Environmental Issues and Suistainable Agriculture

Environmental Issues and Sustainable Agriculture

First Edition: 2019

ISBN: 978-3-96492-154-3

Price: Rs. 1500 (€ 14)

Disclaimer: The authors are solely responsible for the contents of the book chapters compiled in this book. The editors or publisher do not take any, responsibility for same in any manner. Errors, if any are purely unintentional and readers are requested to communicate such errors to the editors or publisher to avoid discrepancies in future.

Printed & Published by:

Weser Books No. 78737, Aussere Webserstr.57 02763 Zittau, Germany e-mail: [email protected] Website: www.weserbooks.com Editors

Dr. Rajendra Singh Associate Professor, Entomology S. V. P. University of Agriculture & Technology, Meerut, UP

Dr. Joginder Singh Assistant Professor, Horticulture Janta Vedic College, Baraut, Baghpat, UP

Dr. Rashmi Nigam Assistant Professor, Plant Pathology Janta Vedic College, Baraut, Baghpat, UP

Dr. Wajid Hasan Scientist, Entomology K.V.K., Jehanabad (Bihar Agricultural University, Sabour) Bihar

Mr. Rahul Kr. Verma Subject Matter Specialist, Horticulture K.V.K., Madhepura (Bihar Agricultural University, Sabour) Bihar

Weser Books Zittau, Germany

Preface The tropical span a wide area and a diverse range of farming system: therefore in this book we have sought to cover the particularly important in this book for “Environmental Issues and Sustainable Agriculture”. Immense commercialization of agriculture has a very negative effect on the environment. The use of pesticides has led to chemical build-up in our environment, in soil, water, air, in animals and agro forestry losses due to reason development of road buildings etc. Fertilizers have a short-term effect on productivity of crops but a longer- term negative effect on the environment where they remain for years after leaching and running off, contaminating ground water and water bodies. The use of hybrid seeds and the practice of monoculture have led to a severe threat to local and indigenous varieties, whose germplasm can be lost forever all this for "productivity". The bigger picture that rarely makes news however is that millions of people are still underfed and where they do get enough to eat, the food they eat has the capability to eventually kill them. Another negative effect of this trend has been on the fortunes of the farming communities worldwide. This is where organic farming comes in. Organic farming has the capability to take care of each of these problems. Besides the obvious immediate and positive effects organic or natural farming has on the environment and quality of food, it also greatly helps a farmer to become self-sufficient in his requirements for agro-inputs and reduce his costs. Modern farming affects our world, by the way of land exhaustion, nitrate run off, soil erosion, soil compaction, loss of cultivated biodiversity, habitat destruction, contaminated food and destruction of traditional knowledge systems and traditions. Organic farming methods are studied in the field of agro forestry and ecology. While conventional agriculture uses synthetic pesticides and water-soluble synthetically purified fertilizers, organic farmers are restricted by regulations to using natural pesticides and fertilizers. The principal methods of organic farming include crop rotation, green manures and compost, biological pest control, and mechanical cultivation. These measures use the natural environment to enhance agricultural productivity: legumes are planted to fix nitrogen into the soil, natural insect predators are encouraged, crops are rotated to confuse pests and renew soil, and natural materials such as potassium bicarbonate and mulches are used to control disease and weeds. Organic farmers are careful in their selection of plant breeds, and organic researchers produce hardier plants through plant breeding rather than genetic engineering. In intensive farming systems, organic agriculture decreases yield; the range depends on the intensity of external input used before conversion. We have tried to present a logical progression by dividing the book into three main sections: general agriculture and soils, followed by sections on crops and animals. It has been impossible to cover, in any sort of depth, specific agricultural sciences (such as crop protection or nutrition chemistry) or agricultural economics. We hope that liberal illustration of the text will serve continually to help the reader to relate studies to the practical situation. The objectives of the book are:  To provide a concise guide to important information for tropical agriculture and stimulate systematic study of this fascinating subject this is foundational in any sound economy.  To encourage a whole or integrated view of the subject showing interrelationships within agriculture and within other important facets of man’s life, such as health Incorporating green manure crops, into the soil to suppress pests, disrupt their life cycles and to provide the additional benefits of fixing nitrogen and improving soil properties  Managing the frequency with which a crop is grown within a rotation and maintaining the rotation's diversified habitat due to global warming, which provides parasites and predators of pests with alternative sources of food, shelter and breeding sites To manage pests and diseases effectively, producers need to understand the biology and growth habits of both pest and crop. The type and concentration of pests are often responses to previous crop history, pest life cycles, soil conditions and local weather patterns. Any crop management technique that contributes to a vigorous, competitive crop is a tool of insect and disease management. Dr. Rajendra Singh CONTENT

S.N. Chapters Author’s Name Pg. N. 1. Biodiversity and natural resources Ankaj Tiwari, Shivendra 1-7 management and their conservation Pratap Singh, Anjali Singh and Vishal Singh 2. Agroforestry system: diversified Akanksha Bisht and Praveen 8-11 perspective Kumar Singh 3. Ecological succession, ecosystem and Vishnu K Solanki and J. S. 12-18 environment Ranawat 4. Climate Change and Global Warming: Swati Garbyal and Ritu 16-21 Policies, Planning and Management Mittal

5. Biomass estimation of Peltophorum Namo Narayan Mishra and 22-26 ferruginium species in Bilaspur region Kalpana Mishra 6. Atmospheric Pollution and its harmful Lekhika Borgohain, K.N. 27-34 effect on Climate and Crop Production Das, Danish Tamuly, Prem Kumar Bharteey 7. Importance of Wetlands in Water Anupama Gaur 35-38 Conservation and Ecological Balance 8. Agroforestry for mitigating climatic extremesDhanyashri P.V., M. S. 39-43 Malik, Anil Kumar, M. Jadegowda, Saraswati Sahu, Aishwarya Routray, Isha Thakur, Shashikumar M.C., Anush Patric 9. Water Conservation Practices in Deepa Tomar, Nity Nishant, 44-55 Agriculture: A Review Rupa Upadhyay 10. Watershed Management Indu Bala Sethi, Mahesh 56-72 Jajoria, Suresh Kumar, Niranjan Kumar Braod, Laxman Prasad Balai, Lokesh Kumar Jat, Hansram Maliand Suresh Muralia 11. Hybrid Cooling System: A Review Soumitra Tiwari and 73-76 Yashwant Kumar Patel 12. Agroforestry Mohit Husain, Joginder 77-96 Singh, M. A. Islam, Mevada R. J., Azeem Raja 13. Introduction to Important Tree Species Mohit Husain, M. A. Islam 97-108 and M. J. Dobriyal 14. Utilization Pattern as fuel: by Yashwant Kumar Patel and 109-116 collection of wastes, site handling, Soumitra Tiwari1 storage and processing 15. Salt Affected Soils and their Sukirtee, Vikas, Simmi, 117-125 Management Aspects Paras Kamboj and P K Bharteey 16. Agroforestry: Habitat for Biodiversity Shashi Kumar M C, C L 126-137 conservation Thakur, Dhanyashri P.V., Rakshith Kumar S, Jagadish MR and S S Inamatti 17. Marine Pollution: Obstructive Impact Alka Vyas 138-143 on Biodiversities 18. Analytical Techniques for Soil Testing Trilok Nath Rai, Kedar Nath 144-146 Rai, Sanjeev Kumar Rai and Sadhna Rai 19. Role of water for growth and Trilok Nath Rai, Kedar Nath 147-149 development of crops Rai, Sanjeev Kumar Rai and Sadhna Rai 20. Linear Regression Model and its Ankita and Bharti 150-153 Applications in Forestry Research 21. Role of water in relation to plant Paras Kamboj, Vikas and 154-166 growth: An integrated water Sukirtee management approach 22. Physiological Basis of Abiotic Stresses Ashutosh Singh, Susheel 167-176 and Resilience Kumar Singh, Anshuman Singh, Pankaj Lavania and Prabhat Tiwari 23. Ecological and environmental Punam S. Thakur 177-179 justification by learning community participatory research in indoor environmental sciences

Environmental Issues and Sustainable Agriculture

Chapter-1

Biodiversity and natural resources management and their conservation

Ankaj Tiwari, Shivendra Pratap Singh, Anjali Singh and Vishal Singh Narendra Deva University of Agriculture & Technology, Kumarganj, Ayodhya, UP

Biodiversity is defining as the richness in variety and variability of species of all living organism. Biological diversity or biodiversity is the variety of all living organisms, including all species. It can be defined as ‘the variety of life forms, the different plants, animals and microorganisms, the genes they contain, and the ecosystems they form’. The concept accentuates the dynamic interrelation ships occurring in the biological world in which humans now play an integral management role and is usually considered at three levels.

Level of biodiversity: its includes three hierarchical level 1. Genetic 3. Community 2. Species 4. Ecosystem

Genetic Diversity Genetic diversity can be defined as the vast array of species of living organism present on earth. The variety of genetic information contained in all individual plants, animals and microorganisms. Plants out of an estimated total of 30,000 edible plant species, only 30 ‘feed the world’, with the three major crops being maize (Zea mays), wheat (Triticuma estivum) and rice (Oryza sativa ) (FAO 1996). Genetic resources can be defined as whole materials that are existing for improvement of a cultivated plant species (Haussmann et al. 2004). Plant genetic resources are the biological basis of food security and, directly or indirectly, support the livelihoods of every person on Earth Plant genetic resources for food and agriculture (PGRFA) comprise of diversity of seeds and planting material of conventional varieties and modern cultivars, crop wild relatives and other wild plant species. These resources are used as food, feed for domestic animals, fiber, clothing, shelter and energy. The preservation and sustainable use of PGRFA are necessary to safeguard crop production and meet growing environmental challenges and climate change. The erosion of these resources posses a severe threat to the world’s food security in the long term countries are fundamentally inter dependent with regard to plant genetic resources and in particular for crop genetic resources which have been systematically developed, improved and exchanged without interruption over millennia. Food and agriculture production are dependent on genetic resources domesticated elsewhere and subsequently developed in other countries and regions. Continued access to plant genetic resources and a fair and equitable sharing of the benefits arising from their use are there for essential for food security Much of the spectacular success in plant variety development of the rich industrialized countries in the north are attributed to the richness of genetic diversity at the centres of origin and primary diversity of economic species located in the poorer developing countries of the south. While the genetic in indebtness the north to the south is widely recognized, sharing of economic benefits ensuing from genetic wealth is still a matter of debate and discussion. The advent of the era of molecular biology and recombinant DNA research has brought home the point that all forms of genetic diversity have potential commercial value and therefore needs protection. The basic feed stock for biotechnology industry is biodiversity. This is why in the global biodiversity convention the linkages between the two have been stressed. Worldwide 1,308 gene banks are registered in the WIEWS (World

Environmental Issues and Sustainable Agriculture

Information and Early warning System on PGR) database and conserve a total of 6.1 million assents, including major crops, minor or neglected crop species, as well as trees and wild plants. Of the 30 main crops, more than 3.6 million accessions are conserved ex situ.

Species Diversity The variety of species on earth Species diversity is generally a measure of the number of species and their relative richness for a given area at a given point in time on this planet Earth there are about 30 million insects; 15,210 mammals, reptiles and amphibians;9,225 birds; 21,000 fishes; about 4,80,000plants; and 3 million other invertebrates and micro organisms. Many among them have not been identified. For instance, out of 30 million insects only 7,51,000 have been identified Figures for other organisms identified are (total number of species in brackets): mammals, reptiles, and amphibians 14,484 (15,210); birds 9,040 (9,225); fish 19,056 (21,000); plants 3,22,311 (4,80,000); and other invertebrates and micro organisms 2,76,594 (3,000,000), making a total of 1,392,485 (33,525,435).The number of angiospermous species in different countries .Most of the 1,700 million hectares of tropical forests, rich in biodiversity, are located in poor countries. While such forests covered barely 7 % of the land surface, they harbor half of the species of the world’s flora and fauna.

Species Richness Species richness has become a crucial component of biodiversity assessment now it is very commonly used as a similar of species diversity. Similarly, global biodiversity is very often considered in terms of global number of species in each of the different taxonomic groups. In other words, measures of biodiversity for particular areas, habitats or ecosystems are habitually largely reduced to a straight forward measure of species richness (Krishnamurthy2003). Although species richness data may provide relatively little ecologically major information, in practice such data are the most simply derived. Thus, they are perhaps the most useful indices for comparisons of diversity on a larger geographical range more over at present species richness data are the only type of information available for most areas of the world. Such data are also important for prioritizing conservation strategies since they allow identification of geographic regions of the world with exceptional or with very poor diversity. One of the major limitations with species diversity measures is that they treat all species (even within a specific group of organisms) equally, i.e. they take no account of differences between species in relation to their place in a natural hierarchical system ataxic diversity approach, therefore, is based on the view that ‘individual species vary extremely in the contribution they make to diversity because of their taxonomic position’. Taxonomically isolated species or species of taxonomically isolated genera are of very enormous value (e.g. Ginkgo biloba) in diversity assessment in an area. An area containing taxonomically diverse species is considered to have greater diversity than an area with closely related species in identical numbers

Ecosystem Diversity Ecosystem diversity is the variety of habitats, biotic communities and ecological processes. An ecosystem consists of plant, animal, fungal and micro-organism communities and the related non-living environment interacting as an ecological unit.

Ecosystem Diversity has two Interrelated Components The diversity of communities of species and the diversity of interactions between community members (called processes) The wide variety in physical features and climate situations have resulted in a diversity of ecological habitats like forests, grasslands, wetlands

Environmental Issues and Sustainable Agriculture coastal and marine ecosystems and desert ecosystems, which harbour and sustain the massive biodiversity.

Forest Ecosystem A forest ecosystem is natural wood land unit consist of all plants animals and micro organisms (biotic components) in that area execution together with all the non living physical factors of the environment.

Types of Forests Forests can be classified in different types and to different degrees of specificity. One such way is in terms of the ‘biome’ in which they subsist, combined with leaf longevity of the major species (whether they are evergreen or deciduous).another distinction is whether the forests are composed predominantly of broad leaf trees, coniferous (needle-leaved) trees or mixed. Boreal forests occupy the subarctic zone and are usually evergreen and coniferous Temperate zones support both broad leaf deciduous forests (e.g. temperate deciduous forest) and evergreen coniferous forests (e.g. temperate coniferous forests and temperate rain forests) Warm temperate zones support broad leaf evergreen forests, including laurel forests. Tropical and subtropical forests include tropical and subtropical moist forests, tropical and subtropical dry forests and tropical and sub tropical coniferous forests. Physiognomy classifies forests based on their overall physical structure or developmental stage (e.g. old growth vs. second growth). Forests can also be classified additional specifically based on the climate and the dominant tree species present, resulting in numerous different forest types (e.g. ponderosa pine).a number of global forest classification systems have been proposed, but none has gained general receipt. UNEP-WCMC’s forest category classification system is a simplification of other more complex systems (e.g. UNESCO’s forest and woodland ‘sub formations’). This system divides the world’s forests into 26 major types, which reflect climatic zones as well as the chief types of trees. These 26 main types can be reclassified into 6 broader categories: temperate needle leaf, temperate broad leaf and mixed, tropical moist, tropical dry, sparse trees and park land and forest plantations. Each category is described as a separate section below. Temperate needle leaf forests temperate needle leaf forests mostly occupy the higher latitude regions of the Northern Hemisphere, as well as high altitude zones and some warm temperate areas, particularly on nutrient- poor or otherwise unfavourable soils. These forests are composed entirely, or nearly so, of coniferous species (Coniferophyta). In the Northern Hemisphere pines (Pinus) spruces (Picea), larches (Larix), firs (Abies), Douglasfir (Pseudotsuga) and hemlocks (Tsuga) make up the canopy, but other taxa are also significant. In the Southern Hemisphere, most coniferous trees (members of the Araucariaceae and Podocarpaceae) occur in mixtures with broad leaf species and are classed as broad leaf and mixed forests. Temperate Broad Leaf and Mixed Forests Temperate broad leaf and mixed forests include an ample component of trees in the anthophyta. They are usually characteristic of the warmer temperate latitudes but expand to cool temperate ones, mainly in the Southern Hemisphere. They include such forest types as the mixed deciduous forests of the USA and their counterpart in China and Japan; the broad leaf ever green rain forests of Japan, Chile and Tasmania; the Sclerophyllous forests of Australia, central Chile, the Mediterranean and California; and the southern beech Nothofagus forests of Chile and Newzealand. 6 Plant Biodiversity Tropical Moist Forests there are several different types of tropical moist forests, although most extensive are the low land evergreen broad leaf rainforests, .forests located on mountains are also included in this category, divided largely into upper and lower mountain formations on the basis of the variation of physiognomy corresponding to changes in latitude.

Environmental Issues and Sustainable Agriculture

Tropical dry forests are characteristic of areas in the tropics affected by seasonal drought. The seasonality of rainfall is usually reflected in the deciduousness of the forest canopy, with most trees being leafless for several months of the year. However, under some conditions, e.g. less fertile soils or less predictable drought regimes, the proportion of evergreen species increases and the forests are Characterized as ‘sclerophyllous’. Thorn forest a dense forest of low stature with a high frequency of thorny or spiny species, is found where drought is prolonged and particularly where grazing animals are ample. On very poor soils, and particularly where fire is a recurrent phenomenon, woody savannas develop Sparse Trees and Park lands sparse trees and parkland are forests with open canopies of 10–30 % crown cover. They occur chiefly in areas of transition from forested to non-forested landscapes. The two major zones in which these ecosystems occur are in the boreal region and in the seasonally dry tropics. At high latitudes, north of the main zone of boreal forest or taiga, growing conditions are not adequate to maintain a continuous closed forest cover, so tree cover is both sparse and discontinuous. This vegetation is variously called open taiga, open lichen woodland and forest tundra. It is species poor, has high bryophyte cover and is usually affected by fire Forest Plantations Forest plantations, generally have in mind for the production of timber and pulp wood, increase the total area of forest worldwide. Commonly mono specific and/or composed of introduced tree species these ecosystems are not generally important as habitat for native biodiversity. However, they can be managed in ways that enhance their biodiversity defense functions and they are important providers of ecosystem services such as maintaining nutrient capital, protecting watersheds and soil structure as well as storing carbon they may also play an important role in alleviating pressure on natural forests for timber and fuel wood production.

Grasslands Grasslands, which are also known at steppes, prairies, pampas and savannas in various parts of the world, are vegetation types with predominance of grass and grass-like species. Grasslands are an important part of the Earth’s many ecological communities, originally covering as much as 25 % of the Earth’s surface. They have provided expansive grazing land for both wild and domesticated animals and offered flat areas that have been ploughed to grow crop .Grass lands occur in areas with hot summer temperatures and low precipitation. Areas with less rainfall are deserts and areas with more rain fall tend to be forested. There are two broad types of grasslands in the world: tropical savannah and temperate grassland.

Tropical Savannah Tropical savannah occurs in Africa, Australia, South America and Indonesia. Rainfall of50–130 cm a year is concentrated in 6–8 months with drought the rest of the year. Soils are usually very thin, supporting only grasses and forbs (flowering plants), with only scattered trees and shrubs. Differences in climate and soils create many variations in the plant communities and animal species throughout the savannah in many areas, the grasslands have been burned to maintain a healthy grass crop for grazing animals.

Temperate Grasslands Temperate grasslands have less rainfall (25–90 cm) than tropical grasslands and a much greater range of temperatures from winter to summer than savannah. There are two broad types of grasslands in temperate latitudes prairie and steppe.

Prairie Grasslands Prairie grasslands are found across the globe. They have a variety of names in other parts of the world: pampas in South America, veldt in South Africa These areas have deep, rich soils

Environmental Issues and Sustainable Agriculture and are dominated by tall grasses; trees and shrubs are restricted to river valleys, wetlands and other areas with more moisture. Over the years the native grass species on the extensive areas of level ground have been ploughed and fields seeded. Many of these grasslands have been lost to cereal crops.

Steppe Grasslands Steppe grasslands receive only 25–50 cm of rain fall each year and the grasses are much shorter than those on prairie grasslands. They are also not as widespread, occurring only in Central and Eastern Europe, Northern Eurasia and Western North America.

Wetland Ecosystem Wetlands are transitional zones that occupy intermediate position between dry land and open water These ecosystems are dominated by the influence of water; they encompass diverse and heterogeneous habitats ranging from rivers, flood plains and rain fed lakes to swamps, estuaries and salt marshes wetlands are productive ecosystems which serve as habitat for a variety of plants and animals. Wetlands perform essential functions including flood control, natural sewage treatment stabilization of shorelines against wave erosion, recharging of aquifers and supporting rich biodiversity. Many wetlands serve as the winter habitats for migratory birds. Many of the wetland areas have been drained and reclaimed for agricultural and urban expansion. Siltation problems particularly in shallow wetlands are also subjected to the stresses such as agricultural run-offs, pesticides and construction of dams and barrages. Wetlands are found throughout the world except in Antarctica. The world has 7–9 million km 2 of wetland which is 4 to 6 % of the land surface.56 % of the 4–6 % of land surface is found in the tropical and subtropical regions. In 1987Matthews and Fung estimated the extent of wet lands in the world by climatic zones they found polar/boreal 2.7 million km 2 temperate 0.7 million km 2 , subtropical/tropical 1.9 million km 2 ,rice paddies 1.5 million km 2 and total wetland area 6.8 million km 2.

Measuring Biodiversity 1.α-diversity- local diversity or diversity within the community 2. β-diversity- diversity b/w two community 3.λ-diversity- (Regional diversity) represented total richness of species in the all the habitats

Pattern of Biodiversity 1. Latitudinal gradient spp. Diversity decrease as we moved away from the equator 2. Altitudinal gradient >leads to

Why is biodiversity important, biodiversity values are important because • At the most basic level, biodiversity provides the basis for all life on earth, ensuring clean air and water, fertile soils and healthy, functioning ecosystems necessary to maintain essential ecosystem services such as soil formation and nutrient storage and cycling. • Biodiversity provides all of our food and the raw materials for a wide range of products, for example clothing and medicinal goods. • Biodiversity provides opportunities for recreation, tourism, scientific research and education. • Biodiversity is a source of cultural distinctiveness, particularly for aboriginal and Torres Strait Islander people. • There is growing community acknowledgment of the intrinsic values of biodiversity such as the right of all species to exist regardless of their value to humans Financial profit of the value of biodiversity are difficult to estimation but can be described both as the economic benefits of

Environmental Issues and Sustainable Agriculture biodiversity and the costs of not defending biodiversity. This is almost twice the global gross national product. Closer to home, examples of financial estimates include Biodiversity the Convention on Biological Diversity (CBD) defines biodiversity as “the variability among living organisms from all sources together with, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part this includes diversity within species, between species and of ecosystems 5 Biodiversity occurs in genes, species and ecosystems, underpinning the functioning of ecosystems that maintain life and provide society with food, medicines, natural resources, ecological services and spiritual and aesthetic benefits.

Ecosystem An ecosystem is a dynamic complex of plant, animal, and micro-organism communities and their nonliving environment interacting as a functional unit. Ecosystem approach is a strategy for the integrated management of land, water and living resources that promotes conservation and sustainable use in an equitable way. The approach is a key framework for addressing the three objectives of the CBD in a balanced way.6 Ecosystem services are the benefits that people derive from ecosystems. Ecosystem services may be organized into four types: (I) Provisioning services, which are the goods people achieve from ecosystems (i.e. food, freshwater, timber, fibers medicinal plants). (ii) Regulating services, which are the benefits people achieve from the regulation of ecosystem processes (e.g. surface water purification, carbon storage and sequestration, climate regulation protection from natural hazards). (iii) Cultural services which are the non material benefits people obtain from ecosystems (e.g. sacred sites, areas of significance for recreation and aesthetic enjoyment). (iv) Supporting services which are the natural processes that maintain the other services (e.g. soil formation, nutrient cycling, primary production). 7 Annex 1 provides an indicative list of ecosystem services. Habitat refers to terrestrial, freshwater, or marine areas or airways that support assemblages of living organisms and their interactions with the non-living environment. Habitats vary in their sensitivity to impacts and in the various values society attributes to them. For the purposes of Standard 1, habitats are divided into modified, natural, and critical habitats: • Modified habitats are areas that may include a large proportion of plant and/or animal species of non native origin, and/or areas where human activity has considerably modified an area's primary ecological functions and species composition. Modified habitats may consist of areas managed for agriculture, forest plantations, reclaimed costal zones, reclaimed wetlands, and regenerated forests and grasslands. • Natural habitats are land and water areas where the biological communities are formed largely by native plant and animal species, and where human activity has not essentially modified the area’s primary ecological functions and species composition. • Important habitats are a subset of both modified and natural habitats that have need of special attention. Critical habitats are areas with high biodiversity value, including any of the following features: (I) habitat of significant importance to Critically Endangered, Endangered or Vulnerable species; (ii) habitat of significant importance to endemic and/or restricted-range species; (iii) habitat supporting globally significant concentrations of migratory species and/or congregatory species; (iv) highly threatened and/or unique

Conservation of Biological Diversity Diversity can be conserved in the form of two way – in situ and ex situ. Ex situ protection of species is provided by botanic gardens, Zoos and aquaria and of Gene pools by Germplasm banks (seed stores, in vitro collections and field gene banks) and grass-root collections of plant

Environmental Issues and Sustainable Agriculture cultivars and animal breeds. Botanic gardens probably have a greater capacity with respect to plant species. But clearly it is possible to maintain ex situ only a tiny fraction of the world’s species.

1. In Situ Conservation Biosphere reserve Sacred groves. National parks whole organisms Protected land scapes Wild life Sanctuaries Ethnobiological reserves Wet lands Reserve and protected forests. Mangroves. Preservation plots and sample plots 2. Ex Situ Conservation Seed pollen bank Cryo preservation Sperm culture Tissue culture Embryo culture Gene bank In situ conservation protect area where rich in biodiversity such area is natural park biosphere reserve or gene sanctuary The main objective of this concept is to save for the present and future use the diversity and integrity of biotic communities of plants and animals within natural ecosystems and to protect the genetic diversity of species on which their continuing evolution depends. Such reserves are to comprise of terrestrial and marine ecosystems and to coincide with national parks and sanctuaries. Ex situ conservation of biodiversity away from its natural habitat such as seed gene bank, shoot tip bank, cell gene bank, DNA gene bank

Use of Biodiversity 1. Source of food and improved variety: Used in modern agriculture as a source of new crop breeding material for improved varieties, new bio degradable pesticide. 2. Drugs and medicines: Several important harm accuticals are plant based substances, e.g. morphine 3. Industries: The industrial products like timber, oil lubricant perfume etc. can be derived various plant spp. 4. Turism and recreation: Biodiversity is a source of economical wealth attracts many visitor 5. Aesthetic and cultural benefits: It has great aesthetic value many plant and animal are considered sacred worshipped.

References FAO (1996); Report on the state of the world’s plant genetic resources for food and agriculture arranged for the international technical conferences on Plant Genetic Resources Leipzig, 17-23 June 1996, Rome Hausmann BIG, Parzies HK, Presterl T, Sušić Z, Miedaner T (2004) Plant genetic resources in crop improvement, Plant Genet Res 2:3–21 Hayden BP, Ray GC, Dolan R (1984) Classification of coastal and marine environments. Environ Conserv11:199–207. Krishnamurthy KV (2003) An advanced textbook on biodiversity: principles and practices. Oxford & IBH Publishing Co., New Delhi. Myers N (1988) Threatened biotas: ‘hotspots’ in tropical forests. Environmentalist 8:187–208 Myers N(1990) The biodiversity challenge: expanded hotspots analysis. environmentalist 10:243-256 Myers N, Mittermeirs R. A. Mittermier, CG, da Fonseca GAB, Kent J (2000) Biodiversity hotspots for conservation priorities. Nature 403(6772): 853–858. Pullaiah T (2012) An overview on biodiversity and conservation perspectives. Bioherald 29:1–146 Plant Biodiversity.

Environmental Issues and Sustainable Agriculture

Chapter-2

Agroforestry system: diversified perspective

Akanksha Bisht1 and Praveen Kumar Singh2 Sam Higginbottom University of Agriculture, Technology & Sciences, Prayagraj, U.P. Teerthanker Mahaveer University, Moradabad, U.P. Email: [email protected]

Abstract Over time, agroforestry research has thus been transformed into a rigorous scientific activity. The research agenda, which started with a high priority on soil fertility and other biophysical forms of tree crop interactions, has, over time, encompassed more emphasis on socioeconomic issues, and it has moved on from plot and field level to landscape and ecosystem levels. New practices have developed over the past year to increase the potential of land. Building on the experience of traditional practices, research, and the initiative of pioneer farmers, new systems have been developed which are more adapted to modern production constraints. These adaptations of agroforestry have occurred in sectors such as field crops such as agricultural or horticultural crops, apiculture with trees, aquaculture around tree species, livestock farming etc. Keywords: agroforesty, tree crop interaction, different systems

Introduction It was toward the latter part of the twentieth century that the age-old practice of growing trees and crops together on the same unit of land became recognized as a promising approach to land use by the scientific and developmental communities. This transitioning of agroforestry was signified by the establishment of ICRAF, the World Agroforestry Centre, in 1977 as the point of convergence of efforts in developing these traditional forms of land use to address portion of the land management issues that were not addressed, but were often exacerbated, by developments in commercial agriculture and forestry. Nair (1979) defines agro forestry as a land use system that integrates trees, crops and animals in a way that is scientifically sound, ecologically desirable, practically feasible and socially acceptable to the farmers. Subsequently, agroforestry gradually became a major component or activity of the programs of many international, regional, national, and local institutions, both public and private, dealing with various branches of agriculture, forestry, and allied disciplines. Thanks to the collective efforts of the various institutions and countless millions of agroforestry practitioners, today agroforestry has carved out a distinct niche as a robust land management discipline, and it is now recognized as being at the heart of the global community’s commitment to banish hunger and poverty and rebuild resilient rural environments. The developments in the discipline worldwide during the past three decades have been quite substantial. A set of practices that used to be denigrated as being in search of science has now been transformed into a science-based integrated discipline of land management. Sanchez (1987) stated that, "appropriate agro forestry systems improve soils physical properties, maintain soil organic matter and promote nutrient cycling". Nitrogen fixing trees are mentioned as one of the most promising component of agro forestry system. As world population increases, the need for more productive and sustainable use of the land becomes more urgent. According to the United Nations, more than 7 billion people populated the Earth in 2011 and this number is expected to go up to 9.3 billion by the mid-century. To meet the demand for food by 2050, production will have to increase by over 60%. These figures, coupled with current problems borne out of past and

Environmental Issues and Sustainable Agriculture existing non-sustainable land use practices, provide the case for changing the way we manage lands and our production of agricultural and tree goods. Trees and forests were always considered as an integral part of the Indian culture. Planting of trees was regarded as noble acts during the ancient times. Now, due to increasing population and huge gap between demand and supply, forests were ruthlessly exploited to meet the increasing demand of fuel, fodder and timber. Hence, in the light of ever increasing demand, concept of multiple use of land with multipurpose tree species has become immensely important. In this context, agroforestry, which is a form of multiple land use system, should be adopted and encouraged. The Selection of intercrops depends mainly on edapho-climatic conditions of the area, farmer’s need/traditions and resource availability (Saroj and Dadhwal 1997). Agroforestry produce multiple products such as food/vegetables/fruits, fodder and forage needed for livestock, fuel wood, timber, and leaf litter needed for organic manure production. Cover crops represent an effective way to preserve the soil and improve fertility. Fresh organic matter produced by cover crops is degraded by biological activity and can improve soil properties by the return of organic matter to the ground, thus creating a virtuous circle. Cover crops mechanically limit soil erosion and hence soil loss. The root system allows good structuring of the soil, thereby limiting compaction. Cover crops also play a protective role for example reducing soil temperatures and reducing nitrogen leaching. In combination with agroforestry, the protective effects of cover crops would be even larger.

Profitable Approach India has been meeting its growing demand for agroforestry products such as plywood, timber, pulp and paper through imports, while the domestic industries have been under- performing. According to the National Research Centre for Agroforestry (NCRA), the country imported six million cubic metres of timber and round logs and spent Rs 18,000 crore last year.

Benefits Trees in agroforestry systems modify microclimatic conditions including temperature, water vapour content of air and wind speed, which can have beneficial effects on crop growth and animal welfare. Additionally a wide range of other services can be provided including: Environmental benefits Carbon sequestration Soil health management Nutrient recycling Weed control management Biodiversity richness Natural fencing

Some of the Agroforestry systems are given below:

Agri-Silvicultural System It involves the conscious and deliberate use of land for the concurrent production of agricultural crops including tree crops. This system Improve and sustain the crop productivity which increases the level of income of the farmers. This is also the best practice for soil nutrient recycling, which also helps to reduce chemical fertilizer purchase. Following are some example of agrisilvicultural system-

Alley Cropping (Hedge-Row Intercropping) Alley Cropping is planting rows of trees at wide spacing with a companion crop grown in the alleyways between the rows. Alley cropping can diversify farm income, improve crop production and provide protection and conservation benefits to crops. Trees for alley cropping should fix nitrogen, coppice very easily after trimming and have leaves that are preferred by

Environmental Issues and Sustainable Agriculture livestock or that decompose easily when applied as mulch. Gliricidia sepium, Sesbania sesban, Leucaena leucocephala are commonly used tree species for alley cropping.

Multipurpose Trees and Shrubs on Farmlands Suitable multipurpose trees can be incorporated on farm lands for a variety of uses. Many tree species, such as eucalyptus, can be grown around farm boundaries for additional returns without adversely affecting crop yields. Care must be taken in site selection to avoid crop shading. Multipurpose trees, grown on the farm in an organized manner, can significantly improve farm incomes by providing food, fodder, fuel wood, timber, gum, poles, fence etc. Examples of multipurpose tree species employed in agroforestry are Acacia albida, Cassia siamea, Cocus nucifera, Acacia senegal, Azadirachta indica etc.

Agri-Silvipastoral System This is the system in which the forest tree crops for are taken with intercrops of grasses are taken for fodder purpose as well as the food grain crop are taken in between the strips of forest tree species. The forest tree species are planted at 10 to 12 m distance and in the lines the grasses and food grains are cultivated as intercrops. Following are the types of agri-silvipastoral system:

Home Garden This is one of the oldest agroforestry practices found extensively in high rain fall areas in tropical South East Asia (Kerala and Tamil Nadu). Many species of trees, shrubs, vegetables and other various plants are grown near about the home which supports the variety of animals. Fodder and legumes are widely grown to meet the daily fodder requirement of cattle. The waste material and wastes from home are used for fodder and barn waste is used as manure for crops. Every home stead has around 0.2 - 0.5 ha of land for personal production. These home gardens represents land use system involving deliberate use of multipurpose trees and shrub along with annual crops and animals within the compound of individual houses. This system is highly productive and extremely sustainable and practicable. Mangifera indica, Cocus nucifera, Anacardium occidentale (Cashewnut), Garcinia indica (Kokum), Tea, Coffee, medicinal plants like Black pepper, Cardamom, cumin etc. are some of the crops which are taken in the home gardens.

Woody Hedge Rows In this system, various woody plants and shrub are grown in the form of hedges especially fast growing and coppicing. Fodder trees/shrubs are planted for the purpose of fodder for cattle, green manure and soil conservation. Prosopis juliflora, Leucaena leucocephala, Sesbania species etc. are planted for hedges.

Silvipastoral System The production of woody plants combined with pasture is referred to as Silvipastoral system. The trees and shrubs used primarily to produce fodder for livestock. This system is needed in dry area to meet the fodder demand throughout the year. In this system forest tree species for fodder purpose are taken in rows in between the lines the grasses are taken as intercrops. This system is suitable for providing the fodder for milch cattle and thus for development of dairy industry. There are three types of this system:

Protein Bank Protein rich multipurpose trees are raised on and around farm lands like Anogeissus latifolia, Leucaena leucocephala, Acacia nilotica, Delbergia sissoo, Zizyphus jujuba, Prosopis juliflora, Bombax malabaricum etc, are planted. 10

Environmental Issues and Sustainable Agriculture

Live Fences Fodder trees are raised in the form of hedges or fences e.g. Sesbania gandiflora, Sesbania aegyptiaca, Prosopis juliflora, Gliricidia sepium, Carissa carandas, Erythrina indica etc.

Trees and Shrub on Pasture Fodder, trees and shrub are scattered irregularly or arranged according to some system on the pasture land e.g. Emblica officinalis, Tamarindusindica,Prosopisjuliflora, Psidiumguajavaetc.

Other Systems 1. Aquaforestry: In this system various trees and shrubs preferred by fish are planted on the boundary and around fish ponds. Tree leaves are used as forage for fish. The main aim of this system is fish production and bund stabilization around fish ponds. 2. Apiculture with Trees: In this system various honey producing tree species frequently visited by honeybees are planted on the boundary, mixed with an agriculture crop. The main purpose of this system is the production of honey. 3. Multipurpose Wood lots: In this system special location specific MPTS are grown mixed or separately planted for various purposes such as wood, fodder, soil protection, soil reclamation etc.

Agroforestry for Future Agroforestry as presently recommended tend to encourage the greatest possible diversity of the planted species to enhance the strength of framework. These tree species can be forest or fruit trees, with other species to occupy the space between two trees along the lines. In order to practice agroforestry on a wider scale, it is necessary to upgrade agronomic perspectives such as diversity and production capacity from trees to allow diversification of income sources and products on the farm. At last the advancement of agroforestry may require a more prominent spotlight on enhancing land productivity in terms of biomass production and enhanced ecosystem services in existing riparian forests, buffer strips, and intra-plot trees.

References Nair, P.K.R. (1979).Agro forestry Research: A retrospective and prospective appraisal Proc. Int. Conf. International Cooperation in Agro forestry. ICRAF Nairobi, 275-296. Sanchez, P.A. (1987). Soil productivity and sustainability in agro forestry systems. In: Steppler, M.A. and Nair, P.K.R. (Ed.,) Agro forestry: a decade of development. ICRAF, Nairobi. Saroj, P. L. and Dadhwal, K. S. (1997). Present Status and Future Scope of Mango Based Agroforestry Systems in India,Indian Journal of Soil Conservation, 25 (2), 118-127.

Environmental Issues and Sustainable Agriculture

Chapter-3

Ecological succession, ecosystem and environment

*Vishnu K Solanki1 and J.S.Ranawat2 1College of Agriculture, Ganjbasoda, JNKVV, Jabalpur (MP) 2College of Horticulture & Forestry, Jhalawar, AUK, Kota (Raj) *Email:- [email protected]

Abstract Succession is a key process in a healthy forest and given a chance woodland can regenerate itself. However to have really healthy, dynamic ecosystems with all stages of succession present, we would need to establish large areas of forest, ideally with a range of large herbivores and carnivores, so that a wider range of natural processes can take place. Succession access minerals in bare rock and help to begin the process of creating soil. Mosses and grasses can then get established along with annual and perennial herbs then shrubs, pioneer woodland. The plants that colonise will be affected by environmental conditions such as soil type and wetness, altitude, the number of herbivores and which seed sources are nearly. The general trend in succession is for dominant plants in the earlier stages to be herbaceous annuals and for those in later stages to be slow growing woody perennials. Ecosystems are continuously undergoing natural change. This natural change occurs through such processes as long term evolution or through relatively short term processes such as succession, in which one plant community gradually supplants another. Replacement of early succession trees by late successional trees is driven by small scale disturbances caused by wind, tree diseases and tree removal. Large scale disturbance such as forest fire, clear cutting and some rare catastrophic events e.g. volcano eruptions significantly change the successional stage of forest stands by promoting development of early successional species. Key words- Succession, Ecosystems, Environmental, Herbivores, Carnivores.

Introduction Succession is a directional non-seasonal cumulative change in the types of plant species that occupy a given area through time. It involves the processes of colonization, establishment and extinction which act on the participating plant species. Most successions contain a number of stages that can be recognized by the collection of species that dominate at that point in the succession. Succession begins when an area is made partially or completely devoid of vegetation because of a disturbance. Some common mechanisms of disturbance are fires, wind storms, volcanic eruptions, logging, climate change, flooding, diseases and pest infestation. Succession stops when species composition changes no longer occur with time and this community is said to be a climax community. The concept of a climax community assumes that the plants colonizing and establishing themselves in a given region can achieve stable equilibrium. The idea that succession ends in the development of a climax community has had a long history in the fields of biogeography and ecology. Disturbance acts on communities at a variety of spatial and temporal scales. Further, the effect of disturbance is not always hundred percent. Many disturbances remove only a part of the previous plant community. As a result of these new ideas, plant communities are now generally seen as being composed of numerous patches of various size at different stages of successional development.

Environmental Issues and Sustainable Agriculture

The first stage of succession was characterized by the pioneering colonization of annual plant species on bare ground and nutrient poor soils. These annual species had short life spans one growing season, rapid maturity and produce numerous small easily dispersed seeds. The annuals were then quickly replaced in dominance in the next year by biennial plants and grasses. After about 3 to 4 years, the biennial and grass species gave way to perennial herbs and shrubs. These plants live for many years and have the ability to reproduce several times over their life spans.

Ecological Succession Occur Every species has a set of environmental conditions under which it will grow and reproduce most optimally. In a given ecosystem and under that ecosystem's set of environmental conditions, those species that can grow the most efficiently and produce the most viable offspring will become the most abundant organisms. As long as the ecosystem's set of environmental conditions remains constant, those species optimally adapted to those conditions will flourish. The engine of succession, the cause of ecosystem change, is the impacts of established species have upon their own environments. A consequence of living is the sometimes subtle and sometimes overt alteration of one's own environment. The original environment may have been optimal for the first species of plant or animal but the newly altered environment is often optimal for some other species of plant or animal. Under the changed conditions of the environment, the previously dominant species may fail and another species may become ascendant. Change from one biological community to another can happen because: Smaller species of plants and animals generally grow and reproduce rapidly. Larger plants and animals take more time to grow and their population growth is slower. As a result, the rapidly growing plants and animals populate a site first and the slower ones take over later. For example, if a fire or logging destroys a forest, there will be many species of grass growing on the site within months because grasses grow quickly. Later, shrubs grow over the grasses and after that trees grow over the shrubs. A biological community can create conditions that lead to its own destruction. For example, as trees grow older, they become weak and vulnerable to destruction by insects or diseases. When this happens, a biological community grows old and dies and another biological community takes its place. One biological community can create conditions that are more suitable for another biological community. A biological community can change the physical or biological conditions of a site, making it more favourable for another biological community. One biological community therefore leads to another. A biological community can be destroyed by natural or human generated disturbances and replaced by another biological community. Fires, storms and floods are examples of natural disturbances. Human activities such as logging or clearing land to make agricultural or urban ecosystems can also destroy a biological community. Activities such as excessive fishing or livestock grazing can change a biological community so much that it is replaced by a different community.

Types of Succession

Primary succession – It is the establishment of plants on land that has not been previously vegetated and begins with colonization and establishment of pioneer species. Secondary succession – It is the invasion of a habitat by plants on land that was previously vegetated. Removal of past vegetation may be caused by natural or human disturbances such as fire, logging, cultivation or hurricanes. 13

Environmental Issues and Sustainable Agriculture

Allogenic succession – It is caused by a change in environmental conditions which in turn influences the composition of the plant community. Autogenic succession – It is a succession where both the plant community and environment change and this change is caused by the activities of the plants over time. Progressive succession – It is a succession where the community becomes complex and contains more species and biomass over time. Retrogressive succession – It is a succession where the community becomes simplistic and contains fewer species and less biomass over time. Some retrogressive successions are allogenic in nature. For example, the introductions of grazing animals result in degenerated rangeland.

Comparison of plant, community and ecosystem characteristics between early and late stages of succession Late Stages of Attribute Early Stages of Succession Succession Plant Biomass Small Large Plant Longevity Short Long Seed Dispersal Characteristics of Well dispersed Poorly dispersed Dominant Plants Plant Morphology and Physiology Simple Complex Photosynthetic Efficiency of Dominant Low High Plants at Low Light Rate of Soil Nutrient Resource Fast Slow Consumption by Plants Plant Recovery Rate from Resource Fast Slow Limitation Plant Leaf Canopy Structure Multilayered Monolayer Living Biomass and Site of Nutrient Storage Litter and Soil Litter Role of Decomposers in Cycling Nutrients Minor Great to Plants Biogeochemical Cycling Open and Rapid Closed and Slow Rate of Net Primary Productivity High Low Community Site Characteristics Extreme Moderate (Mesic) Importance of Macro environment on Great Moderate Plant Success Ecosystem Stability Low High Plant Species Diversity Low High Life-History Type r K Seed Longevity Long Short

Environmental Issues and Sustainable Agriculture

Process of Plant Succession

Nudation - An area is exposed. Migration - The process of dispersal of seeds, spores and other structures of propagation of the species to bare area is known as migration. Germination - It occurs when conditions are favourable. Ecesis - Successful germination of propagules and their establishment in a bare area is known as ecesis. Colonisation and Aggregation - After ecesis, the individuals of the species increase in number as the result of reproduction. Competition and Co-action - Due to limited resources, species show both inter and intraspecific competition. This results into elimination of unsuitable and weaker plants. Invasion - Various other types of plants try to establish in the spaces left by the elimination of plants due to competition. Reaction - The newly arrived plants interrupt with the existing ones. As a result of reaction, environment is modified and becomes unsuitable for the existing community which sooner or later is replaced by another community. Stabilisation - Finally, there occurs a stage in the process when the climax community becomes more or less stabilized for a longer period of time and it can maintain itself in equilibrium with the climate of the area. As compared to seral stage community, the climax community has larger size of individuals, complex organization, complex food chains and food webs, more efficient energy use and more nutrient conservation.

Major Trends during Succession There is an increase in structural Increase in non-living matter complexity Food chain relationship becomes complex Diversity of species tends to increase Niche becomes special and narrower Biomass and standing crop increase Energy use and nutrient conservation There is a decrease in net community efficiency increases production Stability increases

Conclusion Ecological succession is the observed process of change in the species structure of an ecological community over time. Within any community some species may become less abundant over some time interval or they may even vanish from the ecosystem altogether. Similarly, over some time interval, other species within the community may become more abundant or new species may even invade into the community from adjacent ecosystems. This observed change over time in what is living in a particular ecosystem. Ecological succession may occur when the conditions of an environment suddenly and drastically change. A forest fires, wind storms and human activities like agriculture all greatly alter the conditions of an environment. These massive forces may also destroy species and thus alter the dynamics of the ecological community triggering a scramble for dominance among the species still present.

Environmental Issues and Sustainable Agriculture

Chapter-4

Climate Change and Global Warming: Policies, Planning and Management

*Swati Garbyal and Ritu Mittal Punjab Agricultural University, Ludhiana, Punjab *Email: [email protected]

(Mahatma Gandhi) “Earth provides enough to satisfy every man’s needs, but not every man’s greed”

Abstract Global climate change is one of the major concerns of the present world. Climate change occurs when changes in atmosphere system result in new weather patterns that last for couple of decades, or may be for millions of years. The balance between entering and leaving the energy from Earth, and the passage of the energy through the climate system, determines Earth's temperature. When the incoming energy is greater than the outgoing, earth's energy budget is positive and the climate becomes hot. If more energy goes out, the energy budget is negative and earth experiences cooling. As this energy moves through Earth's climate system, it creates Earth's weather and this long-term averages of weather are called "climate". Changes in the long term average are called "climate change". Both natural factor and human factors are responsible for climate change. Human activities (industrialization, transportation, agriculture, etc) are presently driving climate change through global warming. Global warming is a gradual increment in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other contaminants. Global warming is anticipated to have a number of consequences on atmosphere. Ongoing effects include rising sea levels due to thermal expansion and melting of glaciers and ice sheets, and warming of the ocean surface, prompting increased temperature stratification. Climate change will continue, and accelerate, in the years ahead, with serious impacts on the health of our oceans, forests, freshwater, and our towns and cities and will have serious consequences unless strict policies and plans to reduce global warming are not taken. Therefore, there is a need for action, regardless of the uncertainties of anticipated changes, yet action requires concrete settings to facilitate expectant measures by the decision/policy makers. In order to resolve the issue, one should search for certain solution, to rectify this issue. Keywords: Global warming, climate change, green house emission, temperature.

The current paper reviews the climate change, global warming and its causes, impact, implication and measures to mitigate the current problem. Climate change is about abnormal variations to the climate, and the effects of these variations on other parts of the Earth. Whereas global warming is a long-term rise in the average temperature of the Earth's climate system, an aspect of climate change shown by temperature measurements and by multiple effects of the warming. Global warming in recent decades has taken global temperature to its highest level in the past millennium (Mann et al. 1999). There is a growing consensus (IPCC 1996) that the warming is at least in part a consequence of increasing anthropogenic greenhouse gases. Ravindranath et al (2005) said Climate change is one of the most important global environmental challenges, with inference for food production, water supply, health, energy, etc. Addressing climate change requires a good scientific understanding as well as coordinated action at national and global level.

Environmental Issues and Sustainable Agriculture

Vijaya Venkata Raman et al (2012) said that Global climate change is a change in the long-term weather patterns that characterize the regions of the world. Vijaya Venkata Raman et al (2012) said there are many factors, both natural and human, that can cause climate change. Recent climate changes, however, cannot be explained by natural as well as human causes alone. Scientists state unambiguously that the earth is warming. Not only natural variability alone but human activities, especially the burning of coal and oil have warmed the earth by prominently increasing the concentrations of heat-trapping gases in the atmosphere. The more of these gases humans put into the atmosphere, the more the earth will warm in the decades and centuries ahead. He further showed the Third Assessment report published by the IPCC in 2001 states, ‘there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities’. Hence, to a certain level it is possible to mitigate the climate change and GHG emissions. Greenhouse gases (GHGs) cause a global climate forcing, i.e., an imposed perturbation of Earth's energy balance with space (Hansen et al. 1997). Specifically, GHGs reduce heat radiation to space, causing Earth to warm. There are many competing natural and anthropogenic climate forcing, but increasing GHGs are estimated to be the largest forcing and to result in a net positive forcing, especially during the past few decades (IPCC 1996, Hansen et al. 1998). Hans –Werner Sinn (2007) said human activities such as industrialization and subsequent release of greenhouse gases have been linked to climate change. The subject of climate change has been the topic of discussions around the globe for many reasons. With the occurrence of the phenomenon, various impacts such as increased rate of adverse climatic events such as floods, global warming have been identified. One of the major impacts associated with climate change with regards to human life is the agricultural production patterns. Changes in climatic conditions have led to adverse changes in the agricultural sector such as reduced production of various cereals (Hulme, 2009). However, contrary to expectations, the impacts of climate change are more severe in the developing countries than in the developed and more industrialized countries. This is due to resource scarcity and ineffective adaptation measures among other factors. Agriculture is the backbone of Indian economy which in turn relies on the monsoon season. The Intergovernmental Panel on Climate Change (IPCC) projected that the global mean surface temperature will likely rise and may result into uneven climatic changes such as change in rainfall patterns, elevated global temperature and increased CO2 emission in the atmosphere. Shah and Srivastava (2017) indicated that crop yield falls by 3-5% for every 1°F increase in the temperature. Additionally, losses in agricultural productivity, occurrence of adverse climatic events such as cyclones, hurricanes, flood, drought are the results of climate change. Because of the adverse climatic events, transportation systems are destroyed or limited in various ways leading to down time and subsequently financial losses (Stern, 2007). In the agricultural sector, adverse climatic conditions not only effect food production but increase in pest populations since the warm climate favors pest breeding. If the plants and animals are to survive, adaptation to the changing conditions would be the only viable option. However, they are also limited by the speed of adaptation. Bhardwaj Kriti (2010) in her study ‘Impact of climate change policies on the growth of the Indian economy conclude that Climate change is a global problem. It affects everyone, the rich and the poor, the developing and the developed without any discrimination. The contributors whether major or minor are all affected by the adverse impact of climate change. She revealed that putting the extra financial burden on the developing countries is a major cause of economic crisis in these countries. Vijaya Venkata Raman et al (2012) said that the impact of warming can already be observed in many places, from increased sea levels to melting of glaciers and polar ice sheets to changing weather patterns. Climate change is already affecting ecosystems, freshwater supplies, 17

Environmental Issues and Sustainable Agriculture and human health. Although climate change cannot be avoided entirely, the most severe impacts of climate change can be avoided by substantially decreasing the emission of Green house gases released into the atmosphere. Researcher further discussed the proving facts for the impact of climate change on various components of the biosphere like air, water, plants, animals and human beings, which, if not acted upon, may lead to disaster. Climate change influences quality of air, increases the dominance of cyanobacteria in water bodies, reduces drinking water quality, a change in the hydrological cycle, adverse impacts on wildlife. The paramount problem that the world is facing today, the global warming is discussed, including the global warming potential (GWP) and its influence on economy. Climate change also affect fisheries, marine economy, water resources and water bodies, land carrying capacity and animal health, on tourism affecting the GDP by −0.3–0.5% in 2050 and agriculture based on temperature rise, water quality and availability. The potential impacts of climate change on human health are significant, ranging from direct effects such as heat stress and flooding, to indirect influences including increase in disease transmission and malnutrition. It changes the epidemiology of infectious diseases and the vector- borne diseases, as earth become warmer disease will become more and its impacts on mortality through ill health, particularly among the elderly, in summer. Nagaveni and Anand(2017) in their study Climate change and its impact on India: A comment, discussed the growing concerns faced by India regarding climate change. They said there is an urgent need to enact specific ratification, which address climate change. Since, the current legal system in India lacks heavily when it comes to execution, appropriate legislations need to be enacted by various State governments to minimize outflows of greenhouse gases and address environmental change. It may also be useful to set long-term targets to decrease emissions of these harmful gases. Other individual initiatives may include increase in the usage of LED lighting, use of compressed natural gas as fuel, providing for rigid vehicle emission norms and usage of renewable sources of energy. They further said while giving licenses to industrial houses, there must be a strong national environmental policy which should have clear cut rules regarding environmental pollution and waste management, they further said that, vehicles contributes to air pollution in a significant manner, a practical solution needs to be developed to solve this issue. The State must take initiative to encourage community participation in monitoring pollutions. When the State, Judiciary and Civil society holds hands, then only climate change can be tackled to a large extent and the impact it has on the people, especially the marginalized section can be lessened to a minimum. The responsibility for greenhouse gas emissions' depends largely on industrialized world, however the developing countries are more likely to be the source of future emissions. The projected climate change under different scenarios is likely to have implications on food production, water supply, coastal settlements, forest ecosystems, health, natural resource, etc. Developing countries has low adaptive capacity of communities likely to be impacted by climate change. To address the climate change challenge, the efforts of UNFCCC (United Nations Framework Convention on Climate Change) and the Kyoto Protocol provisions are clearly inadequate .Ravindranath et al (2005) said that in order to address climate change, adoption of sustainable development pathway by shifting to environmentally sustainable technologies and promotion of energy efficiency, renewable energy, forest conservation, reforestation, water conservation, etc seems to be most effective. The issue of highest importance to developing countries is reducing the vulnerability of their natural and socio-economic systems to the projected climate change. India and other developing countries will face the challenge of promoting mitigation and adaptation strategies, bearing the cost of such an effort, and its implications for economic development. India is a large developing country with nearly two-thirds of the population depending directly on the climate-sensitive sectors such as agriculture, fisheries and 18

Environmental Issues and Sustainable Agriculture forests. Thus, India has a noteworthy stake in scientific advancement as well as an international understanding to promote mitigation and adaptation. This requires improved scientific understanding, capacity building, systems administration and broad based consultation processes. Ravindranath et al (2005) Mukherjee Manju Mohan (2017) in his article ‘Global Warming and Climate Change in India: A Social Work Perspective’ suggested some measure to solve the problem related to global warming and climate change. Some measures are: Insulate our home, clean our air conditioning filters and install energy efficient showerheads, replacing of current home appliances (refrigerator, washing machine, dish washer) with high efficient models, recycle home’s waste newsprint, cardboard, glass and metal. Installation of solar heated system for hot water. Replacement of incandescent light bulbs with compact fluorescent bulbs or LEDs. Avoid purchase of food and other products with non recyclable packaging, instead use reusable or recyclable packaging. Minimize the use of foods that are prepared with GMOs, because it use fuel from conventional energy sources. Stop smoking or at least follow the “No Smoking” sign. In order to avoid smoke emissions keep car properly maintained to keep it in good running condition. Share a ride or engage in car-pooling. Whenever possible choose to walk or ride a bicycle. Live green by using green power supply like solar and wind energy. To lessen the use of air conditioning system, enjoy fresh air from open windows. Hang our laundry to dry to minimise use of gas or electricity from dryers. Avoid plastic instead use eco- friendly or biodegradable materials as plastics are highly toxic substances injurious to our health. Plant more trees and put indoor plants in homes. Place a proper waste disposal system especially for toxic wastes. Never throw, run or drain or dispose into the water, air, or land any substance in solid, liquid or gaseous form that shall cause pollution. Do not cause loud noises and unwanted sounds to avoid noise pollution. Do not litter in public places. Anti-litter campaigns can educate the populace. Industries should examine their air emissions regularly and take measures to ensure compliance with the prescribed emission standards. There should be strict application of government regulations on pollution control by various. Organic waste should be dumped in places far from residential areas. Adopt the 3Rs of solid waste management: reduce, reuse and recycle. Inorganic materials such as metals, glass and plastic, also organic materials like paper can be reclaimed and recycled. Celebrate birthday and rituals by planting tree not lighting the candle. Vijaya Venkata Raman et al (2012) said that there should be high carbon tax for carbon intensive sectors in the cooperating countries that will reduce the production of goods so that CO2 emissions in the cooperating countries will get reduce. The existing policies and the amendments need to be reviewed. The portfolios of policy instruments used by the industrialized countries in their evolving climate change strategies should be widened there should be increase in the coverage of those policy instruments to all sectors. In scaling the policy responses to climate change, local plans need to be coupled with global and national scales of action in order to achieve the levels of CO2 reductions in order to avoid dreadful climatic condition. Hans-Werner Sinn (2007) suggested that sequestration and afforestation are exceptions to the rule that carbon extraction is proportional to the accumulation of CO2 in the atmosphere.. If the CO2 originating from combustion were pumped back into the Earth’s soil and stored underground, it could not pollute the air and hence could not contribute to global warming. There is a unique opportunity to cut the problematic link between the carbon extracted and its accumulation in the atmosphere. He further concluded that useful policy measures that mitigate the problem of global warming must succeed in flattening the carbon supply path in the world energy markets. Among the public finance measures, unit taxes on carbon extraction and source taxes on capital income are feasible policy options that satisfy this requirement. A complete world-wide system of emissions trading that effectively combines the consuming countries to a monopsony would be 19

Environmental Issues and Sustainable Agriculture able to enforce a more conservative carbon consumption path while in addition providing these countries with monopsony rents. Where possible, a stabilization of property rights in the resource extracting countries could also be tried to strengthen the conservation motive. Particular emphasis could be given to measures that try to dissociate carbon extraction from the accumulation of carbon in the atmosphere. Sequestration is useful but difficult due to the gigantic quantities involved. Bhardwaj Kriti (2010) India, being a fast growing economy has many commitment towards its own citizens to provide them with better standards of living which can only be obtained through a massive expansion of the economy. To decrease the problems of poverty and enhance standard of living, the wealth of the country needs to be increased and distributed in a holistic manner. Indian infrastructure sector which is the major driver of economic growth cannot be unnecessarily burdened with the monumental task of mitigating climate change and incurring huge financial expenditure in the process when it itself is financially starved and in need of assistance from private sector. Shah Ruchita and Srivastava Rohit (2017) concluded the clean development mechanism (CDM), one of the most recommended and promising technology for mitigation, introduced under the Kyoto Protocol is reviewed. Cost-effective and immediate to implement CDM is the need of the hour. Funding for GHG mitigation projects in developing countries is crucial for addressing the global climate change problem. Hans-Werner Sinn (2007) concluded the adaptation measures taken by various countries are all aimed at reducing the impacts of climate change particularly to enhance food security. In the agricultural sector, measures are taken to curb the impacts of climate change and thus maintain food security (Seinfeld & Pandis, 2012). Climate change have various impacts in human life. For instance, the constant increase in atmospheric temperatures is linked to increased air pollution which adversely effect human health. While making climate change prevention programs, policy makers should take into consideration the need for protection of human life. The process will require an evaluation of various risks and returns that can be associated with each of the programs. Mukherjee Manju Mohan (2007) said Breathing is life and we know that we will survive without food for several weeks and without water for few days, but without oxygen, we will die in a matter of minutes. The oxygen, the air we breathe sustains us. So, let us make today and everyday a good day for everyone. Allow the earth to have more clean air. Help control pollution. Otherwise, Earth will eventually have an atmosphere incompatible with life. From the above reviews we can say that climate change and global warming is leading problem around the globe, affecting each and every nation, We are experiencing a significant impact of global warming and climate change, today if we are not controlling this problem, it will be uncontrollable later and will lead to unpredictable adverse condition. There is an urgent need to enact explicit enactments, which address climate change. Since, the existing legal system in India or even around the globe, lacks vigorously when it comes to execution, appropriate enactments should be enacted by different State governments to limit emissions of greenhouse gases and address global warming and climate change. We should set long-term targets to reduce emissions of these harmful gases. Raising awareness of people towards global warming and climate change and its ill affect through radio, television, campaigns, educational institute is required. There should be strict enforcement of laws relating to protection of forests, environment and pollution control by the authorities. There should be strict appropriate government policies regarding climate and global warming. Not only government but also NGOs, cooperatives, public sector undertakings and corporate sector should work together to mitigate this problem only than we can sustain the climate otherwise consequence will be disastrous.

