Nakuru County by Dr

FARM MANAGEMENT HANDBOOK OF KENYA

VOL. II

– Natural Conditions and Farm Management Information –

ANNEX: – Atlas of Agro - Ecological Zones, Soils and Fertilising by Group of Districts –

Subpart B1a Southern Rift Valley Province Na k u r u County This project was supported by the German Agency for Technical Cooperation (GTZ)

Farm Management Handbook of Kenya

VOL. I Labour Requirement, Availability and Costs of Mechanisation

VOL. II Natural Conditions and Farm Management Information

Part II/A WEST KENYA Subpart A1 Western Province Subpart A2 Nyanza Province

Part II/B CENTRAL KENYA Subpart B l Rift Valley Province, Northern and Southern Part Subpart B2 Central Province

Part II /C EAST KENYA Subpart C1 Eastern Province, Middle and Southern Part Subpart C2 Coast Province

VOL. III Farm Management Information - Annual Publications were planned. The idea changed to Farm Managament Guidelines, produced by the District Agricultural Offices annually and delivered to the Ministry in April

VOL. IV Production Techniques and Economics of Smallholder Livestock Production Systems

VOL. V Horticultural Production Guidelines

Publisher: Ministry of Agriculture, Kenya, in Cooperation with the German Agency for Technical Cooperation (GTZ) VOL. II is supplemented by CD-ROMs with the information and maps in a Geographical Information System. Additionally there will be wall maps of the Agro-Ecological Zones per district group (= the former large districts) for offices and schools.

Vol. II/A Printed by Continental Graphics, Nairobi 2009 Layout by Susanne Meissner and Ruben Kempf, Trier, Germany. Ministry of Agriculture

FARM MANAGEMENT HANDBOOK OF KENYA VOL. II

Annex: – Atlas of Agro - Ecological Zones, Soils and Fertilising by Group of Districts in Southern Rift Valley –

Subpart B1a Nakuru County by Dr. Ralph Jaetzold Prof. emeritus of Geography, University of Trier / Germany

Helmut Schmidt Former Farm Management Research Officer from the former German Agricultural Team of the GTZ in the Ministry of Agriculture, Nairobi

Dr. Berthold Hornetz Prof. of Agricultural Geography, University of Trier / Germany Dr. Chris Shisanya Prof. of Agroclimatology, Dept. of Geography Kenyatta University, Nairobi Contributions to the 1st Edition by: C.M. Kang´e & J.G.M. Muasya – assessment of farm management data; Dr. Mechthild Kronen – soil requirements list; Prof. Dr. H. Kutsch – computing of crop-water relations for yield probabilities; F.N. Muchena, B.J.A. van der Pouw, W. Siderius and W.G. Sombroek – basic soil maps; H. Ritz – district climate tables; R. Swoboda – execution of Small Farm Survey; C.G. Wenner & S.N. Njoroge – soil conservation; W. Zettelmeyer – computing farm data. Additional Contributions to the 2nd Edition by: G. Awinyo (GTZ) – assisting R. J. & digitizing of soil maps into GIS; Th. Buettel – support by analyzing remote sensing data; M. Fiebiger – rainfall data analysis, probability calculations, yield probabilities by simulation programs; B. Girkens - final computerized drawing of maps in GIS and other maps; Heike Hoeffler – project coordination in GTZ Nairobi; Ph. Karuri – assistance in the Farm Survey; Anna Kauf- hold - final computerized drawing of fertiliser maps; Ruben Kempf – typing and layout; Elizabeth Kimenyi & Anne Njoroge – coordination of farm survey; Z. Mairura, Ass. Dir. of Farm Business Subdivision; S. N. Maobe (KARI); N. M. Maweu (KARI); Susanne Meissner - water availability & requirement diagrams, typing; M. Mueller – calculation and diagrams of growing periods, ENSO influence; Dr. Anne W. Muriuki & J.N. Qureshi – soil and fertiliser recommendation maps and information; Francis Muthami (GTZ); Dr. Dorothy Mutisya and Dr. J Ochieng – crops and fodder list; Birgit Schmidt – basics for maintaining and regaining soil fertility; Joshua Shivachi & Ch. R. Wambongo– analysing the Farm Survey data using SPSS software; M. Teucher - final computerized drawing of soil and fertilizer maps; Dr. Lusike Wasilwa – horticult. part of the crop list; J. Wieczorek – computerization of maps in GIS; tables and diagrams. PREFACE TO THE ATLAS

The internet and CD versions of the handbook have technically a reduction of details: The most important information, the maps, are due to reduction of the 24 MB to the CD-size of 6 MB, not well readable (esp. formulas of the AEZ Subzones and of the soils). Therefore we prepared additional Atlas- CDs for each group of districts, containing the maps of Rainfall, Agro - Ecol. Zones and Subzones, Soils, anhd Fertilizer Recommendations together with the legends. These maps are produced as pdf-files and can be zoomed for easy reading.

ACKNOWLEDGEMENT for the Support to the First Edition

In compiling this Handbook, we have relied on the support of many officers from a variety of institutions too numerous to mention, who made available their data and experience. We would like to thank them for their invaluable assistance. I would also like to thank my colleagues, the Research Officers, the District Land and Farm management Officers, for their cooperation, and a special thank you to those who typed the draft edition. Our particular thanks go to Prof. Dr. Ralph Jaetzold, University of Trier, for his selfless support in compiling this handbook and for his assessment of the natural conditions including land and population. His deep understanding of the needs of agricultural extension officers and farmers was a great asset. Our thanks also to Dr. H. Kutsch, University of Trier, who computerized a large and complex amount of information involved in establishing the AEZs. Many thanks also to the staff of the Geographical Department of the University of Trier, Germany, for their major effort in drawing up maps of outstanding quality, the centrepiece of the work.

Helmut Schmidt Farm Management Research Officer Nairobi, May 1982

ACKNOWLEDGEMENT for the Support to the Second Edition

In revising this Handbook, various personalities and institutions were relied upon to provide the necessary data required to update the previous data sets. In this regard, we would like to sincerely thank them for their invaluable input in the exercise. Most valuable assistance gave Zacharias Mairura, Assistant Director of Farm Business Division of the Ministry of Agriculture. Special thanks go to the Ministry of Agriculture staff who undertook the Farm Surveys to elucidate on the fundamental changes that have taken place in farming at the household level. We are indeed very grateful to the people of Germany, who despite their limited financial resources, have continued to support Kenya. Of importance here is the German Agency for Technical Cooperation (GTZ) and the German scientists who have been working for Kenya over the years. Last but not least, thanks to Mr. Reimund Hoffmann, the PSDA Coordinator, Nairobi, whose office ably managed the Handbook revision project.

Chris Shisanya Elizabeth Kimenyi Prof. of Agroclimatology Assistant Director of Agriculture Dept. of Geography FMD, MOA Kenyatta University, Nairobi Kenya Nairobi, January 2009 Nairobi, January 2009 PREFACE to the Second Edition

Institutional memory is of paramount importance for planning and development. For any research or agricultural extension to be successful, information on the natural farming potential is equally important.

In an effort to consolidate research - extension work of many years, the first edition of the Farm Manage- ment Handbook (FMHB) of Kenya Vol II (Natural conditions and farm management information), which described the conditions of the Kenyan farming community at that time, was produced in 1982/83. The handbook was in three parts i.e.:

A – for Western Kenya (Western and Nyanza provinces) B – for Central Kenya (Central and Rift Valley provinces). C – for Eastern Kenya (Eastern and Coast provinces)

For more than two decades, the handbook has proved very valuable to researchers, planners, extensionists, developers etc. This is a document that has been sought for enormously and hence the need to revise it in order to accommodate the changes that have taken place in our country since the production of the first edition. Some of these include: changes in the administrative boundaries, opening up of new farming areas due to population pressure, etc.

