the then Bikaner State had a spacing of 1.90 m. A similar and further down in the then Bahawalpur ploughing pattern is in vogue in the area State (where the river is known as the today and the two kinds of furrows are Hakra) as early as the early forties of this used for sowing two different crops. The century. But in the early fifties, it was antiquity of this practice can be trayed to the systematic exploration by Ghosh the Pre-Harappan times. The discovery (1952) which led to the discovery of 25 of barley grains testifies to its cultivation. Harappan sites and a large number of A series of radio-carbon dates puts the later settlements on this river in the Sri­ duration of this culture between 2300 ganganagar District. One of these sites, B.C. and 2100 B.C. namely Kalibangan, has been horizontally The Harappan culture appeared at the excavated by the Archaeological Survey of site while the Pre-Harappan settlement was India over several years. It has brought to still a functioning entity. For some time, light not only. a large and fortified Harap­ the two cultures coexisted, but slowly pan township, but also an earlier and the Harappan element proved more domi­ fortified Pre-Harappan settlement (Thapar, nant and completely replaced the Pre­ 1973, 1975). Harappan culture. There are two mounds at Kalibangan. The Harappan occupation took place Whereas both these mounds were occupied over the earlier Pre-Harappan settlement during the Harappan times, the Pre­ as well as over a new area to the east Harappan settlement is known only from (KLB-2). The Harappan settlement the western mound or Kalibangan 1. comprised two parts as at other Harappan This Pre-Harappan settlement was forti­ cities-a citadel to the west and a residen­ fied with a mud-brick wall which was tial area to the east. The city was plan­ initially 1.90 m in width but was later ned on the well-known Indus chess-board enlarged to almost double the width. The pattern. It was fortified with a mud-brick houses were also made of mud-bricks and wall. The houses were made of mud were provided with underground as well bricks, though burnt bricks were used in as overground ovens of the tandoor drains and wells. The citadel was also type. The pottery of these people, though fortified with a mud-brick wall, and the possessing considerable variety, is thinner structures which have largely disappeared and less perfectly baked than the Harappan were constructed on massive mud-brick pottery. _ Some of the pots are roughened· platforms. On one of these platforms ori the outer surface by the application of have been found several fire altars con­ sand and some have de~oration of deeply sisting of shallow pits with a cylindrical or incised lines on the outer surface as well as rectangular clay bricks inside. They cer­ on the inner surface. tainly had a religious function. The Pre-Harappan settlers knew the use The Harappans also cultivated barley, of copper for making axes, but also used but we do not know about other grains. small stone blades for cutting. Their orna­ They domesticated cattle, buffalo, pig, ments included beads of steatite, shell, elephant, ass and camel, and hunted bara­ carnelian, terracotta and copper and singh a and rhinoceros. They buried their bangles of terracotta, shell and copper. dead in a cemetery away from the settle­ The discovery of a terracotta cart with ment. Usually, the dead were buried in _a single-sided hub shows their knowledge oblong pits in an extended position with of wheeled transport. The most note­ head to the north, and a number of pots worthy finding of the Pre-Harappan culture (originally, no doubt, containing food and at K~libangan is the discovery of a ploug- water) were placed near the head. The

·18 EVOLUTION OF THE PATTERN OF HUMAN SETTLEMENT

second type of graves consist of circular on the surface. Though no C14 dates or oval pits. The' third type of graves is are available, archaeological evidence rectangular or oval in plan, but, curiously, ,suggests this culture to have flourished in these have yielded no skeletal remains. the second half of the second millennium There is evidence that the Kalibangan B.C. people practised trepanning or skull sur­ The culture which succeeded the O.C.P. gery. is represented by black-and-red wares. Un­ Their material culture was rich and like the black-and-red wares of Harappa varied. Their pottery was wheel-made, and Ahar cultures, this pottery bears no sturdy, well-baked and decorated with decoration. Associated with these wares painted designs in black over a red sur­ are coarse red ware and black-slipped face. Their ornaments included beads and ware. Unfortunately, our knowledge of bangles in shell, terracotta, semi-precious the other aspects of this culture is negligi­ stones and faience'. They had weights and ble, again because of very limited excava­ measures of the Harappan type, carts, tions. metal tools and seals with Harappan writ­ On the other side of the Aravallis, in ing. A large number of radio-carbon dates Mewar, a well-developed culture flourished show that the Harappan culture here lasted in the early second millennium B.C. This from 2100 B.C. to 1800 B.C, culture is known as 'Ahar' after the type The presence of a string of Harappan site or 'Banas' after the river basin in which and Pre-Harappan settlements along the it flourished. Some fifty sites of this Ghaggar from Hanumangarh to the Pakis­ culture are known in the valleys of the tan border amply shows that the river at Banas and its tributaries in Udaipur, Chi­ this time was regularly flowing and car­ ttorgarh, Bhilwara, Ajmer and Tonk dis­ ried enough water to support agriculture tricts of Rajasthan (Misra, 1967, 1969). for a large population. Two of these, namely, Ahar near Udaipur In our present state of knowledge, the (Sankalia, Deo and Ansari, 1969) and Harappan culture does not appear to have Gilund on the Banas in the Chittorgarh extended beyond the Ghaggar Valley in district (fAR, 1959-60, pp. 40-45), have Rajasthan. In north-east Rajasthan, the been excavated. The Aharians lived in earliest occupation is represented by ochre­ houses made of undressed stones, though coloured pottery (O.C.P.) culture. It is at Gilund there is evidence of the use known from many sites, two of which, of mud-bricks and baked bricks. The namely Jodhpura on the Sabi Nadi, 100 houses had chulhas or ovens of the type km north of Jaipur, and Noh near Bharat­ in vogue in rural India today. They cultiva­ pur (JAR 1963-64, pp. 29-30, 1964-65, pp. ted rice and perhaps other crops also. 65-66, 1965-66, pp. 69-70) have been ex­ They reared cattle, sheep, goat and pig. cavated by the State Department of Ar­ Unlike other contemporary cultures, they chaeology and Museums, Rajasthan. Be­ made little use of stone blades. Instead, cause of the small size of excavations, they used metal more commonly and knew very little is known of the life of the people the art of smelting copper ores and casting at that time. The pottery is wheel-m<1de metal objects. Their ceramic industry is and has an ochre-coloured wash. It is rich and varied. Whereas in the earlier decorated with incised and less often with stages, there exists in small quantities the painted designs. The fabric and shapes Harappan type of pottery, the most dis­ suggest it to be a degenerate version of the' tinctive ceramic of Ahar culture is black­ Harappan pottery. There are also traces and-red ware with decoration of geo­ of mud-brick and wattle-and-daub struc­ metric designs in black. Radio-carbon tures. Circumstantial evidence suggests dates put the period of this culture between that the makers of O.C.P. were also the 2100 B.C. and 1300 B.C. authors of copper objects, generally known Recent researches by Suraj Bhan (1972, as Copper Hoards which have been found 1973) and the State Department of Ar-

19 DESERTIFICATION AND ITS CONTROL chaeology, Haryana, have thrown valuable mud-brick houses plastered with clay. light on the early human colonization of Their material culture included saddle the Saraswati, Drishadvati and Upper querns, terracotta cakes, sling balls, chert Yamuna valleys. Till a decade ago, our blades, copper and clay bangles and beads knowledge of the subject was confined to of copper, terracotta and semi-precious the discovery of the Harappan culture at stones. Rupar and Bara (JAR, 1954-55) in the The Siswal B culture is known from former Ambala district (and now in the over 30 sites most of which are located in newly created Ropar district). As a the Drishadvati and old Ya~una valleys. result of explorations by Suraj Bhan, However, the distribution of other sites nearly 100 Chalcolithic sites have been shows that these people had colonized brought to light in these valleys .. Small the whole of Haryana right up to the excavations have been done at Siswal, Siwalik foothills. On the basis of radio­ Mitathal and Daulatpur in the Hissar carbon dates from Rajasthan, the duration District. Two large settlements, namely, of the Siswal culture can be put from Banawali in the Hissar District and 2300 to 2000 B. c. Bhagwanpura in the Kurukshetra District The next stage in cultural evolution be­ are now being excavated on a large scale longs to the full-fledged Harappan culture by the State Department of Archaeology, which, at present, is known only from a Haryana, and the Archaeological Survey d07en sites.' Of these, Mitathal on the old of India, respectively. Consequently, our Yamuna course, Rakhigarhi on the knowledge of the prehistoric cultural Drishadvati and Banawali on the Saraswati development is confined to the sequence river all in the Hissar District represent of cultures. The way of life during the urban centres. Each of these sites various periods can be known only after has twin mounds-the citadel and the resi­ horizontal excavations are completed and dential areas-so typical of the Harappan published. city-planning. Current excavations at The earliest human colonization in Banawali show that both the citadel and the Haryana belongs to the Pre-Harappan residential areas were fortified, and the two or Kalibangan I culture which in Haryana were connected by a gate in the interven­ has been given the name Siswal A. It is ing defence wall. The houses were made represented by bichrome (black-and-white) of mud-bricks but baked bricks were used painted and incised ceramics of the types in wells and drains. At all these sites, the known from Kalibangan. This pottery material culture includes typical Harappan is known from nearly 20 sites, most of elements, such as black painted sturdy which are located on the Drishadvati river. pottery, chert blades, steatite seals, cubical However, the presence of sites tm the stone weights, terracotta cakes, beads Saraswati and along a now dried-up chan­ and bangles of paste and faience, terra­ nel running pa~aIlel to the Yamuna on its cotta wheeled toys and animal figurines western side shows that the whole of and copper objects. Unlike in north Haryana was colonized by the Siswal A Rajasthan, the Siswal B cultural elements people. survive right through the Harappan culture, The next cultural phase is represented showing that the Harappans coexisted by Siswal B or a late phase of the Pre­ peacefully with their Siswal predecessors Harappan Kalibangari I culture. The pot­ and were slowly able to assimilate them tery of these people is similar to that of in their own culture. The Harappan cul­ Siswal A people. It is sturdier and better ture probably lasted from 2000 B.C. to made, but lacks variety in types and 1700 B.C. designs. Some typical Harappan culture The final phase of Chalcolithic or Bronze types also appear, showing contact between Age in Haryana is represented by the late Pre-Harappan and Harappan (Mitathal II Harappa (Mitathal II B) culture. Sites A) . cultures. Siswal B people lived in of this culture are relatively few and are

20 EVOLUTION OF THE PATTERN OF HUMAN SETTLEMENT confined to the middle and upp:::r -reaches the consequent expansion of human coloni­ of the Saraswati and Drishadvati zation in northern Rajasthan, the Indo­ valleys. The absence of this cul,ture Gangetic Divide and the Ganga-Yamuna in northern Rajasthan and southern Doab are associated with the Painted Grey Haryana suggests that the lower courses Ware (P.G.W.) culture. The authors of of the Saraswati and the Drishadvati were this culture used a fine, thin grey pottery already drying up, perhaps owing to hydro­ painted with black geometric designs. logical changes in the courses of the rivers. This pottery is totally different from the In this culture, the classical Harappan Late Harappan pottery in fabric, shapes, pottery with shapes similar to those of the decorative patterns and baking technique, goblet, beaker, perforated jar, handled and is not even remotely derived from the saucepan, etc., either become very rare or latter. The Painted-Grey-Ware people disappear completely. Other shapes, like lived in mud-houses, cultivated wheat and dish-on-stand and storage jar, undergo rice and kept cattle, sheep, goat and horse. modification in form. The pottery shows They had no knowledge of town-plann­ a general decline in fabric, manufacturing ing, the use of kiln-baked bricks and writ­ skill and surface treatment. Certain types ing. Their culture was essentially rural and designs of Cemetery H culture pottery and its appearance marks a loss of the are also seen in the Late Harappan pottery Harappan urban tradition. The P.G.W. at Mitathal and other sites. Similarly, the culture is associated with the Mahabharata Late Harappan pottery shows close simi­ period. larity to the ochre-coloured pottery of the A number of Painted-Grey-Ware sites Ganga-Yamuna Doab. The discovery of have been found in the Ghaggar Valley Copper Hoard objects at Mitathal, Baha­ in the Sriganganagar District of Rajasthan. darabad and Saipai in association with the But these sites never occur over the older late Harappan and O.c.P. cultures streng­ Harappan mounds and, therefore, show a thens the belief that the Copper Hoards clear chronological gap and break in belong to the late Harappan or O.C.P human habitation between the Harappan cultures. The rarity of the Late Harappan, culture and the P.G.W. culture. In north­ O.C.P. and Copper Hoard sites in Haryana east Rajasthan, numerous sites of this cul­ and the Punjab and their abundance in ture are known in Jaipur, Ajmer and western Uttar Pradesh clearly shows th&t Bharatpur districts. The profusion of towards the end of the Harappan culture, P.G.-Ware sites in the Ganga-Yamuna the focus of human habitation shifted from Doab testifies to the further shift of human the Indo-Gangetic Divide to the Ganga­ habitation to the east of the previous Yamuna Doab, most probably owing to centre of human colonization. the increased desiccation caused either by At Jodhpura, in the Jaipur District and changes in river courses, or in climate or at Noh in the Bharatpur District, the both. P.G.W. culture overlies the black-and-red . Though Suraj Bhan estimated the dura­ ware deposit. Though an iron arrowhead bon of the Late Harappan culture from has been found in the black-and-red ware 1700 B.C. to 1500 B.C., the recent discovery deposit at Noh, the regular use of iron is of the absence of any gap between the attested only in the P.G.W. phase. At Harappan culture and the P.G.W. culture Jodhpura, furnaces with slag and a at Bhagwanpura in the Kurukshetra Dis­ nodule of haematite-containing iron trict in Haryana suggests the pos·sibility ore have been found, providing evidence tha~ the .culture may have endured in this for the local practice of iron metallurgy. regIOn tIll the end of the second millen­ Further south, the P.G. Ware sites extend nium B.C. down to Deoli in the Bundi district on the Khari River. At Chosla the P.G. Wares Emergence of Iron age have been found on a Ahar culture mound. The emergence of iron technology and The exact cultural and -chronological rela-

21 DESERTIFICATION AND ITS CONTROL

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C"-.C"-.e--0 .,._. 0:-' .,._. .,._.

o o o o o o o o V'l o o o -.r" ~f 0" o - N '" EVOLUTION OF THE PATTERN OF HUMAN SETTLEMENT

tionship between Ahar and P'.G.W. cul­ tory of saline lakes in western Rajasthan. tures can be deciphered only after exca­ While palynology shows a very humid cli­ vation at sites like Chosla. . mate in the semi-arid and arid zone from The radio-carbon dates available from . C. 3000 B.C. to C. 1500 B.C., no agricultural Noh and several other sites do not take the settlemep.js developed in the Luni Valley antiquity of P.G. Wares earlier than 800 or on the shores of the then freshwater B.C. But the discovery of P.G. Ware lakes. The Ghaggar Valley, where such at Bhagwanpura immediately over and, settlements did develop, is a few hundred in fact, in association with the Harappan kilometres to the north of these lakes. culture hold out the possibility of an ear­ If the climatic changes reflected in the lier beginning of these wares. palynological record of these lakes affected At all the sites of this culture the P.G. the emergence of settled life in the Ghag­ Ware deposits are invariably succeeded gar Valley, surely their impact should by the deposits of the Northern Black have been felt nearer home as well. Polished (N.B.P.) Wares. This was pro­ Recently, Raikes (1968), on the basis bably evolved from the P.G. Ware to­ of the study of bore holes on the Ghaggar wards the end of the sixth century B.C. and bed, has revived the old theory that the saw its development and diffusion during Yamuna flowed in the past in the Ghaggar the Mauryan times. This is a thin, very bed. In fact, his theory is that the Yamuna well-baked and lustrous pottery and marks was alternately captured by the Indus a high point in the evolution of Indian and Ganga systems, and whenever it ceramic technology. The N.B.P. period flowed in the Ghaggar bed, settlements witnessed the emergence of urbanization flourished along that river. in the entire Ganga Valley. From now Suraj Bhan (1972) has traced an old onwards, we enter the period when recor­ course of the Yamuna over a length of ded history began. In the Ghaggar Valley 180 km from Indri in the north-east to there is no evidence of N.B.P. culture. Tigrana in the south-west in Haryana. The area seems to have been abandoned He has also located nearly twenty Pre­ after the P.G.W. period. After a gap of Harappan and Harappan sites along the several centuries, new settlements appea­ banks of this old channel. Two other red there during the Kushana period in the channels between this course and the early centuries of the Christian era. present-day Yamuna course testify to the In the whole of the semi-arid and arid gradual eastward shifting of the Yamuna zone of western Rajasthan (leaving aside course. The Late Harappan and P.G. the Ghaggar Valley in the extreme north) Ware sites have been found along these there is no evidence of agricultural settle­ channels. It, therefore, appears very ments of Chalcolithic Age. The same is likely that the development of early farm­ true in respect of the Gujarat plain. In­ ing and urban cultures in the Ghaggar deed, there is no evidence in this region of Valley in Rajasthan and in the Saraswati­ such settlements even in the late first mil­ Drishadvati-Yamuna valleys in Haryana lennium B.C. when the Iron Age had al­ was largely conditioned by hydrological ready commenced in north-east Rajasthan changes rather than by climatic factors. and the Indo-Ganga plains. The absence The chart on facing page gives a broad of .such settlements cannot be explained picture of the evolution of prehistoric OWIng. to the lack of archaeological work. cultures in the arid and semi-arid zone of In sp~te of extensive and systematic ex­ north-west India. ploratIOns, this vast region remains a big blan~ on. the Chalcolithic map of India. REFERENCES It IS dIfficult to reconcile this archaeo­ AGRAWAL, D.P. 1966. Cli dates, Banas culture lo.gical evidence-or rather the lack of it­ and the Aryans. Curro Sci. 35 (5). ALLCHIN, B. and GOUDIE, A. 1971. Dunes, aridity w.Ith the climatic picture worked out by and early man in Gujarat, .Western India. SIngh on the basis of palynological his- Man 6 (2).

23 DESERTIFICATION AND ITS CONTROL

ALLCHIN, B. and GOUDIE, A. 1974. Pushkar: settlements in Rajasthan-a review of investi­ prehistory and climatic change in western gations. Journal of Poona University (Huma­ India. World Archaeology 5 (3). nities Section) 35: 59-77. ALLCHIN B., HEGDE, K.T.M. and GOUDIE, A. 1972. MISRA, V. N. 1972. Burials from prehistoric Prehistory and environmental change in Bagor, Rajasthan. in: (ed.) Deo, S.B., western India; a note on the Budha-Pushkar Archaeological Congress and Seminar Papers, basin, Rajasthan. Man 7 (4). Nagpur, University of Nagpur. ALLCHIN, F. R. and JOSHI, J. P. 1972. "Malvan" MISRA, V. N. 1973. Problems of Palaeo-ecology, in: Archaeological Congress and Semincr palaeo-climate and chronology of the micro­ Papers Ex. S.B. Deo, Nagpur, pp. 36-42. lithic cultures of north-western India. in: BROWN, J. G. 1917. Catalogue Raisonne of Pre­ (ed.) Agrawal, D.P. and Ghosh, A. Radio­ historic Antiquities in the Indian Museum, carbon and Indian Archaeology, TIFR, Simla. Bombay. EHRHARDT, S. and KENNEDY, K.A.R. 1965. MISRA V.N. and NAGAR, M: 1963. Two Stone Excavations at Langhnaj 1944-63, Part III : Age sites on the river Chambal, Rajasthan. Human Remains, Poona: Deccan College. Buffetin of the Deccan College Research FOOTE, R. B. 1893. The Foote Coflection of Indian Institute 22: 156-169. Prehistoric and Protohistoric Antiquities­ RAIKES, R. L. 1968. Kalibangan death from natu­ Notes Oil their Ages and Distribution, Madras: ral causes. Antiquity 42 : 266-291. Government Museum. RAo, S. R. 1973. Lothal and the Indus Civi­ GHOSH, A. 1952. The Rajputana desert-its lizations. Bombay, Asia Publishing House. archaeologi<;al aspect. In: Hora, S.L. (ed.), SANKALJA, H.D. 1965. Excavations at Langhnaj Symposium on Rajputana Desert. Buffetin 1944-63, Part I Archaeology. Deccan College, of the National Institute of Sciences of India, Poona. . 1: 37-42. SANKALIA, H. D., DEO, S. B. and ANSARI, Z. D. GHOSH, A. 1965. The Indus civilization: Its 1969. Excavations at Ahar (Tambavati) origins, authors, extent and chronology. In: 1961-62. Poona, Deccan College. Misra, V.N. and Mate, M.S. (ed.) Indian SIl'lGH, G. 1971. The Indus Valley Culture seen Prehistory 1964, Deccan College, Poona. in the context of Post-glacial Climatic and IAR, 1954-55 to 1967-68. Indian Archaeology­ Ecological Studies in Northwest India. a Review. Archaeology and Physical Anthropology in JOSHI, J. P. 1972. Fresh light on the Archaeology Oceania 4 (2) : 177-189. of Kutch. in: Deo, S.B. (ed.), Archaeo­ STEIN, SIR AUREL 1942. A survey of ancient logical Congress and Seminar Papers, pp. sites along the 'Lost' Saraswati River. 21-35. Nagpur, Nagpur University. Geographical Journal 29 (4). MISRA, V.N. 1961. The Stone Age Cultures of SURA] BHAN 1972. Changes in the course of Rajputana. Ph.D. Thesis, Poona University. Yamuna, and their bearing on the proto­ MISRA, V. N. 1965. Govindgarh, a Palaeolithic historic cultures of Haryana. in: Deo, S.B. site in western Rajasthan. Journal of the (ed.) Archaeological Congress and Seminar Asiatic Society of Bombay 38 : 205-208. Papers, pp : 125-128, Nagpur, Nagpur MISRA, V. N. 1967. Pre- and proto-history of the University. Berach Basin South Rajasthan, Deccan SURA] BHAN 1973. The Sequence and Spread of College, Poona. Prehistoric Culture in the Upper Saraswati MISRA, V. N. 1968. Middle Stone Age in Rajas­ Basin. in: Radio-carbon and Indian Archaeo­ than. in La Prehistoire Problems et Tendan­ logy, (eds.) D.P. Agrawal and A. Ghosh, ces,.pp: 295-302, Paris: CNR. Bombay, pp: 252-263. MISRA, V. N. 1969. Early village communities THAPAR, B. K. 1973a. Synthesis of multiple of the Banas Basin, Rajasthan. in: Pradhan, data as obtained from Kalibagan: in Agra­ M.C. et al. (ed.), Anthropology and Archaeo­ wal, D.P. and Ghosh, A. (ed.). Radiocarbon logy: Essays in Memory of Verrier Elwin, and Indian Archaeology, pp. 264-271. TIFR, Bombay, Oxford University Press. Bombay. MISRA, V. N. 1970. Evidence for a new Chal­ THAPAR, B. K. 1975. Kalibangan, a Harappan colithic culture in Rajasthan. Indian Anti­ metropolis beyond the Indus 'Valley. Expe­ quary 4 (1-4): 85-95. dition, Winter, 1975. MISRA, V. N. 1971a. Two Microlithic sites in THOMAS, P.K. 1975. Role of animals in the food Rajasthan-a preliminary investigation. economy of the Mesolithic cultures of western The Eastern Anthropologist 24 (3) : 237-288. and Central India, in (ed.) Clason, A.T. MISRA, V. N. 1971b. Two late Microlithic Archaeozoological Studies, Amsterdam.

24 4 CLJMA TIC CHANGES IN TJ:IE INDIAN DESERT

GURDIP SINGH

IN the early fifties, great concern was of the opinion: "Desert conditions must expressed over the reportedly rapid spread have gradually set in well after man of the Rajasthan desert into the hitherto appeared, possibly in geologically sub­ fertile tracts surrounding the region: recent times." It was generally held that "Recent topographical surveys show that the desert conditions had deteriorated as the great Indian desert of Rajasthan has compared with conditions obtaining dur­ been spreading outwards in a great convex ing the period of the Harappan Culture arc through Ferozepur, Patiala and Agra (2300-1750 B.C.) and also to some extent towards Aligarh and Kasganj at the rate in relation to some later cultures which of about half a mile per year for the last flourished in north-western India in the 50 years, and is encroaching upon appro­ early centuries of the Christian Era ximately 50 square miles of fertile land (Ghosh, 1952). Later on similar views every year" (Report of the Planning were expressed by Wadia (1960) and Commission of the Government of India Wheeler (1966). However, as the deduc­ in Its First Five-Year Pian). The claim tions on the nature of the climate during for the extension of the desert, however, the time of these cultures rested on indirect did not find support from the large body evidence provided by human artifacts, of expert opinion, then available, as such as sculptures, drawings and engrav­ brought out in the Proceedings of the ings of animals and plants on potsherds Symposium on the Rajputana Desert, and stalactite seals, burnt bricks, animal organized by the National Institute of bones, wood and charcoal remains, the Sciences of India in 1952. Indeed, the size of major cities and the location of meteorological record over the previous habitation sites with respect to river cour­ 70. years showed no significant change in ses, flooding horizons, the existence of an ramfall, temperature, humidity and wind elaborate drainage system, the occurrence velocity over the desert areas and, therefore, of "gabar bands", the testimony to higher no plausible case could be made to sup­ rainfall argued from each of these lines port the contention of the progressive of evidence was cast in doubt by some spread of the Rajasthan desert in recent authors (Raikes and Dyson, 1961; Raikes, years as indicated in the report (Pramanik 1964; Dales, 1966). According to these et al., 1952). .authors, there was not appreciable cli­ matic change in the South Asian area DETERIORATION IN DESERT CONDITIONS during the last four to five thousand . Regarding another important ques­ years and that it was not the climatic t10n whether the desert conditions had change but the flooding 0 f the rivers, det~riorated gradually over a longer with a major flood about once in 140 years pen.od, there was no precise information that weakened the power structure of the. avaIlable, though Krishnan (1952) was Indus Valley civilization, so that" the more

25 DESERTIFICATION AND ITS CONTROL

remote areas to the north became vulnera­ stratigraphy, radiocarbon dating and pol­ ble to outside pressures (Dales, 1966; len analysis of the salt-lake deposits at Raikes and Dyson. 1961). Sambhar, Lunkaransar and Didwana in Following the decline of the Harappan western Rajasthan, and a freshwater lake culture, 1750 B.C. (Agrawal et al., 1964), deposit at Pushkar in the Aravalli Hills, the Bainted Gray Ware culture is said to have been published and the reader is refer­ have established itself in the area about red to them for fuller details (Singh, 1967, 1000 B.C. According to Ghosh (1952), 1969, 1971; Singh et al., 1972; Singh et its establishment was associated with a al., 1974). These studies were carried out shaky water-supply, together with an in conjunction with a general survey of the impoverishment of the land. Later on, modern pollen fall-out from the vegeta­ it is shown that the Rangmahal culture, tion of north-western India (Singh et al., which occupied the same region during 1973). This survey was conducted from the early centuries of the Christian Era, 114 modern pollen spectra from sixty­ had an adequate water-supply and that lour different sites spread all over north­ there was probably a partial resuscitation western India with a view to finding of the river system until its decay in the modern analogues of the changing plant seventh or eighth century when the popu­ assemblages in the fossil pollen records, so lation seems to have turned to a nomadic that deductions could be made about the existence (Ghosh, 1952). Nevertheless, palaeoclimates in the region. The studies Ghosh mentions that according to the also encompassed the pollen analysis of Mahabharata, generally placed in the early the dated archaeological soil samples from centuries of the Christian Era, Bikaner the Indus Valley site at Kalibangan in was arid during that period. northern Rajasthan (Singh, 1971; Singh The evidence on climatic conditions for et al., 1974). the subsequent periods is rather sketchy. In this article, attention is focussed on From the eighth century to the twelfth the evidence pertaining to the Late­ century, Junah (now Chotun) is said to Quaternary desertification m the have had 12,000 habitable dwellings (Todd, stratigraphical records. So far, two 1829), when the same place is now no periods of desertification, described here more than a small village of 200 huts. as Desertification I and II, are discernible Yet, according to Nazim (1931), Mahmud in the Late-Quaternary sequence (Figure). of Ghazni, during the course of his inva­ Of these, the one dating from before 10,000 sion of north-western India in the eleventh B.P. is by far the severest. In the earlier century, had to make elaborate arrange­ epochs, palaeobotanical evidence indicat­ ments for water-supply to cross the desert ing the tropical rainforest conditions in from Multan to Somnath. . • Rajasthan is available from the Eocene Until the advent' of palynological stu­ period, some 60 million ye,\fS ago (Kaul, dies of the lake deposits. in the Rajasthan 1951; Lakhanpal and Bose, 1951; Bose, desert in the late sixties, the evidence of 1952), but this period is fo~lowed by a Late Quaternary climatic history had great gap in the information Llsting until suffered greatly from a lack of continuity the Late-Quaternary period. in its chronological sequence. The archa­ Desertification I. At each of the salt eological and geological . records were lakes worked out in western Rajasthan, marked by long gaps, for which there was it is seen that lacustrine deposits overlie no evidence, one way or another. This the beds of aeolian sand, and represent the lack of continuity had obviously resulted fossil dune fields dating from before from the nature of the sites investigated 10,000 B.P. (Singh, 1971; Singh et al., where the records could not survive in an 1972, 1974). In the section (Singh et al., unbroken order. 1974. pp. 480, 485, 487), the dune fields The observations made by the present extend inwards from the margins of the author, and bis associates, based on the encircling sand-dunes and lie directly

26 CLIMATIC CHANGES IN THE INDIAN DESERT below a sequence of laminated clays. pics.. It is now accepted that a fall in At lower levels, the sand grades into a temperature during the last ice age, III kankar pan resulting from leaching as well fact, led to a decreased rainfall. as from the cementing of sand particles by 1;'he latter part of Desertification I, in calcium carbonate. At Sambhar, the Rajasthan, was contemporaneous with a presence of thin layers of cemented sand­ warming trend which was already in stone in the otherwise loose sand-bed progress 14,000-15,000 years ago in the perhaps. indicate~ some ver~ short-term Kashmir Himalayas, following the last inundatIOns. ThIs feature IS, however, full-glacial (Singh and Agrawal, 1976). not seen at the other two sites. From the But since there was a time-lag between the combined stratigraphical evidence from actual rise in temperatures and the warm­ all the three sites, it is suggested that some­ ing of the ocean surface, the reversal time before about 10,000 B.P. (Figure), in the trend, in terms of increased extremely severe arid conditions with dry precipitation, was probably delayed. winds prevailed in western Rajasthan (cf. Nevertheless, as pointed out earlier, some Allchin and Goudie, 1971), with the result short-term inundations of the basin of that extensive dunes were deposited and the Sambhar Lake did take place occa­ they led to the choking of valleys with sionally, as evidenced by the cemented sand to give shape to closed inland basins, sandstone layers intercalated in the aeo­ such as at Sambhar, Lunkaransar and lian sand-bed, suggesting some increase Didwana. No firm date has been assign­ in precipitation before the final infilling ed to the beginning of this period of of the lake basin about 10,000 B.P. desertification, but its upper limit coin­ Sub-humid interval. The infilling of the cides with the Late Weichseliam/Faland­ lake basins with fresh water about 10,000 rian boundary (8,000 B.C.) of western B.P. (8,000 B.C.), in Rajasthan, finally Europe. The closest parallel situations brought Desertification I to a close to this phase of aridity in Rajasthan is (Figure). The lakes once filled remained seen in Iran where the pre-Holocene arid fresh for 6,000-7,000 years (Singh et al., phase has been equated with the last full­ 1974). In view of the fact that there was glacial times (Van Zeist, 1967). The des­ no intercalation of sand layers in the ertification, 10,000 years ago, in Rajasthan, laminated lacustrine clays deposited during is one of the several pieces of evidence this period, it was inferred that the sand­ that now disprove the long-standing theory dunes remained stabilized throughout. that ice ages in the north necessarily The vegetation, as evidenced by the pollen correspond with abundant rain in the tro- record, first comprised an openland steppe Figure BROAD TRENDS OF DESERTIFICATION IN THE LATE-QUATERNARY HISTORY OF CLIMATE IN RAJASTHAN DESERTIFICATION II LAKES START TO DRY AND TURN SALT SLIGHT AMELIORATIONS MESOPHYTIC VEGETATION DISAPPEARS --OF CLIMATE---

AMELIORATION OF CLIMATE SAND-DUNES STABILIZED PRESENT SALT-LAKE BASINS FILLED WITH FRESHWATER VEGETATION MORE MESOPHYTIC THAN THE PRESENT

DESERTIFICATION I SAND-DUNES ACTIVE

27 DESERTIFICATION AND ITS CONTROL which was rich in grasses, Artemisia and 1971). From 3,500-3,000 B.P. (1,500- sedges, and poor in salt-tolerant halo­ 1,000 B.C.) there was some recovery in phytic species. Artemisia, Typha angus­ the vegetation, but none of the mesophytic tata, Mimosa fubicaulis and Oldenlandia, species occurring earlier returned to which now grow under areas of compara­ Sambhar, showing that the recovery was tively high average annual rainfall (above not a substantial one. Thus Desertifica­ 500 mm), appear to have flourished in the tion II in Rajasthan may be suggested to contemporary semi-arid belt (250-500 mm have started around 4,000 B.P. (Fig.). average annual rainfall), whereas the first The first evidence of the onset of this two taxa had encroached upon even as phase is seen in the breakdown of the far as the arid belt (100-250 mm average laminations in the lake sediments at annual rainfall). Both facts suggest that Lunkaransar, in the a rid belt, about a general westward shift of the rainfall 4,000 B.P. (2,000 B.C.), together with the belts had taken place. From this situa­ lack of preservation of pollen above that tion it was estimated that there was at level. At Sambhar, in the semi-arid least 250 mm more of rain than that at belt, the evidence comes from the final present in the arid belt (Singh et al., 1974). disappearance of me sophy tic elements from Similar ,increase in precipitation over those the flora about 3,803 B.P. (1,800 B.C.) even witnessed in Rajasthan during the early though the breakdown in the laminations Holocene are now well documented from and also the. lack of pollen preservation several other parts of the world (e.g., in the lake sediments did not take place Kershaw, 1974). In Queensland, Austra­ until 3,000 B.P. (1,000 B.C.) at this site. lia, for instance, as much as four- to five­ It has been suggested earlier that this on­ fold increase in precipitation is estimated set of aridity in Rajasthan was fatal to the to have taken place during the Holocene Indus Valley culture and that it greatly as compared with that during the full­ contributed to its downfall (Singh, 1971). glacial times (Kershaw. 1974). The question, however, arises as to what Except for the period from 9,500-5,000 led to this desertification? Was it due B.P. (7,500-3,000 B.C.), when the rainfall to the activities of man or was it natural, was marginally diminished (but remained or both? These questions have been dis­ above that of the present day) as evi­ cussed at length earlier by Singh et al. denced by the rise in the number of halo­ (1974) and the force of arguments, on the phytes, the period from 10,000-4,000 whole, favoured the idea of a natural cli­ B.P. (8,000-2,000 B.C.) enjoyed a substan­ matic change for the region. The paly­ tially greater rainfall than the present in nological studies have shown quite clearly both the arid and semi-arid zones. The in­ that the tree vegetation in Rajasthan in­ crease in swamp vegetation and the in­ creased hand in hand with the expansion tensification of tree and other vegetation of the Neolithic and Chalcolithic cultures cover inland together with the maxima despite the fact that the burning of vege­ of all mesophytic elements (e.g., Syzygium, tation (as part of primitive agricultural Mimosa .rubicaulis, etc.) between 5,000 practices) had gone on over the previous and 3,800 B.P. (3,000 and 1,800 B.C.) four millenl;lia in the region. The increase at Sambhar, indicate a period of opti­ in vegetation along with the spread of mum rainfall. human cultures could not have gone' on Desertification II. Following the above without an extraordinarily favourable cli­ amelioration of the climate, there was a mate prevailing during that period. Later short relatively dry time about 3,800- on, the fact that the lakes dried out, to­ 3,500 B.P. (1,800-1500 B.C.) during which gether with a decline in the mesophytic all the mesophytic species disappeared at plant species showed that the onset of Sambhar and the disappearance is corre­ aridity was independent of human in­ lated with the decline of the Indus Valley fluence. According to Eriksson (1959), culture in north-western India (Singh, during the latter part of the post-glacial

28 CLIMATIC CHANGES IN THE INDIAN DESERT

period, Rajputana (including a part of tion of the river system during the period Rajasthan) has become more arid and the of occupation by this culture. At Lun­ amount of wind-borne sand resulting from karansar, there is evidence for some rene­ dune instability has increased. Recently, wed preservation of pollen in the upper a sample from a pollen zone (Stage g) in layers, but. the plant assemblage, as dedu­ a pollen diagram from Toshmaidan (3,120 ced from the pollen record in these layers, m a.s.l.-Singh, 1963), indicating the is much the same as that of today, again falling temperatures in the latter half of the showing that the climatic change since post-glacial period in the Kashmir Valley, the beginning of the second desertification gave a date of 2790-160 B.P. (PRL-2 B) phase has been rather insignificant. (Singh and Agrawal, 1976), showing that the fall in temperatures must have pre­ REFERENCES ceded this date. Thus a case can be made that the onset of Desertification II in AGRAWAL, D. P., KUSUMGAR, S. and SARNA, R. P. 1964. Radiocarbon dates of archaeo­ Rajasthan was probably synchronous with logical samples. Curro Sci. 33(9) : 266. the lowering of temperatures in north­ ALLCIDN, B. and GOUDIE, A. 1971. Dunes, western India. aridity and early man in Gujarat, Western The course of minor oscillations of India. Man 6(2) : 248-265. BOSE, M. N. 1952. Plant remains from Barmer climate since the second desertification district, Rajasthan. J. Scient. Ind. Res. 11 began needs further elucidation. The B (5) : 185-190. pollen diagram from Pushkar, in the DALES, G. F. 1966. Recent trends in the Pre­ Aravalli Hills, which holds the pollen and Proto-historic archaeology in South India. Proc. Am. Phil. Soc. 110(2) : 130-139. records for this interval, has not yet been ERIKSSON, K. G. 1959. Studies on the dry bed dated by means of radiocarbon. As a of the river Ghaggar at Rangmahal, Rajas­ result, the dates assigned to the various than, India. Acta Archaeologica Lundensia levels in the Pushkar pollen profile are series, in : 4, No.3, in : H. Rydh, Rangmahal, tlze Swedish Expedition to India, 1953-1954. still very tentative. GH9sH, A. 1952. The Rajputana desert-its At Pushkar, a mesophytic community, arChaeological aspects. Bull. natn. Inst. consisting of Anogeissus pendula, gives way Sci. India I: 37-42. to a vegetation dominated by desert spe­ KAUL, K. W. 1951. A palm fruit from Kapurdi (Jodhpur, Rajasthan desert), Cocos sohni; cies, such as Calligonum, May tenus, sp. nov. Curro Sci. 20 : 138. Ephedra, Capparis and Prosopis cineraria KERSHAW, A. P. 1970. A pollen diagram from during a period which has been corre­ Lake Euramoo, north-east Queensland, lated with Desertification II in western Australia. New Phvtol. 69 : 785-805. KERSHAW, A. P. 1974. ·A long continuous pollen Rajasthan. Later on, this trend was sequence from north-eastern Australia. reversed at a date estimated around A.D. Nature, Lond. 251 : 222-223. 400 with the result that the desert species KRISHNAN, M. S. 1952. Geological history of declined, giving place to Anogeisslls pen­ Rajasthan and its relation to present-day conditions. Bull. naln. Insl. Sci. India dllla, Ficus and a number of other mes')­ 1:19-31. phytic species which have lasted to the LAKHANPAL, R. N. and BOSE, M. N. 1951. Some prescnt day (Singh et al., 1974). How­ tertiary leaves and fruits of the Guttiferae ever, as the salt-lakes in western Rajasthan from Rajasthan. J. Indian bot. Soc. 30 (1-4) : 132-136. remained saline and mostly as dryas NAZIM, M. 1931. The Life and Times of Sultan tod~y since the beginning of Desertification Mahmud 0/ Ghazlli, Cambridge. II, It is likely that the reversal in the PRAMANIK, S. K., HARlHARAN, S. P. and desertification trend seen in the Aravallis GHOSH, S. K. 1952. Meteorological condi­ tions in the extension of the Rajasthan d~sert. ~round A.D. 400 was rather small. This Bull. natn. Inst. Sci. India, 1. ?sUpported by the archaeological evidence RAIKES, R. L. 1964. The end of ancient cities rom sites occupied by the Rangmahal of the Indus. American Anthropologist 66 cult?r~ during the early centuries of the (2) : 284-299. RAIKES, R. L. and DYSON, R. H. 1961. The pre­ Chnshan Era. According to Ghosh historic climate of Baluchistan and the Indus (1952), there was only a partial resuscita- Valley. American Anthropologist 63(2): 4

29 DESERTIFICATION AND ITS CONTROL

265-281. SINGH, G., CHOPRA, S. K. and SINGH, A. B. 1973. SINGH, G. 1963. A preliminary survey of the Pollen-grain from the vegetation of north­ post-glacial vegetational history of the west India. New Phytol. 72: 191-206. Kashmir Valley. Palaeobotanist 12(1) : 73- SINGH, G., Josm, R. D., CHOPRA, S. K. and SINGH, 108. A. B. 1974. Late Quaternary history of SINGH, G. 1967. A palynological approach to­ vegetation and climate of the Rajasthan wards the resolution of some important desert, India. Phil. Trans. 267B : 467-501. desert problems i.il Rajasthan. Ind. Geohyd. TODD, JAMES LIEUT, COL. 1829. Reprinted 1957. 3 : 111-128. Annals and Antiquities of Rajasthan. Routledge SINGH, G. 1969. Palaeobotanical features of the and Kegan Paul Ltd., London. Thar desert. Ann. Arid Zone 8(2): 188-194. WADIA, D. N. 1960. The post-glacial desiccation SINGH, G. 1971. The Indus Valley culture seen central Asia: evolution of the arid zone of in the context of post-glacial climatic and Asia. Nat. Inst. Sci. India Monograph, ecological studies in northwest India. Delhi. Archaeol. & Phy. Anthropol. Oceania 6: WHEELER, SIR, MORTIMER, 1960. Civilization of 177-189. the Indus Valley and beyond. London, Thomes SINGH, G. and AGRAWAL, D. P. 1976. Radio­ and Hudson. cJ.rbon evidence for deglacialation in north­ VAN ZEIST, W. 1967. Late-Quaternary history of western Himalaya, India. Nature, Lond. Western Iran. Rev. Palaeobot. Palynol. 260: 232. 2 : 301-311.

30 S PALYNOLOGICAL EVIDENCE ON CLIMATIC CHANGES IN JAISALMER BASIN, RAJASTHAN

N.G. LUKOSE

WESTERN Rajasthan is a paleo-shelf, mation is considered homotaxial with the bounded by the Aravalli range to the east, Bilara Formation of Bap-Bikaner area. by the Indus geosyncline dissected by the Freshwater environments must have pre­ basement ridges to the south and by the vailed during the deposition of the Bir­ Delhi-Lahore ridge to the north. A mania Formation, whereas the marine transverse basement ridge, the Mari­ environment prevailed during the deposi­ Jaisalmer arch separated the basin con­ tion of the Bilara group of rocks. The figuration of this part. The sediments prevalence of oxidation environment is that were deposited in the tectonic depres­ indicated during the deposition of the sions NE and SW of the ridge include the overlying Nagaur Group, as evidenced Trans-Aravalli Vindyans. These sedi­ from red beds. From the marked simi­ ments are classified into the arenaceous larity between the Salt Range Saline Series Jodhpur group, the calcareous Bilara of Pakistan and the rock formations of group and arenaceous Nagaur group. the Trans-Aravalli Vindhyans, the existence The Jodhpur group of rocks are deposited of a wide and long basin is inferred. It in sublittoral intertidal zone. The arena­ is believed that most of western Rajas­ ceous to calcareous facies change suggests than remained as land during the period epineritic to infraneritic environment. The from the early Palaeozoic to the beginn­ presence of stromatolites in the Bilara ing of the Mesozoic. A large part of Sind, Formation indicates that the water column Baluchistan, Rajasthan and Cutch was would not have been greater than 100 covered by the sea during the Middle metre deep (Pareek, 1975). Jurassic period. The Lathi For­ The studies carried out on the sedi­ mation (Liassic) has a wide extension mentary structures (Khan and Mukho­ from near Barmer to Jaisalmer and Lathi. padhyay, 1971-72; Mukhopadhyay and The Jurassic sediments are represented by Sinha, 1973-74) indicate the prevalence the lower arenaceous Lathi Formation, of a general westward palaeo-current the middle Calcareous Jaisalmer For­ flow direction, indicating the easterly mation and the upper Baisakhi and Dede­ Source area. The sedimentological ana­ sir Formations. The Neocomian sedi­ lysis (Mukhopadhyay, 1970-73) indicates ments are represented by the Pariwar the sandstones of Girbhankar (Jodhpur Formation, indicating shallow marine Formation) and Nagaur Formation Were to brackish and continental environments. deposited in deltaic-intertidal to beach The Aptian and the Albian to Turonian environment and shallow marine environ­ sediments are represented by Abur ment. Contemporaneous with this sedi­ Goru Parh Formations, indicating a mentation the Randa and Birmania For­ shallow marine environment. The over­ mations were deposited near Birmania in lying Ranikot, Laki and Kirthar For­ the Jaisalmer basin. The Birmania For- mations (Paleocene-Middl~ Eocene) are

31 DESERTIFlCATION AND ITS CONTROL mainly deposited under a shallow marine It commences. with glauconitic clay base, environment, except for small regressive grades into gravelly sands, sandstones, facies in Ranikot. This time-gap did limestone and aeolian sand with reworked not exist in Cutch and in the Salt Range Eocene fossils, suggesting arid to desert where continuous deposition is evidenced conditions. The general sub-surface stra­ (Pareek, 1975). During the Sub-Recent tigraphy and lithology of the .Jaisalmer period, the Shumar Formation got depo­ basin are ,given in Table I .. sited under the freshwater environment.

Table 1. General sub-surface stratigraphy, laisalmer basin

Group System Series Stage Forma- Member Lithology tion Quaternary Recent Dune sand « Sand and clay ~ Limestone and calcareous sandstone Sub- Shumar ~ Sandstone and variegated Recent clay .8 Alternating variegated clay and coarse-grained sand- stone and glauconitic clay T UNCONFORMITY B Middle Lutetian Kirthar Bakhri Clay Eocene Tibba Limestone R Habib Clay Eocene Rahi Limestone T Lower Yprecian Ghazij Shale Eocene Limestone I Laki Shale A Dunghan Limestone Marl R Palaeocene Limestone Y Marl/clay/shale Ranikot DISCONFORMITY Limestone Clay and marl, sandstone Clay sandstone M UNCONFORMITY E Conia- Parh Marl cian S Turonian Clay/marl/limestone Clay/marl/I Clay and marl 0 Upper Limestone

Z Creta- ceous 0 C~noma- Upper Marl and silty shale/clay nian Gom Silty and sandy clay, clay with siltstone intercalation I Creta- Arenaceous shales ceous C Albian Lower Sand

32 PALYNOLOGICAL EVIDENCE ON CLIMATIC CHANGES

Table 1. (Contd)

Group System Series Stage Forma­ Member Lithology tion Goru Shale-siltstone intercala­ tions Argillaceous bed sand! C sandstone fine-grained with shale intercalations R Lower Creta­ Sandy clay/shale with lime­ E ceous stone intercalations shale/ grey-greenish clay with T siltstone intercalations A Shale grey greenish clay with siltstone intercalations C Argillaceous sandstone and E shale intercalations and siltstone intercalations o Sandy shales-glauconitic U Sandstone fine to medium and shales S Argillaceous sandstone and black carbonaceous clay Sandstone coarse-grained and argillaceous Neoco­ Pariwar mian Sandstone with shale inter­ calations Sandstone and silty shale, black shale Grey to brown silty clay shale, sandstone argilla­ ceous Mesozoic Shale and argillaceous standstone intercalations Sandstone/clay/siltstone in­ tercalation Upper Portlan- Baisakhi Sandstone argillaceous Jurassic dian Bedesir Sandstone and carbonace­ ous shales Kimmeri­ Sandstone medium to coarse dgian and argillaceous Sandstone fine to medium and hard Silty clay/silty shale golden oolite Microcrystalline and oolitic limestone

33 DESERTIFICATION AND ITS CONTROL

Table 1. (Contd)

Group System Series Stage Forma- Member Lithology tion

Lime- Sandstone with shale streaks stone member Coquinoidal limestone/ sandstone with alternating Jaisal- band of shale' Jurassic Oxfor- mer dian Callo- Shale Shale dark grey, with alter- vian member nations of sandstones Limestone (oolitic ) with siltstone Mesozoic Shale dark grey. Coquinoi- dal sandstone with car- bonaceous material Claystone variegated, grey- greenish maroon, brick-red Sandstone greyish white, coarse-grained, calcareous Sandstone cream-coloured medium to coarse-grained. Lower Liassic Lathi Claystone chocolate brown Jura- with sandstone intercala- ssic tions Sandstone greyish, white coarse to medium-grained with claystone streaks Siltstone, grey, brown to chocolate brown, yellowish brown and pink

Claystone grey, greenish brown Sandstone brown, grey with variegated clay/shale Triassic streaks Pre- Lathi Palaeozoic Sandstone coarse-grained with rhyolite and quartzite chips Permian Siltstone sandstone non- calcareous with carbona- ceous shale bands Shale-sandstone alternation

34 PALYNOLOGICAL EVIDENCE ON CLIMATIC CHANGES

In western Rajasthan after the Early sen ted by the Habur Formation (Aptian). Palaeozoic transgression, the first the Goru Formation (Albian to Ceno­ transgression of the sea in the Jaisalmer manian) and the Parh Formation Turo­ basin is represented by the marine Per­ nian to Coniacian in age. The regression mian sediments, as evidenced in the Shu­ of the sea and the break in sedimentation marwali' Talai and Bhuana wells drilled is o15served during the Post-Coniacian to by the Oil and Natural Gas Commission Modstrichian periods. A part of the during the explorative drilling for hydro­ Lower Paleocene beds of the Ranikot carbons. Regressive facies occur to the Formation represent a freshwater environ­ top of the Permian sediments. The Trias­ ment. The last and major transgression sic sediments are represented by the basal of the sea in the Jaisalmer basin is during regressive beds, middle transgressive beds the middle Paleocene and this transgres­ and upper regressive beds. The Liassic sive facies are represented by the upper sediments are represented by the conti­ beds of the Ranikot Formation (Middle nental Lathi Formation. This is overlain Paleocene), the Laki Formation (Upper by carbonate rocks of the Jaisalmer For­ Paleocene to Lower Eocene) and the Kir­ mation, representing Callovo-Oxfordian thar Formation (Middle Eocene). At age, and the shaly Baisakhi Formation the close of the Lutetian, the sea receded (Kimmeridgian), representing marine completely from the laisalmer basin and transgression. The overlying Bedesir For­ the area remained as land during the mation (Tithonian) represents the regres­ Upper Eocene, Oligocene, Miocene periods sive phase, succeeded by the shallow till the beginning of the Sub-Recent Shu­ marine-brackish and continental Pariwar mar sedimentation. The paleo-environ­ Formation of the Neocomian Age. The ments of deposition of the laisalmer basin next major transgressive facies are repre- sediments are given in Table 2.

Table 2. Paleo-environment, Jaisalmer basin sediments

Time Rock unit Rock unit Paleo-environment Group System Series Stage Formation Quaternary Sub-Recent Shumar Continental Unconformity T Eocene Middle Lutetian Kirthar E Lower Ypresian Laki Shallow marine R T Paleocene Upper I A Middle Ranikot R Lower Y Fresh water

C Unconformity R E T Upper Coniacian A Turonian Parh C Shallow marine E Cenomanian Gom 0 U Albian S Aptian Habur Lower Neocomian Pari war Shallow marine-brac- kish and continental

35 DESERTIFICATION AND ITS CONTROL

Table 2. (Conld) M E J S U o R Tithonian Bedesir Regressive Z A Kimmcrid- Baisakhi o S Upper gian I S C I Oxfordian Jaisalmer C Middle Callovian Shallow marine Lower Liassic Lathi Continental Triassic Regressive Shallow marine Regressive P Permian Regressive A Shallow marine L Unconformity A Birmania E Unconformity o Randa Z Unco.nformity o I C Malani Igneous Suite

Table 3. Paleo-climate and Paleo-environment, Jaisalmer basin

System Series Paleo-basin envi­ Terrestrial flora (rela- Paleo-climate ronment tive) Sub-Recent Continental Insignificant. Pteri- Arid dophytic spores pra­ ctically nil Lutetian Shallow marine Poor flora and pteri- Semi-arid dophytic element in particular Eocene Yprecian Paleocene Shallow marine Considerable reduc- Freshwater (regres­ tion in total land flora sive facies) and significant reduc- tion in peteridophy- Semi-humid tic elements Coniacian Shallow marine Turonian Cretaceous Cenomanian Shallow marine Luxuriant and pteri- Warm-humid Albian Aptian dophytic elements plenty Neocomian Shallow marine con­ tinental Upper (Tithonian Continental and shal­ Warm and temperate Kimmeridgian) low marine Jurassic Luxuriant Middle (Callovo- Shallow marine Oxfordian) Liassic Continental Triassic Continental As compared with Shallow marine Permian, reduction Temperate Continental is 0 bserved in terres- trial flora Permian Continental Luxuriant Temperate and cool Shallow marine

36 PALYNOLOGICAL EVIDENCE ON CLIMATIC CHANGES

The time and the various factors that regionally over the earth and with time. led to the origin of the Rajasthan desert, and differs from place to place. whereas popularly known as ~he Thar De~ert e?,­ weather varies from day to day. The cause tending between latItudes 24°35 North of several climatic elements varies from and 30° 10' North, and between longitudes place to place and season to season, result­ 69°30' East and 76°East, covering about ing in the season being hot or cold in 2,00,000 sq. km of western. India have some places, wet in another place and, remained obscure. The vanous factors dry in still another place. These varia­ which contributed to the formation of this tions are due to climatic controls, namely desert, as postulated by various authors latitude, distribution of land and sea are: (1) that this region lies along the (water), winds and air masses, altitude, well-known northern desert belt, and the mountain barriers high-and-Iow-pressure aridity and the large diurnal variations of centres, ocean currents and various kinds temperature disintegrate the rocks and of storms. These controls, acting with help to form sand which is distributed by various intensities and combinations, pro­ the action of winds (Krishnan, 1956); duce the changes in temperature, precipi­ (2) that owing to a long-continued and tation and evaporation which, in turn, extreme degree of aridity of the region, give rise to varieties of weather and cli­ combined with the sand-drifting action mate. The natural vegetation in different of the south-western monsoon sweeps parts of the world has all the time not through Rajputana for several months of existed in its present form. It had never the year without precipitating any part been static, but as the climate changed of their combined moisture (Wadia, 1957); in the past, the vegetation also changed. (3) that this region is located on the leeward Modifications and varieties within the side of the Aravallis and, therefore, the climatically induced larger plant commu­ precipitation is small; (4) that it is located nities are usually the result of secondary in the trade-wind belt where the air is factors, chiefly the soil and biotic elements moving towards the Equator, causing warm and they are associated with exposure, and increased capacity to hold moisture drainage, climatic, and human exploita­ which causes high evaporation and trans­ tion. Thus whereas the climatic control piration loss resulting in aridity, (5) that is of primary importance in plant growth, the rising of the Himalayas and the lower­ development and distribution, the edaphic ing of the Aravallis have changed the control is secondary. However, soil and course of the moisture-bearing winds climate are not completely independent (Sen, 1964); (6) that owing to the im­ factors, as soil characters are greatly in­ poverishment of and the consequent fluenced by climate and natural vegetation. deepening of the subsoil water-table, there Still in the soils, there are many local varia­ took place the diversion of the Himalayan tions, which are the result of non-climatic waters (Rode, 1964). factors, such as the parent soil material The weather is the condition of atmos­ and the bedrock drainage conditions, and phere at any time or place and is expressed the slope. As such, the soil may vary by the combination of elements, primarily almost from one spot to another, and as t~e temperature, precipitation and humi­ a result, produce local variations in vege­ dIty, wind and air pressure. They are tational cover. In addition to climatic the ingredients, out of which seasons, and edaphic factors, there is the biotic weather and climatic types are formed. factor. Thus overgrazing can change the The weather of any place is the sum total native vegetation of a region. Other of its atmospheric conditions, namely biotic factors are associated with pollinat­ temperature, winds, moisture and precipi­ ing insects, the relation between hosts and tation for a short period whereas the cli­ parasites, and the obligatory food depen­ mate is a composite variety of day-to-day dency. Since the plants are immobile weather conditions. The climate varies they must adapt themselves to their en-

37 DESERTlFICA nON AND ITS CONTROL

vironment and thus a plant is a captive ceous sediments with a conspicuous reduc­ of its environment. Similarly, unlike tion in pteridophytic spores in relation animals, the plants do not generate heat. to its percentage in Albian-Cenomanian As a consequence their very existence sediments. Whereas the total sporo­ is greatly influenced by the air and soil morph percentage remained unchanged temperature and thus for every plant spe­ in relation to the Upper Cretaceous sedi­ cies, there are three critical temperatures, ments, the percentage of pteridophytic namely a lower and an upper limit, beyond elements has been considerably reduced which it cannot survive, and the third, an to 0 5 % in the Ranikot (Paleocene) sedi­ optimum temperature at which it vigo­ ments. The total percentage of terrestrial rously flourishes (Finch et al., 1957). sporomorph has been reduced in the The palynological assemblage of the overlying Laki and Kirthar (Eocene) Iaisalmer basin, the Permo-Triassic sedi­ sediments with a progressive reduction in ments (Tikku et at., 1976; Lukose and pteridophytic spores to a meagre 0 3 per Misra, 1976), the Lathi Formation Liassic, cent. As regards the Sub-Recent Shumar the Jaisalmer Formation Ca1!ovo-Oxfor­ Formation, the presence of sporomorph dian (Lukose, 1971) suggest the prevalence is very meagre and practically the sedi­ of a cool to temperate climate and luxu­ ments are devoid of spores and pollen­ riant terrestrial vegetation near and around grains .. the shore of the basin of deposition. The Unless nearby shore areas of a sedi­ palynology of the Baisakhi-Bedesir Form­ mentary basin had luxuriant vegetational ation-Upper Jurassic, and theHabur, Pari­ cover consistent with time and space, the war and Goru Formations and the Lower sporomorph representation in ~ given Cretaceous (Neocomian to Cenomanian) quantity of sediment will be insignificant indicate that during the deposition of these in quantity, if the basin preservational sediments, the vegetation near and around environment has otherwise remained good. the basin had been luxuriant, and the warm The occurrence of lignite and halite and humid climate prevailed, as evidenced reported by Sinha et al. (1973) within the by the presence of a high percentage of Tertiary sediments further confirms the pteridophytic spores in the sediments. prevalence of severe and continued ari­ However, a gradual but steady decrease in dity. It may be argued that the quantita­ the sporomorph, in general, and the tive and qualitative differences in 'spore pteridophytic elements, in particular, and pollen content in the sediments be­ have been observed in the overlying Upper longing to the same or different lithozones Cretaceous, Paleocene, Lower and Middle or different geological periods may be Eocene sediments and practically devoid due to unfavourable edaphic factors or of sporomorph in the'Sub-Recent Shumar geochemical conditions of the basin dur­ Formation (Lukose, 1974). ing or after the deposition or both. In Figure 1 shows the percentage of terres­ such an event, the sporomorph recovered trial and non-terrestrial elements calcu­ from the respective sediments will show a lated from the total sporomorph count bad state of preservation. But the occur­ obtained from the sub-surface Goru, rence of well-preserved sporomorph in Parh, Ranikot, Laki, Kirthar and Shu­ the various sedimentary sequences indi­ mar Formation, o.f Iaisalmer basin corres­ cates the existence of favourable geo­ ponding to Albian-Canomanian, Turo­ chemical and other basin conditions dur­ nian-Conician, Paleocene, Yprecian, ing the deposition of the various sedi­ Lutetian and Sub-Recent periods. Out mentary sequences. The progressively of 44 % of the terrestrial sporomorph, diminishing quantity of pteridophytic 15 % are of pteridophytic spores in Albian­ spores and other terrestrial pollen-grains Cenomanian sediments. The total per­ from one period to another in the post­ centage of terrestrial sporomorph is al­ Cenomanian sediments could be attri­ 'most reduced to 1/6 in the Upper Creta- buted to the prevalence of adverse climatic

38 PALYNOLCGICAL EVIDFr-iCE ON CLIMATIC CHANGES

Formation Terestrial.sporom~Hph Aquatic forms

40 Shu-mar I " rns;gnrant flora Arid· Kirthar Conslderabl.y poor 'flora 1 Semi-arid LaK, 5. 3 0.3 1

1 _ o~51 Considerably Parh reduced flora Semi-humid 2.5 7

l 15 25 "E .s::.::J -0 ·Gor!.! c:

39 DESERTIFICATION AND ITS ceNTROL

little doubt that the Rajasthan desert was tation and evaporation, wind and air mass. occupied by sea, and marine communica­ The prevalence of the disturbed climatic tion existed from Kutch to western Rajas­ control over a period of 35 miIIion years than. However, the microfossil evidence resulted in semi-arid to arid climate dur­ indicates the prevalence of unstable basin ing the Post-Lutetian period, causing the environment and frequent fluctuations in destruction of whatever land flora remain­ the sea-level during the Neocomian and ed during the Paleocene-Middle Eocene Cenomanian periods and the regression transgressive period. However, after the of the sea from the basin during the Post­ regression of the sea, some flora still may Coniacian period and a break in sedimen­ have flourished in isolation near and tation during the Upper Cretaceous period around the left-out, lakes and other water corresponding to the Coniacian to Masd­ bodies. Further, it is not possible to rule strichian over a period of 20 million years. out the prevalence of the wet period or Possibly, the unstable basin environment, cycle during the Middle Eocene to the and later the withdrawal of the vast water Sub-Recent unconformity period. But body due to regression, and the upliftment there is no sedimentary evidence to support of land must have affected adversely the this statement, as it would have been quite climate owing to the change in one of the insignificant in time and space. major climatic factors, namely the dis­ In the geological history of the laisalmer tribution of land and sea, which in turn, basin, the last sedimentation cycle is re­ had altered the wind and air mass to make presented by the Sub-Recent Shumar For­ changes in temperature, precipitation and mation. The palynological evidence sug­ evaporation. This change might have ge,ts that these sediments were deposited resulted in less and less humid conditions under the non-marine environment and over a period of 20 million years, which the continuance of aridity and scanty vege­ ultimately effected the destruction of the tation near and around the basin while the land flora near and around the basin. Shumar was being deposited. Lakhanpal and Bose (1951), and Lakhanpal The spores and pollen grains 'are very (1964) reported the occurrence of numerous meagre in the Shumar sediments and the angiosperm leaves and fruit impressions pteridophytic elements are practically nil. of Guttiferae, Mesua and Garcinia from The presence of organic matter in the sedi­ Fuller's Earth sediments. Kaul (1951) ments, in general, is very poor as compar­ reported the impression of palm fruit ed with that in the underlying Eocene sedi­ Cocos sallllii from Kapurdi. The prolific ments. Further in these sediments, fair occurrence of the fossils belonging to the distribution of reworked Eocene Foramini­ rain-forest and coastal vegetation in the fera and the occurrence of variegated clays above Eocene sediments furthe'r supports were observed. All these factors suggest a large-scale destruction of such flora weathering, erosion and the reworking of during the Eocene period. sediments, besides the prevalence of aridity. During the Paleocene, the basin submerg­ Had a prolific land flora thrived over the ed under the transgressed . sea and it reo uplifed land during thc Post-Eocene un­ mained submerged till the close of the conformity, plenty of organic matter, plant Lutetian time, but under the unstable and microfossils and megafossils would have frequently fluctuating basin environment. occurred in the Shumar sediments owing The last major regression of the sea from to the submergence of this flora during western Rajasthan is during the close of the deposition of the Sub-Recent Shumar the Lutetian and the basin uplifted and Formation. remained without sedimentation for a Favourable climatic variation for a period of 35-40 million years. This reo number of years in succession may very gression had once again disturbed the cli· well bring up a good vegetational cover matic control (land-water distribution), re· in isolation. But it may perish in the next suIting in changes in temperature, precipi. spell of aridity, even though a few of them

40 PALYNOLOGICAL· EVIDENCE ON CLIMATIC CHANGES

roay adapt themselves to a certain extent Ind. Progress report (unpublished). KRISHNAN, M. S. 1956. Geology of India and and survive immediate destruction, As Burma. Higginbothams, Madras. such, the flora will not sustain its~lf, if LAKHANPAL, R. N. 1964. Specific identification unfavourable arid climate prevails for long of the Guttiferous leaves from the Tertiary periods. A favourable climate consistent of Rajasthan. Palaeobotanist 12 (3): 265- 266. with time and space al10ws the growth, LAKHANPAL, R. N. and BOSE, M. N. 1951. Some development, and natural replenishment Tertiary leaves and fruits of Guttiferae from of the flora. The luxuriant flora establi­ Rajasthan. Ind. Bot. Soc. 30 : 132-139. shes the microclimate, maintains atmos­ LUKOSE, N. G. 1971. Palynology of the Sub· Surface sediments of Manhera Tibba Struc­ pheric humidity, increases soil productivity ture, Jaisalmer, Western Rajasthan, India. besides stopping soil erosion and other Palaeobotanist 21(3) : 285-297. principal sand-forming activities, namely LUKOSE, N. G. 1972. Palynological evidence on weathering exfoliation and the crumbling the age of Lathi Formation, Western Rajas­ than, India. Proc. Semi. Paleopalynology, of rocks. Indian Stratigraphy, Calcutta 1971: 155- The palaeoclimate and the palaeoenvi­ 159. ronment of the deposition of the sediments LUKOSE, N. B. and MISRA, C. M. 1975. Geonell's in the Jaisalmer basin, as evidenced from 5 (3,4): 35. MUKHOPADHYAY, A.K. 1970-73. A report on the palynology, is summarized in Table 3. the geological mapping and hydrogeochemical The palynological evidence of the Jai­ sampling for potash in parts of Nagaur, salmer basin suggests the prevalence of a Jodhpur and Bikaner district, Rajasthan. cool temperate to temperate warm climate Geo!. Surv. Ind. (unpublished report). MUKHOPADHYAY, A. K. and SINHA, A. A. K. and the existence of luxuriant land vegeta­ 1973-74. A report on the mapping in parts of tion during the Permo-Jurassic period; a Jodhpur and Barmer districts, Rajasthan. Warm and humid climate and luxuriant Geo!. Surv. Ind. (unpublished report). flora during the Lower Cretaceous period, PAREEK, 1975. Geological Configuration of North Western Rajasthan. Geo). Suev. Ind. (un­ semihumid climate and reduced land flora published). during the Upper Cretaceous-Paleocene RODE, K. P. 1964. Geomorphology and evolu­ period, semi-arid climate during the Early tion of Rajasthan desert. Proc. Sym. Pro­ Eocene and the arid climate during the blems Ind. Arid Zone Govt. of India, New Sub-Recent times while the Shumar sedi­ Delhi. SEN, A. K. 1964. Some geographic features of ments are being deposited, the Rajasthan desert. Proc. Sym. Problems. Ind. Arid Zone Govt. of India, New Delhi. REFERENCES SINHA, B. P. C., SINGH., C. D. S., BAKSHI, A. R. and BHATNAOAR, G. C. 1973. A note on FINCH, v.C., TREVARTHA, G. T., ROBINSON, A. H. the discovery of Halite, Bikaner area, Rajas­ and HAMMOND, E. H. 1957. Physical Ele­ than. Curro Sci. 42 (24) : 874. ments of Geography. McGraw-Hill Book TIKKU, C. L., LUKOSE, N. G., SINGH, N.P., MISRA, Co. New York. C.M., GUPTA, V. K. and ABBASI, N. A. KAtlL, K.N. 1951. A palm fruit from Kapurdi 1976. Note on the presence of Triassic Jodhpur, Rajasthan, Cocos Sahnii sp. nov. and Permian sediments in sub-surface Curro Sci. 20 : 138. Jaisalmer District, Rajasthan. Curro Sci. KHAN, E. A. and MUKHOPADHYAY, A. K. 1971-72. 45(15). A report on the Geological mapping in parts WADIA, D. N. 1957. Geology of India. Mac­ of Jodhpur district, Rajasthan. Geol. Surv. Millan & Co. Ltd. New York.

41 6 A CLIMATIC ANALYSIS OF THE ARID ZONE OF NORTH-WESTERN INDIA

A. KRISHNAN

ARID zones are characterized by sparse siderably numerous. Thornthwaite's and highly variable precipitation, extreme (1948) moisture indices were worked out variation of diurnal and annual tempera­ for each of these stations and the areas ture and high evaporation. The crop or with moisture index values less than 40 pasture production in this zone should, were delineated as the arid zone. A therefore, aim at using the available water study made by Krishnan and Shankarna­ most efficiently. Thus a detailed study of rayan (1964) revealed that the climatic various climatic factors in these regions is clas~jfications made by using Emberger extremely important. The object of this and Thornthwaite's methods agree well chapter is, therefore, to study in detail the with the distribution of vegetation in these climatic patterns of the arid zone in north­ zones. western India, especially with regard to The State-wise areas of the arid zone in changes and trends with a view to getting India and the percentage of the total area a better insight into the occurrence of the in the arid zone in the country are pre­ desertification process, if any. sented in Table 1.

DELIMITATION OF THE ARID ZONE Table 1. State-wise areas of tile arid zone in OF INDIA India Pramanik, Hariharan and Ghosh (1952) State Area under Percentage of classified the climates of various places in the arid zone the total arid and around Rajasthan by using isopleths (km') zone in India of De-martonne's indices of aridity. The climatic classification of' India and the Rajasthan 1,96,150 62 delineation of the arid zones have been Gujarat 62,180 20 carried out by Carter (1954). Subraman­ Punjab 14,510 5 yam (1956), Subramanyam et al. (1965), Haryana 12,840 4 Shanbagh (1956) and Bhatia (1957). But Maharashtra 1,290 0·4 Karnataka 8,570 3 these studies were based on the data of only Andhra Pradesh 21,550 7 meteorological observatories, for which Total area 3,17,090 long-period normals were available. Since Jammu and Kashmir* 70,300 the network of such stations is not dense enough for carrying out the detailed delineation of the arid areas in the coun­ *Cold arid zone try, Krishnan (1968a) classified the arid Thus the area in the arid zone in north­ and semi-arid zones of India by utilizing western India constitutes almost 90 per not only the normals of meteorological cent of the total arid zone in the coun­ observatories but also those of the pro­ try (excluding the cold desert of Ladakh vincial raingauge stations which are con- in the Jammu and Kashmir State).

42 A CLIMATIC ANALYSIS OF ARID ZONE

Rajasthan tion, more so from 800 E longitude on­ wards towards the east. Krishnan (1968b) has furnished infor­ The moisture-detention values are uni­ mation on the district-wise areas of the formly high in the longitudinal range arid zone in Rajasthan. The boundary bet­ 800-1200E. Thus the comparatively little ween the arid and the semi-arid zones in coverage of the arid zone in the belt 20°_ Rajasthan cuts across the Jalore and Pali 30° N and the occurrence of the arid districts, goes roughly along the boundaries zone right in the regio1_l of the lowest of the Ajmer and Nagaur districts. The pressure during the main rainy season are districts in Rajasthan lying wholly in the peculiar to our longitudinal range. This arid zone are Ganganagar, Bikaner, may be mainly ascribed to the large cir­ Jaisalmer, Barmer, Jodhpur and Churu. culation changes owing to the Asiatic The districts lying partly in the arid zone monsoon. Further, the intertropical con­ and partly in the semi-arid zone are as vergence zone lies only within 3°_10° N follows: (The percentage of area falling latitude in the Pacific Ocean up to 18° in the arid zone is given in brackets). latitude in Africa and up to 300 N latitude Nagaur (96), Jalore (88), Jhunjhunu (69), in India and South-east Asia. In view Sikar (65), Pali (48) and Ajmer (9). of the above-mentioned peculiarities in the circulation, the Indian arid zone Punjab-Haryana falls in a peculiar category (Krishnan, To the north of Rajasthan, the demar­ 1973). cation line of the arid zone intersects the Though much rainfall is not received in Mahendragarh and Hissar districts of this desert, atmospheric humidity is usu­ Haryana and the Sangrur, Bhatinda and ally fairly high and is comparable with Ferozepur districts of the Punjab State. that of places with higher rainfall in the The percentages of the arid zone in the semi-arid and sub-humid zones, as shown above-mentioned districts are as follows: in Table 2 (Krishnan, 1968a). Ferozepur (77), Bhatinda (88), Sangrur Thus there is hardly any difference in (8), Hissar (90), and Mahendragarh (9). the actual humidity values. Not only in the surface level, but also in the upper Gujarat levels, the humidity conditions in the To the South ofRajasthan, the boundary Indian arid zone are high. For instance, of the arid zone passes through the follow­ the precipitable water vapour in grammes ing districts (arid area expressed as per­ over Jodhpur is almost of the same magni­ centage in brackets): Banaskantha (18), tude as over the humid parts of the coun­ Mehsana (7), Ahmedabad (6), Surendra­ try, as can be seen from the following nagar (29), Rajkot (6), Jamnagar (80) data. and Junagadh (20). In Gujarat, the only July August Sep­ district which is wholly included in the tember arid zone is Kutch. Jodhpur 5.5 5.1 4.3 PECULIARITY OF THE INDIAN Nagpur 5.5 5.4 4. 7 ARID ZONE Bombay 6.2 6.0 5.3 Krishnan (l968a) presented data on Trivandrum 4.6 4.4 4.5 the moisture retained in or on the sur­ face of the land in each 10° longitude zone There is little difference in respect of the of the belt contained between 30° and dewpoint depression between New Delhi 40° latitude. These data indicate that (semi-arid) and Jodhpur (arid) in May, t~er~ is extremely poor moisture reten­ both at 850 mb and at 700 mb. In July, tlOn In this latitude belt in the longitudinal at the 850 mb level, the humidity values range from 200 W to 700E. However, at both the stations are nearly the same, there is a sharp increase in moisture deten- whereas at 700 mb level, the dewpoint

43 DESERT1FlCATION AND ns CONTROL

Table 2. Rainfall and vapour pressure at selected stations in the arid, semi-arid and sub-humid zones of India

Barmer Jodhpur Kotah (semi- .Indore (sub- Bhopal (sub- (arid) (arid) arid) humid) humid)

Mean July 28 7 27·9 28·7 26·6 27·1 vapour pressure (mb) August 28·1 28 0 28 7 25 9 27 0 Mean annual rainfall (mm) 310 380 941 1053 1209 depression is lower at New Delhi. This mm are noticed in respect of Barmer, Jai­ lower depression of the dewpoint should salmer, Bikaner and Ganganagar. In be expected, since a more humid air mass the case of all stations, the data in respect prevails over that region at that height. of which were examined, except Hissar, But the order of humidity at 1. 5-km and the mean values are less than the median 3-km levels at Jodhpur is the same. values which can be expected on 50 per It, therefore, becomes clear that the 'cent of the occasions. In contrast, the Indian arid zone does not get adequate skewness is to the right in the case of rainfall in spite of the prevalence of high Hissar. humidity and the availability of a large In view of the skewness in the distribu­ quantity of precipitable water. tion pattern of rainfall, a knowledge of the percentage frequency distribution of CLIMATOLOGICAL FEATURES IN THE rainfall, based on the data collected over ARID ZONE OF NORTH-WESTERN INDIA a large number of years becomes ex­ Rainfall pattern tremely important. Accordingly, the fre­ quency distribution of rainfall data of An analysis of the isohyet map of the several stations for the period 1901-1970 arid regions of north-western India were analysed and the decile rainfall values indicates that the mean annual rainfall corresponding to 10 per cent, 20 per cent varies from 100 mm in the north-western .... , .. , 90 per cent probabilities were sector of the Jaisalmer district to 450 mm worked out for all stations. in the eastern boundary of the arid Zone The analyses revealed that once in 10 in Rajasthan. It varies from less than 300 years, the annual rainfall of the entire mm to 500 mrri in the arid zone of Gujarat arid zone of north-western India can be 'and from 200 to 450 mm in the Haryana­ less than 200 mm, except for Jhunjhunu, Punjab region. The general decreasing Hissar, Sikar and Pali. For Jaisalmer, gradient is from the south-east to the probability value is only 66 mm. When north-west. The year-to-year variability, we consider 20 per cent probability represented by the coefficient of variation, (viz. The deficit pattern expected once in is very high in the western parts of the 5 years), the annual rainfall is less than 200 arid zone of the Rajasthan and Gujarat mm for Jaisalmer, Barmer, Bikaner, Gan­ States. It" varies from less than 40 per ganagar, Jodhpur and Nagaur. For Jai­ cent in the Sikar and Jhunjhunu districts salmer, this value is even less than 100 mm. to more than 70 per cent in western Jaisal­ The median values represented by 50 per mer and in the Barmer district. Apart cent frequency values are invariably less from the high variability of rainfall, there than the mean values, thereby confirming is considerable skewness in the distribution the skewness in the distribution. also. Rainfall years of high surplus (flood The lowest mean values of less than 300 years) are common in Jaisalmer, Barmer,

44 A CLIMATIC ANALYSIS OF ARID ZONE

Jalore, Bikaner and Jodhpur with less of to 22nd January and the frosts can occur rainfall. Rainfall years of large deficit continually for more than 20 days. Such (drought years) are more :frequent in severe winters were found to have occurred Harmer and Jaisalmer distriCts, with the in five years out of sixteen years, when the percentage frequency values exceeding ~O weather data were studied, showing a per cent. Years with a large deficiency in probability of roughly one frost year in rainfall started occurring more frequently three years. In the severest winter, forty during the decade 1961-1970 in Rajasthan consecutive days of frost had occurred and Gujarat. (Krishnan and Thanvi, 1973). In the Sikar and Jhunjhunu districts of Both the normal values of maximum Rajasthan, and in the arid zone of the and minimum temperatures during this Haryana and Punjab States, the frequen­ season follow roughly the latitudinal cies of both flood years and drought years pattern. The least value is in respect of are very much less. Ganganagar. In exceptional years, tem­ As regards the seasonal distribution, perature in the region can be as low as the main rainy season is from June to -4. 4°C. Frosts can occur at all the stations. September. In Gujarat as well as in The means of the lowest minimum screen southern and central Rajasthan, the con­ temperatures in the individual year~ a~e tribution of the period from June to less than 4°C in respect of Phalodl, Jm­ September to the annual rainfall varies salmer, Ganganagar, Bikaner and Hissar, from 90 to 95 per cent. In view of the thereby showing that frosts frequently winter rainfall contributing from 9 to 12 occur at these stations. This is an impor­ per cent to the total annual precipitation, tant feature which should be taken into the monsoonal contribution is of the order account while planning the afforestation of 78 per cent in the Punjab and 80 to 85 programmes for stabilizing dunes and per cent in Haryana and northern Rajas­ doing crop-planning. The mean diurnal than. variation during the season varies from 14° to 16°C. The winter is very dry. GENERAL CLIMATIC FEATURES OF THE ARID ZONE OF NORTH-WESTERN INDIA The mean values of vapour pressure are less than 10 mb. The relative humidity, During winter, clear skies, fine weather however, is high, especially in the morning and low humidity, large diurnal variations owing to very low air temperature. of temperature, and light north-easterly In summer heating takes place earlier in winds are the features of weather. These the southern regions than in the northern features are changed only when western regions. The high-pressure system during disturbances pass over the region and winter is replaced by a low-pressure area, cloudy conditions and sometimes even with a trough extending up to Chhota rain may occur. Winter rainfall is 7 to Nagpur. The desert in north-western 12 per cent in the arid zone of the Punjab India becomes the seat of the greatest heat and Haryana States, 3 to 6 per cent in in the country. May and June are the Rajasthan and is negligible in the arid zone hottest months of the year. During these of Gujarat. The southern regions get months, dry and hot dust-raising winds, rain when the secondary of the main dis­ popularly known as "100" and dust storms t~rbances, which move across the Punjab (andhi) occur very frequently. The sandy hllls, Occur over Rajasthan or northern soil of the area,the scantiness of rainfall ~ujarat. Western disturbances bring due to which the soil is not compacted, the In their wake cold waves, so that frosts occurrence of steep pressure gradients and frequently occur in the northern portion super adiabatic lapse rates of temperatures of the north-western Indian arid zone. between the surface and the air are the For instance, a study of the frosts at Bika­ main causes of these convective pheno­ ner indicates that the period during which mena. frosts are common is from 18th December The mean maximum temperarure dur-

45 DESERTIFICATION AND ITS CONTROL

ing summer is 40°C, except in Bhuj, where locations of the region. it is slightly lower because of coastal The normal maximum temperature dur­ effects. The mean of the highest tempera­ ing the monsoon exceeds 35°C, except tures recorded at various stations during in Bhuj, where a somewhat lower each individual year falls in the range of temperature occurs during the seasQn ow­ 44° to 45°C. The highest temperatures ing to the blowing of cool equatorial mari­ recorded in the region are, however, in the time (Em) airmass during most of the range of 48 ° to 50°C. season. The values for Ganganagar and The values of vapour pressure during Bikaner are higher because of the occur­ summer are higher than those in winter. rence of more frequent incursions of However, the actual values of relative drier and hotter north-westerly dry con­ humidity are lower in summer than those tinental airmasses at these stations. The in winter owing to the very high tempera­ normal minimum temperatures during tures that occur during summer. The this season are even slightly higher than values of vapour pressure in the region those of the summer season. Thus the vary from 9 to 18 mb, but may suddenly mean diurnal variation during the season increase in certain areas to more than 20 to is the least, varying from 7. 4°C at Bhuj to 25 nib in the region during the 3rd or 4th 11. 4°C at Bikaner. week of May. The values of vapour pressure during Though the onset of the south-westerly the monsoon exceed 25 mb and the values monsoon takes place by the 1st of June of relative humidity range from 75 to 80 in the southern tip of the country, it occurs per cent in the mornings and 50 to 60 in the north-western Indian arid zone only per cent in the afternoons at all stations, by the last week of June to the first week except Bikaner and Ganganagar where the of July. values are slightly lower. The low-pressure area over western Ra­ After the withdrawal of the south­ jasthan during the monsoon months is not westerly monsoon, dry and fairly warm of great depth, and circulation becomes weather prevails till the end of October. anticyclonic at the higher levels. Further, This weather is usually referred to as the at elevations of 1 to 3 kilometres, dry 'second summer'. An anticyclonic cir­ continental wind blows from Iran and culation tends to establish itself over north­ Afghanistan, and it, in turn, prevents the western India. The values of vapour ascending of the seasonal current and the pressure fall during this season and are formation of massive clouds. Only when comparable with values during the early the westward-moving monsoon depres­ summer. sions reach Rajasthan, a large volume of During the post-monsoon season, the "deep and moist monsoon"al air is-brought maximum temperature varies from 32. 1°C in, the development of weather takes place in Hissar to 33. 9°C at Bhuj, and follows and well-distributed rainfall occurs. Since roughly the latitudinal pattern. The same the monsoon depressions recurve and turn pattern holds good for the minimum towards the north after reaching Madhya temperature also. The highest diurnal Pradesh, rainfall generally does not occur variation in temperature is noticed during in the Indian desert. Only in those years this season, and it ranges from 14. 9°C in when a few depre-ssiqns move right across Barmer to 19.2°C in Ganganagar. The the desert, heavy rainfall occurs in the values of vapour pressure vary from 10 desert. But it is rare. Thus the direc­ to 16 mb, which are similar to those tion of the movement of the monsoon of the early summer. depressions is one of the important factors The mean evaporation during summer in the decrease of precipitation in the arid exceeds 12 mm per day at the arid-zone zone of India. The persistence of the axis stations examined so far. The evaporation of the monsoon trough over the region values during the monsoon are higher than also causes precipitation in specified those during the post-monsoon season.

46 A CLIMATIC ANALYSIS OF ARID ZONE

The least evaporation values of 5-6 mm/ tion with evaporation under the arid­ day are recorded during the winter season, zone conditions are the saturation deficit the annual evaporation works out at 3,437 at the maximum-temperature epoch and mm at Jodhpur, 3,195 mm at Pali and the daily mean wind speed. These fac­ 2,809 mm at Ahmedabad. tors explain 83 per cent of the variance in The seasonal means of potential eva­ evaporation. The addition of measured potranspiration at various arid-zone sta­ total global radiation increases the ex­ tions computed bY'using Penman's (1948) plained variance only by 5 per cent. method, which takes into account the factors, such as radiation, temperature, Soil-moisture regime and wind speed and saturation deficit have water-balance pattern been presented in Table 3. The values are Sand-dunes. In the unstabilized sand­ applicable to crop surfaces, since an dunes, a sharp discontinuity in moisture albedo value of 0.25 has been used for content in the layer 1.5 to 2 metres below computing the energy-balance term. the soil surface has been observed. Below The potential evapotranspiration during this layer, the soil moisture reached summer varies from 7 to 9 mm/day. Dur­ more than 5 per cent by weight (i.e. the ing the monsoon, it varies from 5.2 mm field-capacity value) throughout the year. at Bhuj to 6-7 mm/day at the northern However, in the stabilized sand-dunes, stations, whereas in winter it is higher this feature was not observed and the at the southern stations than at those in moisture content was generally found to the north. It is noticed that the seasonal be less than 1. 5 per cent up to a depth of means of potential evapotranspiration 3 metres with the values increasing as the computed by using Penman's (1948) depth increased. The patterns below this method are very much less than the pan­ layer were complicated owing to the diffe­ evaporation values. A study by Krishnan rential extraction patterns of trees. shrubs and Kushwaha (1971) also indicates that and grasses over the stabilized sand-dunes. under the arid-zone conditions of Jodh­ This feature explains the surer establish­ pur, Penman's method underestimates ment of, and a better growth in, the trees the potential values owing to insufficient planted on unstabilized dunes. weightage given to the aerodynamic term Sandy plains. A comprehensive ex­ which is much more significant in deter­ periment on the water balance of the typi­ mining the evaporation than the energy­ cal native vegetation of the arid zone of balance term. north-western India was conducted at the It has also been brought out by Krishnan Central Research Farm of the Central and Kushwaha (1973) that, though as a Arid-Zone Research Institute, Jodhpur, single factor, the total global radiation has from 1963 to 1967. Apart from the trees the maximum correlation coefficient of of Prosopis cineraria several important 0.70 with evaporation, the best pair of species of grasses, e.g. Dactyloctenium factors which has the maximum associa- sindicum, Eleusine compressa, Cenchrus

Table 3. Seasonal means of potential evapotranspiration (mm/day)

Winter Summer Monsoon Post-monsoon Annual total (mm) Bhuj 3·2 ·7·7 5 2 4·3 1,897 Barmer 2'9 7·7 5·4 3·9 1,858 Jodhpur 2'9 7·9 5 3 3·6 2,063 laisalmer 2·5 g·8 5·3 3·8 2,04J Phalodi 2·5 8·8 6 5 4'2 1,771 Bikaner 2·0 7·3 6·3 3·2 1,662 Ganganagar 1'8 6·9 6·4 2'9 1,843 Hissar 1 ·9 6·8 5·6 3 ·1 1,616

47 DESERTIFICATION AND ITS CONTROL

hi/lorus, Cenchrus setigerus, Panicum anti­ vegetation (Krishnan, 1970). The agree­ dotale, Aristida adscensionis and Cyperus ment between the values p~edicted on the rotundus were included in the experiment. basis of the model and the actually mea­ The soil at the experimental site is sand sured values was quite close. up to a depth of 15 cm (6% clay content) Observations on the comparative soil and sand to loamy sand downwards up moisture during the years from 1965 to to a depth of 200 cm (average clay 1967 in respect of (a) the bare land (free content 8 per cent). Below this depth from weeds), (b) the land cropped with there is a kankar pan. The soil texture baira, and (c) the land with native vegeta­ is quite uniform and unaggregated, with tion indicate that the residual moisture 3 constant bulk density of 1.5 gicm • Dur­ storage after the growing season is maxi­ ing 1963, 1964 and 1965, the rainfall mum in the bare plot,' followed by crop­ amounted to 156.9, 536.2 and 234.6 ped land and then in the grasslands. mm (the normal annual rainfall at Jodh­ The last category has moisture below pur is 366 mm). The monsoon commenced the wilting percentage value. The mois­ very late in 1963, i.e. on 30 July; very ture content of the plot under the native early, in June, in 1964 and very close to vegetation reached the wilting percentage the normal date in 1965, i.e. on 4 July. value in September during the deflcit­ The water-balance analysis indicates rainfall year.s of 1965 and 1966, and in that the period 30 July to 27 September November during the surplus-rainfall (60 days) accounted for 156 mm of evapo­ year of 1967, though the wilting-point­ transpiration during the deficient-rainfall value was not reached in the bare plot year of 1963, whereas the period IO May and the cropped land at that time during to 6 October (150 days) accounted for an these years. evapotranspiration of 321.9 mm and a deep drainage of 34. 9 mm during the sur­ The pattern of soil thermal regime plus-rainfall year of 1964. The measured In the arid zone of north-western runoff losses were O. 7 mm (0.4 per cent) India, where the predominant soil type is for 1963 and 125.9 mm (23 per cent) for sandy to loamy sand, there are two princi­ 1964. The very high runoff loss during pal regimes of soil temperature, i.e. (1) the 1964 was due to the very high intensity of summer pattern when the soil temperature rainfall between 8 July and 18 August, decreases from the surface to a depth of together with a good antecedent moisture 120 cm during the maximum-temperature conditions in the soil due to well-distri­ epoch and increases up to a depth of 30 cm buted rainfall in the season. During the with a decrease thereafter in respect of the medium-rainfall year of 1965, the period minimum-temperature epoch and (2) the 29 June to 7 October (100 days) had an winter pattern when the soil temperature evapotranspiration loss of 219. 5 mm, and during the maximum-temperature epoch a runoff loss of 5 per cent. Thus there decreases only up to a depth of 30 cm with was a high variability from year to year in an increase thereafter and increases conti­ the available growth period for the nuously during the minimum-temperature native vegetation. From the transpira­ epoch from the surface to a depth of 120 tion measurements made during the cm. The summer pattern lasts from the experiment. it was inferred that the trees middle of March to the middle of October, of Prosopis cineraria extracted moisture with a few breaks during the rainy spells not only from large area, but also through in the monsoon season, when the winter the kankar zone (Krishnan et al., 1968). pattern occurs owing to increased cloudi­ An evapotranspiration model applica­ ness and higher moisture content. ble to the native vegetation was evolved The diurnal variation of soil tempera­ from this experiment for predicting the tures is present only up to a depth of 30 storage of soil moisture under native vege- cm. It ranges from 19° to 28°C at a depth , tation during the growing season of the of 1 em, from 4° to 7°C at a depth of 15

48 A CLIMATIC ANALYSIS OF ARID ZONE

cm and from O. ] ° to 0.-30°C at a depth calories/cm2/week or more or negative of 30 cm. The diurnal variation is con­ fluxes in association with cold spells. siderably reduced during the mons.oon The spectacular feature is, however, the season. occurrence of large oscillations of very In view of the vapour-pressure gradients much higher order during the mon­ with the depth on account of changes soon. The range of fluctuation is from in soil temperature conditions are favour­ +84 to -116 cal/cm2/week. The weeks of able to the upward movement of mois­ rainfall usually have negative heat fluxes, ture in the vapour phase during the morn­ whereas the intervening dry spells between ing hours and are favourable to a down­ the two rainy weeks have large ,positive ward flow during the afternoon hours fluxes. These huge flux values during throughout the year. From April to the the rainy season may be partly due to the end of October, these gradients are stron­ flow of appreciable heat on account of the ger. However, during the monsoon, the mass movement of water and the flow of downward vapour-pressure gradients in water in the vapour phase in the arid-zone the afternoon are much less than those in soils during the monsoon. The post­ other seasons, thereby indicating that the monsoon season is one of continuous general upward vapour-phase movement decrease of heat storage with the least of water from the deeper layers to the fluctuations (Krishnan and Kushwaha, upper layers during the growing season 1974). exists in the arid zone. Thus, to a certain Over the sand-dunes, also, the soil extent, the ill-effects of low water retenti­ temperatures reveal diurnal and seasonal vity of the arid-zone soils are reduced. variations similar to the pattern observed Though many workers have reported in sandy plains. that the annual soil-temperature cycle is well represented by the first harmonic Frequency of occurrence of dust storms alone, it has been found under the arid­ in western Rajasthan zone conditions of Jodhpur that the first The mean number of dust storms harmonic explains only 69 to 85 per cent. (approx. 8.7 per year) is maximum in The change in the soil-temperature pattern Jalore and rang~s from 5 to 6 per year in during the monsoon is well reflected only Nagaur, Churu, Ganganagar, Jodhpur if the third harmonic is superposed over and Phalodi. Most of the storms occur the sum of the first two harmonics. The in May and June. A detailed analysis amplitude of the first harmonic represen­ of the hourly visibilities and wind speeds tation of the annual cycle of soil tempera­ recorded at Jodhpur during May and June ture varies between 4.8°C and 9.1 °C at of each year from 1967 to 1972 was carried various depths. The amplitude decreases out and the frequencies of occurrence of sharply with the higher-order harmonics. the dust haze were compiled. The dust In other countries, where there is no mon­ haze is classified as thick, if the visibility soon activity, the peak of annual wave of is reduced to less than 1 km, moderate, if soil temperature is reached in August or it is between 1 and 2 km, and thin, if it is so, whereas under the arid-zone conditions between 2 and 4 km. Out of 140 dust of north-western India, the warmest soil hazes during 1967-1972, 36 were thick, near the surface is noticed on the average 38 moderate and 66 thin. on 28 June, whereas at a depth of. 120 em Though May and June during these six the highest temperature occurs on 29 July, years experienced 68 and 72 dust hazes Le. a time-lag of one month (Krishnan respectively, thick and moderate dust and Kushwaha, 1972). hazes occurred more during May. There - On an average, a soil heat flux of ± 25 is a considerable year-to-year variation <:alories/cm2/week occurs during the in the occurrence of dust hazes. Both period from January to May. But there dust hazes and dust storms were most are weeks having a positive flux of' 60 numerous during 1969 and 1970, since they

49 DESERTIFICATION AND ITS CONTROL were the years subsequent to the severe hazes in the subsequent year, particularly drought years in the Jodhpur region. in the windier months of April to June. This aspect would be clearer from Thus the incidence of drought years has a Fig. 1, showing the frequency of dust multiplier effect on desertification. storms and the subsequent monsoon The area covering the arid zone of north­ rainfall of that year. On the aver­ western India and the adjoining arid-zone age, 8. 3 dust storm per year occur at regions of Pakistan, Iran, etc. is one of Jodhpur. But this frequency varies the dustiest places in the world. Obser­ from year to year. It may be seen from vations indicate that the dust blows up Fig. 1 that during the period 1951 to to 20,000 to 30,000 feet. It is also postu­ 1972, there was an increasing trend of dus t lated that the dust over this arid zone is storms, whereas rainfall showed a decreas­ the main cause of the mid-tropospheric ing trend. This is so, because whenever divergence' that occurs over the region the rainfall falls steeply and is very low, which does not allow sufficient precipi­ in the year subsequent to it there is a sharp tation to occur in spite of good atmos­ rise in the occurrence of dust storms. pheric humidity. This finding has a considerable significance The data of monthly variations of the in'the mechanism of soil erosion and deser­ average daily total and diffuse radiation on tification. Drought years and below­ a horizontal surface at Jodhpur indicate normal rainfall conditions result in sparse that though its total radiation is more than vegetation which, with excessive biotic that at New Delhi for all the months, interference, deteriorates fast and causes the increase varies from 24 to 70 cal/cm'/ the soil to be blown off more vigorously. day and its mean monthly diffuse radia­ This wind erosion results in the occurrence tion is either equal to, or less than, that of of a larger number of dust storms and dust New Delhi for all the months. Espe-

o-----t) Monsoon rail'lfall (mm) 3. 600 ~ - --0 No. of dust storms

2'5 500

10 400 E ~ £ g 2 c:

, Q ~ .., , ' 300 "0 " " I. 'q ~ .; \ <> Z I• ;:;:" A I . 10 ,,'...... "q , . \ , \ 200 ~ \ \ • . \ , \ • , \ \ , 0.. ~~"q : • \ 0-, \ , , , \ . 5 , \ 'd \ . ''1$ 100 \ I. ~ \ \ . \ . \ .. 195~ 53 55 57 58 59 60 61 62 63 64· 65 67 68 69 70 71 72 Years' Fig. 1. Relationship between frequency of dust storms and monsoon

50 A CLIMATIC ANALYSIS OF ARID ZONE ciaIly, the diffuse radiation over New Delhi usefulness of wind-breaks in arresting soil is higher by as much as 46 caljcm2/day erosion and fertility loss (Krishnan and during the hot weather period of March Gupta, 1976). to June. This phenomenon may be due to the suspension of dust in the atmosphere Pattern of variation of wind speeds in over Jodhpur, especially in view of the fact the arid zone of north-western India that this effect is absent in August when Very high wind speeds are recorded at the dust generally clears out after a few almost all stations within the arid zone good rains (Garg and Krishnan, 1974). during the summer and monsoon seasons. Measurements conducted over a 3-year The highest wind speeds are recorded in period (1973·-1975) of dust blowing from the Jaisalmer and Phalodi regions, and the the surface to a height of 3 metres indicate next highest in the Bhuj region. The wind that the average amount of dust blowing speeds decrease towards the north as on the day of a dust storm varies from well as towards the south from the high­ 0.50 to 4.20 quintals per hectare in Jodh­ wind belt of laisalmer and Phalodi regions. pur. In the case of Jaisalmer, however, But the decrease is sharper towards the where wind speeds are high, an average of northern side than towards the southern 5 _11 quintals per hectare is recorded. In side, as revealed by the higher values in Chandan, 50 km east of Jaisalmer, the respect of Jodhpur and Barmer than those removal of the grass cover over an area in respect of Bikaner and Ganganagar of 2,007 m2 resulted in soil depletion of regions. The least wind speeds are recor- , 1,065 cu.m within 3 years, i.e. a loss of ded during the post-monsoon season. 0.53 metres of soil depth. There appear to be good possibilities of The analysis of the particle-size distri­ wind-power utilization in Jaisalmer, bution of these dust samples collected from Phalodi, Jodhpur, Bhuj and Barmer different land-use conditions at Jodhpur regions. indicates that the percentage of fine sand varies from 60 to 75 close to the surface CLIMATIC CHANGES AND TRENDS and decreases with the height, being 55 to 70 per cent at a height of 3 m. The Trends in the annual rainfall clay percentage varies from 6 to 9 in the of the arid zone of north-western India bare cultivated soil and 7 to 15 in sites Banerji (1952) observed that there had under native vegetation. Thus the higher been a slight decrease in rainfall during the percentage of clay in the dust particles 50 years ending in 1950 in Rajasthan, than what is actually present in the soil except at the stations situated in the of the experimental site indicates that Aravallis. But this statement has been these soil particles have been transported disproved by Pramanik. Hariharan and f~om distant places. There is also a very Ghosh (1952), Pramanik and Jaganna­ hIgh amount of silt which varies from 14 than (1954) and Rao (1958). It has, how­ to 29 per cent in the bare cultivated soil, ever, been brought out by Krishnan and I~ to 28 per cent in afforestation sites Ananthakrishnan (1962) that there are no wIth eucalyptus-trees and 28 to 39 per secular trends in the incidence of droughts. cent in the sites of native vegetation. To study this aspect in greater detail, Thus there are large quantities of silt in considering the recent data, graphs show­ the dust blowing at 2 to 3 metres above the ing five-year moving averages at various ground level, thereby ind-ic:lting the stations from 1891-1975 were prepared movement of the fertile fraction of the (Figs. 2 to 4). The portion of the graph eroded soil to large distances. The in respect of the years when the below­ comparatively small quantities of silt normal rainfall condition existed have found in the dust blowing over the bare been shaded. It may be seen that one cultivated soil protected by a series of eu­ such spell of large magnitude and dura­ calyptus and other trees indicates the tion occurred during 1962-1971 in res-

51 DESERTIFICATION AND ITS CONT ROL

pect of most of the stations. Actually, the decreasing trend thereafter. To a certain decreasing trend started from 1956. extent, this feature is noticeable in respect Though there are 3 or 4 such spells of be­ of Ihunjhunu also. low-normal years, which occurred during 1901-1960, they are of very small magni­ Trends in the frequency of occurrence of tude, and the below-normal rainfall spell highly deficient rainfall weeks during the of the decade 1962-1971 is comparable rainy season only with a very large below-normal rain­ An examination of the occurrence of fall spell that occurred in the decade 1895- large deficient-rainfall years during each 1905. However, owing to the occurrence decade during 1901-1970 indicates that of excessive rainfall during 1970, 1973, years with large deficiencies in rainfall 1975 and 1976, the trend appears to have have started' occurring more frequently been reversed slightly. Thus in respect of since 1961 at most of the stations. This the most of the stations, the pattern of study has been carried in respect of 11 annual rainfall is a decrease from 1956 to district headquarters stations of the arid 1969 and an increase thereafter. The zone of western Rajasthan, based on only exception to this pattern is Churll weekly rainfall data collected during 1901- • where just the reverse appears to have 1970, assuming that a week has a deficit­ taken place, i.e. there has been an in­ rainfall period, if it fails to receive at least creasing trend during 1951 to 1963, and a half of its normal amount.

Normal

-;;; Blkaner E (; c 140 "0 120 S""'" c:: Normal '"~ Co'" '" -;;;'" 60 C .~ Barmer -;;; ::> c: «0::

Normal

1900 1910 1920 1930 1940 1950 1960 1970 1980

Fig. 2. Five-year moving averages of the annual rainfall of arid zone of India during 1891-1975

52 A CLIMATIC ANALYSIS OF ARID ZONE

There does nol appear to be much varia­ year, the arid-zone conditions prevailed tion in the total number of deficient-rain­ in the whole State, except in the Banswara fall weeks during different, decades. and Ihalawar regions, whereas during However, there is an indicatiqn that the 1944, the arid-zone conditions were con­ number of such drought weeks increased fined only to the north-western portion during 1961-1970 as compared with tnat of the Bikaner, Phalodi and Ganganagar during the earlier decade. except in the regions. The Barmer and laisalmer case of certain northern stations, e.g. regions came under the category of sub­ Churu, Ganganagar and Ihunjhunu. humid zone. The occurrence of consi­ derable year-to-year variation in actual Aridity shifts in the arid zone of evapotranspiration and moisture deficien­ western Rajasthan cies in western Rajasthan during 1941- In view of the high year-to-year variabi­ 1960 has been pointed out by Krishnan lity in rainfall, considerable year-to-year and Thanvi (1969). Thus the mean aridity variations occur in the climatic pattern of index in respect of all stations in various western Rajasthan. Krishnan (1968b) districts of western Rajasthan during studied the climatic classification of different decades of the period 1901- Rajasthan during the high-deficit rain­ 1970 were computed, using Penman's fall year of 1941 and the surplus-rain­ mean potential evapotranspiration values. f:ill year of 1944. During the former Fig. 5 shows in respect of western

Judl'pllr ",

120

100

80 60 ;;; E . Pafi (; c 140 (;

.,'C> 120 !!! .,c 100 ~ Q." 80 '" ;;;"" 60 c: 40 ~ Jalore ;;; ;;;, 1 c c

Normal 80 60 40

1890 1900 1910 1920 1930 1940 1950 1960 ) 1970 1989 Fig. 3. Five-year moving averages of the annual rainfall of the arid zone of India during 1891-1975

53 Ganganaoar

140] :::j+-_____---=\.....,~md_f\U-[\..l£/l~AJ\~~ 80 I ~ fI ~ Normal

60 iii E <; c: 140 "0 ~ 120 .'!! ~ 100 u a; Q. fiO '" co Sikar

Normal

1890 1900 1910 i920 1930 1940 1950 1960 1970 1980 Fig. 4. Five-year moving averages of the annual rainfall of the arid zone of India during 1891-1975

Rajasthan the aridity index line of 80 for attained its eastern most position. How­ different decades of 1901 to 1970. The ever, the portion improved in 1961-1970, data in respect of all rain-gauge stations thereby showing that this region had been in western Rajasthan have been used for becoming very much drier since recently. drawing isopleths. In case of J alore, the eastern shift was I~ has been notiCed that the aridity index maximum in 1961-1970. The implication line has shifted eastwards between the of this eastward shift of the aridity index first and second decades of the twentieth line is that desert conditions are extend­ century, especially in the Ganganagar, ing towards the east, especially in the Bikaner, Churu and Jodhpur districts. southern region. This deterioration was not noticed in the Trends in temperature, humidity and wind Barmer and Jalore districts during that speed in the arid zone of north-western period. There;:tfter, there were to-and-fro India oscillations of small magnitude of this line during different decades from 1920 This analysis has been carried out in to 1970. However, such shifts were more respect of a typical station of the arid zone marked in the north in the Churu district of north-western India, viz. Jodhpur. and in the south in the Jalore district. Summer temperatures have generally been Tn the ChufU district, the maximum dry­ more than the normal, except during the ness was recorded in the decade 1951- period 1965-1971. A decreasing trend 1960, when the aridity index line of 80 has commenced from 1960. The mini-

54 A CLIMATIC ANALYSIS OF ARID ZONE mum temperatures in winter also are pressure. However, there are considera­ mostly more than the normal, based on ble year-to-year variations. Interestingly, the data of 1891-1940. There has been vapour pressures during 1961-1970, were a slight increasing trend since 1961 on­ below the 1940 normal values with res­ wards. pect to winter, from 1951 onwards with Except for minor oscillations, there is respect to summer and from 1964 on­ very little seasonal fluctuation in vapour wards with' respect to the monsoon.

/ I I i / ,- - , '- ..... /''''\.~,. ___ I i I / _,J / I • \ BMI / .r·"• ", .--._..... ;" I i \...... \', _!..-_r-l / ,_ ,/ ,,' , -,, I .. '-, JSM I \., I, '_') r-'-, { --_ ')' ...... _/-...... I , /-:' . \ ...... -, .. BRM

',\

,~ "' ... ,,. ,I

Fig. 5. Decade-wise shifts in aridity index line of 80% in Western Rajasthan © Government of India Copyright, 1977 Based upon Survey of India map with the permission of the Surveyor General of India. The territorial waters of India extend into the sea to a distance of twelve nautical miles measured from the appropriate base line. DESERTIFICA nON AND ITS CONTROL

Table 4. Decade-wise surplus water available for runoff and recharge of aquifers

1901- 1911- 1921- 1931- 1941- 1951- 1961- 1910 1920 1930 1940 1950 1960 1970

The number of years giv- ing surplus runoff and recharge of aquifers 2 3 4 3 4 2 3 The total amount of surplus water (mm) 376 365 341 326 555 143 81

There has been a steep fall in wind water is assumed. From this water­ speeds during 1941 to 1947. However, budgeting analysis, an estimate of the the speeds gradually increased thereafter surplus water available in the region for up to 1956. There is also a further gra­ runoff and deep percolation and for the dual decline in wind speed fwm 1952 to ultimate recharge of aquifers has been 1975. Throughout the period 1941-1955, obtained. This information. in respect of the mean wind speeds during April and various decades of the period 1901-1970 September were much lower than the is given in Table 4. 1940 normals. Thi~ normal was based on It is interesting to notice that th.e availa­ the data in respect of 1897-1940. bility of surplus water for the runoff and The normal wind speed at Jodhpur for recharge of aquifers was steady during the period 1897-1940 was 15.8 km/hr, 1901 to 1940 and it was maximum during whereas speed for the period 1931- the decade 1941-1950. From the decade 1960 was 14 km/hr and that for the period 1951-1960, the availability began to dec­ 1941-1975 was 12 km/hr, thereby clearly rease and the least value of 81 mm was indicating the decreasing trend in the wind recorded for the decade 1961-70. This speeds at Jodhpur. decrease is consistent with the decreasing pattern of rainfall during the decade Trends in the surplus water available for the mentioned earlier. runoff and recharge of aquifers at a typical station in the north-western arid zone ACKNOWLEDGEMENT A water-balance analysis for a typical The 3llthor is thankful to Dr H.S. station of the region, viz. Jodhpur, was Mann, Director, Central Arid Zone Re­ completed in respect of1:he period 1901 search Institute, Jodhpur, for his helpful to 1970, during which the precipitation guidance and encouragement during the was added in successive months to the course of this study. Grateful thanks soil-water storage which was, in turn, are also due to Shri G.G.S.N. Rao and to depleted through evapotranspiration los­ Shri J odh Singh Rao for their help in the ses as well as through losses due to computation of the data. runoff and deep drainage, subject to the upper and lower limits of the soil reservoir. The mean m'onthly potential evapotrans­ REFERENCES piration calculated according to Pen­ man's method was used and the actual BANERJI, S. K. 1952. Weather factors in the crea­ tion and maintenance of the Rajputana desert. evapoh'anspiration was computed by adop­ Bull. naln. Insl. Sci. India. 153-166. ting the water-budgeting procedure of Thornthwaite and Mather (1955), in which BHATIA, S. S. 1957. Arid Zone of India and Pakistan-A study of its water balance a linear relationship between the relative and delimitation. Indian J. Meleor. & transpiration rate and the available soil Geophys. 8(2) : 355-366.

56 A CLIMATIC ANALYSIS OF ARID ZONE

CARTER, D. B. 1954. Climates of Africa and arid and semi-arid zones of Rajasthan. India according to Thornthwaite's 1948 Indian J. Meteor. & Geophys.23 : 153- 160. classification. Publications in Climatology, KRISHNAN, A. 1973. Why does it not rain in the John Hopkins Univ. Lab. 'of Climatology Indian desert? Indian Fmg. 23 (3): USA 7 (4). 21-24. VARG, H. P. and KRISHNAN, A. 1974. Solar KRISHNAN, A. and KVSHWAHA, R. S. 1973. A energy utilization potential in Jodhpur and multiple regression of analysis of evaporation New Delhi. Indian J. Meteor. & Geophys. during the growing season of vegetation 25 ; 473-478. in the arid zone of India. Agric. Meteor. KRISHNAN, A. and ANANTA KRIsHNAN, K. A. 1962. 12 : 297-307. Is incidence of drought in Rajasthan in­ creasing? Proc. Symp. on Arid Zone Pro­ KRISHNAN, A. and KUSHWAHA, R. S. 1974. blems, Jodhpur, pp. 149. Study of average heat fluxes in various KRISHNAN, A. and SHANKARNARAYAN, K. A. layers of the soil and their seasonal variation 1964. Criteria for the delimitation of the in Jodhpur. Archiv fur Meteorologie and arid zone of Rajasthan. Proc. Symp. on Bioklimalologie 22 : 247-256. Problems of Indian Arid Zone, Jodhpur, KRISHNAN, A. and GUPTA, J. P. 1916. Dust 380-387. movement under different land-use conditions KRISHNAN, A. 1968a. Distribution of arid areas in the arid zone of western Rajasthan (under in India. Proc. Symp. on Arid Zone, 21st publication) International Geog. Congo Jodhpur. 11-19. PENMAN, H. L. 1948. Natural evaporation KRISHNAN, A. 1968b. Delineation of diffe­ from open water, bare soil and grass. rent climatic zones in Rajasthan and their Proc. Roy. Soc. London. A. 193 : 120-145. variability. Indian J. Geog. 3: 33-40. PRAMANIK, S. K., HARIHARAN, P. S. and GHOSH, KRISHNAN, A., BLAOOVESCHENSKY, E. N. and s. K. 1952. Indian J. Meteor. & Geophys. RAKHECHA, P. 1968. Water balance of 3(2). Prosopis spicigera community. Indian J. Meteor. & Geophys. 19: 181-192. PRAMANIK, S. K. and JAGANNATHAN, P. 1954. KRISHNAN, A. and THANVI, K. P. 1969. Water Proceedings of 1. U.O.G. IJJternational Asso­ budget in the arid zone of Rajasthan during ciation, Rome. 1941-1960. Ann. Arid Zone 8(2) : 291-299. RAO, K. N. 1958. Some studies of rainfall of KRISHNAN, A. and THANVI, K. P. 1973. Agro­ Rajasthan with particular reference to trends. climatological report of Bikaner district. Indian J. Meteor. & Geophys. 9: 97-116. Report of Division IV, CAZRI. SHANBHAG, G. Y. 1956. The climates of India KRISHNAN, A. 1970. Evaluation of evapotrans­ ·and its vicinity according to new method of piration models for prediction of classification. Indian Geogr. J. 31 : 1-25. soil moisture storage under a Prosopis SUBRAMANYAM, V.P. 1956. Climate types of cineraria community and estimation of India according to the rainfall classification potential evaporation. Proc. Uppsala Symp. of Thornthwaite. Indian J. Meteor. & 547-553. Geophys.7 : 253. KRISHNAN, A., PANDEY, S. and THANVI, K. V. 197{. Occurrence of heat waves in Jodhpur. SUBRAMANYAM, V. P., SUBBARAO, B. and National Geographical Journal of India SUBRAMANYAM, A. R. 1965. Koppen and 17 (2 & 3) : 138-142. Thornthwaite climatic classification as ap­ KRISHNAN, A. and KUSHWAHA, R. S. 1971. A plied to India. Ann. Arid Zone 4 : 46-55. critical study of evaporation by Penman's THORNTHWAITE, C. W. 1948. An approach to­ method during the growing season of vege­ wards a rational classification of climate. tation in the arid zone of India. Archiv for Geogr. Rev. 38 : 35-94. Meteorologie and Bioklimalologie. Ser B. THORNTHWAITE, C. W. and MATHER, J. R. 1955. 19: 267-76. The water balance. Pub. in Climatology. KRISHNAN, A. and KUSHWAHA, R. S. 1972. Drexel Inst. of Tech. Lab. of Climat. Conter­ Mathematical distribution of rainfall, in ton, New Jersey, U.S.A. 8 (1).

57 7

GEOLOGICAL HISTORY OF THE NORTH-WESTERN ARID ZONE OF INDIA

P. C. CHATTERJI

THE geological succes5ion of the north­ mentaries comprise slates, phyllites, mica­ western arid zone of India (Table I) is schists, limestones and calc-schists, with discussed in this paper. subordinate quartzites. This fundamen­ The Pre-Camtrian Eon. This is the tal formation has been intruded by basic oldest rock-forming eon and comprises the rocks of two ages, i.e. the older forma­ banded gneissic complex, followed by the tions comprising epidiorites, hornblende Aravalli system, the Delhi system and the schists, tremolite schists and amphiloilites Vindhyan system. which are older than the Erinpura gra­ Banded Gneissic Complex. The banded nite. The younger intrusions are dolerite gneissic complex is represented by meta­ and belong in some cases to a period bet­ sedimentary rocks of two alternate bands, ween Erinpura (purana) and the Malani which are : (i) darker formations com­ granite (lower Vindhyan) and in other posed of mafic minerals and (ii) light­ cases to the post-Malani Epoch. The coloured formations composed of felsic lower member of the Sirohi Aravalli ap­ minerals. The banded gneissic complex is pears to be an anticlinally folded conglo­ unconformably underlain by the Aravallis merate which forms the bulk of the hills in the Nagaur, Pali and Sirohi districts of running north from the village Sindrat. western Rajasthan and continues in the The Sindrat conglomerate is overlain by Gujarat State. The formations are expos­ thin beds of ferruginous shales which are ed in small isolated locations. further overlain by amgodoloidal basalts The Aruvalli System. This system of and tuffs, a' socia ted with which are fur­ rock formations covers the NW arid zone ther intermittent thin shales and quart­ ,of India and continues'right up to the zites. Impure argillaceous limestones are NW plain of Gujarat (Palanpur region), represented by calc-schists and calc-gneis­ with occasional irregular interruptions. ses, whereas calciphyres occur among the Some isolated outcrops of these rocks are large exposures of calcic rocks west of also found in the Jodhpur, Nagaur and Kotra. In the Nagaur District, these ex­ Bikaner regions. The general strike of posures form a group of ruggedly peaked these formations is NE-SW. Across the hi11s of quartzite. To the south-west of Sirohi District lies a belt of fMdamental Gopalpura (Sujangarh), just inside the schists, irregularly interrupted by instru­ southern frontier of Bikane'r, these rocks sive tongues of the post-Delhi Erinpura are quite disturbed, both in strike and and Malani granites. These schists also dip, but show no signs of igneous intru­ enter Palanpur for a short distance where sion. These beds strike parallel to the they are injected with thin interfoliar veins main range of the Aravallis (NW-SW). of pegmatite which, at place!!, are so The other outcrops of these beds towards abundant. as . to f<;>rm a composite gneiss. the south lie NW and SW of the Salt-lake In, the Suohl regIOn, the unsorted sedi- of Didwana where the strike is NNE-SSW.

58 GEOLOGICAL HISTORY OF NORTH-WEST ARID ZONE

Table 1. Th~ geological succession of north-western Indian arid zone

Eon Era Period Epoch Formation

Cenozoic Quaternary Recent------Sand and alluvium, Rann-blown sand, phyllites, etc. older alluvium and grits Pleistocene ----Porbander series --Calcareous and oolitIc limes­ tone. ------Major unconformity (1) 1----­ Plio-Pleistocene--Shumar, Mar (7) formation. ------Major unconformity (25) 13,------­ Western Rajasthan Kutch region Pliocene Gaj series (Dwarka beds), Kankawati series Tertiary Disconformity ---­ Miocene Khari series. Oligocene Lakhapat series ------Paraconformity Eocene Kapurdi. Mandal Babia stage (Kirthar) formations. Berwali B..mdah, Jogira series Kakadistage (Laki) --Angular Unconformity---Disconformit)' Palaeocene Palane, Laki, Khuaila, Marh, Akali Madh series formations Pb.anerozoic------Major Unconformity (60) 120------Cretaceous Barmer sandstone Deccan Traps Abur beds, Fatehgarh Bhuj series, Umia beds. Formation ------Unconformity ------­ Parihar formation Mesozoic Upper Jurassic ----Unconformity ------­ Bedesar formation Katrol series Unconformity ------­ Besakhi formation Unconformity---- Chari series Middle Jaisalmer formation Jurassic Lower Lathi formation, Patcham series Jurassic Mayakor formation ------Major Unconformity (170) 24,0----- Permian Badhawra formation ------Major Unconformity (215) 35,-----·---- Permucarboni­ ferous Bap Boulder Bed Palaeozoic Major Unconformity (275) 6u------­ Birmania/Bilara formation/ Nagaur series Early ----Unconformity,------Palaeozoics Randha formation Unconformity------­ Early Jodhpur formation/Rol Palaeozolcs Quazian-Bhakari series. ------Major Unconformity·------Vindhyan Villdhyan system rVindhyan sandstone ~ (Bhander series) , Unconformity---­ LMalani series

59 DESERTIFICATION AND ITS CONTROL

Table 1. (Contd.)

Cryptozoic Algonkian Major Unconformity (500) 610-725,------or Pre-Cambrian Proterozoic Basic Intrusion Delhi system ((Ajabgarh series) ~ Erinpura granite LAlwar series M.Prc- Raialo series-Eparchaean Cambrian interval (1000) . ------Aravalli system . Unconformity------Archaean L.Pre- Cambrian Banded gneissic complex. ------Major unconformIty (l,500)------Note: Figures without brackets show the total duration of the group or system in million years, where- as those within the brackets show lapses of time from the beginning of the particular era or period to the present.