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Reference Bhardwaj Kriti (2010) Impact of climate change policies on the growth of the Indian economy retrieved from https://www.greatlakes.edu.in/gurgaon/sites/default/files/IMPACT_OF_CLIMATE_CHANGE .pdf Hans-Werner Sinn (2007) Policies against global warming .National Bureau of Economic Research :3-38. o Hulme M (2009) Why we disagree about climate change: understanding controversy, inaction and opportunity. UK: Cambridge Intergovernmental Panel on Climate Change 1996. Climate Change 1995. eds. Houghton J.T., L.G. MeiraFilho, B.A. Callander, N. Harris, A. Kattenberg, and K. Maskell. Cambridge Univ. Press, Cambridge. Mann, M.E., R.S. Bradley, and M.K. Hughes 1999. Geophys. Res. Lett. 26, 759-762. Mukherjee M M (2017) Global Warming and Climate Change in India: A Social Work Perspective, Whanake: the Pacific Journal ofCommunity Development. 3(1): 28-36. Nagaveni P L and Anand A (2017) Climate change and its impact on India: A comment retrieved from http://eprints.lancs.ac.uk/125076/1/ CLIMATE_CHANGE_AND_ITS_IMPACT_ON_INDIA_A_COMMENT.pdf. Sathaye J, Shukla P R andRavindranath N (2006) Climate change, sustainable development and India: Global and national concerns. Current science 90(3): 314-25. Seinfeld, J. H., &Pandis, S. N. (2012). Atmospheric chemistry and physics: from air pollution to climate change. Hoboken: John Wiley & Sons. Shah R and Srivastava R (2017) Effect of Global Warming on Indian Agriculture. Sustainability in Environment. 2(4): 366-78. Stern, N. N. H. (Ed.). (2007) The economics of climate change: the Stern review. London: Cambridge University Press. VijayaVenkataRamana S, Iniyanb S , RankoGoicc S and VijayaVenkata Raman (2012) A review of climate change, mitigation and adaptation. Renewable and Sustainable Energy16 (1):878– 97.

Environmental Issues and Sustainable Agriculture

Chapter-5

Biomass estimation of Peltophorum ferruginium species in Bilaspur region

Namo Narayan Mishra and Kalpana Mishra College of Forestry, Sam Higginbottom University of Agriculture, Technology & Sciences, Prayagraj, UP Email: [email protected]

Abstract Trees of Peltophorum ferruginium was grown for maximum biomass production under the same climatic (1220mm mean annual rainfall and 300 C mean annual air temperature) and edaphic and conditions in the Bilaspur region (lat. 22.12930N, Long. 82.13600E) management was very intensive during early growth and establishment phases there were no. of trees present 390. The estimation was done allometric equation. The trees were total no. of 390 and total taken 10 no of sample plot. The total average diameter was came 14.04cm. And average height was 4.6 m. biomass was 68.66 kg. Carbon stock was 34.33kg. Keywords: Biomass, Allometric Equation, Climatic, Edaphic.

Introduction Plant plays an important role in an ecosystem. Biomass of plants strongly affects the structure and function of ecosystem. Trees plays vital role in mitigating the diverse effect of environmental carbon degradation and on reducing global warming. Trees promote sequestration of carbon into soil and biomass therefore, tree based land use practice could be viable alternatives to store atmospheric carbon di oxide due to their cost effectiveness, high potential of carbon uptake and associated environmental as well as social benefits due to as forest maintain over 86% of the terrestrial carbon stock on earth during photosynthesis and storing excess carbon as biomass. An accurate estimate of forest carbon storages including natural forest plantation etc. separately for different trees land of various locality will be of great significant to the research on the productivity of terrestrial ecosystem. Carbon cycle and global warming determination of above ground biomass (AGB) is an important step in planning the protection and sustainable use of deciduous trees resources. Biomass determination can be in or direct way by cutting and weighing all the plants in sample areas. This requires considerable efforts and time. Destroys vegetation in these areas and in some situation is not desirable or may even be illegal. Therefore, allometric relationships for estimating (AGB) of deciduous trees from measurement of stem diameter at breast height (DBH) and tree height (H). Have been devised and reported by a no. by workers (Tam et al.1995; Saintilan 1997; clough et al. 1997; Ross et al.2001 Liao et al.2004; comely and McGuinness 2005; Cue and Ninomiya 2007; Komiyama et al. 2008; Medeiros and Sampaio,2008). To evaluate such uses and effects data on biomass production and nutrients demands on the site are needed. Here we present results of an experiment in which five tree species were intensively managed under identical environmental conditions to compare their efficiency of biomass production and nutrients utilization. A forthcoming companion article will contain the nutrition aspects of study. Studies such as these are needed to assess species suitability for sustained yield energy plantation in the tropics.

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Peltophorum ferruginium

Domain: Eukaryota Order: Fabales Kingdom: Plantae Family: Fabaceae Phylum: Spermatophyta Subfamily: Caesalpinioideae Subphylum: Angiospermae Genus: Peltophorum Class: Dicotyledonae Species: Peltophorumferruginium

Description It is a deciduous tree growing to 15–25 m tall, with a trunk diameter of up to 1 m belonging to Family Leguminosae and sub-family Caesalpiniaceaea. The leaves are bipinnate, 30– 60 cm long, with 16-20 pinnae, each pinna with 20-40 oval leaflets 8–25 mm long and 4–10 mm broad. The flowers are yellow, 2.5–4 cm diameter, produced in large compound racemes up to 20 cm long. The fruit is a pod 5–10 cm long and 2.5 cm broad, red at first, ripening black, and containing one to four seeds. Trees begin to flower after about four years.

Distribution Peltophorum ferruginiumis native to tropical southeastern Asia and northern Australasia, in Sri Lanka, Thailand, Vietnam, Indonesia, Malaysia, Papua New Guinea and the islands off the coast of Northern Territory, Australia.

Uses The tree is widely grown in tropical regions as an ornamental tree, particularly in India, Nigeria, Pakistan, and Florida and Hawaii in the United States. The trees have been planted alternately in India as a common scheme for avenue trees in India alternately with Delonixregia (Poinciana) to give a striking yellow and red effect in summer, as has been done on Hughes road in Mumbai.

Physiology and Penology P. ferruginium is fast-growing, and can reach a height of 9 m in 3 years (Troup and Joshi, 1983). In the Philippines, panicles appear from May to September (De Guzman et al., 1986), with flowering in March-April (Merrill 1912; Steiner 1986). In India, the general flowering period is March to May, although sporadic flowering may occur throughout the year (particularly in young trees), and a second flush of flowers may occur in September-November. As a fast-growing species, young trees raised from seed will, under good conditions, flower from age 4 years (Lemmens and Wuli.

Study Site The study was conducted in the Bilaspur region Chhattisgarh Lat.22.12930N, 82.13600E at less than 264m elevation. The climate is pleasant and mild in the winter minimum temperature 100C and maximum temperature 450. The relative humidity is higher during the monsoon season 23

Environmental Issues and Sustainable Agriculture being generally over 75%after monsoon season humidity decreases and during the winter air is fairly dry. The month of July and august the heaviest rainfall month and nearly 95% of annual rainfall is received during June- September months. The rainfall is unevenly distributed and also the amount of rainfall varies from year to year and experiences and a not semi humid climate.

Materials and Methods Volume of the tree was measured by the formula V = пr2h ……… (1) Where, V= volume of the tree in m3, r= radius of the trunk in m, h = Height of the tree. As very less taper was observed in trees, hence average volume was estimated by using above formula. AGB (Above ground biomass) includes the all living biomass above the soil. AGB are calculated by multiplying volume to the green wood density of the tree species. AGB= VxD ……….. (2) Where, AGB= Above Ground Biomass, V= Volume of the tree in M3 and D= Wood Density of species. Wood density is used from global wood density database. The standard average density of 0.6 g/cm3 is applied wherever the density value is not available for tree species. BGB (Below Ground Biomass) has been calculated by the multiplying the AGB by 0.26, as per factor prescribed by Hangargeet al. BGB= AGBx0.26 ……….. (3) TB (Total Biomass) has calculated by the sum total of AGB and BGB. Total biomass= AGB+BGB ………… (4) In present study, we have calculated carbon with assumption, that any tree species contain 50% of its biomass. Carbon storage = Biomass x 50% ….……. (5)

Biomass estimation of Peltophorum ferruginium Species: Peltophorum ferruginium No. of trees Present: 390 trees. Sample taken: 10 trees.

Diameter Height Volume biomass (in cm) (in inch) (in m) (in feet) (in m³) (in kg) 12.10 4.76 05 16.40 0.038 51.20 9.23 3.63 04 13.12 0.021 23.48 11.78 4.63 04 13.12 0.034 38.22 19.10 7.52 06 19.68 0.135 151.23 14.96 5.88 04 13.12 0.052 61.64 14.01 5.51 04 13.12 0.048 54.12 14.33 5.64 4.5 14.76 0.056 63.79 13.37 5.26 04 13.12 0.044 49.32 18.47 7.27 06 19.68 0.123 141.34 13.05 5.14 4.5 14.76 0.047 52.98 14.04 cm 4.6m 0.0598m³ 68.66 kg

Result and Discussion The estimation of the aboveground and belowground biomass in the selected tree species was performed by estimating carbon percentage and by measuring the tree height, DBH and wood density. The carbon concentration of different tree parts was rarely measured directly, but

Environmental Issues and Sustainable Agriculture generally assumed to be 50% of the dry weight on the basis of literature (Chavan and Rasal, 2011; Jana et al, 2009) as the content of carbon in woody biomass in any component of forest on average is around 50% of dry matter (Paladinic et al, 2009; Chavan and Rasal, 2011; 2012a; 2012b). The trees were total no. of 390 and total taken 10 no of sample plot. The total average diameter was came 14.04cm. And average height was 4.6 m. biomass was 68.66 kg. Carbon stock was 34.33kg.

Conclusion Research on carbon aboveground estimations in seedlings and reforested areas in the tropics is still in an early stage. Therefore, this study is a valuable contribution to increase knowledge on this topic. This study is possibly the first of its type in Ecuador and is of crucial importance for establishing a base line for future monitoring campaigns on the reforested areas of the project, but as it is the first estimation (only one point in time) the scope of the analysis remains limited. The above ground biomass estimations based on allometric equations for secondary forest introduced error in the estimations performed. Firstly because these equations were performed for consolidated forest, and secondly because the equations used diameter a breast height as single predictor variable and this parameter was not available in all of the cases as the majority of trees were smaller than 1.3 m. Also, the correction used for DBH in the allometric models introduced another source of the error in the estimation. As an alternative, basal area and tree height performed well as biomass indicators.

References A.O., Global forest resources assessment 2010 – main report. FAO forest Paper No. 163, Rome (2010) Borah, N, Nath, A.J. and Das, A.K.,Above ground biomass and carbon stocks of tree species in tropical forests of Cachar district, Assam, North east India. International Journal of Ecology and Environmental Sciences, 39(2): 97-106 (2013) Chavan BL and Rasal GB, 2010.Sequestered standing carbon stock in selective tree species grown in University campus at Aurangabad, Maharashtra, India.IJEST, 2(7): 3003-3007. Chavan BL and Rasal GB, 2011.Potentiality of Carbon sequestration in six year ages young plant from University campus of Aurangabad, Global Journal of Researches in Engineering, 11(7): 15-20. Chavan BL and Rasal GB, 2011.Sequestered carbon potential and status of Eucalyptus tree, International Journal of Applied Engineering and Technology, 1(1): 41-47. Chavan BL and Rasal GB, 2012.Total sequestered carbon stock of Mangiferaindica, Journal of Earth and Environmental science, IISTE, (US) 2(1): 37-48. Chavan BL and Rasal GB, 2009.Carbon storage in Selective Tree Species in University Campus at Aurangabad, Maharashtra, India.Proceeding of International conference & Exhibition on RAEP, Agra, India, 119-130. Chaturvedi, R.K., Raghubanshi, A.S. and Singh, J.S., Carbon density and accumulation in woody species of tropical dry forest of India. Forest Ecology and Management, 262: 1576- 1588 (2011) Dhruw, S.K., Singh, and Singh, A.K., Storage and Sequestration of carbon by leguminous and non leguminous trees on red lateritic soil of Chhattisgarh. Indian Forester, 135 (4): 531-538 (2008) Hangarge, L.M., Kulkarni, D.K., Gaikwad, V.B., Mahajan, D.M. and Chaudhari, N., 2012. Carbon sequestration potential of tree species in Somjaichrai (Sacred grove) at Nadghur

Environmental Issues and Sustainable Agriculture village, in Bhor region of Pune district, Maharastra State India. Annals of Biological Research, 3(7): 3426-3429 (2012) Kaul, M., Mohren, G.M.J. and Dadhwal, V.K., Carbon storage and sequestration potential of selected tree species in India. Mitigation Adoption Strategy Global Change, 15: 489-510 (2010) Keeling, C.D. and Khorf, T.P., Atmospheric CO2 records from site in the SIO air sampling network II trends: A compendium of Data on Global Change, Carbon Dioxide. Information analysis Center. Oak Ridge Laboratory, US Department of Energy, Oak Ridge Tenn, USA (2002) Liu, G.H., Fu, B.J. and Fang, J.Y., Carbon dynamics of Chines forests and its contribution to global carbon balance. Act EcologicaSinica, 20 (5): 733-740 (2000) Pandya, I.Y., Salvi, H., Chahar, O. and Vaghela, N., Quantitative analysis on carbon storage of 25 valuable tree species of Gujarat, Incredible India. Indian Journal of Science Research, 4(1): 137-141 (2013) Sohrabi, H., Bakhtiari, S.B. and ahmadi, K.,Above and below ground biomass and carbon stocks of different tree plantations in Central Iran. Journal of Arid Land, 8(1): 138-145 (2016) Suryawanshi, M.N., Patel, A.R., Kale, T.S. and Patil, P.R., Carbon sequestration Potential of tree species in the environment of North Maharastra University campus, Jalgaon [MS] India. Bioscience Discovery, 5(2): 175-179 (2014) Yin, W., Yin, M., Zhao, L. and Yand, L., Research on the measurement of carbon storage in plantation tree trunks based on the carbon storage dynamic analysis method. International Journal of Forestry Research, 2012: 1-10 (2012) Yuanqi, C., Zhanfeng, L., Xingquan, R., Xiaoling, , Chenfei, L.,Yongbiao, L., Lixia, Z., Xi-an, C. and Shenglei, Fu., Carbon Storage and Allocation Pattern in Plant Biomass among different forest plantation stands in Guangdong, China. Forests, 6: 794-808 (2015) Zanne, A.E., Lopez, G., Comes, G., Ilie, D.A., Jonson, S. and Lewis, S.L., Global wood density database (2009)

Environmental Issues and Sustainable Agriculture

Chapter-6

Atmospheric Pollution and its harmful effect on Climate and Crop Production

Lekhika Borgohain1*, K.N. Das2, Danish Tamuly3, Prem Kumar Bharteey4 1*&4Ph.D. scholar, Department of Soil Science, Assam Agricultural University, Jorhat-13, Assam 2Professor, Department of Soil Science, Assam Agricultural University, Jorhat-13, Assam, India 3Asst. Professor, Department of Soil Science, Assam Agricultural University, Jorhat-13, Assam *Email-id- [email protected]

Introduction Pollution is defined as any undesirable or intolerable or unacceptable change in the physical, chemical or biological characteristics of our environment; eg. Air, water, soil, atmosphere that may affect living organisms adversely. Air pollution has become an extremely serious problem for the modern industrialized world air. Many forms of atmospheric pollution affect human health and the environment at levels from local to global. These contaminants are emitted from diverse sources, and some of them react together to form new compounds in the air. Industrialized nations have made important progress toward controlling some pollutants in recent decades, but air quality is much worse in many developing countries, and global circulation patterns can transport some types of pollution rapidly around the world (Heck et al., 1988). Atmospheric pollution is the release of a harmful chemical or material into the atmosphere. The constituent of N2, O2, CO2 and other gases in the air is definite and any change in the proportion would affect the human being, plant and environment, Such change in air is called air pollution and the agents responsible for air pollution is called air pollutant. Atmospheric pollutants are substances that accumulate in the air to a degree that is harmful to living organisms or to materials exposed to the air. Common air pollutants include smoke, smog, and gases such as carbon monoxide, nitrogen and sulphur oxides, and hydrocarbon fumes. One of the major causes of air pollution is increased the concentration of CO2, while increased concentration of nitrogen oxide and sulphur dioxide combine to form harmful acid rain. Not all pollution is directly man-made, however, such as the release of ammonia from livestock. Ammonia is toxic to many aquatic animals and can lead to soil acidification and smog. Atmospheric pollution is also harmful to human health. It has driven cancer to be the main cause of death in China and more than half of Americans are breathing unacceptable standards of air. In the UK alone it is thought that air pollution causes 29,000 deaths every year (World Bank, 2009).

Types of Air Pollutants

Primary Pollutants There are many types of primary pollutants, including carbon oxides, nitrogen oxides, sulfur oxides, particulates, lead, and volatile organic compounds. Some primary pollutants are natural, such as volcanic ash. Dust is natural but exacerbated by human activities. Most primary pollutants are the result of human activities for example, the direct emissions from vehicles and smokestacks. Primary pollutants include Carbon oxides include carbon monoxide (CO) and carbon dioxide (CO2) (Garg et al., 2001). Both are colorless, odorless gases. CO is toxic to both plants and animals. CO and CO2 are both greenhouse gases. Volatile organic compounds (VOCs) are mostly hydrocarbons. Important VOCs include methane, chlorofluorocarbons and dioxin.

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Secondary Pollutants Secondary pollutants form from chemical reactions that occur when pollution is exposed to sunlight. Any city can have photochemical smog, but it is most common in sunny, dry locations. A rise in the number of vehicles in cities worldwide has increased photochemical smog. Nitrogen oxides, ozone, and several other compounds are some of the components of this type of air pollution. Nitrogen oxide is created by gas combustion in cars and then into the air. In the presence of sunshine, the NO2 splits and releases an oxygen ion (O). The O then combines with an oxygen molecule (O2) to form ozone (O3). This reaction can also go in reverse: Nitric oxide (NO) removes an oxygen atom from ozone to make it O2. The direction the reaction goes depends on how much NO2 and NO are in the air. If NO2 is three times more abundant than NO, ozone will be produced. If nitric oxide levels are high, ozone will not be created (Gurjar et al., 2004).

Ozone Ozone is one of the major secondary pollutants. Ozone is also a greenhouse gas. Tropospheric ozone (O3) formation depends on the presence of methane, carbon monoxide, or volatile organic compounds (VOCs) and nitrogen oxides (NOx = NO + NO2). Ozone damages crops by entering leaves during normal gas exchange. As a strong oxidant, ozone causes symptoms in crops such as yellowing, cell injury, tiny light-tan irregular spots, bronzing, and reddening. This directly affects the growth of crops and thus reduces their yield. Ozone is the key pollutant causing the yield loss of crops, for example wheat, which is very sensitive to ozone exposure. Ozone exposure could have an even bigger impact on yields of soybean, peanut and cotton.

Black Carbon Black Carbon is also major secondary pollutants that emitted mainly from burning plants and fossil fuels. It directly absorbs sunlight, reducing the amount of light available for crops to photosynthesise. Black carbon alone has caused more damage to Indian wheat yields than climate change. The direct impacts of BC on radiation and crop growth are straightforward as BC is an absorbing aerosol that reduces both direct and diffuse light available to plants and therefore lower yields. However, this effect is difficult to isolate because BC is usually emitted or mixes in the atmosphere with other scattering aerosols to create compound particles of varying radioactive properties. Scattering aerosols also reduce total surface radiation but increase the diffuse fraction; research has shown that plants are often able to more efficiently use diffuse light for photosynthesis. Fortunately ozone and black carbon have short atmospheric lifetimes (unlike some greenhouse gases which can survive for decades or centuries). This means there is a strong, direct benefit to addressing such pollution, and it would be apparently relatively soon.

Effect on Climate Air pollution and climate change are closely related. The main sources of CO2 emissions the extraction and burning of fossil fuels are not only key drivers of climate change, but also major sources of air pollutants. Furthermore, many air pollutants that are harmful to human health and ecosystems also contribute to climate change by affecting the amount of incoming sunlight that is reflected or absorbed by the atmosphere, with some pollutants caused warming and others cooling the Earth. These climate pollutants include methane, black carbon, ground-level ozone, and sulfate aerosols. They have significant impacts on the climate; black carbon and methane in particular are among the top contributors to global warming after CO2. Approximately 91%of the world’s population lives in places where air quality exceeds WHO guideline limits. By trapping the earth’s heat in the atmosphere, greenhouse gases lead to warmer temperatures (Cofala et al., 2007). 28

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Highest concentration in troposphere has been found in case of carbon dioxide followed by CH4 and NOx, O3 etc., but methane is significantly more potent, as per as global warming potential has concerned. So it’s also very destructive. Another class of greenhouse gases, hydrofluoro carbons (HFCs), are thousands of times more powerful than carbon dioxide in their ability to trap heat which is mainly used in refrigerators and air-conditioners. In October 2016, more than 140 countries reached an agreement to reduce the use of these chemicals which are used in air conditioners and refrigerators and find greener alternatives over time. CO2 has fewer lifetimes than CH4 (12 years) and NOx (114 years). Some of the major effect of air pollution are:

Acid Rain Rains with high concentration of sulphuric acid, Nitric acid, hydrochloric acid having pH less than 7.0 (HARC, 2008).. Sulfur dioxide in the atmosphere it can combine with water vapor to form sulfuric acid, a major component of acid rain. These SOx and NOx, which released into the atmosphere by different natural processes or by different man made activities.

Ozone Pollution The ozone layer is a umbrella like cover, present in Earth's stratosphere (25km above from earth’s surface) that absorbs most of the Sun's ultraviolet radiation. but the ozone present in troposphere or ground level ozone, which is injurious for plant and toxic in nature. Due to the dramatic increase in transportation sector throughout the world, atmospheric build up of secondary air pollutant O3 has also been reported. During the past few decades, the problem of tropospheric O3 as an air pollutant intensified several fold and assumed global concern (NRC, 2001). Ozone in lower atmosphere is produced mainly by 1. The action of sunlight on various waste product of combustion, 2.Minor amount of O3 produced by electrical discharges 3.NO2 split under sunlight to form NO and atomic oxygen. Atomic O combined with molecular O2 to form Ozone. It is a GH gas and it absorbed UV radiation and long wave radiation emitted from earth surface (Krupa and Manning, 1988). High levels of O3 may be found hundreds or thousands of kilometres away from the original sources, often affecting remote rural areas (Prather et al., 2003). Surface O3 concentration has risen from an estimated pre- industrial concentration of 10 ppb to average summer concentrations between 30 and 50 ppb in the mid latitudes of the northern hemisphere with episodic levels as high as 50- 100 ppb (Morgan et al., 2006). It is predicted that surface O3 may rise to 20% over the next 50 years due to likely three fold increases in NOx and CH4 emissions (Prather et al., 2001). Wang and Mauzerall (2004) predicted that daytime surface O3 concentrations in July 2020 will exceed 55 ppb in most parts of China. The increase in annual mean O3 concentration varied from 0.1 to 1 ppb year-1 (Coyle et al., 2003). Permadi and Oanh (2008) reported high surface O3 levels in Jakarta during January 2002-March 2004, which frequently exceeded the hourly national ambient air quality standard (120 ppb). A maximum 1 hr O3 concentration was reported as 243 ppb during the dry season of 2002 was reported (Permadi and Oanh, 2008).

Greenhouse Gas Effect The greenhouse effect is a natural process that warms the Earth's surface. When the Sun's energy reaches the Earth's atmosphere as short wave radiation, but the gas present in atmosphere like CO2, CH4, N2O, CFC, Water vapour though present in smaller proportions, but due to the increased in their concentration due to air pollution, block the outgoing long wave radiation emitted by the earth. This phenomenon increased the temperature and it is called Greenhouse effect.

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Global warming Increase the global temperature by trapping the outgoing long wave solar radiation. (CO2 conc. increasing in the rate of 0.7 to 1.5ppm per year). According to the fourth report of UN IPCC (2007), the average temperature of the earth will rise by up to 6.4℃ by the end of the 21st century (2001~2100) and the sea level will rise by 59cm. The average temperature of the earth has risen 0.74℃ over the past 100 years (1906~2005) (Korea Meteorological Agency, 2008). Many of the metropolitan cities in India are ranked amongst the top few cities of the world for air pollutants concentrations (Baldasano et al., 2003). The analysis of National Environmental Engineering Research Institute (NEERI), India air quality data in 1990 for annual average of SO2 concentrations reveals a trend for increasing concentrations (from 3.8 to 15.2 ppb) in most of the parts of northern region, except for a few cities including Delhi, that had mean annual SO2 concentration above 22.8 ppb after 1985 (Agarwal et al., 1999). Among metropolitan cities SO2 concentrations in Delhi, Mumbai, Chennai and Kolkata were 2.3, 2.3, 3.4 and 6.1 ppb, respectively (ENVIS, 2010). Studies conducted in Varanasi city during 1999-2001 showed that SO2 concentration ranged from 5.32 – 5.5 ppb (Trivedi et al., 2003).

Effect on Crop Production Agricultural crops can be injured when exposed to high concentrations of various air pollutants. Injury ranges from visible markings on the foliage, to reduced growth and yield, to premature death of the plant (Legge and Krupa, 2002). The development and severity of the injury depends not only on the concentration of the particular pollutant, but also on a number of other factors. These include the length of exposure to the pollutant, the plant species and its stage of development as well as the environmental factors conducive to a build-up of the pollutant and to the preconditioning of the plant, which make it either susceptible or resistant to injury. Air pollution injury to plants can be evident in several ways. Injury to foliage may be visible in a short time and appear as necrotic lesions (dead tissue), or it can develop slowly as a yellowing or chlorosis of the leaf. There may be a reduction in growth of various portions of a plant. Plants may be killed outright, but they usually do not succumb until they have suffered recurrent injury. Sulphur dioxide, one of the major phytotoxic primary pollutants, is emitted mainly from the combustion of coal and fuel oil, with increased emissions associated with the rapidly increasing energy demands in many developing countries. For example, According to Van Aardenne et al. in 1999, Asian energy demand is doubling every 12 years, and 80 percent of the demand is met by burning fossil fuels, mainly coal. As a result, SO2emission in Asia is predicted to increase from 34 x 106 tonnes in 1990 to 110 x 106 tonnes by 2020. In China, coal burning alone accounted for 72% of total energy consumption in 1998, causing more than half of the country’s SO2 emissions . China is now the leading emitter of SO2 in the world.

Plant injury may be of different ways: 1. Ozone injury to soybean foliage Ozone symptoms characteristically occur on the upper surface of affected leaves and appear as a flecking, bronzing or bleaching of the leaf tissues (Taylor et al., 1987). Although yield reductions are usually with visible foliar injury, crop loss can also occur without any sign of pollutant stress. Conversely, some crops can sustain visible foliar injury without any adverse effect on yield.

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2. Acute sulfur dioxide injury to raspberry Sulfur dioxide enters the leaves mainly through the stomata (microscopic openings) and the resultant injury is classified as either acute or chronic (Heath et al., 2009). Acute injury is caused by absorption of high concentrations of sulfur dioxide in a relatively short time. The symptoms appear as two sided (bifacial) lesions that usually occur between the veins and occasionally along the margins of the leaves. The colour of the necrotic area can vary from a light tan or near white to an orange-red or brown depending on the time of year, the plant species affected and weather conditions (Pfanz et al., 1987). (DeKok, 1990). Most leaves have the capacity to detoxify, sulphite and bisulphite, if the concentrations are not excessively high, by oxidizing them to less toxic sulphate ion (Rao, 1992). The low concentrations of SO2 have been shown to stimulate the growth and physiological responses, especially in plants growing in sulphur deficient soil (Darrall, 1989), where SO2 might be metabolized to fulfill the demand of sulphur as nutrient (DeKok, 1990). However, the higher uptake of SO2 turns toxic and is reported to damage plants and reduce growth and productivity by interfering with different physiological and metabolic processes (Agrawal and Deepak, 2003; Agrawal et al., 2006). The effects of SO2 on physiological and biochemical characteristics of plants have been well documented (Darrall, 1989; Agrawal et al., 2006; Chauhan and Joshi, 2010).

3. Fluoride injury to plum foliage Fluorides absorbed by leaves are conducted towards the margins of broad leaves (grapes) and to the tips of monocotyledonous leaves (gladiolus). Little injury takes place at the site of absorption, whereas the margins or the tips of the leaves build up injurious concentrations. The injury starts as a gray or light-green water-soaked lesion, which turns tan to reddish-brown. With continued exposure the necrotic areas increase in size, spreading inward to the midrib on broad leaves and downward on monocotyledonous leaves (Rai et al., 2010).

4. Severe ammonia injury to apple foliage Ammonia injury to vegetation has been observed frequently in Ontario in recent years following accidents involving the storage, transportation or application of anhydrous and aqua ammonia fertilizers (FAOSTAT, 2014.

5. Cement-dust coating on apple leaves and fruit Particulate matter such as cement dust, magnesium-lime dust and carbon soot deposited on vegetation can inhibit the normal respiration and photosynthesis mechanisms within the leaf. Cement dust may cause chlorosis and death of leaf tissue by the combination of a thick crust and alkaline toxicity produced in wet weather.

Mitigation Strategy Protecting the atmosphere from air pollution is a priority for many countries and international organisations and contributes to the aim of sustainable development. Many conventions and treaties have been signed which limit the emissions of harmful substances into the air and encourage the use of new cleaner technologies. The main assumption of sustainable development is that economic growth should be stable, balanced and satisfy social needs, but should not damage the natural environment. Protecting the atmosphere means limiting or preventing the emissions of harmful substances. Maximum allowed concentrations of particular substances over different time periods have been defined to try and limit their damage. Because pollutants are transported by the wind, air pollution problems in a particular location can be the result of emissions from many different sources, often far away. To obtain 31

Environmental Issues and Sustainable Agriculture information about pollution concentrations, national networks of environmental monitoring have been set up which gather, analyse and publish air quality data. The Kyoto Protocol is an international treaty which extends the 1992 United Nations Framework Convention on Climate Change (UNFCCC) that commits state parties to reduce greenhouse gas emissions, based on the scientific consensus. The air pollution regulations exist which give the maximum allowed pollutant concentrations in each country (Emberson et al., 2009). However, air pollutants are transported by the wind from one country to another and the construction of high chimneys (which protect the immediate vicinity from the effects of the pollutants) enhances this transport process. Problems associated with these trans boundary emission have resulted in international agreements on air pollution, for example the actions started in 1991 by the governments of Germany, Poland and the Czech Republic regarding the "Black Triangle" (United Nations Environment Programme and World Meteorological Organization, 2011). Protecting the atmosphere requires huge amounts of money to cover the costs of introducing new technologies and to organise and conduct environmental monitoring. Various economic instruments are used to support those actions. One is eco-conversion, where the foreign debts of a country are converted into "ecological" investments. Another tool is emissions trading, although this method is not favoured by everyone. Here companies are given limits on the amount of pollution they can emit. If a company emits less pollution than its limit, it can sell the remaining part to another company. The highest emission of air pollutant is from the developed country (highest emission is from USA), whereas the lowest is from developing and underdeveloped country (ENVIS, 2010).

Conclusion The air pollution, climate change and crop production are interlinked with each other. The recent regional changes in atmospheric constituents which leads to the climate change, particularly increase temperature, have already affected a diverse set of physical and biological systems in many part of the world. Air pollution resulting in atmospheric deposition of toxic gases which have a range of effects on terrestrial and aquatic ecosystems, including increased plant growth, decreased plant biodiversity, soil acidification, increased invasive species, increased damages from pests and frost, and elevated nitrogen pollution to surface waters impacting aquatic biota. Researchers have developed quantitative thresholds for N and S deposition levels above which negative effects occur, termed critical loads (CL). We should adopt mitigation strategies to reduce air pollution and should follow climate resilience cropping system to maintain yield of the crop.

Reference Agarwal, A., Narain, S., Srabani, S., 1999. State of India’s Environment: The Citizens Fifth Report. Part I. National Overview Centre for Science and Environment, New Delhi. Agrawal, M., Singh B., Agrawal S.B., Bell, J.N.B., Marshall, F., 2006. The effect of air pollution on yield and quality of mungbean grown in periurban areas of Varanasi. Water, Air, Soil Pollution 169, 239- 254. Baldasano, J.M., Valera, Jimènez, P., 2003. Air quality data from large cities. The Science of the Total Environment 307, 141- 165. Chauhan, A., Joshi, P.C., 2010. Effect of ambient air pollutants on wheat and mustard crops growing in the vicinity of urban and industrial areas. New York Science Journal 3, 52- 60.

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Cofala, J., Amann, M., Klimont, Z., Kupiainen,K., Hoglund-isksson,L., 2007. Scenarios of global anthropogenic emissions of air pollutants and methane until 2030. Atmospheric Environment 41, 8486- 8499. Coyle, M., Flower, D., Ashmore, M.R., 2003, New directions: implications of increasing tropospheric background ozone concentrations for vegetation. Atmospheric Environment 37, 153–154. Darrall, N.M. 1989. The effect of air pollutants on physiological processes in plants. Plant, Cell and Environment. 12:1-30. DeKok, L.J. 1990. Sulphur metabolism in plants exposed to atmospheric sulphur. In: Sulphur Nutrition and Sulphur Assimilation in Higher Plants. (eds. Rennenberg, H., Brunold, C., DeKok, L.J. and Stulen, I.). Fundamental, Environment and Agricultural Aspects. SPB Academic Publishing, The Hague. pp. 125-138. Emberson L., 2009. A comparison of North American and Asian exposure response data for ozone effects on crop yields. Atmos Environ 43(12):1945–1953. Emberson, L.D., Simpson, D., Thiovinea, J.-P., Ashmore, M.R., Cambridge, H.M., 2000. Towards a model of ozone deposition and stomatal uptake over Europe. Norwegian Meteorological Institute, Oslo, EMEP MSC-W Note X 100, pp57. ENVIS, 2010. ENVIS newsletter. Centre for control of pollution. pp 10- 12. Garg, A., Shukla, P.R., Bhattacharya, S., Dadhwal, V.K., 2001. Sub-region (district) and sector level SO2 and NOx emissions for India: assessment of inventories and mitigation flexibility. Atmospheric Environment 35, 703–713. Gurjar, B.R., van Aardenne, J.A., Lelieveld, J., Moham, M., 2004. Emission estimates and trends (1990-2000) for megacity Delhi and implications. Atmospheric Environment 38, 2919- 2928. HARC, 2008. Houston Advanced Research Centre. NOx emissions impacts from widespread deployment of CHP in Houston. www.files.harc.edu/Sites/GulfcoastCHP/Reports/ NOxEmissionImpacts Heath, R.L., Lefohn, A.S., Musselman, R.C., 2009. Temporal processes that contribute to nonlinearity in vegetation responses to ozone exposure and dose. Atmospheric Environment 43, 2919- 2928. Heck, W.W., Taylor, O.C., Tingey, D.T., 1988. Tingey. 1988. Assessment of Crop Loss from Air Pollutants. London: Elsevier Applied Science. Krupa, S.V., Manning, W.J., 1988. Atmospheric ozone: formation and effects on vegetation. Environmental Pollution 50, 101-137. Legge,A.H., Krupa, S.V., 2002. Effects of sulphur dioxide. In Bell, J.N.B., Treshow, M., eds, Air Pollution and Plant Life. John Wiley & Sons, West Sussex, England pp 130- 162. Lobell DB, Schlenker W, Costa-Roberts J., 2011. Climate trends and global crop production since 1980. Science 333(6042):616–620. Morgan, P. B., Mies, T. A., Bollero, G. A., Nelson, R. L., Long S. P., 2006. Season-long elevation of ozone concentration to projected 2050 levels under fully open-air conditions substantially decreases the growth and production of soybean. New Phytologist 170, 333–343. NRC, 2001. National Research Council 2001: Global air quality. An imperative for long-term observational changes. National Academy Press, Washington. Organization of the United Nations Statistical Database (FAOSTAT). Available at www.faostat.org. Accessed June 5, 2014. Permadi, DA, Oanh, N.T.K., 2008. Episodic ozone air quality in Jakarta in relation to meteorological conditions. Atmospheric Environment 42, 6806-6815.

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Pfanz, H., E. Martinoia, E. Lange O.L. Heber, U. 1987. Flux of SO2 into leaf cells and cellular acidification by SO2. Plant Physiology 85, 928-933. Prather, M., Ehhalt, D., Dentener, F., Derwent, R.G., Dlugokencky, E., Holland, E., Isaksen, I.S.A., Katina, J., Kirchoff, V., Matson, P., Midgley, P.M., Wang, M. 2001. Atmospheric Chemistry and Greenhouse Gases, in Climate Change 2001: The Scientific Basis, In: Houghton, J.T., et al. (eds), Cambridge U. Press, Cambridge. pp. 239-287. Prather, M., Gauss, M., Berntsen, T., Isaksen, I., Sundet, J., Bey, I., Brasseur, G., Dentener, F., Derwent, R., Stevenson, D., Grenfell, L., Hauglustaine, D., Horowitz, L., Jacob, D., Mickley, L., Lawrence, M., von Kuhlmann, R., Muller, J. F., Pitari, G., Rogers, H., Johnson, M., Pyle, J., Law, K., vanWeele, M. and Wild, O., 2003. Fresh air in the 21st century? Geophysical Research Letter 30, art. no. 1100. Rai, R., Agrawal, M., Agrawal, S.B., 2010. Threat to food security under current levels of ground level ozone: a case study for Indian cultivars of rice. Atmospheric Environment 44, 4272- 4282. Rao, M.V., 1992. Cellular detoxifying mechanisms determine age dependent injury in tropical plants exposed to SO2. Plant Physiology 140, 733-740. Trivedi, S., Agrawal, M. and Rajput, M. 2003. Trends in sulphur dioxide and nitrogen dioxide concentrations in and around Varanasi over the period 1989-2001. Indian Journal of Air Pollution Control 3, 44- 53. United Nations Environment Programme and World Meteorological Organization (2011) Integrated Assessment of Black Carbon and Tropospheric Ozone (United Nations Office at Nairobi Publishing Services Section, Nairobi). Wang, X., Mauzerall, L., 2004. Characterizing distributions of surface ozone and its impact on grain production in China, Japan, and South Korea: 1990 and 2020. Atmospheric Environment International- Asia 38, 4383- 4402. World Bank, 2009. The world bank annual report 2009. Year in review

Environmental Issues and Sustainable Agriculture

Chapter-7

Importance of Wetlands in Water Conservation and Ecological Balance

Anupama Gaur Department of Zoology, M. M. H. College, Ghaziabad, UP Email: [email protected]

Introduction World is in a potable water crisis. It is already estimated that millions of people in the world currently have no access to potable water. And environmentalists warn that if conservation efforts to better maintain current water sources are not increased, the India may also run out of water altogether by 2030. Wetlands serve as natural water conservation tools and natural purifier. Wetlands are transitional zones that occupy an intermediate position between dry land and open waters. These ecosystems are dominated by the influence of water and possess characteristics of both terrestrial and aquatic ecosystems and properties that are uniquely their own.

Wetlands Wetlands are considered to be one of the productive and biologically rich inland surface water ecosystem. They are transitional zones that occupy an intermediate position between dry lands and open waters. These ecosystems are dominated by the influence of water and possesses characteristics of both terrestrial and aquatic eco system and also properties that are unique of their own. The term wetland encompasses a diverse and heterogenous assemblages of habitats ranging from rivers, flood plains, rain-fed lakes to mangrove, swamps, estuaries and salt marshes. A selected, unifying factor that characterizes the wetland ecosystem, is the abundance of water for at least a major part of the year. A wetland is an area of land whose soil is saturated with moisture either permanently or seasonally. Such areas may also be covered partially or completely by shallow pools of water. Wetlands are natural purifier of water and rich in productivity ecosystem, it provides food and clean water. Wetlands are home to some of the richest biodiversity on earth. Wetlands have vast capacity to absorb chemicals, filter pollutants, sediments and cleanse life bearing water and capable of breaking down suspended solids and neutralizing harmful bacteria. Many species of wetland flora and fauna show extreme sensitivity to any deterioration in the quality of their environment. These can act as ‘Early Warning System’ that indicate the falling health of their habitats and alert man to take preventive measure. Wetlands are fragile – Multifunctional ecosystems with a high degree of environmental heterogeneity (Guswa et al., 2014).This complexity is favored by the diverse interactions and transitions between climate geomorphology, precipitation, water flow and its river’s systems (Alvial et al.,2012). However, the health of these ecosystems is affected by various anthropogenic pressures (Van Ael et al., 2015 and Chapman et al., 2016) both in their structure and in the services they provide; groundwater recharge water retention of flood, contributions of base flow, biogeochemical processing, improvement of water quality and wildlife habitat (Jackson et al., 2016).

Conservation of Water “Conservation is management of the Earth’s resources in a way which aims to restore and maintain the balance between human requirements and the other species in the world.”

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It is ironic that inspite of so much of Education, Intelligence and Awareness, a sizable number of people do not know or understand the meaning or the need of Water Conservation. About ¾ of the Earth’s surface is occupied by oceans which contain about 97.5% of Earth’s water in strongly saline condition. The rest 2.5% is fresh water and all of this is not available for direct human use. Most of the fresh water is frozen as polar or glacial ice (1.97%), remaining fresh water occurs as groundwater (0.5%) and water in lakes and rivers (0.02%), soil (0.01%) and atmosphere (0.001%). Thus only a small fraction of fresh water is available for human consumption. So, in effect, we are here talking about 0.531% of water to be conserved: Right!!! No. Wrong. We are talking about conservation of 100% water in its original form. Let me explain why and how— Let us first appreciate that all lives and life-forms on Earth exist because of water. Had there been no water (both saline and fresh), there would not have been any life. Barring the marine lives, which only survive and thrive in marine (saline) water, all other living (both mobile and immobile) things survive only on fresh water. Where does the fresh water come from? Fresh water is a 100% resultant of Rain (in the form of water or snow). The sea water turns into vapour, which is pure, turns into cloud and falls in the form of rain or snow. These rain water and snow (depending on the geographical location) seep through the Earth, finds small paths (orifices) and keeps going down till it is trapped in a rock formation. A very insignificant amount of water also seeps down from the large bodies of saline water through orifices and gets filtered in the process, but its accessibility is very very difficult due to its depth. Glaciers, rivers and sweet water lakes are again the result of rain only. However, most of the rain water rolls back into the seas in the form of rivers and glaciers, so only a small percentage of rain water is stored underground and is called Ground water. Now, why is it important to talk about water conservation when this cycle of rain has been there for eons? There are reasons that this ground water and the water or snow on the surface are changing their pattern and percentage. Unfortunately, all reasons are man- made. Unchecked population growth—too many people using the limited resources. Pollution of fresh surface water—effluents and chemicals and religious reasons Pollution of ground water—again through effluents and chemicals Global warming—effecting surface water, glaciers, rivers and other sources of fresh water. With the diversification of human activities and population growth, there is an increased demand for water, accompanied by a decrease in quality, resulting in environmental and social problems. The industries are responsible for 22% all water used. The main uses of water are: -- domestic supply, creation of species, supply industrial, power generation, irrigation, navigation, watering livestock, scenic harmony preservation of flora and fauna, and dilution and transporting recreation and leisure, effluents.

Ramsar Convention The UN Convention on the Conservation of Migratory Species of Wild Animals (CMS), known as the Bonn Convention, which focuses on wild animals crossing national boundaries, has included the Ganges river dolphin. Several wetlands in India support habitats for rare, threatened and endangered wildlife. The flora and fauna of theses wetlands are sensitive to any change in quality of their environment. After February, 2, 2007, every year on this day is observed as world wetland’s day. It marks the date of the signing of the convention on wetlands on 2nd February, 1971, in the Iranian city of Ramsar on the shores of Caspian Sea. Therefore this convention came to be known as the Ramsar convention In 1991, the Government of India notified a stretch of 150

Environmental Issues and Sustainable Agriculture kms (middle Ganga) between Kahalgaon to Bhagalpur as a Dolphin Sanctuary. On 8th November, 2005, another 82 km of stretch (Upper Ganga) from Brijghat to Narora was declared as a Ramsar Site, especially for the conservation of dolphins. Subsequently in 2009, the Indian Government accorded the status of ‘National Aquatic Animal’ to the Ganges river dolphin (WWF.2011). The most important objective of convention on wetlands is, or should be to send a very clear cut and simple message that wetlands are not “wastelands”; rather they are one of the most important factors of Ecology.

Conservation of Wetlands “Waterfowl Habitat” or Ramsar Convention is one such international treaty designed to address such concerns across the world. The objective of this treaty is to list and highlight the wetlands of international importance and to preserve them. It does so by secluding the wetlands and restricting the human access and also educating the people about the importance of wetlands. The convention works closely with Five International organizations viz. --Birdlife, IUCN, International Water Management Institute, Wetlands International and WWF. These organizations provide technical expertise, facilitate field studies and also provide financial support. These organizations also participate in all meetings of the parties regularly and also act as full members of scientific and technical review panels. Wetlands perform two important functions—a). they have mitigation effects through their ability to sink and store Carbon and-- b). adaptation effects through their ability to store and regulate water. Today the wetlands are being abused by being drained, mined, burned or overgrazed, which in turn are affecting the climate severely. Wetland degradation amounts to close to 7-10% fossil fuel CO2 emissions. The organic Carbon, that was built up over thousands of years and is normally under water gets exposed to air and forms CO2. In some places like Southeast Asia, dams are being built to arrest the degradation of wetlands. Aforestation with native tree species as well as setting up setting up community fire brigade system is also an integral part of the activity o save the wetlands. Promoting such wetlands can reduce the impact of precipitation, storms, glacier melting and sea level rise. Wetlands play a key role in ground water recharge and discharge. Plentiful water and high productivity are the major factors that have made wetlands among the richest and most biologically diverse ecosystems in the world. Many plant and animal species are either confined to particular wetland or depend greatly on them for their survival (ADSORBS, 2005 – 06). Propagation of wildlife habitat for Gangetic Dolphins is one of the important designated best use of wetland of River Ganga at Ramsar site of Garhmukteshwar. The water quality requirement in this stretch demands highly productive bio-diversity to support use of water body for wild life propagation and fisheries (Gaur. A.et al.,2010). Sightings of Ganges river dolphin in many pockets between Bijnor and Narora indicate a patchy distribution of dolphins in this stretch. The deep pools and presence of food have compelled dolphins to restrict themselves to these pockets. Dolphins are decreasing day by day because of rampant poaching and loss of their habitat. Poisoning of water systems from industrial and agricultural chemicals has resulted in decline of fish as well as planktons, which are the main diet of dolphins. The toxicity of the river has also resulted in decline in their population. Their breeding patterns have been affected. The dolphins are also hunted for their meat and oil (Gaur. A.et al., 2009). The discharge by hundreds of industries enter the Ganga river directly or indirectly and pollute the river to a considerable extent. The Ganga river also has religious and mythological significance. All along the Ganga, most of the ghats have religious importance. Pilgrims in large numbers take a holy bath, cremate their dead and perform other post-cremation activities on the banks of the river and thus contribute to the pollution of the river.

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Fig- Wetland of Garhmukteshwar

Conclusion This is only one river we are that we are talking about. There are thousands of rivers in the world. If the human species has to survive, it will have to learn to respect the wetlands and will have to ensure that they thrive. Wetlands are fragile ecosystem and require protection from continued development. Only then the current alarming situation will taper off. Or else, over a period of time, we may end up having a world war over fresh water.

References ADSORBS/ 40/ May, 2005-06. Bio-monitoring of wetlands in Kashmir Valley. Alvial et al. I.E. Alvial, D.H. Tapia, M.J. Castro, B.C. Duran, C.A. Verdugo.Analysis of benthic macroinvertebrates and biotic indices to evaluate water quality in rivers impacted by mining activities in northern Chile. Knowledge Manage. Aquat. Ecosyst., 1 (2012) Chapman et al. D.V. Chapman, C. Bradley, G.M. Gettel, I.G. Hatvani, T. Hein, J.Kovács, I. Liska, D.M. Olive r, P. Tanos, B. Trásy, G. Várbíró. Developments in water quality monitoring and management in large river catchments using the Danube River as an example. Environ. Sci. Policy, 64 (2016), pp. 141-154. Gaur, A., Akolkar, P., Arora, M.P., (2010). Seasonal variation in hydro – biological characteristics of benthic macro invertebrates in wetland of upper Ganga stretch – A Ramsar site. J . Exp. Zool. India vol 13, No 2, pp: 475 - 479. Gaur,A., Akolkar ,P.,Arora,M.P.,(2009). Water quality assessment of River Ganga for conservation of Gangetic Dolphins (Platanista – gangetica ) at Garhmukteshwar. Environment Conservation Journal 10, 57-62 Guswa et al., A.J. Guswa, K.A. Brauman, C. Brown, P. Hamel, B.L. Keeler, S.S. Sayre.Ecosystem services: challenges and opportunities for hydrologic modeling to support decision making. Water Resour. Res., 50 (2014), pp. 4535-4544 Jackson et al., M.C. Jackson, C.J.G. Loewen, R.D. Vinebrooke, C.T. Chimimba. Net effects of multiple stressors in freshwater ecosystems: a meta-analysis. Glob. Change Biol. (2016) Van Ael et al., E. Van Ael, W. De Cooman, R. Blust, L. Bervoets. Use of a macroinvertebrate based biotic index to estimate critical metal concentrations for good ecological water quality. Chemosphere, 119 (2015), pp. 138-144. WWF-India. (2011). Behera, S., G. Areendran, P. Gautam and V. Sagar. For A Living Ganga– Working with People and Aquatic Species, New Delhi: WWF-India, 84 pp.

Environmental Issues and Sustainable Agriculture

Chapter-8

Agroforestry for mitigating climatic extremes

Dhanyashri P.V.* M.S.Malik* Anil kumar* M.Jadegowda* Saraswati sahu** Aishwarya routray**Isha thakur** Shashikumar M.C.** Anush patric** *Department of Silviculture and Agroforestry, **Department of Forest Products and Utilization, Dr. Y S Parmar University of Horticulture and Forestry, Solan (H.P) Email: [email protected]

Contents Climate change/ Agroforestry for land degradation/ Reclamation of degraded pasture lands/ How it work to reclaim soil/ Processes, which augment additions to the soil/ Agroforestry for flood/ INDC (Intended Nationally Determined Contribution) targets to be achieved by 2030/ India’s agroforestry policy to promote climate- smart agriculture/ Agroforestry models in relation to climate-smart agriculture/ Conclusion.

Introduction “Agroforestry is collective name for land-use systems technologies where woody perennials are deliberately used on the same land management units as agricultural crops and animals, in some form of spatial arrangement and temporal sequence” (ICRAF). Agroforestry combines agriculture and forestry technologies to create more integrated, diverse, productive, profitable, healthy and sustainable land-use systems. Agroforestry has high potential for simultaneously satisfying protection and stabilizing the ecosystems. Producing a high level of output of economic goods; and improving income and basic materials to rural population. Besides, agroforestry is capable to conserve natural resources through various systems under different agro climatic regions. The livelihood security through agroforestry and its potential in meeting basic needs. Crop diversification under agroforestry makes it resilient for various destructive causes. It can sequester CO2 along with producing grain for human consumption. Area under AF in India according to study by Chavan et al. (2015) Current science CAFRI, Jhansi – 13.75 m ha FSI, Dehradun – 11.15 m ha

Climate Change Climate change is one of the greatest challenges currently being faced by humankind in all sectors of life and causing irreversible and drastic changes in crops and reducing productivity. The series of intergovernmental panel on climate change (IPCC) reports cautions that global concentration of greenhouse gases ( GHG) have increased significantly as a result of anthropogenic activities like fossil fuel burning, deforestation and other land degradation activities. A more uncertain rainfall pattern is one of the biggest impacts of climate change (Kumar, 2011). In this context, Agroforestry is received global attention as an alternate land use practice that is more resource efficient and environment friendly (Jose et al.2008).

Agroforestry for Land Degradation Land degradation is one of the major ecological issues of the world. Land degradation means loss in the capacity of a given land to support growth of useful plants on a sustained basis [Singh, 1994]. Provision of wind breaks and shelterbelts is vital for prevention of wind erosion. Agroforestry has an important role in reclaiming the waste lands and degraded land of our country

Environmental Issues and Sustainable Agriculture as control erosion, enhance soil properties, control wind and water erosion adapt well and holds soil tightly.

Reclamation of Degraded Pasture Lands (Agroforestry) Provision for suitable soil and moisture conservation followed by planting of fodder trees and shrubs (Leucena leucocephala, Prosopis juliflora, Acacia nilotica, Atriplex etc) and also avoids fire occurrence in pasture lands.

How it work to Reclaim Soil The tree component in agroforestry is known to improve soil physical properties, maintain soil organic matter and promote nutrient cycling in the degraded land and use of appropriate agroforestry leads to positive interaction which increase crop production too (Lavania et al., 1998) . With the growing realization that agroforestry is a practical, low cost alternatives for food production as well as environmental protection, forest departments of many countries are integrating agroforestry programmes with conventional silvicultural practices [Swaminathan,1987]

Processes, which augment additions to the soil Maintenance or increase of soil organic matter through carbon fixation in photosynthesis and its transfer via litter and root decay, nitrogen fixation by some leguminous and a few non leguminous trees, nutrient uptake: the taking up of nutrients released by rock weathering in deeper layers of the soil, agroforestry has an important role in reclaiming the waste lands and degraded land of our country as control erosion, enhance soil properties, control wind and water erosion , adapt well and holds soil tightly.

Agroforestry for Flood Increasing rainfall intensities will produce larger storm flows in streams and rivers. In response, flooding will increase and stream channels and banks will experience accelerated erosion as waterways adjust to the new flow regime. Increasing area under agroforestry in watersheds can reduce the total amount of runoff and lessen peak storm flows (Vose et al. 2016). Establishment of streamside forest can reduce critical summer base flows because water uptake and transpiration rates by trees is greater than by other types of vegetative cover. Agricultural field with forest vegetation on streambanks and floodplains provides better protection from the erosive forces of storm flow than do annual crops and natural herbaceous cover. Forested banks in floodplains experience much lower rates of erosion than those that are unforested (Horton and Hart 1998, Yu et al. 2013). Along unstable streams, agroforestry is more effective than herbaceous vegetation alone at reducing high bank erosion rates. Computer models can reveal specific sites along 8 stream courses where bank erosion is more likely to occur and where establishment of riparian forest buffers would be most effective at controlling the erosion. (Scott et al. 2000, Shafroth et al. 2005, Wilcox et al. 2007). Trees help rain seep into soil because living and decaying roots make soil porous by creating a network of well-connected, minuscule channels in the soil. Rainwater seeps into soil with such channels several hundred times faster than it seeps through soil without channels. However, tree-planting reduces these high intensity events and creates a more sustainable flow that is available even after rain ceases. It also limits soil erosion. Thus, land under tree cover is more capable of absorbing rainwater. This reduces the volume of water flowing over the surface after a rain event, and thus reduces the volume of water entering rivers and streams. Computational models show that if reforesting is done in 20- 35% of the river’s catchment, a 10-15% reduction is seen in flood peak heights after 25 years of Forest growth when trees are taken off, floods often increase because most of the rainwater enters streams and rivers in a very short timeframe. 40

Environmental Issues and Sustainable Agriculture

INDC (Intended Nationally Determined Contribution) targets to be achieved by 2030 Natural forests are contributing about 95% to the forest cover of the country. The tree cover of the country is 9.26 million ha which is 2.82% of the geographical area of the country. Total forest and tree cover in the country is 24.16% of the geographical area of the country. The growing stock of India’s forests is 4,195.05 million cum and growing stock of TOF is 1,573.34 million cum (FSI 2015). There is increase of open forests but reduction of 0.33 million ha of moderately dense forests, which indicates the forest degradation. Major driver for forest degradation is unsustainable harvest of fuelwood and minor forest produce. Forests are home to 80% of country’s biodiversity (FAO 2010), provides 40% of energy needs, 30% of fodder supply, and 50% of grazing requirement along with other NTFPs. The sector provides livelihood support to one-fourth of population living in 173,000 forest-dependent villages. It contributes in sustainable development and meeting the SDGs. In view of the above, it is evident that the anthropogenic pressure endured by nation’s forests is enormous. Roadmap for achieving additional 3 billion tonnes of CO2 sequestration It is important to understand the latest status of forests and tree resource in India before preparing a roadmap to achieve 3 billion tonnes of CO2 sequestration targets. We have scope of converting around 30 million ha open forests into moderately dense forests and part of moderately dense forests into dense forests through conservation approach and assisting natural regeneration. We will be able to achieve around one- third of the target with 14 conservation approach. Rest two-thirds target could be met through afforestation on nonforest land. As forest is concurrent subject governed by both state and central government, to achieve 3000 million tonnes of additional sequestration in the next 15 years through forestry sector in India, all states have to contribute. The target is thus being distributed among the states on the basis of Forest cover and total area of productive wastelands.

India’s agroforestry policy to promote climate- smart agriculture The Indian agricultural production system faces the daunting task of having to feed 17.5 percent of the global population with only 2.4 per cent of land and 4 per cent of the water resources at its disposal. With the continuously degrading natural resource base compounded further by global warming and associated climate changes resulting in increased frequency and intensity of extreme weather events, “business as usual” approach will not be able to ensure food and nutrition security to the vast population as well as environmental security (the need of the hour). The challenge is formidable because more has to be produced with reduced carbon and water footprints. To achieve this task of paving the way for climate smart agriculture, we need to take several measures that will have enabling policies, institutions and infrastructure in place and the farming community be better informed and empowered with necessary resources.