This second edition has been produced on the basis of Provincial administrative boundaries for the six Provinces i.e. Western, Nyanza, Rift Valley, Central, Eastern and Coast. The information will be availed in hard copies and in CD – ROMS to facilitate updating any future changes.

It is not possible to acknowledge the contribution of all the individuals who made this edition a reality but I need to mention the following individuals:

Thanks to the Ministry of Agriculture officers, especially the Farm Management Division officers at the headquarters (Mrs. E.W. Kimenyi, Mr. F.N. Nderitu, Mrs. H.W. Njoroge, Mrs. A.W Njoroge, Mrs. A. W. Wanyama and Mr. P.T Karuri), and the District staff, for their selfless contribution; Prof. Dr. Chris Shisanya, leader of the revision team, for his tireless efforts and guidance; Prof. Dr. em. Ralph Jaetzold for his enormous knowledge on the definition of the agroecological zones and his great contribution to their map- ping; George Awinyo (German Technical Cooperation (GTZ) – Private Sector Development in Agriculture (PSDA)) for his expertise and contribution in the area of Geographical Information Systems (GIS).

I also wish to thank the GTZ who have facilitated the production of this edition both financially and by the use of their personnel, specifically the late Prof. Werner van der Ohe who supported the idea of the revision, and Mr. Reimund Hoffmann (GTZ – Team Leader Private Sector Development in Agriculture PSDA), for supporting and taking up the task to completion.

Dr. Wilson Songa, OGW AGRICULTURAL SECRETARY Nairobi, January 2009 NAKURU GROUP 1 NAKURU GROUP 2

3.3 NAKURU GROUP OF DISTRICTS

TABLE OF CONTENTS District Page

3.3.1 Natural Potential (R. Jaetzold et al.) 3 Introduction 3 Annual Rainfall Map (R. J.) 4 Table 1: Rainfall Figures 5 Seasonal Rainfall Maps (R. J.) 8 Table 2: Temperature 10 Table 3: Climate in the Agro-Ecological-Zones 11 Agro-Humid Periods Map (R.J.) 12 Agro-Ecological Zones Map (R. J.) 14 Agro-Ecological Zones and Subzones (= Legend to the AEZ Map) 15 Soil Map (R. J. & KSS) 31 Soil Distribution, Fertility and Major Characteristics with Legend to the Soil Map (R. J., W. Siderius & KSS) 32

3.2.4 Farm Survey (Min. of Agric., Chr. Shisanya & R. Jaetzold) 37 Table 27: Farm Survey Sites Representative of the Dominating Agro-Ecological Subzones and Units 38 Farm Survey Areas Map (R. Jaetzold) 39

3.2.5 Introduction to the Actual Land Use Systems and to the Potential Intensification by Better Farm Management in Dominating Agro-Ecological Subzones (Min. of Agr., C. A. Shisanya & R. Jaetzold) 40 UH 2 vl i or two of the Wheat-Pyrethrum Zone 41 Table 30: Increase of Yields by Better Farm Management 42 LH 3 vl/l or two of the Wheat/Maize-Barley Zone 43 Table 31: Increase of Yields by Better Farm Management 44 LH 3 (l/vl) of the Wheat/Maize-Barley Zone 45 Table 32: Increase of Yields by Better Farm Management 46 UM 4 (l) or two of the Maize-Sunflower Zone 47 Table 33: Increase of Yields by Better Farm Management 48

3.2.6 Fertiliser and Manure Recommendations for Important Agro-Ecological Units 49 Map of Important Agro-Ecological Units & Fertil. Recommendations (R. Jaetzold) 51 Tables 22 a–c: Fertilisers and Manure Recommendations (B. Hornetz) 52

3.2.7 Final Statement 62 Table 35a: Projected Agricultural Incomes in Zone LH 2 of Nakuru North District 62 Table 35b: Projected Agricultural Incomes in Zones LH 3 & UM 4 of Rongai District 63

Note: Numbering of chapters is equivalent to numbering in Farm Management Handbook of Kenya NAKURU GROUP 3

3.3.1 NATURAL POTENTIAL

INTRODUCTION

The Nakuru group of districts covers the highest part of the Rift Valley and includes the bordering escarpments and plateaus. The western plateau, (the Mau Hills above the Mau Escarpment) rises to about 3000 m. The climate there is cold and wet with a mean temperature of 10-15°C and an annual average rainfall of 1180-1400 mm increasing westward to 1800 mm. The area belongs mainly to Agro-Ecological Zone UH 1, is excellent sheep country and to a lesser extent also good for dairy. The forests there are necessary for the water supply of Nakuru and the Lake Basin. The zone UH 1 is also found on the eastern plateau, but mainly outside of Nakuru district group.

The western escarpment bordering the Rift Valley floor is clearly divided into two levels, with a small but long plateau at an elevation of about 2300 m stretching from Molo to Njoro. This is mainly a Wheat/Maize- Pyrethrum Zone, LH 2. The higher parts form the Wheat (& Barley)-Pyrethrum Zone UH 2 because maize there is affected by cold weather and frosts.

At slightly lower altitudes, it is too dry for pyrethrum but still good for wheat and malt barley. There stretches the Wheat-Barley Zone LH 3, which is mainly situated between 2100 and 2400 m. We find LH 3 and UH 2 also on the old volcanic ridges of Eburu (Opuru) outside the Forest Reserve. On the floor of the Rift Valley, wheat is only promising on the highest parts (near the escarpments northwest and northeast of Nakuru or around Menengai Volcano), otherwise it is too dry or too hot. Where it is too dry, a Livestock- Barley Zone LH 4 borders LH 3. Here ranching is the most important enterprise. The zone is better suited for fodder barley than for malt barley. Nowadays, however, this forage crop is scarcely cultivated because sufficient cheaper grazing is still available. The lowest parts are the Ranching Zone UM 6 anyway.

From the culmination of the Rift Valley near Menengai, the floor slopes gently down towards Nakuru in the south and towards Mogotio in the north. These areas have still some maize and sunflower potential (UM 4), but are not so favourable for these crops as the Kigale area, because of the predominantly weak perform- ances of the rainy season. Therefore, sisal is a safer crop, although the altitude is close to the upper limit for sisal. This zone is followed downward by the Livestock-Sorghum Zone UM 5 for the same reason (low and unreliable rainfall). The annual average rainfall is still 800-900 mm, but the 66% reliability of the first rainy season is only 190-240mm, and of the second rainy season 240-290 mm. Between both seasons there are some middle rains, but they are scattered and also unreliable (July-August 210 mm, 66% probability 165 mm). In agricultural practice, the middle rains are either combined with the first rainy season or the second one. Therefore, the rainfall maps show both these combinations.