Slates predominate, but minor amounts of pura age. They are without limestone quartzites and small veins of white quartz (Adyalkar, 1964). also occur in the area. Near Khatu,- slates In Godwar area, the calcareous schists underlie the Vindhyans and a ridge of iti contact with the Erinpura granite are quartzite projects from the plain east of seen to have been transformed into a the Vindhyan scarps. Near Degana, the similar white crystalline marble which is phyllites are associated with the wolfram­ quarried at Saraungwa. The Raialo basin bearing granite of the Rewat HilJ which of sedimentation forms a part of the great intrudes into the phyllite. Similar expo­ and more extensive geosyncline, in which sures also occur at several localities near were later deposited the rocks of the Delhi the gneissic area of Harsor (Pascoe, 1950). system, and in respect of time interval be­ Raialo Series. Resting unconformably long to the Great Eparckaean interval of on the softer and weathered Aravallis Indian Geology (Pascoe, 1950). there are thick series of sediments forming The Delhi System. With further uncon­ the finest marbles in India. It is these formable relations are found the rocks of marbles that contributed to the grandeur the Delhi system extending from Narnaul and beauty of the famous Tajmahal. They in the NE to Sirohi and Palanpur in the are about 600 m in thickness comprising SW with detached outcrops at Khetri, limestone with basal conglomerate, sand­ Saladipura, Sikar and Sirohi-Godwar bor­ stone and quartzite. The famous Maka­ ders. The strike and dip of this system rana marble is' of the calcite type, possi­ are the same as those of the Aravalli sys­ bly injected by thin vein lets of pegmatite tem. The rock formation comprises quart­ and epidiorite. The other Raialo expo­ zite, arkose, grits, sandstone and conglo­ sures are at Ras and Godwar, both in merates of the older Alwar series, followed Marwar. The strike of Makarana marble is by a set of younger rocks comprising NNE-SSW with a steep eastern dip. Near phyllites, biotite-schists, calc-schists, gneis­ Ras, several outliers of the Raialo series ses limestones, etc. The rocks of the ~re ~isposed in two elongated, overfolded Delhi system are presumably deposited in IsocI.mes, striking NE-SW. This group the Aravalli geosyncline basin after the of lImestones extends for about 60 m folding and erosion of the Raialos and a along the strike in the form of almost further deepening of the basin. The continuous ridges. At Ras, the limestone Delhis are invaded extensi'vely by large bears a similar concordant but uncon­ bodies of granite and pegmatite of the form!lble relationship to the overlying Erinpura suite, resulting in the metamor­ DeIhl .system. The enveloping gneiss is phism of the Delhis and of the pre-Delhi much mtruded by pegmatites of the Erin- sediments with the maximum intensity

60 GEOLOGICAL HISTORY OF NORTH-WEST ARID ZONE

Recent and sub·Recent Soil, blown sand, alluvium and (Quaternary) kankar Delhi Ajabgarh Series Slates, phyllites, mica schists, quar­ System tzitic sandstone and impure lime­ (Algonkian) Hornstone breccia, Kusalgarh stone limestone Alwai Series Quartzites, arkase, grits, conglo­ merates, mica schists and contem­ poraneous volcanic rocks

in the core and decreasing outwards dhyan time when the basic dykes and the (Heron, 1935). acid igneous suite of the Malani series The general succession of the Delhi came into existence (Adyalkar, 1964). system of rocks in the Mahendragarh However, Saxena and Chatterji (1965) District (Haryana), as proposed by Heron have reported the occurrence of the Vin­ (1917), is given above. dhyan sandstone, sand witched between two Basic /ntrllsiJ'es. The amphibiotic rocks, beds of rhyolite, the lower one porphyritic though older than Erinpura granite, are and the upper one tuffaceous. Blandford intrusive in nature. Dolerite and basalt (1876) observed the basic dykes of the are younger than Erinpura granites Lower Vindhyan age at Lawa and Pokaran. (pascoe, 1950). The Malani Series. The Malani series Erinpura Granite: The Erinpura granite forms a group of acid igneous rocks in the and its modifications are found extensive­ form of volcanic flows and tuffs, together ly developed within the Delhi belt from with their plutonic and hypabyssal equi­ Palanpur and Idar, up to Godwar and valents in the form of Jalore aud Siwana Sirohi, with interrupted exposures beyond granites. Malani rhyolites are of acidic Ras, Sikar and Narnaul. The Abu batho­ type and embrace felsites, depetrified lavas lith is composed of the Erinpura granite and glassy rhyolites intercalated with acid suite. At Mundwara, this granite is tuffs and pyroclastic material. The flow affected by the Malani suite (of different structure in rhyolite is very clearly and types) of igneous rocks. At the village of significantly seen. Pascoe (1950) has fur­ Duata, this granite is intruded by the ther regrouped the Malani series as under: Malani suite. Waloria and Bhamoria are (a) MALANI GRANITE AND VOLCANIC t~e other exposures of the Erinpura gra­ SUITE. The lower boundary of the Malani mte in the Sirohi District. At Chokre­ rhyolite in Marwar is seen in the Miniari Chopali, in the Sikar District, the granite section only. contains fluorite. At Bairat, numerous (b) MALANI GRANITE AND ITS HYPA­ veins of a fine variety of granite can be BYSSAL EQUIVALENTS. These minerals are ?bserved penetrating the epidiorite adjoin­ found in the Sirohi, Jodhpur region and mg the main base (Pascoe" 1950). in the Hissar District (Haryana). In the Three Phases of Basic Intrusion. Three Sirohi District, tbey are found in the Banu, phases of basic intrusion have been des­ Isri and Nandwar hills. In the Jodhpur cribed for Sirohi, of which the first occur­ region, they occur at Sarora, Jalore, De­ red .during the Aravalli time, the second gana (Rewat HiIJ). and Lodsar and Taonra­ dunng the Delhi and the third during the Khuli (Bikaner District) and at the Tus­ post-Erinpura age. These intrusions pro­ ham Hill, Khankak Hill and at Deosir in d~ced dykes, intersecting the Erinpura gra­ the Hissar District. nites, and are regarded as pre-Malani and (c) MALANI VOLCANICS. The Malani POst-Erinpuragranites in age (Pascoe, 1950). volcanics are present in the Jodhpur re­ The Vindhyan Syst'em. In the north­ gion and in the Sirohi, Jhunjhunu, Churu, testern arid zone after the formation of Jaisalmer and Hissar districts. In the ~. e Delhi system, the sedimentary deposi­ Jodhpur region, the lavas have been traced IOn was stopped during the Lower Vin- from Pokaran to the centre of the Sirohi

61 DESERTIFICATION AND ITS CONTROL

District, where it is encountered at Jha- arid and semi-arid conditions, unlike roli-Ban, Panta Hill and Mirpur-Undwa- those in the cis-Aravalli region where it is ria. Rhyolite also occurs in the area marine. From the overlying Gondwanas west of Barmer. In the Churu District, in the region, the deposition has been as­ the Biramsar hill is composed of the signed an age between the Late Pre-Cam­ Malani rhyolite tuffs converted into rough brian and the Early Palaeozoic (Adyal­ grey slates, which have been crushed and kar, 1964). broken. The beds are vertical and strike At two places, Sojat and Khatu, the NNW-SSW. Rhyolites also occur at almost horizontal Vindhyans are clearly Randisar, Lodsar and Taonra. seen lying unconformably upon the nearly (d) BASIC INSTRUSIYES. The suite of the vertical Aravalli slates, elsewhere the basic igneous rocks around Sankra in the Vindhyan sediments have been laid down Jaisalmer District is only the last phase of upon a floor of Malani volcanic rocks or the basic intrusions (Bhushan, 1973). upon that of the Malani granite in the Chatterji (1966) is of the opinion that the north of the Jodhpur city. Sir Cyril Malani acidic suite erupted much later Fox has equated the Jodhpur sand­ and had flowed over the granitic pluton stones with those of Pokaran and as slowly creeping lavas. The basic mag- both with the Vindhyan. He has remark­ mas erupted at a later period when the ed on the resemblance between the Po­ granitic magmas had already solidified. karan sandstone and the purple sandstone Sedimentaries of the Upper Vindhyan of Salt Range (Pascoe, 1950). Age. At the end of the volcanic activity, According to Pareek (1975), these se­ there was a period of quiescence in the diments, which were deposited, included Late Vindhyan times, with the establish- the trans-Aravalli Vindhyans (Mar war­ ment of two (or possibly one continuous super group) traceable from Ladnu, in the earlier times) arcuate sedimentation Ratangarh, Sardarshar in the east to basins in which there were laid down the near Pokaran and north of Pokaran in deposits forming the Vindhyan system of the west and Jodhpur and Sojat in the the Trans.-Aravalli region. These two south to as far as Hanumangarh in basins meet at a point near Jodhpur. the north. This basin must have con­ The lower red to fawn sandstone member, tinued NW in the Salt Range. The trans­ with a basal conglomerate band often Aravalli Vindhyans got truncated from rests unconformably on the steeply dip- Merta Road to Bilara, but are widespread ping Aravalli slates. It is coarse-textured, in the NW portion. The rock formations with occasional gritty bands and with an have been classified into the arenaceous abundance of ripple marks of varied na- Jodhpur group, the calcareous Bilara ture. The sandstone member is' succeeded group and the arenaceous Nagaur upwards by limestone. To the east ofBilara, group. The initial deposition of rock dark-grey bituminous limestone crops out. formations took place in the sublittoral It emits fetid odour when freshly chipped intertidal zone. The stratigraphic sequence and, on distillation yields a small quantity of the rock formations, based on lithologi­ of oil and a dirty-smelling inflammable gas. cal characters, order of superposition From the association of the rich gypsum and strike continuity, is given below: beds in the Nagau~ area, it is inferred that The Plaeozoic Era. After the end of the the deposition of the upper Vindhyans Pre-Cambrian Era, rock fotmation of the must have taken place under continental, Early Palaeozoic Era, such as the Randha, Nagaur group Tunklian formation, Nagaur formation Bilara group Pondlo formation, Gotan formation, Dhanappa formation Jodhpur group Girbhakar formation (Upper Garsuria formation) Sonia formation (Lower Garsuria formation)

62 GEOLOGICAL HISTORY OF NORTH-WEST ARID ZONE

Jurassic Jaisalmer formation, 'Lathi formation ---- Unconformity Nagaur series-Bilara limestone Palaeozoic (?) Birmania formation Roll Quazian series-Jodbpur sandstone, Bhakrod series. Unconformity Randha formation __-_ Unconformity Pre-Cambrian Malani, Jalore, Siwana Igneous suites. Birmania/Bilara formations, came into north-west (Adyalkar, 1964). existence. Palynological studies indicate that the The Randha and Birmania formations. bed of the Bap boulder is of the post­ Isolated outcrops of the Randha and Bir­ Miocene (Pliocene-Pleistocene) age (Lukose mania formations occur near Virbhani in et al., 1974). Based on field relationships the Jaisalmer District and they are consi­ and geomorphological and structural con­ dered to be correlated with the Jodhpur siderations, MUkhopadhyay (1971-73) and Bilara groups of the Marwar super regards the bed of the Bap boulder youn­ group of the trans-Aravalli Vindhyans. The ger than the Bhadawara formation. geological succession of the rock forma­ Bhadawara formation. This formation tions, as given by Muktinath (1969), and occurs as fossiliferous sandstone outcrops recently by Madhava Rao (1973-74), are near Bap and Bhadawara. It is interpret­ shown above. ed that the marine Bhadawara formation The structural feature of the Birmania overlies the bed of the Bap boulder and area is considered to be a system of sym­ that its age is upper Carboniferous. The metric, doubly plunging, longitudinal sharp outcrop is located about one km, NW of apex, open folds, having a general strike Bhadawara up to Harbans. of NNE~SSW dipping at 35°-80°. The Mesozoic Era. At the end of the The Permo-Carboniferous period. After PalaeozoIc Era, the temperature increased the Birmania formation, the lowering of and it caused aridity during the early temperature had taken place in the Whole Mesozoic (Triassic period). There has of the Godwana land during the Permo­ been no deposition in this region during carboniferous period and the glaciation this period and, as a result, a major break led to the deposition of the Bap Boulders in the sequence of deposition took place. and the Pokaran Beds. The Jurassic system of Kutch. The Tethys B_ap boulder. In the vicinity of Bap is sea of Jurassic and early Cretaceous times an megular expo,<,ure of a boulder bed, in is considered to have extended beyond the all probability equivalent to the Talchir, main Himalayan axis into the region of representing thereby evidences of Permo­ the lesser Himalaya. It is considered to carboniferous glaciation in the trans­ have extended into Baluchistan, the Salt Arll:valli region. The Bap bed consists Range further south through a portion of tYpIcally of sub-rounded to rounded peb­ Rajasthan into the region of Kutch, and bles, boulders and cobbles of Malanis, thereafter westwards as far as Madagascar. calcareous suite of Vindhyans and the Pascoe, (1950) has given a synopsis of the A.ravallis embedded in a matrix of mad Kutch Mesozoic succession as shown in with abundant evidences of striations. A the following page. ~oulder bed of smaller magnitude has also Mesozoics of Western Rajasthcn. In een reported to the east of Pokaran. It is western Rajasthan, no depositional records °hver this land of Bap-Pokaran that thick of Triassic period are seen. The triassic s eets of ice had once accumulated, and period was followed by the deposition of ?ver which descended the glaciers in their Lathi, Jaisalmer, Baisakhi and Bedesar JOurney towards the Salt Range in the formations of Jurassic time3 and Parihar

63 DESERTIFICATION AND ITS CONTROL

Tertiary period ------Major unconformity'------_ Creataceous Deccan Traps, Bhuj series Fossils, ammonites Umia series including Ukra beds Mesozoic Era Katrol series (Agrovian Brown and red iron stone. Brachiopods, Actinozoa to Kimmordigian) Basal ammonite beds Lamellibranch Cepha- ' Jurum Belemnite marls lopoda, etc. Kant Kot sandstones, Jurassic Period Chari series (Calovian DhosaooJite, Atheleta to Divesian) stage, Ancept stage, Reh- mani stage, G

64 GEOLOGICAL mSTORY OF NORTH-WEST ARID ZONE

Quaternary Period Recent and Sub-Recent Porbandar series Pleistocene _------Major unconformity Pliocene (Mancher) Kankaltati series -----Disconformity Tertiary period Miocene, Oligocene Khari series, Lakhapat series ----Paraconformity Eocene Kirther Lakhi Berwali series-Babia stage-Kakdi stage -----Disconformity Paleocene Madh series _------Major unconformity Mesozoics Deccan traps This formation contains ammonitee, Tertiary period. The Tertiary forma­ balemnites and some ferns. tions are found in the Kutch region and Bedesar formation. With further un­ western Rajasthan. conformable relation overlapping the Bai­ Tertiary formations of the Kutch and sakhis, there is a group of sandstones and Jamnagar districts. Vyas (1973) has re­ grits, called Bedesar Sandstones, striking ported that this formation forms the fringes N 300E to N400E. The Bedesar formation of the entire southern rocky strip of the has beds of golden oHiles. Ammonites, vir­ main land of Kutch and also borders on gatosphinates. densiolicatus, V. communis, the Jurassics in Patcham, Khadir and Bala aulacosphinates, belemnite, terebratulids, and the Cretaceous and Jurassics in Wagde fish teeth, etc. are associated with this for­ highlands. The Nummulitic limestones mation. and shales of Eocene are exposed and bor­ Parihar formation. Sandstones of the der on the traps in the south up to Lakha­ Parihar group overlie conformably the pat. Various types of fossils·foraminifers, Bedesar formation. The Parihar series lamellibranchs, echinoderms, gastropods, resembles the Umia beds of Kutch and has corals, bryozia, etc. are associated with no fossils associated with it, although these formations. The general trend is some plant remains have been found. Das East to West. The geological succession Gupta (1975) has redesignated the Parihar is given above : formation as Habur formation, with a 1n the Jamnagar District, Tertiaries maximum thickness of 200 m. are represented by the Gaj and the Abur beds. This formation occurs above Dwarka beds. The geological succession the Parihar series extending from the vill­ is as shown above. age of Sanu to Habur, and comprises sands­ Tertiary formations of western Rajasthan. tones, shales and fossiliferous limestones. The Tertiary formations in western Fossils, ammonites, belemnites and de shy­ Rajasthan comprise mainly fossil-bearing sites are associated with this formation. limestones and sandstones. The fossil Rarmer sandstones. This formation assemblage consists of formanifers (num­ Occurs to the NE of Barmer, and has fine mulites, sp., Discocyclina, Assilina sp.),. to medium buff sandstone and conglome­ Lemallibranches, echinoids, etc. (Naraya­ rates, and contain fossils of fish teeth and nan, 1964). The geological succession is plants. given below: Alluvium, wind-blown sands, Recent limestone, kankars ------Major unconforrnit) Tertiary period Dwaraka and Gaj beds M~ddle Cretaceous to MIddle Eocene Deccan traps-Basaltic lava .flows ------,---Major ·unconformity----- Base not observed

65 DESERTIFICATION AND ITS CONTROL

Quaternary period Recent Blow sands Pleistocene Alluvium -----Major unconformity Plio-Pleistocene Shumar, Mar formation (?) -----Major unconformity Tertiary period Eocene Lakhi, Kirthar, Bandah Jogri formations -----Angular unconformity Palaeocene Lakhri, Khuiala, Mar (?) Pal\ina formations -----Major unconformity Mesozoics Abur formations

Pareek (1975) has suggested geological succession for the Barmer basin as under:

Quaternary period Recent Blown sand, gypsite ------Unconformity Tertiary period Upper Eocene Kapurdi formation Fuller's earth, sandstone Middle Eocene MandaI formation with plant impressions, Palaeocene Akali formatIOn sandstone, lentonite ------Major unconformity Mesozoic ------Fatehgar formation Lathi formation

Quaternary period. After the close of owing to physico-chemical reactions on the Tertiary period, the entire region stood the granite rocks of the region (Chatterji, above the sea-level and was subjected to 1968; Roy et al., 1969). pronounced climatic episodes and weathe­ Recent formations. These formations ring agencies. Owing to the physico­ are made up of younger alluvium and chemical reactions of the weathering blown sands which comprise unconsoli­ agencies the rocks were weathered, eroded, dated stream-laid silt, sand and gravel and transported and deposited. The litholo­ generally occur along the courses of gical sequence during this period is divided ephemeral channels and streams. These into two major groups as shown below: deposits are generally medium to fine­ Sub-Recent formations. These forma­ grained and comprise largely well-roun. tions are classified as older alluvium and ded grains of quartz with subordinate are the most extensive formations of this amounts of felspar and other ferromag­ region. These deposits are derived in nesium minerals. The gravels consist of part from the erosion and stream trans­ pebbles and cobbles of older rock forma­ portation of bed rock debris and in part tions of the reg"ion. Such deposits have from in situ weathering as sheet-wash been encountered up to a depth of over eeposits. These formations are generaJIy 230 m towards the Rann of Kutch. In cemented together by carbonates and other this formation, gypsum and calcareous, salts and clay, rendering them hard and silicious or ferruginous bands of varying compact. These salts have originated thicknesses, from 0.5 to over 10 m, occur

Recent (Holocene) Blown sand and alluvium and ranns Quaternary period Sub-Recent Older alluvium and grit Pleistocene Porbandar series-calcareous and oolic limestone.

66 GEOLOGICAL HISTORY OF NORTH-WEST ARID ZONE

three to four times at different depth towards the upper portion ofthe sequence. horizons, thus indicating that the This platform, after the close of the deposition of younger alluvium took Vindhyan sedimentation, experienced a place during occasional floods and there positive movement and remained uplifted bad been a few changes in the clima­ till the end of the middle Carboni­ tic cycles during this period (Chafterji, ferous. The next stage is represented by 1968). the Permo-Carboniferous glaciation evidences furnished by the Bap and Tectonic History Pokaran boulder beds. The next struc­ The Tectonic divisions of the north tural stage is represented by the deposition western Indian arid zone are given of Mesozoic sequence which marks a below: distinct change in the trend of furtb(;!r Folded Belts of Pre-Cambrian Age tectonic evolution of this platform. After (1) Areas of Delhi folding the Mesozoics, the Tertiary formation was (2) Areas of Aravalli folding deposited without any disturbance and Platform structures with an abundance of fossils. During tha (1) Super-order structures Quaternary period, the Pleistocene glacial (i) Vindhyan syncline phases occurred, though only loose sedi­ (2) First order structures ments and alluvium were formed. In (i) Saurashtra-Kutch shelf recent times, because of climatic episodes, (ii) Rajasthan shelf weathering has increased and the net (3) Second-order structures result is the great Thar Desert. (i) Meri-Iaisalmer arch Palaeoclimate Tectonic evolution. The Archaean The geological record in India suggests Proterozoic folded belts, consequent upon several alternations of arid and fluvial their consolidation, formed the basement conditions in the Pre-Cambrian times. of this platform. The tectonic evolution During the Carboniferous times, a glacial of the platform started with the develop­ climate prevailed over what is now tbe ment of the several major super-order arid zone of Indo-Pakistan. The AravaIIi and first-order negative structures with range at that time was occupied by an the deposition of the Delhi sequence ice-sheet which extended northwards up to (Proterozoic), which represents the oldest the Salt Range. During the Permian sedimentary sequence of this platform period, desiccation started with the advent (Narayanaswami, 1966). The Delhi sequ­ of warm and humid climate and as a ence occupies the Delhi depression result, the Permo-Triassic period had a an~ shows in part epi-grade metamor­ dry climate. This dry period was follo­ phIsm and considerable faulting and wed by a humid period and during the thrusting. The next stage of tectonic rest of the Mesozoic period, normal evolution of this platform has been traced climatic conditions seem to have pre­ through the Vindhyan sequences, where­ vailed. Ver they occur together, they are separa­ From the middle Miocene to the close ted by a period of intense tectonic activity, of the Pliocene, the climate was humid re~ul~ing in a major change in the pre­ and warm. This climate was replaced by ~XIstmg structural pattern,. The Vindhyan distinctly cooler conditions in the Pleis­ IS much less disturbed, practically devoid tocene. The middle and upper Pleistocene ?f me!amorphism with less frequent basic was a period of repeated glaciation (at mtruslves. This sequence has extensive least four major episodes have been recog­ development in the Rajasthan shelf. nized). Because of extensive glaciation Th~ Vindhyans represent stable shelf over the Himalayas down to its lower sedIments in the lower sequence, and they altitudes, the summers in the present arid change to the continental red sandstones zone became cooler and evaporation

67 DESERTIFICATION AND ITS CONTROL

became less. After the last glacial period LUKOSE, N. G. and MISHRA, C.M. 1974. Palyno­ logy and age of Badhaura formation (after Pleistocene), the western part of Western Rajasthan, India. Proc. Fourth Rajasthan began to get gradually dry Colloquium on Indian Micropalaeontology (Krishnan, 1952). & Stratigraphy, Dehradun. Dec. 1974-Jan. 1975. REFERENCES MADHAVA, RAo, M. R. 1973-74. Geological AnYALKAR, P. G. 1964. Palaeogeography, sedi­ mopping in parts of Barmer and Jaisalmer mentological framework and ground-water Dist. G.S.I. (unpublished report). potentiality of the arid zone of Western MUKHOPADHYAY, A. K. 1971-73. A report on India. Proc. of Symp. on Problems oj Indian the Geol. Mapp. & Hydro geochemical Arid Zone, Jodhpur, 1964. sampling for Potash in parts & Nagaur, BHUSON, S.K. 1973. Phases of Igneous activity Jodhpur and Bikaner Dist. G. S. I. during Malani Igneous Schite around Sankra (unpuhlished'report). Dist. Jaisalmer. Seminar on the Recent MUKTlNATH. 1969. Phosphate deposits in Rajas­ Advances in the Geology of Rajasthan & than. Ind. Mins. 23(7) : 2942. Gujarat, abstract p. 30. NARAYANAN, K. 1964. Stratigraphy of the BLANFORD, W.T. )876. On the Physical Geography Rajasthan shelf. Proc. Symp. on Problems of the Great Raj. Desert, etc. J. Asiat. Soc. of Indian Arid Zone, Jodhpur, UNESCO! Beng.45 : 86-103. Gov!. of India. 'CHAITERJI, P. C. 1966. A study of joint pattern NARAYANASWAl\II, S. 1965. Tectonics of the and ground-water measurement in Jalore Cuddapah Basin. J. geol. Soc. India 7: granite, Rajasthan India. J. Min. Geological 33-50. & Metallurgical Institute of Indio. pp. 45- PAREEK, H. S. 1975. Geological configuration 53. of north-western Rajasthan. Proc. Workshop CHATTERJI, P. C. 1968. Some characteristics of on the Problems of the Deserts ill India, the Quaternary sediments from central Jaipur, 1975. Luni Region, Western Rajasthan. Geo­ PASCOE, E. 1950. A Manual of the Geology OJ graphical Outlook 5, Department of Geo­ india alld Burma. 1, 2 &3. Geological Survey graphy, Ranchi University, Ranchi, India. of India, Calcutta. DAS GUPTA, S. K. 1975. A Revision of the Mesozoic Tertiary, Stratigraphy of the Jai­ Roy, B.B., CHAITERJI, P. C. and PANDEY, S. salmer Basin, Rajasthan, India. J. Earth 1969. Genesis of carbonate pan in arid Sci. 2 (1) : 77-94. region of Rajasthan. Ann. Arid Zone 8 HERON, A. M. 1917. Geology of North-Eastern (2): 181-187. Rajputana and adjacent district. G.S.I. SAXENA, R. K. and CHAITERJI, P. C. 1965. A Memoirs 45: 1-128. new stratigraphic aspect of Vindhyan sand­ HERON, A. M. 1935. Trans. natn. Inst. Sci. India stone. Agr. Research 5(3): 228-230. 1 :17-33. VYAS, M. P. 1973.A brief note on the ground­ KRISHNAN, M. S. 1952. Geological history of water potentiality of Kutch dist. Hydrogeo­ Rajasthan and its relation to present day logy of Saurashtra and Kutch : An Internal conditions. Proc. of Symp. on Rajputana Manual for Geohydrological Survey and Desert. Naw. Inst. of Sci. India. Investigation. 1.

68 Plate a. T he strong desert winds leave gaping holes in the hardest of rocks Plate b. Semi-circular tafonis developed along the jOints and On individual boulders

Plate c. Rocky, gravelly pediments wit h gentle lope. veneer gravelly deposits and rhyolite hills in the background GEOMORPHOLOGY OF THE RAJASTHAN DESERT

BIMAL GHOSE, S. SINGH AND AMAL KAR

STUDIES cn the evolution of landforms to prolonged subaerial denudation during through geomorphological processes, their the Algonkian era. The igneous activities geomorphological characteristics and the which took place during this era had gone mapping of their distribution help to on pari passlI with the upliftment, assess and evaluate the physical potential and these activities produced the of the land for development and rational Erinpura suite of granite along the land-use planning of the desert regions. isoclinal foldings of the Aravallis of In view of the importance of the practical this region. The weathering and erosion application of geomorphology in the of the Aravallis continued for a long environmental development and manage­ period, during which the sediments of the ment, geomorphological investigations on Raialo series, mainly limestone, and sub­ the evolution, classification. distribution, sequently the sediments of the Delhi analysis and mapping of the landforms by system, were laid down in the denudation employing the photo-geomorphological valleys of the softer and weathered Ara­ and conventional research techniques, vallis or in the basement granites (Heron, have been carried out in different parts of 1917). Consequent upon the upliftment the Rajasthan Desert by various workers. of the Aravalli range, a second cycle of These are summarized by Ahmed (1969), erosion started when the low-lying areas Ghose (1964), Ghose et af. (1977), Pandey of the eroded surface of the Aravallis and (1968) and Singh and Ghose (1976) and the exposed Erinpura granite suite were the results of these investigations are deeply weathered. whereas the uplands integrated in this chapter. were unaffected (Plate a). This weathered zone was later on eroded in part, exposing GEOMORPHOLOGICAL EVOLUTION the underlying rocks. The exposed rocks, OF LANDFORMS constituting the Algonkian surface, started Geomorphological investigations on the being worn down by the subaerial denu­ evolution of the landforms of the Rajas­ dation. During the Lower Vindhyan than Desert have revealed that they have period, another igneous activity took place. been sculptured to the present forms by The intrusives formed the Jalore and the the orogenic, erosional and depositional Siwana granites and the extrusives, the processes. The geomorphogeny of the Malani rhyolite. During the second crus­ area is quite old and landforms from the tal movement, the Upper Vindh~'an for­ ~rchaean era to the Quaternary era occur mations came into being. Glaciation took In this region. The argillaceous Aravallis place during the Carboniferous period of the Archaean era were laid down in a and it was responsible for the formation syncline existing at that time among the of the boulder beds of Bap and Pokaran gneissic Archaean. After the depositional (La Touche, 1902). In the western dis­ phase, the Aravallis were uplifted and put tricts of the desert, namely Jaisaimer, Bar-

69 DESERTIFICATION AND ITS CONTROL

mer and Bikaner, there are evidences of their major tributaries. This major humid marine deposits due to several marine phase was replaced by another arid phase transgressions and regressions during the probably in the late HoJ..ocene period: Mesozoic and Tertiary eras. After the around 38,~0 years B.P. ~Singh et al., Tertiary period, this region was subjected 1974). OWIng to renewed aeolian activi­ to different climatic fluctuations, subaerial ties, the younger aeolian landforms, viz. denudation and deposition. The existing barchan dunes, shrub-coppice dunes and major landforms of this region were for­ sand ripples were formed on the old med during the Quaternary period by the fluvial and aeolian landforms. The fresh­ fluvial and aeolian processes operating on water lakes dried up and turned into saline various lithological formations and under depressions. In the recent period, the different climatic phases. An interpre­ increasing biotic activities in association tation of aerial photographs and field with occasional severe droughts reactiva­ surveys revealed that the Aravalli drainage ted the crests of the stabilized sand-dunes, system, comprising the Luni River and its deflated and deposited the sands on fluvial tributaries, and the drainage system of the and aeolian landforms, turned the fertile Himalayan origin, constituting the Ghag­ lands into saline lands, and intense fluvial gar and its tributaries, were well integrated activities dissected the old landforms. in the past humid period and they were responsible for the formation of the vast DISTRIBUTION AND SALIENT GEOMORPHOLOGICAL CHARACTERISTICS existing alluvial plains, with varying thick­ OF LANDFORMS nesses of alluvial sediments (Ghose, 1965). The piedmont plains and the pediments The Rajasthan Desert, on the basis of were formed as the results of slope retreat its evolutionary history, form characteris­ at the base of the hills of different for­ tics, depth, size and nature of the sedi­ mations. This major humid phase was ments, slope and erosional, depositional! followed by a major arid phase, probably salinity hazards, has been divided into in the pre-Holocene period and was ter­ fourteen major landform units. The minated around 10,000 years B.P. (Singh distribution and salient geomorphological et al., 1974). During this arid phase, the characteristics of these landform units high active sand-dunes, sandy undulating are described below: aggraded older alluvial and interdune Hills. The major hilly tract of the plains were formed and two major drain­ Rajasthan Desert is the Aravalli mountain age systems were disintegrated and dis­ range which occurs along its eastern boun­ organized. The barriers created by the dary and is composed of quartzite, schists, 'formation of the sand-dunes astride the slate, etc. These hill ranges generally have major drainage channels segmented many narrow ridges, conical shape and a high valleys into sandy inland basins (Ghose relative relief. The hill slopes are gene­ et al., 1975). The desert extended to the rally rectilinear, with 25° to 30° angles, east of its present limit and there was and their lower parts are covered with widespread desiccation. thick aeolian and colluvial sediments. From 10,000 to 3,800 years B.P., the All the hill slopes are dissected by nume­ climate again became humid, but it rous streams draining into the Luni and was less humid from' 9,500 to 5,000 its major tributaries. years B.P. (Singh et al., 1974). The To the west of the Aravalli range, in fluvial activities became intense and the the south-western part, there are hills high active dunes were stabilized and composed of granites and rhyolites, flank­ dissected. The sandy inland basins were ing the range in Sirohi, J alore, Jodhpur .filled in with water and sediments and and Pali districts. Around Sirohi, Abu the freshwater lakes were developed at and Erinpura, the hills are composed of ~ertain places. The younger alluvial Erinpura granite and pegmatite and are plains were formed along the rivers and in the form of batholiths. The hills com-

70 GEOMORPHOLOGY OF THE RAJASTHAN DESERT

posed of intrusive and extrusive igneous Pokaran-Jaisalmer- Ramgarh sector. rocks of the Lower Vindhyan period are Piedmont plains. In the central Luni scatteredly distributed over the southern, basin, around Jalore, Siwana, Bujawar, central and western parts of the deser~ etc., the hills are flanked at their bases by in the form of domes and inselbergs. The piedmont plains (Ghose et al., 1966), chief constituents of these hills are the and :;tre composed of thick colluvial debris Jalore and the Siwana granites or the rhyo­ derived from the adjoining hills. The total lites. All the granite hills are dome­ thickness of the sediments varies from 10 shaped, with convex summits and concave to 25 m in the upper part and 3 to 5 m in basal slopes. The convexities of the domes the lower part. In the upper part, large have, however, been interrupted by several boulders and angular rock fragments of concavities owing to weathering and ero­ 2 to 3 m in diameter are dominant and the sion along the horizontal joint planes. slope varies from 5° to 10°. The lower In many cases, the domes have also been part is covered with small pebbles, gravels split along the vertical joints of granite. and gritty sand particles of 2 to 3 mm, Spheroidal weathering along the granite along with silt. The slope varies from hills has produced boulders of different 3° to 5°. At certain places, obstacle shapes and sizes and cavernous weathering dunes and whalebacks are formed on the has produced tafonis a)ong the joint planes colluvial sediments of the piedmont plains. (Plate b). All these deposits have been dissected The rhyolite, with its vertical and hori­ by gullies of 5 to 25 m depth and 15 zontal joints, is more resistant to weather­ to 60 m width. The drainage patterns ing and is standing as rugged inselbergs in this unit vary from dendritic to sub­ and domed inselbergs. However, where parallel. These plains are affected by the rock is more felsic than glassy, it is severe wind and by slight to severe water more susceptible to chemical weathering, hazards. producing angular and platy fragments Rocky or gravelly pediments. This unit which cover the foothills in the form of occurs along the base of the rhyolite, talus. Cavernous weathering features sandstone and limestone hills. The rhyo­ have also been observed along these hills, lite pediments occur mainly around Jodh­ but the caverns are more elongated than pur, Thob, Agolai, Barmer, Bhadrajan, spherical. The average slope varies from etc., and are characterized by gentler slo­ 15° to 35°. pes (Plate c). Observations on two rhyo­ The hills composed of horizontally lite pediments near Agolai (Kar et al., bedded Vindhyan sandstone of early 1976) have shown that the slope varies ~alaeozoic age occur as mesas and buttes from 3° to 8° in the upper part, 1° to 3° In continuous chains around Jodhpur, in the middle part and 0°8' to 1° in the D.eriya, Meriya, Osian, Bhopalgarh and lower part. The micro-variations in the Bllara. The hills are flat-topped, with rock characters have. however, a defi­ s~eep escarpments of up to 90° and a deb­ nite impact on the production of debris f1s-covered basal slope unit. The slope and on the maintenance of a rocky pedi­ varies from 20° to 35°. ment. It was observed that the ideal The hills of the Vindhyan limestone condition of a pediment is maintained ~ccur near Bilara, Borunda, Jeti and Barna when the rhyolite is more glassy than felsic ~n the Jodhpur District and around Sojat and the joints are more widely spaced. In the Pali District. These hills have rug­ In most cases, the p~diments are covered ged topography and the hill-slopes are with rock fragments of various sizes and Covered with sub-angular to sub-rounded a shiny desert varnish is observed on their boulders of different sizes. Chemical surface. The pediments developed on w.eathering is prominent in these hills. The sandstone formations occur around hIlls comprising the Jurassic sandstones Bhopalgarh, Osian, Chohtan, Jodhpur, and fossiliferous limestones, occur in the Pokaran and Jaisalmer. The slope along

71· DESERTIFICATION AND ITS CONTROL

these pediments varies from 1° to 8° and 1° to 3°. In the eastern part, these sandy in most cases the different layers of the deposits have been dissected by rills and horizontally bedded sandstone are exposed gullies of l'to 10 m depth and 5 t«;> 20 m in the form of micro-steps. The pedi­ width. ments, formed on limestone, lie near Deh, Flat aggraded older alluvial plains. Rol Quazian and Pundlu and are covered This unit is most extensive and occurs with gravels owing to the easy susceptibi­ predominantly in the eastern part of the lity of limestone to chemical weathering. desert. It occurs from Ringas and Kucha­ The slope varies from 1° to 5°. The vast man in the north to Bali and Bhinmal in gravelly pediments around Kolayat and the south, and from Sojat in the east to Bap are the ideal examples of desert Pachpadra in the west. To the west of pavements. The surface of these pedi­ this zone another wide zone runs from ments are covered with angular to sub­ Bikaner in the north to Bainsra in the rounded quartz, sandstone, limestone and south The third major zone of this quartzite fragments of 10 to 50 mm in plain is around Ganganagar in the north­ diameter. The gravels are underlain by west The alluvial sediments of these alluvial and colluviaJ deposits. These plains have been deposited by well-inte­ rocky surfaces are n9t suitable for cultiva­ grated prior drainage systems which were tion, but they can be developed into good active during the past humid phases desert catchments from which surface (Ghose, 1965). Within .the alluvial de­ runoff can be harvested for drinking and posits, a thick alluviated layer of CaC03 irrigation. has developed at depths of 7 to 180 em, Flat-buried pediments. This unit, flank­ and in the form of nodules. This layer ing the rocky or gravelly pediments, is has been dated back to 28,000 to 30,000 covered with 1 to 3 m deep sediments, years B.P., and is called as the kankar which are mainly transported by stream pan. The nature of the sediments varies channels from the adjoining hills and pedi­ from loamy sand to sandy loam and also mented surfaces and are partly developed loam, but at certain places in pockets in situ. These sediments are underlain silty clay loam to clay loam are found. , by hard rocky strata, but the kankar pan The average diameter of the sediment is absent. More than 50 % of the sedi­ particles is 0.06 to 0.18 mm. The slope ment particles are of 0.06 to 0.12 mm in is less than 1° in this unit and the surface­ diameter. The slope of these plains is less drainage channels are almost absent, ex­ than 1° and the drainage channels are only cept in the eastern fringe. But the cour­ a few. The surface runoff that comes from ses of the prior drainage channels have th~ adjoining hills and rocky pediments, good potentials of ground-water at 6-15m sinks underground and accumulates along depth. In parts of these plains under­ the courses of the previous drainage chan­ lain by a kankar pan at a shallow depth, nels at depth from 10 to 40 metres. This the surface runoff can be harvested and unit has good agricultural and ground­ stored in tanks and reservoirs. water potentials. Saline flat aggraded older alluvial plains. Sandy undulating buried pediments. These This unit occurs mainly around Bijasni, pediments occur around Ramgarh, Sri Manaklav, Mori Manana, Bhetanada, Mohangarh, Girab, Utambar and to the Bhawi, etc., in the Jodhpur District, around east of Sikar. The mode of the formation Hemawas and Raghunathgarh in the Pali of this unit is similar to that of the flat­ District around Suyali, Karmawas and buried pediments, but later on these pedi­ Burad in the Barmer District and at certa­ ments have been affected by intense. aeo­ in places in the Ganganagar and Nagaur lian activities which created sand sheets districts. The genesis of these plains is ·of 50 'to 200 em thickness and sand- linked with the buried courses of the dunes of 2 to 10 m height. The slope prior drainage channels. The construction is irregular in this unit and it varies from . , of tanks and canals across the courses of

72 GEOMORPHOLOGY OF THE RAJASTHAN DESERT

buried channels result in surface and sub­ high dunes with much reactivation along surface waterlogging. Consequently, the their crests and flanks. To the east of sub~urface salts along tl:;le prior drainage this zone, another zone of high sand­ channels come up to the surface through dunes I{uns through the eastern parts of evaporation and capillary action and turn the Bikaner and Churu districts. Both the agricultural fields saline (Ohose et the above zones an~ separated by the vast al., 1975). Mostly, such salinity occurs rocky tract of Jaisalmer-Pokaran-Bikaner­ in the medium to heavy-textured flat Bap sector, but they again meet in the aggraded older alluvial plains. The slope north of the Bikaner District and extend is nearly level, with less than I ° slope into the Ganganagar District. Another The diameter of the sediment particles of zone runs in discontinuous patches from this unit varies from 0.06 to 0.25 mm. Sanchor through Saila, Phinch, Didwana Sandy undulating aggraded older alluvial and Lachmangarh and meets the above plains. This unit occurs around Hanu­ two zones in the Ratangarh-Churu area. mangarh, Raisingnagar, Pilani, Jhunjhunu, These three zones comprise six types of etc. in the north, around Amarpura, Bida­ sand-dunes, viz. obstacle, parabolic and sar, Ladnu, Sanju, Phalodi, and to the coalesced parabolic, longitudinal, trans­ east of Jodhpur in the central part and verse, barchan and shrub-coppice. around Ahor, Bhinmal and Sanchor in The obstacle dunes have been formed by the south. The mode of evolution of this the deposition of sand against the wind­ unit is the same as that of the flat aggra­ ward or leeward slopes or both of the ded older alluvial plain, but later on this existing hills and are termed windward unit was affected by .intense aeolian activi­ and leeward obstacle dunes. These dunes ties which have created moderate to severe are generally 10 to 50 m in height and have wind depositional hazards in the form of been dissected by numerous gullies of 3 sand sheets of 20 to 300 cm thickness, to 20 m in depth and 5 to 60 m in width. longitudinal and transverse dunes of 90 The parabolic and coalesced parabolic em to 5 m height and sandy hummocks dunes are most dominant and are found and ridges of 30 cm to I m height over almost in all parts of the tracts with dunes. the flat alluvial plains. As a result, the The parabolic dunes are of 10 to 50 m in slope in this unit is irregular and it varies height. The slope along the crest of these from 1° to 3°. Within the sandy depo­ dunes vary from 12° to 14° and that of the sits, a weakly developed layer of CaC03 windward side is from 2° to 5°. The co ales­ has been observed in some parts of the ed parabolic dunes are also numerous desert. The hard layer of CaC03 within and have been formed by the fusing to­ the alluvial deposits which are overlain gether of 5 to 40 uncoalesced parabolic by aeolian deposits, has been found at a dunes by a transverse ridge. The height depth of 400 cm or more. The diameter generally varies from 10 to 80 m. In of the sedi!11ent particles varies from 0.6 the case of these dunes, the slope of the to 0.59 mm. Surface-drainage channels crest varies from 8° to 16°. The parabolic are almost absent in this unit and rain­ and coalesced parabolic dunes are formed water flows subterraneously along the in the prevailing south-westerly wind di­ courses of the buried channels where rection and their orientation varies from ground-water has been found at 20 to N 42°E to N 48°E. The longitudinal dunes 40 ill depth. occur mainly in the western and southern Sand-dunes. Sand-dunes are the most parts of the Jaisalmer District, in the spectacular landforms of the Rajasthan eastern part of the Barmer District, in the Desert and cover 58 % of the total desert south-western part of the lalore District. area. There are two major zones of in the north of Phalodi in the Jodhpur ~and-dunes. The westernmost zone lies District and in the north-east of the In the western parts of Barmer, Jaisalmer Nagaur District. The orientation of these and Bikaner districts and is covered with dunes varies from N 400 E to N 50 0 E and

73 DESERTIFICATION AND ITS CONTROL

the height varies from 10 to 80 m. The the crests, flanks and windward side of slope of the leeward side is 19° to 22°, these dunes are 8° to 13°,3° to 7° and2° to and that of the flanks and windward side 3° respectively. The sand grains of 0.18 are 15° and 6° respectively. The trans­ mm in diameter are dominant. The verse dunes are mainly concentrated in shrub-coppice dunes are generally of 0.5 the western part of the Bikaner District to 3 m in height and occur in the form of and the eastern part of the Nagaur Dis­ sand mounds, fence-line hummocks and trict and are scatteredly distributed in the low longitudinal and transverse ridges. Churu, Jhunjhunu, Jodhpur and Barmer The average diameter of the sand grains districts. The dunes are of 5 to 40 m in is O. Ilmm. These dunes have good mois­ height and the orientation generally varies ture at a depth of 50 cm throughout the from N 300 W to N 500 W. The slopes of year and they can be stabilized by adopt­ the crests, flanks and windward side of ing suitable stabilization techniques. these dunes are 22°, 13° and 5° respec­ Flat inter-dunal plains. This unit in the tively. tracts with dunes mostly occurs between The above four types of dunes are of the stabilized coalesced parabolic, longi­ the old dune system (Pandey et al., tudinal and transverse dunes in the north­ 1964; Vats et aI., 1976), because they were east around Taranagar, Rajgarh, Nohar, formed in the earlier arid climatic phases. etc., and in the western parts of Churu, All these dunes are stabilized and fossi­ Bikaner, Nagaur, Jodhpur and Barmer lized and have well-developed nodular or districts. The slope here is less than 1°. finger-type lime concretions of 1 to 100 The texture of the surface sediments mm in diameter. In general, the dunes varies from loamy sand to sandy loam to the east of the 300-mm isohyet have no and loam in pockets. The ground-water fresh sand accumulation along their crests along the courses of the buried drai­ and flanks but the dunes to the west nage channels occurs at 15 to 20 m depth. of that isohyet have 1- to 3-m-thick Owing to the hard kankar pans occurr­ fresh-sand accumulations, and even ing 30 to 180 cm below the alluvial sedi­ barchans along their crests and flanks. ments, this unit provides suitable sites Sand grains of 0.06 to 0.12 mm in dia­ for collecting surface runoff in tanks and meter are dominant in all these dunes. reservoirs. In the obstacle dunes, the flanks have finer Sandy undulating inter-dunal plains. sands than the windward and leeward This unit is more widespread than the slopes. The dunes of this system can be flat inter-dunal plains. J ntense aeolian developed into good grasslands by protect­ activities have created undulations on the ing them against biotic interference. alluvial surfaces of this unit in the form Barchan and shrub-coppice dunes, con­ .of sand sheets, 100 to 400 cm thick, sandy stitu,ting the non-calcareous sands and hummocks, 1 to 3 m high, and low longi­ being devoid of vegetation, are active and tudinal and transverse dunes, 3 to 5 m in they belong to the dunes 'of the new sys­ height. The slope is irregular and varies tem. The majority of the barchan dunes from 1° to 3°. This unit is affected by are formed to the west of the 250 mm severe to very severe wind erosion. isohyet, in the Barmer and Jaisalmer dis­ Shallow saline depressions. The saline tricts and in the western parts of Jodhpur, depressions of different shapes and sizes Jhunjhunu, Churu and Bikaner districts. are distributed in the desert. They mostly The existing high dunes of the old sys­ occur at Sambhar, Kuchaman, Didwana, tem, the sandy aggraded older alluvial Lunkaransar, Jamsar, Bap, Thob, Pach­ plains and the river-beds are the source padra, Sanwarla and around Pokaran and of sand for these dunes. The barchan Jaisalmer. Among these depressions, the dunes are 3 to 10 m in height, and gene­ saline Sambhar Lake covers the largest rally 5 to 10 barchans coalesce to form area. These saline depressions are the coalesced barchan dunes. The slopes of gathering-grounds of salts and evaporites

74 GEOMORPHOLOGY OF THE RAJASTHAN DESERT

(Ghose and Singh, 1968). The generalized the above parts, the plains are nearly level stratigraphy of tpe saline depressions is with less than 10 slope and sustain good characterized by a layer of silt and clay, cultivation. At certain places of these with an admixture of sand, overlain by a level plains, in the Ganganagar, Jodhpur, thin layer of blown sand and underlain Pali and J alon~ districts, salinity has deve­ by a layer of sand, followed by another loped because of the construction of dams Jayer of silt and clay, with kankar nodules across the Luni, the Mitri, the Bandi and (Singh and Ghose, 1976). The surface of the Jawai rivers. these depressions is nearly level with less than 10 slope. The diameter of the sedi­ SUMMARY AND CONCLUSION ment particles varies from 0.06 to 1. 19 The geomorphological evolutionary his­ mm. tory of the region has revealed that the Graded river-beds. The Luni River and landforms of the Pre-Quaternary eras in its major tributaries, viz. the Jojri, the the Rajasthan Desert have evolved through Guhia, the Bandi, the Sukri, the Jawai, the long periods of subaerial degradation and Bandi (Khari) and the Sagi, have graded aggradation, interrupted by short periods their courses in the long period of their of tectonic activities. The major existing evolutionary history. The longitudinal landforms have resulted owing to the profiles of the Luni, the Jojri, the Sukri, climato-morphogenetic processes operating the Jawai and the Khari have the gradients during the Late Quaternary period on vari­ of 1 : 600, I :700, I :600, I :500 and 1:550 ous lithological formations and under respectively (Singh et al., 1971). All different climatic phases. The fluvial and the above streams have ~ide and flat sandy aeolian landforms of the region are poly­ beds, with sand bars of different sizes. genic and bear the imprints of the past Sediment particles of 0.59 to 1. 19 mm climates. The vast alluvial plains were for­ diameter are dominant in the river-beds. med by the well-integrated drainage systems The river banks are cut vertically during in the Pleistocene period and they form the the heavy floods. In general, the banks backbone of the region. The sand-dunes, are 1. 5 to 5 m high, but the banks of the sandy plains and inland basins were created Luni, the Jawai, and the Sukri have been by intense aeolian activities during the dissected laterally by even 7 to 10 m. prolonged arid phase of the Pre-Holocene Younger alluvial plains. These plains, period. These aeolian landforms were in narrow strips, have been formed along stabilized and dissected during the pro­ the banks of the above-mentioned major longed humid phase of the early Holocene rivers and along the courses of the Gaggar, period. The renewed aeolian activities of owing' to occasional floods in the rivers the late Holocene period created active and the consequent overbank deposition of barchan and shrub-coppice sand-dunes and the riverine materials. The width of the sand sheets on the existing landforms of plains varies from 1,000 to 5,000 m, and the region. In the Recent period, the incre­ it is widest along the lower and middle asing biotic activities have also become reaches of the Luni. The depth of the important in sculpturing the landforms. sediments varies from 10 to 20 m, and the Taking into consideration all the geomor­ kankar pan is absent. The size of the phological factors, such as the evolutionary sediment particles varies from 0.06 to history of the landforms, their slopes and 1.19 mm in diameter. In some parts oC form characteristics, nature, size and depth these plains, especially near the banks, of sediments and associated hazards, the sandy hummocks of 50 cm to 2 m Rajasthan Desert has been divided into height and longitudinal and transverse fourteen major landform units. The distri­ dunes of 3 to 6 m height have been bution and geomorphological characteris­ formed owing to the reworking of the tics of these landform units have been ana­ riVerine sands and their deposition along lysed and mapped in their correct positions the banks by aeolian processes. Except and mutual relationships. Each geomor-

75 DESERTIFICATION AND ITS CONTROL

phological nomenclature indicates the HERON, A. M. 1917. Geology of north-eastern agricultural and water potentials of the Rajputana and adjacent districts. Mem. Geol. Surv. India 45(1). region. These landform units, thus, have KAR AMAL SINGH, S. and GHOSE, B. 1976. different production potentials and physi­ , Geomo~phological characteristi~s and. pala­ cal limitations which can be developed by eoclimatic significance of rhyolite pedIments suitable management techniques. in Jodhpur district, western Rajasthan (lndia). Man and Environment 1 : 16-20. REFERENCES LA TOUCHE, T. H. D. 1902. Geology of western Rajputana. Mem. (Seal. Surv. India 35(1). AHMED, ENAYAT. 1969. Origin and geomorphology PANDEY, S., SINGH, S. and GHOSE, B. 1964. of the Thar desert. Ann. Arid Zone 8(2): Orientation, distribution and origin of sand 171-80. dunes in the central Luni basin. Proc. GHOSE, B. 1964. Geomorphological aspects of Symp. Prob. Indian Arid Zone, Jodhpur, the formation of salt basins in western pp.84-91. Rajasthan. Proc. Symp. Prob. Indian Arid PANDEY, S. 1968. Some aspects of geomorpho­ Zone, Jodhpur, pp. 79-83. logy of Indian desert. Proc. Symp. Arid Zone, GHOSE, B. 1965. The genesis of the desert plains Jodhpur. pp. 28-32. in the central Luni ba5in of western Rajas­ SINGH, G., JOSHI, R. D .. CHOPRA, S. K. and SINGH, than. J. Indian Soc. Soil Sci. 13 (2): 123-126. A. B. 1974. Late Quaternary history of GHOSE, B., PANDEY, S., SINGH, S. and GHEESA vegetation and climate of the Rajasthan • . LAL 1966. Geomorphology of the central desert, India. Phil. Trans. Royal Soc., Luni basin, western Rajasthan. Ann. Arid London 267(b) : 467-501. Zone 5(1) : 10-25. SINGH, S., PANDEY, S. and GHOSE, B. 1971. GHOSE, B. and SINGH, S. 1968. Geomorphologi­ Geomorphology of the middle Luni basin cal control on the distribution of evaporites of western Rajasthan, India. Ann. Arid in the arid zone of Rajasthan, India. Proc. Zone 10(1) : 1-14. Symp. Arid Zone, Jodhpur. pp. 54-57. . SINGH, S. and GHOSE, B. 1976. Geom~rph?lo.gy GHOSE, B., SINGH, S. and KAR, AMAL 1975. Some of the Luni basin and its palaeoclimatic Ill­ geomorphic aspects of salinity hazards in ferences. Workshop, Palaeoclimate and Ar­ Rajasthan desert, India. Workshop on chaeology of Rajasthan and Gujarat, Problems of Deserts in India, Jaipur. Ahmedabad. GHOSE, B., SINGH, S. and KAR, AMAL 1977. VATS, P.C., SINGH, S., GH('SE, B. and ~A~TH, Desertification around the Thar-a geo­ D.S. 1976. Types, orientation and dlstnbu­ morphological interpretation. Ann. Arid tion of sand-dunes in Bikaner district. Geog. Zone (in Press). Observer 12: 67-75

76 Plate d. Profile of light brown andy soil showing range of calcium carton ate concretionary horizon

Plate e. Profi Ie of grey brown loam Plate c. Saline flats - a typical feature of the desert ]andscape 9 THE METHODOLOGY OF MAPP1NG LAND RESOURCES FOR RATIONAL UTILIZATION

K. A. SHANKARNARAYAN AND AMAL KUMAR SEN

THE need for accurate data and informa­ and Stewart, 1953; Mabbutt and McAl­ tion on the physical resources of an area pine, 1965). Such an approach adopted for scielltific planning hardly needs em­ at the Central Arid Zone Research Insti­ phasis. For this purpose, the Central tute, Jodhpur, since 1959, has remained Arid Zone Research Institute is conduct­ bristled with difficulties in areas with im­ ing surVeYS of basic resources through a mense biotic activity, such as the Thar multidisciplinary team of scientists who, Desert of India. after classifying the lands of the areas sur­ Subsequently, realizing the need to put veyed, will prepare a composite land-re­ more emphasis on soil and vegetation, source map having the following charac­ along with land form and field investiga­ teristics. tions, a new concept of composite map­ a) A recurring pattern of abiotic environ­ ping was developed in Australia termed ment, mainly landform, soil and vege­ the unique mapping-area concept tation' ('UMA'). In this system, the specialists individually draw the boundaries of soil, b) Distinct resource potentials and re­ Jand form vegetation, Jand use, water re­ source trends under any given set of sources, etc. on the same aerial photo­ conditions graph, aided by the local knowledge of c) Overall means for recommending the terrain. The concept was applied to the utilization of the resources of the the Indian arid zone by Mr McAlpine area. , (CSIRO, Australia) and the specialists of To realize the above obejective, the in­ this Institute in_ 1973. tegrated land surveys had their initial Based on the land system and the 'UMA' start in Australia where the Division of concept and recognizing the need to ac­ .Land Research and Regional Survey of count for intense biotic interference, a the CSIRO has been conducting land sur­ new composite mapping-unit termed the veys since the conclusion of the second Major Land-Resources Units (MLR U) WO!ld War. Christian and Stewart (1953) was developed by Abichandani and Sen d.evIsed the 'Land system' as the compo­ . (1975). This unit enables the composite SIte mapping-unit which has been defined mapping of areas having similar resource as "an are~ or group of areas, through­ potential and similar management needs. out Which there is a recurring pattern of In other words, besides the recurring pat­ topography, soils and vegetation". This tern of soil, land form and vegetation, system is based on the premise that the the MLRV has the recurring pattern of land system is expressed on aerial photo­ human activities and resource potential of graphs by a distinctive pattern and, as an area for development-planning. The such, the l~nd system can be directly map­ following steps are involved in the resour­ ped from aerial phptographs (Christian ce-mapping technique.

77 DESERTIFICATION AND ITS CONTROL

Base maps for integrated survey tion to a suitable scale at this Institute is • the 1:50,000 or 1:126,720 scale maps of The documentation and cartography of the areas to be surveyed. the base map for integrated land surveys, based on aerial photographs, was earlier, Methods and techniques reported by Sen (1967). Preparation of the initial 1lZ;]p. The The preparation of the base maps is police-station boundaries and the village viewed from two different ,points: boundaries are transferred from the availa­ 1) To provide the topographical and ble documents to the large-scale Survey other informations required for the of India sheets. As the district maps and surveys the cadastal maps ,have different scales, 2) To provide easy means for the scale adjustments are necessary. transfer of the survey results from Aerial photographs: Orientation of the the aerial photo to the base maps photo coverage. The available photographs are treated in the laboratory if required, Features to make the images more legible. The The following features are represented locations of important land features re­ on the base map : corded on the initial map are then examin­ a) The boundary and the boundary des­ ed in relation to the photographs. Addi­ cription of the base map tional land features, not shown on the b) The village boundaries with the loca­ map but discernible on the photographs, tions of settlemen [s are marked on the photogrphs for sub­ c) Physical features, such as drainage, sequent transfer to the initial map. The hills and depressions extent of the photo coverage of a Commu­ d) The auxiliary and control points for nity Development Block is worked out by traversing and for the subsequent comparing the layout with the initial transfer of details to the final map map, and an index map of the photo­ e) The aerial photo coverage graphs for the block is prepared. f) The co-ordinates at 5' intervals The coverage of each photograph is plotted on the initial map, and this cove­ Documentation rage involves the following operations : The above features are of a diverse na­ (1) Reduction of the photographs to' the ture and are not readily available. These scale of the map, through an over­ are collected from the following sources : head projector or through a procota (1) One-inch (1 :63,360) and half inch drawing machine (1 :126,720) topographical sheets pro­ (2) To orient the photographs in re­ duced by the Survey of India: lation to their positions in the map (2) Quarter-inch planimetric maps of (3) Corrections of tilt, distortions and the districts, showing the vil1age relief deplacement in the photo­ boundaries, and cadastral survey graphs maps The plotting of controls and auxiliary (3) A list of the community develop­ points for traversing and transferring de­ ment blocks and the villages included tails. In the proposed base map, four con­ in each block trol points for each photograph are given. (4) Aerial photographs on scales, of They are marked simultaneously on the 1: 30,000, 1 :40,000 and 1:25,00) as photograph and the map. They are selected supplied by the Surveyor-General and plotted by adopting the stereo study of India and, if required, their positions are plotted (5) Geodetic reports published by the on the base map by using the radial line­ Survey of India plotting. The exact locations, if required The background map on which all the are verified with a plane-table survey in the information is transferred after reduc- the field. The central points of the set-

78 METHODOLOGY OF MAPPING LAND RESOURCES tlements are worked out on the photo­ lar land unit, can: often be delineated and graphs and subsequently transferred to many aspects of land, e.g. the land form, the initial map with aerial photo coverage. the soil, vegetation and the land-use These points can also be used as control settlement, can be inferred. After field points. While selecting the points, im­ checking, the previous interpretation is portance is given to the following aspects : corrected, if necessary, and the final car­ (1) The accessibility of the points in the tographic operations (Sen, 1967) are un­ field for traversing dertaken (the transferring of details, the (2) To frame triangulation on the compilation, the edi ting of the data, maximum level to transfer the survey etc.). details (i.e. they should be on an ave­ rage elevation) Final mapping technique (3) To give the maximum control for The first order. The individual maps, transferring the survey details through e.g. those of soil, geomorphology, vegeta­ a vertical sketch master or a proeota tion, geology and water resources, are drawing-machine (i.e. they should be prepared on these base maps by respec­ easily located both on the photo­ tive scientists through photo interpreta­ graphs and on the map) tion and subsequent field surveys. By Aerial photo interpretation for integrated faithful correlations and overlaying the survey and mqppillg. The aerial photo­ units having the same landform, vegeta­ interpretation techniques are now being tion and soils are worked out, irrespective employed extensively at the Central Arid of their area or size. Thus a single land­ Zone Research Institute for resource­ form or vegetation or soil may OCCur in mapping. The different land units can units. The units, thus worked out, are be interpreted in aerial photographs by likely to be more than in any individual studying the pattern and variation of the map. Thus in the Bikaner District in the image characterstics of the objects in the first order of mapping, 35 units are dis­ photographs (Sen, 1974a, b) reflecting a tinguished, although the number of map­ similarity in land type. Hence primary ping-units in individual maps is far less, importance has been attached to prepare being 14 in geomorphology, 12 in soils photo maps on the basis of similar photo and 19 in vegetation maps. Images. To identify the objects, the imag­ The second order of mopping. The es are analysed and classified on the basis units, thus recognized, are further examin­ of their 'texture', 'sructure' and 'form' ed by the specialists to find out the pos­ and their correlations (edge-gradient stu­ sibilities to eliminate the smaller ones. If dy); Studies on 'fishing expeditions' or necessary, further photo interpretation or on 'probability tests' are then carried out field Checking are carried out. The details to study the photo elements. This step is of the area have been limited by the map­ followed by the study of the 'convergence ping scale. In the mapping of 1 : 50,000 of evidence' to correlate the photo ele­ (the Jodhpur District) or 2 cm = 1 km, ments with the existing information and the MLRU with a minimum area of 0.5 documents. sq. km or a minimum width of 0.25 km Three sets of interpretations are carried or a minimum width of 1 km can be map­ out before the field survey, viz. studies on ped. If the mapping is done without the the regional aspects, pattern elements and help of aerial photographs, the details to photo elements. These studies have en­ be cartographed will be much less. Here a~led us to prepare photo maps with si­ on 1 : 253,440 mapping, a minimum area ~J]ar image and the 'key' of interpreta­ of 4 sq. km or the minimum width of 2 bon for field checking (Sen, 1972). Once km can be mapped. In the Bikaner Dis­ th.e photographic images are correlated trict mapping 8 sq. km and 4 km were WIth the type of land in the field, the the minimum aimed at. Accordingly, the sequence of events, which form a particu- first-order map is revised and only 12

79 DESFRTlFICATION AND ITS CONTROL

units are delineated. Such units are cha­ REFERENCES racterized by the recurring patterns of ABICHANDANI, C. T. and SEN, A. K. 1975. 'MLRU' landform, soil and vegetation and can be mapping-a concept of composite mapping termed as biophysica units. unit for integrated land survey. Geographical The third order of mapping; To assess Review of India (in Press). the resource potential of the units, the ABICHANDANJ, C. T., SINGH, S., S-AXENA, S. K., KOLARKAR, A. S. and SEN, A. K. 1975. land use, the water resources, the climate, Assessment and management of the bio­ the socio-economic conditions and the exis­ physical resources in district Bikaner, ting plans, if any, for the development of Western Rajasthan. Ann. Arid Zone 14(4): the units are then examined in each unit. 292-301. Accordingly, the biophysical boundaries CHRISTIAN, C. S. and STEWART, G. A. 1953. General Report on Survey of Katherine­ earlier delineated are revised according to Darwin Region. C.S.I.R.O. Aust, Land Res. the necessity to frame the units on the Ser. No.1, Melbourne, Australia. basis of the homogeneity of the human MABBuTT, J. A. and McALPINE, J. R. 1965. factors and the planning of resources Introduction to lands of the port Moresby­ as wall. Such an exercise reduces the Karaiku area. C.S.I.R.O Aus!, Land Res. number of units and at the same time sim- Ser. No. 14, Melbourne, Australia. . plifies the map. In this way, the twelve SEN, A. K. 1967. Documentation and carto­ graphy of the base map for co-ordinated units earlier delineated in the Bikaner land survey, based on aerial photographs. District are further reduced to ten compo­ 'Ann. Arid Zone 6(2): 170-77. site mapping units. Such units are the ex­ SEN, A. K. 1972. Land-utilization mapping to pression of homogeneous land resources estimate the waste lands of arid zone in according to a certain scale. As such, the Rajasthan by photo interpretation techni­ que. Indian natn. Sci. A cad. Bull. No. 44: units are termed 'major land resources' 66-71. or MLRU. SEN, A. K. 1974a. Categorization of land utili­ Using the above technique, the resource zation units in arid zone. Dec. Geog. 12 survey of the Jodhpur and Bikaner (1) : 61-72. districts have been completed. In the Bika­ SEN, A. K. 1974b. Land-use mapping for arid ner District, ten major land-resources zone by aerial photo-interpretation tech­ nique. Proceedings Summer Institute-Desert units were recognized (Abichandani et ai., Ecosystem and its Improvement. ICAR, 1975). Jodhpur, October, 1974.

80 10 THE EXTENT, RESOURCES AND PROSPECTS OF THE COASTAL DESBRT OF NORTH-WESTERN INDIA

AMAL KUMAR SEN AND K. A. SHANKARNARAYAN

THE normal features of tropical and rainfall variability (based on the 1901-50 subtropical deserts-hot summers, large data) and rainfall, temperature and humi­ annual and diurnal temperature ranges, dity characteristics (standard normals low humidity and a small amount of cloudi­ based on the data from 1931 to 1960) of ness-are modified to a considerable ex­ this area are presented in Table 1. tent along the littorals owing to oceanic The Indian coastal· desert conforms to influences. Such areas are known as hot Meigs' (1973) hot subtropical type so far coastal deserts. Here, high humidity is as the climatic aspects are concerned. associated with high temperature owing But from the locational point of view, it to direct evaporation from sea~water. belongs to the Tropical Belt. Meigs' The Indian coastal desert is concentrated map (1973) includes this area within his along the gulf of Kutch and extends into "Kathiawar Makran Coastal Deserts" the interior of Gujarat and into a small of Iran, India and Pakistan. But his portion of Rajasthan. The oceanic in­ delimitation of coastal deserts in India and fluence is extended in the north up to the Pakistan cannot be universally accepted, head of the Luni delta. Geographically, particularly the northern limit of the it is concentrated mostly around the boundary up to Sukkar in Pakistan and Rann of Kutch. The annual precipita­ Barmer, Tilwara and Jalore in India. tion of the region is below 500 mm and Considering the aridity indices, drought the coefficient of variability of the annual factors, littoral locations and associated rainfall (based on the data of 1901-50 oceanic influences, the coastal desert of rainfall) is above 60 % and it means that India extends approximately from 22°N the degree of rainfall reliability here is to 25°0' Nand 68°E to 73°0' E. From the, exceptionally low. The coefficient of administrative point of view, the Indian

Table 1. Rainfall, temperature and humidity conditions in the Indian coastal desert

Station Normal Coeffi- Mean monthly tem- Average relative humidity % annual cient of perature ("C) rainfall rainfall inmm variabi- Warmest Coldest 0830 1730 0830 1730 Iity in % month month hrs hrs hrs hrs Bhuj (Arid) 322 62·29 32·1 18 ·1 66 33 45 24 Jamnagar (Arid) 471 88 ·38 31·5 18·5 70 54 60 37 Raikot (Semi-arid) 589 38·08 32·6 19·4 72 27 51 22

81 DESERTIFICATION AND ITS CONTROL

coastal desert comprises a part of the San­ studded with sand-dunes, of 1 to 2 metres chore Tahsil of the Jalore District (the height. Luni delta) which includes 13 villages and The Luni delta. In the Jalore or San­ the southern tip of the Chohtan Block chore section the influence of the coastal (14 villages) of the Barmer District in desert extends up to the head of the Luni Rajasthan, Bhuj (Kutch), Jamnagar, Delta. The Luni has a well-defined delta parts of Rajkot (Maliya Tahsil) and the although no fresh delta-formation has Banaskantha or Palanpur (Santalpur or been occurring any longer. The delta Varh, Tharad and Vav Tahsil) districts section starts fom, Chitalwana. The in Gujarat. The total area of this coastal Luni Delta consists of a flood plain from desert is about 65,520.8 km!. This Chitalwana to Rathora, a distance of coastal desert includes the Rann of Kutch about 6.5 km', and a delta plain from which covers about 9,000 km!. Rathora to the Rann of Kutch, about 44. 8 km in length. In the deltaic plain, 'topset PHYSICAL RESOURCES beds' are covered with sand and sediments The coastal desert, although enclosed for about 16 km. In the vicinity of the by sand-dunes and sandy hummocks, is Rann, there are "grassland beds". In . not an extensive sandy area. The Kutch the "bottom-set beds" there are grass­ District, which forms part of the Gujarat lands, along with silted-up deposits. The peninsula is a saline tract, with stray following additional characteristics have hills. Salt marshes sandy undulating been identified: (l) the Luni has almost plains, sand-dunes and gravelly areas no water left when it reaches the delta characterize the topography of the coastal and much of the load is deposited near deserts. The narrow strip along the Gulf the apex. Its frontal growth is, therefore, of Cambay in the Jamnagar and Kutch slow; (ii) the sediments being finer, the districts have an average height of less distributaries of the river tend to develop than 25 metres. The plains of Rajkot or meandering courses; (iii) the supply of Banaskantha range between 25 and 75 water to the delta has not kept itself up metres in height. The rivers draining with the deposition, with the result that into the Rann of Kutch for the Gulf of some of the distributaries have lost their Cambay are all consequent streams having heads within the present delta. their own local base levels. The Luni, Degree and extent of sand-dunes. About the Rakhari, the Bhukhi, the Banas, the 12,486 km" or ] 9.41 % of the coastal Saraswati, the Bambhan, the Nachhu and desert in Gujarat is affected by sand­ the Demi are the important rivers of this dunes. As much as 12.57 per cent tract. The relative relief varies from 0 (8,288 sq. km) of the area is slightly dune­ (in the coastal area) to 150 metres (in the infested. The sand-dunes are mostly con­ central part of the Kutch peninsula). centrated along the coast and arc of low The coastal desert of Gujarat is underlain height. About 4,558 sq. km or 6.85 % by a variety of rocks. The area of the of the total area is moderately dune-fed Rann of Kutch practically the whole of where 20 to 40 per cent of the area is the Kutch District and the north-western affected by sand-dunes. About 18 strip of the Jamnagar District is a vast km', of the area of the coastal desert of expanse of tidal mud flats flanked by saline Rajasthan is slightly dunt<-fed (0 to 20 % efflorescences. . of the area being affected). The Chohtan In the Barmer Section (Chohtan­ section is strongly affected by sand-dunes Bhakasar area), the northern part of (40 to 60 % of the area is affected), whereas the Rann of Kutch extends for about 3 the dunes affect 20 to 40 % of the land area km in width and 25 km in length. Its (moderately affected) in the Sanchore remnants representing a saline depression Section in Rajasthan. are evident up to Bhakasar in the north. Ecosystem, vegetation and grasslands. The surface is an expanse of mud flats The littoral type of forest is found in the

82 RESOURCES OF THE COASTAL DESERT creaks of the coastline in Kutch and Jam­ gas plumosus, (4) Halopyrum mucronatum, nagar. The Rajasthan counterpart is (5) Cyperus conglomeratus, (6) Cyperus devoid of any forest. There are no reser­ aristatus, (7) Sporobolus termulus, (8) ved forests in this desert. Based on the Leptadenia pyrotec1mica and ~9) Cynodon ecosystem consi?erations (Fig.) of the dactylon. The first two are found all tract the vegetatIOn has been grouped by along the coast and the second one is Rao and Aggrawal (1964) under two an excellent sand-binder. The third type, heads viz. (a) strand and (b) salt-marsh. if found on the sandy bars, is often gra­ Th~ strand communities are again stu­ zed. In the coastal area, the fourth type died under two subheads: (a) sandy strand, is a conspicuous component of the strand and (b) rocky sandy strand. The sandy­ flora. The fifth, sixth and seventh com­ strand communities are composed of either munities exhibit dense patches on dry halophytes or psammoph¥tes. Since the sandy spots and are found associated habitat is more or less umform, over vast more or less with all types of strand vege­ distances, the same species with a wide tation. The eighth community type is range of distribution can be seen almost found growing in abundance on the sand­ everywhere on tropical beaches. Ipo­ dunes. The last community, a ubiqui­ moea pescaprae forms the dominant com­ tous grass, is found throughout the coast, munity on the sandy shores. Rao and adjoining the strand vegetation. Aggrawal (1964) have identified nine com­ The sandy-strand habitat is composed munity types under the sandy-strand eco­ of water-laid loose sands which have given system. These are: (1) Hydrophylax mari­ rise to sand-hills or sand-dunes. tima. (2) Ipomoea pescaprae, (3) Aspara- The rocky-sandy strand habitat in the

SAL T w._ SLACK • MUD

.. OKH o ..

"RABI"" ...SEA .....

Fig. Ecosystem of the cO.1stal desert of N. W. India © Government of India Copyright, 1977 . Based upon Survey of India map with the permission of the Surveyor Gen~ral o~ IndIa. The territorial waters of India extend into the sea to a distance of 12 nautIcal mIles measured from the appropriate base line. . DESERTIFICATION AND ITS CONTROL coastal desert is characterized either by (i) Soils of sandy strand. These soils the presence of sand in the rock: crevices are sandy to loamy-sand desert soils. or by the presence of a thin mantle of soil Their pH exhibits moderate alkalinity. over the underlying rocks. This ecosystem Organic matter ranges between 0.02 and is marked by the following predominant 0.64 per cent. The values of total dis­ plant communities: (1) Capparis cartila­ solved solids and sodium chloride point ginea, (2) Fagonia cretica, (3) Indigofera to the effect of salt-spray, but not to cordifolia, (4) Kickxia ramosissima, (5) the direct inundation with sea-water. Lepidagathis trinervis, (6) Sericostoma pau­ (ii) Soils of the rocky-sandy strand. The cijlorum, and (7) Enicostema. verticullatum soil cover over the underlying rocks has mixed species. been formed by the weathering of rocks The salt-marsh vegetation occurs in the in situ. The soil is mixed with conglo­ littoral sub-littoral belt and in the Luni merates. In some places, water-laid or Del tao The flora comprises mainly the wind-blown sands are present in thin following species: (1) Avicennia alba, (2) layers over the underlying rock, and hence Suaeda nudiflora, (3) Aeluropus lagopoides, become mixed with the soil from the (4) Fimbristylis cymosa, (5) Scirptls mari­ weathering rock. The soil is loamy sand. 'timus, (6) Uroclzondra setulosa and (7) The pH shows mild to moderate alkalinity. Atriplex stocksii. The first one is met all Orga,nic matter ranges from 0.22 to along the fringes of the inland creeks and 0.81 %. The contents of the total dissolved shallow muddy areas. The second one solids and sodium chloride indicate the is the characteristic feature of saline effects of salt spray only. Soils are highly areas. Others are found in the interior calcareous. areas. (iii) Soils of the salt-marsh. Soils are Behind the strand habitat, salt-marshes, saline and those from salt pans are sandy slacks and mud formations there lies the loam, loam or silt loam with a mild degree semi-arid coastal plain. of alkalinity. Organic matter is much In short, the dominant floristic species higher. Dissolved solids and sodium of the Indian coastal desert are: Capparis chloride are very high as the result of the decidua, Zizyphus jujuba, Prosopis cinera­ direct influence of sea-water. ria, A vicennia officinalis and Rhizophora (iv) Soils of slack and mudformations. mucronata. These soils are loamy sand to sandy loam Geology. The Indian coastal desert to sandy clay loam with mild to moderate has the following geological formations: alkalinity. Organic matter of the surface 1 Recent and Subrecent: Alluvium, soils varies within wide limits (0.26 to blown sand, milolites, tidal flats, 4.69 %), depending upon the age of these raised beaches . • slacks and mud formations. The content 2 Tertiary: (i) Pliocene - Dewarka of dissolved solids and sodium chloride beds suggests that the soils are not under the (ii) Miocene-Gaj beds direct influence of sea-water. All the The Deccan trap encompasses the Kutch soils are highly calcareous (40.97 to 56.58 area to a little extent. The saline mar­ per cent CaC03). shes predominate in the Rann of Kutch Ground-water resources. The geology and its adjoining areas. The major por­ and water-bearing formations of the area tion of the coastal sands is of marine origin have been earlier reviewed by Adyalkar composed of shells of marine microfauna (1964). In Kutch, rocks of Patcham and and is very rich in CaC03 • Chari series comprise calcareous shales and limestone and the quality of water Soils is, therefore, saline. The Umia series Soils of the Indian coastal desert have were deposited only under fluviatile and been described by Rao and Aggrawal estuarine conditions and partly under (1964) as follows: marine condition. The marine formation

84 RESOURCES OF THE COASTAL DESERT of the series yields>only saline water and along the joints, fractures and secon­ hence, there is no development of ground­ dary partings, which are generally limited water in the fossiliferous sediments of the in depth up to 50 m. The static water series. In the Bhuj sandstone, ground­ level in the dugwells ranges from 4 to water occurs under both confined and .12 m, with yield capacities of O. 05 to 0.20 unconfined conditions. The static water ips. The yield capacities of the Tertiaries level in the dug well ranges from 2 to 30.5 in Kutch ranges from 0.06 to 0.24 Ips, m b.g. 1. and that in the dug-cum-bore­ with slight to moderate saline water. wells and tube-wells tapping-confined Irrigation with ground-water is the uni­ aquifers from 3.4 to 31. 4 m b.g 1. Over versal local practice. 9,000 and 26,000 million litres of ground­ water have been utilized for the purpose of HUMAN RESOURCES irrigation in the lower and upper Bhuj Data on the distribution and density of series respectively in Kutch. The tube­ popUlation in the Indian coastal desert wells located well within the Bhuj sand­ are presented in Table 2. It is evident stones yield about 13. 55 Ips. The quality that the density is very low (below 35 of water is generaJly good. In the Deccan persons per sq. km on an average). The trap in Kutch, ground-water occurs intercensal decadal variation (1961-71)

Table 2. Distribution and density of population (1971)

State District Section Area in (Icm2) Total population Density (Icm')

Gujarat Bhuj (Kutch) 45,612'3 849,557 19 Jamnagar 14,125 ·1 11,11,376 79 Rajkot/Maliya Tahsil 657'9 58,771 89 Benaskenta Varh (Santalpur) 1,356 -1 55,652 41 of Tharad 1,356 1 1,09,058 80 Palanpur Vav 1,651'2 97,262 59 Rajasthan Barrner Chohtan Bhakasar Section (14 viIIages) 289·4 8,701 30 Jalorl! Sanchore 472·7 9,140 19 (13 villages) Total 65,520-8 22,99,517 35

Table 3. Rural-urban occupational structure (1971)

Percentage of total working population Industrial categories Rural % Urban % Male Female Male Female

1. Primary activities (cultivation agricultural-labour, mining, quarrying) 43 31 5 4 2. Secondary activities (household industries, manufac­ turing other than household and construction) 10 3 23 4 3. Tertiary activities (trade and commerce, transport, storage and communications and other services) 10 3 58 6

85 DESERTIFICATION AND ITS CONTROL is about 30 % being lowest in the Kutch (including short and long fallows) and District (21.99 %). about 60 to 80 % of the land is availa­ Workers constitute about 40% of-the ble for grazing. The agricultural land total population of the coastal arid zone when not under cultivation, is also availa­ and have a male: female ratio of 28:12. ble for grazing. The intensity of cropping In the rural areas, about 45 % of the peo­ is very low (100. 1 to 102.3). ple are workers (male: female ratio of Agriculture. Bajra, jowar and maize 29 : 16). The rural and urban occupa­ are the major cereals produced. Wheat is tional structure (average) as a whole is cultivated under irrigation. Bajra repre­ given in Table 3 sents more than 80 per cent .of the total There is only one city, viz. Jamnagar, cropped area. P,ulses, e.g. gram and peas, which has a population exceeding 1,00,000 are generally grown in winter as a second (2,14,816 in 1971). Bhuj in the Kutch crop after millets, and some of the pul­ District is the next important city which ses, e.g. tur, mung, moth, are grown had a population of 52,861 during 1971. mixed with bajra in the kharif season. About 30 per cent of the total population The largest area under pulses is in the is urban. The increase in urban popula­ Kutch District. Among oilseeds, the cul­ tion during the last decade (1961-71) is tivation of ground nut is gaining impor­ of the order of 50 to 60 per cent. There tance.. Commercial crops are of no im­ are one class-I, one class-II, 4 class-III, portance. Cotton and sugarcane are 12 class-IV, 7 class-V and 6 class-VI towns, grown to some e£tent. The yields of all located in the Gujarat sector. different crops are, however, very low. The yields in 1b per acre of bajra, jowar, RESOURCE UTILIZATION AND ECONOMIC ASPECTS wheat, barley and maize are approxi­ mately 160, 155, 900, 780 and 530 res­ Land use. In Bhuj in the Kutch Dis­ pectively (Trivedi, 1966). trict, only 36 % of the total area is cultiva­ On an average, less than 5 % of the net ted. Of it, 53 % is regularly cultivated, sown area is irrigated. It varies from 24 % of it constitutes current fallows 2% in Kutch to 4 to 8 % in Jam­ and 23 % of it is long fallow, cultivated in nagar, Chohtan and JaIore sectors. Wells 2 to 5 years rotation. About 4 % of the are the main source of irrigation, comman­ total non-agricultural land is under per­ ding 60, 96 and 99 % of the total irrigated manent pastures, 6 % under forests and 3 % area in Kutch, Jamnagar and in other parts under settlements and water features. of the Gujarat coastal desert, and Rajas­ The remaining 87% of the non-agricultural than sector respectively. Canals irrigate area is barren and culturable waste. The about 20 % of the total irrigated area in Rann, of Kutch is extensively exploited Kutch and 5 % in the Jamnagar district for salt. In the Jamnagar District of of Gujarat. Gujarat, about 66 per cent of the land is The gross value of the agricultural out­ arable and comprises net sown, short­ put per acre of the cropped area is very fallow and long fallow areas. The land low (Trivedi, 1966). The agricultural hold­ use pattern of non-agricultural land (34 % ing per cultivating household is above of the total area) in Jamnagar is as fol­ 17 acres in Gujarat and 21 acres in lows: barren and culturable wastes-53 Rajasthan; the agricultural holding per, per cent. forests 7 %, settlements and head in the rural areas varies from 2 to 3 water features 16 % and permanent acres in Gujarat and from 4 to 6 acres in pastures 24 %. The land-use systems fol­ the Rajasthan coastal desert (Trivedi, lowed in other sectors of the coastal 1966; Gupta, 1969). The percentage desert are more or less similar to those ratio between the supply per head and the of the Jamnagar District. Taking the requirement per head of the staple food coastal desert as a whole about 55 to 60 crops varies between 117 and 175 in per cent of the total area is cultivated Rajasthan (Gupta, 1969) and from 50 to

86 RESOURCES OF THE COASTAL DESERT

60 in Gujarat (Trivedi, 1966) and the coas­ The available minerals, such as salt, tal desert. bauxite, calcite and limestone, should be Minerals. The coastaJ desert of Rajas­ properly extracted. The modernization than has practically no minerals; although of the mines will increase the output and salts are often extracted from saline income per head. Investigations on soil depressions. However, mining is not and natural gas should be continued. economical in this sector. The Gujarat The coastal areas of Jamnagar, and parti­ sector is richer. Salt is extracted at cularly the areas along the gulf of Kutch, Jokhan, Padana, Kandla and Mundra in may produce oil. the Kutch District, Jamnagar, Sikka, (iii) Fishery. The coastal area of the Salaya, Mithapup in the Jamnagar District Gulf of Kutch contains good fishing­ and Maliya in the Rajkot District. Bau­ grounds. This particular industry has a xite is mined in Mahadevia, Nandana, good prospect in the Kutch and Jam­ Bhatia, Gandhvi, Lamba, Bankodi, nagar districts. Okha, Dwarka, Jam­ Kenedi, Ran and Virpur. Calcite is min­ nagar, Gandhidham, Kandla port, etc. ed in Govana, Lakhasar and Narmand; may become the centre of this industry. limestone in Bavdial and Motigapall in Proper investment to develop this indus­ the Jamnagar District. There has been try is needed. an upward trend in the production of these (iv) Urban and industrial development. minerals recently (Trivedi, 1966). There The planning of urban development in are extensive areas underlain by strata the coastal arid zone should be considered hopefully containing petroleum and natu­ from the following viewpoints: (a) the ral gas. development of ports, e.g. Okha, Kandla Industries. The Indian coastal desert and Dwarka, (b) the industrial develop­ has not yet been industrially developed, ment of settlements, e.g. Gandhidham unlike similar tracts in western Asia and and Jamnagar. in the Southern Hemisphere. Gandhi­ (v) Tourism. There are great prospects dham in Kutch and Okha and Jamnagar to develop tourism and its associated in the Jamnagar District are the most industries in this arid zone. Seaside important industrial centres. resorts can be developed along the Gulf of Cambay and the Gulf of Kutch. The PROSPECTS FOR DEVELOPMENT usually sunny weather and the scenic Considering the limitation of resources beauty of the regions may also help to and the constraints imposed by the arid attract tourists. The historical and archi­ environment, the Indian coastal deserts tectural significance of places, e.g. Dwarka, have restricted choices for development. may also help to develop tourism. The The resources of the region have not yet prospects of having a view of the desert ( been fully assessed. For this assessment, and of the Rann of Kutch should provide integrated basic resources survey in the much scope for the development of a region should prove useful. Amiran viable tourism industry. (1973) has given some guidelines for the With the development of tourism, it is d~velopment of the arid zone. Following almost certain that the local arts and crafts h~s suggestions, the developmental plan­ will find avenues for fuller expression. nIng of the Indian coastal deserts may be Game sanctuaries can also be developed recommended in the following order of in the Rann of Kutch area and in the priority: Kutch District. The Rann of Kutch (i) Rangeland development and dairy­ receives many migratory birds, e.g. the farming. The existing permanent pas­ flamingo from coastal Africa, Asia and ture lands and other available grazing­ other countries. Other interesting birds, grounds should be fenced, and controlled e.g. florican, imperial sand-grouse and grazing should be introduced. Houbara are also found in large numbers. (ii) The development a/mineral resources. Wildlife sanctuaries can also be deve-

87 DESERTIFICATION AND ITS CONTROL

loped in the area, particularly for the cations in the development of arid lands. Chincara, the wild ass and the blue-bull. Coastal Deserts-Their Natural and Human Environments. Pt. 1. Chapter 3. (eds. Amiran Jamnagar, and Okha can be developed D.H.K. and Wilson, A.W.) The University as transport centres to visit the lion sanc­ of Arizona Press. Tucson, Arizona, pp. tuary in the Gir forest. Tourism and the 25-32. resort industry have developed the eco­ ADYALKAR, P. G. 1964. Palaeogeography, sedi­ nomy of many coastal deserts in countries, mentological framework and ground-water such as Peru, Chili and Israel. There is potentiality of the arid zone of western enough scope to develop the Indian coas­ India. Proc. Symp. Prob. Indian Arid Zone, Jodhpur (23rd Nov. to 22nd Dec. 1974), tal desert, too, in this respect. pp. 4-17, Ministry of Education. Govt. of (vi) Agriculture. Agriculture is still the India,- New Delhi. main occupation of the people. But ANANDA RAO, T. and AGGRAWAL, K. R. 1964. owing to extremely arid conditions, high Ecological studies of Saurashtra coast and salinity, limited irrigational facilities and neighbouring islands. Proc. Symp. Prob. marshy land; it is doubtful how best it can Indian Arid Zone, Jodhpur, pp. 31-42. be developed further. Dry farming tech­ GUPTA, C. S. 1969. Census of India 1961, Rajas­ niques may be tried to develop agricul­ than Census Atlas 14 pt. I-B, Jaipur. ture. For the development of this coastal desert, as in other coastal deserts of the MEIGS, P. 1973. World distribution of coastal desert. Coastal Deserts-Their Natural world (Amiran, 1973), agriculture should and Human Environments (eds. Amiran, necessarily receive the lowest priority. D.H.K. and Wilson, A. W.) Pt. 1 Chapter 1, The University of Arizona Press, Tucson, Arizona, pp. 3-12. REFERENCES TRIVEDI, R. K. 1966. Census of India 1961, AMIRAN, DAVID, H. K. 1973. Problems and impli- Gujarat Census Atlas 5 pt. IX, Ahmedabad.

88 11 LAND AND RESOURCE UTILIZATION IN THE ARID ZONE

H. S. MANN, S. P. MALHOTRA AND K. A. SHANKARNARAYAN

THE arid regions of India (including the surveys to assess the existing resources, cold desert of Ladakh) comprise about their present use and the resource poten­ 12 % of the total area of the country. tial in the Indian arid zone for their The diverse problems imposed by aridity rational utilization have been under way and the excessive biotic interference in the at the Central Arid Zone Research Insti­ Indian arid zone have often been high­ tute for the last sixteen years. The lighted as thwarting any development present paper examines these aspects, with measures in the region. However, the specific reference to the available resour­ availability of the resources potential in ces, their present and the recommended terms of land, livestock, ground-water and use for optimum utilization, vegetation is undeniable and it is now realized that the Indian desert, unlike LAND USE others, is not so intractable as is often The land-use data of 1970-71 (Table 1) imagined. The major break-through lies reveals the respective percentages of in the planned exploitation of the resour­ forests, land not available for cultivation, ces based on scientific data, which could other uncultivated land excluding fallow enable the optimum harnessing of the lands, fallow lands and the net area sown available resources. The prerequisite for worked out at 1.58, 23.85, 19.30, 11.72 formulating the strategies to utilize the and 43.25. land and other resources is to carry out The land-use data (Fig. 1) compiled an integrated resources survey in a for the period 1951-52 to 1973-74 for the comprehensive manner. The integrated twelve western districts of Rajasthan

Table 1. Land utilization (1970-71) in India and in the Indian arid zone Area (million ha)

India The Indian arid zone Land-use category Area % Area % 1. Forests 65·9 21'54 0·53 1·88 2. Not available for cultivation (Area put to non-agricul- tural uses + barren and uncultivable lands) 46·2 15 ·10 6·70 23'85 3. Other uncultivated land excluding fallow lands (Perma- nent pastures and grazing lands+land under tree crops and groves + cultivable waste) 32·5 10·62 5·42 19·30 4. Fallow lands (current fallows + others) 20'2 6·60 3·3 11·72 5. Net area sown 141·2 46·14 12·2 43'25 Total reported for land utilization 306·0 28·1 Total geographical area 328·0 31·9

89 DESERTIFICATION AND ITS CONTROL further indicate that land in this region decline in the grazing-lands due to the is, by and large, unsuitable for crop extension of cultivation of marginal culture and over 50 per cent of it is lands. accounted for by current fallows, old The land-use capability classification faIIows, cuIturable wastes and uncuIti­ forms an important criterion for assessing vable barren lands. the resource potential of an area. The Viewing historically it is observed that limitations, which primarily determine the the percentage of the net sown area had land-use capability classes in the arid zone been 28.61 in ]951, and 45.05 in 1971, are the arid climate, the' coarse sandy whereas the percentage of the double­ texture of the' soil with very low water­ cropped area during this period ranged retention capacity, proneness to severe from 0.41 to 1.45 per cent only. The net wind erosion, duny physiography, effective sown area increased by 44.64 per cent soil deplh and a high salinity hazard. during 1951-61 and by an additional Table 2 reveals that there are hardly any 9.47% during 1961-71. Barren, cultivable Class 1 or Class Illands in the arid region. and uncuHivable wastelands, permanent Class III lands occupy about 27 % of pastures and faIIow lands declined by the area, Class IV lands 16 % and 16.83'% during 1951-61 and further by Class V lands about 1.2 %. The Class VI 6.95 % during 196]-71. Thus during lands predominate and aecount for as 1951-71 there had been a significant high as 45 % of the area and they are

Average 1951-6~·'71 1951-52 TO:'73 ~74

LEGEND 1111 FOREST ~ LAND PUT TO NON AGRI. USE B BARREN' a UNCULTIVABLE LAND PERMANENT PASTURE a []]] OTHER GRAZING LAND s::-J CULTIVABLE WASTE LAN.D ~ OTHER FALL~N 1::::;:1 CURRENT FALLOW ~ NET SOWN AREA Fig. 1. Land utilization in arid zones

90 LAND AND R!=SOURCE UTILIZATION

highly susceptible to wind erosion, parti­ permanent pasture from the present cularly in less than 200-mm-rainfall :z;one. 4.8-7.3% to 25-38% in the range districts The rocky or saline lands occupy h!udly of Jodhpur, lalore and Barmer. 1.97 and 0.6% respectively. An area of 84,893 km2 or 26.52 % of tbe total arid area has been Table 2. Land-use capability classes in the wes­ traversed either by reconnaissance, detai­ tern arid region led reconnaissance, or detailed survey. About 90 % of this area covers the 5 Land-capability Area (km2) Percentage of districts of western Rajasthan, namely classes the total Bikaner, Jodhpur, Jalore, Barmer and Nagaur. Based on the assessment of the II C* 333·0 0·70 land resources and their examination in nrc 1,762'7 3 70 III C.W. 325·7 0'68 relation to human resources, the climate IIXCe 8,691'2 18 25 and the present land-utilization, mapping­ III C, Sh. 2,086'6 4·38 units or major land-resources units have I1V Sa 23 1 005 been worked out on the basis of the units lVe, e 7,456' 3 15·66 IV e, Sh 221·4 0-46 having the recurring pattern of biotic V 88·4 0·19 and abiotic environment. The units, thus V Sa. f. 501·1 1'05 framed, have not only a certain amount VIEe 21,604'6 45·37 of environmental homogeneity, but have VII Sh, e,e 3,184'4 6 69 VII Sa 2'2 0005 the same magnitude of problems and, VIII Sa 285 8 0·60 therefore, the management practices to VlIIR 937'9 1 97 be adopted are likely to be the same

\ within the units concerned. So far, 10 47,504'4 units have been tentatively standardized *C = Climate, Sa = Salinity, e = Wind erosion, and their resources, present land use, nature and magnitude of desertification W = Wetness, Sh = ShaIlow soil hazards and the recommended manage­ ment are presented in Table 3. The surveys conducted covering 64,140 km2 (32.7 % the arid Rajasthan) have POPULATION AND ECONOMY shown that the present land use is The hot Indian desert is one of the most inconsistent with the land-use capability thickly populated deserts of the world dictated by the inherent soil characteris­ having a population of over 19 million tics. Investigations have revealed that people and an average density of 61 only 46 to 60 % of the area in the arid persons (1971) per km', as against 3 zone of Rajasthan is suitable for arable persons per km2 in most other deserts of farming. The rest 21 to 24 % of the area the world. The growth rate of popula­ i~ made up either of dunes highly suscep­ tion in the region had been relatively high tIble to wind erosion and hummocky and the present demographic features plains or light-textured hardpan soil in show high potentialities of future growth danger of turning barren on account of of population (Malhotra et al., 1972). surface stripping. This area should be The percentage of literacy in the region is put under permanent pasture for sustained low, being only 22.72 of the total popu­ production and resource conservation. lation as compared with 29.~4 per cent in Rocky pediments exposure which consti­ the country. Apart from the other appa­ t~lte 5.6 to 8.8 % are presently con­ rent reasons, the low percentage of SIdered barren. They need also to be literacy in the extreme arid areas brought under permanent silvi-pastoral (Rajasthan) may be attributed to the <:over with a light grazing intensity. The nomadic way of life of the people, noma­ capability-based, recommended land use, dism being inversely related with the rate therefore, requires an increase under of literacy.

91 DESERTIFICATION AND ITS CONTROL

Table 3. Present land use, magnitude of desertification and recommended management in the major land-resource units of the western arid region

Major land-resource Present land use Nature and magnitude Recommended mana­ unit of desertification ha­ gement zard

1. Flat aggraded older Klzarij non-cropping In low-rainfall areas Single-cropped area to alluvial plain of mixture of moth and (200 mm), severe wind be managed by rational bajra, kharij pulses erosion hazard is ,dryfarming techniques: and oilseeds, e.g. til. highly conducive to (i) wind-strip crop- The intensity of crop­ desertification. In rain­ ping; ping varies according fall areas above 200 (ii) stubble - mulching; to rainfall conditions mm, the desertifica­ (iii) windbreaks; tion hazard is medium (iv) water-harvesting. 2. Sandy undulating aggra- Rainfed crops, such as Moderate to severe To be developed for dable alluvial plains bajra+moth wind-erosion hazard, rangeland in blocks of having about 25 per 1,000 ha; fencing es­ cent lower fertility than sential. After initial ideally managed soil grubbing, to be re­ seeded with Cenchrus/ Lasiurus sindicus @ 5-7kg/ha. 3. Flat inter-dunal plains Rainfed mono-crop­ Moderate to severe Farm forestry, runoff ping, such as bajra wind-erosion hazard. farming and develop­ and bajra + moth with Cultivation on margi­ ment of rangelands, long fallows of 2-5 nal lands is a menace as per topographic years rotation to soil. Wind-erosion location and micro­ hazard and the casting climate of sands in the adjoin­ ing lands 4. Sandy undulating inter­ Mono-cropping of low Same as above To be developed for dunal plains intensity, with long rangeland, farm fores­ fallows ranging from try and runoff farming 3 to 5 years 5. Flood plain: Often mono-cropping; Wind- and water - Requires a judicious (i) Narrow rivet: in but double-cropping erosion hazard-redu- cropping pattern; dra­ tracts on certain occasions ction of soil fertility inage control essential under irrigated condi­ tions (ii) Sandy complex-gra­ Sandy waste-grazing 25 per cent to 50 per To be used for grazing, ded river-bed for livestock cent reduction in soil silvipastoral manage­ fertility ment needed (iii) Duny area of aeo- Low-intensity mono- More than 50 per cen t Development as range­ Iian complex cropping loss in soil fertility land; with L. sindicus and C. ciliaris 6. Sand-dunes: Cultivated only in Severe wind erosion, Plantation of top-feed (i) Below 200 mm of years of good rainfall, leading to 50 to 75 per and fuel species in a annual rainfall otherwise wasteland (i) cent reduction in crop­ phased manner in the base and the lower ped and plant popula­ blocks of 1,000 ha or flanks are cultivated. tion; degradation for­ more. The reseeding Upper flanks and tunately is not serious of suitable grasses re­ crests are grazing-land to develop range- commended on the management practices windward side, flankS and crests (ii) Rainfall above 200 Wasteland comprises mm about 70 per cent. Base and flanks are cultivated and crests are sandy waste

92 LAND AND RESOURCE UTILIZATION

Table. 3. (Contd)

7. Mobile or active sand- Sandy wa,ste Highly affected, severe Closure of the area for dunes desertification hazards 10-15 years. Silvi­ pastoral managements are recommended 8. Gravelly aggraded older Gravelly waste to rain- Moderately severe Water-harvesting and alluvial plains fed mono-cropping wind-erosion hazard, rangeland develop­ grazing-land for live­ leading to about 25 per ment stock cent lower fertility than in the ideally managed soil 9. Eroded rocky lands Stony and rocky waste Already desertified. Water-harvesting and grazing -land practically lost 70-80 catchment manage­ per cent of soil cover ment 10. Saline depression Saline waste-extrac­ Highly desertified Mining, rangeland tion of salt and gyp­ development as post sum mining operations

Approximetely two-thirds of the total total cultivated area under foodgrains. population constitute the non-working During 1970-71, the region produced class. The high percentage of economi­ about 6% of the total cereals and cally inactive population may be attribu­ over 16 % of the total pulses produced in ted to the high 'concentration of population the country. in the lowt;:r age-groups. The occupati­ The average size of the land holding in onal distribution (1971 Census) reveals the arid zone of Rajasthan worked out that the res pective percentages of workers at 9.9 ha, which is almost double the engaged in the occupation of cultivation, average size of the holding in the State. agricultural labour and other occupations A lorenz curve (Fig. 2) drawn reveals the came to 53, 19 and 28. It may be obser­ uneven distribution ofland and the extent yed that the percentage of workers engaged of concentration of land holding. In the occupation of cultivation and Householders to the extent of 11.2 % had agricultural labour combined is relatively high (72 %) in the region. Animal hus­ 100 bandry is, however, often followed as a subsidiary occupation by the majority of 90 the households and in certain pockets 80 (where the aridity index is relatively high), such as the Anupgarh-Pugal region, it 70 formed the main occupation of over two­ thirds of the total workers (Malhotra et af, 1966). Another major occupation fOllowed by the workers is the operation of household industries. The percentage of workers engaged in trade and ~ommerce, transport and in other services 20 IS much lower. .

AGRICULTURE . The data on the principal crops grown 10 20 30 40 50 60 70 80 9J 100 ~n the region (Table 4) reveal that bajra Holders ('Yo) IS the chief cereal crop produced and Fig. 2. Distribution of cultivated land in arid occUpies approximately three-fifths of the . Rajasthan

93 DESERTIFICATION AND ITS CONTROL

Table 4. Area and production of principal crops for the year 1970-71

Crops Indian arid zone India Area Production Yield Area Production Yield

Rice ]40 ·1 252 8 1 8044 37,592 42,425 1·1232 (l'03) (3, 53) (32 '86) (41' 24) Jowar 809·6 331·8 0·4098 17,374 , 8,105 o 4665 (5, 97) (4 63) (I5 19) (7 92) Bajra 7,825,4 2,536 7 0·3241 12,9q 8,029 0·6218 (57'71) (35·41) (11'29) (7' 84) Maize 67·6 93·1 1 3772 5,852 7,486 1·2792 (0' 50) (l 30) (5 '12) (7 .31) Wheat 1,232' 5 2216·6 1·7984 18,241 23,832 1·3065 (9 '09) (30 94) (15 94) (23 '27) Barley 129·6 129·3 0·9976 2.555 2,784 1'0896 (0 '96) (1 . 81) (2 23) (2,72) Gram 1,267'0 858·8 o 6776 7,839 5.199 0·6632 (9' 34) (11 '99) (6 85) (5,08) Other pulses 2,087'8 744·1 0·3564 12,040 4,736 o 3934 (15 40) (l0'39) (10 52) (4 62) Total food grains 13,559'6 7,163 ·2 1,14,406 1,02,396 over 50 % of the total cultivated land, It may be observed that the area under whereas 47.3 % of the small farmers held important crops, e.g. bajra (pearI-miIlet), only 10 % of it. As a consequence of the pulses and sesamum, shows an annual increasing population, the small holders increase, whereas in respect of production are making more and more constant use only bajra shows an annual increase. The of the land for cropping, thus disturbing negative linear growth rate is mainly due the earlier practice of leaving it fallow for to the bringing of marginal and sub­ replenishing its fertility. Therefore the magrinal lands under cultivation, and this overcrowding of the . labour force on pre­ practice keeps on, and rather, accelerates modern agriculture has been' resulting in desertification, the use of land beyond its ecological The system of agriculture followed capabilities and its productivity has subs­ tantially declined. Table 5. The annual linear growth rate of the Fig. 3 (a, b) represents area, production area, production and productivity in and productivity during 1954 to 1970 of respect of various crops (1954-70) the important crops grown in the arid zone of Rajasthan. It may be observed Crop Area Production Productivity that the area under different crops and the production from them has increased, but Bajra +2'41 +1'34 -0·66 Jowar -3·41 -542 -4·88 the productivity per unit area has declined. Wheat -0·82 -0·24 +0'60 The annual linear growth rate, i.e. the Barley -1 16 -0,05 +068 percentage of annual increase or decrease Gram -6,31 -1·67 -1 59 (1954-70) in the area, the total production Sesamum +3·24 -:-3'57 -4'23 and the productivity of different crops are Other presented in Table 5. pulses +1 91 -1·08 -2·70

94 LAND A:r-rD RESOURCE UTILIZATION

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95 DESERTIFICATION AND ITS CONTROL

__ AREA 90 480 800 0- - -0 PRODUCTION ~5 450 750 ,;• ~ .-----A PRODUCTIVITY ~ ~ co :~," 0 " , ,,­ , 7 ~ 390 ~650 , \, , , 0 ~ , , 0 0 •: (I "I "- S! ;;; I x\ , ~ ~ 065 ~ 330 550 / " f" 0 >- of 1\ 0 t-- : I ,\ " .9 ;;: I,J,' I; " ~ 5 t; 450 Jr \ \ , :> I <1 0 I',' ~,' ? c 0 a:UJ 0 a: <145 g: 210 "-350 I:' \ 1 I" o" 35 ISO 250 cl "b 25 90 ISO ~55 57 59 61 63 65 67 6970 YEARS

OTHER PULSES ______AREA

0-- - --0 PRODU<:TION zao 340 245 ... ----.. PRODUCTIVITY ZIO 32 230

19() ~280 ~ o ,~ o .. Fig_ 3b Area, production and ]17 2 40 : 170 productivity of crops g ~ ~ (1954-70) 9 ISO ~ 20 ~ 14 ?f ti b ;,3130 g'60 g a: a: a: .. Q. 0.

It 120

90 eo 50 ~ 54-55 57 61 63 67 YEARS

• SEASAMUM __ AREA

0-- - --0 PRODUCTION .. ____ ~ PRODUcnvrrY 43 BO '260 41 745 240

37 . 625 200 .co co a 0 33 I- 505 ?,,16"" a 0 '" 0"" 2 !' c 120 0 '!O 3B >- 2 I- Z ;; 0 ~25 ;: 265 lJ ~SO ::> ::>

17 2 a LAND AND RESOURCE UTILIZATION

indicates the limitations imposed by cant area under irrigation, coupled with aridity. Subsistenc~ farming is largely in scanty, iII-distributed and erratic rainfall. vogue and it tends to make, the farmer fails to be a built-in process, efficient security-oriented. This is an important enough to increase productivity and arrest cause of the low level of income. Low desertification. capital investment, labour-intensive agri­ It may, however, be worth while to add cultural operations, poor means of here that the available irrigation facilities communication and inadequate marketing could not only be much more effectively facilities impose further checks on efficient utilized and higher production achieved by agriculture. The human effort to bring the use of drip and sprinkler methods of water up from the aquifers, which could irrigation (Singh et al., 1973), but will also be a factor in bringing about improvement facilitate the use of highly saline waters and a built-in check on de-desertification, (10 mmhos), commonly found in this also present a dismal picture. region, for irrigation. Additionally, the The data suggest that the irrigation introduction of the Rajasthan Canal shows (Table 6) in absolute as well as in relative a great promise and it is hoped that the terms, has been more or less static, ranging region will achieve the status of a border­ from 2.37% of the total area in 1966-67 to ing region which came under the flow of 4.25% in 1969-70. As regards the annual the Gang Canal in 1927 and which is now changes also, the desert region has been not only a granary of the country, but characteristically following almost a also a good forest plantation. rhythmic pattern regarding rainfall. It The existing water sources and the thus seems certain that poor rainfall might Rajasthan Canal Project, when completed have resulted in the poor recharging of will irrigate about 11 % of the wester~ the aquifers, leading to a reduction in the Rajasthan, leaving about 89% as rainfed. reported irrigated areas. Thus an insignifi- The available technology for dryland.

Table 6. Irrigated area and its changes in the arid region of western Rajasthan (1956-73) including Ganganagar .

Years Total reported area Irrigated area Irrigated area as % % Annual change ('000 ha) ('000 ha) of the total area (+ or-)

1956-57 21461 533 ·14 2·48 1957-58 21420 588 ·15 2·75 +10·32 1958-59 21363 595·65 2 79 + 1·28 1959-60 21341 721·00 3 38 +21·04 1960-61 21314 649'02 3·05 - 9 98 1961-62 21360 733·86 3·44 +13'07 1962-63 21451 764'01 3·56 + 4'10 1963-64 21348 844'56 3·96 +10'54 1964-65 21363 823'99 3·86 - 2·44 1965-66 21363 683'06 3 20 -17'10 1966-67 21361 506·65 2·37 -25'83 1967-68 21361 868·29 4·06 +71'38 1968-69 21377 839·23 3 95 - 3'35 1969-70 21377 903·90 4·23 +771 1970-71 21380 827·70 3·87 - 8'43 1971-72 21381 842 ·15 3·94 + 1'75 1972-73 21376 895·55 4·19 + 6'34 Mean ('OOOha) 21,377 88 742·34 3·47 Changeover 1956-57 to 1973-74 S.D. ('000 ha) 34·66 129 ·18 0·61 C.y. (%) o 16 17·40 17 45

97 DESERTIFICATION AND ITS CONTROL management (Mann and Singh, 1975) tant role than through the media of mass suggest considerable potentialities in the communication. arid areas through scientific land-soil-crop management. It may, however, be empha­ ANIMAL HUSBANDRY sized that adopting the technology of Animal husbandry is the next important desert control and development has so sector of agriculture. Table 7 indicates that long made only a small leeway 'among the cattle, buffaloes, sheep, goats, camels and farming community and steps for adopting other livestock constitute 7.30, 2.65, 6.86, them more quickly are essential. Studies 5.07,0.65 and 0.19 millions respectively (Malhotra et al., 1974) on the relative of the total 23 million livestock population. importance of some socio-economic factors The livestock population exceeds the in the adoption of agricultural innovations human population, the ratio being 117 suggest that it will be useful to encourage head of livestock per 100 persons. The as much participation and involvement of density of livestock which indicates pres­ the farmers in various activities as possi­ sure on the grazing-land is much higher ble and to fully explore the ways and in the region, being 1,022 head of livestock means to impart full knowledge of the per every 100 acres of permanent pastures innovations, as these two factors incline and grazing lands. In the context of the the farmers to a quicker adoption of them. arid zope of Rajasthan it may be observed It has further been found that in the that the livestock population increased propagation or diffusion of innovations from 10.27 millions in 1951 to 16.44 the inter-personal communication along millions in 1972. informal channels plays a far more impor- Table 8 presents ,the number and com-

Table 7. The number of livestock for various regions of the arid zone of India (million-1966)

States Cattle Buffaloes Sheep Goats Camels Other Total livestock livestock

Arid zone of Rajasthan 4·20 0'9~ 5·00 3·76 0·52 0·09 14 50 Arid zone of Gujarat 0·99 0·31 0·49 0'51 0·01 0·03 2 34 Arid zone of the Punjab 0·65 064 0·22 0'20 006 0·03 1 80 Arid zone of Haryana 0·42 0·37 0·20 0·17 0·06 o 01 1·23 Arid zone of Andhra Pradesh o 68 0·30 077 0·31 o 03 2·09 Arid zone of Karnataka 0·30 0·09 0'16 o 10 neg. neg. o 65 Arid zone of Maharashtra o 06 o 01 o 02 0'02 neg. neg. 0·11 (Arid zone) Total 7 ·30 _ 2·65 6·86 5·07 0·65 0·19 22 72 (32 ,13) (11'60) (30 '19) (22 32) (2 86) (0 84) (100 00) India 176·05 52·92 42·01 64'56 1 03 7·23 343·80 (51'21) (15' 39) (12 '22) (18'78) (0' 30) (2 ·10) (100 00)

Table 8. The number of livestock (in millions) in the arid zone of Rajasthan

1951 1956 1960-61 1965-66 1971-72 Livestock 0;': 0/ Num- ,0 Num- % Num- % Num- /0 Num- % ber ber ber ber ber Cattle 3·431 33 41 4·142 29'59 4·635 32·02 4·944 30-09 3·712 22·58 Buffaloes 0·775 7'55 0·826 5·90 1 030 7·12 1 ·218 7 41 1·167 7·10 Sheep 3'374 32·86 4·896 34·98 4'501 31·09 5 403 32·89 5·082 30 91 Goats 2·370 23·08 3·746 26·76 3·661 25·29 4·283 2() 07 5·747 34·96 Camels 0·214 2'08 0'288 2'06 0'541 3·73 0·472 2·87 0·630 3·83 Others 0'104 1·02 0'099 0·71 0'108 0·75 0'109 0·67 0'101 0·62

98 LAND AND RESOURCE UTILIZATION

position of livestock in the arid zone of vegetation cover and, as mentioned earlier, Rajasthan during the gifl'erent quinquen- the area occupied by forests worked out nia from 1951 onwards. I only at 0.8 % of the total land. Champion It may be observed that of ~he total (1936) has recognized the following princi­ livestock, the percentage of sheep and pal types of vegetation in Rajasthan: (1) goats ranged from 55.94 to 65.87 during- The northern desert thorn forest, (2) the 1951-72. Owing to recurring droughts and northern Acacia scrub forest, (3) the famines between 1967 and 1971, the num­ northern Euphorbia scrub, (4) the inland ber of cattle declined heavily (24.92 % de­ dune scrub. Mathur (1960) further classi­ crease) owing to huge mortality, whereas fied the above types and recognized the the number of hardy animals, e.g. goats, following: (1) The dry teak forest, (2) the increased (34.18 % increase) to a substan­ Anogeissus pendula forest, (3) the mixed tial level. This situation not only reveals deciduous forest, (4) the tropical thorn the preponderance of goats and sheep in forest, (5) the Butea monosperma forests, the total livestock population in the arid (6) the tropical thorn forest, (7) the sub­ Rajasthan, but also the increase in goat tropical thorn forests. Joshi (1956), Jain population during the famine years. (1963), Nair and Joshi (1956), Shantisarup Of the limiting factors in improving and Bhandari (1957), Shantisarup (1957, sheep production in the arid and semi­ 1958), Satyanarayan (1963) and Satyana­ arid regions, inadequate forage and rayan and Shankarnarayan (1964) have drinking-water are resulting mainly from conducted such investigations. the improper use of resources. Owing to increased population not only The high pressure of livestock on the has more land been brought under the grazing-lands in view of their low carrying plough, thereby reducing the number of capacity results in the overuse of these trees and shrubs but also the increasing lands resulting in depletion of the natural demand for wood has led to an unwise vegetation resources. The population has exploitation of the surplus vegetation often to resort to migration and nomadic sources. Trees and shrubs are put to life for meeting the needs of their livestock. multifarious uses by households, particu­ Studies (Malhotra, 1968) have revealed larly for meeting the requirements of fuel­ that each type of nomad community is wood, housing, fencing, animal feed and associated with some kind of livestock for making ropes and baskets. For making which make an indiscriminate use of the agricultural implements, however, some­ meagre water available and grazing times the timber is purchased, when the resources and nullify the local soil-conser­ local resources prove to be inadequate for vation measures. The nomads in the present the purpose. day are, thus, proving to be a menace to The requirement and the ever-increasing ~h~ whole society and their sedentarization demand is huge and the overexploitation IS Imperative and inescapable. of the vegetal resources is inescapable. The grasslands and pastures (Ahuja and Most of the villagers in the rural areas Mann, 1975) are valuable resources and procure firewood free from their own ~ainly provide fodder and forage for the fields or from unoccupied lands. Digging livestock. Research was, therefore, under­ phog (Calligonum po!ygonoides) is a regular t~ken to establish the prmciples and prac­ vocation and gives employment to a !Ices of better pa_sture ma~agement to large number of people and makes use of Improve livestock productivity which also their camels when not otherwise occupied. Would contribute to the reclamation and The digging of the roots loosens the soil development of the region. and accelerates wind erosion. Unless alternative sources for meeting the fuel VEGETATION RESOURCES needs are developed, the process is likely . Owing to the harsh agro-climatic condi­ to continue and will add to the desertifica­ tIons, the region does not abound in a thick tion of the area.

99 DESERTIFICATION AND ITS CONTROL

The rural population should be encoura­ Paradoxical as it may appear, there has ged to plant trees around their habitations. been a shrinkage in grazing-lands, on the The religious feelings of the womenfolk one hand, and an increase in the livestock should be exploited by having small groves population, on the other. This situation of peepul (Ficus religiosa) trees planted. has led to excessive livestock pressure on It has been observed in the arid-zone grazing-lands and the people have often vil1ages that women pour water on the to resort to migration and nomadism for bases of the trunks of peepul trees at the survival of their livestock. Of the their own initiative, as this ritual is regar­ limiting factors in sheep production and ded as a pious act. Similarly, on the oran animal husbandry in the arid region, lands (lands left for religious temples), inadequate forage and drinking-water are tree-plantation should be intensified, as important because they impoverish the the cutting of vegetation from these lands resources. is religiously prohibited. The tree species, The high biotic interference has consi­ such as Acacia torti/is, Dichrostachys derably influenced the occurrence and giomerata, are well adapted to the arid distribution of vegetation. Also, valuable regions, with low moisture requirement cow-dung, otherwise an excellent manure, and, • hence, can be advantageously used has been always wastefully used as fuel. for social forestry to meet the energy These existing problems cannot, however, demands of rural inhabitantS:t Also there be solved through technology alone. Social is ample scope for harnessing solar energy action and awareness are essential. for its utilization in various ways (Garg, Historically, religions have adapted them­ 1975Y A low-cost solar water-heater and selves to the changing economic conditions solar oven have been developed and if and it is inevitable that adjustments in they are widely used, the shrubs and the outlook, compatible with basic religious trees can be spared to some extent and beliefs, but more in keeping with economic desertification can be partly checked. The demands, must take place, if the resources use of the gobar-gas plants has also been of the arid areas are to be fully used for well demonstrated in the area of the the benefit of the people. operational Research Project adopted in ~he Jodhpur District by the Central Arid­ REFERENCES Zone Research Institute and, in addition to providing good manure, the plant will AHUJA, L. D. and MANN, H. S. 1975. Range­ provide gas for fuel as bonus. It is hoped land development and management in west Rajasthan. Ann. Arid Zone 14(1) ; that the gobar-gas plant will get a good 29-44. popularity in the region. CHAMPION, H. G. 1936. A preliminary survey of the forest types of India and Bunna. CONCLUSION I"dian For. Record New Series, 1(1): 1-204. GARG. H. P. 1975. Solar Energy Utilization It may be observed that with the Research. Monograph No.3. Central Arid­ increase in the working force, the diversi­ zone Research Institute, Jodhpur, June, 1975. fication in adopting occupations other than JAIN, S. K. 1963. The vegetation of Dangs District in Gujarat. Bull. Bot. Survey India cultivation has not occurred, as the region 5 (3 &4): 351-61. " lacks a diversified base. The available JOSHI, M. C. 1956. Plant ecology of Bikaner and proven technology on dry land management its adjacent areas in comparison with the suggests that enormoos potentialities exist rest of western Rajasthan. J. Indian bot. in the arid areas to transform the existing Soc. MANN, H. ~. a!ld SINGH! R. P. 1~75. Crop subsistence or deficit-oriented farming into productIon III the and zone, WIth special th~t :with marketable surplus through reference to western Rajasthan. Ann. Arid SCIentIfic land-crop management, consis­ Zone 14(4) : 347-357. tent with the land-use capability and adop­ MALHOTRA, S. P., BHARARA, L. P. and JOSHI P. L. 1966. Socio-economic characteristics tion .of the .recommended management of inhabitants of Anupgarh-Pugal region. practIces for ddferent land-resources units. Indian Social. Bull. 15(2): January.

100 LAND AND 'RESOURCE UTILIZATION

MALHOTRA, S. P. 1968. Nomads of Indian arid SATYANARAYAN, Y. 1963. Ecology of Luni Basin. zone. Proceedings of the International Geo­ Ann. Arid Zone 2(1) : 82-97. graphical Symposium. SATYANARAYAN, Y. and SHANKARNARAYAN, MALHOTRA, S.P., RAo, J. S., GOYAL, D. and K. A. 1964. Vegetation of Bellary district, PATWA, F. C. 1972. Population, land use­ Mysore State. Ann. Arid Zone 2(1) : 123- and livestock composition in India and its 149. arid zone. Ann. Arid Zone 11(1 & 2): 116- SHANTISARUP 1957. A List of Common Plants of 127. Bikaner and its Neighbourhood. The United MALHOTRA, S. P., JOSHI, P. L. and RAO, J. S. Printers, Jaipur, pp. 1-12. 1974. Relative importance of some socio­ ---, and BHANDARI, M.M. 1957. Progress of economic factors in the adoption of agri­ desert ecology in India during 1950-56, cultural innovation. Indian J. Ext. Education. Rajasthan Univ. Studies Bull. 3: 55-60. NAIR, N. C. and JOSHI, M. C. 1956. Sand-dune SINGH, S. D., SINOH, PANJAB and RAM NIWAS, vegetation of Pilani and its neighbourhood. 1973. Trickle irrigation ensures higher Symp. Vegetation Types of India, Baroda. water-use efficiency. Indian Fmg 23(7): Abst.2-3. 14-17.