Agroforestry models in relation to climate-smart agriculture Several forms of agroforestry systems exist such as agrisilviculture, agrihorticulture, block and other types of plantations. Agroforestry has evolved long ago by tradition or experimentation and the concept of CSA is very recent. The objectives of CSA are fulfilled by agroforestry, therefore those agroforestry models existing in India are considered as climate-smart. Apart from this, suitable agroforestry models have been developed by Government research institutes, SAUs and private organizations (Industries, NGOs and Nurseries) that are specific to locality based on ecological and edaphic conditions. These are enlisted below: 1) In North eastern region, Patchouli based agroforestry model, an aromatic plant considered as crucial ingredient for fragrance has promising market. The patchouli plants are highly suitable for planting in shade under the tree gardens of species such as Arecanut and Agar (Gera and Bhojvaid, 2013). 2) Mulberry and muga sericulture based agroforestry system for north eastern hill region was 41

Environmental Issues and Sustainable Agriculture successfully developed and demonstrated by NRCAF. Three systems viz., with i) fruit trees and fodder grasses ii) with field (upland crops) and with lowland rice were developed as models with sustained productivity and frequent returns. Sericulture with fruit plants and grass model was highly preferred by farmers followed by sericulture with field (upland) crops (NRCAF Newsletter, 2012). In Himachal Pradesh, suitable models have been developed by Himalayan Forest Research Institute, Shimla for intercropping medicinal viz., Aconitum heterophyllum, Valeriana jatamansi, Picrorhiza kurrooa, Polygonatum verticillatum and Angelica glauca with horticultural tree especially apple (Gera and Bhojvaid, 2013). Poplar based agroforestry model with wheat and sugarcane in north India is dynamic, vibrant and contributed tremendously in creation of new timber resources with productivity up to 50 m3/ha/yr (Dhiman, 2013). Ailanthus-green gram based agrisilvicultural system in Gujarat, Hardwickia-based agroforestry model in Southern Uttar Pradesh, Madhya Pradesh, Chhattisgarh Maharashtra and Karnataka are also prominent models (AICRPAF, 2008). Prosopis cineraia-based agroforestry models with pearlmillet, moong bean, moth bean, cowpea and cluster bean. Hardwickia-based, Acacia nilotica based and Zizyphus nummularia (Ber) based are some of the prevalent models in arid and semi-arid region of Rajasthan (Gera and Bhojvaid, 2013).

Conclusion Agroforestry can improve the resilience of agricultural production to current climate variability as long-term climate through the use of trees for intensification and diversification and buffering of faming systems. It helps to increase yields (property reduction and food security), make yield more resilient in the face of weather extremes and slow onset climate changes (adaption), and make a farm as solution to climate change rather than being part of the problem (mitigation), which is basic requirement of Climate Smart Agriculture (CSA). Tree based production systems often produce crops of higher value than row crops. Thus, diversifying the production system to include as significant tree component may buffer against income risk associated with climate variability. Another agroforestry systems which is well-known buffer against production risk associated with climate variability is the parkland or scattered tree systems. Agroforestry provides win-win situation to adapt and mitigate climate change effect. Enhancing the tree cover is the primary concern which can alleviate the perceived havocs of climatic extremes. Suitable tree crop combinations need to be screened-optimizing the economic and ecological productivity. More consistent efforts are required to go with green agriculture/forestry practices to ensure sustainable production consistent with the changing climate. Hence, there is need to evolve agroforestry models with tree and crops that tolerate the extreme climatic events.

References Hairiah, K., 2006. Can agroforestry improve the livehood of smallholder farmers and environmental services on degraded soil. The role of agroforestry education in revitalization of agriculture, fishery and forestry program. Hairiah, K., 2006. Can agroforestry improve the livehood of smallholder farmers and environmental services on degraded soil. The role of agroforestry education in revitalization of agriculture, fishery and forestry program. Jose, S. and Gordon, A.M., 2008. Ecological knowledge and agroforestry design: an introduction. In Toward Agroforestry Design (pp. 3-9). Springer, Dordrecht. Joy, J., Raj, A.K., Kunhamu, T.K. and Jamaludheen, V., 2018. Forage yield and nutritive quality of three-years-old calliandra (Calliandra calothyrsus Meissn.) under different management options in coconut plantations of Kerala, India. Indian Journal of Agroforestry, 20(1), pp.11-15.

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Kumar, S.N., Aggarwal, P.K., Rani, S., Jain, S., Saxena, R. and Chauhan, N., 2011. Impact of climate change on crop productivity in Western Ghats, coastal and northeastern regions of India. Current Science, pp.332-341. Kunhamu, T.K., Aneesh, S., Kumar, B.M., Jamaludheen, V., Raj, A.K. and Niyas, P., Biomass production, carbon sequestration and nutrient characteristics of 22-year-old support trees in black pepper (Piper nigrum. L) production systems in Kerala, India. Agroforestry Systems, pp.1-13. Mattsson, E., Ostwald, M., Nissanka, S.P. and Marambe, B., 2013. Homegardens as a multifunctional land-use strategy in Sri Lanka with focus on carbon sequestration. Ambio, 42(7), pp.892-902. Ravindranath, N.H. and Murthy, I.K., 2010. Greening India Mission. Current Science, pp.444- 449. Saha, S.K., Nair, P.R., Nair, V.D. and Kumar, B.M., 2010. Carbon storage in relation to soil size-fractions under tropical tree-based land-use systems. Plant and soil, 328(1-2), pp.433- 446. 18. Varsha, K.M., Raj, A.K., Kurien, E.K., Bastin, B., Kunhamu, T.K. and Pradeep, K.P., High density silvopasture systems for quality forage production and carbon sequestration in humid tropics of Southern India. Agroforestry Systems, pp.1-14. Verchot, L.V., Van Noordwijk, M., Kandji, S., Tomich, T., Ong, C., Albrecht, A., Mackensen, J., Bantilan, C., Anupama, K.V. and Palm, C., 2007. Climate change: linking adaptation and mitigation through agroforestry. Mitigation and adaptation strategies for global change, 12(5), pp.901-918.

Environmental Issues and Sustainable Agriculture

Chapter-9

Water Conservation Practices in Agriculture: A Review

Deepa Tomar, Nity Nishant, Rupa Upadhyay 1Ph.D. Scholar, 1Ph.D. Scholar, 1*Faculty, University of Delhi, New Delhi, India Email: [email protected]

Abstract Water is an essential resource for life on universe. On earth, only 2.5% water is fresh water. India has 4% of world water resource. As India`s economy is blooming and as population is soaring; enhanced demand of water has not matched with supply. Increase requirement of water for meeting domestic, industrial, and agricultural needs is quite understandable, but overutilization of water resources has already made India a “water stressed nation”. On top of that we are not conserving it properly for future needs. There are various traditional practices of water conservation that are easily forgotten on the name of advancement. Water is an integral part of agriculture. Agriculture requires a large amount of water for irrigation to cultivate food crops. Irrigation is one of the main sources of withdrawing fresh water. Demand of water for irrigation put pressure on water resources. Sometimes it leads to water scarcity for agricultural operations. It is also reported to increase water pollution, degradation of wetland ecosystem, soil degradation etc. In India various traditional practices have been performed to utilize at the same time conserve water for future. With time, few practices have become extinct and innovative techniques have developed to cater the need of water supply for agricultural purposes. This review paper is an attempt to explore traditional and modern water conservation techniques in use which are beneficial to achieve food security. Keywords: Water, irrigation, agriculture, traditional, innovative techniques, food security.

Introduction All major civilizations begin from the land of major rivers. A river is like a soul of any place whether it is about the history or its cultural heritage. It also bears important systems like transportation, industries, agriculture etc. In India, numerous rivers and its tributaries exist. Large number of people prefer to live near rivers to fulfil the daily requirement of water. With increasing population, requirement of water has also been increasing. Being a source of fresh water, stress on river has been increasing. Advancement leads to industrialization near rivers to which in turn leads to dumping of the effluents in river. Numerous industries and human population on the bank of river pollute fresh water.

Reasons for deterioration in rivers As per EPA (1986), the causes of water pollution are the release of toxic and hazardous pollutants into ground water bodies and surface water bodies like stream, river, lakes etc. River being a major source of fresh water is always in high demand. In less developed countries, many rivers and streams are heavily polluted due to anthropogenic activities (Jonnalagadda and Mhere, 2000). Agriculture pollution, industrial pollution and urbanization are the main man-made causes that affect the quality of water bodies. With the increase of population, demand of water for household activities increases so increases the waste generation also. There are numerous reasons fordegradation in the quality of river water (figure 1):

Environmental Issues and Sustainable Agriculture

1. Industrial 2. Dumping effluents of Religious waste Reasons of river pollution 3. 4. Agricultural Untreated run off domestic wastewater 5. Open sanitation

Figure 1: Reason for deterioration in rivers

Industrial effluents are directly or indirectly discharged into the environment (Glyn & Gary, 1996). Release of industrial effluents contains highly toxic chemicals, when released without treatment into water bodies makes them unfit for drinking, bathing, irrigation or other purposes. Untreated domestic wastewater, dead body dumping, open defecation near river bank and cattle washing cause bacterial contamination in river water. In 2018, a study done by Tarekegn&Truye stated that main causes of pollution of a river name Shankila are dumping of uncontrolled industrial waste, untreated domestic effluents, untreated sewage waste, defecation along the course, vehicle washing effluents etc. Agriculture uses inputs such as commercial fertilizers, pesticides, and imported forages and food grains. In 2009, a study conducted by Keskin examined nitrate and heavy metals in river due to agricultural run-off and detected lead and mercury with high amount of nitrates. It also concluded that these pollutants are due to the usage of high amount of pesticides and fertilizers in agricultural activities. Agricultural run-off carries deadly pesticides and chemical fertilizers like hexa- chloro hydrocarbon, DDT etc. into the river. Another significant source of river water pollution is immersion of idols and religious waste. Since ages, there has been a strong relation between customs, rituals, religion and rivers. The worship of rivers is associated with many occasions like birth, death and other festivals. The chemicals used in making idols are toxic in nature which leads to water pollution and life- threatening problems to ecological system. Immersion of chemicals and colours in water bodies leads to alteration in the quality of water bodies (Mishra,2010). Immersion of puja leftover into river is very old practice poses a threat to water bodies. Mostly idols are made up of plaster of Paris which contains sulphur, gypsum, magnesium and phosphorus. Mercury, lead, cadmium& carbon are mainly found in chemical paints used for these idols (Bhagat and Singh, 2014). Immersion of idols increases acidity and heavy metal content in river water which damage aquatic ecosystem and pollute water. Other than idols, immersion articles like polythene bags, foam, decorations, metal, polish, plastic sheets also contribute in adding pollution to the rivers. A study was doneby Bhagat and Singh (2014) to assess the physical-chemical parameters of Arrey and Malad lake of Mumbai during Ganesh festival in Maharashtra to relate its impact on water pollution. It was revealed by the study that idol immersion during this festival leads to negative impact on water quality. Careless dumping of idols blocks the natural flow and chemicals used in making these idols make the river toxic.

Environmental Issues and Sustainable Agriculture

Types of Pollutants Main types of pollutants that come into the contact of aquatic environment are organic i.e. pesticides, dioxins, polycyclic aromatic hydrocarbons etc. and inorganic compounds like metals, phosphorous and nitrogenous compound. Approximately 1500 substances are listed as pollutants in freshwater ecosystem. The generalized list of pollutants comprises alkalis, acids, anions (sulphite, sulphide, cyanide), domestic sewage, detergents, farm manure, gases, metals (zinc, mercury, cadmium etc), nutrients (phosphates, nitrates etc.), pathogens, pesticides, organic toxic waste etc. (Tripathi et al., 1990). Heavy metals are non-biodegradable natural constituents that normally occurs at low concentration. With urbanization and industrialization, these heavy metals have been increasing due to anthropogenic activities. These metals are not visible in water but their effects are toxic.As perTomar and Upadhyay (2018), origin point of Yamuna river i.e. Yamunotri, is almost free from heavy metals, while as it passes from states to states, level of heavy metals increases in Yamuna river due to industrialization and urbanization.

Water Scarcity Urbanization and industrialization play important role in advancement of nation. In result they put extreme pressure on our resources. Over utilization of resources with no conservation measures results sometimes in extinction of resources. River is a major source of fulfilling fresh water demand. People living near river extract water for various purposes and in return usually makes it polluted. In the past there have been so many rivers with good flow but with time the flow reduced and now they are left as “sewer”. In Guwahati city of Assam state, a river named ‘Bharalu’ bifurcates into two rivulets i.e. Basistha and Bhaini after flowing few kilometers. There was a time when the demand of whole city was fulfilled by these rivulets but these are reduced to mere sewer on the name of unplanned, rapid developmental activities and urbanization process. Today the term used for this river is “Mora Bharalu” means “Dead Bahralu” as this river barely exists today (Borthakur & Singh,2016). There has been an increase in global population at the same time there is depletion in water level so it is predicted that large population of the world would face severe water shortages by 2025. Water scarcity is increasing at many folds which is a serious concern. Water scarcity can be considered as an imbalance between demand and availability of water (FAO, 2010). This scarcity is increasing due to the usage of water resources in multiple sectors (Wada et al.,2011; Florke et al.,2013).A review done by Kummu and coworkers in 2016 to analyse the shortage of water and stresses on water security due to high consumption of water; concluded that the consumption of water has increased fourfold within study period and population under water scarcity has increased from 0.24 billion (14% global population) in 1900s to 3.8 billion (58% global population) in 2000s. Extensive water is used for irrigation purposes whether it is to combat pests, to protect crops from frost, to dissolve nutrients before application, to remove excess salinity from soil, to improve pH etc. High demand of water for irrigation makes it one of the highest water demanding sector of the economy. Water pollution is enhancing stresses on nations to conserve water to fulfill current as well as future needs.

Water conservation practices in India Water scarcity and ever-increasing population has widened the gap between supply and demand; put tremendous pressure on water bodies. The usage of water has been increasing and continue to increase across various sectors in India. Therefore, sustainable management of water resource is essential to meet the water demand not only for today but also for future. India is vast country and since ages people have experienced water related problems due to varied rainfall and 46

Environmental Issues and Sustainable Agriculture topography of land. Hence, they used to practice localized water harvesting methods to irrigate their lands. Even today, there are many traditional methods which are less popular but very efficient. Water harvesting systems are traditional technologies that have been used by local population of India for many centuries to meet their needs. There are numerous simple to complex systems in India to conserve water likeGhul of western Himalayas; Kund, Khadin, Talabs, Beri, Johad, Baoli etc. of Rajasthan; Zabo of Nagaland etc. (table 1):

Table 1: Traditional water conservation techniques

States Traditional water References conservation techniques Arunachal Pradesh Apatani Bhattacharya, 2015; Dabral, 2002 Assam Dongs, Garh Dara Bhattacharya, 2015; Sarma and Goswani, 2015 Himachal Pradesh Ghul, Baudi, Khatris, Khuls Sharma and Kanwar, 2009; Bhattacharya, 2015 Meghalaya Bamboo drip irrigation Bhattacharya, 2015; Dabral, 2002; Sarma and Goswani, 2015 Nagaland Zabo, Cheo-ozihi Bhattacharya, 2015; Dabral, 2002; Sarma and Goswani, 2015 Rajasthan Kui, Khadins, Nadis, Tanks, Saxena, 2017; Bhattacharya, 2015 Baolis, Tobas Uttarakhand Naula, Dhan, Ghul Rawat and shah, 2009; Bhattacharya, 2015

Arunachal Pradesh Apatani: It is a multipurpose system of water management which integrates water, land and farming system. It conserves water for irrigation; protects soil erosion and for paddy cum fish culture. In this system, streams coming from hills is diverted through channels. Irrigation channels of 0.61x 0.61metre and same-sized embankments in each plot are made. Water is drawn from irrigation channels to the plots to irrigate fields. In the middle of the plot, a vertical dug is made to collect water for fish culture. A semi-circular bamboo net is installed at the inlet to prevent trashes of fishes; wooden strikes or planks are placed at the outlet to reduce the beating of flowers that results in erosion of soil. Above 15 to 25 cm of bed level of fields, “huburs” are installed to maintain the water level. Huburs are trunks of different woods with different diameters (Sarma and Goswami, 2015).

Assam Dongs: Dongs are traditional water canals to harvest water for irrigation. Mainly found in Bodo populated area. These are owned individually. Natural streams are the sources of water from which canals are cut to divert water for irrigation. Dongs only carry rain water and surface water. In fields, water is accumulated in a “pond like structure” and is lifted when necessary with the help of instrument called “Lahoni”. “Koon” is another structure like a wooden boat which is used to harvest water from “pond like structure” to irrigate fields (Sarma and Goswami, 2015). Garh and Dara: Garh is like a big sewer, both sides of which have long embankment. It is constructed to divert the river water to irrigate the agricultural fields. In fields. Plot is divided

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into small square size embankment to store rain water. These small sized square embankments are called Dara (Bhattacharya, 2015). According to Borthakur (2008), this technique has been used as rain water harvesting technique since ancient times.

Himachal Pradesh Ghul:Thisstructure that is 1 to 15 km in length and carries approximately 15-100 litre of water per second. In this system, water is tapped from hill slopes. A cut is made in the streams, which is further extended by stone embankment, mainly made up of piles of stones (Bhattacharya,2015; Borthakur, 2008). Baudi:It is circular or square in shape, basically a pit. It is dug where water naturally percolates from earth. Stones are placed in a manner to have continuous percolation of water (Sharma &Kanwar,2009). Khatris:They are deep rectangular shaped pits where rain water is harvested through rock seepage. At the foothills, a horizontal 3-4 metre tunnels are made followed by a vertical basin at inner end. Many khatris can be dug but they must be at the same level (Sharma and Kanwar,2009). Khuls:These aretraditional water management system for irrigation. A community khuls is sufficient for 6 to 30 farmers, having an area of approximately 20 hectares. This system comprises temporary headwall of boulders across a ravine to divert water flow through a canal to the agricultural field. The surface channels that divert water from streams are called khuds. Khuds are at upstream than stream to irrigate the lands that are at higher elevation. Water reaches to every field and remaining water drains back to khuds (Sharma and Kanwar,2009).

Meghalaya Bamboo drip irrigation: In this system, water is extracted from natural streams which is conveyed with the help of bamboo channel on ground surface with bamboo or wooden support. Through this process, water is discharged from 15 to 25 litres/ minute without any leakage. This system is highly effective in reducing soil erosion in hilly slopes. Several diversions can be made depending on how much water resources are available and the number of plants to be irrigated (Dabral,2002). This method is considered to be the best to provide water for crops and to avoid water logging in fields (Kapadia,n.d).

Nagaland Zabo: Zabo isan indigenous system of farming. It means “impounding of water”. This system manages land and water along with agriculture. It covers approximately 960 hectares, out of which 1.5 hectare is covered by forest, 0.2 hectare by water harvesting tanks and remaining by paddy fields (Debral, 2002). Forest, on the top of hills is the catchment area for rainfall. Due to steepness, water flows downward and gets collected in tanks. These tanks comprise main storage tank and siltation tank. Siltation tanks are earthen tank, bottom of these tanks is covered with mud and straw to avoid seepage. Organic matters, impurities and soil accumulate in this tank and then enter into the main tank (Sharma and Sharma, 2003). Cheo-ozihi: Cheo means “the person who is responsible for laying 8 to 10 km long channel with various branches” and Oziihi means “water”. Water of Mezii River in Nagaland is tapped in seven different places in different elevation through channel diversion. Different branches of channels take off the river water and divert water to terraces though bamboo pipes. One of these channels is known as Cheo-oziihi (Agarwal and Narain, 1997).

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Rajasthan Nadis: Nadis is an ancient system for harnessing rain water; form of village pond that is adjoining to natural catchment during rainy season. It fills during rainy season and its availability would range from few months to a year depending upon the amount of the rain area. In Nagaur, Barmer and Jaisalmer there were 1,436, 592 and 1,822 nadis respectively (Saxena, 2017). The factors that affect the effectiveness of nadis are high evaporative loss, high seepage, water pollution and heavy sedimentation. Tanks: Tanks are constructed with massive four-sided wall and impermeable floor; either rectangular or square. They have huge water holding capacity. Tanks are built with efficient canal system to fetch rain water from catchment area (Saxena, 2017). Raju and Shah (2000), mentioned the importance and need of tanks even today to fulfil the global water requirement. They did a project and concluded that 60 minor irrigation tanks with management regeneration were completed to fulfil the requirement of water. Baoris: It is also known as community step well which has shallow depth. They have the capacity to hold water for long time with negligible water evaporation (Saxena, 2017). Tobas: in arid areas, tobas were made artificially to harvest water. As per Saxena, 2017, hard plot with low porosity comprised a depression with a natural catchment area is considered to be tobas. Kui: Kui is also called as beris. They are made (dugs) next to tanks to collect their seepage in order to minimize the wastage of water. These dugs are 10-12 m deep kuchcha structure; covered with plank of wood. Mouth of the dug is narrow to reduce the evaporation. These are used to irrigate fields where rainfall is meagre (Saxena, 2017). Khadins: In this system, runoff water from high catchment area is stored during monsoon season(Saxena, 2017). It is based on the principle of rain water harvesting on farmland. Stored water is used to enrich the field for production of crop. It helps to maintain the fertility of soil.

Uttarakhand Khal: In mountainous regions, large depressions that are used to harvest rainwater are known as Khal. Between two crests, they are on the top of ridges in the saddle. Small ponds are also dug to collect rain water. In summer, water accumulated in khals is used to irrigate agricultural fields (Rawat and Sah, 2009). Dhan: Water is collected from large and small streams in a depression, which resembles with the shape of a lake (Rawat & Sah,2009). Water of Dhan is used to irrigate fields.

Modern Water Conservation Techniques During 1960s, the need of high cultivation techniques was arisen to achieve food security. After, green revolution, many works had been done in the field of agriculture specially in terms of harvesting of water for irrigation. Finite water resources had provided the impetus to develop water conserving technologies in agriculture as agriculture sector demands large amount of water for irrigation purposes. Micro-irrigation technologies were first perfected in Israel during 1960s and then spread to many countries of the world, particularly in water scarce regions. Micro-irrigation (MI) is proved to be an efficient method of saving water than conventional surface method of irrigation.Micro irrigation includes drip and sprinkle irrigation method. In drip irrigation, water supplies directly to the roots of the crops through pipes with the help of emitters and in sprinkler irrigation method, water sprinkles in the field through nozzles and water breaks into small water drops and fall on field surface(INCID, 1994, Narayanamoorthy, 1996; Narayanamoorthy, 1997). In 1970s, this technology was introduced in Indiamainly on orchards of grapes and orangein

Environmental Issues and Sustainable Agriculture

MaharashtraKarnataka and Tamil Nadu. Use of micro irrigation has increased in India to avert water crisis by saving water for irrigation in agriculture (Narayanamoorthy, 2003; Shah and Keller 2002; Polak et al. 1997). There are many studies that confirm that drip irrigation increases the productivity of crops and are efficient way of using water for irrigation (Soussa, 2010; Hanson & May,2004; Kumar et al., 2016). Drip irrigation uses less water in comparison to sprinkle irrigation system in irrigating fields (INCID, 1994; Kulkarni, 2005). Scenario of global irrigation has been changing with increased need of high agricultural productivity and scarcity of water. Automated solar power-based drip irrigation system is an efficient way that is linked to soil moisture sensor by android mobile. Sensors are used to remote monitoring and controlling of the devices by global system of mobiles or short message services. With the help of solar panel, pump can run for approximately 7-9 hours per day. Pump can be controlled by mobile phones and android apps. Status of pumps and moisture value is obtained by mobile with the help of GSM module or Bluetooth module HC-05 (Kumar et al.,2016).Android mobiles is used to check moisture of soil as well as temperature on particular interval of time to check on soil condition and nutrient composition of plants. Advantages ofautomated solar power- based drip irrigation system includes decreasing the wastage of water and energy, improving quality and yield of crops and reduction in the requirement of fertilizers (Alaofe` et al., 2016; Pande et al.,2003). This system is easy to maintain and its battery free configuration makes it suitable for developing countries like India except the high initial cost of photovoltaic system (Kolhe et al.,2002) In the last decade, recurrence of droughts has worsened the scenario of ground water resources, forcing farmers to look for alternative methods which would not only be cost effective but also increases the water productivity. In late 90s, a new innovation in micro irrigation technology came as “Pepsee” in India, which was low-cost water saving technology. In local market of India, small manufacturers used light weight transparent 20 cm plastic (disposable) to fill ice candies which was named as “pepsee”. This plastic came in continuous rolls. In the places of drip tubes, these plastic rollsare being used in a way to provide water directly at the root of the plants (Verma et al.,2003). Pepsee is an inexpensive system and adopted at place where there is acute scarcity of irrigation water. This system minimizes the losses by evaporation and percolation (Kasle et al.,2017). The deficit irrigation technology is dependent on physiological water requirement control that increases the water efficiency of crops. Regulated deficit irrigation (RDI) is an irrigation practice with water, which is less than the required amount of water for plants. This technique is highly beneficial in those areas’ where rainfall is less or ground level of water is very low. Many studies concluded that through this technique water demand can be reduced without affecting the yield of plant (Greven et al.,2005; Stewart et al.,2011) with better quality (Dolker et al.,2017). Chai et al., 2016 concluded that out of three approaches (growth stage-based, partial root-zone and sub-surface dripper) of Regulated Deficit Irrigation (RDI), partial root zone was the most effective in saving irrigation water with minimum effect on yield. In 1940, centre-pivot irrigation was invented by a farmer named Frank Zybach of Colorado (Vispute,2016)to improve water distribution to fields. This system is a form of overhead sprinkler irrigation comprises many segments of pipes joined together by trusses to support each other. The whole assembly is mounted on tires due to which it rotates in circular manner around a central point known as Pivot Point. The space between two tires is known as Span. The average quantity of water from sprinkler can be controlled by Control Unit. Water is mainly pumped from well or river though a pump which is connected to pivot at the pivot point. The machines move in circular motion and provide water from pivot point to centre. Central pivot irrigation system is a flexible system and its operation can be controlled with high efficiency. This irrigation system is used to irrigate almost every crop under any 50

Environmental Issues and Sustainable Agriculture climatic condition. Chemicals and nutrients can also be applied through central pivot irrigation system with less labour. Central pivot irrigation system is suitable for soil type ranged from sandy, clay, silt, flat, dunes. Productivity of crops improved when they are irrigated with central pivot irrigation system (Elzubeir, 2018; Ahmed et al., 2017). An experiment was conducted by Shirgure and Srivastava (2014) and found that the automatic drip irrigation is a better substitute than manual drip irrigation in terms of enhancing the yield, fruit quality and water usage. Vispute (2016) mentioned about the importance of this system that it is an economical and efficient method of irrigation, requires less water than traditional method, can be used on unlevelled soil and requires less labour. Automated irrigation system was developed to optimize the use of water for agriculture. There are distributed wireless network of soil-moisture and temperature sensors that are placed in the roots area of plants. Gateway units handle sensor related information and transmit data to web application. The automated irrigation system comprises two components i.e. wireless sensor units (WSUs) and a wireless information unit (WIU); both are linked by radio transmitter to transmit data of soil moisture and temperature through Zig Bee technology. This system is powered by photovoltaic panels and has a communication link between cellular-Internet interface that allow inspection of data and scheduling of irrigation through a web page. This irrigation system helps to maintain soil and water balance in the root of plant for optimal growth (Irmak and Haman, 2001). In 2011, Boutraa and other researchers compared automated irrigation system with manual irrigation systems and found out that automated irrigation helps to save water for irrigation, helps to have higher photosynthesis that leads to higher biomass and yield. Various automated irrigation systems related model have been proposed by many researchers to use this system as per Indian context with best usage (Hade and Sengupta, 2014; Nallani and Hency, 2015).

Water Conservation and Food Security Food security exists when all people, at all times have access to sufficient, safe and nutritious food to meet their dietary needs and food preference for an active and healthy life, as stated by the FAO and accepted by the World Food Summit in 1996 (FAO, 2009). As per report of “Rome Declaration on World Food Security and World Food Summit Plan of Action”,1996: the food security is subdivided into three components: (i) availability the means adequacy of food; (ii) access, or the ability to obtain (physically or economically) appropriate and nutritious food; and (iii) utilization, or the ability to consume and benefit from nutritious foods. Water is a key to food security. Excessive use of water resources and making them polluted threatens the security of food (Falkenmark, 2002). The question of whether there would be sufficient food in future is correlated to whether there would be enough water for the production of enough food. Population growth and economic development have increased the demand of food as well as associated water demand. Limited supply of water for various needs including fulfilling the demand of water for agricultural activities puts pressure on water and plays an important role in water scarcity. In 2007, Cline assessed the impact of water scarcity on the production of food. He found out that water scarcity subdued the production of food and would adversely affect the food security. It is predicted that in upcoming decades water scarcity will become a risk for food security. Not only availability of water for food production, pollution free water is necessary for irrigation purposes. Irrigation water containing heavy metals makes it unsuitable and affects the health of people. A study conducted by Ahmed et al., 2019 revealed that the heavy metals those were present in irrigation water were transferred to soil though irrigation water and reached to vegetables. Similar studies were conducted by Latheef and Soundhirarajan, 2018 and Malan et al., 2015. In India, large population is dependent on agriculture directly or indirectly. Tremendous increase in population puts extra stress on agricultural sector. Availability of water to get 51

Environmental Issues and Sustainable Agriculture maximum production of crops is indispensable yet difficult to meet the food requirement of the vast population. It is unrealistic to solely depend on “monsoon” or on “natural sources” for irrigation and get optimal production. In 2007, Cline suggested some measures to control water scarcity to achieve food security i.e. population control, enhancement of yield of crops, advancement of already existing irrigation infrastructure, construction of small dams and management of water resources.

Conclusions In India, where a large population is dependent on agriculture directly or indirectly, availability of water to get maximum production of crops is a major concern especially when rain is so erratic. It is unrealistic to solely depend on “monsoon” or on “natural sources” for irrigation and get optimal production. Traditional water conservation practices are well thought practices and very efficient in conserving water since ages. In today`s world where India is a water stressed nation and many states suffer from inadequate availability of water for irrigation, there is a need to revive our traditional irrigation practices coupled with new techniques. To get safe food production availability of safe water is of utmost concern. Traditional and innovative irrigation practices can go hand in hand to remedy the situation, improve agricultural conditions and achieve food security.

References Agarwal, A. and Narain, S.(1997) Dying wisdom: Rise, fall and potential of India's traditional water harvesting systems, (State of India's Environment – A Citizens' report, No. 4) Centre for Science & Environment (CSE), New Delhi,11-12. Ahmed,T.F., Sheikh,A.A., Shah,S., Khan,M.A and Afzal,M.A.(2017).Enhancing water and crop productivity by means of centre pivot irrigation system. Academia Journal of Agricultural Research,5(8), 169-178. Alaofe,H. B., Naylor,R., Taren,D.(2016). Solar-Powered Drip Irrigation Impacts on Crops Production Diversity and Dietary Diversity in Northern Benin.Food and Nutrition Bulletin,37(2),164-175. Bhagat,S., and Singh,A.(2014). Environmental Impact of Ganpati Idol Immersion on Water Quality of Two Lakes in Mumbai.International journal of scientific research,3(2),180. Bhattacharya,S.(2015). Traditional water harvesting structures and sustainable water management in India: A socio-hydrological review.International Letters of Natural Sciences, 37,30-38.

Borthakur,A., and Singh,P.(2016). India’s lost rivers and rivulets. Energ. Ecol. Environ.,1(5) ,310–314. Borthakur,S.(2008).Traditional rain water harvesting techniques and its applicability. Indian Journal of Traditional Knowledge,, 8(4),525-530. Boutraa,T.,Akhkha,A., Alshuaibi,A., and Atta,R.(2011). Evaluation of the effectiveness of an automated irrigation system using wheat crops. Agriculture and biology journal of north America,2151-7517. Chai,Q.,Gan,Y., Zhao,C.,Xu,H.L.,Reagan,M.,Niu,Y.,Kadambot,H.M.,Siddique(2015). Regulated deficit irrigation for crop production under drought stress.: A review. Springer J. Cline,W.R.(2003).World Agriculture Faces Serious Decline from Global Warming. Centre for Global Development, Washington,DC. Dabral,P.P.(2002). Indigenous techniques of soil and water conservation of Northeast Region of India, 12TH ISCO Conference, Beijing.

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Dolker,D.,Bakshi,P.,Dorjey,S.,Choudhary,P.,Kour,K.,and Singh.M.(2017). Effect of Deficit Irrigation Scheduling on Yield and Quality of Kinnow Mandarin Fruits.International Journal of Current Microbiology and Applied Sciences,6(7). The Environment (Protection) Act.(1986).Retrieved from website:http://bch.cbd.int/database/attachm ent/?id=19052. Elzubeir,A.O.(2018).Survey Study of Centre Pivot Irrigation System in Northern State (Sudan) . International Journal of Science and Qualitative Analysis, 4(1),27-33. Falkenmark,M.(2002). Growing water scarcity in agriculture: future challenge to global water security.Philos Trans A Math Phys Eng Sci.. FAO.(1996).Food Production:The Critical Role of Water. Rome: World Food Summit. FAO. (2009). Pathways to Success- Success Stories in Agricultural Production and Food Security, FAO, Rome. Flörke,M., Kynast,E., Bärlund,I., Eisner,S., Wimmer,F. and Alcamo,J.(2013).Domestic and industrial water uses of the past 60 years as a mirror of socio-economic development: A global simulation study.Global Environmental Change,23, 144–156. Greven,M.,Green,S.,Neal,S.,Clothier,B.,Neal,M.,Dryden,G.,andDavidson,P.(2005). Regulated Deficit Irrigation (RDI) to save water and improve Sauvignon Blanc quality. WaterScienceandTechnology.51(1).9–17. Glyn,H.J. and Gary,W.H.(1996). Environmental Sciences and Engineering Prentice Hall International inc.,778. Hade,A.H. and Sengupta,M.K.(2014). Automatic Control of Drip Irrigation System & Monitoring Of Soil by Wireless. Journal of Agriculture and Veterinary Science,7(4),55-61. Hason,B and May,D.(2004).Effect of subsurface drip irrigation on processing tomato yield, water table depth, soil salinity, and profitability.Agricultural Water Management,68(1). INCID, (1994). Drip Irrigation in India, Indian National Committee on Irrigation and Drainage, New Delhi. Jonnanlagadda,S and Mhere,G.(2000). Water quality of the odzi river in the eastern highlands of Zimbabwe.Pergamon,35(10), 2371–2376. Irmak,S. and Haman,D.Z.(2001). Performance of the Watermark granular matrix sensor in sandy soils. Applied Engineering in Agriculture, 17, 787-795. Kapadia,V.P.(n.d). Relevance of Traditional Indian Methods of Water Management in the Present Era. Narmada, Water Resources, Water Supply and Kalpsar Department, Government of Gujarat,Gandhinagar, Gujarat, India. Kasle,S., Jain,P., Akbarali,S.,Maniyar,F.,Davala,A.(2017). Drip Irrigation by PEPSEE System.7(4). Keskin,T.E.(2009). Nitrate and heavy metal pollution resulting from agricultural activity: A case study from Eskipazar (Karabuk, Turkey).Environmental Earth Sciences,61(4),703-721. Kolhe,M., Kolhe,S., Joshi,J.C.(2002). Economic viability of stand-alone solar photovoltaic system in comparison with diesel-powered system for India. Energ Econ,24,155–165. Kulkarni, S.A.(2005). Looking beyond eight sprinklers. National Conference on Micro- Irrigation. G. B. Pant University of Agriculture and Technology, Pantnagar, India,3-5. Kumar,R.,Trivedi,H.,Yadav,R., Das,B. and Bist,A.S.(2016).Effect of drip irrigation on yield and water use efficiency on brinjal (solanum melongena) cv. pant Samrat.International journal of engineering sciences & research technology,5(10). Kummu,M.,Guillaume,J. H. A., Moel,H.,Eisner,S.,Flörke,M., Porkka,M., Siebert,S. and Veldkamp,T. I. E.(2016).The world’s road to water scarcity: shortage and stress in the 20th century and pathways towards sustainability.Science reports.

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Latheef,S., and Soundhirarajan,K.(2018). Heavy metal contamination in irrigation water and its effects on plants. International Research Journal of Engineering and Technology,5(5). Li,J.(1997). Effect of Pressure and Nozzle Shape on the Characteristics of Sprinkler Droplet Spectra. Journal of Agric. Eng. Res., 66, 15-21. Malan,M.,Müller,F.,Cyster,L., Raitt,L.,Aalbers,J.(2015). Heavy metals in the irrigation water, soils and vegetables in the Philippi horticultural area in the Western Cape Province of South Africa,Environmental monitoring and assessment,187(1). Mishra,A.(2010).River about to die. Journal of Water Resource and Protection,2(5). Molden,D., and Barker,R.(1999). Water scarcity in the twenty-first century. International Water Management Institute.15(1-2). Nallani,S. and Hency,V.B.(2015). Low Power Cost Effective Automatic Irrigation System. Indian Journal of Science and Technology,8(23). Narayanamoorthy, A. (1996).Evaluation of Drip Irrigation System in Maharashtra, Mimeograph Series No. 42.Agro-Economic Research Centre, Gokhale Institute of Politics and Economics, Pune, Maharashtra. Narayanamoorthy, A.(1997).“Economic Viability of Drip Irrigation: An Empirical Analysis from Maharashtra”.Indian Journal of Agricultural Economics, 52(4),728-739. Narayanamoorthy, A. (2003).“Averting Water Crisis by Drip Method of Irrigation: A Study of Two Water-Intensive Crops”.Indian Journal of Agricultural Economics,58(3),427-437. Pande,P.C., Singh,A.K., Ansari,S., Vyas,S.K., Dave,B.K.(2003).Design development and testing of a solar PV pump based drip system for orchards.Renewable Energy,28(3),385-396. Polak,P., Nanes,B., and Adhikari,D.(1997). A low cost drip irrigation system for small farmers in developing countries.Journal of the American water resources association, 33(1). Raju,K.V. and Shah,T.(2000). Revitalisation of Irrigation Tanks in Rajasthan.Economic and Political Weekly. Rawat,A.S., and Shah,R.(2009).Traditional knowledge of water management in Kumaon Himalaya. Indigenous water conservation systems.Indian Journal Of Traditional Knowledge,8(2),249-254. Rome Declaration on World Food Security and World Food Summit Plan of Action (1996). Retreived from website: http://www.fao.org/3/w3613e/w3613e00.html. Sarma,A., and Goswami,D.C.(2015). Sustainable agricultural practices and the methods of traditional water harvesting in North East Region of India. Archives of Applied Science Research,7(4),23-30. Saxena,D.(2017). Water Conservation: Traditional Rain Water Harvesting Systems in Rajasthan. International Journal of Engineering Trends and Technology,52(2). Shah,T.and Keller,J.(2002). Micro-irrigation and the poor: A marketing challenge in smallholder irrigation development. Technical Centre for Agricultural and Rural Cooperation,165-183. Sharma,N. and Kanwar,P.(2009).Indigenous water conservation systems.Indian Journal Of Traditional Knowledge,8(4),510-513. Sharma, U.C. and Sharma,V.(2003).The “Zabo” soil and water management and conservation system in development of water resources and their impact on society-an historical account of a success story,IAHS Publication,286,188-189. Shirgure,P.S., and Srivastava,A.K.(2014). Effect of automatic micro-irrigation scheduling on productivity and quality of Nagpur mandarin. Indian Journal of Horticulture,71(1),112-116.

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Soussa,H.(2010). Effects of Drip Irrigation Water Amount on Crop Yield, Productivity and Efficiency of Water Use in Desert Regions in Egypt.Nile Basin Water Science& Engineering Journal,3(2). Stewart,W.L., Fulton,A.E., Krueger,W.H., Lampinen,B.D., and Shackel,K.A.(2011). Regulated deficit irrigation reduces water use of almonds without affecting yield.California agriculture,65(2). Tarekegn, M.M and Truye,A.Z.(2018).Causes and impacts of Shankila river water pollution in Addis Ababa, Ethiopia.Environ Risk Assess Remediat,2(4). Tomar,D. and Upadhyay,R.(2018).Heavy metals in Yamuna river: A Review.International Journal of Advanced Scientific Research and Management,3(11). Tom,M., Fletcher,T.D., and McCarthy,D.T.(2014). Heavy Metal Contamination of Vegetables Irrigated by Urban Stormwater: A Matter of Time?.PLoS ONE 9(11).https://doi.org/10 .1371/journal.pone.0112441. Tripathi, B.D., Misra, K., Pandey, V.S. and Srivastva, J.(1990). Effect of tissue-N content on decomposition of water hyacinth (Eichhornia Crassipes ) (Mart.) Solms. Geobios. 17(2- 3),67-69. Verma,S., Tsephalb,S. and Josec,T.(2003). Pepsee systems: grassroots innovation under groundwater stress.Water Policy. Vispute,P.(2016). Centre Pivot Irrigation-A Modern Method of Irrigation in Indian Perspective Pavan. International Journal of advances research in scientific management and technology,2(12). Wada,Y., Van Beek,L., and Bierkens,M.(2011). Modelling global water stress of the recent past: on the relative importance of trends in water demand and climate variability. Hydrology and Earth System Sciences.

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Chapter-10

Watershed Management

Indu Bala Sethi*, Mahesh Jajoria, Suresh Kumar, Niranjan Kumar Braod, Laxman Prasad Balai, Lokesh Kumar Jat, Hansram Maliand Suresh Muralia S.K.N Agriculture University, Jobner-301025, Rajasthan *Corresponding author: [email protected]

Introduction In general, watershed-based planning of resource management has generated wide appreciation, particularly for assured dividends. Recently, the concept of maintaining an ecological balance embedded in the watershed programme has also started getting major attention in different sections of society. But all this does not lower down the importance of scientific irrigated morning. Atthe national level, 10 to 15 million hectares, out, of the total 55 million hectares of drought-prone area (spread over 99 districts), maybe conveniently covered under the watershed programme; but still 40-45 million hectares are likely to depend on irrigation water having the source beyond the watershed. Though the history of land and water management is as old as that of agriculture itself, the issue of providing substantial Government support to the programme has always remained debatable. However, national consensus in respect of watersheds emerged in the early eighties. Presently, the watershed management programme in the rainfed areas is getting momentum in a big way through National Watershed Development Project for Rainfed Agriculture. Watershed is dynamic in nature and at transition induced by changes in management activities. Therefore constant review of the progress is needed. For development of a watershed detailed inventories of natural resources, and socio economic features are made, analysis of problems and potentials is done to develop a suitable technology for all round improvement of the area The watershed management and its principles and practices have been highlighted in this chapter.

Concept Watershed is an area of land and water bounded by a drainage divide within which the surface runoff collects and flows out of the area through a single outlet into a river or other body of water. It is also used as a synonym for catchment area or a drainage basin. Watershed is the smallest soil hydrological unit draining into a common outlet. A watershed is also defined as any spatial area from which rain or irrigation water is collected and drained through a common point. There is no definite size for a watershed as it may way from a few hectares to several hundred hectares. Scientific watershed management practices help in increase of agricultural production, reduce flood hazards and siltation problems, pasture improvement and efficient soil and water management. The watershed approach is a strategy for soil and water conservation, drought prove area programme, dry farming, river valley projects, flood control and hill area development programmes. At places where watershed have been in operation, soil and water runoff has been checked, denuded forests and devastated posture lands have been brought under cultivation ground water levels and crop yields have gone up, and so have to farmer’s income. With poverty having been relegated to the background, farmer’s life styles have witnessed a sea change in such areas. A watershed provides a limited surface area within which physical process pertinent to the morphology and hydrology could be appreciates.

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The climatic variables, the water and sediment discharge, water storage and evaporated and transpiration of a watershed help in determining denudation rates, moisture and energy balances. This determinates help, in their turn the management of land, water crops and energy.

Fig. 1: Watershed management

Characteristics of Watershed Each watershed shows distinct characteristics, which are so much variable that no two watersheds are identical. All these characteristics affect the disposal of water. Several characteristics namely: size, shape, slope, drainage, vegetation, geology, soil, climate, land use, etc. are considered as important.

1. Size: The size of a watershed forms a basis for further classification into different categories as: a) Sub watershed (100-500 sq. km) b) Milli watershed (10-100 sq. km) c) Micro watershed (1-10 sq. km) d) Mini watershed (less than 1 sq. km) The size helps in computing many parameters like precipitation received, retained and drained off. Large the watershed, more the heterogeneity of the other characters.

Ministry of Agriculture, Government of India proposed a classification of watershed as shown below:

Nomenclature Area (ha) Watershed 50,000 – 200,000 Sub Watershed 10,000 – 50,000 Milli-Watershed 1000 – 10,000 Micro-Watershed 100 – 1000 Mini-Watershed 10 – 100

3. Shape: Watersheds differ in their shape based on morph metric parameters like geology and structure. The general shapes are elongated, triangular, circular etc. shapes determines the length with ratio which affects the run off characteristics like run off time.

3. Physiography: Type of land, its attitude and physical disposition immensely speak about a watershed as to the climate and planning the activities in greening. For example a hilly tract could be useful mainly for trees and plains of populated area could be utilized only for crops.

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4. Slopes: It controls the rain fall distribution and movement, land utilization and watershed behavior. The degree of slope affects the velocity of overland flow and run off, infiltration rate and thus soil transportation.

5. Climate: Meteorological parameters like precipitation, temperature, wind velocity, humidity and evaporation decide and quantitative approach for arriving at water availability in a watershed. Climate is a determining factor for management etc. It determines the flow characteristics and thus erosion behavior.

6. Vegetation: Detailed information on vegetation helps in choosing tie, made and manner of greening the watershed. Information on local species gives a sure guide for selecting plants and crops. It confirms what greenery can be grown and where. With care soil capabilities could be analyzed, compared and profitably confirmed for management.

7. Geology and Soils: Rocks and their structures control the formation of a watershed itself their nature determines size, shape, Physiography, drainage and ground water conditions, soil parameters as to depth, nature, moisture and fertility determine crops. Rock and soils together influence water storage, movement and infiltration.

8. Hydrology: Availability, quantity, and distribution of surface water is basic to the final goal of growing greenery in a watershed. Hydrology parameters help in quantification of water available, utilized and additional exploited resources. They determine the location and design of conservation structures.

9. Socio-economics: Statistics on people, and their health, hygiene, wants, wishes, cattle and farming practices and share of participation are important in managing watershed.

10. Hydrogeology: The demand for ground water is ever on the increase. As such, the appreciation of ground water resources for determining their further availability in the context of conjunctive use of water.

11. Water resources in India: The average rainfall of India is 1194 mm when consider geographical area of 328 m ha this rainfall amounts to 392 million hectare meter of H2O. This may be rounded off to 400 m ha of rainfall including snowfall which is not yet fully determined. Out of this 400 m ha m of rainfall, 75% is received during the South-West monsoon period (June-Sept) and the rest in the remaining 8 months. A major portion of water is soaked with the soil and other is lost.

Problems of Watersheds Although India has enormous potentiality of use water, the watershed areas of the country are suffering from (1) various degradation problems (2) improper land use (3) excessive cropping (4) shifting cultivation (5) slope cultivation (6) over grazing (7) human and animal pressure etc cause severe soil erosion, desertification, siltation of harbour reservoirs and crop lands, floods, droughts, fertility and soil moisture loss and migration. It has been estimated that in India about 5334 mt of soil is eroded annually out of which 29% is permanently lost to the sea, 10% is deposited in reservoirs and 61% is transported from one loss varies from 5.3 to 8.4 mt. It is predicted that 1/3rd of arable land is likely to the lost in 20 years, if the present trend continues. Table 1 shows the land degradation problems of the country.

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Table 1: Land degradation problems in India

S. No. Nature of problem Area ( m ha)

1. Area subject to water and wind erosion 144.13 2. Area degraded through special problem 29.52 a) Water logged area 8.53 b) Alkali soils 3.88 c) Saline soil including sodic areas 5.50 d) Ravines and gullies 3.97 e) Area subject to shifting cultivation 4.91 f) Ravines and torrents 2.73 3. Total problem area 173.65 4. Total flood prone area 40.00 5. Total drought prone area 260.00

Management of Watershed in India It involves management of water, land, energy and greenery, integrating all the relevant scientific approaches appropriate to socio-economic background for a pragmatic development of a watershed. In practice, it means allowing load free rainfall run off from the watershed. Clear outflow imply management of effective soil and water conservation and generating a lush green carpet in whole of the area. In other worlds, it is greening of a watershed through proper management of land, water and energy sources. The comprehensive development of watershed seems to make productive use of all its natural resources and also protect them is termed as watershed management. The Behave terraces in Indonesia and those in Nepal, Mediterranean are examples of integration of human elements into a system of land management, which is an early achievement in watershed management (IAO, 1986). Watershed lies at height as well as along coastal tracts of the sea. However the former laying interior are far in excess than the latter. If the upper watershed is not protected, the conservation measures and progressive approaches along the lower catchment are liable to damage from uncontrolled run off from the upper area is dependent upon the stability of hilly watersheds. Thus the watershed management should commence from upper reaches and progressively proceed towards lower level. It helps in an integrated development of different parts of watershed in accordance with their nature, problems and potentialities. Watershed management is not merely anti-erosion and anti-run off approach but also a comprehensive integrated approach of land and water resources management. The approach is preventive, progressive, corrective as well as curative. Here wasted land resources could be fruit fully harvested into a productive face for rural development.

The Chief Objectives of Watershed Management are: i) Conserving soil and water ii) Improving the ability of land to hold water iii) Rain water harvesting and recharging iv) Growing greenery trees, crops and grasses In order to obtain maximum benefit from technological development, it is imperative that the natural resources, soil and water be properly protected and judicially utilized to improve their

Environmental Issues and Sustainable Agriculture productivity constantly. When a watershed is properly managed for water, it is also property managed for soil and vegetation. Watershed being natural hydrological entities, they respond effectively to various engineering, biological and cultural treatments designed to maximize production.

Management Practices 1. Hydrological Various analysis for different agro-climatic zones and sub-zones of the country have shown clearly that overwhelming majority of the production areas (including some in sub-humid and humid regions) is subject to water stress and drought conditions. This is not only due to low annual rainfall but also erratic distribution during the year and over the years apart from unfavorable rains and improper land use system. Realizing this, hydrological manipulations through cover management and structural (micro) measures had received priority attention. No plant can survive / grow without a minimum quality of water and of appropriate quality. This, the conservation, augmentation and regulation of the supply of moisture vis-à-vis various plant growth stages been recognized as the most important aspect in the redevelopment programme. Since the supply of rainfall is not under the control of human beings, only manipulation of the incident rainfall or ground water could help achieve this objective to a great extent. Again all users, such as plant, animal and man can get water after it has routed through land surface and soil profile. Thus in situ moisture conservation techniques and in-situ and near site water harvesting system should be the pre-requisites in water shed management plans. a) In situ moisture conservation and H2O harvesting system Managing and making available moisture to the primary production systems as well as the plants which are used for stabilization of protection of degraded/degrading areas, is pre- requisite. For in situ conservation over extensive areas, mechanical barriers across the slope have in use both on arable as well as non-arable areas. These are effective to reduce velocity and erosive power of run off and also promote absorption especially in immediate upstream and downstream area. However, for uniform and good performance of plants in terms of regeneration and growth, uniform absorption and distribution of moisture over as large as possible is needed. This is calls for micro treatment such as dead and contour furrows, racking etc. in between the barriers across the slope. Practice of growing grasses and legumes in the intervening area goes a long way to distribute the benefit of conservation and augmentation of moisture over extensive area. Complete replacement of mechanical barriers by vegetative ones may be possible only at some sites where slope is not very steep, over land run off is not a very big problem and process of erosion is not very advance. More important and technically sound measure is to develop the net work of micro water harvesting structure over extensive areas. This would directly enhance the possibility of quicker establishment of plants and their better growth and development. There is a scope to improve design specification and lay out of such systems specially by adopting some of the details from the traditional system such as nullah ploughing, nullah bunding, bunches, small ponds and other models in use for generations in arid, semi-arid and even in sub-humid areas. b) Cover Management The moisture conservation and augmentation would not be lasting by themselves. All these measures need to be taken up with the complementary support of vegetative regeneration. In many areas, the pressure of livestock and small and marginal farmers and landless labourers are great. These areas must yield in short term and number of produce such as fodder, ,fuel, wood and small items for consumption by promoting appropriate agro-forestry models with distinct thrust on

Environmental Issues and Sustainable Agriculture improving hydrologic regimes. The relation between contributing areas to storage and submergence area of micro structure need to be critically studied and appropriate guidelines developed for varying site conditions. Similarly interrelationship between volume and recharge and area of rense call for better analysis, for identification of indicators that will help developing design specification. For selection of plant species, greater understanding of the root-system and the contribution to expansion of soil volume that increases watershed retention needs to be studied and appropriate norms should be provided.

2. Biological Initial thrust of biological measures has been to increase the vegetative cover of varied quantity. But in mid seventies stress on trees seem to have edged out other plant species such as bash, shrub, grass and other legumes. In degraded areas, establishing and promoting tree growth at a faster rate which can protect the land is difficult at least for a period of two years. Hence the emphasis should be equally on grass and legumes so that a ground cover and quick incorporation of organic residues, including additional nitrogen could be achieved. Emphasis showed is on growing legumes grasses, which not only enrich soil but also offer good fodder which is extremely in short supply all over the country. In respect of biological measures, mono-planting needs to be replaced by mixed plantation. For selection of species their impact on hydrologic regime should receive more scientific consideration. For degraded lands emphasis should be given to grasses legumes of reduce no. of trees ha-1 substantially. The strategy to achieve maximum dividend would include different innovative models of agro forestry. According to the need of the area to model should include livestock management, donkey, viniculture and sericulture to generate economic activities besides small scale enterprises based on biomass.

3. Bio-inputs Reasonable research evidences are available to open a new dimension in accelerating the pace of establishment and growth of vegetation in degraded areas particularly arid lands, mixed areas, coasts and those affected by industrial and urban wastes, the application of bio-inputs such as mycorrhizae, rhizobiun, and organic chemicals like bactrin, natrin, phospin, etc. to overcome various limitations and increase tolerance of the plants to water stress, chemical imbalances etc. In the watershed management programme, application of these new bio-inputs has yet be initiated and popularized.

4. Waste reuse The sewage and garbage from the urban settlements and industrial affluent are being disposed through dumping on the low lying areas or wet lands and discharging into water bodies as well as agricultural and other lands. These have been not only polluting water and degrading environment but also rendering large areas unproductive. In the other hand, the nutrients and the fresh H2O available in these waste products have been successfully used by many in greening and also growing many consumable items. As there are contamination hazards, watershed management programme may at least initiates utilizing waste H2O and garbage as a source of nutrient and H2O for redeveloping the degraded areas which such risks don’t exist or can be utilized.

5. Land management Land management is another very crucial factor in watershed management. Proper land management decreases the runoff loss, increases H2O recharge and keeps the soil fertile. The management practices are:

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i) Ploughing: Plough and ploughing are part of village life. Ploughing along the slope increases runoff, loses 50-80% of rainfall, decreases soil moisture and finally erodes soil. Just ploughing along the contains, soil erosion can be reduced upto 50 per cent. ii) Furrowing: Ploughing deeper for even 2-10 lines is another measure for consumption. This practice coupled with intercropping and hedging give good results. Ploughing leaves minor furrows and they harvest rainwater flows. This process is further accelerated by double ploughing along the row for a chosen spacing depending upon the scope. If hedging and planting are carried out, this practice contains > 50 rainfall. A broad bed and furrow system (BBF), involving graded, wide beds separated by furrow draining into grassed water ways in experimented by ICRISAT with good results. The BBF system is laid out on grades 0.4-0.8% for optimum performance. The raised position acts as bund ensuring soil stability while the shallow furrows provide change and erosion. This system is flexible with variables spacing for accommodating different crops, continuous furrowing along the contours and ridge development across the furrows is another practice adopted in low rainfall regions for cent percent harvesting. iii) Trenching: Narrow excavation along the contours is another conservation technique. The economical dimensions are 0.3 m width and 0.6 m depth in lands with low slopes or good rains. While the dimensions can be interchanged in gently sloping fields or when low intensity rains are common. Whereas the degree of erosion is very high due to soft soil, intensive rains or high run off and velocity, higher dimension of the trenching are to be adopted. This soil excavated is to be conveniently but as a bend on the down slope side. Trenching proves to be a good conservation technique, especially when plants are grown along the trench for utilizing the high moisture available along the trench. iv) Bunding: Bunding along the contours controls the erosion very effectively. In well drained red soils in low rainfall areas, bunding is an accepted practice. The existing stream system is utilized as waterways. Furrow bunding is the only option in certain sleep sloping lands. There are 3 types of bunding, graded, inter and compartment. Graded bunding consists of bunding with 0.2% gradient for checking he overland flow. For accommodating storm rain water, water way system is developed using the existing streams. For efficient soil conservation gully stabilization measures are a also carried out. In interbunding, gaps are left alternatively for conserving more rainfall through reversing the direction of water spreads in between the beds. In this method, the computation must be precise. In compartmental bunding the lands are bunded perpendicular to contour also for cent per cent harvesting of the rainfall in semi-arid and desert regimes. It is an excellent practice for growing greenery in low rainfall regions. v) Gradoni: Narrow trenches built along contours for collecting overland flow and increasing soil moisture is known as gradoni. They are either continuous, intermittent or build for individual plants. In slopes upto 30% level trenches are built; on steep slopes of 30-70% reverse sloped trenches are practiced; while for dissected slopes with undulating terrain short or individual gradoni are prepared. For uniform slopes, continuous gradoni, synonymous to minor trenching are prepared. vi) Hedging: The method not only solves the conservation problem, but also produces biomass and stabilizes the ground further by root system. No additional costs are involved. Though vetiver

Environmental Issues and Sustainable Agriculture grass is strongly recommended, subabul hedging produces good biomass for feeding the cattle with nutritious feed. Hedging gives excellent results in catching rain water and improving soil moisture. It also forms a wind breaker contains even storm winds as system on regional scale. Hedging is practiced from gentle to moderate sloping lands for increasing crop yields. Hedges are grown either the furrows, trenches or a bunds. They are grown across the stream for conserving flood load. When practiced in combination with other methods, they conserve almost all the rain water in drought prone areas. vii) Terracing: Bunding and terracing are common practice among the Jamaican high lands. The effectiveness of terraces depends also on green cover management. Bench terraces are a series of uniform, continuous, level strips running across the slope at vertical intervals supported by steep banks. The banks are built by earth and protected by grass or easily accessible racks. They are good for irrigation utilizing the rain water and interflow between the rains. In high rainfall regions outward slopes benches allow free flow of water without benching the terraces. In low rainfall region reverse scope terraces help in water harvesting. These two types of terraces are used for crops mainly. One advantage of sloped terraces is that the cost of banks or raiser is reduced. Intermittent terracing is another combination of level benching with outward sloping terraces. In hill side ditches, level benching and onward sloping berth terraces are combined. This practice is good for semi-permanent rainfed crops. Individual basins and outward terraces are narrow benches alternating with-inward slopes. Fruit plants can be implanted either in pits or basin depending upon the soil profile and water requirement. Hexagon pattern is practiced in this system in heaving rainfall regions for crops requiring good transport routes. In convertible terraces, bench terraces sand witching the basin. This practice is ideal for mixed farming. The slopes of all these terraces are protected by grasses or crops. viii) Measures against shifting cultivation: Agro-horti-pastoral system is a good alternative the shifting cultivation. Here top sleep hills are used for forest trees followed by horticulture and the lower portion is used for agriculture. Local resources based soil and water conservation measures like contour bund, bench terraces, half moon terraces and grass ways are adopted. Watershed based farming system thus ensures adequate protection of land against soil erosion, retain maximum rain water without affecting the crop and the harvested water can be reutilized for pisciculture or any other purpose according to local used.