In the slightly lower areas between Hyrax Hill and Longonot, scattered distribution of rainfall (see Diagram of Gilgil) makes additional irrigation necessary for succesful cultivation of crops. This is therefore a vast ranching area. Irrigated crops, especially flowers, are found to a large extent around Lake Naivasha, already endangering its size and biological system. NAKURU GROUP 4 NAKURU GROUP 5

TABLE 1: RAINFALL FIGURES FROM SELECTED TYPICAL STATIONS IN NAKURU GROUP OF DISTRICTS HAVING RECENTLY AT LEAST 15 YEARS OF RECORDS

Monthly & seasonal average rainfall in mm No. and Agro-Ecol. Annual altitude Name of station Zone and rainfall Subzone mm J F M A M J J A S O N D

36 46 84 165 129 88 125 134 77 65 92 58 9035011 Elburgon LH 2 1099 2377 m Forest Station = 466 = 336 = 215

31 45 84 164 131 106 128 162 87 55 86 58 9035018 Molo UH 2 1137 2458 m Railway Station vl i or two = 485 = 377 = 199

29 38 67 140 117 75 100 124 66 55 79 47 9035021 Njoro LH 3 935 2160 m Plant breeding vl/l or two = 399 = 290 = 181

27 38 61 153 114 92 141 155 88 47 62 48 9035038 Mau UH 2 1025 2537 m Summit vl i or two = 420 = 384 = 157

32 35 64 145 115 78 114 112 66 53 75 48 9035073 Rongai UM 4 937 1890 m Gogar Farms (l) = 402 = 292 = 176

34 40 65 160 118 77 101 139 79 58 91 52 9035092 Egerton LH 3 1013 2238 m Agriculture College vl/l or two = 420 = 319 = 201

41 43 68 175 128 99 140 166 99 62 99 62 9035093 Molo Pyrethrum UH 2 1181 2500 m Experiment Stn. vl i or two = 470 = 405 = 223

52 53 84 178 140 90 131 157 88 79 126 79 9035117 Mariashon UH 1 1256 2605 m Forest Station = 492 = 376 = 284

41 46 69 162 125 77 113 149 70 67 103 61 9035119 Nessuit UH 2 1084 2410 m Forest Station = 433 = 332 = 231

41 48 66 151 125 98 133 203 101 71 88 57 9035129 Marindas UH 2 1181 2804 m Pyrethrum Farm vl i or two = 440 = 437 = 216

48 41 81 164 140 107 138 191 116 73 104 65 9035228 Elburgon, Kiptunga UH 0 - 1 1269 2960 m Forest Station = 492 = 445 = 242

42 48 78 193 110 86 114 141 77 77 114 73 9035232 Likia UH 2 1152 2805 m Forest Station = 467 = 332 = 264

40 47 72 167 116 83 101 126 75 72 114 71 9035233 Teret UH 2 1085 2440 m Forest Station = 438 = 302 = 257

54 49 90 188 134 91 128 169 86 76 140 83 9035237 Elburgon Div. UH 2 1287 2560 m Forest Office vl i or two = 503 = 383 = 299

63 67 89 176 199 180 192 231 144 82 84 54 9035240 Londiani, Keresoi UH 2 1559 2680 m Forest Station = 644 = 567 = 220

46 43 70 147 144 92 148 187 105 74 92 49 9035241 Elburgon, Baraget UH 1 1198 2865 m Forest Station = 453 = 440 = 215

36 45 68 153 113 70 104 114 70 56 30 36 9035254 Kinan Farm, LH 3 894 2197 m Njoro vl/l or two = 404 = 288 = 122 NAKURU GROUP 6

TABLE 1: CONTINUATION Monthly & seasonal average rainfall in mm No. and Agro-Ecol. Annual altitude Name of station Zone and rainfall Subzone mm J F M A M J J A S O N D

41 49 83 176 130 91 136 154 85 63 132 62 9035266 Molo Water LH 2 1201 2440 m Bailiff’s Office vl or two = 480 = 375 = 257

35 42 59 156 129 81 97 117 85 59 72 37 9035267 Menengai LH 3 968 1968 m Farm l/vl = 425 = 299 = 168

52 51 89 207 142 130 120 188 94 64 108 44 9035273 Molo UH 2 1288 2591 m Forest Station = 568 = 402 = 216

20 32 60 156 114 85 107 125 61 56 73 44 9035310 Valley Enterprises UM 4 932 2050 m LTD, Rongai (l) = 415 = 293 = 173

25 36 58 114 83 41 34 44 43 49 61 40 9036002 Naivasha D.O. UM 5 626 1900 m (s/vs) + (vu) = 296 = 121 = 150

22 34 62 125 117 77 95 104 70 39 63 35 9036020 Nakuru UM 4 842 1850 m Railway Station (l) = 381 = 269 = 137

24 29 57 155 211 127 140 165 120 102 89 38 9036032 Bahati LH 2 1257 2408 m Forest Station = 550 = 425 = 229

23 28 52 99 72 53 61 63 39 50 60 40 9036034 Gilgil LH 5 640 2006 m Railway Station tr = 276 = 163 = 150

36 53 62 120 82 57 35 31 41 38 51 59 9036062 Naivasha UM 6 665 2012 m Kongoni Farm ur i – LH 5 = 321 = 107 = 148

27 33 47 101 83 50 41 50 34 39 53 39 9036073 Naivasha K.C.C. UM 5 596 1950 m LTD. vs/s + (vu) = 281 = 125 = 131

22 35 64 136 132 81 98 119 74 58 72 37 9036076 Technology Farm, UM 4 928 1920 m Nakuru (l) = 413 = 291 = 167

34 37 55 115 97 52 43 53 42 61 68 43 9036081 Naivasha Vet. Expt. UM 5 700 1968 m Station (s/vs) + (vu) = 319 = 138 = 172

31 33 49 112 84 48 47 58 40 48 62 44 9036109 Naivasha Marula UM 5 656 2042 m Estate vs/s + (vu) = 293 = 145 = 154

26 28 47 109 79 56 66 76 60 49 61 43 9036147 Elementaita, UM 6 699 1849 m Soysambu Est. ur i = 291 = 202 = 153

22 28 53 107 72 53 55 69 38 47 59 39 9036150 Gilgil, LH 5 642 2134 m Kikopey Ranch ur i = 285 = 162 = 145

31 36 54 163 175 94 133 157 111 88 91 59 9036151 Subukia Pyrethr. LH 2 1192 2135 m Nursery vl/l or two = 486 = 401 = 238

9036179 29 33 49 118 110 56 49 49 35 39 46 42 Naivasha Korongo 1890 m UM 5 654 Farm = 333 = 133 = 127 NAKURU GROUP 7

TABLE 1: CONTINUATION Monthly & seasonal average rainfall in mm No. and Agro-Ecol. Annual altitude Name of station Zone and rainfall Subzone mm J F M A M J J A S O N D

35 40 55 138 87 34 27 75 46 50 53 45 9036214 Naivasha Longonot UM 6 684 1890 m Farm = 314 = 148 = 148

28 33 51 150 102 66 66 102 59 52 76 48 9036227 Elementaita Nderit UM 5 834 1825 m Ranger Post (s) i + (vu) = 369 = 227 = 176

29 36 53 124 103 72 76 96 76 88 97 43 9036236 Nakuru Lanet Police UM 4 893 1890 m Post (l) = 352 = 248 = 228

27 28 66 146 162 122 121 133 104 107 99 38 9036243 Dundori LH 2 1153 2255 m Forest Station = 496 = 150 = 244

69 37 64 148 130 75 93 115 97 82 100 36 9036252 Menengai LH 2 1045 2160 m Forest Station = 417 = 305 = 218

28 50 46 172 108 59 54 87 55 66 119 77 9036253 Thome LH 4 921 2350 m Farmers No. 2 (l) = 385 = 196 = 262

Nakuru 26 42 65 140 122 78 94 120 88 68 71 35 9036261 Meteorological UM 4 949 1900 m Station (l) = 405 = 302 = 174

30 49 59 123 80 48 45 58 44 62 71 44 9036262 Olaragwai Farm, LH 4 715 2020 m Naivasha (l) = 310 = 147 = 177

34 48 60 118 77 50 35 44 46 60 63 47 9036281 Naivasha W.D.D. UM 5 680 2680 m (s/vs) i (vs) = 305 = 125 = 186 NAKURU GROUP 8 NAKURU GROUP 9 NAKURU GROUP 10