101 12 WESTERN RAJASTHAN SOILS: THEIR CHARACTERISTICS AND PROPERTIES

R. P. DHlR

REGULAR surveys of some areas in western results of analysis of some of these concre­ Rajasthan, aided by exploratory traverses tions (Table 1) show that calcium car­ in the rest of the State by various agencies, bonate is by far the major constituent, have furnished valuable data on soil dis­ followed by a small amount of magne­ tribution in the region. But the position sium carbonate. Some of these concre­ of the soils in the major genetic classifica­ tions were subjected also to radiocarbon tions remains yet to be established. dating which showed their ages to be Soils under an autonomous situation are 14,080 and 27,875 years B.P. For obvious devoid of any accumulation of significant possibilities of contamination, these dates soluble salts, with dominant E.C. 1:2 may not be absolute, but these do suggest and pH values of 0.12 to O. 34 mmhos and the ancientness of the formation. 7.8 to 8.7 respectively. The distribu­ Soils that have developed on wind-re­ tion of alkaline earth salts, however, shows worked sediments of major aeolian acti­ an interesting picture. The solum proper vity or recent alluvium are devoid of dis­ is often only moderately calcareous (0.2 cernible pedogenic activity. While describ­ -5 % CaCO.). However, below the ing the monotonous character of tne dune solum at depths of 40 to 120 em, there soil, Abichandani (1964) has indicated starts a pronounced, often sharply diffe­ the occurrence of calcareous nests and rentiated zone rich in alkaline earth car­ crusts in the profile. The present author bonates (5 to 45 % CaCO. equivalent). also observed a catenary sequence in the Much of the free carbonates is present landscape with dunes and with a transect as well as defined, rounded, hard, crystal- from the dune flank to the centre of inter­ - line concretions. This substratum is dune showing an increasing enrichment many metres thick. Roy et al. (1969) with silt, clay and carbonate (Dhir and have 'attributed the occurrence of these Kolarkar, 1974). strata to the ketamorphism in the weathe­ red zone of igneous rocks. The process, Brief description of the major soils of according to them is geologically old, western Rajasthan though it may _be continuing even in The soils of western Rajasthan have been present-day envirop.ment. This obser­ studied from the viewpoint of their classi­ vation may explain the genesis of the zone fication. Raychaudhuri et al. (1963) of carbonate accumulation in peneplains, described the soils of the area as 'Desert but for the vast alluvial plains, the princi­ soils' and 'Gray brown soils'. Follow­ pal process seems to be the redistribution ing Thorp and Smith (1949), Roy and and segregation of the alkaline earth Sen (1968) and Mathur et al. (1972) classi­ sediments deposited along with the silicate fied the medium-textured soils of the old sediments during a major alluvial activity alluvial plains in the 300-500-mm-rain­ under a seasonally dry environment. The fall zone as 'Sierozems' and those with a

102 '" loll 1 loKN KAJAII 1 HAN IIVILII

Table 1. Dilute acid-soluble constituents of carbonate concretions of some arid-zone soils

S.No. Location Na.C03 K.C03 CaC03 MgC03 Insoluble silicate residue %

1. Girab 0·55 Tr 82·40 1·35 14 4 2. Dodo Hills 0·45 .. 74·15 o 95 21·5 3. Jaisalmer 0'55 76·00 3·80 20 9 4. Jaisalmer 3·0 48 25 3·10 45·9 5. Pokaran 0·60 88 05 5·20 3·9 6. Pokaran 0·60 85 15 2 45 13·2 7. Bikaner 0·60 85·45 3 ·15 10·2 8. Jodhpur 0·55 81 25 2 40 16 4 9. Jodhpur 0·55 82·50 2 95 11·2 10. Jodhpur 0·55 74 15 2·90 20'2 11. Jodhpur o 60 84·50 1·35 14'5 12. Jodhpur 0·55 80 35 0·85 19·5 13. Pali 0·60 83·70 5·20 11'1 14. Barmer 0·55 81·25 o 80 16·2 15. Jaisalmer 580·45 65·20 2·0 33·9 less expressed structure in the 200-400- alkaline earth content. The major soils mm-rainfall zone as 'Red desert soils'. recognized on the basis of profile charac­ Light-textured soils of sandy plains were teristics are listed in Table 2. Also given grouped as 'Desert soils'. These latter is the placement of these soils in the soils in the most arid part had earlier USDA and the FAD systems of soil (Mathur et al., 1968) been shown as 'Cal­ classification. cic brown desert soils'. Comparing the Brief description, together with labo­ western Rajasthan soils with similar soils ratory characteristics are as follows: elsewhere, it appears that the former dis­ Dunes are a dominant formation in tinguish themselves by a lower content of 30. 6 % and a subdominant associate organic carbon and a greater expression of in 34 % of the total area. They are

Table 2. Soils of western Rajasthan and their corresponding nomenclatures

Soils identified USDA system FAO/UNESCO

Dunes Typic Torripsamments Eutric Arenosols Light Coarse loamy Typic Calcic Yermosels lirown Calciorthids Sandy Coarse loamy Typic Camborthids Brown Coarse Loamy Typic -do- Light Calciorthids Loam Grey Fine loamy Typic --do- Brown Calciorthids Loam Coarse loamy Typic Calciorthids Hardpan Coarse loamy Typic -do- Paleorthids Sierozem Coarse loamy Typic -do- Calciorthids Fine loamy Typic Camborthids Recent Typic Torrifluvents Alluvial (Coarse loamy, fine loamy) -de}-

N.B. All family names in the USDA system carry prefix mixed, hyperthermic.

103 DESERTIFICATION AND ITS CONTROL mostly coalesced parabolic type, though devoid of any pedogenic features, except longitudinal transverse and barchan types for a very weak segregation of alkaline are also noticed. They are highly sandy, earth carbonates as filaments or nests. with 1. 8 to 4.5% clay, 0.4 to 1. 3% silt, Otherwise, the profile, exhibits a Ulll- 63.7 to 87.3% fine sand and II. 3 to formly structureiess, sandy mass with 30. 3 % coarse sand (Table 3). Alkaline colour at different l'ocalities ranging from earth carbonate is largely present in a pale brown to brown (10 YR 6/3, 5/3, diffuse form, with a dominant range of 5/4 D). The dune landscape has 0.6 to 5.0%, though some in Barmer some accumulative'interdunes with 2.9 (Roy et al., 1969) have been found to to 12.3% clay, 2 1 to 16.5% silt and 1. 5 contain up to 15%. The dunes are to 29.9% free alkaline earth carbonates. J Table 3. Mechanical composition and other characteristics of the arid-zone soils

Depth pH E.C.l :2 Clay Silt Fine Coarse CaC03 Alka- C.E.C. Orga- sand sand equi- line con- me/ nic valent cretions lOOg car- bon %

Dunes 0-15 8·8 0·07 4·2 0·7 81·6 134 5 4 Nil 2·9 0·11 15-30 8'6 0.07 4.1 0.9 83.8 11.2 4.8 " 2.7 0·09 30-60 8·6 0·06 4·3 0·8 84·2 9 8 5 1 N.D. 0·07 60-90 8 5 o 06 4·4 1·4 83 ·1 10·6 4·9 0·07 90-150 8·6 0·06 4·6 0·8 83 5 11·3 5·5 N.D. 150-210 8'5 0·07 4·4 0·9 81·8 13 ·1 6·6 " 0-20 8·4 0·08 5·2 0·9 77·2 16·4 3·2 3·3 0·09 20-45 8·4 o 07 5·1 1·3 77'5 15·8 4·2 2 9 o 07 45-90 8 3 0·07 5·3 1 "1 77 4 16·7 4·0 2·8 o 04 90-135 8·3 0·08 4·8 1· 5 76·0 17 ·3 5·3 2 6 0·04 Light-brown sandy 0-15 8·2 0·09 6 1 4·3 77·8 11·2 1·3 Nil 4·1 0'16 15-40 8·5 0·12 7·0 4'5 77·7 10 6 3·6 " 4·0 0·13 40-120 8'5 0·13 8·8 4 8 74·8 8·2 8·7 1·3 4·2 N.D. 120-190 8·6 0·16 8 4 4'0 74 3 13 2 6·4 6·4 4·0 .. 190-300 8·6 0·16 9·4 5 3 74 0 10·8 7'2 4·8 4-4 Brown light loams 0-15 8·2 0·13 10·4 5·9 73·1 9·6 0·3 Nil 6 9 0·28 15-40 8 3 0·14 13·8 7·3 70·5 8 2 0·3 " 7·2 0·24 40-75 8 3 0'14 14·4 7·5 70'0 8·0 2·1 0·1 7 1 N.D. 75-90 8·7 0·18 12·8 8·3 70·6 7'9 7·8 10·6 6·8 " Grey-brown loams 0-15 8 3 0·24 18 4 12·2 55 0 14·2 0·8 Nil 12 3 0·38 15-60 '8 5 0·27 22·6 13·8 49·8 13·6 1·3 " ]2·0 0·30 60-100 8·6 0·35 19·3 12·6 55 3 12 8 18·6 18 -4 102 N.D. 100 8·8 o 54 18 3 10·5 57-4 13·9 14·2 9·3 10·0 " 0-12 8 3 0·31 25·4 13·7 50 5 10·2 1·3 Nil 17·2 0·45 12-25 8·5 o 37 28·1 12 4 50·0 10·0 3·7 " 19·0 0·40 25-65 8'5 o 41 28·7 11·7 52·2 8 3 5·8 1·3 18·8 N.D. 65-90 g'7 0·73 28·2 13·6 48·3 9·6 15·8 15·8 17·3 " 90+ g'8 0'57 31·3 13·2 43·7 10·5 14·3 17·3 16 8

104 WESTERN RAJASTHAN SOILS

Light brown sandy soils, associated scattered throughout. The thickness of respectively with a few to many dunes, the indurated horizon is more than a metre occur in 34 and 30.6 % of the area. The thick and it is formed by a calcium car­ soils are characterized by a varying hum­ bonate cementation of gravels and con­ mocky surface (3.6 to 6.2% clay, 1. 8 cretions. The stratum is slightly per­ to 3.1 % silt), very weakly .blocky loamy meable to water and difficult for plant fine sand, dominantly brown (10 YR 5/3 roots, particularly for useful top-feed D), sometimes pale-brown (10 YR 6/3), species, the growth of which is severely weakly calcareous subsoil, followed at restricted. HO to 120 cm by a weakly to moderately Sierozems (1.6 %) are a southward eX­ developed zone of alkaline earth car­ tension of a much larger occurrence in bonates (Plate d). The calcium carbo­ the neighbouring Haryana and Punjab nate concretions form 3 to 25 % by States. These soils are developed on weight and, besides their diffused form, the alluvium of the Ghaggar and allied another 5 to 10%. Within this streams. The soils are brown to light dominant picture are found sizeable brownish grey (10 YR 5/3-6/2 D), often patches, apparently associated with old moderately calcareous, very fine loamy drainage lines of soils which have heavier sand or finer with a moderately developed texture and a massive concretionary stra­ blocky structure. At depths of 60 to 120 tum of calcium carbonate. cm is a weekly to moderately developed Brown light loams have prolluvium zone of concretions of calcium carbonate. and alluvium derived from fine-grained The alluvial soils with dunes (6.8 %) sandstone as their parent material. The are of recent origin and are devoid of any soils occupy 1. 7 % of the area and are appreciable pedogenic activity, except characterized by loamy fine sand to fine for some structure formation and some sandy loam, brown, weakly blocky sur­ redistribution of alkaline-earth carbonates. face, a slightly heavier, darker (10 YR The profile is often stratified with large 5/4 D), calcareous subsoil, followed at 40 variations in particle size. Soils in the to 90 cm by a zone of lime concretions. north-west are often saline sodic and cal­ The grey brown loams occupy 13. 6 % careous. They are interspersed with dunes of the area and occur in the alluvium and and hummocks. Besides these, hills and weathering zone of medium and fine­ pediments, often partly buried under sand grained sedimentary rocks in the south­ (Regosols and Lithosol), form another eastern and central parts. These soils are 5. 6 %. There is a small area under saline devoid of wind-worked deposits and have depressions. apparently escaped the deflation breakdown SOIL FERTILITY CHARACTERISTICS experienced on other landscapes. Soils def­ f lation are dark greyish brown to brown Clay mineralogy. Krishnamurti and (10 YR 4/3, 4/3, 5/3 D), moderately sub an­ Narayana (1968) studied soil profiles gular blocky, sandy loam to loam on the from seven localities in the rainfall_ zone surface. The subsoil is heavier with a of 450 to 170 mm and a summarized form well-developed sub-angular blocky struc­ of their results is given in Table 4. ture. It is followed by a zone of calcium This finding shows that illite is the pre­ carbonate as concretions and as coatings dominant mineral in all soils. The grey on gravels (Plate e) .. brown loams are the only exception Soils with hard pan (5.9%) are brown where montmorillonite dominates and this (10 YR 5/3, 5/4 D), generally light-tex­ condition was attributed by the authors to tured, with a hard, largely indurated pan advanced weathering under a higher rain­ at depths of 40 to 80 cm. At places, the fall. Attapulgite has not been reported hard pan is close and even exposed. from any Indian soil, whereas it is present The major area of the soils is located in the in all the arid-zone soils, except in these central part, though small pockets are in the -450-mm-rainfall zone. Table 5

105 DESERTU'ICATION AND ITS CONTROL

Table 4. Clay mineralogy of the arid-zone soils

Mean clay mineral composition in % Soil group Rainfall in mm Montmorillo- Illite Kaolinite Attapulgite nite'"

Grey-brown loams (1) 450 60 25 10 Light-brown sandy soils (4) 280-350 25 52 10 ' 13 2 170 20 50 10 20

"'Non-expanding type, except on the surface of gre} brown loams

gives the C.E.C. values of the clay frac­ They found that whereas the bare dunes tion of some soils in the arid zone from had around 0,03 % organic carbon, the the work done in the Pedology and Sur­ vegetation-stabilized dunes had 0, I %. vey Section of the CAZRI, and these The former, however, had 70 to 100 ppm values also suggest the dominance of an of mineral nitrogen, whereas the latter illite-like mineral in the soils. had only 45 to 65 ppm of it. Aggarwal et al. (1975) have also found that in a Table 5. The cation-exchange-capacity val~es of 300-400-mm-rainfall zone, the CjN ratio clays in some arid-zone sOlIs varied from 7. 9 to 13 in the surface soils and from 3. 9 to 7,2 in the subsoil. Their Number Range Mean results also showed that among the various of nitrogen fractions, amino acid and samples unidentified fractions dominated. The mean percentage values for the amino Dunes 4 36-45 42 acid (unidentified), ammoniacal and hexa­ Light brown sandy 12 38-49 43 samine fractions were 18.8 to 40.0, 14.1 Brown light loams 10 38-52 45 to 50,0, 3.1 to 9.4 and 0.8 to 3.1% Grey brown loams 24 45-70 61 Recent alluvium 6 38-45 42 respectively. Comparing the results with those of other tropical soils, the authors found a higher relative concentration of Organic matter. Jenny and Ray­ the amino-acid fraction in the arid zone chaudhuri (1960) during an excellent study soils. have brought out the effect of climate and Phosphorus. Ram Deo and Ruha! , cultivation on the nitrogen and organic­ (1972) reported that light-textured soils carbon status in the soils. They have of the arid zone had 285 ppm of total phos­ also emphasiied the role of texture. In phorus as compared with 327 to 450 ppm Fig. 1 are plotted the data on organic in the soils of the semi-arid zone of Rajas­ carbon in relation to the clay content. than. Pareek and Mathur (1969) also The results show that with the rising clay reported comparable values in respect of content, there is a sharp rise in the organic­ the arid zone soils. In the extreme carbon content an'd that the soils in north-west, the soils developed from the the 300-450-mm-rainfaII zone have a Indus and the Ghaggar alluvia were found slightly higher content than the soils in to have higher values of 408 to 716 ppm the below 300-mm zone. Aggarwal and of phosphorus (Talati et al., 1975). Phos­ Lahiri (1976), while bringing out the low phorus occurs in a variety of forms, fixed organic carbon of the dune soils, in gene­ with varying intensity, to the-individual ral, have shown a difference owing to the soil constituents. The above studies also degree of colonization by vegetation. showed that 40 to 50 % Qf total phospho-

106 WESTERN RAJASTHAN SOILS

0.7 '

0.6 . / 0,5 /.

" " ~ t: 0.4 " x -- 0

-2 1( Ill, o x U x 0 "

::! o. x t: rIII " 0 0.3 "

J( 0'

0.2

", 0,1 Rainfall zone 01 < 300 m =- XXx 300 .500 mm =....

10 20 30 Clay 'Y~ Fig. 1. Distribution of organic carbon content in .relation to clay percentage in arid zone soils

107 DESERTIFICATION AND ITS CONTR,OL rus in the arid-zone soils, in general. and potassium which gives the soil a capacity up to 72 % in the G~aggar alluvium to withstand depletion, constitutes 8 to soils is bound with calcIUm. This frac­ 15% of the total. Lodha and Seth (1970) tion is proportionately more in the arid­ and Chaudhri and Pareek (1976) found zone soils than in the adj oining soils of the that the reserve potassium and the total semi-arid zone. However, these soils potassium are correlated with the silt still contained appreciable amounts of and sand fractions respectively in the soil. aluminium and saloid-bound phosphorus, This finding, together with mineralogical which have been found (Ram Deo and composition, reported earlier shows the Ruhal, 1972; Sacheti and Saxena, 1973) presence of large potassium reserves in the to be correlated with the available phos­ arid-zone soils: Besides, the potassium­ phorus content. This condition may ex­ fixing capacity (Lodha et 01., 1976; plain the presence of a fair amount of (Chaudhri and Pareek, 1976) has been available phosphorus in the arid-zone found to be lower in the arid-zone soils soils, despite soil calcareousness. The than in those outside, largely because of results of available phosphorus status the lower clay content of the soil. of the arid-zone soils are dealt with Micronutrient status. Seth et al. (I 97 I) elsewhere in this paper. The amount of found that the total manganese content added phosphorus that becomes available in the arid-zone soils ranged from 212 to plants is dependent upon the fixation to 437 ppm. Of this amount, on an capacity of the soil. Dhawan et 01. average, 32 ppm and 6 ppm were in the (1969) showed that the arid-zone soils reducible and available forms, respectively. fixed O. 87 to 1. 35 g, with an average 1.053 Mondal (1965) also reported similar values g of phosphorus per 100 g of soil, and this in respect of the arid-zone soils. The amount was quite high. However, Ram values of reducible and available forms Deo and Ruhal (1972) found that the were lower than those of the soils outside buffering capacity or the amount of phos­ the arid zone, though adequate for plant phorus that needs to be added for a unit nutrition according to the existing criteria increase in intensity in the arid-zone soils of 20 and 5 ppm respectively. Sand­ was less than half that found in the adjoin­ dune soils are seen to have lower contents ing soils. This situation is advanta­ of available and reducible forms than geous, since a smaller amount of phos­ other soils. phorus will be needed to raise its concent­ Copper. The total copper content of ration in the labile pool and also that the soil profiles at Jodhpur varies from even lower values of phosphorus in the 10 to 11. 5 ppm (Mondal, 1965) in all the soil will be adequate for a good growth of layers up to 170 cm. Seth et 01. (1971) crops. reported that the total copper content of Potassiu11l. Soils of the arid zone are the Rajasthan soils ranges from 19.6 to generally well ,supplied with potassium. 228.48 ppm, with a lower value (64.99 Dhawan et 01. (1968) and Chaudhri and ppm) for desert soils. The available Pareek (1976) have shown that with the copper varies from 0.21 t6 4.28 ppm exception of a few localities, the total and, in general, the arid soils are not low potassium is between 825 and 1890 mg/IOO in this element. However, Lal and g of soil, and this amount compares Biswas (1973) reported O. 12 to 0.28 favourably with the mean value of 806 ppm of available copper in the Rajasthan mg/IOO g of the Rajasthan soils as a soils. whole. Water-soluble and exchangeable Zinc. Seth et 01. (1971) and Lal and potassium together form 1. 5 to 2 % of the Biswas (1973) observed that the total total potassium and, therefore, by far the zinc content ranged from 5.0 to 95.2 major proportion is present in a non­ ppm and the available zinc from 0 to 4.83 exchangeable fixed form or partly as a ppm in the Rajasthan soils. On an primary mineral lattice. The reserve average, 2. 07 ppm of available zinc had

108 WESTERN RAJASTHAN SOILS

been reported in the arid soils, and this for the mustard and wheat plants were amount is sufficient for normal plant between 0.9 and 1.4 and between 0.71 growth as per accepted norms. , and O. 85 respectively. Iron. Mondal (1965) reported,' a dec­ The salinity-alkali /)foblem. Though rease in the water-soluble iron content the ground waters and substrata contain with the depth from O. 95 ppm for the .0·20 a large concentration of dissolved salts, em layer to 0.03 ppm in the surface layer salinity in the solum proper is fortunately below 170 cm. Lal and Biswas (1973) a localized feature. Its occurrences are observed the available iron to range from associated with (i) the natural salt basin 0.3 to 5.6 ppm in the Rajasthan soils and playas, (ii) the flood plain of the Gha­ and it was low (2 ppm) in the desert ggar and the Luni systems, (iii) the close­ soils. ness of the saline-sodic waters due to the Boron. The water-soluble boron in recent tampering with the natural drain­ desert soils varied from l. 9 to 12.2 ppm age, and (iv) irrigation with highly saline (Satyanarayan, 1958) and slightly increased waters. The approximate area occupied with the depth. Seth et al. (1971) repor­ by each of these areas is as follows (Table ted that the boron concentration in the 6). desert soils, undifferential alluvium and grey brown soils of the river basin, in Table 6. Saline-infested areas general, was higher (0 5 to 8.2 ppm) than the safe limit. They observed a Area in % of the significant correlation of available boron sq. km total area with pH, but the organic carbon and of western CaC03 contents of the soils were not Rajasthan related with it. Nathani et af. (1970) also observed similar ranges for the (i) Major salt basins 431 022 Rajasthan soils. (i1) Flood plains of the Sulphur. The total sulphur content of Ghaggar and the sierozems, alluvial and desert soils ap­ Luni river systems 2434 1'24 (iii) Salmity due to the peared to be higher (Joshi et al., 1973). recent rise in saline This higher content may be attributed to ground waters 559 o 28 the inorganic forms. In desert and (iv) Irrigation with saline sierozem soils, the organic sulphur con­ sodie waters 1722 0'88 tent ranged from 50-180 ppm (30-50% of the total sulphur). Sulphur in the Of these, salinity due to the use of saline sulphate and non-sulphate forms were water is by choice, since the system has highest, up to 200 ppm, in the arid soils some distinct advantages which out­ When compared with 70.160 ppm in the weigh the limitations. Some of the salt adjoining soils and constituted the major basins serve as a major industry. In the part of the total sulphur. The available other two categories, salinity is a pro­ sulphur content of the desert soils ranged blem, particularly since either the area from 40 to 133 ppm. Joshi et al. (1973) falls in the command of the ongoing irri­ and Joshi and Seth (1975), while working gation projects or had once been produc­ to determine the interaction between sul­ tive or deteriorating. Considerable work phur. and phosphorus in the .soil and in has been done in characterizing soil the mustard and wheat crops indicated salinity. The analysis of 205 soil samples that there was an increase in the available (the Rajasthan Department of Agricul­ SUlphur and available phosphorus con­ ture, Agricultural Chemistry Section, tents of the soils due to the application 1970-71) showed that 26 3, 20.1, 17.5 of SUlphur to all loamy-sand soils. But and 36. 1 per cent of soil samples had a higher sulphur uptake depressed the E.C. of the saturation extract less than :P uptake. Tht! most effective SIP ratio 4, 4 to 8, 8 to 12 and over 12 mmhos

109 DESERTIFICATION AND ITS CONTROL

respectively. The analysis of 103 sam­ measured from the moisture equivalent, ples collected during the soil survey of the show as vast range from 3.3 % by weight Bikaner District by the CAZRI also sho­ in the dunes to as high as 25 % in some wed high salinity in the flood plain as well of the grey brown ]oams. Kolarkar as in the playas. In all, except 9 % and Singh (1971) have shown the depen­ of the samples, salinity was of sodium dence of this property on the clay plus silt chloride or sulphate type, with nearly content of the soils. Besides, the total 33 per cent showing significant quantities moisture retained in the soils depends on of calcium sulphate. Mehta et al. (1969) the soil depth, as limited by the presence have analysed the reclamation problems of hard pans, which are often somewhat of these soils and have showed the scope pervious to water, but less so to the roots of leaching, amendments and the use of of annual plants. In some playas soils, fertilizers in well-drained situations. the low intake rate limits the entry of the rainwater itself. THE AVAILABLE NUTRIENT STATUS 40 Since the establishment of the soil testing service as part of the farmers' atlvisory programme of the Rajasthan State Department of Agriculture, valuable 30 data have been built up on the soils of the arid zone. Results of these activities are presented ~ ., 20 in Tables 7a, 7b and 7c. The results -:; ~ show that by far the majority of the arid­ '0 zone soils test low in organic carbon or :? available nitrogen. As regards potassium 10 GajSlnghpur9 a negligible percentage of samples falls in the low category, the rest being in medium ~ ~~-:.-_-=:~-:. -_-= ==* ______-<> Chlral or high categories. Concerning phos­ - ---- Ouna phorus, the picture is variable. Whereas o 5' 10 15.' in some areas, the soils are dominantly TenSion ATM low in phosphorus, in others they are Fig. 2. Soil moisture-tension relationship of some medium or even high in this element. soils. Chirai and Gajsinghpura soils belong to light brown sandy and grey Moisture-retention and conservation brown loams respectively properties The light-textured soils, whereas having The .field-capacity values of soils, as low retention, have the ability to make

Table 7a. The available-nutrient status of the soils in the surveyed areas (CAZRI)

The number of Organic carbon Available phosphorus Available potassium Block s::tmples Low Med- High Low Med- High Low Med- High ium ium ium

Saila 179 84 5 7 ·1 8·4 56'2 35'6 8·2 11·0 59 3 29·7 Ahore 65 84·6 10 8 4 6 79 4 20·6 41·2 58 8 Chohtan 18 100·0 94·1 5·9 - 35 3 35· 3 29·4 Balotra 24 87'5 4·2 8·3 50 0 29'2 20·8 4·2 37 5 58·3 lalore 104 88·9 ]0·2 0·9 5] ·3 43·3 5 4 28·2 46·2 25·6 Luni 102 96 2 3·8 37 1 59'1 3·8 20 0 75 8 4'1 Bikaner District 75 98·7 1·3 41 ·8 41·8 16'4 4·0 52 0 44·0 Jodhpur District 402 97·8 1 5 o 7 56 6 40 1 3·3 23·3 70·7 6·0

110 WESTERN RAJASTHAN SOILS

0 0 0 o...... 0 s "? 0 \0 ....,\0 I-'~ 00 6 0 ~ t'l 0 ::r:~ <'I '"' on '

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III DESERTIFICATION AND ITS CONTROL

>. ~o 8 8 ;::J ..c: : : >. :atlll :I:

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112 WESTERN RAJASTHAN SOILS

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OjO _ ~~-a ""0 .2 '0 e:.,;:: ~:~ ; "OC ~O~~d ,5 ~§ 0) e: oj:;:; ;::::I'P Q) C;~ e: ~~ .. ~ 0 ~d'~ ..9.9.5 o'p d ._;,;..ct#-t:: oj .. 8 -e: ",8 ., ",0" .S g::o "'oj 0 .... ., '" -Cd"c_ ~-to-l ::s~ c:O c 'E"'O 'v] ~ ..§ ~~.o 'O~ .... ~cUt;a at> 8c 8EB d'- ::l d52:;:; 00'" ~§elI 0"" o ::l'_ .... s <;; a~~ u .... 0 j~ CI.lEi CI.loil= -<::.::: c ~ 8 oj ~ rI.ldd o.e. < &.9 .3 g ll.. fa V V ~ '- >. ~ ~ .S 0 .:.= 8 c 0 (.) ..9 ° 03 e::s oi 0 ~oj :§ V <3 ,.Q .... ~ '" .c 0 0) <3 .. c: Ei ~ '" :0 V Ei .... '" ~ -0 j 0 i5 t) t:i ::l "0 c 8 ~ ~ ~ ..c:: c E oj .....11> .,'" ~ 0 g oj '" Vi c 0 ..::- '" .... c '" ..c:: c 0", .... '0 t£ .g OIl '"A "0 ..... ed !IJ .~ c: cr0 .2 .s ..c:..... :.a 2 oC: '"c o;S .;;; 8 2 0 <1) :::s e~ c: .... 8... ] "0 -5 0 "0'0 -B .9 ...... c .~ "0 C.~ .... '0 0 " d .S >. O;e. '" c =0 .:.= S ~'" S .~ •Oil f s= c ~ c"o 0. oj .:.=.9 0 ._ .... !IJ 0 '<;; ., 0'" ::s'" ~ .... E cO'" 2 "0 "0 ~ 0 cd ,_ ... 0 !IJ... 0>"' ... Z ., ... '0 !IJ . '6 ._ oj ~~ dc ~ ;.'_~] c= do ",._ ~ .S 0) ..c::;:; ~.g ",0 <~=CI.l'O ~~ ;2;£ CI.l.c: CI.l", til'" z.g ii: ~~ Z DESERTIFICATION AND ITS' CONTROL available the bulk of the stored moisture, REFERENCES as may be seen from the moisture-release ABICHANDANI, C. T. 1964. Genesis, morphology curves in Fig. 2 (Courtesy, Dr H.P. Singh, and management of arid zone soils. Proc. Soil Physicist). Symp. Prob. Indian Arid Zone, Jodhpur, The light-textured soils have also the 122-28. property of conserving moisture in face ABICHANDANI, C. T., KRISHNAN, A., BHATT, P. N. and RAKHECHA, P. 1967. Some obser­ of strong atmospheric moisture deficit, vations on soil moisture changes in arid zone amounting to over 2,000 mm per year. soils. J. Indian Soc. Soil Sci. 15 (1) : 7-15. Abichandani et al. (1967) observed that AGGARWAL, R. K., DHIR, R. P., BHOLA, S. N. and KAUL, PRAMILA 1975. Distribution of such a soil kept as a bare fallow lost only nitrogen fractions in Jodhpur soils. Ann. 67 mm of the stored moisture during the Arid Zone 14 (2): 183. year. Out of this amount 75 % loss was AGGARWAL, R. K, and LAHIRI, A. N .. 1976. from the top 30 cm and the soil below Evaluation of soil fertility status of stabi­ lised and unstabilised dunes of Indian 30 cm remained close to the field capacity desert. Agrochimica (In press). throughout the year. CHAUDHARI, J. S. and PAREEK, B. L. 1976. Ex­ changeable reserve potassium in soils of Aggregation and erodibility Rajasthan. J. Indian Soc. Soil Sci. 24: 57-61. DHAWAN, S., PAREEK, B. L. and MATHUR, C. M. The author's observations on a light­ 1968. Forms of potassium in Rajasthan t'extured soil, having 7.4 %clay and 6.2 % soils. J. Illdian Soc. Soil Sci. 16 (1) : 55-60. silt, show that upon sieving for two min­ DHAWAN, S., SETH, S. P. and MATHUR, C. M. utes, it had 8.9+ 2. 2 %soil mass in aggre­ 1969. Phosphate fixing capacity of Rajasthan soils. J. II/dian Soc. Soil Sci. 17 gates over 5 mm, and 16.7+ 4.1% in (1) : 487-91. aggregates over 2 mm. In comparison, DHIR, R. P. and KOLARKAR, A. S. 1974. Obser­ the dune soil, with 3.2-4.5% clay and vations on genesis and evolution of arid zone 1. 1-3 % silt was devoid of such an aggre­ soils. Proc. Symp. Soil Genesis, Classifi­ cation al/d Land Management, Indian Soc. gation, indicating the significance of a Soil Sci. Calcutta small increase in fine particles. The JENNY, H. and RAYCHAUDHARY, S. P. 1960. Ef­ importance of soil texture in imparting fect of climate and cultivation on nitrogen stability against wind erosion was also and organic matter reserves in Indian soils. Indian Council of Agril. Res., New Delhi. seen in the absence of hummocks and the JOSHI, D. C., SETH, S. P. and PAREEK, B.L. piling up of loose sand in certain soils. 1973. Studies on sulphur and phosphorus The results of such observations on lands uptake by mustard. J. Indian Soc. Soil Sci. under rainfed farming for many decades 21 (2) : 167-172. JOSHI, D. C. and SETH, S. P. 1975. Effect of are given in Table 8. With the clay con­ sulphur and phosphorus application on soil tent over 15%, the erosion features totally characteristics, nutrient uptake and yield of disappear. The only exception is a soil wheat crop. J. Indiall Soc. Soil Sci. 23 (2) : with an extraordinarily high amount of 217-21. KOLARKAR, A. S. and SINGH, N. 1971, Moisture particles over 0.2 mm. In that soil, storage capacities in relation to textural in spite of a higher clay content, fence­ composition of Western Rajasthan soils. line hummocks are seen. Ann. Arid Zone 10 (1) : 29-32. KRISHNAMURTI, G. S. R. and NARAYANA, M. R. THE NATURE AND EXTENT OF 1968. Clay mineralogy of a few desert LAND HAZARDS soils of Western Rajasthan. Indian J. agric. Sci. 38 (6) : 945-49. Wind erosion is particularly more dama­ LAL, F. and BrswAs, T. D. 1973. Factors affecting ging where the s.oil depth is already a the distribution and availability of micronu­ limitation because of the closeness of the trient elements in major soil groups of Rajasthan surface soils. J. Indian Soc. hard strata, and the arid zone has a signi­ Soil Sci. 21 (4): 455-66. ficant area of such soils. Table 9 gives an LODHA, R. K. and SETH, S. P. 1970. The indication of the extent of the area affected relationship between different forms of by various limitations in some of the dis­ potassium and particle size in different soil groups of Rajasthan. J. Indian Soc. Soil tricts surveyed. The results show that Sci. 18 (2): 121-6. wind erosion is by far a major hazard. MATHUR, C. M., GANU. S. N., MOGHE, V. B. and

114 WESTERN RAJASTHAN SOILS

JAIN, S. V,' 1972. Soils of Rajasthan. Soil of Rajasthan. Ann. Arid Zone 7 (1) : 1-14. Survey Org. Dep. Agric. Rajasthan. Roy, B. B., CHATTERJI, P. C. and PANDEY, S. 1969. MEHTA, K. M., MATHUR, C. M., SHANKARNARAYA­ Genesis of carhonate pan in arid region NA'I, M. S. and MOGHE, Y. B. 1969. Saline­ of Rajasthan. Ann. Arid Zone 5 (2) : 181-7. A}kali Soils in Rajasthan-Their Nature, SACHET!, A. K. and SAXENA, S. N. 1973. Rela­ Extent alld Management. Dep. Agric. Rajas- tionship between soil characteristics and than, Research Monog. 1. - various inorganic phosphate fractions of NATHANl, G. P., SHANKARANARAYANA, H. S. and soils of Rajasthan. J. Indian Soc. Soil Sci. 21 MATHUR, C. M. 1970. Status of water­ (2) : 143-8. soluble boron in soils of Rajasthan. J. SANGHI, C. L., LODHA, B. K. and JAIN, S. V. 1976. Indian Soc. Soil Sci. 18: 341-44. Morphology and soil fertility of western PAREEK, B. L. and MATHUR, C. M. 1969. Rajasthan (Jodhpur district). Ann. Arid Available and total phosphorus status of Zone 15 : 23-8. soils of Rajasthan. J. Indian Soc. Soil Sci. SATYANARAYAN, Y. 1958. Water-soluble boron 17 (1) : 147-9. in some desert soils of India. J. Indian Soc. RAM -DEO and RUHAL, D. S. 1972. Status and Soil Sci. 6: 223. availability of phosphorus in calcareous SETH, S. P., BHATNAGAR, R. K., NATHANI, G. P. soils of Rajasthan. Indian J. agric. Sci. 42 and ZAMAN, Q. U. 1971. Micronutrient (4) : 316-20. status of Rajasthan soils. Soils Sci. Pl. Natur. RAYCHAUDHRI, S. P., AGARWAL, R. R., DATTA 17 (1) : 15-9. BISWAS, N. R., GUPTA, S. P. and THOMAS, TALATI, N. R., MATHUR, G. S. and ATTRr, S. C. P. K. 1963. Soils oj India. Indian Council 1975. Distribution of various forms of of Agricultural Research, New Delhi. phosphorus in north-west Rajasthan soils. Roy, B. B. and SEN, A. K. 1968. Soil map J. Indian Soc. Soil Sci. 23 (2) : 202-6.

115 13 GEOMORPHOLOGY, SOIL AND LAND USE IN DESERT REGIONS OF GUJARAT, PUNJAB J AND HARYANA

R. S. MURTHY AND S. PANDEY

.ALTHOUGH a major part of the hot GUJARAT Indian desert falls,in the west of the Rajas­ than State, the adjoining areas of the Geomorphology .States of Gujarat in the south and the Hills of moderate heights, pediments, Punjab and Haryana in the north also mud flats, saline flats and sandy plains form the constituent parts of the desert. (Plates f, g) constitute the dominant land­ According to Krishnan (1969), the Guja­ forms. The hills are made of sedi­ rat part consists of 62,180 km2, i.e., nearly mentary rocks of the Jurassic period 20 per cent of the total desert area of the lapped by the Deccan traps (the Deccan country, extending to the districts of lavas-basalts) and the sediments of the Ter­ Banaskantha, Surendranagar, Rajkot, tiary period. The sedimel1ts were deposit­ Kutch and Jamnagar. Deserts occupy ed in the shallow basin of the marine en­ an area of 14,510 km2 or about 5 per vironments. This region, according to cent of such area in the Ferozepur and the observations of Adyalkar (1964) and Bhatinda districts of the Punjab State. Wadia (1966), was in the grip of stupen­ Likewise the southern parts of Hissar, dous marine activities during the Jurassic, Rohtak, Bhiwani and Sirsa districts Upper Cretaceous and Miocene periods. of Haryana account for an area of The Jurassics are resting over the Pre­ 12,840 km2 or4 percent of the total desert Cambrian basement bordered on the south area. by the Deccan traps and the Tertiaries, and The Indian hot desert has 19 million on the north by the Ranns. They occupy . people as per 1971 Census. Of this popu­ t]1ree anticlinal ridges trending east-west, lation, IS per cent live in Gujarat, 14 per and owing to parallel faulting the whole cent in the Punjab and 10 per cent in sequence is repeated. While the northern Haryana. Most of them .are cultivators 160-km range is broken up into 4 islands and agricultural labourers. About 28 per of Patcham, Karrir, Bela, and Chorar .in cent are engaged in other occupations, the Rann, the middle range, which is 165 such as the salt industry and stone-quarry­ km long, extends from Lakhapat east­ ing (Malhotra et al., 1972). south-eastwards and the southern ridge In Gujarat, three kinds of de~erts are south of Bhuj, 65 km long, occupies identified. They are salt desert, clay desert Charwar and Katrol hills. In between and stone desert whereas in the Punjab Bhopalka and Baradia are the lateritic and Haryana. only the sandy desert is formations. This is the product of the commoner. Each of these deserts has sub-aerial alteration of the basalts. The certain features unique of its own in Deccan-trap region consists of small hills respect of geomorphology, soil and land of basalts and clusters of dykes and sills use in the respective States. These are of low heights throughout the districts of describeq below: Jamnagar, Rajkot, Surendranagar and

116 Plate g. Pediments formed along the hilts of Bhuj area

Plate h. Desiccated unbroken surface of dark silt incrusted with salt Plate i. Animals graze over almost bare surface

Plate j. Typical soi I profile jn sandy tract GEOMORPHOLOGY, SOIL AND LAND USE southern part of Kutch. as 94.6 in the upper horizori is a reflection The pediments with thin cover of coarse of coarser material in the soils. The soils detritus have developed over the above are non-calcareous. They are neutral' to rocks. They are mostly flat, except near mildly alkaline and have good drainage. the hills where the slopes vary from 3° to The soils are sandy and they show a go. The evidences of desert varnish are very high permeability (58 em/hr). The also met with. maximum water-holding capacity is about There is extensive coastal tract stretch­ 25 per cent; the field capacity is 12 to 15 ing from Lakhapat to Okha interspersed per cent; the pore space is 45 per cent and with the several creeks. Owing to silta­ the expansion is 3 per cent. tion and uprising of the continental . Roy et al. (1971) have described light­ shelves, mud flats have been formed. The textured deep soils in the Banaskantha tides affect these flats by inundating them District. They are calcareous throughout. almost every day. The mud flats are un­ (2) Medium black soils. Being derived stable land surfaces remaining almost from the basaltic trap, the depth of the wet throughout the year. soils varies from a few ceritimetres to The saline flats which.are known as the about 0.6 metre or more and, as such, at Great Rann of Kutch and the Little Rann some places they are very shallow and of Kutch were once part and parcel of the can thus be termed even shallow black Arabian Sea. Presently, they have been soils. They are calcareous imd residual silted up by sediments of finer texture by in character, except in low-lying the Luni, the Banas, the Saraswati, the areas. A lilyer of murum (decomposed Rupen, the Phulka, the Bambhor, the trap) is found at a depth of !'A to 0.6 Machhu and several other small streams metre. Carbonate concretions are found draining into them. It is a vast desiccated throughout the depth of the profile. The unbroken bare surface of dark silt incrust­ colour varies from dark grey to light grey. ed with salts (Plate h). They cover about The soils are clayey though clayey 2~ lakhs of hectares. loams are also common. The soil is The sandy plains are mostly found near neutral to alkaline, with calcium carbo­ the dry beds of the ephemeral streams. nate ranging from 3.56 to as high as 22.56 The sand cover is of limited depth. These per cent in different horizons of the pro­ plains are not so extensive as those formed file. Calcium is the dominant exchange­ in other parts of the desert in the country. able cation, followed by magnesium. The streams originating from the up­ Sodium and potassium, although present lands,are very few. They are shorter in to some extent on the surface, have a length. Water flows only when there is tenden~y to increase with depth. The con­ rainfall in the catchment. tents of silica (acid-insoluble), alumina and iron are fairly constant. Soils (3) Dark heavy-textured soils. In depres­ Roy et al. (1971) and Kanzaria (1972) sional areas and also in small pockets, the have classified the soils of the desert lracts top soil is a dark heavy clay which is of Gujarat into the following: underlain by light-coloured sand or loamy (1) Sandy soils. These soils include sand. The soil has been formed by the loamy sand to sandy loams in the upper washing of the fine clay particles into the horizon, with a considerably high percen­ low-lying areas. There is thus a distinct tage of coarse fractions. The fine demarcation in the profile between the material has been leached to lower hori­ original sandy soil at the bottom and the zons, as revealed by the accumulation of dark clay soil on the top. This deposition clay. The exchangeable bases are much horizon is variable in thickness from 20 less than those in black soils because of cm to at least a metre or so. Being situa­ the low percentage of clay. The percentage ted in the low-lying position, the soil has of silica (aci.d~insoluble) which is .as high developed salinity of varying degrees.

117 DESERTIFlCATION AND ITS CONTROL

A typical soil profile is described below: per cent. Calcium is the dominant cation 0-20 cm Dark-greyish-brown to very in the clay complex. The saturation of dark-greyish-brown clay; strong sodium in the clay complex has raised angular blocky structure; dry the pH to 9 in some layers. and extremely hard; strong (6) Shallow skeletal or lilhasalie soils. effervescence with HCI. The skeletal and lithosolic soils derived 20-28 cm Greyish-brown to dark-greyish­ from ferruginous sandstones, limestones, brown silty clay; prismatic shales and basalt are found on the pedi­ structure breaking into strong ment. These are reddish-brown shallow angular blocks; dry and ex­ soils of light texture. In pockets, however, tremely hard; strong efferve­ the soil is of sufficient thickness to permit scence wlth HC!. cultivation. 28-45 cm Pale-brown to dark-greyish­ (7) Deep gravelly soils in the foothills. brown silt; no structure, slight­ These soils are sandy loams but are mixed ly moist and plastic; strong with gravel which distinguishes them from effervescence with HCl; white the light soils in the region. The water­ crystals of salt present. retention capacity is low. The soils are 45-60 cm Pale-brown to brown loamy susceptible to water erosion. sand impregnated with white salt crystals; no structure; some­ Land Use what moist. Cultivated lands are limited in extent. Where salinity is not high, cultivation is As reported by Malhotra et al. (1972), practised. the land classified under non-agricultural (4) Coastal alluvial soils. Occurring as uses and the barren and un·culturable a narrow strip these soils are formed from waste occupy nearly 58 per cent and a mixture of black clayey material and old the net sown area is about 28 per cent of marine silt deposits; they are fairly deep the arid region of the State. The culturable sandy clay loams. They are calcareous; waste takes the share of the rest. Th~ posi­ both the' exchangeable and the total cal­ tion of pasture and grazing lands is not cium are high; so are iron and alumina. encouraging. Animals graze almost on bare The maximum water-holding capacity is surface (Plate i). The double-cropped about 35 per: cent; the field capacity is 15 area is negligible, except along the valleys per cent; apparent specific gravity is 1.433, where groundwater has been tapped and the pore space is 47 per cent, expansion is used for irrigation. The major crops 8 per cent and the downward movement grown, with poor yields in this tract, are of water is 2'7 cm/hr. bajra, jowar,. groundnut and cotton. (5) Saline soils. ~aline soils occur along Wherever water is available, wheat and the seacoast formed owing to the effect of sugarcane are grown. tidal water. The Bhal tract is the area • ·with a ·flat topography formed because of PUNJAB AND HARYANA the alluvial deposits brought by the rivers Geomorphology flowing into the Little Rann. The area under the Little Rann is 3.5 lakh hec-_ The areas affected by desertification in tares. The area under the Great Rann is the States of Punjab and Haryana are 15.7 lakh of hectares. With the turning sandy and consist of sand-dunes of diffe­ of tides, when water comes to a standstill rent types and low barren hills. Along the for a short while, the silt contained in streams, marginal flood plains have deve­ tide water is deposited as a thin film over loped. Most of the dUnes are of low a large ar~a. This process, continued over heights, except in individual cases where the years, has created saline conditions the heights may go up to 20 metres. in the soil of the Bhal tract. The salt con­ The dunes are almost barren. The tent varies from 1.5, to as high as 5.7 barchan dunes of low height are being

118 GEOMORPHOLOGY, SOIL AND LAND USE

formed on the flat alluvial plain. ,loams are very deep and well-drained. The The residual hills of the Aravalli . soils are calcareous (Plate j). Range are noticed at places in the Haryana State. Saline lands 'are also found Land Use I in scattered patches. According to Malhotra et al. (1972), the The streams remain almost dry, except net sown areas are about 85 per in the rainy season. Despite their origi­ cent in the arid tracts of both the nating from the Himalayas, they die out States. The double-cropped areas are in the desert sands. nearly 24 per cent in Haryana and 21 per cent in the Punjab. Owing to increased Soil irrigation and power facilities, additional The soils of this region have been stu­ areas are brought under double and triple died and described by several workers, crops. Cotton is the primary crop in the e.g. Roy et al. (1970), Sidhu et al. (1972) western part and gram in the eastern part. and Sekhon et al. (1972). Mostly, sierozem During kharif, baira is the principal crop. and desert soils are found, to occur. Wheat and sugarcane are grown where (1) Sierozem soils. According to Sidhu irrigation facilities are available (Plate k). et al. (I972) these soils are found in parts of Rohtak, Hissar, Sirsa, Bhiwani and Conclusion Mehendragarh districts receiving 300 to The process of desertification being the 500 mm of rainfall in the year. The pH same, the desert conditions in terms of ranges from 8.0-8.6, CaC03 is 1. 84 %, geomorphology, soil and land use should organic matter is 0.50 %, available nitro­ have been the same in thes~ States. But gen is 0.04 %, the available N is 88 kg/ha to a certain extent, they are difi'.!rent. and P 2 0 S is 20 kg/ha. Salinity arid alkali­ The Gujarat part is mostly rocky and nity are serious problems, particularly in saline, with a shallow black soil cover, the irrigated area. Soils are calcareous and whereas the Punjab and Haryana parts are usually have a massive kankar layer at sandy, with dunes of thick deposits of depths of 0.75 to 1.25 m. These soils are sand. From the land-use point of view, the deficient in nitrogen, phosphorus and gap is quite large. This gap can be narro­ potash. Gram, wheat, baira, jowar, barley wed down if water for irrigation and cotton, rape and mustard are the main desalinization is made available in the crops of this zone. desert parts of Gujarat also. Where power (2) Desert soils. The areas receiving less and tube-wells have been provided, the than 300 mm of annual rainfall in the change in land use is towards the positive southern parts of Sirsa, Hissar, Rohtak side and desertification is gradually rever­ and Mahendragarh have these soils. sed. Similarly, the difi'l;':rent resource para­ According to Sidhu et al. (1972), they are meters are being stabilized in the Pun.iab deficient in nitrogen, phosphorus and and Haryana. Thus there is a move to

potash. The available Nand P Z0 5 are 84 make the desert lands also more produc­ kgjha and 18 kg! ha respectively. The tive and prosperous by harnessing the exchangeable copper and zinc are defi­ various resources available in the States. -cient. Iron is sufficient in the south­ western part. In the gently to moderately REFERENCES sloping topography formed on the wind­ ADYALKAR, P.G. 1964. Palaeogeography, sedi­ deposited sand-dunes, the soils that are mentological framework and ground-water potentiality of the arid zone of western predominantly sandy are very deep, India. Proc. Symp. Prob. Indian Arid Zone. pale-brown to)ight-yellowish-brown loamy KANZARIA, M.V. 1972. Soils of Gujarat. Soils sand or fine sand. The subsoil is calca­ Ind. Fert. Ass. Ind. reous. Along the dune slopes (less than 3 KRISHNAN, A. 1969. Some aspects of water management for crop production in arid per cent) and at the toe of the and semi-arid zones of India. Ann. Arid dunes, the soils which are generally sandy Zone 8(1).

119 DESERTIFICATION AND ITS CONTROL

MALHOTRA, S.P., RAO, I.S., GOYAL, D. and Roy, B.B., GUPTA, R. K. and PANDEY, S. 1971. PATWA, F.e. 1972. Population, land use and, Integrated approach for development of livestock composition in India and its arid natural resources in Santalpur block of zone. Ann. Arid Zone 2 (1-2). Gujarat State. Ann. Arid Zone 10 (1). RAYCHAUDURI, S.P., AGARWAL, R. R., DATTA SEKHON, G.S, RANDHAWA, N.S. and DUGGAL, BISWAS, N. R .. GUPTA, S.P. and THOMAS, S.D. 1972. Soils of Punjab. Soils of Ind., P. K. 1963. Soils of India. ICAR, New Delhi. Fert. Ass. Ind. Roy, B.B., GUPTA, R. K. and PANDEY, S. 1970. SIDHU, G.S., SHARMA, A.C. and DHINGRA, D.R. Natural resources and their development in 1972. Soils of Haryana,. Soils of Ind., Fert. Mahendragarh district of Haryana State. Ass. Ind. Ann. Arid Zone 9 (2). WADIA, D. N. 1966. Geology of IJ!dia. Macmillan.

120 14 THE RAJASTHAN CANAL PROJECT

A. S. KAPOOR AND B. S. RAJVANSHI

THE Rajasthan Canal, being constructed show a river joining the sea in-between the in the north-western part of Rajasthan, Indus and the Yamuna. According to covers part of the Thar Desert and the historians, the oft-mentioned Rajput em­ construction of this canal in such an in­ pires could have only existed if there were hospitable and hazardous area is a challen­ extensive afforestation and prosperity. ging task. The Project comprises two The River 'Saraswati' must have been their stages of construction, the first stage cover­ main source of prosperity. With the ing 204 km of the Rajasthan Feeder, 189 passage of time, the afforestation vanished km of the Rajasthan Main Canal and a and along with it the river became extinct service area of O. 54 million hectares is and in an estimated period of abuut 5,000 nearing' completion, while a start has been years, the panorama changed from' a land made in the Stage II. Meanwhile, efforts of plenty to barrenness. High-velocity to colonize the area have started bearing sand-laden winds emanating from the fruit, and the improved methods of agri­ 'Rann', the extreme heat coupled with culture and irrigation are being introduced. coldness and the wind action carved out The Command Area Development and the desert through mechanical disintegra­ on-farm development works for a service tion of the works. The high-velocity area 0.20 million hectares have been sand-laden winds still menace the area taken up. For them, a separate Project, when they are found to reach a velocity costing 1,390 million rupees, was prepared up to 150 km per hour. Today, water is and furnished to the World Bank. The scarce all around and as far as the eye results of the concerted multi-pronged can see, the area is rippled with huge efforts have been found to be self-reward­ sand-dunes and the gleaming surface of ing. An effort has been made in this sand. article to describe the arel1, its hazards, The project area of the Ra.iasthan the methods of execution, the progress canal . achieved, the financial achievements and the targets. The Rajasthan Canal was born with History records that a river, the 'Saras­ delivery point at Harike to transport 9,856 wati', flowed on the extreme eastern side million cum (8 MAF) of the Ravi-Beas of the today's Punjab to join the sea near waters through Punjab and Haryana for a the 'Rann of Kutch'. Historic archaeolo­ distance of 204 km to enter Rajasthan at gical finds in 'Mohenjo-Daro' in Pakistan a point 12 km north of the Hanu­ and 'Kalibangan' on the Indian side reveal mangarh Town in Rajasthan. The the existence of a sophisticated civiliza­ Rajasthan Canal aims at ushering in tion that must have prospered in the area. a new era into this land. It will convert The presence of the 'Saraswati' is further this barren land into a granary humming evidenced by some other old maps which with agricultural activity, resulting in

121 DESERTIFICATION AND ITS CONTROL

development providing for immense job mely poor, only 0,3 to 0.5 quintal per potentialities. It will also enable the hectare. The other means, viz. animal State to colonize the area on modern lines husbandry enables some trade in ghee and also settle the border area with sturdy (clarified butter), wool and hides. Sheep, peasants. The Harike Headworks was goats and camels are found in plenty and constructed in 1951-58. To fulfil the form the main animal wealth. This wealth aims of the optimum utilization of availa­ too, becomes precarious owing to the ble water by cutting down the transit, frequent failures of rains. Every year, seepage or absorption losses, the project the disappearance of grass and wat~r claims was reframed to incorporate into it the a heavy toll of the animals when they are latest technology. The aim of the Project compelled to move tpwards wet regions. has always been to resort to extensive rather The camel is still the ship of the desert to than intensive system of irrigated agri­ traverse the terrain. culture. (Plates J, ro.) Mineral resources lie hidden and un­ The Rajasthan Canal after travelling explored. It is only lately that some through the Punjab and Haryana States search for oil has been started in this has to pass through Sriganganagar, desert near about Jaisalmer but, by and Bikaner and Jaisalmer districts of Rajas­ large, the area has yet to be opened up than. In its initial reaches, it crosses the for full exploitation of its lignite and gyp­ Bhakra command areas or passes adjacent sum which are available in abundance. to the areas covered by the Gang Canal. It enters the heart of the desert near about Physical targets and the means of its 128th km, where not only the water construction for construction is hard to find but even For construction, the Project has been drinking-water is scarce. The problem divided into two stages, the Stage I and becomes more acute on entering areas of the Stage 11, with the following consti­ the Stage II where still larger dunes have tuents: to be traversed. The area is so desolate and without any means of communica­ STAGE I tion that the construction materials and men to do the work are difficult to find. Stage I includes the total length of the The canal system runs through vast sandy Rajasthan Feeder, i.e. 204 km and of the plains and dunes. They consist of very Rajasthan Main Canal, i.e. 189 km, with deep calcareous and wind-blown sand to the gross service area of nearly 0.95 loamy fine sand. The sandy plains are million hectares, of which the cultivable hummocky or slightly undulating, occa­ commanded area is 0.54 million hectares. sionally gently sloping. The infiltration The following are the main branches with rate and subsoil permeability are rapid their off-take points: and the moisture' capacity is low. The major problems of irrigation develop­ Name of the branch Off-take point on ment of the soils are the wind-erosion the Rajasthan hazard and drought. The ground water­ Main Canal table is 50-80 metres deep. The main source of livelihood of the (a) Rawatsar Branch Km 0 people in this area is animal husbandry, (b) Nourangdesar supported by erratic agriculture. The Branch Km 0 agricultural community is miserably poor, (c) Suratgarh Branch Km20 for the crops depend on the rainfall which is scanty, ill-distributed and erratic. Crops (d) Anupgarh Branch Km 74 comprise only about 1 % of the gross area. (e) Loonkaransar- Bajra, jowar, moollg and moth are grown Bikaner Lift Canal Km 74 when rains come, but the yields are extre- (f) Pugal Branch Km 189

122 THE RAJASTHAN CANAL PROJECT

STAGE II' carrying out the earthwork at economical rates. Since then, the un imitable camel­ The Stage II includes the Rajas~han carts have been doing most of the earth­ Main Canal from its 189th km to the tail work. (445 km). The gross service area is The inner sides of the canal embank­ nearly 1.10 m ha, whereas the cultivable ments are made of earth compacted with commanded area is 0.76 m lia. The sheep-footed rollers after laying moiste­ main branches with their off-take points ned earth to the required dry bulk den­ are shown below: sities and cut to the right shape to form the base for lining to be laid over it as Name of branch Off-take an impervious layer to guard against the point on seepage and absorption losses. Various the R.M.C. types of lining to be adopted were tried, Flow (a) Dattor Branch Km 215 but the most suitable and economical (b) Birsalpur Branch Km 232 method was found to line the canal with (c) Charanwali Branch Km 288 burnt-clay tiles of 30 x 15 x 5 cm size (d) Digha Branch Km 445 by laying them in two layers, sandwiching (e) Lilwa Branch Km 445 between them a thick layer of cement plaster (about 16 mm thick) as the im­ Lift (a) System I (Gajner) Km 228.6 permeable film. (b) System II (Kola­ A good quantity of water is necessary yat) Km229 for construction work, e.g. the compaction (c) System III (Pha­ of earthwork, the manufacturing of burnt­ lodi) Km 351 clay tiles, the lining and the curing of the (d) System IV (Poka­ lining so done. As long as we were near ran) Km 366.8 the commanded areas of either the Ganga (e) System V (Nohar- Canal or the Bhakra canals, the water Sahwa) Km 0.0 could be obtained from the nearby contact points and transported to the site of works The earlier proposal was to construct through the pipelines by pumping. Such the main canal lined with burnt clay tiles, pipelines were laid along the main canal, whereas the distribution system was to be wherefrom smaller connections were taken left unlined, whereby intensity of irri­ to the kiln sites. But as we proceeded gation could be kept only at 78 %. Sub­ away from such areas, the arrangements sequently, however, to reduce absorption for water for construction became more losses and to make the maximum con­ and more difficult. To cope with the sumptive use of water, a decision was problem, a small channel in the bed of taken in 1967 to line the branches, distri­ the main canal was also made to supple­ butaries and the minors also, thus genera­ ment the pipe supplies till we reached the ting an intensity of 110% for irrigation of end of Stage I. By that time, it was felt khari{ (April-September) 47 % and raM that for the Stage II areas, which were (October-March) 63 %. The earth work still farther from the water sources, it to form the embankments of the canals was necessary to construct a dependable has either been done with the earth-mov­ water-supply channel and, therefore, it ing machines available with the Project was planned to construct such a channel or with manual or donkey labour or both. with a capacity of 13 mS per sec. (450 While the canal work proceeded along in cusecs), taking off at km 189 and running the earlier reaches, a position was soon parallel to the alignment of the Rajasthan reached when the cutting of large dunes Main Canal. This water-supply channel became essential. It was in 1964 that the is to cater for the needs of construction camel-cart was used in the Project and the as well as those of drinking water for the cart has proved to be of great help in labour and staff engaged in the area.

123 DESERTIFICATION AND ITS CONTROL

The work on the project in Rajasthan overall development in the command area, .was taken up in 1958, having been inau­ the State Government has established a gurated by the late Shri Govind Vallabh development authority for the command Pant, Union Minister for Home Affairs, area. The authority has been in position in Government of India. In the upper during the last two years and it has taken areas, it was seen that clayey soils could up, besides other development works, be found for manufacturing burnt-clay land-levelling and the lining of water­ tiles, but farther in the areas, even the courses for 0.20 million hectares in the clayey soils had become scarce. The project area, for which a loan from the manufacturing of tiles is being done under World Bank has been secured. The the Project by handmoulding and by firing specifications for the lining of water-cour­ them in the trench-type kilns at a tern· ses have been' 'evolved and they provide perature range of nearly 760-860oC. The for a base layer of cement mortar, follo­ tiles have to withstand a tensile strength wed by the sandwich plaster, covered of 8. 5 kg per sq cm and the flexural !';trength by a layer of 30 x 15 x 5 em-sized burnt­ of 15 kg per sq cm. clay tiles. To carry out lining on the In consonance with the earlier decision channels which are in operation is a diffi­ to construct the branches without lining, cult task in itself, as the construction the work on the branches and the system schedule has to be so devised that it does was taken up on a good scale and the up­ not upset the irrigation programme or the permost branches, viz. Naurangdesar production. For this purpose, the lining and Rawatsar branches, along with their of the existing and flowing channels is distribution system, were commissioned being done even by diverting supplies by releasing water into them on 11 Octo­ by making a bypass channel of the re­ ber 1961. Likewise, the Suratgarh Branch quired shape and size. was also commissioned in November 1962, with the part completion of the distri­ Command area development bution system. Similarly, the Anup­ The cost of carrying out the develop­ garh Branch was commissioned when ment works of the area for 0.20 m.ha in water was released into it in June 1967 the Stage I is estimated at 13,90 million for the first time when its distribution rupees and a World Bank credit of 680 system was partly completed. The bran­ million has been secured for it, with the ches and their systems upstream of km 74, participation by the Government of India, earlier left unlined are now being lined the Government of Rajasthan and institu­ with burnt-clay tiles of the same size and tions such as the Agriculture Refinance specifications as those of the main. canal. .Corporation and Commercial Banks. The The construction on Loonkaransar-Bikaner Project is to use labour-intensive methods, Lift Canal was inaugurated on 5 August wherever feasible. Since the work of 1968 by the Hon'ble Shri Mohanlal lining the water-courses and land-shaping Sukhadia, the then Chief Minister of is done at the cost of the farmers through Rajasthan, with the simultaneous taking the loans granted by the banks and the up of the work on the four gigantic pump­ Agriculture Refinance Corporation, the ing-stations. This lined lift channel, too, farmers will have a considerable debt was completed in 1975. The. distribu­ burden. The financial position was, tion system is being lined and has been therefore, examined and the invest­ completed by now to the extent of 70 %. ments on and the returns from the The development project of the com­ farms of 6.32 hectares on sandy or on mand area is to provide amenities, such 'Tal' soils were examined in some detail as . habitation and housing, communica­ over a period of 20 years. After making tions, demonstration farms, industries, appropriate deductions for hired labour, forests, power, education, health and co­ farm inputs (e.g. fertilizers, seed and plant operation. To consider and plan the protection) and water charges and allow·

124 Plate k. Wheat grown in rabi season under irrigation Plate I. For mall. animal and plant, the Rajasthan canal brings in hopes of survival and prosperity

Plate m. The canal water harnessed for agriculture. Water-less wastelands are being turned into agricultural fields THE RAJASTHAN CANAL PROJECT jng a family consumption of Rs 5,000 released into it in November 1975. This per year, the cash position of the project step has eventually facilitated the commen­ farmers was shown to be satisfactory. The cement of earthwork, and the manufac­ farmers would be able to meet their debt turing of burnt-clay tiles in about 30 kilns obligations because of land purchase up is in operation. The making of earthen to Rs 20,000 and on-farm development embankment from km 189 to km 260 loans up to Rs ] 5,000. The incremental has been in progress along with the lin­ net value of production in the 11 th year ing work of the 20 km of the main canal would be 250 million rupees, and on full during 1976-77. development in the 21st year, it would be In respect of the development of the 350 million. The economic rate of command areas by September 1976 the return works out at 25 % and its implemen­ survey and plannipg of the on-farm tation would take six years. development works had been completed The cost of the on-farm development in 536 blocks (chaks) covering more t~an works (as in 1976) for the remaining area 80,000 .hectares. The constructic)ll' of.. of O. 34 million hectares of Stage I (includ­ the lined water-courses had been taken ing 5,8000 ha on the Loonkaransar-Bikaner up in 191 chaks and by March 1977, the Lift Canal) on the above. analogy works on-farm development works would be out at 543.20 million rupees, whereas carried out in about 30,000 hectares. for the. Stage-II area of 0.76 m.ha, it is Irrigation estimated at 1,185 million rupees. This amount would be needed, as and when it Ever since 1961, the irrigation picked is sought, to develop the command areas. up and the steps taken in 1958 star,ted bearing fruit, as shown in the Table below. The up-to-date progress (a) The physical progress on the project Year Area irrigated works. The first stage of the project is now (in hectares) > nearing completion. The position in res­ pect of the main constituents is given be­ 1961-62 1,445 low. Water is running in all these branches 1962-63 1,404 (Table O. 1963-64 6,407 Preliminary works for the Stage II 1964-65 17,808 were started in 1970. The first and fore­ 1965-66 26,950 most work was of water-supply channels. 1966-67 42,268 It has since been completed to a length of 1967-68 81,534 I 10 km downstream of km 189 of the 1968-69 1,00,036 Rajasthan Main Canal and water was 1969-70 1,42,169 (Contd.) Name 0/ the unit Length Slate o/work 1. The Rajasthan Feeder 204km Completed 11. The Rajasthan Main Canal 189 km Completed iii. The Naurangdesar Branch System The complete lining of branches and laterals is being done iv. Rawatsar Branch System v. The Suratgarh Shakha System " vi. The Anupgarh Shakha System " vii. The Loonkaransar- Bikaner The distribution" system Lift. canal duly lined is 70 % complete and will be fully completed by 1977-78 viii. The Pug~1 Branch .. 125 DESERTIFICATION AND ITS CONTROL

1970-71 1,74,000 FIGURES OF COSTS 1971-72 1,85,475 1957 estimates: 2,01,281 610 million rupees 1972-73 1963 estimates: 2,25,055 1,400 million rupees 1973-74 1970 estimates: 2,50,000 2,170 million rupees 1974-75 1975 estimates: 1975-76 2,88,0:0 3,310 million rupees 1976 estimates: 4,060 million rupees I Water was released below km 74 of the Expenditure in­ main canal in June 1974 and below km 128 curred- up to in the Pugal Branch in June 1975. Areas March 1976 1,500 million rupees coming under command from km 74 to km 128 started receiving irrigation water Rupees ilt' millions from the kharif (April-September) crop Stage Stag'e Total ] 974, whereas those between km 128 and I II 189 and the Pugal Branch did so from kharif 1975. All the channels below km Estimated cost (1976) 1,760 2,300 4,060 74 are being constructed complete with Expenditure till lining in the very first instance, whereby March 1977 1,550 185 1,735 the laterals have'taken a longer time in Balance required 210 2,llS 2,330 completion than unlined ones. Efforts Employment potential have, however, been to supply irrigation up to whatever points the laterals were As already explained, the project has ready and in this manner the additional immense employment potential and can venues for irrigation were created in employ up to a hundred thousand skilled 6,5000 ha (CCA). The area opened for and unskilled labourers, but the area is irrigation increased to 0.44 m.hli in Stage famine-stricken, climatically hazardous, 1. The actual irrigation done during devoid of means of communication and 1975-76 was 0.29 m.ha (7,20,000 acres). without habitation, and very desolate. It is only in the famine years that the labour Areas irrigated strength has been reaching 60,000. In nor­ Gross area 2m.ha mal years, it does not exceed 30,000. The Culturable area 1. 30 m.ha project makes the dwelling arrangements Area to be irrigated an­ for the labour and supplied drinfing-water nually 1.26 m.ha free of charges. The tools and plants Area irrigated in 1975-76 0.29 m.ha (T&P) required for doing the work are also supplied free. Even though the project has J,

126 THE RAJASTHAN CANAL PROJECT

o 0\ 01") 00- N .... N N 00 .....

000 000 NOO N \I") N '""

00 t- '",....

00..;-0 on 000 t-N 0000 NO .;,...... ;-\0 '" 0 NC\O 00";­ 00";-0 ..;-­ - ..... N Nt- ("'~ ~ 1,(") C""'I 00",00_ 01")...

.~ DESERTIFICATION AND ITS CONTROL

quently visit the Project sites and have an the Beas is camplete, and the availa­ expressed their satisfaction with the bility af supplies far the annual irrigation arrangemen ts. far the develapment of 1.28 m hectares is assured. Bottlenecks Physical. As explained above, the area Conclusion is desolate and devoid of all means of The praject IS capable af increasing communication and is bereft of all civic faod praductian, creating immense jab amenities. It is climatically hazardaus. oppartunities and transforming the desert The labaurers and ather warkers feel into a granary, raising the standard of ,reluctant to' gO' to' the site at the autset. living of the down-tradden 'and n<;>madic The area is sandy and can be reached people af the area. When the source af either by faur-wheeled vehicles ar by using the indamitable camel. Thus there is a necessity af laying a praper netwark Table 2. The revised cropping pattern of the af cammunicatians which will also ease Rajasthan Canal Project the transportation problem. Even though the praject has constructed a road by the (Perennial irrigation) side of the main canal, it cannot help to feed the distributian systems to any (I) Kharif (Intensity 47 %) significant extent. There are no schaals, 1 Vegetables 1'0 haspitals or dispensaries ar markets to 2 Cotton 16-5 enable narmal habitation. Even the postal 3 Groundnut 5-0 facilities are scarce. These hard condi­ 4 Pulses 7-5 tians deserve to be recagnized and a 5 Fodder crops 4 5 6 Bajra 12'5 suitable formula has, to' be evalved to ameliarate them. (U) Rabi (Intensity 63 %) As we naw enter the heart af the desert, 1 Wheat 30 the rail-heads get farther and farther and 2 Mustard 10 this increases the periad and cost af deliver­ 3 Gram 20 4 Sugar-beet 2 ing the canstructian material and men 5 Berseem (fodder) I at the site af the wark. The wark af laying adequate rail-links needs to be initiated. Total; 63 Financial. The pace af wark under the praject has been restricted mainly because of. the paucity of funds far the gigantic perennial supplies to the canal is assured task. Rajasthan is a backward State and and; with the impraved methods of agri­ has to' cover a lot of leeway in bringing its culture, the virgin area lying uncultivated people on a par with those of

128 THE RAJASTHAN CANAL PROJECT

fillip that .the development of the com­ ture. For providing the p'ersonnel deplo- - mand area would, induce in the production yed on the Project with proper facilities. and economy of the farmer, the remain­ .the base colonies need to be developed and ing areas need also to be developed. For quick means to reach the sites of work the proper opening up of the area, a net­ made available. There is no doubt that work of roads and railway lines shoulq the project will boost the economy of the also be laid to create the proper infrastruc- State and its people to a great extent.

129 15 SALINE WATERS-THEIR POTENTIALITY AS A SOURCE OF IRRIGATION

R. P. DHIR

THE occurrence of saline and highly saline at a number of sites irrigated with highly waters is a common feature of the arid saline water on a variety of soil textures. and semi-arid regions of the country. In The last section constitutes a resume dea­ the arid part of ,Rajasthan, nearly 84 % ling with the usage potentialities of the of the area has ground-water of over saline waters in an arid environment. 2.2 mmhos EC. The adjoining semi-arid IRRIGA TION QUALITY CHARACTERISTICS area of the State as also of the neighbour­ OF GROUND-WATERS ing States of Gujarat, Punjab, Haryana and Uttar Pradesh are also beset with this The·chemical analysis of ground-waters problem, albeit, to a smaller degree. The has been an essential part of many studies . semi-arid areas of peninsular India have aimed at surveying and assessing this im­ high residual carbonate in the majority of portant resource. As a result of decades of waters. Only in small parts of the re­ the activities of different organizations in gions concerned has it been possible to the field, valuable information has been divert good-quality surface waters from obtained in respect of arid and semi-arid outside the area and the major regions in different States and a brief part of ground-waters remain the sole account of the work follows. source to supplement low and erratic Rajasthan. Rajasthan is one of the few' rainfall for crop production. In western well-investigated States in the country. Rajasthan alone, there are over 0.30 mil­ Thanks to the efforts of the State and lion ha under irrigation from ground­ Central Ground-Water Boards, the GeolO­ water and an equally large potential still gical Survey of India, the Central Arid exists. Realizing the importance of ground­ Zoae Research Institute, the State Public water, the Indian Council of Agricultural Health, the Agriculture Department, Research has recently launched an all­ the Defence Science Organization and the India co-ordinated project on the use of Udaipur University, a fairly good picture saline waters. is now available. The findings of most of' The ground-waters, such as those occurr­ these bodies have earlier been summarized ing in the area are considered unfit accord­ by Paliwal (1972). These, updated with ing to most of the internationally accepted major efforts that have been made norms and in our own country also their since then in western Rajathan, are sum­ use is looked upon with great scepticism. marized in Table 1. An attempt has been made in this paper It may be seen that saline to highly to give a brief account of the valuable saline waters, i.e. those above 2. 25 mmhos work done in the countrv on different E.C. constitute over 60 %, with a small .aspects· of the use of saline-water. In one inter-district variation. The results ob­ of the sections, an account is given also of tained by Dasgupta (1975), showing the a medium-term investigation carried out geographical area occupied by different

130 SALINE WATERS-POTENTIALITY FOR IRRIGATION

Table 1. The distribution of water samples in different salinity ranges in western Rajasthan . S. Name of district The number Percentage of samples faIling in E.C. range (in mmhos) No. of water sam- ples Below 0·25- o 75- 2·25- 5-10 10-15 above o 25 0·75 2·25 5·00 15

1. Barmer 322 5·9 4·0 10·6 31 ·4 26·7 14·6 6·8 2. Bikaner 137 1·5 27·0 36·5 21 2 10·2 3·6 3. Churu 244 3·3 16·4 29'5 28·7 14·7 7·4 4. Jaisalmer 295 o 3 18·6 36·6 19 7 20·3 3 8 0·7 5. Jalore 505 9 5 27·7 29·9 19·8 10·3 2·8 6. Jodhpur 357 7·8 37·6 26 6 16·0 7·8 4·2 7. Nagaur 459 0.2 7 6 35·7 28·2 21 ·7 3'8 3'1 8. PaIr 498 12·3 33'5 20·1 17·1 9.0 8.0 Total 2,817 0·8 8·9 29·2 26"8 20·8 8'9 4·6

Table 2. The district-wise distribution of area occupied by waters of different salinity ranges (Dasgupta, 1975)

Districts Area of districts Approximate percentage of the district having total in sq. km dissolved salts Below 2·2 mmhos 2 ,2-3,6 mmhos Above 3 6 mmhos

Barmer 29,031 10 22 68 Bikaner 27,102 5 17 78 Churu 16,261 9 9 82 Jaisalmer 38,475 9 20 71 Jalore 10,428 20 15 65 Jodhpur 22,213 30 15 55 Nagaur 17,292 20 13 67 Pali 11,808 25 19 56

salinity ground-waters based on the iso­ posItIon. For example, in highly saline salinity contour maps (Table 2) also pre­ waters in an area of 5,000 sq.km in Pali, sent a similar picture. the sulphat~ content ranged from 4.8 to The ionic composition of ground-waters 45. 7 % of the total anions. As regards shows considerable variation. The results carbonates plus bicarbonate, they rarely of most of the studies show that in low­ constitute more than 15 % of the total salinity ranges, the waters are of the anions, but in the salinity ranges below carbonate-chloride type and at 2. 5 mmhbs 2.2 mmhos, they occur in a large range of EC these waters become chloride-bicar­ 24 to 78%. bonate type. With a further increase in The sodium-adsorption ratio (SAR) is salinity, the waters are invariably of the an important criterion and defines the chloride-sulphate type. The percentage sodicity of waters. Table 4 presents the of sodium also continuously increases distribution of waters in different SAR with salinity. These trends are excellently ranges. brought out in a compilation study, results It is evident that in waters above 2.25 of which are presented in Table 3. It may mmhos EC, by far the majority of the also be seen that for Rajasthan as a whole, samples have SAR values above 10. At magnesium dominates over calcium in higher salinity, the values, in fact, are 73 % of the water samples. There is an mostly above 26. Waters below 2.25 apprec~able variation also in anion com- mmhos E.C. have SAR values generally

131 DESERTIFICATION AND ITS CONTROL below 10, but knowing that these waters Alwar District, obtained a mean salinity often contain residual carbonate, these of 2.4 mmhos. In 276 samples from waters also are not free from sodium Bharatpur, the mean values were 3. I hazard. Therefore the waters in the arid mmhos, in 235 samples of Bhilwara, they zone of Rajasthan are characterized not were 5. 5 mmhos and in 702 samples of only by salinity but also by high sodium Jaipur and Sawai Madhopur they were content. 2.4 mmhos. These observations show The adjoining semi-arid districts of that even semi-arid tracts of the State have Rajasthan have also been reported to the problem of ground-water salinity. possess the water-quality problem. Pali­ though it is not so acute as in the arid wal (personal communication), on the part. , basis of 334 samples collected from the Boron in irrigation waters can be toxic

Table 3. Ionic composition in relation to electrical conductivity in well waters of Rajasthan (K.V. Paliwal, personal communication)

Ions The mean percentage composition in different salinity ranges (in mmhos) 0-2 2-6 6-10 Above 10

Cations Nat 51·9 70 3 72·2 74 I Kt 1· 5 3'2 2·3 1 6 Catt 20·4 9 4 8'9 9·2 Mgtt 26'2 17·1 16 6 15 1 Anions Cl- 30'·2 54·1 67'2 75·3 SO.-- 10·3 15·3 20·4 15'2

HCOa+C03-- 59·3 30·6 12·4 9'5

Number of 1,671 1,372 545 344 samples

,Table 4. Distribution of waters of western Rajasthan in different sodium-absorption ratio ranges

Salinity group (B.C. Number of Percentage distribution in different sodium adsorption in mmhos) water sam­ ratio ranges ples 0-10 10-18 18-26 26-34 Above 34

Below 0·25 3' 66 7 33'3 0·25-0·75 167 93·4 5·4 1 ·2 0,75-2'25 607 72·8 21 ·5 3·6 1 ·8 o 3 2'25-5 00 659 31 ·0 39 4 22'3 4·7 2·6 5-10 496 6·6 28 6 31·9 21 ·2 11·" 10-15 225 2'2 12·5 30·7 33·3 21·3 Above 15 121 3·3 4'1 12·4 22·3 57·9

Total 2,278

132 SALINE WATERS-POTENTIALlTY FOR IRRIGA110N and can severely limit their utility. 100 Total samples = ~52 Though as high as 5 ppm of boron have been found in'waters, in by far the majority 90 it ranges from O. 67 to 2 5 ppm (Fig. 1)'. 80 MandaI (1967) reported for arid districts a range of 0.28 to 7.66 ppm, with a signi­ -rr 70 .s_~ - cant positive correlation between E.C. E 60 ('J and the boron content. Thus it seems v- plausible that ~~e majority of waters are a 50 unfit for senslttve crops, although they Q; E 40 are moderately suitable for semi-tolerant ::J and tolerant crops. Z 30 Gujarat. A State-wide survey showed that of the 8,952 samples, samples with E.C. values over 3 mmhos and those 10 between 2 and 3 mmhos constitute nearly OL-~--~ ______-- __--~--~ 15% (Shah and Bapat, 1972). Talati 0.33 0.67 1 1.33 ,2 3 and above (1969), while working in the alluvial plains Boron (ppm) of Gujarat, showed that in some pockets Fig. 1. Frequency distribution of boron in salinity was the problem and in other$ ground-waters of Rajasthan (Paliwal, 1972) residual sodium carbonate was the pro­ blem (Table 5). The more saline areas the seacoast is seen affecting sizeable areas are concentrated in northern Gujarat. also in the Bulsar, Jamnagar, Surat and Shah et al. (1966) reported that in the Kaira districts. Santalpur-Mehsana District of this region, Punjab. Singh and Kanwar (1964) ground-water salinity was a problem in during an exploratory study reported the the areas closer to the sea and high residual occurrence of salinity in ground-waters in carbonate was a problem in areas farther the relatively arid tracts of the State. In inland. Salinity due to the proximity of the Ferozepur and Sangrur districts, 54 Table 5. Some mean chemical indices of tube-well waters of northern Gujarat (Talati, 1969)

Salinity Num- Cations Anions Residu- SAR class EC ber of also- sam- meg/l meg!1 dium pIes ---- carbo- + ++ ++ nate Na Ca Mg CI SO~ S03 HCO, meg/l

Samples 'without residual carbonate

Below 1 36 2·3 3 5 2 0 3 2 0·8 3-6 o 4 Nil 1 '4 1-2 133 6·2 4'9 3·5 6, I l' 8 5 4 0,6 Nil 3 1 2-4 34 19 2 7-0 5 3 18 0 54 68 0·6 Nil 7 6 4-6 20 35·2 7 ·1 9'5 37,9 7 6 4 6 1·5 Nil 12·9 Above 6 8 74 3 7·9 .15'2 74 5 12 3 4,4 4,8 Nil 23·4 Samples with residual carhonate

Below 1 28 3·3 2 2 1 9 1 ·6 0·7 3 7 1·6 o 7 2'4 1-2 277 9·5 2'8 2-4 54 ] ·5 4·8 3·2 2 6 4 8 2-4 57 21·2 3'2 14'8 3·0 5, 1 4 9 4 9 3·2 12 0 4-6 3 38·2 1 '9 7'2 26 4 7 7 3·2 9·6 3 8 22·6 Above 6 11 74 7 2·9 5·8 57·0 9 ·1 3·0 138 8·3 35·7

133 DESERTIFICATION AND ITS CONTROL

and 34 % of the samples respectively were Uttar Pradesh. The bulk of the State found to have over 2 mmhos E.C. Bhumbla is fortunately free from the saline-water (1969) found (Table 6) that besides, Feroze­ problem. Of the eighteen districts, saline pur, the Bhatinda District had salinity water occurs in the Mathura and Agra hazard, whereas in the Sangrur District, districts and to a limited extent in the the problem was largely due to high resi­ Etah and Aligarh districts (Mehrotra, dual carbonate. 1969; Tripathi et al., 1969). In Agra and Haryana. Like the Punjab State, poor­ Mathura (Table 8), water .with over 2.25 quality waters in Haryana are also confined rumhos EC form 47 % and 53 % of the to the more arid tracts of the State. The total samples analysed. The waters in Gurgaon and Hissar districts were shown this range are typically of the chloride­ to have the most serious water-quality sulphate-bicarbonate type, with negligi­ problem, as shown by the exploratory ble or slight residual sodium carbonate. studies of Singh and Kanwar (1964). Fur­ The sodium-adsorption ratio varies, with ther detailed studies (Kanwar and Man­ a vast range of 2 to 24. A more detailed chanda, 1964; and Uppal and Khanna, study of the Agra District (Narain et al., 1966) brought out clearly the extent of 1976) showed that of the 471 water samples the saline-water problem in these districts 29 %, 30 %and 25 %occur in the EC ranges and also in the adjoining Rohtak District. of 2-6, 6-10 and· over 10 rumhos res­ It may be seen from Table 7 that 50 to 60 % pectively. Nearly 24 % samples had over of the waters of the area have over 2.25 2.5 m.e. residual sodium carbonate. T.he mmhos E.C. in the lind District, unpubli­ boron content was less than 2 ppm. shed data of the Central Salinity Research Besides the above States, there are Institute shows that waters with over 2 pockets of problematic waters in Andhra and 4 mmhos form 50 and 27 % respecti­ Pradesh, Karnataka and Tamil N adu. vely. :M'any waters, particularly in Gur­ The analysis of 114 ground-water samples gaon, are found to contain also an extra­ from the Challakere taluka in Karnataka ordinary concentration of potassium and showed that 66 % of the samples had EC nitrate. between O. 75 and 2.25 mmhos. Though Table 6. Mean quality indices of ground-waters in some problematic areas of the Punjab State (From Bhumbla, 1969)

+ District. Number of Conductivit) in CI S04 Na SAR RSC samples tested micromhos/cm me/I me/l me/I

Ferozepur ],702 2,062 5·8 5·8 14 8 8·7 3·37 Bhatinda 1,151 2,668 10·7 5'0 18 5 9, 1 2'7i Sangrur 400 1,521 13·7 10 6 11 7 8 ·1 8,00

Table 7. Frequency distribution of some well waters of Haryana in different salinity classes (Uppal and Khanna, 1966) (%)

EC classes micro- Rewari, Jhajjar, Bhiwani. Mohindergarh Narnaul Dadri mhos/em Gurgaon Rohtak Hissar district district district Mohindergarh dist.

250 Nil Nil Nil Nil Nil Nil 251-750 6·0 Nil Nil 6·4 4·7 5 6 751-2250 35·3 38·9 31 0 50·3 45·6 31·9 2.151-S000 28·0 303 48 3 28·8 30·0 33·2 50QO 30·7 30,8 10·7 14·5 10·7 29·3

134 SALINE WATERS-POTENTIALITY FOR IRRIGATION

Table 8. Frequency distribution of ground-waters of some districts in Uttar Pradesh in different salinity " ranges (After, Tripathi et al., 1969)

Range of Ee in Percentage di~tribut on of samples in different districts mmhos Agra Aligarh Etah Mathura

0'25-0'75 4·2 20 9 55 S. 7·7 0·75-2'25 47·9 74·6 40 0 35·6 2 25-5 ·00 23·2 4·5 3 4 34 6 5-10 15·5 O·g 16·3 Above 16 9·2 5·8

Total number of samples 142 134 120 104

SAR was low, over 90 % of samples had waters have not only an appreciable residual sodium carbonate with a maxi­ amount of magnesium but also that mag­ mum of 15 m.e/l and a mean of 4.3 nesium generally dominates over calcium, m.e/I. In the neighbouring Andhra Pra­ they inferred a greater sodium adsorp­ desh also, the ground-waters presented tion on soil than what would be predicted a similar picture. In Coimbatore in by well-known sodium adsorption ratio Tamil Nadu (Balasundaram et al., of the USSL staff (1954). Paliwal and 1969), well waters have salinity range of Maliwal (1971) also proposed a modifi­ o 8 to 4.7 mmhos EC. The coastal area cation of the well-known USSL equation of the State also has the problem of water on the relationship between the sodium­ salinity. adsorption ratio of the saturation extract and the exchangeable sodium percentage EFFECT OF SALINE WATER ON SOIL PROPERTIES of the soil. Kanwar and Kanwar (1969) found that everything else being equal, The potential of saline waters to cause the equivalent concentration of carbonate profound, often adverse, effect on soil in irrigation water led to greater deteriora­ properties has prompted many studies, tion of the soil physical properties than both in the laboratory and the field on the bicarbonate ion. the role of individual cations, their ratios The amount of sodium adsorbed by and the total salinity of irrigation waters the soil from any particular water is also on various properties of the soils. Kanwar dependent on the nature and content of and Ram Deo (1969) found, by varying clay. Ramamoorthy et af. (1972), while the composition of the leaching solution, working with different clays or soils that in causing adverse effect on soil per­ dominated by different clays, observed that meability, potassium acted more like by following the inverse-ratio law, the sodium, though at lower concentrations bentonite or montmorillonite-dominated its presence helped to check sodium soil attained only 10 per cent sodium adsorption. Magnesium in monova­ saturation, whereas the kaolinite- or illite­ lent ratios of 0.2 to 2, behaved dominated soil had 55 and 25 per cent closer to sodium but at higher ratios sodium saturation, when irrigated with a its effect was similar to that of calcium. water of SAR 14. Paliwal (1972) also Likewise, Paliwal and Maliwal (1971) reported a differential behaviour of the also found that in sodium-dominant Rajasthan soils, thus showing the limited waters, the p(!.rtial replacement of application of a common ion-exchange calcium by magnesium in the leaching equation based solely on the composition solution led to an increased adsorption of of the soil solution. sodium by the soil. Since the arid-zone However, granting no such major soil-

135 DESERTIFICATION AND I1S CONTROL

group Ivariation, the sodium-adsorption age is not a problem, Singh and Bhumbla ratio and salinity remain two important (1968) found the following relationship: determining characteristics of the irriga­ tion waters. Results of numerous pot and micro-plot studies bring out the relevance Table 9. Relation between EC of irrigation water and saturation extract of soils (Singh and of these studies in determining the ulti­ Bhumbla, 1968) mate salinity and sodicity of soils. The results of Bhumbla et al. (1964), Kanwar and Kanwar (1969) and Lal et al. (1974) Clay content of Corre- Regression equation the soil lation show from pot culture or micro-plot stu­ 'r' dies with light-to-medium-textured soils that the salinity of the soil is primarily governed by the salinity of the irrigation Less than 10% 0·64 ECe =0·43 ECI +0'47 waters and only secondarily by the sodium­ 10-20% o 61 ECe =0·77 ECI +0 19 adsorption ratio. Realizing the limita­ tion of such studies, more emphasis in 20-30% 0·86 ECe =1·52 ECI +0·75 recent years has been on larger plots or on cultivators' field~. Singh and Kanwar (1964) found that with irrigation waters Gupta and Abichandani (1968, 1970) of 0.2 to 4.0 mmhos Ee, 6-12 SAR observed six long-established sites under and 'some residual carbonate, the salinity irrigation with waters of 3.4 to 8. 9 mmhos of the soil-saturation extract (Eee) was EC and 12 to 32 SAR and found that sali­ generally lower than that of the irrigation nities.of 4 to 12 mmhos Eee were attained water. The sodium adsorption ratio of at harvest time in March. After the rainy the soil extract was correlated significantly season, during which 350 to 450 mm with the residual carbonate of the irriga­ of rain was received, the bulk of the accu­ tion water. Likewise, Lal and Lal (1976) mulated salinity was leached down, leav­ in a survey of light-textured soils, irrigated ing the top 40 cm of the soil only mode­ with waters of O. 5 to 4 mmhos Ee and rately saline, with Eee values less than 2 2 to 20 SAR, found that the Eee of the mmhos. soil was only 63 % of the irrigation water, Besides the salinity regime, irrigation with a near unity relationship between the with saline waters also affects the alkali soil exchangeable sodium percentage and conditions in the soil. Shankarnarayana the sodium adsorption ratio of the water. and Ganu (1963) and Gupta and Abichan­ Tripathi et at. (197l) and Paliwal and dani (1968) found that soils under irriga­ Gandhi (1969) with similar soils also did tion with saline waters of SAR 15 to 40 not observe any salinity build-up even tur.ned saline sodic with exchangeable with the use of more saline waters. Kan­ sodium percentage values of 16 to 59. war and Mehta (1970) observed in soils Singh and Bhumbla (1968), Singh and Lal having 18 to 44% silt plus clay that (1967) and Lal and Lal (1976) also found a Eee was much higher than the EC of the similar build-up of alkali hazard in soils irrigation water. Paliwal and Maliwal with the SARe of the soil comparable (1968) similarly observed that in medium­ with the SAR of the irrigation water. and heavy-textured soils in Rajasthan, the Tripathi et at. (1971), however, observed use of highly saline sodic waters had led a correspondingly small build-up in light­ to 1 to 7 times more salinity in the soil textured soils in the Agra region. Paliwal than that in the irrigation water. The and Gandhi (1969), Mehta (1970) and average was 2.79 times. Thus it appears Paliwal and Maliwal (1971), however, that the soil texture and drainage are very observed a considerable variability in the important factors in determining the soluble sodium percentage and the SAR salinity status of a soil irrigated with a of the soil extract and the irrigation water. particular ,water. However, where drain- Though a positive relationship was found,

136 SALINE WATERS-POTT!NTIALITY FOR IRRIGATION

the degree of determination was so low the studies can be broadly summed up in that it had hardly any prediction value. that with most field crops, with the excep­ Boron. as has been shown earlier, is tion of a few clovers. seed germination is present in appreciable quantities in the not a problem under irrigation-water arid-zone waters. Because of the grdt salinity levels at which satisfactory crop sensitivity of crops to an excess boron growth and maturity are possible. How­ concentration, boron accumulation in eve-r, vegetable crops, particularly some irrigated soils has received considerable varieties of brinjal, tomato and cabbage, emphasis. Singh and Kanwar (1964) did are sensitive at the germination stage. not observe a very significant correlation Maliwal and Paliwal (1970) observed between the boron content of the irriga­ that in influencing germination, the effect tion wat~r and that of some soils showing of salinity was far more pronounced than 10 to 20 times more soluble boron. They that of the relative proportion of sodium attributed the variability to the drainage to other cations or the sodium-adsorption conditions and the mineralogical make­ ratio of the solution. up of the soil. Mehta and Paliwal (1973) Interesting work has been done on the observed that the relative boron accumu­ growth and yield behaviour of crops in lation was 1. 84 times in the irrigation relation to the irrigation-water salinity. water for heavy-textured soils, 1.44 times With high-salinity waters, i.e. those above in medium-textured soils and 1.27 times 5 mmhos Be, wheat is by far the commo­ in light-textured soils. Likewise, Jain nest crop. Bhumbla et al. (1964) obser­ and Saxena (1970) and Moghe and Mathur ved that wheat yield decreased only by (1966) also observed an appreciable build­ 5 and 30 % of that obtained with water of up of boron in the irrigated soils of Rajas­ Be 3. 3 mmhos with increasing salinity than. The available boron in the soil of water up to 5.6 and 11 mmhos Be mostly varied between 1 and 4 ppm, respectively. With a further rise up to with an average of 3.22 ppm. This 20 mmhos, the yield fell sharply. The value was high, according to the usually SAR of the waters varied from 4 to 16 accepted norms, but it did not adversely and its effect on yield was negligible. affect the growth of the common crops Tripathi et al. (1971) observed in a long­ of the area. Tn sandy soils, La} and Lal term study that an excellent crop of wheat (1976) did not observe any boron build­ could be taken continually on a sandy­ up after many years use of water. Mehta loam soil, with a water of 2.7 mmhos (1970) found in equilibrium studies that BC, 9. 1 SAR and 3. 1 m.e. RSC. Simi­ the increasing concentration of other sQlu­ larly, Lal and Singh (1973) observed a ble salts in a constant boron solution good growth of wheat on a loamy-sand caused a decreased adsorption of boron. soil, with water of 3.45 Be, 16. 7 SAR and He, therefore, concluded that the sites 7.2 mel 1 RSC or another water of 7.2 of boron adsorption were also available BC, 36.1 SAR, but with no residual car­ to other constituents in the saline-sodic bonate. However, with a water of 10.5 waters. Be, 36.1 SAR, the yield was reduced. nearly by half. Maliwal et al. (1972) SALINE WATER USE AND CROP GROWTH found that the yield of wheat decreased Massive data are available in the coun­ roughly by 12, 33 and 66% res­ tryon the salt tolerance of crops and their pectively from the maximum with waters varieties at the time of germination.· By of 7, 15 and 20 mmhos BC. They also far, a majority of the data are based on found that among different varieties, the usual filter-paper-bed technique which Kalyansona and Kharchia 65 were more does not take into account changes in tolerant than Sonara 64 and S-227. The salt and moisture contents, to which the present author's work at Jodhpur, on the seeds are exposed under field conditions. other hand, showed that variety Kharchia Subject to this limitation, the results of 65 was more tolerant than Kalyansona,

137 DESERTIfICATlO"J" AND ITS CONTROL the diffet:ence being mainly due to the of nitrate above 1 m.e./l was significant tiller number. Table 10 gives the agrono­ in raising the yields still further. mic characteristics and yields of the two Paliwal (1972) and his associates have varieties. recorded the relative tolerance of mus­ The results show that a better perfor­ tard and vegetable crops. The yield of mance of Kharchia is largely due to its mustard decreased by only 6 % at Ee 7 larger number of effective tillers. mmhos and by 26% at about 15 mmhos Field observations on sites under the Ee. Among vegetable crops, cabbage, prolonged use of saline water give a better radish and spinach proved to be most to­ index of crop growth in relation to the lerant and showed negligible decreases in quality of water. Kanwar (1961) and yield up to 9.5 mmhos. Kanwar and Manchanda (1964) recorded With low-salinity waters, i.e. those below that in the arid tract of Haryana the waters 5 mmhos, field crops perform obviously of 15 mmhos Ee and 15 SAR were pro­ better. However, such waters in the arid ducing bumper crops of wheat. He attri­ zone are used for more economic crops. buted the success to the light texture of The author's observations show that the soil and high nitrate and potassium waters in the range of 0.75 to 2.25 contents of the irriga"tion water. Moghe mmhos Ee and with SAR up to 10 (1968) also reported yields of 20 to 30 are eminently suited for chillies, corian­ q/ha with waters of 7-10 mmhos Ee and der, cumin and plantago. With a rise in 18 to 32 SAR on soils of medium tex­ the SAR or with the presence of residual ture. Paliwal and Maliwal (1968) obser­ carbonate between 2.5 and 7.5 m.e/l, ved in the arid and semi-arid tracts of plantago still grows well, but the yields Rajasthan good growth of wheat with of chillies, coriander and cumin are waters of 5 to 9 mmhos Ee and 11 to reduced by 50 %. With waters in the 20 SAR. In the case of barley, similar Ee range of 2.25 to 5 mmhos, yields were obtained even with higher­ plantago and lucerne grow successfully, salinity waters. Dhir et al. (1975) obser­ but the yields of chillies and cumin fall ved that at long-established saline-water­ by 75 to 40% of the maximum. Lucerne irrigated sites, yields of 15-20 q/ha could grows well with the SAR of 25 or with the be obtained with waters up to 10 mmhos residual carbonate above 5 m.e/l. In all Ee, and yields of 10 to 15 q/ha with these cases, the land is left fallow during waters of 10 to 15 mmhos. The presence the early part of the rainy season.

Table 10. Agronomic characteristics of the two wheat varieties as affected by salinity of irrigation water (1972-73),

EC mmhos Mean yield in Number or' Average num- 1,ODD-grain Grain protein·· qjha effective ber of grains/ weight in % tillers· ear K65 KS. K 65 KS. K 65 KS. K65 KS. K65 KS. 4 32·3 28·4 2·75 1·91 26·25 32'83 34·35 33·91 12 90 12 ·10 8 31·0 24·4 2·76 1·75 2607 31'19 33·96 32·55 13·22 12 93 12 20·3 16 0 1·99 1·51 23 64 24·23 31·46 28·44 13 ·11 13 00 16 9·6 6 9 1 42 1'26 12·93 14'08 24·94 23·20 12·73 12·62 Mean 2·23 1·61 22·18 25'58 31·18 29'53 12·99 12'66 • = Mean of 105 plants each; C.D. for salinity at 1 % level = 0.17; C.D. for varieties at 1 % level = 0.09 . •• = N X 5.75.

138 SALINE WATERS-POTENTIALITY FOR IRRIGATION

Water-quality classification -'of and on the properties of soils irrigated ground-waters with saline waters. Till the time that data become available, a group of workers A major effort on the part of the USSL' in the field assembled in 1972 and reached staff (1954) on water-quality criteria and the folloWing consensus on water quality suitability classes have given a big (Table 11) impetus to the characterization and assess­ ment of surface and ground-waters. Investigations into the use of highly saline Numerous laboratory studies have since waters in a cyclic management system corroborated the general validity of the Results are presented here of a medium­ principles enunciated in this monumental term study during which nearly thirty work. Not going into further details of Sites, covering a large range of waters and these studies, only some modifications soil textures, were regularly monitored based on the native experience in respect for salinity and alkali hazards in the soil of the original classification of the USSL and for crop growth. The sites under staff (1954) ate discussed here. Kanwar study were located in the Pali District, (1961), after observing that even highly with a mean annual rainfall of 415 mm saline waters, far beyond the suitability received almost entirely during the mon­ range of the above classification, were soon from mid-June to September. Irri­ being used successfully in Haryana and gation is from dug wells and wheat (variety also in parts of Africa (Durand, 1955), Kharchia) and barley are the common modified the scheme to extend the suitabi­ crops. During the growing season, 30 lity of waters up to 20 mmhos EC on to 40 cm of water is applied. The crop is light-textured soils for salt-tolerant crops. grown in a cyclic management and after For similar crops on clayey soils, waters harvesting it, the land is left fallow for one up to 2.25 mmhos EC only and with low to two rainy seasons, and this respite sodium hazard were suitable. Rama­ amounts to fallows of seven and nine­ moorthy (1964) slightly modified the sali­ teen months respectively. So as not to nity classes by extending the salinity limit leave the well idle, the holding is divided of class C4 to 6.75 mmhos, keeping into the parcels, each receiving water C~ in the range of 6. 75 to 20.25 mmhos in alternate years. The sites have been EC. He allotted ratings to soil texture, under irrigation for over 10 years and some SAR and EC of the irrigation water and for as long as 50 years. The texture of salt-sensitivity of crop. the subsoil is silty clay loam or finer at Mehta et al. (1969) realizing the feasibi­ six sites, loam to clay loam at nine, sandy lity of using highly saline water in the loam to gravelly loam at eleven and sandy arid environment extended the suitability at two. The depth of the soil is 40 to 80 of waters to 12 mmhos, provided the em, below which there is a concretionary SAR was very low. or gravelly layer. The water-table is With the availability of more data on the seven to twenty metres. performance of crops under saline-water Characteristics of irrigation waters. ,Of irrigation (Paliwal and Maliwal, 1968; the 28 sites, 16 have E.C. between 5 and Shankaranarayana et al., 1965; Gupta 10 mmhos, 10 between 10 and 15 mmhos and Abichandani, 1968; Moghe, 1968 and 2 above 15 mmhos. Among the and others) it became evident that highly cations, sodium is by far the dominant saline waters could be used successfully cation, followed invariably by magnesium even on medium- and heavy-textured soils. and then by calcium. Sodium adsorption Also in the vast salinity range of Cs class ratio is mostly between 15 and 35. Among of the previous workers, the performance the anions, chloride is most dominant one, of even tolerant crops varied greatly. At followed generally by sulphate. The resi­ the same time, a need was felt to gather dual sodium carbonate' is absent in all more data on the performance of crops cases.

139 DESERlIFlCATION AND ITS CONTROL

Table 11. Water quality ratings (Bhumbla and Abrol, 1972)

Nature of the soil Upper permissible limit of E.C. in micromhos of water for the safe use for irrigation of crops Semi-tolerant,jj Tolerant

1. Deep black soils and alluvial soils, having a clay content more than 30 per cent. Soils that are fairly to moderately well- drained 1,500 2,000 2. Heavy-textured soils, having a clay content of 20-30 %. Soils that are well-drained internally and ha ve a good surface-drainage system 2,000 4,000 3. Medium-textured soils, having a clay content of 10-20 %. Soils that are very well-drained internally and have a good surface- drainage system 4,000 6,000 4. Light-textured soils, having a clay content of less than 10%. Soils that have excellent internal and surface drainage 6,000 8,000

- N.B. For the above-proposed limits. satisfactory internal drainage and water-table below 1.5 metres at the site. with the soluhle sodium percentage of irrigatIOn water below 70 per cent. are assumed.

Salinity build-up during the irrigation the crop has been harvested is left fallow phase. At the start of the irrigation during the ensuing rainy s~ason and, in phase of the cycle, the entire profile of the most cases also, for one more year, or till soils up to the loamy texture and up to the second rainy season. Salinity changes the upper 40 cm of the heavier soils mostly during the fallow period were followed by have the saturation-extract values of I. 2 a depth-sampling of the soil after each to 2. 5 mmhos EC. Salinization pro­ rainy season. Results obtained from diff­ gresses with the advancement of the sea­ rent sites grouped according to the tex­ son, and towards the close of the system, ture of the soil for different years are the soils show a huge salinity build-up. presented in Table 12. In preparing this Salinity is distributed throughout, with a Table, leaching of the salts has been worked weak maximum at a soil depth of 0-20 out as the percent"age loss after one or or 20-40 cm. Data on the range and the two rainy seasons, as the case may be, mean value of the saturation"extract - of the accumulated salts. The accumula­ salinity at harvest time in the top 40 cm ted salinity is the salinity added during of the soil thickness for different years a particular irrigation season, i.e. the in relation to the mean salinity of the irri­ difference between the salinity that the gation water and the texture of the sub­ soil had at the start and the close of the soil are presented in Fig. 2. The results irrigation season. The figure of over show that with the irrigation-water sali­ 100 % leaching shown in some cases is due nity between 5 and 17 mmhos, the soil at to the fact that in this particular situation harvest time attains 4.5 to 14'mmhos EC not only all the salinity added during the of the saturation extract with just one sea­ preceding irrigation has been taken care son's irrigation. The magnitude of sali­ of, but also thc residual salinity, parti­ nity build-up rises with the increasing cularly in the 40-80-cm depth, the soils salinity of the irrigation water and the generally, have at the start of the irriga­ texture of the soil. tion season. Results (Table 12) show Salinity changes during the fallow phase. that in 1971 and 1972, each of which As st~ted earlier, a particular parcel after received only 60 % of the mean annual

140 SALINE WATERS-POTENTIALITY FOR IRRIGATION

14 , j '2 I -;;; 0 .r::. E 10' j I .§. .r::. <.> ;;; 8 ~ I t j If\ tf = t (; I I'd.elly loam t • Fine loam - clay loam 2 • Silty clay loam

6 8 10 12 14 16' 18 20 22 24

Mean E.C. irri~atlon water em m 1105) Fig. 2. Mean salinity build-up in O.04-cm soil layer in relation to its texture and mean salinity of irrigation water for the period 1970-73 at different sites rainfall, complete leaching from one year's A fallow for the second year led to rainfall occurred only in the loamy-sand progressive leaching and was particularly site. In the sandy-loam sites, 80 % of the significant when the preceding rainy sea­ accumulated salinity was lost from the top son had been below the average. Rains 40-cm layer. On heavier soils, desalini­ of two consecutive drought years of 1971 zation was of the order of 50-80 % for this and 1972 were enough to wash down depth. During 1970, which received salinity from the 0-40-cm depth from sites 142 % of the average rainfall, the com­ of all textures. The foregoing results plete leaching of accumulated salts· wa~ clearly show that the huge salinity build­ achieved in all soils except in the silty up of the irrigation season is taken care of clay loams. In the latter, the leaching by one above-average year's rainfall or two from the 0-60-cm depth was 70 % only. subnormal rainy seasons. Some salinity is An exceptionally wet year, such as 1973 retained at the 40-60-cm soil depth, parti­ (twice normal) alone was enough for the cularly in clay-loam and heavier soils, complete leaching of all accumu1ated but this condition has not been found to salts from the soils of all textures. As interfere with re-use of the land. seen from the figure of over 100 % The alkali hazard in soils. The alkali during this year, even the residual salinity hazard was measured in terms of exchange­ that is often present at 40-80-cm depth able sodium in the soil at different phases was leached down, besides that added of the cycle. The results showed a large during a particular irrigation season. intersite as well as a cyclic variation. At

141 DESERTIFICATION AND ITS CONTROL

Table 12. Natural leaching of accumulated salts during the fallow period due to rainfall at different sites grouped according to the texture of the subsoil (data expressed as percentage loss of salinity accumulated during the preceding irrigation season)

S. Year 1970 1971 1972 1973 1974 No. Annual rainfall(mm) 596·5 276·8 239·3 892·6 201 5 One- One- Two- One- Two- One- Two- Two- Total amount of year year year year year year year year' rainfall (mm) re- Depth fallow fallow fallow fallow fallow fallow fallow fallow ceived during the fallow period (cm) 596 5 276·8 873 3 239 3 511 5 892·6 1131 9 1,094 ·1

Textural group

1. Silty clay loam 0-20 78 81 101 85 91 102 119 132 0-40 73 53 100 60 73 120 144 152 0-60 72 36 96 44 50 153 148 159 2. Fine loam ,to 0-20 103 67 95 89 94 115 107 105 clay IoaI? 0-40 102 53 99 82 88 116 107 125 0-60 99 45 83 59 70 118 122 150 3. Sandy loam to 0-20 107 93 102 96 '100 96 113 107, gravelly loam 0-40 104 86 101 82 95 102 116 107 0-60 102 65 73 88 107 108 117 4. Sandy to loamy 0-20 113 100 125 100 sand 0-40 110 98 105 94 0-60 116 96 96 90 harvest time, the soils had 1. 3 to 7. 2 mel sites (Table 13) brought out this pheno­ 100 g of exchangeable sodium which menon even more spectacularly. The ex­ constituted 14 to 53 % cation-exchange changeabte sodium percentage values at capacity of the soil with the subsoil gene­ the sites after natural leaching during the rally having somewhat higher values than fallow phase were incredibly lower than those of the upper 20-em soil layer. what had prevailed at the peak of salini­ The values in the top 20:cm layer at this zation phase. In fact, the top layer in stage corresponded very closely with . many cases was not even characteristically what were predicted by the sodillm-adsorp­ sodic after leaching. This favourable tion ratio of the irrigation water. Samples trend in the soil was found to be related collected during the fallow phase showed to the presence of calcium and sulphate a distinct decline in the exchangeable in the irrigation water. They got accumu­ sodium, particularly in the top layer. lated more in the surface layer. Results In all cases but one, the values were much in Table 14 for some of the sites clearly lower and in one case against a value of show that in comparison with the com­ 6 1 me/IOO g, the value reached after position of the irrigation water, the soil­ desalinization was only 1.6 mell00 g. saturation extract had proportionately a Figure 3 shows the mean values of alkali much larger concentration of calcium hazard prevailing in the soil in relation to and a lower concentration of magnesium those predicted from the sodium-adsorp­ than those in the irrigation water. Thus tion ratio of the irrigation water. The during irrigation and the accumulation r~sults interestingly show that the fallow of salts, there is a differential accumulation period, besides leaching the salts led of calcium. In the O-IO-cm layer, the to a significant lowering of the alkali concentration of CaS04 at this time in the hazard at the 0-20-cm soil depth. A sub­ saturation extract was of the order of 25 sa!l1pling of 0-20-cm layer at some of the to 45 m.e/I, which was many times more

142 SALINE WATERS-POTENTIALITY FOR IRRIGATION

than that present in'the irrigation water. lead to a high level of salinity even after However this concentration did not mar­ one season's irrigation. but this build-up kedly' lower the sodium-adsorption ratio is not permanent and is amenable to lea­ at this stage, as the amount of magnesium ching through rainfall. Second, the use was correspondingly less. Thus the al­ of highly saline sadie waters has also not ready stated extraordinarily low values led to a permanent build-up of exchange­ of exchangeable sodium after natural able sodium. In fact, in the 0-20-cm la­ leaching, on the one hand, and a greater yer, the values of alkali hazard prevailing accumulation of calcium, on the other, during the fallow phase are much lower strongly suggest that during leaching, there than what could be predicted from the is a selective leaching of the accumulated sodicity of the irrigation water. salts, leading to a greater retention of Crop growth: Wheat (variety Kharchia) calcium sulphate and its subsequent inter­ and barley are the common crops under action with, the soil. the use of highly saline water. The lands The foregoing results very clearly show are dry-seeded at the rate of 1, 5 to 2 q/ha that the use of highly saline water does and then irrigated. In the course of a

Table 13. Alakali hazard in the soil of some sites at different phases of saline water cycle

Depth in em Exchangeable sodium in soil Depth in cm Exchangeable sodium in the (me/IOQ g) soil (me/IOO g) Crop at har- At the close Crop at har- At the close vesting time of the fal- vesting time of the fal- low phase low phase

2 3 4 5 6

Site 1 Site 6 0-5 2 7 0'36 0-5 2 63 1 '23 5-10 2,9 o 68 5-10 2 62 2, 11 10-20 3,0 1,74 10-20 2,32 4'10 20-40 4,4 4,50 20-40 3 88 4,28 Site 4 Site 17 0-5 5 76 2,21 0-5 3,36 o 27 5-10 5,31 4,56 5-10 3 64 0'80 10-20 5,25 8'79 10-20 3,84 1 54 20-40 9'13 11 ,10 20-40 4 09 3,64 40-60 11 28 11 20 40-60 4 18 4,73 Site 18 Site 41 0-5 2 23 0,21 0-5 4 82 0,7 5-10 2,24 o 44 5-10 422 l' 10 10-20 ?'42 0,38 10-20 4,42 1,86 20-40 3,92 2 97 20-40 5,36 3'66 40-60 3 44 2,91 Site 26 Site 43 0-5 3, 18 0'42 0-5 2,21 o 84 5-10 3'24 o 53 5-10 2,32 1 ,28 10-20 3,20 1,80 10-20 2 45 2 15 20-40 4,99 2,78 20-40 2,80 2,67 40-60 4,17 3, 16 40-60 3,29 2 11

143 DESERTIFICATION AND ITS CONTROL

Table 14. Percentage ionic composition of irrigation water and saturation extract of soils of some sites at the time of harvesting the crop

S. Soil depth Na Ca Mg Cl HeOa SO, No. 2 3 4 5 6 7 8 1 l.W 80·8 9 1 10'1 44·2 9'5 46·3 0-5 77 9 14·7 74 49 9 5 0 45'1 5-10 80·9 135 5·6 40·3 4·3 55'4 10-20 84 3 100 5·7 51·2 3·7 45·1 20-40 83 2 6·2 10 6 30 5 3·5 46'0 4 I.W 86-4 4·4 9·2 81·3 8 7 10 0 0-5 89 6 5·1 5·3 74 1 7·1 18·8 5-10 87·3 5 3 7·4 78·1 4'5 17-4 10-20 87'2 3·6 9·2 81·8 2 9 15·0 20-40 91·2 2·3 6'5 81 7 3·1 16·2 40-60 93·6 2· I 4 3 74·1 4·9 21 0 6 I.W 61·3 9·7 29 0 86·6 4'0 10-4 0-5 60 9 21·3 17 8 87·8 I 6 10 6 5-10 67 0 15 2 17·8 88 8 3 ·1 8· I 10-20 59·7 17·8 21'5 83·8 1 5 13·7 20-40 74·6 9·0 16·4 94 2 2 4 3·4 40-60 82·3 6·4 II ·3 95 2 2·3 2·5 17 I.W 69·2 15·2 15·5 60 0 3·0 37 0 0-5 70 2 21 2 8·6 63·2 36·8 5-10 65·7 23·0 II 3 56 6 2 6 40 8 10-20 65·6 23·8 10·6 58 7 1·9 39·4 20-40 73·9 16 6 9·5 711 3 9 25'0 40-60 76'0 14· I 9·9 62·8 3·1 34· I 43 I.W 69·3 II'1 19·6 58·8 4·1 37· I 0-5 69'0 18·4 II ·6 60·9 1·4 37·7 5-10 62 8 23 5 137 54 3 3·8 41·9 10-20 68·9 19·2 11·9 65 6 2·0 32·4 20-40 76 3 10'5 132 71·6 5 I 24·3 40-060 80-4 10 6 9·0 81·6 7·4 11·0

season, 30 to 40 cm of water is applied With the Eee at the harvest time above as 6 to 8 irrigations. The visual mani­ 11. 5 mmhos, the yields are poor. Ex­ festations of salinity stress are the reduced ceptions are two sites with the above­ height of the plants and the tip burn of the average nitrate content. It was seen that lower leaves. However,' the yields are waters having more than 1 and particularly fair. The results of crop yields for diffe­ 1.5 m.e/l N03 resulted in exceptionally rent years are shown in Fig. 4. Good, good growth. average and poor yields correspond to The results of analysis of the samples of over 15, 15 to 10 and below 10 q/ha grain wheat plants collected at the emergence yield respectively. The results show that of the ears showed that, though with with the Ee of irrigation water below increasing salinity there was a non-linear 10 mmhos and the Ee of the saturation Increase of sodium content in the plants, extract of the soil at harvest time below the contents of potassium, calcium, mag­ 11. 5 mmhos, the yields are good to aver­ nesium, phosphorus and nitrogen were age. Of 44 observations in this group, unaffected. Thus it seems that the saline­ .27 were rated as good, 16 as average and sodie environment created by the highly one as poor. With the Ee above 10 saline waters did not seem to affect the mmhos, but the Eee still below 11. 5 uptake by Kharchia of the essential major mmhos, the, yields are mostly average. nutrients (Dhir and Gajbhiye, 1976).

144 SALINE WATERS-POTENTIALITY FOR IRRIGATION

11

,10

9

c;; 8 Depth? - 20 em 8 .Depth 20 - 40 em 0 0 • ..::. j " .5 c c:: 6 • ~ / Ii 9 "" " 5 ,,/" 5 "0" • g> " 4 ~,,'/"/ . 4' j • / " 3 / . 3 ~ ./. " § 2 ,;"'." . 2 • "E ","'''.. ,. -c" / .I' • •• g . 0 " 2 3 4 7 o 2 3 4 5 6 7 a 9 Sa" predicted values of exchangeable sodium In soil (me/IOO g) Fig. 3. Exchangeable sodium content in soil during the fallow phase, in relation to exchangeable sodium predicted from sodium adsorption ratio of irrigation water. The underlined dots refer to sites having mostly over 15 m.e./I of calcium The protein content of the grain also was salinity resulting from the use of sodium not seen to be adversely affected by the chloride-dominated waters is not perma­ rising salinity of water. nent. In response to rainfall, the salinity is leached fast. In a 400-mm-rainfall Use of potentiality of saline waters in arid area, the salinity build-up is taken care of environment by one year's rainfall in soils of medium In evaluating the suitability of saline texture and by two year's rainfall in waters for the arid zone, a few fac­ heavier soils. Second, it has also been tors deserve special consideration. The found that the use of highly saline-sodie adverse-quality waters are often the sole waters for lengths of period from 10 to source. Rains are erratic in quantity and over 50 years has not led to a dispropor­ distribution and the average yields from tionate build-up of the alkali hazard. In the rainfed crops rarely exceed 4 to 5 q/ha., fact, the cyclic use of waters, such as is The farmers are generally without work feasible with these waters, allows a greater during winter. Therefore even lower re­ accumulation of calcium, which during turns, such as may be considered unremu­ the process of natural leaching results in nerative in other areas, are acceptable. a lower and favourable level of exchangea­ Further, the sunny and frost-free winters ble sodium in the most important surface provide ideal growing conditions for a layer of the soil. Thus highly saline number of commercial crops. The other waters can continue to be used with­ advantages are that even medium- and out reservation that their use may lead heavy-textured soils in most situations ultimately to the land getting unfit even have a pervious substratum and the for such a system. table is low. Based on the experience gained on the Further observations on the saline-water behaviour of crops in relation to the sali­ system under field conditions suggest that nity of irrigation water, the potentiality

145 DESERTIfICATION AND ITS CONTROL

20 II Good • Average 18 A Poor 16 • • 14 . .. • A • • • @®• • •• a --- ~ -- ~ r - ~ ------U) o • ®I ® ® & • E 10 ®I • E • iJ ® • .£ ®",,®~ ~ ••@ • <..S 8 •• • u,j .®.. ~@) I •• 11' • • I • " 1Ii... @ .. 6 .I!!II. ® x .­ . " xx "" " • 2 •

o+-----~2----~4~----6c-----~8----~1~0c----l~2~--~14~--~1~6----~1~8----~2·0

f.C. in mmhos of irngatlon water

Fig. 4. Growth of wheat at different sites in relation to salinity of irrigation water and soil at har­ Vest time. Good, average and poor mean over 15. 10-15 and below 10 q/ha of grain yield respectively. Single and double circles refer to the presence of nitrate in the irrigation water 1.0 to 1.5 and above m.e./l (Dhir et al., 1976)

EC of'water in mmhos 5 10 15 Yield of wheat in g/hli 20 15 10 Frequency of cropping in relation 'to soil texture Up to loamy sand Double cropping Wheat every year Wheat in most years with wheat and bajra Sandy loam to loam -do- Wheat in most years Wheat in most years Clay loam Wheat every year Wheat in alternate Wheat in alternate years years Silty clay loam and clay Wheat in alternate -do- -do- years

(N.B. Where waters contain 1 to 1 . 5 and over 1 . 5 me/I nitrate, 3 to 5 and 5-7 q/ha yield may be added. Wherever the water contains over 15 m.e./! calcium sulphate or a higher concentration of sulphate with calcium in the range of 8 to 15 m.e./I, wheat is possible in most years even on clay loam soils with water of 10 mmhos EC.)