Steps involved in integrated watershed development 1. Crop production assumes importance in watersheds. It is essential to practice in situ moisture consummation and water harvesting. 2. In crop production, priority is for intercropping. 3. Crop substitution, depending upon suitability of soil, can ensure higher returns. 4. Site specific crop production techniques have to be adopted. 5. Afforestation component has to be planned carefully and implemented vigorously so as to provide for the farmers affordable access to fuel, timber and wood, cultivable wastes and marginal lands should be used for this purpose. 6. Dryland horticulture will help to minimize risk and offer scope to improve returns particularly from marginal lands. 7. Discouraging of rice cultivation under existing irrigation facilities and using the water elsewhere. 8. More efficient exploitation and use of ground H2O, coupled with conjunctive use of rain H2O and using it for high value horticultural crops. 9. More efficient use of irrigation water under all resources of water supply.

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10. Encouraging other components of farming system e.g. dairying etc. 11. Stall fed goat and sheep farming, needs to be popularized. 12. Sericulture and ber keeping had to be intensified. 13. Processing of farm of horticultural produce into value added products offer scope for off- season occupation besides ensuring higher returns. 14. Custom hire services at the village level such as ploughing, plant protection, harvesting etc. will provide employment. 15. The extension and training programme should equip the farmers to respond to the emerging complexities of agriculture.

Principles of Watershed Management The main principles of watershed management based on resource conservation, resource generation and resource utilization, are: (i) Utilizing the land according to its Capability; (ii) Protecting productive top soil; (iii) Reducing siltation hazards in storage tanks and reservoirs and lower fertile lands, (iv) Maintaining adequate vegetation cover on soil surface throughout the year, (v) In-situ conservation of rain water, (vi) Safe diversion of excess water to storage points through vegetative waterways, (vii) Stabilization of gullies by providing checks at specified intervals and thereby increasing ground water recharge; (viii) Increasing cropping intensity and land equivalent ratio through intercropping and sequence cropping (ix) Safe utilization of marginal lands through alternate land use systems with agriculture - horticulture - forestry - pasture systems with varied options and combinations; (x) Water harvesting for supplemental and off season irrigation; (xi) Maximizing agricultural productivity per rage at convenient locations for unit area per unit time and per unit of water. (xii) Ensuring sustainability of the eco-system befitting the man-animal- plant water complex. (xiii) Maximizing the combined income from the inter related and dynamic crop- livestock- tree-labour complex over years; (xiv) Stabilizing total income and to cut down risks during aberrant weather situations; (xv) Improving infrastructural facilities with regard to storage, transportation and marketing of the agricultural produce; (xvi) Setting up of small scale agro industries; and (xvii) Improving the socio-economic status of the farmers.

Objectives of Watershed Management As mentioned earlier, watershed management is enshrined with the concept of sustainability meeting the needs of present population without compromising the interests of future generations. It is multi-pronged approach for steady uplift of masses living in the area. The main objectives of this multipurpose programme can be described in symbolic form by the expression: “Power”. Here the letters symbolize the following: P = -Production of food –fodder- fuel – fruit – fibers – fish – milk combine on a sustained basis - Pollution control - Prevention of floods O = - Over exploitation of resources to be minimized by controlling excessive biotic interferences like over-grazing. 64

Environmental Issues and Sustainable Agriculture

- Operational practicability of all on farm operations and follows up programmes including easy approachability to different locations in watershed W = - Water storage at convenient locations for different purposes - Wild animal and indigenous plant life conservation at selected places. E = - Erosion control - Eco – system safety - Economic stability - Employment generation R = - Recharge of ground water - Reduction of drought hazards - Reduction of siltation in multi – purpose reservoirs - Recreation The above objectives can be achieved by planning and implementing the programme in a systematic way with active participation of farmers including constitution of Cooperative Watershed Management Societies. Rather, as a convention not as a rule following guidelines may be followed: 1. The implementation programme should start from the ridge line of the watershed tothe valley - not on piecemeal basis in isolated patches. 2. Development of both arable and no arable lands should be done together. 3. Forest, pasture, cultivable land and waste lands should be treated as inter-linked units of hydrological entity. The condition of all lands has to be improved to meet the demands of increasing man and animal population. 4. Essentially, all developmental activities are to be carried out on watershed basis – whole watershed area needs to be covered – may be in planned phases. However, treatment of some lands lying outside the watershed- but geographically contiguous - can also be taken up based on socio-economic con-sidentions.

Components of Watershed Management Programme The main components of watershed management are: 1. Soil water conservation and water harvesting. 2. Crop management 3. Alternate land use systems Successful implementation of the above three components in the watersheds would lead to the development of livestock, poultry, pisciculture and other associated and allied activities, finally resulting in improved standard of living of the farmers and rural masses.

Soil or Water Conservation and Water Harvesting Soil and water conservation measures coupled with water harvesting help to improve the moisture availability in the soil profile and surface water availability for supplemental and off-season irrigation. The interventions through soil conservation measures have greater role to play in transferring a part of surface water to ground water by recharge. Based on the nature and type of hydraulic barriers and their cost, the conservation measures in arable lands can be divided into following three categories. 1. Hardware treatments 2. Medium software treatments 3. Software treatments

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Hardware Treatments Hardware treatments are generally of permanent type, provided for improvement of relief, Physiography and drainage features of watershed. These are erected with major Government support with the purpose to check soil erosion, regulate overland flow and reduce peak flow. At times, they are imposed to completely divert the upland run-off from running into downstream fertile lands. -Different hardware treatments are explained below.

Waterways Quite often, high run-off volumes are observed, even in drylands, particularly in watersheds located in sloppy areas. Such run-off water should, therefore, be channelized through a few waterways; as far as possible some of the existing waterways may be developed. Waterways draining larger areas may be designed on hydrologic and hydraulic considerations. No doubt, at places, sizeable land strip may be occupied by such waterways, but his may be found highly advantageous for the survival of May multi-purpose useful trees when planted along the waterways. Depending upon land situations alignment of small size waterway may be adjusted with field boundaries; at times, such arrangements are especially useful for safe guarding crops against over stagnation of rain water in black soil areas. Such water course may also be safeguarded against erosion by providing mechanical checks and also by raising vegetation which may be useful fodder for animals. In some salutations, waterways may also have a small section side bund with necessary openings at water entry points.

Bunds These are low height earthen embankments constructed across the slope in cultivated lands after deciding location of waterways. The bunds function to intercept runoff, increase infiltration opportunity time and dispose excess rainfall safely. Such bunds can be either contour bonds or graded bunds; many a time, these bunds are adjusted with field boundaries, if deviation from grade or contour is not too much; no doubt, spacing depends on many engineering considerations. Contour bunds are recommended in dry farming areas with light textured soils of slopes upto 6 per cent and where annual rainfall does not exceed 600 mm. They are designed for an expected run-off of 24 hours duration and 10 years frequency. Surplussing arrangements (waste weirs) are provided to dispose of the excess run off beyond the design storage. The cross section area of contour bunds follows the depth and type of soil; however, 0.5m2 is minimum (Bali, 1988). Graded bunds are constructed in medium to high rainfall areas in poor permeable soils (vertisols), having 2 to 6 per cent slope. They are also quite s6itable for the soils having crust formation tendency like red 'chalka' soils of Telengana region of Andhra Pradesh. -By and large, graded bunds with 0.3 to 0.5 in section are constructed with longitudinal gradient of 0.2 to 0.4 per cent depending on the site condition (Singh et al.1990). Graded bunds particularly are made with the following objectives: (i) To reduce run-off; (ii) To reduce soil loss; and (iii) To divert run off. Thus, graded bunds along with waterways and water harvesting structures not only check soil erosion, but they also provide an ideal rain water management system for many watershed situations. For making bunds, required soil may generally be taken from lower side. Sometimes, excavations and pits for making bunds - in deep black soil areas particularly are made on upper side. But these may be got leveled or ploughed up as early as possible after bund constriction. Invariably -barring a few situations -borrow pits should be made on lower side at the places where 66

Environmental Issues and Sustainable Agriculture the bunds drain into waterways. In real field situations, bunds are covered with natural grass and in most cases, these are dependable sources of forage. In addition, quite often some trees also comp up in their close vicinity, to the liking of cultivators. In some places loose stones are easily available; hence stone bunds are quite advisable in such pockets.

Terracing Cultivated lands having land Slopes a 10 per cent particularly in hilly areas - should be put under bench terracing by converting the lands into series s of platforms. The width of bench terrace depends on the land slope and the permissible depth of cut. Bench terracing is very much effective in reducing soil erosion in hilly areas. At Ootacamund, it has helped in bringing down the annual erosion rate from 39 t/ha to less than 1.0 t/ha on 25 per cent sloping lands (Jayakumar et al 1982). At places where scattered stones are available, loose stone walls can be made to act as risers for bench terrace construction. Zing terrace consists of a contributing (donor) area with mild slope and a receiving levelled area at lower side - half to one third of the donor area. They are particularly suited for areas having medium to deep soils (Joshi 1976).

Medium Software Treatments Medium software’s are also provided particularity as interbunding treatments, where field sizes are large and conventional bunds are constructed along field boundaries. Such treatments are usually of semi-permanent type and are adopted to minimize the velocity of overland flow. They may need major initiative from cultivators in addition to some grants from the Government side. Such measures may last 2 to 10 years; vegetation component and land configurations at times may also provide some direct returns on short term basis. However, they need to be modified at times to maintain effectiveness for erosion control and moisture conservation, and also to minimize risk of providing shelter to harmful pests in and around these measures and in certain situations like taking up corrective measures to avoid too much spread of intro deiced vegetation and being counter-productive.

Small section/key line bunds: A small section bund may be created across the slope at half of the vertical bund spacing. Such bunds can be nearly 0.1 m2 in section; may be renovated at an interval of 2 to 3 years.

Strip Leveling: About 4 to 5 in strip of land above the bund across the major land slope may be levelled for the purpose. Similarly, one or more strips can be created at mid length of slope. Such strips can be created by running blade harrows after ploughing the field with mould board or disc plough. Such minor rough leveling programme may be taken up after every 2 to 4 years.

Live beds: One or two live beds (2-3 m wide) can be created either on contour or on grade in the inter bund space. The vegetation on the beds may be according to the liking of cultivator, it can be annual or perennial or a combination of both.

Vegetative/live barriers: One or two barriers of close growing grasses or legumes can be created along bunds as well as at the mid - length of slop~ to filter the run-off water or slow down, overland flow. Khus could be one of such vegetations. Several other promising grass species that serve as valuable fodder for cattle are being explored as an alternative to Khusgrass. A miniature bund at lower side of barrier is recommended to help in the development of live barriers, particularly in the initial stages.

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Software Treatments A mention was made that hardware type land treatments are useful for safe run-off disposal and similarly, medium software’s are essential to slow down the velocity of overland flow in cultivated fields. However, on several occasions, these are found inadequate in attaining equitable moisture distribution for crop growth. In such cases software treatments are taken up for ensuring fairly uniform soil moisture for satisfactory crop performances. By and large, software treatments are temporary in nature; in that case these are required to be remade or renovated every year. The entire cost of applying such treatments is to be met by the farmers. Because of favorable econornics, a few of these treatments have gained wide acceptance in the recent years.

Contour Farming Contour farming is one of the - easiest and most effective and low cost method of controlling erosion and conserving moisture. With contour fanning, tillage operations are carried out along contours. It creates numerous ridges and furrows for harvesting sizeable amount of runoff inside the field itself.

Compartmental bunds: Compartmental bunds, converting the area into square/rectangular parcels - are useful for temporary impounding of water for improving Moisture status of the soil. These are made using bund formers. In medium deep black soil, they are found advantageous in storing the rainfall received during the rainy season in the soil profile - there by augmenting the soil moisture. for-use by rabi crops. The size of the compartments may be fixed' considering the size, of the inter bunded land.

Broad bed and furrows: Broad bed and furrow system furrows. This technique is especially suited to black soils, where crops are sown on pre-formed beds. This system is made before the season and is maintained year after year. The planting is done on the bed. Generally, the depth of each furrow is kept 0.15 rn and the inter -furrow spacing is maintained at 1.5 m (ICRISAT, 1983).

Dead furrows: Dead furrows are laid across the land slope in rolling lands, to intercept the run-off. The spacing between dead furrows varies between 2 to 5 m or 4 to 7 crop rows. This system works well in alfisols (Singh and Rao, 1988).

Tillage: Tillage operations help in rain water infiltration. Off- season tillage, in particular, has been found quite useful in most rainfed areas. The tillage operations make the soil receptive to rainfall. This practice is very useful in light soils often prone to crusting.

Mulching: Surface mulching protects soil against beating action to rain drops and it also increases water infiltration into the soil. Further it helps in minimizing water evaporation from soil surface. Sometimes dry soil mulch created simply by stirring the soil has been found effective for good performance of crops.

Soil and Water Conservation in Non-Arable Lands Control grazing is one of the simplest approach in reducing soil loss from denuded sloping lands. As seen from the experiences of Operational Research Projects, soil and moisture conservation measures are required even in the non- agricultural lands. These practices include contour and staggered trenches and contour furrows. They help in accelerating vegetation establishment, encouraging natural regeneration of species and combating soil erosion. Contour and staggered trenches are usually spaced 10 to 20 m apart across the slope for raising forest species. In general, 0.45 m wide trenches with 0.45 m depth are made at regular intervals. 68

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Sometimes in place of trenches, contour furrows are formed. At a spacing of 2 to 10 m (Singh et al. 1990). In rocky areas, crescent bunds of loose boulders are constructed in place of trenches. All the above stated measures are useful in slowly regaining the lost forest cover and fertility of most, degraded grasslands; community efforts in the right directionare likely to make major dent in re-greening such areas.

Water Harvesting Measures Since time immemorial, several kinds of water harvesting structures have been in practice in our country. Recently, local experiences and precedence’s were utilized for designing these structures. In order to bring cost effectiveness, efforts are also necessary to harmonize the designing of water harvesting structures based upon traditional wisdom and scientific contemplations. In3act, farm ponds, surface water tanks and percolation tanks need to be viewed as 'conservation structures in addition to sources for supplemental irrigation. In real watershed situations, ponds maybe located in conjunction with waterways - some maybe of a few hundred cubic meter size, .whereas couple of structures may be of bigger size. In selected pockets, integrated catchments -cum - command approach should be followed. To ensure proper storage in light soils, some of the ponds can be lined with sealant materials. All large ponds have to be constructed at Government cost. All such structures are likely to recharge ground water reservoir. When located in proper co-cultural hydrologic matrix, in conjunction with other factors, they also help in reducing load on ground water aquifer. It may be advisable to work out design details of all the required structures in the first phase of the project, no matter construction of a few of these may have to be deferred - may be planned to be taken up in drought years to provide employment to the rural folk. The objectives of water harvesting structures are: i) To store water for supplemental and off season irrigation; ii) To act as silt detention structure; iii) To recharge the ground water; iv) To raise aquaculture species; and v) Recreation and allied agricultural uses. Thus in most situations, in addition to reviving traditional water harvesting systems, other measures are also needed. Some of such typical water harvesting structures adopted in watersheds is as follows:

Minor irrigation -tanks: Minor irrigation tanks are constructed Ross the major streams with canal system for irrigation purpose by constructing low earthen dams. A narrow gorge should be preferred for making the dam in order to keep the ratio of earthwork to storage as minimum. The height of the dam may vary from 5 to 15 m. The tanks are provided with well-designed regular and emergency spill-ways for safety against side cutting. In micro watersheds, water harvesting boundaries, similar to small scale irrigation tanks are also recommended. By and large, the water harvesting boundaries are not integrated with extensive canal system.

Farm ponds: Farm ponds are typical water harvesting structures constructed by raising an embankment across the flow direction or by excavating a pit or a combination of both. Dug out ponds in light soil require lining of the sides as well as the bottom with suitable sealants. This is not the case with heavy black soil. Considering the benefit of the harvested water, different type of linings, viz., brick, concrete, HDPE, etc. may be used.

Nala bunds and percolation tanks: Nala bunds a percolation tanks are located in the nalas having permeable formations with the primary objective of recharging the ground water. A strict regulation on the silt load entering the downstream reservoirs is an additional ad vantage of

Environmental Issues and Sustainable Agriculture percolation tanks. The percolation tanks encourage the digging up of wells downstream of recharged area for irrigation purposes. The percolation tanks are provided with emergency spillways for safe disposal of flow during floods.

Stop dams: Stop dams are permanent engineering structures constructed for raising the water level in the nala for the purpose of providing life saving irrigation during drought periods. These are located over flat nalas at narrow gorges carrying high discharge of long durations. They are created over stable foundation conditions where hard murrum or rocks are encountered. For the stop dam, a site with larger water storage capacity would be desirable.

Crop Management The rainfed areas of our country contribute about 45 per cent of the total food grain production. In the watersheds there is scope of increasing the overall productivity by adopting the integrated farming systems approach. For achieving sustainability in crop production in the watersheds due importance is given to : (i) evolve and follow up simple and low cost crop production technology including improved varieties, (ii) provide alternate crop production technologies to match weather aberrations; and (iii) optimize the use of natural resources like land and water. Considering the availability of rain water over space and time, different crops have been identified as given in Table 4 for different rainfall zones. Depending on the water availability periods, examples of some selected crops for rainy season and post rainy season are given in Table 5. Many drylands of the country are not only thirsty, these are hungry as well. Optimum doses of fertilizers are, therefore, recommended for the crops depending upon physico-chemical properties of soil. And farmers are advised for proper crop residue management stubbles of the plants being left in the field for decomposition and building up the fertility. However, major breakthrough has yet to be achieved in cropping systems in the watersheds by changing over to organic farming with tree based cropping programmes. The research work is being initiated on these lines through alternate land use systems.

Alternate Land Use Systems In the watersheds, most of the uplands are degraded and these are also marginal lands with low productivity level. Due to the population pressure, more and more marginal and sub marginal lands are being brought under cultivation. Apart from being uneconomical in the long run (with more inputs), cultivation of such lands, can lead to serious in balances in the eco-systems. For such lands, some alternate efficient land use system other than arable cropping would be desirable. In alternate land use system, by encouraging tree and grass components, the demand for food and fodder can be solved To some extent, thus, stability in production will be achieved along with the safety of environment. As seen from some model watersheds alternate land use systems not only help in generating much needed off-season employment but they also help in utilizing off- season rain which may otherwise go waste.

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Table 4: Agro-ecological conditions in different rainfall zones of India

Mean Predominant soil types Mean annual Length of growing Predominant annual temperature season under rainfed crops rainfall (0C) rainfed condition (mm) (days < 400 Sandy 20-30 30-80 Grasses, Pearlmillet 0-10 30-90 Short duration pulses 400-1000 Sandy soils (Aridisols); 20-30 80-200 Pearlmillet, Red soils (Alfisols and sorghum maize, relates soils); oilseeds, pulses Black soils (vertisols and - - Cotton vertic inceptisols) 1000-1800 Alluvial soils (Entisols); 20-30 200-300 Maize, Paddy, Laterite soils (Alfisols and wheat, Barley, relates soils); Black soils Mustard and (vertic and vertic Soybean inceptisols) > 1800 Sub-montane soils 15-20 > 300 Paddy, plantation (inceptisols) crops Source: Singh and Das (1989).

Table 5: Major efficient food crop-based double cropping systems for different rain dependent regions of India (based on water availability periods)

Water availability period (days) Rainy season crops Post rainy season crops 110-150 Cowpea/blackgram Safflower/seasons crops Soybean Mustard/safflower Green gram Chickpea/barley 150-175 Green gram Sorghum 175-200 Cowpea Sorghum Green gram Safflower Balckgram Barley/mustard Pearlmillet Chickpea Maize Wheat/wheat+ Chickpea/mustard Rice Chickpea Sesame Chickpea 200-250 Sorghum/groundnut/maize Safflower Soybean Wheat Safflower/chickpea Soybean/maize > 250 Rice/maize/fingermillet/groun Wheat/chickpea/linseed/lent dnut pearlmillet il/ horsegram/barley Soybean Fingermillet Pearlmillet Wheat Source: Singh and Das, (1989)

Environmental Issues and Sustainable Agriculture

In general, land capability classes are the determinant factors for deciding different alternate land use options. By and large, in land classes I to Ill, arable farming can be practiced and beyond that lands should be utilized for forestry and grassland management from economic considerations, agro forestry potions - integrating farming with other land uses like horticulture, agriculture and pasture may find acceptance from the farmers. The evaluations of all these systems are under research investigations. The tree component of the system should be selected according to the soil and climatic conditions. The trees should preferably have the characteristics like fast growing with high palatability, good coppicing ability, and drought resistance also having properties like adding organic manure in soil profile. The pasture component in such systems should have the characteristics like growing well even under shade, drought resistance, easy propagation, high palatability, conserving soil and moisture, withstanding over-grazing etc. Different legumes like style species and grasses including Cenchrus species have been found performing well in many situations. Dryland horticu1ture is promising enterprise in slightly favorable soil conditions especially where there is provision of water harvesting. In this hardy fruit species such as ber, pomegranate, custard apple, guava and aonla may have to be preferred over others.

Reference Bali, Y.P. (1988). A review of soil and water conservation strategies. Proc. Ist meeting of working group on soil and water conservation for formulation of Eighth plan. ICRISAT (international Crops Research Institute for the Semi-Arid Tropics).(1983). Annual Report 1982, 262-264. Joshi, P.G. (1976). Soil and Water Conservation Techniques. Government Text Book Press, Mysore, India, I221. Rai, L., Singh, U.N. and Singh, S.R. 1989. Drylands of Mirzapur spring to life. Indian farming 39(9): 2123. Singh R.P. and Das, SK (1989). Agronomic aspects of plant nutrient management in rain dependent food crop system in India. Paper Presented in FA01FIAC. Technical Sub-Committee Meeting, Rome. Singh, R.P., Sharma, S., Padmanabhan, M.V., Das, SK and Mishra, P.K. (1990). Field Manual on Watershed Management. CRIDA, Hyderabad. Singh, S.P. and Rao, U.M.B. (1998).Rain water management for stabilizing productivity of drylands, Indian Drylands Agri. Res. & Dev., 3(3): 203-214.

Environmental Issues and Sustainable Agriculture

Chapter-11

Hybrid Cooling System: A Review

Soumitra Tiwari1 and Yashwant Kumar Patel1 1 Assistant Professor, Department of Food Processing and Technology, Atal Bihari Vajpayee Vishwavidyalaya, Bilaspur, Chhattisgarh, India Email: [email protected]

Introduction Refrigeration is the process of lowering and maintaining a temperature below the surroundings. The aim to cool some product or space to the desired temperature. The refrigeration commonly used to maintain the closed surrounding temperature for living places and for retard the decay and maintain the freshness of the perishable food products. Refrigeration systems are also used extensively for providing thermal comfort to human beings by means of air conditioning. Air Conditioning refers to the treatment of air so as to simultaneously control its temperature, moisture content, cleanliness, odour and circulation, as required by comfort living, or products in the space. Vapour compression system (VCS) widely used for refrigeration cycle of air-conditioning of residential, offices and domestic refrigerators and warehouses. It consumes more power and increase the Chlorofluorocarbons (CFC) level in the environment leading to depletion of ozone layer. Hybrid system integrates a desiccant dehumidifier with a conventional cooling system (Evaporative Cooling System (ECS) or VCS), that the dehumidifier deals with the latent heat load and the conventional system with the sensible heat loads. Hybrid desiccant systems offer the advantages of independent control of temperature and humidity, reducing energy cost and often equipment size. These type of systems were heavily investigated in the late 1980’s and the early 1990’s by many thermal engineers (Sherman and Walker, 2007). They have been shown to give significant improvements to the COP of the cooling system (Ling et al., 2011).

Working Principle Desiccant cooling systems work on the principle of desiccant dehumidification and cooling. Their unique merit is that the sensible and the latent heat can be processed separately. Thus they are advantageous particularly in hot and humid climates. They can have access to various low grade thermal energy resources, such as solar energy, waste heat, etc. (Henning et al., 2001; Subramanyam et al., 2004). Reduction in the energy consumption and enhancement of the cooling efficiency is the most important proven result of coupled desiccant and traditional cooling system that consequently causes decrease in the amount of the carbon dioxide emissions (Zhang et al., 2003; Liu et al., 2007). Desiccant systems are quite efficient in dealing with the latent load, but considerably less so with regard to the sensible load (Gommed and Grossman, 2002). Desiccants in either solid or liquid forms have a natural affinity for removing moisture based on differences in vapor pressure. For this property, desiccants have been widely applied to marine cargo, pharmaceutical, electronics, plastics, food, storage, etc. (Wurm et al., 2002). Desiccant removes the moisture from the air with release of heat i.e. latent heat becomes sensible heat. The dried warm air can then be cooled to desired comfort conditions by sensible coolers viz. evaporator coils, heat exchangers and refrigeration. To re-use the desiccant, it must be regenerated or reactivated through a process in which moisture is driven off by heat from an energy source such as electricity, waste heat, natural gas, or solar energy.

Environmental Issues and Sustainable Agriculture

Types of Desiccant Desiccant materials attract moisture based on differences in vapor pressure. Due to their enormous affinity to adsorb water and considerable ability to hold water (La et al., 2010). As desiccants can be either solid or liquid.

Solid Desiccant The generally used solid desiccants include silica gel, natural and synthetic zeolites, activated alumina, titanium silicate, synthetic polymers, lithium chloride, etc (Dai et al., 2001; Kanoglu et al., 2004; Cui et al., 2005, Hirunlabh et al., 2007; Jia et al., 2006). It's have strong adsorption capacity but the regeneration temperatures of them are higher than 100 oC.

Liquid desiccant It is a substitute of the solid desiccant and relative technologies are developed quickly recently years owing to the following advantages. Firstly, their operational flexibility and their capability of absorbing pollutants and bacteria (Oberg and Goswami, 1998).Secondly, compared to the solid desiccants, they are generally regenerated at relatively lower temperature (less than 100 0C) (Grossman 2002), this will improve the COP of system greatly. Thirdly, there are no overtaking air and discontinuous running problems in the whole system. Materials typically used in liquid desiccant systems LiCl, LiBr, CaCl2, and KCOOH, LiCl + LiBr solution etc.

Desiccant with Cooler (Evaporative Cooling) ECS assisted desiccant air-conditioning systems can represent a reliable alternative to the vapour compression systems for space cooling (Henning, 2007). In these systems, air is dried by passing through a bed of adsorptive material to adsorb moisture. When the desiccant is saturated, hot air is passed through the bed to release moisture. A number of studies have investigated the design performance of various desiccant cooling and desiccant hybrid cooling cycles ( Dhar and Singh, 2001; Liu et al., 2007; Hao et al., 2007).

Rotary Wheel The desiccant wheel is the most popular solid desiccant carrier and has a similar shape to the enthalpy exchanger wheel. Solid desiccant ES consists of desiccant wheel, energy conservation wheel (ECW) and direct evaporative coolers (DEC). For the desiccant wheel, solid desiccants are attached on the wheel fins; it then absorbs moisture from the fresh air and hot regenerator air is required to recover the saturated adsorbents. But for the enthalpy exchanger wheel, it mainly carries the heat/mass exchanger between indoor and outdoor air streams and does not need extra regeneration energy.

Figure 1: Desiccant wheel working principle 74

Environmental Issues and Sustainable Agriculture

Desiccant with Air Conditioner (Refrigeration Cooling System) The dehumidifier and regenerator are the key components of the hybrid desiccant cooling system. The hybrid cooling system consists of a vapour compression system, efficient in sensible cooling, and desiccant dehumidifiers, efficient in removing latent heat load.

Conclusion The vapour compression refrigeration system is the costlier due to it consume more electric energy in energy conversion. The food products needed being storage for ensure the availability in off season and increase the shelf life. The perishable food also needed storage in high relative humidity environment to hold back moisture migration and quality of food. So, strongly needed low cost refrigeration system, it has been accomplished by the clubbing dessert cooler and air-conditioning with desiccant system. The hybrid cooling system with desiccant is cheaper to conventional cooling system, which is ground-breaking in agriculture storage system.

References Cui, Q., Chen, H., Tao, G., Yao, H. 2005. Performance study of new adsorbent for solid desiccant cooling. Energy 30, 273-279. Dai, Y.J., Wang, H.F., Zhang, H.F. 2001. Parameter analysis to improve rotary desiccant dehumidification using a mathematical model. Int. J. Therm. Sci. 40, 400-408. Dhar, P.L., Singh, S.K., 2001. Studies on solid desiccant based hybrid air-conditioning systems. Appl. Therm. Eng. 21, 119–134. Gommed K., Grossman G. 2002. A liquid desiccant system for solar cooling and dehumidification, in: Proceedings of the International Sorption Heat Pump Conference, September 24-27; Shanghai, P.R. China, pp. 655-660. Grossman G., 2002, “Solar-powered systems for cooling dehumidification and air conditioning”, Solar Energy, 72:53-62. Hao, X., Zhang, G., Chen, Y., Zou, S., Moschandreas, D.J., 2007. A combined system of chilled ceiling, displacement ventilation and desiccant dehumidification. Build. Environ. 42, 3298–3308. Henning H.M. 2007. Solar assisted air conditioning of buildings an overview. Appl Therm Eng;27:1734-49. Henning H.M., Erpenbeck T, Hindenburg C, Santamaria I. S. 2001. The potential of solar energy use in desiccant cooling cycles. International Journal of Refrigeration, 24(3) : 220–9. Hirunlabh J, Charoenwat R, Khedari J and Teekasap S. 2007. Feasibility study of desiccant air conditioning system in Thailand.Building and Environment 42:572-577. Jia CX, Dai YJ, Wu JY, Wang RZ. 2006. Experimental comparison of to honeycombed desiccant wheels fabricated with silica gel and composite desiccant material. Energy Conversion and Management; 47(15–16):2523–34. Kanolu M, C arpınlıolu MO, Yildırım M. Energy and energy analyses of an experimental open-cycle desiccant cooling system. Applied Thermal Engineering 2004;24(5–6):919–32. La D., Y.J. Dai, Y. Li, R.Z. Wang, T.S. Ge. 2010. Technical development of rotary desiccant dehumidification and air conditioning: A review Renewable and Sustainable Energy Reviews 14:130–147. Ling J, O. Kuwabara, Y. Hwang, and R. Radermacher. 2011. “Experimental evaluation and performance enhancement prediction of desiccant assisted separate sensible and latent cooling air-conditioning system,” International Journal of Refrigeration, vol. 34, no. 4, 946–957. Liu W, Lian Z, Radermacher R and Yao Y. 2007. Energy consumption analysis on a dedicated outdoor air system with rotary desiccant wheel Energy 32:1749–1760. 75

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Oberg V and Goswami DY. 1998. A Review of liquid desiccant cooling. In: Boer KW, editor. Advances in solar energy, vol. 12. Boulder, CO: American Solar Energy Society, p. 431–470. Sherman M. H. and Walker I. S. 2007. Energy Impact of Residential Ventilation Norms in the United States. LBNL 56292. Lawrence Berkeley National Laboratory, Berkeley, CA. Subramanyam N., Maiya M.P.,Murthy S.S. 2004. “Application of desiccant wheel to control humidity in air conditioning system”, Applied Thermal Engg., Vol.24,pp. 2277-2788. Wurm J, Kosar D, Clemens T. 2002. Solid desiccant technology review. Bulletin of the International Institute of Refrigeration, 82(3):2–31. Zhang L.Z. and Niu J.L. 2003. A pre-cooling Munters environmental control desiccant cooling cycle in combination with chilled-ceiling panels. Energy;28(3):275–92.

Environmental Issues and Sustainable Agriculture

Chapter-12

Agroforestry

1Mohit Husain, 2Joginder Singh, 3M.A. Islam,4Mevada R.J., 4Azeem Raja 1Senior Research fellow, Dept. of Silviculure& Agroforestry, NAU, Gujarat-396450 2Department of Horticulture, J. V. College, Baraut, UP 3Associate Professor & Head (NRM)-FOF, SKUAST-Kashmir-190025 4Research Scholar, College of Forestry,ACHF, NAU, Gujarat-396450

Definitions of Agroforestry This widely debated land use option, which is requires to be understood thoroughly for its beneficial application, has been defined by several angles of its apparent ambits. Although the task of defining complex milieu of agroforestry has been attempted by many agencies and scientists, still the scope of refinement of the definitions continues on the basis of consistent considerations and reconsiderations of the entire gamut of this complex land use technique. Some of the popular definitions of agroforestry are quoted below to elucidate its meaning for proper elaboration of its concept. (1) “Agroforestry is aland management involving the growing of trees in association with food crops or pastures”. - The Webster’s Dictionary

(2) “The integration of agriculture and/or farming with forestry so the land can simultaneously be used for more than one purpose. This practice is meant to have both environmental and financial benefits. The presence of trees can provide benefits such as sheltering livestock from the elements and improving the soil so that crops will be more productive. The agroforestry system can also provide a more even income for landowners since all of their income is not tied to a few crops or a single season. Agroforestry can also make it easier for farmers to transition from one type of crop to another as market demand for their products changes.” - Investopedia (Source: Cited at http://www.investopedia.com/terms/a/agroforestry.asp)

(3) “Agroforestry is a method and system of land management involving the simultaneous cultivation of farm crops and trees; agriculture incorporating the growing trees……..agroforestry ensures a continuous food supply, some continuous economic return and the avoidance of soil degradation.” - The Dictionary.com (cited at dictionary refrence.com)

(4) “Agroforestry is a method of farming integrating herbaceous and tree crops.” -British dictionary

(5) "Agroforestry is a sustainable management system for land that increases overall production, combines agriculture crops, tree crops, and forest plants and/or animals simultaneously or sequentially, and applies management practices that are compatible with the cultural patterns of the local population". - Bene et al., 1977

(6) "Agroforestry is a sustainable land management system which increases the overall yield of the land, combines the production of crops (including tree crops) and forest plants and/or animals simultaneously or sequentially, on the same unit of land, and applies management practices that are compatible with the cultural practices of the local population". - King and Chandler, 1978

Environmental Issues and Sustainable Agriculture

(7) "Agroforestry is a collective name for all land-use systems and practices where woody perennial plants are deliberately grown on the same land management unit as agricultural crops and/or animals, either in a spatial mixture or in temporal sequence. There must be significant ecological and economic interactions between the woody and non-woody components". - Lundgren, 1987

(8) “Agroforestry is a diverse technical practices that have in common the following: there is at least 2 different plants in biological interaction one of these 2 plants is a perennial one of these 2 plants is a forage, a food crop or a tree crop.” - Somariba, 1992

(9) “Agroforestry is a dynamic, ecologically based, natural resource management system that, through the integration of trees in farm and rangeland, diversifies and sustain smallholder production for increased social, economic and environmental benefits”. - Leakey, 1996

(10) “Agroforestry – the integration of trees with annual crop cultivation, livestock production and other farm activities – is a series of land management approaches practiced by more than 1.2 billion people worldwide. Integration increases farm productivity when the various components occupy complementary niches and their associations are managed effectively”. - Steffan-Dewenter et al., 2007

(11) “Agroforestry is the deliberate management of forest for simultaneous production of wood and agricultural production” - Federal Govt. Advisory Group, Australian Forestry Council, 1980 (Anonymous, 2009)

(12) “Agroforestry is a system of sustainable land management that involves the integration of forestry and agriculture on the same unit of land.” - Victorian Joint Agroforestry Management Committee, Victorian Govt. Advisory Group, 1991 (Anonymous, 2009)

(13) “Agroforestry strictly speaking the production of a timber product and agricultural product from same parcel of land.” - MSW Department of Land & Water Conservation, Cole-larke, 1999 (Anonymous, 2009)

(14) “Agroforestry is the integration of trees with other agricultural enterprises on a farm. The combined profit from forest and agricultural produce can exceed the profit from either alone. Trees are typically planted as timber belts, shelterbelts, alleys or woodlots.”- Western Australia CALM and Ag. WA. (Anonymous, 2009)

(15) “Agroforestry is an intentional combination of trees with crops and/ or livestock”. - USDA National Agroforestry Centre (Anonymous, 2009)

(16) “Agroforestry is an intensive land management system that optimizes the benefits from the biological interactions created when trees and/or shrubs are deliberately combined with crops and/or livestock. There are five basic types of agroforestry practices today in the North America: windbreaks, alley cropping, silvopasture, riparian buffers and forest farming. Within each agroforestry practice, there is a continuum of options available to landowners depending on their own goals (e.g., whether to maximize the production of inter planted crops, animal forage, or

Environmental Issues and Sustainable Agriculture trees).” - Anonymous, 2012b. Association for Temperate Agroforestry (AFTA), (Cited at http://www.aftaweb.org/about/what-is-agroforestry.html)

(17) “Agroforestry is a societal change.”- Lamaison, 2012

(18) “Agroforestry is new market opportunities. Sustainable ‘climate-smart’ agriculture. Land stewardship. Habitat for wildlife. Improved air and water quality. Diversified farm income. Increased wealth for rural communities.”- Anonymous, 2013

(19) “Agroforestry is the deliberate incorporation of trees and other woody species of plants into other types of agricultural activities. By definition the use of woody species must result in the enhancement of either the biological productivity or the economic return of the system, or both.” - Cornell, 2014

(20)“Agroforestry is defined as a land use system which integrates trees and shrubs on farmlands and rural landscapes to enhance productivity, profitability, diversity and ecosystem sustainability. It is a dynamic, ecologically based, natural resource management system that, through integration of woody perennials on farms and in the agricultural landscape, diversifies and sustains production and builds social institutions.”- National Agroforestry Policy of India, 2014 The different types of agroforestry practices under the various agroforestry systems are described herein below.

Importance of Agroforestry The primary benefit of an agroforestry is that it meets a need which people have defined for themselves and have considered sufficiently important to devote their time and resources to satisfy (Islam and Quli, 2016). In doing so, the people may, in many cases, have learned to co-operate and to plan ahead to achieve their objective, skills which can usefully be applied to improve many other aspects of their lives.

Social Benefits The social benefits of agroforestry practices on people are as under. Food habits: Adoption of agroforestry helps in sufficient production of food grains resulting in variation of food habits among people. Communication exposure: Adoption of agroforestry necessitates people to get in contact with field extension functionaries, radio, newspaper etc. to gain more information on agroforestry. Migration: Practicing of agroforestry facilitates increased self-employment opportunities through interventions such as nursery raising, mat weaving, basket making etc. resulting in gradual decrease in migration. Nature of occupation: With the adoption of agroforestry, people stop their traditional profession like hunting, gathering forest produces etc. and concentrate only in farming.

Economic Benefits The economic outcomes of agroforestry practices on people are as under. Family income: With the adoption of agroforestry people start getting more income by selling the fruits and timber every year. Subsidiary activities like mat weaving, basket making, honey collection, sheep / goat rearing etc. are also taken up as an integral part of agroforestry which also in turn contribute to the increased family income.

Environmental Issues and Sustainable Agriculture

Employment status: Agroforestry provides employments to the local people at their door step throughout the year as a result the migration is reduced to a maximum extent. Livestock possession: Agroforestry ensures good and cheap fodder which in turn increases livestock production. Supplementary income: One of the uniqueness of agroforestry is the promotion of traditional subsidiary occupation due to the availability of raw materials for these activities. As a result people start many subsidiary ventures like basket making, mat weaving, bamboo crafts etc. which add to the total family income. Farm expenditure: The expenditure incurred by the people on the farming increases marginally, but not significantly.

Ecological Benefits The ecological consequences of agroforestry practices on people are as under. Biomass production: There is significant increase in biomass production viz. fodder, fuel, timber etc. with the adoption of agroforestry. Plantation of a combination of fodder, timber and fruit species like Prosopis juliflora, Sesbania, Leucaena leucocephala,Tectona grandis, Acacia spp., Azadirachta indica, Anacardiun occidentale, Emblica officinalis, Cassia siamea, Melia dubia, Casuarina spp. etc. not only meets the household fuelwood needs, fodder needs of the cattle and timber needs for agricultural implements but also add organic matter to the soil. Groundwater recharge: Several studies explicitly indicated that there is a significant improvement in the ground water availability due to tree based farming interventions. Farm pond was one such major intervention made to harvest excess runoff rainwater in agroforestry plots. These farm ponds are located in the upper/ middle catchment of the land which enhances the percolation which in turn recharges the groundwater table. Dependency on natural forest: The agroforestry adoption reduces the dependency of people on the natural forests for fuel, fodder, fruits, fibre and timber needs. Incidence of pest and diseases: The incidence of pests like mealy bugs, termites, shoot and stem borer is reduced as they are preyed upon by birds, who make their nests in trees and some birds are also attracted by the fruits in the agroforestry plots. Climate changes: There is significant difference in atmospheric temperature, rainfall pattern and edaphic characters due to the adoption of agroforestry. Possible reason is that tree species might have acted with regard to the modification of micro-climatic parameters. Also the taproot system of various trees acts as a barrier to soil erosion by holding soil particles tightly. Other associated ecological impacts are carbon sequestration, pollution reduction, biodiversity conservation and protection of wildlife habitat.

Cultural Impacts The potential cultural services provided by agroforestry include: Maintenance of local cultural heritage Creation of recreation opportunities Enhancement of landscape Preservation of spirituals, values, beliefs, customary rituals, habits, totems, festivals, taboos, folklore, traditional recipes etc. Thus, the agroforestry can bring significant social, economic, ecological and cultural impacts that are desirable for the society and hence agroforestry can achieve effectively social, economic, ecological and cultural sustainability.

Environmental Issues and Sustainable Agriculture

Criteria of selection of trees in agroforestry While selecting Trees for agroforestry systems, the following desirable characteristics should be taken into consideration (Chundawat and Gautam, 1993). Though all desirable characters are not found in a single species, but their multiple uses are taken care of. MTs selected should not interfere with soil moisture Trees selected for agroforestry should have less water requirement. Should not compete with main agricultural crops for water. Trees should be deep tap rooted so that they can draw water from deep strata of the soil. Trees should not compete for plant nutrients. Trees should not utilize more plant nutrients. They should help in building soil fertility. Leguminous tree species which fix atmospheric nitrogen in their roots should be preferred. The root system and root growth characteristics should ideally result into exploration of soil layers that are different to those being trapped by agricultural crops. Trees should not compete for sunlight Trees should not interrupt sunlight falling on the crops. Trees should be light branching and thin crown in their habit. TREES should permit the penetration of light into the ground and promote better crop, pasture growth and yield. Trees can withstand pruning operation if it posses dense canopy. Trees should have high survival rate and easy establishment Trees should have high survival percentage, Leave little or no gaps after transplanting. Hardy tree species and easy to establish. They have less mortality percentage with high tolerance for transplantation shocks. Trees should have the ability to regenerate lateral roots within a short period of time after transplanting. Trees should have fast growing habit and easy management Trees for agroforestry system should essentially be fast growing, Rapid growth, especially in the early years. Trees should have short rotation (the period between planting and final harvesting). Fast growing species such as Poplar, Casuriana, Leucaena leucocephala etc., are important Trees which provide lot of opportunities to be planted in AFS Trees should have wider adaptability Trees selected for agroforestry combinations must have a wider adaptability. Trees should have high palatability as a fodder Most of the Indian farmers rear livestock separately and cut and carry method of fodder production is quite prevalent. Therefore, in agroforestry, farmer must select those Trees which are palatable to livestock and had a high digestibility. Trees should have soil stabilization attributes Some Trees, because of their inherent growth habit and adaptability, are especially helpful in providing protection for soils, crops and livestock. Poplars (Populus spp.), Willows (Salix spp.), Casuarina equisetifolia, etc. for example, have been widely used in soil erosion control because of their extensive root system and ability to grow in water-logged soils.

Environmental Issues and Sustainable Agriculture

Trees should have capability to withstand management practices Many agroforestry systems demand extensive pruning and lopping of the trees in order to maximize production. In such cases, the Trees must be able to withstand such treatment without any adverse effect on their growth rate. Trees should have nutrient cycling and nitrogen fixation attributes Within an agroforestry system, Trees can play an important role in recycling nutrients, leached down through the soil profile and minerals released from weathering parent material such as rocks and sediments. These nutrients are used in the growth and development of the tree, many returning to the top-soil in form of dead leaves, twigs, flowers and seeds which slowly decompose on the surface, or are eaten by animals. Although all trees play some role in maintaining the nutrient status of the soil through recycling, deciduous trees drop most of their leaves in autumn leaving a thick mat of leaves on the ground, whereas most evergreen species maintain some level of litter fall throughout the year. Another important factor is the ability of many tree species to convert atmospheric nitrogen into organic nitrogen for their own use through complex symbiotic relationship between nitrogen fixing bacteria and their fine roots. The bacteria form root nodules convert nitrogen gas into usable nitrogen for the plant. Most leguminous trees and some non-leguminous ones, such as Acacia, Leucaena and Prosopis as well as Casuarina spp. fix the atmospheric nitrogen, augmenting the soil fertility. The litter of these nitrogen fixing trees is generally high in nitrogen, thus increasing the nitrogen status of the soil. Trees should have thin bark Trees selected for agroforestry combinations should not shed its bark regularly but it should retain for longer period as bark shedding creates unhygienic conditions for under-ground crop. Trees should be free from chemical exudations The Trees selected for agroforestry combination must be free from allelo-chemicals, as these allelo-chemicals affect the growth of under-ground crops. Trees should have easily decomposable leaves The suitable Trees for agroforestry will be that one in which fallen leaves decompose with fast rate. The leaves of most of the legume tree species are small in size, decompose quickly and easily, and add a large quantity of organic matter and nutrients to the soil. Tree species having broad leaves such as teak, mango and banyan should not be preferred for agroforestry system. They contain more fibre matter and also require longer time for decomposition. Further, broad leaves when fall on the tender crop plants, block their photosynthetic activities. Trees should have their multiple uses The selected Trees should have multiple uses. Trees should yield more than one of the main produce like fuelwood, leaf fodder, edible fruit, edible flower and fibre. Trees should have high yield potential High yield potential is the most important criterion of selection of tree species for agroforestry systems as the main aim is to optimize the productivity. Care should be

Environmental Issues and Sustainable Agriculture

taken before collection of seeds and seedlings that they are being procured from reliable source. The role of Trees is not confined to its service and production functions; it must be acceptable in all respects to the farmer and to the local community. The principal factors for farmers are perceived economic benefits and the reduction of risk. A new species or technology will not be adopted by local farmers if it cannot be shown to be superior in these respects. For this reason, long-term research programmes must include the collection of appropriate economic data. Other, 'social', factors have to be taken into account when planning research, although they are more difficult to quantify than economic benefits. These include personal and community preferences, tastes, and cultural and religious behaviour; there are many examples of species that grow well on a particular site but are not favoured by farmers for such reasons. Many of these factors can be identified during diagnostic surveys of rural areas. A research programme must eventually investigate these preferences, attempt to put values on community preferences and provide factual information on growth characteristics and uses of trees to help local communities and development planners in decision making.

Agroforestry systems prevalent in the country The words “systems” “practices” “technologies” and “models” are often construed as synonymous in agroforestry literatures in a fuzzy manner. However, some distinction can be made between them through following basic conceptual specificity: Agroforestry system is characterized by certain types of tree-crop combination taken as a whole, giving details of the given land-use system in a locality. In any one agroforestry system there can be more than one agroforestry practices. Agroforestry practice illustrates precise details of a land management unit elaborating overall biological composition and specific arrangement of components, temporally and/or spatially, with its overall biophysical interactions and intricacy of management for the fixed objectives. Agroforestry technology refers to an innovation or improvement, usually through scientific intervention, to either modify an existing system or practice, or develop a new one. Agroforestry model indicates a tested live package of practices developed under a particular agroforestry system for a certain eco-climatic region, with all details of spacing, calendar of events with special reference to agricultural and silvicultural packages of practices/techniques. Agroforestry models, depicting the biophysical interactions in entirety, are always developed with special considerations, suited to meet the region-specific challenges of biophysical conditions for optimization of farming profitability.

Classification of Agroforestry Systems Agroforestry system (AFS) although, commended as a most beneficial land use option with innumerable gains due to the uncountable spatial and/or temporal permutation and combinations of forest/fruit trees-agricultural/ fodder crops-animals-insects-fishes, make its classification too knotty. As recorded by Nair (1987) several sincere attempts to develop a uniform system of classification during initial phase of agroforestry development were made by Combe and Budowski (1979), King (1979), Grainger (1980), Vergara (1981), Huxley (1983) and Torres (1983). However, these were mostly exercises in concept development rather than aids in evaluating and analyzing agroforestry systems based on field data. While some of them were based on only one criterion such as the role of components (King, 1979) or temporal arrangement of components (Vergara, 1981), others tried to integrate several of these criteria in hierarchical schemes in rather simple ways (Torres, 1983) or more complex ones (Combe & Budowski, 1979; Wiersum, 1980).

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Between 1982 and 1987 an inventory of agroforestry systems and practices being used in the developing countries was compiled (Nair, 1987). This agroforestry system inventory (AFSI) was partly financed by the United States Agency for International Development (USAID). Systematic collection, collation, and evaluation of data pertaining to a large number of such land- use systems around the world were carried out to elucidate a universal system of classification. Such an effort yielded substantial information on a large number of agroforestry systems including their structures and functions and their strengths and weaknesses. The AFSI was so comprehensive and broad-based that, on the one hand it provided an elaborate database for developing a widely-applicable classification scheme, and on the other hand, such a classification scheme became necessary to compile and process the information. The complexities of these requirements revealed that a single classification scheme may not satisfactorily accommodate all of them because of the systems variability on the basis of wide variations in criteria, necessitating a need for series of classifications, with each one based on a definite criterion to serve a different purpose. The most obvious and easy-to-use criteria for classifying agroforestry systems are the spatial and temporal arrangement of components, the importance and role of components, the production aims or outputs from the system, and the social and economic features, which correspond to the systems' structure, function (output), socioeconomic nature, or ecological (environmental) spread. These characteristics also represent the main purpose of a classification scheme. Based upon the versatile documentations of the agroforestry practices prevalent across the globe, Nair (1985) classified the Agroforestry systems on the basis of: Structure, function, socio- economic and ecological bases. Further attempts on classification of agroforestry systems included Young (1987) and Torquebiau (1990). Some Indian authors (Dwivedi, 1992; Tejwani, 1994; Chundawat and Gautam, 1993) in their books of agroforestry have also attempted appreciable compilations of the schemes of classifications of agroforestry systems. However, a most comprehensive but lucid scheme of agroforestry classification is propounded here accommodating all past attempts made by the various agroforesters, scientists and authors of papers and textbooks on this issue. As per this comprehensive scheme the Agroforestry systems are classified on the basis of following seven considerations:

Structural Basis Refers to the composition of the components, including spatial arrangement of the woody component, vertical stratification of all the components, and temporal arrangement of the different components. This criteria has further two pronged basis namely: I. Structure and nature of components; II. Structure of strata of the systems.

I. Structure and Nature of Components Based upon the structure and nature of components the agroforestry systems are divided into following several types as shown by the following schematic diagram (Box 5.1) which cogently illustrates the forestry i.e., the woody perennials, as an integral part of agroforestry systems) except in case of Agrihorticulture system where he horticulture trees become woody perennial component:

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Box. 6.1. Schematic diagram showing components of Agroforestry systems

Nomenclature Priorities The aforesaid nomenclature is also interpreted to represent dominance of the components, as the dominant components are written first e.g. Agri-silviculture illustrates dominance of agricultural crops with subsidiary intervention of forest trees conversely in case of dominance of the forestry with subsidiary agricultural crops, it would be recognized as Silvo-agriculture. Although there is no hard and fast rule/convention to separate the initials of the components (Agri/agro, Pastural/ Pastoral with Silvi/ Silvo) by a hyphen, it is more user-friendly option. The various permutations and combinations reflecting the basic types of AFS are represented below: A. Agri-silviculturalsystem: Crops + Forest trees; B. Horti-silvicultural system: Fruit trees + Forest trees; C. Horti-agri-silvicultural system: Fruit trees + Crops + Forest trees; D. Silvi-pastural system: Trees + Fodder grasses/herbs/shrubs; E. Agri-silvi-pastural system: Crops + Forest trees + Fodder: Grasses shrubs & herbs; F. Agri-horti-silvi-pasturalsystem: Crops+ Fruit trees + Forest trees+ Fodder: Grasses shrubs & herbs; G. Aqua-silvicultural system: Aquaculture (fishes, crustaceans and mollusks etc.) + Forest trees; H. Entomo-silvicultural system: Lac/Api/Seri culture + Forest trees.

A. Agri-silvicultural System This is a land use involving purposive synergistic combinations of agricultural crops with forests trees to optimize the farming returns from per unit area on sustainable basis. Initially trees are planted at wider spacing and intercrops are cultivated till the shade of the trees becomes a limiting factor for growth of intercrops. However, in case of simultaneous systems the intercropping tenures can further be prolonged by planting shade loving and shade tolerant crops between the rows of the trees. This system is more suitable for quality soils. This system includes following practices: 1. Improved ‘fallow’ in shifting cultivation, 5. Scattered trees on farmland (Parklands), 2. Alley cropping (Hedgerow intercropping), 6. Plantation and other crops, 3. Multispecies tree garden, 7. Mixture of plantation crops, 4. Taungya, 8. Biomass transfer,

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9. Shade trees for commercial plantation crops, 12. Rotational woodlots, 10. Trees for fuelwood production, 13. Boundary markings. 11. Shelterbelt, windbreak, Soil Conservation hedges etc.,

B. Horti-silvicultural Systems In case of sites which are not so much conducive for agriculture farming, compatible combinations of fruit and forest trees are grown under this system for optimum returns. With passage of time this system, due to accelerated nutrient recycling, regular soil and water conservation, improves the soil fertility making the site suitable for some appropriate agricultural interventions, transforming this system into a more profitable horti-agri-silvicultural system.

C. Horti-agri-silvicultural Systems As apparent from the name itself, this is a multiple cropping systems facilitating synergistic interaction of three productive components- namely: the fruit trees, agricultural crops and forest trees. The three components of this system further add to the prospect of profitability besides an additional benefit of insurance cover of the fruit and forest trees to cover any eventuality of complete losses of agriculture. D. Silvi-pastural System To augment the farmer’s fodder need, this is a most demanded system, suitable for all types of fallow lands/ culturable wastelands, which, for any reason, are not used for agriculture. This system yields both goods as well services in a sustainable manner by effective management of soil fertility due to leguminous trees and soil and water conservation by arresting the surface runoff, since mostly the undulating terrain are utilized under this. Agroforestry practices under the Silvi-pastural systemsinclude: 1. Protein banks (fodder tree banks), 2. Trees and shrubs on rangeland or pastures, 3. Live fences of fodder trees and shrubs (Living fences), 4. Plantation crops with pastures and animals, 5. Integrated production of animals and wood products.

E. Agri-silvi-pastural System Like the Horti-agri-silvicultural system, this also optimizes the return per unit are of land through its multiple components: crops, forest trees and forage plants and/or pasture. The integration of crops and trees into the pastures requires sites, which are although degraded but still have some potential for selective agricultural crops. It is also observed that after certain number of years the hostile sites being managed under sivipastoral system, become suitable for this system. 1. Home gardens (Homestead gardens), 2. Woody hedgerows for browse, green manure, soil conservation etc. 3. Integrated production of crops, animals and wood (fuelwood, poles

F. Agri-horti-silvi-pastural System This having altogether four components is the most complex system. Agriculture crops and fodder forage is grown in combination with forest and fruit trees under this complex system. Having multiple woody perennials this system helps in expeditious reclamation of the site by effective soil and water conservation and restoration of soil fertility through accelerated recycling of the foliage of trees. The sites chosen for this system are normally slightly deficient, not

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conducive for agriculture farming, which by ameliorative potentials of this system, gradually recovers deficiencies of site with passage of time.

G. Aqua-silvicultural System Also known as Aquaforestry, this system involves tree growing along the banks of the water bodies (ponds/lakes etc.). Some of the fishes like ‘grass carps’ directly consume the leaves and foliages of bank plantations for biomass production. Further, the droppings of the birds, perching on trees of the banks, enrich organic matter of the water, which is used as feed by the fish along with other aquatic communities like crustaceans and mollusks living in the water bodies. Besides direct benefits, the trees, by their shade, control the water temperature, which maintains optimum dissolved oxygen concentration for respiration of fishes and other aquatic communities. The standing trees and shrubs substantially reduce the erosion of pond banks, which increases the health and life span of water bodies by checking the siltation process.

H. Entomo-silvicultural System Some of the literatures have designated this system as ‘Entomo-forestry’. The system is developed on growing stocks of Palas, Arjun, Kusum, Karanj, Mulberry, Fruit trees like Mango Litchi, along with miscellaneous flowering trees etc., which are either existing on the fallow lands or specially planted. The synergistic alliance of the trees and insects like: Honey bees, Lac insect and Tassar / Mulberry worms, multiplies the farmer’s profits from the insect products, which is derived from the flowers, sap or forage of the trees. The additional income from the diverse and precious usufructs of insects (Honey, Tassar, Mulberry and Lac etc.) encourages the tree planting culture among the farming communities leading to increased greenery, which not only facilitates climatic resilience of the area but also helps in soil and water conservation as well as restoration of soil fertility for further agricultural intervention on those lands which were not suitable earlier.

II. Structure of Strata of the System Based upon the structure of stratification the systems are further subdivided using two criteria:

a) Vertical Stratification: On this basis the systems can be grouped as follows: i. Single layered: System consisting of single stories: Tree garden e.g. Silvi-horticultural system; ii. Double layered: System consisting of double stories: Tree gardens e.g. Wheat and Paddy cultivations under popular in Uttarakhand is a common practice under Silvi-agricultural system; iii. Multilayered: System consisting of multiple stories e.g. Horti-silvi-agricultural system or random assemblage of trees of variable heights with shrubs and herb in a home garden.

b) Horizontal stratification (Spacing): On this basis the systems can be grouped as follows: i. Dense: System consisting of close spacing plantations e.g. Fuel wood plantations with shade loving crops under Silvi-agricultural system; ii. Scattered: System consisting of sparse plantations in pastures: Tree gardens of Shade trees with tea/coffee e.g. Silvi-pastoral system; iii. Mixed intercropping: System consisting of mixture of several components having variable spacing e.g. Horti-silvi-agricultural system or random assemblage of trees of variable heights with shrubs and herb in a home garden. 87

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Functional Basis This criterionfocuses the functional role of the system, usually furnished by the woody components. Besides yielding tangible usufructs- a direct source of income for the farmers, the trees also afford important series of intangible services which not only protect the sites rather also accord effective restoration of the lost vitality- an indirect source of profit optimization for the farmers. Based upon this criterion the following types of Agroforestry systems are recognized. a) Productive agroforestry systems: These systems are primarily designed with basic objective of production of goods like timber and non timber forest produce (flower, fiber, floss, fuel, gum, resin, honey, silk, lac, fruits, food, natural, dyes, medicines, condiments etc.) for optimization of returns per unit area and per unit time on sustainable basis. Trees yielding the valuable products are planted on farm bunds with the crops or in alley or on wastelands in combination of other agricultural or horticultural or pastoral crops under these systems in a scientific manner with special care to minimize the tree crop interactions. b) Protective agroforestry systems: These systems are primarily designed with basic objective of protection and amelioration of the adversities of a site. Trees are combined with crops to cope up with the soil fertility problems, reduce erosion hazards and boost climate resilience for optimization of returns per unit area and per unit time on sustainable basis, by restoring the healthy site conditions. These systems primarily include Silvipastoral systems raised on deficient sites. The Wind brakes, Shelter belts, soil conservation plantations with some pastoral crops and cover/ nurse crops etc., also represent the protective agroforestry systems. c) Multipurpose agroforestry systems: If the Agroforestry systems aim at addressing both the benefits- protection and production, this becomes Multipurpose Agroforestry System. Practically all the agroforestry systems can be said to be Multipurpose systems, since whenever there is a tree plantation, both protection and production objects are met with the tangible and intangible benefits of trees.