TABLE 2: TEMPERATURE DATA

No. and Name AEZ Kind of Temperature in °C Belt altitude of records1) limits2) Station J F M A M J J A S O N D Yr. Mean max. 23.7 24.9 24.4 23.8 22.4 21.7 20.9 22.4 23.0 22.4 21.5 23.3 22.6 Njoro, LH 3 2310 m 90 35 021 KARI Mean temp. 16.2 16.7 16.3 16.7 15.9 15.8 14.7 15.5 16.0 15.9 15.5 16.5 15.9 middle LH 2160m Research 3) part Mean min. 8.7 8.4 8.1 9.5 9.3 9.9 8.4 8.6 9.0 9.4 9.5 9.7 9.1 1810 m Station Abs. min. 2.8 3.9 4.4 4.4 2.2 1.7 1.6 1.7 1.7 2.8 2.2 3.3 1.6 Mean max. 26.8 28.5 28.2 25.9 25.4 24.4 23.9 24.4 25.9 25.8 24.4 25.8 25.8 Nakuru UM 3 2020 m 90 36 261 Mean temp. 18.9 19.8 20.1 19.4 19.1 18.4 18.0 18.1 18.6 18.7 18.2 18.5 18.8 Met. upper UM 1890 m Station part Mean min. 11.0 11.0 11.9 12.8 12.7 12.4 12.1 11.8 11.2 11.5 11.9 11.1 11.8 1520 m Abs. min. 5.6 6.4 5.0 8.3 8.4 8.9 8.8 7.5 7.3 7.6 7.1 5.6 7.2

1) Of the last 15 years until 2008 2) Situation around 2008. Global warming will lift up the belt for about 350 m until 2050. 3) The minima are microclimatically extraordinary low by a tree row below the weather hut, stopping the cold air flowing nightly from the highland through the valley. The actual belt limits are at least 100 m higher. NAKURU GROUP 11

TABLE 3: CLIMATE IN THE AGRO-ECOLOGICAL ZONES

Agro- Subzone Altitude Annual Annual av. 66% reliability of 60% reliability of cereal and Ecological in m mean rainfall rainfall 1) legumes growing period Zone temp. in mm in °C 1st rainy Middle 1st rainy Middle Total in season & rains season & rains days 3) middle & 2nd middle & 2nd rains rainy rains in rainy in mm season days 2) season in mm in days TA I Cattle-Sheep 3 000-3 050 10.0-9.8 1 200-1 400 800-900 580-600 No cropping Zone UH 0 Forest Zone 2 400-3 000 15.0-10.1 1 270-1 900 950-1 100 600-700 No cropping UH 1 200-350 210 or more 90-140 300-350 Sheep-Dairy vl i or two 2 400-3 000 15.0-10.1 1 200-1 800 720-1 020 Zone vl i Small, figures almost as above UH 2 Wheat- Pyrethrum vl i or two 2 400-2 800 15.0-11.2 1 100-1 400 550-800 200-300 190 or more 70-100 270-300 Zone UH 3 Wheat-Barley (l/vl) 2 400-2 580 15.0-13.9 850-1 050 260-300 160-180 170 or more 90-100 260-270 Zone LH 2 Wheat/Maize- vl or two 1 000-1 100 620-750 450-600 200 or more 90-110 280-300 Pyrethrum vl/l or two 2 070-2 400 16.7-14.9 1 200-1 400 600-730 500-620 180 or more 80-100 250-275 Zone LH 3 vl/l or two 890-1 100 400-650 430-500 180 or more 70-90 235-260 Wheat/Maize- l/vl 1 890-2 190 17.5-15.7 870-1 000 400-600 350-450 160 or more 65-80 220-235 Barley Zone (l/vl) 850-950 260-450 250-400 150 or more 65-80 225-230 LH 4 Cattle-Sheep- (l) 1 890-2 010 17.5-16.6 800-900 200-400 250-350 120 or more 80-100 195-215 Barley Zone (s/m) i (vs) 700-800 200-280 200-280 105-115 50-65 155-180 LH 5 (s/vs) + (vu) 680-800 180-280 no rel. 75-85 Lower Highland u r i 1 840-2 010 17.8-16.6 650-750 160-200 agroh. no reliable Ranching Zone b r 650-700 200-250 period agrohumid period UM 3 Marginal Coffee vl/l or two 1 830-1 950 18.5-17.5 1 000-1 200 600-650 480-520 180 or more 70-90 250-280 Zone UM 4 l/vl or two 950-1 100 500-600 400-450 160 or more 65-80 230-245 Maize- (l) or two 1 600-1 830 21.0-18.6 850-1 000 500-580 350-430 130 or more 60-75 190-210 Sunflower Zone (l/m) i 800-900 350-500 300-350 120 or more 55-65 175-190 (m/l) i 700-950 300-350 no rel. 155-175 UM 5 (s) i + vu 750-850 180-300 agro- 85-105 no reliable Livestock- (s/vs) + vu 1 660-1 890 19.6-18.3 650-750 230-260 humid 75-85 agrohumid period Sorghum Zone (vs/s) + vu 600-700 200-230 period 55-75 UM 6 Upper Midland u r i 1 620-1 820 19.8-18.5 600-700 no reliable agrohumid period of at least 40 days Ranching Zone b r 550-700

1) Amounts in mm, according to lower and higher areas, surpassed normally in 10 out of 15 years, falling during the agro-humid period which allows growing of most cultivated plants 2) March-June and July-Sept., more if growing cycle of cultivated plants continues by middle rains into the period of second rainy season 3) Only added if rainfall continues at least for survival (>0.25 PET) of most long term crops NAKURU GROUP 12 NAKURU GROUP 13 NAKURU GROUP 14 NAKURU GROUP 15

AGRO-ECOLOGICAL ZONES AND SUBZONES - Introduction

The yield potentials are calculated for the important annual crops with the programs WATBALand MARCROP by B. Hornetz (see chapter 3.1 and Annex). The other crops are classified by estimates according to their temperature and water requirements. Not all suitable crops could be mentioned here because of limited space. More crops and the most suited varieties can be found in the crop list (Table X) and in IRACC: Small Holder Farming Handbook for Self Employment, Nairobi 1997, when comparing both sources with the climatic data of the AEZ and Subzones (Table 3) as well as considering the soil requirements (Table IV) and the soil map. The potentials require optimal fertilising and manuring as well as good crop husbandry to reach the given percentages. Recommended for checking in Table X are the following crops resp. varieties which have not been mentioned in the potentials: Many more maize varieties, most of them commercial ones; more vegetables like french beans, carrots, leek, celery, spinach, beetroot, turnips and others; more fruits like grapefruit, mandarines, limes, lemons, tangerines, passionfruit (>1200 m) and pineapples (canning quality >1350 m). Tea, sugarcane and cotton have also many interesting varieties. For fodder and forage many other plants than the mentioned ones are classified in Table XI by Agro-Ecological Zones.

The tables beneath the diagrams of growing periods may differ from other calculations because they do not include the drier grass growing periods which can give a minimum supply of moisture to low demanding crops.

It must be kept in mind that the potentials are ecological ones. What is economical depends on the present relation of costs-yield-ptizes and the marketing possibilities, of course.