146 SALINE WATERS-POTENTIALITY FOR IRRIGATION

BHUMBLA, D. ~. and AB~O~, I: P. 1972. Is your water sUltabJ~ for Irngatlon? Get it tested. Indian Fmg121X4) ; 15-6. DAS9~PTA, K .. 1975. Ground-water investiga- , Hons carned out and problems encountered in Western Rajasthan. Workshop on Pro­ blems of the Deserts in India. Geo!. Survey of India, Jaipur. DHIR, R. P., KOLARKAR? A. S. and BHOLA, S. N. '

147 DESERTIFICATION AND ITS CONTROL

Arid Zone 15 (1 & 2) : 17-22. PURl, A. N. 1949. Soils, Their Physics and Che­ MBHROTRA, C. L. 1969. Water quality and use of mistry. Reinhold Publishing Corp., pp. 550. saline water for crop growth in U.P. J. RAMAMURTHY, B. 1964. Some aspects of the mdian Soc. Soil Sci. 17 : 441. management of soil water plant climate MEHTA, K. M., MATHUR, C. M., SHANKARA­ complex in arid zone. Proc. Gen. Symp. NARAYANA, H. S. and MOGHE, V. B. 1969. Problems oj Indian Arid Zone 143-47, CAZRI, Saline-alkali soils in Rajasthan-their Nature. Jodhpur. Extent and Management. Department of RAMAMOORTHY, B., WAGDI, M. A. H. A. and Agriculture, Rajasthan. PALIWAL, K. V. 1972 Irrigation with Saline MEHTA, K. K. 1970. Studies on the effect of Water. I.A.R.I., Monog. No.2 (New Series). irrigation water on soil properties and SHAH, R. K., VORA, 1. C. and GANDHI, A. 1. crop growth with special reference to boron. 1966. GeOchemistry of ground-waters of Ph.D. thesis, UdaIpur University, Udaipur. North Gujarat. Proc. Symp. all Grqundwater MOGHE, V. B. and MATHUR, C. M. 1966. Status Studies ill Arid and Semi"arid Regions, pp. of boron in some arid soil of western Rajas­ 405-14, Univ. of Roorkee. ; than. Soil Sci. & Pl. Nutr. 12 : 95-8. SHAH, B. C. and BAPAT, M. V. 1972. Quality of MONDAL, R. C. 1967. Review of work on trace Ground- Waters oj Glijarat. Soil Survey Organi­ elements in Rajasthan. Ann. Arid Zone sation, Govt. of Gujarat (unpublished). 6(2): 161-69. SHANKARANARAYANA, H. S., MOGHE, V. B. and NARAIN P., SINGH, B. and PAL, B. 1976. Quality MATHUR, C. M. 1965. An appraisal of the or'underground irrigation waters in the semi­ quality of saline ground-waters of arid arid tract of Agra district. Ann. Arid Zone tract of western Rajasthan for agricultural 15(1 & 2) : 8-16. utilisation. J. Indian Soc. Soil Sci. 13(2): PALIWAL, K. V. and MALIWAL, G. L.. 1968. 103-108. Quality of irrigation water in relatIon to SINGH, S. S. and KANWAR, 1. S. 1964. Quality plant growth under field conditions. Proc. of well waters of Punjab. Bull. Nat. Inst. Symp. Water Management. pp. 270-283, Sci., India 26: 209-220. held at Udaipur, May 1966. SINGH, B. and BHUMBLA, D. R. 1968. Effect of PALIWAL, K. V. and GANDHI, A. P. 196~. Quality quality of irrigation water on soil properties. oj Irrigation Water oj Nagaur Distrlct. Tech. J. Research 5 : 166-171. BtU: No.2. Agri. Expt. Station University TALATI, R. P. 1969. Water quality and use of of Udaipur. saline waters for crop production with spe­ PALIWAL, K. V. and MALIWAL. G. L. 1971a. cial reference to Gujarat, Symp. all Soil Cation-exchange equilibria Na-Ca-Mg sys­ and Water Management, March. 11-13, tem of soils and clay minerals. II. Proc. 1969, Hissar. Indian natn. Acad. 37 : 114-121. TRIPATHI. B. R., SINGH, R. M. and Dexit, S. P. PALIWAL, K. V. and MALIWAL, G. L. 1971b. 1969. Quality of irrigation water and its Some relationships between constituents of effect on soil characteristics in the semi irrigation waters and properties of irrigated desert tract of Uttar Pradesh. Indian J. soils of western Rajasthan. J. Indian Soc. Agron. 14 : 180-86. Soil Sci. 19 : 299-304. TRIPATHI, B. R., MISHRA, B., SINGH, R. M. and Pl\LIWAL, K. V. and MALIWAL, G ..L. 1971c. SINGH, B. P. 1971. Quality of irrigation Prediction of exchangeable sodIUm .. p~r­ water and its effect on soil characteristics centage from cation exchange eqUl!Ibna. in semi arid tract of Uttar Pradesh. II. Geoderma 6 : 75-8. Effect of water quality on soil properties PALIWAL K. V. 1971. Quality of irrigation water and yield of wheat crop. Indian J. Agron. , and their effect on soil properties in Rajas­ 16: 95-102. than. Ann. Arid Zone 10 (4) : 266. PALIWAL, K. V. 1972. Irrigation under Saline UPPAL, H. L. and KHANNA, P. L. 1966. Artificial Water. I.A.R.1. Monog. 2, (New series). changing of brackish groundwater. Irrig. PALIWAL K. V. and MEHTA, K. K. 1973. Boron Power 23 : 151-62. stat~s of some soils irrigated with saline U.S.S.L. STAFF 1954. Diagnosis and Improvement waters in Kota and Bhilwara region of oj Saline and Alkali Soils, as Handbook 60, Rajasthan. IndianJ. agric. Sci. 43(8) : 766. USA Dept. Agric., pp. 147.

148 ,16 DESALINATION TECHNIQUES FOR CONVERSION OF BRACKISH WATER INTO POTABLE WATER FOR SMALL COMMUNITIES

A. v. RAO AND D. J. MEHTA

THE supply of good-quality potable water valleys where salinity in groundwater is to the community is a measure of the normally expected. degree of civilization which a society can Brackish waters generally have sodium reach, and it is the civic responsibility of chloride in the range of 1000-1500 ppm, those in power to ensure a continued sup­ with the TDS up to 3,000 ppm, whereas ply of good-quality potable water to the the sea-water falls in the category of very masses. (Table 1). There are many large highly saline water in which the TDS is areas in our country which are deficient in up to 3,5000 ppm. The degree of ioniza­ potable water. There are many places in tion and the capability of ground-water Kutch, Saurashtra, Rajasthan, Haryana, to take or reject the salts in order to retain Orissa, Tamil Nadu and Karnataka and, its ionic equilibrium are the principal fac­ for that matter, in almost every State tors governing the waters to become saline where people drink brackish water, with or brackish. Moreover, the ground­ salinity ranging from 1000-5000 ppm. An water is an aqueous solution of carbonates, appraisal of the chemical quality of ground­ bicarbona·es, sulphates and chlorides of water occurring in varied hydrogeological the alkali and alkaline earth metals. settings and ecological environments, as re­ It has been reported that in parts of the vealed through the exploratory drillings, Punjab and Haryana States and in western is outlined in a paper by Ragbava Rao et Rajasthan, the quality of water is highly af. (1971) which covers the information variable from place to place and the TDS from representative areas in the four regions is always above 5,000 ppm. (Raghava of the Indian Subcontinent. Rao et al., 1971) In the Kutch area, (i) The arid tracts of western India, (ii) the deeper aq uifers contain highly saline the semi-arid regions of Rajasthan, partly waters, the TDS being in the range of Gujarat and central India, (iii) the coastal 3,000 ppm and above. In the Banas­ regions from West Bengal to the Madras kantha and Mehsana districts of western State, and (iv) isolated patches in Indo­ Gujarat, highly saline waters are encounter­ Gangetic alluvium and the inland river ed. In them the chloride content shoots up to 12,000 ppm. The waters occurring Table 1. U.S. Public Health Service's Standards in the Saurashtra region are saline and the for Drinking-Water TDS generally ranges from 2,000 to 5,000 ppm. The coastal areas of the Rama­ Max. ppm nathapuram district in Tamil Nadu were 1- Total dissolved solids (TDS) 500 explored by making bore holes aDd the 2. Chloride (CI) 250 data revealed the composition of sea­ 3. Sulphate (SO.) 250 water. Fig. 1. shows the distribution and 4. Magnesium 125 extent of salinity of the ground-waters of the arid zone of western ~ndia.

149 DESERTIFlCA1l0N AND ITS CONTROL LEGEND _.-.-- Intem.tional boundary State boundary • District boundary

Fig. ]. Distribution and extent of salinity of the ground-water of the arid zone of western India © Government of India Copyright, 1977 Based upon Survey of India map with the permission of the Surveyor General of India. The territorial walers of India extend into the sea to a distance of twelve nautical miles measured from the appropriate base line. DESALINATION TECHNIQUES

The ground-waters from three develop­ vapour is condensed on the underside of ment blocks in the central Luni River basin the roof and runs down into the troughs of Rajasthan have been classified according which conduct the distilled water to a to their TDS range by MandaI (1964): The reservoir. The still acts as a heat-trap, classification shows that nearly 45 % of because the incoming sunlight passes the ground-water coverage is in range -of through the transparent roof, but the roof 1,SOO-7,000ppm. Sometimes, these waters, is opaque to the long infrared radiation besides being saline, contain undesirable emitted by the hot water. The roof en­ or injurious chemicals which are respon­ closes all the vapour and prevents its loss sible for some peculiar diseases. For in­ and at the same time keeps the wind from stance, fluorine in water causes what is reaching the salt water and cooling it. The commonly known as fluorosis. The con­ water wets the glass and gives a smooth tinued neglect and indifference on the part transparent film of liquid. Table 2 shows of the authorities without paying any at­ the distribution of solar energy in glass­ tention to solve this problem, in itself, roofed stills, whereas Table 3 gives the constitutes a civic crime. It is precisely performance of a typical glass-roofed still. here that they can have recourse to science and technology; adopt techniques which Table 2. Distribution of solar energy in glass­ have been developed and solve some of roofed still the environmental problems for the welfare ------of society. The Central Salt & Marine Reflectl'on Dec. May Chemicals Research Institute has develop- Absorption by glass cover 114 ·18 % 114 8 4 % ed some desalination techniques which are Los~ by radiation frqm heated eminently suited to a given set of condi- water 36 0 16 9 tions. The most important of these tech- Internal circulation of air 136 8 45 . ( f 11 Ground and edge losses 2 1 3 mques are: 1) the use a solar sti s, (2) Re-evaporation, shading, etc. 7·9 lA 5 reverse osmosis, and (3) electrodialysis. Distillation of water 24' 5 40 5 Solar stills Table 3. Performance of glass-roofed still Solar stills are ideal for small isolated (Daniels, 1964) communities where water requirement is not much, the needed power is not avail­ able and the water is saline. The trans­ Dec. May port of water from the neighbouring places Average solar radIation, BTU ft 2 duy-l 756 2,318 is neither easy nor feasible. The advant­ Average solar radiation, ages of solar stiI1s are that no expendable Langleys day-l 205 628 energy is required; salinity can be to any Average cover tem- degree; they are simple in construction and perature 71°F 22°C 98°F 37°C Average brine tem- the operating and maintenance costs are perature 82°F 28°C 111°F 44°C small. Average production gal ft- 2 day-l 0·021 o 105 Glass-roofed solar stills (Gal day-l ft- 2 heat vaporization (8,913 BTU A solar still consists of a long, narrow, ______gal-l) x 100 black tray which holds the salt water and 24% 40% is covered with an A-shaped tent -roof of (Solar radiation BTU ft-" day-l) glass with gently sloping sides that end over a trough at each side of the tray. The sun's rays pass through the glass roof After extensive studies on both labora­ and are absorbed by the blackened bottom tory and pilot-plant scales of 1,000 litres of the tray which holds about 2.5-cm deep per day, this Institute. ha~ gaine? suffici~nt salt water. As the water becomes heated, experience and expertIse In the mstallatIOn its vapour pressure increases, the water of solar stills of any' suitable capacity.

151 DESERTIFICATION AND ITS CONTROL

The average output of the still is about permeability for water, so that high water 2.5 litres per Sq metre per day. The de- outputs (product water flux) coulq be ob­ sign developed by the Institute can be tained. Membranes with satisfactory per­ adapted for the installation of solar stills formance have been fabricated from indi­ an ground or terraces and the construc- genous cellulose acetate and are currently tion materials are those commonly em- used in our reverse-osmosis plants. ployed in building construction. This Based on the experience and expertise Institute has also designed solar stills and gained in fabricating the reverse-osmosis has helped to install them at (1) Navinar plants for drinking-water as well as for Lighthouse (l30-litre-per-day capacity), (2) industrial separation problems, this In8ti­ The Engineering Research Institute, Baroda tute has set up one plant of 9,000 Ijtres of (80-litre-per-day capacity), besides instaIl- potable water per day in the border area ing its own unit at the Experimental Salt (Vigakot) and another of ] 5,000 litres per Farm (l,OOO-litre-per-day capacity), and - day was operated for 3 months at Rajas­ another of 100-litre-per-day capacity on thali-a village in the Amreli district. the terrace. Recently, this Institute has Likewise, one plant of 10,000 litres per undertaken the construction of the two day was fabricated and demonstrated to the solar stills, each 'of 5,OOO-litre-per-day Defence Establishment at Jodhpur, where­ capacity in two villages in the Gujarat as another plant of 1,0.00 litres per day State as part of the general programme to was supplied to the Sunderban Develop­ be extended to other States also. ment Board, Government of West Bengal. One plant of 10,000 litres per day was ope­ Reverse osmosis rated round the clock for 21 days at the Reverse osmosis is a membrane process Hissar Textile Mills, Hissar, Haryana, on in the sense that it employs semi-perme­ their well water. able non-ionic membranes for the purifi­ cation of water. It is suitable for medium ELECTRODIALYSIS requirements up to 100,000 litres per day. Electrodialysis employs perm selective Salinity can be as high as 10,000 ppm. membranes for the desalination of brack­ The advantages of the reverse osmosis are: ish water. This process is more economi­ (i) energy costs are only the pumping cal for salinities below 5,000 ppm. The costs; (ii) it is simple in operation and energy costs are directly proportional to maintenance; (iii) it finds varied applica­ the salinity and, hence, beyond 5,000 ppm,

tions in many process industries j involving reverse osmosis has a distinct advantage separation, concentration and purification over electrodialysis. of chemical species. Electrodialysis-properly called muIti­ In the reverse osmosis, the saline water ple:ion-exchange-membrane electrodialysis flows under pressure through a semi-per­ (MIEME)-is a relatively new unit pro­ meable membrane inserted with a suitable cess. In this process, both cation- and backing support in a perforated aluminium anion-exchange membranes are used. The tube when the solvent water permeates cation-exchange membranes allow only through the membrane and is collected in the cations to pass through them, but are a trough. The rejected solute species virtually impermeable to the anions. Simi­ which get concentrated as a result of the larly, the anion-exchange membranes allow removal of water are carried along with only the anions to pass through them, with the effluent which is discharged as a waste a negligible permeation by the cations. As stream. The heart of the technique lies in these membranes are ionic in character, the membrane which should behave as an they act as ionic conductors and the ionic ideal semi-permeable membrane, so that transport takes place under the influence . the maximum rejection of the solute spe­ of an electrical potential. cies is achieved. At the same time, the By packing the cation- and the anion­ _membrane I;lhould have a reasonably good exchange mambranes alternately in-bet-

152 DESALINATION'TECHNIQUES

ween two electrodes, thin chambers are nate chambers in the stack get depleted in formed with the help of gaskets and spa­ salt content, whereas the remaining cham­ cers, which are non-conducting plastic: bers get concentrated with salts. The materials. Any feed-water to be desalted process is made continuous as the concen­ is split into two streams and fed into alter­ trated and ·dilute solutions are drawn out nate sets of compartments in the stack. continuously from the system. The most The electrode chambers are separately attractive feature of this process is the flushed with the feed-water to remove the control on the product water salinity by products of electrolysis. When a direct suitable adjustments of the flow-rate and electric current is passed through this unit, current input. One plant of 10,000 Iitres of the ions in solution migrate towards the potable water per day was set up and electrodes of the opposite polarity, but operated by this Institute for 6 months at owing to the membrane barriers, the alter- a village of Diu and another of 12,000 litres per day was operated for one year at Table 4. Construction costs of a standard Motagokharwada, a village in the AmreIi solar still district. Likewise, one plant of 25,000 Iitres per day was fabricated and demons­ (20 (m') area, 50-lit./day capacity) trated to the Defence Establishment at

Break-up of costs Rs/m' Table 5. Cost of product water from solar stills of 5,000 litres/day capacity 1. Foundation and sand-filling 8·00 2. End and side walls complete with plaster 32 00 = Life of the still is assumed 20 years 3. Still bottom, i.e., plastered masonry with paint 21·00 = Annual charges combining dep­ 4. Top support, aluminium tee 4·00 reciation and interest (amorti­ 5. Product channel of aluminium 15·00 zation) is taken as 8· 0 % 6. Glass cover fitting with sealing, etc. 30·00 Annual cost Rs Cost of distiller per m" 110 00 (Basis: 365 days)

Solar still 1. Amortization @ 8 % 17,680 for villages 2. Labour charges: 1. CapacitY,litres/day 5,000 (i) Operator @ Rs 200 per men- sem 2,400 2. Area, m" 1,850 (ii) Additional labour for clean- iog and maintenance-l00 Construc- man-days per year per 1000 tion costs in m'; for 1850 m'; 185 man- Rs days per year @ Rs 5 per man- day. . 925 1. Distiller unit 2,03,500 3. Maintenance and repair @ 1 . 0 % 2,210 2. Storage tank 2,500 ---- 3. Blending tank 2,500 Total cost of production 23,215 4. Raw water storage tank 2,500 ---- 5. Shed to house the materials 2,000 6. Hand-pump, pipe fittings, etc. 8,000 Total production per annum 1825 m" Cost per m3 (1,000 litres) Rs 12·8 Total costs of the unit 2,21,000

Contingencies @ 5 % 11,000 Assuming the blending of distilled Miscellaneous such as visits to the water with feed-water in the ratio site, etc. @ 10 % 22,100 of 4:1, then daily output is 6250 litres, and cost per m3 Estimated input per unit 2,54,100 10·2

153 DESERTIFICATION AND ITS CONTROL

Jodhpur, whereas another plant of 5,000 Total operating cost per day Iitres per day was supplied to the Sunder­ (sum of 1 to 4) 80-60 ban Development Board, West Bengal. The estimated capital costs and the .'. Cost of desalted water per operating costs for plants of 5,000-litre­ J ,000 litres 8-06 per-day-capacity of solar stills and 10,000 litre-per-day of reverse osmosis and a electrodialysis are given in Tables 4 to 7, Table 7. Cost estimates for one electrodialysis whereas Table 8 summarizes the compa­ desalination plant rative costs of three techniques. Capacity 10,000 Table 6. Cost estimates for reverse osmosis litres of desalination plant potable water/ day Capacity 10,000 litres pota­ Feed-water salinity 5000 ppm ble water! day Product water quality 1000 ppm

Feed-water salinity 5,000 ppm CAPITAL INVESTMENT

Product water quality 500-1,000 Principal items (P.T.) ppm Rs 1. Electrodialysis stacks 35,000 CAPITAL INVESTMENT 2. Membrane 10,000 3. Pumps 3,000 Principal items (P.I.) 4. Rectifier 6,000 Rs Total P.I. 54,000 1. Plant module 30,000 2. Membrane 3,000 3. High-pressure pump 17,000 Subsidiary costs 5. Instrumentation.@l0% of Total P.I. 50.000 P.L 5,400 6. Erection & Assembly @ 10 % P.I. 5,400 Subsidiary costs 7. Contingencies @ 5 % of P.L ·2,700 4. Instrumentation @ 6 % ofP.I. 3,000 Total capital investment 5. Erection & assembly @ 10% (C_L) (sum of 1 to 7) 67,500 of P.I. 5,000 6. Contingencies @ 5 % of P.L 2,5~0 OPERATING COST PER DAY Total 'capital investment (sum of 1 to 6) 60,500 Items Rs 1. Energy cost 11-00 2. Labour & supervision (one OPERATING COST PER DAY skilled person per shift) 30 00 Rs 3. Maintenance (2 % of C.l.) 4 00 Items 4. Depreciation: 18 00 1. Energy cost (a) On membrane (20 %) 6 00 3. Labour & supervision (one (b) On pump (10%) 1-00- skilled person per shift) 3D-DO 3. Maintenance (2 % of C.L) 3-60 (c) On plant (7 -5 %) g-OO 4. Depreciation: Total operating cost per day (a) On membrane (replace­ (sum of 1 to 4) 60 00 ment every 6 months) 17 -DO (b) On pump (10%) 5-00 . '. Cost of desalted water (c) On plant (7 -5 %) 7-00 per 1,000 litres 600

154 DESALINATION TECHNIQUES

Table 8. Comparative costs of three desalination (2) Amortization 97 29 15 techniques (3) Labour and super- vision 18 30 30 (4) Maintenance & Capacity of the plant: 10,000 lit: repairs 12 3 4 res/day of (5) Cost per m S 12'7* 8 6 product water * Assuming the blending of distilled water with feed water in the ratio of 4:1, then the cost Desalination ratio 5 per m 3 is Rs 10. (For R. O. & E. D. plants only) REFERENCES Standard Methods for Examination of Water, Desalination techni­ Sewage and Industrial Wastes (10th Edition), ques Published by American Public Health Asso­ Cost estimates ciation, pp. 177,58, 196 and 333. Solar Reverse E1ec­ RAGHAVA RAO, K. V., RAO, A. A. and DOSHI, stills osmo- tro­ C. S. Brackish and saline ground-water sis dialy­ resources lIS revealed through ground-water sis exploration in India. International Hydro­ logical Decade News Letter, India No. II, Jan. 1971. I Capital investment Rs MANDAL, R. C. Quantity of ground waters in in lakhs 5·08 0 63 0·68 Siwana, Jalore and Saila Development Blocks. General Symposium on Problems of II Operating costs Rs per Indian Arid Zone: Jodhpur, 23rd November- day 2nd December 1964. DANIELS, F. Direct use of the sun's energy. Yale (1) Energy costs 18 11 University Press, 1964.

155 17

GROUND-WATER RESOURCES OF THE ARID ZONE OF INDIA

T. N. MEHRA AND AMAL KUMAR SEN

THE great Indian desert, also called the drainage system, except the Luni River, Arid Zone ofNorth- Western India, extends which has a flood cycle of 16 years. The between 22° 30' Nand 32° 05' N latitude rest of the drainage lines are mostly inter­ and from 68° 05' E to 75° 45' E longitude. nal and ephemeral and carry water only In the entire area, the total annual eva­ during short cloud bursts and die out soon potranspiration exceeds the total annual owing to the alluvial suffocation or exces­ precipitation. Highly unfavourable hydro­ sive evaporation (Sen, 1972). The general meteorological conditions in these areas slope of the area is towards the south­ not only create a shortage of surface west. Owing to the internal drainage water, but are also responsible for the very (Sen, 1972), salt lakes or saline depressions. low permeability of the soils, enriched with locally known as rann, are common, parti­ highly alkaline and soluble salts, with cularly in the Rajasthan Desert. Prach­ very low organic content, resulting in poor padra, Sambhar, Deedwana and Bap are vegetation, salt lakes. The depressions exist in Sans­ The requirements of water for drinking warla Ka Rann, Thob, Khatu, Lunkaran­ for livestock and for irrigation are met sar, Pokaran, Kaparda and in the laisal­ either from the ground-water resources mer area of Rajasthan. or from a network of canals from the The drainage lines of the arid zone of neighbouring sub-humid regions, or from Gujarat are all consequent, having their the local tanks. Own local base levels. The drainage lines Physiographically, the entire arid zone of the Punjab and Haryana States are in is 'characterized by vast tracts, almost the south-east. The Ghaggar River once covered bv a thick blanket of dune sand, flowed through the Ganganagar District except at' a few places which are rocky (Rajasthan) and drained into the Arabian desert. The arid zone has the most un­ Sea, after joining the Indus, and is now a favourable climatic conditions. 'dry bed' except during rains. The Ghag­ A study of the rainfall map of the north­ gar up to 1000 B.C. was known by its western Indian arid zone (Sen, 1972) indi­ more prominent tributary, Saraswati. cates that the region has three rainfall belts, viz. (a) 500 mm to 300 mm; from the GEOLOGY: WATER-BEARING FORMATIONS foothills of the Aravallis in the easrto the The north-western zone of India is con­ desert plains in the west. The zone has sidered a shelf, bounded to the south-east typical steppe desert conditions; (b) 300 by the Aravalli ranges and to the north­ mm to 100 mm, the hot sandy desert, and west by the Indus plains. . (c) below 100 mm, the extremely sandy A brief description in relation to the desert with dunes. The trends of the iso­ water-bearing formations of the main hyets are NE to SW. lithological units is summarized below. The area, is devoid of any well-defined The details of the geology are given else-

156 GROUND-WATER RESOURCES OF ARID ZONE

where in this publication. series are impervious, yielding only a The rocks of the Aravalli sy§tem com­ meagre supply of salty water. The Umia prise gneisses, schists, phyllites, slates and series were deposited only under fluviatile quartzites, and occur in a part of the Sikar,' and esturine conditions and partly under and Nagaur districts. These rocks are marine conditions. The marine formation hard and crystalline. Ground-water in of the series yields only saline water, and, these rocks moves through joints, frac­ hence, there is no development of ground­ tures, foliation planes and weathered zones. water in the fossiliferous sediment of the Wells dug to tap these formations yield a series. Ground-water in the Bhuj sand­ poor' discharge, ranging from 30 to 60 stone occurs under both confined and cubic metres per day. unconfined conditions. The static water The Raialo series comprises crystalline level in the dug wells ranges from 2 to limestones with dolomites. Ground-water 30.5 m.b.g.I. and that in the dug-cum­ occurs in joints, fissures and cavities bore wells and the tube-wells tapping the which yield water up to 30 cubic metres confined aquifers from 3. 4 to 31. 4 m. per hour. b.g.1. Ground-water to the tune of over The rocks of the Delhi system include 9,000 to 26,000 million litres has been mica schists, phyllites, calc gneisses and made availabJe for irrigation in the lower schists and quartzites. Ground-water in and upper Bhuj series respectively in these rocks also occurs and moves through Kutch. The tube-wells located well the joints, fractures, foliation planes and within the Bhuj sandstones yield about weathered zones. Wells tapping these 48.78 cubic metres of water per hour. formations yield discharges ranging from The quality of water is generally good. 40 to 80 cubic metres per day. The Ajab­ In the Deccan traps, in Kutch and in garhs in the Punjab and in Haryana are Kathiawar, ground-water occurs along fairly good as water-carriers and the wells joints, fractures and secondary partings, in them yield discharges ranging from which are generally limited in depth up 3.6 to 10 cubic metres per hour (Adyalkar, to 50 m. The static water level in the dug 1964). wells ranges from 4 to 12 m. The yield of The rocks of Jalore, Siwara, and Erin­ wells tapping these formations is moderate. pura granites, and Malani rhyolites, The semi-consolidated sandstones of the which are known as the igneous suite of Eocene age and the Alluvial formations intrusive rocks are very poor aquifers. of the Quaternary system occupy the These rocks yield very limited supplies major. part of the area in western Rajas­ of ground-water through joints, fractures than and form good aquifers of potable to and weathered zones. brackish water. Wells tapping these for­ The sandstones and limestones of the mations are capable of yielding good Vindhyan age, locally termed the Jodhpur, supplies, ranging from 40 to 80 cubic Bilara and Nagaur group of rocks form metres per hour. good aquifers in these areas. Well tap­ ping these formations are capable of GROUND-WATER yielding good discharges ranging from The ground-water in the arid zone 50 to 100 cubic metres per hour. occurs in rocks ranging in age from the The Lathi sandstone of Lr. Jurassic age Pre-Cambrian to the Quaternary system. of Jaisalmer is a good aquifer of fresh In hard crystalline rocks, such as gneisses, .water. It is c~pable of yielding high dis­ schists, phyllites and quartzites, the charge to ",)'-ells ranging from 100 to 175 ground-water occurs and moves through cubic metres per hour. the joints, fractures, foliation planes In Kutch, the rocks of Patcham and and weathered zones, whereas in the Chari series comprises calcarious shales sedimentary rocks, like sandstones, the and limestone and the quality of water is, ground-water occurs and moves through therefore, saline. The rocks of the Katrol the porespaces and interstitial openings of

157 DESERTIFICATION AND ITS CONTROL

granular sediments. arid zone ranges from less than 10 m to Ground-water in western Rajasthan as high as 140 m below the land surface. generally occurs under water-table con­ The deepest water-table has been observed ditions (unconfined) in hard crystalline in the area south of Bikaner in Rajasthan. and alluvial formations. In sandstones At a few places in western Rajasthan, of the Tertiary and older ages, ground­ perched water bodies have been observed, water also occurs under semi-confined to and they yield a very limited quantity of confined conditions owing to the presence fresh water through shallow wells (locally of overlying impermeable horizons. The known as 'berries') for drinking. The. depth up to which water is available in the depths of such bodies range from 8 to 20 metres only, whereas the regional water­ table in the area is quite deep. Table 1. Area (in sq km) under fresh and saline water THE QUALITY OF GROUND-WATER District Total Area Area The quality of ground-water in western area of having having Rajasthan deteriorates along with the the fresh saline district water water decrease in precipitation towards north­ west. The saline waters in the arid zone are dominated by sodium and chloride Churu 16,261 3,140 13,676 ions. The less saline waters are rich in Bikaner 27,102 5,302 21,800 Pali 11,808 9,408 2,400 bicarbonate, sulphate and divalent cations Jalore ]0,428 3,166 7,262 (Paliwal, 1971). Jaisalmer 38,475 11,797 26,678 Based on the ground-water investiga­ Banner 29,031 7,000 22,031 Nagaur 17,592 12,300 5,292 tions, and drillings carried out in the desert Jodhpur 22,213 16,213 6,000 areas of Rajasthan, it has been found that Sikar 7,658 7,328 330 the area of about 1,25,009 sq. km has Jhunjhunu 5,648 5,443 205 ground-water having chlorides exceeding , Ganganagar 20,384 ],041 19,343 1,000 ppm. This area forms about 60 % of the total area (2,06,600 sq. km) of ],25,009 2,06,600 western Rajasthan (Table 1).

Table 2. Exploitable ground-water potential in the arid zone of Rajasthan (in mem)

S. District Estimated annual re- Existing annual Surplus exploitable No. charge / annual eco- pum-page potential mically mining yield

1. Barmer . 85 40 45 2. Bikaner 33 10 23 3. Churu 7 3 4+89* 4. Sriganganagar 189 75 114 5. Jaisalmer 930** 8 885**+143+ 6. Jalore 410 200 210 7. Jhunjhunu 170 96 74 8. Jodhpur 235 150 85 9. Nagaur 250 125 125 10. Pali 330 170 160 11. Sikar 230 120 110

Total ],939 997 950/],117

• Denotes the economic mining yield in the ChufU District. •• Denotes the economic mining yield in the Jaisalmer District. + Denotes the economic mining yield of the Lathi series in the Jaisalmer District.

158 GROUND-WATER RESOURCES OF ARID ZONE·

THE GROUND-WATER RESOURCES The above Table indicates that at pre­ sent about 50 % of the annual recharge is The arid zone of Rajasthan comprises being tapped in the arid districts of Rajas­ a total area of about 206,600 sq. km and, than, leaving behind 950 mcm of surplus consists of 11 districts. Owing to the potential and 1,117 mcm of economic poor surface and subsurface drainage, the mining yield for the districts of Churu ground-water in a large part of the area and J aisalmer. is highly saline and, therefore, cannot be Out of the total area of the arid zone of put to any beneficial use. The hydro­ Rajasthan, 40 % of the area contains geology of the arid region is also very potable water, whereas in the rest of complex and is entirely different from the the area, the quality is saline to highly remaining areas. With a view to .locatin_g saline. freshwater aquifers and for assessmg their exploitable surplus, systematic .studies REFERENCES have been initiated by the Rajasthan AVYALKAR, P. G. 1964. Paleogeography, sedi­ Ground-water Department since 1964-65 mentological framework and ground-water and by the Central Arid Zone Research potentiality of the Arid Zone of Western Institute since 1962-63. The results of India. Proc. Symp. Prob. Indian Arid Zone (23rd Nov. to 22nd Dec. 1964). JI1inistry of these surveys are being published by these Education, Government of Indla, New organizations in the form of technical Delhi. pp. 4-17. reports and research papers. MEHRA, T. N. 1976. Ground-water potential The hydrogeological investigations car­ and its exploitation in Rajasthan. Report of Rajasthan Ground-Water Board (For ried out by the Rajasthan Ground-water official use only). Department have indicated a large ex­ PALIWAL K. V. 1971. Quality of irrigation ploitable surplus potential of ground­ waters and their effect on soil properties in water in the arid zone of Rajasthan. An Rajasthan-A review. Ann. Arid Zone 10 (4) : 266-278. account of this potential is given in SEN, A. K. 1972. Agricultural Atlas of Rajasthan. Table 2 (Mehra, 1976). ICAR, New Delhi.

159 18 THE ARID ZONES OF INDIA: BIO-CLIMATIC AND VEGETATIONAL ASPECTS

v. M. MEHER-HOMJJ

ARID zones in their broadest sense may be humid. Subsequent degrees of decreas­ defined as the zones experiencing chronic ing aridity may be recognized on the basis water deficit. However, there are large of the number of dry months. Defining areas in India with w,ater shortage at one a dry month in terms of rainfall poses time or another. The monsoon regime several problems; the definition of Bag­ leaves the major part of the country dry nouls and Gaussen (1953), .though empiri­ for a period varying from 3 to 11 months cal, is shown to be of practical use (Meher­ on an average, but the inter-yearly varia­ Homji, 1963, 1964a). However, the length tions are quite important and a station of a dry period in itself does not convey a experiencing on an average 3 months true picture of the aridity and the amount dryness may be subject to 6 months of dry of precipitation is also to be taken into spell. The mean dryness of 5 months consideration. A station, e.g. Bombay, may be prolonged to 8 months, that of receiving 2,000 mm of rainfall annually 8 months to 11 months, and the zone has a dry season of 8 months; another having 11 months of average dryness may e.g. Mysore having a dry season of 4 pass a couple of years without a drop of months may have an annual average of rain (Meher-Homji, 1974a). Whereas the 800 mm of rain only. Therefore Meher­ normal dry season, when rains are not Homji (1962, 1964b) in his index of aridity­ expected, goes unnoticed, the extension humidity proposed the combining of the of the dry spell beyond the time of the value of the factor precipitation quantity onset of the normal rainy season poses with that of the length of the dry period. a severe threat to water-management and The stations having the values of the index agricultural operations. This is also the more. than 81 characterize the dry zones. case when several weeks pass without Another approach that has been follo­ receiving any precipitation during the wed by Meher-Homji (1972) to define the rainy season. arid regions is to apply the climatic for­ mulae of several authors. * The stations Degree of aridity that are considered to be arid, according Several degrees of aridity may be to the formulae of all the authors for every recognized. The extremely arid zones are individual year, have been classified as the ones not experiencing any rain. for truly arid. A tower degree of aridity may more than a year at a stretch. Only be granted to the stations turning out to a very small portion of the extreme be arid on the average basis as per these western Rajasthan belongs to this cate­ formulae, but all the individual years do gory. In other cases, all the 12 months not fall into the arid category. Further in a year may be dry; there may be a few degrees may be recognized o,n the basis sporadic showers of very low intensity and *These formulae have been discussed earlier duration to characterise any month as (Meher-Homji, 1967).

160 ARID ZONES-BID-CLIMATE AND VEGETATION

of a number of formulae classifying the of. years tallying with the probable year. stations as arid, semi-arid or sub-humid. Only a few individual years agree with Finally, the clin~atic regimes·· (the season the probable year in the case of unstable of occurrence of rains) may vary for the : climate. In Table 1, at one extreme lies stations having the same degree of aridity. , Ahmedabad with 65 % of the years confor­ ming to the pattern of the probable in all Stability of climate the four factors. At the other extreme The climatic data are subject to strong is Dera Ismail Khan, with only 8 % of the Table 1. Degree of stability of 31 stations of the Indian Sub-continent (Mter Meher-Homji, 1974a)

Station Percentage No. of years tally- Station Percentage No. of years tally­ ing with probable ing with probable year year

Ahmedabad 65 Gilgit 39* Peshawar 60* Dalbandin 39 Sriganganagar 60* Bombay 38 Sibi 57* Drosh 38* Bannu 56* Kalat 35 Las Bela 56* Sri nagar 33* Parachinar 49* VVana 33* New Delhi 49* Sukkur 33* Rawalpindi 48* Barmer 33* Sialkot 47* Lahore 32 Ambala 46* Nokkundi 31* Miranshah 44* Coimbatore 30* Fort Sandeman 44 Murree 28 Quetta 42 Chitradurga 20 Chaman 41 Dera IsmaIl Khan 8 Sholapur 40* *Probable regime of more than one type inter-yearly fluctuations, especially in the years agreeing with the probable year in dry zones (Meher-Homji, 1971 a,b,c, 1972, which case not only the concept of average 1973a). There are variations not only in year breaks down, but also that of the the amount of rainfall, but also in its probable year in view of the small number duration and regimes. Meher-Homji of years falling within the limits set by (1 974a) proposed the assessment of climate the probable type. in terms of a probable year rather than in terms of an average year, as the latter On the recent climatic change tends to mask the bio-climatic pheno­ Linked to the variability and stability mena. of the climate is the problem of ascertain­ Meher-Homji established the degree of ing whether the rain in the Indian arid stability of climate of 31 stations of the zone is on the wane. This has been a Indian Sub-continent (Table 1) on the basis debated subject; the publications appear­ of the percentage number of years tally­ ing till 1963 argued in favour of no cli­ ing with the probable year, the latter matic change (Pramanik et al., 1952; Rao, being defined as the one during which the **The regime based on the season of occur­ values of precipitation, rainy days and dry rence of rains is either of tropical, Mediterranean, months correspond to the figures of the bixeric or irregular type. Tn the tropical regime, mean value plus or minus the standard rains are concentrated in summer and in the Medi­ deviation, and the regime.is of the com- terranean regime, in winter-spring. The bixeric type is characterized by two dry periods and two . monest type(s). The more stable the cli­ rainy seasons in a year. The remaining type with­ mate, the higher is the percentage number out seasonal rhythm is termed irregular.

161 DESERTIFICATION AND ITS CONTROL

1958, 1963). However, recently Win­ ness is assessed by using two parameters: stanley (1973) has come out with the (1) the amount of rainfall, and (2) the theory that since the late 1920s, the sum­ number of rainy days. It may happen mer rainfall in the Sahel zone (south that the quantity of rainfall may fluctuate of the Sahara) and in the north-western widely from year to year, without there India has been showing a declining trend, being any considerable change in the with a corresponding increase in the win­ number of rainy days. On the other hand, ter spring precipitation of the Middle the decrease in precipitation may be closely East and of regions to the north of the linked with the number of days when it Sahara along the Mediterranean coast. rains. The third possibility is that' the There was a temporary reversal in the rainfall may become too concentrated, 1950s but from 1960s the summer-mon­ a few rainy days giving a high tptal. soon rainfall in the Sahel and Rajasthan ]f the quantity of rainfall seems a delicate is once again at a low point of irregular parameter to appreciate from a bio­ fluctuation with a decreasing trend, where­ climatological view point, the number of as the cold-season precipitation of the rainy days could be equally tricky. In the ccuntries around the Mediterranean Sea is meteorological archives: just 2 mm of rain at a high point of an irregular fluctua­ suffices to make a rainy day. Of what agro­ tion with an increasing trend. climatic use could be such a low quantity One striking point in Winstanley'S (I.e.) in the tropics, with h~gh temperatures and analysis is that he combines the data of especially if preceded and followed by long different stations, sometimes even of sta­ spells of drought? We may assign equal tions having totally different regimes; for weightage both to the amount of rainfall example in his Figs. 3 and 5, Marrakeeh, and the number of rainy days. Tunis, Tripoli, Jerusalem, Beirut, Mosul, Besides the total rainfall and the number Shiraz are Mediterranean, having a bulk of rainy days, due consideration has to be of the rains in winter-spring, but Atar, given to the seasons. As it is pertinent Bikaner and Jodhpur are tropical, with to know the trends during the main crop­ rains concentrated in summer. ping period, two seasons are considered: Using the data of only six stations of the (1) the relatively warm period (May­ Sahel zone, Winstanley (I.e.) worked out October) coinciding with the prevalence an average decrease of 65 mm from 1960 of the south-westerly monsoon over the to 1970. Assuming that rainfall in this greater part of the peninsula, and (2) the zone and in Rajasthan would continue to relatively cool winter-spring season decrease at the same rate as it has done (November-April). In the northern and since the late 1920s, he predicts that north-western parts of the Subcontinent, within the,next 55 yeaJs, rainfall would be .the western disturbances bring rains during 40 to 45 % lower than in the optimum this cool season. years. He further goes on to generalize The trends of increasing or diminishing that by that time, the Sahara and the Thar rainfall and the rainy days for eight stations deserts will have advanced some 100 km are presented in Table 2 after Legris and farther south. Meher-Homji (1976). In'view of the fact that only two Indian Of the eight stations, Sriganganagar, stations, Jodhpur and Bikaner, were con­ New Delhi and Sholapur show an increas­ sidered in the above study and- their data ing tendency in the total rainfall, whereas "ere not analysed individually, Legris Ambala, Barmer, Ahmedabad, Chitra­ and Meher-Homji (1976) investigated the durga and Coimbatore present a decreas­ trend of precipitation of 13 Indian stations ing trend. from a bio-climatological point of view. In the case of Am bala, though the total 'Inter-yearly variations have been noti­ rainfall is on the decline, the rainfall of ced in the total and seasonal rainfall and the main rainy season, i.e. May-October in the ~ainy days. The character of rain i- with 84 % of the total rainfall, shows an

162 ARID ZONES-BlO-CLlMATE AND VEGETATION

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163 DESERTIFICATION AND ITS CONTROL

increase of 1 % since 1960. On the other tive side (Fig.2b). hand. the dry season, i.e., November­ It may be noticed from Table 2 that April, registers a fall in the rainfall at out of the six parameters (rainfall and the Sholapur and New Delhi where the total rainy days, the total and of the two sea­ and the May-October rains show an in­ sons), Sriganganagar presents decreas­ crease. The contribution of this dry ing trend only in the November-April season to the total rainfall is only 8 to rainfall. Sholapur is marked by decrea­ 12%. ses in two parameters-the November­ If the total number of rainy days is April rainfall and the rainy days. Bear.­ taken into consideration, New Delhi, ing in mind that this is the statistically dry Chitradurga, Ambala, Coimbatore, Bar­ season, the trend is not significan,t from mer, and Ahmedabad present a waning the agro-meteorological angle.· New trend and Sriganganagar and Sholapur Delhi presents decreases in three para­ an increasing tendency. meters viz., in the November-April rain­ However, New Delhi, Barmer and fall and rainy days, and in the total number Ahmedabad present an increasing trend of rainy days. Chitradurga maintains in the number of rainy days of the princi­ an average tendency only in May-O;;to­ pal rainy season, i.e. May-October, with ber; the total and the November-April over 80 % of the rainy days concentrated rainfall and rainy days register decreases. in this period. Chitradurga presents an Ambala, Coimbatore, Bllrmer, and Ahme­ average trend. dabad show the increasing trend in one No geographic correlation is noticed bet­ parameter only, i.e., that pertaining to ween the increasing trend alld the decreas­ rainfall in respect of the first two stations, ing trend. Even two neighbouring sta­ and to the May-October rainy days in tions may show an opposing tendency as respect of the remaining two. Thus no in the case of Barmer (the total rainfall station shows an out-and-out increasing or having decreased since 1958) and Sri­ decreasing tendency. ganganagar (with an increasing trend In conclusion, whereas it would not since 1948). be correct to say that India has become The trends may be illustrated with a drier in the recent years, the population few examples. Figs. I and 2 show the explosion and the attendant water needs variability in the seasonal rainfall and the for domestic and agricultural purposes. rainy days in respect of New Delhi and has increased the human dependence on Barmer. The yearly fluctuations as well the weather so much that the low-rainfall as the curves of the 5-year and the 20- years weigh heavily on the economy. year running means are presented. The Recently, Raman (1974) has prepared a strong inter-yearly variations may be noti­ monsoon map of Maharashtra, emphasi­ ced both in respect of the rainfall and the zing the sowing dates for various agro­ rainy days. The 5-year moving means climatic regions, bearing in mind the likewise fluctuate between the surplus variability in the commencement of the rainfall and the deficit rainfall at irregular monsoon. Legris et al. (1971) analysed intervals. In Figs. la, Ib, the 20-year the daily rainfall records of several years moving average curves show the general of the drought-prone Anantapur region upward trend of the total· and the of Andhra Pradesh and recommended May-October rainfall and the rainy days that the sowing of paddy should be don~ at New Delhi. Figs. Ic and Id outline in the second half of July when rains. the diminishing trend for the November­ become reliable, rather than with the first April rainfall and the rainy days. Figs. rains in June or May which are followed 2a to 2d show the declining trends at Bar­ by days without effective rains. Fast­ mer, ·with reference to the 20-year avera­ growing varieties could amply make up ge~, though in the case of the May-October for the delay in sowing. ramy daysl the values remain on the posi- Given the variability of the climatic-

164 ARID ZONE-BIO-CLIMATE AND VEGETATION

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165 DESERTIFICATION AND ITS CONTROL .,' ~o3~1 , % ,j 200 ", ZG~ Ii" I?O j r. "11 ~ " ", I, ," ' Zl~ 140 \ " ;, " " " " , " , I ,'I " ," , '65 , , 100 ' , , 60 , !

" " ' " ~.: ~;: I :; " ' 50 " , .' " .." \; 20 '940 '950 '960 1970 1940 1900 '196_0 1!l70

% 0' 300 I.; ; I, I'" " 250 " "r', I," " " ': " 400 200 " I " " " , " ,I I " " " " " " " " 300 ': " 160 I ", ' " " " I, " " , ': " ," , '00 200 " ,'" " '00 50 I" f , t,.. 0 1940 /950 '970 "

YEARLY 3 VEAR RUNNING MEANS 20 YEAR RUNNING MEANS CENTRED ON YEAR GIVEN CENTRED ON YEAR GIVEN Fig, 2a (Top left) Barmer-Rainfall for the Fig. 2b (Top right) Barmer-Number of rainy period May-Oct. days fo~ the period May-Oct. Fig. 2c (Bottom left) Darmer-Rainfall for the Fig. 2d (Bottom right) Barmer-Number of period Nov.-April. rainy days for the period Nov.-April. factors, another logical approach would The plant-cover is a good reflector of the be to delimit the bio-climatic zones purely environmental conditions and also inte­ on the basis of the natural vegetation. grates the variability aspect of the climate.

166 ARID ZONES-BIO-CLIMATE AND VEGETATION

Further, the regions derived from vegeta­ such formations are frequently subject to tional criteria point out the various water stress. land-units having a certain ecological uniformity and a particular degree of J. CaIIigoDum polygonoides type** aridity*. The most arid parts of western Rajas­ Yegetation types and their controlling than and Pakistan are characterized by the factors community of Calligonum polygonoides L. which physiognomically occurs in the The physiognomic aspect of the desert shape of scattered shrubs. It is encoun­ is poor, scanty, xerophytic vegetation, tered mostly on sand-dunes and sometimes \~idely dispersed, leaving large areas bare. also on loose sands. The annual average The sub-deserts comprise steppes or thorn­ rainfall is less than 400 mm and the length forests. Whereas the steppe is an expres­ of the dry season exceeds 9 months. sion of the cold-sub-desertic climates, the The characteristic species of this type, thorn-forest is the rule under hot but besides C. polygonoides itself, are Lepta­ equally dry regions. denia pyrotec1mica (Forsk.) Decne., Halo­ The following vegetation types of India xylon salicornicum Bunge ex Boiss., Cype­ may be listed under the category "arid" rus arenariliS Retz., Rhynchosia arenaria in its broadest sense in the decreasing Blatt. et Rallb. and Dipterygium glaucum order of aridity: (1) Ca/ligonum polygo­ Decne. ;Joides; (2) Prosopis cineraria-Capparis Whereas C. polygonaides is confined decidua-Zizyphus-Salmdora; (3) Acacia­ to the dune slopes, H. salicornicum is Capparis decidua; (4) Acacia senegaI­ commoner in the inter-dunal areas and Allogeissus pendula and (5) Acacia catechu besides occurs in the north-western part -Anogeisslls pendlila. ,The arid zone in of Rajasthan where rainfall is exceedingly the classical sense would include only the low (200 mm, with 11 months dry). fl rst two types, viz. Calligonum, and Pro­ L. pyrotcclmica requires a gravelly sub­ ,\opis-Capparis-Zizyphus-Salvadora. The soil. Together with, another Asclepia­ type Acacia-Capparis would characterize daceae, Sarcostemma acidum (Roxb.) Voigt, th~ semi-arid zones of Rajasthan, it forms a degradation stage of Calligonllm. northern Gujarat and the Deccan. The Among the common species may be Acacia planifrons type (the southern mentioned Aerva persica (Burm. f.) Merr., umbrella thorn forest of Champion, 1936) A.pseudotomentosa Blatt. et Hallb., Panicum and the Acacia-Anogeissus pendula types turgidum Forsk., Calotropis pro cera R.Br., of the Aravallis would also be included Crotalaria burhia Buch.-Ham., Indigofera in the typical semi-arid class. cordi/olia Heyne ex Roth, I. argentea L. Some other types, such as Anogeissus and Tephrosiafalciformis Ramasw. pendula - Anogeisslls lati/olia, Albizzia The following species are occasionally amara, A. amara - Anogeissus lati/olia, encountered in the Cal/igol1um com­ A. laiifolia and Hardwickia binata, which munity: Cleome pipillosa Steud., Citrullus do not include teak and mostly fringe the colocynthis Schrad., Gisekia pharnace­ semi-arid Acacia - Capparis community aides L., Ephedra foliata Boiss., Aristida may be included under the marginally mutabilis Trill. et Rupr., CCllchrus bifloru~ 5ub-dry category as they grow under co~­ Roxb., C. cifiaris L., C. prieurii (Kunth) dirions less favourable than the sub-humId belt where the teak (Tectona grandis LJ.)· * Meher-Homji (1975) has used specie~-area makes its appearance. The optimum floristic statistics in combination with climatic physiognomic state which these types characters to give a better indication of the bio­ climatic degrees of aridity-humidity than the cli­ reach, is a forest but under the pressure matic data alone. of a high density of human and cattle­ **The description of vegetation is after Gaussen, goats population the woodlands often Meher-Homji et al. (1972) and Gaussen, Legris degenerate into thickets and savannas and et al. (1968a).

167 DESERTIFICATION AND ITS CONTROL

Maire, Dactyloctenium aegyptiacum (L.) thickets, shrub-savannas and scattered Beauv., D. sindicum Boiss., Lasiurus hir­ shrubs. sutus (Forsk.) Boiss, Eragrostis ciliaris In the orans of the southern part of (L.) R.Br., E. tremula Hochst., Panicum western Rajasthan, the main species are antidotale Retz., Saccharum bengalense Prosopis cineraria, Capparis decidua, Retz., Leucas aspera Link., Indigofera lini­ Salvadora oleoides Decne.; Zizyphus folia Retz., Lycium barbarum L., Tribulus Ilummularia W.et A. is better represented alatus Del., T. terrestris L. in the northern parts (the Bikaner, On the low dunes are found Acacia Churu districts ) where winter tempera­ jacquemontii Benth., Leptadenia pyrote­ tures are lower. Other elements en­ elmica, Aerva persica, Balanites aegyptiaca countered in the disconti'nuous thicket are (L.) Del., Lycium barbarum, Capparis Acacia nilotica (L.) Del., Sail'adora persica decidua (Forsk.) Pax and Calotropis pro­ L., Zizyphus mauritiana, Balanites aegy­ cera, but only the first two species are ptiaca, Lycium barbarum, L. europaeum, very conspicuous. Sand-dunes are usually Calotropis procera, Aerva persica, A. cultivated with bajra (Pennisetum typhoides pseudotomentosa, Crotalaria burhia, .Ephe­ (Burm.) Stapf et Hubb.), but in the eastern dra {oliata Boiss., Teplzrosia purpurea part of the Jaipur District, even wheat is Pers., and Saccharum bengalense. grown on fixed dunes in terraces. In Prosopis juliflora DC. is also occasion­ the less drier areas, such as parts of Churu, nally encountered in the southern parts Bikaner, Nagaur and Sikar districts, the of Rajasthan. In the northern regions dunes have been fixed by afforestation it suffers because of the low temperature. and they support thickets of Prosopis P. cineraria is a light demander. Sensi­ cineraria (L.) Druce, Zizyphus nummularia tive to frost and drought in juvenile stage, W.et A., Z. mauritiana Lam. Acacia spiro­ the older plants resist these adverse condi­ carpa Hochst. ex A. Rich. var. torti/is, an tions. It prefers loose sandy soils, tole­ exotic, has given good results in fixing rates moderately sandy soils but avoids some protected dunes near Bikaner and heavier, clayey soils. It is rare around Na­ Jhunjhunu. gaur where the soils are of a red gravelly type; because of the lack of soil depth II. Prosopis cineraria-Capparis decidua­ on the exposed kankar pan, its growth Zizyphlls-Salvadora type is not favoured. However, if the calcite The range of rainfall is 150 to 400 mm, concretions (kankar) lie at a depth of 70 with 9 to 11 months dry. The mean to 80 cm, the growth of P. cineraria is temperature of the coldest month ranges favoured because these concretions leave from 10° to 20°C. From the edaphic point a large number of sand-filled pockets that of view, the type is mainly confined to' the tr~p the infiltrating water. Blagoveschen­ old alluvial sandy soils. skiy (1968) has traced a correlation among The type is found in the Barmer, Bika­ the height and density of P. cineraria, the ner, Jaisalmer, Jodhpur, Nagaur districts underneath grass-cover and the climatic and in the western parts of Jalore and Pali characters. In the north-eastern part of districts of Rajasthan and also in Kutch. Rajasthan, around Jaipur, with 500- The human interference in this arid 600 mm of rainfall Prosopis trees are 7 belt has obliterated almost completely the to 8 m high, with a density of 150-200 per natural vegetation and only traces of it hectare. The height of the herbage under the are left in protected places such as the trees is 100-120 cm, with a predominance orans which are the areas dedicated to the of tall grasses of the Andropogonae tribe. local deities. Usually the oralls occur on In the central part around Ajmer, the the outskirts of the villages. The best annual precipitation is of the order of stands are in the form of thorny thickets, 300-400 mm. Here, Prosopis-trees are but they are of rare occurrence. More 5 to 6 m tall, 50 to 100 per hectare. The commonly encountered are discontinuous grass cover is 50-60 cm high and almost

168 ARID ZONES-BIO-CLIMATE AND VEGETATION

all the tall grasses (Lasiurus hirsutus and somewhat saline soils. In the older (Forsk.) Boiss., Desmostachya bipinnata alluvial plains, it is a co-dominant element (L.) Stapf. are preserved, but are reduced with Prosopis cineraria (Gupta and Saxena, in height and numbers. Low xerophytic 1968). S. persica L. is grown in com­ members of the tribe Agrostidae (mainly pounds and hedges because of its econa. the genus Aristida) begin to playa signi­ mic "importance. Its fruits produce an oil ficant role in the composition of the her­ used for burning in lamps; the fruits are bage. In the west around Phalodi, the also fed to cattle to increase the fat con­ annual precipitation is reduced to about tent of their milk. It occurs in areas 200 mm; the density of P. cineraria of 3 that are slightly saline, but the salinity is to 4 m in height is 25-30 per hectare. subterranean. Aristida spp. dominate among the grasses. Acacia jacquemontii is seen along the The representatives of Andropogonae, sides of the rivers but is also encountered especially Lasiurus, are present but are not on hillside dunes dissected by water dominant. channels. Zizyphus nummularia is conspi­ Capparis decidua is generally absent cuous in northern' Rajasthan where tem­ from sand-dunes and deep loose sandy peratures are lower. It needs sandy to soils, but tolerates the moderately sandy sandy-loam soil. According to Satya­ texture. It prefers loamy or clayey soils, narayan (1964), Z. nummularia is a seral is common in river valleys, comes up even stage leading to the climax of Prosopis on gravelly soils and is found in higher cineraria-Salvadora oleoides. Given the numbers in areas which have a kankar good development of Zizyp!zus in the pan underneath. It may occur in low­ northern region, the species deserves the lying areas and depressions where the soil status of plesioclimax (Sensu Gaussen, is either derived from rock or is heavy. 1959). The example of the first type is observed The convergence of growth forms in between Phulera and Jaipur and of the Capparis decidua, Calligonum polygonoi­ second type between Sardarshahr and des, Leptadenia pyrotechnica, Ephedra Bikaner. fo/iata, Crota/aria burhia is noteworthy. When sand overlies a lime or gypsum In the shrub-savanna physiognomy, bed, the dominant elements of the vegeta­ some shrubs are left standing amidst tion are Calotropis pro cera, Aerva persica grasses. These grazing-lands are locally and A. pseudotomentosa serving as indi­ known as hirs. Among the shrubs, cators of these minerals. Gillet (1968) Prosopis cineraria is common. Others has described C. pro cera as an anthropo­ are Capparis decidua, Zizyphus nllm­ philous nitratophilous psammophyte of mu/aria, Lycium europaeum, May tenus Ennedi Massif (Sahara) where it comes up emarginata (Willd.) Ding Hou, Acacia on the sites that were once the camps nilotica (L.) Del., Z. Jaquemontii, A. of the nomads and invades impoverish~d leucophloea, Leptadenia pyrotechnica, fields, ruined lands and sandy soils. In Sericostoma pauci/lorum Stocks, Aerva Rajasthan, it behaves as a psammophyte persica, Crotalaria burhia. and anthropophilous plant as it grows on The grasses under protection reach a sandy soils, sand-dunes and has a ten­ height of 75 cm to 1m in the rainy sea­ dency to come up on the sites disturbed son. The common grasses are Aristida by man, including the areas mined for adscensionis L., A. funiculata Trin. et gypsum. The nitratophilous nature is Rupr., Cenchrus hiflorus, C. setigerus not as strongly exhibited by C. pro cera as Vahl, C. ciliaris, Cymbopogon jwarancusa its vicarious species C. gigantea Br. of the (Jones) Schult, Dactyloctenium aegypti­ more humid parts of India. In Rajasthan, acum, D. sindicum, Dichanthium annulatum C. procera is related to the calcium con­ (Forsk.) Stapf, Digitaria adscendens (Hk.) tent of the soil. Henr., Eragrostis ciliaris, E. tremula, Salvadora oleoides occurs on heavier Eleusine compressa (Forsk:) Aschers. et

169 DESERTIFICATION AND ITS CONTROL

Schweinf., Eremopogon Joveolalus (Dal.) enneaphylla L., 1. liniJolia Retz., I. tri­ Stapf., Melanocenchris jacquemontii Jaub. gonelloides Jaub. et Spach, Leptadenia et Spach. In the northern and western pyrotechnica, Sa/ria aegyptiaca L. regions, Lasiurus sindicus Henr. is impor­ tant. Closure favours palatable grasses, III. Acacia-Capparis type such as Cenclzrus ciliaris. This type which physiognomically oc­ The effect of controlled grazing on the curs in the shape of a thicket, scattered grass-cover tn the Jodhpur District is shrubs or shrub savanna characterizes demonstrated by Das and Bhimaya the semi-arid regions. In Rajasthan, it (1964). Annuals in the initial stages occurs in the piedmont plains west of the constituted 71 % with Aristida funiculata AravaJlis in Sirohi, Jalore and Pali dis­ and A. adscensionis jointly contributing tricts; the altitudinal range varies from 55 %. After three years of controlled 150 to 300 m. In Gujarat, the type is grazing, the percentage of perennial gras­ encountered in the western parts of the ses, such as Eleusine compressa, -Cenchrus Broach and Baroda districts, the Kaira, ciliaris, C. setigerus and Eremopogon foveo­ Ahmedabad, Mehsana districts and al­ latus increased by almost 13 % over the most the whole of Kathiawar peninsula, initial index. • excluding the hilly regions above 300-m After the termination of the rainy sea­ altitude. In Maharashtra, it covers the son, an acute dearth of fodder is felt; the dry interior Deccan area throughout its nomads with their herds set out eastwards. entire length from the south of Dhulia There is heavy pressure on the grazing­ to the south ofMiraj. It extends but very lands and only the unpalatable scattered little in northern' Karnataka, the limit of shrubs are left. Tree species, e.g. Pro­ the type tallying fairly well with the Deccan sopis cineraria and Salvadora oleoides, Trap geological formation to the south of are lopped during the lean periods. Miraj, Bijapur and Gulbarga, the geology Acacia senegal Willd. and May tenus changes from the Trap to gneissic complex emarginata grow on rocky soil or on rocks shale, sandstone, quartzite and chlorite covered by sand. They are the indicators schist and the Acacia-Capparis decidua of a rocky substratum covered by sand. type is replaced by Albizzia amara. In Fagonia cretica L. tolerates lime and Madhya Pradesh, this series occupies gypsum. Tithonia rot!l1ldifolia (Mill.) a limited area near Barwani, north-west Blake is an exotic, now spreading in of Khargon. Rajasthan. Mukia maderaspatana M. From the edaphic point of view, the Roem. is a climber seen quite frequently type occurs on several soils, viz. black on Capparis decidua; Otrul/us colocynthis soils on alluvia or on the Trap, red ferru- Schrad. is a frailer. Saccharum bellgalense . ginous .soils and alluvial soils. Albizzia is found in the -northern . and north­ amara, an acidophilous species, on the eastern parts into which it has been intro­ other hand, cannot tolerate black clayey duced. Blagoveschenskiy (I 968) has calcimorphic soils and is thus eliminated used this species to name the type Pro­ from the Deccan Trap country. The sopis-Saccharum in his map. In view of range of rainfall is 400 to 700 mm, with its introduced nature, the validity of the 8 to 9 months dry. type is questionable. Besides, S. benga­ Floristically, the differences between this lense occurs only in the fields or hedges. type and the preceding one in Rajasthan On gravelly soils, the following scattered and northern Gujarat are mainly undershrubs and herbs are encountered: quantitative. Almost all the important Barleria acanthoides Vahl, Boerhaavia dif­ species of the Acacia-Capparis type, such lusa L., B. verticil/ata Poir., Bonamia as Acacia nilotica, A. leucophloea Willd., latifolia (Hochst. et Steud.) Sant., Cleome Capparis decidua, Commip/zora. mukul papillosa Steud., Corbichonia decumbens (Hook. ex Stocks) Engl., Euphorbia cadu­ (Forsk.) Exell, Fagonia cretica, Indigofera ciJolia Haines, Zizyphus spp., are pre- - , 170 ARID ,ZONES-BID-CLIMATE AND VEGETATION

sent in the Prosopis-Capparis-Zizyphus but in the more humid parts of Eastern Salvadora type, where Prosopis cineraria, Rajasthan (rainfall : 550-900 mm; 8-9 Salvadora oleoides, Zi';:yphus nummularia months dry), Acacia catechu Willd. is the also are better represented. Certain vicarious species. The two types, Acacia species, such as Acacia facquemontii, senegal-Anogeissus pendufa and Acacia Cordia gharaf(F orsk.) Ehr. et Asch., Teco­ catechu-Anogeissus pendula, are closely !nella undulata (Smith) Seem, Leptadenia allied having many species in common. pyrotechnica, Aerva persica, Crotalaria However, the latter is richer in species at burhia, are preferential of Prosopis-Cappa­ least in the forest stage. ris-Zizyphus type, whereas Cassia auricu­ Acacia senegal-Anogeissus pendufa lata L. is confined to the Acacia-Capparis type has its largest extension in the Sirohi, type. Pali, Ajmer, Jaipur and Sikar districts, Other shrubby species are Alhagi came­ though it also occurs on the isolated hills lorum Fisch., Balanites aegyptiaca (L.) and hillocks of the Jalore, Barmer, Jodh­ Dei., Clerodendrum phlomidis L.f, Dichro­ pur and Nagaur districts. The type is stachya cinere~ W. & A., Flacourtia associated mainly with brown soils. indica (Burm. f.) Merr., Grewia tenax Acacia catechu-Anogeissus pendula (Forsk.) Fiori, Grewia villosa Willd., type is developed mostly in the eas­ Lycium europaeum L., Taverniera num­ tern districts: Alwar, Sawai Madhopur, mularia DC., Xeromphis spinosa (Thunb.) Tonk, Bundi, Morena, Kota, Bhilwara, Keay. Chittaurgarh and Shahjapur. It is also In the Deccan, Euphorbia nerifolia on found on the Aravalli range in the Sirohi, the trap is a geographic vicariant of E. Pali and Ajmer districts. The soils are of caducifolia of Rajastha~-Kathiawar. brown and black types under this type. Acacia planifrons W. & A. of the Por­ The altitudinal range of the type in the bandar region of Kathiawar also occurs Pali, Sirohi and Udaipur districts is about in the semi-arid south-eastern corner of 500 m, above which it makes room for India near Tuticorin and Pamban in the the Anogeissus latifolia-Terminalia foresL Tirunelveli and Ramanathapuram dis­ Acacia leucophloea dominates in the tricts and in a few localities in the Madurai piedmont zone. and Coimbatore districts of Tamil Nadu. It is found also in Bellary, but it is plan­ Dry deciduous low forest ted there. Morphologically, the species The dry deciduous low forest consists is closely allied to Acacia spirocarpa of four tiers, viz; Hochst. ex A. Rich. of North-East Africa (i) The emergent tree layer and Arabia. The important trade of horses (ii) The small trees forming an under­ in the past via the sea route between storey Arabia, Africa and the ancient ports of (iii) The undergrowth of shrubs and clim­ India may explain the disjunct distribu­ bers tion (Viart, 1963; Meher-Homji, 1970). (iv) The ground cover of herbs-and grasses. IV-V. Acacia senegal-Anogeissus pendula Top storey type . and Acacia catechu-Anogeissus The average height of the trees in the pendula type top canopy is 10 m. Anogeissus pendula The hills of the Aravalli range and other is the dominant species, mostly forming hillocks protruding in the Thar are charac­ almost pure stands. terized by a vegetation of their own. Though the tree seeds profusely, the Anogeissus pendula Edgew. is the most germination of the seeds is very poor. remarkable species of the Aravallis. In What is seen as profuse natural crop of the comparatively dry tract (rainfall : seedlings in the forest is actually the pro­ 400-700 mm; 8f-l0 months dry), fuse reproduction by the root suckers. it is usually associated with Acacia senegal, Species common in the top canopy of

171 DESERTIFICATION AND ITS CONTROL

the forests of both the types are: Acacia indicum Kuntze are encountered on the leucoph/oea, Butea monosperma (Lam.) rocky sites. Taub. (at the foot hills), Bauhinia racemosa Among those encountered only in the Lam., Holoptelea integrifolia Planch., Acacia catechu-Anogeissus pendula type Moringa coneanensis Nimmo, Wrightia are Capparis spinosa L., C. zeylanica L., tinctoria R.Br., Mitragyna parvifolia Ehretia laevis Roxb., Clerodendrum phlo­ (Roxb.) Korth. (along the streams), Bos­ midis, Seeurinega obovata Muell. Arg. wellia serrata Roxb., Lannea coromande­ and Euphorbia nivulia Buch-Ham., the Iiea (Houtt.) Merr., Sterculia urens Roxb., last-mentioned in the rocky habitat. Diospyros melanoxylon Roxb., Albizzia Climbers and twiners, common to both odoratissima Benth. (on the upper slopes the types, include Abrus precatorius L., and crests of the hills). Coeeulus pendulus (Forst.) Diels; Cusqlla Deciduous species, such as Aegle marme­ reflexa Roxb. and Asparagus dumosus losCorr., Bombax ceiba L., Dalbergiapani­ Baker. There are some more seen only culata Roxb., Cassia fistula L., Soymida in the Acacia caleehu-Anogeisslls pell­ febrifuga Juss., Crataeva religiosa Forst. dula type; Asparagus raeemosus Willd., f .. Feronia limonia (L.) Swingle, Anogeis­ Tinospora cordifolia Miers, Mucuna pru­ ,sus latifolia Wall., and, the evergreen spe­ rita Hook., Ichnocarpus frutescens R. cies of more moist sites (e.g. Ranthambor Br., Hemidesmus indiclls R.Br. Hill, Sawai Madhopur Dist.) like Syzy­ Ground-cover is compos!,!d of herbs, giuln clfmini (L.) Skeels, Mangifera indica such as Cassia lora L., Borreria hispida (L.) L., Mal/otus philippensis Muel!. Arg. occur Schum. and Tridax procumbens. Where­ occasionally in the Acacia catechu-Ano­ ever there are openings, the ground is geissus pendula type. covered with grasses such as Apluda mUlica The under storey is about 6 m in height, L., Aristida /zystrix L.f., Eremopogon fove­ with an average density ofO. 3. It is com­ olalus, Heteropogon contortlls (L.) Beauv., posed of : Melanocenchris jaequemontii Jaub. et Diehrostachya cinerea Spach, Chrysopogonfulvus (Spreng.) Chioy. Zizyphus mauriliana Lam. Riparian facies: Along the nalas occur Balanites aegyptiaea (L.) Del Ficus glomerata Roxb., Phoenix sylvestris May tenus emarginata Roxb., Syzygium jambos (L.) Alst., Mitra­ Cordia gharaf and the bamboo gyna parv!fo/ia, Soymida febrifuga. Ficus Dendrocalamus strietus Nees. glomerata is affected by frost. In the Flacourtia indica, Zizyphus glaberrima Sariska Game Sanctuary (Alwar District), Sant., Zizyphus xylopyrus Willd., Nyctan­ frost occurs in the first fortnight of thes arbortristis L., Helieteres isora L., D~cember. On an average, there are 3 Xeromplzis spinosa, Holarrhena antidysell-. frosty .days in December. terica Wall. occur exclusively in the Acacia catechu-Anogeissus pendu/a type. The thorny thicket The undergrowth is about 2 m high, This is a degraded stage of the low comprising forest. The general height of the crop is 3 Grewiaflavescens Juss. to 4 m. This formation resembles the Grewia tenax Acacia-Capparis and the Prosopis­ Rhus mysorensis Heyne Capparis-Zizyphus types in floristic com­ Commipliora mukul position. Species typical of these two dry types, Mimosa rubicaulis Lam. such as Aerva persica, Prosopis cineraria, Seeurinega virosa (Roxb. ex Capparis decidua, Sericostoma paucif/orum, Willd.)Pax etHoffm. are present in the thickets of the Acacia Zizyphus nummularia senegal-Anogeisslls pendula type and the Adhatoda vas;ea Nees. Acacia catechu-Anogeissus pendlila type; Euphorbia cadueifolia and Dyerophytum Acacia jaequemontii, Calotropis procera.

172 ARID ZONES-BIO-CLlMATE AND VEGETATION

Capparis decidua, Cassia auriculata, Lep­ ing. They are interspersed with cultiva­ tadenia pyrotechnica, Lycium europaeum tion. Shrubs about 3 to 4 m in height occur in the thickets of the Acacia are scattered amidst grass-cover attaining senegal-Anogeissus pendula type only. a height of 1 m and even more during the However, the presence of Anogeissus rains. Herbs are very few. pendula, Grewia lenax, G. flavescens, Flacourtia indica, Rhus mysorensis, Secu­ VI. The marginal sub-dry vegetation types rinega virosa, Capparis sepiaria L., Cassia Among the marginal vegetation types, tora in these thickets indicate a higher sta­ indicating the sub-dry zones, Albizzia tus-the potentiality to evolve towards amara type occurs mostly in the Coro­ the Acacia-Anogeissus pendula type on mandel-Circar plains of Tamil Nadu and further protection. Andhra Pradesh. The most striking fea­ Euphorbia caduc(folia, Zizyphus nummu­ ture of the climate is the tropical dissym­ laria, Zizyp/zus 11'!auritiana, Balanites metric regime. The rains are light during aegyptiaca are also reprtsented. July-September, but heavy in October­ Bushes of Anogeissus pendula are heavily November, mainly from the depressions browsed and are hardly 1 m tall. When originating in the Bay of Bengal during protection is better, it is about 2 m high. the N.E. monsoon season (Meher-Homji, Acacia senegal and May tenus emargi­ 1973b, 1974b). The rainfall within the nata are indicators of rocky substratum belt of Albizzia amara varies from 600 (the occurrence of bed rock at a shallow mm to 1,500 mm. The variability is also depth). When the rocks and even entire quite large, depending on the frequency hillocks are buried under the sand, they of the depressions. The length of the dry point out their presence season ranges from 6 to 8 months. The Some thickets are invaded by Prosopis thickets and scrub-woodlands of Albizzia julO(lora. ' amara are confined to ferruginous, ferra­ llitic or skeletal soils. Discontinuous thicket In the transitional zone where the This is the next stage of degradation rainfall regime changes from the dissym­ where the regeneration, both coppice and metric type to the true tropical type (with seed, is not allowed to come up because rains from May-June to October), the of continual browsing and grazing. The Albizzia amara-Anogeissus latifolia com­ site conditions have also deteriorated ow­ munity occurs as an ecotone. A good ing to soil erosion. example is seen in the Mysore-Hunsur Anogeissus pendula is cut recklessly and tract (Meher-Homji, 1977a). is so badly browsed that it almost touches Generally, teak (Tectona grandis) dis­ the ground. The spreading of such appears from the dry deciduous forests bushes is almost 2 m in diameter. of the regions of low rainfall, usually Euphorbia caducifolia and Rhus mysoren­ less than 750 mm, with the dry season sis are two common shrubs. Among the exceeding 8 months (as in northern Guja­ others, mention may be made of Acacia rat, Rajasthan and the Deccan). The leucophloea, A. senegal, A. catechu, Dich­ resultant community is termed Anogeissus rostachys cinerea, Balanites aegyptiaca, lat({o/ia type. Teak, as a rule, also dis­ May tenus emarginata, Zizyphus nummu­ appears from the forests adjoining the laria, Dyerophytum indicum, Adhatoda sal (Shorea robusta Gaertn.) type, though vasica, Grewia spp. The ground flora is rainfall is more than 750 mm; rarely do very sparse. teak and sal occur together in a "tension" belt. The dry deciduous miscellaneous Shrub-savanna forests without teak or sal of central India Certain areas, known locally as jors are also classified in the Anogeissus lati­ or hirs (grass reserves), are earmarked folia type. for the production of grass and for graz- In parts of the Udaipur, Sirohi, Pali,

173 DESERTIFICATION AND lTS CONTROL

Ajmer and Kota districts of Rajasthan, mations or those containing teak or sal two species of Anogeissus-A. pendula and may be excluded from the arid or semi­ A. latijolia overlap each other. The arid category; a probable exception may rainfall in this tract is of the order of 600 be the Acacia-Anogeissus pendula forests to 800 mm, with a dry season of 8 months. of the Aravallis, but these are, in fact Finally, it remains to make a mention low or open formations. The paper of the Hardwickia binata type of dry deci­ terminates with a discussion on physiog­ duous forest which has a very wide range nomy, flora and main climate and soil of rainfall (500 to 1,200 mm, spread over factors of the vegetation types of the dry 4 to 6 months) and soil types (from hard zones. gravelly to deep black clayey). The dis­ junct patchy distribution of this type has REFERENCES been explained on the basis of anthropo­ BAGNOULS, F. and GAUSSEN, H. 1953. Saison genic interference (Meher-Homji, 1970, seche et regime xerothermique. Documents 1977b). pour les cartes des productions vegetales 3 One may well question the placing of (1): 1-47. the forests and other arborescent forma­ BLAGOVESCHENSKIY, E. N. 1968. The dry savanna of north-west India. Soviet Geography: tions of these marginal types under the arid Review and Translation 9: 519-537. category. However, when such wooded CHAMPION, H. G. 1936. A preliminary survey areas are degraded by man and his domes­ of the forest types of India and Burma. ticated animals, they get converted into Indian For. Rec. (N.S.) 1. low thickets, scattered shrubs or over­ DAS, R. B. and BHIMAYA, C. P. 1964. Pasture ecology of grasslands of Western Rajasthan. grazed grasslands and often become Unesco Symp. Problems oj Indian Arid Zoile, drought-prone. pp. 379-401. GAUSSEN, H. 1959. Vegetation maps of India. Summary and conclusion Inst. Fr. Pondicherry. Trav. Sect. Sci. Tech. 1(4) : 155-79. The present paper reviews some of the GAUSSEN, H., LEGRIS, P. and VIART, M. 1961. approaches to define the degrees of aridity Sheet Cape Comorin. International map from a bio-climatic viewpoint. It also of vegetation and environmental conditions. highlights the variability in the amount of ICAR, New Delhi and Inst. Fr. Pondicherry. Trav. Sect. Sci. Tech. Hors. Series No. 1. rainfall, its duration and seasonal dis­ --- 1962. Sheet Madras. Ibid. Hors. Series tribution and points out the need of deli­ No.2. neating a probable year rather than an --- 1963b. Sheet Jagannath. Ibid. Hors. average year, taking into consideration Series No.4. GAUSSEN, H., LEGRIS, P., VIART, M., MEHER­ the instability of the climates of the dry HOMJI, V. M. and LABROUS, L. 1965a. belts. The waning trend of precipitation Sheet Mysore.Ibid. Hors. Series No.7. proposed for the Indian arid zone .has --.- 1965b. Sheet Bombay, Ibid. Hors. Series. not been supported by' the 20-year mov­ No.8. GAUSSEN, H., LEGRIS, P., BLASCO, F., MEHER­ ing averages. The natural vegetation HOMJI, V. M. and TROY, J. P. 1968a. Sheet which integrates the variability aspect of Kathiawar.Ibid. Hors. Series No.9. the climate provides convenient guide- --- 1968b. Sheet Satpura Mts. Ibid. Hors. . lines for delimiting the arid (with Calli­ Series. No. 10 . GAUSSEN, H., MEHER-HoMJI, V. M., LEGRIS, P., gO/lum and Prosopis-Capparis-Zizyphus BLASCO, F., DELACOUT, A., GUPTA, R .K. Salvadora types), the semi-arid (Acacia­ and TROY, J. P. 1972. Sheet Rajasthan. Capparis and Acacia-Anogeissus 'pendula Ibid. Hors. Series No. 12. types) and the marginal sub-dry zones GILLET, H. 1968. Note on ecologique at ethno­ botanique sur Calotropis procera. J. Agric. (Albizzia amara; Anogeissus latijolia and trop. Bot. Appl. 15(12) : 543-45. Hardwickia binata types). In the last GUPTA, R. K. and SAXENA, S. K. 1968. Resource category, it is mainly through excessive survey of Salvadora oleo ides Decne. and anthropogenic interference that the terrain S. persica Linn. for non edible oil in Western Rajasthan. Trop. Ecol. 9 : 140-52. turns drought-prone. Those areas of LEGRIS, P., COUGET, Y. and MEHER-HoMJI, V. M. peninsular India having good forest for- 1971. Drought climatology of Anantapur

174 ARID ZONES-BJO-CLIMATE AND VEGETATION

district, A. P. Proc. 58th Indian Sci. Congr. ---1973b. A phytosociological study on the 3 : 379. " Albizzia amara Boiv. community of India. LEGRIS, P. and ~EHER-HoMJI, V. M. 1976. Is Phytocoenologi? 1.(~) : 114-29. the rain in India on the wane? A bio- "---1974a. Vanablhty and the concept of climatic consideration. I!ltd. J. Biometeor. a probable climatic year in bioclimatology 20(3) : 190~93. wIth reference to th~ Indian sub-continent. MARLANGE, M. and MEHER-HOMJI, V. M. 1963a. Arch." Met. Gcoph. l!u!kl. 22B : 149--:67. Sheet Godavari, Ibid. HOTS. Series No.3. ---1974b. On the ongm of the t.roplcal dry MEHER-HoMJI, V. M. 1962. Phytogeographical evergreen. forest _of South India. Int. J. " f th .." . f I d' Ecol. EnViron. SCI. 1(1): 19-39. St U dles 0 . e seml-anu ~eglons 0 n la. ---1975. On the ,species area floristic Ph.D. ThesIs, Bombay Umv.. . statistics in relation to degree of aridity- ~--. 1963. Drought : Its. eco.log!cal defim- humidity. Geobios 2(4): 95-98. tlOn a~d phyt~g.eographlc slgmficance. I. ---1977a. Vegetation-climate parallelism EcologIcal defimtlOn. Trop. Ecol. 5 : 17-31. along Pondicherry-Mysore-Murkal transect, --- 1964a. Drought : Its ecological defini- South India. Phytocoenologia 4 (2): 206-217. tion and phytogeographic significance. II. ---1977b. Tropical dry deciduous forests Phytogeographic sigmficance of drought. of Peninsular India. Feddes Repertorium Ibid. 6 : 19-33. 88 (2) : 113-34 ___ 1964b. Aridity and semi-aridIty : A PRAMANIK, S. K., HARIHA_RAN, S. P .. and GHOSH, phytoclimatic consideration with reference S. ~. 1952. AnalYSIS ~f the ch1T!ate of the to India. Ann. Arid Zone 4(2) : 152-58. Rajasthan desert and ItS extensIOn. Indian · ., 'd d "d J. Met. Geoplzys. 3: 131-40. --- 1967 . n d e IImltIng an an semI-an RAM NCR V 1974 A aly . f c climat . I d' I d' G J 4"(1 2) . A,... . n SIS 0 ommence- 1-6 es In° n la. n lall eogr. . - -. ment of monsoon rains o~er Maharashtra . State for agriculture plannmg. India Mel. --- 1970. Not,:s on. sO.me peculiar cases ot Dept. Sci. Reporl216 : 1-19. phytog~ographlc dlstnbutlOns. J. Bombay RAo, K. N. 1958. Some studies on rainfall of nat. H'M .. Soc. 67 (1) : 81-86. Rajasthan with particular reference to trends. --- 1971a. Bioclimatic, variability with spe- Indian J ..Met. Geophys. 9(2): 97-116. cial reference to India. Trop. Ecol. 12(2): RAo, K. N. 1963. Climatic changes in India, 155-176. Ill: Changes of clImate Proc. Rome Symp. --- 1971 b. A diagram for depicting the inter- Arid Zone Res. 20, UNESCO, Paris. yearly variability in bioclimatIc factors. SATYANARAYAN, Y. 1964. Habitat and plant com- illld. J. Biometeor. 14(4) : 343-47. munities of the Indian desert UNESCO --- 1971c. The climate of Srinagar. Geogr. Symp. Problems of Indian Arid Zone (cyclo- Rev. India 33(1) : 1-14. styled). ---1972. An approach to the problem of VIART, M. 1963. Contribution a I'etude de defining aridity in the Indo-Pakistan sub- l'action de I'homme sur la vegetation dans continent. Ibid. 34(3) : 205-15. Ie Sud de l'Inde, These Sci., Touluouse. --1973a. Is the Sind-Rajasthan desert the WINSTANLEY, D. 1973. Rainfall patterns and result of a recent climatic change? Geo- general atmospheric circulation. Nalllre, forum 15 : 47-57. Lond. 245 : 190-94.

175 19 VEGETATION AND ITS SUCCESSION IN THE INDIAN DESERT

S. K. SAXENA

VEGETATION is a part of the complex eco­ Gaussen et al. (1971) classified the vege­ system which includes the plant cover, the tation of the region into twelve types, landform and the features of its surface constituting three formations. In an ac­ deposits. In a desert,' a close relationship count of the ecology of the Jodhpur Teh­ exists among the habitat, the vegetation sil, Shantisarup and Vyas. (1957) have and its environment. This relationship of recognized six plant associations accord­ an arid zone is always in a dynamic equili­ ing to different "situations". Saxena (1972) brium. Minor changes in the physical recognized seven ecosystems in western environment entail dynamic changes in Rajasthan and the description of the vege­ plant life. The vegetation differs in the tation was based on the five formations sequence of species (landform and surface recognized by Satyanarayan (1963). Gupta deposits) and varies in sequence of time (1975) enlisted six formations which bad a as well (seasonal and year-to-year). The little enlargement of the vegetation types dynamic rhythm of plant life varies in classified by Satyanarayan (1963). In magnitude as one passes from the extre­ the present investigation, six formations mely arid region (l00-150 mm) of rainfall have been recognized, with a slight of ' the western part of Jaisalmer to the modification of the classification made eastern part of Rajasthan (200-750 mm) by Satyanarayan (1963) and Gupta and beyond. Within the same environ­ (1975). The3e are (A) the mixed xero­ mental conditions, the sharp changes in morphic thorn forest, (B) the mixed topographical features, there is a distinct xeromorphic woodland, (C) the mixed delimitation of the plant community xeromorphic riverine thorn forest, (D) the (stand). The present communication deals lithopbytic scrub desert, (E) the psam­ with the vegetation types on different land­ mophytic scrub desert, and (F) the halo­ forms under various bioc1imatic zones, phytic scrub desert. Emphasis has been laid on the potential vegetation, the existing status, the extent VEGETATION TYPES of degradation and the possible succes- sional trends. . (A) Mixed xeromorphic thorn forest Blatter and Halberg (1918-1921) r~cog­ Besides the Aravallis as the boundary nized five forma~ions from western Rajas­ line, there are several rugged hills scatter­ than. Champion (1936) classified the ed in western Rajasthan. They are mostly vegetation into four main types which were of sandstone, granite and rhyolite. The later reclassified into eight forest types of plant communities growing on these hills Champion and Seth(1964). Mathur (1960), are grouped under the 'mixed xeromorphic however, .described six forest types only. thorn forest' because the communities are !haradwaJ .(1961) distinguished three pri- largely dominated by thorny and spiny ary and SIX ,secondary landform regions. species, which include some evergreen non-

176 VEGETATION AND ITS SUCCESSION

thorny sp~cies as well. Here, the soils are fera cordi/olia, I. linnei, Lepidagathis tri­ skeletal, yellowish brown to brown loamy nervis, Blepharis sindica, Tephrosia pur­ sands. Low hills and rocky regions falling purea and Tridax procumbens. All these in a zone of 150 to 300 mm of rainfall are species come up during the monsoon and largely dominated by the Acacia senegal impart a light-green hue to the landscape. community under due protection with a In the higher-rainfall zone (350-750 mm) density of 72 plants per ha and 100 % fre­ some more species, besides the above men~ quency. The Anogeissus pendula-Acacia tioned ones, viz. Eremopogon foveolalus, senegal community covers a rainfall zone of Heteropogon contortus, Brachiaria ramosa, 350-500 mm, whereas in the zone of 500- Bathriochloa pertusa, Hackelochloa granu­ 750 mm and above, the Anogeissus pendula laris, Sehim::t nervosum, Indigofera tinc­ community predominates. Here, Acacia toria, Tephrosia petrosa, Boerhavia diffusa, catechu becomes the chief associate, but on Pupalia /appacea and Achyranthus aspera, higher elevations A. pendula combines with are quite prevalent. The hilly areas under Boswellia serrata. The plant density ran­ low rainfall are generally dominated by ges from 200 to 500 plants per ha, with Eleusine compressa-Aristida sp. commu­ 15-35 cm DBH. nity, whereas in the higher-rainfall zone, (i) In the low-rainfall zone (150-250 the optimum expression is given by the mm), A. senegal forms a low layer of 3-4 Sehima nervosum community, contributing m in height and the trees are sparsely dis­ 11.5% ground cover and 46.7 q peI: ha tributed, with 5-12 per cent crown cover. above-ground biomass. Several intermeof The associated shrubs and trees are short, ate communities of other grasses are en­ with crooked boles and include Salvadora countered in the hilly tracts. oleoides and Maytenus efJJ:lrginatus. The The majority of the hillocks possess de­ chief shrub associates in this rainfall zone graded vegetation owing to severe lopping are Commiphora wightii, Zizyphus nummu­ and cutting by man and owing to grazing laria, Grewia tenax, Euphorbia caducifolia, by large herds of animals. One can en­ Mimosa hamata and Sericostemma acidum. counter cut and coppiced stamps of A. Their density varies from 85-540 per ha. pendula which assume a cushioned, crawl­ The aboveground biomass contributed by ing structure, whereas A. senegal, rarely these species ranges from 18.5 to 45.5 q coppices and gives bushy appearance. per ha. The associates of A. senegal com­ Degraded seral communities are represent­ munity in the medium (250-350 mm)-rain­ ed by Euphorbia caducifolia and Cassia fall zones include,Wrightia tinctoria, Morin­ auriculata in shrub layers, whereas Lepi­ ga concanensis, Azadirachta indica, Bauhi­ dagathis trinervis-Oropetium thomaeum nia racemosa, Cordia gharaf, A. leucoph­ community covers the ground. Euphorbia loea. In the higher-rainfall regions (300- contributes about 5% of the crown cover, 70:) mm), some more species are found, 'with 16.0 q per ha of above-ground bio­ e.g. Securinega leucopyrus, Dichrostachya mass, O. thomaeum produces almost a cinerea, Grewia villosa, Barleria prionites, negligible biomass (0.14 qjha). B. acanthoides, Cassia auriculata, Abuti/on indicum and Dipteracanthus patulus, which (B) Mixed xeromorphic woodlands had 8-18 per cent crown cover and 115- This formation is largely constituted by 750 p:ants per ha constituting 47.5 q per spiny species mixed with non-spiny and ha above-ground. biomass. The ground evergreen species or with those species flora in the low-rainfall zone is also quite having stems and branches or both green. poor and includes a few species of grasses It occurs on the fiat older alluvial plains and forbs, such as Cym'.Jopogon jwaran­ and lower piedmont plains, with deep soil cusa, Aristidafuniculata, Eleusine compres­ depositions. Here, the soils are deep, sa, A. hirtigluma, Tragus' bi/lorus, Drope­ sandy loam, loamy, sandy elay loam and tium thom::teum, Melanocenchris jacque­ clay with a hard kankar pan a~ varying montii, Enneapogon brachystachys, Indigo- depths (25 em-IOO cm). The type of in-

177 DESERTIFICATION AND ITS CONTROL

duration (Indurated and _semi-indurated) village grazing-land), the plant density of differences in the depth of the soil are the community ranges from 1S0-390 with well expressed by the plan~ community 4.8 to 17.76 per cent crown cover. Such and its overall performance. The natural a community yields 18.5 to 75:6 q per ha vegetation of the plains is highly modified of above-ground biomass. Under de­ owing to cultivation. In general, the cli­ graded conditions, there is an increase of matic climax of the Indian Thar Desert shrub density (347 per ha), but less of is represented by Prosopis cineraria and crOWn cover (6.7%). Salvadora oleoides community, which is Other plant communities encountered in distributed throughout the plains of west­ the desert plains are (3) Salvadora oleoides­ ern Rajasthan. P. cineraria has a wider Copparis decidu7-P. cineraria, (4) Salva­ ecological amplitude and its optimum den­ dora oleoifles; (5) Copporis decidua-So oTt;­ sity (150-200 per ha) and vigour can be oides, P. cineraria, (6) S. oleoides-C. deci­ seen in the districts of Sikar, Churu and dua, (7) P. cineraria-So oleoides-Z. num­ Nagaur (300-400 mm). Its density dec­ mularia, (8) S. o leo ides-Cassia aurfcll/ata, reases on both sides of this rainfall zone. (9) P. cineraria-C. decidua, (10) P. cine­ Various degraded stages of this formation raria-Z. llummularia, (11) C. decidua, (12) are met all over the plains of western Zizyp/zys lIummularia, (13) S. oleoides-P. Rajasthan. The representative vegetation cineraria-Z. nummlilaria, (14) P. cineraria­ is as follows : Acacia nilolica. 1. Salvadora oleo ides-Prosopis cine­ The above plant communities by the raria are generally recorded on the lower inclusion or exclusion of anyone species piedmont plains, which are covered with affect the association significantly. 1 here­ a very deep sand deposition in a zone of fore these may be regarded as phases 300-400 mm rainfall. S. oleoides occurs "facies" of the climax community and both in tree and shrub forms. Other asso­ indicate the extent of degradation. The ciated trees and shrubs are Maytenus emar­ absence of all the above 4-S species re­ 'gina/us, Acacia leucophloea, Z. nummu­ present severely degraded stages, shown laria, C. decidua, Euphorbia caducifolia, by Tephrosia purpurea, Cretalaria burhia GrelVia lenox and Balanites aegyptiaca. and IndigrJera oblongifolia with 2.5-3.S% The plant density ranges from 180-215 crown cover and 6.2 to 8.6 q per ha of the plants per ha, with 8-10 per cent crown above-ground biomass. cover which contributes 30-3S q per ha of The common shrub associates of all the the above-ground biomass. The same above communities include Calotrcpis pro­ plaht community on flat older aIJuvial cera, Balanites aegyptiaca and A. jacque­ plains, with deep heavy soil, produces as montii. The forbs and grasses are Aerva high as '146.0 q/ha of the above-ground perslca, Tephrosia purpurea, Crotalaria biomass, with 17.6% crown cover. burhia, Convohuilis micropiJyllus, Helio­ 2. Prosopis cineraria-Zizyphus nummu­ tropium subulatum, Pulicaria wightiana~ laria-Capparis decidua community is most Celosia argentea; Eleusine compressa, prevalent on a large part of the flat plains. Dactyloctenium sindicum, Desmostachya Because of the year-to-year cutting, Z. bipinnata, Cenchrus ciliaris, C. setigerus. nummularia plants do not show any visi­ The maximum expression of Cenchrus type ble impact on the cultivated fields whereas of grassland has 18.7% basal cover, with this species plays a dominant role in the 34.6 q per ha of the above-ground bio­ shallow soils of the low-rainfall zone (IS0- mass. The values under severe degrada­ 300 mm). On an average, there are IS- tion get reduced to 1.5 % cover and 9.35 20 plants per ha of Prosopis. They grow q/ha of the above-ground biomass. to a height of 10-14 m, with SO-80 cm of girth at breast height. In a cultivated (C) Mixed xeromorphic riverine thoro . field, 90 % dominance is indicated by Pro­ forest . sopis. In a beer, or oralt (the common The Jawai, the Sukri, the Mitri and the'

178 VEGE1ATION AND ITS SUCCESSION

Luni rivers and their tributaries in west­ Other plant communities on the terraces ern Rajasthan form a narrow belt 'of of the river banks are: (i) Acacia jacque­ younger alluvium on both sides of their montii-Cassia auriculata, (ii) A. jacque­ courses. These areas ,are liable to inun­ montii-Aerva pseudotomentosa, both on dation. The soils have heterogeneous de­ hummocky terraces, (iii) Salvadora per­ posits comprising sand, silt and gravel and sica-Tamarix articulata, (iv) Salvadora form deep sandy soils without a hard pan. oleo ides-C. decidua. These communities The lands are almost flat, but at certain represent the disclimax and are represent­ places, hummock formations are encoun­ ed by shrub species (1-3 m in height). tered along the banks. Enough under­ They produce 5-11 % crown cover and ground water, sweet to' brackish, is avail­ 5.7-14.5 q per ha of the above-ground bio­ able at shallower depths. Numerous wells mass. are dug for irrigated rabi crops. Invari­ The grasses and forbs under these com­ ably, there is a very good density and munities are Cenchrus ciliaris, C. seti­ growth of a few species, e.g. Acacia nilo­ gerus, Aristida adscensionis, Digitaria ads­ fica, A. nilotica ssp. cupressijormis, Sal­ cendens, Dacty/octeJlium aegyptium, Chlo­ vadora oleo ides, S. persica and Tam2rix ris virgata, Cynodon, Tephrosia purpurea, articulata, Tecomella undulata. Around the Solanum surattense, Vernonia cinerascens, wells, the farmers maintain a few trees, Heliotropium subulatum, Crota/aria bur­ e.g. Azadirachta indica, Tamarindus indi­ hia, Boerhal'ia diffusa, Digera muricata, ca, Albizzia lebbek, Ailanthus exce/sa, Fi­ Pulicaria wightiana, Voluterella divari­ cus religiosa, F. bengalensis, Moringa olei­ cata, Xanthium strumarium, Kylinga sp., fera and Zizyphus m:mritiana. These trees Launea sp. and Indigo/era cordifolia. provide shade and top-feed D;laterial for (D) Lithophytic scrub desert the livestock. . Acacia nilotica-Prosopis cineraria com­ Eroded rocky surfaces, gravelly plains munity is most prevalent on irrigated and pediment plains of sandstones, limes­ fields along the river course and the cli­ tone, granite, quartzite, slate, etc. are matic climax of this region. There are scattered in the districts of 10dhpur generally 25-45 plants per ha with the Nagaur, laisalmer and Harmer. Thes~ height averaging 7-10 m and 25-40 cm plains serve as upland to the adjoining flat diameter at breast height. Acacia has a plains. They are covered with gravel and high regeneration capacity in these soils, rock fragments of various sizes and are but owing to cultivation, the density of subject to water erosion. The soil cover is the trees is always under control. A den­ very shallow. Soil deposition takes place sity of 68 per ha makes up 12.4 per cent in depressional pockets and folds where crown cover and produces 47.7 q/ha of stunted, multi-branched shrub and tree the above-ground biomass on sandy-loam species form cushion-shaped structures. soils. Whereas on medium heavy soils, S. They are largely utilized as grazing-lands oleo ides and P. cineraria dominate, with and are covered with "scrub desert" 52 plants per ha in shrubby form bearing vegetation. only 7.5% crown cover and 17.5 q per ha ~f the above-ground biomass. Degrada­ Capparis decidua community tIon beyond this stage is quite rapid and It is the most prevalent shrub commu­ species, e.g. Tamarix, Zizyphus, A. jacque­ nity pf eroded rocky surfaces and piedmont mOlftii. flourish for a short spell and they plains. Here, the community is quite open, dWlUdle sharply under severe biotic stress with a low density (5-25 plants per ha) and which finally leaves the grass community very poor growth (3-5 q per ha of the o! Desmostachya bipinnata-Cyperus arena­ above-ground biomass) due to skeletal soil FlUS and C. biflorus, producing 2.5 q per cover. Stray plants of Acacia sel1egal and ha of the above-ground biomass and 3-4 % Prosopis cineraria, 2-3 m in height, can ground cover. also be seen along the deep tunnels. Asso-

179 DESERTIFICATION AND ITS CONTROL dated shrubs, undershrub, forbs and Rajasthan and occupy approximately 50 % grasses are: (Pandey et al., 1%4) of the total area. So (i) Leptadenia pyrotechnica, Calotropts far, five types of sand-dunes, namely para­ pro cera, Zizyphus nummularia, (ii) Aerva bolic, longitudinal, transverse, barchan and persica, Tephrosia purpurea, Crotalaria shrub-coppice dunes (Saxena and Singh, burhia, Sericostemma pauciflorum, Bona­ 1976) have been recognized in western mia latifolia, Tribulus terrestris, Orygia Rajasthan. The first type of dunes are a declmzbens, (iii) Cleome popillosa, C. brachy­ few prominent centres of dune concentra­ carpa, Boerhavia elegans, B. diffusa, tion and they make the indistinct provinces. Mollugo cervimta, Indigo/era cordifolia, These dunes have been recorded in' higher Salvia aegyptiaca, (iv) Dactyloctenium concentration in each province. They are sindicum, Oropetium thomaeum, Eleusine generally closely spaced and get coalesced compressa, Eragrostis sp., Aristida hirtig­ owing to the action of cross winds. Several [uma. coalesced dunes at the leeward end present a shape of zigzag transverse dunes. Ih-bet­ Zizyphus nummularia-C.decidua commu­ ween the chains of parabolicdunes.1pngitu­ nity. dina] dunes are generally formed in the same The gravelly plains where sheet wash axial direction. The sand of these stabili­ has resulted in exposing the kankar pan zed dunes is quite compact and calcareous. (i.e. from Nal to Kolayat in the Bikaner In some cases, lime nodules, 1 em to 10 District) are dominated by this community. cm in size, have' been recorded on the The shrubs are fairly numerous, being 80- dune flank and windward side. Stabilized 120 per ha, especially in those spots where dunes whose flanks and crest have fresh reaccumulation of sand has taken place up sand deposition. 1-5 m in depth, mostly to 50 cm. Here, the community grows to bear shrub vegetation with a few distantly a height of 1.5 to 3 m, with 6-8 % crown scattered trees, whereas the sand· dunes cover and 25-35 q/ha of the above-ground free from fresh sand deposition are invari­ biomass in a partially protected site ably occupied by more trees and a few (Gajner). It represents the stable disclimax shrubs only. There is a gradual change in of this habitat. But once more, the soil the vegetation of the stabilized dunes from accumulation takes place, it may lead to the low-rainfall zone (100-200 mm) to the the climax community of Prosopis cine­ higher-rainfall zone (350-500 mm). raria. Dune vegetation in the much-Iower­ rainfall zone (IOO-200 mm) is quite scanty (E) Psammopbytic scrub desert with a limited number of species. In this This formation has woody vegetation tract, the longitudinal, parabolic and trans­ predominantly of shrubs, }-3.5 m in height. verse dunes are very high (30-60 m) which They are mostly localized on' aeolian· are largely dominated by "psammophytic'· deposits; i.e. on stabilized sand-dunes arid species. These dunes are recorded to be undulating hummocky older a11uvial plains in highly disturbed conditions. Continuous and inter-dunal hummocky plains. Here, droughts, together with biota, have aggra­ soils are very deep loamy sands and are vated sand erosion which has resulted in calcareous. The fresh sand deposition and deposition of a large amount of loose sand the subsequent colonization is well depic­ on the crest and flank of these dunes. In ted by typical psammophillous species, some cases, the flanks of longitudinal and namely Aerva persica, A. pseudotcmentosa, parabolic dunes are covered by chains of Crotalaria burhia, Pallicum turgidum, barchan dunes. Such dunes have skeleton Cyperus laevigalus, Calligonum polygonoi­ vegetation on the surface. Spaces left des, ClerodendrOll plzlomoides, Cenclzrus between the barchan dunes are occupied hi/lorus, Aristida /ulliculata, Citrullus by Aerva pseudotomentosa, Indigo/era ar­ colocyntlzis. gentea, Crotalaria burhia, Dipterygium sp. Sand-dunes are extensive in western Citrullus co!ocynthis, PaniCllnl, tllrgidum,.

180 VEGETATION AND ITS SUCCESSION

Cenchru5 biflorus, Aristida funiculata, aspects indicating the extent of stabiliza­ Eragrostis sp., Tephrosia falciform is, tion. Rhynchosia minima var. memnonia ap.d Common associates of the above plant stray shrubs of Calligonum polygonoid,es, communities on different aspects of the Calotropis pro cera, Haloxylon salicornicum dunes are: and Acacia jacquemontii. Sand-dunes with (i) Dune crest: Panicum turgidum, their active crest and leeward end have the Cymbopogon jwarancusa, Panicum antido­ following communities: (a) Calligonum tale, Aerva pseudotomentosa, Citrullus colo­ polygonoi'des-Panicum turgidum, (b) Acacia cynthis, Cyperus laevigatus, Farsetia hamil­ jacquembntii-Calligonum polygonoides, (c) tond, Crotalaria burhia, A. funiculata, C. Calligonum polygonoides-Haloxylon sali­ biflorus. cornicum-P. turgidum. (ii) Leeward side: Calotropis procera, The above species are well distributed Aerva pseudotomentosa, Calligonum poly­ over the lower and upper flanks and wind­ gonoides. ward side of the dunes indicating compara­ (iii) Duneflanks: (x) Upper slopes: Clero­ tively 10,ose layer of sand over them. dendron phlomoides, Acacia jacquemontii, Highly disturbed dunes have very low pro­ Maytenus emarginatus, Calotropis pro cera, ductivity (I -2 q/ha), and plant density (20- Lasiurus sindicus, Citrullus calocynthis, 60 plants per ha), whereas the moderately Eragrostis sp., Cyperus bulbosus, Crotala­ effected dunes, on an average, bear 3-5 ~Io ria burhia, C. biflorus, (y) Dune bases and crown cover. The plant density varies lower slopes: Prosopis cineraria, Tecomella from 70-210 plants per ha which put up undulata, Leptadenia pyrotechnica, Lasiurus 5 q/ha of the: above-ground biomass. sindicus, Aerva persica, Indigojera cordi­ The three stabilized dunes in the low­ jolia, l. trigonelloides, Polycarpea corym­ rainfall zone (200-250 mm) are compara­ bosa, C. ciliaris, C. biflorus, Aristida tively much compact, except for their crest juniculata. and Cymbopogolt jwarancusa. and leeward end. A few dunes under Some of the dunes have partial protec­ severe biotic stress have a similar fate as ted conditions under religious bindings in the lower-rainfall zone. The formation where grazing by large herds of animals of barchan dunes on flat land and on is permitted, whereas cutting and lopping stabilized parabolic dunes can be seen are almost restricted. These dunes develop near big settlements, e.g. Phalodi. In this into a smaIl forest of Acacia senegal­ zone, all the three types of dunes are culti­ M aytenus em arg inatus. It had 10-14 % vated for kharif crops right from the lower crown cover, with 200-310 plants per ha. slopes of the flanks to the crest. Sand-dunes The estimated above-ground biomass with moderate sand deposition are found ranges from 30-42 q per ha. Dunes with , with the following communities: a similar community but under cultivation (1) Calligonum polygonoides-Cleroden­ have only 5 % crown cover and 5.7 to droit phlomoides, (2) C. polygoltoides- 14.9 qJha of the above-ground biomass. , Panicum turgidum, (3) Acaciajacquemontii­ The absence of C. polygonoides and Acacia senegal, (4) Maytenus emarginatus­ Clerodendron plzlomoides from such dunes Calotropis procera, (5) M. emarginatus-A. also indicates the compactness of the senegal, (6) A. senegal-Calligonum polygo­ topmost sand. Most of the Shergarh ,dunes noides. (7) Crotalaria burhia-Aervapseudo­ (Jodhpur District) are highly stabilized tomentosa, (8). C. hurhia-Sericostemma and do not show any sand-piling. Such pauciflorum-Leptadenia pyrotechnica. ' dunes mostly bear tree and shrub species Continued cultivation on dune slope of the alIuvial plains. reduces the shrub species. Few trees can The same dunes in the moderate-rainfalI be seen on the lower and middle slopes of zone (250-300 mm) are more stabilized and the dune flanks and in some cases on the bear a larger number of small trees and a stabilized leeward face. In this zone A few shrub species, such as Prosopis cine­ senegal comes up very well on all dune raria, Salvadora oleoides, ,Balanites aegyp-

181 DESERTIFICATION AND ITS CONTROL

tiaca, Tecomella undulata, May tenus emar­ extent. Shrub species e.g. Leptadenia pyro­ ginatus, Lycium barbarum and Acacia technica, Calotropis procera, Mimosa jacquemontii. The occurrence of trees on hamata, Lycium barbarum, C. decidua and_ various aspects. of dunes indicates the Z. nummll!aria are concentrated on the stabilization over a considerable period of upper ridges of the longitudinal dunes. time (La Touche, 1902). The trees and This shrub line takes the shape of a hedge shrubs are widely scattered and do not separating the two fields. The ground form a plant community. But some of the species include Tephrosia purpurea, Saccha­ dunes under a long duration of protection rum spontalleum, Crotalaria burhia, Aerya support distinct communities, e.g. (I) persica and I. /alciformis. Acacia senegal-Maytenus, (2) Maytenus Sandy undulating hummocky plains and emarginatus-Lycium barbarum-A. senegal, inter-dunal plains are formed through (3) C. polygonoides-Prosopis cineraria­ aeolian action, owing to which the sand has Saccharum bellgalense. Regular cultivation been deposited in the form of sand sheets on t.he stabilized dunes restricts the growth or hummocks, colonized by psammophyl­ of shrub species, whereas distantly spaced lous species. e.g. Calligonum pa/ygonoides, trees are allowed to grow. A protected Aerva pseudotomentosa, Leptadenia pyro­ dune has 10-18% crown cover, 150-350 technica, Acacia jacquemontii, forming plants per ha, producing 60-90 q per ha cushion-shaped bushes. Interspaces between of the above-ground biomass. Whereas the mounds are occupied by Lasiurus these figures get reduced to 3-4 % crown sindiclls, Cymhopogon jwarancusa, Teph­ cover,60-110 plants per ha and 10-21 q rosia purpurea and Cratalaria burhia and per ha of the above-ground biomass on Citrllllll~ colocynthis. In the 100-200 mm­ the periodically cultivated dunes. The rainfall zone, Haloxyloll salicornicllm is forage species of the ground flora on the prevalent species, whereas in the these dunes include Lasiurus sindicus. higher-rainfall (200-350 mm) zone, Zizyp­ Cenchrus ciliaris, Cymbopogon schoenan­ hus nummularia is common. Sparsely thus, C. jwaran::usa, Panicum turgidum, scattered trees of Tecomella undulata, C. bi/lorus, Aristida mutabilis, Indigo/era Prosopis cineraria and Salvadora oleo ides cordi/olia, 1. lini/olia, Crotalaria burhia, are present throughout this terrain. In the Farsetia hami/tonii and Saccharum benga­ district of Barmer, Bikaner, Jaisalmer and lense. The production of above-ground Jodhpur the following shrub communities biomass from these species varies from are listed: 14-26 q per ha, with 8.0-9.9 % basal cover (1) Calligonum polygonoides-Haloxylon (Chohtan-Barmer). salicornicum; (2)C. polygonaides-Leptadenia The sand-dunes in a higher-rainfall zone pyrote~hnica; (3) C. polygonoides-Zizyphus (:300-400 mm) are highly stabilized and nU{l1mularia; (4) C. polygonoides-Lasiurus suppor~ "mixed xeromorphic woodland" sindicus; (5) C. pol}gono ides-A cacia jacque­ instead of psammophytic scrub desert. A montii; (6) Calotropis procera-Aerva pseu­ good number of Prosopis trees (40-60jha) dotomentosa; (7) Acacia jacquemolltii-A. form a definite plant community. The trees pseudotomentosa; (8) Cratalaria burhia-A. grow right from the base to the top of pseudotomentosa-Leptadenia pyrotechnica; the dune. The trees are well spaced all and (9) Mimosa hamata-Clerodendron along the upper slopes. These. dunes are phlomoides. comparatively low (20-40 m). Almost all These species are good soil-binders but the aspects are put under cultivation. This grazing, cutting and 'the revival of these practice leads to sand erosion which con­ practices results in wind erosion. A shrub tributes to the formation of new dunes community of Calligonum and A. jacque­ and hummocks, etc. Saccharum bengalense, montii with 302 plants per ha, produces once introduced into the area of these S5 q per ha of the above-ground biomass, dunes, helps to conserve the soils on these occupying 9% crown cover. The degrada­ cultivated or uncultivated dunes to a great tion of this intermediate stage reduces the

182 VEGETATION AND ITS SUCCESSION

crown cover to 3.3 per cent and 6.7 q per thema portulacastrum, Echinochloa colo­ ha of the above-ground biomass. The num, Chloris l'irgata, Schoenfeldia gracilis, Prosopis-Teromella community or the Elellsine compressa, Dactyloctenium aegyp­ Prosopis-Balallites community has, on an Hum, Sporobolus heh,o/us, S. marginatlls average, 30 plants per ha, bearing 18.5 % and Dichanthium annulatllm. crown cover, whereas the above-ground I:Jalophyfic scrub communities of the biomass is as high as 64.7 q per hectare. peripteral areas of the rann, on an aver­ age, ha,e)64-2J3 plants per ha with 4.4 % (F) Halophytic scrub desert basal cover. The above-ground biomass This formation is characteristic of the ranges from 6-8 q per ha. This scrub arid areas. It is generally localized in stage remains more or less stable as long low-lying saline basin and depressional as the situation prevails. In some of the areas. The saline basins are almost level, ranns sand dC'po,ition in the form of with 1 % slope. The runoff water from sand sheet or hummocks gather species of the surrounding areas brings silt and clay, higher successional ~tatus, e.g. Lycillm along with fine. sand, which gets deposited barbarum, Salvadora/oleoides, Acacia jac­ in thin layers. Here the soils are heavy quemontii, ZizyphusJ--nummularia and Ta­ clay loam to clay, deep and highly saline. marix aphylla. Further the improvement The water stagnates for a few days to a of the substratum ultimately may lead to few months. The surface layer on drying the climax stage of Salvadora oleoides-Aca­ is covered with a white crust of salt in the cia nilotica. In Pachpadara, the salt basin form of patches which remain almost de­ with a large amount of sand deposition at void of vegetation. Malhar, Sanwarla, the periphery is largely dominated by Pro­ Thob, Pokaran, Pa~hpadra, Uterlai, sopis juliflora, a fifty-year-old introduc­ Lawana, Loonkaransar, Kharia, and tion of this exotic into the basin. This Mitha Rann of Jaisalmer are worth men­ species has virtually suppressed the growth tioning from western Rajasthan. of indigenous species. P. juliflora has In the Rann (playa), the salinity decrea­ 65 % relative dominance and a density of ses towards the periphery where succulent 140-160 plants per ha; producing 35-45 q halophytic nano-phanerophytes and chae· per ha of the above-ground biomass. mophytes, generally of Chenopodiaceae, Zygophyllaceae, Aizoaceae and Portula­ Succession caceae are prevalent. The plants of these There are two schools of thought, viz. families get a foothold on the spots the dynamic concept of Anglo-American where some sand deposition has taken School and the stati, concept of the Euro­ place or the salinity level is low. pean School of Phytosociologists, based The plant communities recorded on on the Clementsian concept (1916), ac­ various ranns are: cording to which a given climatic zone (I) Suaedafruticosa-Aeluropus /agopoides will have only one potential climax (Mono­ (San·warIa-Pachpadra, Malhar); (2) Halo­ climax) i.e. the climatic climax. The xylon salicornicum-Salsola bal'yosma-Spo­ monoclimate theory cannot fulfil the cri­ robolus marginatu~ (Malhar, Khari Rann); teria for the preclimax to change towards (3) Sporobolus helvolus-Cyperus rotundus progression, unless and until the whole (Thob); (4) Peganum harmala-Eleusine climate itself changes. Therefore there is compressa-Sporobolus marginatus (Jamsar, much inclination towards the "polycli­ Lunkaransar, Nal); (5) Desmostachya bi- ' max" view, according to which the term pinnata-Eleusine compressa (Uterlai). climax is used in its ordinary sense-it Other halophytic species common to the can be applied to every relatively stable-self above communities are: Haloxylon recur­ perpetuating community that terminates vum, Zygophyllum simplex, Cressa cretica. succession (Oosting, 1956). Euphorbia granulata, Portulaca oleracea. The vegetation account discussed in this Fagonia ere/iea, Sa/sola baryosma, Trian- paper indicates that it is adopted to the

183 DESERTIFICATION AND ITS CONTROL

whole pattern of environmental factors, not possible to use the term climax for but demonstrates a clear change along a desert vegetation. continuous environmental gradient. Since Champion (1936), Champion. and Seth whatever factors are responsible for plant (I964) from the Indian desert, Chaudhari communities, there is no absolute climatic (1960) and Iftikhar Ahmad (1964) from climax for the whole of western Rajasthan, Pakistan recognize Prosopis-Salvadora as but, on the other hand, it has shown a the climatic climax of the region (monocli­ poIyc1imax pattern. Bharucha (1951) and max), indicating that this formation covers Satyanarayan (1963) favour the polycli­ an extensive area from the Aravalli range max concept in this tract, whereas White­ to the Tbar Desert into Pakistan. Gupta kar (1953) prefers the term "prevailing and Saxena (1972) described seven grass­ climax" to the plant popUlation occupy­ land types in western Rajasthan ;and they ing the majority of the sites in an area. have been incorporated into this paper. Shreve (1951) demonstrated that each In the dynamic concept of succession habitat in each such division of the desert all communities, except the climax, are area had its own climax. Therefore it is considered the seral stage. Each seral . Anogeissl.ls pendllla-Acacia senegal Sehima nervosum (Climax) . 11 11 Maytenus emarginatus Eremopogon foveolatus Grewia tenax Cymbopogon jwarancusa ZizyphllS nummlllaria Heteropogon contortus 11 11 Euphorbia granulata Eleusine compressa Commiphora weightii Cenchrus hi/lorus Indigofera cordifolia Aristida funiculata 11 11 Barleria prionitis Enneapogon brachystachys Dipteracanthlls patllllls M elanocenchris jacquemontii Indigo/eta tinctoria Tragus hi/lorus 11 . [1 Lepidagathis trinervis Blepharis sindica Oropetillm thomaeum Tephrosia purpllrea 11 Aristida, Oropetillm 11 Bare rock Bare rock 1.1 (WOODLAND) 1.2 (GRAssLAND) Fig. 1. Succession on rocks

184 VEGETATION AND ITS SUCCESSION

stage makes the habitat favourable to its rate and increased to an extent of 169 % next higher stage and it ·itself gets elimi­ over the unprotected site. Beside this nated. In arid, zones, the successional .shrub, species, e.g. Grewia tenax and Ziz­ process is very slow, as the formation of yphus nummularia, have also shown some mature soils take pretty long to build up percentage increase over the control. Corn­ and they are destroyed very easily. In rniphora· wightii and Euphorbia caducifolia spite of all the limiting factors, the suc­ started declining in the first decade (Bhi­ cessional process does take place and it maya et al., 1964). may be faster in the initial stage, but Older alluvial plains. Flat alluvial plains may become very slow after the first and interdunal plains with 0-1 % slopes few phases owing to unfavourable edaphic with loamy sand to sandy-loam soils get conditions. the invasion of Aristida, Mefanocenchris, A large-scale destruction of the original Tephrosia, Indigo/era and Crotalaria in the vegetation from this part of the country early stage of colonization. Under pro­ due to heavy pressure' of man, and the tection, perennial grasses and undershrubs animal population makes it difficult to re­ gain the upper hand in three to four years. construct the whole progressional stage If the area continues to be undisturbed, into its correct perspective. Extensive eco­ spiny species, e.g. Zizyphus and Capparis logical studies in western Rajasthan for gather ascendency, which simultaneously the last sixteen years have led to build up culminates into the climax stage of Prosopis the probable successional stages on various cineraria (Fig. 2). The fiat older alluvial habitat which are described as follows: plains, with heavy soils (clay loam and Hills. The denuded rocks, in initial clay), show deviation in seral stages. Early stages are colonized by tough grasses and colonisers are altogether different, i.e. Dac­ forbs species, e.g. 0: thomaeum, Tragus tyfoctenium aegyptium, Echinochloa and biflorus, Enneapogon brachystachys, Mel­ Cyperus rotundus (Fig. 2.1.). These plants anocenchris jacquemontii, Lepidagathis tri­ provide a base for biennial and perennial nervis and Blepharis sindica (Fig. 1). With species, e.g. Tephrosia and Cynodon, to the accumulation and build-up of the establish themselves and dominate. This substratum shrub species, such as Euphor­ stage is followed by hardy perennial shrub bia caducifolia, Grewia lenax, Zizyphus species, e.g. Indigo/era oblongifolia and nummularia, get foothold. Simultaneous­ Cassia auriculata. These in turn are re­ ly, higher grass species, such as Eleusine placed by Zizyphus nummularia and C. compressa start dominating. The shrub decidua, and they culminate into the Sal­ species pave the way for tree species, e.g. vadora climax. The sandy-clay-loam soils Maylenus emarginatus, Moringa canca­ of older alluvial plains scattered in the nesis and Cordia ghara/. If these species higher-rainfall zone (300-500 mm) have an remain undisturbed, they appear to. end early successional pattern of loamy sand up ultimately in the climax community of or sandy-loam soils and later the species Anogeissus pendula-Acacia senegal. The of both the successional ladder form the soils build-up also helps the grassland intermediate stage which ultimately reach community to reach its climax with Sehi­ as the disclimax stage of Capparis-Zizyphus rna nervosum (Fig. 1.2). The slow build­ (common to both types). This stage, up of the soil arrests the grassland com­ under a long period of protection, gains munity to the Eleusine stage only. In the dominance over the climax community of higher-rainfall zone, grass species, e.g~ S. oleoides-P. cineraria. Hackelochloa, Bothriochloa and Brachiaria, The high palatability of Cenchrus species maintain tke disclimax for S. nervosum resul~s in its quicker eliminations owing to types of grasslands. Studies carried out severe grazing. Second, this species cannot in a twenty years exc10sure at the rocky stand competition with other weeds under side of KaHana (Jodhpur) have indicated the grazed condition. Thus grazing pro­ that Acacia senegal regenerated at a faster vides an opportunity for the ~stablishment

185 DESERTIFICATION AND ITS CONTROL

Salvadora oleoides Salvadora oleo ides Prosopis cineraria Prosopis cineraria t1 11 Capparis decidua doU Zizyphus nummularia Zizyphus nummularia Capparis decidua [1 11 11 Cassia auriculata Balanites aegyptiaca Indigofera do Ca/o/ropis procer:a oblongiJofia Eleusine compressa

11 ... TephrosiaII purpurea IndigoferaII sp. Cynodon dactylon do Crotalaria burhia Tephrosia purpurea 11 t1 n. Dactyloctenium aegyptium Aristida /uniculata Echinochloa colonum do Eragrostis sp. Cyperus rotundus Melanocenchris sp. 11 11 Barel1 soils Bare soils Bare soils 2.1 (CLAY LOAM TO CLAY 2.2 (SANDY CLAY 2.3 (SANDY LOAM TO SOILS) LOAM SOILS) LOAMY SAND SOILS) Fig. 2. Woodland succession on older alluvial plains of Jess palatable species. Aristida/uniculata, diate stage in succession. Both these spe­ C. hi/lorus, Eragrostis species represent the cies very much resist overgrazing, but once extent of degradation and Eleusine com­ they are removed or killed, the deteriora­ presSa as an intermediate stage (Fig. 3). It tion of the grassland takes place at a faster may be regarded as a precursor of the ' rate. H"eteropogoll and Cenc1lrU'i represent penultimate'stage of Cellchrus. a higher stage of succession with moderate , Dichallthium anllulatum grasslaqds occur intensity of grazing. Once this stage is in small patches on clay loam to clay soils. given complete protection for more than This grass is more prevalent in a zone with five years, it records the dominance of rainfall above 300 mm. The optimum ex­ Dicllallthillm amllilatum. pression obtained on protected lower pied­ Sandy undulating plains. The initial col­ mont plains had 24 per cent basal 'cover, onizers of sandy plains and undulating with 36 q per hectare of the above-ground plains include the annual species. e.g. biomass. Under grazing stress, it is im­ Aristida jimiculata, Gisekia pharnacoides, mediately replaced by less palatable spe­ Indigo/era lilli/olia, Latipes sellegalensis, cies, such as Digitaria adscelldens, Cynodon Eragrostis sp., Cellchrus bi/loms (Fig. 4). dactylon, {iremopogoll foveolatus, Eragros­ The species make a base for perennial tis ~nd Cenchrus bi/lorus which represent grasses and weeds to establish. These vanous stages of degradation (Fig. 3.2.) undershrubs and grasses, in turn, are re­ CY,nodoll and E,leusine form the interme- placed by shrub species such as Calli-

186 VEGETATION AND ITS SUC;CESSION

Cenchrus ciliaris Dichanthium annulatum C. setigerus t1 t1 Eleusine compressa Cenchrus ciliaris Cynodon dactylon Heteropogon contortus Eremopogon foveolatus 11 Dactyloctenium sindicum Eleusine compressat1 Digitaria adscendens Cynodon dactylon Urochloa panicoides Indigofera sp. 11 Indigo/era cordi/olia Brachiaria sp.U Cenchrus hiflorus Urochloa panicoides Tragus biflorus Cenchrus bi/lorus 11 ,Eragrostis. U sp. Eragrostis sp. Ari'stida adscensionis Tragus biflorus A. funiculata. Cyperus sp. 11 11 Bare soils Bare soils

3.1 LOAMY SAND TO SANDY LOAM SOILS 3.2 MEDIUM HEAVY TO HEAVY SOILS Fig. 3. Grassland succession on older alluvial plains gonum, Leptadenia and A. jacquemontii, tat are more or less phaeratophytics. Fal­ forming the intermediate stage which has low or abandoned fields in two to three a larger coverage. When this stage remains years are colonized by Cyperus sp., Sola­ undisturbed for long period it runs into num surattense, X anthium strumarium, the penultimate stage of Prosopis cineraria. Tephrosia purpurea and Crotalaria burhia_ Loose sandy calcareous soils of the 100- These species provide a base for perennial 250 mm zone of rainfall are initially colo­ shrub species, e.g. Tam'lrix eriocoides, Vitex nized by annual species of Cenchrus and negundo and Leptadenia pyrotechnica. Eragrostis. These are replaced by Eleusine These species are subsequently replaced by and Dactyloctenium which, under a few spiny shrubs, such as Balanites aegyptiaca, years of protection, lead to the preponder­ Zizyphus nummularia and Capparis decidua. ance and dominance by Lasiurus sindicus, This disclimax stage, if left undisturbed, the climatic climax grassland of this zone. culminates into a climax community of Younger alluvial pla"ills. This habitat, Aca.cia nilotica-Prosopis cineraria (Fig. 5)_ being highly potential is never allowed to Along the dry river courses, some parts gain climatic climax. More often, the of the plains are liable to inundation and Successionary processes are held up at the they show the dominance of Desmostachya pre-climax stage. The rate of succession hipinnata community. This community, IS farily rapid because of the availability on an average produces 24.5 q per ha of more moisture throughout the year. Al­ of the above-ground forage biomass, with most all the trees, which grow in this habi- 7% basal cover. Excessive grazing and

187 DESERTIFICATION AND ITS CONTROL cultivation lead to degradation with 2-5 % and C. setigerus are invariably encounter­ cover and 7.5 q per ha of the above-ground ed. Their occurrence indicates that these biomass. This grass is only slightly palat­ two species may be the potential disdimax able in its early vegetative growth period of this habitat. Continual cultivation and as compared with other perennial and an­ grazing do not permit these palatable gras­ nual forage species. Clumps of C. ci/iaris ses to dominate. Desmostachya, being only

Prosopis cineraria II Tecomella undulata Maytenus emarginatus 11 Zizyphus nummularia Lasiurus sindicus Acacia jacquemontii Balanites aegyptiaca l1 . Cymbopogontl jwarancusa Calligonum polygonoides Cenchrus sp. Lycium barbarum Mimosa hamata 11 11 E/eusine compressa PaniCllm turgidum Dactyloctenium sindicum Lasiurlls sindicus Crotalaria burhia t1 t1 Cenchrus bi/lorus Cymbopogon jwarancusa Latipes senegalensis E/eusine compressa Dacty/octenium sindicum II [1 Indigo/era linifolia Indigo/era lini/olia Eragrostis spp. Latipes senega/ensis Aristida adscensionis Cenchrus biflorus [1 U Aristida spp. Aristida sp. Mollugo sp. Gisekia pharnacoides Mollugo nudicaulis 11 U Loose sand Loose sand 4.1 GRASSLAND 4.2 WOODLAND Fig. 4. Succession on sandy undulating hummocky plains

188 VEGETATION AND ITS SUCCESSION slightly palatable, regenerates with its dominance by Saccharum. strong rhizomes and resists rigorous cul­ Sand-dunes: Various stages of develop­ tivatIon practices. 'Cyperus rotundus, Cen­ ment or degradation of plant communities chrus biflorus, Aristida and Eragrostis spe­ on 'the sand-dunes are encountered in wes­ cies are the initial colonizers (Fig. 5), and tern Rajastha~. Out of those stages, one these species persist year after year of cul­ can reconstruct its successional pattern. tivation. On the other hand, fields under Cyperlls arenarius, Aristida funiculata, long fallows show the dominance of Eleu­ Cenchrus b!florz~s, Indigo/era cordi/olia, I. sine compre-ssa, with a few clumps of Cen­ argentea, Farsetia hamiltonii, Crotalaria chrus sp. and Desmostachya. The return burhia and Aerva pseudotomentosa are the of Desmostachya turns the whole field into pioneer species (Fig. 6). A large-scale cover­ its grassland. Once established, it is very age by Crotalaria, Aerva and Cyperus sp. difficult to eradicate this grass. Pretty brings about the stabilization of sand to a long undisturbed condition may lead to greater extent. Now, the substratum be-

Saccharum sp. Acacia nilotica Prosopis cineraria

Desmostachyal1 Capparis decidua!1 bipi1tl1ata Zizyphus nummularia i1 Balanites aegyp/iacal1 II Leptadenia pyrotechnica

CenchrusII species Tamarix eriocoides11 T. troupii !1 Vitex negundo l! Eleusine compressa 11 Dactyloctenium sindicum Desmostachya bipinnata Xanthium strumarium 11 L 11 Indigo/era cordifolia Crotalaria burMa Cenchrus biflorus Tephrosia purpurea Eragrostis spp. 11 Aristida sp.l1 Solanum surratense Cyperus rotundus Cyperlls sp.