Spatial and Temporal Basis a) Spatial agroforestry systems: The Spatial (also named as simultaneous) agroforestry systems the tree and crop components occupy the same land unitat the same time. There is significant overlap in the growth cycles of tree/crop components. As a result there is a direct interaction between the two componentsi.e. the trees and the crops. The spatial agroforestry systems may have any of the following variants: Mixed dense plantations: Components (Trees and Crops) are closely planted to form a high density agroforestry plantation, e.g. Home gardens; Mixed sparse plantations: Components (trees and crops) are planted at wide spacing to form a low density agroforestry plantation, e.g. Trees in pastures, Scattered trees on agricultural lands. Strip plantations: The components are aligned in fixed rows or strips. Tree may be used in single rows on farm bunds as boundary plantations of in strips as in case of Alley Cropping. Simultaneous agroforestry systems include following practices: - Alley cropping - Live fences - Parklands - Line/ boundary plantings and - Fodder/protein banks - Home gardens.

Environmental Issues and Sustainable Agriculture b) Temporal agroforestry systems: The Temporal (also named as Sequential) agroforestry systems are those in which trees and crops occupy the same land unit at different timesand interaction between them is indirect. The growth of the crop and the tree components occur at different times even when both components may have been planted at the same time. One component species may grow rapidly, while the other grows slowly. Nutrient uptake peaks of the component species may also occur in a sequence, which makes the species complementary in the use of soil resources. Interactions between tree and crop components are reduced with time in this agroforestry practice. In simultaneous agroforestry systems, management should aim at limiting inter-specific competition while in sequential practice, the farmer utilizes the residual effects of the trees. Thus, in shifting cultivation the farmers pile the cut trees into smaller area, burn them and then plant a new crop, which depends on the accumulated ash. In improved fallows, nitrogen fixing trees are deliberately planted to improve soil physical conditions and soil fertility in general, which benefits subsequent crops grown after harvesting the trees. The Temporal or Sequential agroforestry systems may have any of the following variants: Coincident: The components under this variant of AFS occupy the land together e.g. Tea/ Coffee under trees or pastures under trees. Concomitant: The components under this variant of AFS the components stay together for certain period of time, e.g.Taungya Intermittent: The components under this variant of AFS the annual/ seasonal crops are grown with perennial trees e.g. Paddy under Coconut or other MPTs or seasonal grazing under trees. Interpolated: The crop components (the annual/ seasonal crops) under this variant of AFS may vary with same space and time, e.g. Home garden Separate: The components under this variant of AFS the annual/ seasonal occupy the space during separate phases of time e.g. Shifting Cultivation. Temporal or Sequential agroforestry systems are implanted through following practices: - Improved Fallows - Rotational Wood lots - Taungya

Physiognomical Basis Systems recognized with the Physiognomical characters are grouped under this classification system like: Xero-morphic systems (under deserts’ conditions with acute water shortage and extreme climatic conditions); Meso-morphic systems (common land conditions with moderate water availability and moderate climate) and Hydro-morphic systems (in aqueous conditions, like paddy & fish etc.).

Floristical Basis This criterion classifies the AFS on the basis of floristic compositions depicting the species contributing in the agroforestry e.g. Systems like: Wheat-Poplar; Sugar cane-Eucalyptus/ Poplar; Babool-Wheat-Vegetables; Teak-Moringa-grass-Palas-Bamboo; Rice-Tobacco-Chillies- Albizia, etc.

Ecological Basis

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This criterion classifies the AFS on the basis of specific ecological (Climatic and edaphic) condition which support the AFS. Based upon this criterion the systems are classified into: Tropical; Subalpine Subtropical Alpine Temperate Further based upon the moisture conditions each of the aforesaid groups can further be distinguished into following types:

Wet Dry systems Moist & For a country like India which has a very wide variation in climatic, edaphic and physiographic conditions and with a large biodiversity of flora and fauna, it is really a difficult task to segregate systems into distinct forms upon this ecological criterion.

Socio-Economical Basis Socio-economic criterion such as the scale of production and objective of production The AFSs are classified into following types:

Commercial AFS: This covers the large scale production AFS with basic objective of trade. Normally farmers with high economic profile having large farms practice this AFS. Under this system the land may be of Government or corporate sector and the system is managed by corporate sectors or companies for production of industrial raw materials e.g. Eucalyptus with Sugarcane or Popular with sugarcane.

Subsistence AFS: This covers the scale production AFS with basic objective of subsistence to satisfy the livelihoods requirements. Normally farmers with moderate to low economic profile having medium area of farm sizes practice this AFS. Under this system the land is of farmer and the products are need based consisting of food, fodder, fruits and variety of non wood forest products useful for livelihood support.

Intermediate AFS: As he name itself indicates, these systems are having both subsistence and some commercial objectives. The surplus products of these systems are sold for economic gains which exceed the subsistence needs. The best example of these systems is Casuarina plantations with agricultural crops, or gum Arabic with paddy.

Shifting Cultivation The term shifting cultivation refers to farming or agricultural systems in which land under natural vegetation is cleared, cropped with agricultural crops for a few years, and then left untended while the natural vegetation regenerates. The cultivation phase is usually short (2-3 years), but the regeneration phase, known as the fallow or bush fallow phase, is much longer (traditionally 10-20 years). The clearing is usually accomplished by the slash-and-burn method (hence the name slash-and-burn agriculture), employing simple hand tools. Useful trees and shrubs are left standing, and are sometimes lightly pruned; other trees and shrubs are pruned down to stumps of varying height to facilitate fast regeneration and support for climbing species that require staking. The lengths of the cropping and fallow phases vary considerably, the former being more variable; usually the fallow phase is several times longer than the cropping phase. The length of the fallow phase is considered critical to the success and sustainability of the practice. During

Environmental Issues and Sustainable Agriculture this period the soil, having been depleted of its fertility during the cropping period, regains its fertility through the regenerative action of the woody vegetation.

System Overview Shifting cultivation is still the mainstay of traditional farming systems over vast areas of the tropics and subtropics. Estimates of area under shifting cultivation vary. One estimate still used repeatedly is that it extends over approximately 360 million hectares or 30 % of the exploitable soils of the world, and supports over 250 million people. Crutzen and Andreae (1990) estimated that shifting cultivation is practiced by 200 million people over 300 million-500 million hectares in the tropics. Although the system is dominant mainly in sparsely populated and lesser developed areas, where technological inputs for advanced agriculture such as fertilizers and farm machinery are not available, it is found in most parts of the tropics, especially in the humid and subhumid tropics of Africa and Latin America. Even in densely populated Southeast Asia, it is a major land-use in some parts

Taungya System The word Taungya is a Burmese word which literarily means Hill cultivation (“Taung = Hill & ya = cultivation). Originally it was the local term in Burma for shifting cultivation. The Taungya system essentially consists of cultivation of annual agricultural crops along with forest trees during the early years of establishment of the forest plantation. In order words, taungya system is a forest plantation establishment system in which forest trees are raised in “combination with temporary cultivation of field or agricultural crops”. The Taungya system can be considered as a step forward in the process of transformation from shifting cultivation to agroforestry. Shifting cultivation is a sequential practice of growing woody species and agricultural crops, whereas Taungya consists of simultaneous combinations of the two components during the early stages of forest plantation establishment. Although wood production is the ultimate objective in the Taungya system, the immediate motivation for practicing it, as in shifting cultivation and other smallholder systems, is food production. In 1862 the Taungya system was used in Burma for the first time and it was introduced to Nigeria in 1928 in a silvicultural experiment at Sapoba (Edo State). It is now a widely used agroforestry practice in the rainforest and derived zones of Nigeria. The system which has been modified in various parts of the tropics in general and India in particular is essentially a variation of the traditional shifting cultivation whereby the farmers raise food crops for at least one year in a forest land, usually a part of a forest reserve. The successive areas are then converted into plantations as the farmers shift their farming activities progressively to new reforestation areas. Teak (Tectona grandis) and Gamhaar Gmelina arborea are the most popular trees used in taungya, planted as stumps or seedlings. Apart from the growth of tree crops for the production of timber and other traditional wood products, the taungya system may be used to raise each crop such as cashew (Anacardiun occidentale). This species has been successfully introduced on poor sites in the savannas of southern Guinea, sown at a spacing of 2 × 4 m with maize, or sometimes cotton, between the rows of trees. The cashew begins fruit production around the fifth year; which provides good returns to the farmers. The tree crops are planted with agricultural crops at a wider spacing to avoid early shade impacts over the intercrops to ensure longer production duration from the agricultural crops. The choice of agricultural crops is based upon need and feeding habits of the farmers. The most commonly cultivated agricultural crops are bajara, barley, beans, bhajee (Amaranthus spp.), brinjal (Solanum melangena), cabbage (Brassica spp.), castor (Ricinus communis), chilli peppers (Capsicum spp.), coco yam (Colocasia antiquarum), cotton (Gossypum spp.), cucumber (Cucumis sativus), dasheen (Colocasia esculenta), dhal (Cajanus spp), ginger (Zingibar officinale), groundnut (Arachis hypogaea), linseed 91

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(Linum usitatissimum), melon (Citrullus vulgaris - Cucumis melo), millet (Pennisetum spp, Panicum spp.), mustard (Brassica spp.), oats (Avena sativa), ochra (Hibiscus esculentus), papaya (Carica papaya), pineapple (Ananas comosus), potato (Solanum tuberosum), pumpkin (Cucurbita maxima), rye (Secale cereale), sesame (Sesamum indicum), sorrel (Hibiscus sabdariffa), soyabean (Glycine soja), sweet potato (Ipomoea batatas), tomato (Lycopersicum esculentum), tumeric (Curcuma longa spp.), wheat (Triticum spp.). There are several agricultural species which are controversial and are excluded in plantations in some countries, such as bananas and plantains (Musa spp.), cassava (Manihot utilissima), maize (Zea mays), rice (Oryza sativa), sugar cane (Saccharum officinarium), tobacco (Nicotina tabacum) and yam (Dioscorea spp.). Limitation or exclusion of bananas and plantains is due to various reasons, among which are: to avoid human interference in the plantations (since the farmers are reluctant to cut or abandon a plant which continues to produce foodstuff), to conserve soil fertility, and to prevent young trees from being deformed. However, at Mayumbe, Congo Brazzaville, bananas combined with Terminalia superba seedlings are exploited during four or five years in state sylvo-bananiers, the spacing of the trees being 12 × 4 m with bananas in two or three intervening rows. Cassava is excluded in Dahomey and Uganda because it exhausts the soil, it has a long life and it attains a height of 2-3 m rapidly, thereby retarding the development of the tree crop. The same reason, fast growth, is given for the exclusion of maize in Malawi, Mauritius and Senegal. However, maize has had no significant effect on the mortality of teak (from stumps and seedlings) in plantations made in Gambari in Nigeria, but may have an effect on height growth according to the type of planting stock used. Tobacco may be excluded because it has a deleterious effect on soil nutrients and because of its inability to provide adequate soil cover and therefore the liability of the land on which it is planted to erode. Hill rice is grown with tree crops particularly in Malaysia, Senegal and India (Assam and Kerala). The growth of trees gets enhanced because the rice suppresses the weeds. However, in Sri Lanka it is felt that the returns from rice are so high that farmers are likely to exert their influence to convert the land to single use agriculture. Sugar cane is generally excluded because it is a long- growing crop, because of fear of soil depletion and because it casts a heavy shade. Nevertheless, where it has been cultivated with considerable success in Assam, India and in Burma, the presence of the cane led to increased height growth of the tree seedlings. Intercropping is not only regarded as a tending operation to replace weeding but also a multiple land-use practice for joint production of wood with food. Depending on soil quality, crops may be sweet potatoes, soyabeans, peanuts, watermelons, or maize. In general, intercropping with legumes is preferred as it enriches the soil, provides green manure and also feed for animals. Depending on crops and, on the management skill, intercropping may yield 1.4-4.0 tons of food per hectare. In some places, it may yield 20 tons/ha of green leaves which are used as feed for animals (pigs) or as manure. The effect on tree growth has been observed as very favourable. Survival rate of Cunning hamiana is 5 percent higher than that of non-intercropped plantations and plant height is 33 percent greater. A further example of mixed cropping can be taken from the southern Pacific coast of Colombia where Cordia alliodora and Cedrela odorata are planted on small landholdings concurrently with the traditional crops of plantain, maize and cocoa (Theobroma cacao). Although mixed cropping may be contrary to the thought of many foresters, accustomed to the tidy and regular appearance of their plantations, this system is practiced not only for traditional reasons, but because it suite the environment, maintains soil fertility and combats erosion and leaching. There is also an economic justification, since more production may be achieved from mixtures of crops, thus making full use of the space available. Good management is an important factor in intercropping with strict enforcement of any rules that may be laid down. In cultivating and in harvesting the agricultural crops, and particularly tubers, great care must be 92

Environmental Issues and Sustainable Agriculture exercised in order not to damage the roots of the tree crop. If creeping species are used, against the general rule, the farmers should provide bean-stakes or poles (in the case of yams) to prevent strangulation of the tree seedlings. It is important to emphasize that growth and yield of the agricultural crops are directly influenced by the spacing and density of the tree crop. Concomitant with these two factors are the rate of growth and relative crown size of the tree species. The taungya system is a way to reduce the costs of forest plantations, and at the same time to contribute to solving social problems. In Campeche, Mexico where Cedrela mexicana, Swietenia macrophylla and Cordia ciricote were main species planted, the cost per hectare for planting and tending during 5 years, were reduced to as much as 27 percent of the normal cost because the revenues from the maize harvest. If mechanization is used the costs would further drop to 18 percent. The taungya system is practiced under following four variants: a) Traditional Taungya: Also known as called ‘own your crop’ type. In this type, each farmer is allocated one or more plots and a plot area is about 0.5ha. Under this system, the farmers are responsible for site preparation for the tree planting, and in return for their labour, they are allowed to grow some food crops. e. g. maize, yams, cassava, etc.; till the forest trees such as Gmelina arborea, Tectona grandis, and Shorea robusta etc., inter-planted by the Forestry Department close their canopy. Planting of the food crops can continue up to 3-4 years depending, among other things, on the species raised after which the common agricultural crops are replaced by shade bearing crops like ginger, turmeric, black pepper etc., when the shade effect becomes a limiting factor for the agricultural crops. b) Departmental taungya: This second type of taungya is also called as farming for pay. This has been extensively practiced in the high sal forest areas of Gorakhpur in Uttar Pradesh. Under this system, farming is practiced by selected families under control of the Forestry Department. The families involved earn wages besides having the agricultural produce. c) Hybrid Taungya: The third type, a hybrid version of the two systems, which implies that the local farmers under the traditional taungya assist the Forestry department in planting the tree crops. d) Leased Taungya: The land is leased to families, who bid the highest value for raising crops of specified number of years with simultaneous tree planting.

Alley Cropping (Hedgerow Intercropping) Alley Cropping (Fig.6.1) involves intercropping of arable crops between hedgerows of woody species that can be used for producing mulch and green manure to improve soil fertility and to produce high quality fodder. This is also known as Hedgerow Intercropping, a simultaneous agroforestry system where arable (food) crops are grown between hedgerows of planted shrubs and trees, preferably leguminous species, which are pruned or lopped periodically during the crop’s growth to provide green manure (which, upon natural recycling, enriches the soil nutrient status and improves physical properties) and to prevent shading of the growing crop(s). The hedgerows are allowed to grow freely to shade the inter-rows when there are no crops. Alley cropping retains the basic restorative attributes of the bush fallow through nutrient recycling, fertility regeneration besides effective weed suppression and combines these with arable cropping so that all processes occur concurrently on the same land, allowing the farmer to crop the land for an extended period. It is recommended that: a) Trees used in alley cropping must have deep roots, to minimize the competition for water and nutrients with food crops; 93

Environmental Issues and Sustainable Agriculture b) They should be fast growing; c) They should be able to re-sprout easily after pruning, coppicing or pollarding; d) They should ideally be multipurpose, i.e. capable of producing poles, wood, food, fodder, medicinal and other products; e) They should preferably be leguminous, able to fix their own nitrogen, so they provide protein rich leaves for livestock and nitrogen-rich organic matter for the soil. Trees and shrubs in the Alley cropping system give the following benefits: a) Provide green manure or mulch for companion food crops. In this way plant nutrients are recycled from deeper soil layers; b) Provide, pruning yields that are applied as mulch besides giving shade during the fallow to suppress weeds; c) Provides favourable conditions for soil macro- and microorganisms; d) When planted along the contours of sloping lands, provide a barrier to reduce soil erosion; e) The pruning yields provide browse (to feed livestock), staking materials and firewood; and f) Provides biologically fixed nitrogen to the companion crop(s). The major advantage of alley cropping over traditional shifting cultivation and bush fallow systems is that the cropping and fallow phases can take place concurrently on the same land, thus allowing the farmer to crop for an extended period without returning the land to bush fallow. Overall beneficial effects that are yielded by Alley cropping include: a) Better crop productivity due to the addition of nutrients and organic matter to the soil/plant system; b) Enhanced profitability by reduction in use of the chemical fertilizers due to green manuring and nitrogen fixing trees; c) Improves the physical nature of the soil environment; d) The addition of mulch lowers down soil temperatures, reduces evaporation, and improves soil fauna activity and soil structure for better infiltration, reduced run-off and improved water use efficiency; e) On undulating topography, the tree rows across the slope act as a physical barrier to surface runoff resulting in significant soil and water conservation; f) The additional products such as forage, firewood or stakes enhances profitability by the multipurpose tree legume used in the hedgerow; g) Improved weed control during the fallow period by shading of the interspaces, while in the cropping phase, the mulch may inhibit germination and establishment of weeds. Benefits of scattered trees on farmland include: a) Farmers antipathy for tree planting is reversed by the systems which adds value to the crops rather than behaving as competitors to the food crops; b) Trees provide shade for livestock during intense heat of the long dry season; c) The trees diversify farmers’ products, optimize crop production on sustainable basis and prolongs the duration of cropping the land without fertilizer use; d) Wind erosion control by the tree canopies in parklands which intercept wind-blown soil; e) Sale of non-timber products, such as fruits, fodder, floss, natural dyes, spices, medicines etc., significantly increases income. Limitations of scattered trees on farmland include: a) Scattered trees are often not at the optimum density that would confer maximum benefits to the environment and crop production; b) Reliance on naturally regenerating trees makes it difficult to improve the system through use of better germplasm; c) The trees are often browsed by livestock that are allowed to graze crop residues during the dry seasons. 94

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Windbreaks and Shelterbelts Wind in hot and arid zones is a menace causing serious damage over the sites through soil erosion. From the farmer’s point of view, gentle winds are advantageous as that facilitates pollination of crops and ensure proper seed dispersal for effective natural regeneration. Strong winds, on the other hand, are devastative and could be detrimental to agricultural crops, human life and properties. Some of the detrimental effects of strong winds on crops are listed below: a) Wind may increase transpiration rate, and this may exacerbate soil moisture deficits. b) It can spread pests and diseases because disease-causing spores and insects are dropped whenever wind speed is reduced. c) It can deform plants, cause crop lodging and/or affect carbon dioxide circulation. d) It can increase loss of top-soil through rill erosion, which may impair seedling growth especially in semi-arid areas. e) It can cause drifts during herbicide and insecticide spray; hence, leading to wasteful application and eco-toxicity.

Windbreaks: Windbreaks (Fig. 6.6)comprise narrow strips of trees, shrubs and/or grasses planted across the wind direction to protect fields, homes, canals, and areas from wind and blowing sand. In the areas having soil erosion and moisture loss problems due to desiccating strong winds, windbreaks can make a significant contribution to sustainable production.

Shelterbelt: Shelterbelt consist of comparatively wider strips of trees, shrubs and herbs (Fig. 6.7) that reduces wind speeds, thereby minimizing wind erosion, evaporation hazards and damage to sites, villages and adjoining farmlands. A shelterbelt acts as a mechanical barrier to the impact of the wind, and separates two zones; the windward and the leeward zones. The windward zone refers to the side from which the wind blows, whilst the leeward zone relates to the side behind the shelterbelts. As a thumb rule, a belt protects a distance up to its height on the windward side and up to 20 times its height on the leeward side.

Orientation of shelterbelts: As their main function is to protect agricultural lands against the hazards of wind and wind speed, shelterbelts are placed on the upwind side of the land to be protected. They are most effective when the shelterbelt is situated across (at right angles) to the prevailing wind direction. In case of a situation where wind direction changes throughout the year, a chessboard pattern is the best possible way to plant shelterbelts.

Home gardens (Tree-livestock-crop mix around homesteads) The word “home garden” has rather been used loosely to describe diverse practices, from growing vegetables behind houses to complex multistoried systems (Fig. 6.9). It is used here to refer to intimate association of multipurpose trees and shrubs with annual and permanent crops and, invariably livestock within the compounds of individual houses, with the whole crop-tree- animal unit being managed by family labour. These practices are common in all ecological regions in the tropics and subtropics, especially in humid lowlands with high population density. The average size of a home garden is usually much less than 1ha, yet in many parts of the world the fruit, nuts, edible leaves and other foodstuff grown in home gardens provide a substantial part of the household food requirement. An aspect of food production in home gardens is the almost consistent production that occurs throughout the year. The combination of crops with different production cycles and rhythms results in a relatively uninterrupted supply of food products. In most cases, animals are kept in the home garden. The animals can browse there and rest in the shade. Cattle, like buffaloes, are mostly kept for dairy products and land cultivation. Sheep, goats,

Environmental Issues and Sustainable Agriculture chickens and fish are kept for household consumption. Products from animals or the animals themselves can of course also be sold in the market.

Structure of home gardens: The layered configurations and combination of compatible species are the most conspicuous characteristics of all home gardens. Contrary to the appearance of random arrangement, the gardens are usually carefully structured systems with every component having a specific place and function. In general terms, all home gardens consist of a herbaceous layer near the ground, a tree layer at upper levels, and intermediate layers in between. The lower layer can usually be partitioned into two, with the lowermost (less than 1m height) dominated by different vegetable and medicinal plants, and the second layer (1-3m height) being composed of food plants such as cassava, banana, papaya, yam and so on. The upper tree layer can also be divided in two, consisting of emergent, fully grown timber and fruit trees occupying the uppermost layer of over 25m height, and medium-sized trees of 10-20m occupying the next lower layer. The intermediate layer of 3-10m height is dominated by various fruit trees, some of which would continue to grow taller. This layered structure is never static; the pool of replacement species results in a productive structure which is always dynamic while the overall structure and function of the system are maintained. Food production from home gardens: A conspicuous trait of the tree-crop component in home gardens is the predominance of fruit trees, and other food-producing trees. Apart from providing a steady supply of various types of edible products, these fruit and food trees are also compatible – both biologically and environmentally – with other components of the system. While fruit trees such as guava, mango and other food-producing trees such as Moringa oleifera and Sesbania grandiflora dominate the Asian home gardens, indigenous plants that produce leafy vegetables, fruits and condiments dominate the West African compound farms. Benefits of home gardens: Some of the benefits of home gardens are: a) Production is very diverse and continuous; risk is minimized and there is a daily flow of products such as food, fuel, fodder, fruit, spices and wood for construction; b) The protective function of home gardens is very high: soil protection, water retention and pleasant micro-climate for humans, animals and some plants; c) The use of labour for the farm is very efficient due to proximity of the garden to the house; also the walking distances in the garden from job to job are short; d) Valuable crops or animals in need of protection can be given extra care by the farm family (especially at night) because of the short distance from the house; e) Home gardens ensure a pleasant living environment; shade, wind shelter and provision of privacy; they can also satisfy aesthetic values and open patches often serve as family or village gathering places. Constraints of home gardens: the constraints of the home gardens include following: a) A specific constraintencountered in practicing home gardens is that; because of the high diversity of ecological niches, a home garden can provide a habitat for species that can become pests or introduce diseases, like snakes, insects and fungi. b) During tree harvesting other plants are often damaged. c) Proximity to homesteads makes houses prone to damage from falling branches and extensive lateral roots from trees.

Environmental Issues and Sustainable Agriculture

Chapter-13

Introduction to Important Tree Species

1Mohit Husain, 2M.A. Islam and 3M.J. Dobriyal 1Senior Research fellow, Dept. of Silviculure& Agoforestry, NAU, Gujarat-396450 2Associate Professor & Head (NRM)-FOF, SKUAST-Kashmir-190025 3Associate Professor & Head (SAF)-ACHF, NAU, Gujarat-396450

Fast Growing Tree Species Fast-growing species are those which yield a minimum of 10 cubic meters of wood per hectare per annum. In case of younger plantation, a height increment of 60 cm per annum is considered necessary for fast growing species. This concept of fast growth in forestry is relative and it depends upon several factors like locality, age, management objective. To meet rising population demand for food and wood in India there is intense pressure on cultivable land and existing forests. The escalating demand of food can be attained either by increasing the farm area or the productivity, however, to increase the farm area has limited options therefore, enhancing the productivity of agricultural field with integration of trees, as agroforestry is the only economic and viable option. In the order to meet the requirement, particularly for wood and tree derived produce the fast growing species are playing major role to increase the productivity. On the other hand the increasing concentration of Carbon in the atmosphere is creating difficulty to the biological entities which needs to be minimized, where fast growing tree are playing role in Carbon Sequestration. At present the thrust has been given to the exotic species in India like Eucalyptus, Populur, Casurina, Robinia, Mangium etc. in Haryana, Punjab, Western Uttar Pradesh and parts of Uttarakhand along with some other states plantation under agroforestry are mainly comprised Eucalyptus and Poplar. Moreover the tree species like Acacia, Casurina, and Teak etc. are being encouraged in agroforestry but still adoption is average only. These trees has limitation for the most of the agro-climatic regions of India particularly Madhya Pradesh, Assam, West Bengal, North Eastern states and Maharashtra.

Description of some important tree species with their cultivation practices in India

Lal Chandan or Rakta Chandan Common name- Red Sanders, Red Sandalwood, Ruby Wood Botanical name- Pterocarpus santalinus Family- Fabaceae Red sander is a light-demanding moderate sized tree growing upto 8 m tall with a trunk 50–150 cm diameter. It is fast-growing when young, reaching 5 m tall in three years even on degraded soils. It is not frost tolerant, being killed by temperatures of -1 °C but stays well at semi- arid climatic conditions. The leaves are alternate, 3–9 cm long, trifoliate with three leaflets. The flowers are produced in short racemes. In Hinduism, this wood has been traditionally used as a sacred wood. The priests and higher class casts such as Brahmin extensively use this wood on many of their rituals. It is observed that the red sanders grown on the shale type of subsoil, at an altitude of 750 meters above sea level. Red sanders with wavy grain margin fetch a higher price than the non- wavy wood. It is used in diseases like cough, vomiting, fever, hyperdipsia, helminthiasis, diseases of the blood and eye, wounds etc. The heartwood and fruits of Rakta chandan have great medicinal value. It reduces the burning sensation, arrests bleeding, alleviates edema and ameliorates various

Environmental Issues and Sustainable Agriculture skin disorders, hence, is an effective external application as a paste, in burning sensation, headache, dermatoses and ophthalcopathies.This species is listed as Endangered by the IUCN, because of overexploitation for its timber.

Semul Common name- Cotton Tree, Bombax, Red Silk Cotton Tree and Kapok Botanical name- Bombax ceiba Family- Malvaceae Semul grows to an average of 20 meters, with old trees up to 60 meters in wet tropical weather. This tree has a straight trunk and its leaves are deciduous in winter. Red flowers with 5 petals appear in the spring before the new foliage. It produces a capsule which, when ripe, contains white fibres like cotton. Trees from seeds begin flowering when 8 to 10 feet tall, and can reach 30 feet in five years. Although its stout trunk suggests that it is useful for timber, its wood is too soft to be very useful. It is easy to work but not durable anywhere other than under water. So it is popular for construction work, but is very good and prized for manufacture of plywood, match boxes and sticks, scabbards, patterns, moulds, etc. Also for making canoes and light duty boats and or other structures required under water. Semul trees bear beautiful red-colored flowers during January to March when the tree is deciduous. The flowers are 6 to 7 inches long and are up to 7 inches wide. They are borne solitary or in clusters at or near the ends of the branches. The flower consist of five satiny, red, scarlet, or sometimes white petals. The fruit, a ball like structure, on maturity appears during March and April. These are full of cotton-like fibrous stuff. It is for the fiber that villagers gather the semul fruit and extract the cotton substance called "kopak". This substance is used for filling economically priced pillows, quilts, sofas etc. The fruit is cooked and eaten and also pickled. The roots are used in the treatment of diarrhea, dysentery, menorrhagia, styptic and for wounds. The gum is useful in dysentery, hemoptysis, pulmonary tuberculosis, influenza, burning sensation, menorrhagia and enteritis. Bark is used for healing wounds and to stop bleeding. Flowers are astringent and good for skin troubles and haemorrhoids. Seeds are useful in treating gonorrhea and chronic cystitis. Young fruits are useful in calculus affections, chronic inflammations and ulceration of bladder and kidney.

Mahua or Mahuwa Common name- Mahua and IIuppi Botanical name- Madhuca longifolia Family-Sapotaceae Mahua is a tropical deciduous fast-growing tree that grows to 20 meters in height and possesses evergreen or semi-evergreen foliage. It is cultivated in warm and humid regions for its oleaginous seeds, flowers and wood. The tree grows on a wide variety of soils but thrives best on sandy soil. The species is drought-resistant, strong light demander and readily suppressed under shade. It is not frost-hardy. It also grows on shallow, clayey and calcareous soils.The fat is used for the care of the skin, to manufacture soap or detergents, and as a vegetable butter. It can also be used as a fuel oil. A full grown tree can produce up to 90 kg of flowers in a year. The fruit contains 51% valuable oil known as mahua oil or butter of commerce that is used for cooking, illumination, soap and candle making.Outer fruit coat is eaten as a vegetable and the fleshy cotyledons are dried and ground into a meal. The product is often used in sweets and chocolates under the name "illipe". The seed cakes obtained after extraction of oil constitute very good fertilizer. The flowers are used to produce an alcoholic drink in tropical India. Several parts of the tree, including the bark, are used for their medicinal properties. It is considered holy by many tribal communities because of its usefulness.

Environmental Issues and Sustainable Agriculture

The tree is considered a boon by the tribes who are forest dwellers and keenly conserve this tree. However, conservation of this tree has been marginalized, as it is not favoured by non- tribes. The leaves of Madhuca longifolia are fed on by the moth Antheraea paphia, which produces tassar silk (tussah), a form of wild silk of commercial importance in India. Leaves, flowers and fruits are also lopped to feed goats and sheep. The mahua flower is edible and is a food item for tribes. They are used to make syrup for medicinal purposes.

Sagaun Common name- Teak and Indian oak Botanical name- Tectona grandis Family- Lamiaceae Teak isa tall deciduous tree. It has yellowish blonde to reddish brown wood. It attains the height of about 30 meter.Teak will survive and grow under a wide range of climatic and edaphic conditions. It grows best in a warm, moist, tropical climate with a significant difference between dry and wet seasons. It is a pioneer species, but with a long life span. The fruit is a drupe. It has bluish to white flowers. Teak timber fetches very high price because of its grain, colour and strength. The very name of the tree translates into Carpenters Pride and is one of the most sought after timber in Indian market. It is used in the furniture making, boat decks and for indoor flooring. It is widely used to make the doors and house windows. It is resistant to the attack of termites. Its wood contains scented oil which is the repellent to insects. The leaves yield the dye which is used to colour the clothes and edible. Teak is probably the best protected commercial species in the world. Mature teak fetches a very good price. It is grown extensively by forest departments of different states in forest areas. Teak's high oil content, strong tensile strength and tight grain makes it particularly suitable for outdoor furniture applications. Teak is durable even when not treated with oil or varnish.Teak also holds medicinal value. The bark is bitter tonic and is considered useful in fever. It is also useful in headache and stomach problems. Digestion may be enhanced by the teak wood or bark.

Sissoo or Biradi Common name-Shisham, Bombay Blackwood and Indian Rosewood Botanical name-Dalbergia sissoo Family-Fabaceae Shisham is a medium to large fast growing deciduous tree, native to India, with a light crown which reproduces by seeds and suckers. It can grow up to a maximum of 25 m in height and 2m to 3m in diameter, but is usually smaller. It has been established in irrigated plantations, along roadsides and canals, and around farms and orchards as windbreaks. Dalbergia sissoo is best known internationally as a premier timber species of the rosewood genus. However, sissoo is also an important fuelwood, shade, shelter and fodder tree. With its multiple products, tolerance of light frosts and long dry seasons, this species deserves greater consideration for agroforestry applications. Sissoo is among the finest cabinet, furniture and veneer timbers. The heartwood is golden to dark brown, and sapwood white to pale brownish white. The heartwood is extremely durable and is resistant to dry-wood termites. Young branches and foliage form an excellent fodder with a dry-matter content. It is used for high-quality furniture, cabinets, decorative veneer, marine and aircraft grade plywood, ornamental turnery, carving, engraving, tool handles and sporting goods. Its root wood is used for tobacco pipes.Oil obtained from the seeds is used to cure skin diseases. The powdered wood, applied externally as a paste, is reportedly used to treat leprosy and skin diseases. The roots contain tectoridin, which is used medicinally. 99

Environmental Issues and Sustainable Agriculture

Babool Common name- Gum arabic tree, Thorn mimosa and thorny acacia Botanical name-Vachellia nilotica Family-Fabaceae Baboolis a tree 5m – 20 m high preferring sandy or sterile regions, with the climate dry during the greater part of the year. The crown is somewhat flattened or rounded, with a moderate density. The branches have a tendency to droop downwards if the crown is roundish. Babool is a slow growing species but is moderately long-lived. The species can withstand extremely dry environments and can also endure floods. Acacia nilotica makes a good protective hedge because of its thorns. In part of its range small stock consume the pods and leaves, but elsewhere it is also very popular with cattle. Pods are used as a supplement to poultry rations in India. In India branches are commonly lopped for fodder. In the wild, the pods- especially when dried-and leaves are consumed by small animals like sheep, but cattle also seem to find them very tasty. The pods are toxic to goats. They are best fed dry as a supplement, not as a green fodder. The wood is strong, durable, hard, very shock resistant, and is used for construction, mine props, tool handles and carts. It has a high calorific value and makes excellent fuelwood and quality charcoal. The bark contains a 12 percent to 20 percent concentration of tannin, which is used in tanning all kinds of leather. The ink made from acacia nilotica has been used for centuries to dye calico cloth. Babool has a wealth of medicinal uses. It is used for stomach upset and pain, the bark is chewed to protect against scurvy, an infusion is taken for dysentery and diarrhoea. The species has also been used in veterinary medicine, for example as a molluscicide to reduce liver- flukes in cattle. The pods are desirable as fodder for cattle, and the leaves, young shoots and young pods are thought to aid milk production. The trees begin fruiting within 5-7 years and yield about 18 kg pods/year.

Arjun Common name-Arjuna and arjun tree Botanical name-Terminalia arjuna Family- Combretaceae Arjuna is a large, deciduous, fast growing tree usually has a buttressed trunk, and forms a wide canopy at the crown, from which branches drop downwards. The arjuna tree is usually found growing on river banks or near dry river beds in West Bengal and south and central India. It is an evergreen tree with yellow flowers and conical leaves. The arjuna tree is one of the species whose leaves are fed on by the Antheraea paphia moth which produces the tassar silk (tussah), a wild silk of commercial importance. The arjuna tree was introduced into Ayurveda as a treatment for heart disease. It is traditionally prepared as a milk decoction. It has many health benefits, some of which are listed below:-

Anti-inflammatory properties: The Arjun tree bark has anti-inflammatory properties which act anti-inflammatory agents. Controls cholesterol: Studies have shown that Arjuna tree is effective in bringing down LDL cholesterol levels. Keeps diabetes in check: Extracts from Arjun tree bark were very effective in controlling diabetes, concluding Arjuna to be a potent diabetes reducing agent. Treats asthma: The Arjuna tree bark can be very effective in the treatment of asthma. Fine powder of the dried bark must be taken with kheer or rice and milk pudding. Fractures and other injuries: The powdered dry bark of Arjun tree can be taken along with honey to restore strength to fractured bones. 100

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Arjun Tea is herbal, caffeine-free tea made from the bark of arjuna tree. The tea is useful for almost every other health problem. Arjuna helps maintain a healthy heart and reduces the effects of stress and nervousness. It induces a drug-dependent decrease in blood pressure and heart rate. Arjuna can also relieve symptomatic complaints of essential hypertension such as giddiness, insomnia, lassitude, headache and the inability to concentrate. Its wood is used in boat and house building as it is very hard. Its wood is also used in the making of the agricultural implements and weapons too. It is grown in the cities and towns for the purpose of shade.

Mangroves Common name-Mangrove Botanical name-Rhizophora mangle Family-Rhizophoraceae Mangroves are a family of about 70 different species of trees worldwide. Mangroves grow in the tropics only and mainly in coastal areas. Mangrove forests have an important function in our ecosystem as natural coastal protection; the extended root systems of every mangrove tree are a nursery. Mangrove forests are among the most productive terrestrial eco systems. Mangrove plants require a number of physiological adaptations to overcome the problems of anoxia, high salinity and frequent tidal inundation. For instance, to adapt to the anaerobic mud, some mangroves have developed pencil like roots which come out into the air and is called Pneumatophores (breathing roots).They provide critical habitat for a diverse marine and terrestrial flora and fauna. It provides habitats for fish, crabs, oysters, lobsters and shrimps. Their roots provide attachment surfaces for marine organisms such as colorful sponges. Mangroves plants filter out pollution, stabilize sediments, hold nutrients, protect the shoreline from erosions and provide food, nesting and nursery areas for a variety of animals. These plants are specially adapted to harsh environmental conditions and protect shorelines. They are a source of honey, firewood and medicines. Fruits of some Mangroves are used in making pickle. Bark of some Mangroves are used for treating several ailments and it also produces substances used in tanning and dye making. Oil from seeds of some Mangrove species are used in making Soaps in Rajasthan. Meswak is a popular Mangrove which is scientifically proven to help in preventing tooth decay. Some Mangroves produce high quality honey which is commercially of high value.

Shikakai Common name-Shikakai Botanical name-Acacia concinna Family-Fabaceae Shikakai is a climbing shrub native to Asia, common in the warm plains of central and south India. The plants are medium fast growing and which is bushy cum creeper. These plants having curvy thorns, once the plants are developed animals even elephants not able to cross. The benefits of Acacia concinna are extracted from the pods of the shrub. Acacia Concinna grows in abundance in the hot, dry climates of Central Asia and the Far East. The pods of this plant are rich in saponins which are foam forming substances. Acacia concinna is known in Ayurvedic medicine as Shikakai.The shikakai fruits are having good market, which will fetch good prices, these dried fruits are used to manufacture in herbal products and shampoo. For centuries the people who have had access to Acacia concinna tree have used its pod-like fruit to clean their hair. They collect, dry and grind this pods into a powder, which is considered a superior cleanser for "lustrous long hair" and has been reported as "promoting hair growth and preventing dandruff and Premature graying hair". Because of these benefits, this powder was named "Shikakai" which literally translates as "fruit for the hair”. Wherein Shika means Hair and Kai means fruit. The bark contains high levels 101

Environmental Issues and Sustainable Agriculture of saponins, which foaming agents are found in several other plant species used as shampoos or soaps.An infusion of the leaves is used in malarial fever. A decoction of the pods relieves biliousness and acts as a purgative. It is used to remove dandruff. An ointment, prepared from the ground pods, is good for skin diseases. The pods are reported to be used in north Bengal for poisoning fish.

Neem Common name-Indian Lilac, Chinaberry, Margosa Tree, Paradise Tree and White Cedar Botanical name-Azadirachta indica Family-Meliaceae Neem is perhaps the most useful traditional medicinal plant in India. Each part of the neem tree has some medicinal property and is thus commercially exploitable. It has, for a very long time, been a friend and protector of the Indian villager. Brihat Samhita, an ancient Hindu treatise, contains a chapter of verses on plant medicines. It contains recommendations for specific trees to be planted in the vicinity of one's house. Neem was highly recommended. Neem is a medium to large sized tree and has straight trunk and long spreading branches forming a broad round crown and hence grown as Avenue tree. Bark is moderately thick, furrowed dark brown to grey black. The tree matures in 10 - 15 years and has a religious significance. All parts of tree are bitter and medicinal. In India it is said that, where there are large number of Neem trees, there are no diseases. With an extensive and deep root system, the hardy Neem can grow luxuriantly even in marginal and leached soils, and thrives up to an elevation of 1500m. The Neem flowers between February and May. The honey-scented white flowers, found in clusters, are a good source of nectar for bees. Neem fruits are green drupes which turn golden yellow on ripening in summers in India. The kernels have about 45% oil. The termite resistant Neem timber is used as a building material, and in making furniture and farm implements. The bark yields tannin and gum. The amber hued gum is used as a dye in textiles and in traditional medicines. Neem fruits, seeds, oil, leaves, bark and roots have such uses as general antiseptics, antimicrobials, treatment of urinary disorders, diarrhoea, fever and bronchitis, skin diseases, septic sores, infected burns, hypertension and inflammatory diseases. Neem has proved effective against certain fungi that infect the human body. Neem tree starts fruiting from 3 to 5 years and is fully productive by 10 years.

Moringa Common name-Drumstick Tree Botanical name-Moringa oleifera Family-Moringaceae Moringa one of the most cultivated tree in India. It is also known as drumstick tree, from the appearance of the long, slender, triangular seed pods. It is a small, shrub or tree that can reach 12m in height at maturity and can live for up to 20 years. It has deep roots, and therefore it can survive in dry regions, and a wide-open crown with a single stem. Moringa oleifera is a nutritious vegetable tree with a variety of potential uses. It is a fast-growing, drought-resistant tree; it is considered one of the world's most useful trees. Every part of the Moringa tree, from the roots to the leaves has beneficial properties that can serve humanity. Moringa oleifera tree can be used for food or has some other beneficial property. In many countries, Moringa oleifera is used as a micronutrient powder to treat diseases. Moringa grows in many subtropical areas, where malnutrition is most prevalent. Leaves can be eaten fresh, cooked, or stored as dried powder for many months without refrigeration, and reportedly without loss of nutritional value. Moringa oleifera is especially promising as a food source in the tropics because the tree is in full leaf at the end of the dry season when other foods are typically scarce. Moringa trees have been used to 102

Environmental Issues and Sustainable Agriculture combat malnutrition, especially among infants and nursing mothers. In developing countries moringa has potential to improve nutrition, boost food security, foster rural development and support sustainable land care. It may be used as forage for livestock, a micronutrient liquid, a natural anthelmintic and possible adjuvant. A coarse fibre that is obtained from the bark is used in making mats, paper and cordage. Mature seeds yield 38–40% edible oil called ben oil from its high concentration of behenic acid. The refined oil is clear, odorless and resists rancidity. Moringa seed oil also has potential for use as a biofuel.

Karanj Common name-Indian beech, Mugul karanda and Kanju Botanical name-Pongamia pinnata Family-Fabaceae Karanj is a medium sized tree and is normally planted along the highways, roads and canals to stop soil erosion. It is one of the few nitrogen fixing trees to produce seeds containing 30-32% oil. Pongamia grows into a large tree with a 10-metre taproot, creating a huge carbon sink. It is often planted as an ornamental and shade tree. It is well-adapted to arid zones and has many traditional uses. It is often used for landscaping purposes as a windbreak or for shade due to the large canopy and showy fragrant flowers. The flowers are used by gardeners as compost for plants requiring rich nutrients. The bark can be used to make twine or rope and it also yields a black gum that has historically been used to treat wounds caused by poisonous fish. The wood is said to be beautifully grained but splits easily when sawn thus relegating it to firewood, posts, and tool handles. Oil made from the seeds, known as honge oil, is an important asset of this tree and has been used as lamp oil, in soap making, and as a lubricant for thousands of years. It acts an important feedstock for Bio-diesel. In India, Pongamia is used in land reclamation as a soil stabilizer and now majorly as a biodiesel crop.

Kala Siris Common name-Lebbek Tree, Flea Tree and woman’s tongue tree Botanical name-Albizia lebbeck Family-Fabaceae Albiziais a well-known tree in the Indian subcontinent for its range of uses. It appears to have potential for increasing pastoral production in extensive systems in the wet-dry tropics where the major problem is low feed quality of the basal diet, mature tropical grasses. Albizia lebbeck addresses this problem in three ways: as a feed, as a supplement and by improving grass quality. A medium to large tree, of multi-stemmed widely spreading habit (to 30 m diameter) when grown in the open, but capable of good log form in plantation. It is a nitrogen-fixing tree, with value for shade, quality hardwood (cabinet, veneer and construction), fuel-wood and charcoal, and honey (source of nectar and pollen). The extensive, shallow root system makes it a good soil binder and suited to soil conservation and erosion control. Various parts of the tree are used in folk remedies for many ailments. It is also used as an ornamental and avenue tree, and sometimes as a shade tree in coffee and tea. The bark contains saponins and tannins, used for making soap and in tanning. It is grown in some areas primarily as fodder for camels, water buffalo and cattle. The leaves are reported to be good fodder, with 17-26% crude protein; 100 kg of leaves yield 11-12 kg of digestible protein, and 37 kg of digestible carbohydrates.

Beleric Common name-Bahera and Bastard myrobalan Botanical name-Terminalia bellirica Family-Combretaceae 103

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Beleric is a large deciduous tree found throughout India, in areas up to an altitude of 1,000 meters. The tree takes a height of 30 meters, while the bark is brownish grey in color. The tree yields a good-quality firewood and charcoal with calorific value of sapwood being 5000 kcal/kg. The leaves are about 15 cm long and crowded toward the ends of the branches. It is considered a good fodder for cattle. It seeds have an oil content of 40%, whose fatty-acid methyl ester meets all of the major biodiesel requirements in the USA, Germany and European Union. The fruit rind is astringent, laxative, anthelmintic, pungent, germicidal and antipyretic. It is applied ina diverse range of conditions including cough, tuberculosis, eye diseases, anti-HIV-1, dyspepsia, diarrhoea, dysentery, inflammation of the small intestine, biliousness, flatulence, liver disease, leprosy, cleanse the blood and promote hair growth in the Ayurvedic drug. The kernel produces a non-edible oil used in toilet soap.

Harad Common name-Harra and Black or chebulic myrobalan Botanical name-Terminalia chebula Family-Combretaceae Harra is a deciduous tree growing to 30-metre (98 ft.) tall, with a trunk up to 1 m (3 ft. 3 in) in diameter. Highly esteemed by the Hindus, and a mythological origin has been assigned to it. It is said that when Indra(king of dieties in Hindu mythology) was drinking nectar in heaven, a drop of the fluid fell on the earth and produced Haritaki. The flowers are dull white with spikes and can be found at the end of the branches. The fruit is hard and yellowish green in color. Each fruit has a single seed that is light yellow in color. The tree can be found in the sub Himalayan tracks, from Ravi to West Bengal and in the deciduous forests of Madhya Pradesh, Bihar, Assam and Maharashtra. Small, ribbed and nut-like fruits which are picked when still green and then pickled, boiled with a little added sugar in their own syrup or used in preserves. The seed of the fruit, which has an elliptical shape, is an abrasive seed enveloped by a fleshy and firm pulp. It is regarded as a universal panacea in the Ayurvedic-Vedic Medicine and in the Traditional Tibetan medicine. It is reputed to cure blindness and it is believed to inhibit the growth of malignant tumors. Haritiki is one of the three constituents of "Triphala" which is a renowned Ayurvedic prescription for variety of ailments. Haritaki is a rejuvenative, laxative (unripe), astringent (ripe), anthelmintic, nervine, expectorant, tonic, carminative, and appetite stimulant.

Jungle Jalebi Common name-Ganges Tamarind, Monkeypodand Madras thorn Botanical name-Pithecellobium dulce Family-Fabaceae P. dulce is atree that reaches a height of about 10 to 15 m. Its hardy American tree is native along coasts from California through Mexico to South America but is now found throughout the tropics. It is now common and naturalized in India and tropical Africa, especially along coasts. Its trunk is spiny and its leaves are bipinnate. The flowers are greenish-white, fragrant, sessile and reach about 12 cm in length, though appear shorter due to coiling. The flowers produce a pod with an edible pulp. The seeds are black. The seeds are dispersed via birds that feed on the sweet pod. It is drought resistant and can survive in dry lands from sea level to an elevation of 300 m making it suitable for cultivation as a street tree. The seed pods contain a sweet pulp that can be eaten raw or prepared as a smoothie. In India seeds are used fresh or in curries. The pods are relished by monkeys and livestock. The flowers are attractive to bees as source of pollen. The resulting honey is of high quality. Although the pods are attractive fodder to most animals. The leaves are browsed but not considered an important animal fodder. The wood of P. dulce is strong and durable vet soft and flexible. It can be used in construction and for posts. The 104

Environmental Issues and Sustainable Agriculture reddish-brown heartwood is dense and difficult to cut. The short spines and irregular. Crooked growth make it less attractive for wood uses. The tree is used extensively as a shade or shelterbelt tree with a great tolerance of arid and harsh sites. It coppices readily and can be managed as a hedge.

Cassia Common name-Bombay Blackwood, Iron wood and Kassod Tree Botanical name-Cassia siamea Family-Fabaceae Cassia siamea isa medium sized evergreen tree having a great many branches. The leaves are arranged in cascades and the flowers hang in bunches not unlike grapes. The petals are yellow and are from 5 cm to 7 cm in length. The tree can be utilized to reforest denuded hills and mining sites, as host for sandalwood, for shade and hedges, as windbreaks, and it can be planted as an ornamental. The dense, dark-coloured wood of Sanna siamea makes good fuel, although it produces some smoke when burning. The energy value of the wood is 22 400 kJ/kg, and the density is 600-800 kg/m³. The wood was formerly preferred for locomotive engines. Its charcoal is also of excellent quality. The wood is hard to very hard, resistant to termites, strong, durable and difficult to work with a tendency to pick up in planning and it takes a high polish. Sapwood is permeable to pressure impregnation. The dark heartwood of S. siamea, which is often nicely figured, is used for joinery, cabinet making, inlaying, handles, sticks and other decorative uses. The wood has also been used for poles, posts, bridges, mine poles and beams. All parts of the plant can be used for tanning. The concentrations of tannin vary slightly from 17% in the leaves to 9% in the bark and 7% in the fruits. In traditional medicine, the fruit is used to charm away intestinal worms and to prevent convulsions in children. The heartwood is said to be a laxative, and in Cambodia a decoction is used against scabies. Cassia siamea functions as an excellent tranquillizer and has also been described as an anxiolytic (anti-anxiety agent). Furthermore, it has some analgesic (pain killing) and diuretic (promoting the removal of excess fluid) properties. In contrast to its pharmaceutic counterparts, cassia siamea does not produce side effects or toxicity, has no lethal dose, and above all does not lead to dependency (addiction). Cassia siamea is also a first class psycho pharmaceutical.

Cultivation practices of two important fast growing tree species of the region

Eucalyptus Common name- Safeda Botanical name- Eucalyptus spp. Family- Myrtaceae Eucalyptus is an Australian genus comprising of 140 species. They are evergreen species, all more or less aromatic and containing oil glands in their leaves. Eucalyptus regnans is the tallest known flowering plant on Earth Mysore gum (Eucalyptus tereticornis), flooded gum (Eucalyptus grandis), blue gum (Eucalyptus globulus) and lemon-scented gum (Eucalyptus citriodora) are the important eucalyptus species grown in Kerala. Mysore gum and flooded gum are important timber species in the low- and mid-altitudinal zones of the state, respectively. Australia is covered by 92,000,000 hectares (227,336,951 acres) of eucalypt forest, comprising three quarters of the area covered by native forest. The cultivation practices of these two species are described below. E. grandis grows best in deep, permanently moist, well-drained soils. E. tereticornis also prefers moist and well-drained soils such as loamy sands or alluvial loams, with high nutrient availability. A certain degree of salinity is tolerated, but strongly acid soils are ill suited. E. tereticornis adapts to a variety of sites, but responds poorly to excessively long dry periods. It is 105

Environmental Issues and Sustainable Agriculture very easy to regenerate both species and they are good coppicers. The number of seeds per kilogram for E. grandis is 2.5 million, whereby roughly 630 viable seeds can be expected per gram. In the case of E. tereticornis one gram contains approximately 540 seeds.

Fig.01. Eucalyptus plantation

Planting Stock Three-month-old containerized stock (polybag seedlings or. root trainer seedlings) is recommended for planting. For seedling production, sow the seeds in seed tray in February. Trays should be kept moist with a fine spray of water until germination begins. Germination begins 7-9 days after sowing. The seedlings should be pricked out when they have two pairs of leaves into poly-bags of size' 22 cm x 10 cm or root trainers. Planting stock of high yielding disease resistant clones are available at the KFRI / Kerala Forest Department nurseries.

Planting and Stand Management Best time for planting is the beginning of rains. Planting is usually done in 20 cm x 20 cm x 20 cm pits (for clones use 30 cm cube pits) at 3 m x 3 m spacing. For production of pulpwood and fuel-wood, 6 -10 year rotations are used without thinning. Depending on site conditions, E. grandis and E. tereticornis may respond to mineral fertilization with accelerated growth. Fertilizers may be applied at the rate of 30 g N, 30 g P2O5 and 15 K 2O per sapling per year during the second, third and fourth years.

Injuries and Protection Polyphagous insects seem to attack the nursery stock. Quinalphos or malathion 0.05% is recommended against them. Drenching the containers with chlorpyrifos is a preventive measure against termite attack in plantations. Quinalphos 0.2% solution is recommended to control stem borer attack. Cylindrocladium leaf blight and pink diseases are common in eucalyptus trees. To control. Cylindrocladium leaf blight, drench the nursery with carbendazim 0.05%. Bordeaux paste is recommended against pink disease. Using disease tolerant clones is a sure means of preventing the incidence of both diseases.

Uses E. grandis wood is pink to pale reddish brown in colour. It has good bending properties. It is used for housing construction, floors, furniture, crates, and veneers, in the paper industry and as fuel-wood. E. tereticornis produces dark red wood. It is hard, strong, tough, heavy, very durable and resistant to termite attack. It is used for a wide range of construction applications, suited for trench linings and fuel-wood.

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Casuarina Common name- Casuarina Botanical name- Casuarina equisetifolia Family- Casuarinaceae Commonly known as the she-oak, ironwood, or beefwood. Casuarina is a genus of 17 tree species in the family Casuarinaceae. It isnative to Australia, Indian subcontinent, South East Asia and islands of the western Pacific Ocean. They are evergreen shrubs and trees growing to 35 meter tall. The foliage consists of slender, much-branched green to grey-green twigs bearing minute scale-leaves in whorls of 5–20.The apetalous flowers are produced in small catkin-like inflorescence. Most species are dioecious but a few are monoecious. The fruit is a woody, oval structure superficially resembling a conifer cone, made up of numerous carpels, each containing a single seed with a small wing. The generic name is derived from the Malay word for the cassowary, kasuari, alluding to the similarities between the bird's feathers and the plant's foliage, though the tree is called rhu in current standard Malay. Casuarina is a large evergreen tree with a straight bole and numerous, long, slender, drooping, jointed, leafless branchlets arising from rough woody branches. The jointed branchlets, which are partly deciduous, are green and perform the functions of leaves. Leaves are minute scale like and arranged in the form of a cup at the joints of the branchlets. Bark is brown, rough, fibrous and exfoliating in longitudinal strips. Wood is very hard, but liable to crack and split. It is used as timber, poles, pulp and paper besides fuel-wood. Casuarina is grown as an ornamental tree throughout the tropical and subtropical parts of India. In addition, it can be grown in agroforestry combinations involving diverse crops. Fodder grasses, other agronomic crops such as pulses, oil seeds and vegetables, coconut palms and tree crops such as teak and ailanthus are important in this respect.

Fig.02. Casuarina plantation

Propagation Propagation is by seeds or through vegetative means. For seedling production, about half kg seeds are sown on raised nursery beds of 10m x 1m. This will produce about 10,000 good quality seedlings. If the soil is sandy, mix farmyard manure with the topsoil. After sowing the seeds, a thin layer of sand is sprinkled to cover the seeds. Usually sowing is done in Nov- December. Regular watering and shading of the nursery beds are necessary to facilitate rapid seed germination. Germination takes about 10 days and seedlings attain a height of 10-15 cm in 6 weeks. They are then pricked out into polythene bags or transplanted into beds of size 1m x 10m in January-February. Vegetative propagation is by branch cuttings, stump cuttings and layering. For vegetative propagation by rooting of branch cuttings, treat 5-7 cm long cladode cuttings with rooting hormones. The hormone treated cladodes are transferred to presoaked vermiculite and kept in a mist chamber. About hundred per cent rooting is obtained within 15 days. The rooted cuttings are

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Environmental Issues and Sustainable Agriculture then transferred to a mixture of sand, soil and farm yard manure (2: 1: 1) for hardening. After 15 days, the hardened propagules can be transferred to the field.

Planting and Stand Management Casuarina has a wide environmental adaptability and hence occupies sites ranging from arid regions to coastal zones. Being an actinorhizal plant, casuarina is capable of biological nitrogen fixation.Therefore, it thrives best on sandy soils low in nitrogen and has the potential to improve the nitrogen capital of impoverished sites. Site preparation includes ploughing the land 2-3 times and making 30 x 30 x 30 cm pits before the onset of monsoon. The pits are filled with farm yard manure and topsoil. Planting is done immediately after the first rains. Block planting, row planting and line or strip planting are common. Spacing varies depending on the objective and the end product. Usually a spacing of 75 cm x 75 cm is adopted. One or two weeding is done immediately after the rains. When the trees are about 3 m in height, the lateral branches are pruned to a height of about 2 m. Pruning is usually done at the end of the second year or after the beginning of the third year. In plantations established at close spacing (75cm x 75 cm), one thinning in the second year or third year depending on tree growth is desirable, where 25-50% of the trees are felled. In mixed species systems such as agroforestry, spacing and thinning practices are mainly dependent on the cropping systems and the nature of the associated species. If the associated crops are shade intolerant generally wider spacing and or intensive thinning are recommended. Fertilizers may be applied at the rate of 20-25 g N, 15-20 g P2O5 and 1520 g K2O per seedling per year from the second year to the fifth year.

Injuries and Protection Damping off, seedling blight, stem canker and seedling rot are encountered in the nurseries. Emisan 0.01% is effective against these diseases. Stem-wilt or bark blister disease caused by Trichosporium vesiculosum is a serious disease in the plantations. The disease affects trees of 3-4 years and causes mortality up to 80%. Maintaining a soil pH of 6.5 to 6.8 and treating the plantation with fungicidal sprays can control this disease. Other diseases include stem canker and dieback caused by Phomopsis casuarinae, pink disease caused by Corticium salmonicolor, root rot disease caused by Ganoderma lucidum and heart rot caused by Polyporus glomeratus, Fomes fastuosus and F. senex. Stem canker and dieback can be controlled by carbendazim @ 0.01 %. Insect pest problems to the tune of regular epidemic infestations inflicting extensive economic losses rarely occur in casuarina.