AGRO-ECOLOGICAL ZONES AND SUBZONES (Legend to the Map)

TA = TROPICAL-ALPINE ZONES TA I = C a t t l e a n d Sh e e p Z o n e High altitude grasslands at about 3000 m. Very suitable for Corriedale sheep, fairly suited for cattle and Merino sheep

UH = UPPER HIGHLAND ZONES UH 0 = Fo re s t Z o n e UH 1 = Sh e e p - D a i r y Z o n e UH 1 = Sheep-Dairy Zone vl i or with a very long 1) cropping season, two dividable in two variable cropping seasons Here mainly forest reserve G o o d y i e l d p o t e n t i a l (av. 60 - 80% of the optimum) 1st rainy season (to 2nd r. s.), start norm. March1): Oats (April-S.); peas; potatoes; m. mat. rapeseed; (~60%); cabbage; carrots; kohlrabi; celery; endive; rampion; leek; radish 2nd rainy season, start norm. end of June1): The same but normally crops of first rainy season are not yet ready; planting from end of August onward, then yield expectations only fair Whole year: Kales

Fa i r y i e l d p o t e n t i a l (av. 40 - 60% of the optimum) 1st rainy season: Triticale, late or very late mat. maize in frost free lower places, higher places very marginal 2nd rainy season: M. mat. wheat (June/July - D./Jan.), m. mat. barley; 3rd crop of potatoes (N. - F., ~40% on microclimatic frostfree slopes) Whole year, best planting time end of March: Pyrethrum (50 - 60%), strawberries NAKURU GROUP 16

Pa s t u r e a n d f o r a g e > 0.8 ha/LU (lower places) to 1.2 ha/LU (drier upper places) on sec. pasture of Kikuyu grass, very suitable for Corriedale sheep, up to 2700 m also for grade dairy cows and Merino; rye grass (Lolium perenne) to improve pasture for dairy (not near wheat fields because it is a weed); Kenya white clover and rapeseed foliage as add. forage, others see Table XI. UH 1 = Sheep-Dairy Zone vl i with a very long cropping season and intermediate rains Small, potential almost as above but rainy season still less divided, rainfall nearly trimodal UH 2 = Wheat-Pyrethrum Zone UH 2 = Wheat-Pyrethrum Zone vl i or with a very long cropping season, two dividable in two variable cropping seasons (See Diagram Molo)

Good yield potential 1st rainy season (to 2nd r.s.), start norm. end of March: Late mat. wheat (70 - 80%, May - N./D.), late mat. triticale (Apr. - O.), m. mat. barley (May - S./O.), oats, lima beans, horse beans, peas (~60%), potatoes (March - July); m. mat. rapeseed (April/May - S.); cabbages (nearly 80%), kales, carrots (nearly 80%), kohlrabi, celery, endive, rampion, leek, radish 2nd rainy season, start norm. b. of July: Oats, m. mat. barley; e. mat. rapeseed; peas and the above vegetables excl. kohlrabi, but if planted from mid August onward only fair expectations Whole year: Pyrethrum, strawberries Fair yield potential 1st rainy season: Very late mat. maize (risk by frosts in valleys and on higher plateaus) 2nd rainy season: Potatoes (Au. - N., 50 - 60%), kohlrabi Whole year: Plums, pears, apples (below 2700 m) Pa s t u r e a n d f o r a g e About 0.8 ha/LU on sec. pasture of Kikuyu and tufted grass (if not overgrazed, otherwise Kikuyu grass is disappearing) suitable for Merino and Corriedale sheep and grade dairy cows; rye grass to improve pasture for dairy (not to combine with wheat cultivation), down to about 0.5 ha/LU with Kenya white clover and lucerne as add. forage, green maize for silage in lower places

UH 2 vl i Nr.: 9035018 Molo Station 0° 15`S 35° 44`E 2458 m

Average rainfall per decade Reliable rainfall, surpassed in 10 out of 15 years Approx. pot. evapotranspiration of a permanent crop (pyrethrum) Approx. pot. evapotranspiration of late mat. maize 685 Rainfall per indicated growing period, surpassed in 10 out of 15 years NAKURU GROUP 17

UH 2 = Wheat-Pyrethrum Zone vl/l with a very long to long cropping season Small, potential almost as above but very late mat. maize not recommended

UH 3 = W h e a t - B a rl e y Z o n e UH 3 = Wheat-Barley Zone l/vl with a long to very long cropping season Very small, potential see Nyandarua group of districts UH 3 = Wheat-Barley Zone (l/vl) with a (weak) long to very long cropping season Very small, potential see Nyandarua group of districts UH 3 = Wheat-Barley Zone m i with a medium cropping season, intermediate rains, (vs/s) i a (weak) very short to short one and i. r. Very small, potential see Nyandarua group of districts

LH = LOWER HIGHLAND ZONES LH 2 = M a i z e / W h e a t - P y re t h r u m Z o n e LH 2 = Maize/Wheat-Pyrethrum Zone vl or with a very long cropping season, two dividable in two variable cropping seasons Good yield potential 1st rainy season, start norm. mid March: M. or late mat. wheat (60-70 %, April/May – O./N.), late mat. maize (March/April – N./D., 80 % on deep soils); peas, horse beans; potatoes (April – Aug.); late mat. sunflower, linseed, rapeseed; cabbages, kales, cauliflower, carrots, beetroot, spinach, celery, lettuce 2nd rainy season, start norm. end of June: M. mat. barley (June – O.); linseed; kales, cauliflower, carrots, beetroot, spinach, tomatoes, celery. Whole year: Black Wattle, New Zealand flax Fair yield potential 1st rainy season: Finger millet; m. mat. beans (lower places), lima beans (also higher places); leek, tomatoes, onions 2nd rainy season: Peas, potatoes (S. – D./J.); cabbages, onions, lettuce Whole year: Pyrethrum, tea; apples, pears and plums above 2200 m; strawberries Pasture and Forage Around 1.2 ha/LU on highland savanna of Kikuyu, red oats and tufted grass 3) between Cedar forest remnants; about 0.6 ha on art. pasture of Nandi Setaria above 2000 m or Rhodes grass below 2000 m; suitable for grade dairy cows; Silver leaf desmodium best add. forage, others see Table XI.

LH 2 = Wheat/Maize-Pyrethrum Zone vl/l or with a very long to long cropping season, two dividable in two variable cropping seasons Almost the same potential as LH 2 vl less about 5%, pyrethrum and wheat less suitable (-10%)

LH 3 = Wheat/(Maize)-Barley Zone 2) LH 3 = Wheat/Maize-Barley Zone vl/l or with a very long to long cropping season, two dividable in two variable cropping seasons (See Diagram Njoro) NAKURU GROUP 18

Good yield potential 1st rainy season, start norm. b. of March: M. mat. wheat (March/Apr. - S., 70-80%), m. mat. durum wheat, late mat. triticale, m. mat. barley, late mat. maize; peas; linseed, rapeseed, late mat. sunflower; cabbages, kales 2nd rainy season, start indistinctly around July/Aug.: M. mat. barley (Aug. - D.) Whole year: Black wattle Fair yield potential 1st rainy season: Potatoes; beans, cauliflower, beetroot, onions, carrots 2nd rainy season: M. mat. wheat (Aug. - end of D.); beans (lower places), lima beans; tomatoes, beetroot Whole year: Avocadoes (lower places), strawberries, peaches Pasture and forage About 1.4 ha/LU on highland savanna; about 1 ha/LU on art. pasture of Nandi Setaria between 2050 m and 2200 m, or Rhodes grass below that; feeding Rhodes grass, subterranean clover, Lotononis, maize silage and fodder barley down to about 0.25 ha/LU (in lower places); suited for grade dairy cows and grade cattle

LH 3 = Wheat/(Maize)-Barley Zone (l/vl) with a (weak) long to very long cropping season Good yield potential 1st rainy season, start norm. b. of April: M. mat. wheat (Apr. - S., 60-70%), m. mat. barley (60-70%) Whole year: Black Wattle (deep soils)

Fair yield potential 1st rainy season: Late mat. maize; peas, linseed, late mat. sunflower; cabbages and other vegetables Pasture and forage About 1.5 - 2 ha/LU on nat. pasture of red oats and wire grass; down to 1.2 ha/LU on art. pasture of Nandi Setaria between 2000 m and 2180 m, below 2000 m Rhodes grass; suited for grade cattle; subterr. clover and fodder barley best add. forage

LH 3 vl/l Nr.: 9035021 Njoro, Plant Breeding Station 0° 20`S 35° 56`E 2160 m

Average rainfall per decade Reliable rainfall, surpassed in 10 out of 15 years Approx. pot. evapotranspiration of a permanent crop (pyrethrum) Approx. pot. evapotranspiration of late mat. maize 615 Rainfall per indicated growing period, surpassed in 10 out of 15 years NAKURU GROUP 19