Bare soil Bare soil

5.1 GRASSLAND 5.2 WOODLAND Fig. 5. Succession on younger alluvial plains.

189 DESERTIFICATION AND ITS CONTROL

Prosopis cineraria [1 Acacia senegal 11 Maytenus emarginatus Acacia jacquemontii Balanites aegyptiaca ..(1cacia jacquemontii Saccharum bengalellse S. spontaneum 11 U Panicum antidotale Calotropis pro cera Lycium barbarum Calligonum polygonoides U Leptadenia pyrotechnica Calotropis pro cera Panicumif/ turgidum Haloxylon salicornicum 11 Panicum turgidum Clerodendron­ phlomoides 11 Calligonum­ Cymbopogon spp. polygonoides Lasiurus sindicus Panicum turgidum Cenchrus sp. Dipterygium glau~um Sericostemma pauciflorum Aerva pseudotomentosa 11 (1 Sericostemma Eleusine pauciflorum Dactyloctenium Crotalaria burMa Indigo/era Aerva pseudotomentosa [1 Cenchrus bi/lorus Aristidat1 spp. 100-200mm Aristida/uniculat(J; Cenchrus spp. Indigo/era linnii [1 Eragrostis spp. Cyperust1 arenarius Cyperus arenarius .iJ 11 Bare sand dune Loose sand

6.1 WOODLAND (200- 6.2 GRASSLAND (200- 350 MM) 350MM) Fig. 6. Succession on sand dunes

190 VEGETATION AND ITS SUCCESSION

Salradora oleo ides­ Acacia nilatica II Dichanthium annulatum Tamarix ~phylla Sporobolus marginatus Zizyphus nllmmularia Capparis decidua t1 Haloxylon salicornicum Sporobolus sp. Suaeda frut icosa Salsola baryosma

Sporobolustl marginatus Eremopogon foveolatus Desmostachya bipinnata Cenchrus species Peganum harmala U Eleusine compressal1 Eleusine compressa Echinochloa colonum Schoenfeldia gracilis Dactyloctenium aegyptium Chloris virgata Chloris virgata 11 11 Aeluroplls lagopoides Trianthema portulacastrum Portulaca oleracea Cressa ereliea [1 Cyperus rotundus Aleuroplls lagopoides Scirpus sp. Cyperus rotllndus Scirplls sp.

Clayey salineII soils Clayey IIsaline soils

7.1 GRA5SLAND 7.2 WOODLAND Fig. 7. Succession on saline depressional areas 'Rann' comes more suitable for invasion by under­ barum, Balanites aegyptiaea and Maytenus shrub, shrubs and perennial grasses, e.g. emarginatlls. The last three species form Sericostemma pauci/lorum, Leptadenia the penultimate stage for the climax com­ pyrotechnica, Clerodendron phlomoides, munity of Prosopis cineraria. The grass­ Calligonum polygonoides, Calotrapis procera, land development in the low-rainfall zone Panicum turgidllm, P. antidotale, Lasiurus (below 300 mm) gets arrested up to Pani­ sindicus and Cenchrus ciliaris. Subsequent cum tllrgidllm type only, whereas in the stabilization and undisturbed conditions br­ higher-rainfall zone (above 350), the same ing about Acacia jacquemontii, Lycium bar- stage is surpassed by Saccharum species.

191 DESERTIFICATION AND ITS CONTROL

The highest grass community is represent­ CHAMPION, H.G. and SETH, S. K. 1964. A Revised ed by Saccharum bengalense. Survey of the Forest Types of India (Mimeo) Saline depression. Sp.Jrobollls marginatlls Dehradun, pp. 1-653. CHAUDHARI, J. I. 1957. Succession of vegetation represents the optimum expression of the in the arid regions of West Pakistan plains. grasslands of the saline habitat. When Proc. UNESCO. Symposium on Soil Erosion nngrazed, a pattern of grass communities and Its Control in the Arid and-Semi-arid develops, according to the micro-relief and Zone, Karachi, 140-155. silt concentration in the soils. Dichanthium CLEMENT, F. E. 1916. p,lant Succession : An Analysis of the Development of Vegetation. annlllatllm establishes itself near trenches Pub!. Carnegie Inst., Wash., 242. pp. 512. and bunds where most of the salts are lea­ GAUSSEN,H., LEGRIS,P., GUPTA, R.K. and MEHER­ ched out during the rains. The most saIt­ HOMJI, V. M. 1971. Illternational map of tolerant grass is Aeluroplls lagopoides which vegetation alld environmental conditions. comes right on the salt incrustation. Sheet Rajputana. ICAR, New Delhi, Inst. Fr. POlldicherry. Trail. Sect. ,Sci. Tech. Hols. Water-logged areas support Cyperlls and Series No. 17. Scirpus species. The earlier colonizers are GUPTA, R. K. 1975. Plant Life in the ThaI' desert. (Fig. 7) Zygophyllum simplex, Cressa Environmental Analysis of the ThaI' Desert. cretica, SensuviUln portulacastrum, S~hoen­ English Book Depot. pp. 202-236. GUPTA, R. K. and SAXENA, S. K. 1972. Potential feldia gracilis and, Chloris virgata. Here grassland types and their ecological succes­ again, Eleusine compressa forms the inter­ sion in Rajasthan desert. Ann. Arid Zone mediate stage in the successional ladder. 11(3 & 4) : 198-218. The leaching of salt and subsequent sand IFTEKHAR, AHMAD 1964. Vegetation of salt range. Pakistan J. For. 14(1) : 36-64. deposition on such a habitat stages the LA TOUCHE, 1902. Geology of western Rajasthan. arrival of shrub species, such as, Suaeda Mem. Geol. Surv. India, 35, pt. 1. fruticosa, Salsola baryosma; Haloxylon MATHUR, C. M. 1960. Forest types of Rajasthan. salicornicum, Zizyphus itummularia and Indian For. 86(12) : 734-739 .. OASTING,H. J.1956. The study of plant communi­ Tamarix species, which continue to grow ties. An Introduction 'to Plant Ecology. W. H. as discJimax. A further improvement of Freeman and Co., New York. these species may lead to the penultimate PANDEY, S., SINGH, S. and GHOSE, B.1964. stage of Salvadora oleoides-Acacia nilotica. Orientation, distribution and origin of sand­ dunes in the Central Luni Basin. Proc. REFERENCES Symp. on Problem of Jndian Arid Zone. pp. 84-91. BHIMAYA, C. P., CHERIAN, A. and SATYANARAYAN, SAXENA, S. K. 1972. The concept of ecosystem as Y. 1964. Preliminary studies on the. vege­ exemplified by the vegetation of western tation of Kailana, Rajasthan. Indian For. Rajasthan. Vegetation 24(1-3) : 215-27. 90(10) : 667-675. SAXENA, S. K. and SINGH, S. 1975. Some observa­ BHARDWAJ, O. P. 1971. The arid zone of India tions on the sand-dunes and vegetation of and Pakistan, pp. 143-174. A History of Bikaner district in western Rajasthan. Ann. Land Use in Arid Regions (Ed. L. Dudley • Arid Zone (in press). Stamp), Arid Zone Research, XVII UNESCO SATYA1~ARAYAN, Y. 1963. Ecology of Luni Paris. Basin. Ann. Arid Zone 2(1) : 82-97. BHARUCHA, F. R.1951. Proc. of Eight Silvicultural SATYANARAYAN, Y. 1964. Habitat and plant Conferences, Dehradun (quoted from Satya­ communities of Indian desert. Proc. Symp. narayan, 1964). on Problems of Indian Arid Zone. pp. 59-68. BLATTER, E. and HALLBERG, F. 1918-21. The SHANTISARUP and VYAS, L. N. 1958. Ecological flora of the Indian desert (Jodhpur and studies on the vegetation of Jodhpur tehsil. Jaisalmer). J. Bombay nat. Hist. Soc. 26: Raj. Univ. Studies 3 : 77-97. 218--46,1-12,1918; 525-51,13-25, 811-18; SHREVE, F. 1951. The vegetation of Sonaran 26-31, 1919; 968-87, 1920; 27.: 40-47, Desert. Can. Inst. Washington Publ. No. 270-79, 32-34, 1920; 506-19; 35-57, 1921. 591. CHAMPION, H. G. 1936. A preliminary survey WHITAKER, 1953. A criticism of the plant asso­ of the forest types of India and Burma. ciation and climate concepts. North-west Indian For. Rec. (MS). Science 25 : 17.

10') 20; MEASURING DESERTIFICATION THROUGH PLANT-INDICATORS

VINOD SHANKAR

THE relationship of the species amplitudes ported a tropical rain-forest during the and quantities to the environmental gra­ Tertiary, (2) the present-day xerophytic dients has found many practical applica­ vegetation was well established at the tions. The development of plants,' inter beginning of the Holocene (10,000 years alia, to read out the environmental gra-, B.P.) and (3) no palaeobotanical records dient is one of them. The environmental belonging to the 50 million years that elap­ gradient sought to be explored may be sed between the two epochs are available. single or a combination of both, and may The Holocene vegetation was, therefore, be temporal and spatial. For a purpose chosen as a starting-point. Attempts like the measurement of desertification were made (Singh, 1967, 1969; Singh et with the aid of plant-'indicators, stress is al., 1972, 1974; Meher-Homji, 1970, laid on selecting criteria out of the tem­ 1973; Vishnu-Mittre, 1975) to recon­ poral developments within a specified struct the physiognomy of the Holocene habitat. While going in for the selection vegetation. The soundness of this how­ of plant-indicators and working out a ever, seems to have suffered because of score-card for measuring desertification (1) the lack of real knowledge of the micro­ trends in western Rajasthan, the approach and macro-transitional phases in vegeta­ has been similar to that adopted for the tion-environment interactions, and (2) range-condition surveys (Dyksterhuis, deflected succession caused by biotic in­ 1958). fluences. The gross reconstruction (Singh To build up the guidelines for the selec­ et al., 1974), the climo-vegetation relation­ tion of criteria and for the grading of the ship (Legris and Meher-Homji, 1975) scores, an attempt was first made to scan and the successional trend in the past through the pertinent literature to search vegetation (Vishnu·Mittre, 1975) is, never­ out the very premise on which the whole theless, a worthy attempt. For the pur­ thing would be developed. The enquiry pose, enunciated in this paper, it has about the premise was as to what the been broadly accepted that a shrub­ d~sert formation would be a woodland, savanna, with species content varying a shrubland, a grassland or a savanna according to the habitat, was a bio-eda­ type. Whether 'a reconstruction of the phic disclimax during the Holocene. past vegetation and a link-up with the Vishnu-Mittre (1975) calls it climax vege­ present one is possible or not. The en-' tation but it does not appear to be a very quiry, to put into simple words, was as to wise and viable proposition. how the past vegetation looked like and It becomes clear from the foregoing What relationship, if any, the present account that for measuring desertification vegetation would have with it. in terms of vegetation parameters, the Palaeobotanical evidences gathered so following points must be kept in view: far reveal that (1) western Rajasthan sup- (1) A shrub-savanna was the.desert for-

193 DESERTIFICATION AND ITS CONTROL

mation, (2) the relationships between the 4. Vigour of perennial grasses landform and the plant cover were simi­ 4·1 Normal vigour under protec. lar to what are now, (3) abusive land use in tion (robust, dark green plant the form of overgrazing, excessive felling, not pedestalled) . shifting cultivation, burning, etc. brought 4 2 As above, plant slightly pede­ stalled 3 about deterioration in the shrub-savanna 4·3 Vigour medium, plant ob­ formation, (4) the knowledge of the ecolo­ viously pedestalled or pillow gical status of plants and their habitat, form 5 as obtaining now (Satyanarayan, 1964) 4 4 Vigour poor, roots exposed, distinctly pedestalled or pillow can be employed to numerically express form 7 the degree of desertification. In doing so, there is no denying the fact that an 5. Weeds element of sUbjectivity and a justifiable 5 1 Rare 1 limit of arbitrariness in assigning numbers 5 . 2 Occasional 2 to each parameter remain and all this can 5 . 3 Frequent 3 be further improved upon. 5 -4 Abundant 4

THE SCORE CARD 6. Shrubs The parameters selected are the ecologi­ 6 1 Crown cover 14 % or less 1 cal status and the developmental stage of 6·2 " " 15 to 25'% 3 the vegetation, analytical attributes of 6 3 26 to 39% 5 perennial grasses, including dom!!lance on 6·4 40% and over 7 production basis, vigour of perennial 7. Grazing intensity grasses, weeds, shrubs and the grazing or browsing intensity. 7 1 Zero grazing (0) 7 2 Light grazing (less than 25 % herbage removed) 3 Plant-indicators Check 7· 3 Moderate grazing (26-50 % points herbage removed) 5 7 4 Heavy grazing (51 % and above 1. Ecological status and developmental herbage removed) 7 Jtage Magnitude of desertification: 1·1 Stage final (disclimax) 1 1 ·2 .. fourth (2nd or penulti­ Grading Score mate sere) 3 1. Zero 7 and below 1 ·3 .. second (2nd seral stage) 5 2. Light 8 to 20 1 4 .. first (pioneer colcnizers) 7 3. Moderate 21 to 33 4. Heavy 34 to 46 2. Relative importance vallie index 5. Severe "'" 47 and above. (summation of relative frequency, relative density and relative basal CONCLUSION cover) of perennial grasses The objective of the above score-card 2·1 76 to 100 1 is to measure negative and positive changes 2·2 51 t075 3 in the ecological status of the plants caused 2 3 26 to 50 5 by biotic factors, specially the herbivory. 2·4 0 to 25 7 Such changes can be seen from compari­ 3. Dominance (on the basis of dry. sons between the disturbed vegetation matter yield) and the relict or reserve vegetation. The applied use of the score-card includes its 3·1 Exclusive dominance of higher perennial grasses 1 use from the angle of range management, 3 2 A mixed stand of higher and as it considers the plant-indicators within lo.wer perennials 3 the broader framework of an open xero­ 3· 3 Exclusive dominance of lower morphic scrub vegetation. From the perennials 5 3· 4 Patchy dIstribution of annual forestry angle, the ecological status of the grasses, 7 plants has to be fixed with the open

194 MEASURING DESERTIFICATION xeromorphic woodland as a marker and Govt. of India, New Delhi. SINGH, GURDIP, JOSHI, R. D., and SINGH, A. B. the tree parameters and not with the under 1972. Stratigraphic and radiocarbon evi­ storey. dence for the age and development of three salt lake deposits in Rajasthan, India. REFERENCES Quaternary Res. 2(4) : 496-505. SINGH, GURDIP. JOSHI, R. D., CHOPRA, S. K. and DYKSTERHUIS, E. J. 1958. Ecological principles SINGH, A. B. 1974. Late Quaternary of range evaluation. Bot. Rev. 24: 253-72. history of vegetation and climate of the LEGRIS, P. and .MEHER-HoMJI, V. M. 1975. Rajasthan desert, India. Phil. Trans. Roy. Bioclimatology and vegetation of the Rajas­ Soc., London 267B(889) : 467-501. than desert. Paper read at the Workshop SINGH, GURDIP, 1967. A palynological approach on the Problems of the Dese,.ts in India, held towards the resolution of some important at GSI. Jaipur, Sept. 1975. desert problems in Rajasthan. Indian Geohydr. MEHER-HoMJI, V. M. 1970. Some phytogeo­ 3(1) : 111-28. graphic aspects of Rajasthan, India. Vege­ SINGH, GURDIP, 1969. Palaeobotanical features ·tallio 21 : 299-320. of the Thar desert. Ann. Arid Zone 8(2) : MEHER-HoMJI, V. M. 1973. Is the Sind-Rajasthan 188-95. desert the result of a recent climatic change? VISHNu-MITTRE, 1975. Problems and prospects Ge%rum 15 : 47-57. of palaeobotanical approach towards the SATYANARAYAN, Y. 1964. Habitats and plant investigation of the history of Rajasthan communities of the Indian desert. pp. 59- desert. Paper read at the Workshop on thl! 68. Proc. Symp. Problems of Indian Arid Problems of the Deserts in India, G. S. I., Zone, . Jodhpur, Ministry of Education, Jaipur, September 1975.

195 21 FOREST-TREE PLANTING IN ARID ZONES

R. N. KAUL AND GYAN CHAND

THE establishment of social and protective brate pests. With these problems in view ~ forests in low-rainfall zones is an effective a research programme was formulated and means of raising the level of the local initiated in 1958 at the Central Arid Zone' economy and improving the ecology of Research Institute, Jodhpur, and the­ these regions. Rehabilitation by tree­ results obtained are .briefly discussed planting is by no means restricted to areas below: that formerly bore forest growth. Even in the regions that apparently had always FOREST SPECIES AND VARIETIES been devoid of trees, transplanting is not Introduced species. The local tree spe­ only feasible but extremely important in cies of the region are not only a few but any programme of land improvement. It are also extremely slow-growing and it, is estimated that between 300 and 500 therefore, becomes necessary to introduce million seedlings of forest trees are plan­ tree species of higher growth rate and of ted every year in the arid and semi-arid better resistance to drought and cold. zones of the world with varying degrees One hundred and twelve species of diffe­ of success. This paper describes the rent provenances of Eucalyptus, 64 species techniques and species of proven merit of difTerent provenances of Acacia, and for large-scale tree-planting in the Indian 82 species of 44 other genera from more or arid zone under varying edaphic and cli­ less isoclimatic regions of the world were matic conditions. tried in the arboreata at Jodhpur and Pali. I SILVICULTURAL PROBLEMS Eucalyptus. The order of performance­ The most urgent practical problem' in of "the different species has been different applied'silviculture is the development of with respect of three growth attributes, practical methods for afforesting different namely the percentage survival, height land types met within the arid zone, with growth, and the diameter at breast height. utilizable species. This problem demands At Jodhpur, Eucalyptus melanophloia has studies on : (i) the selection of species, distinctly shown promise, whereas at Pali, both indigenous and exotic, and their eco­ E. tessellasis, E. melanophloia, E. oleosa types for different sites; (ii) the proquction and E. camaldulensis have performed well. of seedling transplants; (iii) silvicuItural Acacia. The Acacia species which have characteristics of selected tree and shrub shown performance in growth and survival species; (iv) soil-working techniques and equal to or better than, the indigenous cultural operations in relation to the Acacia senegal have been designated as harnessing of the uncertain and erratic promising. Among Acacia species A. rainfall, particularly during periods when tortilis has proved to be the most pro­ the lack of soil moisture is felt most; and mising introduction from Israel. Eight­ . (v) protection against diseases and verte- year-old trees at Jodhpur showed 100·

196 FOREST-TREE J:'LANTING

per . cent survival. The mean height compared with earthen containers. In growth attained was 6.4 Dl. A. tortilis general, the increased levels of watering has now been successfully introduced on resulted in increased survival and growth an extensive scale into the arid and semi­ in height of A. lebbek and P. juliflora. arid regions of the country. However, nine litres of water at a time per Miscellaneous genera. The species be­ set of 50 containers was found to be the longing to different genera were selected most economic dose of watering for the with a view to meeting the twin objective successful raising of nursery seedlings. of providing fodder and shade for ani­ When grown in shade, the water need of mals in rangelands. Casuarina cristata, seedlings was less by 9.6 per cent than the Grevillea pterosperma, Myporum monta­ need of those grown in the open. Seed­ num, Zizyphus spinachristi, Colophos­ lings kept in cemented beds under nine permum mopane, Schinus molle, etc. have Iitres of watering level required 29. 8 per shown promise (Kaul, 1970). cent less water than those kept in earthen beds because of a smal1er number of INDIGENOUS SPECIES root clippings in cemented beds. The When soil conditions are taken into ac­ use of metallic containers effected an count, the indigenous species are the best overall economy of Rs 6 in the produc­ adapted to the local conditions. The only tion per 100 seedlings (Kaul and Ganguli, problem in the case of indigenous species 1963b). is their excessively slow growth rate, Further studies on the media and sizes at least during the early years. For exam­ of receptacles for growing nursery stock: ple, in 14 years Prosopis cineraria, Acacia of four desert tree species, namely Albizzia senegal and Tecome(la undulata under lebbek, Acacia senegal, Prosopis cineraria Jodhpur conditions attained a height of and Tecomella undulata, showed superio­ 2.8, 3.5 and 3.1 m respectively. The rity of the metallic containers to those valuable indigenous tree species are P. made of baked earth and polythene. cineraria, A. senegal, T. undulata, Albizzia Larger containers compared with smaller lebbek, Salvadora oleoides and Azadirachta ones proved better for seedling survival indica. and growth (Kaul and Gyan Chand, 1967). Nursery trials were carried out to test NURSERY TECHNIQUES the growth-promoting effect of gibberellic In the nursery, the maximum seedling acid (G.A.) on three indigenous species, mortality occurred during August to viz. Prosopis cineraria, Acacia senegal November and, to a much less extent dur­ and Albi::zia lebbek, and two exotic spe­ ing February to March; thereafter, no cies, viz. Eucalyptus cama/dulensis and seedling mortality took place tiII July. Acacia torti/is, with a view to shortening Of the four species studied, Acacia senegal the period required for seedling growth in showed the maximum seedling mortality the nursery. In general, the indigenous (8.5 per cent), foIl owed by Albizzia lebbek species did not show a significant increase (3.7 per cent), Tecomella undulata (3.5 in the shoot growth of the treated seedlings per cent) and Prosopis cineraria (2.7 per over that of the control seedlings. The cent). Changes in the ambient tempera­ seedlings of Acacia torti/is showed the ture during the juvenile seedling stage (3 maximum increase in shoot growth under months old) of these species appeared to 10 ppm of G.A. treatment, though this be the cause of seedling mortality. . difference was not significant when com­ The seedlings of Albizzia lebbek and pared with the control treatment. Trea­ Prosopis julif/ora in metal1ic containers ted seedlings of E. camaldu/ensis showed a showed higher survival rates and growth in significant increase in height growth of ~eight than those in earthen pots. Metal­ shoots as compared with that of the con­ hc containers also resulted in economy in trol ones, the maximum increase being Watering to the extent of 25 per cent as under 30 ppm G.A. treatment. Similar

197 DESERTIFICATION AND ITS CONTROL

trends were observed in respect of shoot­ Root characteristics. The initial root to-root ratio. The lack of response of habit of a given species, its ramifications the three indigenous species to the appli­ and its inherent capacity for adjustment to cation of G.A. is probably due to the variations in soil moisture conditions natural presence of optimal amounts of appear to be very important factors in this chemical in them (Kaul, 1964b). seedling survival in the first growing sea­ Different sizes of root and shoot cuttings son following germination as evidenced in of Prosopis juliflora, varying in collar the case of Albizzia lebbek and Tecomella diameter and root length, influenced the undulata. However, a very low inherent sprouting period, whereas the survival in top-root ratio appears to bring about a the nursery was affected by root length better hydro-economic effect resulting in alone. Root-shoot cuttings of 1. 5-cm greater initial seedling survival as in the collar diameter and 17.5-cm root length case of Acacia senegal. The root-system in the case of Prosopis juliflora appeared characteristics 'of Prosopis cineraria seed­ to be the most suitable sizes for pre­ ling, however, do not have the drought­ sprouting them in the nursery (Bhimaya escaping properties at least in the juvenile et al., 1965). seedling stage (Bhimaya and Kaul, 1966). Further studies on six-year-old plants of SILVICULTURAL CHARACTERISTICS OF T. undulata, A. lebbek, P. cineraria and A. INDIGENOUS TREE AND SHRUB SPECIES senegal, obtained from direct seeding and Age of seedlings. The data recorded transplanting, revealed that the transplan­ at the end of 10 years revealed that one­ ted plants of all the species showed an in­ year-old seedlings of Prosopis cineraria creased length of the tap-root. The species (99. 1 per cent), two-year-old seedlings of did not differ markedly in their maximum Albizzia lebbek (67.5 per cent), and one­ lateral spread of root under seeding and year-old seedlings of Acacia senegal transplanting. The transplanted plants (95.8 per cent) exhibited the highest sur­ of all the species, excepting T. undulata vival although, differences within a species recorded an increased number of secon­ among the ages of seedlings (6-,9-.12-, dary roots compared with plants raised and 24-month-old seedlings) were not from direct seeding. The transplanted significant. plants of T. undulata and A. senegal Time of planting. Prosopis cineraria showed a higher root-shoot ratio, whereas (97.5), Albizzia lebbek (60), Tecomella the plants of A. lebbek and P. cineraria undulata (90.8) showed the maximum raised from direct seeding showed a higher percentage of survival when planted in root-shoot ratio (Bhimaya and Kaul, the second fortnight of July as compared 1965). with plantings in first fortnight of July Spadng. When planted at a spacement and the first fortnight of August. There of 1.6 m x 1.6 m, the crowns of these was, however, no significant differences species touched each other within seven among the three planting periods. The years, thus necessitating thinning. Since best planting period synchronizes with in the arid environment these species do the onset of the monsoon (Kaul, I 964a). not attain any usable size within this Soil-working and the method of rehoise­ period, it is better to follow an initial wider ment. Compared with direct seeding. spacing (at least 3. 5 m), as that will not transplanting proved to be an assured only obviate the necessity of early inter­ method of reboisement in the case of mediate thinning but will also be condu­ Prosopis cineraria, Acacia senegal, Albizzia cive to a better plant growth and facilitate lebbek and Tecomella undulata. Soil­ mechanical weeding in the plantation. working c9mprising 60 cm' half-filled pits with a crescent-shaped ridge across the PLANTING TECHNIQUES IN RELATION TO local slope resulted in a higher rate of LAND TYPES estl!blishment. The special features of soil-working

198 FOREST-TREE PLANTING

techniques and cultural methods for the these species were found to be frost­ establishment of plantations in different resistant. land types are briefly· summarized below: Sap.d-dunes afforested in this way sho­ Shifting sand-dunes: In low-rainfall areas wed wide variations in fuel yield, both in (150 mm to 400 mm), shifting dunes are respect of the age of the tree and the habi­ commonly met with, particularly near tat. Tl}e difference in fuel yield between habitations and townships. Techniques the habitats followed the pattern of in­ of afforestating the shifting dunes were crease in the rainfall from west to east standardized after 10 years of experimenta­ (Bhimaya et al., 1967). tion (Kaul, 1970). These techniques con­ The data on the expenses incurred and sist of (i) protection against biotic inter­ the revenue from fuel, fodder, seeds and ferences; (ii) the treatment of shifting other things for the sand-dune stabiliza­ sand-dunes by fixing barriers in parallel tion areas of the Bikaner and Jhunjhunu strips or in a chess-board design, using the districts indicate that the technology of local shrub material starting from the sand-dune stabilization had a break-point crest down to the heel of the dune to even after 15 years. The average cost per protect the seedlings from burial or ex­ hectare, induding fencing, mulching, aff­ posure by the blowing of sand; and (iii) orestation, major repairs and operational afforestation of such treated dunes by costs worked out at Rs 55l.60 for Udram­ direct seeding and planting. The two sar, Rs 753.76 for Shri Kolayatji, Rs species commonly used for erecting brush­ 1,039 for Shivbari and Rs 455.50 for the wood barriers (Micro-windbreaks) are Jhunjhunu areas. The average benefits Zizyphus nummularia and Crotalaria bur­ per hectare comprising fuel, fodder, hia. The direct seeding of grass species munja, forage grasses, tree seeds, etc. and creepers is carried out',in lines, 2 to came to Rs 1,560 for Udramsar, Rs 616 5 metres apart, on the leeward side of the for Shri Kolayatji, Rs 637 for Shivbari and micro-wind break. The nursery stocks Rs 2,086 for the Jhunjhunu areas (Gyan are raised, either in containers or in Chand et al., 1976). specially prepared sun-dried planting Shallow soils. Earlier experiments on bricks, consisting of a mixture of sand, the establishment of three seedlings clay and farmyard manure in the ratio of on shallow soils (22.5 cm deep) overlying 1: 1 : 1, with a height of 30 cm and a cross­ hard calcareous pans under a rainfall of section at the top and bottom of 10 cm 375 mm showed that Albizzia lebbek, and 15 cm square respectively. When Eucalyptus cama'ldulensis and Casuarina transplanted at this stage, a high degree equisetifoUa gave the highest seedling sur­ of establishment is achieved. vival in pits 30 cm in diameter and 60 cm The indigenous and exotic species deep (Bhimaya and Kaul, 1969). Casua­ which have proved successful are: Trees­ rina equisetifolia su bsequently failed to Acacia senegal, Prosopis juliflora (in non­ est1l:blish itself, whereas the other two frosty localities only), Albizzia lebbek, species remained stunted and did not put Cordia rothii, Dalbergia sissoo (in regions on any appreciable increment even after with mean annual rainfall of 250 mm) seven years of growth. Subsequent experi­ and Zizyphus jujuba; shrubs-Calligonum ments with deep soil-working in pits, 60 polygonoides, Cassia auriculata, Ricinus cm in diameter and 90 cm in depth per­ communis (in non-frosty localities), and forating much of the hard-pan consistently Zizyphus nummularia; grasses-Lasiurus resulted in cent per cent survival and a sindicus, Panicum turgidum and Erianthus mean annual height increment of 28.9 munia (Bhimaya et al., 1964). Among cm and 25.18 cm in Azadirachta indica exotic species, EucalJptus oleosa (Aust­ and A. lebbek respectively. Studies have ralia), Acacia tortiUs, Parkinsonia aculeata conclusively shown that two weedings, and Acacia victoriae (Australia) were one at the end of July and the other at the found to be promising, especially, as end of January are extremely necessary

199 DESERTIFICATION AND ITS CONTROL

for proper plant growth. The plants of the local slope. Pre-sprouted stumps of Acacia torti/is attained 54. 8 per cent in­ Prosopis juli/lora showed 98 per cent sur­ crease in the mean annual height incre­ vival and a mean growth in height of 4.8 ment under the treatment of two weedings m at the end of 9 years. Albizzia amara a year carried out for the first three years (96 per cent), Azadirachta indica (95 per compared with the control. These trees cent), and Holoptelia integrifolia (90 per at end of 11 years have attained an aver­ cent) were next in order of percentage age height of 5. 6 m and a diameter of survival. Recent studies indicate that 7 cm at breast height. Acacia tortilis, having exhibited JOO % Studies on soil-working with the direct survival and a height growth of 6 m at seeding of Acacia ni/otica ssp. indica and the end of 5 years, is the most promising Prosopis cineraria have shown that soil­ of all the species that have 'so far been working can be carried out at any time tried. from March to June; that in relatively Rocky areas. Barren rocky hills, cove­ flat areas a smaller cross-section (30x 30 ring extensive areas form one of the cm) of ridge-cum-trench is as effective as characteristic features of the landscape. that of a wider cross-section (60x 30 cm) Studies show that only those patches where and that a progressive spacing of seedlings, the depth of soil of about 43.5 cm has by removing excess seedlings during the accumulated should be planted with tree first two years of seeding, is extremely species. Pre-sprouted stumps of Prosopis essential for proper seedling growth (Kaul juliflora in 60 cm2 half-filled pits and direct and Gyan Chand, 1966). In shallower seeding of Acacia senegal on ridges have soils, transplanting in 0.3-m-deep pits given reasonably good establishment. compared with direct seeding has been Recent studies on the comparative per­ found to be a better technique for raising formance of Acacia tortilis and Acacia plantations. senegal under direct seeding and trans­ Semi-rocky areas. Semi-rocky areas planting showed that A. tortilis attained are characterized by their shallow depth three times more growth in height under at the foothills in the 225-to-350-mm both the methods than A. senegal and is rainfall tract and are formed by colluvial likely to do better in such land types. silt and rock fragments. Among the Recent studies (Kaul et al., 1966) revealed different soil-working techniques tried in that in the piedmont geomorphic units, the experimental afforestation on 283 soils depth was highly related to micro­ hectares, the seeding of Acacia senegal, relief and that it should be taken as an Prosopis juliflora, Tecomella undulata, important factor in the planning of affores­ Acacia ni/otica ssp. indica, and Prosopis tation in such areas. cineraria. on staggered contour ridge-' Roadside avenue and wind-break planting. cum-trenches, each' 2 m in length and 60 Experimental shelterbelts in the form of x 60 cm in cross section, proved success­ roadside avenue along the principal high­ ful. Among these species, at the end of 9 ways were established in different parts years, the maximum survival was recorded of the region to the extent of 200 km at a in the case of P. juliflora (50 per cent), cost of Rs 625 per km. followed by A. senegal (30 per cent) and The technique consisted in planting Cassia auriculata (15 per cent). However, three staggered rows of trees on each side the average increases in height and dia­ of the road (Kaul, 1957). In low-rainfall meter at breast height recorded for these (120 to 350 mm) tracts, the regular water­ species were : P. juliflora-4.8 m and ing of plants at 9 litres per seedling during 3.2 cm; A. senegal-I. 5 m and 1.4 cm; the summer months for at least the first and C. auriculata-l.3 m and 2.5 cm two years after planting, and with tree respectively. guards as protection against cattle gave Planting was done in 60 cm3 half-filled a survival percentage of 62.4. The spe­ pits w,ith a crescent-shaped ridge across cies in order of performance were Prosopis

200 FOREST-TREE PLANTING

juliflora, Azadirachta indica and Albizzia also give shade and shelter to the grazing Jebbek. In moderate-rainfall (350 mm) animals, thereby help to utilize forage tracts, these species, under similar treat­ uniformly on the range. In addition, ments, gave 95 per cent survival, whereaS fodder trees and shrubs will ameliorate in the higher-rainfall zone (400 mm), the micro-climatic conditions and thereby Azadirachta indica, Albizzia lebbek and create conditions conducive to the na­ Dalbergia sissoo achieved 80-90 per cent tural regeneration of grasses which are establishment without supplemental irri­ higher in succession. Studies have shown gation. Recent trials on the comparative that a density of 14 per cent of Zizyphus efficiency of different methods of protec­ nummularia is optimum for increased tion, viz. one-metre-wide tree-guard (made forage production (Kaul and Ganguly, out of empty coal-tar drums) and the usual 1963a). Prosopis cineraria is an impor­ circular ridge-cum-trench have shown that tant forage-tree species which grows in the former method is more efficient in the cultivated fields (sometimes more than 60- case of species with wide-spreading lateral 80 trees per hectare) without any detri­ roots, such as Acacia tortilis, whereas the ment to the crops grown in association latter method appeared to be suitable for with it. The tree is lopped for its pro­ deep-rooted species. Narrow tree-guards, tein-rich (17.49 per cent) leaves. Stu­ 45 cm in diameter, were found to be dies have shown that complete lopping inimical to plant growth. (lopping of the entire tree) gives a signi­ Successful shelterbelts of Acacia nilolica ficantly higher fodder yield (58-72 kg per ssp. indica and Dalbergia sissoo were tree) than the lopping of the lower two­ established over a length of 102 km at the thirds (28.48 kg per tree); and the lower Central Mechanized Farm, Suratgarh, in one-third (19. 73 kg per tree) of the crown. the Bikaner District. The soil-working There was no significant difference bet­ consisted in digging ditches of triangular ween two-thirds and one-third lopping cross-section, i.e. 45 cm wide and 45 cm treatments (Bhimaya et al., 1964). Sixteen deep, along the planting line with a indigenous tree and shrub species which mechanical ditcher. Planting-pits, 30 have been found to be browsed by diffe­ cma, were dug staggered with one another rent species of livestock at one time or on both sides of the ditches. The seeding another have been studied for their palata­ of A. nilotica ssp. indica were carried bility and nutritive value (Ganguly et al., out on each side of the ditch in such a 1964). Among the many exotic fodder tree way that the sown lines remained just species tried at Jodhpur and Pali, Acacia above the level of irrigation water whereas aneura (Australia), Pittosporum phi/lyra~ the pre-sprouted stumps of D. sissoo eo ides (Australia), Brasilettia mollis (Ven­ were planted in the pits. The cost of ezuela), Geoffroea decorticans (Chile), raising such shelterbelts worked out at Prosopis alba (Argentina) and Colophos­ Rs 330 per km (Bhimaya and ,Chowdhari, permum mopane (Southern Rhodesia) 1961). showed great adaptability. All these species had flowered and produced viable SILVI-PASTORAL APPROACH TO LAND USE seeds. C. mopane was even found to be Considering that livestock husbandry naturally regenerating in the arboretum occupies the most important place in the at Jodhpur (Kaul, 1970). It is, therefore, economy of the arid region and that fre­ necessary that the planting of fodder tree quent droughts results in a loss of cattle and shrub species should form an essen­ wealth owing to the shortage of fodder tial part of any range-improvement pro­ resources, it is necessary that range im­ gramme in the arid zones. provement should be complemented with the raising of fodder tree and shrub species REFERENCES Which not only give the much-needed BHIMAYA, C. P., AHU1A, L. D., PRAKASH, M., forage during the scarcity periods, but GOPINATH, C. and VA~OANI, N. S. 1966.

201 DESERTIFICATION AND ITS CONTROL

The economics and efficiency of different stabilization technology in western Rajas­ types of fencing for soil conservation in than. Indian For. (in press). Western Rajasthan. Ann. Arid Zone 5 : 159- KAUL, O. N. 1957. Roadside planting in arid' 172. wastes of Rajasthan. Indian For.' 38 : 457- BHIMAYA, C. P., KAUL, R. N. and GANGULI, B. N. 461. 1964. Studies on lopping intensities of KAUL, R. N. 1960. Dying of Eucalyptus gom­ Prosopis spicigera. Indian For. 90 (1) : 20-23. phocephala. Indian For. 86 : 177. BHIMAYA, C. P .• JAIN, M. S., KAUL, R. N., and KAUL, R. N. 1964a, Effect of time of planting GANGULI, B. N. 1967. A study on age and on seedling survival. Agric. Res. J. 4 : 58-59. habitat differences in fuel yield of Prosopis ---1964b. Response of tree seedlings in juliflora. Indian For. 93 : 355-358. Gibberellic Acid. Agric. Res. J. 4 : 269. BmMAYA, C. P. and KAUL, R. N. 1960. Some ---1966. Silvical characteristics of Cal- afforestation problems and research needs Iigonum polygonoides Linn. La' Yaarall 15 :' in relation to erosion control in arid and 1-8. semi-arid parts of Rajasthan. Indian For. ---1970. Indo-Pakistan, ill AjJorestatiol1' 86 : 453-468. in arid zones. (ed. R. N. KAUL), pp.155-209, ---1965. Root system of four desert tree The Hague Dr. V. Junk, N.V. Publisher. species. Anll. Arid Zone 4 : 185-194. KAUL, R. N., CHERIAN, A., and DAULAY, H. S. ---1966. Seedling root habit in some 1966. Micro-relief as a decisive factor in desert-tree species and its bearing on initial the development of vegetation ,in arid seedling survival. Sci. Cult. 32 : 204-206. zone. La' Yaaran. 16: 122-128. BHIMAYA, C. P., KAUL, R. N. and GANGULJ, B. N. 1965. Studies on presprouted stumps of KAUL, R. N. and GAN(;ULl, B.N. 1963a. Fodder Prosopis julifiora. Ann. Arid Zone 4 : 4-9. potential of Zizyphus in scrub grazing-lands BmMAYA, C. P. and CHOWDHRI, M. D. 1961. of arid zone. Indian For. 89 : 623-630. Plantations of windbreak in the Central ---1963b. Studies on the economy of raising Mechanised Farm, Suratgarh-An appraisal nursery seedlings in arid zone. Ann. Aria of technique and results. Indian For. 90 : Zone 1 : 85-105. 667-675. KAUL, R. N. and GYAN CHAND. 1966. Response CHAMPION, H. G. 1961. A preliminary SUf\'ey of Acacia nilotica ssp. indica (Benth.) of the forest types of India and Burma. Brenan (syn. A. arabica) seedlings to Indian For. Record N.S. I. Forest Res. Inst., progressive spacing, type and time of Dehra Dun. soil-working. Ann. Arid Zone 5 : 26-30. GANGULI, B. N., KAUL, R. N. and NAMBIAR, ---1967. Studies on media and sizes of K. T. N. 1964. Preliminary study on a few receptacle for growing nursery stock in arid top feed species. Anll. Arid Zone 3 : 33-37. zone. Anll. Arid Zone 6 : 95-106. 'GOVERNMENT OF INDIA. 1963. Climatological Observations in India. Manager of Publi­ UNESCO. 1958. In/ormation Manual No.3, cations, Govt. of India, New Delhi. UNESCO Programme of Arid lands. GYAN CHAND, KALLA, J. C. and VYAS, D. L. YADAV, J. S. P. 1960. Soils of the dry zone of 1976. Economic evaluation of sand-dune India. Indian For. 86: 274-295.

202 22.· IMPROVING RANGELAND PRODUCTIVITY

L. D. AHUJA

ARID zones are marked by hostile agro­ outset in such class of lands, in areas climatic conditions and frequently recur­ with easy accessibility and water facility, ring famines because of scanty and erratic so that local people can visit the places rainfall. The local people obtain their frequently and realize the value of such sustenance from livestock to ameliorate development. A long-term grass-crop their plight. Livestock is dependent rotation is desirable on class IV lands to mostly on native rangelands which have reduce erosion hazards, improve soil ferti­ become degraded and denuded owing to a lity and vegetative production. high pressure of livestock-grazing. With Fencing. In this part of the country, a view to evolving scientific technology for no development project involving land can speedy re!feneration, the improvement and be successful without proper fencing be­ utilization of such rangelands, studies were cause of heavy livestock pressure. Among initiated on 52 paddocks, each of about various types of fencing, viz. the one with 80 hectares (in 10 districts of western barbed wire with different posts, e.g. Rajasthan, India), under different habitats angle-iron, stone and wooden posts; ditch and different class rangelands (Table 1) and bund, corewall and thorns, stone wall, in 1959 to find out suitable-techniques live hedge with cactus tried and studied, for upgrading the existing rangelands it has been found that angle-iron posts and utilizing them. with a fencing of barbed wire is by far the The number of paddocks was reduced to most effective and economical means in 28 and 12 during 1963 and 1969 respecti­ the long run. With proper maintenance, vely. The main results obtained are it can last for over 20 years (Bhimaya et reviewed as under: a/., 1966; Mann and Ahuja, 1975). As Selection of sites. It will be desirable iron or steel material is not easily availa­ to take up pasture development at the ble, trench and corewall fencing, corewall

Table 1. Distribution of different rangeland paddocks under experiment

Condition of Average annual rainfall above Average annual rainfall below Total rangeland 380 mm 380 mm Heavy soils Light soils Heavy soils Light soils

Poor 6 6 5 8 25 Fair 5 4 2 7 18 Good 3 2 2 2 9 Total 14 12 9 17 52

203 DESERTIFICATION AND ITS CONTROL

thorn fencing, etc. may be constructed on classes of rangelands for six years are co-operative or "sharamdan" basis by presented in Table 2. villagers during the forced idle period or The forage yield on rangelands after two lean periods and such types of fencing years of protection and controlled grazing need regular care and repairs, otherwise increased by 148.3, 91.9 and 116.3 they do not serve any purpose at all. The per cent in 'poor', 'fair', and 'good' condi­ present cost of angle-iron posts and bar­ tion classes respectively. The rangelands of bed-wire fencing is Rs 9 per running 'good' condition class were obtained in metre. The smaller the size of the block, 1960; and the data are presented for that the greater is the proportionate cost per year onwards. Rainfall in 1962, 1963 and hectare (Ahuja, 1975). 1964 was below normal and Qf. shorter Forage production. Grassland cover of duration; the forage yields did riot show this region is Lasiurus-Cenchrus-Dichan­ any appreciable increase (Bhimaya et al., thium; Lasiurus sindicus, Cenchrus ciliaris, 1967). Cenchrus setigerus and Dichanthium annu­ Detailed studies on 12 range-manage­ latum are the climax grasses (Dabadghao, ment paddocks for 14 years revealed that 1960). Owing to indiscriminate overgraz­ forage production varied with rainfall; ing because of high livestock population, within different rainfall zones, forage pro­ rangelands have reached the last stage of duction was higher on heavier soils. Data degradation. About 80 to 90 per cent of pertaining to the average forage yield on rangelands are under 'poor' to 'very poor' rangelands under different land forms are condition class (Raheja, 1962). Those presented in Table 3. under climax to subclimax cover have Forage yields increased as the rainfall existed owing to highly restricted grazing increased from western to the eastern under severe water scarcity (Ahuja and Rajasthan. Forage production was also Bhimaya, 1966a). found to be dependent on habitat, parti­ Efficient grassland management aims at cularly the soils for obvious reasons. the maximum utilization of forage with­ Production was low on shallow gravelly out undue interference with growth and habitat and highest on heavy deep soils. vigour of important fodder and other use­ Grubbing of un wall ted bushes. Unwant­ ful species. With protection and grazing, ed thorny plants, such as Lycium barbarum, the native range on the carrying capacity, Balanites aegyptiaca, Acacia Jeucophloea aiming at 70 per cent forage-utilisation and Mimosa hamata, which hinder the level, the forage yield increased. The data growth of grass species and are too trou­ on forage yield under different condition blesome to grazing animals should be

, Table 2. Forage yield (air-dried kg/ha) in different types of rangelands in arid zone

Year of observations Type of rangeland 1959 1960 1961 1962 1963 1964 1965

Poor 337 450 837 688 642 770 885 (9) ql) (18) (12) (8) (9) (9) Fair 552 873 J,065 869 817 1,074 835 (10) (22) (21) (17) (11) (10) (10) Good 704 1,068 1,523 1,263 1,480 1,163 (4) (6) (8) (9) (8) (8)

(Figures in parentheses indicate the number of paddocks studied. Source: Bhi!llaya el al., 1967).

204 IMPROVING RANGELAND PRODUCTIVITY

Table' 3. The forage yield (air-dried, in kg/ha/year) on rangelands under different rainfall and soil conditions (average of 14 years 1959-72)

S.No. Rainfall zone and the Soils Type of plant cover Average forage name[l of substations yield/kg/ha

1. Average annual rainfall below 200 mm (range 31-535 mm) 1. 1·1 laisalmer Sandy-rocky Lasiurus-Cymbopogon­ 473 Aristida 2. 1·2 Chandan Sandy Lasiurtls - Aristida- Tribulus 424 3. 1 ·3 Khetolai Gravelly Aristida-Cenchrus biflorus­ 334 Tribulus 4. 1·4 Lawan -do- -do- 339 2. A verage annual rainfall 200-300 mm (range 50-577 mm) 5. 2· 1 Beechwal Sandy Aristida-Eleusine-Lasiurus 445 3. Average annual rainfall 300-400 mm 6. 3·1 Bhopalgarh Gravelly Aristida-Eleusine-Cenchrus 478 7. 3·2 Samdari Deep sandy Aristida-Cenchrus biflorus 905 8. 3·3 Jadan Shallow saline Sporoboills-Cenchrlls 1,184 bi/lorus 9. 3· 4 Jaswantgarh Heavy saline Cyperlls-Sporobolus-Eleusine 1,145 10. 3·5 Borunda Rocky-loamy Cenchrus setigerlls-Aristida 1,335 4. Average annual rainfall above 400 mm (range 214-840 mm) 11. 4·1 Palsana Deep sandy Cellchrlls setigerus 925 12. 4·2 Bisalpur Shallow & rocky heavy Aristida-Dichallthium 1,630

(Source: Mann and Ahuja, 1975) grubbed out mechanically, followed by the area under forests under Zone 'A' the application of the herbicide 2-4-5 T (average annual rainfall below 300 mm) (trichlorophenoxyacetic acid) immediately and Zone 'B' (average annual rainfall after cutting away the aerial parts of the above 300 mm) and the over all average bushes (Dabadghao, 1969). Even useful of the arid districts of Rajasthan is 0.4, top-feed species, e.g. Zizyphus nummu­ 1.3 and 0.8 per cent respectively of the iaria, should not have crown over more totalland. The forest in western Rajasthan than. 14 per cent on a range if proper (arid regions) is characterized as scrub forage production from the pasture is forest; and grasslands occur in plains on desired (Ganguli et al., 1964). the lower hill slopes and on the undulating Top-feed-cum-shade-trees on grasslands. terrain in the arid parts of the State. The Trees on the rangelands provide shade for important grasses found in the area al'e grazing animals on the range and are an Cenclzrus species, Lasiurus sindicus, Di­ important source of timber and fuel for. clzantlzium annulatum, Eleusine compressa, range use. They are an important source Eremopogoll foveolatas, Apluda mutica, of top-feed in the form of nutritious leaves Sehima nerVOSllnl, Aristida species, etc. and pods (rich in proteins and minerals) To improve livestock production and to the livestock during the lean periods economy at large, it is imperative to o! the year, thereby increasing producti­ introduce some suitable top-feed tree VIty. Although forests are a source for species on rangelands to provide shade for providing top-feed in some regions, yet grazing animals and the top-feed during

205 DESERTIFICATION AND ITS CONTROL

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206 IMPROVING RANGE LAND PRODUCTIVITY lean periods. These trees can be planted vals of 60.96 cm across the slope. One a~ong the \Joundaries, inspection paths and spillway of random rubble dry stone approach roads of the compartments of masonry, with a clear crest length of 3.05 the pastures in single or double rows. m and a height of 30.5 em above the They will also act as wind-breaks. In ground level was constructed in each of addition, the trees should be planted in a the contour bunds to permit the excess staggered manner in the pasture. A good storm water to overflow and avoid brea­ pasture may have about 30 such trees per ches. hectare (Ahuja and Mann, 1975). 3. Staggered contour trenches were dug at vertical intervals of 60.96 em, having Choice of top-feed species. On the basis of a depth of 30. 5 cm and a width of 60.96 the nutritent cq_ntent and palatability em in section of 61 metres long across ratings of the leaves, the order of preference the slope with an unexcavated portion of of different top-feed species is as follows: 1 . 52 m to serve as a spilling section dur­ Acacia arabica, Prosopis spicigera, Sal­ ing heavy rains. vadora oleoides, Zizyphus ll11111I11Ularia, To estimate the effect of soil-conserva­ Acacia senegal, A lbiz::ia lebbek, Anogeisslls tion measures on forage production, a rolundi/olia, A. pendula, Calligonum poly­ pair of sample plots each 22.1 m, along gonoides, Azadirachta indica, Grewia lenax, the slope and 3.66 m across were laid out G. spinosa, Prosopisjuliflora and Tecomella in each of the treatments and the control undufala (Table 4) (Ganguli et al., 1964). plots, and were protected well. Care Soil conservatioll. Grasslands generally was taken to see that the slope, the soil exist on class 'It to class VIII lands which type and the vegetation cover in plots un­ are subject to erosion. Soil conservation der treatments and the control were identi­ through mechanical or biological means is cal, as far as possible. The studies were essential for optimized production. continued for ten years (1991-70). The average air-dried forage yield per hectare Soil conserl'ation (mechanical means). A under different soil-conservation struc­ considerable area in the Indian arid tures are presented in Table 5. zone is rocky, with shallow soils and rol­ Soil-conservation measures increased ing topography. Studies were undertaken the forage production significantly. The in 1961 at one of the paddocks, with the average increased yields, as a result of average rainfall of about 400 mm (average contour furrowing, contour bunding and of 14 years) to find out suitable soil- and contour trenching, were of the order of water-conservation measures and their 638.7, 168.8 and 165.0 per cent res­ effect on forage production. The soils pectively per year. were classified as medium loam, highly The distance between two successive eroded, thereby exposing the rocky sur­ bunds and contour trenches was greater face, stones and boulders. The topo­ than that in the case of contour furrows. graphy was rolling with a slope of about 2 Hence there was a more uniform spread per cent. The soil-conservation treat­ of water in the latter, thus enhancing the ments were as follows: soil-moisture regime, which resulted in a 1. Contour furrows, 8 to 10 metres apart, better growth of the grass (Ahuja et al., 22.86 cm (9") deep and 60.96 cm (2 1973). The available soil moisture in the feet) wide, forming a cross-section of contour-furrowed plots was higher than 929 em" (1 sq ft) were dug and the earth that in the contour-bunded and contour­ was excavated to form a mound on the trenched plots (Murty and Mathur, 1971; down-slope side. Wasi Ullah et at., 1972). The forage 2. Contour bunds, 167.64 cm base, yields, therefore, were higher in the con­ 15.48 cm wid e at the top, 60. 96 cm high, tour-furrowed plots. having the cross-section area of 5,574 In the case of lands. at the foothills, sq. em, were constructed at vertical inter- the flowing nalas should be harnessed with

207 DESERTIFICATION AND ITS CONTROL

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208 IMPROVING RANGELAND· PRODUCTIVITY

pucca masonry and earthen bunds across distance of about 300 metres, depending the slope to serve as water-spreading-devi­ upon the slope, helps to drain away ces. Gully and nalla-plugging should qcessive salinity and saIts. In such a be carried out on the rangelands. system, grasses, e.g. Sporobolus he/vo/us Soil comervation on rangelands­ (k/zarada) comes up (Ahuja and Bhimaya, average rainfall below 200 mm. In ex­ I966b). Its protein content during the tremely arid regions in Lawan (Jaisalmer flowering stage is about 9 per cent and is District), rangeland with gravelly, barren relished by livestock, specially cattle and shallow soils was protected with ditch sheep. It remains green for a pretty long and mound fencing (about 500 m apart), time. It is advisable to sow or plant in 1959; during 1961, contour furrows, salt-resistant tree species, such as Acacia each with a cross-section of 929 cm2 nilotica, Prosopis juliflora, Tamarix arti­ and spaced 8 to 10 m apart, were con­ culata, Salvadora persica, and Acacia structed. tortilis, on the mound of the trenches to The stabilization of sand-dunes. In stabilize them and save them from being arid zones, shifting sand-dunes are active, damaged during rains. As the reclamation except during the monsoon. They threa­ of salinity progresses, the production ten the existence of nearby villages, increases, and in fairly well-leached pat­ towns and fertile lands. If stabilized ches, Dichanthium annulatum comes up and managed properly, these mobile sand luxuriantly. Such managed pastures masses offer a potential productive site could yield 1.0 to 1.5 tonnes of air-dried for afforestation and grassland develop­ forage per hectare. ment (Kaul, 1968). For the stabilization Reseeding the grasslands. A natural and rehabilitation of the sand-dunes, four succession or superior species of grasses distinct processes are involved, viz. (a) in arid and semi-arid regions is a time­ protection against biotic influence, (b) consuming process. Hence reseeding with the treatment of shifting sand-dunes by a suitable perennial grass species, hav­ fixing barriers (mulches) from the crest ing a high nutritive value and yielding high down to the heel of the dune across the tonnage under rainfed condition, suiting wind direction, (c) afforestation by direct different agroclimatic tracts, is the only sowing and or by plantings of suitable tree solution. The reseeding of grasslands species, and (d) for the planting of involves: seedlings or root slips of drought-hardy (a) SELECTION OF SUITABLE SPECIES FOR perennial tussocky grass species. In such RESEEDING IN DIFFERENT TRACTS. Diehan­ areas, grazing should not be allowed till thium annulatum gives a high yield in the dunes are stabilized. Grass may be heavy soils, with an annual rainfall above harvested manually. The cost of stabili­ 380 mm. Cenchrus ciliaris and Cenehrus zing the dunes presently works out at Rs setigerus produce high forag<: on well­ 600 to 800 per hectare (Muthana and drained soils under medium to low rain­ Ahuja, 1973). fall; Lasiurus sindicus gives high forage Rangelands with salinity. Vast areas yield on sandy soils receiving low precipi­ in desert regions are highly saline, with a tation. Paneium antidotale performs well high salt concentration. If managed and on well-textured soils with an annual utilized properly, they offer potential sit~s rainfall of 250 mm and above under pro­ for grass production. The first step 1ll. tected conditions; whereas Sehima nervo­ reclaiming such land is to drain away ex­ sum yields good forage on the hilly ter­ cessive salts. Digging trenches with the rain. (4' + 2') (b) RESEEDING. Owing to erratic rain­ dimensions of a trench being -2~-'-- fall conditions, and poor germination of seeds of Lasiurus sindicus and Diehanthium x 3' or (1.22 ; 0.61)m x 0.914 m at a annulatum, the sowing of the mixture of seeds of Cenchrus species and Lasiurus

209 DESERTIFICATION AND ITS CONTROL

sindicus and of Cenchrus species and Different strains of the above-mentioned Dichanthium annulatum is recommended high perennial grass sp.ecies have been for low and high-rainfall tracts respecti­ sorted out and their performance is under vely (Ahuja and Bhimaya, 1967). The study at the substations (of the Central seed-rate of different mixtures is 5 to 7 kg Arid Zone Research Institute, Jodhpur) per hectare. The requisite quantity of under different agroclimatic sub-regions. unhusked seeds of grasses, suiting the (c) WEEDING. Such reseeded rangelands tract, should be mixed with moist sandy need at least two weedings during their soil three to four times the volume of seeds first year of establishment (Chakarvarty and drilled uniformly in lines, 75 cm apart, and Verma, 1972). _ immediately after the first effective showers (d) PRODUCTION. The results concern­ in 8-to-1O-cm-deep furrows at a depth of ing the increase in forage production due not more than 1-3 cm under the soil. to reseeding under different condition In view of the fairly high cost involved classes of rangelands are presented in and slow juvenile growth of high peren- Table 6.

Table 6. The average forage yield (air-dried kg/ha) due to reseeding under different • class rangelands

Poor Fair Percent- Year Increase age in- Reseeded Control Increase in Reseeded Control Increase crease strip (kg/ha) percentage strip (kg/ha)

1960 1,066 750 316 42·1 1,173 800 373 45 4 (3) (2)

1961 1,609 885 724 81·8 2,002 1,556 446 28 7 (5) (3) 1962 990 692 298 30'1 1,686 869 817 940 (4) (7) 1963 1,501 675 826 122 3 1,741 964 777 80 6 (2) (6) 1964 1,552 715 837 117·1 2,516 1,213 1,303 107 3 (7) (8)

Figures in parentheses indicate the number of trials (number of rangelands under different locations studied). Increase in forage yield due to reseeding was from 30 to 122 per cent in 'poor' and 29 to 107 per cent in 'fair' rangeland. nial grass species, it is advisable to resort Increase in forage yield due to reseed­ to root-slip planting of grasses, e.g. ing was from 30 to 122 per cent in 'poor' Lasiurus sindicus and Dichanthium anllu­ . and 29 to 107 per cent in 'fair' rangelands. latum, and nurseries should be established Optimum forage yield. The optimum for the purpose (Ahuja and Bhimaya, forage yield in well-established plots of 1966b). Chakarvarty and Verma (1969) different high perennial species was stu­ found a better establishment of the pas­ died and the results are presented in Table tures of Lasiurus sindicus by planting seed­ 7. lings than with rooted slips. But owing Yields up to 3.6, 4.7 and 9.9 tonnes to water scarcity, presently the use of per hectare were obtained from the esta­ seedlings is not recommended. blished stands of Lasiurus Silldicus, Cench-

210 IMPROVING RANGELAND PRODUCTIVITY rus species' and Dichallthium allllulatum mals are l';iWer and some run-off water is (Mann and Ahuja; 1975). availabl!,!~{n open ponds for animals and livestock-owners, (2) by dividing the area Table 7. The optimum forage production (air-dry) of three high perennial grass species in into suitable blocks for practising rota­ reseeded strips (1960-1964). tional grazing. Fertilization. The nutrient content and Dry forage yield (kg/ha) LasiurllS production potentials of forage species Year Diehan- Cenehrus ciliaris sindi- on the rangelands in western India is thium Cenehrus setigerlls ellS quite high (crude protein, about 7 to 12 annulatum per cent, Mann and Ahuja, 1975). For 1960 3,600 optimized production, it is essential to (4) provide adequate nutrients in the soil, 1961 8,894 2,596 2,250 more so because the rangelands are highly 1962 8,340 2,530 2,800 depleted of soil nutrients and are subject­ (8) (16) (9) 1963 4,710 2,059 ed to erosion hazards. The application of 5'11~~ (5) (8) farmyard manure to vast areas of grass­ 1964 5,013 3,517 1,543 lands, forest lands, fallows, etc. is too (8) (11 ) (8) costly and is not a practical proposition. Desert soils of Rajasthan are generally Figures in parentheses indicate the number of rangelands studied. not deficient in potash, but they are, how­ ever, deficient in nitrogen. The broad­ (e) HILLY AND GRAVELLY TERRAIN. In casting of nitrogenous and phosphatic hilly tracts, at the foothills and gravelly fertilizers has not given tangible results. areas, reseeding is generally not a practical The placement of fertilizers, e.g. sulphate proposition. Such areas should be brought of ammonia, urea and superphosphate, under the purview of the Forest Act and have given encouraging results. The appli­ the State Soil Conservation Act, protected cation of sulphate of ammonia at 113 kg! and vegetation allowed to come up. ha (20 1b nitrogen per acre) has resulted (f) SALINE SOILS. In highly saline soils, in increased yields of forage by 50 to 70 reseeding with high perennial grass spe­ per cent over their respective controls dur­ cies has not given encouraging results. ing the years of normal rainfall. The In rangelands with saline soils where good increase in the air-dried forage yield due species fail to come up; a lower perennial, to fertilization is of the order of 460 to e.g. Sporobolus helvolus, performs well. 1,912 kg/ha. The protein content of It is quite nutritious and possesses forage on fertilized pastures was higher high production potentials (Ahuja and than that in the control plots (Ahuja, Bhimaya, 1966b). 1975). (g) RANGELANDS WITH CLIMAX VEGETA­ In areas with annual rainfall of 300 mm TION. Extensive areas in the low-rain­ and below, fertilization with 20 kg of fall regions of the Jaisalmer, Bikaner and nitrogen per hectare in the form of ammo­ Barmer districts are covered with high­ nium sulphate or urea, through place­ yielding nutritious grasses, e.g. Lasiurus ment in the soil, is recommended. In sindicus. But these pasture remain under­ areas with the annual rainfall above 300 utilized owing to the shortage of potable mm, a dose of 40 kg/ha of nitrogen per water in the region or are subjected to hect~re is recommended. In gravelly over-grazing where watering facilities exist. soils, the application of fertilizer is not Such vast areas are recommended to be recommended for the present (Ahuja, brought under the purview of the State 1975). Forest Act or the State Soil-Conservation The role of legumes on rangelands. As Act. In such areas, grazing could be the availability of fertilizers is a problem regulated (1) during the monsoon when and their cost is quite high, the role of water requirements of domesticated ani- legumes on grassland production is under

211 DESERTIFICATION AND ITS CONTROL

study. In limited trials, legumes, in low-set and low-yielding grass species. combination with cultivated pastures, Livestock, while grazing, work up the have resulted in a higher forage yield with soils with their hooves, break up the top higher nutrient (specially crude protein) crust of the soil, thereby encouraging a content in the composite forage material. ,better J:ercolation of water for plant use Studies on the compatability and per­ and better range production. Their ex­ formance of promising legumes, e.g. crements, i,e. dung and urine, add to Dolichos lab/ab, Phaseolus atropurpureus, the plant nutrient contents of the soil elitoria ternatea, Rhyncosia minima, and improve its fertility. Alylosia scarabaeoides, Cyamopsis tetrago­ noloba, Phaseolus aurea, P. aconiti/olius The palatability of different _ species of and Vigna sinensis, on grasslands under grasses and the grazing behaviour of different agroclimatic sub-regions are in animals progress. In areas, e.g. the Bikaner Dis­ On the rangeland, various types of trict, in pure stands of Lasiurus sindi­ plant species come up. Their growing cus, legumes, e.g. Phaseolus aconiti/olius habits, morphological and physiological (moth) is taken as an interspace crop. characteristics differ considerably, and It improves production and adds to the they affect their utilization by different resultant product (Ahuja, 1975). species of farm animals. Among all grasses, Cellchrus ciliaris and Cellchrus Provision for drinking-water setigerus, the perennial species, are most on rangelands palatable to all species of farm animals No range-management programme will during the entire year. The annual spe­ be successful unless adequate arrangements cies, such as Aristida fUlliculata and Cell- ' for drinking-water for animals and wor­ chrus biflorus, on maturity cause servere kers are made. In the interior of the discomfort to sheep from the middle of desert, water is one of the main limiting August to the beginning of November, as factors for the proper utilization of range­ their awns and burrs pierce through the lands and livestock production. Vast mouthparts and the skin of the grazing stretches of grasslands under the cli­ animals. Such species are also trouble­ max to sub-climax cover of Lasiurus sindi­ some to cattle. During this period, ens (sewan) remain underutilized owing perennial species, such as Dichanthium to the non-availability of drinking-water. anllulatum and Lasiurus sindicus, are reli­ Till some permanent arrangement for shed most. From November onwards, water-supply is made, it will be advisable these perennial species become woody. to provide underground water, reservoirs Then they are not liked by cattle and cause (tankas) for livestock and human con~ discotnfort to sheep by injuring their sumption 'on the range (Prajapati et at, mouthparts with the sharp ends of the 1973). , stems. Therefore the annuals whose A 'tanka' with a capacity of 200 kilo­ burrs and awns have been shed are reli­ litres is sufficient for 100 hectares of shed. From March onwards, when the "Good" condition class rangeland; but annual grasses get exhausted, the l]igh it would also suffice for 200 hectares of perennials get broken down and are eaten. rangeland in areas where the season-al graz­ Details have been discussed by Ahuja ing during the monsoon is to be practised (1971). During the hot weather, animals owing to acute water scarcity (Ahuja and are crazy after greens. Cattle eat the Bhimaya, 1967). green shoots of Calligonum polygonoides, Utilizatio_n. The utilization of forage Capparis aphylla, Aerva pseudotomentosa. from gr~sslands can be through (a) har­ etc. Tribulus terrestris is poisonous to vesting, preserving and then feeding it to cattle, whereas it is nutritive for sheep. the livestock, (b) grazing. Pagonia cretica and Blepharis sp. are _ Grazing saves the cost of harvesting,of palatable to sheep, but are not palatable

212 IMPROVING RANGELAND PRODUCTIVITY

to cattle. Owing to the thorny nature of To have a regular supply of good and some plant species, e.g. Lycium barbarum, nutritious forage, it is essential to process Balanites aegyptiaca and Mimosa hamata, and preserve it under proper condition. they are harmful to cattle on the range, Forage can be preserved by making hay but their leaves are eaten mostly by goats or silage. and to some extent by sheep. Tussocky Hay-making. Materials from range. grasses, e.g. Dichanthium annulatum and lands which are most suitable for hay­ Lasiurus sindicus during maturity, are un­ making are perennial grasses, viz. palatable to sheep and goats, but are graz­ Lasiurus sindicus, Cenchrus ciliaris, C. ed upon by cattle. Low-set grasses, such setigerus, Panicum antidotale, Dichan­ as Oropetium thomaeum and the species of thium annulatum, and tall high-yielding Enneapogon, can be grazed by sheep only. annual grass species and legumes. To have the best utilization of rangeland To have optimum nutrients in the cured production, it is best that sheep and goats forage (hay), the plants should be harves­ follow cattle-the goats will eat up thorny ted at the pre-flowering to flowering stage bushes, which otherwise are troublesome in the morning hours after the dew has to cattle. dried up. Hay-making reduces moisture Suitable species Qf farm animals for in the green forage through drying or grazing on different types of rangelands. dehydrating. Hay-making should be Different species of farm animals utilize quick, as far as possible, so as to have the different plant species, depending upon maximum nutrient content, including their chemical composition, growth, mor­ carotene, in the resultant product. phological, physiological and other charac­ teristics. A rangeland infested with bushes The developmental cost and expected re­ and thorny vegetation can be used by turns from rangeland development goats. Low-set plant species are used The cost of upgrading rangeland de­ well by sheep. Tussocky grasses, such pends on the locality, the land form, the as Lasiurus sindicus, Dichanthium annu­ availability of potable water, the size of latum and Panicum antidotale, are better the block, etc. The estimated cost of used by large animals, e.g. cattle. Hence upgrading the rangeland under denuded the choice of introducing farm animals conditions through fencing, soil and water on the range depends upon the botanical conservation, if necessary, the reseeding, composition of the latter. provision of stock water, etc. (based on a I,OOO-hectare block) works out at Rs 500 Preservation of forage to 1,400 per hectare, depending upon the Specially in the arid regions, there is an land form, locality, etc. (Ahuja, 1975). acute shortage of forage from November The needs of livestock and dairy pro­ onwards when the rangelands get grazed. ducts will continually increase owing to The supply of fodder during dry months the increasing human population. The is a problem, except in irrigated areas. increasing of livestock feeds and fodders

Table 8. Livestock population and forage budget in the arid districts of Rajasthan

Forage in miIlion tonnes Year Adult cattle unit Forage shortage (ACU) Needs Availability Shortage % 1975 6·733 16·833 10·169 6·664 39·6 1980 7·405 18·571 11·693 6 824 36·8 1985 8·146 20·366 13·316 7.050 34·6 11990 8·961 22·400 15·466 6·934 30·9 11995 9·858 24·645 17·785 6·860 . 27·8 2000 10·834 27·085 20·159 6·626 23·8

\;.V'"" 213 DESERTIFICATION AND ITS CONTROL will have to be phased. Assuming a in arid and semi-arid rangelands of Rajas­ than. Proc. Joint Symp. National Instl. yearly increase in ,livestock population of Sci. India and I.C.A.R. on Sci. and India's at 2 per cent and the forage production Food Problem New Delhi-Oct. 1967, pp. at 3 %, and 2 years out of five years as 215-223. scarcity years in the arid regions, the for­ BHIMAYA, C. P. and AHuJA, L. D. 1967. Effect of contour furrows on grassland production age production from all sources and its in western Rajasthan. Proc. Workshop in budget are presented in Table 8. Soil Sciences North Zone Hissar 21-23 Feb., In the light of the continued shortage 1967. of fodder for livestock, it is essential to DABADGHAO, P. M. 1960. Type of grassland covers in India and their management. Eighth improve and upgrade the existing range­ International Grassland Congress Paper 9-415. lands speedily and use them rationally DABADGHAO, P. M.1969. Eradication of shrubs to improve the economy. and thorny bushes from rangelands. Personal communications. REFERENCES GANOULI, B. N., KAUL, R. N. and NAMBIAR, K. T. N. 1964. Preliminary studies on a AHUJA, L. D. 1971. Grazing behaviour of farm few top-feed species. Ann. Arid Zone animals on different plant species on range­ 3(1 & 2) : 33-37. lands in arid areas of Rajasthan. Indian Vet. KAUL, R. N. 1968. How sand-dunes can be made J. 48 (2) : 167-172. productive. Indian Fmg 18 (5) ; 54-56. AHUJA, L. D. 1975. Forage Production with spe­ MANN, H. S. and AHUJA, L .. D. 1975. Range cial reference to Arid Zone. Write up for Management Research in Arid zone of National Commission on Agriculture, Govt. India. Proc. Annual Meeting Society 0/ of India, New Delhi and Monograph Central Range Management U.S.A. Mexico City, Arid Zone Research Institute, Jodhpur­ Feb. 1975. India. MUTHANA, K. D. and AHUJA, L. D. 1973. Sand­ AHUJA, L. D. and MANN, H. S. 1975. Rangeland dunes. The way to stabilise and manage. development and management in west Indian Fmg 23 (3) : 25-29. Rajasthan. Ann. Arid Zone 14 (1) : 29-44. MURTY, K. N. K. and MATHUR, C. P. 1971. Soil AHUJA, L. D., VANGANI, N. S. and BHIMAYA, C.P. moisture regime under different soil and 1973. Range management studies. Effect water conservation practices in rangelands of different soil-conservation measures on in arid zone of W. Rajasthan (Unpublished rangeland production in arid zone. 43rd data). Ann. Session National Academy of Sci. PRAJAPATI, M.C., VANGANI, N. S. and AHUJA, India, Jodhpur Oct. 1973. L. D. 1973. In the dry range l:rnds of W. AHUJA, L. D. and BHIMAYA, C.P. 1966a. Deve­ Rajasthan "Tanka" can be the answer. lopment of pasture land and their manage­ Indian Fmg 22(1l} : 127-32. ment in western Rajasthan. Gosamvardhana RAHEJA, P. C. 1962. Range Management. 14 (9) : 16-21. Gosamvardhana 10 : 1-6. AHUJA, L. D. and BmMAYA, C.P. 1966b. Reseed­ VERMA, C. M. and CHAKARVARTY, A. K. 1972. ing rangelands for better production in Study on the pasture establishment techni­ 'Rajasthan. Indian Fmg 16 (5): 19-23. que. Ann. Arid Zone 11 (1 & 2) : 60-66. AHUJA, L. D. and· BHIMAYA, C.P. 1967. Gernii­ VERMA, C. M. and CHAKARVARTY, A. K. 1969. natiorl studies of perenni'al grass seeds. Ann. Study on the pasture establishment techni­ Arid Zone 6(2}: 146-152. que. IV. Comparative efficiency of seedlings BHIMAYA, C. P., AHUJA, L. D., PRAKASH, M., and rooted slips as for transplanting ma­ GOPIN~TH, C. and VANGANI, N. S. 1966. terial Lasiurus sindicus pasture. Ann. Arid The economics and efficiency of different Zone 8 (1): 52-57. types of fencmg for soil conservation in WASI ULLAH, CHAKARVARTY, A. K., MATHUR, western Rajasthan. Ann. Arid Zone 5 (2) : C. P. and VANGANI, N. S. 1972. Effect of 159-172. contour furrows and contour bunds on water BmMAYA, C.P., KAUL, R. N. and AHUJA! L.D. conservation in grasslands of western Rajas­ 1967. Forage production and utilization than. Ann. Arid Zone 11 (3 & 4) : 169-82. 23 CROP PRODUCTION IN THE INDIAN ARID ZONE

H. S. MANN AND R.P. SINGH

DESPITE water scarcity being a limiting of productivity is responsible for limiting factor in crop production, about 45 per the consistency of a remunerative crop cent of the total land area (3.2 lakh km2) production in these regions. Harsh and of the Indian arid zone is sown to crops unfavourable climatic conditions, coupled annually. More than 85 per cent of the with wind-blown soils low in organic cultivated area is rainfed and is subject matter and poor in moisture retention are to the vagaries of the monsoon. Estimates responsible for a sparse vegetative cover are that even if all the irrigation potential and low unstable yields of dryland crops. is achieved by the turn of this century, For example, in western Rajasthan, the a sizeable portion of the cultivated land problems imposed by low annual precipi­ in the arid regions of Rajasthan, Gujarat, tation (366 mm) are accentuated by its Haryana, Punjab, Andhra Pradesh and frequent erratic distribution .from season Karnataka will continue to be rainfed. to season, a high solar incidence of 450 For instance, in the arid zone of Rajasthan, to 500 calories per cm2 per day and a comprising about 60 per cent of the wind velocity of 10 to 20 km per hour Indian arid zone, the total area to be irri­ resulting in high P.E.T. (6 mm/day) and a gated by the Rajasthan Canal and other consequent high mean aridity index of 78 groundwater resources will be about 11 per cent. Soils are mostly sandy, with a per cent. Thus the remaining 89 per cent low organic matter content (0.1 to 0.45 of the region will ultimately remain such per cent) and with a poor moisture-holding that farmers will have to learn to live capacity (25 to 28 per cent) and a high better with natural rainfall as the major infiltration rate of 9 cm/hour. Soil salinity source of water. The problems of rainfed and alkalinity to the extent of 45 per cent agriculture should, therefore, receive due of the unirrigated area and the surface attention of scientists and planners. crust-formation after kharif sowing, fol­ Crop production in the rainfed areas, lowing light showers, complicate the situa­ in general, and in the arid regions, in par­ tion (Singh et al., 1974). ticular, is unstable and risky, leading to Although the conventional dryland low and unremunerative yield levels. Bajra crops, viz. pearl-millet or bajra (Penni­ (Pennisetum typhoides), kharif pulses, setum typhoides), sesamum and khar(! jowar (Sorghum vulgare) and sesamum are pulses, particularly mung (Vigna radiata), the principal crops grown. guar (Cyamopsis tetragonoloba) and moth (Phaseolus aconitifolius) are adapted to THEPROBLFM the existing conditions of low soil fertility An analysis of the problems of crop and moisture stress, the local varieties production in the rainfed areas of the offer a limited choice for increasing crop Indian arid zone reveals that an acute production under varying rainfall situa­ ecological imbalance of the components tions.

215 DFSERTIFICATlON AND.,. ITS CONTROL

THE EXISTING SITUATION per cent probability) and at flowering and An analysis of the rainfall data from grain-formation stages (August and the 1901 onwards reveals that the western first fortnight of September), possible in parts of Rajasthan, representing about two out of five years (40 per cent probabi­ 60 per cent of the Indian arid zone, have lity) form an essential part in combating (i) normal (350-400mm) and (ii) good drought and stabilizing crop production rainfall (>400 mm) years occurring in one on drylands of western Rajasthan. out of two years (48 per cent probability) In good-rainfall vears, the moisture which are to be capitalized through im­ losses under· run-off and deep drainage proved yield plateaus to tide mer the lean ta ken together reach as high as 40 per cent years (52 per cent probability). One in­ of the seasonal rainfall, each accounting teresting point that emerges from the rain­ for almost half of the total losses. It has fall distribution during the past 75 years been estimated that the moisture availabi­ (1901-1975) is that 20 of these normal and lity of the order of 284,214, 173 and 124 good-rainfall years have been quite favour­ mm could b~ obtained during the cropping able e,en for double cropping in drylands season" experiencing good (>400 mm), (Anonymous, 1976 a). normal (350-400 mm), below-normal (250- Situations, such. as the early onset of 350 mm) and poor (>250 mm) rainfall the monsoon (occurring in one out of three (Anonymous, 1976 a). seasons), and the Jate onset of adequate The existing cropping patterns on the rains (possible in one out of 4 years) call rainfed lands are traditional and sub­ for adequate and advance preparations. sistence-oriented. The following analysis Also, proper management practices for of the cause-and-effect relationship will situations of prolonged drought (3 to 4 help us to understand the predominan t weeks) occurring at the seedling stage maladies afflicting crop production in these (during July) in one out of five years (20 regions:

Causes Effects (a) Lack of moisture and restricted (i) Restricted choice of crops and period of moistute availability varieties (ii) Low cropping intensity (iii) Inefficient utilization of inputs

, (b) Lack of crops and varieties fit­ 0) ~ow and unstable crop yields ting into the existing rainfall pattern, appropriate soil-and­ moisture-conservation measu­ res, fertilizer use and plant pro­ tection. (c) The removal of natural vegeta­ (i) Inadequate vegetative cover, leading to tion as a result of uncontrolled a large-scale soil and nutrient loss due grazing, the felling of trees and to wind erosion shrubs for fuel (d) Pressure of population (i) The extension of cultivation to margi­ nal and sub-marginal lands, leading to low productivity on the one hand and a greater risk of soil erosion on the other

216 CROP PRODUCTION IN'THE ARID ZONE

It thus appears that the lack of ade­ moist zone, leading to optimum quate vegetative cover, leading to devasta­ crop stands ting wind erosion, is the primary malady (e) A judicious fertilizer use commensu­ responsible for upsetting the ecological rate with the status of soil nutrient balance of this region. needs of crops, plant population and available soil moisture THE APPROACH (f) The adoption of appropriate water­ The amelioration of arid regions falling harvesting techniques so as to ensure in the rainfall range of 300 mm and below higher amounts of moisture for can be best achieved by a large-scale af­ longer periods forestation with suitable species of trees (g) The conservation of moisture through and by developing a grass cover by grow­ the use of partial or complete sub­ ing adapted species of grasses. Crop surface moisture barriers and orga­ production in such regions should be nic mulches to cut down losses discouraged. Animal husbandry backed owing to deep percolation and eva­ up by range-land management and forestry poration respectively should be the mainstay in these regions. (h) A timely control of weeds and the In the transition belts, with an annual adoption of effe~tive plant-protection precipitation ranging from 300~OO mm, measures an integration of crop husbandry and (i) The harvesting of crops of appro­ animal husbandry should go together for priate cropping systems so as to stabilized production (Singh and Prasad, impart stability in years of sub­ 1975). The National Commission on normal rainfall and to increase pro­ Agriculture has also laid emphasis on duction in years of normal and animal husbandry-orientated programmes above-normal rainfall for improving the economy of such re­ Three basic approaches are suggested gions. to cope with the problem of instability In areas receiving 400 mm of rainfall in crop production in the rainfed areas of and above technology for dryland crop the arid zone. These are: crop diversi­ production should be adopted for impro­ fication, intercropping systems and the ving and stabilizing crop yields. In order recycling of run-off water in the event of to make crop production a remunerative prolonged drought or supplemental irriga­ enterprise in these areas, the following tion (Singh, 1976). Castor and guar, measures should be adopted: among dryland crops, and Cenchrus (a) Selection of crops and varieties hav­ ciliaris among perennial forage crops, have ing growth patterns matching the been found to result in the stability of rainfall pattern and possessing higher agricultural production on rainfed lands. moisture-use efficiency Bajra (pearl-millet) remains the most un­ (b) Selection of suitable crops and stable crop among cereals. In view of the varieties for conditions of delayed fact that it occupies about 60 per cent of onset of the monsoon and other the cultivated area in the rainfed areas of weather aberrations Rajasthan, and is the staple food of mil­ (c) The adjustment cf sowing time so as lions of dryland farmers, efforts have to to ensure that the periods of flower­ be directed towards the stabilization of ing and grain-filling coincide with its production. Transplanting, although the periods of adequate moisture· labour-intensive, is a surer technique by availability which reasonably good yields can be (d) Tillage practices conducive to good obtained even in years of low or subnor­ seed-bed preparation without much mal rainfall. In 1974 (with 136 mm of loss of soil, moisture and nutrients. rainfall), whereas the direct-seeded crop Techniques ensuring a proper place­ of bajra failed, the transplanting of 20 to ment of seed and fertilizers in the 25-day-old seedlings resulted. in 7 q of

217 DESERTIFICATION AND ITS CONTROL

grain yield/ha (Anonymous, 1974). In kharif crops, this period falls in the third good-rainfall years also, the transplanting and fourth weeks of August in western of 24-day-old seedlings of bajra (B1104) Rajasthan. As such, the appropriate resulted in more than 30 per cent increase sowing time would be the last week of June in grain yield over the direct-seeded crop to the first week of July, when the pro­ (18.6 qJha) planted in the third week of bability of receiving showers (30 to 40 mm) July (Anonymous, 1976 b). is usually high. Considering the staple dryland crops, viz. bajra, its sowing after SELECTION OF CROPS AND VARIETIES the second or third week of July invariably MATCHING THE RAINFALL PATTERN results in either poor yield or total failure. It appears that owing to inadequate Therefore, under the delayed onset of the efforts to dovetail the plant-breeding pro­ monsoon, nursery-sowing and transplant­ grammes with other improvements in ing of bajra are recommended. dryland agriculture in the past, the indi­ vidual practices developed by the scientists TILLAGE AND SEEDING PRACTICES for moisture and soil conservation have CO~DUCIVE TO GOOD CROP STANDS not found wide adoption because of their Inadequate crop stands constitute one of marginal impact on productivity. High­ the major reasons for low crop yields on yielding varieties of crops developed have drylands. An ideal tillage practice should given a silver lining to the otherwise dark result in a uniform initial stand, maximum picture of rain fed agriculture. Despite weed control and should also result in the their excellent yield potentials and favoura­ coverage of large areas during the restrict­ ble developmental and maturity patterns, ed sowing period. One sub-surface cultiva­ these crop varieties need modification to tion with a sweep cultivator coinciding conform to the prevailing climatic condi­ with the onset of the monsoon and again tions. To obtain a consistently high level once before sowing was found to result in of production, crop varieties to be grown a higher grain yield of bajra. Almost a on dryJands should possess a considerable complete control of the weed (Cyperlls degree of tolerance to drought, should rotundlls) was achieved with seed-bed pre­ mature early and have high yield poten­ paration, using a heavy-duty mouldboard tials. Keeping these objectives in view, plough (Plate n). high-yielding varieties of cereals, pulses For obtaining a uniform crop stand, it and oilseeds have been developed. They is necessary that the seed is placed at the are: crops and varieties, apart from NHB3 proper depth in relation to its size and of bajra, S8 and M8 (mutant of RS4) of soil moisture and is uniformly distributed. mung, FS68 of cowpeas, Var4-2 and T13 Sowing with a drill having hoe-type fur­ of sesamum, 2470(12), 4210(26) and KVS-. row-openers and on the row-press wheels 1 of guar, Aruna, CH3 and· R63 of castor has been found to result in a uniform and EC68414 and EC69874 of sunflower stand leading to a higher grain yield of (Anonymous. 1976 a). It has been found bojra than when it is sown with disc-type that whereas crops, such as pearl-millet furrow-openers. Post-sowing compaction and sesamum, failed totally owing to the results in a higher coefficient of the rate of late onset of the monsoon, crops such as seedling emergence, which at times is very mung, cowpeas, castor and sunflower, gave important on drylands. remunerative yields. JUDICIOUS FERTILIZER USE ADJUSTMENT OF SOWING TIME Fertilizer use on drylands has almost The sowing time of kharif crops has to been non-existent, mainly owing to uncer­ be so adjusted that flowering and fruiting tain rainfall and the cultivation of non­ which are considered to be most crucial, responsive crop varieties. As such, the coincide with the periods of adequate mois­ earlier belief of the dryland farmers that ture. availability, in the soil profile. For fertilizer application was injurious to dry-

218 CROP PRODUCTION IN THE ARID ZONE land crops was justified. With the avail­ turns due to fertilizer use in the case of ability of fertilizer-responsive varieties of cereals, grain legumes, oilseeds crops and dryland crops and the knowledge gained forag¢ grasses can be had from the data on the quantity, time and method of nut­ presented in Table 1. It is evident that rient application, a judicious fertilizer use high net returns of the order of Rs 2,700 can offer enormous possibilities of increas­ to Rs 3,260 per hectare can be obtained as ing dryland crop production under normal the result of fertilizer use in the case of and above-normal rainfall situations and cereal crops, e.g. pearl-millet and sorghum stabilizing them in years of subnormal in years of good rainfall. rainfall. Appropriate fertilizer-use techno­ The efficiency of fertilizer use can be logy will assume greater importance in. enhanced manifold by placing the ferti­ double-cropping systems found to be lizer 5 to 10 em below the seeds in the feasible in years of high rainfall occurring moist zone at the time of sowing. Further in 20 out of 75 years. Researches carried economy in fertilizer use can be effected out so far on fertilizer use on drylands by withholding a part of nitrogen, which have clearly indicated the beneficial effects can be applied when moisture becomes of optimum nutrient application to most available at an appropriate stage of deve­ of the crops. For instance, ~J(periments lopment. In case moisture is scanty, the conducted at the Central Arid Zone Re­ application of the second dose of nitrogen search Institute,' Jodhpur, have indicated can be withheld, thereby bringing about tha t yield increases of the order of 35 to a saving in fertilizer use. 150 per cent in the case of pearl. millet, The beneficial effects of Fe, Zn, Mg and 150 to 190 per cent in the case of sorghum, a mixture of all trace elements had been 22 to 100 per cent in the case of green exhibited well over the control in a four­ gram, 11 to 77 per cent in the case of sun­ year study at Jodhpur (Misra, 1961). The flower and 180 per cent in the case of mean percentage increases in the grain sesamum in good-rainfall years were ob­ yield of bajra were 21.6, 18, 15 and 5.4 tained with the application of 40 kg of N due to Fe, Zn. Mg and a mixture of all and 40 kg of P20S' and 60 kg ofN and trace elements and Mn respectively. 40 kg of P 0 ' 15 kg of Nand 40 kg of 2 S WATER-HARVESTING SYSTEMS P20S' 40 kg of Nand 40 kg ofP20 s and 40 kg of Nand 40 kg of P 205 per hectare Owing to low rainfall and its erratic dis­ respectively. The response of pearl-millet tribution, the dryland crops encounter and s~nfl.ow~r to nitrogen application was drought during critical growth periods, the hIghest, 10.2 and 7.0 kg/kg N, at 40 leading to low yields or to the total failure and 30 kg nitrogen levels respectively. In of crops. This problem can be overcome the case of forage grasses, Cenchrus seli­ to a great extent by adopting an appro­ genls and Panicum antidotale responded priate water-harvesting system which can favourably to fertilizer use in the drought provide for additional quantities of mois­ year (1974) also, the response being of the ture. For the situations obtainable in the order of 44.7 to 55.3 kg of green forage/ rainfed areas of the arid zone, two water­ kg/N hectare. In the normal-rainfall years harvesting systems, viz. inter-plot and (I97! and 1972), the response of C. seti­ inter-row systems, have been found to offer genls to fertilizer nitrogen ranged from 55 opportunities for in situ water-harvesting. t~ 62 kg of green forage/kg N; whereas in Studies at the Central Arid Zone Research t e case of P. antidotale, the response Institute, Jodhpur, have shown that the !anged from 97 to 203.3 kg/kg N. Thus, total production by cropping only two­ I~respective of the quantum and distribu­ thirds of the field (leaving one-third for ~on of rainfall fertilizer use was found to micro-catchment) by adopting the run-off e beneficial in the case of forage grasses farming is the same as obtained from con­ CAnO~ymous, 1976 a). ventional cropping on a fiat surface. ' The An Idea of additional yields and net re- run ·off farming has been found to offer DESERTIFICATION AND ITS CONTROL

potentialities for increasing and stabilizing crop-production in the rainfed areas. In yields, thereby lowering the risk of crop the past, increased agricultural production failure and saving inputs required for crop as. a result of soil- and moisture-conserva­ production (Anonymous, 1976c) How­ tion measures has been of the order of 15 ever, in case no land is to be sacrificed for to 50 per cent, which itself is low primarily water-harvesting as catchment, the inter­ because of the limitations of the biological row system of water-harvesting is more material responsive to the environment. practicable than the inter-plot water-har­ The reorientation of the soil- and moisture­ vesting system. The modified inter-row conservation programme and its linkage water-harvesting system (MIRWHS) deve­ with plant material and package of. prac­ loped at the Central Arid Zone Research tices ha, been suggested for increasing Institute induces an additional run-off in agricultural production in the rainfed the trenches from the ridges and also areas of the country. In the arid zone, from the micro-catchments provided in­ contour-farming is. no doubt, vital from between the trenches. There was 13.4 per the point of view of soil and moisture cent more moisture in the soil profile under conservation. More significant, however, this system than under the flat system at is the wind action which may particularly the time of harvesting the bajra crop-a be serious during summer. Stubble-mulch­ distinct advatnage conferred on the yield ing and wind strip-cropping are the basic of succeeding crop. Recent studies have remedies for the maladies caused by the shown that there was a lower weed popu­ action of wind. Misra (1964) reported lation in the case of the modified inter­ that: (i) soil loss due to wind erosion in­ row water-harvesting system than in the creased with the decrease in the size of the case of the flat and inter-row water­ stubble of pearl-millet left at the time of harvesting systems. harvesting, the minimum (761 kg/ha) and In the drought-prone areas, it may not the maximum (2,088 kgjha) having been only be feasible but desirable to set apart recorded in the case of whole stubble and , a portion of the land for water-harvesting control plots respectively. A stubble height and provide for a pond or a tank to collect of 15 cm was found to be the optimum, and store the run-off water. The stored both from the point of view of fodder water can be applied to the standing crops yield and wind-erosion control; (ii) in nearby as a life-saving device during studies on wind strip-cropping, the aver­ periods of prolonged drought either at the age yields of 272 kg and 257 kg per hectare seeedling stage or at the grain-filling stage of Phaseo/us radia/us (now renamed Vigna of ,the cereal crops. A good' rainfall dis­ radiata) and Phaseo/us aconitifolius respec­ tribution during the cropping season, "in tively obtained under unprotected plots in­ some years, may not warrant the use of creased to 484 kg and 372 kg per hectare stured water for supplemental irrigation. respectively, when the cropped strips were In that event, the stored water' can be used protected by perennial protective strips of to provide a supplemental irrigation for Lasiurus sindicus and Ricillus communis, long-duration crops, e.g. cluster-bean and established at right angles to the general castor. The recycling procedure can also direction of the prevailing winds. Soil be used with advantage for giving one pre­ moisture in the protected cropped land sowing irrigation to supplement the'mois­ was found to be higher (0.5 to 1.5 per ture stored in the soil for raising two cent) than that in tbe unprotected land. crops on the same field in the above-nor­ One of the basic principles of wind­ mal monsoon years. erosion control is to keep a reasonable plant cover of the soil surface to reduce SOIL- AND MOISTURE-CONSERVATION the action of the wind. An analysis of MEASURES the rainfall data of Jodhpur for 75 years Soil- and moisture-conservation pro­ (1901-1975) has revealed that the pattern gramme is basic to any programme of of rainfall distribution during 20 years has

220 CROP PRODUCTION IN THE ARID ZONE

Table '1. Additional yields and net returns due to fertilizer use in a good-rainfall year

Additional yield (q/ha) Gross Cost of fer- Net returns Returns Crops returns tilizer +appli- (Rs/ha) (Rs) Grain Straw (Rs/ha) cation cost per rupee (Rs/ha) invested

A. Cereals 1. Pearl-millet 26 0 95,6 2,878·4 182·0 2,696'9 15 82 2. Sorghum 30'6 49·6 3,487 ·9 227 0 3,260 ·9 15·37 B. Grain legumes 1. Green gram 2 ·1 11·2 654 5 159·5 495 0 4 10 2. Cluster-bean (guar) 1··2 8·4 248 4 159'5 88·9 1·56 C. Oilseeds 1. Sunflower 2·0 710·0 182·0 528·0 3·90 2. Sesamum 5·6 11·5 2,0340 136·0 1,898 ·0 14·95 D. Forage grasses (fresh forage) 1. Cenchrus ciliaris 190·0 1,9000 136'5 1,763'5 13-91 2, Panicum antidotale 156,0 1,560 1365 1,423' 5 11,42

Table 2. Yield of tinda (qlha) as affected by the sub-surface moisture barrier (bentonite clay)

Yield of linda in q/ha Mean yield Percentage in- Treatments (qjha) crease in yield 1973 1974 1975 1976 over that in the absence of the barrier

1. No barrier 110 11 78 57 65 2. Moisture barrier (ben- tonite clay placed 75 em deep) 160 33 93 66 88 35

Table 3. The yield of linda (q/ha) as influenced by the run-off concentration and the barrier in a low-rainfall year-1974

Treatments With microcatch­ Flat ments

Barrier 43·1 19·7 Barrier+bajra husk mulch 45·1 23·8 Mulch only 22·1 14·2 Control 18·2 13·4 'F'Test SE.m± CD 5% CD 1% Run-off NS 2'52 Barrier and mulch Sig. 2·71 8,34 11 ,7 Run-off x barrier NS 3'83

221 DESERTIFICATION AND ITS CONTROL

been quite favourable to a double-cropping (Cilrullus vulgaris var. fistulosus) against system which can be followed with ad­ 110 qjha obtained from the control (no­ vantage on drylands. In khan! 1975 (rain­ barrier) in 1973 which was a good-rainfall fall, 560 mm), it was demonstrated that year-a rainfall of 544 mm having been 9.5 q/ha of raya (Brassica jultcea) and 7.3 recorded during the kharif season. Consi­ q/ha of safflower could be obtained on the dering the performance of linda with and residual soil moisture after ha~vestjng without barrier over a period of 4 years, hajra (pearl-millet) and mung, the yields it was observed that the use of the barrier of bajra and mung being 32 q and 8 q/ha resulted in 35 per cent increase in the­ respectively. Thus the emphasis should be yield of the vegetable over that in the ab- to keep the land covered as long as possi­ sence of the barrier (Table 2). ; ble. However, under this system of con­ It has now been shown that the techni­ servation-cum-production farming, the que works very well when the barrier and tillage should be minimum and the use of run-off concentration systems are com­ heavy disc implements should generally be bined. In the low-rainfall years, the in­ avoided. Sweep tillers, rod-weeders and corporation of the barrier alone may not wide-blade cultivators are the ideal tools help to increase the storage of moisture in for use in areas prone to wind erosion. the soil. It is only in combination with a In an experiment conducted recently, a run-off concentration system that the stor­ I-metre-wide strip of bajra (pearl-millet) age of soil moisture increased by 20 to 25 planted as a shelter barrier against the per cent during diff~rent rainy spells. In prevailing wind direction reduced the wind a low-rainfall year (136 mm), the run-off speed by 63 per cent in the cropped area concentration (with micro-catchment) in under cowpeas and lady's-finger. Also the combination with a sub-surface barrier of bajra shelter barrier increased the yields bentonite clay resulted in 43 q/ha vegetable by 190 per cent and 90 per cent in the case yield against 19.7 and 13.4 qjha on a flat of lady's-finger and cowpeas respectively system with and without barrier respec­ (Anonymous, 1975). tively (Table 3). In the arid zone, having sandy soils, The use of organic mulches, such as surface evaporation is as important as bajra husk, wheat straw and grass mulch, deep percolation, for once the surface soil helped to maintain a high moisture regime (which is mostly sand to loamy sand) dries in the soil profile (for more than 30 days up, it acts as a natural mulch against the after application) and a uniform thermal loss of moisture through evaporation. regime conducive to plant growth in the­ N~vertheless, the drying of the surface soil-surface zone. soil quickly and the excessive evaporation just after rainfall pose problems in seed 1- TIMELY WEED CONTROL ling emergence and proper crop establish­ Weeds compete with crops for both ment, if there occurs a spell' of drought moisture and nutrients. The timely con­ after sowing or during the establishment trol of weeds, as such, assumes great im­ stage when the root-zone is restricted to portance in the rainfed areas, it should a soil depth of 15 to 20 cm from the sur­ therefore, be restored to within the first face. Under such conditions, the use of 30 days in the case of pearl-millet and surface mulches is advantageous in·delay­ within 20 days in the case·of mung. Weed ing the drying of the soil surface. control thereafter is of little or no use, as To cut down losses owing to deep per­ the damage already done is irreversible. colation, a technique of partial moisture However, the weeds should not be distur­ barrier (bentonite clay) incorporation has bed on lands lying fallow during rabi until . been developed at the Central Arid Zone the first shower which generally comes Research Institute, Jodhpur. The place­ sometime in the second half of June. ment of a bentonite barrier 75 cm deep in Here, a compromise has to be made bet­ . pits gave a'll yield of 160 qjha of linda ween the conservation of soil fertility and

222 CROP PRODUCTION IN TIiE ARID ZONE soil as such. Obviously, soil conservation (ii) The use of 11on-monetary inputs in is the prime consideration, because fertility dry/and agriculture. The importance of can be restored if there is soil, but soil non-monetary inputs for a small farmer once lost cannot be brought back. More­ engaged in dryland agriculture needs no over, if the weeds are incorporated into emphasis. For instance, simple practices, the soil with inversion ploughing, the e.g. the soaking of seeds in water and nutrients they extract are brought back to growing crops in the paired-row system, the soil and may be available to the have been found to result in good crop succeeding crop certainly at a later stage, establishment and higher yields. The soak­ may be in the next season. ing of seeds of sunflower, safflower and castor in water for 24 hours before sow­ FARMING SYSTEMS FOR DRYLANDS ing has been found to result in early seed­ To ameliorate the problem of low and ling emergence and a good crop stand. unstable crop production in the rainfed Five cm as the depth sowing for sunflower lands of the Indian arid zone, steps for and safflower and 15 cm for castor have stabilizing and increasing yields of dry­ been found to be optimum (Anonymous, land crops will have to be taken. Any 1976a). Such depths may be important in teChnology developed for these regions areas where a quick drying-out of the should be able to impart stability in years upper soil layer after sowing takes place of sub-normal rainfall, increase production and where the establishment of crops is a in years of normal and above-normal problem. Similarly, a paired-row system !ainfall:. !he role of crop diversification of planting has been found to result in m stabllizmg production on dry lands I;tas higher yields and a better moisture-use already been stressed. The intercroppmg efficiency than a uniform system of plant­ of annual grain legumes in perennial ing in years of low and normal rainfall in grasses is yet another tool which can be the case of bajra, grain legumes and capitalized on for stabilizing production. Cenchrus dliaris. Recent experiments (i) Intercropping system for drylands. carried out on the systems of planting have Grasses are important in an arid zone shown that growing one row of pearl­ from various aspects, viz. soil improve­ millet in the paired- and triple-row system ment, animal feed and soil conservation of planting mung led to 2 to 21 times against wind erosion. Legumes can be more productivity than the planting of grown with advantage as intercrops with mung according to the above sys­ grasses, the former benefiting frpm the tems. The yield of the principal crop improved physical condition of the soil in­ (mung) is no doubt reduced (by about 50 duced by the grass ·sod and the latter per cent) under the intercropping systems, utilizing the improved fertility conditions but the decline in the yield is more than resulting from the fixation of nitrogen by compensated for much higher total pro­ the legumes. Also in the event of failure ductivity, the major 'share being contri­ of rains, grasses may give a reasonable buted by the companion crop (pearl­ yield to avert a complete failure of crop. millet). For obtaining-higher producti­ For instance, in 1974, with 136 mm of vity per unit area per unit time, therefore, kharif rainfall, though the legume crops the planting of one row of pearl-millet in failed, grass (C. ciliaris). as the base crop the inter-row spaces of mung may be re­ gave a yield of 49 q/ha as green fodder ·warding. Recent studies have further re­ (Anonymous, 1974). On the other hand vealed that the yield of bajra grain is III 1975, which was a year of very good appreciably reduced (62 per cent), if it is rainfall (650 mm), the yield of guar (clus­ taken in the bajra-bajra rotation as com­ ter-bean) grain grown as an intercrop was pared with the mung-bajra rotation. Bajra 15 qjha, with a forage yield of 108 qjha taken after mung inoculated with the ap­ from the base crop of Cenchrus ciliaris propriate Rhizobium culture in. the pre­ (Anonymous, 1975). vious year resulted in the same yield level

223 DESERTIfiCATION AND ITS CONTROL

as that obtained after the uninoculated crops during the foreseable future. To put mung fertilised with 40 kg of P20S per the economv of the arid areas on a sound hectare (Anonymous, 1976). Inoculation footing, it becomes necessary to develop of the seeds of legumes can bring about a an appropriate crop-production technolo­ great saving in the use of fertilizers. logy dovetailed with the variation in agro­ meteorological conditions. Scientific crop GAPS IN KNOWLEDGE AND THE FUTURE production based on the principles of con­ LINES OF WORK servation and organic recycling, apart from Much valuable work has been done to enhancing the productivity of the arid-zone stabilize and increase crop production on ecosystem, can also check desertification the rainfed land of the arid zone. How­ appreciably in the long run. All the research ever, there are many gaps in our present­ and development efforts should be directed day knowledge pertaining to rainfed agri­ towards 'this. achievement of this objective. culture. Some of the gaps are listed below: (a) Knowledge regarding the plant types REFERENCES for intercropping' and managing in­ ANON. 1973. Annual Progress Report. Dry Far­ tercropping systems in relation to ming Research Main Centre, Central Arid Zone Research Institute, Jodhpur. nutritional parameters and radiant ANON. 1974. Annual Progress Report. Dry Far­ energy; ming Research Main centre, Central Arid (b) tillage in relation to soil and nutri­ Zone Research Institute, Jodhpur. ent conservation crop establishment; ANON. 1975. Progress Report, Dry Farming Re­ search Main Centre, Central Arid Zone (c) organic recycling; and Research Institute, Jodhpur. (d) run-off collection and its recycling. ANON. 1976a. Improved Dryland Agriculture Basic knowledge on the following for Western Rajasthan, Central Arid Zone points is still lacking: Research Institute, Jodhpur. Tech. Bult. No. 1. pp. 28. (ed. R.P. Singh) (a) The crusting of soil and its control; ANON. 1976b. Annual Progress Report, Dry Far­ (b) the soil-water-plant relationships in ming Research Main Centre, Central Arid respect of moisture stress; Zone Research Institute, Jodhpur. (c) the movement of moisture in arid­ ANON. 1976c. Fifteen Years of Arid Zone Re­ zone soils; and search at the Central Arid Zone Research Institute, Jodhpur (d) water balance, as influenced by diffe­ ICAR 1976. Crop Life Saving Research.ICAR­ rent management conditions. IDRC Seminar Proceedings (1972-73), ICAR, More research efforts have to be made New Delhi. MANN, H.S. and SrNGH, RP. 1975. Crop Pro­ to realize the yield potentials of legumes. duction in the arid Zone, with special re­ Th_ese efforts will encompass the tailor­ ference to western Rajasthan. Ann Arid ing of suitable varieties in the case of neg­ -Zone 14(4): 347-357. lected crops, e.g. moth and guar and the nu­ MISRA, D.K. 1961. Fertilizer Promote Agricul­ tritional requirements of legumes, especi­ tural Production in Arid Zone, presented at the Fertilizer Seminar. Indian Agri. Statis­ ally in respect of phosphorus. Fodder and tics, 14th conv. January. forage agronomy has not received the MISRA, D.K. 1964. Agronomic Investigations in attention it deserves and more work needs Arid Zone. Proc. Symp. Problems of Indian Arid Zone, Jodhpur (Nov. 23-Dec. 2, 1964~, to be done before fodders and forage can Ministry of Education, G.O.!., New DeIhl, become popular with the farmers. Suitable pp. 165-169. farming systems integrating various aspects SINGH, R.P. 1976. Towards Stabilizing Crop of dryland crop production with sylvi­ Production on Drylands of Western Rajas­ pastoral management and with due regard than, Farmer and Parliament 11(7): 13-14, 27-29. to soil productivity and ecological balance SINGH, R.P., DAULAY, H-S., PRASAD, M.V.R. and have to be evolved for sustained producti- SINGH, H.P. 1974. Hungry drylands of . vity of the arid-zone ecosystem. Western Rajasthan need a new technology. Although it is often said that the bulk Indian Fmg 23(12): 5-6. SINGH, R.P. and PRASAD, M.V.R. 1975. IncreaS­ of t~e arid lands are unfit for crop pro­ ing plant productivity in the Indian arid -ductlOn, farmers would continue to grow zone. Farmer and Parliament 11(2) : 11-12.