Harvest Casuarina seedlings growing rapidly at the rate of about 1.2 to 1.5 m per annum during the initial seven to eight years are usually harvested in about 7-10 years. Yield of high density fuelwood plantations varies from 10-20 tonnes per ha per year on 7-10 years rotations. Higher yields are reported from irrigated and fertilized sites.

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Chapter-14

Utilization Pattern as fuel: by collection of wastes, site handling, storage and processing

Yashwant Kumar Patel1 and Soumitra Tiwari1 1 Assistant Professor, Department of Food Processing and Technology, Atal Bihari Vajpayee Vishwavidyalaya, Bilaspur, Chhattisgarh, India *Corresponding email: [email protected]

Introduction Onsite means these functions are concerned with solid waste at the place where the waste is generated. For residential waste this means at home in the household. Onsite handling is the very first step in waste management. It involves individual family members, households and communities, all of whom need to know how to handle waste properly at this level. ‘Handling’ means the separation of wastes into their different types so they can be dealt with in the most appropriate way, for example, separating putrescible waste for composting. The benefits of appropriate onsite handling include reducing the volume of waste for final disposal and recovering usable materials. Onsite storage means the temporary collection of waste at the household level. It is important that waste is stored in proper containers. These could be baskets, preferably made from locally available materials, plastic buckets or metal containers. Larger containers or dustbins, especially those used for food waste, should be leakproof, have tight lids and be long-lasting. The size of the container should be sufficient to hold at least the amount of solid waste that is generated per day at household level. Institutions and businesses should consider having onsite storage facilities with greater capacity. The proper location of storage containers and the frequency and time of emptying are important factors to be considered for efficient onsite storage. Some wastes will need some sort of onsite processing before the next steps, for example, in areas where false banana (enset) is used as a staple crop, the byproducts should be chopped into pieces before composting to speed up the rate of decomposition (http://labspace.open.ac.uk).

Collection, Transfer and Transport of Solid Waste In urban centres, collection is a function that has its own process and services. Waste is collected and held at central transfer stations where waste is stored before it is transported to a final disposal site. In rural areas, waste is not normally collected in this way and disposal is limited to onsite processing options, although sometimes there may be communal collection of solid waste using animal carts (http://labspace.open.ac.uk).

Storage and Disposal • The Organiser is unable to provide storage facilities for packing materials, carton boxes or other property of the Exhibitor. • Exhibitors requiring storage facilities should make prior arrangements with the Official Forwarding & Logistics Agents or through their own transport agent. • The Organiser reserves the rights to remove/dispose of any carton, cases and/packing materials left or abandoned in the exhibition halls or their vicinity (entrance and exit, loading bay, etc) on the eve of exhibition/exhibition day or after the dismantling period. Any cost incurred will be borned by the Exhibitor (http://www.iffs.com.sg).

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Waste Handling, Packaging and Labeling

Packaging Bulk liquid should be moved using pumps of material compatible with and capable of handling the type of liquid waste being stored. During transfer of bulk solid hazardous waste, attention should be paid to spillage as of the waste is moved to the container. Drums should be transferred using forklifts which sometimes must be flame-proofed. 1) An internal communications or alarm system. 2) A telephone or hand-held tv.'o-way radio. 3) Portable fire extinguishers, fire and spill control equipment 4) First aid stations to include emergency showers, eye-wash facilities, basic first aid facilities, stretchers, fire blankets, emergency lighting, and luminous tape.

Labeling Labels is given below: - 1) Clear signs or symbols indicating the hazardous nature of the contents. 2) The container's contents active substances, and concentrations. 3) The original source of the waste. 4) Total and net weights. 5) Dare when the container was filled and when the waste was generated. 6) Name and contacts for the person responsible for filling the container. 7) Safe storage method and mixing with other reactive substances or wastes. 8) Personal protective gear needed for handling. 9) The best manner for dealing with emergencies (leakage, spills, fire, etc.). 10) Special precautions for opening and emptying.

Waste to Energy Conversion Introduction The enormous increase in the quantum and diversity of waste materials generated by human activity and their potentially harmful effects on the general environment and public health, have led to an increasing awareness, world-wide, about an urgent need to adopt scientific methods for safe disposal of wastes. While there is an obvious need to minimize the generation of wastes and to reuse and recycle them, the technologies for recovery of energy from wastes can play a vital role in mitigating the problems. Besides recovery of substantial energy, these technologies can lead to a substantial reduction in the overall waste quantities requiring final disposal, which can be better managed for safe disposal in a controlled manner while meeting the pollution control standards. Waste generation rates are affected by socioeconomic development, degree of industrialization, and climate. Generally, the greater the economic prosperity and the higher percentage of urban population, the greater the amount of solid waste produced. Reduction in the volume and mass of solid waste is a crucial issue especially in the light of limited availability of final disposal sites in many parts of the world. Although numerous waste and byproduct recovery processes have been introduced, anaerobic digestion has unique and integrative potential, simultaneously acting as a waste treatment and recovery process.

Waste-to-Energy Conversion Pathways There are three main pathways for conversion of organic waste material to energy – thermochemical, biochemical and physicochemical. Thermochemical conversion, characterized by higher temperature and conversion rates, is best suited for lower moisture feedstock and is 110

Environmental Issues and Sustainable Agriculture generally less selective for products. Thermochemical conversion includes incineration, pyrolysis and gasification. The incineration technology is the controlled combustion of waste with the recovery of heat to produce steam which in turn produces power through steam turbines. Pyrolysis and gasification represent refined thermal treatment methods as alternatives to incineration and are characterized by the transformation of the waste into product gas as energy carrier for later combustion in, for example, a boiler or a gas engine. The bio-chemical conversion processes, which include anaerobic digestion and fermentation, are preferred for wastes having high percentage of organic biodegradable (putrescible) matter and high moisture content. Anaerobic digestion can be used to recover both nutrients and energy contained in organic wastes such as animal manure. The process generates gases with a high content of methane (55–70 %) as well as biofertilizer. Alcohol fermentation is the transformation of organic fraction of waste to ethanol by a series of biochemical reactions using specialized microorganisms. The physico-chemical technology involves various processes to improve physical and chemical properties of solid waste. The combustible fraction of the waste is converted into high- energy fuel pellets which may be used in steam generation. Fuel pellets have several distinct advantages over coal and wood because it is cleaner, free from incombustibles, has lower ash and moisture contents, is of uniform size, cost-effective, and eco-friendly.

Factors Affecting Energy Recovery The two main factors which determine the potential of recovery of energy from wastes are the quantity and quality (physico-chemical characteristics) of the waste. Some of the important physico-chemical parameters requiring consideration include: Size of constituents Fixed carbon Density Total inerts Moisture content Calorific value Volatile solids / Organic matter Often, an analysis of waste to determine the proportion of carbon, hydrogen, oxygen, nitrogen and sulfur (ultimate analysis) is done to make mass balance calculations, for both thermochemical and biochemical processes. In case of anaerobic digestion, the parameters C/N ratio (a measure of nutrient concentration available for bacterial growth) and toxicity (representing the presence of hazardous materials which inhibit bacterial growth), also require consideration.

Significance of Waste-to- Energy (WTE) Plants While some still confuse modern waste-to-energy plants with incinerators of the past, the environmental performance of the industry is beyond reproach. Studies have shown that communities that employ waste-to-energy technology have higher recycling rates than communities that do not utilize waste-to-energy. The recovery of ferrous and non-ferrous metals from waste-to-energy plants for recycling is strong and growing each year. In addition, numerous studies have determined that waste-to-energy plants actually reduce the amount of greenhouse gases that enter the atmosphere. Nowadays, waste-to-energy plants based on combustion technologies are highly efficient power plants that utilize municipal solid waste as their fuel rather than coal, oil or natural gas. Far better than expending energy to explore, recover, process and transport the fuel from some distant source, waste-to-energy plants find value in what others consider garbage. Waste-to-energy plants recover the thermal energy contained in the trash in highly efficient boilers that generate steam that can then be sold directly to industrial customers, or used on-site to drive turbines for electricity production. WTE plants are highly efficient in harnessing the untapped energy potential of organic waste by converting the biodegradable fraction of the waste into high calorific value 111

Environmental Issues and Sustainable Agriculture gases like methane. The digested portion of the waste is highly rich in nutrients and is widely used as biofertilizer in many parts of the world. Waste-to-Energy around the World To an even greater extent than in the United States, waste-to-energy has thrived in Europe and Asia as the preeminent method of waste disposal. Lauding waste-to-energy for its ability to reduce the volume of waste in an environmentally-friendly manner, generate valuable energy, and reduce greenhouse gas emissions, European nations rely on waste-to-energy as the preferred method of waste disposal. In fact, the European Union has issued a legally binding requirement for its member States to limit the land filling of biodegradable waste. The Confederation of European Waste-to-Energy Plants (CEWEP) notes that Europe currently treats 50 million ton of wastes at waste-to-energy plants each year, generating an amount of energy that can supply electricity for 27 million people or heat for 13 million people. Upcoming changes to EU legislation will have a profound impact on how much further the technology will help achieve environmental protection goals. Describing the advances of waste-to-energy, the German Ministry for the Environment cites drastic reductions in emissions of dioxin, dust and mercury. Twenty years ago, 18 Swedish waste-to-energy plants emitted a total of about 100 grams of dioxins every year. Today, the collective dioxin emissions from all 29 Swedish waste-to-energy plants amount to 0.7 of a gram. It is clear that Europe has made similar strides as the United States with respect to emissions reductions.

Feedstock for Waste-to-Energy Conversion Plants Agricultural Residues Large quantities of crop residues are produced annually worldwide, and are vastly underutilised. The most common agricultural residue is the rice husk, which makes up 25% of rice by mass. Other residues include sugar cane fibre (known as bagasse), coconut husks and shells, groundnut shells, cereal straw etc. Current farming practice is usually to plough these residues back into the soil, or they are burnt, left to decompose, or grazed by cattle. A number of agricultural and biomass studies, however, have concluded that it may be appropriate to remove and utilise a portion of crop residue for energy production, providing large volumes of low cost material. These residues could be processed into liquid fuels or combusted/gasified to produce electricity and heat.

Animal Waste There are a wide range of animal wastes that can be used as sources of biomass energy. The most common sources are animal and poultry manures. In the past this waste was recovered and sold as a fertilizer or simply spread onto agricultural land, but the introduction of tighter environmental controls on odour and water pollution means that some form of waste management is now required, which provides further incentives for waste-to-energy conversion. The most attractive method of converting these waste materials to useful form is anaerobic digestion which gives biogas that can be used as a fuel for internal combustion engines, to generate electricity from small gas turbines, burnt directly for cooking, or for space and water heating. Food processing and abattoir wastes are also a potential anaerobic digestion feedstock.

Sugar Industry Wastes The sugar cane industry produces large volumes of bagasse each year. Bagasse is potentially a major source of biomass energy as it can be used as boiler feedstock to generate steam for process heat and electricity production. Most sugar cane mills utilise bagasse to produce

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electricity for their own needs but some sugar mills are able to export substantial amount of electricity to the grid.

Forestry Residues Forestry residues are generated by operations such as thinning of plantations, clearing for logging roads, extracting stem-wood for pulp and timber, and natural attrition. Wood processing also generates significant volumes of residues usually in the form of sawdust, off-cuts, bark and woodchip rejects. This waste material is often not utilised and often left to rot on site. However it can be collected and used in a biomass gasifier to produce hot gases for generating steam.

Industrial Wastes The food industry produces a large number of residues and by-products that can be used as biomass energy sources. These waste materials are generated from all sectors of the food industry with everything from meat production to confectionery producing waste that can be utilised as an energy source. Solid wastes include peelings and scraps from fruit and vegetables, food that does not meet quality control standards, pulp and fibre from sugar and starch extraction, filter sludges and coffee grounds. These wastes are usually disposed of in landfill dumps. Liquid wastes are generated by washing meat, fruit and vegetables, blanching fruit and vegetables, pre-cooking meats, poultry and fish, cleaning and processing operations as well as wine making. These waste waters contain sugars, starches and other dissolved and solid organic matter. The potential exists for these industrial wastes to be anaerobically digested to produce biogas, or fermented to produce ethanol, and several commercial examples of waste-to-energy conversion already exist.

Municipal Solid Waste (MSW) Millions of tonnes of household waste are collected each year with the vast majority disposed of in landfill dumps. The biomass resource in MSW comprises the putrescibles, paper and plastic and averages 80% of the total MSW collected. Municipal solid waste can be converted into energy by direct combustion, or by natural anaerobic digestion in the landfill. At the landfill sites the gas produced by the natural decomposition of MSW (approximately 50% methane and 50% carbon dioxide) is collected from the stored material and scrubbed and cleaned before feeding into internal combustion engines or gas turbines to generate heat and power. The organic fraction of MSW can be anaerobically stabilized in a high-rate digester to obtain biogas for electricity or steam generation.

Sewage Sewage is a source of biomass energy that is very similar to the other animal wastes. Energy can be extracted from sewage using anaerobic digestion to produce biogas. The sewage sludge that remains can be incinerated or undergo pyrolysis to produce more biogas

Black Liquor Pulp and Paper Industry is considered to be one of the highly polluting industries and consumes large amount of energy and water in various unit operations. The wastewater discharged by this industry is highly heterogeneous as it contains compounds from wood or other raw materials, processed chemicals as well as compound formed during processing. Black liquor can be judiciously utilized for production of biogas using UASB technology.

Commercial Applications M2 Gasification Technology, USA, Commercial 113

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Crop : Sugarcane, forest Residue : Tar sands, cane stock, forestry, pulp or paper waste Process : Gasification Equipment : M2 Gasifier Main Product : Syngas

Technical Description of Technology (http://www.syngasinternational.com) The M2 uses gasification processes to convert any carbon based material into a synthetic gas. Gasification uses heat and pressure which converts any carbon containing materials into synthetic gas composed primarily of carbon monoxide and hydrogen which has a large number of uses. Gasification adds value to low or negative value feedstock’s by converting them to marketable fuels. The feed stocks used to create syngas depends on what’s readily available. Cheap low grade coal is a readily available supply. In Alberta, Tar Sands provide an abundant fuel source. An application in India under consideration utilizes cane stock from farming waste. Urban applications include garbage and tires. Throughout North America, forestry, pulp and paper waste can be used to be recycled into syngas and fed back into power plants. Various other industrial wastes can be fed back into plants to recycle “lost energy”, that would otherwise go to landfills. According to the US department of energy, gasification may be one of the best ways to produce clean-burning hydrogen for tomorrow's automobiles and power generating fuel cells. Hydrogen and other coal gases can also be used to fuel power generating turbines or as the chemical "building blocks" for a wide range of commercial products. Figure 1 shows the DOE IGCC Concept.

Fig. 1: DOE IGCC Concept

Celunol's "wet" biomass conversion process, USA, Pilot Demonstration Crop : Sugarcane, wood, etc. Residue : Sugarcane bagasse and wood, cellulosic biomass Process : Fermentation Equipment : SunOpta's patented pre-treatment equipment Main Product : Ethanol

Technical Description of Technology (http://thefraserdomain.typepad.com) Celunol is a leader in the effort to commercialize the production of cellulosic ethanol. The Company’s technology achieves high ethanol yields from cellulosic biomass at costs competitive with conventional ethanol processes using sugar and starch crops as feedstock.

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Celunol’s technology enables almost complete conversion of all the sugars found in cellulosic biomass. This efficiency advantage, combined with the low input cost of cellulosic biomass, results in superior economics in the production of ethanol.

Cellulose contains glucose, the same type of sugar—a six-carbon (C6) sugar—that is found in cornstarch and that can be fermented to ethanol using conventional yeasts. However, hemicellulose contains mainly non-glucose sugars—five-carbon (C5) sugars. Conventional yeasts cannot ferment most non-glucose sugars to ethanol with commercially acceptable yields. Celunol's technology is based on the metabolic engineering of microorganisms. Its key element is a set of genetically engineered strains of Escherichia coli bacteria that are capable of fermenting, into ethanol, essentially all of the sugars released from many types of cellulosic biomass. This trait enables Celunol to achieve the required efficiency to make the process commercially feasible. Celunol will use SunOpta's patented pre-treatment equipment and technology in the Jennings facility. SunOpta’s pretreatment and hydrolysis technology will prepare sugar cane bagasse and possibly hard wood waste for conversion into ethanol.

Specific Considerations for Developing Countries Celunol’s biomass ethanol technology offers numerous marketplace advantages: Feedstocks costs will be lower, and less volatile, than corn. Cellulosic ethanol facilities can be fueled by lignin waste streams derived from the process itself, avoiding the high and volatile price of natural gas as a boiler fuel for steam and electricity. Plants can be located outside traditional ethanol manufacturing areas and near end-use markets, creating a transportation cost advantage. Plants handling agricultural or urban wastes, pulp and paper sludge, etc. can simultaneously meet acute waste remediation needs, earn tipping fees, and yield valuable products.

Examples of Real Life Applications Celunol operates the Jennings pilot facility, on a 140-acre company-owned site in Jennings LA, designed to produce up to 50,000 gallons of ethanol per year. Celunol commenced operation of its newly expanded pilot facility in November 2006. It is building a 1.4 million gallon demonstration facility to produce ethanol from sugarcane bagasse and wood, targeted for completion in mid 2007. This will be the first

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Environmental Issues and Sustainable Agriculture commercial scale cellulosic ethanol plant in the United States. Later, the Company is planning a commercial-scale cellulosic ethanol facility at the site. The company has also licensed its technology to Marubeni Corp., a Japanese conglomerate, which has recently started up, the world’s first commercial cellulosic ethanol facility in Osaka, Japan that employs wood waste as a feedstock. The Osaka Project utilizes wood waste as feedstock in producing up to 1.3 million liters of cellulosic ethanol annually. A second phase, planned for completion in 2008, will increase production to 4 million liters per year.

Preparation of Charcoal Using Agricultural Wastes Wood charcoal has been the primary fuel for cooking in Ethiopia because it is cheap and easily available. However, using wood charcoal has consequences on health and pollution because of smoking. This study aims at providing a biomass as an alternative to wood charcoal using agricultural wastes (dry leaves, coffee husk, sugarcane trash, grass, etc) converted into charcoal briquettes to provide much needed source of cheap fuel that is cleaner in burning. Simple extruder machine is used as die to make the briquette charcoal. Moreover, an effective carbonizer to change the agricultural waste into charcoal and an effective stove to burn and use the charcoal for cooking is used. The manual extruder machine has a capacity of pressing 30kg/hr and the carbonizer converts 15kg of input agricultural wastes into 5kg of burned charcoal with in 25 minutes. The stove is effective so that three meals are cooked at a time using 100g briquette charcoal. As compared to wood charcoal the charcoal briquette produced from agricultural wastes are economical, environmentally friendly, healthy (no smoke at all) and reduce impact of deforestation.

Conclusions The waste-to-energy plants offer two important benefits of environmentally safe waste management and disposal, as well as the generation of clean electric power. Waste-to-energy facilities produce clean, renewable energy through thermochemical, biochemical and physicochemical methods. The growing use of waste-to-energy as a method to dispose off solid and liquid wastes and generate power has greatly reduced environmental impacts of municipal solid waste management, including emissions of greenhouse gases. Waste-to-energy conversion reduces greenhouse gas emissions in two ways. Electricity is generated which reduces the dependence on electrical production from power plants based on fossil fuels. The greenhouse gas emissions are significantly reduced by preventing methane emissions from landfills. Moreover, waste-to-energy plants are highly efficient in harnessing the untapped sources of energy from a variety of wastes.

References http://labspace.open.ac.uk/mod/oucontent/view.php?id=453833§ion=1.4.1 http://labspace.open.ac.uk/mod/oucontent/view.php?id=453833§ion=1.4.2 http://www.iffs.com.sg/pdf/forms/2012/On-site%20Handling.pdf http://www.syngasinternational.com/technology.html http://thefraserdomain.typepad.com/energy/2007/02/celunol_cellose.html

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Chapter-15

Salt Affected Soils and their Management Aspects

*Sukirtee, 1Vikas ,2Simmi3Paras Kamboj and 4P K Bharteey *,1,2,Department of Soil Science, ChaudharyCharan Singh Haryana Agricultural University, Hisar 2Department of Agronomy, ChaudharyCharan Singh Haryana Agricultural University, Hisar 3Department of soil science, Assam Agricultural university, Jorhat *Email: [email protected]

Introduction Salt-affected are considered naturally originated due to, but recent salinization trends indicate human induced salinity affects about 2 % of the global dry lands and 20 % of the irrigated lands. The productivity of irrigated lands getting reduced day by day which was earlier almost two-fold higher than the yields obtained in dry lands (Munns2006). Annually about 0.25-0.5 million ha land is coming under irrigation-induced salinization (Wicke et al. 2011). Faulty irrigation practices are responsible for excessive salinity build-up in cultivated lands such that wheat and even salt-tolerant barley crops failed to grow (Pitman and Läuchli 2002). There are so many evidences to prove that some of the fertile soils of the world is suffering from salinity for many decades. In many dryland (Fitzpatrick 2002) and irrigated (Datta and DeJong 2002) regions of the world, the problem of secondary salinity is becoming severe with each passing day. As a result the soils which were once highly productive have become unproductive. Replacement of perennial vegetation by the annual crops like in case of Land clearing for agricultural development changes the water balance such that considerably high deep percolation occurs beyond the crop root zone (Lambers2003) water use by annual crops and pastures is far below that of perennial trees and shrubs. Deep drainage in drier regions has increased from <0.1 mm year−1 in the preclearing phase to >10 mm year−1 at present. Unrestricted water leakage beyond the root zone causes gradual rise of the water tables (~0.5 m year−1) resulting in salt movement from subsurface to the surface layers (Stirzaker et al. 1999). In a study from the Western Yamuna and Bhakra canal commands in Haryana, India, it is found that salinity cause by water logging highly reduced the crop yield and leads to decrease in farm income and farm employment (Singh and Singh 1995). In Tungabhadra irrigation project in Karnataka state, problem of drainage managements and poor irrigation are main factors responsible for large- scale land degradation. the economic loss due to soil degradation alone in lower left bank main canal of the projectwas estimated about 14.5 % of the system’s productive potential (Janmaat 2004). In Haryana state of India, the annual loss in monetary terms due to secondary salinity was estimated at Rs. 1669 million at 1998–1999 constant prices (Datta and De Jong 2002). Salt-affected soils are mainly found in arid and semiarid regions of the world, and many salt affected lands once were there in the category of productive lands (Qadir et al. 2000). Worldwide, around 95 million hectares of land is having primary salinization (salt accumulation through parent rocks and minerals) whereas about 77million hectares suffer from secondary salinization (due to anthropic activities) (Metternicht and Zink 2003). There are so many adverse effects of high salt concentration including negative effect on soil microbial activity along with soil chemical and physical properties, all in combination reduces soil productivity. Presence of excess salts in the root zone induces high osmotic potential which induces partial or complete loss of soil productivity. Soil salinity is wide spread in the arid and semi-arid regions but salt affected soils may also occur extensively in sub-humid and humid

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Environmental Issues and Sustainable Agriculture climates, mainly in coastal regions where the inundation of sea water through estuaries and rivers and through groundwater causes large-scale salinization. Keeping the fact in view that plant growth can be restricted by increased levels of salinity and alkalinity proper knowledge of their origin, classification, distribution, properties and reclamation is become the need of the present time.

Origin, Classification and Distribution of Saline Soils Salt-affected soils are present everywhere under almost all climatic conditions. But their distribution, is found more extensive in the arid and semi-arid regions as compared to the humid regions. Because of the diverse nature of these soils they require specific approaches for their reclamation and management to maintain their long term productivity. For implication of any long-term management practice, it is, necessary to understand the mode of origin of salt-affected soils and to classify them, by keeping a view of their physico-chemical characteristics, processes responsible for their formation and accordingly the approaches for their reclamation and successful management. The presence of excess salts on the soil surface and in the root zone characterizes saline soils. Main source of all salts in the soil is the primary minerals present on earth‘s crust which act as parent material. the process of chemical weathering which involves hydrolysis, hydration, solution, oxidation, carbonation and other processes, are responsible for gradual release of salts and made them soluble. Salts released by these processes are transported away from their source of origin by surface or groundwater streams. In case of humid region the salt formed will be dissolved and leach down with the help of percolating water down the profile. In arid regions, the salts are concentrated and the concentration may become high enough to result in precipitation of salts because of low precipitation.

Table-1 Extent of saline and alkali soil in different states of India Coastal saline Saline soils Alkali soils Total State soil (ha) (ha) (ha) (ha) Andhra Pradesh 0 196609 77598 274207 A & N islands 0 0 77000 77000 Bihar 47301 105852 0 153153 Gujarat 1218255 541430 462315 2222000 Haryana 49157 183399 0 232556 J & K* 0 17500 0 17500 Karnataka 1307 148136 586 150029 Kerala 0 0 20000 20000 Maharashtra 177093 422670 6996 606759 Madhya Pradesh 0 139720 0 139720 Orissa 0 0 147138 147138 Punjab 0 151717 0 151717 Rajasthan 195571 179371 0 374942 Tamil Nadu 0 354784 13231 368015 Uttar Pradesh 21989 1346971 0 1368960 West Bengal 0 0 441272 441272 Total 1710673 3788159 1246136 6744968 Source* CSSRI (2019)

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Fig: 1 Salinity Map of India Source* CSSRI (2019) i. Saline Soils Saline soils are those having a conductivity of saturation extract greater than 4 dSm-1and exchangeable sodium percentage (ESP) less than 15. The pH is usually less than 8.5. these soils are also known as white alkali soils because of presence of surface crust of white salts. These Soils contains sufficient neutral soluble salts which adversely affect the growth crop plants. The soluble salts are chiefly sodium chloride and sodium sulphate. But saline soils also contain appreciable quantities of chlorides and sulphates of calcium and magnesium. ii. Sodic Soils Sodic soils are those having a conductivity of saturation extract less than 4 dSm-1and exchangeable sodium percentage (ESP) more than 15. The pH is usually more than 8.5. these soils are also known as black alkali soils. These Soils generally contains carbonates and bicarbonates of sodium, calcium and magnesium ions .The distinguishing features of these two broad groups of salt-affected soils are presented in Table 3.Although the above two categories account for a very large fraction of salt affected soils the world over, there are transitional or borderline formations which are likely to have properties intermediate between those of the two broad categories. iii. Saline –Alkali Soil Sodic soils are those having a conductivity of saturation extract more than 4 dSm-1and exchangeable sodium percentage (ESP) more than 15. The pH is usually more than 8.5. depending upon the amount of exchangeable sodium and other salts present. When the soil is dominated with sodium the pH will be more than 8.5 and if soil is dominated with other soluble salts the pH will be less than 8.5.

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Environmental Issues and Sustainable Agriculture iv. Degraded Sodic Soils Degraded sodic soils are usually considered to be an advanced stage of soil development resulting from the washing out of salts. If the expensive leaching of saline sodic soils occurs in the absence of any source of calcium and magnesium, the exchangeable sodium is gradually replaced by hydrogen. The structure become unstable and slightly acidic such soils are called degraded alkali. In the lower layer there will be deposit of dissolved humus due to the action of Na2CO3. Clay] Na + H2O ↔ Clay] H + NaOH ↓ leaching NaOH + CO2 → Na2CO3 + H2O

Table-2 Distinguishing features of saline and sodic soils

Soil class ECe pH ESP SAR Saline >4.0 <8.5 <15 <13 Alkali <4.0 >8.5 >15 >13 Saline-alkali >4.0 >8.5 >15 >13

Formation of Salt Affected Soils Presence of primary minerals is the chief source of all salts, salt-affected soils rarely form through accumulation of salts in situ. Other major factors responsible for the formation of salt- affected soils are discussed below:

Saline Soils a. Primary Minerals These are original and important source of all salt present in soil. During the process of chemical weathering various constituents like Ca2+, Mg2+ and Na+ are released and made soluble. b. Arid and Semi-Arid Climate Salt affected soils are mostly formed under arid and semi arid climatic condition due to low rainfall and high evaporation occurs in this region. The low rainfall thus not sufficient for the leaching of soluble salts as a result salts accumulate in the soil. When little amount of rain occurs these salts goes down in soil but to a lesser distance and again when evaporation prevails these salts come on the surface and deposition occurs there. c. Saline Ground Water When groundwater is the only source available for irrigation, high salinity of the ground water can cause a build-up of salts in the root zone. (Kanwar,1961) particularly in high water table salts move upward along with capillary water to the surface. d. Saline Seeps These are common in North America, Australia and other countries, they results when leaching is very high and evapo-transpiration is low after a change in land use from natural forest vegetation to a cereal grain crop or a shift in cropping pattern such as the introduction of a fallow season in a grain farming system. The water during percolation passes through saline sediments is intercepted by impermeable horizontal layers and flows laterally to landscape depressions causing extensive soil salinization.

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Environmental Issues and Sustainable Agriculture e. Ocean or Sea water Salinity problems are also caused by the inundation and deposition of sea water, through tidal waves, underground aquifers or through wind transport of salt spray. Soluble salts have also been continually exchanged between land and sea - most transfer of salts from the sea taking place through the uplift of marine sediments and exposure on the earth‘s surface. f. Irrigation Water Problem of Salinity are most extensive in the irrigated arid and semi-arid areas. Prior to the introduction of irrigation, a water balance between all the sources exists like among rainfalls and stream flow, groundwater level and evaporation and transpiration. This balance is disturbed when large additional quantities of water are artificially spread on the land for agriculture. Seepage from irrigation channels, causes rise in water table and salinity as well. g. Salts Blown by Wind In arid region near the sea the salts are blown by wind and deposited on the surface of the soil. Due to low rainfall these salts are not washed back to the sea again. And with low rainfall it get deposited to the lower horizons. h. Excessive Use of Basic Fertilizers Long term use of basic fertilizers like sodium nitrate and basic slag may develop soil alkalinity.

Sodic Soils The mechanisms responsible for the formation of sodium carbonate in soils which characterize sodic (alkali) soils, Groundwater containing carbonate and bicarbonate is one of the major contributing factors in the formation of sodic soils in many regions. According to Bhargava et al. (1980) the alternate wet and dry seasons and the topographic (drainage) conditions are the contributing factors in the formation of vast areas of sodic soils in the Indo-Gangetic plains of India. During the wet season water containing products of mineral weathering accumulated in the low lying areas. In the dry season, as a result of evaporation, the soil solution is concentrated resulting in precipitation of the divalent cations, causing an increase in the proportion of sodium ions in the soil solution and on the exchange complex which causes increase in pH. This process repeated over years resulted in the formation of sodic soils.

Management and Reclamation of Salt Affected Soils

Scraping Removing of upper salts accumulated layer of soil surface by mechanical means. This metod is limited successful because this method might temporarily improve crop growth, the ultimate disposal of salts still poses a major problem.

Flushing Washing away the surface accumulated salts by flushing water over the surface is sometimes used to desalinize soils having surface salt crusts. This method can be used if amount of salts present are quite small, this method does not have much practical significance.

Leaching This the most effective procedure for removing salts from the root zone of soils. Leaching is most often accomplished by ponding good quality water on the soil surface and 121

Environmental Issues and Sustainable Agriculture allowing it to infiltrate. Leaching is effective when the salty drainage water is discharged through subsurface drains that carry the leached salts out of the area under reclamation. Leaching may reduce salinity levels provided when there is sufficient natural drainage. Leaching should preferably be done when the soil moisture content is low and the groundwater table is deep. Leaching during the summer months is, as a rule, less effective because large quantities of water are lost by evaporation. Intermittent ponding is found more beneficial than continuous ponding.

Amendments Whether an amendment (e.g. gypsum) is necessary or not for the reclamation of salt- affected soils is a matter of practical importance. In case of saline soil proper amount of salts of calcium and magnesium are present in sufficient amounts to meet the plant growth needs. Saline soils are dominated by neutral soluble salts and at high salinities sodium chloride is most often the dominant salt.

Drainage In surface drainage, ditches are provided so that excess water will run off before it enters the soil. However the water intake rates of soils should be kept as high as possible so that water which could be stored will not be drained off. Field ditches empty into collecting ditches built to follow a natural water course. A natural grade or fall is needed to carry the water away from the area to be drained. The location of areas needing surface drainage can be determined by observing where water is standing on the ground after heavy rain. Field ditches and collection or outlet ditches should be large enough to remove at least 5 cm of water in 24 hours from a level to a gently sloping land. The capacity of a drainage system should be based on the amount and frequency of heavy rains. How quickly water runs into ditches depends on the rate of rainfall, land slope and the condition of the soil surface including the plant cover. The area that a ditch can satisfactorily drain depends on how quickly water runs into the ditch, the size of the ditch, its grade or slope and its irregularity. The latter is measured by the roughness and the contents of debris and growing vegetation in the ditch. In relatively level areas (slope < 0.2%) a collecting ditch may be installed along one side and shallow v-shaped field ditches constructed to discharge into this collecting ditch. Field ditches used to discharge water into collecting ditches should be laid out parallel to each other 20 to 60 m apart. They should be 30 to 45 cm deep depending upon the depth of the collecting ditch. Care should be taken to avoid sharp curves in the ditches to lessen erosion of the banks.

Subsurface Drainage If the natural subsurface drainage is insufficient to carry the excess water and dissolved salts away from the soil without the groundwater table rise there is no meaning of application of good quality water for the reclamation of salt affected soils drainage system for the control of the groundwater table at a specified safe depth. The principal types of drainage systems may consist of horizontal relief drains such as open ditches, buried tiles or perforated pipes or in some cases pumped drainage wells.

Crops in Saline Soils Crop plants which should be choose for the cultivation in sodic soils need to be salt tolerant to some extent. Information on the relative tolerance of crops to a saline soil environment is of practical importance in planning cropping schedules for optimum returns. Salt tolerant crops are a good alternative for those areas where farmers have to stay with the problem of salinity, in areas having saline water as the only source of water for irrigation.

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Reclamation and management of Sodic Soils

Amendments Reclamation of sodic soils needs the removal of part of the exchangeable sodium and its replacement by the more favourable calcium ions in the root zone. This can be done by many ways, the best dictated by local conditions, available resources and the kind of crops to be grown on the reclaimed soils. If the cultivator can spend very little for reclamation and the amendments are expensive or not available, and he is willing to wait many years before he can get good crop yields, soil can still be reclaimed but at a slow rate by long-continued irrigated cropping, ideally including a rice crop and sodic tolerant crops in the cropping sequence, along with the incorporation of organic residues and/or farmyard manure. For reasonably quick results cropping must be preceded by the application of chemical soil amendments followed by leaching for removal of salts derived from the reaction of the amendment with the sodic soil. Soil amendments are materials, such as gypsum or calcium chloride, that directly supply soluble calcium for the replacement of exchangeable sodium, or other substances, such as sulphuric acid and sulphur, that indirectly through chemical or biological action, make the relatively insoluble calcium carbonate commonly found in sodic soils, available for replacement of sodium. Organic matter (i.e. straw, farm and green manures), decomposition and plant root action also help dissolve the calcium compounds found in most soils, thus promoting reclamation but this is relatively a slow process. The kind and quantity of a chemical amendment to be used for replacement of exchangeable sodium in the soils depend on the soil characteristics including the extent of soil deterioration, desired level of soil improvement including crops intended to be grown and economic considerations.

Table: 3 Relative tolerance of crops to soil sodicity

ESP Crop 2-10 Deciduous fruits, citrus, avocado 10-15 Safflower, black gram, peas, lentil 16-20 Chickpea , soybean 20-25 Clover, groundnut, onion, pearlmillet 25-30 Linseed, garlic, cluster beans 30-50 Oats, mustard, wheat, tomatoes 50-60 Beet, barley, sesbania 60-70 Rice

Kind of Amendments Chemical amendments for sodic soil reclamation can be broadly grouped into three categories: a. Soluble calcium salts, e.g. gypsum, calcium chloride. b. Acids or acid forming substances, e.g. sulphuric acid, iron sulphate, aluminium sulphate, lime-sulphur, sulphur, pyrite, etc. c. Calcium salts of low solubility, e.g. ground limestone. Suitability of any amendment largely depends on the soil properties and market prices of that amendment. Ground limestone, CaCO3, is an effective amendment only in soils having pH below about 7.0 because its solubility rapidly decreases as the soil pH increases. It is apparent that the effectiveness of limestone as an amendment is markedly decreased at pH values above 7.0. Some soils that contain excess exchangeable sodium also contain appreciable quantities of exchangeable hydrogen and therefore have an acidic reaction, e.g. degraded sodic soils. Lime reacts in such soils according to the reaction: Na, H - clay micelle + CaCO3 →Ca - clay micelle + NaHCO3

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However, lime is not an effective amendment for most sodic soils as their pH is always high. In fact, sodic soils contain measurable to appreciable quantities of sodium carbonate which imparts to these soils a high pH, always more than 8.2 when measured on a saturated soil paste and up to 10.8 or so when appreciable quantities of free sodium carbonate are present. In such soils only amendments comprising soluble calcium salts or acids or acid-forming substances are beneficial.

Gypsum Gypsum is chemically CaSO4.2H2O and is a white mineral that occurs extensively in natural deposits. It must be ground before it is applied to the soil. Gypsum is soluble in water to the extent of about one-fourth of 1 percent and is, therefore, a direct source of soluble calcium. Gypsum reacts with both the Na2CO3 and the adsorbed sodium as follows: Na2CO3 + CaSO4 → CaCO3 + Na2SO4 (leachable) Calcium Chloride Calcium chloride is chemically CaCl2 2H2O. It is a soluble salt which supplies soluble calcium immediately. Na2CO3 + CaCl2 → CaCO3 + 2NaCl (leachable) Sulphuric Acid Sulphuric acid is chemically H2SO4. It is an oily corrosive liquid and is usually about 95 percent pure. It is useful to apply sulphuric acid only if there is presence of native calcium containing minerals in soil in large amount. After application calcium carbonate immediately reacts to form calcium sulphate and thus provides soluble calcium indirectly. H2SO4 + CaCO3→ CaSO4+ Ca(HCO3)

Iron Sulphate and Aluminium Sulphate (Alum) Chemically these com-pounds are FeSO4.7H2O and Al2(SO4)3.18H2O respectively. Both these are highly pure and soluble in water. When applied to soils, these compounds dissolve in soil water and hydrolyse to form sulphuric acid, which supplies soluble calcium by reacting with lime present in sodic soils.

Pyrite Pyrite (FeS2) is another material that has been suggested as a possible amendment for sodic soil reclamation. This is also known as fool’s gold. Reactions leading to oxidation of pyrite are complex and appear to consist of chemical as well as biological processes. 2 FeS2 + 2 H2O + 7 O2 → 2 FeSO4 + 2 H2SO4 CaCO3+ H2SO4 → CaSO4 + H2O + CO2 2 NaCO3 + CaSO4 → CaCO3 + Na2SO4 References C. G. E. M. Van beek n. Van Breemen. (1973) The Alkalinity Of Alkali Soils, European journal of soil science, 24, 5513-5521. CSSIR. Central soil salinity research institute, Karnal, Haryana. Datta, K. K., & De Jong, C. (2002).Adverse effect of water logging and soil salinity on crop and land productivity in northwest region of Haryana, India. Agricultural Water Management, 57(3), 223–238.

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Fitzpatrick, R. W. (2002). Land degradation processes. In T. R. McVicar et al. (Eds.), Regional water and soil assessment for managing sustainable agriculture in China and Australia (ACIAR Monograph No. 84, 119–129. Janmaat, J. (2004). Calculating the cost of irrigation induced soil salinization in the Tungabhadra project. Agricultural Economics, 31, 81–96. Kanwar, J.S (1961). Quality of water as an index of its suitability of water for irrigation purposes. Potash Review.24 (13). Lambers, H. (2003). Dryland salinity: A key environmental issue in southern Australia. Plant and Soil, 257, 5–7. Martinez-Beltran J, Manzur C.L. (2005). Overview of salinity problems in the world and FAO strategies to address the problem. Paper presented at the International salinity forum, Riverside Metternicht, G and Zink, J. (2003). Remote sensing of soil salinity: potentials and constraints.Remote Sensing Environment. 85, 1–20. Munns, R., James, R. A., & Läuchli, A. (2006). Approaches to increasing the salt tolerance of wheat and other cereals. Journal of Experimental Botany, 57, 1025–1043. NLWRA (2001).National dryland salinity assessment. National land and water resources audit Pitman, M. G., & Läuchli, A. (2002).Global impact of salinity and agricultural ecosystems. In Salinity: Environment-plants-molecules, 3–20. Springer Netherlands. Qadir M, Ghafoor A and Murtaza, G. (2000). Amelioration strategies for saline soils: a review. Land Degradation Development, 11, 501–521. Singh, J., & Singh, J. P.(1995).Land degradation and economic sustainability. Ecological Economics, 15(1), 77–86. Stirzaker, R. J., Cook, F. J., & Knight, J. H. (1999). Where to plant trees on cropping land for control of dryland salinity: Some approximate solutions. Agricultural Water Management, 39, 115–133. Szabolcs, I.(1994) Soils and salinization. Hand book of plant and crop stress. Marcel Dekker, New York, 3–11. Wicke, B. (2011). The global technical and economic potential of bioenergy from salt-affected soils.Energy & Environmental Science, 4, 2669–2681. Wong, V.N.L., Dalal, R.C. and Greene, R.S.B. (2009). Carbon dynamics of sodic and saline soils following gypsum and organic material additions: laboratory incubation. Applied Soil Ecology,41,29–40.

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Chapter-16

Agroforestry: Habitat for Biodiversity conservation

Shashi Kumar M C*, C L Thakur*, Dhanyashri P.V.*, Rakshith Kumar S ***, Jagadish MR*** and S S Inamatti*** *- Dept of Silviculture and Agroforestry, Dr. Y. S. Parmar University of Horticulture and Forestry, Solan, H.P. **Dept of Silviculture and Agroforestry, Birsa Agriculture University. Ranchi, Jharkhand ***-Dept of Silviculture and Agroforestry, University of Agricultural Sciences, Dharwad, Karnataka Email: [email protected]

Abstract As tropics is mounted with ever increasing human population necessitating the deforestation and clearing of wealthy biodiversity areas, there disappearance is at exponential rate hence causing the most common problems of modern world like global warming, floods and drought, threatened biodiversity and pollution etc. But sometimes thirst for land causes many problems in order to supply food and other commodities along with maintaining the diversity, hence a farming system like agroforestry that can maintain balance between them is necessary. Agroforestry is a sustainable land use system that not only conserves the resource base along with providing wide array of benefits and also conserves biodiversity. It is a combination of multiple components like perennials, annuals and other animal components ranging from soil microorganisms to large mammals like cattle. Even though it cannot be equated to any natural forest yet it has wide role in supporting and conserving the biodiversity when compared to any other farming systems. Agroforestry plays very important role in maintaining the biological balance in ecosystems where the landscapes are mosaic, highly fragmented and honeycombed habitats particularly where the human activities are prominent. Biodiversity threat is a common problem that is a result of many threats like declining natural base, over exploitation, habitat loss, fire, invasive alien species, climate change, developmental projects, urbanization and pollution. Agroforestry plays very important role in biodiversity conservation as it provides habitat, germplasm conservation, corridor for movement of wildlife and reduction of pressure on natural forests along with improvement of socio-economic status of the people. Past and present evidence clearly indicates that agroforestry, as part of a multifunctional working landscape, can be a viable land-use option that, in addition to alleviating poverty, and improving living standard of people it also offers a number of ecosystem services and environmental beneﬁts. This realization should help promote agroforestry and its role as an integral part of a multifunctional working landscape the world over. Keywords: Agroforestry, Biodiversity, threats, habitat, corridor, sustainable, viable, multifunctional, ecological services, economc benefits.

Introduction Biodiversity is not simply a measure of species rather it also encompasses genetic variability within and between the populations, species evolutionary histories and other measures of life. High biodiversity in tropics as mainly attributed to many reasons like maximum sunlight, most productive soils, mega-biodiversity centers, stable climate, prevalence of specialized habitats evolutionary history and diversity leading to competition and evolution. Guillerme et al. (2011) reported decline in diversity of indigenous multipurpose trees and shrubs and herbaceous 126

Environmental Issues and Sustainable Agriculture components such as traditional vegetable crops and ornamental plants owing to the conversion of agroforestry systems (including home gardens or their parts) to monospecific production systems and introduction of exotic fast growing multipurpose trees. It is estimated that 99.9 per cent of the plant and animal have extinct since life appeared on the earth (Leakey and Lewin 1996). Further, it is believed that about 60,000 of the world 2, 40,000 plants species and higher proportions of vertebrate and insect species could lose their lease on life over the next three decades. Since, man cannot stop utilizing biodiversity, therefore, a system is required to harness the biodiversity on sustainable basis. Causes for loss of biodiversity are numerous with every activity of humans affecting the biodiversity in one or other way. Threats that made the phase of losing biodiversity fast are mainly anthropogenic causes like habitat fragmentation, invasive alien species, overexploitation, loss of habitat, pollution, urbanization, industrialization, pest and diseases and other natural causes like mass extinction and natural calamities. Devastation of tropical Brazilian coastal rainforest by European immigrants for growing sugarcane, coffee, cocoa and other commodities is one of the examples of wasteful agricultural use of a biodiversity rich ecosystem in tropics (Dean.1995). With rapid increase of tropical and global markets in the twentieth centuary human impacts on tropical and global ecosystems have reached new dimensions (Mc Neil 2000). However, the loss of biodiversity is dependent on many factors like rate of loss of natural habitat, natural resource base, population density in the area, land use history, proximity of humans to natural forests, urbanization rate, industrialization rate, government policies and frequency of natural calamities. Main reason being population explosion necessitating the expansion of agriculture land for food production and clearing of forests for its products. Agroforestry being a multiple land use system that can produce ample of benefits both economic and ecological is being seen as an option that can satisfy the multiple needs without leading to any negative effects compared to sole agriculture systems. Recent definition by World Agroforestry Centre (ICRAF 2000), agroforestry is defined as a dynamic ecologically based natural resource management practice that through the integration of trees and other tall woody plants an farm lands and in agricultural landscapes, diversifies production for increased social, economic and environmental benefits. Agroforestry acts as a landscape that influences the ecological processes and it influences the presence, diversity, dispersal of fauna and flora along with resource availability, microclimate amelioration, carbon sequestration and pest and disease control. From last three decades agroforestry has been extensively seen as natural resource management strategy and it attempts to balance the goods of agricultural development along with conservation of soil, water, local and regional climate and more recently biodiversity (Izac and Sanchez. 2001). Even though the agroforestry is a multipurpose full farming its role in biodiversity conservation is often underestimated and questioned hence this chapter covers in detail how agroforestry plays a pivotal role in biodiversity conservation by interpreting some of the research findings and field studies. India being a tropical facing the problems of modern world needs agroforestry the current area under agroforestry in India is estimated as 25.32 m ha, or 8.2 per cent of the total geographical area of the country (Dhyani et al., 2013). This includes 20.0 m ha in cultivated lands and 5.32 m ha in other areas. The preliminary estimates for agroforestry area in the country indicate 17.45 million ha (Rizvi et al., 2013, 2014) which is not enough we need to bring more and more areas under agroforestry in order to green more area along with producing economic commodities. Agroforestry helps in biodiversity conservation by reducing the pressure on natural forests, providing habitat cover, germplasm conservation, control of pest and disease, control of invasive alien species, acting as a corridor for the movement of animals from one landscape to other and because of its diversity of components and the competition for resources it leads to evolution of species. Agroforestry systems are considered as diversity enhancing land use system especially in the context of inter-species diversity as it brings together crops, shrubs, trees and in 127

Environmental Issues and Sustainable Agriculture some cases livestock on the same piece of land (Atta-Krah et al. 2004). Price and Gordon (1999) reported that earthworm densities were greatest next to poplar and white ash tree-rows, due to greater litter contributions. Zomer et al. (2001) found that an agroforestry system involving Alnus nepalensis and cardamom contributed to the integrity of riparian corridors for wildlife conservation around the Makalu Barun National Park and Conservation Area of eastern Nepal. When landscapes are increasingly being fragmented and remaining patches of natural vegetation are reduced to isolated habitat islands consequent to human activities, mixed-species AFS could play a significant role in helping to maintain a higher level of biodiversity and provide greater landscape connectivity (Montagnini et al., 2011). This can occur in at least these ways: intensification of AFS leading to reduced exploitation of protected areas, increasing biodiversity in working landscapes through the expansion of AFS into traditional farmlands, and as a habitat corridor for movement of animals increasing the species diversity of plants in farming systems. germplasam of plants by providing other ecosystem services like erosion control, water conservation etc. control of invasive alien species

Agroforestry as a Habitat Several agroforestry systems like improved fallows, taungya, Multipurpose woodlots, alley cropping, silvipasture, shade trees in plantations, tropical homegardens consists of trees and annual crops which acts as the habitat for flora and fauna that depends on forest trees and that cannot grow, survive and reproduce on pure agriculture cropping. Structurally heterogenous perennial vegetation can provide more niches for native flora and fauna than structurally simpler monocultures and pastures (Thiollay.1995). Not only the aerial diversity gets its habitats the soil also encompasses wide diversity of micro flora and fauna. Soil that is rich in organic matter and humus with balanced fertility status can be a habitat for many soil borne fauna and flora which is not present in simpler and regular agriculture systems although little is known about such below ground biodiversity benefits of complex land use systems (Lavelle et al. 2003). Mostly bird species use tree component of agroforestry for nesting, food, ambush cover and movement while movement they also carry seeds from one place to other place leading to migration and biodiversity enrichment. Trees in agroforestry systems support threatened cavity nesting birds, and offer forage and habitat to many species of birds (Pandey 1991; Pandey and Mohan 1993). Insects also use trees for food and also they are responsible for pollination and pollen transfer from one tree to tree making the genetic diversity richer. Due to presence of moisture in agroforestry the amphibians and reptiles are also attracted and they survive better that in any sole cropping system. Mammals are not an exception as agroforestry provide multiple products like food, fodder, fibre and medicine for mankind and his domestic animals and acts as a habitat for their survival. Higher plant diversity in agroforestry and forest systems provided diverse micro-habitats and heterogeneous litter, contributing to greater biological diversity in the soil. Harvey and Gonzalez Villalobos (2007) characterized bat and bird assemblages occurring in forests in two types of agroforestry systems (cacao and banana) and plantain monocultures in the indigenous reserves of Talamanca, Costa Rica. Agroforestry systems had bat assemblages that were as (or more) species-rich, abundant, and diverse as forests, contained the same basic suite of dominant species, but also contained more nectarivorous bats than forests. Agroforestry systems also harbored bird assemblages that were as abundant, species-rich, and diverse as forests. Kumar 128

Environmental Issues and Sustainable Agriculture and Nair (2004) reported species richness of tropical home gardens varying from 27 (Sri Lanka) to 602 (West Java). Hence some of agroforestry systems as a habitat for many organisms is described in detail based on the research studies available from different parts of world:

Shaded coffee with trees (Coffea spp.) Coffee is a plantation crop that requires shade for its growth and development hence they are planted along with shade trees that can help coffee along with providing other benefits. Petit and Petit (2003) studied bird communities associated with 11 natural and human-modified habitats in Panama and assessed the importance of those shade tree habitats for species of different vulnerability to disturbance. Calculating habitat importance scores using both relative habitat preferences and vulnerability indices for all species present, they reported that species of moderate and high vulnerability were those categorized principally as forest specialists or forest generalists. As expected, even species-rich in non-forest habitats provided little conservation value for the most vulnerable species. Shaded coffee plantations were modified habitats with relatively high conservation value however, as were gallery forest corridors. Sugarcane (Saccharum officinarum) fields and Caribbean pine (Pinus caribaea) plantations, important land uses in much of Central America, offered virtually no conservation value for birds. In Latin America, for instance, numerous studies have shown that the traditional coffee agroforests (coffee integrated with 2-5 other tree species) are second only to undisturbed tropical forests in their diversity of birds, insect life, bats, and even mammals. However, agroforestry, especially systems that use native species, can provide substantial biodiversity benefits.

Benzoin gardens of Sumatra Garcia-Fernandez et al. (2003) sought to determine the impact of benzoin garden management on forest structure, species composition, and diversity. They chose 45 gardens for study in two northern Sumatra villages, where data on management practices and ecological structure were gathered. Ecological information was also collected from abandoned benzoin gardens and what they considered primary forest areas for purposes of comparison. Although benzoin management requires thinning of competing vegetation, these activities are not intensive, allowing species that coppice to remain in the garden and thereby reducing the effects of competitive exclusion mechanisms on species composition. Studies revealed that tree species diversity in abandoned gardens was similar to that in primary forest, but endemic species and species characteristic of mature habitats were less common. They concluded that traditional benzoin garden management represents only a low-intensity disturbance and maintains an ecological structure that allows effective accumulation of forest species over the long term making them a suitable option for biodiversity conservation. Atta-Krah et al. (2004) reported that well designed agroforest, can spontaneously attract and support higher biodiversity. In the lowlands of Sumatra, resin-producing agroforests planted several generations ago are now some of the last reservoirs of biodiversity as they are harboring rare epiphytes and herbs as well as 46 species of mammals, 92 species of birds, and much of the native soil fauna.

Shelterbelts and Windbreaks Shelterbelts and winbreaks acta as a barriers and fence for the field that can provide multiple benefits along with protecting it from wind and providing shade to livestock components. Usually the effectiveness of shelterbelt and windbreak depends upon the design and composition and the area which it protects varies according to its height. Brandle et al. (2004) reported greater density and diversity of insect populations in windbreaks. They attributed this diversity to the

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Environmental Issues and Sustainable Agriculture heterogeneity of the edges that provided varied micro-habitats for life-cycle activities and a variety of hosts, prey, pollen, and nectar sources. Jhonson (1988) reported that shelterbelts provide benefits to wildlife in several ways, including protection from wind and adverse weather, escape or refuge cover, food and foraging sites, reproductive habitat and travel corridors. At least 108 species of birds and 28 species of mammals are known to use shelterbelt habitats. In agricultural areas, 29 species of birds, benefit substantially, 37 moderately and 42 very little or accidentally. At least 57 species of birds have been recorded using shelterbelts during the breeding season and, of these, 28 are known to have nested in them at densities from about 0.3–186 nests ha−1.Shelterbelts provide only a portion of most wildlife needs, and thus should be viewed in relation to other nearby resources so that all needs of desired wildlife are met. Adjacent food resources are of particular importance to some wildlife species. Wildlife associated with shelterbelts may provide economic, educational, recreational and aesthetic benefits. In contrast, some species may cause damage or nuisance problems in adjacent areas. Overall, these problems are minor/or can be controlled. Relationships among wildlife, shelterbelts and people are not well studied, so numerous research opportunities and needs exist. Hence shelterbelts and windbreaks not only replace concrete fence walls they can also be a living forest ecosystem for many flora and fauna making biodiversity sustenance. Temparate agroforestry systems Agroforestry is more prominent in tropics when compared to temperate areas because of many factors like market availability, land availability, sunlight availability and other socio- economic reasons but when practised in temperate it can give all benefits that are evidenced in tropical regions. Stamps et al (1997) reported that polyculture in crop agroecosystems has been examined in numerous studies with the aim of reducing pest populations by increasing diversity among insect populations over those found in traditional monoculture. Resource concentration and enemies’ hypotheses predict decreased pest populations in more diverse plant communities. Although results have been mixed, insect diversity has been generally increased in polyculture over traditional monoculture. Maintaining natural insect diversity in managed forests to limit possible pest outbreaks has been the goal in forestry systems. Increased arthropod diversity with increased tree diversity has been observed, though fewer studies have been conducted in forestry compared to agriculture. Agroforestry holds promise for increasing insect diversity and reducing pest problems because the combination of trees and crops provides greater niche diversity and complexity in both time and space than does polyculture of annual crops.

Alley cropping Systems of Missouri, US Alley cropping is a agroforestry system where trees are grown in alleys/rows and the available interspaces between rows is used for cultivation of crops and the alleys are thinned regularly to provide light to the crop hence it’s also called as hedge row intercropping. Alley cropping consists of both annuals and perennials its more of a agri-silviculture combination gthat makes it diverse which can satisfy both ecological and ecological needs. Stamps et al. (2002) reported that alley cropped forages (Medicago sativa and Bromis inermis) supported a more diverse and even arthropod fauna than adjacent mono-cropped forages. In another alley cropping trial with peas (Pisum sativum) and four tree species (Juglans, Platanus, Fraxinus and Prunus), Peng et al. (1993) found an increase in insect diversity and improved natural enemy abundance compared to mono cultured peas.

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Tropical Home gardens of India Home gardens are the common feature of many sub humid and tropical regions usually they are small in area but with high diversity and density. Primarily they are managed for household purpose to supply vegetables, fruits and other needy commodities that can be a germplasm conservation for many plants. Sometimes many endemic and endangered plants are also seen in home gardens for ex. Aquilaria malaccunsis (Agarwood) in home gardens of Assam. Tropical home gardens harbour wide diversity of organisms ranging from soil biota go mammals and the number of species per unit area are more because of its high density and component compositions. The home gardens, ecologically sustainable and diversifies livelihood of local community; are considered as excellent tools for biodiversity conservation (Linger 2014). Das and Das (2005) have reported 122 species in home gardens of Barak valley of Assam, India. Similarly, 68 species were reported in home gardens of Karnataka (Shastri et al. 2002) and 127 species in Kerala (Kumar et al. 1994). 74 species of different plants had been reported in the home gardens of North Bengal in addition to poultry, various milch and meat animals which are linked socially and economically to the owner (Panwar and Chakravarty 2010). Roy et al. (2013) reported that the number of bird species like Streptopelia chinensis, Psittacula krameri, Eudynamys scolopaceus, Micropternus brachyurus, Dinopium benghalense, Oriolus xanthornus, Dicrurus macrocercus, Acridothere stristis, Corvus splendens, Turdus cafer, Orthotomus sutorius, Copsychus saularis, Nectarinia zeylonica, Anthus campestris, Passer domesticus, and Ploceus philippinus attracted to collect their food from fruit tress like Aegle marmelos, Annona squamosa, Areca catechu, Averrhoa carambola, Carica papaya, Carissa carandas, Cocos nucifera, Dillenia indica, Elaeocarpus floribundus, Mangifera indica, Phyllanthus acidus, Phyllanthus emblica, Psidium guajava, Spondias pinnata, Syzygium cumini, Tamarindus indica and Zizyphus mauritiana from homestead gardens. Kumar and Nair (2004) reported species richness of tropical homegardens varying from 27 (Sri Lanka) to 602 (West Java). In various parts of the world where land clearing for agriculture has decimated forest cover, home gardens and similar agroforestry systems serve as refugia of species diversity. For example, in Bangladesh where natural forest cover is less than 10% of the total geographic area, home gardens, which are maintained by at least 20 millions households, represent one possible strategy for biodiversity conservation (Kabir and Webb 2009) Agricultural crop diversity also varies considerably among homegardens. Prominent understorey crops in the Kerala home gardens include vegetables such as brinjal, ladies finger, cow pea, ash guard, bitter guard, snake guard, black pepper, tuber crops such as colocasia, elephant food yam, diascoria. Banana is the common intercrop in home gardens throughout Kerala. Cassava, papaya, fodder grasses, pineapple, Curcuma longa, C. aromatic, Zingiber officinale, are the other common intercrops (Kumar and Nair, 2004). Maintaining diversity in approaches to management of agroforestry systems will provide humanity with the widest range of options for adapting to changing conditions. Clear government policy frameworks are needed that support alliances among the many interest groups involved in forest biodiversity. Callo-Concha et al. (2009) found that agroforestry system can help to preserve a higher level of biodiversity as well as provide sustainable landscape connectivity through the encouragement and intensification of the agricultural practices. It can tolerate certain level of disturbance by providing sustainable and productive agriculture practices instead of practicing monoculture systems. This is because the systems involve the clearance of natural forests, and disturb the habitat of various species of flora and fauna. The rationale behind the positive response towards biodiversity of agroforestry system is based on three factors (Nair, 2006): 131

Environmental Issues and Sustainable Agriculture i. accumulation of agroforestry system preserve protected areas from any corruption actions; ii. expansion of agroforestry system increase land area for biodiversity habitation in relation to landscape purposes; and iii. diversification of plant materials species in farming systems. The analyses in the work of Callo-Concha et al. (2009) found that species diversifications are among the factors that influence the availability of habitat for various biodiversity in agricultural land. It is based on the advantages of components integration that provides different structure and dynamic natural cycle, thus, is able to reduce deforestation through its successful implementation (Callo-Concha et al., 2009). By integrating various types of trees species in agricultural land, it has the potential to provide sustainable supply diverse range of tree products which formerly harvested in forest area. Therefore, the integration of suitable components in agricultural land is proven not affecting but increasing the quality and quantity of main agricultural crops.