LH 4 = C a t t l e - Sh e e p - B a rl e y Z o n e LH 4 = Cattle-Sheep-Barley Zone (l) with a (weak) long cropping season Fair yield potential 1st rainy season, start norm. b. of April: M. mat. fodder barley (other crops mostly marginal, esp. maize) The variability of rainfall is so high that crop failures occur from time to time. Ranching is therefore more advisable Pasture and forage More than 2 ha/LU on nat. pasture of short grass highland savanna; down to 1.4 ha/LU on art. pasture of Rhodes grass; suited for grade cattle; subterr. clover and m. mat. fodder barley best add. forage

LH 4 = Cattle-Sheep-Barley Zone (m/s) with a (weak) medium to short cropping season, intermediate rains, i (vs) and a (weak) very short one Potential nearly the same as above, but e. mat. barley and var. Boma of Rhodes grass most suited

LH 4 = Cattle-Sheep-Barley Zone s/m + with a short to medium cropping season, (vs) and a (weak) very short one Potential nearly the same as above, but smaller grazing capacity

LH 5 = L owe r Hi g h l a n d R a n c h i n g Z o n e LH 5 = Lower Highland Ranching Zone (s/vs) with a (weak) short to very short cropping season + (vu) and a (weak) very uncertain second rainy season Very marginal for agriculture. V. e mat. barley (on good soils in higher places, fair to poor results) Pasture and forage About 2.5 ha/LU on highland short grass savanna; down to about 1.8 ha/LU on art. pasture with Rhodes grass, with supplementary irrigation 1.0 ha/LU

LH 5 = Lower Highland Ranching Zone u r i with unimodal rainfall and intermediate rains (See Diagram Gilgil) Not suitable for rainfed agriculture Pasture and forage About 3 ha/LU on highland short grass savanna; down to about 2 ha/LU on art. pasture with Rhodes grass, with supplementary irrigation 1.2 ha/LU

LH 5 = Lower Highland Ranching Zone b r with bimodal rainfall Potential nearly the same as above, but chances for v. e. mat. barley only if seeding starts beginning to mid April. To establish Rhodes grass pasture is more difficult, and it is less stockable. NAKURU GROUP 20

Station name Cereal and legumes growing period Dry conditions Precipitation is cumulated Lanet, Police Post = agro-humid period (AHP), during agro-humid period in mm Station no. Altitude AEZ min. 40 days Subzone: 9036236 2034m LH 3 = grass growing period only l/m

Year Year Rainfall / c.& leg. gr.p. January February March April May June July August September October November December 1st AHP & 2nd AHP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 mm days continuing 1950 50/51 1951 51/52 1952 52/53 1953 53/54 1954 54/55 1955 55/56 1956 56/57 1957 57/58 1958 58/59 1959 0000000038 47 104 125 145 163 232 311 313 331 332 353 427 437 470 486 543 551 557 12 24 59 80 89 108 125 136 g 59/60 703 270 1960 g 00000037 69 96 142 163 185 204 252 275 277 293 313 321 329 360 409 469 533 571 627 12 45 119 153 205 207 213 234 234 60/61 861 300 + 1961 g 0000000g 52 83 96 149 166 176 197 199 208 223 227 286 335 366 385 416 440 448 6 37 132 253 354 438 450 500 556 61/62 1089 300 + 1962 635 639 641 gggggg32 86 137 216 230 252 280 311 334 352 358 391 467 491 523 527 566 582 6 52 94 121 123 185 190 204 245 62/63 845 290 + 1963 253 263 ggggg47 49 69 149 266 288 326 418 448 502 510 519 538 552 572 632 675 679 679 0031 57 73 101 118 222 232 274 63/64 679 190 - 1964 287 287 gggggggggggggg000051 67 78 90 108 176 222 76 102 140 158 182 216 230 254 260 64/65 497 170 + 1965 275 gg000000084 151 172 217 239 242 242 266 305 332 332 337 357 368 375 413 423 4 31 70 100 108 144 149 191 191 65/66 614 270 + 1966 191 00000045 51 77 156 246 263 266 294 328 362 362 383 408 413 447 496 586 642 684 716 25 47 83 131 136 168 169 169 0 66/67 885 280 - 1967 000000ggg46 101 149 230 283 333 340 370 395 413 479 493 511 529 534 537 556 574 3 22 68 104 141 194 197 197 0 67/68 771 260 - 1968 000077 119 64 94 119 173 188 301 326 347 380 426 459 467 474 g 50 74 152 162 172 182 194 9 33 89 148 170 225 287 287 289 68/69 474 150 - 1969 0057 62 104 135 11 12 120 127 153 161 251 277 294 300 349 351 360 374 385 401 414 420 441 468 468 16 44 135 162 181 195 218 218 220 69/70 829 300 + 1970 265 312 346 359 361 g 41 51 148 223 247 314 345 357 387 387 451 459 470 531 552 564 588 622 650 723 751 31 63 84 94 108 116 gg0 70/71 867 270 - 1971 000000000051 105 188 226 242 271 271 305 316 340 350 395 423 468 476 485 520 14 14 38 38 51 63 69 113 135 71/72 672 280 + 1972 152 152 g 73 90 111 ggggggggg46 71 88 97 115 150 171 240 248 252 ggg40 61 85 152 221 221 225 0 72/73 252 100 - 1973 000000000051 83 91 115 197 222 228 229 0 30 51 83 143 228 238 264 327 14 55 66 80 89 89 g 0073/74 416 140 - 1974 00000051 57 144 213 259 266 272 292 303 389 428 465 513 520 592 612 651 694 730 749 793 32 39 101 131 145 149 153 g 0 74/75 946 280 - 1975 000000000043 90 101 110 173 197 207 284 306 386 413 431 519 558 619 679 692 53 119 156 159 187 188 211 211 g 75/76 903 250 - 1976 0000000000029 47 77 96 108 118 149 169 198 214 250 260 308 334 354 366 12 25 27 gggggg76/77 393 190 - 1977 ggggg00gg75 98 187 269 360 379 393 421 451 488 491 544 579 590 613 625 641 647 g 40 112 190 232 257 306 331 362 77/78 647 180 - 1978 371 419 419 419 469 521 25 44 84 136 189 264 326 351 356 364 373 407 419 457 471 483 539 584 596 629 697 35 49 76 91 134 146 150 186 195 78/79 1227 360 + 1979 232 266 347 446 525 530 g 25 25 59 105 144 212 232 253 272 294 313 341 368 380 396 424 425 457 477 519 gg000000079/80 519 200 - 1980 80/81 1981 81/82 1982 82/83 1983 83/84 1984 000000000ggggggggggggggg58 99 114 gg0 g 52 61 85 90 90 84/85 114 30 - 1985 00gggg0094 120 242 297 325 371 432 444 517 517 530 561 577 595 606 632 671 671 678 gggggggg0 85/86 678 190 - 1986 00000000046 113 154 176 191 211 218 245 276 316 333 359 362 377 390 413 432 455 3 3 0000 86/87 461 200 - 1987 0000000ggggggggggg00000000000ggggg0087/88 - - - 1988 000gg38 72 138 224 238 285 305 343 352 373 373 414 436 452 475 524 563 591 624 24 24 54 81 92 106 115 140 145 88/89 888 340 + 1989 158 168 168 225 235 264 3 22 41 88 98 129 170 241 248 273 291 291 gggggg29 102 114 114 g 45 65 65 94 89/90 291 120 - 1990 138 148 182 182 g 52 55 89 114 128 134 172 174 191 209 220 ggggggggggg00ggggggg90/91 220 100 - 1991 91/92 1992 92/93 1993 93/94 1994 94/95 1995 95/96 no AH cd. 1618202121212117149544443445534443458567767813Median rain- 678 AHP cd. 11 9 7 7 7 7 7 11 14 19 23 24 24 24 24 25 24 24 22 22 24 24 24 24 25 24 23 20 23 22 21 21 22 20 19 14 fall in AHPs #### 0 %AHP/val.y 41% 33% 26% 25% 25% 25% 25% 39% 50% 68% 82% 86% 86% 86% 86% 89% 86% 86% 81% 81% 89% 86% 86% 86% 89% 86% 82% 71% 82% 79% 75% 75% 79% 74% 70% 52% 66% reliab. of 519 median AHP rainf. in AHPs median GGP 52% 41% 48% 43% 46% 43% 50% 64% 75% 82% 96% #### #### #### #### #### 96% 96% 89% 93% 96% 96% 96% 96% 96% 96% 93% 89% 93% 89% 93% 93% 93% 96% 89% 67% 60%-reliable 190 Martin Mueller 2008 length of AHP 2 2 28