224 24 PLANTS IN REbATION TO SOIL·MOISTURE CONDITIONS OF THE ARID AREAS

A. N. LAlDRI

THE compelling needs of desert reclama­ the extremely poor growth and yield of tion and the global efforts to arrest the plants and in the latter case, the dry desertification are, in fact, directed largely matter production and yield of the crop .towards resolving an apparent contradic­ may fluctuate from one year to another, tion of essentiality of water for plant life dopending on the stage of growth at which and its general shortage in the arid areas. the drought was experienced. Besides, The low and erratic rainfall being the most variabilities in the intensity and distribution serious constraint among all other factors of rainfall may often cause wide deviations which run counter to the establishment, in soil-moisture conditions from one area growth and yield of plants in desert areas, to another in the same season. the gathering of information on plant res­ Influence of topography, landform and ponses to soil-water conditions assumes a soil. Variations in soil-moisture conditions great practical significance. The cruX of brought about by the topographical and the problem is to determine the variabili­ landform variations have a significant ties of soil-water conditions and the water bearing on the land use and plant produc­ balance of the soil profile invaded by the tion in the arid areas. Although there is a roots, the availability of moisture and its general appreciation of rainfall variations use over time and the responses of plants due to topography, soil-moisture variations under the given conditions of the soil­ because of slope, soil depth, and soil environment. The purpose of this paper character, there still remains ample scope is to examine briefly some of the above­ for the quantification of the moisture mentioned aspect, with special reference regime of different soil-geomorphic units to the plants of the desert of western of the desert. The importance of this Rajasthan. ,aspect is easily realized if we consider that variations in the depth of soil alone may VARIABILITIES OF SOIL-WATER often influence the moisture availability CONDITIONS and plant growth. It has often been obser­ Influence of rainfall. A study (Lahiri, ved in certain regions that the inter-dunal 1975b) of the soil-water conditions in the areas may have higher soil moisture than active root-zone of a pearl-millet field . the top of the dune. A contrasting picture over several years at Jodhpur suggested of the soil-moisture condition again two major conditions of soil drought. In emerges when the moisture status of the one case, low soil-water conditions prevail stabilized (with vegetation) and bare (with­ owing to the low precipitation throughout out vegetation) dunes of this area are the growing period of the crop, and in compared (Lahiri, 1964; Krishnan et al., another, the erratic distribution of precipi­ 1966). The data presented in Table 1 tation subjects the plants to sporadic indicate that a substantial build-up of droughts. The former condition leads to moisture is possible in the bare dunes, pre-

225 DESFRTIFICATION AND ITS CONTROL

Table 1. Soil-moisture status of stabilized and unstabilized dunes near Bikaner

October 1973 % moisture January 1974 % moisture April 1974 % moisture Depth (cm) Stabilized Un stabilized Stabilized Unstabilized Stabilized UnstabiJized 0-15 0·2 0·8 o 1 1 ·0 0·3 1 ·1 15-30 o 4 2 8 0·2 3·1 o 5 3·4 30-45 o 6 4·6 0·5 5 0 0·7 3 8 45-60 0'5 50 o 6 5'5 0·6 4·9 60-75 1 0 5'5 04 5'9 o 8 5 6 75-90 0·8 5·8 o 7 6 0 0'5 5·8 Moisture content in mm 7·87 55·12 5·63 59·61 7 65 55·36

sumably because of the absence of trans­ indicate a considerable deversity of soil pirational losses from plants. as encoun­ conditions. In the Jodhpur District (area tered in the stabilized dunes and the about 22,640 km') alone, seventeen soil mulching action of the 'Sand on the surface. series have been indentified on the basis of The available reports (Mann et al., 1976) soil texture (R.P. Dbir, personal communi­ indicate that this conserved moisture cation). The observation has an obvious supplemented with the prevailing rainfall significance on the regional soil-water is adequate for the cultivation of water­ condition and land use. For instance, the melon and long-melon on the bare dunes average water-holding capacity of the of the Indian desert. sandy to loamy-sand soils of the Chirai The frequent occurrences of carbonate series was about 27 %, that of the loamy pan or kankar pan (known as 'rotha' in soil of Gajasinghpura series it was about common parlance) in the soil profile also 42 %, whereas in the heavy-textured soil has an important bearing on the soil­ (clay loam) of Asap series, it was about moisture status and vegetation. Roy et al. 54 %. These variations, apart from other (1969) from theirinvestigations in Jodhpur, diversities of the desert, suggest the Barmer, Jalore and Pali districts indicated need for the standardization of separate that these pans had developed owing to strategies for production optimization in the catamorphic processes in the weathered the different regions. The presence of silt zone of the regional geological formation and clay particularly needs a special recko­ (i.e. granite and volcanics), and when this ning in this respect. Kolarkar and Singh pan is one to one metre and a half in' (I 971) from their analyses of two hundred thickness, it is impervious. Such a pan' soil samples from various parts of Rajas­ may be found exposed to the surface or than indicated a significant relationship may lie at various depths up to 100 cm or among silt, clay, silt+clay and the moisture more. Plant growth is impeded ciwing t~ constants, such as the moisture equivalent the limitations of moisture and root and the water-holding capacity. Silt growth in the shallow soils over such was found to have the maximum influence calcareous pans. Kaul and Ganguli (1964) on both these moisture constants, clay being reported that the success of plantations of the next and silt+clay the last. This finding forest-trees could be achieved in such areas is very meaningful owing to the general (soil depth, 22.5 cm; rainfall, 375 mm) pre ponderance of sand in the soils of only by deep soil working in the pits. western Rajasthan. The amount of organic Apart from above factors, variations in matter generally being low (0.03 to 0.45 per soil conditions, as such, have a significant cent organic carbon), it may not have any bearing on the problem. Although sandy special relevance to moisture retention in soils generally predominate over vast the soil. It has been found (Aggarwal and stretches of western Rajasthan, reports of Lahiri, 1976) that the growing of vegeta­ the Basic Resources Survey of this Instiutte tion on the bare dunes of Bikaner (average

226 PLANTS'IN RELATION TO SOIL MOISTURE rainfall, 291.3 mm) Md the associated'silvi­ than under certain other species, e.g. P. pastoral management for over 18 years juliflora, Albizzia lebbek and Acacia has brought about only a slight increase in senef!,al. This could be one of the reasons the organic carbon of the surface soils. The of the increased growth of the ground percentage of organic carbon of the cover, often observed beneath the trees of surface soils of the stabilized dunes varied P. cineraria. Shankar et al. (1976) obtained from 0.08 to 0.12, against 0.02 to 0.04 a yield of 2 3 t/ha of dry herbage from un­ found in the adjacent unstabilized dunes. der P. cineraria against 1.66, 1.32, 0.85, The rocky areas in this respect pose a and 0.78 t/ha from under T. undulata, A. unique problem. In such habitat, grasses, lebbek, P. juliflora and A. senegal respec­ e.g. Eleusine compressa and Aristida ad­ tively. Since this tree (i.e. P. cineraria) has scencionis and trees, e.g. Acacia senegal a capacity to absorb moisture from and Anogeissus pendula, are often found. sporadic rains through its foliage (Bhatt It is presumed that roots follow physical and Lahiri, 1964), the enrichment of soil weathering and the acidic root exudates moisture may be possible only under help often to disintegrate the rocks. It is conditions of heavy showers. possible that a process of water absorption by the rocks during the rainy season and SOIL TEMPERATURE IN THE CONTEXT its.release to the invading roots in summer OF SOIL MOISTURE may also be operating in the rocky areas. A number of studies (Shankarnarayan Rain interception by l'egetation and its et al., 1965; Abichandani et al., 1967; influence on soil moisture. Long-term Krishnan et al., 1966; Mann et al., 1976) studies elsewhere have shown (Baver, 1956; have been undertaken on the temperature Rutter, 1958) that 10 to 55 "per cent of the profile of the soils of western Rajasthan. rainfall may reach the soil, depending on The findings generally indicate that during the degree of vegetation cover and the type summer, high surface soil temperature of plants. The proportion is obviously declines fast with the depth and levels off influenced as much by the size, frequency at lower depths. The diurnal temperature and duration of the component showers as changes at the lower depths are smaller by the differences in the structure of the than those on the surface of the soil. cover. There are also other considerations During winter, the lower soil layers are of foliage characteristics, their wetting warmer than the top. Abichandani et al. properties, absorption by dead plant parts, (lac. cit.) observed that the cooling of the stem flow, etc. Although such information layers of the surface soil during the night is rather scarce in respect of western and in the early hours of the morning Rajasthan, yet it has an important bearing resulted in a marked drop in vapour on the agri-silva and silvi-pastoral prog­ pressure, with a consequent movement of ramme in all arid areas. Studies under­ water vapour from the warm moist zone taken by Gupta et al. (1975) under Jodhpur below. This was followed by warming up conditions indicated that the soil moisture during the day and this warming up i.n the 9O-cm profile of the Eucalyptus forest caused the evaporation of surface stored Increased from about 4 cm to 7.S cm water with censequent lowering of evapo­ after a 38.1 mm shower during September ration front. During summer, the tempera­ 1969, but the order of increase was much tures of the surface layers were higher less in the fallow land, grassland and in the than those at the lower depths. This A~acia forest. A comparative study on the observation suggested a possibility of the SoIl-moisture status in the 120·cm soil vapour-phase transfer of moisture to profile of different tree communities under­ lower depths. t~ken here by J.P. Gupta (personal commu­ These observations funher indicate that IDcation) indicated that the moisture relatively low temperature conditions of regime remained generally higher under the lower soil layers, particularly during Prosopis cineraria and Tecomella undulata the hot summers, permit the root-Systems

227 DESERTIFICATION AND ITS CONTROL to avoid hyperthermic conditions. Again, The use of the hydrological equation for it appears that wide temperature differen­ the water balance of field plots has help­ ces in the profile obviously bring about a ed to ascertain the consumptive use of vapour-phase movement of the moisture moisture of such plants. In a study un­ which has a far-reaching influence on the dertaken during 1963, it was observed that overall soil water balance. Recent eviden­ 162.9 mm of water was utilized by the ces suggest that in the desert soil with a ground cover of Dactyloctenium sindicurn, strong daily temperature wave, the vapour Cenchrus setigerus, Eleusine compressa, flux in the soil may be of a magnitude Crotalaria burhia, Aristidafuniculata, Cen­ comparable with the liquid flux. chrus hiflorus, Cyperus rotundus, Gisekia phanaceoides, Brachiaria rarnosq, etc., WATER USE BY DESERT VEGETATION when the rainfall during the growing Since the soil moisture conditions have period (July-September) was 163.8 mm. a direct influence on the utilization of The soil moisture in the profile up to a moisture by plants, the quantification of depth of 2 metres beyond September was water use by the desert vegetation assumes below the permanent wilting percentage a singular importance. The close rela­ and it was obvious that the ground cover tionship of water use with plant produc­ of vegetation completely utilized the avail­ tion, on the one hand and the hydrological able moisture in. the upper layer of the cycle on the other, makes it again an soil. Moisture seems to be the main limi­ important area of study, more so, in the ting factor in the formation of the ground arid and semi-arid areas, where rainfall is cover of vegetation, as supplemental irri­ meagre and evaporation is large. gation during the dry period led to the Water loss from desert trees. Specific rejuvenation of growth and to an increase studies (Lahiri, 1975a) on the water-use in net assimilation and the leaf area. behaviour of the vegetation components Studies undertaken during the favour­ of the Indian desert have indicated that able-rainfall year of 1976 (total rainfall, most desert trees display a large water 639.7 mm; rainfall during July to Novem­ turnover which is possibly due to their ber, 334.3 mm indicated that in a pure capacity to tap water from great depths. A stand of Cenchrus ciliaris (Str. No. 358), community of Prosopis cineraria, consist­ the consumptive use of moisture increased ing of 50 trees may lose as much as ap­ from 152,2 mm at IO-day intervals of cut­ proximately 222 mm of moisture annually ting (cutting at 5-cm height) to 162.2 mm from a hectare of land. Changes in the at 6O-day intervals of cutting. Similarly, moisture conditions in the upper soil in Lasiurus sindicus (Str. No. 319), 168.8 layers hardly influence the transpiration mm of water use at IO-day intervals of and relative turgidity of the established cuiting increased to 185.8 mm at 60-day trees, as is discernible in: the case of their cutting intervals. It was found that the seedlings with a limited root-$ystem. Cer­ fodder yields increased significantly at tain plants, e.g. those of Tecomella undu­ longer intervals of cutting, associated with lata, have the capacity to reduce the total an increase of water-use efficiency. Such water output by reducing their transpiring informations on specific soil-rainfall con­ surface (either by reducing their leaf ditions should provide useful guidelines growth or by shedding their leaves) under for range management in the arid and adverse soil-moisture conditions, although semi-arid areas. the rate of transpiration per unit of the The water-use by crop plants. The quanti­ leaf area may often remain undiminished. fication of water-use behaviour of the The water-use by grasses. Owing to the principal crops of this area has been large­ shallo,w root-system, the growth of rain­ ly achieved by using the hydrological equa­ fed crops and grasses is largely restricted tion for water balance in field plots. to the rainy season, which extends from The weekly assessment of the consuIU­ about the ,mIddle of July to September. ptive use of moisture of different varieties

228 PLANTS IN RELATION TO, SOIL MOISTURE of legumes, e.g. Cyamopsis tetragonoloba, Table 2. The consumptive use of moisture and the losses due to deep drainage in differ­ Phaseolus aconitifolius and P. aureus_, over ent years from fields under different va­ two consecutive cropping seasons of 1964 rietiesofpearlmillet. Nand P,O. each@ and 1965 suggested that the moisture loss 20 kgjha were applied in all cases increased with the age of the plant and declined again at maturity. It has often Year Variety Total Consump- Deep been observed that the consumptive use in precipi- tive use drain- tation ofmois- age certain weeks may (not having rains) be (mm) ture (mIl) low, or may even become negative. This (mm) observation suggested the possibility of a recharge of moisture which was about the 1966 RSK 263·3 180·0 54·5 same as, or slightly more 1han, the actual RSJ 1768 30·5 Ghana 183 5 20 9 consumptive use. Again, the sum of the RSK 131 8 Nil consumptive use and other losses of mois­ RSJ 120·0 -do- ture for the whole growing period may 1968 Ghana 178·6 130·3 -do- often be found 'to be higher than the actual HBI 158·8 -do- HB2 1334 -do- precipjtation. Since an upward movement RSK 68·3 Nil of water due to capillarity is low in these RSJ 79 7 -do- sandy soils, the lateral movement of mois­ 1969 Ghana 92·7 73·1 -do- ture or a vapour-phase movement through Chaddi 63 2 -do- HB 1 86·3 -do- temperature gradient, as discussed earlier, RSK 155 ·8 297·7 may be a possible cause of this pheno­ RSJ 130·8 306 6 menon. 1970 Ghana 594 8 152·5 326·4 This study on the legume varieties again Chaddi 154·1 353·9 HB 1 171·1 290·3 indicates that the water use, on the one RSK 214·4 38 2 hand, may vary owing to the species and RSJ 183 ·7 77·7 varietal differences, and due to the rainfall 1971 Ghana 307 6 108·7 37·7 conditions, on the other. Further infor­ Chaddi 204·0 49 6 mation in this respect was gained from HBI 187 7 55 5 the water balance of field plots under different varieties of pearl-millet (Table 2). more during 1970. The distribution pat­ It may be observed that the water use by tern of rainfall during these two years different varieties of pearl-millet changed (Table 3) shows that an even distribution widely in different years, depending on the of rains during 1971 helped the plants to prevailing rain-fall conditions. Low rain- utilize more moisture but during 1970, fall decreased the water use owing to the higher rainfall in the major spells (as in decrease in vegetative growth and con- August and September) enhanced deep versely it increased under high-rainfall and drainage. favourable soil-moisture conditions. which led to an increase in growth. Similarly, PLANT RESPONSES TO SOIL-MOISTURE CONDITIONS deep drainage increased from zero (as during 1968 and 1969) to a high value (as Considerable effort has been diverted in 1970) because of the variation in rain- towards the understanding of the in flu­ fall conditions. However, the proportion ences of soil-moisture conditions on the of rainfall which will be used by the plant. germination, growth and yield of plants of component and that which will go down this area as also on their effects on as deep drainage seems to depend largely metabolism. on the distribution ()f rains. For instance, Germination in relation to soil moisture. precipitation was more during 1970 than Apart from low rainfall, the quick deple­ that during 1971, but the utilization of tion of moisture from the surface soils moisture by most of the varieties was more poses a serious threat to good germina­ during 1971, whereas deep drainage was tion and plant establishment. In order to

229 DESERTIFICATION AND ITS CONTROL

Table 3. Distribution of rains in mm during 1970 and 1971 at Jodhpur

Rainfall In mm In dIfferent months

Year Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Total

1970 8 3 1 2 26 3 44 0 59 4 364 2 91 4 594·8 1971 2·9 2·5 25 9 57·4 79·8 103 6 32 7 29 307 6

evade these difficulties, certain plants, e.g. emergence under rain fed field conditions Aerva tomentosa, Dichrostachys glomerata, dropped to hardly 30 to 40 per ~ cent. Elusine compressa, Dactyloctenium sindi­ However, diverse uncertainties, such as cum, and Sporobolus sp., display adapta­ long germinative period, the burial of seeds tions of vegetative propagation by pro­ under sand, the destruction of seeds by ducing runners, stolens, etc. rodents and other pests preclude the pros­ However, specific studies (Lahiri and pects of successful tree establishment by Kharabanda, 1963a) on the moisture re­ direct sowing in the desert. The trans­ quirements for the germination of promi­ plantation of nursery seedlings in this con­ nent fodder grasses, such as Lasiurus sin­ nection is favoured more than direct dicus, Cenchrus ci[;aris and Cenchrus seeding. setigerus, have indicated differences in the Influences of soil-water deficit on need for moisture for germination and in plant performance : The influence of soil­ the rates of water uptake of their seeds. water deficit at different stages of deve­ The glumes which enclose the seeds of lopment of pearl-millet have been inves­ these species also display marked differ­ tigated by Lahiri and Kharabanda (1963) ences in their hygroscopic properties. Al­ and Lahiri and Kumar (1966), with spe­ though the capacity of quick water uptake cial references to the alterations of diffe­ by the seeds has generally been found to rent indice~ of plant performan~e. It was be an essential trait for successful propa­ observed that, in general, susceptibility to gation under desert conditions, the occur­ drought increases with age of plant, al­ rence of germination inhibitors in the though the magnitude of responses altered propagative bodies of the above-mentioned in different phases with respect to diffe­ grasses (Lahiri and Kharabanda, 1963b) rent characters under consideration. It and also in the leaf litter of certain tree spe­ was further observed that water stress at ci~s, such as Prosopis juliflora (tahiri and the onset of the reproductive phase has Gaur, 1969), emphasizes the indirect need the maximum adverse effect on the yield. of water for leaching these water-soluble The reversion of drought effect in the inhibitors either from the propagative young plants and the weakening of this bodies for the germination of the enclosed reversion mechanism with age suggested a seeds or for leaching them from the close relationship of drought sensitivity leaf litter and the soil, as in the latter and senescence in the case of pearl-millet. case, to enable other species to grow with­ An increase in grain yields due to early in the tree community. drought has been observed in this crop, as Studies on the germination of the tree reported earlier in the case of wheat (Chi­ species, e.g. Prosopis cineraria, P. juliflora noy, as quoted by Asana, 1960). However, and Albizzia lebbek, have indicated that when the period of this drought is long and unfavourable soil-moisture and tempera­ the intensity is high, a large mortality of ture conditions (optimum temperature seedlings inevitably decreases the yield. around 40°C) prolong the germinative Rainfed crops, e.g. pearl-millet, are period. Although their germination under usually subject to higher soil-water stress the op~imum conditions of the laboratory at the advanced stages of flowering and . Was hIgh (ca. 70-80 per cent), yet their ripening. Supplemental irrigation, where-

230 PLANTS IN RELATION TO SOIL MOISTURE ver possible, at the critical stage of the soil moisture fluctuated between ca. 1/3 onset of ear emergence seems, therefore, and 15 atm. tension, the yield was depres­ to be an easy way of stabilising yield., sed equally in all the varieties. The results Similarly, the adverse effects or early generally suggested that varietal traits drought on pearl-millet may be avoided, were discernible when the soil-moisture if the seedlings are raised in irrigated condition was not too critical, although micro· plots, and transplanted during ade­ the performance, as such, in all cases was quate rains. Although this crop is nor­ adversly affected under higher-tension re­ maJly sown in early July whh the break of gimes (ie.ca. J/3 to 1 atm. and ]/3 to 8. the monsoon, transplantation may be done atm.) than in control (ca. 1/3 atm.). The up to the middle of August without any choice of improved varieties, therefore, adverse effects on yield. In one study has a singular importance in the drought­ conducted during 1971, transplanted pearl­ prone areas. millet (var. HB 4) gave a yield of 26 qJha, It has further been observed that the with 80 kgjha each of Nand P.Os. vegetative growth, as such may be reduced Effects of moisture stress on nitrogen under adverse soil-moisture tension, but metabolism and nitrogen uptake: Studies the concentrations of both total nitrogen on the nitrogen metabolism (Lahiri and and protein nitrogen increase in the tissue, Singh, 1968) indicated that in the initial irrespective of the age of the plant. A stages of tissue dehydration, protein syn­ reduction in dry matter may lead to a thesis was impeded and proteolysis was higher total N concentration, whereas the trIggered off at wilting. During the higher protein synthesis during the 'wet' drought cycle, there was an indication phase after the dry spell may account for of an increase ~n nitrogen concen­ the higher protein N concentration in the tration in the tissue. Ammoniacal nitro­ tissue. Unfavourable soil-water condi­ gen which could be detected in the wilted tions also increase the N concentration of plants showed a sharp decrease on re­ the grains of pearl-millet, although the yield watering, with an associated increase in was decreased. It has been speculated the level of amide nitrogen, suggesting a that the flow of nitrogen in the grains was quick incorporation of ammonia into less subjected to unfavourable moisture organic acids as a measure against ammo­ conditions than the flow of carbohydrates. nia toxicity. Studies on the effects of hy­ It is, therefore, a natural redemption that perthermia on nitrogen metabolism despite the low productivity from arid (Lahiri and Singh, 1969) indicated that, areas,the quality of the produce is gene­ unlike moisture stress, high temperature di­ raI1y superior to that obtained from areas rectly caused a breakdown of proteins. 111- having favourable soil-moisture condi­ vestigaticllls on the influences of soil mois­ tions. ture on the nitrogen metabolism further indicated that rewatering after a period of PRINCIPLES OF PRODUCTION STABILI­ ZATION UNDER LOW SOIL-MOISTURE drought enhanced the synthesis of pro­ CONDITIONS teins and, consequently, the protein con­ centration after the termination of a Drought-causing sustained [ow-mOisture drought cycle was more than the initial regime. Drought caused by low preci­ concentration. pitation in some years as described earlier, The alterations of plant growth ~nd may be encountered very frequently in this metabolism under different regimes of soil area, and the production stabilization moisture are very relevant in the present under these conditions becomes extremely context, as in nature there is a continuous difficult. It has been found that under drift of soil-moisture tension. Studies such conditions, effects due to fertilizers (Lahiri and Singh, 1970) undertaken on and those due to varieties do not become different varieties of pearl-millet indicate significant. These effects in a good­ that under critical conditions, when the rainfall year display a ·high order of

231 DESERTIFICATION AND ITS CONTROL statistical significance. Investigations cluded (Lahiri, 1975b) that the adverse (Lahiri,1975b) directed towards the effects of droughts, no matter at which stabilization of production in such low­ stage of growth the water shortage is rainfall years have indicated that when experienced, could be substantially evaded rainfall is delayed and is expected to be where optimum plant vigour was induced low, it may be advantageous to grow by adequate soil fertility. This concept certain legumes, e.g. Cyamopsis tetragono­ of nutrition-induced vigour as a means of loba (guar) and Phaseolus aconitifolius drought avoidance has further gai ne1i (moth), which use less water than pearl­ support from studies (Kathju and Lahiri, millet, which has a relatively high water 1976), which indicated that. plants raised need. under optimum soil fertility displayed C-4 plants of western Rajasthan in higher activity of enzymes and showed a relation to the efficiency of water use. higher chlorophyll content of leaves under During the recent yelrs (Huber et at., desiccation than plants raised under low 1973; Sankhla et al., 1975), a large number soil fertility. It has been found that the of species (including grasses) of the tissue turgor is unlikely to be the key to Indian desert have been found to have general growth reduction under water C-4-dicarboxylic acid paJhway for photo­ shortage. It has been speculated that synthesis. However, while discussing the growth and metabolic .efficiency is more water-use behaviour of grasses, it has dependent on nutrition rather than on been mentioned earlier that the consump­ tissue hydration atleast up to a certain tive use of moisture of C.ciliaris, level of water shortage. The flow diagram L sindicus, which are C4 plants, may be under Fig: 1 explains the overall mecha­ substantial, when there is no constr.aint nism of actions that has been derived of soil moisture. Again, it has been from various experiments. found that the water-use efficiency in the The foregoing concept holds considera­ context of dry-matter production may ble promise for arresting desertification also vary widely among the C4 plants. of the semi-arid and high-rainfall areas For instance, the water-use efficiency of located at the fringes of the desert. C. ciliaris, C. setigefus, and L.sindicus Prospects for the reduction of irrigation grown under indentical conditions was in need. The increasing emphasis on the order of 21.8,8.4, and 19.1, respec­ irrigation in the Indian arid zone necessi­ tively. These observations indicated that tates the standardization of irrigation wide variations in productivity ranges norms in the contex.t of the regional might be encountered among the C4 plants environment. Water being the most of this area. It is, thus, necessary to precious input, attempts were made to ascertain the productivity ranges in the apply the foregoing concept of nutrition­ context of soil-moisture and management induced vigour for the stabilization of conditions, even if the plant is generally wheat yield under a low level of irrigation. considered well adapted to arid con­ It was found (Lahiri, loc.cit.) that a ditions. substantial production of wheat (var. RS 31-1) could be achieved with less INSULATION MEASURES UNDER water by optimizing the il1puts, e.g. SPORADIC DROUGHT nitrogen and phosphorus. A yield of The irregular distribution of' precipi­ about 20.8 q/ha under' 80 kg/ha each of tation often creates another condition of Nand PzOs was achieved when the plants drought where the plants may be subjec­ received only 24.5 cm of water. However, ted to moisture stress at any stage of plants without any nitrogen and phos­ growth. Such sporadic droughts may be phorus, in the loamy-sand soil of encountered both in high and low-rain­ Jodhpur gave a yield of only 65 q/ha fall area~. On the basis of a large number with 39.5 cm of irrigation water. Experi­ of expenqlental data, it has been con- ments under both open and pot-culture

232 PLANTS IN RELATION TO SOIL MOISTURE

HIGH TRANSPIRATION POTENTIAL IS ASSOCIATED WITH UNI­ SUBSTANTIAlPRODUCTION UNDER LOW SOIL FORM INCREASE IN NITRATE INTAKE MOISTURE REGIME (Within the available limits)

Fig. 1. The mechanism of actions envisaged for the nutrition-induced vigour as a measure for avoiding the adverse effects of sporadic droughts conditions suggested that different levels in this contest emphasized the point that of production could be achieved at the a lower average yield over a larger area same level of water use, under irrigated could bring about a higher total benefit in conditions, by a progressive optimization the arid areas than from the most profi­ of inputs. Ram and Lahiri (1974) from table yields from a small area. t~e economic analyses of wheat produc­ An understanding of the basic principle tion under 'high' (ca.l/3 to 1 atm. tension) governing the process of nutrient use and 'low' (ca. 6 to 15 atm. tension) mois­ under low soil water condition was possi­ !ure availability (with adequate fertilizers) bie when our results indicated that within Indicated that the returns over fertilizer the available limits of soil moisture in­ cost would be Rs 2,668.80 under high crease in the level of soil nutrients, and Rs 861.29 under low-moisture increased the absolute quantities of these availability (the selling price of wheat was nutrients in the plant with an associated assumed to be Rs 90 per quintal). . improvement of the performance, irres­ The foregoing results indicate that a pective of the tension. The magnitude of ~armer in this area, having a well of this increase was, however, less at high h~ited discharge, may expect a reasonable tension ranges., The trend of result has YIeld by spreading the limited water been illustrated in the Fig. 2· with special resOurce over a larger area. Singh (1976) reference to the root growth and the

233 DESERTIFICATION AND ITS CONTROL

ROOT 2·0

... 3,of ~2·0 1·2 _J t-i Z .~ 1·0

22 '"

5

4

3 I­ Z

Cl E

35 55 . 75 . 95 115 35 . 55 75 95 115 OAYS FROM SOWING DAYS FROM SOWING FIXED SOIL WATER TENSION. 6 A.TM @...--0.CONTROL (0 Kg/ha) ~ 40Kg/ha-EACH OF N a P205 -- eOKg/hO-EACH OF N 6P2 05 0----0 120 Kg/ha-EACH. OF H a P 0 2 5 Fig. 2. Root growth and absolute quantities of nitrogen, phosphorus and potassium in the root of wheat raised under different soil fertility conditions and at water tension of ca. 6 atm. nitrogen, phosphorus and potassium have also been evolved over time for the contents of the roots of wheat plants, improvement of soil water conditions grown at ca. 6 atm. tension and under and plant production in the dry regions different soil fertility conditions. (National Academy of Sciences, Washing~ Innovati{Jns related to improvement of ton 1974). In arid areas of Rajasthan, soil water conditions. Various technologies . promising results have been obtained by

234 PLANTS IN RELATION TO SOIL MOISTURE land shaping and use of runoff water in LAHIRI A. N. and KHARABANDA, B. C. 1963a. Germination studies on arid zone plants. agriculture (Singh et al., 1973; Singh, 1976), I. Germination in relation to moisture up­ water harvesting from natural catchments take by grass seeds and the probable role of (Prajapati et al., 1973), bunding in san~y­ 'coumarin in this mechanism. Proc. natn. loam soils (Misra, 1966), contour bunding Inst. Sci. India 29 : 287-296. ---and---·1963b. Germination studies and furrowing (Ullah et al., 1972), use of on arid zone plants II. Germination inhibi­ subsurface barriers, breeding of sandy tors in the spikelet glumes of Lasiurus sindi­ soils with pond silt (Gupta, personal cus, Cenchrus ciliaris, and Cenchrlls seti­ communication) and also by subsurface gertls. Ann. Arid Zone 1 : 114-126. ---1964. Moisture relations of some desert incorporation of the plant parts of a latex plants. Proc. Symp. o.n .Problems of In£!ian containing plant like Calotropis pro cera Arid Zone. Pub. MInistry of EducatIOn. (Singh, 1973). Government of India, pp. 154-160. ---and KHARABANDA, B. C. 1965. Studies on REFERENCES plant-water relationship. Effects of moisture deficit at verious developmental stages of ABICHANDANI, C. T., KRISHNAN, A., BHATT, P: N. bulrush millet. Proc. natn. Inst. Sci. India and RAKHECHA, P. 1967. Some observatIOns 31 : 14-23. on soil-moisture changes in arid-zone soils. ---and KUMAR, V. 1966. Studies on plant­ J. Indian Soc. Soil Sci. 15: 7-15. water relationships III. Further studies on AGGARWAL, R. K. and LAHlRI, A. N. 1976. In­ the drought-mediated alterations in the per­ fluence of vegetation on the fertIlity build-up formance of bulrush millet. Ibid. 32: 116-127. of the desert soils of western Rajasthan. ---and SINGH, S. 1968. Studies on plant-water relationship IV. Impact of water Sci. & Cult. (in press). deprivation on the nitrogen metabolism of ASANA, R. D. 1960. Physiology of drought Pennisetllm typhoides. Proc. naln. Inst. Sci. resistance. Proceedings oj First Conference India 34: 313-322. oj Research Workers 011 Plant Physiology, --and--1969. Effect of hyperthermia ICAR, New Delhi, pp. 57~69. on the nitrogen metabolism of Pennisetum BAVER, L. D. 1956. Soil Physics. 3rd edition, typhoides. ibid. 35 : 131-138. New York, J. Willey & Sons. pp. 489. ---and GAUR, Y. D. 1969. Germination BHATT, P.N. and LAHIRI, A.N. 1964. Some studies on arid zone plants V. The nature evidence of foliar absorption of water in a and role of germination inhibitors present xeric tree, Prosopis spicigera, Naturwiss. in leaves of Prosopisjlllijfora. Ibid. 35 : 60-71. 14 : 341-342. ---and SINGH, S. 1970. Studies on plant­ water relationship. V. Influence of soil GUPTA, J. P., ULLAH, WASI, and ISSAC, V. C. 1975. moisture on plant performance and nitrogen Note on some soil moisture changes under status of the shoot tissue. Ibid. 36 : 112-125. permanent vegetative cover. Indian Forester ----1975a. Water use by desertic vege­ 101 : 523-526. tation and its hydrological implications. HUBER, W., SANKHLA, N. and ZIEGLER, H. 1973. Ann. Arid Zone 14 : .135-48. Ecophysiological studies on Indian arid --- 1975b. Plant responses to soil-water ZOne plants 1. Photosynthetic characteristics status under arid conditions. Proceedings of Pennisetum typhoides (Burm. f.) Stapf. of the ICAR Symp. on Crop Plant Response Hubbard and Lasiurus sindicus Hem. Oeco­ to Environmental Stresses, held at Vivekananda logia 13 : 65-71. Laboratory for Hill Agriculture, Almora, KATHJTJ, S. and LAHIRI, A. N. 1976. Effect of soil u.P. pp. 13-24. fertility on the activities of certain enzymes MANN, H. S., LAHIRJ, A. N. and PAREEK, O. P. of desiccated wheat leaves. Pl. Soil 44 : 1976. A study on the moisture availability 709-713. and other conditions of unstabihsed dunes KAUL, R. N. and GANGULI, B. N. 1964. Af­ in the context of present land use and the forestation studies in the arid zone of India. future prospects of diversification. Ann. Proceedings of the Symposium on Problems Arid Zone 15(4) : 270-284. oj Indian Arid Zone, Jodhpur. Pub. Ministry MISRA, D. K. 1966. The moisture conservation of Education, Government of India, New by bunding in semi-arid region of Pali. Delhi, pp. 183-196. Proceedings of Symp. on Water Management, KOLARKAR, A. S. and SINGH, S. 1971. Moisture­ Udaipur, organized jointly by Indian Soc. storage capacities in relations to textural of Agronomyand lCAR, pp. 62-65. composition of western Rajasthan soils. NATIONAL ACADEMY of SCIENCES, USA 1974. Ann. Arid Zone 10: 29-32. More Water for Arid Lands. KRISHNAN, A., BHATT, P. N. and RAKHECHA, P. PRAJAPATI, M. C., VANGANI, B. S. and AHUJA, 1966. A soil-moisture regime and micro­ L. D. 1973. Tanka can be the answer in the climatological study of sand-dunes in western dry rangelands of western Rajasthan. Indian Rajasthan. Ann. Arid Zone 5 : 1-9. Fmg

235 DESERTIFICATION AND ITS CONTROL

RAM, K. and LAHIRI, A. N. 1974. Economic SHANKAR VINOD, DADIDCH, N. K. and SAXENA analysis of wheat production with fertiliser S. K. 1976. Effect of Khejri tree (Prosopi; under adequate and limiting irrigation water. cineraria Macbride) on the productivity of Indian J. agric. Res. 8: 25-36. range grasses growing in its vicinity. Forage Roy, B. B., CHATI"ERJl, P. C. and PANDEY, S. Research 2 : 91-96. 1969. Genesis of carbonate pan in arid SINGH, H. P. 1973. Soils of western Rajasthan region of Rajasthan. Ann. Arid Zone 8 : 181- and the problem of their low moisture storage 187. capacity. Winter School on the "Develop­ RUITER, A. J. 1958. The effects of afforestation ment of Rajasthan Desert", organised by the on rainfall and runoff. J/. R. Ins!. publ. Hlth. indian natn. Sci. Acad. (in Press). London, pp. 119-138. SINGH, S. D., DAULAY, H. S. and MUTHANA, K. D. SANKHLA, N.,ZmGLER, H., VYAS, O. P., SncHLER 1973. Runoff farming making the best of W. and TRIMBORN, P. 1975. Eco-physiologi­ available water. Indian Fmg. cal studies on Indian arid zone plants V. ---1976. New approaches to use of scarce A screening of some species for the C, water resources. Trans. Indian I Soc. Desert pathway of photosynthetic COs fixation. Tech. 1 : 83-87. Oecologia 21 : 123-129. ULLAH WASI, CHAKRAVARTI, A. K., MATHUR, SHANKARANARAYAN, K. A., CHERIAN, A. and C. P. and VANGANI, N. S. 1972. Effect of GAUR, Y. D. 1965. Ecology of dune vege­ contour furrows and contour bunds on water tation of Osian (Rajasthan). J. Indian bot. conservation in grasslands of western Soc. 44 : 37-50. Rajasthan. Ann. Arid Zone 11 : 169-82.

236 25 OPTIMUM UTILIZATION OF ·LIMITED WATER SUPPLY

S. D. SINGH

THE maximum yield is usually obtained by ter will be placed only on that part of these applying irrigation at the rate of potential aspects which are either manageable or evapotranspiration (ET). In the fulfil­ have notable policy implications in the ment of this expectation, water is used water-project planning rather than in the wastefully because of the inverse relation­ reporting of voluminous literature relating ships between evaporative losses and the to these SUbjects. extent of crop cover until it is 50 % com­ The ET is the field-level water para­ plete, and between irrigation efficiency meter, derived from the rainfall, irriga­ (the percentage of irrigation used in ET) tion, and the available soil water at plant­ and the non-ET water uses (deep percola­ ing. Obviously, a wholesome emphasis tion and unutilized moisture at maturity) would be on the management aspects of under conditions of potential EY rate. water after it has reached the field through From these observations, a few things can one or all of the three ET sources. Parti­ be inferred. First, for crops which do cular reference will be made to arid and not have complete cover at all times, the semi-arid regions of Rajasthan. But the amount of ET required for maximum basic principles and approaches developed yield would be less. Second, the oppor­ to achieve the optimum use of limited tunity for the rational use of limited water water may serve as a guide to other arid lies in methods that vary the relative and semi-arid regions of the world. proportion of the nongrowth-related eva­ poration to the growth-related transpira­ MECHANrSMS THAT VARY THE RELATIVE tion and eliminate the non-ET water uses. PROPORTION OF EVAPORATION TO Third, the continuing adherence to the TRANSPIRATION "traditional approach" to the problem of Tn field agriculture where the basic water improving water-use efficiency best suited parameter ET includes surface evapora­ to the area of water abundance, limited tion, any amount of technology, no matter land is no more justified in water-deficient how efficient, can eliminate evaporation regions. Time has come for a switch­ from the soil. Nevertheless, the mecha­ over from "this" to the "optimization" nisms capable of restricting the availabi­ approach which attempts to minimise the lity of water to the evaporative site, reduc­ seasonal ET per unit area or per unit yield ing the availability of energy to the soil, with the least accompanying loss in and limiting heat or vapour exchange harvestable yield. between the soil and the atmosphere can Interwoven is the need for a shift from minimize it, making water available more individual crop water-management ap­ for transpiration which is most directly proach to water management of the "farm related to yield. Therefore, the best unit" as a whole in all matters of limited opportunity for saving ~ater lies in water allocations. Emphasis in this chap- methods influencing these factors of eva-

.237 DESERTIFICATION AND ITS CONTROL

poration and the relative proportion of is very slow because of pore discontinui­ evaporation to transpiration. Some of ties. As a result, the evaporative site these factors are: the elimination of weeds, dries up quickly, the thermal contact co­ the use of mulches, the application of the efficient is reduced, the liquid flow of water optimum leaf-area concept, and irriga­ ceases, the evaporative cooling of the tion in terms of ground cover. soil surface becpmes nil, and much of the energy is transmitted to the soil until A. Mulches related to moisture ground cover becomes incomplete and is conservation consumed in heating the air which, in turn, The effectiveness of mulches for moisture heats up the immediate soil surface. conservation has varied, depending upon Nevertheless, the evaporative losses will the soil, the climate, the crop, the type be less. Because the dry layer retards­ of material used, and the degree of cover vapour escape owing to pore discontinui­ on the soil. There is no controversy as ties, and also because the dry air within a result with one's experiment, but with the and immediately below the evaporative interpretation and application of results. &ite is an effective thermal insulator. The objective here is not to resolve the Under these conditions, it is doubtful that controversy but to analyse how far mulches the net effect of organic mulches, and the would be helpful or not helpful in mois­ ineffective barrier to v.apour escape may be ture conservation under specific soil­ of any utility. Frequent reference to climate situations of this region. There­ mulching will also be made in the context fore how the evaporation proceeds and of the asphalt moisture barrier. what processes inside the suil contribute to it should be sufficiently known so that B. Optimum leaf-area concept related necessary manipulation in the use of mul­ to better use of water ches can be done to reduce the evapora­ Here we limit our discussion to the leaf­ tive loss to its minimum. It is in the area concept synonymous with crop cover, context that some elementary facts are as related to the relative proportion of briefly mentioned here. evaporation to transpiration. As seen For a day or two after wetting, the water from Fig. 1, the leaf-area index (LAI) of is freely available, evaporation proceeds annual crops, e.g. wheat, starts from zero at a rate in direct proportion to the energy early in the season, increases rapidly to a available, but slows down as the soil dries maximum, remains at the maximum lev::! at a rate proportional to the water content for a short period, and then declines and universally proportional to time. The rapidly. Hence to maintain the "opti­ - drying front advances into the soil profile mum" leaf area at all times is difficult. linearly with time, but the evaporative However, the system which comes closest site seldom exceeds 5 cm below the soil to this ideal will be the most efficient. or is generally at or near the surface. Early in the season when ground cover Thus we see that the water content and is least, ET is also least. A large part of hydraulic conductivity are interacting to water use is in the form of evaporation characterize the water diffusivity and their and is least through transpiration contributions are texturally. controlled. (Table 1). In coarse-textured soils, the surface To ensure that the radiant energy is used lO-cm layer is single-grained, dry aggre­ in transpiration much more than evapo­ gates of size>2 mm are hardly 1 %, capil­ ration early in the season, it is desirable larity is almost nil, pore discontinuities to have an optimum density of vegetative are predominant, and hydraulic conducti­ cover by properly adjusting the row-spac­ vity is high at low, and is low at high suc­ ing and seed-rate, by selecting the most tion. Added water thus moves down at a favourable time of planting, and by a fast rapid rate and is placed deep in the profile development of crop canopy through ade­ safe from evaporation. Its upward flow quate fertilization early in the season.

238 OPTIMUM UTILIZATION OF lIMITED WATER SUPPLY

Table 1. Relative amounts (inchesj of transpira­ extent. The crop will have attained its tion T by the maize crop and evapo­ ration E:from the soil in Ohio (Harrold maximum aerodynamic roughness. Any et al., 1959) expanse of canopy thereafter through management manipUlations will have no Period T E important effect on transpiration, be­ cause the increased interception of energy May I-June 5 0 3·69 will be compensated for by a decreased June 6-June 30 1·77 2'47 effect of turbulent transfer. During this July I-July 31 4·14 2'53 period of crop cover> 50 % complete, the August I-August 31 2·40 1·59 September I-September 9 0·16 0'38 ET crop exceeded the evaporation (Fig.l), Season: March I-September 98·47 10·66 and the evaporation from the soil con­ tributed only a small portion of the total ET. Cultural practices, e.g. weeding and Or transplant seedlings, where the nature mulching, which effect only the direct of the crop and the labour needed do not evaporation from the soil will have but a place added constraints on the economics small effect thereafter on the total ET. of the practice. The elimination of weed canopy early in As the percentage crop cover increased the season, therefore, is one of the impor­ up to 50 % through an increase in the leaf­ tant practices to reduce the water per unit area index from 0.3 to at about 1. 2, yield and the yield of commodity needed ET increased, more through an increase from a smaller total available water-supply. in transpiration and less through eva­ The evaporation contributed a sub­ poration (Table 1), during weeks 7 to stantial part of water-use again when the 12, the LAI is more than 3, or the ground crop approached maturity, the leaf-area cover is>50% complete. But beyond a index declined fast (Fig. I), as the canopy certain point (LAI = 3.5 in this case), allowed a substantial transmission of the ground cover did not increase because radiant energy to the soil. During this of the mutual shading of leaves to a large time, the ET continued, but at a diminish-

CROWN ROOT GRAIN MATU- INITIATION TlLLERING BOOT HEADJNU DEVELOPMENT RLTY "2 6 1'1 1'0 5 . 0'9 >< 0'8 4 ~ ILl z ..... 0'7 .... <{ ILI O' S 3 w Q: a:: <{ P 0'5 ~0'4 EO o a 'E 0'3 0 0 '2 25 I ·0" 0 o 25 NOV DECEMBER JANUARY FEBRUARY MARCH

Fig. 1. Per cent ground cover (G.C.), ET, E (Evaporation) in class A pan and ET/E ratio in relation to seasonal changes with time iu leaf area index (LAI)

239 DESERTIFICATION AND ITS CONTROL

ing rate. In most crops, it is for this Together, these sources constitute what reason that the soil moisture should not may be termed field water-supply. Note be maintained at a high level after matura­ that the irrigation is not all converted into tion. ET. Whereas the available soil water in the root-zone at sowing time is converted c. Irrigation in terms of ground cover into ET to the extent of 100 per cent, the conversion of rainfall into ET is generally It may also be mentioned (though not close to 100 % and irrigation include non­ shown in Fig. 1) that frequent irrigation ET water uses. In this way, irrigation until the ground cover is incomplete water=ET +non-ET, and irrigation effi­ (LAI < 1.2) will cause low ratios of trans­ ciency is the ET expressed as the. percent­ piration to evaporation for 2-3 days sub­ age of irrigation water purchased and sequent to irrigation by excessive evapo­ applied. Therefore, water is greatest of ration from the wet soil surface. Once concern to policy-makers, economists and the ground cover is complete (LAI = 1.2 engineers. to 3. 5), the ratio is more than unity through If this irrigation efficiency were 100 %, the preponderance of transpiration, and the non-ET portion of water use would be evaporation, whatever value it may have, eliminated and the relation between yield­ appears to become a constant percentage field and water-suppl)! would be similar of ET. Efficient water management re­ to the linear yield-ET relationship. Un­ quires some restrictions on frequent fortunately, the irrigation efficiency typi­ irrigation early in the season until the cally decreases as we approach the maxi­ maximum energy available is used through mum ET (ET max) to attain the~aximum evaporation, on the one hand, and a yield (Y max). The reasons for these things prudent use of water is made during the are obvious. If irrigation is at some level period of complete ground cover, on the well below that required for Y max, deep other. percolation losses can be made minimal On the basis of this observation the or even eliminated. Additionally, all general recommendation (Misra et al., available soil water at sowing time will 1969) after the first irrigation to dwarf be extracted by the crop roots before wheat 21 days after sowing does not appear maturity. When irrigation is sufficient to be sound. More so, when the ET early to assure no ET deficit, some deep per­ in the season is less, and if the presowing colation is inevitable, and some availa­ irrigation has initially brought the soil ble soil water will remain in storage at profile to field capacity it can continue maturity. The non-ET water disposition to meet the maximum or the near maxi­ also occurs when rainfall exceeds the mum ET demand easily for a month or size of soil storage, and the sandier the so after sowing. The potential thus soil, the greater are the losses through exists for saving an irrigation early in the deep percolation. season without impairing the prospects From the foregoing account it appear~ of a better yield. The works of Cheema that the optimum water-use policy in and Malhotra (1975), Ram Niwas (1975), arid and semi-arid regions should be to and Jaswant Singh (personal communi­ use subsurface barrier to apply the concept cation) are cited as evidences that.suggest of modest irrigation, and to terminate the application of the first irrigation in the . irrigation at an appropriate stage to ensure case of dwarf wheat at the active tillering that losses due to deep percolation are stage. minimal, or even eliminated, and no avai­ lable soil water remains· in storage at REMOVAL OF NON-ET WATER USES maturity. The termination of irrigation The ET is derived from irrigation, the will be discussed in the context of water­ profile-water storage at the time of sow­ use optimization programme. The remai­ ing and ,the growing season rainfall. ning two points are discussed here:

240 OPTIMUM UTILIZATION Ol' LIMITED WA.TER SUPPLY

A. SUBSURFACE BARRIERS FOR MOISTURE ment of the stratified profile. Nor is CONSERVATION there any scope for rain-induced leaching by fallowing during the following rainy To minimize deep percolation, the season, in spite of the fact that AMoBar Japanese Desert Development Institute allows free water to seep down, but at a has introduced a technique for injecting very low rate. a 3-mm-thick asphalt layer at a depth AMoBar confines the rain or irrigation of 45 to 90 cm. In addition to making water to a depth of 60 to 75 cm and the an effective use of the limited supply depth of its placement. The added water­ of irrigation water, the technique is supply and higher water diffusivity from claimed to prevent the salt in the desert shallow-perched water-table will result in sand from filtering up into the surface considerably larger evaporative losses soil. In a recent study by J.P. Gupta than from a uniform profile. Experi­ (personal communication), deep per­ mental data of H.P. Singh (personal colation from asphalt-barriered profile was communication) regarding the probable 4 out of 54 cm of rainfall. From the greater evaporative loss and less added uniform profile, the loss was 22 cm. The yield from stratified profile than from a additional low-tension water held in the uniform profile are shown in Table 2. root-zone boosted the yield of pearl-millet In 1974, a dry year, the added water- under rainfed conditions and of wheat under irrigated conditions. The claims Table 2. Yields of round-gourd with and without of AMOCO (1971) regarding the ability bentonite moisture barrier during poor of asphalt moisture barrier (AMoBar) to (-) and good-rainfall seasons increase yields and iIpprove farm pro­ fitability are further stimulating our in­ Yield terest, though at a price of $ 700 to 800/ Treatments 1974 1975 ha, which, they claim, the US farmers can (dry) (wet) afford. Runoff + barrier 4,310 10,000 kg/ha kg/ha Possible hazards of AMoBar Runoff+barrier 4,510 10,800 +muIch Though the results are of special signi­ Flat-surface control 1,970 10,100 ficance, AMoBar is not for every farmer, + barrier for every crop, on all soils and under all Flat surface control 2,380 10,400 +barrier +mulch conditions. It has particular promise in LSD (0-05) 834 1,290 the case of money-spinning crops (vege­ tables, including groundnut and maize for cobs), in "sand" and some loamy supply by run off concentration + bar­ sand, under natural-rainfall conditions. rier+organic mulch at 4 tonnes/ha brought For irrigated conditions, the technique 200 kg/ha extra yield of round gourd, presumes that the water is of excellent over that from the runoff+barrier treat­ quality in the requirement difficult to ment. Under the fiat-surface unstrati­ meet in this region where the problem of fied control, the water got the opportunity salinity in irrigation water is moderate to to move deep into the profile safe from acute and wide-spread. The use of poor­ evaporation, and that water the crop utili­ quality irrigation water over and over­ zed and so was able to yield extra 410 again will accentuate the salinity level kg/ha. During 1975, a normal year, of the potential root-zone to such a degree regular rainfall in abundance overshado­ that will render the cultivation of even wed the ill effects of greater evaporation t?lerant crops most difficult. The hand­ from the stratified profile and the yields hng of salinity will become difficult, es­ for various treatments, as a result, did pecially when the leaching of salts cannot not differ significantly. be integrated into the irrigation manage- Fig. 2 illustrates the comparative

2.:11 DESERTIFICATION AND ITS CONTROL 36r------__ --___ 30cm

30

45cm 'e ": 24 60em ~ 22 I- - .q: ~,f! 75cm Q. § Ie lU-

lU > ~

~ II 90cm c.J

120cm 5

18 24 30 36 42 48 82 DAYS AFTER WETTING Fig. 2. Comparative evoporation for various depths from bare surface of loamy sand in 82 days (S.D. Singh, 1976-unpublished) evaporation for various depths from the of high power requirement, not so difficult bare surface of the loamy sand for an 82- to meet. Internatio'nal Harvester Com­ day period from 4 March to 25 May 1976, pany of the U.S.A. has developed a and emphasizes the importance of select­ machine (see Figure on p. 9 of AMoBar ing a reasonably optimum depth of asphalt information bulletin, AMOCO, Chicago) floor where mechanical feasibility and. which lays a 2'. 3 metre-wide barrier to a th~ evaporative control are at a compro­ predetermined depth. or covers one hec­ mise. The major evaporative losses rang­ tare in 2.5 hours. ing from 18 to 33 mm took place from Agronomic practices concomitants the first four depths, 12 to 15 days afte~ wetting, but were less from depths of 90 of AMoBar and 120 cm. After this period, the eva­ (a) Insulative mulches: The evaporation poration, especially 75 cm, below the sur­ rate-amount advance illustrated in Fig. face, was of least practical significance. 3 suggests the importance of integrating From these data the ideal depth of AMo­ insulative mulches with AMoBar es­ Bar would be around 90 cm below the pecially "early" in the season. Perhaps surface. Much of the larger water sto­ warranted by a similar situation, the rage deep in the profile is safe from eva­ Hawaiian planters have been using black poration, is conducive to deep root pro­ paper and plastic mulches in the case ~f liferation, delays the arrival of the drying pineapple since early 1920's, since thIS front to the site of the perched water-table, crop uses the maximum amount of water but has one and the only one disadvantage when the plants are small and direct

242 OPTIMUM UTILIZA nON OF LIMITED WATER SUPPLY evaporation from the soil is great. How-, obvious from these data, though limited, ever, in view of the "self-mulching" action that the insulative mulches as a companion will this integration be necessary? In, practice to profile stratification is short­ "sand", certainly not. But as may be' lived, early in the season until the crop seen from Fig. 3, a distinct possibility for cover is< ~Q % complete. .once the crop AMoBar-mulch integration does exist cover 'is>50% complete, evaporation re­ in "loamy sand", but only for a short mains a negligible fraction of the total period early in the season. For the eva­ ET. Mulching over the "full" crop sea­ poration from the highest mean rate of son then hardly serves its intended objec­ 10.3 mm/day two days after wetting dec­ tive. lines to a 0.7 mm/day 19 days after, and Plastic is an effective barrier against the total loss is 107 mm. From this to the evaporation, but is subject to heavy 82-day period, the total loss is 6 mml photothermal deterioration and damage day, at a mean rate of O. 1 mm/day, a by aerodynamic uplift. Necessity of this rate hardly of any practical significance. kind of insulative mulch for the short Also shown in Fig. 3 are the evapo­ period early in the season may be advanta­ ration (in regular line) from a wheat field geous. After use for a month or so, it for an eight-day period from the date of may be collected and stored for subse­ planting on 25 November to 2 December quent use. Over seasons, the cost, as a 1975, and the ET (in broken line) for result, may be low but the initial cost 14 days thereafter. During this cool requirement (for 90 % cover) is about period also, the evaporative losses are $ 1,379jha. So, for all its success, the high when the plants are small. It is benefits from the additional moisture

120~------~------'12

113 o 100 0 10-

SO 8 E E z Q ,." I- 0 '

30 36 42 48 82 0 DAYS AFTER WETTING Fig. 3. Rate and cumulative evaporation from a wheat field after harvest over an 82-day period (S.D. Singh 1976-unpublished) -

243 DESERTIFICATION AND ITS CONTROL

conserved because of mulch must be suffi­ Table 3. Yield Y, ET. Y/ET. and yield to irriga- cient to pay for its cost. But as seen from tion water ratio (Y/Wa) of the wheat crop at five populations. Water and N the data in Table 2, the quantum of extra fixed at 56 em and 150 kg/ha yields due to the integration of organic mulch with bentonite barrier will sel­ dom pay for its cost. It is also evident Seed Yield ET Y/ET Y/Wa from yield differences due to mulching under the runoff concentration system and --kg/ha em --kg/em- flat-surface control that organic mulch even at 4 tonnesjha was not an effective 75 3,554 58·8 60 63 barrier against evaporation. With in­ 95 4,342 60·6 72 77 sulative plastic mulch (90% cover). the yields may be much greater on the mul­ 125 4.717 62'0 76 84 ched plot because of most of the water '<;6 use through transpiration on the mulched 155 4,740 62 5 85 plots early in the season. However, the 175 4,904 69·7 70 88 additional gain from the integration of such a practice with AMoBar on a coarse- textured soil of this region remains to be over such a range, the plaximum irriga­ seen. tion efficiency can be obtained. But it (b) Higher plant densities: Higher may be recognized that in the case of plant density has been a shot-gun easy- most crops, there will be a dispropor­ to-control practice known for its p~tential , tionate fall in the yield corresponding to in enhancing transpiration relatIVe to ET less than the "optimum", and after the non-growth-related evaporation since increasing at a diminishing rate up to the the date it was originally proposed by genetic maximum, the yield will not in­ Chang (1968). One should not be mis- crease by ET increase beyond the ETmax. taken that a twofold increase in plant This kind of situation is noticed in the , density will require twice as much water. data illustrated in Table 3. As may be The consumptive use remains about the seen. the seed-rate optimal for the leaf­ same or increases only slightly (Ram area index closest to the ideal we want for Niwas, 1975). whereas the yield increases the efficient use of water ranges from the up to the density where the compensation "optimum" (125 kg/ha seed in this case) in individual and group performance of pinpointed by the "old approach" to a plants is compromising (Table 3). This level where (Y /Wa) ratio is maximum is-how the "traditional approach" of Viets (i.e. at 175 kg/ha seed). But the added (1965) and Jensen (l972) seeks to maxi- benefits from each added unit of seed mise the efficiency of irrigation by increas- input above the "optimum irrigation ing yield without changing Qr increasing efficiency" defining term is preponderantly slightly the seasonal ET. overgeneralization of the "old approach" Later, Shmueli (1973) proposed the term to the problem of increasing irrigation "optimum irrigation efficiency" which by efficiency. definition reaches where the ratio of yield Higher plant densities may be helpful (Y) to the seasonal water applied (Wa) in improved water management also is maximum. But he emphasizes the through a control on water flow below the importance of the range of optimum ET root-zone. Fig. 4 shows water dis­ which can ensure maximum yields and not tribution under three population densi­ necessarily the maximal (Y /Wa) ratio. ties of tomatoes. viz. 48, 96, and 192 COQsidering mathematics, it is clear that plants per 12-metre length of drip irriga­ - if (Y /Wa) ratio remains constant or tion lateral, each receiving an equal amount either increases or decreases in any steady of water based on the daily crop ET _fashion witl;l a change in the seasonal ET demand. Water distribution in the pro-

244 OPTIMUM lJTlLlZATION OF LlMITED WATER SUPPLY

SOIL MOISTURE BY WEIGHT. 0/0 0 3 4 5 6 7 9 10 12

15 .~ \l/' 30 \ F\ E <>45 ....:I: /' A r Q. UJ °60 ..J (5 / /' '\ r II> 75 192PLAI\jTSfLATERAL--! /0 '\ \

90 96 P~ANTS/LATERAL -1 \\ x\ /\ x 105.L _------~~ FIELD CAPACITY \ \ 4B PLANTSfLATe:RAL~\ 1. x

120 Fig. 4. Effect of plant densitIes on water distribution in the root zone of the tomato (S.D. Singh, 1976-unpublished) file pertains to the stage tomatoes were B. CONCEPT OF MODEST IRRIGATION finally picked. In each case, the plants had to share the same amount of finite The ratio of crop ET to applied water water-supply. As may be seen from three should approach unity for maximum effi­ curves, the low-population crop exerted ciency in water use and application. If a less use thrust on added water. The it were true, the ET to applied water ration net result is that soil moisture at all depths would always be unity and follow the path was never reduced to values where drain­ shown in broken line in Fig. 5. As seen age could cease. On the contrary, where from ET-applied water, yield-ET and a large number of plants had to share the yield-irrigation relations superimposed on same amount of finite water-supply, the yield-to-field water-supply relationships in soil moisture at all depths below 45 em Fig. 5, this ideal can be achieved by irFi­ was reduced to values where no drainage gation in the low range of application. could occur. Dry soils below 105 cm As we approach the maximum ET to attain on 96 plants/lateral plot, and below 90 the maximum wheat yield, the non ET cm on 192 plants/lateral plot further water use increased, the ET to applied confirm that no water was lost from the water ratio becomes less than unity, and potential root-zone. This mechanism the efficiency of water use declines. On may Il,ot be applicable to AMoBar, but the other hand, when water application the control on water flow below the root­ is limited up to a certain level (56 em in Zone by a higher plant density may be a this case) below that required for the complementary practice to bentonite or maximum yield, the non-ET water use is pond-silt barrier that allows a sizeable eliminated and irrigation efficiency be­ percentage of deep drainage. comes' 100 %. It seems that there is an

245 DESERTIFICATION AND ITS CONTROL

optimum yield-water relationship that (Hillel, 1972) of maxlmlZlng plant res­ can be employed to the problem of water ponse by making water complet(!ly non­ distribution in each of the three common limiting to growth in the arid region is a situations encountered, i.e. the attainment great fallacy. Let Hillel not lose sight of the greatest yield per unit of land when of the fact that the "maximum" or "most the land is limited, the greatest yield per profitable yield" concept (89 cm) of unit of water when water is short or applied water for the maximum wheat yield expensive, and the "lowest acceptable of 5,460 kg/ha, or 73 cm of it to maximize yield" when benefits from the limited the profit at 5,266 kg/ha yield level (see available water-supply to the greatest Fig. 5), is applicable to the area of water number of farmers are to be assured. abundance and limited land: Either of From the foregoing account the appli­ 89 or 73 cm of irrigation falls in the upper cation of the much-emphasized concepts end of the ET applied water relation i} /. 60 (Ymoll.,ETmox) (Ymoll.,lmG!t) 120 " / " " 50 " 100 ,- " / /

C\I 19 41·0 o ,. 40 80 z Q 0' ....: ~ 0:: o ir ~ ...... 30 60 ~ o « ...J 0:: LLI I­o :;: 0.. ~ I- ::> LLI ~ 40 w 20 MAX WUE MAX PROFIT j

10 20 41 61 81 101 35 73 SEA~ON IRRIGA:rJON ( I) DEPTH (em) 0 o 20 40 60 80 100 120 19 54 92

SEASON TOTAL FIELD WATER SUPPLY (em)

. Fig. S. Applied water-ET yield-ET and yield-irrigation relationships plotted within yield-field , , water supply functional relationship

246 OPTIMUM UTILIZATION OF LIMITED WATER SUPPLY

where the non-ET water use is great. cient, photosynthetic efficiency etc. Be­ Have we so much water to waste? Cer­ cause of these differences, they differ tainly not. Therefore in the arid areas, widely in their efficiency to produce dry the objective is to increase production per matter and water use. unit of water and not per unit of land, Crop speci_es of high potosynthetic effi­ since the water and not the land limits ciency use water efficiently. For exam· production. Here, a lower average yield pIe, C 3 plants (pulses) have a low rate of from a modest depth of irrigation on a photosynthesis, so they have a low water­ large area can resul t in higher total bene­ use efficiency. The C4 (millet and sor­ fits than by most profitable yields from ghum) plants, on the contrary, have a a small area. In this case, one may be higher rate of photosynthesis and their interested in the use of water at a maxi­ water-use efficiency is twice as high. Yet mum water-use efficiency point (in this much headway in this aspect of plant case, 35 em of water, and a yield of 4,100 improvement remains to be made. The kg/ha or 1 kg of wheat for 0.85 m" of additional scope lies in increasing leaf irrigation water), or to optimize yield­ reflectivity, although numerous studies water relation that attempts to maximize indicate minor species differences regard­ yield from the least number of irrigations ing their leaf reflectivity. with minimal depth of seasonal irrigation Some workers have tried to relate ET water. This ~s respectively what the requirement to plant height. But very "traditional" or "optimization" approach little conclusive field evidence is available is all about. to support that a tall variety requires more water than a short one. Take, for exam­ TRADITIONAL APPRQACH TO THE PROBLEM OF OPTIMUM WATER USES ple, wheat. In the case of this crop, there has been no difference in ET (for The agronomic aspect of water use by any given irrigation treatment) between a crop is generally described in terms of the tall and the dwarf varieties (Singh water-use efficiency. Since it is a ratio et al., 1970; Shimshi et al., 1973). It harl'esfable yield . lb' o f C Its va ue can e Ill- means that the higher yields obtained rop ET from a dwarf variety does not necessarily creased either by increasing yield or by require more water. Nor does a short­ decreasing the ET. The "traditional statu red or dwarf variety transpire less approach" seeks to increase the water­ than a tall variety. A more efficient use use efficiency by increasing the yield with of radiant energy, a better conversion of little change, if any, in ET. So if we dry matter into grains, and a continued assume that ET is constant or relatively response to higher fertility levels are all so over the range of management, the set for higher yields and thereby a more defining equation can be written as: efficient water use by a dwarf variety. Water-use efficiency = constant x yield. Some morphological characters are Hence the traditional approach seeks to reported to influence the water-use effi­ increase the water-use efficiency by seek­ ciency. The awned varieties of wheat and ing ways of improving yields. Much of barley perform, in general, better than the information of this kind is given by awnless varieties, possibly because the Pendleton (1965). Emphasis here will awns result in cooler canopies owing to be on some of the important plant and .increased sensible heat transfer. Signi­ cultural factors of immediate practical ficant yield breakthroughs are being concern. sought by changing the shape or morpho­ logy of our crop plants. For example, A. CROP SPECIES AND VARIETIES the daily canopy synthesis is much higher Crops differ in respect of their growing in an erectophile than in a planophile season, root-system, density, spacings, canopy. The optimum leaf-area index height, leaf orientation, reflection coeffi- is between 4 and 7 for erectophile and 2

247 DESERTIFICATION AND ITS CONTROL

for planophilic canopies; so the transpira­ (61 kgjha) and a seed-rate of 75 kg/ha tion efficiency is much greater in the case was 1916 kg/ha. When the nitrogen of an erectophile canopy. Yet far more application and seeding-rate were main­ work is needed to understand clearly the tained at levels appropriate for optimum whole dynamics of soil-water-plant-atmo­ water level (150 kg of Nand 125 kg/ha sphere to predict the water-use efficiency seed), the yield was 3,155 kg/ha. This of crops with contrasting leaf sizes, shapes, essentially lends strong support to the and angles. view that crop yields can be increased greatly by combining the optimal levels of B. AGRONOMIC PRACTICES RELATING TO fertilizer application and seeding-rate with WATER USE short water-supply. ' Time and depth of sowing His study further indicates that when water is a nonlimiting factor water-use The objective in the adjustment of sow­ efficiency in relation to plant density and ing time and depth is to ensure a proper fertilizer application depends on the effect temperature and other physical conditions of these inputs on the yield-ET relation­ of the soil favouraple to seedling emer­ ship. As long as the change in the yield gence, vigour and finally the crop yield. relative to ET is greater, the water-use On a broader scale, such adjustments are efficiency increases. After increasing at a done with a view to shortening the growing diminishing rate up to a point of genetic season, match growth and development maximum, the yield remains constant or either with the rainy season or with a cool decreases, whereas the relative change in period or to avoid cropping in the season ET is gradual up to ETmax. The water­ of the highest ET. Implications of these use efficiency, as a result, attains the maxi­ aspects on yield and water-use efficiency mum value at the point of input use (150 are well known and need not be elaborated. kg ofN and 155 kg/ha of seed in his case) where yield is maximum. The moment the Level of management yield diminishes from its point of maxi­ The management factors have an impor­ mum, the ET still remains ~t ETmax or tant bearing on the efficient use of limited becomes inflated owing to excessive eva­ water. In fact, controversy abounds in poration by frequent irrigation early in agronomic literature regarding the adjust­ the season or at maturity, the water-use ment of fertilizer application and plant efficiency begins to decline. population to suboptimal irrigation water. Contrary to common belief, more ferti­ Some agronomic literature seems to sug­ lizer requires more water, Table 4, how­ gest that when the water-supply is short, eveJ:, shows that a wheat crop twice as the crop.yields·will not be affected greatly large will not require twice as much water. if fertilizer applications and seeding-rates Its ET is about the same or is only slightly are maintained at those appropriate for more. Optimally, a fertilized crop pro­ optimal water availability. Other evi­ duce much higher yield per unit of water dences, on the contrary, suggest the poten­ than a poorly fertilized crop. tially higher yield realization incidental to smaller nitrogen and smaller-seed-rates OPTIMIZATION APPROACH TO THE under suboptimal water availability. USE OF WATER A better knowledge of the interaction There are two basic assumptions in the among fertilizer, water and the seeding­ traditional approach: (1) the complete rate is needed to determine the reasons for avoidance of ET deficit, and (2) additional such divergent responses, now reported. water application for leaching down salts . . A study along these lines by Ram Niwas Having assured that water is a nonlimiting (1975) shows that under suboptimal water­ factor in plant growth, it seeks ways of supply (29 cm in his case), the production improving yield with little change, if any, 'of wheat with a low level of nitrogen in crop ET.

248 OPTIMUM UTILIZATION OF LIMITED WATER SUPPLY

Table 4. Yield Y, ET, and Y/ET of wheat for five short water-supply) an ET deficit within nitrogen application rates. Water and seed-rate fixed at 56 em and 125 kg/ha the limit of tolerance in stage(s) less (Ram Niwas, 1975) sensitive to water and avoid as far as possible, the occurrences of th~ ET deficit during the critical stage. Nitrogen Yield ET Y/ET Ram Niwas (1975) has identified the ---kg/ha-- em kg/cm periods sensitive to water in the life-cycle of the wheat crop. According to him the 0 2,332 60 39 booting or heading stage is most critical 3,984 60 66 in wheat, followed by the period from 61 flowering to grain development, and the 150 4,717 62 76 active tillering stage. An early period of growth is the least sensitive. The ET 239 4,535 62 73 deficit, 10 to 18 % in vegetative stage con­ 300 4,532 65 70 ditions the crop to tolerate 30 to 35 % ET deficit in the critical booting or heading stage. Similarly, the allowable ET deficit The water-use planning in accordance introduced in the booting or heading stage with the doctrine of complete avoidance hardens the crop to tolerate as much as of water deficits and reduction of irrigated 39 % ET deficit during the period from hectare age in short water-supply years for flowering to grain formation. The flower­ fully meeting the water requirements of ing stage in mustard, a week before flower­ each hectare and additional water need ing in sunflower, and the normal peria j for leaching down the salts in water-defi­ of branching and flowering or grain cient region is inadequate. We propose development in safflower are most sensi­ a new water-planning premise which tive to water-supply. assumes that it is possible to apply water For the number and depth of irrigation less than the seasonal ET. No additional to be the least, our optimal irrigation pro­ application of water is necessary for leach­ gramme must be developed with due con­ ing down salts. It assumes that under sideration to all sources of crop water­ conditions of poor-quality irrigation water supply from which ET is derived. We use, the' subsequent rainy season will propose to deal with this point taking the remain one or two seasons fallow, depen­ wheat crop as an example. ding upon the amount of rainfull received As indicated earlier, ET is derived from to leach down the salts accumulated during irrigation, available soil water at planting, the irrigation season. and the growing-season rainfall. Rainfall expectations during the growing season A. OPTIMAL IRRIGATION PROGRAMME of wheat is nil. Only stored soil mois­ To apply a volume of water smaller ture remains to be considered in the opti­ than ET requires that, the loss in yield mal programme. To include the contri­ should be minimal. For that reason, it bution of stored soil moisture to ET in the requires to increase the ET from the least model, it is necessary to determine the number of irrigations and the least depth genetic potentiality of the root-system to of seasonal irrigation, provided the growth­ explore the soil profile and extract water stage effects are controlled. Hence a . from there under unirrigated-plot condi­ quantitative knowledge of the growth­ tions (designated ETbasal). Changes in stage effects on yield is essential. Because the ET basal as well as in the ETmax are once the critical periods in the life-cycles to be expressed as a function of time, so of various crops are identified and sequen­ that the irrigation is optimally timed. The ced in order of relative sensitivity, it would upper limit to water uptake in response be possible to generate an irrigation pro­ to root growth requires that neither the gramme which will impose (warranted by soil depth nor the structure is limiting

249 DESERTIFICATION AND ITS CONTROL to root growth, nor should there be any Furthermore, the optimal irrigation interference by rain or intermittent programme with limited water requires irrigation. a cut in that irrigation which contributes In a large part of the sandy arid plains only a little to the objective functions, ET of Jodhpur, the soils are sufficiently deep deficits, as far as possible, are eliminated (120-150 cm). Being light in texture, at sensitive stages, and some ET'deficits their physical conditions are seldom likely are imposed in stage(s) less sensitive to to limit root growth. The only require­ water. The programme of imposing the ment difficult to meet in this area is the estimate of the upper limit to water up­ 80..------

take from non-irrigated wheat plot, for CRI TILLE RING EAR EMERGENCE over the entire sandy arid belt of Rajas­ than wheat cultivation under unirrigated 70 conditions is not possible. Therefore, a plot was simulated to represent non-irri­ gated wheat by a preplant irrigation to 60 bring profile moisture to field capacity.

The time functions of cumulative ET­ '50 max and ET from available soil water at 63·4 COl ET O£f the time of sowing are combined in Fig. AT MATURITY 6 with a view to showing the importance of ET derived from the stored soil water in meeting the water needs of the crop, reducing the seasonal-irrigation require­ ment, the ET deficit expectations, and to

optimize the irrigation programme in ad­ 20 vance of the season. Fig. 6 shows that the ET from the .available soil water at the time of sowing (from the plot simulated to represent non­ irrigated conditions) continued to meet

the water needs of the crop all through o 20 60 80 100 120 .the season. The peak supply was during SOWING ",ATUR£ the period of tillering to the early booting OAYS AFTER SOW~G Fig. 6. Time functions of cumulative ET max stage. From then on, until maturity, the and ET basal averaged over 1971-73 contribution of ET from profile storage • to quantify ET deficits at various stages was only a fraction of a centimetre. Thus of the wheat the greatest need for ET from irrigation coincided with the peak water-w;e period. ET deficit must remain within the limit The knowledge of ET deficit expectations mentioned earlier, i.e. the tolerance when emergent from time functions of the there has been no prior ET deficit and the cumulative maximum ET and ET derived tolerance due to conditioning by prior from the available soil water at sowing deficit. allowed the development of optimal irri­ Fig. 6 shows that our climate sets up gation programme for wheat. An optimal an ET demand (ETmax) of about 82 irrigation programme is that which reduces cm in a certain time sequence over the the number of irrigations, projects their season. It further shows that the exploi­ dates, and reduces the depths of all-season tation of soil water by root growth into irrigations through a better understanding the profile which was at the field capacity of the open soil-water storage capacity in at the time of sowing resulted in an actual the root-zone when irrigations are applied ET (ETbasal) of 19.0 cm, again in a cer­ apd they are ,terminated timely. tain time sequences. Thus the ET deficit

250 OPTIMUM UTILIZATION OF LIMITED WATER SUPPLY

to be satisfied by an irrigation programme in this case. The water depth infiltered intended to achieve ETmax is 82-19 = during irrigation will be taken to equal 63 cm, and, of course, this deficit also percolation, i.e. the amount of irrigation occurred in a certain time sequence which water that will seep down when the root­ was dictated to by the sequence of ETmax zone is refilled. ETbasal. The optimal programme must The optimization is based on many provide 63 cm of ~T to be derived from assumptions and definitions; therefore, irrigation water, WIth the least number, it may be considered the first approxi­ and with the minimal depth (in the light mation. With the availability of more of the built-on unevenness of water dis­ data, it wiII be extended. At this stage it tribution which characterizes our irriga­ is intended simply to suggest some c~n­ tion method) of irrigation water. Such siderations required for the optimization irrigation, barring the last, must refill the of an irrigation programme when water­ soil profile (to assure ETmax at every supply is limited. point in the field, otherwise the unevenness With these considerations and limita­ of water application would leave some tions, an optimal irrigation programme spots with excess water where it may be has been developed (Ram Niwas, 1975). subjected to loss through deep percola­ Part of the data set forth in Table 5 show tion). The final irrigation may be given how such optimal programme projects at any time the water-storage capacity the number, dates and depths of all­ exceeds the needed depth of water with season irrigation, pinpoints irrigation ter­ which to finish out the season at the ET­ mination, eliminates those units of irri­ max rate. So, though unevenly dis­ gation which are contributing the least tributed, all of the final iirrigation will be to the yield per unit of applied water, stored (storage=irrigation). No residual imposes ET deficit at less sensitive stage moisture remains. (s) of growth, thus offering opportunity Of gross irrigation water depth in storage for the achievement of maximum ET, hence immediately following any irrigation, only the maximum yield, with the least num­ 70 % can be utiliz~d before the actual rate ber and the least depth of irrigation water or ET (ETbasal) wIll fall below the ETmax and reducing yield losses owing to the rate. Additionally, some assumptions limited use of water. As for example, and definitions will be considered in order. irrigation required for the maximum yield The goal of programming irrigations is (5,430 kgjha) of wheat at Jodhpur=84 to increase the yield, or to increase em. The uses of 40 and 20 cm of irriga­ the irrigation efficiency. In optimiza­ tion optimally planned produce 4,724 tion at hand, the irrigation efficiency will and 3,668 kg/ha of wheat respectively. be defined as the percentage of irrigation This means that against 52 and 76 % water used in ET. The open soil-water reduced uses of water, the losses in yield storage capacity within the root-zone at respectively are merely 13 and 32 %. any irrigation will be expressed as irri­ The optimization approach seeks to fulfil gation. It is assumed that the depth of this objective. irrigation water actually stored=the sto­ rage capacity (except the final irrigation). B. CONCEPT OF EXTENSIVE IRRIGATION Thus the irrigation water stored or the The above water-planning philosophy, storage capacity = 1, and the minimum ~ore or less, corroborates the concept depth of irrigation which can refill the of extensive irrigation which seeks to apply root-zone=the storage eapacity+deep a small quantity of water over a large area percolation due to the maldistribution of rather than a large quantity of it over a water. The dispersion of water depths small area. How this new concept of irri­ infiltered during irrigation will be assumed gation will enable considerable increase to be 2 cm of irrigation water, without any in production from the same amount of allowance for runoff, a non-existent factor applied water and provide eventually two

251 DESERTIFICATION AND ITS CONTROL

Table 5. Optimal irrigation programme for wheat 'Kalyansona'

IRR days after IRR Yield Total Season IRR Reduced Eff. reduc- yield water use 21 40 54 68 78 90 100 tion cm % cm % % kg/ha 84 1 nil 72 10·4 11·8 13·2 14 14·9 12 6 75 nil 5,430 ORR max.) 40·0 52 2·5 10 5 10 12 5 87 \3 4,724 (IRR med.) 20·0 76 2·5 5 7·5 5 95 32 3,668 (IRRlow) to three times more rural employment and at the same time for finite water resource opportunity for the distribution of social on a farm. How much area of what crops benefits can be judged from the following be allocated for the maximum gross production figures shown in Table 6. returns from a given level ~f water-supply? Extensive irrigation will mean a smaller What impact will the severe restrictions addition of salts per unit area per irriga­ on fertilizer availability have on gross tion, besides the least chances of salts returns? An attempt has been made to filtering up from the perched brine to the answer such questions of the farmer. surface. Twelve optimum farm plans have been prepared for twelve alternative situations Table 6. Production for a given water quantity arising from a mUltiple of three water­ used over different areas supplies (tube-wells having 2, 4, and 10 thousand gallons/hr discharge) and four Crop Water On area Produc- levels of fertilizer availability, i.e. un­ used (cm) (ha) tion (kg) restricted fertilizer supply (UFS), and 75, 50 and 25 % of it. As seen from the Wheat 84 1 5,500 3 9,100 optimal farm plans shown in Table 7, under all levels of water availability and Hyb. bajra 25 1 4,200 unrestricted use of fertilizer as well as 75 % 4 10,300 of it, the area under wheat, mustard, and Grain sorghum 28 1 4,400. safflower should be respectively 38, 31 and 2.5 6.400 31 %' (mustard=saffiower) of the total Sunflower 50 1 1.600 area that could be commanded by any of 2 2,700 the above tube wells. If the supply of 1 1.100 Mustard 25 1.5 2,000 fertilizer is reduced to half or even less of the unrestricted use, the area under wheat and mustard respectively comes to C. OPTIMAL ALLOCATION OF WATER TO 55 and 45 ~~, safflower being eliminated CROPS from the plan. Sunflower does not find The recommended irrigation practiCes in place in any of the 12 optimum farm plans. respect of each crop may be important in In the final analysis, the input combi­ their own right, but the water allocation nations most optimum for wheat and for the farm unit as a whole confronts the mustard under the optimal farm plan, farmer with the decisions loaded with high when both water and fertilizer constrain prices, product and input variabilities. Sup­ production, will be like the one shown in pose that the crops, e.g. wheat, mustard, Table 8. Further, it has been established sunflower and safflower, are competing that such optimal nitrogen plant-

252 OPTIMUM UTILIZATION OF LIMITED WATER ~UPPLY

Table 7. Optimal allocation of water nearly 2 times better water-use efficiency and the installation cost (the only addi­ Crop % of command area tional expenditure on drip system) pays off in 1 or 2 seasons (Singh and Singh, UFS and 75 % of UFS 1976). Further, 20 to 32 % less yield of Wheat 38 water-melon and round gourd with daily sprinkler irrigation than with drip irri­ Mustard 31 gation shows that on loamy sand in the hot arid belt daily irrigation is advanta­ Safflower 31 geous by using the drip method and not necessarily with a sprinkler. 50% and 25% of UFS The evaluation of the drip method of irrigation with sweet and saline water on Wheat 55 the yield of potatoes and tomatoes has Mustard 45 further shown that for identical yields it requires 50 % less water than furrow irri­ density combination increases yield with gation( Singh et al., 1976). This method a slight increase, if at all, in ET. This of irrigation may, therefore, be a positive observation indicates a reduction in irri­ means of saving 50 % of water in the pro­ gation water required per unit production duction of potatoes. With drip irrigation, and the production of the quantity of saline water of 3,000u mhos/cm is not so the commodity needed with less total water. much a limiting factor in yield but at 10,000 u mhos/em it causes a 91 % reduc­ , Table 8. Optimum farm plan when both water tion in yield of potatoes and only a 35 % and nitrogen constrain production reduction in that of tomatoes. These results are consistent with the relative Crop Water Nitrogen Density sensitivities of the two crops to poor­ quality water. cm kg/ha kg/ha cm Salts are found to be concentrated in the (rowx plant) surface 15-20 cm of the soil at the mid­ point between emitters and towards the Wheat 45 105 125 periphery of the wetted band, with a dis­ Mustard 18 30 40x20 tinct salt-free zone beneath the emitter to the full depth of the soil profile. This accumulation pattern derives importance D. EFFICIENT WATER USE BY DRIP from the fact that salts removed from the IRRIGATION active root-zone accumulated in the sur­ Finite water resource in arid and semi­ face soil at some distance away from the arid region has aroused interest in apply­ plant would be positionally unavailable ing water by a newer irrigation method for causing injury to plants in all those known as the trickle or drip irrigation. areas where the in-season rainfall is non­ The system has shown yields far in excess existent. However, in areas experiencing of what at one time was thought possible the growing-season rainfall, this pattern with conventional irrigation. Compared of salt accumulation would become a ~ith sprinkler per 5-day cycle and furrow matter of serious concern. Obviously. it Irrigation, a 45 to 47 % increase in yield would either impose a limit to the use of on long gourd, 21 to 38 % in that of round brackish water by using the drip method gourd, 10 to 22% in water-melon, and a in areas with the growing-season rainfall, ~it~le yield gain in ridge-gourd with drip or else a package of special management I~ngation indicate that daily drip irriga­ practices will be necessary. hon has a potential to increase the yield The drip method of irrigation has origi­ of most, if not of all, vegetable crops, with nally been designed on the "one plant, one

253 DESERTIFICATION AND ITS CONTROL

dripper concept", i.e. providing a dripper of 0.5, each hectare of cropped area near each plant. Because of this arrange­ receives 23 to 108 mm of runoff as irriga­ ment, the initial cost is high. However, tion water from the catchment in addi­ the cost reduces to half when a 25 cm tion to 117 to 528 mm from direct rain. square or equilateral planting of vegetables The additional low tension water results is integrated into the drip system. In in increasing and stabilizing crop yields, addition, a 50 % saving in water occurs. in lowering the risk of crop failure, in saving inputs of production, and, above IMPROVING EFFICIENCY OF PRECIPITATION all, in making the best of every rain drop that falls on the farm. The stored soil water is converted into Occasionally, the rainfall eXgeeds the ET 100%. Whereas the conversion of profile storage, more frequently in shallow rainfall, a primary source of stored water, sandy-loam soil of the region. When into ET will be closed 200%, provided the water received during the period of sur­ known mechanical measures for runoff plus cannot be stored in the soil profile control, tiIlage technology for higher water for use during the deficient period, at least intake, organic, amendments for water it can be conveyed to a reservoir located retention after it enters the soil, profile somewhere at the lowest point on the stratification with layers that impede catchment and recycled as drought-evad­ drainage, good germplasm and protection ing irrigation. For the requirement of a against insects and disease, adequate nut­ slope, such a practice has a locational feasi­ rient supply, etc. are all integrated into bility near the foothills. However, by the system under consideration. Never­ removing the permeable top soil and sui­ theless, in low-rainfall years, though the tably shaping it, the author proposes the stored water will be converted 100 % into construction of "roaded catchment" on ET, it will not be sufficient for crop con­ the flat surface. The technique will pro­ sumptive requirements; however, so crop vide about 5 to 10 % slope on the "roads" failures and zero rainfall efficiency are for runoff and some 0.5 to 1 % slope for common occurrences in arid and semi­ runoff flow from ditches to the reservoir. arid regions. There are two aspects of this problem. CONCLUSION A sure approach to rectify it is supple­ The problem of a volume of water less mental irrigation. Work by the author than the seasonal crop evapotranspiration shows a rainfall supplement by sprinkling (ET) may be resolved at least in two ways. 25 cm of water over four hectares of hy- First, the "traditional approach" to. the 'brid bajra, and 27.5 cm of water over 2.5 Ilfoblem of efficient water uses. This hectares of grain sorghum resulted in the approach seeks ways of improving crop total production of 10,332 kg of b_ajra yields with little change, if any, in the crop and 6,385 kg of sorghum respectively. ET. Basic assumptions inherent in this Where any supplement to rain was not approach are the replenishment of full made, the crops succumbed to drought ET demand and -the application of addi­ and rainfall efficiency declined to zero. tional water for leaching. An improve­ Another way, presumably. as sure, is ment over this approach is the "optimi­ the runoff concentration that is also irri­ zation approach" which obviates the need gation. A variety of runoff concentra­ for water application for leaching down tion methods have been used by workers salts. In addition, it is possible to apply all over the world. To provide more run­ irrigation water less than the crop ET off as irrigation water by the concept and and simultaneously reduce yield losses method suited to this summer-rainfall by an optimal irrigation-planning that region, an innovative technology has been seeks to impose optimally sequenced ET developed (Singh, 1976; his Fig. 1). From deficits at less sensitive stage(s) and to the catchment to the cultivated-area ratio avoid, as far as possible, the water deficits

254 OPTIMUM UTILIZATION OF LIMITED WATER SUPPLY

at the critical stagy. The optimal pro­ HILLEL, D. 1972. The field water balance and gramme considers all sources of water water-use efficiency. Optimizing the Soil Physical Environment Towards Greater Crop from which ET is derived and thus fulfils Yields (D. Hillel, ed.); p. 95. New York the maximum ET with the least number Academic Press. ' and the least depth of irrigations. Em­ JENSON, M.E. 1972. Programming irrigation for bedded in the "optimization approach" greater efficiency. Optimizing the Soil Physical Environment Towards Greater Crop is the concept of extensive irrigation and Yields (D. Hillel, ed.): pp. 133-161, New a newer method, of irrigation known as the York, Academic Press. drip irrigation. The two have special PENDLETON, J.W. 1965. Increasing water-use promise in squeezing the best out of the efficiency by crop management. Plant Environment and Efficient Water Use (W.H. low total water-supply. Pierre et al., eds.): pp. 236-258. Amer. Soc. Increasing the amount of water storage of Agron. and Soil Sci. Soc. of Amer. Madi­ per unit volume of soil by stratifying the son, Wisconsin. profile with asphalt moisture barrier, and RAM NIWAS, 1975. Yield-water relations, irri­ gation programming, and alIocation of scarce the removal of the non-ET water use by water, for winter cereal and oilseed crops employing the concept of modest irriga­ in arid region of Rajasthan. Ph.D. Thesis tion are other two prongs of water­ submitted to the University of Jodhpur. SmMsHI, D., BIELORAI, H. and MANTELL A. 1973. use optimization strategy. The integra­ Irrigation of field crops. Arid ZO;le Irriga­ tion of insultative mulches "early" in the tion (B. Yaron et al., eds), Ecolgical season, high plant density, adequate Studies, 5: 370-371, Chapman & Hall supply of plant nutrients, and good germ­ Limited London, Springer-Verlag Berlin­ Heidelberg-New York. plasm into these practices will further SHMUEU, E. 1973. Efficient utilization of water brighten the future of the optimization' in irrigation. Arid Zone Irrigation (B. approach in solving the problem of efficient Yaron et al., eds.), Ecological Studies 5: water use in water-deficient regions of the 411-423, Chapman & Hall Limited London, Springer-Verlag Berlin Heidelberg-New world. York. SINGH, N.P., DASTANE, N.G. and YUSUF, M. 1970. REFERENCES Relative performance and evaporation studies in dwarf wheat varieties. Indian J. AMoco MOISTURE BARRIER COMPANY 1971. Pro­ Agron. 15 : 330-334. ductive soil from sand, AMoBar, 910 South SINGH, S.D. 1976. New approaches to use oV Michigan Avenue, Chicago, Illinois 60605. scarce water resources. Transactions Intlifin CHANG, JEN-Hu 1968. Climate and Agriculture­ Soc. of Desert Tech. 1 (1) : 83-87. \ An Ecological Survey. Aldine Publishing SINGH, S. D. and PANJAB SINGH 1976. Drip Company, Chicago. versus conventional irrigation for vegetable CHEEMA, S. S., and MALHOTRA, O.P. 1975. Effect production in hot arid zone. Agron. J. of stored moisture and supplemental irriga­ (communicated). tions on different crops. Seminar on Dry SINGH, S.D., GUPTA, J.P. and PAN}AB SINGH 1976. Farming in Southern Districts of Punjab, Water economy and saline water use by Punjab Agric. Univ., Ludhiana, October drip irrigation. Agron. J. (communicated). 21-22. VIETS, F.G., (Jr) 1965. Increasing water-use HARROLD, L. L.. PETERS, D.B., DREIBELBIS, F.R. efficiency by soil management. Plant and MCGUINNESS, J. L. 1959. Transpiration Environment and Efficient Water Use (W. H. evaluation of corn grown on a plastic­ Pierre et al., eds.), pp. 259-274. Amer. covered Lysimeter. Proc. Soil Sci. Soc. Soc. of Agron. and Soil Sci. Soc. of Arne,.. Amer.23 : 174-178. Madison, Wisconsin.

255 26 ARID HORTICULTURE

o. P.PAREEK

THERE are hardly any orchards in the These crops can be grown, with or with­ arid regions in spite of a great potential out the use of runoff concentration or for fruit-growing . (Pareek, 1975). The with water-conservation systems or both characteristic soil and climatological depending upon the average annual features of these regions are most favour­ rainfall of the region. able for the production of certain fruits The fruit crops having deep root-sys­ and offer conditions for the development tems have the capacity to draw water of a distinct fruit quality (Mann and from the deeper layers of the soil profile Pareek, 1974). These features, however, and would, therefore, be capable of sur­ restrict the choice of fruit crops for such viving droughts. It must be appreciated regions and also necessitate the use of that whereas, on the one hand, desert special growing techniques for their suc­ soils are very poor in water-holding cessful cultivation. capacity, they are also generally shallow and are underlain with a kankar layer of I Selection of crops 70-100 cm thickness at depths varying The rainfall in the hot Indian arid from 10 to 150 cm. Fruit crops capable zone is very low and is confined to the of striking their roots in and through this period from July to September, with 9 layer are, therefore, most adaptable to to 21 rainy days out of 12 to 30 rainy days desert conditions. Roots of Zizyphus in the whole year, resulting both in soil­ rotundifolia rootstock (having Z. maud­ moisture stress and atmospheric water tiana as the scion) penetrated through a stress to the plants after the rainy season. 100.,cm-thick kankar layer (Plate 0). Some After April, the vapour-pressure deficit crops, for example, ber and gOllda (Cordia is more than 24 mb and exceeds 30 mb myxa) , conserve moisture by shedding during May and June. The 'fruit crops their leaves during summer. This is a very selected for cultivation in these regions useful drought-evading mechanism. The must be such that their maximal growth conservation of moisture is also brought period falls during the period of maximum about by certain water-binding chemical wate!! availability in the soil and low constituents in the tissues, resulting in vapour-pressure deficit in the atmosphere. high 'bound water' contents, e.g., in the Ideally, the most part of their reproduc­ case of fig. Other xerophytic leaf charac­ tive cycle, i.e., the period from flowering ters, e.g., a thick cuticle, a coating of wax to fruiting, must also fall during this on the surface, hairiness, sunken and period and the fruit-ripening must be covered stomata, help to minimize t~e ·completed before the onset of the dry loss of water through transpiration. FrUIt summer. Fruit crops, e.g., the ber, pome­ crops, e.g., fig, phalsa, ber and Cordia granate, guava, custard-apple, aonla and myxa have such characters. karonda, conform to this pre-requisite. There is another group of fruit crops

256 ARID HORTICUliTURE

which can be profitably grown in the arid ing, etc. tracts having irrigation facility, e.g., Moisture conservation. The arid­ date-palm, papaya,phalsa, mulberry, cit­ zqne soils are poor in moisture-storage rus fruits (kinnow mandarin, musambi, capacity and dry out quickly. Moisture malta, sour lime and grape fruit), grape conservation through careful manage­ and mango. These crops require dry ment is, therefore, essential for achieving and hot summer for the development of success. The structure less character of good-quality fruits. At present, hardly the surface soil, which often acts as 4,000 ha and 1,000 ha of such orchards are . a mulch, offers a unique opportunity to present, in the arid regions of Rajasthan achieve this object. The surface of the and Gujarat respectively. The cultiva­ soil, therefore, must be kept weed-free. tion of these fruits will become popular Methods of sub-surface irrigation to wherever irrigation facility will come uP. supply water to the root-zones with a view particularly from canals. Date-palm, to avoiding losses of moisture through pomegranate and Cordia myxa can tolerate evaporation and gravitation is more high salinity in irrigation water and, there­ profitable. fore, can form an important component Rainfed fruit production. For rain fed of the crops to be grown under the com­ fruit production the accumulation of, run· mand of a large number of brackish­ off water can be secured to make up the water wells found in these regions. deficit of water requirement. Fortunately. Rocky and gravelly wastelands are in the arid regions, even in light soils very suitable for the systematic planta­ with high infiltration rate, there is a possi­ tions of Capparis decidua (kair), supported bility of concentrating runoff to the extent by cottage-preservation, units. Wild plan­ of 10 to 40 %, depending on the extent tations of this species are already preva­ and pattern of rainfall (Ramakrishna lent on such lIites in the arid zone. and Singh, 1974), which can be much more in the case of slopy lands, hills Special techniques and rocky areas (Abichandani and Yadav. Protection against adverse weather. The 1974). A rational management of the storms cause mechanical damage to the catchment can further increase the run­ fruits and branches, and lead to excessive off yield (Evenari et aT., 1971). transpirational loss of water resulting in The runoff can be used for growing water stress and desiccation. Owing to trees in such a way that each tree has its the sticky nature at ripening, the fruits, own micro-catchment area. The layout e.g., dates are spoiled by sand particles of the micro-catchment in relation to the from the storms. Cold winds also cause location of the tree would depend upon damage. The planting of wind-breaks the topography of the area. On hill and shelter-belts is, therefore, absolutely slopes, or at the foothills, the fruit­ necessary. For a wind break of a large tree will obviously be planted at the area, the double-row planting of the trees' lower end of the catchment. Resear­ of Acacia tortilis, with an internal row of chers in Israel have tried a square basin, Cordia myxa is recommended. For the shaped like a flat truncated pyramid at protection of internal blocks of fruit­ the lowest point in the micro-catchment trees, a single row of closely planted trees for planting fruit-trees. The fruit-trees of either Acacia nilotica var. cupressi-. were planted on 125-1,000 m" catch­ formis or Cordia myxa around the blocks ments. In the plains, however, the catch­ of 1-2 ha is beneficial. ment area may either be all around the Protection against intense radiation can tree or on two sides of it. be secured by selecting plant types with a For determining the size of the micro­ suitable canopy architecture (e.g., Kin­ catchment for a tree species, various now mandarin bearing fruits shaded by factors will have to be kept in view. its well-formed dense foliage), close spac- Every fruit-tree has a water require.

257 DESERTIFICATION AND ITS CONTROL

ment for its optimum production. Indian desert and is an important source This requirement must be met from the of leaf fodder and fuel. The small, round local precipitation and from the runoff fruits have very little edible portion. Z. from the micro-catchment. It also has rotundifolia (bordi) is found wild under its own characteristics·of root depth and conditions of somewhat better rainfall, spread. These factors determine the which produce round and slightly larger volume of the soil profile as a source for fruits than those of Z. nummularia. But water-supply to the roots. The runoff the fruits still have very little pulp as water should be concentrated for sto­ compared with the large stone. The tree, rage in this soil profile. This would also however, is vigorous and upright unlike mean that the runoff from the micro­ the slow-growing and spreading tree of catchment at one incidence of recharge Z. nummularia. Its wood is quite strong should not ordinarily exceed the moisture­ and is of a marginal timber value. The storage capacity. Considering the rain­ fruits are eaten fresh as well as after dry­ fall and catchment characteristics, in ing. A ber (z. mauritialla) cultivar, likadi, addition to the above factors, the size of is popular in certain locations of the Thar the micro-catchment for a fruit-tree desert. Its fruits are oblong, small, can be worked 'out (Mann and Pareek, weighing 6-8 g each, and have lower pulp 1974). Experimental evidence for suggest­ content than its stpne. The fruits in ing a precise plant population per unit green or yellow stage are acrid and become area in a particular system of runoff edible only when they turn red. The pulp concentration (micro-catchment geo­ at this stage has about 28° Brix total solu­ metry) and the most efficient model of ble solids (T.S.S.). Among the improved runoff generation and utilization is, ber cultivars introduced from other regions however, required. of the country, the early-maturing cul­ A good number of varieties of fig, tivars have proved to be the best because almond, plum, olive, pomegranate, pis­ of their bearing synchronising with the tachio, peach, apricot, grapevine, sour and period of maximum availability of natural sweet cherries and apple have been moisture. The cultivars, e.g., Gola, Seb, grown in micro-catchments in Avdat and and Mundia, have proved better in these Shivta highlands under the rainfall pattern regions, although the commercial ber of Israel (Evenari et al., 1971). At Avdat, cultivars of the Punjab and Haryana peaches, apricots, almonds and logan­ States are Umran, Kaithli, Sanaur No.2, berries were most successful, whereas at Sanaur No. 5 and Thornless; of U.P. are Shivta, fig, grapevine, pomegranate, olive Banarasi Karaka, Narma, Banarasi ,and carob succeeded best. In the desert Pewandi, Aliganj, Jogia and Mundia; and plains of India at the Central Arid-Zone Of Rajasthan are Katha and Chomu. Research Institute, Jodhpur, ber (Z. Five-year-old trees of Gala, Mundia and mauritiana) has been grown under various Seb have yielded 50-60 kg of fruit under combinations of catchment size and rainfed conditions, with T.S.S. of 15-18° slope, where the catchment is provided Brix. When irrigated, the yields of 80 on both sides of the tree row. The data to 140 kg per tree have been recorded in on the survival and growth have indicated the case of Gola and Mundia . cultivars that a combination of 54 m2 catchment (Table 1). area per tree with 5 % slope has given At Jodhpur, the flowering in the case of the best results one year after the planta­ ber occurs during August and the fruit tion. starts maturing from the first week of January, i.e. earlier than in other parts Fruits of the arid zone of the country. Ber (Zizyp!Jus mauritiana). It is the most Fruitfly (Carpomyia vesuviana) is a drought-hardy fruit tree. Z. nummularia serious problem in ber cultivation. A (jharberi} is found growing wild in the preventive spray schedule incorporating

258 ARID HORTICULTURE

three sprays of 0.02 per cent Parathion prevalent in this region during the period at three-week intervals starting. (rom the of fruit developm~nt. These climatic fruit-set can, however, completely con-, characteristics cause faster maturity and trol the pest. . result in avoiding fruit spoilage owing to Date-palm (Phoenix dactylifera). The checking and splitting. Date-palm pro­ date-palm cultivation in the Thar Desert duction in the Thar Desert is, however, has considerable promise as compared possible under irrigated conditions. For­ with other regions of India because tunately, the underground water reserves of the sufficient amount of heat-unit accu­ are abundant in this tract. mulation (Table 2) even by the end of The results on the performance para­ June (before the monsoon sets in) and the meters of date-palm under arid conditions high vapour-pressure deficit «25 mb) indicated that the spathe-opening, doka

Table 1. Fruit yield per tree under rainfed and irrigated conditions in the case of some her cultivars

Rainfed Under irrigation Cultivar Age (yr) Yield (kg) Age (yr) Yield (kg) Gola 6 45-50 5 85-110 Mundia 7 55-60 5 80-140 Seb 5 50-55 3 30-45 Jogia 7 45 5 60-80

Table 2. Heat-unit accumulation (above 50°F) at six arid-zone locations

Location March March-April MarCh-May March-June March-July

Jodhpur 1,155 2,314 3,710 4,995 6,196 Bikaner '1,082 2,192 3,664 5,041 6,365 Sriganganagar 992 2,080 3,558 4,901 6,255 Barmer 856 2,029 3,417 4,692 5,885 Jaisalmer 825 1,884 3,207 4,524 5,758 Bhuj (Kutch) 921 2,059 3,287 4,443 5,510

Table 3. Maturity and yield characteristics of some date-palm cultivars in the Thar Desert (7-year-old trees)

Maturity stage Cultivar Yield of Pulp T.S.S. Doka Dang doka (doka) (OBrix) fruits % Doka (kg) Dang

Shamran July 1 July 18 57·1 76·3 24 63 Hillawy June 25 July 7 22·9 88'1 32 67 Khadrawy June 27 July 10 3 8 88'8 36

259 DESERTIFICATION AND ITS CONTROL

formation and dang-formation were com­ October-December) is generalI! grown. pleted during the 3rd to 4th week of The cultivars Mandor (Jodhpur), Saharan­ March, the 4th week of June to the 1st puri and Seedless have been tried (Table week of July and the 1st to 3rd week of 5), of which the first cultivar is commonly July respectively (Table 3). grown. The orchards are generally under Sucker-production by the date culti­ irrigated conditions. vars started four years after planta­ Fruit-cracking is a serious problem. tion. The evaluation of the relative The fluctuating conditions of soil mois­ performance of the date-palm cultivars ture and atmospheric vapour-pressure revealed that Shamran was the best variety deficit, along with the dry and hard nature in respect of growth (Table 4) and fruit of the peel, seem to be 'the prominent yield, whereas Hillawy produced the best­ causes of fruit-cracking. ' quality fruits (Table 3). Under Jodhpur Guava (Psidium guajava). Although conditions, the fruits must be harvested frost susceptible, is very drought-hardy. at the doka stage either for the preparation The orchard is seldom watered after har­ of dry dates (clzllOlzara) or for sale as fresh vesting the fruit in places where water is fruit; if it is a high-rainfall year like 1973 scarce till the advent of the monsoon rains. or 1975. If it i's a dry year, the fruits At Jodhpur, the fruits ripen by the end of may also be harvested at the late dang December. Varieties. Allahabad Safeda stage for the soft-date (pind khajur) pre­ and Lucknow-49 have given the best per­ paration. The ripening of the dates formance with regard to the yield and the on the trees may not be possible under the quality of fruits in the arid zone. prevalent rainfall conditions. Sweet orallge (Citrus sinensis). The Pomegranate (Punica granatum). It is finest quality of Blood Red malta fruits another drought- and salt-tolerant fruit­ are produced under the climatic conditions tree. The variety Mrig bahar (flower­ of Sriganganagar. Recently, Kinnow ing in July and maturing its fruit during mandarin is becoming more popular, as

Table 4. Growth characteristics of some date-palm cultivars (7-year-old trees)

The number of suckers per palm-tree Cultivar Crown height (cm) 1972 1973 1975 Total

Sharnran 115 0·5 5·2 0·7 64 Hillawy: 95 6'0 6'0 12·0 Khadrawy 59 1·6 74 90 I Medjool 46 3·0 1·7 0·7 5·4

Table 5. Fruiting characteristics of some pomegranate cultivars

Cultivars Yield of fruits per Fruit size T.S.S. Acidity tree (g) ,.0';: Mandor 100-250 150 13-16 0·3 Saharanpuri 150-300 180 16-18 0·56 Seedless 150-250 130 16 0·3

260 ARID HORTICULTURE it is more adaptable to arid conditions. gal diseases which limit papaya cultiva­ Out of the four varieties of sweet orange, tion in the humid regions of the country namely Musambi, Jaffa, Navalencia and 'are of a little occurrence in the arid zone. Valencia Late, tried at the CAZRI, Musa­ The papaya fruit develops an excellent mbi gave the best results with regard to flavour under the dry and hot conditions yield (100 fruits per tree) and quality of this region. Many people do not relish (26% juice) of fruits. Musambi-trees the undesirable odour which develops in have, however, started declining ten years the fruits grown under the climatic con­ after planting. The causes are being ditions of other regions. Papaya-grow­ investigated. ing is, therefore, becoming popular in Sour lime (Citrus auranti/olia). At these dry regions, wherever irrigation is Jodhpur, sour lime (Kagzi) has given ex­ available. cellent performance. The yield per tree The commonly grown variety is Honey is about 100 kg, with the juice percentage Dew which gives 30 to 50 kg of fruit per being 30 to 35. Decline in the trees of plant, with a T.S.S. of 12-13° Brix. sour lime has started 10 to 15 years after Other varieties, namely Washington, Bar­ planting. wani Yellow, Co. 1 and Coorg Honey, are At one of the substations of the CAZRI, new introductions into this region. The Samdari, in the Barmer District, Kagzi variety Washington has yielded 40 to 60 lime, grapefruit and Pineapple malta have kg of fruit per plant. given satisfactory performance. Lasoda or gonda (Cordia myxa). It is a Grape (Vitis vinifera). Grape requires drought-tolerant tree which hardly needs dry weather during flowering and fruiting. any irrigation after one year's growth. Rain or humid weather at the time of Flowering takes place in February and the ripening causes the splitting of berries and fruits mature for harvesting in April-May. induces fungus diseases. In the arid The small roundish green fruits are zone, the berries ripen well before the on­ borne in clusters, and have a slimy and set of the monsoon. At Jodhpur, the acrid pulp around a hard stone. The berries of Beauty Seedless mature in the fruits are harvested in the green stage and last week of May and those of Thompson are used for making pickle. The yield Seedle~s in the first week of June. per tree is about 100 to 200 kg. Ripe A large number of varieties of grape fruits are orange yellow when the pulp were tried at Jodhpur. Out of them, becomes more slimy and sweet. The leaves Beauty Seedless has been found to be the are large and coarse and are used for hardiest. Although Thompson Seedless covering the fruits of pomegranate to has given the best-quality fruits, yet it protect them against birds, squirrels and has declined after giving a couple of good dry weather. crops. Vineyards of other varieties, e.g. The other fruits which have performed Anab-e-Shahi, Selection-7, Kandhari well are mulberry, phalsa (Grewia sub­ and Black Prince, though adjudged har­ inequalis), custard-apple and bael (Aegle dier than Thompson Seedless, have also marmelos). declined 6-7 years after planting. An Arid regions, with their irrigated sites, analysis of the reasons of this decline in in particular, are, therefore, the potential fruit production after an initial good per­ foci for meeting the increasing demand of formance has revealed a causal relation­ fruits. Fruit-growing assumes greater im­ ships with (1) pests, such as thrips and portance in view of the need to fight nematodes, (2) diseases, such as anthrac­ against malnutrition prevalent in the n?se and powdery mildew, (3) deficien­ underdeveloped regions of the country. CIes of nitrogen, zinc and manganese and ~4) faults in relation to training and prun­ REFERENCES lng. ABICHANDANI, C. T. and YADAV, .R. C. 1974. Sur­ Papaya (Carica papaya). Viral and fun- face water potential of desert catchments,

261 DESERTIFICATION AND ITS CONTROL

Seminar on DE!sert Technology, CAZRI, Arid Zone 15 (4): 270-284. Jodhpur, August, 30-31. PAREEK, O. P. 1974. Horticulture in the arid EVENARI, M., SHANON, L. and TADMOR, N. 1971. zone ecosystem: fruit-growing. Summer The Negev-the Challenge of a Desert. Institute on Desert Ecosystem and its Improve­ Harvard University Press, Cambridge, ment, CAZRI. October 1974. Massachussetts. PAREEK, O. P. 1975. Horticulture in the land use MANN, H. S. and PAREEK, O. P. 1974. Potential­ pattern of arid zone. Workshop on the ities of growing fruit in the hot arid zone. Problems of the Desert in India, Jaipur, Indian Horticulture, Oct.-Dec. 1974. September 16-18, 1975. MANN, H. S., LAHIRI, A. N. and PAREEK, O. P. RAMAKRISHNA, Y. S. and SINGH, R. P. 1974. Crop 1976. A study on the moisture availability production strategy in the arid zone in rela­ and other conditions of unstabilized dunes tion to rainfall distribution model. Seminar in the context of present land use and the on Desert Technology, CAZRI, Jodhpur, future prospects of diversification. Ann. August 30-31. '

262 27 ' DESERT RODENTS AND THEIR MANAGEMENT /'

ISHWAR PRAKASH

ANIMALS, domesticated as well as wild, agents of soil erosion, as they excavate are known to play an important role in a good deal of soil from their burrows altering the natural conditions in various every now and then. The compact soil, environments. Since the deserts are per­ thus loosened, is kept piled up near the petually threatened scarcity zones, their burrow openings and is carried away by impact on the land and resources is more the strong desert winds. To the crop apparent. The rodents not only deplete fields, the rodents are dangerous only next the vegetation resources, but also some­ to locust. Grasslands in the arid and times alter their composition because of semi-arid regions of India are so much over-utilization from productive to less affected by the presence of a variety of productive and unpalatable species. The rodent species that no serious animal pro­ numbers of rodents fluctuate considerably, ductIOn can be achieved without their seasonally as well as from year to year. management. Thus the rodents are a Depending upon their density in the desert, potent factor responsible for accentuating they have been observed to be serious desertification. Thus communication deals with the Table 1. Percentage distribution of rodents in salient features of the biology of rodents various habitats in the desert biome of of the Indian arid zone (Punjab, Haryana, Rajasthan (after Prakash et at., 1971) Rajasthan and Gujarat) and their management to an economically effective level. Rodent Sandy Gra- Rocky Rude- species velly ral DESERT RODENTS

F.pennanti 14,2 35·8 50'0 Habitat diversity and rodent associations G. n. indus 1000 Eighteen species of rodents occur in the G. gleadowi 56 0 44 0 T. i. indica 28 8 10 0 3 6 57,6 desert zone. Several of them are widely M. hurrianae 60 0 17'0 23 0 distributed in the Rajasthan desert, where­ R. c. cutchicus 100·0 as some are restricted to a particular R. mellada habitat. Among the widely distributed pallidior 37·0 1·6 5 1 56'0 R. gleadowi 66 6 33 3 rodent species are Ftmambulus pennanti, M. musculus ]00,0 Tatera indica, Meriones /turriallae, Rattus N. b. booduga 100'0 me/tada pallidior, Mus platythrix sadhu M. cervicolor and Golunda ellioti gujerati. These are ssp. ]00 0 M. c. phillips; 100·0 found in more than two habitat types M,p.sadhu 28 0 133 53·3 13'3 (Table 1). G. e. gujerati 25 0 ]2 5 62'5 The Indian Gerbil, Tatera indica indica and Rattus me/tada pallidior ar:e associated

263 DESERTIFICATION AND ITS CONTROL

in the crop fields on the outskirts of villa­ in the soil was relatively high and the soil ges. In the northernmost district of the had a higher permeability for the seepage desert, the mole rat, Nesokia indica, is also of water (Table 2). About 40 years ago, found with them. In the south-eastern when there were no canals in the Sri­ desert, Tatera-R. me/tada association is ganganagar district and the country had joined by Go/unda e. gujerati. rolling sand-dunes, the predominant rodent In the irrigated fields in the Punjab and fauna consisted of Gerbil/us gleadowi Haryana States, Rattus meltada and Mus and Meriones hurrianae. With the com­ spp. are most predominant. Bandicota ing of the Ganga Canal, the soil texture bengaiellsis, Tatera indica and Nesokia of the region changed and it became more indica are also common. In Gujarat, clayey and Meriones hurrianae .has since however, the species composition of rodents been replaced by Nesokia indica indica, is more or less like that in the Rajasthan which, it is speculated, mirgrated into the desert. district along with the canal system and has now finally established itself in the Relative abundance in relation to canal-irrigated crop fields. edaphic factors With regard to the ecological distribu­ Table 2. Density of Meriones hurrianae in different bioclimatic zones of the tion of rodents, three major soil types have IQ.dian desert been recognized, viz. dune soils, desert soils, and red and yellow soils in the desert laisalmer- Palsana­ Barmer­ (Prakash et al., 1971). The first type of Chandan Lachh- Gadra soils generally occur in the Barmer, Jaisal­ tract mangarh Road mer, Bikaner, ChuTU and Jhunjhunu dis­ tract tract tricts. Gerbillus gleadowi is the commonest rodent found in the dune soils (Prakash Average annual and Rana, 1973). Desert soils are usually number of M. found in the inter-dunal regions and in the hurrianae per 90 sandy plains. These soils are spread all x 90mplot 31 247 458 over the desert region, where M. hurrianae Percentage of and Tatera indica are commonest, parti­ clay in the soil 5.3 4.5 3.1 cularly in parts of the Pali, Jodhpur, Nagaur and Bikaner districts. The red and yellow Permeability glhr 0·8081 0·3485 0·1622 soils are found along the foothills of the Aravalli ranges and are mainly represented Population fluctuations ,in the southern parts of the Pali, Sirohi, and Jalore districts. Golunda ellioti' guje­ • The seasonal variations in the numbers rati, 'Mus platythrix sadhu and Rattus of various species of rodents of the Rajas­ meltada pallidior are mqre commonly than desert have been studied in some found in such types of soils. To some ex­ detail (Prakash, 1975 a,b). Among the tent, R. m. paIlidior and Mus b. booduga field rodents, the peaks in density differ are associated with the soils which are from season to season. On an overall irrigated from wells, and Nesokia indica basis, the density of most species is lowest indica with soils irrigated with ground­ during the summer months and tends to water (in the Sriganganagar . district). increase after the rainy season. In saline soils, Meriones hurrianae and Behaviour patterns Tatera indica are common. During a quantitative study of the den­ Locomotion: Almost all the desert ro­ sity of the Indian desert gerbil, Meriones dents are good climbers. Those belonging hurrianae (Prakash et al., 1971), it was to M. hurrianae have been observed on revealed that their average annual number Capparis decidua shrubs for feeding upon tended to, be low, where the clay percentage its ripe fruits, and on Acacia tortilis, Pro-

264 RODENTS AND THEIR MANAGEMENT

sopis cineraria and Albizzia lebbek for out the day, beginning their activity late debarking them. Rattus c. cutchicus, a in the morning and ceasing it early in the crevice-dweller, feeds on the flowers of. evening (Prakash, 1962). This shifting Euphorbia caducifolia, a thorny shrub,' activity pattern in rodents is probably an 2 to 4 metres tall. The flowers are usually indication of adaptation to withstand ex­ lodged on the apical portions of the shrub. tremes of desert temperature. The palm squirrel, Funambulus pennanti, Territoriality: None of the rodents found is arboreal. Rattus rattus and Mus mus­ in the Indian desert is territorial in the culus, usually found commensal with man, strict sense. The individual home ranges are also excellent climbers. of all the rodents studied overlap one Activity pattern : Quantitative studies another, clearly suggesting that they do on the activity pattern of most of the not defend their entire ranges. Field rodents are wanting. The psammophile observations indicate, however, that the gerbils, Gerbil/us species, venture out of palm squirrels show territorial behaviour their burrows at dusk during summer when they are on the branches of the trees and continue to be active throughout the or near the crevices where they take shelter night and cease their outside activity before in their nests. At feeding time, as many as dawn. 15 squirrels have, however, been observed The crevice-dweller and nocturnal Rattus in a small space of about 5 mi. During e. cutchicus also, probably, behaves like the mating season as well, 4-5 male suitors Tatera indica indica, some quantitative chase and surround a single female. No data about the activity pattern of which sooner is one of them accepted than the are available with us. In a particular others wait for their turn, as the female street in the Bikaner. Town, the Indian ger­ palm squirrels are promiscuous in their bils were counted during summer and win­ mating habit and a female mates with 2-4 ter at every hour at night. During sum­ males during one oestrus. mer, the gerbils ventured out late at about In the case of Meriones hurrianae, al­ 22 hours and the peak numbers were seen most a similar situation has been observed at 23 hours and the activity gradually (Fitzwater and Prakash, 1969). Intra- and declined till 05 hours. During winter, intersexual fights and chasing were obser­ however, the peak activity reached early ved quite often. After a few chases, during the night and started declining however, they tolerate one another and quickly after 2400 hours, presumably a spend most of the time in foraging. How­ behavioural shift to shun very cold nights. ever, they are liable to resent too close an The diurnal rodents are also not active intrusion upon one another's vicinity and throughout the day. The palm squirrel, start throwing dirt at one another with during summer, climbs up the trees and their hind feet. This behavioural trait of passes the hottest period in a state of inac­ throwing dirt* on other members of the tivity. It i~ active during the morning and species is perhaps indicative of territorial during the late evening when it is cool. A behaviour among gerbils. The gerbils similar behaviour is observed in the case start digging on sighting another member of the desert gerbils, Meriones hurrianae, of the species too close, and it, usually, which were observed in a quadrat during quickly retreats. This signal also indi­ summer and winter. The desert gerbils cates a sort of threat behaviour. It ap­ move out of their burrows early in the pears that desert gerbils adjust themselves morning and cease their activity by 11 to the presence of one another by main­ a.m. During this period also, they visit taining a distance ranging from two to their burrows frequently and are not four metres. The defence of territory is out for a long time. They venture out again in the evening and many of them can * Meriones and Tatera throw dirt on the chas­ be seen up to 6-7 p.m. whereas during ing snakes, hedgehogs and large spiders, probably winter they remain outside almost through- as a means to divert these enemies.

265 DESERTIFICATION "'ND ITS CONTROL

initiated only when another member tries the ground. No sooner do the wing beats to cross these limits. They only protect of predatory birds make the colony 'duck' the immediate vicinity of the burrow open­ inside the burrows, than the desert gerbils ings which they use more frequently. perform drumming from inside the burrows. The nocturnal gerbil, Gerbil/us nan us This drumming is not produced whilea ger­ indus, quite often lives in the burrows of bil is chased by another of the same species. the diurnal M. hurrianae over sandy plains. During mating also, thumping is done by It seldom stays with T. indica which is the male, presumably to warn other ger­ more aggressive species and is also noc­ bils in the surrounding area. l;his thum­ turnal. Their interrelationship inside the ping lasts for 0.3 second, on an average. burrows is not known. In the laboratory There are evidences to suggest that the cages, M. hurrianae and G.n. indus, when auditory faculty in this desert rodent is maintained together, seldom fight, but much more efficient than the visual one. T. indica indica gives them a hard time Contrary to the conjecture that their and usually kills them. preception of sound travelling through the Communication, visllal: The eyes of T. solid soil medium is stronger, we also indica indica are larger than those of other observed (Fitzwater and Prakash, 1969) desert rodents, but its vision is not very that the noise of the wing-beats of the good as was evidenced by our field ob­ predatory birds, pariah kites (Milvus serva.tions made during nights in dim light. migrans), shikra (Astur badius), tawny But the squirrel, F. pennanti, appears to eagle (Aqila rapax) and the house crow have an excellent eyesight. Our knowledge (Corvus splendens) are quickly preceived of the visual aspects of nocturnal rodents by the merion gerbil. Interestingly, is limited. However, observations in however, the sound of the wing-beats large cages indicate that all can see very of babblers (Turdoides spp.), which afe well during the day. Therefore the visual not predatory, never disturb them. It communications should play an impor­ may indicate that the desert gerbils can tant role, at least for a short distance. possibly differentiate between the wing­ Auditory. The squirrel, F. pennanti, is beat noises of harmless and predatory very vocal and has several notes signifying birds. This specialized differentiation different signals. Its alarm call is more may be achieved owing to the hypertro­ often produced while defending the young phi sed tympanic bullae. The length of in the nest. This squeak is usually accom­ the tympanic bulla of AI. hurrianae is panied with a jerk of the tail. No sooner 35.4% of the condylobassal length of the does one squirrel emit these shrill calls skull and this condition indicates that their than all the squirrels in the near vicinity typanic bullae are enlarged (as compared join .the chorus. Tatera indica, Meriones with those of rodent species inhabiting /zurrianae also squeak when they are trap­ humid climate) and probably help the ped. When they are handled, they some­ gerbils to detect and differentiate various times emit a long shrill call, but it is not types of sounds. It has also been sugges­ so loud as that of the squirrel. Rattus ted that this hypertrophy of the tympanic rattus also squeaks when handled, but bullae helps to resonate and amplify the whether it is meant for communicating sound for enhancing preception. The the danger to others or it is a distress call hypertrophy of the tympanic bullae is is not definitely known. . regarded to be an adaptation to the in­ Drumming: The desert gerbil, M. lzurri­ creased perceptibility of the mating call anae, thumps on the sand, under several and the sounds of movements of snakes situations, almost invariably signifying and predatory birds. da~er and it is, thus, regarded as an alarm On the basis of these ecological and signal. The thumping noise or drumming ethological studies, we have based all our is produced repeatedly and with great strategies of control operations. Most speed by striking one of the hind feet on of these strategies have been incorporated

266 RODENTS AND THEIR MANAGEMENT

into the National Programme for Rodent cracked grains 97 parts and vegetable oil Pest Management. 3 parts in the form of 19 balls or lumps, 6 g per active burrow opening) done on LOSSES INFLICTED BY RODENTS the first and third day. On the fifth day, Owing to scanty rainfall and other 2 % zinc phosphide is added and the baits climatic adversities in the arid zone, crop are distributed. This operation will take production and the survival of a substan­ care of 70 to 80 % of the population of tial vegetative cover are rather difficult. the field rodents. The residual population The unduly dense population of field cannot be tackled by poisoning with zinc rodents in the Indian desert further lowers phosphide, as most of the rodent species the possibilities of enhancing the produc­ develop poison and bait shyness after tivity of the arid-lands. a single exposure to this toxic chemical. The natural desert vegetation has gra­ The residual population should be con­ dually changed from highly palatable and trolled by fumigating the burrows. On nutritious perennial grasses to inedible the sixth or seventh day, all burrow open­ annual weeds because of rodent depreda­ ings are closed. On the eighth day in tions assisted by the process of overgrazing reopened burrows, tablets of aluminium by livestock (Prakash, 1976). The losses phosphide are put at the rate of 1.5 g caused by rodents to grasses have been per active burrow opening. This opera­ extensively studied and it has been found tion will control the residual population that unless the rodents are controlled, of the rodents and must be taken up at the chances of range improvement the beginning of the kharif and rabi sea­ are only feeble. To standing crops sons. also-both k,harif and rabi-damages are Residential premises and godowns: On substantial. The attack of rodents on the first day, the volunteers should collect the bajra crop in western Rajasthan dur­ 1 kg of food material representing the bait ing 1973 and on groundnut in Saurashtra requirement from each household for during 1976 was severe. Rodents, Tatera fields as well as for houses. They should indica and Rattus meltada, damage the visit individual houses in a village and gram, wheat and sarson crops also. They predetermine the places where baits are damage irrigation channels, dams, soil­ to be placed. An assessment of the total conservation furrows and are potential and daily requirements of the bait the agents of soil erosion (Fitzwater and poison and the manpower required should Prakash, 1973; Barnett and Prakash, also be made. To prepare the bait mate­ 1975; Prakash and Ghosh, 1975; Prakash, rial, the collected cereals will be crushed 1976). and 5 % master mix (0.5%) concentrate of an anticoagulant (Warfarin) will be THE CONTROL STRATEGY mixed and kept ready for distribution. A large number of toxicants and anti­ On the second day, the bait will be placed coagulants have been evaluated by us at in suitable containers, such as broken pit­ the CAZRI for assessing their efficacy chers, mud channels, coconut shells and in the control of the predominant rodent bamboos. In each house, the bait will be species, occurring in the Indian desert placed at 2-4 points with about 300 g of and extensive experiments have been it per house and the baiting should con­ carried out to find suitable baits· for them. tinue for three weeks. The dead rats On the basis of such results, the control should be collected and buried. This strategy has been outlined as follows. operation must be repeated once in six Crop fields and threshing-yards : As far months to keep the village comparatively as possible, rodent-control operations rodent-free. should be taken up before the sowing of This method will bring down the popu­ crops. The active burrows are to be sur­ lation of the house rat, Rattus rattus, to veyed and pre-baiting (cereal-flour of a very low level, hut some house mice.

267 DESERTIFICATION AND ITS CONTROL

Mus musculus, will survive and to control FITZWATER, W. D. and PRAKASH, I. 1973. Hand­ which, regular trapping should be carried book of Vertebrate Pest Control. ICAR, New out by the villagers. Various principles Delhi, pp. 1-92. of rodent control have been discussed in PRAKASH, ISHWAR 1962. Ecology of gerbils of the Rajasthan Desert, "India. Mammalia 26 ; detail elsewhere (Barnett and Prakash, 311-31. 1975; Prakash, 1976). PRAKASH, I. 1975a. The ecology and zoogeo­ SUMMARY graphy of mammals, Chapter XIX in: En­ viroll/nental Analysis oj the Thar Desert. Rodents are a serious pest all over the R.K. Gupta and Ishwar Prakash, English country and especially in the desert biome. Book Depot, Dehradun. pp. 468-80. Their preponderance, relationship with PRAKASH, I. 1975b. Population - ecology of habitats and edaphic factors, population rodents in the Rajasthan desert, India. fluctuations and behaviour in the Indian Chapter V in: Rodents ill Desert Environments (by I. Prakash and P.K. Ghosh), Dr W. desert have been discussed. The losses Junk Publishers, Thc Hague, the Nether­ caused by them to the crop fields, thre­ lands, pp. 75-186. shing-yards, residential premises and stored PRAKASH, I. 1976. Rodent Pest Management­ foodgrains have been outlined. Proven Principles and Practices. Monograph No.4. control strategies have been described. CAZRI,1-28. PRAKASH, I., GUPTA, R.K., JAIN, A. P., RANA. REFERENCES B. D. and DUTTA, B. K. 1971. Ecological BARNETT, S. A. and PRAKASH, 1. 1975. Rodents evaluation of rodent population in the of Economic Importance ill Illdia. Arnold­ desert biome of Rajasthan. Mammalia 3S : Heinemann, New Delhi & London. pp. 384-423. 1-175. FITZWATER, W. D. and PRAKASH, ISHWAR 1969. PRAKASH, I. and RANA, B. D. 1973. A study of Burrows, behaviour and horne range of the field population of rodents in the Indian Indian Desert Gerbil. Meriones hurrianae desert. III. Sand-dunes in 100-mm rainfall Jerdon. Mammalia 33 ; 598-606. zone. Z. angew. Zool. 60; 31-41.