Different agroforestry systems and their biodiversity issues Table 1. Biodiversity dimensions in traditional agroforestry systems Agroforestry system Biodiversity issues Shifting cultivation or Fallows consist of multiple species; and biological diversity, in Slash and burn both inter and intra species, is intense. Long fallow periods of 15 to 20 years preserve wild species diversity. Home-gardens and High inter- and intra-species diversity involving a number of compound farms fruits, fodder and timber trees and shrubs, food crops, medicinal and other plants of economic value. Forest High species diversity similar to natural forests but dominated by gardens/agroforests a few carefully managed economically valuable tree species Parkland systems A variety of crops grown in association with naturally propagated trees ensure wide species diversity. Parklands range from monospecific to multispecific with up to 20 tree species. Trees on farmlands Diversity is more at the landscape level rather than at (field level boundary plantings and in terms of both inter and intra-species.) scattered trees Source: Atta Krah et al. (2004)

Table 2. Biodiversity dimensions in research developed agroforestry systems Agroforestry technology Biodiversity issues Alley cropping/ hedgerow intercropping Diversity limited to intra species. Emphasis on a few tree species has raised concerns on pests and diseases. Improved fallows or planted fallows. Mostly based on mono-tree species. Fodder banks Sole stands of either leguminous trees or shrubs or high yielding fodder grasses makes the system less diverse. Rotational woodlots Planted using sole stands of fastgrowing species for short-cycle harvest. Tree based intercropping systems Less diverse due to planting of single species. Source: Atta Krah et al. (2004)

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The indicators from which increase and decrease of biodiversity was deduced were aggregated into plant diversity, insects and diversity of soil organisms. The agroforestry practice (a–h, see table footnote) in which the effect was recorded are listed in respective columns and described in detail in Table 3. References to the studies are numbered and listed in the footnote of table. a) a – alley cropping, d –dispersed intercropping, f – home gardens, g – improved tree fallow, h – multistrata agroforestry. b) 1. (Adejuyigbe et al. 1999); 2. (Bisseleua et al. 2013); 3. (Kang et al. 1999); 4. (Sileshi & Mafongoya 2006a); 5. (Sileshi et al. 2008a); 6. (Sileshi & Mafongoya 2006b); 7. (Oke & Odebiyi 2007); 8. (Kandji et al. 2002); 9. (Kandji et al. 2001).

Table 3: Reported effects of trees on biodiversity in Sub-Saharan African agricultural landscapes

Effect Indicator of biodiversity Scale Agro-

ecological zone (a)

(b) (b)

No of studies studies No of diversity Plant diversity Animal Insect diversity microorganism Soil Farm field landscape Semiarid humid Sub Humid practise Agroforestry Reference

14 3 8 9 2 1 1 8 1 5 a,d,f,g 1,4,5,6,7,9 1

Increase Increase

7 4 1 2 1 2 4 2 5 a,d,g,h 3,8

No effect No effect

4 3 1 2 2 1 3 a,g,h 2,9

Decrease Decrease (Source: Kuyah et al 2016).

Agroforestry for biodiversity conservation approach is comprised of six key components. i. Integrated natural resource management by agroforestry that cam improve the socio economic status of people by tree based diversified farming. ii. Integrated protected areas encompassing various levels of management and administration, including the national, provincial, and local governments, nongovernmental organizations, local communities and indigenous peoples, the private sector, and other stakeholders

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Environmental Issues and Sustainable Agriculture iii. Civil society engagement in economic development that includes managing production forests, agroforests, and protected areas, especially for tourism and the sustainable use of certain natural resources iv. Bioregional or ecoregional resource management frameworks, that include farms, agroforests, protected areas, harvested forests, human settlements, and infrastructures as part of a diverse landscape v. Multi-stakeholder cooperation in agroforestry between private landowners, indigenous peoples, other local communities, industry and resource users. vi. Economic mechanisms to support agroforestry including ﬁnancial incentives, tax arrangements and land exchanges to promote biodiversity conservation. vii. Diversification of farming systems with proper selection and management. viii. Enhancing the knowledge base of agroforestry so as to cover conservation efforts. ix. Institutional capacities which encourage local stakeholders, universities, research institutions, and public agencies to harmonize their efforts in agroforestry and biodiversity conservation. Table 4: Desirable characteristics of agroforestry systems for biodiversity conservation (after Harvey et al. 2007)

Type of Variable Desirable characteristics activity Design of Species Diverse species composition, mixture of early, mid and agroforestry composition late succession species, preferably native species system Tree/Shrub Higher tree/shrub density (and greater areas) leads to density greater biodiversity Type of Any system as long as it is floristically and structurally agroforestry diverse system Duration of Long rotation is desirable to provide stability agroforestry system Management of Management Minimal management is preferable agroforestry regime Management strategies should maximize habitat system heterogeneity and availability of diverse resources for wildlife Soil Minimal management Harvesting of Minimal harvesting or harvesting that emulates natural products disturbance regimes Management of Maintain coarse woody debris as habitat for certain coarse woody species debris Spatial Location within Landscape connectivity, by functionally linking habitat configuration broader fragments. landscape Position adjacent to protected areas, riparian corridors and remnant native habitat,to buffer these areas from agricultural impacts Types of land Regeneration of degraded sites, through agroforestry will have a beneficial impact on biodiversity.

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Conclusion Agroforestry can be a principle land use system that combines two other systems like agriculture and forestry for ecological and economic benefits. It can a habitat for diverse of species depending upon the locality and other components hence it can be practiced in place of sole agriculture whenever possible so that along with production the diversity is also managed. The number of species present many vary from system to system and mere numbers are not important when the species are using the ecosystem it is enough to say that agroforestry benefits the biodiversity. Along with other aspects agroforestry is a habitat for many species of flora and fauna both underground biota and above ground biota.

References Adejuyigbe CO, Tian G and Adeoye GO. 1999. Soil microarthropod populations under natural and planted fallows in southwestern Nigeria. Agroforestry Syst. 47:263–272. Atta-Krah K, Kindt R, Skilton JN and Amaral W .2004. Managing biological and genetic diversity in tropical agroforestry. Agroforestry Systems 61:183-194. Bisseleua BHB, Fotio D, Yede, Missoup AD and Vidal S, Hector A. 2013. Shade tree diversity, cocoa pest damage, yield compensating inputs and farmers’ net returns in West Africa. PLoS One. 8:56-115. Brandle JR, Hodges L and Zhou X .2004. Windbreaks in sustainable agriculture. Agroforestry Systems 61:6578. Callo-Concha D, Denich M and Vlek PLG. 2009. Environmental services in agroforestry systems. How to assess them?: Functional biodiversity in Tome-Acu, Northern Brazil. Biophysical and socio-economic Frame Conditions for the Sustainable Management of Natural Resources. Tropentag, Hamburg.pp 65-70. Das T and Das AK .2005. Inventorying plant biodiversity in home gardens: A case study in Barak valley, Assam, Northeast India. Current Science 89(1):155-163. Dean.1995.With boredeaux and firebrand the destruction of the brazilizn atlantic forest, Berkerly.University of Californis Press pp 25-36. Dhyani S K, Handa A K and Uma 2013. Area under agroforestry in India: An Assessment for Present Status and Future Perspective. Indian J Agroforestry 15(1): 1-10. Garcia-Fernandez C, Casado M and Ruiz Perez M. 2003. Benzoin gardens in north Sumatra, Indonesia: effects of management on tree diversity. Conserv Biol 17: 829–836. Guillerme S, Kumar BM, Menon A, Hinnewinkel C, Maire E and Santhoshkumar AV .2011. Impacts of public policies and farmer preferences on agroforestry practices in Kerala, India. Environmental Management 48 (2): 351-364. Harvey CA and Gonzalez VJA . 2007.Agroforestry systems conserve species-rich but modified assemblages of tropical birds and bats. Biodiversity Conservation 16:2257-2292. ICRAF. 2000. Paths to prosperity through agroforestry.ICRAFS corporation strategy.2001- 2002, Nairobi.International Centre for Research in Agroforestry. Izac ZMN and Sanchez PA.2001.Towards a natural resource management paradigm for international agriculture, the example of agroforestry research. Agricultural systems.69.5-25 Jhonson RJ and Beck MM.1988. Influences of shelterbelts on wildlife management and biology. Agroforestry systems.22-23:301-335. Kabir EM and Webb EL .2009. Can home gardens conserve biodiversity in Bangladesh? Biotropica 40: 95-103.

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Kandji ST, Ogol CKPO and Albrecht A. 2001. Diversity of plant-parasitic nematodes and their relationships with some soil physico-chemical characteristics in improved fallows in western Kenya. Appl Soil Ecol. 18:143–157. Kandji ST, Ogol CKPO and Albrecht A. 2002. Influence of some agroforestry practices on the temporal structures of nematodes in western Kenya. Eur J Soil Biol. 38:197–203. Kang BT, Caveness FE, Tian and Kolawole GO. 1999. Longterm alley cropping with four hedgerow species on an Alfisol in southwestern Nigeria – effect on crop performance, soil chemical properties and nematode population. Nutr Cycl Agroecosyst. 54:145–155. Kumar BM, George SJ and Chinnamani S .1994. Diversity, structure and standing stock of wood in the home gardens of Kerala in Peninsular India. Agroforestry Systems 25:243-262. Kumar BM, and Nair PKR. 2004. Tropical Home Gardens: A TimeTested Example of Sustainable Agroforestry. Advances in agroforestry vol 3. Springer, Dordrecht. pp.355-370. Lavelle PBK, Senapati and E Barros. 2003. Soil macrofauna. Pp 303-327 in GSchorth and FL Sinclair (eds) Trees, crops and soil fertility; Concepts and reserch methods, Walling ford, UK.CAB international. Leakey RE and Lewin R .1996. The Sixth Extinction: Biodiversity and its Survival. Weidenfeld and Nicholson, London, 271p. Linger E .2014. Agro-ecosystem and socio-economic role of home garden agroforestry in Jabithenan District, North-Western Ethiopia: implication for climate change adaptation. Springer Plus 3:154: 1-9. Mc Neil J.2000.Something new under the sun; an environmental history of the tweinth centuary.London.Penguin press pp65-72. Montagnini F .2011. Environmental services of agroforestry systems. Food Products Press, USA 126 Nair, P.K.R. and Kumar B.M. 2006. Introduction. In: Kumar B.M. and Nair P.K.R. (eds), Tropical homegardens: A time-tested example of sustainable agroforestry, pp 1 – 10, Springer Science, Dordrecht. Oke DO and Odebiyi KA. 2007. Traditional cocoa-based agroforestry and forest species conservation in Ondo State, Nigeria. Agric Ecosyst Environ. 122:305–311. Pandey DN .1991. Carbon sequestration in agroforestry systems. Climate Policy 2: 367-377. Pandey DN and Mohan D .1993. Nest site selection by cavity nesting birds on Melia azedarach L. and management of multiple use forests. Journal of Bombay Natural History Society 90: 58- 61. Panwar P, Chakravarty S .2010. Floristic structure and ecological function of home gardens in humid tropics of West Bengal, India. Indian Journal of Agroforestry 12(2): 69-78. Peng RK, Incoll LD, Sutton SL, Wright C and Chadwick A .1993. Diversity of airborne arthropods in a silvoarable agro-forestry system. Journal of Applied Ecology 30: 551-562. Petit L. and Petit D. 2003. Evaluating the importance of humanmodiﬁed lands for Neotropical bird conservation. Conserv Biol 17(3): 687–694. Price GW and Gordon AM .1999. Spatial and temporal distribution of earthworms in a temperate intercropping system in southern Ontario, Canada. Agroforestry Systems 44: 141- 149. Rizvi R H, Dhyani S K, Ram Newaj, Karmakar P S and Saxena A. 2014. Mapping agroforestry area in India through remote sensing and preliminary estimates. Indian Farming 63(11): 62- 64. Rizvi R H, Dhyani S K, Ram Newaj, Saxena A and Karmakar P S .2013. Mapping extent of agroforestry area through remote sensing: Issues, estmates and methodology. Indian J Agroforestry 15(2): 26-30.

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Roy B, Rahman MH and Fardusi MJ .2013. Status, diversity, and traditional uses of homestead gardens in northern Bangladesh: a means of sustainable biodiversity conservation. ISRN Biodiversity 2013: 1-11. Shastri CM, Bhat DM, Nataraj DC, Murall KS and Ravindranath NH .2002. Tree species diversity in a village ecosystem in Uttara Kannada district in Western Ghats, Karnataka. Current Science 82: 1080-1084. Shem Kuyah, Ingrid Oborn, Mattias Jonsson, A Sigrun Dahlin, Edmundo Barrios, Catherine Muthuri, Anders Malmer, John Nyaga, Christine Magaju, Sara Namirembe, Ylva Nyberg and Fergus L Sinclair.2016. Trees in agricultural landscapes enhance provision of ecosystem services in Sub-Saharan Africa. International Journal of Biodiversity Science, Ecosystem Services & Management.1. pp. 1-12 Sileshi G and Mafongoya PL. 2006a. Long-term effects of improved legume fallows on soil invertebrate macrofauna and maize yield in eastern Zambia. Agric Ecosyst Environ. 115:69– 78. Sileshi G and Mafongoya PL. 2006b. Variation in macrofaunal communities under contrasting land use systems in eastern Zambia. Appl Soil Ecol. 33:49–60. Sileshi G, Mafongoya P, Chintu R and Akinnifesi F.2008.Mixedspecies legume fallows affect faunal abundance and richness and N cycling compared to single species in maizefallow rotations. Soil Biol Biochem. 40:3065–3075 Stamps WT and Linit MJ.1997. Plant diversity and arthropod communities: Implications for temperate agroforestry. Agroforestry Systems.39:73 Stamps WT, Woods TW, Linit MJ and Garret HE .2002. Arthropods diversity in alley cropped black walnut (Juglans nigra L.) stands in eastern Missouri, U.S.A. Agroforestry Systems 56: 167-175. Thiollay JM .1995. The role of traditional agroforests in the conservation of rain forest bird diversity in Sumatra. Conservation Biology 9: 335-353. Zomer, R.J., S.L. Ustin and C.C. Carpenter 2001. Land cover change along tropical and subtropical riparian corridors within the Makalu Barun National Park and Conservation Area, Nepal. Mountain Research and Development 21(2): 175–183.

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Chapter-17

Marine Pollution: Obstructive Impact on Biodiversities

Alka Vyas Zoology Department, M.M.H. College, Ghaziabad, Uttar Pradesh Email: [email protected]

Abstract Since the industrial revolution human-initiated emissions of carbon dioxide (Co2), methane and nitrous oxide have increased markedly leading to increased concentrations of these gases in the atmosphere. These green house gases reflect radiation back towards the Earth and resulting warming of the oceans as well. Due to industrialization and urbanization, other pollutants like oil, petroleum, pesticides, and insecticides are the major cause of marine pollution. This marine pollution will have a wide range of impacts on several aquatic species and ecosystems. Government of India has established many marine protected areas for conservation of fauna and flora. Keywords: green house gases, radiation, marine pollution, industrialization, fauna, flora.

Introduction Global climate change caused by increased amount of green house gases in the environment. Oceans play an important role in both short and long term weather and climatic patterns. But global climate change is regional rather than global climate models (Clark, 2006). This causes rising sea levels, changes in storm climates, changes in the precipitation patterns etc. Research also shows that climate change may cause adverse effect on agriculture and fisheries both. The Inter-governmental Panel on climate change (IPCC) has projected that the global annual seawater temperature would rise by 0.8-2.50C by 2050 and the sea level would rise by 8 to 25centemer. This will accelerate erosion and increase the risk of flooding (Nicholls et al.1999). The cause of global warming is mainly due to increase in percentage of carbon-dioxide, methane, nitrous oxide, chlorofluorocarbons (CFCs) and water vapour (Jaeger, 1998). CFCs are mainly used in refrigerator and air conditioners, carbon dioxide from combustion of fossil fuels, from deforestation and methane and from agricultural practices and ruminants (Blake and Rowland, 1988). Now an international study led by scientists from Pune-based Indian Institute of Tropical Meteorology (IITM) has shown that warming of Indian Ocean is affecting productivity of its marine ecosystem. Almost all the countries bordering the Indian Ocean are developing countries. Their major sources of revenue are agriculture, industry and mining. These activities are continuously responsible for marine pollution. This marine pollution affects some sensitive and fragile environments such as coral reefs, mangroves, fishes and sea grass beds.

Effect of climate change on coastal systems In relation to the equator, the Indian Ocean has an asymmetric shape largely due to the presence of the Asian continent. Such an asymmetric configuration leads to a weak circulation and poor renewal at depths of the Northern Indian Ocean (Dietrich, 1973). The Indian Ocean occupies an area of 74.92x 106km2 including the marginal seas (Dietrich, 1963). Indian coastal line is approximately 8000km which is very productive and ecological diverse. WWF has been reported some important underlying impact of climate change on marine ecosystems such as rise in SST,

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Environmental Issues and Sustainable Agriculture decreasing pH, shifting ocean currents and rise in sea level. WWF India has been working in some of India’s most critical ecosystems and landscape –like Sunderbans, coastal regions of South India and in the Himalayan zone. India is vulnerable to major climate changes because of a long coastline on the east and west and the Himalayan mountain range in the north. The fourth assessment report of the IPCC (2007) has suggested that climate change is affected coastal India in various ways- More hot days-More heat waves and more death from heat strokes in recent years. Intrusion of saline water into ground water in coastal aquifer. Decline in precipitation, droughts in most of the delta regions of India and drying of wetlands. The Sunderbans is the world’s largest delta which is formed by the deposition of sediments of three great rivers, the Ganga, Bhrama–putra and Meghna. It has rich flora and fauna which makes this one of the most diverse and productive ecosystems in the country. The Sunderbans is now under serious problem due to sea level rise and some other associated problems.

Environmental Issues Problems of sewage, industrial effluents, agricultural wastes and oil spills are greatly increased in coastal areas. Continuous use of pesticides is also a major problem. It is estimated about 25% of the land-applied pesticides reach the coastal waters and contaminate it. This is a twofold threat to both the ecology of the coastal waters and human beings. The prominent marine pollutants are as follows-

Oil Pollutants It has been estimated that about 40% of total oil spilled into world’s ocean discharges into the Indian Ocean basin (Saify and Chaghtai, 1988). Oil pollution is mainly due to crude petroleum or refined petroleum products. Severe oil pollution takes place by tanker disaster in 1967 when the Torrey Canyon ran aground off Cornwall, England. Another major incident took place in 1969 in the Santa Barbara Channel, U.S.A., Oil is the only visible pollutant on the surface of the sea. It affects as reduction of light transmission in the sea, reduction in dissolved oxygen and asphyxiation of avifauna and bentic fauna. Spilled oil spreads quickly on the sea surface with an average thickness of 100mm. Sometimes the water-in-oil emulsion forms a gel-like substance called as “Chocolate mousse”. Coral reef and sandy beach ecosystems have been severely affected by oil pollution in the Kenya, Madagascar and Tanzania (Sen Gupta and Quasim, 1988). Total oil spilled from tanker traffic harbour operations and coastal industries come to about 33,000 tons/year in East Africa (Sen Gupta and Quasim, 1988).

Heavy Metal Pollutants Oil pollution is only that pollution which is visible easily but most of other types of pollutants are not visible and understood only by their damaging effects. Heavy metal pollution can occur by natural and human activities both. Main natural processes are submarine volcanic activity and weathering etc. Industrial wastes are major pollutants by human activity. Most of the metal like Hg, Cd and Pb are responsible for Minmata disease caused by the consumption of fish. Heavy metals are persistent pollutants and cannot be degraded biologically or chemically in nature. Metals can be classified as essential or non-essential elements for biological processes. Most of the metals come under the essential category, while other ones like HG, Cd, Pb are among the non-essential ones. They are toxic and also disrupt some enzyme-related biological function of

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Environmental Issues and Sustainable Agriculture the body and affected food chain. Resulting in some plants and animals becoming health hazard when used as food.

Agricultural Wastes Tonnes of fertilizers and pesticides are used every year in agriculture pest control and disease- vector control. Nearly 25% can be expected to reach the marine environment through atmosphere, river run off and direct discharges. While organochlorine and organomercurial pesticides have been banned in industrial countries, still they are being manufactured and used in developing countries (UNESCO-UNEP, 1982).DDT and other agrochemical compounds are used on sugarcane and cotton fields (Bliss-Guest, 1983). These compounds are very toxic and also induce behavioural changes regarding rate of the young ones is also affected. DDT caused thinning of egg- shell in marine birds feeding on fishes. Agricultural wastes are also responsible for eutrophication.

Domestic Wastes Domestic wastes are generally containing a high concentration of organic substances with N and P. They also help in multiplication of pathogenic bacteria in an appropriate environment. Eutrophication from sewage and domestic discharge can result in serious damage to corals in tropical areas, which promote algal growth and resulting turbidity (Ormand, 1988). Sewage pollution of coral reefs has been a serious problem in Kenya, Mauritius, Tanzania and the Seychelles (Salm 1983). This disrupts the ecological balance tremendously changes in environmental conditions, caused by entrophication which release many metals in their toxic forms from non-toxic compounds.

Tourism Tourism is growing rapidly in the developing countries. This is associated with construction, land development and interference with sensitive biota.(Hatcher et al. 1989). Degradation of many reef areas is mainly due to tourism. Tourism is an important as growing source of revenue in parts of the Western Indian Ocean region. Too many large and luxury hotels are being constructed along the sea face. Domestic wastes from these hotels create serious problems in the adjacent marine areas. Garbage and other solid wastes spoil the beaches by the formation of H2S. Since 1984, a record number of tourists have visited Mauritius each year. Beach tourism on the coast near Dar of Salaam emerged as one of the three major types of tourism (Curry, 1990). The acceleration of the relative sea-level rise is the major cause of coastal erosion and along the Mahe, Seychelles coast the entire circumference is subject to erosion. (Wagle and Hashimi, 1990)

Critical Marine Habitats Impact on Coral reefs- Coral reefs are diverse underwater ecosystems held together by calcium carbonate structures secreted by corals. They provide a home for at least 25% of all marine species (Spalding et al. 1997) (Spalding et al. 2001). It has been reported that more than 75% of tall Indian Ocean island archipelagos and isolated islands were formed by reef deposition. In many areas of the Western Indian Ocean region coral reefs support important commercial fish species (Ormond, 1988). As the number of coral reefs degraded in southwest Madagascar, the species diversity of the fishes can decrease by more than 50% (Vasseur et. al 1988) Despite of great economic and ecological value of reef communities’ degradation and destruction is occurring at an alarming rate in tropical region. A study released in April 2013 has shown not by water pollution but air pollution can also stunt the growth of coral reefs.

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Another cause for the death of coral reefs is bio erosion. In El Nino-year 2010 reports shows global coral bleaching reached its worst level. 95% of coral reefs are at risk due to local threats in Southeast Asia (Gable et al, 1991). Several coral bleaching have been seen in the Western Indian Ocean particularly in Mayotte and on the coast of Tanzania (UFWS 2013). Indian coral reefs have experienced 29 widespread bleaching events since 1989 and intense bleaching occurred in 1998 and 2002. Vivekanandan et al. (2009b) have been reported the vulnerability of corals in the Indian areas. Reefs are likely to become remnant between 2030 and 2040 in the Lakshadweep Sea and between 2050 and 2060 in other regions in the Indian seas. Buddemeier and Smith (1988) have been reported the growth of coral reef communities may not be able to keep pace with the increase in temperature. This problem has been mainly acute in the Kenya, Madagascar, Mozambique and the Seychelles. (Greeen and Sussman,1990; Salm 1983.)

Impact on Mangroves Mangrove communities also constitutes an important natural resource to countries bordering the Indian Ocean. The Indian Mangroves cover about 4827 km2, with about 57% of them along the east coast, 23% along the west coast and 20% in Andaman and Nicobar Islands. They are very productive and serve as an important habitat for a myriad of species (Ormond, 1988). The Sundarbans mangroves in India and Bangladesh is one of the largest such area in the world. They act as a buffer zone and offer protection to valuable communities like Coral reefs. They also stabilise the sediments, control the mean water level and direction of flow. Due to continuous increasing demand for land and fuel many mangrove areas of the Indian Ocean region have been denuded. Coastal populations use timber from mangroves for fuel, construction material from homes and for boat building. In addition, mangroves have been cleared for the development of tourist resorts (Bliss- Guest, 1983). Mangroves are very important to the ecology and economy of coastal areas for many reasons. They constitute a nursery and feed time ground. Their decomposed leaves provide food for molluscs, crustaceans and fin fishes. Same as mangroves provide important habitat for marine invertebrates, vertebrates, birds and mammal species (Ormond, 1988) Siltation and erosion can coat mangrove aerial roots. Oil pollution is also a cause of killing of mangrove plants within 48-72 hours (Ormond, 1988). Mangroves are very sensitive to herbicide damage to the foliage, which is responsible for salt secretion and photosynthesis.

Impact on Marine Fisheries Production from marine fisheries has been stagnant during the past 10 years due to overfishing; unregulated fishing, habitat destruction and marine pollution. Due to increase in water temperature may impact fish diversity, distribution, abundance and phenology. Rise in sea level will also lower fish production and damage the livelihoods of communities. Most of the fish species have a narrow range of optimum temperatures; even a difference of 1oC in seawater may affect their distribution and life process. The oil sardine (Sardinella longiceps) and the Indian mackerel (Rastrelliger kanagurta) are tropical coastal and small pelagic fishes. The oil sardine distributed between latitude 8oN and 14oN and longitude75oE and 770E and annual average sea surface temperature ranges from 27-29oC. As the Indian seas are warming by 0.04oC per decade these fishes extend their northern boundaries and found to descend to deeper waters in the last two decades (CMFRI, 2008). The threadfin breams, Nemipterus japonicas and N. mesoprion are distributed along the entire Indian coast. They are short-lived, fast growing, highly fecund. The present occurrence of spawerners of the two species decreased with increasing temperature during April to September but increased with increasing temperature during October-March. These changes may have impact 141

Environmental Issues and Sustainable Agriculture on nature and value of fisheries (Perry et al; 2005). If small-sized, low value fish species with rapid turnover of generations are able to cope up with changing climate, they may replace large- sized high value species. (Vivekanandan et al; 2005).

Conclusion In the context of climate change, the primary challenge to the fisheries and aquaculture sector will be to ensure food supply, improve livelihood and ensure ecosystem safety. These objectives call for identifying and addressing the concerns arising out of climate change and implement action across all stakeholders at national, regional and international levels. Several policies have made by government. One anticipatory policy is purchasing options on land in order to maintain coastal ecosystems so that coast lines may remain natural and armoured by sea-walls. Development of Coastal Area Management plans should be fermented as a way to integrated land with multiple uses zoning of shores and seas under national jurisdiction. The enactment of Water Pollution Act in 1974 and Environment Protection Act 1986 have helped in regulating the disposal of wastes from the industries. These measures have resulted in reduction of pollution loads of the coastal waters to certain extent.

References BLAKE. D. R. and ROWLAND. F.S.(1988) Continuing worldwide increase in tropospheric methane . 1978-1987, Science, 239, 1129-1131. BLISS-GUEST, P.(1983) Environmental stress in the East African region,Ambio,12(6),290- 295. Clark, B M (2006): Climate change: a looming challenge for fisheries management in southern Africa. Marine Policy, 30, 84-95. CMFRI (2008) Research Highlights 2007-2008, Central Marine Fisheries Research Institute, Cochin, India: 36 p CURRY S.(1990) Tourism development in Tanzania. Ann. Tourism Res. , 17(1), 133-149. Dietrich, G. 1963 General Oceanography, Interscience, New York, 588 pp. Dietrich, G. 1973 The unique situation in the environment of the Indian Ocean, In: The Biology of the Indian Ocean, editor B. Zeitzchel, Springer, Verlag, Berlin 1-6. Gable,F.D.Aubrey and J.Gentile.GLOBAL ENVIRONMENTAL CHANGE ISSUES IN Washington ,D.C., EPA/600/J-93/312(NTIS PB93229342),1991. GREEN, G.M. and SUSSMAN, R. W. (1990) Deforestation history of the eastern rain forests of Madagascar from satellite images, Science, 248,212-215. HATCHER,B,G.. JOHANNES, R. E. and ROBERT-SON,A.I.(1989) Review of research relevant to the conversation of shallow tropical marine ecosystems, A. Rev Oceanogr. mar. Biol., 27,337-414. JAEGER,J. (1988) Anticipating climate change , Environment,30(7),12-15,30-33. Nicholls, R J, Hoozemans, F M J and Marchand, M (1999): Increasing flood risk and wetland losses due to global sea level rise: regional and global analyses. Global Environmental Change, 9: S69-S87. ORMOND,R.(1988) Status of critical marine habitats in the Indian Ocean, In: IOCIUNESCO Workshop on Regional Co-operation in Marine Science in the Central Indian Ocean and Adjacent Seas and Gulfs, pp. 167–193. Workshop Report No. 37. Supplement. Perry, A.L. , Low, P.J., Ellis, J.R., Reynolds, J.D. (2005) Climate change and distribution shifts in marine fishes. Science 308, 1912 - 1915.

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SAIFY,T and CHAGHTAI,S.A. (1988) Sources of pollution in Indian Ocean - risk and management, In: Chemical Spills and Emergency Management at Sea. Pp: 479-488. P.Bockholts and I. Heidebrink (Eds). Kluwer, Deventer. SALM,R.V. (1983) Coral reefs of the Western Indian Ocean: a threatened heritage, Ambio, 13(3), 200-201. SEN GUPTA, R. and QASIM, S.Z. (1988) The Indian Ocean - an environmental overview, In: IOCIUNESCO Workshop on Regional Co-operation in Marine Science in the Central Indian Ocean and Adjacent Seas and Gulfs, pp. 9-41. Workshop Report No. 37. Supplement. UNESCO-UNEP (1982) Marine and coastal area development in the East African region, United Nations Environment Programme Regional Seas Reports and Studies No. 6. Spalding MD,Grenfell AM(1997). “New estimates of global and regional coral reef areas”. Coral Reefs 16 (4): 225-230. doi:10.1007/s003380050078. Spalding , Mark , Corinna Ravilious, and Edmund Green(2001). World Atlas of Coral Reefs. Berkeley, CA: University of California Press and UNEP/WCMC ISBN 0520232550 TITUS,J.G. (1986) Greenhouse effect, sea level rise, and coastal zone management , Coastal Zone Mgmt J., 14(30, 147-171. U.S. Fish & Wildlife Service –Birds of Midway Atoll. Archived from the original on May 22,2013.Retrieved August 19,2009. Vivekanandan, E, Srinath, M and Somy Kuriakose (2005): Fishing the food web along the Indian coast. Fisheries Research, 72, 241- 252. Vivekanandan, E, Hussain Ali, M, Rajagopalan, M (2009b): Vulnerability of corals to seawater warming. In: Aggarwal, P K (ed) Impact, Adaptation and Vulnerability of Indian Agriculture to Climate Change, Indian Council of Agricultural Research, New Delhi (in press) VASSEUR,P., GABRIEL,C. and HARMELIN-VIVIEN, M. (1988) State of coral reefs and mangroves of the Tulear region (SW Madagascar): assessment of human activities and suggestions for management, In: Proceedings of the Sixth International Coral Reef Symposium, Australia, 2, 421-426.

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Chapter-18

Analytical Techniques for Soil Testing

*Trilok Nath Rai, Kedar Nath Rai, Sanjeev Kumar Rai and Sadhna Rai *Subject Matter Specialist, Soil Science /Agronomy, Krishi Vigyan Kendra (ICAR-IIVR, Varanasi) Sargatia, Seorahi, Kushinagar-274406 (U.P.) Email Id. [email protected]

Soil Sampling Principle Soil testing is an essential component of soil resource management. Each sample collected must be a true representative of the area being sampled. Utility of the results obtained from the laboratory analysis depends on the sampling precision. Hence, collection of large number of samples is advisable so that sample of desired size can be obtained by sub-sampling. In general, sampling is done at the rate of one sample for every two hectare area. However, at-least one sample should be collected for a maximum area of five hectares. For soil survey work, samples are collected from a soil profile representative to the soil of the surrounding area.

Materials Required 1. Spade or auger (screw or tube or post hole type))4. Sampling bags 2. Khurpi 5. Plastic tray or bucket 3. Core sampler

Points to be considered 1. Collect the soil sample during fallow period. 2. In the standing crop, collect samples between rows. 3. Sampling at several locations in a zig-zag pattern ensures homogeneity. 4. Fields, which are similar in appearance, production and past-management practices, can be grouped into a single sampling unit. 5. Collect separate samples from fields that differ in colour, slope, drainage, past management practices like liming, gypsum application, fertilization, cropping system etc. 6. Avoid sampling in dead furrows, wet spots, areas near main bund, trees, manure heaps and irrigation channels. 7. For shallow rooted crops, collect samples up to 15 cm depth. For deep rooted crops, collect samples up to 30 cm depth. For tree crops, collect profile samples. 8. Always collect the soil sample in presence of the farm owner who knows the farm better

Procedure 1. Divide the field into different homogenous units based on the visual observation and farmer’s experience. 2. Remove the surface litter at the sampling spot. 3. Drive the auger to a plough depth of 15 cm and draw the soil sample. 4. Collect at least 10 to 15 samples from each sampling unit and place in a bucket or tray. 5. If auger is not available, make a ‘V’ shaped cut to a depth of 15 cm in the sampling spot using spade.

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6. Remove thick slices of soil from top to bottom of exposed face of the ‘V’ shaped cut and place in a clean container.

1 inch / 2.5 cm 6 inches (15 cm) 1. Mix the samples thoroughly and remove foreign materials like roots, stones, pebbles and gravels. 2. Reduce the bulk to about half to one kilogram by quartering or compartmentalization. 3. Quartering is done by dividing the thoroughly mixed sample into four equal parts. The two opposite quarters are discarded and the remaining two quarters are remixed and the process repeated until the desired sample size is obtained. 4. Compartmentalization is done by uniformly spreading the soil over a clean hard surface and dividing into smaller compartments by drawing lines along and across the length and breadth. From each compartment a pinch of soil is collected. This process is repeated till the desired quantity of sample is obtained. 5. Collect the sample in a clean cloth or polythene bag. 6. Label the bag with information like name of the farmer, location of the farm, survey number, previous crop grown, present crop, crop to be grown in the next season, date of collection, name of the sampler etc. Collection of soil samples from a profile 1. After the profile has been exposed, clean one face of the pit carefully with a spade and note the succession and depth of each horizon. 2. Prick the surface with a knife or edge of the spade to show up structure, colour and compactness. 3. Collect samples starting from the bottom most horizon first by holding a large basin at the bottom limit of the horizon while the soil above is loosened by a khurpi. 4. Mix the sample and transfer to a polythene or cloth bag and label it. Processing and storage 1. Assign the sample number and enter it in the laboratory soil sample register. 2. Dry the sample collected from the field in shade by spreading on a clean sheet of paper after breaking the large lumps, if present. 3. Spread the soil on a paper or polythene sheet on a hard surface and powder the sample by breaking the clods to its ultimate soil particle using a wooden mallet. 4. Sieve the soil material through 2 mm sieve. 5. Repeat powdering and sieving until only materials of >2 mm (no soil or clod) are left on the sieve. 6. Collect the material passing through the sieve and store in a clean glass or plastic container or polythene bag with proper labeling for laboratory analysis. 7. For the determination of organic matter it is desirable to grind a representative sub sample and sieve it through 0.2 mm sieve. 8. If the samples are meant for the analysis of micronutrients at-most care is needed in handling the sample to avoid contamination of iron, zinc and copper. Brass sieves should be avoided and it is better to use stainless steel or polythene materials for collection, processing and storage of samples.

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9. Air-drying of soils must be avoided if the samples are to be analyzed for NO3-N and NH4-N as well as for bacterial count. 10. Field moisture content must be estimated in un-dried sample or to be preserved in a sealed polythene bag immediately after collection. 11. Estimate the moisture content of sample before every analysis to express the results on dry weight basis. Guidelines for Sampling Depth Soil sampling depth S.No. Crop Inches cm 1 Grasses and grasslands 2 5 Rice, finger millet, groundnut, pearl 2 millet, small millets etc.(shallow rooted 6 15 crops) Cotton, sugarcane, banana, tapioca, 3 9 22 vegetables etc. (deep rooted crops) Perennial crops, plantations and orchard Three soil samples at 12, Three soil samples at 4 crops 24 and 36 inches 30, 60 and 90 cm

Soil sampling and testing by Krishi Vigyan Kendra (ICAR-IIVR, Varanasi) Sargatia, Seorahi, Kushinagar-274406 (U.P.)

Soil sampling and testing Methods of Soil Sampling

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Chapter-19

Role of water for growth and development of crops

Role of Water 1. Water is a constituent of protoplasm 2. Water acts as a solvent. Plants can absorb nutrients when these nutrients are dissolved in water 3. Water is used for transpiration carrier of nutrients from the soil to green plant tissues. 4. They are used for photosynthesis and the end product is also conveyed through water to various plant parts 5. Water forms over 90% of the plant body by green or fresh weight basis. 6. Plants can synthesis food through photosynthesis only in the presence of water in their system. 7. Water helps to maintain the turgidity of cell walls. Water helps in cell enlargement due to turgor pressure and cell division which ultimately increase the growth of plant. 8. Water is essential for the germination of seeds, growth of plant roots, and nutrition and multiplication of soil organism. 9. Water is essential in hydraulic process in the plant. It helps in the conversion of starch to sugar. 10. Water helps in the transpiration, which is very essential for maintaining the absorption of nutrient from the soil.

# Water regulates the temperature and cools the plant. # Water helps in the chemical, physical and biological reaction in soil. # So, water is applied externally, if availability seems limited through soil, not sufficient to meet the requirement due to drought or excess losses. We call the external application of water to the soil to supplement the requirement as `Irrigation'.

Development of Irrigation in India Irrigation has been practiced in India and other Asian countries from early times. Of course civilization started through irrigation systems. All these early civilization are in South and South West Asia. In Tamil Nadu the early Chola kingdom is reported with well developed technologies for irrigation management. The check dam at Kallanai to regulate the river for irrigation is a typical example.

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80% of rainfall in India is received during monsoon period. Monsoon rainfall is very uncertain. So irrigation is very important to supply water to plants also and when needed.

Uneven distribution of rainfall: To compensate the uneven distribution in an area, supplemental irrigation is needed.

Effect of winter rainfall (N India)/ Effect of SWM in S. India: Supplemental irrigation is inevitable in the regions due to poor rainfall.

Cultivation of high yielding crops: High yielding crops produce heavy biomass and economic yield. Higher biomass need more water for its production. Hence supplementation of water as irrigation is essential.

Difference in water holding capacity of the soil: Sandy soil - low WHC – frequent irrigation. Clay soil - high WHC - frequency is less.

Water Requirements of Agricultural Crops in Surface Irrigation Methods (5cm depth at each irrigation) Crop Duration Total Water Requirement (mm) Rice 110 1250 Sugarcane 360 2200 Groundnut 105 510 Sorghum 105 500 Maize 100 500 Ragi 95 310 Cotton 165 600 Blackgram 65 280 Soybean 85 320 Sesame 85 150 Sunflower 110 450

Suitability of Water for Irrigation Quality of Irrigation Water The suitability of irrigation water is mainly depends on the amounts and type of salts present in water. The main soluble constituents are calcium, magnesium, sodium as cations and chloride, sulphate, biocarbonate as anions. The other ions are present in minute quantities are boron, selenium, molybdenum and fluorine which are harmful to animals fed on plants grown with excess concentration of these ions.

Quality of irrigation is judged with three parameters: Total salt concentration 1. Sodium Adsorption ratio water 2. Boron content

Total Salt Concentration Salt concentration of irrigation water is measured as electrical conductivity (EC). Conventionally, water containing total dissolved salts to the extent of more than 1.5 m mhos/cm

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Environmental Issues and Sustainable Agriculture has been classified as saline. Saline waters are those which have sodium chloride as the predominant salt.

Classification of irrigation water based on total salt content EC Class Quality characterisation Soils for which suitable (ds/m) C1 <1.5 Normal waters All soils C2 1.5 – 3 Low salinity waters Light and medium textured soils C3 3 – 5 Medium salinity waters Light and medium textured soils for semi – tolerant crops Light and medium textured soils for tolerant C4 5 – 10 Saline waters crops C5 > 10 High salinity waters Not suitable

Sodium Adsorption Ratio Sodium Adsorption ratio (SAR) and residual sodium carbonate (RSC) are also the main criterion to determine the quality of irrigation water.

Boron Content Irrigation water which contains more than 3 ppm boron is harmful to crops, especially on light soils.

Classification of irrigation water based on boron content Boron Class Characterisation Soils suitable (ppm) B1 3 Normal waters All soils B2 3 – 4 Low boron waters Clay soils and medium textured soils B3 4 – 5 Medium boron waters Heavy textured soils B4 5 – 10 Boron waters Heavy textured soils B5 > 10 High boron waters Not suitable

Critical Stages for Irrigation

Crops Critical Stages Rice Initial tillering, flowering Most critical stage: Crown root initiation, tillering, Wheat jointing,. booting, flowering, milk and dough stages Wheat Boot stage; dough stage Pulses Flowering and podding. Peas Pre bloom stage. Berseem After each cutting. Gram Pre flowering and flowering. Pigeonpea Flower initiation, pod filling. Sorghum Initial seedling, pre flowering, flowering, grain formation. Barley Boot stage, dough stage Maize Early vegetative, taselling and silking stage.

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Chapter-20

Linear Regression Model and its Applications in Forestry Research

Ankita1* and Bharti2 1Department of Farm Engineering, Institute of Agricultural Sciences, BHU, Varanasi, U.P. 2Statistics, Department of Basic Sciences, Dr YSP UHF, CoH&FNeri, Himachal Pradesh *Corresponding Author: [email protected]

Abstract In this chapter along with a brief introduction, we have discussed basics of regression analysis. Properties of coefficient of regression have been listed. Applications of regression analysis in the field of forestry research have been discussed. SAS code for simple linear regression has also been provided in this chapter. Keywords: Regression analysis, Linear, carbon sequestration and biomass

Introduction Regression models have been routinely used for data analysis and empirical modelling in forestry and related fields. Regression analysis is the technique used for determining average relationship between variables. Term “regression” was coined by Sir Francis Galton in the nineteenth century. He discovered that sons of very tall fathers tended to be shorter than their fathers and sons of very short fathers tended to be taller than their fathers i.e. heights move toward the mean of all humans. This phenomenon of regression to the mean holds for more than human heights. He called this phenomenon as “regression to the mean”. He supposed that regression to the mean did not occur. Then, on the average, the sons of tall fathers would be as tall as their fathers and sons of small fathers would be as small as their fathers. This does not happen because heights of humans on an average tend to remain stable. Thus, he put this relationship into a mathematical measure. The aim of regression analysis is to break down the relationship between variables in terms of equations. Finding relationship between variables in terms of equations will enable us to predict the value of one variable when we know value of the other variable. The variable whose values are estimated is known as dependent variable or response and the variable which is used to estimate the value of the other variable is called independent variable or explanatory variable. In this chapter dependent variable will be denoted by ‘Y’ and explanatory variable by ‘X’. The line which shows the relationship between variables X and Y is called regression line is:

푌 = β0 + β푋 This the mathematical equation of a straight line where, β0 is the intercept and β is the slope.

푌 = β0 + β푋 + 푒 After adding the error term in the equation, it becomes statistical model where, β0 and β are parameters of the regression equation, e is the residual term which accounts for the variation in Y which is not explained by the explanatory variable X.β is known as regression coefficient which measures the magnitude of change in dependent variable for a unit change in the value of explanatory variable. Two lines of regression can be obtained, one is obtained when we consider X as independent variable and Y as dependent variable and the other when we consider X as dependent variable and Y as independent variable. For Y on X regression coefficient is represented as βYX and for X on Y regression coefficient is represented as βXY.

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When there are only two variables involved in the analysis, it is known simple regression and when the relationship between the two variables involved is linear, it is known as simple linear regression, otherwise it is non linear regression. When the number of explanatory variables is more than two and the relationship is linear then the regression equation is multiple linear regression equation. Most commonly linear regression equation is used but many of the biological processes are inherently non-linear in nature. The computation of non linear equations is quite difficult and requires more mathematical skills. So, for the purpose of easy computation non linear equations are converted into linear equations by the use of logarithmic transformation. But the logarithmic transformations have several inherent drawbacks in evaluating the usual coefficient of determination, R2, standard error of the estimate and significance in terms of the original data. With the advancement of Computer, software were developed to analyse regression models such as R, SPSS, SAS etc.

Following is the SAS code for fitting of simple linear regression Title‘Simple Linear Regression’; Data class ;Class; Input Name $ Y X @@; Datalines; ……… ……… ; Proc reg; Model Y = X; run;

Mathematical properties of regression coefficients: i) Geometric mean between two regression coefficients is equal to correlation coefficientr =

√byxbxy ii) Arithmetic mean between two regression coefficients is greater than or equal to correlation b + b coefficient yx xy r 2 iii) If one of regression coefficient is greater than 1, other will be less than 1. Both regression coefficientsCLASS cannot site be simultaneouslyrep trt; greater than 1, but both may be less than 1. iv) Sign of both regression coefficients and correlation coefficient is same (sign will depends upon covarianceMODEL between yld X = and site Y, rep(site) if covariance trt site*trt/ss3; is positive, all of them will be positive and if covariance is negative all of three will be negative) v) RegressionTEST coefficient h=trt e=trt*site; is independent of change of origin but not of change of scale vi) Angle between two regression line: If is acute angle between two regression lines, then = RUN;2 -1 1−r σxσy tan ( 2 2 ) rPROCσx+ σy GLM;

If correlationCLASS (r) betweensite rep trt;X and Y is 0, then = 900i.e. two regression lines are perpendicular to each other If correlationMODEL coefficient yld = siteis perfect, rep(site) r = +1 trt/ss3; or -1, then = 00 i.e. two regression lines coincide each other TheRUN; main aim of regression analysis is to estimate the parameters of the equation and checking its validity through validation techniques. Once the regression equation fitted well, value 151

Environmental Issues and Sustainable Agriculture of X can be used to predict the value of Y. Method of ordinary least square (OLS) is used to estimate the regression parameters. Method of ordinary least square (OLS) is used to estimate the regression parameters. The parameters can be estimated using following formula ∑n (X − X̅) ∗ (Y − Y̅) β = i=1 i i n ̅ 2 ∑i=1(Xi − X) ̅ ̅ and β0 = 푌 − βX Where, X̅ is the the means of variable X and Y̅the means of variable Y. And Xi and Yi are the observations corresponding to variable X and Y respectively. While deciding what model to fit to the data three criteria have to be considered i) Statistical significance of regression coefficient, 훃: The regression coefficient of the selected model should be significant i.e. the values of response variable should significantly depend on values of the explanatory variable. Significance of regression coefficient can be tested using t test. ii) Standard error, S.E.: Such model should be chosen in which standard error is comparatively small to ensure precise and accurate prediction of values corresponding to dependent variable. iii) Coefficient of determination R2: coefficient of determination which accounts for the variation of the dependent variable explained by the independent variable. The range of coefficient of determination is between 0 and 1. While choosing the model we should ensure that the R2value is always greater than 0.5. The model which satisfies all the three criteria is the best model and is recommended for fitting of the data.

Application of Regression Analysis in Forestry There is not even a single discipline in which the statistics has not crept in. In this chapter we will restrict our discussion to the application of regression analysis in the field forestry. 1. In forest mensuration, the main aim is to estimate the quantity of timber contained in the forest. No doubt, tree volume can be estimated by falling the tree but it will lead to cutting of many trees for research purpose alone which is highly undesirable. So, an alternative to this is development of multiple regression equations for tree volume estimation in which tree volume can be considered as dependent variable and tree diameter, height, basal area, bark thickness, crown height, crown length, form can be considered as explanatory variables. The precise estimation of tree volume and biomass in forest ecosystems is essential for commercial timber extraction and above-ground biomass (AGB) carbon stock assessment. 2. Assessment of carbon sequestration potential in terrestrial ecosystems using regression models is a commonly used method. Several regression models have been developed to estimate biomass or carbon stock for forestry species which are being used to prepare volume tables and to estimate carbon in different forest types. The strength properties of wood can be expressed as a function of specific gravity, age, average rate of radial growth etc. Akay et al (2006) used regression analysis to study the economic factors affecting the import of forest industry products in Turkey. Adekunle (2007) used non linear regression to estimate timber volume. Kahyani (2011) used simple linear regression to study the relationship between basal area and tree coverage of Quercus brantii Lindl. Giri (2019) used regression equations for estimating tree volume and biomass of important timber species in Meghalaya, India.

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References Adekunle VAJ. 2007. Non-linear regression models for timber volume estimation in natural forest ecosystem, Southwest Nigeria. Research Journal of Forestry, 1: 40-54. Akay M, Gunduz O and Esengun K. 2006.A regression analysis of the economic factors affecting the import of forest industry products in TurkeyJournal of Applied Sciences6 (2): 357-361. Giri, Pandey R ,Jayaraj RS , Nainamalai R and Ashutosh S. 2019. Regression equations for estimating tree volume and biomass of important timber species in Meghalaya, India Krishna Current Science 116 (1) Kahyani, S. 2011. The basic of analytical of simple linear regression in forestry studies (case study: relationship between basal area and tree coverage of Quercus brantiiLindl. World Applied Sciences Journal 14 (10): 1599-1606

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Chapter-21

Role of water in relation to plant growth: An integrated water management approach

*Paras Kamboj, Vikas1 and Sukirtee2 * Department of Agronomy, CCS Haryana Agricultural University, Hisar - 125004 1,2Department of Soil Science, CCS Haryana Agricultural University,Hisar– 125004 Email: [email protected]

Abstract Water is very important for the living organisms both plants and animals. It takes part in the various biochemical reactions like - photosynthesis which is very important process in plant. Plants are able to complete their cycle only with the availability of water. It acts as a solvent of various chemicals present in the soils. It also acts as medium of transport because nutrient required by the plants are taken through their roots. About 99 percent of the water taken by the plants is loss through transpiration. Plants creates transpiration pull through which water is up taken from the soil and along with the water nutrients are enters in the plants and these moves through the xylem tissues. Water is also important because it serve as a medium of transport of biochemical such as products of photosynthesis, hormones, etc. from source tissue to sink tissue. Plants require water throughout their life but its demand depends on the stage of the crop. The plant moves towards againg its water requirement declines. Under proper availability of water, plants are able to complete all its stages in correct manner. Otherwise there is reduction in the yield and its components. Under water stress condition it closes the stomata because of secreation of ABA (abscisic acid) enzyme, which is generally a growth inhibitor. Under severe conditions plant shows wilting symptoms and under severe losses it may die. So it is very important to apply water at right time and in right amount to the crop plants. Keywords: Biochemical reaction, Water stress, Stomatal closure, Transpiration

Introduction Water is essential for all living organisms and plants are no exception. In fact, most of the actively growing plants may contain almost 90 per cent of water. Although it is generally stated that less than one per cent of the total water used by the plant (consumptive use) is needed for its metabolic activities, water plays a multifaceted role, which can be enumerated as follows: 1. It serves as a solvent for various chemicals present in the cells 2. It acts as a reactant in various biochemical processes, such as photosynthesis, hydrolysis, hydration, etc., and is a source of proton for synthesis of various biochemical molecules. 3. It functions as a medium of transport of minerals from the soil to the plant leaf 4. It also serves as a medium of transport of biochemicals such as products of photosynthesis, hormones, etc. from source tissue to sink tissue 5. It provides the turgor pressure necessary for cell expansion and maintenance of cell shape. 6. Though transpiration is a process of loss of water vapour from the stomata of plant to the atmosphere, it helps in uptake of CO2, a primary substrate for photosynthesis, and cooling the plant canopy. 7. It acts as buffering agent to maintenance of plant tissue temperature.

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Soil Water Relations Soil has been defined as a three-dimensional, dynamic, natural body occurring on the surface of the earth that is a medium for plant growth and whose characteristics have resulted from the forces of climate and living organisms acting upon parents material, as modified by relief, over a period of time (Tamhane et al., 1970). To serve as a favorable medium for plant growth, soil must store and supply water and nutrients in addition to the anchorage it provides. Soil is a porous medium; therefore, due to the geometry of the pore spaces between the soil particles and the nature of the surfaces, soil has the capacity to hold water. This property of soil enables it to retain precipitation or irrigation water in the root zone to be used by plants over time. The amount of water held depends upon the porosity and pore size distribution and the capillary pressure of water in the soil. The force by which the water is held by soil (soil water suction/tension) is the force that the plant roots have to overcome for extracting water retained by soil. It is expressed in the units of pressure. Earlier, it was generally expressed in bars (or atmospheres) but is now expressed in Pascal’s (Pa). The relationship between the various units is given below: 1 bar = 1020 cm of water column*

1 atm = 1030 cm of water column 1 bar = 105 Pa = 100 kPa = 0.1 MPa *Pressure exerted by a column of water 1020 cm high. Conventionally, the soil water potential is expressed in terms of hydraulic head i.e. soil water potential expressed in terms of height of water column. For example, if the soil water tension is 1 bar (soil water potential of -1 bar), in terms of water column height, it will be 1020 cm. For the sake of convenience, 1 bar is considered equivalent to 1 atm and approximately 1000 cm of water column height. Since these are fairly large numbers and handling such numbers is cumbersome, Schofield (1935) suggested the use of ‘pF’, which was defined as the logarithm of the negative pressure (tension or suction) head expressed in centimeters of water column. A tension head of 10 cm of water would be pF of 1, a tension head of 1000 cm would be pF of 3. Soil Moisture Constants There are many terms that are associated with the water that is contained or retained by the soil. The common ones are saturation, field capacity, permanent wilting point and hygroscopic coefficient. The water held by the soil at these points is shown schematically in Fig. 1.

Fig. 1: Volumes water and air associated with soil solids at different moisture levels (Source: Modified from “Irrigation on Western Farms, U.S. Departments of Agriculture and Interior).

Saturation Soil is a porous medium and when all the pores of the soil are filled with water, it is referred to as saturated soil. Saturation percentage or the water held by soil can be determined by: Bringing the soil core/soil sample in contact with water column at a height corresponding to the

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Environmental Issues and Sustainable Agriculture midpoint of the sample and determining the moisture held by soil, or by using the formula for porosity: P = {1 - BD/PD} x 100 ------(1) Where, P is the porosity in percent, BD is bulk density (g cm-3) and PD is particle density (g cm-3) of soil. PD can be generally assumed to be 2.65 (g cm-3) for mineral soils. It can also be estimated by determining the moisture content of the core of which saturated hydraulic conductivity has been determined without allowing any water to drain out of the sample.

Field Capacity (FC) It is the term used to describe the maximum amount of water that a soil will retain after allowing free drainage. It does not generally correspond to a fixed soil water suction (or potential) varying from 1/10 bar for coarse textured soils to 1/3 bar for fine textured soils. It is, therefore, best estimated in the field by saturating the root zone and determining soil moisture after free internal drainage ceases. It takes about 24 to 36 hrs in coarse and 2-3 days in medium textured soils.

Permanent Wilting Point (PWP) It is the soil water content at which the sunflower or some other indicator plants will wilt and will not recover even when placed in a humid environment. It is important to mention that plants can some time exhibit wilting symptoms but will recover when placed in a humid environment, i.e., the reduction in atmospheric demand. This is referred to as temporary wilting. It is considered equivalent to the water held by the soil against an applied pressure of 15 bars. It is generally estimated in the laboratory using either a pressure plate or a pressure membrane apparatus. It consists of a chamber in which saturated soil samples either disturbed or intact in cores, are placed over a ceramic-plate or cellulose membrane, the bottom of which is connected to the atmosphere. Compressed air is then forced into the chamber (called the extractor). Pressure is maintained at the desired level e.g. 15 bars till the outflow of water ceases i.e. the soil is in equilibrium with the applied pressure. Hygroscopic coefficient: It is the water held by the soil at 31 bars (3.1 MPa) soil moisture tension and can be determined using a pressure membrane assembly meant for higher pressures. It can also be approximated by allowing an oven dry soil to absorb moisture from the air till constant weight is attained. The water between saturation and field capacity is called gravitational water. It flows out under the influence of gravity and is considered unavailable to plants. The water between field capacity and hygroscopic coefficient is referred to as capillary water as it is bound to the soil by capillary forces. The water held by the soil between field capacity and permanent wilting point is termed as available water for plants while the water held between permanent wilting point and hygroscopic coefficient is considered unavailable to plants. Some plants are able to survive even at moisture contents below PWP for short periods. Field capacity can also be determined in the laboratory with this equipment using an applied pressure of 1/3 bar for clayey soils and 0.1 to 0.2 bar for sandy to sandy loam soils. Field capacity is considered as the upper limit of available water to plants and the permanent wilting point as the lower limit. The relationship between the amounts of water held in a soil and the force by which it is held (capillary pressure or suction or tension) is depicted in the form of a curve commonly referred to as the soil water characteristic or release curve or simply the pF curve (Fig.2). Two points of this curve are of particular interest to agriculturists i.e. the field capacity and the permanent wilting point.

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Fig. 2: Soil water retention characteristic curve of three texturally different soils

Soil Water Storage and Availability to Plants The soil water storage capacity is generally expressed in terms of Available Water Capacity (AWC). The total available water in soil is regarded as the difference between soil moisture content of "field capacity" and "wilting point". It is customary to express available water capacity in terms of depth dimensions so that it can be considered with irrigation, evaporation rate, rainfall and irrigation water quantity, which are generally expressed in terms of depth. The available water capacity of specific layers, generally available as percent by weight, can be expressed as ‘cm’ if bulk density values and depth of soil layer of the root zone are also determined as illustrated below: Dw= {(FC - PWP) x BD x D5}/100 ------(2) in which Dw = Depth of water contained in a specific soil layer (cm) Ds = Thickness of the soil layer (cm) BD = Bulk density of the particular soil layer (g cm-3) FC = Soil water content at Field Capacity (% by wt) PWP = Soil water content at Permanent Wilting Point (% by wt) The value of ‘Dw’ is computed for each soil layer and then added up for the entire profile. However, the values of BD, FC and PWP vary from layer to layer within a soil profile, soil to soil and location to location even under the same major soil group for the simple reason that there will be a variation in soil depth and available water capacity limits also. Therefore, as already emphasized earlier the actual determination has to be made for the specific soil under consideration. A school of thought led by Veihmeyer and Hendrickson (1948) maintains that soil moisture is available for plant growth equally over the range between field capacity and permanent wilting point. According to this view, transpiration/plant growth is unaffected by the magnitude of soil moisture content unless PWP is reached when the water suddenly becomes non-available. Another view point states that the water held by the soil becomes progressively less available with a linear decreasing trend as the water content decreases from FC to PWP (Thornthwaite and Mather, 1955). Yet another school of thought maintains that transpiration/plant growth is unaffected by the magnitude of soil moisture content from field capacity up to certain threshold value below which almost linear decrease in rate of transpiration occurs (Ritchie et al., 1972). The magnitude of the threshold value would, however, depend upon a variety of factors related to soil, plant and atmospheric conditions. The approach of Ritchie et al. (1992) is the one generally subscribed to by most workers for its practicality. All the three approaches have been depicted in Fig. 3.