First and second rainy season: Av. end of March - end of December - years of usable records: 28 1)

Chances for the right growing periods: Late mat. maize 21 gr. p. of at least 170 days = 75 % of all seasons Late mat. finger millet 21 gr. p. of at least 160 days = 75 % of all seasons Med. mat. barley 22 gr. p. of at least 150 days = 79 % of all seasons Med. mat. beans 22 gr. p. of at least 150 days = 79 % of all seasons Med. mat. wheat 23 gr. p. of at least 140 days = 82 % of all seasons Med. mat. maize 23 gr. p. of at least 140 days = 82 % of all seasons

Existential risks: No cereal growing period in a year or more: 2 times = 8 % of the years WATBAL run specifications by B. Hornetz 2) 2 or more consecutive rainy seasons without the min. AHP of 50 d.: 0 times in 28 years ISUM ESUM ELIM OLIM STOCK RE No grass growing period in a season: 0 times = 0 % of the seasons 1 2,4 2,4 0,4 1 320 0,9 No grass growing period in a year or more: 0 times = 0 % of the years � 1,5 1,2 0,2 1 320 0,9 rainfall scenario: DISCON

1) valid = no significant gaps in the records 2) AHP = Agro-humid period ~ growing period for cereals and legumes; GGP = grass growing period + : Growing period is continuing into January, sometimes February NAKURU GROUP 21

TABLE 4: CLIMATIC YIELD POTENTIALS OF SELECTED ANNUAL CROPS 1) in LH 5 (vs/s) i vu or LH 5 tr resp. u r i (calc. for station 9036034 Gilgil Railway Station with locally dominating ando-luvic Phaeozems)

First rainy season Middle rainy season and (av. start mid of April till July) Second rainy season 3) Total Yield crop Estim. Total Potential Estim. failures average crop (in % Crop variety average out Crop variety yield failures yield 2) out of Opti- 2) of 10 (kg/ha) (kg/ha) of 10 mum) seasons seasons Very good (80 – 100 %) Foxtail millet (ISe 285) 1860 1 Finger millet (Ekalakala) 1760 1 Good Sorghum (KARI Mtama 1) 1880 1 (60 – 80 %) Cowpeas (Kunde 1) 720 1 Dolichos beans (Kat/DL-2) 1880 1 1 Barley (Bima) 1280 1 Barley (Karne) 1750 1 Barley (Tumaini) 1580 1 Wheat (Africa Mayo) 1240 Wheat (Ngiri, Kenya 1 see Tembo) 1620 Fair 1 Wheat (KS Mamba) 1260 (40 – 60 %) 1 next Wheat (Kenya Kongoni) 1580 1 Triticale (T65, T74, T62) 1500 2 page Beans (Rosecoco) 790 2 Beans (Red Haricot) 440 1 Sunflower (H 8998) 1460 1 Soyabeans (Gazelle) 870

Poor Maize (KH 500-44A) 2220 2 (20 – 40 %)

1) Only crops listed with total crop failures (TCF) generally less than 33 % (acc. to calculations with MARCROP model of HORNETZ, 2001; see Methodology Annex). 2) Well manured, fertilized and protected. Water loss as surface runoff is stopped by contour ridges. 3) Calculations see next Table.

NAKURU GROUP 22

TABLE 4: CONTINUATION

Middle rains to 2 nd rainy season Second rainy season (av. start August till November) (av. start mid of October till January)

Yield Total Estim. Total Potential Estim. crop average crop (in % Crop variety average failures Crop variety yield failures yield out 2) out of Opti- 2) (kg/ha) (kg/ha) of 10 of 10 mum) seasons seasons Very good (80 – 100 %) Good (60 – 80 %) Foxtail millet (ISe 285) 1280 1 Foxtail millet (ISe 285) 1310 1 Finger millet (Ekalakala) 1150 1 Fair Cowpeas (Kunde 1) 480 2 Sorghum (KARI Mtama 1) 1400 1 (40 – 60 %) Dolichos beans (Kat/DL-2) 1330 2 Cowpeas (Kunde 1) 540 1 Soyabeans (Gazelle) 620 2 Dolichos beans (Kat/DL-2) 1410 1

Wheat (KS Mamba) 740 3 Barley (Karne) 890 3 Wheat (Kenya Kongoni) 920 3 Barley (Tumaini) 880 3 Poor Triticale (T65, T74, T62) 880 3 Wheat (Africa Mayo) 640 3 (20 – 40 %) Finger millet (Ekalakala) 1070 2 Sunflower (H 8998) 750 3 Sorghum (KARI Mtama 1) 1300 2 Soyabeans (Gazelle) 480 2 Sunflower (H 8998) 980 3

LH 5 u r i Nr.: 9036034 Gilgil Railway Station 0° 30`S 36° 20`E 2006 m

Average rainfall per decade Reliable rainfall, surpassed in 10 out of 15 years Approx. pot. evapotranspiration of a permanent crop (sisal)

UM = UPPER MIDLAND ZONES UM 3 = M a r g i n a l C o f f e e Z o n e UM 3 = Marginal Coffee Zone vl/l with a very long to long cropping season or two dividable in two variable cropping seasons Small area, situated on upper altitude limit of coffee cultivation Good yield potential 1st rainy season, start norm. end of March: Late mat. maize (~60%), finger millet, m. mat. beans, lima beans; sweet potatoes, potatoes; late and m. mat. sunflower; cabbages, kales, egg plants 2nd rainy season, start indistinctly end of June: Beans, potatoes; onions (on light soils) Whole year: Citrus (on deep soils), castor, Macadamia nuts, guavas Fair yield potential 1st rainy season: Cold tolerant sorghum 2nd rainy season: Sweet potatoes Whole year, best planting time b. of April: Arabica coffee (on deep soils with good husbandry, esp. mulching, otherwise poor) Pasture and forage About 1.2 ha/LU on sec. highland savanna; about 0.8 ha/LU on art. pasture of Rhodes grass; feeding Bana and Napier grass, Lotononis and barrel medicago down to about 0.25 ha/LU; suitable for grade cattle, for grade dairy cows with mentioned add. forage (a. o., see Table XI.)