268 28' INSECT PESTS AND THEIR CONTROL

K. S. KUSHWAHA AND S. K. PAL

FARMERS in the arid zone need to adopt tissue-borers which have become endemic, an ecodevelopment-orientated programme the major pests of the region have been of animal and crop production under listed along with their chemical control, conditions of natural rainfall, not exceed­ based on an easy access of the cultivator ing 300-400 mm annually, as the major to the commercial insecticidal products source of water. During a few showers (Table 1). In the case of bajra, the type in the arid zone of Rajasthan, which forms of damage and the incidence of pests have a part of the great Indian desert, the been categorized as (i) leaf damage due people gamble with agriculture by throw­ to grasshoppers, caterpillars and beetles, ing seeds of bajra on the sand-dunes, (ii) the presence of deadhearts, (iii) the hoping to harvest the crop after the rains. incidence of the shoot bug, Perigrinus Occasionally, they get a good crop, but maidis Ash., and the earhead caterpillar, failure is the normal rule. Bublemma silicula Swinhoe, to assess the Ninety-three per cent of the area under extent of damage caused by the popula­ coarse grains (20-25 % of the total food­ tion in each case. Since 1968, the inci­ grains) and 91 per cent of the area under dence of Pyrilla perpusil/a Walk. has unu­ pulses (9-11 % of the total food pro­ sually been recorded in the case of bajra, duction) is dependent upon rainfall. The jowar and maize. Searching for the sour­ coarse grains and pulses together cover ces of resistance in the germplasms is an about 50 per cent of the total area under important current approach in breeding foodgrains, but they account for merely crop varieties, but the factor complicating 33 per cent of the total production. As this problem in the unirrigated areas is such, production and protection research that the insect fauna tends towards poly­ on coarse grains and pulses must be in­ phagy (Pradhan and Pant, 1970). How­ tensified. ever, the screening of bajra varieties for resistance to white grub at Tabiji Farm PROBLEMS AND PROSPECTS (Rajasthan) indicated the possibility of To highlight the vagaries of pestilence getting certain lines which may show some under the cropping pattern of the arid type of resistance in the world germ plasm and semi-arid zones, the major pests. of bajra to this pest. infesting the traditional and some new In the case of sorghum, the germplasms crop introductions to supplement the have been studied for resistance to three deficiency in terms of remunerative returns major pests, viz. the sorghum stem-borer, are discussed in this paper. Chilo partellus (Swinhoe), the shootfly, Atherigona varia soccata Rand. and the GENERAL PESTS sorghum midge, Contarinia sorghicola Coarse grains. Generally, the sporadic Coq. (Anonymous, 1971). epidemics of different pests,. except the The timely use of insecticides can reduce

269 DESERTIFICATION AND ITS CONTROL

Table 1. Insect pests of bajra, sorghum and maize

Pest species (family) according to sequence of Control measures incidence

Termites (Termitidae); Odontotermes obesus Aldrin or heptachlor (5 %) or BHC (10%) dust Ramb.; Microtermes anandi Holmg. @ 25 kg/ha to be incorporated into soil about 15 cm deep , White grub (Melolanthinae); Holotrichia con.ran­ Phorate (10 G) or thiodemeton(5 %) or lindane guinea Bl.; H. serrta Fabr.; H. insularis Hrenske (6 %)@ 20 kg/ha mixed with the soil. (For con­ Anomala bengalensis HI. trollIng beetles, use mechanica\-cum-chemical method, vide text) Sorghum shootfiy (Anthomyidae); Atherigona varia Seed treatment with carbofuran (50 WP) @ soccata Rond.; Bajra shootfiy, A. approximata 60-100 g(kg (or a pre-sowing soil application Malloch. of phorate or thiodemeton granules @ 20 kg/ha, 40 kg(ha respectively) Grasshoppers (Acridiidae); Chrotogonus trachyp­ BHC (5 %) dust @ 25 kg(ha terus HI.; Hieroglyphus nigrorepletus Bol.; Oxya ebneri Will. . Shoot-borers; Chilo partellus (Swinh) (pyralidae); Endosulfan (4 G) or carbaryl (4 G) or lindane Sesamia inferens (Walk.) (Noctuidae). (2 G) or quinalphos. (5 G) three times @ 5 O. 7· 5 and 10 0 kg/ha, after 20, 30 and 40 days of germination Hairy caterpillars (Arctiidae); Amsacta moore; Endosulfan (4 %) or carbaryl (5 %) dust @ 15-20 Butl.; A. afbistriga Walk.; A.lineola Fabr. kg/ha Armyworm (Noctuidae); Mythimna separata Walk.; BHC (5 %) or carbaryl (5 %) dust @ 20-25 kg(ha Grey weevil (CurcuIionidae). ; Mylfocerus maculo­ or carbaryl 0 1 % or endosulfan 0'075% spray sus Desb. Phosphamidon or dimethoate O' 03 % or methyl Aphid (Aphididae); Rhopa/osiphum maidis Fitch. demeton 0 025 % spray Endosulfan 0 05 % or carbaryl 0·1 % or lindane Sorghum midge (Cecidomyiidae): Contayinia sor­ 0·1 % or malathion 0 ·03 % spray (or endosulfan ghicola Coq.; Earhead bug (Miridae) Calocoris 4 % or carbaryl 10% dust @ 12 kg(ha) after angustatus Leth. 90 per cent earhead emergence; repeat 4-5 days after the first application

the loss to the extent of 54.91, 50.26 and The shoot-fly remains active through­ 61.15 per cent on account of A. soccata, out the year, but has low threshold activity C. partellus and C. sorghicola respectively. during the first week of July, as evinced But while working out the cost-benefit by the low percentage of deadhearts. In ratio, the cost of control measures would _ case, therefore, this period is adhered to involve ail outlay of Rs 370 to 440 per as a normal time of sowing, the infesta­ hectare, depending on two or three appli­ tion is avoided to a considerable degree. cations of carbofuran and endosulfan. On the other hand, the delayed sowing This high cost of insecticides, added to increases it to a great extent. The early the cost of application on account of sowing ensures the protection of the crop labour, besides the cost of cultivation, is against shoot-fly without any chemical evidently beyond the means. of an average control. Additionally, the infestation of cultivator. The circumstances) consider­ the crop with the midge, which appears ing the spending capacity of the cultivator, by the end of September, is also avoided make it incumbent upon researchers to because the grains mature and, conse­ explore cheaper methods of avoiding the quently, no injury can be expected in such depredations of these pests. Conse­ an early crop. In sequence of the inte­ quently, the alternative methods of pest grated approach, the insecticidal con­ management have been investigated, in­ trol is needed for the stem-borer alone. volving a more judicious use of insectici­ As such, the two or three applications of des to supplement the cultural methods. endosulfan (granules) would achieve the

270 INSECT PESTS AND THEIR CONTROL

control of the borer effectively at a mere saic of cowpea (Vigna sinensis SavL). The cost of Rs 87 to 156 per hectare instead granular systemic insecticides applied to of Rs 370 to 440. the seed furrows have proved quite effec­ In the case of maize, the germplasms, tive. Table 2 shows the pesticides found have been screened for resistance to the useful against the common pests of pulse borer, C. partellus (Mathur and Jain, crops. 1972). Besides the adjustment of the Oi/seeds. A major contribution has date of sowing, the disposal of stu bble been made to the knowledge of the pests after harvesting the crop is an important of oilseed crops in India and their control­ practice worth adopting. The ploughing (Rai, 1976). The major pests recorded down of stubble reduces the borer attack on various crops cultivated in Rajasthan, substantially. The larvae hibernating in together with the insecticides commonly the stubble are a source of infestation for recommended to control them, are presen­ the next crop and should be destroyed ted in Table 3. in situ. Hence cultural operations, viz. the Forage crops and pasture. Significant early and timely sowing and the plough­ advances have been made in the field of ing down of stubble make it possible to forage and pasture pests under an ICAR avoid the shoot-fly and midge infestations Project 'Investigations on Forage and without entailing high costs to control Pasture Insect Pests of Rajasthan' (Kush­ them. waha and Bhardwaj, 1977). Pests of the Pulses. Pulses, as a group, are more desert grasses have been studied by Pal drought-resistant than cereals and, hence, (1975). have found a niche in the cropping pattern characterized . by moisture stress. Of PESTS OF SPECIAL ECONOMIC these, gram is the major crop in terms of IMPORTANCE hectares and production. Timing the use White grubs. The polyphagous white of insecticidal measures, particularly grub or leaf-chafer species, the major against the pod borer, Helicoverpa armi­ being Holotrichia cOllsanguinea Blanchard gera (Hubn.), just when the first pods have (Scarabaeidae: Melolonthinae), has pro­ been formed is most important, but the ved to be the deadliest pest threatening treatment may have to be repeated after the entire crop production, nullifying the three weeks. It may be mentioned that gains of high-yielding-variety programme th~ whitefly, Bemisia tabaci Genn., trans­ in the arid and semi-arid zones. The mits the yellow mosaic of green gram crops worst affected by the underground (mung, Phaseolus aureus Roxb.) and moth grub infestation are bajra, groundnut, (P. aconitifolius Jacq.) whereas the aphid, sorghum, maize, kharif pulses and chillies. Aphis craccivora Koch., transmits the mo- The beetles crawl out of their subterranean

Table 2. Insect pests of pulses (green-gram, moth, gram, cowpea)

Pest species (family according to sequence ofinci­ Control measures dence) White grub and termite spp. Cutworms (Noctui­ Vide Table 1 dae) Agrotis ipsilon Hugnagel, A. spinijera Hub­ Aldrin or heptachlor 5 % dust @ 25 kg/ha ner Galerucid beetle (Galerucidae), Madurasia BHC 5 % or carbaryl 5 % dust @ 20-25 kg(ha obscurel/a Jacoby Green Jassid (Jassidae), Amrasca kern D. Vide Table 3 Hairy caterpillars (Arctiidae), Amsacta moorei Vide Table 1 ButL, Diacrisia obliqua Walk. Caterpillars (Noctuidae), Plusia orichalcea Fabr, BHC 5 %, carbaryl 5 % dust @ 20-25 .kg/ha P. nigrisigna Walk. Anticarsia irrorata Fa br. Laphygma exigua Hubn.

271 DESERTIFICATION AND ITS CONTROL

Table 3. Insect pests of oilseed crops

Pest species (family) according to sequence of inci­ Control measures dence

Mustard, Brassica campestris Mustard sawfly Seed treatment with lindane and phorate (Tenthredinida) Athalia proxima Klug. @ 2· 5 kg and 1 ·0 kg/lOO kg of seed Mustard aphid (Aphididae) Lipaphis erysimi Spray malathion 0'05% (Kalt.) Painted bug (Pentatomidae) Bagrada cruciferarum Phosphamidon 0 '03 % Kirk. Leaf-miner (Agromyzidae), Phytomyza atricornis Methyl demeton O' 03 % Meigen. Dimethoate 0'08%; CarbaryI0'2% Til, Sesamum indicum: Til caterpillar (Pyralidae) Carbaryl O· 1 ~ Antigastra catalaunalis (Dupon) Til hawk moth (Sphingidae) Acherontia styx BRC 5% dust Westw. Castor, Ricinus communis Castor semilooper Carbaryl O· 1 % (Noctuidae), Achaea janata Linn. Hairy caterpillar (Lymantriidae) Euproctis lunata BRC 10% dust Walk. • Castor mite (Tetranychidae), Tetranychus telarius Phosphamidon 0 ·03 % Linn. Castor capsule-borer (pyralidae) Dichocroces Malathion 0·1 % punctiferalis Guen. Groundnut (Arachis hypogaea) Termite Odonoto­ Vide Table 1 termes obesus; White grup H%trichia consanguinea Amsacta moorei Safllower (Carthamus tinctorius) Safilower aphid Methyl demeton 0'03% (Aphididae) Uroleucon (Uromelan) compositae Dimethoate 0·03 % Theob. Sunflower (Helianthus annus Aphid) (Aphididae) Vide Table 1 Brachycaudus helichrysi (Kalt.) Aphis gossypii Glov. Jassids (Jassidae) Distantasca terminalis (Dist.) Phosphamidon O· 03 % Empoasca Iybica deG., E. motti, Pruthi, Amrasca sp. Whitefly (Aleurodidae) Bemisia tabaciGen. Dimethoate O' 03 %

abodes immediately after the first pre­ soil by about 4.30 a.m. After feeding monsoon or monsoon shower, ·between for sometime, they start mating when they 7.30 and 8.00 p.m. and congregate on become sluggish. Then, they can be their host plants in large numbers. This jerked down from the trees in large num­ is the most vulnerable stage of the pest bers and killed by drowning them in kero­ and the most appropriate time for adopt­ senized water. Their host plants can also ing large-scale control oper.ations. be kept sprayed before the emergence of A wide-ranging recommendations have the insects, with 0.2% carbaryl (50 WP) been made on the chemical control of or 0.05 % monocrotophos (40 EC). grubs and beetles under Rajasthan condi­ Termites. Investigations by Roonwal tions (Kaul et al., 1966; Rai et al., 1969; and co-workers have made a major contri­ Pal and Doval, 1970; Sharma and Shinde, bution to the faunal composition and eco­ 1970; Pal, 1972; Sachan and Pal, logy of termites in the desert area, cul­ 1976). Phorate (10 G) at the rate of minating in a monograph Termite Fauna 1. 0-1. 5 kg a.i. per hectare is commonly of Rajasthan, India (Roonwal and Bose, recommended for application to the soil. 1964). Of the 32 termite species known Additionally, a strategy for adoption on from Rajasthan, 25 occur ,in the desert community basis is to attack the adults portion. Kushwaha (1972) studied the while they are congregating for feeding pest aspects of four species of termites in . during the night before their retreat to the Rajasthan, and discussed their damage t(}

272 INSECT PESTS AND THEIR CONTROL fruit-trees and pastures. T~rmite manage­ succulent branches are cut, but the damage ment needs greater attention in view of varies from variety to variety; more woody their attack on pulses, cereals and forest­ ~arieties are damaged less. Peculiarly, trees in the desert agro-ecosystem. How­ they destroy many more plants than they ever, their control under complex sub­ actually co_nsume. terranean habitation is by no means easy .. Four generations occur in the plains. The common species infesting the various It is speculated that they are regular crops (Tables 1, 2 and 3) and the forest migrants from the plains to the hills at the plantations of shisham (Dalbergia latifolia) end of spring, and return to the plains at were protected by the application of aldrin the end of autumn. But it is possible that and heptachlor up to two years. certain species undergo aestivation or Grasshoppers and locusts. Pradhan breeding in remote situations to a limited and Peswani (1961) estimated that the extent on some unknown weeds during 'phadka' grasshopper. Hieroglyphus nig­ this critical summer duration. Imma­ rorepletus Bolivar, individually consumed ture stages are susceptible to direct sun. on an average 42 grammes of green foliage of maize (Zea mays L.) during its lifetime, INSECTICIDE RESIDUES and thus the loss calculated was 18 per cent, The safe limits of malathion and car­ presuming that during normal years at baryl on lucerne and cowpea necessitated Delhi, the population in the maize fields the determination of residues. Malathion goes up to 10 per square yard. reached the below-tolerance limits in 1-6 Roonwal's (1945, 1953) hypothesis for days on lucerne (Amin et al., 1970), where­ the prediction of swarming in the case of as carbaryl became dissipated below the the desert locust, and discourses by Uvarov tolerance limits in 3-5 days on cowpea (Sri­ on new evolutionary effect are significant vastava and Sharma, 1976). The milk of contributions to locust biology. Desert cows fed on malathion-treated lucerne had locust breed only in such areas at such no detectable residue (Amin et al., 1970). times as may be characterized roughly by The endosulfan-treated ber fruits at 0.1 per a temperature range of 20°-30°C and at cent dosage showed no detectable residue the relative humidity range of 45-80 per after 20 days and were recommended fit cent. Bhanotar (1975) has reviewed locust for human consumption after two days, activities in the arid and semi-arid regions since the residues left were below the of Rajasthan. tolerance limit (Kushwaha and Pal, 1976). Cutworms. Cutworms (Noctuidae: Agrotinae) comprise the most notorious REFERENCES group of insect pests. They are poly­ AMIN, M., KUSHWAHA, K. S. and KAVADIA, V. S. phagous sporadic pests, which feed vora­ 1970. Malathion residues on lucerne and in ciously during dark hours. Most of the milk. Univ. Udaipur Res. Stud. 8 : 12-74. species have high preference for gram, ANONYMOUS 1971. Investigations on insect pests of sorghum and millets, Final Technical potato and tobacco. Severe damage has Report (1965-1970), Division of Entomology, been recorded during the rabi season, lARI. New Delhi, p. 157. particularly in low-lying areas, flooded BHANOTAR. R. K. 1975. Environmental Analysis during the previous monsoon. Generally, of TOOr Desert, R.K. Gupta and Ishwar Agrotis ipsilon Hufn. and A. flammatra Prakash (ed.), English Book Depot, Dehra Schif. commonly infest crops in the plains, Dun. KAUL, C. L., MATHUR, Y. K. and SRIVASTAVA, whereas Euxoa segetis Schif., in addition B. K. 1966. Laboratory evaluaion of to the above speci'es, is a regular major insecticides against the white grub, Holotri­ pest in the hills. They crawl out of their chia consanguinea Blanch. Indian J. Ent. subterranean abode at night and cut foli­ 28(1) : 84-87. age or shoots to drag them into the soil. KUSHWAHA, K. S. 1972. Termite pests of fruit­ trees and grasses India. Termite Pro­ Gram in the seedling stage is nibbled close blem in India. M.L. Roonwal (ed.) CSIR, to ground and at a later stage, the upper New Delhi. pp. 1-4. .

273 DESERTIFICATION AND ITS CONTROL

KUSHWAHA, K. S. and BHARDWAJ, S. C. 1977. RAI, B. K. 1976. Pests of Oilseed Crops in India Investigations on Forage and Pasture Insect and their Control. ICAR, New Delhi Pests of Rajasthan. ICAR, New Delhi pp. 121. ' (in Press). RAJ, B. K., JOSHI, H. C., RATHORE, Y. K., DUTTA, KUSHWAHA, K. S. and PAL, S. K. 1976. Dissi­ pation of endosulfan residues from ber S. M. and SHINDE, V. K. R. 1969. Studies (Zizyphus mauritiana Lamk.) fruit and leaves on the bionomics and control of white J. grub H%trichia consanguinea Blanch. in under arid conditions. Indian Ent. Lalsot, district Jaipur, Rajasthan. Indian J. (submitted). Ent. 31(2) : 132-42. MATHUR, L. M. L. and JAIN, P. C. 1972. Effect of maize germplasm on the survival and ROONWAL, M. L. 1945. New hypothesis for the development of Chilo zonellus S. under prediction of the swarming of the desert laboratory conditions. Madras agric. J. locust. Bull. ent. Res. 35(4) : 391-93. 59(1): 54-56. ROONWAL, M. L. 1953. Food preference ex­ PAL, S. K. 1972. Efficacy of different insecticidal periments on desert locust in its permanent formulations on the control of white grub breeding-grounds in Makran. J. Zool. Soc. Aserica sp. (Melolonthidae: Coleoptera) India 5(1) : 44-58. . in desert area of Rajasthan. Indian J. agric. ROONWAL, M. L. and BOSE, G. 1964. Termite Res. 6(3) : 215-20. fauna of Rajasthan, India. Zoologica, PAL, S. K. 1975. Pest records of desert grasses Stuttgart 40(3) (Heft 113), vit: 58 pp. and legumes. Entomologists' Newl. 5(8-9) : 40. SACHAN, J. N. and PAL, S. K. 1976. Insecticides PAL, S. K. and DOVAL, S. L. 1970. Some obser­ and cakes for the control of white grub vations on the white grub Holotrichia insularis Holotrichia insularis Br. in Western Rajas­ Brenske (Melolonthidae: Coleoptera) and its than. Pesticides 10(6): 37-38. control in Jodhpur Division of Rajasthan. SHARMA, S. K. and SHINDE, V. K. R. 1970. Control Ann. Arid Zone 9(3) : 151-56. of white grub, LachlUJsterna (Holotrichia) PRADHAN, S. and PANT, N. C. 1970. Pest pro­ consanguinea Blanch. (Coloeoptera Scara­ blems in chapter on plant protection. A baeidae) PANS 16(1): 176-179. New Technology for Dryland Farming. IARI, New Delhi. pp. 140-46. SRIVASTAVA, A. K. and SHARMA, L. S. 1976. PRADHAN, S. and PESWANI, K. M. 1961. Studies Extent of carbaryl residue in cowpea leaves on the ecology and control of Hieroglyphus and pods. All-India Symposium on Modern nigrorepletus Bolivar (Phadka). Indian J. Concepts in Plant Protection, Univ. Udaipur En!. 23(2) : 79-105. (March 26-28, 1976). pp. 74-75.

274 29 LIVESTOCK PRODUCTION-PROBLEMS AND PROSPECTS

R. M. ACHARYA, B. C. PATNAYAK AND L. D. AHUJA

LIVESTOCK-FARMING plays an important indicate that goats are 40 to 160 % more role in the economy of the arid region, economical than sheep (Abidi, 1970; as there are risks involved in crop-farm­ Wahid,1975). Knoss (1969), on the basis ing because of scanty and uncertain rain­ of his work done at Hissar, has also indi­ fall. It provides a very sizeable propor­ cated that goats are more economical than tion of the population of the region with sheep and the two species do not compete employment. A socio-economic survey with each other in utilizing the naturally conducted by the Central Arid-Zone available vegetation resources. Theoreti­ Research Institute (CAZRI), Jodhpur, cal considerations on the relative econo­ indicates that about two-thirds of the mics of the rearing of cattle, sheep and earning members in the households sur­ goats in the arid region of Rajasthan, veyed in this region followed animal while primarily maintained on free-range husbandry as their main occupation grazing or browsing, with some supple­ (CAZRI, 1965). The livestock sector in mentary feeding to cattle during lacta­ Rajasthan accounts for 12 % of the total tion, only indicates that goats are 130 % income of the State (Planning Commis­ more economical than cattle and 123 % sion, 1973) and considering that this more economical than sheep, whereas sector provides two-thirds of the popula­ sheep are 7 % more economical than cattle tion in the arid areas with employment, (Acharya and Patnayak, 1974). the contribution of livestock to the eco­ nomy of this region would even be much ROLE OF DIFFERENT LIVESTOCK SPECIES higher. In addition to managing live­ The contribution of livestock to deserti­ stock, a sizeable population in the region fication is relatively small as compared is engaged in the handicraft industry, with the climatic and human factors. The utilizing animal products, such as wool, climatic and human factors are specially skins, hides, hair, and in marketing milk, related to the utilization of marginal and milk products and livestock. The arid sub-marginal lands for crop-farming, the region contributes almost 40 % of the total felling of trees for fuel and timber and the wool produced in the country. Similarly, mismanagement of the livestock. The the contribution of this region to the pro- . plasticity of the livestock enterprise due duction of meat, milk and other animal to the possibilities of increasing or de­ products in the country is quite substan­ creasing the livestock numbers and their tial. mobility has prompted more and more Cattle, sheep, goats and camel are the people in the arid region to adopt live­ important livestock species contributing stock-farming. This factor, coupled with to the economy of the region. Studies on the utilization of the grazing-land for the comparative economics of sheep and crop··farming, has resulted in serious pro­ goats under range-managemen,t conditions blems of overgrazing, thus adding to the

275 DESERTIFICATION AND ITS CONTROL

forces causing desertification. The num­ buffaloes contribute the maximum to ber oflivestock per unit area in this region animal population. The population of is very high, and it is necessary to reduce goats as a percentage of the total live­ their numbers. This would, however, be stock populationl is quite sizeable in the possible without detriment to the eco­ arid regions of both Rajasthan and nomy of the region if the productivity of Gujarat. The population trends of differ­ animals per head is considerably im­ ent livestock species from 1951-72 in the proved. arid regions of Rajasthan and Gujarat Among the species of livestock in the are given in Figures 1 and 2 respectively. arid region, sheep would perhaps con­ There is an overall increase in the, popula­ tribute the maximum to soil erosion tion of all the livestock species during because of their close-grazing habit. these years. However, the largest in­ Goats prefer browsing and will graze crease is in the population of goats, only under conditions when nothing is closely followed by that of camels in available for browsing. They are not Rajasthan, followed by that of goats and so selective as sheep and would consume buffaloes in Gujarat and followed by that a wide variety of vegetation, especially of cattle in Haryana. The increase in the weeds, shrubs, bushes and young trees. population of goats, both in Rajasthan Because of their ability to utilize such and Gujarat, has been phenomenal, in vegetation, goats are able to thrive better, spite of the fact that there have been whereas cattle and sheep may starve when serious droughts during the last quinquen­ grazed on extremely poor rangelands. nium. This fact shows the better adapta­ This fact is reflected in a tremendous rise bility of goats to such conditions. The in goat population in the arid region rela­ increase in the number of buffaloes indi­ tive to the other two species. cates the availability of irrigation facili­ ties in some of these areas and the better LIVESTOCK POPULATION TRENDS performance of buffaloes as dairy animals under the system of mixed farming. The population of different livestock species, according to the 1971-72 Census PRODUCTIVITY OF THE in the arid areas of the three states, viz. i.LIVESTOCK Rajasthan, Gujarat and Haryana, is pre­ Although a large percentage of live­ serited in Table 1. Sheep and goats con­ stock in the arid region, like any other tribute the maximum (68 %) to the total region of the country, are nondescript, livestock population in Rajasthan, where­ there are some important dairy (Thar­ as in Gujarat an~ Haryana, cattle and 'parkar, • Rathi, Gir) , draft (Kankarej,

Table 1. Livestock population· (000) in the arid districts of Rajasthan, Gujarat and Haryana

State Cattle Buffaloes Sheep Goats Camels Total

Rajasthan 3,481 1,109 5,249 5,814 624 16,287 (27'9) (24·1) (61' 3) (47'8) (83 '7) (41'9) Gujarat 280 135 150 250 11 826 (4'3) (3 '9) (8,7) (7'8) (17, 5) (5'5) Haryana 514 575 206 190 91 1,576 (20·9) (22,8) (44,8) (39 '6) (68'4) (25 '1)

Note : The figures in parentheses indicate the population of a particular species in the arid region as a percentage of the total population of that species in the State. ·1971'-72 Census.

276 LIVESTOCK PRODUCTION

Nagauri), and dual-purpose (Haryana) breeds of cattle. The age at the first ,6 calving of these cattle is high and they

5

If) z 0 3 :::; _J :i O!" ~ 2

1961 1966 1971

r,."... lIIJ1fjJ m.m IZ:J lI1IIIII L....-J CATT lE BUFFAlO SHEEP GOAT OT HER L.S CATTL£ BUFFALO SHEEP GOAT CAMEL Fig. 1 Livestock population in arid districts of Fig. 2 Livestock population in arid districts of Gujarat Rajasthan have a low milk-production level, short bari is a short and light breed, and the lactation and long calving interval. The other breeds are medium in size and body­ buffaloes are mostly of the Murrah breed weight. Most of the breeds are highly or its grades and of the Mehsana breed, prolific and twins and triplets are quite which are good dairy breeds. Their frequent. The goats are primarily used average milk production is better than for meat, which is preferred in the greater that of cows, but they are seasonal part of the country. They have a poorer breeders and have poor reproductive milk-production level than the exotic efficiency. dairy goat breeds. Some of the these The important breeds of sheep in· the breeds, e.g. Marwari, produce hair which region are Chokla, Pattanwadi, Magra, is shorn and has a good export market. Marwari, Nali, Pugal and Jaisalmeri. POOR PRODUCTIVITY OF THE The first two breeds produce medium LIVESTOCK apparel or good carpet-quality wool, whereas the other five breeds produce The major reason underlying the low medium to good carpet-quality wool. productivity of livestock in the arid Most of these breeds are lighter in body­ region is the lack of adequate feed resour­ weight and produce small lamb crops and ces. Not only the quality of grazing and have lighter fleeces. However, compared supplementary feed available from crop with the breeds of sheep in other regions residues is poor, but even the total dry­ of the country, their production of wool matter requirement is not being met, in and its quality are superior. The im­ addition, there has been indiscriminate portant breeds of goats in the area are breeding and little effort in effecting any Marwari, Jhankrana, Sirohi, Beetal, genetic improvement. The stock-watering Jamnapari and Barbari. Jamnapari and facilities also are very inadequate in the Beetal are heavier and taller breeds; Bar- greater part of this region and, wherever

277 DESERTIFICATION AND ITS CONTROL

available, the water is brackish. The the year on the reseeded CenchrllS ciliaris lack of grazing and stock-watering resour­ pasture (Acharya el al., 1975). The ces force 'the livestock-breeders to resort mtroduction of, some drought-resistant to migration to distant places in search perennial legumes and fodder-trees, e.g. of them. Some breeders are continually Prosopis cineraria and Acacia species, in on the move, whereas others follow defi­ the pastures will further improve the nite migratory routes to the seasonal carrying capacity and production of the grazing-areas and return to their permanent livestock maintained on such pastures. abodes during the monsoon season. The To meet ~he req~ire~ent of fodder during large-scale migration of the livestock the scarCIty peflod, It would be essential results in tremendous hardship to the to establish fodder banks by 'harvesting livestock-breeders and to the livestock the grasses and tree leaves available during themselves. It further makes it difficult the years of better rainfall. The utili­ to take up any livestock-improvement zation of technology for enriching low­ programmes. These livestock are exposed quality forages and crop residues with to the hazards of disease and there are urea and molasses can be adopted to meet seriolis marketing problems. Because of the nutrient requirements of the livestock. the latter, the breedets do not show any In spite of the large genetic variability serious interest in adopting stock-im- present in most of the production traits, provement measures. ' the selection among or within the breeds In the arid region of Rajasthan, the of livestock available will be slow because estimated forage (dry matter) availability of the very low level of performance. from the rangeland, top feeds, crop resi­ It may take about 75 years to double the dues, etc. is about 15.41 million. tonnes milk production in the case of cattle against the total dry matter reqUirement through selection. Crossbreeding with of 17.46 million tonnes for the existing superior exotic dairy cattle, e.g. Hoistein­ livestock population, showing a shortfall Friesian, Brown Swiss, Jersey and Red of 7..05 million tonnes. Similar would Dane, improves milk production to an be the situation in the arid regions of economic level and also improves repro­ Gujarat and Haryana. About 80-90 % ductive efficiency. A level of exotic of the rangeland is in a poor to very poor inheritance around 50 % is found to be condition and some of the land under the most optimum (Acharya, 1970). In good vegetation cover is not fully uti- the case of buffaloes, selection for milk 1ized owing to the lack of stock-watering production within Murrah and Mehsana facilities. breeds and the upgrading of other non­ descript buffaloes with these breeds would TECHNOLOGY FOR IMPROVEMENT improve their productivity. Numerous experiments have been car­ Improvement in the production of wool ried out to develop technology for im­ and its quality regarding the apparel wool proving rangelands through protection is possible through crossing the carpet­ and soil- and water-conservation practices wool breeds such as Chokla, Pattanwadi and on the management of such improved and Nali, with exotic fine-wool breeds, rangelands (Mann and Ahuja, .1975). such as Merino and Rambouillet. The A carrying capacity of 2.47 sheep per exotic inheritance at 50 % seems to result hectare on a year-long basis on poor in the maximum overall improvement rangeland has been recommended (Das (Acharya, 1974). Selection within the et al., 1963). The reseeding of rangeland other carpet-wool breeds (Marwari, Magra with suitable perennial giasses can im­ Pugal, Jaisalmeri) for fleece weight and prove them faster. Experiments conduc­ against medullation will improve both ted under semi-arid conditions indicate the production and the carpet quality of that 5 ewes per hectare can be maintained the wool. There will be some improve­ with expected productivity throughout ment in the body-weight through crosS-

278 LIVESTOCK PRODUCtION

breeding, but such improvement can be stock, it is necessary to locate service fully realized only when such animals are centres on the migratory routes to provide maintained on an adequate level of nutri­ breeding and health service. These cen­ tion. tres may also act as fodder and drinking­ The improvement of the nondescript water resources and advise the farmers goats for milk production can be brought on migration. about through upgrading them with breeds such as Beetal, Jhakrana and Jamana­ PROBLEMS REQUIRING FURTHER pari. The improvement of the three INVESTIGATION above-mentioned breeds for milk produc­ Investigations are required to study tion can be done through selection within the competition among different livestock the breeds and also by crossbreeding species for the utilization of vegetation them with exotic dairy breeds, e.g. Alpine resources available on the improved range­ and Saanen. Crossbreeding with the above lands, their relative economic returns, exotic breeds would produce much faster the relative role of different livestock growth and will also reduce the age at species in causing desertification and to which the first kidding will take place. determine the most appropriate species Heavy losses in livestock productivity of livestock and their relative proportions occur owing to the mortality and mor­ on a specific type of rangeland. These bidity caused by a number of diseases studies will help to develop systems of prevalent in the area. Prophylactic health livestock production which will increase cover against important endemic diseases the output per unit area of land without through regular vaccination, dosing, dip­ bringing about any serious deterioration ping or spraying, etc. would reduce such of the soil. Investigations are also re­ losses. The provision of some shelter, quired to develop technology for har­ specially during rains and winter, for vesting and conserving range grasses and young animals would improve their chan­ top-feeds to meet the feed requirements ces of survival. The shearing of sheep during the scarcity period. before the commencement of rains and protecting them from solar radiation REFERENCES until the wool is grown more than 1 cm ABIOI, S. M. H. 1970. Final Report of the Scheme reduces the yellow staining of it. The on InVestigation and Research in Pakistan yellowing of wool which occurs only Animal Husbandry. Dept. of Agriculture, during autumn in the case of most of the Marketing and Grading, Govt. of Pakistan, Islamabad, Pakistan. native breeds in the arid region conside­ ACHARYA, R. M. 1970. Crossbreeding o( zebu rably reduces the market value of the cattle with exotic breeds for milk production. autumn-clipped wool. Washing the ani­ Indian J. Anim. Sci. 40: 110. mals about a week before shearing im­ ACHARYA, R. M. 1974. Evaluation of native breeds of sheep for wool and mutton and proves the efficiency of shearing and the scope for introduction of exotic inheritance. quality of the fleece. Shearing twice a Proc. 2nd General Congress SABRAO, year, machine-shearing, skirting and the New Delhi, 1973, Indian J. Genetics 34A, primary classing of wool further improve 1945. ACHARYA, R. M. and PATNAYAK, B. C. 1974. the market price. Role of sheep in the desert eco-system and As the present development organi­ drought-proofing through improved sheep zation cannot undertake the livestock­ production with special reference to Rajas­ than. Mimeograph, Central Sheep & Wool development programmes up to the ex­ Research Institute, Avikanagar (Malpura) tent required, efforts are being made for Rajasthan. organizing livestock producers' co-op­ ACHARYA, R. M., MALIK, R. C., DEVESH GAUR, ratives to provide the input service and MEHTA, B. S., CHAUHAN, D. S., HAJRA, A. and MATHUR, P. B. 1975. Relative to undertake the marketing of the live­ performance of fine wool (Avikouillet F) stock produce and live animals. For and ideal carpet wool (Avikalin) strains of the improvement of the migratory live- sheep evolved at CSWRI, Avikanagar,

279 DESERTIFICATION AND ITS CONTROL

maintained on reseeded Cenchrus pastures. Untersuchungen. Inaugural- Dissertation Annual Report 1975, Central Sheep & Wool Der Justus Liebig-Universitat Giessen: Research Institute, Avikanagar, Rajasthan. F.R.G. CENTRAL ARID' ZoNE RESEARCH INSTITUTE, 1965. MANN, H. S. and AHUJA, L. D. 1975. Range Socio-economic survey of livestock breeders, management research in arid zone of India. in Anupgarh-Pugal region of Western Paper presented at the annual meeting, Rajasthan. Human Factor Studies Division, Society of Range Management, U.S.A. Report No. 65/2, Central Arid-Zone Research Mexico city, February 1-13, 1975. ' Institute. Jodhpur, India. PLANNING COMMISSION 1973. Integrated agri­ DAS, R. B., DABADOHAO, P. M., MARwAHA, S. P. cultural development in drough~-prone and DEB Roy, R. 1963. Grazing capacity areas. Report of Task Force on integrated studies in grasslands of Western Rajasthan. Rural Development. Planning Commission, Ann. Arid Zone 2(4). Govt. of India, May, 1955. KNOSS, K. H. 1969. Fruchtbarkeit, Wachstum WAHID, A. 1975. Livestock-resources of Pakis­ und Legistungen bei Schaf und Ziege in tan-Pakistan Goals. Mimeograph-S, Uni­ einem nordindischen Bistop. Vergleichende versity of Karachi, Pakistan.

280 30 SALT AND BY-PRODUCT RESOURCES OF GUJARAT AND RAJASTHAN

M. P. BHATT, G. T. GADRE AND D. J. MErnA

IN spite of several odds, the socio-econo­ cm and 48 cm respectively, and is unevenly mic factors have stimulated the growth, distributed, is unreliable and extremely establishment and development of various erratic. Droughts and water famines are need-based industries in India since In­ of frequent reoccurrence. Drought-prone dependence. The salt industry is one of districts of these States occupy one-third them. Salt is one of the major and impor­ and three-fifths of the total area of res­ tant raw materials which has played a pective States, as shown in Table 2. very significant role in the industrial deve­ However, such a climate has proved to be lopment and growth of the country. It a boon to the salt industry which has also is a basic raw material for the production provided considerable employment for of heavy chemicals, such as soda-ash, the people residing near the coastal areas. caustic-soda and chlorine which, in turn, The principle sources of salt in India is are required by a large array of industries. sea-water, inland brine and lake brine. Having realized the importance of salt, It is proposed to discuss in this paper the appropriate and expeditious measures were sources for the recovery of salt and bittern­ taken by the Government of India to based chemicals of Gujarat and Rajasthan boost salt production in the country. under the present status of salt industry. This trend is evident from Table 1, showing increases in production targets SALT RESOURCES since 1951. Gujarat. All along the coast of Gujarat, Among the various States in India, Saurashtra and Kutch, salt is manu­ Gujarat and Rajasthan have larger areas factured through the solar evaporation of as semi-arid or arid regions. The average sea-water and subsoil brines. The rapid rainfall in Gujarat and Rajasthan is 75 development of the salt industry in Gujarat

Table 1. Targets of salt production in India during 1951 to 1985 (Figures in million tonnes)

Year 1951-56 1956-61 1961-66 1966-71 1971-80 1980-85

Human consumPtion 2·07 2·67 3·2 3·6 4·2 4·8 Industrial use 1·00 1·20 1 ·7 2·3 5·2 6'5 For export 0·5 0'5 1 0 1'5 Total 3 ·07 3·67 5·4 6·4 10·4 12·8

281 DESERTIFICATION AND ITS CONTROL

Table 2. Drought-prone districts of Gujarat and Rajasthan

Name of districts

Gujarat Ahmedabad, Amreli, Banaskantha, Bhavnagar, Broach Jamnagar Kheda, Kutch, Mehsana, Rajkot, Surendranagar. ' , Rajasthan Barmer, Bikaner, Churu, Jaisalmer, Jodhpur, Ajmer, Banswara, Aspur, Udaipur

Table 3. Salt production in Gujarat and Rajasthan during different years after Independence (Figures in lakh tonnes)

Years 1951 1961 1971 1972 1973 1974 1975

Gujarat 5·01 17'32 26 34 33·46 39 40 33·66 29 37 Rajasthan 2·52 2·45 4·88 4 83 4·97 472 3 ·15

is due to its suitable climatic conditions, major saItworks and 44 minor saltworks. low rainfall, long periods of dry. weat~er, This progress shows the great strides which fairly high temperatures and h1gh wmd the salt industry has made in this State. velocity, suitable soil conditions and the In comparison with Gujarat, the climatolo­ availability of an inexhaustible source of gical conditions are not suitable in Andhra sea-water and subsoil brine. Added to Pradesh, Orissa, West Bengal, etc., and the these, the required business acumen of the feasibility of growth of large-scale saIt­ region, good support from the State works appears to be remote. Thus Guja­ Government and the Salt Department and rat still remains in the forefront as a the salt-based industries and research maior salt-producing State. efforts of the Central Salt and Marine Tpe method of manufacturing salt is Chemicals Res'earch Institute have contri­ based on fractional crystallization. It buted largely to the growth of the salt consists in the intake and storage of sea­ industry in Gujarat. At present, Gujarat water in reservoirs through the natural is on the top of the salt-producing States, tide or pumping or both, followed by gra­ contributing 60 to 65 per cent of the total dually condensing it to the salt (NaCI)­ salt production in the country (Table 3). saturation level, say 24°-25° Be and then Marine salt resources. Important areas feeding it to well-prepared crystallizing based on solar evaporation of the sea­ pans. The salt is crystallized between 25<> water are Jamnagar, Kandla, Mundra, and 30° Be and a layer of 5 to 8 cm is Jakhau, Navalakhi, Okha, Jafrabad, allowed to grow with a multiple irrigation Bhavnagar, Porbander, Bherai, Maliya, system before harvesting. Three to four etc. In 1950, Gujarat had 9 big salt- crops of salt are harvested per season. . works' each producing 50,000 to 100,000 The present production of marine salt­ tonnes, and 4 medium-scale saltworks, each works is about 26 to 30 lakh tonnes producing 30,000 to 50,000 tonnes of salt per annum (Table 4). 'per annum.' Today in ] 976, there are 20 Inland salt resources. The Little Rann

282 SALT AND BY-PRODUCT RESOURCES

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283 DESERTIFICA nON AND ITS CONTROL

of Kutch is another important source, market for domestic use in northern India contributing 20 to 25 per cent to the salt and Nepal. The present salt production production of the State. Geological stu­ and the quality of salt produced in the dies have indicated that the natural sub­ Little Rann is shown in Table 4. soil brine in the Rann of Kutch has origi­ nated from the concentration of sea-water. IMPROVING THE QUALITY AND YIELD The Little Rann of Kutch, once a naviga­ OF SALT ble sea, has been raised by natural convul­ During the early fifties, salt manufac­ sions and earthquakes, and covers 3,200 ture in many regions of the country was sq km. Its natural depression gets inun­ not based on scientific lines. It was mostly dated every year by high spring tides and handled by non-technical, illiterate qgarias by a few rivers during the monsoon and and the quality of salt produced was much thus the subsoil brine-table is replenished. below that required for edible, industrial The dry season, October to May, is availed or export purposes. In 1948-49, the of for salt production. The brine for Government of India appointed a Salt salt production is obtained by digging Expert Committee which surveyed practi­ open wells. The composition of brine is cally the entire salt-producing area in the akin to that of sea-water, except for the country. The Committee reported the sulphate content, which is low, but the methods in vogue at that time and made magnesium content is high. The area is valuable suggestions to 'modify the91 to largely utilized by small saltworks owned by improve the quality of salt. Conse­ private parties and co-operative societies. In quently, in 1954, the Central Salt and mostof the saltworks, salt is manufactured Marine- Chemicals Research Institute was by using an age-'old method, The method established by the CSIR to undertake sys­ consists in fetching the brine of 17° to 20° tematic research and development to Be from a well with a dhenkava manually improve the quality of solar salt and to and feeding it to condenser and raising it increase its yield per acre, to manu­ to 23° to 24° Be. It is then charged to well­ facture different grades of salt and to deve­ prepared crystallizers of 66 x 33 x O.3m. lop economic processes for the recovery The crystallizers are occasionally char­ of marine chemkals from sea and inland ged with brine from condensers to main­ bitterns. tain the density between 27° and 30° Be' After its establishment, the CSMCRI and only one crop is raised at the end of has been in close contact with the salt the season. Big crystals or crystal aggre­ industry in India. The Institute has helped gates, known as "Baragara Salt" are ob­ to improve the quality of salt and its yield tained. This type of salt has a good per acre. Today, many large marine salt-

Table 5. Compositions of brines from various sources in India-sea-water. inland lakes and well brines

Percentage on dry Sea-water Kharaghoda Kuda Sambhar Pachbhadra Didwana basis Lake brine

CaCO. 0'345 _ 0 060 0,073 CaSO. 3 600 2-120 1 961 2-970 NaCl 77-758 70 -800 72,342 87,300 85,660 77 ,190 MgSO. 4'737 2,313 2,320 9 440 KCI 2'465 2,000 1-250 0,129 MgCI. 10'878 22-360 21 ,975 1 ,930 MgBr. 0'217 0,347 0,259 0,051 Na.SO, 8,650 20,650 . Na.CO. 3 870 0,600 NaHCO. 1'560 CaCh

284 SALT AND BY-PRODUCT RESOURCES

•..,0 .. ,:Q-'" x~ -+ ~ o~::= "'0"1

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works in Gujarat have achieved a yield of over and above the salt by large saltworks 50 to 60 tonnes per acre and the average in Gujarat is shown in Table 7, which purity of salt is over 98 % (Table 4). also shows the value of recoverable che­ micals. Based on the CSMCRI know­ BY-PRODUCTS RECOVERY how. it is possible to establish marine Based on the phase equilibria on the chemical complexes at Jamnagar and progressive solar evoparation on sea­ Kutch, where a number of large saltworks water, various evaporites are separated by exist. keeping strict control on density (Table 5). The recovery of bittern evaporites from The large salt-works in Gujarat are com­ saltworks in the Little Rann of Kutch paratively well laid out and are capable requires careful and extensive planning, of processing the sea-bittern to obtain keeping in view the collection of bittern at various coproducts evaporites. The quan­ some suitable central place from a large tum of the recoverable coproducts based number of small and scattered saltworks. on 1,000 tonnes of solar salt production Based on the availability of bitterns, the is shown in Table 6. These coproducts potential recovery of 7,000 tonnes of have to be further processed to obtain potassium fertiliz!!r has been reported. edible salt, epsom salt, sodium sulphate, Similar possibilities exist in the Great Rann potassium fertilizer and magnesium chlo­ of Kutch where the subsoil brines are ride. Bromine can be directly recovered known to contain potassium chloride. from 29° Be bittern, whereas gypsum sepa­ Exploratory work is being done by the rates from brine in the density range of CSM CRI in collaboration with the Geo­ 17° to 24° Be. Processes for the commer­ logy and Mining Department of the cial exploitation of these evaporites and Gujarat State and the Geological Survey the economic recovery of the marine of India. chemicals from them have been success­ fully developed by the CSMCRI for Rajasthan the benefit of the salt industry. The Many parts of Rajasthan are rich in 'potential recovery of various chemicals saliferous earth and sub-soil brine which

Table 7. Potential marine chemicals recovery from brines and bitterns available from large marine saltworks in Gujarat Basis: 15 lakh tonnes of salt production per annum by large salt works

Sr. No. Name of evaporite Quantity of eva- Chemical that can be recovered Total value of porite in tonnes from (2) recovered chemical. Rs Name Quantity in in lakhs tonnes 2 3 4 5

(i) Gypsum 45,000 Washed gypsum 40,000 12 Oi) Crude salt 1,20,000 Edible salt 96,000 19 (iii) . Sel's Mixt 1,05,000 Sodium sulphate 12,000 150 (iv) Mixed salt 90,000 Potassium schoenite 40,000 240 (v) Magnesium 37,500 Washed and upgra­ 30,000 150 chloride (Considering 25 % ded.magnesiwn chlo­ bittern utilization) ride crystalline varie­ ty 7 (vi) Bittern· 30° Be I 70·8 X 10 Iitres Bromine 1,500 270 (50 % bittern utili­ zation) •. The quantity of bittern is expressed in litres in column (2).

286 SALT AND BY-PRODUCT RESOURCES

are exploited for the production of salt. digging the wells 4 to 5 m deep and 2 m Important among these are the Sambhar in diameter and are renovated every lake, Didwana, Pachbhadra, Phalodi, year. The density of the brine ranges Kuchaman and Sujangarh. frolI). 15° to 23° Be and is rich in sodium SamMar Lake. The Sambhar lake is chloride and sodium sulphate. The the largest salt source in Rajasthan situated analysis of the brine is given in Table 5. in latitude 26° 58' N and longitude 75° The manufacturing operation does not 5' E. The lake proper is 40 km in length start till the end of February owing to the and 3 to 10 km in width, covering 235 sq. possibility of sodium sulphate being depo­ km. During the monsoon, the lake gets sited along with the salt during the cold filled up to a depth of 50 to 90 em depend­ winter. The brine, as obtained from the ing upon the rains. The lake is 'not per­ wells, is charged directly to crystallizers manent, but recedes and dries up during (20m x 60mor 16m x 40m) without prior the dry season. The bed of the lake is condensation. The first crop is usually covered with saliferous black silt which taken after 60 days and the subsequent is 3 to 5 m deep at the edges and 19 m crops are harvested at intervals of 20 to 25 at the centre of the depression. The days. The bitterns are not discharged soluble compounds of the mud consist from the crystallizer. Consequently, the largely of sodium chloride, with an appre­ salt of inferior quality is obtained as the ciable quantity of sodium sulphate and season progresses. The analyses of various sodium carbonate and bicarbonate. The grades of salt obtained are given in Table composition of the brine is given in 4. The annual production varies from Table 5. 50,000 to 70,000 tonnes. Climatic and soil conditions are quite Pachbhadra. Pachbhadra is situated 90 favourable and salt is being manufactured km from Jodhpur and 240 km south-west here from ancient times. The present of the Sambhar lake. It is an oval depres­ process is fairly simple and is based upon 'sion, 11-12 km long and 5-11 km wide; the density control at different stages. however, salt production is resorted to on When the lake brine reaches 3° to 5° Be, a tract of 3 x 9 km. The brine occurs at a it is transferred to reservoirs and conden­ depth of 3-3,5 m and its density ranges sers situated at the periphery of the lake. from 14° to 21 ° Be'. The analysis of Here it is condensed to 25° to 26° Be and brine is given in Table 5. It will be seen then charged to crystallizers (3 to 7 acres). that it is somewhat similar to sea-water. Salt ·is allowed to crystallize up to 29° Salt is manufactured here in a peculiar Be by a multiple irrigation system and a way. Tn the subsoil tract, the pits of 130 single crop is harvested at the end of the x 30 x 3-5 m are excavated and brine is season. To increase the production of allowed to percolate from sidewards and salt, brine from percolation canals is also upwards through the pit-bed. About 60 mixed with the lake brine. The analysis to 90 em of brine is collected in the pit of salt obtained is shown in Table 4. The and is evaporated as the result of sblar average production of salt for the last so heat. The salt starts crystallizing at 25° many years varies from 2 to 2.5 lakh of Be and the crystallization of the salt tonnes per annum. and the incoming of brine continue. After Didwana. Didwana is situated in the a' salt-bed 60 to 75 em thick, is formed, Nagaur District, at about 65 km north­ it is harvested. It is not possible to sepa­ west of the Sambhar lake. This depres­ rate the impurities from the salt, as there sion is 6. 5 km long and 2. 5 km wide, are no separate stages, and the quality covering an area of 16.25 km". The soil of of the salt obtained is not uniform and the basin is black saliferous silt similar good. The analysis of the salt is shown to that of the Sambhar lake and extends in Table 4. The average production of to a depth of 3 to 5 metres. Brine for salt in this area is about 40,000 tonnes. the manufacture of salt is obtained by Phalodi. Phalodi is situated ·between

287 DESERTIFICATION AND ITS CONTROL

Jaisalmer and Bikaner, about 112 km 15,000 tonnes of sodium sulphate, 8,000 from Jodhpur. It is a depression of 8 tonnes of sodium carbonate and 40,000 x 4.8 km. Formerly, saltworks situated tonnes of good-quality salt can be pre­ here were closed down because of an pared. If the bittern is subjected to solar inadequate market for salt, but since evaporation, the first fraction obtained 1958-59, the land has been leased to many is the substandard salt unifit for human private salt manufacturers. The method consumption, followed by solid bitterns of manufacture is more or less similar to on complete drying. The typical analysis that of Didwana. of the substandard salt, solid and liquid The present salt production is about bitterns is given in Table 8. 50,000 to 60,000 tonnes per annum. Seshadri and Buch (1959) worked out a Kuchaman and Sujanf?arh. These sources process for the recovery of sodium sul­ are comparatively recent, and salt pro­ phate, sodium chloride and sodium car­ duction was started only a few years back. bonate. The process consists in the Kuchaman is situated about 32 km away chlorination of bittern to eliminate algae, from the Sambhar lake and comprises followed by chilling it to O°C after adjust­ about 10 small saltworks, producing about ing it to a suitable composition. Sodium 60,000 to 70,000 tonnes of salt, whereas at sulphate decahydrate separates and it is Sujangarh, 30,000 to 40,000 tonnes of salt dehydrated with solar t(nergy. The resi­ is manufactured. dual brine is subjected to solar evaporation till the concentration of sodium carbonate BY-PRODUCTS FROM RAJASTHAN SALT reaches 7 per cent (w/v) , whereby pure RESOURCES sodium chloride is obtained. Finally, the The composition of brine of the Sam­ desalted bittern is carbonated to obtain bhar lake, Didwana and Phalodi differs sodium bicarbonate which is decomposed from that of sea-brine. Here, the main to get sodium carbonate. This process constituents are sodium chloride, sodium has been further improved by enriching sulphate and ,sodium carbonate. On the the sulphate content of the bittern by other hand, the brines of Pachbhadra and reacting it with powdered gypsum (100 Sujangarh are akin to sea-water. Efforts B.S. mesh) in the solution phase. Practi­ have been made to recover sodium sul­ cally, most of the sodium carbonate is phate and burkite from the Sambhar and converted into sodium sulphate. The resul­ Didwana bittern, based on the work car­ ting solution, after settling, is chilled at ried out at the CSMCRI. O°C to crystallize out sodium sulphate Sambhar Lake. The present production decahydrate which is subsequently solar­ of salt from the Sambhar lake varies from dehydrated to obtain anhydrous sodium 2 to 2.5 lakhs of tonnes. From the sulphate. The overall recovery is 95 per bitterns' available from this source, about cent with purity up to 98 per cent.

Table 8. Analysis ~f liquid bittern, substandard salt and solid bitterns

g/100ml % by wt. on dry basis Liquid bitterns Sub-standard salt Solid bitterns

NaCl 19 5-21·0 91'5 66·1 NazSO, 6,5- 7·5 7'5 30·1 NagCO. 2'8- 3·2 0·6 2·0

NaHCOa 0·8- 0·9 Insolubles 0·4 1·2

288 SALT AND BY-PRODUCT RESOURCES

Sapre and Baxi (1959) worked out the cessed for the recovery of sodium sul­ process for the recovery of burkite from phate, about 15,000 to 20,000 tonnes of the Sambhar bittern. By a suitable it. can be obtained, and simultaneously adjustment of the concentration of bittern the quality of common salt can be very and heating it to 100°C, a double salt much improved. burkite (2Na2S04.Na2C03) is separated No efforts have as yet been made to and the mother-liquor on, solar evapora­ recover by-products from these sources, tion, yields 97 to 99 per cent pure salt. probably because of salt production on a Burkite can be further processed by using small scale. As these brines have a the - modified trona process to recover composition similar to that of the sea­ sodium sulphate and sodium carbonate. brine, the processes developed by the The process is claimed to be economically CSM CRr can be made use of for the feasible. economic recovery of chemicals by establi­ Malhotra and Acharya (1964) of Hindus­ shing a co-operative sector, so as to pool tan Salts Ltd., developed the process for the raw material at a central place for pro­ the recovery of burkite. Solid bittern cessing it. is digested with hot water under controlled conditions to leave a residue having a CONCLUSI9N composition similar to that of burkite The availability of suitable climatic and (Na2S04: 70·75%, Na2C03 : 22-25%, soil conditions and ample quantities of NaCl: 2%). A pilot plant producing brine and other socio-economic factors 250 to 300 tonnes of burkite per annum, have gone a long way in establishing and utilizing this process is in operation at the developing the salt industry in Gujarat Sambhar lake. and Rajasthan. Owing to the unique and Didwalla: Didwana brine at 24° Be' favourable location for manufacturing (Table 9) is richer in sodium sulphate than salt through solar evaporation of sea­ the brine of the Sambhar Lake. water and inland brines, Gujarat will con­ tinue to remain a major contributor to Table 9. The analysis of the Sambhar and Didwana brine at 24° Be salt production in the country. In spite of increased salt production up to 33 lakh tonnes per annum, sincere efforts are yet g/IOOml Sambhar Didwana to be made for the recovery of by-products NaCI 19'0 16·0 by the salt-manufacturers. The CSMCRI technical know-how for the recovery of 3·1 7·0 most of the marine chemicals has been 1·4 1·0 proved to be effective and useful in the case of commercial plants. The production of salt at the inland Owing to extreme climatic conditions, salt works at Kharaghoda and Kuda is the Didwana brine gets chilled during about 7 lakhs of tonnes. -Only a small winter and sodium sulphate separates quantity of bittern is used at present by out as decahydrate. For the last 6 to 7 the Pioneer Magnesia Works for the pro­ years, a plant based on the artificial chill­ duction of fused magnesium chloride. ing of Didwana brine, producing about Hindustan Salts Ltd. is now taking steps 20 tonnes of sodium sulphate per day, is to install a 500-kg-per-day bromine plant in operation at Didwana. The annual" (150 tonnes per annum) by utilizing the production is about 5,000 to 5,200 tonnes. CSMCRI know-how. Systematic and plan­ After the recovery of sodium sulphate, ned efforts will be necessary for the utili­ the residual brine is subjected to solar zation of inland bitterns for the recovery evaporation to obtain good-quality com­ of potassium fertilisers. mon salt. It has been estimated that if The salt sources of Rajasthan produce all the brine available at Didwana is pro- at present 4 to 4.5 lakhs of tonnes of salt.

289 DESERTIFICAlION AND ITS CONTROL

The production of salt is solely dependent DUTr, P.K., GOMKALE S.D. KAVA R.M., SHAH upon rainfall. Insufficient and excessive H.N. and MEHTA D.J. (1974), Im-en- rainfall may hinder salt production con­ tion Intelligence 9 (12) : 441. DUTr, P.K., GOMR;ALE, S.D., and MEHTA D.l. siderably. In spite of these, the salt 1975. Chemical concepts 3, 6, 29. industry has shown a steady progress. GAORE, G.T. and DATAR, D.S. 1967. Chem, Age Sodium sulphate is the principal by­ of India, 18 (11) : 821. product of Sambhar, Didwana and Phalodi MEHTA, D.J., UOWADIA, N.N. and KAVA, R. M. resources. A plant of 20 tonnes of sodium 1965. Salt Res. and Industry 2 (4): sulphate per day is under production at 145. . MALHOTRA, C.L. and ACHARYA C.A. 1964. Didwana for the last 6 or 7 years, whereas CSMCRI Seminar 011 Sail & ByprodUCIS, the pilot plants producing 150 tonnes of April 11, 12, Abstracts. sodium sulphate and 300 tonnes of burkite Report of Irrigation Commission, Ministry Of Irri­ per annum are under operation at Sam­ gation and Power, Govt. of India, 1972. 1, Appendix 8.1. 420.421, 424. bhar. It is possible to recover 25,000 Report on Salt Industry ill Gujarat, Directorate of tonnes and 15,000 to 20,000 tonnes of Industries, GOVt. of Gujarat, July 1975, sodium sulphate at Sambhar and Didwana, pp. 4, 31-47. if full utilization of Qitterns and brines Salt E:cperts committee Report, Govt. of India 1950. available at these p,laces is carried out. SAPRE, R. K. and BAXI, D.R- 1959. J. Sci. Ind. Research and development are necessary Res., 18A : 430. to recover by-products from other sources, SESHADRI, K. 1964. CSMCRI Seminar on Salt and viz. those at Pachbhadra, Sujangarh and By-Product s, 11, 12, April. SESHADRI,K., BHATTG.D., and DESAI, R.L. 1959. Kuchaman. Chem Age of India, 453-55. SESHADRI, K. & (Late) BlICH S.D. 1959. J. Sci. REFERENCES Ind. Res. 18A : 132. SESHArRI, K. and VYAS, R.P. 1960 J, Sci. Ind. Annual Reports. Salt Departmellt, Govt. of India. Res. 19 : 321. BHATr, G.D., SANGHAVI, J.R., DAVE UOWADIA, N.N., GADRE G.T., KAVA R.M., Lele CoOJ. and SESHADRI, K. 1970. Salt Res. V.N., MEH1A D.J. and DATAR. D.S. 1962. and Industry 7 : 2-3, 39. Res. and Ind. 11(2) : 71-74. .

290 31 THE UTILIZATION OF WIND ENERGY AND WIND REGIMES OF ARID AREAS IN INDIA

S. K. TEWARI

A renewable source of energy, associated characteristics of wind energy. They are with the movement of air masses, has discussed below. apparently remained unutilized. How­ Power in the winds is expressed by the ever, the limited supplies of fossil fuels and formula the ecological implication of their utili­ =!cpAva ...... 1 zation, the long gestation period of hydro­ where Cfl = density of the air electric projects, some uncertainties and A = Cross-sectional areas of rising costs of nuclear power, the desira­ the wind stream bility of curbing deforestation, etc. provide V = Wind speed an opportunity for cons'i~ering alternative On the basis of unit area, the power is sources of energy. A welcome psychologi­ seen to depend on the wind speed which cal change is being noticed, as the case is has been accepted as the main indicating being made by many workers and decision­ parameter for wind power. makers for the appropriateness of energy Wind speeds have been noticed to utilization. The growing awareness for fluctuate from time to time and the energy considering the full implications, such as from winds over a length of time is given social costs and not merely the market costs by the formula. of energy business, are providing the much-' needed encouragement for the growth of E = t JA ~ Vi 3 hi ...... 2 alternative sources of energy. In this i-I study, we shall consider some of these aspects in relation to the possibilities of hi = duration of wind speed Vi utilizing the wind power of the arid regions = N corresponds to the upper limit of India. We shall begin with the analysis for the utilization of wind speed of energy needs to identify the niche for (VN) and its associated dura­ wind energy and then proceed on to a tion (hN) study of wind regimes of such areas. Energy computations are easily made, using equation-2, if the velocity duration­ WIND ENERGY FOR PROVIDING curves are available. SHAFT WORK Fig. 1 shows the annual average wind Wind energy offers exceptional possibili­ . speeds for some of the locations in Gujarat, ties against other alternatives, provided Haryana and Rajasthan. To a limited the windmills are designed to be cost­ extent, one can infer the relative windiness effective. Cost considerations here should of one location as compared with that of include, in addition to economic costs, another. If two places have the same some related social costs as well. To annual average wind speed, these may not arrive at some conclusion in this matter, necessarily produce the same amount of one needs to study the potential and other energy. This is so, because the relation-

291 DESERTIFICATION AND ITS CONTROL

20 18.3 18

.E. 16 ~ ." 14 ~ ~ ." 12 S ~ 10 "g> i 8 ;; c 6 "c q 4

2 0 Expo&ure HeIght above 14 ,9 12 10 10 8 13 ' 19 10 II 13 12 '9 the ground " ,II 39() 23 224 234 Above BarometriC height 486 ~'94 SO 224 11 171 221 242 138 ~ MSL . ;;; .0:: . 0:: <{ ffi <{ 0: 0:: ~ .. 0:: i: :; is -' 0:: . '" ::> <{ w <{ ...., « ::> ""0:: ~ -' ~ .. 0 "z ::> ...... J: '3 :0: 0:: :> i .. II> "Z <{ ~ '".. ., l: c '" q ;: '" :;:'" :; 0 l: iii"" 0 .. ~ .. ffi l:" ~ ~ ...... , g ... a: " '" ttl '" '" L~"'ude 26'27 25'45' 21'45' 2S'1S' 2S'OO 22'22 2!O'SS 29'10' 2649' 26'S4' 22'97 26"18 21'08 22'18 2054 Long,'udo 74'37' 71'23' 12'11 69'48' 73'18' 69'05 73'53; 75'44 7548' 7e'55' 70'12 7301' 72'12 70'47' 7022

0

" 200 ~'"

! 400 E E 600 ~ ..i! 800 '" 1000 q'" 1------.:'1120 Al1lnd,. average ______1200

S· : Satlsfactorv V.S· ~ Very Satrsfactory G•• ~ Good e· : Exct!lIe~1 •• Alfoort dartt

'Fig. 1. Average wind speeds for some of the locations in the arid zone. Speeds of 17-18 km/he are not uncommon in the region ship between the cube of wind speed and to 5.30 p.m.) and night (5.30 p.m. to its duration, which. may differ from one 8.30 a.m.) averages from which the data place to another, even though the average in respect of velocity duration cannot be value remains the same. For example, derived. Therefore, in this study, we five places having the same annual average may have to depend on the monthly and speed of 9 km/hr were found to differ in annual average wind speeds only. energy potentiality by as much as 75 % (Fig. 2). However, the computation of ener­ THE WIND ENERGY POTENTIAL OF gy potential requires the velocity duration ARID AREAS data which are obtained from the installa­ Energy could be computed from a velo­ tions' provided with anemographs. In city-duration curve with the help of the arid zone, there are only 1 such installa­ equation 2, but we do not have sufficient tions and the other approximately 12 information on this point for most places installations give day (9 hours: 8.30 a.m. in the arid region. We may now try to

292 WIND-ENERGY UTILIZATION

attempt an indirect technique. For those Annual average soeed : 9 tt.mJh r places, where the velocity-duration data are available, we can determine the rated 26.0 24.6 254 design speed which could maximize pro­ 15.4 duction of kilowatt hours of energy per 14.8 :11 .~. kw installation. Windmills rated for a ~ ~ ~ ~ particular wind speed do not generate Calr_utta G3ya Hyder abad Jodhpur Lucknow substantial energy while responding to ,0 .~ lower speeds. We may, therefore, neglect E (':1_ this contribution. Also, with the regulat­ > Annual average speed: llJ- 10 Cl design speed of 20 km/hr the same power :0 ~ ~ ~ is also generated at higher speeds, such as c., Bhopal Bombay Kodalltanal Poona -0 30 and 40 km/hr. With this assumption, ~ 70 73.6 an attempt was made to calculate the eo Annual average speed: 13 kmJhr 46.6. design speeds for those places, not neces­ 50 37.9 sarily in the arid zone, where the velocity­ 40 duration data were obtained earlier. Fig. 30 3 gives the information relating to the 20 annual average speeds with the associated 10 :..L-__:jU-_-J<.l-_...... design speeds that maximize energy Bangalore Gopalpur Madras output, utilizing the criteria mentioned above. Fig. 3 also gives the number of Fig. 2. Average wind speeds do not necessa­ hours per year one would get the rated rily reflect wind energy potentiality of output, if a particular design speed was a place. selected. 20 r-- With reference to Figs. I and 3, we find ~ 18 E 0 that some locations in the districts of Raj­ "'" 16 "0 kot, Junagadh (location: Veraval) and ~ 14 Q • • Jaisalmer obtain an annual average exceed­ : 12 j-1---- •t- - ing 14 km/hr, which would permit one g> 10 ... to select a rated speed of 25 km/hr and i 8 .1- -1 0; 6 obtain a rated output for more than 1,200 ~ E 4 hours per year. The annual speed of or:( 2 Dwarka may be combined with that of o Jamnagar and thus obtain a mean of 14 o 2 4 6 8 10 12 14 16.l.8 2022 24262830 kph, which may be taken as the represen­ Rated speed kin/hr tative figure for the entire Jamnagar Dis­ ~!~ 2800 trict. Similarly, for the district of Jodh­ ;:"" ! m'~ ~ 2400 ! pur, the combining of the data obtained ~g~ 2000 I I at the Jodhpur Airport and Phalodi gives ctl-g ~ 1600 · r- a me\ln value of 13 km/hr. With refe:' §"',," 5;-£ 1200 • *- renee to Fig. 3 we may select 25 kph as -6 -g 15 800 6 i · the design speed for the districts of Jam­ 5 ~& 400 • I I ~£~ 0 I nagar and Jodhpur. o 2 4 6 8 10 12 14 16 18 2022 24 2628 30 For Barmer, Bhavnagar, Jaipur and Rated spepd km/hr Kutch districts, we may select the rated speed as 25 km/hr which would allow Fig. 3. Rated: wind speeds, annual average speeds' I and the number of hours of the generation of the rated output for full. output operation per year

293 DESERTIFICATION AND ITS CONTROL

about 1,200 hours per year. We may NEED TO COLLECT THE WIND DATA AT not consider here other places for which THE SITE the annual average speed was less than 9 While examining the data displayed in km/hr. Fig. 1, it may be understood that this information is not quite relevant to the It is n~cessary to note that it is not recommending of wind-power utilization quite correct to say that not enough wind for the region. Sites for installing ane­ energy is available in the Ajmer, Bikaner, mometers were selected from several view­ Ganganagar and Hissar districts. Only points, their usefulness for wind-power the places where the wind data were so utilization may have at the most remained far collected were not the windy ones. one among the several factors. Wind The possibility of locating the windy sites speeds, as measured at a p~rticular loca­ in such districts cannot be ruled out, tion, are considerably influenced by the though in our estimation we may proceed roughness of the surrounding terrain. by excluding the consideration of these Fig. 4 shows that large variations in wind areas. speeds can be expected even between the . locations within 10-15 km of each other . Let us assume that we wish to install a The height of the anemometer above the windmill per hectare. The arid areas ground level also introduces a need for generally require about 1 hectare-metre the interpretation of the data recorded at of water per season for food crops, ex­ a particular installation. Substantial cluding rice. We may assume that water efforts have been made for studying this pumped by a windmill for about 300 aspect and power law coefficients have hours per season could be applied to the been determined for several types of fields by some technique, and that the terrains. For instance, if the surrounding water-table in the arid areas would necessi­ area is free from all obstacles, such as tate an average head of 30 metres for water- buildings and trees, the following equation , pumping. With thes~ assumptions, one can be applied. calculates a power ratmg of 2. 5 kw at the pump. If one designs an efficient water­ V I/V z = (hl/hz)a ...... 3 pumping windmill to operate with 15 % where V1 = wind velocity at a height hl efficiency, the diameters to be swept by above the ground level the windmill rotors are 12 m with the V 2 = wind velocity at a height hz rated speed of 20 kmjhr (5.5m/sec) and above the ground level 9 :tn with the rated speed of 25 kmjhr a = power coefficient (7m/sec). Windmills sweeping a circle = 0.16 for open terrain 4 of 12 m'spaced apart by more than 200 = 0.40 for very rough terrain metres would not suffer any serious inter- with large buildings surround­ ference problem. ' ing the point of measurement 4 The area of the districts of Rajkot, In principle it is possible to take account Junagadh, Jaisalmer, Jamnagar, Jodhpur, of the changes in the type of terrain and Barmer, Bhavnagar, Jaipur and Kutch thus extrapolate the wind data from one totals up to nearly 200,000 square 'kilo­ place to another. In practice this is metres. If 10 % of this area, which is quite tedious and not quite dependable. 20,000 square kilometres or 2 million It is generally desired that data are hectares, is farmed with windmills, the collected for a place where one wishes to installed power capacity amounts to 5 install a windmill. This collection of the -million' kilowatts, more than two and a data is considered essential if one envisages half times the existing combined capacity installing a single large windmill or a for electricity generation of Gujarat and cluster of them and take advantage of the Rajasthan. uninterrupted winds available at a pre-

294 WIND-ENERGY UTILIZATION

14t ble at higher latitudes where the bulk 13 of the wind energy comes from storms. The fact is that the results from this ap­ 12 11 proach are of high practical value. 1: 10 E YEARLY VARIATION IN WIND ENERGY 9 ~ AT A PLACE "0 8 "0 7 "'00~'" We may start our inquiry concerning "O<{) 6 £0> the annual variation in the wind data for 5 ~-= a particular place. We may accept the ro ~, 4 E annual mean hourly wind speed as an ~ indicating parameter for the annual energy ~ from the winds. For a location in 2 ::;;" Bangalore, the values of annual as well as monthly average hourly wind speed + • t + Central observatory Airport Colaba Airport were examined for six consecutive years. Ban9alore Bombay Location Statistical techniques were applied to obtain the variation from the mean 19.0 m 16.1 III 26.0"., 15.0 m 4- values of six years for an arbitrarily Anemometer height above ground level selected confidence level. From Fig. 5 it can be seen that the variation around Fig. 4. Spatial variation of' wind speeds obtain­ the mean value, calculated from 6 years ed in the heart of the cities and those records of annual average speeds, is± at the airport differ 7.4% associated with a confidence level -+ ferred site. In such cases, the record of o 10'/, 20,," 30% wind speeds may have to be obtained for 8.9_ Jan! _----95°/0 Confidence an extended period of a few years. For == S.3km/hr =12.5' instance, in Oregon, USA, wind-pros­ 13.4 _ Feb _(99°/o ConfIdence pecting for locating suitable sites has been 9.7 km/hr lB.9 carried on since 1973. 11.8_ Mar 9.B km/hr ===16.6 7.5_ Apr _ METHODOLOGY FOR EXTRAPOLATION == 9.7 km/hr = 10.6 FROM LIMITED DATA 14.6_ ,Mav - 20.9 15.6 km/hr Suppose that we have wind data at a 134_ Jun _ station A and wish to predict the behaviour 24.2 km/hr 24.2 5.8- Jul - of the wind speeds at another station B, 25.1 klll/hr-=B.1. separated by several kilometres from sta­ 8.6_ Aug - tion A. It appears that there is no = 20.2 km/hr =12.2 20.5 Sep :~~~~c::2 published study on the extrapolation of 14.4 km/hr 28:9 the data from station A to station B as 12.7_ Oct _ B.5 km/hr 17.9 a function of the distance, nature of 10.6_ Nov terrain, etc. = 7.5 km/hr = 14.4 Dec - A more positive line of inquiry could B.6 km/hr 12.2 be to base the prediction of the data ob­ ~ 5.6- Annual_ tained for a limited period and extrapolate oz=> 13.6 km/hr == 7.4 them for the remaining portion of the CONFIDENCE INTERVAL year and also from one year to another. FOR T~E ME"N WINO SPEEDS OF' 51)< YEARS This approach is made possible by the AT BANGALORE (~"''''''J relatively predictable behaviour of the Fig. 5. Wind energy variations in different winds associated in India with the mon­ months (mean of six consecutive years). soons-an advantage not normally availa- Bangalore

295 DESERTIFICATION AND ITS CONTROL

in monthly average are somewhat higher, .0 , i as much as ± 28.9 % for September. .9 Some applications like the pumping of .8 I i r T irrigation water may probably need a .7 . • 6 .1'-..... better prediction for the monthly output of 5 ° energy, which may be alternatively taken '. I t.4 • :_1 ...... T : care of by a slight over-rating of the wind­ J _.-..--: 1· ? mill or by providing for the storage of 2 . water. ,. ~ . ~ ""- .1 Since it has been found that at one 1. Of-e-.--:--C-! 91-! __~ L-i:- place, namely Bangalore, "the Variation O. . . .. !- . O. in wind energy on yearly basis is not much, 8r-~~-: _o! ! O. 71 '--'---.. .:tL-!.-J~ one would possibly like to generalize on O. 6f-- .. o_ ;.;-_ t-to; • ° this aspect for other places, too. Per­ O. 5 • :,. haps, it would be more prudent to exa­ O. 4 • _J mine the wind data for some places in the O. 3 i-' 0.2 arid areas as well. However, for the O. 1 time being, we may asume that variations o in wind energy from Yflar to year are not Jan Feb Mar Apr May Jdn Jul Aug Sep Oct No\! Oec intolerably high. Fig. 6. The energy contribution for each month of the year for 15 locations given in THE PREDICTION OF THE ANNUAL Fig. 1 AVERAGE VELOCITY FROM LIMITED OBSERVATION OF WIND SPEEDS 20 19 The next inquiry is concerning the pre­ 18 diction of the wind energy expected to be 1.7 available for the entire year based on 1.6 ..,1- observations collected during a particular 1.5 ~!:- month at a particular place. The practical 1.4 benefit lies in saving substantial time and 1.3 . effort, otherwise required in the absence 1.2 -;~ of such a technique. Again, we may accept 1.1 . - 10 . epa. "' monthly and annual hourly average wind 0.9 speeds as the parameters indicating energy. .!!I ). 0'8 i:. Wind data for 15 places in the arid areas 0.7 ... II ~ ~I- ...... of Gujarat, Rajasthan and Haryana, hav­ 0.6 ing annual rainfall of less than 750 mm, 0.5 were extracted from the Climatological 0.4 Tables published by the India Meteorolo­ 0.3 0.2 gical Department for the period 1931-60. 01 The data were normalized in the follow­ Jan preb Mar Apr May Jun Jul Aug Sep Oct Nov Oec ++++++++++t+ ing manner: Feb Mar Apr Mav Jun Jul Aug Sep Oct Nov D~c Jan ""\ Suppose that the average wind speed at a location in the month of, say March, was 'x' km/hr, and the annual average Fig. 7. 'Windl speed variations determined -on at the same place was 'y', we divide 'x' the basis of average of two conse­ cutive months by 'y' and obtain a coefficient. This pro­ cedure was applied to the values for a.ll of 99 %. This variation should be accep­ other months. For other places, theIr table in most applications of wind energy. - respective annual average speeds were " However, it may be noted that variations utilized to normalize their respective

296 WIND-ENERGY UTILIZATION

monthly averages. For 15 places, the of two successive months. The confi­ mean values of the coefficient 'x/y' per­ dence level of 90 % may be considered taining to each month were calculated. 'luite satisfactory for most practical pur­ One would be able to appreciate the pur­ poses. For the purpose of noting pre­ pose of this exercise with the help of the dictions, better reliance can be placed on following example. wind speeds recorded in months other than For a new location in the arid region, November, December, January and Feb­ one measures wind speed for a period of a ruary. month, say September, and let us call this While examining Figs. 6 and 7, one average speed 'z' km/hr. The mean observed a positive trend in obtaining value of the coefficient x/y for September, higher wind speeds during May, June as calculated earlier for 15 locations, and July than those obtained during other was say (xjy). One can then pre­ months of the year. One might feel tempted to do some curve-fitting exercise dict a likely annual average of z/ex/Y) to obtain an elegant formula giving the km/hr. The question that remains to be mean monthly values against the parti­ answered is regarding the confidence asso­ cular month of interest. Even without ciated with this prediction. a curve one can easily work out the values Fig. 6 shows a plot of normalized co­ for monthly average speeds with the help efficients of monthly average speeds for of Fig. 6 or 7, once the annual average has 15 places for each month of the year. The been determined. With this process, mean values are also indicated and one information concerning variability in the observes a significan~ scatter around the confidence levels for each month is also respective mean values. retained. Fig. 7 gives information which differs from that given by Fig. 5 in that the aver­ SOME ASPECTS CONCERNING WIND DATA ages for any two consecutive months of normalized coefficients are plotted. In Shortcoming of the derived averages other words, if (x/yh and (x(Y)s were For obtaining velocity-duration curves, the normalized monthly averages for it is a normal practice to utilize the data July and August, the ordinate in Figure in respect of the mean hourly wind speeds. 7 shows Y2 {(x/yh+(x(y)s} and we may The choice of the hourly average seems call this (x/yh-s. Now suppose that we to have been guided by the fact that one record wind speeds at a new place during needs to arrive at stable averages. The August and September and calculate the time base of an hour would be insensi­ average for these two months. Let us tive to gusts (with the time base of a call this speed Y7-S. From Fig. 7 we few seconds) as well as larger atmospheric note the mean coefficient for the two con­ movements, such as a depression (with the secutive months of August and September time scale of several hours and at time as (x/y) 7-S. The predicted annual ave­ even a couple of days). It is worth rage speed is given by v7 - s/(x/Yh-s. noting that whereas depressions may occur For obtaining the confidence level on occasionally, the structure of the wind the mean values, we may define intervals of is such that its speed varies almost every acceptable variation around the means as instant and this aspect is sometimes over­ ±lO%, ±15%, etc. Out of a maximum looked while dealing with derived averages. of 15 cases, the number of cases actually Slow-running, multi-bladed water-pump­ falling within the defined interval of ing windmills have been found to be less variation would give the confidence level. sensitive to the instantaneous variations The probabilities calculated in the above in the wind speed and quite often do not manner are shown in Fig. 8. It is evident respond to gusts, unlike the high-speed that a much better confidence is obtained rotors of low solidity, normally used in in ±20 % interval and with the averages electricity generation.

297 DESERTIFICATION AND ITS CONTROL

AcCeplable variatIon ± 10% aboulthe mean values 100'1< ~ 90%

80'1<<> 175%- 60'1.,-

40')'u

20% , o ... -_ ...... I- .... u JJ AA 5S 00 NN DO j~ J FF MM AA MM JJ ~ u F M A A J J A SON 0 J

Acceptable variatIOn, ± t5% about the mean value, 100;' - , 90~ (/) Q) BOY, > 75% Q) 60% Q) u c 400/. 0) "0 20% I c -0 ... I.. I.. ... U 0 U J J FF MM AA MM JJ J J A A 55 o 0 N~ N o~ D 0 ~ F M A A J J A 5 N D J -0 o

Acceptable Vd(latlon, ± 20"/:, about the mean values l00'/{ 90",

80°;' ,

60% I- , 40%

20'~ , J o ~ ...... JJ FF- MM AA MM JJ jJ AA- 55 00- NN- DO F M A. A J J ;:.. SON D J Fig. '.8. Prediction of wind energy'from limited data, with an error of ± 15 %, the data pertaining to any two consecutive months from May to October would suffice The data consisting of average wind tasks for a windmill-designer is to minimize speeds cannot form a basis for the struc­ the material consumption in the design tural design of windmills. It has been of a windmill rotor and tower, the impor­ found that the peak gust speed could be tance of a closer scrutiny of wind data 5-10 times higher than the monthly or cannot be overemphasized. It is also annual average speeds. Since one of the clear that a windmill responding to gusts

29S WIND-ENERGY UTILIZATION

would deliver significantly mo~e output Wind-speed and rainfall distribution than what would be indicated by the, average speeds. Since the bulk of the rainfall in arid areas occurs during the south-westerly Changes in wind· speed with height above monsoon, the need for pumping water the ground level from the wells may not ,be very much A piece of information normally re­ during the kharif season (July-October). quired by windmill-designers is concerning On the other hand, the raM season depends the selection of the height of the windmill almost entirely on irrigation, but then the towers. According to equation 3, for an winds are not at their best during Novem­ open terrain, one would obtain 58 % of ber to March. The highest wind speeds the free wind speed (obtained immediately are obtained during April, May and June after crossing the earth's boundary layer) whereas the maximum rainfall occur~ at 10 metres, 75 % at 50 metres and 84 % during July and August. Thus if the at 100 metres above .the ground level. groundwater is available, windmills can On the other hand, for a place surroun­ do their best to raise a summer crop ded by a number of tall trees and build­ (March-June) apart from alleviating the ings, the speeds obtainable at 10 m, 50 m drinking-water shortages in the arid areas. and 100 mare 20%,38% and 50% of the speed of free wind, respectively. These SOME DESIGN ASPECTS CONCERNING THE WINDMILLS SPECIFICALLY FOR data are useful in cost studies in which USE IN THE ARID REGIONS case on.e may like to select an optimum height for windmill towers. Finally we may consider some aspects connected with the designing of windmills Changes in the wind direction specifically [or arid areas. First, the An examination of the records of in­ water-table IS generally lower; a depth stantaneous wind velocity would reveal of 100 feet is not uncommon. Such a that, apart from fluctuation in the speed depth necessitates the use of deep-well every instant, the direction also changes. pumps. A proper design of the windmill During a day, the average direction does rotor to provide desirable torque charac­ not normally alter too much though a teristics is extremely important. The variation of±30 degrees is not uncom­ direct coupling of the windmill with a mon. It would, therefore, appear that rotodynamic pump is yet to be tried in windmills without automatic orientation, India, though this alternative is quite but with some manual attendance, may welcome for somewhat larger windmills also be considered if this arrangement in the 5-10 hp range. offers reduction in the cost. Of course, Cost reduction by utilizing suitable this would apply only to large-inertia, materials for the rotor is an attractive multi-bladed, slow-running water-pump­ possibility. Some experiments with low­ ing windmills. cost sail-type windmills have demonstrated the feasibility of such an idea. Whether, Diurnal variation in wind speeds in the long run, this is a more cost-effective In arid areas, just like most other places idea than the conventional metal-bladed in India, wind speeds are relatively high design is yet to be established. Simi­ during the daytime as compared with those larly, satisfactory furling arrangements during the night. This information is have to be developed with the sail-type useful in designing mUltipurpose wind­ windmills. mills for pumping water and electriclty Studies regarding the selection of a safe generation in which case winds of the night design speed for towers to withstand sand could electrify homes, and the strong winds storms, the optimum height for energy of the day could power water-pumps and and cost maximization, etc. are required, other mechanical devices. as these would help to effect some cost

299 DESERTIFICATION AND ITS CONTROL

savings. Similarly, the possibility of dis­ it would not be attractive for a normal pensing with automatic directional orien­ farmer to accept the windmill option tation where periodic manual attendance entirely of his own choice. may be available is worth studying. The government supports rural elec­ Perhaps the traditional water-lifts such trification as a socio-economic programme as Shadou (counterpoise lifts), rahat (the which often involves subsidizing for Persian wheel), mhote (rope and bucket), electricity availability in rural areas. It etc. could also be powered by windmills would not be out of place to suggest that as against a complete dependence on a similar subsidy could be provided for human and bullock work in many places. windmills as well. Apart' from the cost A study for designing suitable windmills of electricity at a point in the main trans­ and their matching with such devices can mission network, an additional invest­ also form a useful study. ment is required for the transmission The survivability of windmills against line, specifically for electrifying a parti­ exposure to marine atmosphere near the cular village. So far, when priority for coastal areas of Gujarat, and against the electrification was given to more populous dust storms of western Rajasthan requires villages located near the cities and the a proper selection of materials, protec­ towns, the transmission lines were not tive paints and coatings. The designing required to be laid "for long distances. of foundations for towers in the desert However, for less populated and far­ soil would require a more careful atten­ flung villages, transmission lines have to tion. traverse longer distances which are bound to raise the cost of electricity supply. ECONOMICS OF WIND-POWER There is a relationship between the length UTILIZATION of the transmission line and the associa­ A windmill is a capital-intensive device, ted break-even cost for windmills on a requiring a higher initial investment than per kw basis. It appears possible to that for a diesel engine, a pair of bullocks obtain one kw of power for about 1,500 or an electricity connection from a rural hours a year at most places with a well­ electrification scheme. The cash surplus, designed windmill costing Rs 10,000. if any, of the small and marginal farmer A windmill might prove even economical is not expected to be invested in a wind­ in many cases. Efforts put on designing mill. A farmer can probably raise a the cost-effective windmills are likely to loan from the bank or a co-operative pay good returns as well as provide an ,institution, but this would mean paying appropriate, non-polluting, renewable an annual .interest of 10-15%. Clearly, sOurce of energy.

300 Plate n. Camels are commonly used for ploughing fields in Rajasthan

Plate o. Rooting pattern of her (Zizyphus mauritiana) in relation to soil profiles having kankar pan in arid zones Plate p. A solar oven

Plate q. A banjara with his household belongings 32 THE UTILIZATION OF SOLAR ENERGY IN THE ARID AND SEMI-ARID ZONES OF INDIA

H.P.GARG

THE arid and semi-arid areas of the world The exploitation of solar energy offers have a uniformly high level of solar radia­ India a number of distinct economic and tion throughout the year. These other­ technological advantages in contrast with wise inhospitable areas, thus, have an inex­ the continued reliance on fossil fuels. haustible supply of pollution-free energy. First, it is a nondepletable, indigenous The total energy consumption of our energy resource and its exploitation will country increased from the fuel equivalent allow the country to reduce its dependence of 184.5 million tonnes of coal during on foreign oil. Second, it is abundantly 1953-54 to that of 358. 7 million tonnes of available throughout the country, allow­ coal during 1968-69. With the gradual ing for the decentralization of India's increase in population, our energy con­ energy and power systems. Third, where­ sumption is likely to reach a value of more as highly sophisticated technologies exist than 500 million tonnes of coal equivalent for its exploitation, numerous small­ in the near future. Since the thermal­ scale, low-grade, thermal devices are pre­ energy equivalent of one tonne of black sently available, and they can be pro­ coal is 2.9 x lOSjoules, the energy con­ duced on a cottage-industry level in India. sumption of our country for the year 1968- 69 would work out at O. 01 x 1021 joules per DISTRIBUTION OF SOLAR RADIATION annum. The corresponding values for the Solar energy is collected either with the energy consumption of the world and the help of flat-plate collectors or with focus­ USA are 0.3 x IOU'joules per annum and sing collectors. The flat-plate collectors 0.1 x 1021 joules per annum respectively .. utilize the total solar radiation; whereas Thus our total consumption of energy is the focussing collectors make use of only only 10 % of that of the USA, whereas our the direct solar radiation. Hence it is PQPulation is almost three times that of important to know the values of the total that country. This estimate indicates the solar radiation and the direct solar radia­ very low consumption of energy per head tion at normal incidence at a given place. in our country. In India, there are about 30 radiation The bulk of our energy consumption, stations, recording the total solar radiation unlike in other countries, comes from non­ of a horizontal surface (Rao and Ganesan, commercial fuels, such as dung, fire-wood 1972). The seasonal mean values of the and agricultural wastes. Since these fuels total solar radiation (caIJcm'Jday) on a can contribute valuable organic matter to horizontal surface for various arid and the soil of our agricultural fields, and semi-arid regions of the country are shown because the cutting of trees causes consi­ in Table 1. derable soil erosion, the use of these non­ The position of the sun in the sky can be commercial fuels must necessarily be dis­ known if the altitude angle and the azimuth couraged. angle of the sun is known. These angles

301 DESERTIFICATION AND ITS CONTROL

Table 1. The seasonal mean values of the total solar radiation (cal/cm'l/day)

Station Arid or semi- Winter Hot weather Monsoon Post-monsoon Annual arid (Dec.-Feb.) (Mar.-May) (June-Sept. ) (Oct.-Nov.) average Ahmedabad Semi-arid 429 611 466 458 491 Bangalore Semi-arid 461 580 392 400 458 Bhavnagar Semi-arid 442 618 452 481 498 Hyderahad Semi-arid 436 544 372 369 430 Jodhpur Arid 414 612 534 479 510 New Delhi Semi-arid 363 576 479 420 460 Poona Semi-arid 459 602 435 461 489

can be computed for a given place at any The total area of the Rajasthan State hour of the day with the help of trigono­ is 3,38,413 km2. This state may be assu­ metric relations, or can be read with the med to receive, on an average, about 5,100 help of a solar chart. A solar chart for kcal of solar radiation per m2 in a day. Jodhpur has been drawn and is shown in This quantity works out at 18,61,500 Fig. 1. With the help of t'his chart, the kcal/m" per year Thus the total solar altitude and the azimuth of the sun and the radiation received over Rajasthan in a number of the possible sunshine hours for year is of the order of 6,29,955 x IOu kcal. surfaces of any orientation can be easily This energy is equivalent to 91.131 million found out. tonnes of coal which is even more than the After knowing the components of total energy consumption of the world in direct, diffuse and reflected radiations and a year. Thus the solar energy has a large the various sun-earth relationships, the potential for being used as an energy radiation on the inclined planes can be source in our country. computed. The total radiation on an in­ The focussing type of solar-energy collec­ clined plane kept at an optimum tilt has tors make use of the direct solar radiation. been camputed for 10 Indian stations. Hence a knowledge of the direct solar From these data, it can be concluded radiation at normal incidence at a place that a surface kept at the optimum tilt is essential for knowing the effectiveness collects nearly 50 % more radiation than of the focussing collectors. Jodhpur may what a horizontal surface receives at the be taken as a representative place for find­ northern stations, e.g. Jodhpur and Delhi, ing out the potential of solar-energy utili­ and 35 % more in the interior peninsular zation with focussing collectors. Table 2 stations, e.g. Nagpur and Poona. For shows the moon values of the direct solar­ other stations, this increase varies from radiation intensities for different seasons 20 to 25%. for air masses 1 to 5 at Jodhpur. It may

Table 2. The mean values of intensities of the direct solar radiation in cal/cm' min. for different air masses at Jodhpur

Air mass Winter Hot weather Monsoon Post-monsoon Annual

1·0 1·44 1·18 1·10 1·34 1·26 1·5 1·22 1·02 094 1·16 1'0& 20 1·08 0·90 o 82 1 00 0·94 2·5 0·96 0·80 o 70 0·90 o 84 3·0 0·88 0·72 0·56 0·82 0·76 3.'5 0·84 0'66 0·48 0·74 0·70 40 0·70 0·64 0'42 o 70 0'66 4·5 0·68 o 60 o 38 0·68 o 62 5·0 o 66 0'58 0·36 o 68 o 60

302 SOLAR ENERGY UTILlZA TION

N i

100

I 170 S Fig. 1. Solar chart for Jodhpur be seen that the intensity is higher during SOLAR WATER-HEATER winter than during summer for the same Solar water-heaters may be divided into optical air mass. It may also be seen two main types and several variations of here that when the sun is sufficiently high each exist. Both utilize the flat-plate prin­ in the sky or during the period from 10 ciple, whereby solar energy is absorbed by a.m. to about 3 p.m., more than one the water being heated. No concentra­ cal/cm" min. is received, and this is a tion or focussing is employed in the sys­ sufficiently high amount of energy for tems now in practical use. The primary focussing collectors. These figures clearly distinction between the two types is that indicate the possibilities of a large-scale one comprises separate solar-heating and use of appliances for utilizing solar energy water-storage facilities, whereas the other in the arid and semi-arid regions of our combines the heating and storage func­ country. tions in a single unit. 303 DESERTIFICATION AND ITS CONTROL

The combined collector-and-storage-type as on the four sides and with one colour­ solar water-heater. In this solar water­ less glass (3 mm thick) cover at the top. heater, the flat-plate collector performs the The bulging of the tank under water pres­ dual function of absorbing the solar heat sure is reduced by using angle-iron flats and storing the heated water. A simple bolted on the sides of the box. The front collector-cum-storage-type solar water­ face of the tank is blackened with lamp­ heater, with optimized configuration was black paint. This absorber-cum-tank per­ first developed by Garg et aZ. (1972) in forms the dual function of absorbing the India and has since been extensively tested heat and storing the heated water. The by him, first at Roorkee, and then at main water-supply line is connected Jodhpur, with some modifications. The through a gate valve to the inlet pipe (12 advantages of this solar water-heater are mm in diameter) fixed at the bottom of that it is cheap, operates at a high effi­ the tank. A vent pipe is also provided for ciency rating, reaching up to 70 % and is safety purposes. The heater is of the non­ easy to install and operate, the only dis­ pressure type and works on the push­ advantage being that it does not ordinarily through principle. Hot water can be provide hot water for use in the early morn­ taken out from the heater by opening the ing. For this purpose, th'e system has gate valve provided on the inlet side of the been modified by Garg (1975) by incor­ heater. The heater is inclined at 41 degrees porating a reflector-cum-insulation cover from the horizontal and is orientated due for use during night. Another alter­ south to collect the maximum solar radia­ native would be to drain the hot water pro­ tion during winter at Jodhpur (latitude duced during the day into a separate in­ 26.30 deg. N). sulated drum in the evening and store it For rural use, where there is no mains for use in the early morning. for water-supply, a bucket is fixed at This combined collector-cum-storage­ the top of the heater and its lower end type solar water-heater consists of a rect­ is connected to the inlet pipe of the angular, 20-guage, galvanized-iron tank, heater through a piece of flexible plastic with ad optimized configuration, measur­ hosepipe. Hot water can be taken out ing 112 x 80 x 10 em, with a capacity of immediately by putting the same amount 90 litres. It is contained in a box of of cold water in the bucket. In order to mild-steel sheet, with a 5-cm layer of obtain hot water early in the morning, a fibreglass insulation on the rear as well hinged aluminium reflector-cum-insulation

Table 3. The monthly means of maximum water temperature (DC) reached in the low-cost solar water­ heaters, along with the monthly means of the daily total solar radiation (cal/cm/day) on a horizontal surface at Jodhpur during 1973-75

1973 1974 1975 Months Water Solar Water Solar Water Solar temp. radiation temp. radiation temp. radiation . January 53·7 369 60·9 395 5&·0 353 February 60·2 429 61·4 455 61·5 428 March 63·9 483 . 64·6 499 64·6 533 April 66·3 550 63'3 517 64'5 557 May 66'4 520 64'4 638 63'2 559 June 56'2 397 59·7 558 61·4 615 July 54·8 425 58·8 448 52·6 514 August 54'0 325 64·2 470 55'0 434 Septemb& 63·0 409 75'1 475 52·8 351 October 70·8 459 74·} 452 59·7 435 November 68·4 366 72'5 398 62·3 385 December. 59·3 343 61'5 343 60·0 372

304 SOLAR ENERGY UTILIZATION cover has been fixed to this heater (Garg, concluded that a depth of 10 em gives the 1976). This cover has a 5-cm fibreglass optimum performance. insulation and an aluminium reflector, Natural circulation-type domestic solar facing the glass of the heater. The in­ water-heaters. In this type of solar water­ sulation cover can easily be put on the heaters, the storage tank and absorbers heater like a lid of the box. are separate and the water gets circulated Data on the monthly means of maxi­ through the thermosyphon action. Here. mum water temperature reached in the generally; the tube-in-plate type of collec­ water-heater, recorded at 4 p.m., alongwith tors are employed. The efficiency of this the total solar radiation on a horizontal type-of collectors depends on a number of surface, are shown in Table 3. It is evi­ design parameters, such as the tube mate­ dent from this Table that in winter, the rial and its diameter, the spacing between maximum attainable temperature of the tubes, the plate material and its thickness water would be 50° to 60°C, whereas in and bond conductance. The following summer and the monsoon (except on a combination of materials and dimensions few rainy days), water at a temperature has given the minimum cost per unit of from 50° to 75°C can be obtained. efficiency. As this water-heater works on the princi­ G.I. tube diameter 10 mm ple of the push-through system, the tem­ Plate material Aluminium perature of water goes on decreasing as Thickness of plate 28 SWG one goes on drawing hot water from the Tube spacing 10 cm gadget. The performance of this type Once the configuration of the collector of water-heaters during winter has been has been optimized, it can be made in any observed and the data are pr~sented in size, depending on the requirement. A Table 4. few characteristics of this type of collec­ It has been observed that as the depth of tors have been shown in Fig. 2. This the storage tank increases, the collection figure can be used for designing. efficiency increases, since the thermal losses of the outside air decreases. SOLAR DRYING From the efficiency curve, it can be seen Since the dawn of history, solar energy that up to a depth of 10 em, the rise in has been used for open air-drying of a efficiency is very fast, but after that there is number of agricultural products, such as a negligible rise in efficiency. Thus it is hay, cereals, fruits, vegetables, timber

Table 4. The effect of insulation cover on the water temperature (OC in the improved solar water-heater in winter at Jodhpur during 1973-75)

Month and year Without insulation cover at With insulation cover at night Tap-water night temperature at 4p.rn. 8a.rn. 4p.rn. Sp.rn. 8a.m. (next day) eC) Jan. 1973 48·3 18·5 48·6 33·0 16·2 Feb. 1973 52·2 21·3 51·5 33·8 17·3 Nov. 1973 53·3 24·5 54·1 34·5 23·1 Dec. 1973 52·1 21·8 53·0 33·5 19·4 Jan. 1974 51·6 21·2 50·2 33·9 17·0 Feb. 1974 52·5 22·6 51·3 32·3 17·5 Nov. 1974 58·3 26·3 57·2 41·3 24·2 Dec. 1974 53·1 20·0 53·3 35·5 16·8 Jan. 1975 47·6 18·8 48·2 30·9 15·9 Feb. 1975 49·6 19·6 50·1 32·5 16·3 Nov. 1975 54·6 25·5 53·2 37·0 23·2 Dec. 1975 51·5 21·3 50·4 31·8 19·5

305 DESERTIFICATION AND ITS CONTROL

and fish, and non-agricultural products, material is directly exposed to solar radia­ such as bricks, the retrieving of salt from tion in a hot box-like arrangement and the sea-water, rubber sheets and paper. because of the absorption of solar energy In these free natural sun-drying processes, and air circulation, the moisture gets usually the high labour cost, the inferior vaporized. These dryers are very suitable quality due to contamination by dirt and for drying different products. In the in­ insects, the degradation of the products, direct type of solar dryers, generally known 90 as the forced-circulation-type dryers, the , material is kept in a separate drying-unit 40 BO _--f-. I - in some convenient place, and the air ... EHlclency heated by passing through solar air-hea­ ... -- 70 i? ... , ters, dries the material. These dryers 30 can be used for drying large quantities of 1 I",'" I'>: BOO produce and can also be used in industries. ~ c: ' ...... l!' 120 I:':> r-.. ~,600 ~ CABINET DRYERS FOR FRUITS AND :J!! I VEGETABLES :;:; 1,( tsO(), f"'.- m i'-- ~ i'-.. Z / ...... 400 I'" r-...... In India small cabinet dryers for drying ~ 10 l:::' 300' t--- ~ ~ :----... 20 fruits and vegetables have been de.veloped D. I E I ~ , ~ t--~ f::::: ~ 1-0 at the CAZRI, Jodhpur, at the LLT., ....'" I , --- --. ~ r--. ::-::: Kanpur, and at the Annamalai University, --- o Tamil Nadu. A number of trials for the 0 ,20 40-- 50 dehydration of chillies and ber (fruit of Mass floI/II rrile Kg/m' hr Zizyphus nummularia) and for convertin~ Fig. 2. Design curves for natura] circulation type solar water heater with optimized collec­ grapes into raisins have been conducted tor configuration at the Central Arid Zone Research Insti­ tute, Jodhpur. The Forest Research Insti­ wastages, etc. are frequently encountered. tue, Dehra Dun, has developed a solar In India-, only O. 5 % of the 32 million ton­ timber-seasoning kiln which cuts off 40 % nes of fruits and vegetables produced of the time required for seasoning. Forced every year is processed and preserved by convection-type dryers are presently being the industries and about 25 % of the total developed in the country at the CAZRI, production gets spoiled before it reaches Jodhpur, at the JARI, New Delhi, at the the consumers. Similarly, a considerable I.I.T., Kharagpur and at the Annamalai amount of farm produce, e.g. wheat and University, Tamil Nadu. paddy, is spoiled because of high humidity The dryer consists of a rectangular at the time of storing. Therefore the need wooden box" made of wooden planks for adopting moderately controlled (25 mm thick) with a basal area of metho,ds, such as mechanical drying with 1. 5 mS. The bottom of the dryer is insu­ . heated air or steam, have become apparent lated with a 5-cm-thick sawdust insulation in recent times, since such methods are and a glass cover at the top at an angle of independent of weather conditions and 23 degrees from the horizontal to receive 'give rise to good-quality products. The the maximum solar radiation throughout high cost of operating mechanical dryers tl;te year. The inside walls and the base of make the end-products so expensive as to the dryer are painted black and the drying make it imperative to search for cheaper material can be placed on perforated trays means. through a door provided on the back With the application of minor techno­ side. A number of holes are provided at logy and at a relatively little cost, sun­ the bottom and on the sides for the move­ drying may be made an efficient process. ment of air. The inside air temperature Solar dryers are broadly of two types. varies from 50°C to 95°C. With the help In the direct drying in solar dryers, the of this dryer, 15 kg of dates can be dehy-

306 SOLAR ENERGY UTILIZATION

drated and 15 kg of grapes can be conver­ heating of water, the colouring of water, ted into raisins within 2. to 4 days at Jodh­ have been experimentally studied at the pur, even during the monsoon season. CAZRI. Now efforts are being made to Practically all types of fruits and vege­ optimize the size of the solar still for tables can be dehydrated with this dryer. dom~stlc use as well as for laboratory use. SOLAR DESALINATION SOLAR COOKING Solar dIstillation is simple in technology According to a recent report published and is full of promise for areas where pota­ by the United Nations Environment Pro­ ble water is not available for drinking. gramme (UNE P), there is shortage of fire­ Moreover, distilled water is required in wood for every third person in the world. laboratories, petrol pumps, and health Be~ides advocating mass tree-planting centres. In isolated places and salt schemes, the report underlines the import­ farms, solar stills should be very useful. ance of developing alternative cooking de­ In some areas in the deserts, the salinity vices, such as the solar and the biogas level of the available underground water cookers. may vary from 5,000 to 10,000 ppm, too I n rural India, about 95 % of the fuel high for drinking. The only source of requirement is met from firewood, dung­ drinking-water in these villages is the cakes and vegetable wastes, of which fire­ rain-water collected in 'tankas'. In view wood constitutes the major share of 58.6 %. of this difficult situation, solar distillation There can be little doubt that the agri­ would seem to have much scope in the cultural sector will benefit immensely, if arid zone. cowdung and agriculture wastes are used The effects of different design variables as organic manure instead of burning them as depth and cover angles and also of indi­ at an efficiency of only 10 %. Solar energy, genous building materials on the output if harnessed economIcally through cheap of distilled water have been studied at the solar cookers, may provide a ready alter­ CAZRI, Jodhpur. Their designs are native source of supply of domestic fuel available in the published literature or can for cooking. Although the technical as­ be obtained from the National Research pects of the development of a solar cooker Development Corporation of Tndia. are simple enough, its advantages become Work on solar distillation at the Central significant only when the solar cookers are Arid Zone Research Institute, Jodhpur, used extpnsively. has been mainly concerned with the speci­ Recently, a systematic techno-economic fic aim of optimizing the size for a domes­ study of the development and field per­ tic solar still under the Indian arid-zone formance of different types of solar cookers conditions. As a result, a number of has been undertaken at the Central Arid single-sloped and double-sloped solar stills, Zone Research Institute, and on the basis both on the ground, with and without of this study, five different types of solar ground insulation, and on raised platforms cookers Or ovens have been designed and have been fabricated and an hourly re­ fabricated and tested in the laboratory. cord of distilled-water output has been The most efficient of these ovens consists maintained for two years and a half. of four square and four triangular plane­ The effect on the output of distilled water glass re~ectors, along with a well-insulated of a number of climatic parameters, such semi-cylindrical box on the back side, as solar radiation, ambient air tem­ made of sheet aluminium and wood, on perature, outside wind speed, outside air the angle-iron stand for adjusting the oven humidity, and design parameters, such as towards the sun (Plate p). A cradle-like base insulation, coverglass inclination, cooking-platform is made in the oven. It orientation of still-single-sloped and double­ helps to keep the vessel containing the sloped, and operational parameters, such food materials to be cooked in the hori­ as the depth of water in the basin, the pre- zontal position, irrespective of the inc1ina-

307 DESERTIFICATION AND ITS CONTROL tion of oven. The maximum temperature availability of 0.35 horse-power. The major in the solar oven with the looking-glass ingredients of an agricultural system are: reflector reaches up to 350°C in summer soil, sunlight, water plants and animals. and 250°C in winter. Some of the cooking Weare rich in all these ingredients, but tests conducted on this oven are listed in ours is one of the least productive farming Table 5. systems because of the inadequate avail­ ability of energy in the rural areas. There Table 5. Cooking trials in a solar oven conducted is a vast scope for multiple- and relay­ at the Central Arid Zone Research Insti­ cropping, provided more power is available tute, Jodhpur for lifting water from wells and other sour­ ces, which are underutilized at present. Type of food Cooking The development of a small solar pump time (minutes) of 2 to 5 kw capacity for irrigation can result in an agricultural revolution. In 1. Cooking most of the arid areas and in some parts of the semi-arid areas, the major portion (a) Rice (1 kg in water) 45 of our agricultural land is rain fed and if a (b) Potatoes (1 kg in water) 50 (c) Arhar dal (1 kg in water) 75 portion of this land can be brought under (d) Other vegetables (1 kg in water) 60 irrigation, crop production can be subs­ tantially increased. As the power requi­ 2. Roasting rements for this purpose are localized in (a) Potatoes (1 kg) 60 small scattered units, small self-sustaineci (b) Chicken (1. 5 kg) 60 energy units would be very useful for this (c) Fish (1 kg) 20 purpose. From the operational point of view also, 3. Baking solar pumps are likely to prove more effi­ (a) Cake (1 kg) 50 cient and provide more years of trouble­ free service than the conventional motors. 4. Boiling Solar pumps can be energized either by (a) Tea (4 cups) 25 converting solar energy into electricity (b) Milk (1 litre) 45 directly by solar cells or by converting (c) Water (1 litre) 45 solar energy into mechanical energy. The solar pumps based on the direct conver­ sion of solar energy into electricity, using The performance of this oven is not solar cells, are highly uneconomical at the affected by the wind; there are no chances present stage of technology. The solar of dust falling into the cooking~pot; the pumps based on the principle of convert­ food remains warm for hours together ing solar energy into mechnical energy are after sunset, if kept inside the oven 'and not only feasible, but have already been this oven does not require frequent adjust­ tried in France, the USA, the USSR an? ments towards the sun. Israel. There is no reason for such deVI­ ces not being put to use in our desert re­ SOLAR PUMP gion. If simple, efficient and low-pressure- To increase agricultural production and . vapour engines or vapour turbines ~re also the income per head, it is very neces­ developed, they can be used for convertlDg sary to increase the energy supply in the solar energy into mechanical energy and rural areas of the country. To attain a finally water can be pumped by using c~n­ production level of 2,000 kg per hec­ trifugal pumps, or with the reciprocatJDg tare . per head energy at an intake type of pumps. Even then, the capjt~l level of 3,000 food calories a day, and maintenance costs are likely to remaIn 0.75 h9rse ·power of energy would be higher than those of the conventional required per hect.are against the present types of pumps.

308 Plate r. A picture of sand-dune before initiation of its stabilization in ORP area

. Plate s. Acacia tortilis trees flourish 0.1 th:l b3rr~n sand.j Jne3 after their stabilization Plate t. Lest the howling winds blow away the top soil - a soil conservation measure in practice SOLAR ENERGY UTlLIZA nON

In a new type of low-cost pump, now at least by 100 times and the celIs are being developed at the CAZRI, a number made resistant to wind, dust, rain, humi­ of f1at-plate-bond-duct type collec­ dity, etc. tors made out of aluminium sheets are In India, work on solar cells was started used. The efficiency of these collectors is at the Indian Institute of Technology, New much higher than that of the c0I1ectors Delhi, in 1965 and at the Solid-State Phy­ used in other solar pumps. An organic sics Laboratory, New Delhi, in 1966 and liquid with a low boiling-point e.g. ether, both the institutions have developed solar is passed through these collectors to give cells with efficiency ratings reaching up to a very high vapour pressure. The vapours 10 %. The cost of these celIs is, how­ at a high pressure operate a diaphragm ever, very high. Obviously, much fur­ pump. The condensation and vaporiza­ ther study in depth is required in this field. tion of the liquid makes the diaphragm to Recently, the Department of Science and move backwards and forwards. This move­ Technology of fndia has established the ment of the diaphragm is utilized for the Central Electronics Limited, which pumping water. This is suitable for pump­ wi]] do R&D work on solar cells and ing water even against high heads, is al­ which will also co-ordinate research in this most free from vibration and needs but field. According to an estimate, by 1985, little maintenance. Flat-plate collectors three miIIion rural families in India will and a diaphragm pump which can operate be able to generate their own electric;ity at a low pressure has already been fabri­ for lighting and for running their radios, cated and tested by the' author for their using solar cells. The major technological performances. A pump of this type, with effort should now be directed towards the no moving parts and with less of heat-ex­ development of materials, techniques and changers, has been fabricated at the processes for large-scale, low-cost produc­ CAZRf and it is expected that the overall tion of solar cells. Attention all over the efficiency of this pump would be higher world is concentrated on this goal and it and the capital and running costs will be is not unlikely that by the turn of the cen­ lower than those of other types of solar tury, we will have solar-cell power-stations pumps. even in the remotest areas of our desert.

RURAL LIGHTING REFERENCES Solar energy has great potentiality for GARG, H. P. 1975a. Year-round performance running rural electrification systems in our studies on a built-in storage type solar water­ country. The direct conversion of solar heater at Jodhpur. Solar Energy 17(3): energy into eIeclricity by using semi-con­ 167-172. ductor photovoltaic ~ells, or 'solar cells' GARQ, H.P. 1976a .• An improved low-cost solar as they are commonly known, is receiving heater. Res. & Ind., 21 (3): 186-187. worldwide attention now. The solar cells GARG, H. P., GANGULI, R. and Puri, J. S. 1972. used for space applications are of extre­ Design and performance prediction of low­ mely high quality and, therefore, the cost cost solar water-heater. Res. & Ind., 17(4) : 129. of. these ceJls is about Rs 1,000 per watt. For terrestrial applications, such high­ RAo, K. N. and GANESAN. H. R. 1972. Global solar and diffuse solar sky radiation over quality cells are not required. Moreover, India. Meteorological Monograph Climato­ a widespread use of these cells can only be . logy No.2. India Meteorological Dept. examined, if the cost per watt is reduced Poona 5.

309 33 SOCIO-DEMOGRAPHIC FACTORS AND NOMADISM IN THE ARID ZONE

S. P. MALHOTRA

SINCE the late fifties, the global view of growth in the region and the policy opt­ population problem has been in focus in ions. A proportion of the population is the deliberations of various international nomadic and forms an important problem organisations. The present rate of popu­ in the Indian arid zone. Their way of life lation growth in the developing countries and rehabilitation measures have a1so been is penalizing hundreds of millions who live discussed. on the margin of subsistence. India is also faced with frightful population prospects, Population density and spatial distribution as the increase in popUlation is more than By the arid-zone standards, the Rajas­ 35,000 a day and has serious consequences than desert is one of the most thickly on our national resources. Examined in populated deserts of the world, and has an the context of the Indian arid zone, it has average density of 48 persons per km2, as been observed that the rate of growth of compared with 3 persons per km2 in most population in the region is relatively high other desert regions of the world. Though and the- dual increase in population and the variations in the densities of popu­ its needs set up an alarming situation, latiqn do occur on account of topography, specifically when viewed in the context of soils, land, the occurrence of economic extremely limited potentialities for agri­ minerals, accessibility and other socio­ cultural and industrial developments in economic factors, water is the most impor­ the arid areas. The arid areas of Raja­ tant factor determining the distribution sthan after Independence and at the time and density of popUlation in the arid zone of the merger of the state into thc Indian of Rajasthan,.where agriculture is predo­ Union inherited a ,poor and un diversified minant and mining is stilI undeveloped. economy, crippled through decades of The coefficient of correlation between the neglect and feudal exploitation. For the rainfall and the density of population in . purpose of the present discussion of socia­ the arid zone of Rajasthan was worked out demographic factors in the arid zone of at +0.6079, which is positively significant, Rajasthan, a part of the State of Rajasthan whereas the values of'r' exhibited a nega­ 'lying west of the AravalJis, covering tive correlation between the population 2,13,800 km2 and constituting 12 districts, density and the average annual rainfall in namely Jaisalmer, Jalore, Jodhpur, Pali, the plain (r= -0.2923) as well as in the Barmer, Churu, Sirohi, Bikaner, Ganga­ hilly regions (r= -0.0172) of Rajasthan. nagar, Nagaur, Sikar and Jhunjhunu, has The population density in the District of been considered. An attempt has been Ganganagar is higher owing to the avai­ made to <.iescribe. the population density lability of surface water through canal and spatial distribution, major popUlation irrigation. Similarly, the districts, such as trends, the growth potential, growth fac­ Jhunjhunu, Nagaur, Jodhpur, Sikar and tors, the implications of popUlation Pali, having greater facilities of well and.