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Fig 3. Concepts of soil water availability to plants

Different views regarding availability of water to plants appear apparently contrasting, however, they can be reconciled if consideration is given to the water transmission characteristics of soils, crop rooting depth and density, and evaporative potential of atmosphere. In general, a greater soil water depletion can be tolerated by plants under the conditions of low evaporativity, deep and dense rooting of plants and medium to fine textured soils. In contrast, under the conditions of high evaporativity, sparse rooting and coarse textured soils, only a small depletion of soil water can be tolerated by plants and frequent light irrigations will be needed to maximize crop growth. Irrigation schedule needs to be optimized in terms of time and amount of irrigation on the basis of permissible water depletion for a given combination of crop, soil and climate. Under limited water supply situations, crop water deficit may be planned by identifying optimal and sub optimal water deficit sequences.

Water Transmission Characteristics Hydro-physical properties of soil, viz., moisture retention characteristics and hydraulic conductivity, greatly influence the availability of water to plant roots. As suction increases i.e. moisture content decreases, hydraulic conductivity decreases more steeply in coarse textured soils than in fine textured soils. Thus, not only is the amount of moisture retained in a coarse textured soil less (Table 1), but also the movement of moisture from the bulk soil to the site of moisture absorption i.e. the root surface is much slower as compared with the fine textured soil.

Table 1: Available water capacity of soils of different textural classes Textured class Available water (cm/cm of soil) Loamy sand 0.074 Sandy Loam 0.146 Loam 0.191 Silt Loam 0.234 Sandy clay loam 0.209 Silty clay loam 0.204

Water retention curves for soil plotted in terms of per cent depletion of available water (Table 2) suggest that a coarse textured soil would get depleted of available water to a large extent even at a relatively lower water tension while a fine textured soil would retain a considerable portion of available water even at a relatively higher tension. Thus, the availability of water in a coarse textured soil would decrease further.

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Table 2: Depletion of available water in light and heavy soils

Suction (bar) Per cent depletion Light soil Heavy soil 0.1 0 0 0.3 48 0 0.5 75 15 1.0 83 26 5.0 98 75 Crop Rooting Behaviour Crop rooting behaviour influences the soil water availability to a very large extent. In general, the greater the proliferation and density of roots, the less is the sensitivity of the crop to soil water depletion. Moreover, compared with the roots in the upper layers, the lower lying roots, although less abundant, are more effective in water uptake because of being younger, less crowded and often growing in a better soil moisture regime. The root completely fills the soil pore under adequate soil moisture conditions, while, under severe stress, shrinkage of cortical cells of root results in root shrinkage and thus, significantly reduces soil-root contact (Fig. 4).

Fig. 4: Cross-section of root surrounded by soil Adequate soil moisture; B) Severe water deficit stress The extent of soil water depletion that leads to the reduction in the rate of transpiration, depends upon evaporative conditions of the atmosphere. Greater soil water depletion can be tolerated by plants without any adverse effect on growth when they grow under conditions of low evaporative potential of the atmosphere. But permissible depletion would be less when plants are exposed to high evaporative potential. According to a report, the actual ET of maize began to fall below the potential rate at a suction value of0.3 bar under an evaporative potential of 1.4 mm/day (Denmead and Shaw, 1962). Information has been compiled showing critical value of available water fraction in the root zone at a given environmental setting below which water availability to crops is constrained (Table 3).

Table 3: Available water fraction for maximum, evapotranspiration in various crops

Crop group Max. Evapotranspiration (mm day-1) 2 4 6 8 10 Onion, potato 0.50 0.65 0.75 0.80 0.825 Cabbage, pea, tomato 0.375 0.525 0.65 0.725 0.775 Beans, groundnut, sunflower, 0.20 0.40 0.55 0.625 0.70 wheat 0.125 0.30 0.45 0.55 0.60 Cotton, maize, sorghum, safflower, soybean, sugarbeet, sugarcane

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When one has control over the amount and time of irrigation within the constraints of water supply at hand, crop water deficit may be planned by identifying optimal and suboptimal water deficit sequences. An optimal water deficit sequence results in minimum yield reduction while a sub-optimal one gives lower yields depending upon ET deficit sequences. Thus maximization of water use efficiency under limited water supply condition can be achieved by planning water deficit to correspond with optimal water sequence based on experimentally determined water deficit-crop yield reduction relationships and applying fertilizers at a rate which will not promote crop growth more than the available water can sustain till maturity. When crops are raised with stored soil water, fertilizer application increases crop yields not only by correcting nutrient deficiency but also by enhancing water use (Singh et al. 1975). The data presented in Table 4 indicate an increase of 4.6 cm in water use by wheat with application of 80 kg N ha-1 resulting mainly from greater sub-soil water extraction compared with unfertilized control. However, fertilizer application must be proportional to soil water availability as excess application might cause luxuriant vegetative growth in earlier phase and development of stress in later growth resulting into lower yield.

Table 4: Profile water use by unirrigated wheat as influenced by fertilizer N application

Profile depth (cm) Water use (cm) -1 Control 80 kg N ha 0-90 10.8 11.2 90-180 4.5 8.7 0-180 15.3 19.9

Plant Water Relations Concept of Water Potential The energy status of water is expressed in terms of water potential, which is a measure of chemical potential of water. Water potential can be defined as the free energy of water available (without temperature change) to do work. Simply water potential is the potential energy of water in a system relative to pure water in the same temperature and pressure. It measures the tendency of water to move through soil plant atmosphere continuum. The chemical potential of the water depends on the mean free energy per molecule and the concentration of water molecules, i.e., on the mole fraction of the water. The degree to which the presence of solute reduces the chemical potential of the water in the solution below that of pure free water can be expressed as: μ - μ° RT ln N ------(3) w w = w μ is the chemical potential of water in the solution w μ° is the chemical potential of pure water at the same temperature and pressure (ergs per mole) w R = the gas constant T = the absolute temperature in °K. Nw = the mole fraction of water For use with ionic solutions, the mole fraction is replaced by the activity of water, a and for w general use, by the relative vapor pressure, e/e°. μ - μ° RT ln (e/e°) ------(4) w w = 160

Environmental Issues and Sustainable Agriculture

When the vapor pressure of the water in the system under consideration is the same as that of pure free water, ln e/e° is zero, and the potential difference is also zero. Thus, pure free water is defined as having a potential of zero. When the vapor pressure of the system is less than that of pure water, ln e/e° is a negative number; hence, the potential of the system is less than that of pure free water and is expressed as a negative number. Since the expression of chemical potential in units of ergs per mole is inconvenient in discussions of cell water relations, units of energy per unit of volume was chosen. The measurements are compatible with pressure units, which can be obtained by dividing both sides of 3 above equation by the partial molal volume of water, V (cm /mol). The resultant term is called w the water potential, Ψw. The symbol for water potential is the Greek letter Psi (Ψ). Ψ = (μ - μ° )/Vw (RT/V ) ln (e/e°) ------(5) w w w = w Water potential = the chemical potential of water / the partial molar volume -1 -1 = J mol / L mol -1 3 -1 = N x m mol / m mol -2 = N m = MPa -1 1 MPa = 10 bars = 10 atm. (1 atm = 760 mm Hg = 14. 7 lbssq in ) Plant water potential expresses the chemical potential of water in the plant system relative to the chemical potential of pure water at the same temperature and pressure.

Note: • Water always moves from high water potential to low water potential. • The addition of solute decreases water potential. • Pressure increases water potential. • In cells, water moves by osmosis to areas where water potential is lower.

Components of Water Potential The total water potential (Ψ) of a system can be partitioned in to different component potentials. Ψ = Ψ + Ψ + Ψ + Ψ ------(6) s p m g where, Ψ , Ψ , Ψ and Ψ are referred to as pressure, solute/osmotic, matric, and gravitational p s m g potential, respectively.

Solute/Osmotic Potential (Ψ ) s It arises due to the presence of dissolved solutes in water. Since presence of solutes reduces the potential of water to below that of pure water, the osmotic potential is below zero or a negative value. Thus, Ψ of a system is determined by the osmolality, i.e., the total concentration s of dissolved particles in a solution without regard for the particle size, density, configuration or electrical charge. The vapor pressure of water in a solution is lowered in proportion to the extent to which the mole fraction of water in the solution is decreased by adding solute. Hence, when water is separated from a solution by a membrane permeable to water but impermeable to the solute, water will move across the membrane along a gradient of decreasing vapor pressure or chemical potential into the solution until the vapor pressures of solution and pure water become equal. The pressure that must be applied to the solution to prevent movement of water in to solution when 161

Environmental Issues and Sustainable Agriculture separated by semi-permeable membrane is termed the osmotic pressure. The negative value of osmotic pressure is equal to osmotic potential. Van't Hoff equation can be used to calculate osmotic pressure of solutions: π = (n /V)RT------(7) s π = the osmotic pressure in pascals V = the volume of solvent in liters n = the moles of solute s R = the gas constant (0.00832 literMPa/degree mol at 273°K) T = the temperature in °K. 5 For 1 mol of solute in 1 liter of solvent at 273°K (0°C), π = 22.7 x 10 Pa or 2.27 MPa (22.4 atm or 22.7 bars). In case of soil, osmotic potential plays a significant role where high concentration of salts occur, for example, in saline soils or waters with high salinity are being used, as that influences the uptake of water by plant. In soil, osmotic potential is given by Ψ = - 0.36 x EC ------(8) s -1 where, EC is electrical conductivity (dS m ). Osmotic potential is generally ignored as far as movement of water within the soil is considered.

Pressure Potential (Ψ ) P It is equivalent to the hydrostatic pressure exerted on the cell wall by plasma membrane due to water uptake induced inflation of protoplast. When a plant cell is having sufficient water, it inflates the cell membrane and hence develops a pressure against the cell wall. At incipient plasmolysis when the cell faces water deficit, turgor potential will be zero. Immediately after cell division, plant cells take up water and expand. Cell expansion ceases once cell wall is fully developed. Hence final size of the cell, and thus size and shape of plant organs depends upon the water availability. Water deficit at any period of plant growth thus may result in smaller organs such as small leaves, fruits and short plant. Loss of cell turgor leads to drooping of shoots, leaves, etc.

Matric Potential (Ψ ) m Interaction of water with matrix (capillary or electrostatic) reduces the potential of water to below that of pure water and hence it is a negative value. Normally matric potential is a negligible component of plant water potential, but it is the most important component of soil water potential. Soil water movement essentially occurs in reference to the hydraulic gradient expressed as change in soil matric potential per unit length.

Gravitational Potential (Ψ ) g It arises due to gravitational forces acting on water. It may be positive or negative depending up on whether the system is above or below the reference point. The contribution of Ψ g to Ψ is negligible except for tall trees as the contribution of Ψ to the Ψ is about 0.01MPa per g meter height. Gravitational component in case of soils will play a significant role depends upon the magnitude of soil matric potential when movement in the vertical direction is being considered. Among these components, the major components of water potential in plants are the turgor potential and osmotic potential, while in soil, the major component of water potential is the matric and gravitational potential.

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Water Uptake by Roots In terrestrial plants, the roots mediate water and nutrient uptake from soil. The maximum water uptake is mediated by 20-200 mm root region from the growing meristem. This region contains large amount of root hairs, which increases the surface area of root and thus, the extraction of soil moisture from a larger soil volume. Root water uptake decreases with the age of the roots, as older roots become suberized. Hence, the root system continuously grows and extracts water and nutrients from the soil. Soil water enters the root apoplast and moves mainly through apoplastic pathway till it reaches the Casparian strip, which seals the radial and transverse walls of endodermis cells, i.e., apoplastic pathway is blocked. At this point water enters the symplatic pathway. A cross-section of a cereal plant root showing types of cells in root and pathway of water and nutrient transport is depicted in Figure 5. Thus at this point of water transport in roots, maximum resistance occurs. Water channel proteins called aquaporins, which are located on the plasma membrane, mediate entry of water through plasma membrane into the symplast. Once water crosses the Casparian strip, water can move both in symplast and apoplast till it reaches apoplastic xylem in the stele. Through xylem water reaches the leaves, where it can take either symplastic or apoplastic pathway until it reaches the stomatal cavity.

Fig. 5: A cross-section of a cereal plant root showing types of cells in root and pathway of water and nutrient transport. A) symplasmic and B) apoplasmic pathway

Ascent of sap or movement of water from root to leaf is explained by the cohesion- tension theory. It relies on the physical properties of water, on mechanisms of liquid transport, and on the anatomical features of the xylem, the sap conducting system. Water within the whole plant forms a continuous network of liquid columns (due to hydrogen bonding of water molecules with each other) from the absorbing surfaces of roots to the evaporating surfaces. About 99% of these water columns consist of xylem vessels and tracheids and remaining 1% is constituted by the wall and cytoplasm of living cells. Surface tension of water at the evaporating surface provides the driving force for movement of water. Due to surface tension and the small radius of the curvature of the capillary menisci at the evaporative surfaces, water potential of adjacent cells is lowered by evaporation. Since water column is continuous in vascular pathway, it transfers the variations of water potential throughout the plant instantaneously. From the stomatal cavity, water vapor evaporates to the atmosphere through stomatal pores present in the epidermis. This loss of water through evaporation from the stomata contained in the leaves of plants is called transpiration. The rate of transpiration is controlled by the energy gradient of water or the water potential gradient. The pathway of movement of water from soil to atmosphere through plant is called Soil- Plant-Atmosphere Continuum (SPAC), an anology to Ohm’s law of flow of electrical current through a system. Water uptake and transport in the plant driven by the energy status of water present in the soil-plant-atmosphere continuum (SPAC). Water moves from high-energy status i.e. high water potential (in soil) to low energy status i.e. low water potential (in atm). Water flow in

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Environmental Issues and Sustainable Agriculture the SPAC depends on water potential gradients and resistances according to the following equations, valid for steady state conditions: Jv = Potential gradient/resistance = ΔΨ/R ------(9) where, Jv = rate of water flow or transpiration; ΔΨ= water potential gradient; R = resistance to water flow. The rate of water flow from soil to root depends upon water potential gradient between root and soil and the resistance in the soil. This can be expressed as: Jv = (Ψ - Ψ ) / R ------(10) soil root soil Similarly, the rates of water flow from root to xylem and xylem to leaf and leaf to air are expressed as: Jv = (Ψ - Ψ )/R ------(11) root xylem root Jv = (Ψ - Ψ )/(R ) ------(12) xylem leaf xylem to leaf Jv = (Ψ - Ψ )/(R ) ------(13) leaf air leaf to air Hence, the rate of transpiration or the rate of flow of water from soil to air through plant system depends upon the water potential gradient between soil and air, and the resistances to water movement in the various paths of soil and plant. Thus, the rate of transpiration (Jv) can be expressed as: Jv = (Ψ - Ψ ) / R ------(14) soil air (soil+root+xylem+leaf) In reality, steady state conditions seldom exist, and water potential in plants quickly decreases after sunrise, and recovers during the night if soil has adequate moisture. Transpiration About 99% of the water taken up by the plant is lost to the atmosphere through transpiration. Evaporation of water from leaf surface occurs through two pathways: 1) direct evaporation from the outer epidermal cell walls through cuticle to the atmosphere, 2) from cell wall to stomatal cavity and then to atmosphere through stomata. Depending upon the thickness and wax load, the water loss through cuticle varies. Majority of the water lost in transpiration through stomatal pathway. Water deficit stress develops when water removed by plant from soil is not replenished through irrigation/rainfall. When water uptake is less than the rate of transpiration cellular water deficit occurs. Figure 6 shows development of water deficit stress in plantsafter withholding irrigation (Slatyer, 1967). It is assumed the same evaporative demand was constant for the period.

Fig. 6 Changes in soil-, root- and leaf-water potential as transpiration proceeds from a plant grown in limited soil volume irrigated to field capacity initially (The horizontal broken line indicates the value of leaf water potential at which wilting occurs. Periods of light and dark are indicated by the unfilled and filled bars, respectively, on the X-axis).

The leaf water potential has to be maintained at a critical value in order to maintain cell turgidity and open stomata to support photosynthesis. The sensitivity of the plant processes to 164

Environmental Issues and Sustainable Agriculture water potential changes vary greatly. Hsiao (1973) identified cell expansion as most sensitive plant process to cellular water deficits. However, wide genetic variation in plant processes for water deficit stress tolerance is found within and across species. For a given genotype, the transpiration rate is regulated by the stomatal opening and closing, depending upon the water availability. The rate of transpiration varies widely in different plant species due to the differences in root architecture, leaf area, leaf structure, leaf number, cuticle thickness and wax load and stomatal characters. Since water vapor is lost to the atmosphere and CO is taken inside the leaf for photosynthesis through the stomata, any reduction in 2 transpiration through stomata will also reduce rate of photosynthesis. Hence, crop yield can be expressed as: Yield = T x WUE x HI ------(15) where T = total seasonal crop transpiration, WUE = crop water-use efficiency and HI = crop harvest index (the ratio of economic yield to total biomass). Hence, to increase the crop yield, either the transpiration or WUE must be increased, keeping HI at its maximum value for each species. Since water is a scarce resource, it is imperative to enhance WUE of crops plants. Water use efficiency (WUE) is defined as the ratio of photosynthesis (A) to water loss in transpiration (E). Simply WUE is the yield per unit amount of water used in evapotranspiration. High WUE is crucial for crop production under water-limited environments. WUE is influenced the rate of transpiration and photosynthesis. C3 plants such as rice, wheat, etc., fix CO in photosynthesis through Calvin cycle in to a three carbon compound. 2 The enzyme Rubisco, which fix CO is can also fix O in a process called photorespiration, which 2 2 leads to about 40 % reduction in photosynthetic carbon fixation. C4 plants such as maize, sugarcane, sorghum, etc., first fix CO in photosynthesis through HATCH- SLACK-cycle in to a 2 four carbon compound, which is then exported to specialized buddle sheath cells, where CO is 2 released and converted in to sugars by Calvin cycle. Because of this CO concentrating 2 mechanism, which increases CO to high level at the site of carbon fixation by Rubisco, 2 photorespiration in these plants is negligible. In general water use efficiency of C4 plants is higher than the C3 plants, mainly due to minimal or negligible amount of photorespiration in C4 plants. Nevertheless, significant variation exists in water use efficiency within each of these categories of plants. Drought (Soil-water deficit) resistance of plants from the point of view of plant growth, drought can be defined as plant water deficit, caused by shortage in precipitation and soil water availability (soil water deficit) and excess of evapotranspiration (atmospheric water deficit) that impairs normal growth and development of plants. The nature of drought stress for a crop depends upon 1) quantity - duration-distribution of rainfall for a rainfed crop, 2) soil moisture availability when crop depends upon stored soil moisture, 3) quantity - frequency of irrigation in irrigated crop, 4) soil type, and 5) evapotranspiration in that environment. In addition to the above factors, occurrence of plant water deficit depends upon the biology of plants, i.e., species, genotype and sensitivity to water deficit at various growth and development stages of plants. Plants may employ the following mechanisms of drought resistance:

1) Drought Avoidance It refers to the ability of the plant to tolerate prolonged soil water deficit periods by maintaining high plant water status. It depends upon maintaining the plants capacity of water uptake (by increasing the rooting depth, root density and hydraulic conductance, osmotic

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Environmental Issues and Sustainable Agriculture adjustment) and/or minimizing water loss from plants (by increased stomatal and cuticular resistance, reduced radiation absorption and reduced leaf area).

2) Drought Tolerance The ability of plants to tolerate prolonged soil water deficit periods by enhancing cellular tolerance to low tissue water potential. It depends upon remodeling of cell ultra structure and reprogramming of cell metabolism, activation of plant defense mechanisms such as reactive oxygen species management, and protection of membranes and macromolecules.

References Denmead OT, Shaw RH. 1960. The effects of soil moisture stress at different stages of growth on the development and yield of corn. Agronomy Journal 52: 272-274. Doorrenbos J, Kassam AH. 1979. Yield Response to Water. FAO Irrigation and Drainage, Paper 33, Rome. Hsiao T. 1973. Plant responses to water stress. Annual Review of Plant Physiology 24, 519– 570. Ritchie JT. 1972. A model for predicting evaporation from a row crop with incomplete cover. Water Resources Research 8: 1204-1213. Schofield RK. 1935. The pF of water in soil. Transactions of 3rd International Congress of Soil Science 2: 37-48. Singh R, Singh Y, Prihar SS, Singh P. 1975. Effect of N fertilization on yield and water use efficiency of dryland winter wheat as affected by stored water and rainfall. Agronomy Journal 67: 599-603. Slatyer RO. 1967. Plant-water relationship. Academic Press, New York Tamhane RV, Motiramani DP, Bali YP, Donahue RL. 1970. Soils: Their Chemistry and Fertility in Tropical Asia. Prentice-Hall of India Pvt. Ltd., New Delhi.p. 475. Thornthwaite CW, Mather JR. 1955. The water budget and its use in irrigation. In: Water: the Yearbook of Agriculture 1955, U. S. Dept. of Agric., pp. 346-358, U.S. Government Printing Office, Washington. Viehmeyer FJ, Hendrickson AH. 1955. Does transpiration decrease as the soil moisture decreases? Transactions of American Geophysical Union 36: 425-428.

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Chapter-22

Physiological Basis of Abiotic Stresses and Resilience

Ashutosh Singh, Susheel Kumar Singh, Anshuman Singh, Pankaj Lavania and Prabhat Tiwari Rani Lakshmi Bai Central Agricultural University, Gwalior road, Jhansi – 284003

Abiotic Stresses Stress physiology deals with the response of plant under adverse environmental condition. The functioning of plants under these stresses or adverse environmental conditions is called as stress physiology. Term biological stress was coined by Lentt (1980), according to him “any environmental change that may change the growth and development of plant is called biological stress”. According to walterLarcher (1987) “biological stress is combined phenomenon that cannot be governed by single factor. Plants are faced various unfavourable conditions like water deficit, heat, cold, flood, salinity etc. Stress is as an overpowering environmental pressure of some adverse forces that prevent or decrease the normal system of functioning (John et al, 1989). Environmental limitations like drought, flood, high temperature, low temperature, water pollution and air pollutions are main cause of the abiotic stresses. Atmospheric and edaphic are the two main factors of the abiotic stresses. Light stress, temperature stress and air pollutants stress are the atmospheric factor while salt and water stress are the edaphic stress. So abiotic stresses may caused by non-living system either due to atmospheric condition or soil condition. Stress is very unstable phenomenon which may occur in any developmental stage of the plants life. The plant performance under abiotic stresses may affect by cumulative as well as adaptive traits. Several constitutive traits like yield, plant phenotype and developmental features may affected. Abiotic stresses severely affect the activities of the key enzymes involved in various metabolic pathways associated with vegetative growth, development and reproductive growth. Abiotic stresses determine the geographical and regional distribution of the crops, according to an estimate, 24.2 % of the world geographical area is potentially arable but only 10.6 % of the total geographical area under actual cultivation and rest of the area is not accessible for cultivation due to one or more abiotic stresses. Characteristics of abiotic stresses may vary considerably depending on the location. Most of the abiotic stresses in mainly region/location specific. The degree of some stress is likely to vary during the crop stage. Some stress can be relatively appropriates management practices e.g. drought, salinity etc. while some others like temperature stress are virtually impossible to manage. Stress during reproductive stage causes more loss than comparable to stress during earlier stage. Light, nutrient and water are the three major environmental resources affecting the crop performance. It has been found that the limiting water and soil nutrient affects the plant growth and development and also cause the reduction of metabolism, biomass (Sultenfuss and Doyle, 1999). The excess of water leading to submergence and excess nutrient leading to the toxicity can also affects the economic crop yields.

Abiotic Stress Tolerance Abiotic stresses are primary source of yield loss and accounts for the 71 % of total reduction in crop yields. The concept of stress is associated with stress tolerance that is the ability of plants to survive in adverse environmental conditions. Degree of tolerance is differing with the degree of plant species. The gene expressions with respect to abiotic stresses play a crucial role in

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Environmental Issues and Sustainable Agriculture the acclimation. However, the genetically determined level of tolerance acquired by the plant through a process of selection over several generations. Screening of germplasm for tolerant to climatic challenges and development of tolerant cultivars is another important approach for promoting crop yield in area with low precipitation or without any proper irrigation system. Genetic improvement for drought resistant has been achieved by the conventional breeding approach for yield and other secondary traits (Farooq et al. 2009). Mutation breeding is another approach for achieving tolerance for several climatic challenges. There are several mutants have been identified and characterized in the many crop varieties using the physical and chemical mutagenic agents (Morten el al, 2006). Singh and Datta (2010) also reported that the plant vigor and grain development in wheat can be achieved by low dose of gamma irradiation. There are several physiological and biochemical parameters are used for rapid identification, screening and improving of cultivars for various stresses like protein profiling, isozyme study, enzymatic activity, phenolic components, NADH oxidase activity. Identification and application of signalling molecules like hydrogen peroxide, kinase activity and their tolerance capacity of the crops grown under various abiotic stresses can be easily achieved (Kumar et al, 2012a, Kumar et al, 2012b). Physiological parameters such as chlorophyll content, membrane stability and permeability, leaf water potential, stomatal conductance, dry and wet weight of the plant, harvest index cab be used as selection criteria for various stress resistance (Neumann 2008).

Temperature Stress High Temperature or Heat Stress The adverse effect of temperature on plant higher than optimal is considered as heat stress. High temperature could affect survival, growth, development, metabolic activities and physiological process. The total respiration increased with temperature. It is more resistant to heat than photosynthesis. The process of photosynthesis is extremely sensitive to heat. The photosystem –II like photolysis of water and reduction of oxygen is more readily inactivated by heat than photosystem – I. Heat may affects membrane composition and stability. When temperature arises, the lipid becomes increasingly liquid. This may affects the membrane function, fatty acid composition of the membrane changes with temperature. Fluid of bulk lipid is decreased due to high temperature.Heat injury due to high temperature to the plants may causes inactivation of enzymes in chloroplast and mitochondria, degradation of proteins, inhibition of protein synthesis and also the loss of membrane integrity (Howarth, 2005). It has also been observed that there will be increase in the temperature in years to come will have drastic effect on the chickpea and other agricultural produce. Heat stress in plants having several effects like seedling mortality, reduced yield, high transpiration, low photosynthesis, death of cell, tissues and organs, denaturation of proteins, change in lipid membrane structure and fatty acid composition.

High Temperature or Heat Stress Tolerance Ability of some genotypes to give better performance than others when subjected to high temperature is called high temperature or heat stress tolerance. Heat stress tolerance can be achieved by heat avoidance by the several mechanisms like reduction in transpiration, reflection of heat by leaves due to waxiness nature and thick cuticle layers and also insulation by bark. Membrane stability and stability of photosystem – II reduced the effect of high temperature under adverse condition in some plants and most of the trees. Most of the osmo-regulators like proline, glycine also play a protective role in heat stress.

Heat Sock Proteins (Hsp)

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Heat sock proteins are specific proteins having possible role in the mechanism for controlling heat tolerance are known as HSP. Heat sock proteins are discovered a first stress induced hormones. It is a group of dozen proteins that normally exist in the cell and their synthesis is accelerated by heat. HSPs are discovered as first heat stress protein from fruit fly (Drosophila melanogaster) and have been also identified in other animals, plants as well as in the microorganism. HSPs are classified on the basis of their molecular weight ranging from 110 KD to 150 KD. High molecular weight HSPs are range of 60 to 110 KD. For example HSP 90, HSP 110 etc. Low molecular weight HSPs are ranging from 30 to 45 KD e.g. HSP 18.1, HSP 17.9 etc. HSP 70 is accumulated in chloroplast, endoplasmic reticulum and chloroplast. HSP 60 is associated with chloroplast and mitochondria. A large changes in cell protein composition as non-HSPs disappear and HSPs appear. All HSPs increased in concentration for limited period. In Pea, expression of gene is membrane is depends upon HSP 18.1 and HSP 17.9 (Garg et al. 1993).

Expression of HSPs at molecular level Expression of heat sock proteins are depends on both transcription and translation. Transcription of HSPs is regulated by heat sock elements (HSE) which is found on the DNA elements of the all HSPs genes. Induction of HSPs occurs when heat sock filaments (HSF) binds with HSE of the HSP gene. HSPs are present in all cells but activated in only stress conditions. The activation of HSPs is multistep process binding with HSE. The interaction between HSPs, HSEs and HSFs regulates the transcription.

Low Temperature or Chilling Stress When temperature is above to freezing it is called as chilling.In many environments crop productivity is influenced due to very low temperature. Chilling stress can be easily shown by the plant organs or at cellular level. Chilling stress affects the seed germination, growth, fruit set and pollen fertility. So chilling stress can be measured in terms of seed germination, vegetative growth and development of plants, fruit set, fruit quality and pollen fertility. Chilling stress also reduced the capacity of root for water and mineral uptake. Chilling stress also results the production of abnormal flowers, fruits and fruit set. Chilling stress causes the poor seedling establishment, stunted growth, wilting, Chlorosis, necrosis. At cellular and sub-cellular level, chilling stress affects membrane stability, chlorophyll synthesis, photosynthesis, respiration as well as may types of toxicity due to the accumulation of hydrogen peroxide inside the plant body. Damage of plant organs due to very low or chilling temperature is called as chilling injury. Due to chilling injury, most of the physiological activities of the plant is decrease due to decrease in chlorophyll content, destroy in several components and decrease in enzymatic activities, metabolism etc.

Chilling Tolerance Ability of some genotypes to give better performance under low temperature than other genotypes is called chilling tolerance. Chilling tolerance involves membrane lipid unsaturation, increased chlorophyll accumulation, reduced sensitivity of photosynthesis, improved germination, pollen fertility etc. Chill hardening leads to an increase in membrane lipid unsaturation. Further, chilling tolerant varieties showed a higher degree of membrane lipid unsaturation. Some plants sensitive to chilling stress and other are chilling resistant li in the proportion of saturated and unsaturated fatty acid components in the lipid bilayer of their cell membrane. The cell membrane of chill-sensitive species or genotypes have higher proportion of saturated fatty acid with higher melting point while chill-resistant or tolerant cultivars or species have higher proportion of the unsaturated fatty acid in their lipid bilayers. This view is supported by the findings of Williams et al, 1998 and Paltaet al.1993, who observed the increased activity of 169

Environmental Issues and Sustainable Agriculture enzyme desaturases and an increase in the level of unsaturated fatty acids during acclimation to low temperature. However, at chilling temperature, the saturated lipids in the membrane will solidify soon disrupting the membrane activity in chill sensitive species. Higher proportion of unsaturated lipids in chill-resistant or chill tolerant species on the other hand, allows the membrane to remain fluid at low temperature and function normally. Chill hardening leads to an increase in membrane lipid unsaturation. Chilling tolerant varieties show high degree of lipid membrane unsaturation. It has been observed in bean, maize, apple etc. (Kashyap, 1987). Reduced in photosynthetic sensitivity is another mechanism of chilling tolerance that is expressed in native vegetation adapted to cool conditions. This has been observed by several works in the maize. Low temperatures inhibit chlorophyll accumulation in some crops. However, in some chilling tolerant crops like Japonica rice accumulate more chlorophyll content under chilling stress. But in Indica rice chlorophyll content is prevented by development of the thylakoid membrane. Another mechanism is chilling stress is to maturity at low temperature may also improve the germination.

Water Stress Water stress is abiotic stress which includes both abundance and absence. Abundance or excess of water is cause of water logging or submergence while absence means water deficit or drought. Loss by water stress (both water deficit and water logging) is about 38% of the total biological stresses, of these water deficit or drought account 26% where water logging or submergence accounts only 12 % of the total biological stresses (Lentt, 1986). Water stress is of two types, water logging or submergence and water deficit or drought.

Water Logging or Submergence Excess of water due to heavy rain fall which affects the normal growth and development of pants is called water logging or submergence. Submergence is one of the serious water stress and more dangerous than drought. Plants under water deficit condition may retain their growth and development in early stage after getting sufficient amount of water but plants under long time in submerged condition may or may not be retain their growth and development.

Mechanism of Plant Adoptation under Submerged Condition or Water Logging Plant adoptation to water logging and submergence is very complex and is not governed by the single components. The plants adoptation to water logging has three major components i.e. morphological adoptation, metabolic adoptation and anatomical adoptation.

Morphological Adoptation Surface rooting and development of fine roots in the surface of aerobic layers are the main features of the plant for survival under submergence condition. High root porosity is another mechanism by facilitating oxygen transport. Cubic type of cell tissues provides maximum porosity (21%) than hexagonal packaging of the cell (9%). Lack of anti-cuticulization at apical tips also - facilitates easy transport of the oxygen, carbon di oxide and HCO3 across leaf surface high porosity. Rapid enlargement of stem, leaves and tallness also facilitates oxygen transport. Development of the areal roots is some plants may help in providing oxygen transport. Lignification of stem reduced phytotoxic entry for the survival under water logged condition.

Metabolic Adoptation Diversification of glycolysis end product and control of energy metabolism is one of the metabolic features developed by some plants under submergence condition. Low membrane lipid peroxidation and pH avoidance under water logged condition may provide the survival chance. 170

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Aquatic carbohydrate supply and high ethylene production, periodicity of ethanol production and high amylose activity for hydrolysis are the major metabolic adoptation features of the plants under water logged condition. Anatomical Adoptation Aerenchymatous tissues found in root rhizome, leaf etc. but it is only in roots are responsible for active transport of oxygen. Dead xylem elements filled with oxygen form the condition for oxygen transport. Intera cellular spaces and development of hydrophobic lenticel may also be helpful for oxygen diffusion wader water logged condition.

Water Deficit or Drought Stress The water deficit condition commonly known as drought is the metrological events caused due to absence of rain fall for a period of time, long enough to cause moisture depletion in the soil with a decrease of water potential in the plant tissue that reduces the growth, yield, physiological acclimation. Drought is the multidimensional and most damaging stress among all the biological stresses. Drought can be considered as a set of climacteric pressure which produces several atmospheric phenomenon like heat, salinity, dryland farming, high wind velocity and water deficiency. Drought is classified on the basis of agricultural, metrological, hydrological and crop stage point of view. According to agricultural point of view drought is considered as permanent drought, seasonal drought, contingent and invisible drought. Permanent drought is the feature of arid zone and seasonal drought is observed in wet and dry region both. Contingent drought is easily observed in any region due to lack of sufficient rain fall while invisible drought can easily be observed from the features appear on the aerial part of plants. According to metrological point of view, drought is considered as moderate (20-50%) deficient rain fall and severe drought (75-85%) deficient rain fall. Dehydration of ground/surface water, dehydration of lakes, river and water reservoir are the main feature of the hydrological drought. According to the crop stage we can categorize drought on various crop stage like germination stage, seedling stage, Tillaring/branching stage, booting stage, flowering stage, grain filling and maturity stage. There are several visible features are appear on the aerial part of the pant under water deficit condition like twisted leaf, wilting of plant, early flowering, early maturity, minimum grain filling, maximum yield loss etc.

Physiological Mechanism of Drought Water deficit or drought is one of the severe water stresseswhich affect the all physiological mechanism related to growth and development. There are three physiological activities of the plants viz. evapotranspiration, transpiration and guttation by which water is loss from plant organs. Loss of water from both soil and aerial organ of plant together by evapotranspiration, loss of water in the form of water vapours from the aerial part especially from leaves through stomata by transpiration and in the form of water droplet by guttation are the main cause of dehydration under water deficit condition. Due to dehydration turgor pressure is loss by the plant cells which causes the change in membrane permeability, due to change in the membrane permeability the level of protein synthesis and enzymatic activity is gradually decreased due to increase in the solute concentration in the cell. Organic substances and sugars are accumulated due to high solute potential in the cell by which the rate of respiration suddenly increase. Plant pigments are broken drown which block the chlorophyll synthesis in the leaves and sufficient amount of the chlorophyll in the leaves are decreases. Rate of photosynthesis decrease with decrease in chlorophyll contents because chlorophyll is the chief constituent of photosynthesis. 171

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Decrease in photosynthesis forced the plants towards aging by increasing the concentration of abscissic acid. Tissues are dead due to continuous increase in ABA hormones causes the abscission. Drought Tolerance Drought tolerance or resistance refers to the ability of crop plants to produce its economic product with minimum loss in a water deficit condition. According to Turnour (1982–1986) ability of a crop to produce satisfactory in area subjected to water deficit condition has been termed as drought tolerance. Kramer, P. J. (1969) defines drought resistance as “referring to various means by which plants survive periods of environment water stress”.

Mechanism of Drought Tolerance The mechanism of drought tolerance have been categorised into various ways

Drought Escape Early maturity is the main attribute of the drought escape. Drought escape may be defined as the ability of plants to mature before water stress becomes serious limiting factor. It is ability of the crop plants to complete its life cycle before acute soil and plant water deficit development. This mechanism involves rapid phenological developments like early flowering, early maturity and development of plasticity. There are some characteristic feature of the drought escape are rapid phenological development, early flowering, early maturity, early growth vigour, development of plasticity, reduced evapotranspiration, reduced leaf growth, easy way of selection by the plant breeders, short duration verities. In arid and semi-arid region because of low rain fall, sowing of crops is generally delayed until there is sufficient soil moisture for better establishment. In pearl millet, moth beans, cluster beans, the seed yield were significantly recorded in early flowering under low rain fall conditions (Garg et al, 2001).

Drought Postponement or Avoidance Ability of plants to maintain high water status during drought is called dehydration postponement or dehydration avoidance.Tissue water status expressed by turgor potential under water deficit condition is the basic measurement dehydration avoidance. Drought postponement can be achieved by maintaining the water status and water potential in the plant cell by reducing transpiration or by increase in water uptake. Dehydration avoidance can be achieved by reducing water loss by reduction in leaf area, erect and narrow leaf, leaf rolling, waxiness nature of leaf reduced water loss through transpiration and guttation. Number of stomata per leaf and stomatal closure is another mechanism of water loss reduction. Such type of mechanism is very common in xerophytes. Water saving species of the crop and other plants may reduce evapotranspiration by closing of stomata. In water stressed, stomata open during early morning and closed on solar radiation. Abscissic acid is known as stress hormones if ABA increase stomata will close and evapotranspiration reduced under water deficit condition.

Dehydration Tolerance Dehydration tolerance by plant is also known as osmotic adjustment. Turner & Jones 1980, Morgan 1984 states that osmotic adjustment is the active accumulation of the solutes within the plant tissues in response to lowering of soil water potential. A wide range of organic solutes play an important role in the osmotic adjustment is known as osmoprotectant. The osmoprotectant include proline, sugars, polyamines,manitol and sorbitol etc. while glycine acts as phytochelatins. There are several advantages of osmotic adjustment like promotes root growth, maintain turgor, protect cell membrane and enzymes, greater uptake of water, delayed leaf rolling, 172

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If high osmotic adjustment cultivar is crossed with low osmotic adjustment cultivar expressed in F4 generation will be dehydration tolerance with little genetic variance (Morgan et al, 1984). Turner, 1997 also states that the degree of osmotic adjustment is varies from species to species and genotypes. He also demonstrates the osmotic adjustment from wheat, sorghum, millet, rice chickpea and other agricultural crops under dehydration tolerance study. The stress includes free accumulation of free proline, free amino acids and sugars has been observed in pearl millet, wheat, cluster bean, moth bean and mustard (Garg et al. 1981 and Vyas 1985). Over production of glycine and proline is acts as osmoprotectant and is correlated with tolerance has been well established (Kishore et al, 1995). There are several approaches related to secondary approaches have been identified in the case of maize under water deficit condition (Chapman and Edmeades, 1999) and wheat (Richard et al, 2000). However, in case of rice, secondary traits did not improve grain yield under reproductive stage in water deficit condition (Kumar et al, 2008). Bouman at al. 2005 reported that the water requirement for aerobic condition from sowing to harvest varied from 790 mm to 1430 mm as compared with 1240 mm to 1880 mm in lowland rice. Metabolic approaches of osmoprotectant and osmolytes is another successful approach in developing transgenic plants tolerant to water stress. First transgenic for drought tolerance related to over proline production was reported in tobacco (K. Kishore el al, 1995) and rice (Zhu et al, 1998).Garg et al, 2002 developed drought tolerant rice varieties by over producing Trehalose with higher photosynthetic capacity and low photo oxidative damage under stressed condition and non- stressed conditions. Abebe et al, 2003 also reported the enhancement of manitol-1-phosphate dehydrogenase (mt1D) genes that causes a small increase in manitol in wheat under water deficit condition. Over expression of NADP-malic enzyme and decarboxylating enzymes in Maze and tobacco reduced stomatal conductance and improve water use efficiency was reported by Laporte et al, 2002).

Gene Expression under Drought Stress Mechanism of gene expression under water stress has been obtained from DNA elements and DNA binding proteins. There are two types of DNA binding elements known to be involved in the gene regulation under acute water deficit condition are ABA responsive elements (ABRE) and dehydration responsive elements (DRE). The ABRE is also called ABA dependent pathway which sometimes requires coupling factors and transcriptional factors. The DRE is also known as ABA independent pathway and is requires a gene encoding transcriptional factor CBP1 which binds with dehydration responsive elements. It is possible to engineer stress tolerance in plants using different stress genes. However, it is reported that the amount of a gene product in not enough to provide tolerance and that the gene has another function in stress tolerance that is not fully understood (Bajaj et al, 1999)

Salt Stress Accumulation of salts or their ions like sodium or potassium in either soil or water which influenced the plant life is called salt stress.Sodocity (Sodic), alkalinity and salinity are the three major constrains of the salt stress. Salt stress covered 5–8% of the total biological stress caused due to sodocity, alkalinity and salinity (Lentt, 1986). Soil salinity is the major constrains of the salt stress. Salt stress may be either excess or shortage of salt in the nutrient medium. Some plants are suited and well adopted to salt stress are called halophytes. Saline soil have high concentration of Na+, water soluble salt, high pH, high bulk density and low level of Ca, N, Zn, low porosity and low water holding capacity.

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Species variations are known to play measure role in decreasing of salty amount in the soil. Some species are known to salt tolerance. Green manuring can improve the soil stricture and increase the phosphate and nitrogenous content i.e. tolerant to salt. Some crops have ability to survive and yield satisfactory when subjected to saline soils are barley, sorghum, soybean, cotton and sugar beet. On the basis of nature of sodic salt, living organism is divided into two groups’ halophytes and non-halophytes/glycophytes. The facultative halophytes can be tolerant to salinity at 3.75 M of NaCl, but do not required high salt concentration for growth and development. The obligate halophytes can easily grow at salinity ranging from 3.7 to 3.5 m of NaCl and grown slowly. Plants need to maintain internal water potential below that of the soil to maintain turgor and water uptake for growth. This requires an increase in osmotica, either by uptake of soil solutes or by synthesis of metabolically benign (compatible) solutes (Tester and Davenport, 2003). Osmotic adjustment, defined as lowering of osmotic potential due to net solute accumulation in water stress, has been considered to be a beneficial drought tolerant mechanism for some crop species (Girma et al., 1992; Hamdia, 2002). When plants experience environmental stress, such as drought, high salinity, they activate various metabolic and defense system to survive. A number of genes corresponding to these stresses and their products were analyzed in Arabidopsis (Ono et al., 2003; Marayama et al., 2004) plants. For example, osmoprotectants, such as proline, glycine betaine, manitol and sugars confer stress tolerance (Yamada et al., 2005). The observed loss of soluble saccharides, soluble protein and amino acids of shoots and roots of salinized maize and broad bean plants was accompanied by a marked increase in the proline content. These results are in accordance with previously reported findings of Devitt et al. (1987), Hamdia and El-Komy (1998). It is worthy to mention that in our experiment when maize and broad bean plants where spraying with proline or phenylalanine the opposite effect was occurred, saccharides as well as proteins progressively increased at all sainization levels. This was accompanied by an increased in amino acids of both shoot and root system. Thus, treatments with either proline or phenylalanine might play an important role in protein synthesis The stress-induced Arabidopsis and rice genes are thought to be involved in the plants response and tolerance to environmental stresses (Seki et al., 2002; Rabbani et al., 2003). Many plants accumulate compatible osmolytes, such as proline (Pro), glycine (Gly) betaine, or sugars, under osmotic stress. Pro biosynthesis from glutamine (Glu) appears to be the predominant pathway under stress conditions, because the repressed salt-stress ornithine omega- aminotransferase expression (the enzyme responsible for synthesis of Pro from Orn), induced the synthesis of Pro from Glu (Delauney and Verma, 1993; Delauney et al., 1993). Osmotic damage (that is, osmotically driven removal of water evaporates could occur as a result of the build-up of high concentrations of Na+ in the leaf apoplast, since Na+ enters leaves in the xylem stream and is left behind as water evaporates (Flowers et al., 1991; Katerji et al., 2000, 2001, Garacia et al., 2010). Na+-specific damage is associated with the accumulation of Na+ in leaf tissues and results in necrosis of older leaves. Growth and yield reductions occur as a result of the shortening of the lifetime of individual leaves, thus reducing net productivity and crop yield (Munns, 1993, 2002). When salt stressed maize and broad bean plant were sprayed with proline or phenylalanine, proline concentration significantly declined, while the amount of dry matter and water content for both maize and broad bean plants increased. This is accordance with the results obtained by (Shaddad and Heikal, 1982; Thakur and Rai, 1985; Hamdia 1987; Cuin and Shabala, 2005). Treatment with proline or phenylalanine increased, to some extent, salt tolerance of these two plants through osmoregulation, using the organic solutes rather than proline. This confirms the view of many authors (Manetas, 1990; Silveira et al., 2003; Yamada et al., 2005).

References

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Abebe T, Guenzi AC, Martin B and Chushman JC (2003) Tolerance of manitol-accumulating transgenic wheat to water stress and salinity. Plant Physiology 131: 1748-1755. Bajaj S, Targolli J, Liu LF, Ho THD and Wu R (1999) Transgenic approaches to increase dehydration-stress tolerance in plants. Molecular Breeding 5:493-503. Bouman BAM, Peng S, Castanea AR and Visperas RM (2005) Yield and water use of irrigated tropical aerobic rice system. Agricultural Water Management 74(2):87-105. Chapman SC and Edmeades GO (1999) Selection improves drought tolerance in tropical maize populations II. Direct an correlated responces among secondary traits. Crop Science. 39: 1315-1324. Cuin TA, Shabala S (2005).Exigenously supplied compatible rapidly ameliorate NaCl- induced potassium efflux from barley roots. Pant and Cell Physiol., 46: 1924-1933. Delauney AJ, Hu CA, Kishor PB, Verma DP (1993). Cloning of ornithine delta-aminotrans from Vignaaconitifoliaby transcomplementation in Escherichia coli and regulation of proline biosynthesis. J. Biol. Chem., 268: 18673-18678. Delauney AJ, Verma DP (1993). Proline biosynthesis and osmoregulation in plants. Plant J., 4: 215-223. Devitt DA, Ktolzy L, Labanauskas CK (1987). Impact of potassium, sodium and salinity on the protein and free amino acid content of wheat grain. Plant Soil, 103: 101-109. Flowers T J, Hajibagheri M A, Yeo AR (1991). Ion accumulation in the cell walls of rice plants growing under salineconditions-evidence for Oertli hypothesis. Plant Cell Environ., 14: 319-325 Garacia JR, Estrada JA, Gonzalez MT, Ayala CR, Moreno DM, (2010).Exogenous application of growth regulators in snap bean under water stress and salinity. J. Stress Physiol., Biochem., 5: 13, 21. Garg AK, Kim Jk, Owens TG, Ranwala AP, Choi YD, Kochian LV and Wu Rj (2002) Trehalose accumulation in rice plant confers high tolerance levels to different abiotic stresses. PNAS USA 99:15898-15903. Girma FS, Krieg DR, Daniel RK (1992).Osmotic adjustment in Sorghum. 1. Mechanisms of diurna osmotic potential changes. Plant Physiol., 99: 577-582. Hamdia MA (1987). Response of some plants to the interactive effects of salinity and amino acids. Thesis in El-Minia University, Fac. Sci. Bot. Dept., pp. 1-127. Hamdia MA (2002). Salt tolerance and interaction with abscissic acid of tomato cultivars. Bull. Fac. Sci. Assiiut Univ., 31: 205-217. Hamdia MA, El-Komy MHA (1998).Effect of salinity, gibberllic acid and Azospirilluminoculation on growth and nitrogen uptake of Zea mays.BiologiaPlantarum, 40: 109-120. Howarth CJ. (2005) Genetic improvement to tolerance to high temperature. In: Ashraf M, HarrisJPC, (Eds.) Abiotic stresses: Plant Resistance Through Breeding and Molecular approaches. Howarth Press Inc., New York. Katerji N, van HJW, HamdyA, Mastrorilli M, Oweis T, Malhotra RS (2001). Response to soil salinity of two chickpea varieties differing in drought tolerance, 50: 88-96. Kavi Kishore PB, Hong Z, Miao GH, Hu CAA and Verma DPS (1995) Over expression of Δ- pyrroline-5-carboxlate synthetase increase proline production and confers osmo-tolerance in transgenic plants. Plant Physiology 108: 1387-1394. Kumar A, Bernier J, Verulkar S, Lafitte HR and Atlin GN (2008) Breeding for drought tolerance: direct selection for yield, response to selection and use of drought-tolerant donors in upland and lowland-adapted populations. Field Crop Research 107:221-231.

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Kumar KS, Kavi and Parikh J (2001a) Socio-economic impacts of climate change on Indian Agriculture, International Review for Environmental Strategies 2(2) Kumar KS, KAvi, and Parikh J (2001b) Indian Agriculture and Climate Sensitivity, Global Environmental Change. 11: 147-154. Laporte MM, Shen B and Tarczynski MC (2002) Engineering for drought avoidance: expression of maize NADP-malic enzyme in tobacco results in altered stomatal function. Journal of Experimental Botany 53:699-705. Manetas (1990). Are-examination of NaCl effects on phosphenol pyruvate carboxylase at high physiological, enzyme concentration. Physiol. Plantarum., 78: 225-229. Maruyama K, Sakama Y, Kasuga M, Ito Y, Seiko M, Goda H, Shimada Y, Yoshida S, Shinozaki K (2004). Identification of cold-inducible downstream genes of the Arabidopsis, DREB1A/CBF3 transcriptional factor using two microarray systems. Plant J., 38: 982-993. Morten C, Guimaraes EP and Ghosh K (2012) Re-orienting crop improvement for the changing climatic conditions of the 21st century.Agriculture and Food Security. 1:7 Munns R (1993). Physiological processes limiting plant growth in saline soils: Some dogmas and halophyted. Plant Cell Environ., 16: 15-24. Munns R (2002). Comparative physiology of salt and water stress. Plant Cell Environ., 25: 239-267. Neumann PM (2008) Coping mechanism for crop plants in drought-prone environments. Annals of Botany 101: 901-907. Ono Y, Seki M, Nanjo T, Narusaka M, Fujita M, Satou M, Sakurai T, Ishida J (2003). Monitoring expression profiles of Arabidopsis gene expression during rehydration process after dehydration using ca 7000 full-length cDNA microrray. Plant J., 34: 868-887. Rabbani MA, Maruyama K, Abe H, Khan M A, Katsura K, Yto Y, Yoshiwara K, Seki M, Shinozaki K, Yamaguchi-Shinozaki K (2003). Monitoring expression profiles of rice genes under cold, high salinity stresses and abscissic acid application using cDNA microarray and -. RNA- gel bolt analysis. Plant Physiol., 133: 1755-1767. Seki M, Narusaka M, Ishida J, Nanjo T, Fujita M, Oono Y, Kamiya A, Nakajima M, Enju A, Sakurai T (2002). Monitoring the expression profiles of 7000 Arabidopsis genes under drought, cold, and high salinity stresses using a full-length cDNA microarray. Plant J., 31: 279-292. Shaddad M A, Heikal MM (1982). Interactive effect of gibberellic acid and salinity on kidney bean. Bull. Fac. Sci. Assiut Univ., 11: 135-149. Silveira J A, Viegas RA, da Rocha IM, Moreira AC, Moreira Rde A, Oliveira JT (2003). Proline accumulation and glutamine synthetase activity and increased by salt-induced proeolysis in cashew leaves. J. Plant Physiol., 160: 115-123. Sultenfuss JH and Doyle WJ (1999) Phosphorus for agriculture. Better Crop Plant Food 83: 1 – 40. Tester M, Davenport R (2003). Na+ tolerance and Na+ transport in higher plants. Ann. Bot., 91: 503-527. Thakur PS, Rai VK (1985). Exogenously supplied amino acids and water deficits in Zea mays cultivars.BiologiaPlantarum, 27: 458-461. Yamada M, Morishita H, Urano K (2005). Effects of free proline accumulation in petunias under drought stress. J. Exp. Bot., 417:1975-1981. Zhu BC, Su J, Chan MC, Verma DPS, Fan YL and Wu R (1998) Over expression of a- pyrroline 5-carboxylate synthetase gene and analysis of tolerance to water and salt stress in transgenic rice. Plant Science 139: 41-48.

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Chapter-23

Ecological and environmental justification by learning community participatory research in indoor environmental sciences

Punam S. Thakur Department of Zoology, ShankarlalAgrawal Science College Salekasa, Gondia, Maharashtra

Introduction Since the early 1990s when the National Institute of Environmental Health Sciencesinitiated a Translational Research Program to encourage collaborative research projects involving researchers and community residents, Community Based, Participatory Research has become an increasingly valued approach to the study of health disparities and environmental justice (Israel, Eng, Schulz, & Parker, 2005). Succinctly defined, it is “systematic inquiry, with the participation of those affected by the problem, for the purposes of education and action and social change” (Minkler, 2010, p. s81). A favored research method by environmental justice scholars and activists, CBPR recognizes and integrates both local knowledge and expert knowledge: community members are deeply involved in all phases of study, including design, implementation, data interpretation, conclusions, dissemination of results, and collaborative actions informed by those results. As such, CBPR is a research and learning strategy at the intersections of research, practice, policy, and collective action to create healthy environments accessible to all. Althoughit is increasingly common in environmental health sciences and highlyencouraged by Healthy Homes Technical Studies research program, this paperfinds that has yet to be deeply embraced by indoor environmental scientists. It then reveals promising new opportunities around the study of home ecology, which involves residentsin the adaptive management of their home environments. These future opportunities areidentified through 1) a historical review of the forgotten field of home ecology, and 2) a literature review of current trends in andadaptive management related to enhancing the resilience of dynamic and socially complex systems like the home environment.

Home Ecology: Learning from the Past Ellen Swallow Richards (ESR), a pioneering chemist and social reformer, established the field of Oekologie, or Home Ecology, in the late 1800’s to address two interrelated problems of her time: 1) the horrible indoor and outdoor environmental conditions facing families in industrial cities, and 2) society’s denial of experimental science education to women and the related depression and subjugation of women. ESR pursued this science through three main routes: 1) research on food, air, and waterat MIT’s Women’s Laboratory (which she led and founded), 2) field experiments in/on her own home, and 3) an international network of women conducting research in their homes through ESR’s correspondence course in Home Ecology. This network intersected with the Municipal Housekeeping movement, a women led movement that led to the first sanitary reform legislation in the U.S. The combinationof these approaches contributed to the empowerment of women, advances in the science and design of indoor environments, and improvements in urban environmental quality (Clarke, 1973; Hoy, 1980; Richardson, 2002).

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Based on ESR’s model, Home Ecology is the trans-disciplinary, multi-scalar study of the interdependent relationships among humans and non-humanlife in the environments they call home. It is a democratic science and an emancipatory social movement intended to enhance the flourishing of life in resilient urban ecosystems. Given today’s environmental and social crises related to the built environment,this field and its lessons are needed now more than ever.

Learning from the Present There are a number of promising trends today that provide a foundation for a renewal of Home Ecology, including the development of adaptivemanagement, and the growing movement for green and healthy home retrofitsis similar to Home Ecology in that it is a transdisciplinary, democratic approach to science used in studying environmental health, yet it has been underemployed in the study of home environments. A Web of Science search reveals that since 2001 there have been 493articles, of which only 7 address indoor residential environments. The results of thisreview suggest that generally when it is used to study indoor environments, therelationship between the researcher and the subject is still largely oneway, with theresearcher testing top down interventions, without engaging the individuals affected by the environmental challenge in research design, data evaluation, or strategizing about actions. Based on the successes of CBPR to date, this paper suggests that some limitations typical of indoor environmental field science could be improvedby involving residents more directly in studies of their homes, including small sample sizes and the difficulty of translating results into action.Adaptive co-management, another participatory research approach related to Home Ecology, employs a systems learning approach to enhance the resilience of dynamic and socially complex ecosystems (Olsson, Folke, &Berkes, 2004). A Web of Science review shows that it is common in the field of ecological management and complexity science, but has yet to be applied to field studies in building science. Adaptive comanagement in indoor environmental science holds promise since home environments are also complex, sociotechnical ecological systems in which experimental controls are difficult, uncertainty is significant, and onesize fits all best practices are generally inappropriate. The growing movement for green and healthy home retrofits relates to Home Ecology in that it includes a national network of professionals striving to enhance indoor and outdoor environmental conditions for all. In particular, the Green and Healthy Homes Initiative (GHHI) (www.greenandhealthyhomes.org) is building a social learning network among 14 GHHI pilot sites to augment innovation and idea exchange related to enhancing health and environmental performance of housing, especially in economically challenged communities. To date, this has been a movement of professionals advocating for these communities, as opposed to a movement of/with these communities.

Opportunities for the Future How might building science experts engage with lowincome residents in an empowering waythat advances indoor environmental science, increases innovation diffusion, and improves environmental conditions now and in the future? These are the questions Home Ecology asks ofus today and they invite new possibilities. For indoor environmental field science, this couldmean involving residents in intervention design and home performance evaluation, drawingfrom CBPR and adaptive management. This could include phone based home assessments and/or checkinmeetings between residents and building specialists. For the GHHI, it could include expanding and deepening its social learning network to enhance innovation and exchange. This paper reviews these and other opportunities for Home Ecology today. 178

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References Clarke, R. (1973). Ellen Swallow: The Woman Who Founded Ecology (First Printing, FirstEdition.). Follett Publishing Company. Hoy, S. (1980). "Municipal Housekeeping": The Role of Women in Improving Urban Sanitation Practices, 18801917. In M. V. Melosi (Ed.), Pollution and Reform in American Cities, 18701930 (pp. 173178). Austin: University of Texas Press. Israel, B. A., Eng, E., Schulz, A. J., & Parker, E. A. (Eds.). (2005). Methods in Community Based Participatory Research for Health (1st ed.). San Francisco, CA: JosseyBass. Minkler, M. (2010). Linking Science and Policy ThroughCommunityBased Participatory Research to Study and Address HealthDisparities. American Journal of PublicHealth, 100, S81S87. Olsson, P., Folke, C., &Berkes, F. (2004). Adaptive comanagement for building resilience in socialecologicalsystems.Environmental Management, 34(1), 7590. Richardson, B. (2002). Ellen Swallow Richards: "Humanistic Oekologist," "Applied Sociologist," and the Founding of Sociolog0y. The American Sociologist, 33(3), 2157.0

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