310 SOCIO-DEMOGRAPHIC FACTORS AND NOMADISM

,-.. ,-.. ,..... 00 :::;- -.r N'" t;" ...... ""' o-.t;"'" t-"? "'~ 1.0 00 0 ~o -.r"? -.0-t- "" ...... 0'10\ Nt- 00 00 1-1- ",,,? 000\ "'''''_ 0'1('1. 0<'1 0; -.0 . l- N_ N'"N '0 0000 -0+' r:.+._, -+._, -+ '0 ...., v+._, "'+ ._, E-< "'+._, "'I'-oJ ._, c:: ,...... 8 :::;- 0 'oi ,-.. ,-.. ,..... ;;0 t- t- t--.r N ""'N 1-<:' 0'":"' r:- -a ooN 0<:' _t- N-.;t ..... 0\ o. ~ 0 <'I'? . 0\ . .r, 00 -0\ 0\ 0 0:1 "" "'0 -.r('l. 01_ 00('1. OIN -...... 0\ -.r", o. E 00_ '" ON . <'I ...,..+ v+ .... - <'1+ <'1+ M+._, ._, ._, + n ~ "" .:...+._, 1 ._, ._, 0 E-< ,-.. ,...... M 00 ,-.. 1.0 ""' '" 00 ...., co t--"" 0<:' <'I OOM -.r<:' VI '" g~ 0) 00 -.01-""' 00 . 0", 000 ...,.. . co "@ ...,..~ "'0 1"1 ...... M r- _1"1 <'I ...... r-'"<'I ::E 00 ·01"1 M+ <'1+ ,;,.,+._, ..:r+._, "'~ + M+._, 1 ._, ._, ...... + c:: '" ,...._ Q 00 :=:0 0,-.. ,-.. ,-.. ""' ,-.. t- ..., t- 1.0 ",01"" ",""'" ...,0 '" 1"1 00 <'I"" ...... , 00 ..... 0 ] "'N <'I ""'-.r 00", ..". ta ~~ --.r 0\0\ <'I", ..".- 1"1 .8 '"on on ...... 0 .... t;"N . N .:..+ '0 '" 0+ .:...+ .:..+...... _, + c:: E-< 0 6+._, 1 ...... o.:± ...... ~ ,-. ,-., 00 -a ,-.. 00 00 rl' 0. ,-.. on ""'-.r Nt- ...,00 0) oorl' r-<:' '"M 0 O\-.r !-"" ..".r:- CO..., '". 000 -on ..... 0. c:: ta ..". 1"1 . -.r ..... ~~ ('I. 0:1 ,_ r-"? ..".r- ""...., '- ,D 8 1"1 N_ -0 ""'1"1 . <'I 0+ "''''6+ 0 0) 01 _o± ...... + IJ;.. 6+ ._, 0+._, 0+ ..c: ;5 0 '-' ~ ,-.. 0 ,-., ,-.. ~ r- oo ""0 6h ,-.. ",,,? ..... <:' o-.;t"" N~ 00'-" -T~ '_o 00 0) ...,_ - J2!&o ...... :; -01 0\ .... 1"1 01 0-. -"" 0 ac~ 0 '"01 ...... ,00:1 -0\ 0\ .... ;..01 .... ~.~ .... '" - - 311 DESERTIFICAlION AND ITS CONTROL

tank irrigation show a higher density of and Sirohi (638.4 mm, 225). The higher population. The density of population physiological densities in the wetter distri­ declines from the foothills of the Aravallis cts are due mainly to intensive cultivation, to the narrow belt between the Sutlej and whereas they are higher in the drier distri­ the dry bed of the Ghaggar and the thirsty cts mainly because of the increases in pas­ sands of the desert. The density of popu­ toral activities. lation per km2 in Ihunjhunu is ] 57 persons; inSikar,I35;inPali, 78; in Nagaur, 71 Major population trends and in Ja!ore, 63. Proceeding towards the As shown in Table 1, starting wich a west, the density per krn 2 decreases fairly base of roughly 3.567 millions in 1901, the rapidly, with 52 persons in Churu, 50 in population in the arid zone of Rajasthan Jodhpur, 27 in Barmer, 21 in Bikaner and registered a linear escalation and increased only 4 in Jaisalmer. to 10.236 millions, i. e. the popUlation of The pressure of population may best be the region registered an increase of over studied by comparing the total population three times its size in 1901. Whereas the and the total sown area (the net sown overall growth rate of population during area + the double-cropped area) in the 1901-1971 had been of the order of 186.78 different arid districts. As shown in Fig. %(males+182.35% and females+191.70%) 1, the number of persons per km2 of the the rural population increased by 176.94% sown area (physiological density) is the (males+170.89 and female+183.78) and lowest (61) in the District of Barmer which the urban popUlation increased by 240.38 % has an average annual rainfall of 277 mm. (males+248.06% and females +232.58 %). The higher urban growth rate as well as % 34 the higher growth rate of the male popula­ tion in the urban areas is attributable to

Arid LOne of Ra,IBsthan ,' .• ' the migration (more of the male popula­ 2 tion) from the rural to the urban areas for livelihood. Meanwhile, as shown in Fig. I, 20 ~ ...... _..... L RaJSsthan StatB it is observed that during each succes­ - ...... ,,1 15 sive decade (except 191 I -1921), the popula­ /---- tion showed a constant increase, indicating thereby that each successive, generation ,/ had been more numerous than the pre­ ,: ceding one. It is further interesting to note that the percentage increase of popu­ .'931.41 1941.51 1951-61 1961-71 lation during each decade had been higher in the arid zone of Rajasthan than in the Rajasthan State as a whole. As against 186 %, the growth rate of population (1901- Fig. 1. Annual growth rate of population in 1971) in the arid zone of Rajasthan, the different census periods Rajasthan State, as a whole registered As the rainfall decreases below this figure, 150 % increase and the increase in the coun­ the physiological density increases, e.g.- in try during the period has been of the order Iaisalmer (rainfall, 164 mm; population' of 132 %. These figures evidently reveal density, 110). Bikaner (263.7 mm, 89) and that the growth rate of population Ganganagar (253.7 mm, 95). On the other in the arid zone of Rajasthan has been hand, where the rainfall increases above higher. Even, when the growth figll;res this figure, the density also increases, i. e. for the Ganganagar District (where Im­ Churu (325 mm, 70), Jalore (421.6 mm, 83), migration had been high) are not included, Jhunjhunu (444.5 mm, 184), Jodhpur it was found that the rate of population (318.7_mm, 97); Nilgaur (388.6 mm, lOl), growth was stilI higher in the arid zone of Pali (490.4 mm, 154), Sikar (441.4 mm, 179), Rajasthan (158 h)'

312 SOCIO-DEMOGRAPHIC FACTORS AND 'NOMADISM

The enormous acceleration of growth in tion that would substantially enhance the recent times is shown by the fact that the population in the near future even if mea­ number of new additions in only ten years sures are taken to check the population (1961-71) was worked out at 62.64% of growth. Taking the population within the number present at the beginning of the the age-range of 15-54 years as productive century. The relatively small growth rate it is found that 47.12% of the population of population in the decade 1901-I 0 and in the productive ages works for 52.88 % the decline in population in the next decade of the popUlation in the non-productive is most likely due to heavy mortality dur­ age5, i. e. every 100 persons in the produc­ ing the period. In recent years, the deve­ tive age-group work to support 112 per­ lopment of the means of communication sons in the non-productive ages. This and the extension of medical facilities have high dependency, unbacked by the adop­ considerably reduced the number of deaths. tion of competent and relevant improved Thus a much higher percentage increase production technologies, thus, presents a in population in the arid tracts of Rajas­ dismal picture. than poses an alarming situation, specifi­ cally when viewed in the context of limited "­ 1961 1971 resource potentials of the region. Age-Group Males Females Age·g;oup 55 and above 55-and above Growth potential 50·54 50·54 45·49 45-49 The future potentialities of the growth 40·44 40·44 of population are indicated by the present 35·39 35·39 age and the sex composition of the popu­ 30·34 30·34 25·29 25-29 lation and its marital status. The age and 20-24 20·24 sex composition (Fig. 2) of the population 15·19 15·19 10·14 10·14 of the arid zone of Rajasthan reveals a f-----'.J'---." pyramid with a broad base and represents 0·9 , 10 9 8 7 6 5 4 3 2 1 0 0 1 a preponderance of the young population --'---1961-1971 e.g. those under 10 years of age represent Scale·1 em_5'1. 31.39 per cent of the total female popula­ Fig. 2. Age and sex composition of popula­ tion and 31.57 per cent of the total male tion inhabiting the arid zone of Rajas­ population. The percentage dis tribution than of children (0-14 years), young (15-34 years), middle-aged (35-54 years) and old Marriage is another important variable (55 years and above) worked out at 43.75, connected with age and sex, which is indi­ 28.18, 17.20 and 7.26 respectively during cative of the future growth of the popula­ 1961 and 43.35, 29.75, 17.38 and 7.52 res­ tion. Marriages in respect of both sexes pectively during 1971. It is thus observ­ in the arid areas show a rather interesting ed that the younger people (0-34 years) pattern. The age distribution of unmar­ constitute over 75 % of the total popula- ried males and females in ]951, 1961 and

Table 2. Age and sex distribution of the unmarried population in the arid zone of Rajasthan

Age-group 1951 1961 1971 in years Male Female Male Female Male Female % % % % % % 0-14 78.20 93.70 79 57 96·15 79·33 94·82 15-34 18.40 5·70 18 28 3·57 18·75 5 11 35-54 2.30 0.40 1.40 0·09 1·39 004 55 and above 1.10 0·20 0·75 0.19 o 53 0·03

313 DESERTIFICATION AND ITS CONTROL

1971 (Table 2) reveal the practice of early country. It is, no doubt, evident that the marriage. population checks would definitely come The data indicate that there are very up, but such wild guesses are only a warn­ few unmarried people over 35 years of ing against the future population pressure age, showing a universal nature of marri­ and a hint at the nature and extent of age. Even in the age-group ]5-34 years, societal efforts necessary to avert the popu­ the percentage of unmarried women is very lation explosion. small. Indications of the future growth rate of the population are further avail­ Growth factors able by analysing the figures relating to the In ~pite of the dearth of reliable vital number of females in the reproductive statistics, the impact of rapidly declining period (15-44). There are 4,037 females in mortality is obvious. The major factor the age-group ]5-44 years for every 10,000 responsible for such a phenomenal rate of women of all ages, and this number is growth of population is the widening gap quite high. The age composition of the qetween the birth and the death rates. By females (Table 3) in the reproductive period and large, the external migration has play­ and their marital status further indicate ed a relatively insignificant role in the the expansive potentiallties of the future population dynamics of the arid zone. Im­ growth of population. It is observed that migration has been very limited in the arid there are a large number of women in areas because of the absence of the factors their first half of tbe reproductive period like productive lands, large-scale industries all through 1951-1971 than in the second and mineral production. In spite of the half of the reproductive period. Further, heavy push factors, viz. overcrowding on the percentage of married women in the the already oversaturated lands, etc. there reproductive period was worked out at has not been much of outmigration main­ 90.31, which is also indicative of the civil ly because of the lack of pull factors (like condition of the female population predis­ absorption in big industries or other urban posed to very high growth rate. vocations) and also because of the back­ wardness of the people, poor means of communication and the sway of the social Table 3. Distribution of women (five-year age­ institutions, such as the joint-family sys­ group) in the reproductive period in the tem, caste-system, early marriage, and the arid areas of Rajasthan illiteracy and conservatism of the people. For instance, the percentage of immigra­ Age-group in years 1951 1961 1971 tion from other States to Rajasthan (1961 Census) h.as worked out at 4.90% of the 15-19 19 10 18 39 20 01 total population, whereas that of outmig­ 20-24 18·40 21 72 19·84 ration from Rajasthan to other States was 25-29 19·60 19-44 18 03 worked out at 5.62%. Thus the net out­ 30-34 17·70 1664 16'85 35-39 12 20 11 45 12 66 migration was worked out at 0.72% of its 40-44 12 90 12 36 12·61 total population. The immigration in the arid zone of Rajasthan had been further low and was worked out at 2.14% of the total One may surmise that if the growth of. population. Of this, the district of Ganga­ population remains unabated and the rate nagar claimed 70.74 % of the inmigrants, of growth remains the same as during the and the other eleven districts did not decade 1961-1971, by the turn of the cen­ attract immigrants, as the social inertia for tury the population of the region will be it is quite limited. The increase in popu­ over 21.54 millions which is much more lation may, therefore, be attributed mainly than the present population of the conti­ to the widening gap between the birth rate nent of Australia. In fourteen decades it and the death rate. The chief factor res­ will m.atch the pr~sent population of the ponsible for the future growth potential of

314 SOCIO-DEMOGRAPHIC FACTORS AND NOMADISM

the population are the social values predis­ city of crop land. This major form of posed for having more children. Positive human occupation is marked by instabi­ sanctions for fertility far outnumber the lity that carries the hazards of sudden fail­ negative ones. Early marriage and the ure, leading to famine conditions. Under begetting of children are important parts such circumstances, to a person, who of the social ethos of these people. Main­ needs a fresh capital to be able to produce ly, to save expenditure on separate feast­ or earn, an extra child is a very good risk ings, marriages of the girls of lineage in capital. And since many of these children which a person has died are performed on do not go to school, the cost of this risk the third day of his death when a death feast capital far outweighs the tempting benefits called 'mossar' is organized. Child marri­ that this will provide right when the child ages are most prevalent and the minimum attains 9-10 years of age. At this small age of marriage of both girls and boys may age, the children are initiated as workers be even less than a month. The actual con­ in desert areas, specifically engaging them summation of marriage (muklawa), how­ in livestock-grazing, etc. Caste is still the ever, takes place when the girl has attain­ pivotal social institution and has restricted ed the age of 12-14 years. Marriages social and occupational mobility and fos­ once enacted cannot be annulled. Any tered values and sanction concerning ferti­ deviation from the established norms being lity. Laden with socio-religious factors not only looked down upon as grossly and values predisposed to having a larger aberrant but also as wholly incompatible number of children, the growth potential with the social fabric of the community. exhibited is quite high. The high growth Divorce is a rarity, if not altogether u.n­ rate of population coupled with the so­ known, and widowhood soon culminates called modern impact has led to the break­ in remarriage. Improved medical care up of the traditional joint families, with in recent times has greatly minimized mor­ their deep ties in the rural community to talityat birth and has increased longevity. the formation of the nuclear families. Of Additionally, more than eight out of the households surveyed (Malhotra and every ten persons still live in the rural Sen, 1964),52% were found to be nuclear. areas, with all their problems, backward­ With this transformation of the house­ ness and daily life saturated with customs holds, individualism has become increas­ and practices which often override prud­ ingly manifest in family relationships. The ence. Their percentage literacy and its disappearing of joint family is thus posing level is rather low and even today, not even a paradox, just at the time when new 2 out of every 10 persons are literates and longevity conditions are generating the the percentage of rural people possessing necessity for the care of the aged in the functional literacy is rather insignificant. joint family. The other forces are cons­ The percentage literacy among the female piring against it and more and more nu­ population was worked out at 5.86 in 1961 clear families are being formed. There and only 7.85 in 1971, thus exhibiting a being no State-mooted old-age security very insignificant increase during a decade. measures (old-age homes, old-age pensions, Similarly, the rural females getting work etc.), the parents like to have an addi­ outside the home (apart from the family tional number of male issues, so that they labour that they provide) would have been can fall back upon at least one during another factor responsible for changing their· old age. the attitude of the females for limiting the number of children that she should bear Implications of population growth has not exhibited a substantial increase. During the feudal times, the population Most of the labour force (over 80 % of size was one of the very important factors the working population) is tied up to a to maintain power, prestige and labour pre-modern agriculture which suffers from force. Owing to changed circumstances, an additional handicap of increasing scar- size per se is not critically as vital as it

315 DI'SERTIFICATION AND ITS CONTROL

was in the past. On the other hand, when that it had so far made only a small we see the impact of increasing density on leeway and the fruits of improved 1echno­ the viability of the ecological unit, the logy had not been harvested to a signifi­ negative effects of the increasing density cant extent by the farming population. As on the socio-economic situation are not a consequence, more and more marginal hard to find. For, instance, the youthful­ lands are being brought under the plough, age structure, the high dependency ratio, as is evident from the land-use statistics. primarily consisting of children and young The net sown area increased by 44.64 ~~ adults, require much heavier outlays for during 1951-61 and by an additional 9,47% simple maintenance, education and train­ during 1961-71 and the area under the less ing for the future as well as for the fast intensive uses of land (barren cultivable multiplication of job prospects. It may and un cultivable wastelands, permanent be observed that the youthful population pastures and fallow lands) declined by in the arid zone of Rajasthan grew at a 16.83% during 1951-61 and further by much faster rate-nearly twice as fast as the 6.95% during 1961-71. Thus during 1951- growth rate of the total population, thus 71, there had been a substantial increase intensifying the difficulties \n meeting the in the SOWn area at the cost of grazing­ demands of the expanding youth cohort. lands because of the extension of cultiva­ The revolution and other forms of radi­ tion to marginal lands. Paradox.ical, as it calism are associated with a preponder­ may appear, on the other hand, the live­ ance of youth population (Weiner, 1971), stock population increased from 10.3 and if the present faster growth rate of millions in 1951 to 14.5 millions in 1961 the youthful population continues, it may and to 16.4 millions in 1971. lead to the problem of a generation gap One of the factors additionally respon­ resulting in serious disruptions. sible for using more and more of marginal The economy of the arid zone of Rajas­ lands for growing crops is the adoption than, based mainly on agriculture, has not of short-term welfare measures for the been able to keep pace with the fast-grow­ growing population rather than the use ing popUlation with the increase in the capability of land in the long run, e.g. the working force, there has been an overcrow­ land-distribution policies in the region have ding in agriculture, as the region lacks a aggravated the maladjustments in the diversified base. The situation is more land-use pattern. Most of land allotted to revealing when we take the man-land landless, marginal farmers, etc. was mar­ ratio and the high proportion of labour ginal and submarginal, and was added to force dependent on land. Fig. 3 represents the crop lands. As a consequence, the the total land availability per household yield per un"it of cultivated area is showing and also the different" categories of land a declining trend. The annual linear growth available per household in I 95 I. 1961 and rate (1954-70) worked out at -0.66, -4.88, 1971 and its estimated availability during -2.17, -6.08, -1.20 and 0.18 respectively 2001. It is observed that while the total for pearl-millet, sorghum, pulses, sesamum, land available per household was only gram and barley. 17.77 ha in 1951, only, 14.69 ha and 12.40 The rapidly growing population has ha was available during 1961 and 1971 inflated the demand for wood for different respectively and only 7.52 ha is likely to . purposes, whereas it has reduced the area be available by the turn of the century. under fallows, wastelands and forests. All Similarly, the total cultivable land availa­ these factors indicate the trend towards an ble per household declined from 13.72 ha increasing scarcity of resources in the to 9.95 ha in 1971, and only 6.03 ha is arid areas. likely, to be available in 2001. Studies conducted on the diffusion and adoption NOMADS AND NOMADISM of improved technology by the rural popu­ Additionally, a sizable proportion of t~e lation '(Malhotra, et al., 1972) revealed population leads nomadic or semi-nomadIC 'j 316 SOCIa-DEMOGRAPHIC FACTORS AND NOMADISM

L:·:·;::;:j LAND "ART T~ NON-AGRICULTURAL USE mIiOO BAMEN 8 UNCULTIVABLE LAND. 17·78 no 8 ~ PERMANANT PASTURE e OTHER GRAZINGLANO. ':!Pho .. FOREST 7 CULTIVABLE LAND. 6- fIIIIIJlI11Il 14·69ho 5- . -4 <: 4 :1 :15ho 3 !I I 12-40 ho ·39)10 2 I

o

9

B 7·52ho

7

6

5

4 3 19 95 ita IE II

2

seA LE I em· I ha

Fig. 3. Land .:available per household per hectare life. The sources of livelihood and the way of common occurrence in the region: To of life of the people have been conditioned cope up with such unfriendly climatic and by the disturbance in the ecological balance environmental conditions, the inhabitants owing to the severity of the arid climate, have been resorting to nomadic and semi­ the continuous deterioration of the soil, nomadic life. They are not a separate the dwindling of natural resources, occa­ ethnic group and do not have a separate sional drought, invasions by outsiders, territory, with exclusive rights and econo­ poor means of communication and conse­ mic framework. The resource use being the quential social and economic uncertainties. decisive factor of the pattern of their Famines of different kinds, namely aka I living, the nomadic groups of the arid (great famine), jalka/ (scarcity of water), zone may be broadly grouped into four tinkal (scarcity of fodder) and trikal (scar­ categories. viz. (a) the pastoral nomads city of fodder, water and grain) have been (Raikas, sindhis, barihars, billoch,f, etc.),

317 DESERTIFICATION AND ITS CONTROL

(b) the trading nomads (banjaras, ghatti­ wala jogis and gawarieas), (c) artisan no­ mads (the gadoliya lahars, sansis and sattias), and Cd) miscellaneous types of 90 nomads (nats, halbeliya jog is) (Malhotra, 80 1971). 70

Relationship with settled population 60

Each type of nomads is associated with 50 some kind of livestock which makes indiscriminate use of the meagre available 40 water and grazing resources and destroy 30 the local soil-conservation measures. The 20 nomads in the present times, thus, are a menace to the whole society and their 10 sedentarization is imperative. The opening up of the means of communication has ., ~ '" >- V> '"!!! .:::-'" -='"

318 SOCIO-DEMOGRAPHIC FACTORS AND NOMADISM searched for constructing the toba and lize in certain trades, much.publicised again this place should form a good gadoliya lohars, sansis and saltias. The catchment area, so that water from all the sattias and the sansis carryon a limited four sides runs and collects at this place. trade in cattle and render veterinarv ser­ Each village of the cattle-breeders has 5-6 vices to the livestock of the villages on to bas dug, depending upon the caste and their routes. It is the nomads, like these, community composition. who are known for their immoral activi· With the onset of the monsoon, there ties, illegal transactions and skill in thie· is a dispersal of herds far and wide within ving and who have created a resentment the boundaries of the viJIage, wherever in the minds of the settled population surface water is available in the dug-out against the hapless nomads. They are tobas which are constructed and kept in placed even by the nomads themselves in repair for the efficient use of the meagre the lowest category of their social available water and grasses. The use of hierarchy. tobas is regulated by conventions and it is The nomadic blacksmiths are locally customary to make use of other tobas called gadoliya lahars. They are one of the when the water in one's toba is exhausted. artisan nomads in the States of Rajasthan. Nobody was thus prepared to deepen his Punjab and Madhya Pradesh. Their terri­ toba lest the grazing resources are utilized torial extension is even in the semi·arid by others. Thus the people stressed that and humid environments. The traditional the tobas had to be dug deep on a large occupation of the gadoliya lohars is black­ scale rather than making any piecemeal smithy and trade in cattle. Their move­ efforts. In case the rains fail, the breeders ments to different places are dependent migrate with their livestock to the irriga. upon the availability of blacksmithy work ted areas of the Ganganagar and Feroze· and prospects of trade in cattle. They have pur districts. Before the formation of developed a symbiotic relationship with Pakistan, they used to go up to the the sedentary farmers for supplying them Bahawalpur region which is now a closed with agricultural tools and implements. boundary. They also sell utensils for the farmers' It has been recommended (Malhotra households. These materials are supplied et al., 1966) that each household in the to the rural population on cash or ex­ canal·commanded area may be allotted change basis. The technology of manufac· 6.3 ha of land and a partial mechanization turing the tools, implements and utensils of cultivation may be resorted to. Dairying of iron is indigenous and it involves hard may be introduced as an industry on work, and a large amount of lahour. scientific lines. Sheep-raising is the chief Almost all the members of a family re­ subsidiary occupation in the region. At main engaged in this occupation. On the present, the sheep-owners have to travel average, a household earns about one long distances and their nomadism can be thousand rupees annually from this occu· arrested by upgrading the short grass pation. Uncertainty of the availability of rangelands by reseeding these pastures with work and risk in earnings has created grasses, e.g. anjan (Cenchrus ciliaris) and feelings of fraternity and mutual give-and­ dhaman (Cenchrus setigerus). The intro. take in society. Unlike other nomadic duction of the mutton industry, the setting groups, generally they do not take loans up of wool· grading and shearing-centres from fQ_e moneylenders. They are economi­ shall further save a lot of their energy and cally and culturally very backward. Their fetch the breeders much higher income children are normally not sent to school, than they earn at present. and as such, illiteracy is very common. The nomads move about in small kin­ Artisan nomads ship bands in their bullock·carts with their The second important category of families. The nature of movement of nomads is constituted by those who specia· different bands of these artisan nomads

319 DESERlIFICATION AND ITS CONTROL

follow a regular cycle on regular monthly households of diff

320 SOCIO-DEMOGRAPHIC FACTORS AND NOMADISM

in eco~omic pursuits (Plate q). so far as it is not based on balanced and With the onset of rains, the banjaras well-conceived plans, and is not adaptable move towards saline basins where salt is to the traditional nomadic way of life, manufactured. After rains, grass and water and their aptitudes. The sedentarization are available en route for their animals. of the nomadic way of life is a gradual In addition to the salt trade, they sell and slow process. Though all-round deve­ Fuller's earth and onions in the remote lopment of the region may result in a villages of the desert tracts. These banj:Jras spontaneous sedentarization of the nomads, move towards the Glljarat State during there is a possibility of social as well as the post-monsoon period. There, they get cultural annihilation of the nomads. The ready employment in the form of hauling question that haunts the ecologists and of commodities, e.g. building materials sociologists today is how to absorb these and grains. by their bullocks. people within the framework of modern The nomadic banjaras do not avail living and make them useful members of themselves of any 'community facility and society by exploiting their natural apti­ have no social and cultural relationships tudes. with the settled population whom they Government efforts made in the past meet only for trade purposes. There is have proved to be of limited success some communication between the money­ because of the short-sighted policy and lenders and the banjaras, as the latter unscientific approach, which completely generally take loans from them for their overlooked the social structures and exis­ trade. ting institutions that could have gone a The banjaras are economically backward long way in keeping the nomads together. and their standard of living is very poor. The experimental attempts of the State As a result of improved means of commu­ Government to rehabilitate the gadoliya nication and the opening up of hitherto lahars in SOjat, Khanpur, Barmer, Shiv, inaccessible an'as to road transport, their Beawar and Kishangarh are classic exam­ traditional relationship of mutual depen­ ples of random allotment of land and dence on the sedentary population has unfulfilled promises. broken down. The balljaras find it difficult to sell their commodities with a good mar­ Policy options gin of profit as in the past. The shortage In Sauvy's (1961) blunt phrasing, it is of grazing-land is another problem for always a question, i.e. which of the four them. Their earnings have sufficiently parameters will be set in motion, viz. declined and several of them are in perpe­ death, emigration, economic level and tual debt. For sedentarizing the trading birth. nomads (banjaras) , the tanda should be The population policy calling for increa­ taken as one unit for settlement purposes sed mortality (Duza, 1975) is unthinkable, in different villages. It shall be highly as it would be culturally and ethically desirable to make use of the existing untenable. Further, as in the case of administrative machinery among the other South-Asian popUlations (Myrdal, nomads rather than supersede it. 1972), the population in the arid areas of The fourth class consists of miscella­ Rajasthan are destined to live "within the neous nomads, e.g. the nats and halbeliya lands of their birth" mainly because of' jogis, who earn their livelihood by showing the J!lck of pull factors, preponderant acrobatics, jugglery and snake-charming illiteracy and the sway of other social at village fairs and to roadside gatherings. institutions. The strong push factors, e.g. The technological, economic and politi­ declining man-land ratio, coupled with the cal changes of the recent times are influen­ recurrent famines to drive out the popula­ cing the nomadic population in this region tion to the cities and towns within the out­ with such rapidity that they are facing a side of the arid zone to work sometimes social decay. This influence is chaotic in as under-employed day labourers. A, sig-

321 ,DESERTIFICA TION AND ITS CONTROL

nificant section of the population leads a of school drop-outs. Such a programme semi-nomadic life, and others migrate also needs a thorough integration with the during famines along with their livestock. running adult-education programme. The All the same, such pastoral nomadism or norms of raising the marriage age and of migration for animal husbandry or other 2 or 3 children per family should ultima­ purposes is temporary and such migrations tely form a part of the value system. are not of any demographic significance. The nomad has to settle down now, but The third factor in Sauvy's scheme, any official attempt at inducing him to involving an economic solution in the form do so should invariably be tampered with of progress in production, cannot be sympathy and understanding of his preju­ ruled out, but owing to the lack of possi­ dices, beliefs, social concepts and, above bilities of technical miracles and limited all, of his basic requirements. Only a resource potentials, the portents on this humane approach can hope to win over count are likely to weigh heavily on the the nomad, so that he may be interwoven promises. with the whole fabric of the day's society The only alternative, therefore, left is in the arid zone. the reduced fertility, leading to small family norms through family-planning REFERENCES efforts. However, the Family-Planning DUZA BADRUD, M. 1975. The cultural conse­ Programmes undertaken in the region quences of population change in Bangladesh. after Independence have yet to make any Report on a seminar held in Bucharest, impact in the region owing mainly to its Romania, on the cultural consequences of inherent weakness in terms of the negli­ poplllation change. The center for the study of man, Smithsonian Institution, Washing­ gence of cultural variables which are ton,D.C. mainly responsible for creating chains of resistance. It may be emphasized that the MYRDAL GUNNAR 1972. Asian drama. Allan Lane, Teh Penguin Press, 74 Grosevenor obstacles to small family norms are not Street, London. primarily technological but sociological. Unless ,the ancient prejudices, deeply MALHOTRA, S. P., BHARARA, L. P. and JOSHI, P. L. 1966. Socio-economic characteristics ingrained beliefs and traditional cultural of inhabitants of Anupgarh-Pugal region. practices are taken into account, it will Indian Sociol. Bull. 3 (2) : 107-21. deprive us of the sources of support to MALHOTRA, S. P., BHARARA, L. P. and JOSHI, any family-planning programme and blind P. L. 1966. Impact of land, water and us to the centres of resistance. A mere vegetation resources on the economy of the addition to the number of family planning cattle breeders of a desert village. Ann. Arid Zone 5 (2) : 219-28. clinics, which do provide the people with . . the necessary information and services, is MALHOTRA, S. P. and BOSE, A. B. 1967. Nyat likely to have limited effect, and the as an agency of social control among the motivation for family-planning will not Banjaras, in Leadership ill India, Vidyarthi, increase in view of these two aspects alone L. P. Asia Publishing House, Bombay. in this traditional social system, oversatu­ MALHOTRA, S. P., SEN, M.L.A. and JOHORY, rated with ancient prejudices and beliefs. C. S. K. 1966. Problem of rehabilitation of nomadic Gadoliya Lohars. Indiall Sociol. . Bold social-security programmes for the Bull. 4(1) : 43-54. poor often in the grips of famine should' be thought out, and the evolvement of MALHOTRA, S. P. 1971. Namads of Indian Arid controlled and directed intra- and inter­ Zone. 21st InteTllational Geographical Con­ gress, Symposium 011 Arid Zone: 117-24. state migration policies for employment MALHOTRA, S. P. and SEN, M. L. A. 1964. A and job opportunities should be worked comparative study of the socio-economic out. Additionally, it may be necessary to characteristics of nuclear and joint house­ have an intensive population-education holds. Family Welfare 11(1) : 21-32. programme, both in and out of the for­ MALHOTRA, S. P., RAO, J. S., GOYAL, D. and mal school system bec;ause of the high rate PATWA, F. C. 1972. Population, land use

322 SOCIO-DEMOGRAPHIC FACTORS AND NOMADISM

and livestock composition in India and Populatiol! Problem from Malthus to its arid zone. Ann. Arid Zone 11(12) : 116- Mao-Tse-Tung, Criterion Books, New York. 27. IALHOTRA, S. P., JOSHI, P.L. and RAO, J. S. 1974. WEINER, MYRON 1971. Political Demography: Relative importance of some socio-econornic An inquiry into the political consequences factors in the adoption of agricultural in­ of population change. Rapid population­ novation. Indian 1. Ext. Education 10 growth: Consequences and policy implication, (l & 2) : 62-64. National Academy of Sciences. The Johns AUVY, ALFRED 1961. Fertility and Survil'a/: Hopkins Press. Baltimore and London.

323 34 ASSET-LIABILITY IMBALANCES IN AGRICULTURAL SECTOR OF THE INDIAN ARID ZONE

H. S. MANN AND JAGDEESH C. KALLA

THE preparation of a dispassionate inven­ dating 20 million human beings and 23 tory of assets and liabilities of the desert million cattle. The desert lands are usual­ lands is a prerequisite for initiating any ly subject to extremes of climatic parame­ meaningful planning. In the present con­ ters and are predominated by its non-crop text, assets and liabilities have been cate­ uses (Table 1). This low-intens1ty use of gorized according to their economic, social land culminates in a low level of produc­ and dynamic purpose, prescribed for the tivity and thus these lands tend to be more society inhabiting the desert region of of a liability than of an asset. This ten­ India. dency of land use is in tune with the ear­ Although, irrespective of the criteria lier findings of Mann et al. (1974), in employed, the desirability of assets lies which the analysis of the time series re­ in their positive and greater value than the vealed a continual shifting of the existing liabilities, the increments in liabilities do crop areas in the pool of degenerated land not ns:cessarily indicate a destitution of forms in eleven arid districts of western society in the socio-dynamic sense. The Rajasthan. The process of conversion of incurrence of liability by society is often good agricultural land into a liability ow­ necessary for creating conditions conduc­ ing to its use is not peculair only to the ive to an enhanced standard of living. So­ arid districts of western Rajasthan. Al­ cial liability by the same token of argument most a similar tendeney of the degenera­ does not necessarily ensure the welfare of tion of land capacities, albeit to varying society. , degrees, in the desert regions occurs in An attempt has, therefore, been made to other Statoo of India. evaluate the economic; social and dynamic Another factor which pushes the present imbalance of the crucial resources to pre­ use of arid lands into the orbit of liability cisely identify the constraints mainly 'attri­ is the existing imbalance in the growth of buted to the present sluggish productive human population, depending directly ()r performance in the agrarian sector of the indirectly for livelihood on a given piece desert lands in India. of land. The immediate effect of the po­ pulation increase on the land can be locat­ STRUCTURAL IMBALANCES IN TECHNO- . ed in its faster tendencies to be fragmented ECONOMIC ASSETS AND LIABILITIES into small uneconomic holdings. The The hot desert region in India is geogra­ results from the census of the holdings for phically distributed (Krishnan, 1968) in years 1970-71 (Table 2) in respect of the the States of Rajasthan (62 P. C.), Haryana States of Rajasthan. where most of the (4 P. C:.), Gujarat (20 P. C.), Andhra Pra­ desert lands are located, reveal that the desh (7 P. C.), Mysore (3 P. C.) and Maha­ increase in popUlation has generated a rashtra (0 40 P. C.). The total desert area, more skewed distrIbution of land among thus occupies 3.17 million km2 accommo- the rural popUlation. About 54 % of the

324 ASSET-LlABILITY IMBALANCES IN ARID-ZONE AGRICULTURE

Table 1. Land-use pattern of the arid districts of western Rajasthan (1961, 1966 and 1971)

Year

1961 1966 1971

Reporting area not available for cultiva­ tion 20,822 20,842 20,862 (a) Forest 163 150 (-7·97) 168 (+12'00) (b) Land put to non-agric. uses 591 655 (+10'82) 662 (+1'06) (c) Barren 2,383 2,370 (-0' 54) 2,349 (-0'88) (d) Total 3,137 3,175 (+1·21) 3,179 (+0 12) Other uncultivated land

(a) Permanent pasture 707 761 (+7'63) 773 (+1'57) (b) Land for misc. tree crops 1 4 (+300 00) 2 (-50'00) (c) Cultivable waste 4,710 4,665 (-'95) 4,561 (-2-22) (d) Total 5,418 5,430 (+0-22) 5,336 (-1· 73) Fallow lalld (a) Fallow land other than current fallow 2,478 1,629 (-34·26) 1,911 (-17 -31) (b) Current fallow 1,580 1,475 (-6-64) 1,191 (-19 25) (c) Total 4,058 3,104 (-23 -50) 3,102 (-0 06) Area ill thousand acres

(a) Net area sown 8,209 9,135 (+ 11 28) 9,247 (+1'22) (b) Total cropped area 8,325 9,308 (+11·80) 9,577 (+2-88) (c) Area sown more than once 116 173 (+49-13) 330 (+90-75) Source: Compiled from Annual Digest. Issued by the Directorate of Economics and Statistics, Govern­ ment of Rajasthan, Jaipur. holdings below 5 acres have occupied only lands to be more of a liability in desert re­ about 11 % of the areas. The data also re­ gions of the country. However, this negative veal a negative association between the balance of the net worth of land can posi­ number of the holdings and the size. Al­ tively be converted into an asset, if for the though the percentage distribution of future, a rationale land use is developed by the households (Table 3) revealed that making use of the available technology, most of the cultivator households pos­ and by considering the socio-economic sesed more than 10 acres, mitigating the pressures and the productivity constraints, alleged pressure of population. But when and the choice of enterprises on the desert viewed in the context of the poor perfor­ lands. mance of productivity of the principal crops grown in the arid areas (Mann et al., Population 1974), this convenience in the operational The importance of combining human holding shrinks and tends to convert the effort with land for its productive use is too assets-orientation of arid lands into it lia­ well known to merit a mention. The past­ bility. comparative review of the data on popula­ It can thus safely be con clued that within tion has revealed that the Indian popula­ the present constraining framework of avail­ tion bas seldom been subjected to more ability of tecbnology and the socio-econo­ quantitative pressures of population than its mic pressures on the pattern ofland use, the counterpart (Malhotra et al., 1972). How­ productivity of land unmistakably renders ever looking from the arid-zone standards

325 DESERTIFICATION AND ITS CONTROL

which are characterized by less productive can be realized if the occuptional distribu­ lands, the population seems to have reach­ tion and the relative shifts of the popula­ ed its productive climax. The question of tion inhabiting the arid areas are studied. limited relevance, thus, is to seek and quan­ The census data at two points in time on the tify the carrying capacity of the arid lands occupational distribution for the arid region which would be able to withstand the pre­ in western Rajasthan, for example Table sure of human population. This object 4, revealed a decline of about 86 % in the

Table 2. Distributional pattern, the number of holdings and the area operated by size class of operauonal holdings for the arid and whole of Rajasthan (1970-71) Farmers in '0000, Area in '0000 ha

Arid zone Rajasthan Attributes range Number of holdings Area (% of total) Number of holdings Area (% of total) (% of total) (% of total)

Below 0·5 4·9053 (3 ·1.5) 3·9754 (0·30) 48 0957 (12 90) 12·4646 (0 ·61) 0·5- 1·0 6 6503 (4 ·27) 49228 (0 37) 45 9067 (12 32) 33·4312 (l ·64) 1·0- 2·0 42·7882 (27·53) 20 9330 (1 60) 69 0620 (lS·53) 100·415.7 (4·93) 2·0- 3·0 12·3334 (7·93) 31·3054 (2 40) 45·5405 (12 02) 112 9353 (5·55) 3·0- 4·0 10·4140 (6·70) 66 5685 (5·10) 31·7003 (8·53) 110·5041 (5 ·43) 4·0- 5 0 8·0977 (5 ·21) 36·4270 (2 ·79) 22·7588 (6 ·12) 101·9083 (5 ·02) 5 0-10·0 29·4711 (18 ·96) 207 3805 (15 ·9) 57 ·5024 (15 43) 400·3299 (19 68) 10.0-20 0 240882 (15 50) 286·7126 (21·98) 33 ·1999 (S ·40) 437·5854 (21 ·52) 20·0-30·0 8 ·1852 (5 ·26) 183 8560 (14·09) 9 ·6180 (2 58) 213 ·9105 (10·51) 30 0-40 0 3 ·6504 (2·34) 133·4590 (10·26) 3·9771 0·06) 145·6740 (7 ·16) 40·0-50 0 1·7122 (1·10) 77 9235 (5 97) 1·8153 (0 48) 82 7961 (407) 500-above 3 0960 (1 ·99) 250·3538 (19 ·19) 3·4777 (0 ·93) 282·0983 (13 86) Total 1155·3920 (100 ·00) 1304 2182 (100 00) 372 6544 (100·00) 2034 0549 (100·00)

Source:' Compiled from Report on Agricultural Census 1970-71 in Rajasthan (Mimeo). Govt. of Rajasthan, pp. 100-254.

Table 3. Percentage distribution of cultivating households in India and arid districts, 1971 (in acres)

Rainfall Less 1·0 to 2 5 to 50 to 10·0to 15·0 to 30·0 to 50 and districts than 2·4 4·9 9·9 14·9 29·9 49·9 above 1 acre acre acre acre • acre acre acre

All-India 11·0 23·5 22·8 21·1 8·7 8 5 2·7 1·5 Less ihan 375 mm Jaisalmer 0·5 1·3 6·4 0·0 25·6 20·4 36·3 Bikaner 02 0·7 3·1 5·2 19 9 23 2 47 7 Barmer 0·2 0·7 2·0 5·8 8 4 23·3 24·0 35·6 Jodhpur o 3 22 4·4 10·2 12 ·1 26·8 22·1 21·9 Churu o 3 0·8 4·6 7·8 25·6 27·3 33·1 375 to 730 mm Nagaur o 1 1·9 5·3 13·6 15 ·1 30·4 19 5 13·9 Jalore 0·2 4 1 7·3 16·9 16·2 27·8 16·2 11·3 Pali 2·0 13 ·8 16·0 21·3 14·9 18·6 7·8 4·6

Source: Government of Rajasthan (1974) Census Report of Holdings in Rajasthan, Department of Revenue, Jaipur, pp. 121.

326 'ASSET-LIABILITY IMBALANCES IN ARID-ZONE AGRICULTURE

Table 4. Distribution of working,and non· working population for years 1961 and 1971 in the arid districts of western Rajasthan

1961 1971 Change over 1961 (-t or -) Workers 55,91,578 (44 91)* 30,90,970 (30 11)" -5,00,608 (-86 ,06) Cultivators 26,54,623 (73 93) 20,10,497 (65 '04) -6,44,126 (-75' 73) Agri. labourers 1,53,671 (4 27) 3,20,531 (10·36) +1,66,860 (+208 '58) Mining industry 44,026 0 22) 82,134 (2'65) +38,108 (+188'55) Household industry 2,38,896 (6, 66) 1,00,852 (3' 26) -1,38,044 (-42 21) Manufacturing 62,945 0'75) 88,266 (2 86) +25,321 (+140'22) Construction 44,575 (1'24) 40,568 (1. 34) -4,007 (-91 '01) Trade and commerce 1,16,475 (3 24) 1,38,981 (4A9) +22,506 (+119,32) Transport 46,136 0'28) 59,488 (1. 22) +13,349 (+128 ,93) Other services 2,30,228 (6 41) 2,49,657 (8 07) +18,429 (+108'43) Non-workers 44,05,107 (55 ,09)'" 71,40,709 (69 '79)* +27,35,602 (+162 '10) Total population 79,96,685 102,31,679 + 22,34,994 (27, 95) .. % to total population Source: Compiled from Census Report of Rajasthan for the Year 1961-1971. professions of the cultivators, household in­ Another dimension of the problem of dustries and construction. Thus the eco­ labour force as a resource is its consump­ nomic pressures for many cultivators tion capacity of what it produces. It has might have become too heavy to continue been established by the National Sample their professions. A noticeable shift of ru­ Surveys that almost 80 % of production, ral occupation in favour of non-agricul­ coupled with fuel, light, spices, and bever­ tural and commercial activities also prob­ ages, is consumed by the labour force. ably reveals a disenchantment of the rural This variation is more acute when culti­ population towards the low returns from vators, agricu1turallabour and non-agricul­ agriculture. The change in preference of ture labour in the rural sector are compar­ occupations reveals that within a decade ed (Table 4). It can be seen from such a (1961-71), a massive shift from workers, comparison that the major desert areas, e.g. cultivators, household industries and cons­ western Rajasthan, have a more pronounc­ truction went to agricultural labour, min­ ed tendency to consume (exceeding ing industry, manufacturing, trade and 100%) of whatever is produced. Thus commerce, transport and non-workers. a further addition to the labour force With the existing technology and produc­ at the rate of 2.7% per annum (as in the tion performance of the crop sector, it can arid districts of western Rajasthan) will be seen that the traditional orientation of accentuate the continua] minimization of values, subsistence economy and the lack marketable surplus. The marketable sur­ of commercialization (Wharton, 1965) will plus is also less than proportional, be­ predictably make the labour to be more of cause the arid societies in India, by and a liability than of an asset. The saving gra­ large, put high social premiums on conspi­ ce however lies in the incorporation of live­ cuous consumption and socio-religious stock as a single enterprise, as in the certain ceremonies, leading to a further deteriora­ north western parts (Anupgarh-Pugal tion in the quality of life (Hopper, 1962; Region) of western Rajasthan (Malhotra, Thorner, 1962; Nakajima, 1965). 1966). If labour as a resource has to remain as In other desert pockets of Haryana, Pun­ an optimum asset in the total milieu of jab and Gujarat, livestock is an important the rural sector of the Indian arid zone, 'mixed-farming' enterprise. This enter­ its density of dependence upon crops and prise, by virtue of its relative stability, livestock will have to be consciously and and employment-absorption capacity tends continually diverted to employment-absor­ to minimize the liability of the rural labour bing agro-based industries located in· the force. rural areas of this region itself. The labour

327 DESERTIFICATION AND ITS CONTROL.

in the agrarian sector will only be an asset sources. This division will naturally lead if the present value of its marginal produ­ to the repetitious creation of assets in the ctivity is enchanced through a size-neutral agricultural sector characterized by brisk and labour-intensive package of technolo­ shifts in the popUlation parameters. For gy in the production of agricultural com­ comparative purposes, in the arid districts modities. of Rajasthan, the data on machinery and implements, e.g. ploughs, cane-crushers, Investment structure pumps and tractors, revealed a continu­ The major transformation of the arid ally increasing trend for the years under region from a predominantly traditional consideration (Table 5). The results con­ agrarian economy to one with a large, firm that despite a spurt in the acquisition growing, modern and commercia~ agricul­ of modern investment inputs, e.g. pumps, tural sector has been one of the major pre­ the traditional investment items did not occupations of the developing countries. show a consequent decline, although this Of the various methods, the capital-forma­ increase in the modern investment might tion approach has been thought of to be have been responsible for enhanced pro­ one of the promising means -to achieve the ductivity. The increase in the number of desired levels of economic growth. The tractors in this region is again dubiously desert region of the country has tradition­ paradoxical. An instance of the' increase ally been the least attractive channel of in the tractor power in 11 arid districts of human and capital investment. In the Rajasthan resulted in an increase in the context of the present analysis, capital has area under cultivation (Table 1) which been defined to include livestock, machi­ was mostly converted from barren, culti­ nery and implements, and irrigation. Other vable wastes, and fallows. Additional pro­ inputs, which are directly related to the use duction has thus been realised at the ex­ of capital, include improved seeds, ferti­ pense of exploitative area-expansive land lizers, plant protection and water avaiI­ use. The tractor power in the arid areas ability~ of western Rajasthan had also a massive The data on the acquired capital-invest­ substitution potentiality for bullock-power. ment inputs for the States including the One tractor in 1961, 1966 and 1972 had the desert reveal that the acquisition of invest­ potentials to replace 102, 78, and 150 ment items, excluding livestock, is almost bullocks respectively. The introduction of uniform ally and negatively related to the the tractor can, thus, be a liability because desert area in each State. The agrarian of its replacement potential of the bullock economy of the peasant families in the power, so naturally adapted, coupled with desert region has more traditional and con­ further additions to the import bill of spicuous investment (like building a house diesel oil. Despite the proven low mar­ or buying a big tractor). The surveys (San­ ginal-value productivity of investment chetl, 1965; Desai, 1969-73 and Rai et at., inputs (Kalla and Vyas, 1972), the far­ 1972-73) in the States of Rajasthan, Guja­ mers in the arid areas continue to ac­ rat and Haryana revealed that the acquisi­ quire traditional investment inputs. This tion of land and land rights, livestock, pattern pushed the total capital struc­ consumer durables and ornaments formed ture towards liability. 1 he balance in fav­ the more important components of the 'our of assets as against the liability of investment by the rural families of the de­ machinery and implements can only be sert regions of the State. established, if the present redistribution of (a) Agriculture machinery and imple­ land allows for an equitable acquisition of ments: It is natural to expect an increase modern investment items which will have in the traditional and modern investment scale-neutral economic properties. The inputs, because any transfer of land from provision of equitable irrigation will fur­ one to another generation inevitably will ther enhance the productivity of the lead to' division in' the ownership of re- modern assets.

328 ASSET-LIABILITY IMBALANCES IN ARID-ZONE AGRICULTURE

Table 5. Quinquennial changes in the acquisition of agricultural machinery and implements in the arid districts of western Rajasthan (1961-71)

Year 1961 1966 1971 Ploughs 9,47,043 10,22,548 10,91,733 (+7'97) (+6·76) Carts 2,20,822 2,58,816 2,42,351 ( +17'20) (-6·36) Sugarcane-crushers 4,008 4,541 7,113 (+13·30) (+56 ·63) Oil engines 594 1,384 10,769 (+132 '99) (+678'10) Electric engines 92 876 9,079 (+873 '91) (+936-41) Persian wheels 19,313 7,140 20,887 (-63 '03) (+192'53) Tractors 2,251 2,553 6,652 (+13 '41) ( +160'55) Ghanis 3,782 3,731 2,615 (-1'35) (-29 '91) Source: Compiled from Quinquennial Livestock Census Reports, Board of Revenue (Records), Ajmer, Rajasthan. (b) Livestock: Animal husbandry is five-year period, only goats, camels and an important productive enterprise in the pigs, and during the succeeding five-year desert areas of India owing to its adapta­ period, goats, buffaloes, camels and pigs tion to the uncertain and erratic climato­ registered an increase .. Whereas the bul­ logical factors. The risk and uncertainty lock population from among the total involved in the production of dryland cattle population remained almost cons­ crops has usually imposed upon the farmer tant (20 %), the milch animals accounted of the desert region the necessity to diver­ for most of the quinquennial variations in sify the production decisions in favour of the population. It can thus be seen that livestock production to cover crop fail­ the population of the livestock themselves ures. Pastoral activities in the arid areas has a pronounced tendency to increase and occupy a vital place because of its capa­ leads to grazing stress. It has been esti­ bility to use nearly the whole of the land. mated that for these three years under Despite its vitality, the livestock sector is consideration, the arid districts of western usually characterized by a low-key per­ Rajasthan had 32.55, 33.48 and 23.39% formance and a certain amount of vulner­ of fodder short of its demand in 1961, 1966 ability which leads to a continuing noma­ and 1972 respectively. This shortage of dism of the cattle-breeders. fodder, coupled with that of water in bad The recent estimates of the Qopulation years, and in the remote hinterlands is of livestock indicate that the Irl"dian arid mainly responsible for the association of zone abounds in livestock popUlation. nomadism (Table 7) with pastoral activi­ The arid region of Rajasthan, in particular ties. For instance, irrespective of the (Table 6), reveals that cattle, sheep, goats severity of climatic factors, animal out­ and camels constitutes the majority of the migration from the arid districts, such as animals. It can be seen that during a Jaisalmer, Barmer, Pali, Jodhpur and Bika-

329 DESERTIFICATION AND ITS CONTROL

Table 6. Distribution of livestock population among arid districts of western Rajasthan (1961, 1966 and 1971)

1961 1966 1972

• Cattle 44,10,470 46,89,228 34,80,752 (6 -32) (-25-77) Buffaloes 9,67,304 10,55,180 11,08,764 (9 -08) (5 07) Sheep 43,54,835 55,41,042 51,59,784 (27 -23) (-6-88) Goats 34,29,127 42,55,888 58,14,174 (24 -10) (36 -61) Horses 18,496 17.023 10,058 (-7 ·96) (-49-91) Mules . 285 201 175 (-29·47) (-12-93) Donkeys 91,962 91,270 76,878 (-0 75) (-15-76) Camels 6,21,340 5,54.935 6,23,926 (-10,68) (12 -43) Pigs 5,334 5,056 9,553 (-5 ,39) (89-31) Total 1,38,67,133 1,62,09,808 1,42,84,358 (16 -89) (-11 -87)

Figures in brackets show the percentage increases over or decreases from those of the previous year. + Computed from Livestock Census for the year under consideration, Board of Revenue (Records). Ajmer, Rajasthan.

Table 7. Percentage of traditional livestock migration from different arid districts of Rajasthan

Districts 1968-69 1969-70 1972-73 1974-75

1. Jaisalmer 22-48 17 -15 54·90 N.A. 2. Barmer 29-78 6-30 3·98 3. Jodhpur 3·07 9 24 4-81 7-96 4. Pali 2-22 38-80 3-40 5. Nagaur 4-16 5'07 26-91 38·72 6. Jalore 10-58 18 14 2-75 13·23 7. Sirohi 1 66 -3-99 33·32 8. Bikaner 2605 1·31 4-21 2·79 9. Ganganagar 2-81 10. Churu 0-21 0 11. Sikar -

Totar 100'00 100,00 10000 100-00

Source: Compiled from Famine (Annual) Reports from the Famine and Relief Cell, Government of Rajasthan. Jaiprlr. 330 .' ASSET-LfABILlTY IMBALANCES IN ARID-ZONE AGRICULTURE

ner, constituted 80 %. Most of this mig­ Even this gain: in the crop sector should ration, irrespective of the year under be interpreted cautiously since the histori­ consideration, went to Madhya Pradesh, cal productivity performance of major followed by inter-district wandering in crops for the last 20 years (1951-72) have Gujarat and Haryana. revealed high degrees of variabilities and It thus seems imminent that under the negative annual linear growth coefficients, present set-up the livestock can be con­ specially for unirrigated crops (Mann et sidered an asset if the reasons associated al., 1974). Under such circumstances, crops with the total dislocation of the livestock can be considered an asset with great industry in the arid areas are properly effort and under heroic assumptions. Live­ identified and mitigated. stock, on the other hand, have revealed more monetary profitability per unit of Comparative performance of resource net input employment for the years under worth-some productivity estimations consideration. This has a potential of Increase in investment inputs, such as enhancement, if diverse marketed and human labour, animals and machinery own-consumed milk products, e.g. curd, may be necessary, but hardly are these butter, ghee, cheese, milk powder and ani­ sufficient conditions for the attainment of mal product, e.g. meat, eggs, hides and an economically optimum level of resource bone-meal, are separately evaluated. Live­ productivity. The measurement of the stock in the long-run analysis have been contribution for the three years (1961, less fluctuating in their productivity per­ 1966 and 1971) and the returns per rupee formance and their profitability can be investment in the tangible resources (hu­ attributed to a comparatively few factors man labour, livestock and implements), (Jodha, 1968) of production. Animal excluding land and land improvements for husbandry is, thus, more of an asset for the arid region of Rajasthan (Table 8) re­ arid districts and is likely to be so in per­ vealed that the livestock sector had con­ petuity, if the population of livestock sistently been more remunerative in all the does not impair the prospects of increased years under consideration. Another notable carrying-capacity resulting from the adop­ feature of the productive resource adjust­ tion of new grassland-management techno­ ment is that crop production has uniform­ logy. ly been employing more labour and less implements. Thus it has not been Technology for the improvement of asset­ possible for desert crop sector to follow liability balances in arid areas an intensification programme for the reali­ The technology evolved for the rational zation of augmented crop production. management of arid lands is aimed at Table 8. Estimated net monetary returns per unit of tangible resource employment in crop and live­ stock enterprise in arid districts of western Rajasthan (1961, 1966 and 1971) Gross returns to fixed resources of Crop sector Livestock sector Year Per rupee Input ratio Per rupee Input ratio return return Imple- Workers Bullocks Labour Natural ments feed 1961 0·1429 1 13·03 3·86 0·2231 1·6466 1966 0·2193 1 19·76 4·83 0·4995 2·7134 1971 0'3533 21-44 1·99 0·6521 2·4040 Source: EstImated from Quinquennial Censlis Reports on Livestock, Board of Revenue (Records), Ajmer, Rajasthan.

331 DESERTIFICATION AND ITS CONTROL

striking a balance between the use and Whereas joint family is a boon, if its every conservation of resource endowments in member socio-economically contributes to this region. This procedure mainly con­ the family pool, the individualistic desires sists in sand-dune stabi]ization, creation have to be curbed in favour of joint of shelter belts and wind-breakes, energy interests. The system of joint living also plantation, creation of improved grass breeds tension within the members of a cover in public grazing-lands and dryland family and they are compelled to act on a farming, wherever technologically feasible. common social stimulus. Whereas it may It has been shown that the technology of be economic help to develop a sense of arid-land management is, by and large, an co-operative living, the possibility of its economically viable proposition. Another being equally harmful to the development advantage of it is that the packages are of individual confidence and personality less complex and more labour-intensive. cannot be denied. Under the present The high labour-capital ratios incidental to circumstances, a joint family can be an the adoption of these technologies have asset, if it is run on the basis of equitable undoubtedly a bright future for the pro­ distribution of responsibilities, work, ductive absorption of surplus labour in income and expenditure. region where most of the farm families de­ Life-cycle obligations. 'The life-cycle' pend on a monoculture crop programme of the population inhabiting a desert (Kalla, 1974). Another implied aspect of region is marked by rituals and rights the technology is its size-neutrality. Since (e.g. Gangoj), social and religious ceremo­ only a limited amount of fixed capital is nies (e.g. death, marriage and birth cere­ required to carry out these technological monies), social taboos and norms mani­ programmes, the concept of size-neutrality fested in certain prohibitions (e.g. no will automatically become operative, result­ agricultural operation on the I I th day of ing in a less than disproportion ate deviation the Hindu calendar, the pursuing of poul­ in per unit costs and benefits incidental to try, piggery and other meat enterprises by variations in the size of the holding. This Brahmins and tobacco by Sikhs). Where­ should not. however, lead one to conclude as other societies in the country also that the available arid-land management follow a similar kind of 'life-cycle' pattern technology is snag-free. One of the most its effects upon the popUlation inhabiting important, and at times, the only limiting the desert region are economically more factor which precludes the uniform adop­ profound, recoil heavily and accentuate tion of this technology lies in its longer the deterioration process of their already gestation periods. Because the pay-back precariously balanced economic status. periods in ..silvi-pastoral land-management These obligations are assets also in the system may vary from 5 to 15 years, it will sense that taey reinforce philosophical and create the bottlenecks for the subsistence cultural values, leading to a psychological farmers to adopt the technology_ Further, stability and power to face climatological the initial protection of the treated limds catastrophes. If the economic impact of from the biotic interference may recoil in such ceremonies is reduced to its bare unreasonable and anti-social pressures, minimum, so that the farm families are resulting in social tensions and disorder in left with more to be invested for the society. enhancement of agricultural production, . these rituals and rights will certainly be SOCIAL ASSET-LIABILITY BALANCES social assets. OF THE DESERT REGION Group dynamics and related liabilities. The family. Despite the effects of recent The rural population inhabiting the desert social forces leading to a tendency to region oflndia is basically nondynamic on prefer 'an individual family, the life style the time-dimensional scale. However, a in the arid areas of India continues to certain element of dynamism in the social be pre90minantly ,a joint-family sy~tem. interaction of certain castes is discernible

332 ASSET-LIABILITY IMBALANCES IN ARID-ZONE AGRICULTURE in the rural society. The society in the arid out the achie~ement of social optima, the zone. is characteristically divided into economic optima of a society will be diffi­ watertight caste compartments with strict­ cult to be achieved. ly defined norms of life. The encroach­ ment of one group upon the socio-Iegal CONCLUSION AND POLICY IMPLICATION sanctions of another often ends in group It would appear from the discussion in factionalism. It is because of this factiona­ the preceding sections that the resources lism and a concept of false prestige which of the agrarian society in desert region of give rise to. frequent grou p clashes resulting India are imbalanced and are away from in time-consuming, expensive and useless the socio-economic optima. Often these litigation and thus hinder the productive attempts at correcting the resources, processes followed by society. More often imbalances range from passe romanticism than not social trivia of allowing potable calling for a return to the traditional forms water from a particular wen has resulted of using the desert region and thus create in group feuds which eventually are sorted show pieces of natural parks for attracting out at a tremendous cost and effort in more or less informed tourists, to a scienti­ courts. On the asset side, the cast struc­ fic and futuristic point of view advocating ture has traditionally been responsible for rather a disproportionate dependence on gearing up an efficient division of labour the imported technology. Resorting to for aquiring perfection in the art and the new technology should, however, not craft handed down from generation to result in too abrupt a snapping off with generation. It is thus natural to expect traditional man-land relationships which a jat in western Rajasthan to be an effi­ exist on the basis of centuries of experience. cient farmer and a mahajan to be an effi­ A careful application of the package of cient market-man. current technology of desert land manage­ Most of the desert region has inherited ment to the remote areas endowed sparse­ the feudalistic .political structure which ly with infrastructural system and thus a created conditions conducive to economic disequilibrium in the spatial and econo­ backwardness. The same system has, mic parities in the pricing of inputs and however, left a rich heritage and cu]tural outputs will go a long way in solving the style of life, courtesy, hospitableness, and development problems of this region. It is crafts. a well-known fact that the values of the It is a fact that the too much of sunshine marginal productivity of water, fertilizer, and too much of wind-power are the plant-protection material and improved crucial factors responsible for low levels seeds are comparatively lower in the desert of productivity in the agricultural sector region than in the lands located in more of the desert region. This liability can be fortunate places and bestowed with a converted into a life-generating asset, if flexible resource-mix. It will thus be proper both sunshine and wind-power are put to if the rural sector of the desert region is generate energy for the use of society. The subjected to hold input-subsidization and in­ dry climate, with plenty of sunshines and centivized product-marketing system. This wind power also, leads to belief of better object can only be achieved, if a strong health and longevity (Mann, 1973), where case for a meticulous socio-economic the incidence of complex diseases is less in planning which incIudes the monetary, for the region. On the liability side, it should fiscal, physical, social and educational be noted that a dusty environment is instruments to correct the parity imbalan­ hazardous to the eyes and the respiratory ces of socio-economic input-output system. relationship, and a resource structure of For the social system to operate at the desert regions is prepared. The improved optimum level it is neccess-ary that the technology brought to the door of the social bottlenecks are gradually removed farm sector on the vehicJe of such a policy in a conscious and planned manner. With- instruments will go a long way in attaining

333 DFSERTIFICATION AND ITS CONTROL

the socia-economic optima subjected to the MANN, H. S. 1972. Science and desert control. constraints of improved equality of life, so Indian Farmer, (Sept. 1972) pp. 5-8. that the desert itself ceases to be a national MANN, H. S. 1973. The future of our arid and and international liability, and the popu­ arid areas. Indian Farmer, pp. 9-11. MANN, H. S., MALHOTRA, S.P., and JAGDEESH, C. lation inhabiting this region will be sealed KA'LLA 1974. 'Desert-Spread' A Quantitative against the despair of famines, helplessness Analysis in the Arid Zone of Rajasthan. and frequent catastrophic devastations. Ann. Arid Zone 13 (2) : 103-13. KRISHNAN, A. 1968. Distribution of Arid Areas REFERENCES in India. Proc. Symp. on Arid Zone, 21st International Geo. Congress, Jodhpur, pp. ANON. 1969. Saline-Alkali Soils in Rajasthan: 11-19. Their Nature, Extent and Management, MALHOTRA, S. P. 1966. Socio-economic charac­ Department of Agriculture, Government teristics of inhabitants of Anupgarh-Pugal of Rajasthan, pp. 15-30 region. Indian Sociological Bulletin 3 (2), ANON. 1972. Government of Rajasthan, Direc­ 107-21. torate of Economics and Statistics. ANON. 1974. Agricultural Diary. Government MALHOTRA, S. P., RAO, J. S., GOYAL, D., and of Rajasthan, pp. 18-1929. PATWA, F. C. 1972. Population, land use DESAI, M. D. 1974. Saving and Investment in an and livestock composition in India and its Agriculturally Prosperous Area in Gujarat. arid zone. Ann. Arid Zone 11 (1,2): Research Study, 30, Agro-Ec'onomic Research 166-167. Centre Sardar Patel University, Vallabh NAKAJIMA CHIHRO 1965. Subsistence and com­ Vidyanagar, Gujarat. mercial family farms: Some Theoretical JODHA, N. S. and VYAS, V. S. 1968. Growth and Models of Subjective Equilibrium. Sub­ Stability in Arid Agriculture. Agro-Economic sistence Agriculture and Economic Develop­ Research Centre, Vallabh Vidya Nagar, ment. Aldine Publishing Company, Chicago, Gujarat. p.165. JODHA, N. S. 1968. Prospect of Dairy Development RAI, K. N., GROVER, D. K. and NANDAL, D. S. in Bikaner Region of Rajasthan. A.E.R.C. 1972. Investment and saving pattern in Vallabh Vidya Nagar. irrigated and unirrigated zones of Haryana KALLA JAGDEESH, C. and VYAS, D. L. 1972. A State. Indian J. agric. Econ. 27(4): 75-82. study in the farm Investment and Income, Pattern of farm families in Arid Zone of SANCHETI, D. C. 1965. A case of greater capital Western Rajasthan. Ann. Arid Zone 11 formation in agriculture for the future planning of Rajasthan. Indian J. agric. (3~) ; 187-97. KALLA JAGDEESH C. 1974. Economic Evaluation Econ. 20(1) : 221-227 .• of Arid-Zone Technology. l.C.A.R. WHARTON, C. R. 1965. Subsistence Agriculture: Summer Institute on Desert Eco-System Concepts and scope. Subsistence Agri­ and its Improvement. CAZRI, Jodhpur culture and Economic Development. Aldine (Mimeo). Publishing Company, Chicago, pp. 12-22.

334 35 LAND-TENURE PROBLEMS AND POLICIES IN THE ARID REGION OF RAJASTHAN

N.S. JODHA

BROADLY-Speaking, land tenure comprises rations, land policies also concern them­ the formal or legal provisions and con­ selves with how lands are used. The ditions surrounding the ownership and regulation of land utilization at times is utilization of land by individuals or a equally or more important than the regu­ group thereof. In more concrete terms, lation of land ownership, distribution, the tenurial situation in a given region is etc. This is particularly so in the case reflected through a number of interrelated of problem areas like the arid region, features, such as the pattern of land owner­ where owing to the inherent poverty of ship and distribution, the formal and the land resource, the unregulated use of informal leasing arrangements, the various land may lead to its permanent depletion regulations relating to land owners' and and continued decline in its productivity. users' obligations in terms of payment of The physical characteristics of the region land taxes and the adherence to norms not only condition the production poten­ and conditions determined by the State tial of the land but also determine the from time to time to regulate the land use suitability of institutional arrangements (Schickele, 1950). to harness the productive potential. Land These essentially institutional arrange­ tenure and related aspects in the arid zone ments governing a person's legal relation of Rajasthan can, therefore, be meaning­ to the land he owns or uses take shape fully examined only in the context of within the broad framework composed of physical features of the region which are physical and human factors. Physical of relevance to agriculture. factors, e.g. the agro-climatic complex, operating in conjunction with the state ARID REGION: PHYSICAL FEATURES of farm technology and the human factors, Some relevant details of the natural e.g. the population pressure and the factor endowments of 11 arid districts in community's approach to the institution Rajasthan are presented in Table I. The of private property in land and the ideal districts are broadly arranged in the des-:­ of egalitarianism, influence the land-tenure cending order of aridity and deficiency systems. of the land-resource base. The impact Since the right or claim on land has of the deficiencies of land-resource base acted as one of the key variables in the is broadly reflected in the relative position socio-political dynamics at different stages of different districts in terms of density of history, the fact of who owns how much of population, size of farm holdings, and land and under what conditions has gene­ importance of livestock in the district. rally been treated as an important concern To understand properly the impli­ of State policy (Tuma, 1965). Depending cations of the physical features of the upon the importance attached to land region vis-a-vis the land tenure and re­ productivity and other technical conside- lated aspects, it will be useful to start ",ith

335 DESERTIFICATION AND ITS CONTROL

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336 LAND-TENURE PROBLEMS AND POLICIES

the use capability of lands in the region. (1969), 10dha and Purohit (1971) and On the basis of the tahsil-wise details Jodha (1972). about the soil, vegetation.and water resour­ Thus, the low permissible use-intensity ces, a team consisting of soil scientists, of the land, their low productivity and agronomists and conservation experts had high instability of crop-farming tend to broadly assessed the use capabilities of impart a comparative advantage to pas­ the land in different districts of the arid ture-based livestock-farming in large parts region of Rajasthan (State Land Utili­ of the arid region. In Zone II, on the zation Committee Report 1960). other hand, restricted cultivation with . The committee subdivided the whole conservation practices characterized by arid region into three zones. rotations between cropping and long Zone I. All the tahsils or parts thereof, fallows can be encouraged, whereas Zone characterized by lands belonging to land III can support annual cropping. classes VI and VII which are suitable only for pasture and range development ac­ IMPERATIVES FOR LAND POLICIES cording to the FAO use-capability classi­ For tenurial policies and land manage­ fication of lands for conservation pur­ ment, the situation described above has poses. the following imperatives: Zone II. All tahsils or parts thereof, (a) Classification of the lands ac­ which possess mainly lands of classes VI cording to their use capabilities and VII, but a few pockets ofland of class is necessary and the tenurial ar­ IV which could be put under cultivation rangements and the planning of under a very restricted manner involving land use can be done only after two crops intervened by long ($ to 4 years') its completion. fallowing and various conservation prac­ (b) The determination and regulation tices. of use-intensity of land in each Zone III. All talrsils and parts thereof, class has to be done at the level having different proportions of lands of operating units, e.g. farm, pas­ belonging to class III (land suited to ture, village. cultivation) and class IV. The detailed provisions through which The three zones account for 56, 23 and the above imperatives can be incorporated 21 per cent respectively of the total area in tenure and land-use policies have been of the arid region (Jodha and Vyas, 1969). broadly indicated in the Statement A on If one ignores the small pockets of good the following page. land within the Zones I and II, nearly 79 % The essence of the Statement A is that of the land in the arid region is not suited an individual's rights in land and his to high land-use intensity involved in decision about the mode and intensity of crop-farming unless transformed by irri­ land use as well as his obligations as a gation. land owner/user have to be assessed in Hence any attempt to increase their keeping with the requirements of different use intensity through putting them under land classes. Thus the very first step the plough, particularly on a regular basis towards evolving the suggested tenurial or by overgrazing, tends to expose them and other arrangements is the classifi­ to greater erosion hazards and leads to a cation of lands according to their physical fall in their production potential even in characteristics and their behaviour under terms of forage. Further, given the limi­ different modes of utilization. tation of these lands, especially in the However, as my earlier review of land context of weather variability in the policies in Rajasth'1n show, the above region, crop-farming cannot offer high technical basis of land classification is and stable yields on a sustained basis as completely neglected in practice (Jodha, discussed by Kaul and Misra (1961), Seth 1970). For the purpose of land-revenue and Mehta (1963), lodha and Vyas administration or agricultural dev.elop-

337 DESERTIFICATION AND ITS CONTROL

Statement A The features of the three zones in the arid region of Rajasthan and the suggested provisions of tenurial and land-use policies

Features Zone I Zone II Zone III

1. Land classes VI, VII VI, VII, IV III, IV 2. Share in arid region(%) 56·33 22'52 21'15 3. Farm activity favoured Pasture-based As under Zone I, and Normal cultivation and most by the land clas- livestock-farming restricted cultivation restricted cultivation ses (on land class IV) 4. Objectives of tenurial Conservation and As under Zone I, con­ High farm productivity policies! arrangements, development of land servation and develop­ with high intensity of as influenced by land resource base for effi­ ment of land for res­ Jand use on land class classification cient livestock-farming tricted cultivation III and restricted cultivation on land class IV 5. Pattern of land use Highly extensive type As under Zone I, and Intensive cropoing on (Land use intensity) of land use through slightly intensive use Jand class III, crop­ natural forage produc­ through crop-fallow fallow rotation on tion on pasture/range rotation system land class IV lands 6. Major area of public Zoning of areas for As under Zone I. and Usual land distribu­ policy specific land uses, law policy for periodical tion, tenancy regula­ relating to develop­ land retirement from tion policies; land re­ ment, utilization, con­ cultivation tirement policies for servation of pasturesj class IV lands range lands 7. Ownership Collectiveorindividual As under Zone I, with Individual with provision for col- special provisions for lective action, when crop lands required 8. Size of holding Extremely large (i.e., As under Zone I, and Normal (as permitted pasture holdings) large holdings for cul­ by ceiling laws in simi­ tivation to facilitate lar dry areas) long fallowing. 9. Need for public regula- Very high; at district, Very high at pasture High at farm level for tion of land use village and pasture level, and high at farm land class IV levels level

10. Issues for public regula~ Land-animalratio,gra- As under Zone I, and Conservation measures tion zing rights, rotational issues related to crop­ and crop fallow rota­ grazing, seasonal mig- fallow rotation and tion on land class IV. ration, conservation conservation measures For land class III, measures, other issues .on crop lands similar to other dry of pasture policies areas II. Basis of taxation, Number of animals Number of animals Land-holding size, penalty/rewards rela- and land size, crop pro- crop produce ted to land duce 12. Land users' obligations Adherence to land- As under Zone I As usual, as in the case use regulation and con- of other dry areas servation laws

338 LAND-TENURE PROBLEMS AND POLICIES

ment. the lands in the arid region are not ration to the use capability of the land. at all classified on the basis of their use Nor did it impose any obligation on the capabilities. The only lan,d classification beneficiaries regarding the regulation of to be found in the official land records is land utilization or collective arrangement the_ 'present use' classification. This is for conservation measures, etc. In other nothing but an inventory of the uses to words, in terms of imparting ownership which the lands are being put and it has rights, etc. the agrarian legislation in nothing to do with the use capability of Rajasthan except the land ceiling laws, 1 the land • treated the desert lands or submarginal Regarding the provision for the regula­ lands in arid areas on a par with the lands tion of use-intensity too, the land policies in well-endowed areas of the southern and seem to be equally indifferent to the re­ south-eastern parts of the State. Its quirements of arid lands. A few illus­ implications will be discussed later. trations will help. Land-use regulation. No land legis­ Land distribution. The tenurial situ­ lation deals specifically with the deter­ ation on the eve of the formation of the mination and regulation of the use inten­ Rajasthan State in 1949 was characterized sity of land. The Rajasthan Tenancy by a variety of formal a,nd informal (Government) Rules, 1955, and the arrangements governing the control and Rajasthan Land Revenue Act, 1956, con­ use of lands in different princely states. A tain some provisions for the regulation variety of intermediaries-Jagirdar, bis­ of land use, but their approach is entirely wedar, muajidar, rajvi, etc. existed and different from what has been described rack-renting, tenurial uncertainties, etc, above. The above legislations merely were the common features'. The early stipulate that it is the duty of the revenue land legislation of the State, therefore, officials to ensure that a given piece of tried to regulate rents, protect tenants and land is put to the same use to which, as finally abolish the intermediaries. The per the revenue records, it was put in the actual tillers of the land were made land­ past. Thus through the above laws, the owners and brought into direct contact State attempts to regulate the use of the with the State'. Further, vast areas of land as per its use status in the revenue submarginal lands (hitherto under grass) records and not as per its physically desir­ were distributed as private holdings for able level of use intensity. In effect, this cultivation under the various legislations, procedure tends to perpetuate the exist­ in particular the Rajasthan Land Revenue ing maladjustments in the land-use (Allotment of Land for Agricultural Pur­ pattern. poses) Rules 1957. However, while mak­ Indeed, the Rajasthan Agricultural ing the tenants owners of the land as well Lands Utilisation Act 1954 goes a step as distributing new lands to private land­ further. The traditional practice of crop­ holders, the State did not give any conside- ping and fallowing is a compromise bet­ ween the intensive and extensive type of land use in the arid area. But the above 1. Patwari records are the ultimate source of Act (Section 4) completely ignoring the land statistics and show that a pasture is classi­ fied as pasture not because it represents land poorer traditional wisdom of the desert farmer, than the lands classified as crop lands, and is, empowers the district collector to prohibit therefore suitable for grass only, but because the the fallowing of the crop lands. If the former J~girdar or panchayat declared it as such land-owner fails to cultivate the land and in view of the nearness of the watering points or the village abadi, i.e. village sett.lement. . obstructs the alternative arrangements for 'For details, refer to the Rajasthan ProtectIOn cultivation made by the collector he is of Tenants Act, 1949; The Rajasthan Agricultural liable to penalty up to Rs 500 per case. Rent Control Act, 1954; The Rajasthan Land Though no cases of implementation of this Reforms and Resumption of Jagir Act, 1952; The Rajasthan Land Reforms and Acquisition of provision have been noted, the law itself Land Owners Estate Act, 1953 etc. illustrates the government's ignorance of

. 339 DESERTIFICATION AND ITS CONTROL the nature of the problem of the arid does it have any provlSlon, whereby lands. conservation measures are made an essen­ Pasture policy. The economy of the tial part of the farming system in the arid arid region, in general, and its north­ areas. western parts, in particular, is dominated by livestock-farming. Practically, every REASONS FOR NEGLECT village has some common pasture lands. The absence of provision conducive But the States has no ligislation reflecting to the conservation, development and its concern for these grazing lands and efficient utilization of arid lands in the no well-structured pasture policy exists. agrarian legislation of Rajasthan can be The State Government, through certain attributed to the following factors: provisions of the Rajasthan Panchayat Act The land-tenure and the related policies 1953 and the Panchayat (General) Rules emerged as a part of the land-reform 1955, has shifted the responsibility for programmes in the State during the 1950s. pasture development ang management to The primary objective of the land reforms the village panchayats. The panchayats, was to replace the feudal agrarian struc­ in turn neither have technical competence ture by a more equitable and just agrarian nor political and administrative strength system in keeping with the ideals of a to introduce any measure to regulate democratic State. The feudal agrarian stocking rates, grazing rights, rotational order, which had developed over a long grazing, etc. A. study revealed that not period in the princely States of Rajasthan, a single panchayat had taken up any step had a number of exploitative features. to manage or develop village pastures The production, distribution and exchange and forests. Thus, as in the past, the relations between the land-owner and the utilization of grazing lands is governed land-user were exploitative. The land­ by informal institutional arrangement un­ use pattern it encouraged was not related der which uncontrolled and unrestricted to the land-use capabilities and hence was grazing, without any obligations to the already over-exploitative. The land re­ grazi~g land is the rule. forms were only concerned with the ex­ Conservation measures. In the case of ploitative features of the feudal order. the arid region, the resource conservation as they related to the tillers of land and needs to be made an essential part of the not to the land itself. Thus the need land-related policies and programmes. for preventing very intensive use of land The only legislation regarding land con­ was completely overlooked, and the con­ servation is the Rajasthan Soil and Water servation needs of land resource base Conservation Act 1964. The second never figured in the land-reforms law. schedule of this Act enumerates a large Indeed, th~ real consequence of agrarian number of conservation measures, which reforms through the distribution of ad­ should form part of the schemes to be ditional submarginal lands for ploughing. undertaken by the Rajasthan Soil' and etc. has been to accentuate the process of Water Conservation Board and other over-exploitation of lands. agencies. However, Chapter II of the The neglect of the conservation needs Act makes it clear that the approach of of the arid lands in the land reforms was the legislation is very specific and narrow. partly due to its relatively poor political In fact, the Act provides for the framework . pay-oft' to the government in the context for initiating and operating the small­ of the immediate socio-political objectives scale departmental conservation schemes of land reforms. Further, in a young in any notified area. It contains no State, with a long feudal background, the provision, whereby the farmer or a group new policy-makers did not fully grasp the of farmers cart be compelled or pursuaded technical factors, which could impart a to adopt conservation measures on a conservation orientation to land policies • catchment' or 'watershed' basis. Nor in the arid region. Moreover, it was easier

340 LAND-TENURE PROBLEMS AND POLICIES

to execute common land policies for the the land or periodically using it for forage whole State rather than having specific rather than for crop production declines policies for different areas. Consequently, with the decline in the size of the holding. the tenurial and 'other policies designed An inte~esting inference which can be for the State as a whole have been ap­ drawn from Table 2 is that in the absence plied to the arid region (including Zones of statutory measures to regulate it, the I and II). Their implications and conse­ use intensity of arid lands can be indirectly quences have been discussed in the rest influenced by a proper distribution of land of the paper. holdings. In other words, farmers can be induced to keep the use intensity at a lower CONSEQUENCES level through the provision of bigger land Land distribution. The immediate con­ holdings, which are conducive to crop­ sequence of the absence of the tenurial ping followed by a long fallow. policies which would have helped to treat The system implies that no newly allo­ the arid lands according to their use capa­ cated land holding should be ofless than a bilities is the indiscriminate allocation or specific size. Similarly, the existing hold­ distribution of the submarginal lands for ings should not be permitted to be frag­ cultivation. As shown in Table I the mented below a certain level, giving rise to extent of the area belonging to private holding smaller than the specific size. This cultivation holding alone far exceeds the amounts to the fixing of the 'floor' limit extent of the lands belonging to classes similar to a ceiling limit for arid lands. III and IV (Zone III) in all the districts, However, the land-distribution policies do except in Sirohi and Pali. Further, as not seem to be concerned about such the bracketed figures in the same table provisions. This is suggested by the dis­ show, in most of the districts more than tribution pattern of land holdings obtain­ 80 % of the area of private holdings is ing in different arid districts (Table 3). actually cultivated. This implies that the Contrary to the general impression, nearly possibility of restricting the lands already 45 % of the land holdings in the arid distributed for less intensive cultivation region are less than 5 hectares. In several (i.e., fallowing to be followed by grass, districts the extent of such holdings range etc.) is quite limited. Even in the driest from 48 to 83 per cent of the total hold­ districts of Jaisalmer, Bikaner and Barmer ings. Even in the driest districts, e.g. (where lands suited to cultivation are too Jaisalmer and Barmer, the proportion of limited), the extent of the area of private holdings lower than 5 hectares is more holdings put under cultivation ranges than 20 %. On such holdings or even from 43 to 67%. on the holdings below 10 hectares (which Even after the distribution of submar­ account for nearly 60% of the total hold­ ginal lands to private land-owners, their ings in the region), adherence to a rotation use intensity can be kept at a low level comprising cropping followed by a long by following a rotation comprising a crop fallow is quite difficult. Owing to low followed by a long fallowing. But this and unstable crop yields, even a farmer rotation requires a fairly large size of with 10 hectare cannot afford to keep a land-holding which can permit the fallow­ large portion of the area under fallow ing of a substantial area on a rotation for 2 to 4. years. basis. The smaller the holding, the shor­ Thus, under the tenurial policies, both ter the duration of the long fallowing and, the opening of the submarginal lands for therefore, the less the chances of main­ ploughing through the distribution of taining a low degree of land-use intensity. such lands as private holdings and the This fact is c1ealry indicated in Table 2 permitting of the holding size to become where the extent of the old fallows (i.e., smaller than required by the use capabili­ fallows other than the current fallows), ties of land tend to encourage the higher representing the extent of the resting of use intensity of land.

341 DESERTIFICATION AND ITS CONTROL

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342 LAND-TENURE PROBLEMS AND POLICIES

Table 3. Distribution of operational holdings by size in the arid districts of Rajasthan 1970-71a

Percentage distribution of holdings Extent % of rented in the total District <0,5-5 0 5·0-10·0 100-20,0 20·0& holdingsb above Holdings Area Iaisalmer 20·65 20·42 25·00 33·92 10·39 2·53 Bikaner 8'34 20·88 33·38 37·39 2·73 2·23 Jodhpur 37 03 21 05 21·84 20'09 6'11 2·80 Barmer 20'90 19·01 25·24 34 85 5·61 2 43 Churu 16 58 26·48 32·17 24·77 4 82 3·35 Nagaur 44·32 25 38 20·96 9·33 5·66 4·57 Ialore 48 94 23 32 18 05 9'69 4·71 3 ·17 Jhunjhunu 67·78 21·17 9·33 1·72 1·99 1·50 Pali 72·62 13·00 9·31 5'08 13 '21 10·60 Sikar 68·61 20·14 9 40 1·86 7'23 5 ·17 Sirohi 82·88 11·22 4·48 1·43 22 14 15 16 Total 44·86 19·02 23·59 12'51 7·10 3·79

(a) Based on details from Report on Agriculwral Census 1970-71 in Rajasthan, Government Press, Bikaner, Government of Rajasthan, 1975. (b) Includes both partly and completely rented in holdings. The degree of land-use intensity en­ 1965); the conversion of fertile lands into couraged by the pattern of land distribu­ patches of saline wastelands in the low-ly­ tion does not get altered by tc:mporary ing areas near the seasonal streams (CAZRI land transfers through private tenancy. 1964-65); the drying up of dug wells As llldicated in Table 3 (last two columns) or the increased salinity of well waters'; except in the better-irrigated districts, the replacement of superior perennials e.g. Pali and Sirohi, only two to ten per by inferior ones or annual grasses includ­ cent of all holdings rent any land from ing non-edibles in the grass-lands (Prakash others. The extent of the area falling et al., 1964); the increased population of under the rented category is still smaller 'malformed' or, 'stunted trees'; and finally and ranges from 2 to 5 %. the increased human miseries reflected by Resource depletion. The ultimate con­ an increased extent of seasonal migration sequences of the tenurial policies and and the accentuated process of pauperi­ arrangement evolved during the feudal zation through recurrent famines (Jodha, system and those initiated during the 1975). post-Independence land reforms are reflec­ Declining crop yields. The impact of ted both in terms of (i) the depletion of extending crop-farming on submarginal land resource, and (ii) the falling produc­ lands, a~ encouraged by the tenurial poli­ tivity of land. cies, is revealed by Table 4. The Table Regarding the resource depletion, no presents the indices of three yearly moving details covering the whole of the arid region average of the area and the yield of princi­ are readily available. Yet the evidence pal crops of the arid region for the period available from different locations clearly 1951-52 to 1972-73. The area under all indicates such a possibility. At several the cro'ps show a rising trend. Only in locations, the following consequences of mismanagement of arid lands have been noted: the deterioration of fertile lands 'In the Jodhpur-Bilara region, the region traditionally famous for the plenty of sweet sub­ due to the removal of top soil or the soil water, nearly 22 per cent of 169 selected wells submersion of fertile land under shifting were found to be suffering from the above pro­ sand-dunes (Ghose et al., 1968; Anon. blems. See Anon (1967).

343 DESERTIFICATION AND ITS CONTROL

,...._ .. .,. "'Q .... ~~M~~~~~O~v~v~v~~®~ ojo., ~ o~~~~~~~~~~~~~~~~_~ ~ ...... ~ ~~~~~~~OOO~~~N~~~~~~ ., 0 -o~OO~OO~~~~~M~~MN N~ .,0. E;:l ~ ;> ., '0..... ~ Cl «I 8 -- ,-0 0 «I ~. .,'" o Cl IZl .,~ ",' -g ~~_~~~~ON~VN~_~V~_N t:Il., "O.~ .,«I M~~~~~M~wO~M~~~OM~_ o~ ..... ~'O., ., 00. -~~~oooo~~~~~~~~~~o~~~______N~NNNNN ____ c -~M~~~®~OOOON~-~~~~ ;>...:::: .,., 0 ~MO-OOO~~W~~~~~M~MN .... 0'" «I .... 0 ~ ------~ ....0"':::: '" -- .. -- '" ~.r: ~ "'d"'~ u:::: '"0.'" 8;:l ., '" 0.... ~ t:Il:-g U N~~O~M~~O~~OO~~M~~~ i5~ oj ~NOOOOO~~~~~M~~~~~M~OO .,.2': CI) "'::::'0 ~~~~~®~~~N~~OONN_~6~N_~OO~~~~~~ u·s. ca0. O ____ N ___ ..... Q ;Sr:.:; ·0 < ..... " c o~ E~ .;:: ------..... 0 o to • 0. Cl...:::: ~ti .... 8~ 0 O~~~N~~~ooN~N~~_~~~~ "'l:'0._ '0 ~~~~~~~~~~~~~~OON~~~ ....,0. ", ...o -0'"' Q) ] 0.0 .;;:' .,'" ~~~~~~_N_~~~~~ON~~~ o~ '" :>< O~v~~~~~V~~MNNO-~~v ~!:) ...... '0.0 ";3 '0 .... Clr<"l 0. ------:::8 ~] oj I( oj ... ~.~ ojM ~ CI)~ .. ~a 'O~ .... ~ o~r:::- oj- '" N_~~M....,~~O~~~W~OOOM~~ N_ .... , ~ oj ~~~_v~VN~N-~_~~O-vv .§~ 0", ~ N66~6M~~~~M~~~M~~M~ .... ~~~~~®~~~~~~-NN-O- ______NNNNMNN __ u:::::3 oj "'~ < f6~oj ~I '0., "00"- - oj- QQ ... ~ .... ~ ::3'-" o.v;> ~~ ...0'" I!J CI)~ d oj;S ...::::~ 00 ~~"'~~~~ON~-~~~OON~~M ..... ~ '0 o~w~~~~~~~oo~o-®_~_ '0 0 c - - . .. - ...... '00 .> <> -O~~~~N~~~~~~~OO~O~~ ., ... s:;: -.... 0 ;>; Oo~~~~~oo~ooOOOO~OO~~ONN 1)..0 ojN ;>'0 E -_ d~ :>. ~ --- 8~ 0)' ';:: ."" ...oj~ E~ -~ oj ~ ::38 .,- NN~~~~~~~~~~~~O~~~v .:a I-f ~ oj E", ., ~~~~~~~~~~~~~~~NO~ ojo;! ~g ... ~~~~~~~~~O~~~~~~~~~ ~~ ~N~V~~~~~~~~OO~~~~~~ "'oj .~ Q ;S ~ ~~~~~~~~~~~~~~~~~~~ ... ", .... '0" ti...:::: 0 a:a :.a~ ., «I CI) '"u S';: cO d'~ :.a ;l:,- 0) o~ s:;: .~ 0 :a'O ...... ~ ~ 0 "...:::: 0 ::3 ~~~~~~~~~~~~~~~~~~~ .~l:' c..~_ d ~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~ ~e'Oa~ oj ..0

344 LAND-TENURE PROBLEMS AND POLICIES

the case of jowar around 1963-64 and In this context, it will not be out of place sesamum around 1965-66 did areas start to mention that progress in agricultural to decline. The reasons for this decline productivity is normally associated with will be mentioned shortly. The more the increasing use intensity of the land. striking feature revealed by Table 4 is that At times, the whole process of agricultural if one excludes the impact of a sequence growth is explained in terms of a progres­ of extremely good years (1970-71 and sive increase in the use intensity of land.4 1971-72) the yields in most of the crops However, the mere intensification of show a declining trend. This decline is land use unaccompanied by an appro­ especially strong in the case of jowar and priate technology may prove counter-pro­ sesamum, a fact which partly explains the ductive, as it seems to have happened in decline in their area in the later period. the arid region of Rajasthan (Jodha, Once the farmers realized the futility of 1972). Thus the first step towards rais­ planting submarginal lands to crops like ing productivity or maintaining the use jowar and sesamum (which need relati­ intensity of arid lands at a high level is to vely good soils), they shifted the area to have the necessary technological comple­ kharijpulses, and to some extent to bajra. ment for both crop lands and grazing Kharifpulses, being the crops most suited lands. In the context of arid lands in to arid lands, show relatively stable, if the absence of irrigation facility, various not rising, yield trends. The rather alarm­ conservation measures may offer the ing inference from Table 4 is that an in­ required technological complement. Con­ crease in the area under crops has accom­ servation technology covers various mea­ panied the decline in the yields of crops. sures, some of which are well-regulated Hence the efforts to raise fopd production farm practices, whereas the others involve through pushing submarginal lands under the creation of physical assets. Rotational the plough may prove counter-productive grazing and rotations between crops and a in the long run. long fallow, for instance, fall in the former category. Measures, such as the stabili­ THE FUTURE COURSE zation of sand-dunes, the creation of shel­ The main burden of the preceding dis­ terbelts and micro-wind breaks, the bund­ cussion is that the land policies in the past ing of crop lands and contour-furrowing, have encouraged a land-use and manage­ contour-trenching, and many other soil ment pattern which is not in keeping with works for range lands fall under the the requirements of the arid lands. The second category. The conservation tech­ reversal of the process will mean the res­ nology, as evolved and recommended by tricting of the use intensity oflands to a the CAZRI, is yet to reach the farmers lower level or the adoption of comple­ (Jodha, 1972). The problems of conser­ mentary provisions which permit a high­ vation technology, the solution of which use intensity without damage to the land­ is linked to the tenurial policies are dis­ resource base. Restriction on the future cussed below: ditribution of submarginal lands for One such problem stems from the indi­ cultivation is the first step. The retirement visibility character of a number of con­ of lands from cultivation and back to the servation measures. The measures, such natural grass is quite a difficult task. In as sand-dune stabilization, shelterbelt cre­ fact, in view of the increased human and ation or the bunding work or the regene- animal pressure on land and the rigidity of land·use pattern encouraged in the past, 'For instance, the shift from the forest fallow the lowering down of the level of use inten­ to the bush fallow and hence to the short fallow sity may not be possible. Hence the alter­ and then to annual cropping and lastly to multiple cropping represented successive stages towards native lies in the adoption of conservation higher degrees of use intensity. giving rise to large measures which enhance the permissible favourable shifts in production possibilities of the level of use intensity of the arid lands. land. See Boserup (1965).

345 DESERTIFICATION AND ITS CONTROL ration of range lands through a variety associations but will also help panchayats of earthworks, can be adopted effectively and revenue authorities to enforce the only on the basis of the catchment rather adoption of conservation technology. than on the basis of individual farms or The individual land users' obligations parts of the catchment. These measures in terms of adherence to conservation require collective action on the village, practices should be specifically incorpora­ pasture or catchment basis (Jodha, 1967). ted in the land laws. These laws can be Similarly, some of the regulatory prac­ enforced with liberal recourse to penalties tices, such as the rotational use of pas­ in the case of default, and the granting utres, also require collective action. Be­ of rent remission, etc. as a reward for fore land reforms, when the jagirdar had adopting conservation measures. absolute authority over the village, such The provisions involving the land collective decisions were not required. users' obligations are more important In some of the villages, the jagirdars used in the case of grazing lands. The present to enforce certain regulatory measures, practices of overstocking unrestricted and for the utilization of pastures and village unregulated grazing, for instance, are forests. Rotational grazing around dif­ largely in vogue, because there is no pro­ ferent watering-points, known as tobas, vision for grazing rights and obligations grazing fees per animal, known as in terms of grazing fees, taxes and penal­ ghasmari, the zoning of village lands for ties in the case of the misuse of resources. grazing and collecting cut fodder through Consequently, there is little 'private cost' declaration known as chait rakhai, etc. are for resource use. The incorporation of a few examples. Most of these provisions the above provisions in the land laws may disappeared with the abolition of the greatly help to rationalize the utilization jagirdari system. The new village pall­ of grazing lands. cllayats which replaced the jagirdars f::lr Finally, it may be added that land poli­ the purpose of village administration cies can play only a complementary role could not enforce such provisions (Jodha, in ushering in the era of conservation­ 1967). 1)1 the changed circumstances farming in the arid region. It cannot be to facilitate or enforce group decisions a substitute for the conservation-oriented and action, it is essential to have some development strategy which encourages form of 'dual tenure" which provides some the production activities having a com­ authority for the group over the lands parative advantage in the arid region. belonging to individal farmers in a given catchment. This system would not only REFERENCES facilitate th~ formation of land users' ANON.' 1961. Report of the State Land Utilisa­ tion Committee. Government of Rajasthan, 'The term 'dual tenure', used in the absence Government Press, Jodhpur. of any more appropriate term, implies that the ANON. 1963. The Pattei'll of Rural Development lands in, a given catchment belong to individual in Rajas/han. Evaluation Organisation, farmers. But when it comes to the catchment­ Government of Rajasthan. based treatment of the lands, all farms should be ANON. 1965. Accumulation of Desert Sand. treated as be~onging to the group having their Agricultural Research, 5(3), ICAR, New land parcels III the concerned catchment- The Delhi. group should have authority to undertake con­ ANON, 1967. Quarterly Report on Preliminary servation measures. It should also be liable to . Geohydrological Survey of Jodhpur-Nagaur punishment for the mismanagement of the catch­ Sector. Report S & J.2 Rajasthan Ground­ ment. water Board, Jodhpur. In formal arrangements, similar to the one CAZRJ 1966. Scientlfic Progress Report 1964-65, mentioned above, already exist in predominantly Central Arid-Zone Research Institute, Jodh­ Bisnoi-caste villages in the Jodhpur region where pur (Mimeo). the villagers. as a group, do not permit an indivi­ GHOSE, B., PANDEY, S, and SINGH, S, 1968. Pro­ dual farmer to cut trees, etc. in his own field. Nor cess and extent of erosion and its effect do they allow the killing of wild animals-deer on land use in Central Luni Basin. Ann. rabbits, etc. ,in the whole or the village territory. ' Arid Zone 7(1). 346 LAND-TENURE PROBLEMS AND POLICIES

JODHA, N. S. Capital Formation in Arid Agricul­ Significance in soil conservation. Pro­ ture: A Study of Resource Conservation ceedings of the National Academy of Sciences, and Reclamation Meqsures applied to Arid India, Section B 31 P. III. Agriculture. Ph.D. Thesis, University of KRISHNAN, A. and THANVI, K. P. 1969. Water Jodhpur (unpublished). budget in the arid zone of Rajasthan during JODHA, N. S. and VYAS, V. S. 1969. Conditions 1941-1960. Ann. Arid Zone 8(2). of Stability and Growth in Arid Agriculture. NCAER 1965. Land and Livestock in Rajasthan. Agro-Economic Research Centre, Vallabh National Council of Applied Economic Vidyanagar, Gujarat. Research; New Delhi. JODHA, N. S. 1970. Land policies of Rajasthan: PR.AKASH, M. and AHUJA, L. D. 1964. Studies in some neglected aspects. Economic & different range condition class grass­ Political Weekly (Quarterly Review lands in Western Rajasthan. Ann. Arid Zone Agriculture) 5(26). 3(1 -2). JODHA, N. S. and PUROHIT, S. D. 1971. Weather ScmCKELE, RAINER. 1950. Objectives of Land and crop instability in the dry region of Policy. Land Problems and Policies (ed. Rajasthan. Indian J. agric. Econ. 26(4). J. F. Timmons and W. G. Murry). The JODHA, N. S. 1972. A strategy for dry land Iowa State College Press. agriculture. Economic & Political Weekly SETH, S. P. and MEHTA, N. K. 1963. Fertility (Quarterly Review of Agriculture) 7(13). survey and soil test summaries of some JODHA, N. S. 1975. Famine and famine policies: districts of the arid regions of Rajasthan. some empirical evidence. Economic & Ann. Arid Zone 2(1). Political Weekly 10(40). TUMA, E. H. 1965. Twenty·Six Centuries 0/ KAUL, R.N. and MISRA, D. K. 1961. 'Land Agrarian Reforms: A Comparative Analysis. utilisation problem in arid zone and its University of California Press.

347 36 GEOTHERMAL ENERGY AND ITS POSSIBLE APPLICATION IN AGRICULTURE IN THE LADAKH REGION

MOHAN L. GUPTA

THE development of regions, located at lems can be solved to a great extentthrough higher altitudes, where very cold condi­ planned and co-ordinated efforts and tions prevail, the reserves of fossil fuel are through a fruitful utilization of the region'S scanty and the periods with .favourable solar and geothermal energy resources, climatic conditions conducive to agricul­ which are available in plenty. tural growth are limited, requires the full mobilization of natural resources and the AGRICULTURAL PRODUCTS OF LADAKH application of techniques for food pro­ As mentioned above, Ladakh's popula­ duction and other uses. The Ladakh tion is very low; it is scattered and found District of the Jammu and Kashmir State in secluded valleys. Naturally, the crops is one of the most elevated regions of the also follow the same pattern. They are world and is located between the great raised with irrigation along the river Central Himalayas and the mountains on banks and on alluvial plateaux. The the edge of the Tibet Plateau. Naturally, important areas for this purpose are the low temperatures prevail there (Table 1). valleys of the Indus, the Nubra and a Moreover, the region received scanty rain portion of the valley of the Shyok River. during the year (Table 2), as the Central Barley is the dominant crop. Wheat, High Himalayas act as a barrier and block buckwheat, pulses, beardless barley, peas, the rain-bearing winds from south. Thus rapeseed, millets, roots and lucerne are cold desert conditions exist in most of the chief crops and are grown in care­ Ladakh region. Generally, the river fully manured soils which are often valleys are the most populated areas. transported from other parts. Fruits However, the population. density of the (mainly apricots and apples) are also region is low (about 3 persons per km». grown in the valley near the Indus. The main occupation of the people is In the neighbourhood of Pangong Tso agriculture and trade in wool. Lake, which is located to the south-east Energy and other supplies reach Ladakh of Leh at an elevation of 4,267 m, crops mostly from Srinagar. Therefore, the of beans and beardless barley are raised. prices of almost all things are prohibitive. Vegetables and other crops are grown in Things have to be stored for the winter 'Ladakh to a limited extent, mainly during when the roads remain closed because of the short summer and autumn. snowfall. The very high price of fossil fuel, the high rate of electricity (which at GEOTHERMAL RESOURCES OF LADAKH present is generated with diesel-sets) and It is well known that the temperature the poor economi~ conditions have stood increases as we go deep down inside the in the way 'of greenhouse cultivation there, earth. The normal temperature increase despite the fact that food supplies have to is about 3° C per 100 m. The average be occasionally made qy air. These prob- global conductive heat flow from the

348 GEOTHERMAL ENERGY, ITS APPLICATION IN AGRICULTURE

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earth's surface is 74.3 milliwatts/m·. Over the Indian peninsular landmass, the geothermal gradients and heat flow vary from 1. 0 to 7. 5°C per 100 metres and from 40 to 104 milliwatts/m2 respectively (Gupta and Rao, 1970). In Ladakh, the geothermal gradients in shallow (20-S0m) exploratory boreholes in the Puga hot-spring area are very high. The lowest observed value

o 0 ..... ~ is 32°C/m (Gupta et af., 1973). tl o '" 0 N o 000 0 Ladakh has had no recent volcanic activity. In fact, this is true for the whole Himalayan mobile belt. However, along with the other parts of the Himalayas, Ladakh has experienced intensive tectonic and orogenic activity. Therefore, apart from the heat derived from the disinte­ gration of radioactive elements, heat has been generated in the region owing to orogenic activity. As a part of the Hima­ layas, great uplifts have occurred during the last few million years in Ladakh, as a consequence of which rocks have been brought out from great depths. Heat is given out when these rocks cool. The movements also create favourable paths 00-N '" ~ of heat transport from the depths. Dur­ o 0 0 0 ing the folding stages and in regions mar­ ked with a tendency of uplift, the emplace­ ment of granitoids takes place, fusion occurs and magma can be locally generated 000 0 owing to the pressure drop during arched block-warping of the highly heated zones of the crust. The emplacement of post­ ... ~ ~ ~ g orogenic granites of various ages have ~ 666 0 been thought of in this way in the Central and Tethys Himalayas. Intrusive bodies which are younger « 10 million years old) could cause high geothermal gradients and heat flow and thus could be a possible heat sour ce for a geothermal field of a moderate degree. Recent investigations in the Puga-Chumatang areas show the evidence of the occurrence of Miocene/ Pliocene granites in the Ladakh range. The combined effect of the above­ mentioned processes has resulted in the concentration of more heat at shallow depths in the earth's crust in the Ladakh region than in the normal continental areas. Therefore there seems to be a great possibility of the development and utiliza-

350 GEOTHERMAL ENERGY, ITS APPLICATION IN AGRICULTURE tion of the geothermal energy resources of drillings, have been carried out in the Puga Ladakh not only for agricultural purposes and Chumatang hot-springs areas (Gupta but also for other uses. et a!., 1975b; Shanker et aI., 1975). The majority of the shallow exploratory bore­ THE HOT SPRINGS OF LADAKH holes at Puga have tapped a mixture of The surface manifestations of the earth's steal~ and hot water at temperatures heat in the form of hot springs are nume­ rangmg from 80 to 13SoC as predic­ rous in the Ladakh region. A famous ted during 1967 by the author. Boreholes ~luster of hot springs occurs at Puga and at Chumatang have also shown thermal Chumatang. A number of prominent hot fluids. springs are located in the Nubra Valley. The Puga Valley has been recognized According to S. N. Dhar (Personal com­ as the most potential geothermal field in munication), the hot springs emerge at India. The chemical analysis of its spring three locations in this valley, viz. at (a) and bor~hole waters in?icates that they Panamik, (b) Rondhu, and (c) Changlung, are domInated by relatIvely high F CI in a strike length of about 100 km. The Si02 , B, H 2 S and Li as well as by lo~ C~ water discharge from Changlung and and Mg. The overall geochemical and Panamik hot springs is very large. The thermal considerations indicate that some surface temperatures are also about 78° phase (or phases) of late magmatic activity and 7 Soc. The temperature and dis­ ha5 (or have) occurred in the area and charge of the Rondhu spring are less than contributes (or contribute) to heat and those of the Panamik springs. Four certain chemical constituents of the ther­ springs having temperatures ranging from mal waters. 43° to 61°C have also been reported at The temperatures of the sub-surface Gaik in the Indus Valley towards the north reservoirs from which the Puga and the of Chumatang (Dua and Singh, 1974). Chumatang hot springs draw the thermal It is most likely that more hot-spring areas water have been estimated from geo­ may be discovered through extensive chemical thermometry and are of the order surveys. of 200°-240°C (Gupta, 1974). In the Puga Valley, a large group of hot EXPERIMENTAL GREENHOUSE springs (more than 100 in number, with CULTIVATION AT CHUMATANG water temperature ranging from 40° to LADAKH ' 84°C), large patches of hot ground, mud pools, along with the seepage of hot water It has already been mentioned in the in the Puga Nala have been observed. beginning that the high cost of fossil fuel The valley is situated towards the south­ did not allow greenhouse cultivation in the east of Leh at a distance of about 220 km Ladakh region. The conditions from the from it and at an altitude of 4,400 m energy point of view have been so bad in above m.s.l, water from some of the Puga the region that in olden days, the refine­ springs is nearly at the boiling temperature ment of borax (which is available at Puga) (84°C) corresponding to the altitude of the at Leh had to be stopped, as it was not springs. A large number of hot springs found economical, though there was a having temperatures from 65° to 86°C good demand for this product. emerge at Chumatang from the bed of the The prospects of the availabity of good Indus through fault zones on its right bank. quantities of thermal fluids at Chumatang The above two hot-spring zones are loca­ and P~ga encouraged such an attempt ted on each side of the Indus Suture zone recently there and the feasibility of the near the collided junction of the Indian studies on cultivation in winter in a and Eurasian plates (Gupta, 1974; Gupta greenhouse heated with geothermal energy et al., 1975a; Shanker et al., 1975). has been done at Chumatang. A steel­ During the last several years, various framed glass and transparent plastic-sheet geo-investigations, including exploratory greenhouse was installed at Chumatang.

351 DESERTIFICATION AND ITS CONTROL

Thermal fluids from the nearby geothermal Ladakh for the production of food stuffs, wells were led into it to heat the environ­ etc., on an effective and rapid rate. There­ ment and the soil separately. The inside fore to obtain substantial benefits and temperature was regulated through a provide a year-round supply of vegetables controlled flow of hot water through inlet (e.g. tomatoes, cabbage, cauliflower, french and outlet valves. It has been possible beans, cucumbers, lettuce, knol-knol, green to maintain the optimum soil and environ­ leafy vegetables) and some tropical fruits, mental temperature for plant growth dur­ fish, eggs, chicken, etc., it is necessary ing winter when the mercury drops much that a planned and co-ordinated effort is below zero. Forty-one varieties of plants, made. The experimental greenhouse, including vegetables and fruits, e.g. straw­ aquaculture and poultry-farming may be berry, as well as flowers were planted. started in the Ladakh region by utilizing Very satisfactory and encouraging results the natural free-flowing thermal water from have been obtained (Behal et aI., 1975). hot springs and also from flowing bore­ holes. PROSPECTIVE AREAS The geotectonic considerat'ions, as men­ ECONOMIC SIGNIFICANCE tioned above, suggest that geothermal The advantage of geothermal waters is gradients higher than 30°C/km, most likely, that no fuel is consumed to get its energy­ will be observed in many parts of the giving heat. These waters can be tapped Ladakh region. Therefore boreholes to at many favourable locations and directly about 1,200 m or more, when drilled in used for agricultural applications in cold selected areas so as to tap waters, will climates. Cold desert conditions similar serve as a good source of low-enthalpy to those of Ladakh, occur in Oregon (50°C) waters which can be fruitfully used (USA). A company named 'Oregon for agricultural purposes. Besides, cer­ Desert Farms' reaped enormous savings tain localized thermally anomalous areas in the last few years turning to geothermal are also there. A few prospective areas greenhouses to protect his vegetables from are listed below : cold desert nights. 1. Various parts of the Puga Valley, The utilization of geothermal energy in where there are no thermal mani­ agriculture is very economical. Green­ festations, and the soil is free from house-heating with geothermal energy has borax and other salts. been estimated to cost $ O. 399jm2 in com­ 2. The area of the Indus basin in the parison with $ 11. 92 1m" operating cost vicinity of Gaik and Chumatang with fuel-oil. Thus the ratio of geo­ hot.. spring zones. thermal to fuel-oil operating cost is 1 to 3. The Nubra Valley. 33".01, in which case the geothermal an­ 4. The Leh Valley, which is' about 10 nual variable cost in agriculture in the km wide, is shut in on both sides by world is $ 2,473,854 ($ 82,188,960/33.01), high peaks averaging about 5,000 resulting in an annual saving of 79. 72 m above the m.s.l. million dollars (Peterson and EI-Ramly, It seems likely that deep boreholes, if 1975). drilled at carefully selected points after The energy content of free-flowing carrying out various geo-investigations, thermal waters, relative to °C, from the may tap low-enthalpy waters. However, . Nubra Valley, Chumatang, Puga and Gaik if this procedure does not work, the earth's hot springs of Ladakh is equivalent to heat for agricultural purposes can be about 8,000 kw. A manifold increase extracted through water circulation in of the availability of this energy can be two deep boreholes connected through attempted by drilling boreholes. Even if hydrofracturing, as is being done in other one-third of this energy, which is going countries. waste, is utilized, it will result in great Greenhouse cult~vation is necessary in saving. Low-salinity thermal waters, if

352 GEOTHERMAL ENERGY, ITS APPLICATION IN AGRICULTURE

found suitable, can also be used for irrigat­ on Himalayan Geology, Nainital 1973. ing the soil directly. The final waste saline Himalayan Geology 4: 492-515. Wadia Institute of Himalayan Geology, New Delhi. water after heating the soil through the GUPTA, M. L., HARI NARAIN and GAUR, V. K. pipes can be further used to melt the snow 1975a. Geothermal provinces of India, and obtain the water-supply for irrigation. as indicated by studies of thermal springs. terrestrial heat flow and other parameters Other benefits will be savings in the cost (abstract). 2nd U.N. Symposium on the of transportation of fuel and foodstuffs to Development and Use of Geothermal Re­ the Ladakh region, the provision of cheap sources, Sail Francisco, California, May 19-29, agriculture products, the optimum utili­ 1975. p. 11-17 (full paper in press). zation of man-hours and ultimately the GUPTA, M. L. and RAO, G. V. 1970. Heat flow studies under the Upper Mantle Project. socio-economic development of the region, NGRl Bull. India 8(5 & 4): 87-112. GUPTA, M. L., RAO, G. V., SINGH, S. B. and RAO, REFERENCES K. M. L. 1973. Report on Thermal Studies and Resistivity Surveys in the Fuga Valley BEHAL, S.O., JAOADESAN, K. and REDDY, D. S. Geothermal Field Ladakh (J&K). NGRl 1975. Some aspects of utilization of thermal Tech. Rep. No. 73-79. fluids from the geothermal fields in North­ PETERSON, RICHARD E. and NABIL EL-RAMLY West Himalayas, India. 2nd U.N. Symposium 1975. The Worldwide Electric and Non­ on the Development and Use of Geothermal electric Geothermal Industry. Geothermal Resources, San Francisco, P. VIII-2 (abstract Energy 3(11): 4-14. volume). SHANKAR, RAVI, PADHI, R. N., ARORA, C. L., DUA, K. J. and PRATAP SINGH, 1974. Geohyd­ PRAKASH, GYAN, THussu, J. L. and DUA, rological investigations on Chumatang, Puga K. J. S. 1975. Geothermal exploration of and Gaik thermal areas, Ladakh district, the Puga and Chumatang Geothermal J & K State. Grollp disclIssions on Geothermal Fields, Ladakh, India. 2nd U.N. Symposium Investigations. Lucknow (unpublished). 011 the Development and Use of Geothermal GUPTA, M. L. 1974. Geothermal resources of Resources, San Francisco, California, May some Himalayan hot-spring areas. Seminar 19-29, p. 1-34.

353 37 AN OPERATIONAL RESEARCH PROJECT FOR ARID-LAND MANAGEMENT

S. P. MALHOTRA

IN spite of the availability of much valu~ tackled from the social, organizational able technical knowhow, there has been and technical angles concurrently. A rather a slow diffusion of the newer scientific-project consortium was organiz~ scientific discoveries to the farmers' fields. ed at the Institute level to adopt an To bridge the communication gap, the Ins­ integrated approach to the use of titute launched an 'Operational Research available human, soil, water, plant, animal Project' on an inter-disciplinary basis and solar-energy resources. Different for arid-land management. On the basis subject-matter specialists available at the of the proven findings of this Institute, Central Arid Zone Research Institute, viz. the following aspects of the development the Agronomist, Horticulturist, Silvicul~ of the arid region have been taken up in turist, Animal Scientists, Physicist and a cluster of five villages in the Jodhpur Social Scientists, have been associated district: to make the programme scientist-oriented. 1. Sand-dune stabilization Also, the various State Government 2. Pasture, grasses and forage develop­ departments, local bodies and, above all, ment the farmers of the area are the partici­ 3. Afforestation and shelter-belt pro­ pants in the programme, both at its gramme conception and execution stages. To 4. Demonstration of higher productivity achieve such a collaboration, a district­ of improved technology on rabi level committee has been set up with the and kharif crops District Collector as its Chairman. Besid­ 5. Demonstration of higher produc­ es the nominees from the Central Arid­ tivity 'by improved technology of Zone Research Institute, one officer each important vegetables and fruits from the State departments concerned with 6. Demonstration of effective control the Drought~Prone-Area Programme, of rodents Agriculture and Animal Husbandry, the 7. Community organization and pro­ Block Development Officer of the con­ grammes of technocracy cerned Panchayat Samiti (Mandore) and 8. Sheep-development programme a representative of the United Commer­ 9. Demonstration of gobar-gas plants; cial Bank and five farmers of the project solar water-heaters, solar dryers area act as members of this committee. and solar cookers. To gain a fuller knowledge of the ana­ tomy of the society inhabiting the area, APPROACH a detailed socio-economic survey was To couple the social aspects of rural conducted before initiating the imple­ transformation effectively with the techno~ mentation of various elements of the pro~ logical aspects, the operational problems gramme. The small and marginal farmers in the transfer of technology are being as well as the lineage heads and the

354 ARID-LAND MANAGEMENT, AN OPERATIONAL RESEARCH PROJECT

.opinion leaders were identified. Sufficient of fuel-wood from each hectare after every time was then allocated for a rapport 10 years and 1 tonne of grass per ha to develop between the project workers every year, besides checking the movement and the inhabitants of the area through of sand significantly. The farm-owner personal discussions, the holdings of of the 'dune has now developed a pro­ farmers' days, etc., to persuade the farm­ found attachment to this previously ers to arrive at a consensus for adopting neglected area and has lately been taking the, various recommended practices. This a good deal of interest in its mainte-ance. was necessary to achieve ultimately a In another case, a sand-dune of about good multiplier effect and involve the 16 ha, threatening the village holdings has total population of the area in the pro­ been taken up under the stabilization pro­ gramme rather than to convert a few at ject, with the co-operation of its owner. a time through piecemeal demonstra­ At the commencement of the rains, tree tions. seedlings of Acacia tortilis, Prosopis juliflora and Dichrostachys nutans were TRANSFERENCE OF ARID-LAND planted, following the standardized tech­ MANAGEMENT TECHNOLOGIES niques. In all, 2200 seedlings have been Sand-dune stabilization planted. All of them are flourishing. Tree-planting has been done in strips of A medium-sized sand-dune belonging 10 rows across the wind direction and a to a farmer, and located in the heart of the space of 50 m has been left between two village, formed by the accumulation of strips for sowing the seeds of Cenchrus fine sand on a rocky surface was taken species. One hundred per cent survival up for stabilizaJion and utilization. The of the tree seedlings planted during the movement of sand particles was posing year has been recorded, along with a hazards to the adjoining fertile cultivable fairly good establishment of the grass. lands of the farmers. This sand-dune This area also is expected to yield quite had been lying fallow for a number of remunerative returns on a 10-year rota­ years and it had hardly any vegetation tional felling schedule. The results so cover at the time it was taken up for far are very encouraging (Plate s). rehabilitation. The owner of the dune area was motivated to carry out the Grassland development technologies evolved by this Institute and The land-use data of the region reveals to put the barren land into productive over-saturation of cultivation and the use use by raising tree plantations and grass­ of marginal and sub-marginal lands for es, which, in turn, would meet his fuel cultivation. Crop production on such and fodder requirements in about 5 years marginal lands is not only low, but is also and also save the adjoining farm holdings a soil-conservation hazard. Farmers were, from being engulfed by the moving sand therefore, motivated to use the margi­ particles (Plate r). nal and sub-marginal lands as pastur­ The sand-dune was fenced with barbed es and rangelands for animal production. wire and angle-iron posts. Seedlings of The plots were sown with Cenchrus Acacia tortili!J and Prosopis juliflora were ciliaris and Cenchrus setigerus seeds, de­ planted in pits of 60 x 60 XC 60 cm. pending on the soil characteristics. These Between the rows of the trees, seeds of the two grass species, planted at a spacing grass, Cenchrus species, were sown. In of 50 cm, have been found to perform all, 650 tree seedlings were planted 5 x 5 very well, with their yields ranging from m apart. The establishment of the seed­ 2.5 to 3 tonnes per ha (dry matter) in lings was excellent, with 90 per cent normal-rainfall years, thereby ensuring success. It has been estimated that the sufficient fodder supplies for the livestock plantations on the dune will make it for the whole year. The farmers have possible for the farmer to obtain 5 tonnes realized the importance of growing grasses

355 DESERTIFICATION AND ITS CONTROL

in their fields by setting aside a portion tion systems on the conventional channel­ of their farms for this purpose. irrigation systems and many other crop management practices, e.g. the timely use Horticultural development of pesticides, insecticides, rodenticides The programme of horticultural deve­ and the maintenance of an optimum plant lopment carried out under this project population, etc., which directly boost has also received good support from the agricultural production. Among the major local farmers. These farmers have be­ crops and varieties, hybrid bajra, castor come well aware of the various varieties (Aruna), wheat (Kalyansona), Kharchia of fruits and have especially developed 65 and potato (Kufri Chandramukhi) liking for the Gola and Seb varieties of have been found to be remunerative ber and for the seedless variety of anar. substitutes for the existing crops and About 4,000 ber seedlings have been plant­ varieties. ed so far in the fields of different farmers With the recommended cultivation in the area of the Operational Research practices and the use of fertilizers based Project. The plantations have been done on soil-test values (40-80 kg of N/ha). under unirrigated as well as under irrigat­ the yield of bajra in such demonstrations ed conditions with sweet and brackish ranged from 30 to 45 q/ha against 12 to water, and also in slopy, levelled and 20 q/ha obtained from local varieties rocky areas. Two- to six-month-old ber and with conventional cultivation 'practic­ seedlings were planted, and they are being es. The introduction of castor variety budded with the improved ber varieties, Aruna not only increased the yield/ha viz. Gola and Seb. Spot-training is also (12 qjha) and the net profit per unit area < offered to the farmers who are anxious (Rs 2,200 per ha) over the local castor to know the budding technique. The variety, but also the variety matured other fruit-tree introduced in the area early and cleared the land for the rabi mentioned above is anar (pomegranate) crops. This variety is being rapidly and, so far, two varieties, viz. Mandore adopted by the farmers. Similar attain­ and Saharanpur have been introduced. ments were demonstrated with wheat To demonstrate to the farmers the (Kalyansona). Potato (Kufri Chandra­ method by which old orchards can be mukhi), a completely new introduction in rejuvenated, spot demonstrations have the village, yielded 200 qjha with the been arranged from time to time to suggest sprinkler irrigation system. All possible proper pruning and other management crop-saving measures have also been operations. The Institute's contribution demonstrated from time to time. In­ to these plantations has been to the extent creasing emphasis is also being laid on of offering technical guidance and supply economizing' the use of costly inputs, the seedlings. A 'good number of farmers such as fertilizers and water. The inte­ have taken up orchard plantations on tbeir grated use of organic and inorganic own and the practice is finding a good manures, weedicides, intercrops (legumes) acceptability and showing a multiplier and the introduction of drip and sprinkler effect. irrigation systems are some of the techno­ logies which are being demonstrated to Crop production meet such objectives. Our problem-orientated efforts in exten­ . Our technologies and packages of sion, since the inception of the Operational practices have received wider acceptance Research Project, have been to demons­ in the area and a large number of farmers trate the impact of the use of improved have adopted the recommended packages crops apd varieties on the existing locals, of practices in respect of bajra, castor, that of the use of economical doses of moong and moth during the kharif and fertilizers on the prevalent fertilizer-use wheat, raya, mustard and potato in the practices, that of the ,use of efficient irriga- rabi season.

356 ARID-LAND MANAGEMENT, AN OPERATIONAL RESEARCH PROJECT

Rodent control whose house a gobar-gas plant has been installed at a total cost of Rs 2,300 are The socio-religious feelings of the in­ in the forms of a saving of about 3 quintals habitants of the area were observed to of fuel-)-Vood previously used by him override prudence in the matter of rodent monthly for cooking, etc., and about 1. 75 control. Further, any piecemeal effort litres of'kerosene oil, as the gas is also be­ on a small-area basis is likely to fail, as ing used for lighting purposes. Addi­ rodents would surely overrun territories. tionally, the farmer is getting good farm­ This situation, therefore, warranted a yard manure and he no longer makes and necessity for the community to take up the burns dung-cakes. work as its own programme. Emphasis was, therefore, laid on frequent individual OPERATIONAL CONSTRAINTS and group discussions, advocating the The ignorance of the farmers rega-rding necessity of their control, and a consensus the new technologies before the launching was ultimately reached that the whole of this programme, and the use by them of community inhabiting this cluster of five comparatively costly inputs, such as seed villages should adopt the programme. (hybrids), fertilizers (commercial) and The rodents mainly occupy the bunds pesticides, which were practically not in and peripheral areas of the irrigated use before. took sufficient time for us to fields. Tn a pre-control rodent-population reach the take-off stage. census, the average trap index in the One of the most serious limiting factors, rodent-infested area indicated 20.2 even after the adoption of the new techno­ rodents/trap/24 hours, whereas the post­ logy, is the limited availability of finance control census revealed 2.4 rodents/trap/ to the farmers in the area of the Opera­ 24 hrs, indicating success in the eradica­ tional Research Project. No doubt, tion of the pest to the extent of 98 per advances and loans through co-operative cent. Such a drastic knock-down of the societies and certain banks have been rodents was achieved by mixing two per made available in these villages, but the cent zinc phosphide and one per cent oil impact of these financing agencies has not with whole grains of bajra. The poison­ been significant to the desired level as bait was placed directly inside the burrows yet. The amount is either not sufficient late in the evening. "The farmers collect­ to meet their requirements, or else it is ed the dead rodents and buried them, but not received in time, thus preventing the the fields emitted an unpleasant odour farmers from adopting the package of owing to the large number of deaths in­ accepted technologies. side the burrows. There was not a single Certain technologies, e.g. the sand-dune case of secondary poisoning. stabilization, are accepted with difficulty by the farmers of the low-income group Installation of solar appliances because of the heavy initial investment and gobar-gas plants and delayed returns. Similarly, the drip The introduction of alternative sQurces and sprinkler systems of irrigation, whose of energy in view of the desertification merits are well appreciated by the farmers, being caused by the overexploitation of the are getting acceptance rather slowly be­ vegetal resources by the fast-increasing cause of the lean financial position of the population was considered to be a dire majority ofthe farmers (Plate t). necessity. The installation of biogas plants, The inability of the co-operative socie­ solar heaters and solar cookers was, ties to supply seeds, fertilizers, pesticides, therefore, taken up. A high demand etc., at the doors of the farmers and in for the installation of biogas plants is an time, and preferably on credit, has been indication of the acceptability of the observed to be another important cons­ system by the community. The benefits traint in accepting the proven technologies that accrued to one of the farmers, in by the farmers. If these facilities are made

357 DESERT'IFICATION AND ITS CONTROL available, many of the farmers will make Questions posed by the farmers regard­ use of the technologies of which they are ing various problems faced by them in the fully convinced, course of the cultivation of crops, grasses The shortage of power supply has not and trees and regarding the utilization of only prevented the farmers from deviating water, regarding the problems of salinity from their conventional cropping systems, the application of fertilizers, rodent con~ but has also prevented many of them from trol and the choice of pesticides are ans­ accepting certain improved technologies, wered by the scientists of the Institute. e.g, the sprinkler and drip-systems of Small handouts in Hindi, providing infor­ irrigation. mation on different dryland agricultural techniques and those on forestry and sand­ Extension activities dune stabilization are distributed to the To overcome the above-mentioned farmers on these occasions. operational constraints, apart from the Each participating farmer is also given help obtained through the district-level two seedlings each of some promising tree committee mentioned earlier, a sufficient species, e,g, Acacia tortilis and pomegra­ number of farmers' days, field days, school nate, and a small packet of dhaman grass children's days, etc. are organized from seeds. The field days include similar time to time, The highlights of the activities, Similarly, on the school chil­ farmers' day are the demonstration of dren's day, each visiting student is given nursery techniques suitable for the arid two seedlings of a tree and some seeds of zone, the use of fertilizers, important de­ castor for planting in their home com­ sert grasses, cafeteria of dry farming crops, pounds, fodder legumes, rodent control and other . Additionally, the institutions of Nav­ pest-control techniques, etc, Besides, yug MandaI and Mahila MandaI have stalls for exhibiting different types of been organized and a sufficient number of improved agricultural implements, the sale leaflets, describing the methodology and of seeds of improved varieties of crops package of practices, have been prepared and the demonstration of pesticides are in Hindi for ensuring the involvement of also organized. the farmers as participants,

358