UM 4 = Maize-Sunflower Zone or Upper Sisal Zone UM 4 = Maize-Sunflower Zone l/vl with a long to very long cropping season, or two dividable in two variable cropping seasons Good yield potential 1st rainy season, start norm. end of March: Late mat. maize (~60%), m. mat. maize, cold tol. sorghum (70-80%, April - S.); late mat. sunflower (~60%); m. and late mat. beans 2nd rainy season, start indistinctly around end of June: E. mat. sunflower Whole year: Sisal, eucalyptus trees NAKURU GROUP 24

Station name Cereal and legumes growing period Dry conditions Precipitation is cumulated Gilgil, Railway Station = agro-humid period (AHP), during agro-humid period in mm Station no. Altitude AEZ min. 50 days Subzone: 9036034 2006m LH 5 = grass growing period only tr

First rainy season & middle rains: Av. mid of April - mid of Sep. Middle rains & second rainy season: Av. mid of Aug. - end of Dec. Years of usable records: 29 1) Years of usable records: 30 1)

Chances for the right growing periods: Medium mat. maize 9 gr. p. of at least 120 days = 31 % of all seasons M. mat. maize 5 gr. p. of at least 120 d. = 17 % of all seasons Early mat. sorghum 10 gr. p. of at least 110 days = 34 % of all seasons E. mat. sorghum 6 gr. p. of at least 110 d. = 20 % of all seasons Early mat. beans 12 gr. p. of at least 90 days = 41 % of the seasons E. mat. beans 9 gr. p. of at least 90 d. = 30 % of all seasons Very early mat. barley12 gr. p. of at least 80 days = 41 % of all seasons V. e. mat. barley10 gr. p. of at least 80 d. = 33 % of all seasons

Existential risks: No cereal growing period in a year or more: 6 times = 20 % of the years WATBAL run specifications by B. Hornetz 2) 2 or more consecutive rainy seasons without the min. AHP of 50 d.: 6 times in 30 years ISUM ESUM ELIM OLIM STOCK RE IR No grass growing period in a season: 3 times = 10 % of the seasons 1 2,4 2,4 0,4 1 320 0,9 25 � 1,5 1,2 0,2 1 320 0,9 15 rainfall scenario: DISCON

1) valid = no significant gaps in the records 2) AHP = Agro-humid period ~ growing period for cereals and legumes; GGP = grass growing period 3) Between these low percentages of good conditions and the total crop failures (Table 4) there is a certain support of growing, shown in the diagram as grass growing periods. NAKURU GROUP 25

Fair yield potential 1st rainy season: Finger millet (50-60%); pigeon peas (lower places, end of March - D.); potatoes, sweet potatoes; egg plants, cabbages, kales 2nd rainy season: E. mat. beans; potatoes, sweet potatoes, e. mat. sunflower, e. mat. soya beans, chick peas; onions Whole year: Pawpaws, mangoes Pasture and forage Around 1.5 ha/LU on undestroyed nat. pasture of highland savanna; about 1 ha/LU on art. pasture of Rhodes grass; down to about 0.35 ha/LU feeding Bana or Napier grass and barrel medicago, esp. for dairy cows; grazing area suited for grade cattle

UM 4 = Maize-Sunflower Zone or Upper Sisal Zone (l) or with a (weak) long cropping season, two dividable in two variable cropping seasons (See Diagram Nakuru) Almost the same potential as UM 4 l/vl less 10% yield expectation of maize and sunflower, 5% less of other crops. Stocking rates around 2 ha/LU

LH 4 (l) Nr.: 9036021 Nakuru 0° 17`S 36° 04`E 1836 m

Average rainfall per decade Reliable rainfall, surpassed in 10 out of 15 years Approx. pot. evapotranspiration of a permanent crop: sisal Approx. pot. evapotranspiration of late mat. maize 520 Rainfall per indicated growing period, surpassed in 10 out of 15 years

UM 4 = Maize-Sunflower Zone or Upper Sisal Zone (l/m) i with a (weak) long to medium cropping season and intermediate rains, or two dividable in two variable cropping seasons and i. r. Small, potential see Baringo group of districts. Here in large scale farms sisal more suited than there. Stocking rate >3 ha/LU NAKURU GROUP 26

UM 5 = Li v e s t o c k - S o r g h u m Z o n e U M 5 Livestock-Sorghum Zone ( m / l ) i with a (weak) medium to long cropping season and intermediate rains Very small, potential see Baringo group of districts UM 5 = Livestock-Sorghum Zone (s) i+(vu) with a (weak) short cropping season, intermediate rains, i and a (weak) very uncertain second rainy season No good yield potential except with add. irrigation (partly possible) Fair yield potential 1st rainy season, start norm. b. of April: Cold tolerant sorghum (April - Aug.) Whole year: Sisal, Marama beans Pasture and forage 2.5 - 4.5 ha/LU on short grass highland savanna, down to about 1.2 ha/LU on art. pasture of Rhodes grass with hedges of salt bushes (Atriplex nummularia) and Mesquite (Prosopis juliflora)

UM 5 = Livestock-Sorghum Zone (s/vs) with a (weak) short to very short cropping season +(vu) and a (weak) very uncertain second rainy season No good yield potential Fair yield potential 1st rainy season, start norm. mid April: Dwarf sorghum (40-50%) Whole year: Sisal (40-50%), Marama beans Pasture and forage More than 2.8 ha/LU on short grass highland savanna, less if near groundwater; art. pasture and forage almost as above

UM 5 = Livestock-Sorghum Zone (vs/s) with a (weak) very short to short cropping season +(vu) and a (weak) very uncertain second rainy season Nearly the same potential as above less 5% in yield expectations and about 10% in stocking rates

UM 6 = Up p e r Mi d l a n d R a n c h i n g Z o n e UM 6 = Upper Midland Ranching Zone u r i with unimodal rainfall and intermediate rains Rainfed agriculture uneconomical. With irrigation good potential for vegetables, flowers and grapes Pasture and forage More than 3.5 ha/LU on open short grass highland savanna; with palatable shrubs like salt bush higher capacity. Near Lake Naivasha supplementary irrigation easy, then cold tolerant sorghum and Columbus grass recommended

UM 6 = Upper Midland Ranching Zone b r with bimodal rainfall Here no relevant differences to UM 6 u r i; more than 4 ha/LU LM = LOWER MIDLAND ZONES LM 5 = Lower Midland Livestock-Millet Zone

LM 5 = Lower Midland Livestock-Millet Zone (vs ^ with a (weak) very short cropping season s/vs) i followed by a (weak) short to very short one and intermediate rains

Very small and unimportant, potential see Baringo District NAKURU GROUP 27

Station name Cereal and legumes growing period Dry conditions Precipitation is cumulated Naivasha WDD = agro-humid period (AHP), during agro-humid period in mm Station no. Altitude AEZ min. 40 days Subzone: 9036281 1936m UM 5 = grass growing period only (s/vs) i (vs)

First rainy season & middle rains: Av. end of March - begin of Sep. Second rainy season: Av. end of August - begin of December Years of usable records: 24 1) Years of usable records: 22 1)

Chances for the right growing periods: M. mat. maize 4 gr. p. of at least 120 days = 17 % of the seasons M. mat. maize 4 gr. p. of at least 120 days = 18 % of all seasons E. mat. sorghum 9 gr. p. of at least 100 days = 38 % of all seasons 3) E. mat. sorghum 6 gr. p. of at least 110 days = 28 % of all seasons E. mat. beans 10 gr. p. of at least 90 days = 42 % of all seasons E. mat. beans 7 gr. p. of at least 90 days = 32 % of all seasons V.e.mat. wheat 13 gr. p. of at least 80 days = 54 % of all seasons V.e.mat. wheat 7 gr. p. of at least 80 days = 32 % of all seasons

Existential risks: No cereal growing period in a year or more: once = 4 % of the years WATBAL run specifications by B. Hornetz 2) 2 or more consecutive rainy seasons without the min. AHP of 50 d.: once in 24 years ISUM ESUM ELIM OLIM STOCK RE IR No grass growing period in a season: once = 4 % of the seasons 1 2,4 2,4 0,4 1 320 0,9 25 No grass growing period in a year or more: never = 0 % of the years � 1,5 1,2 0,2 1 320 0,9 15 rainfall scenario: DISCON

1) valid = no significant gaps in the records 2) AHP = Agro-humid period ~ growing period for cereals and legumes; GGP = grass growing period 3) Plus 4 AHP's with interruptions which can be survived by dormancy it coms to 54 %. > means: AHP is continuing although rainfall records are not complete towards the end of the season. NAKURU GROUP 28

Station name Cereal and legumes growing period Dry conditions Precipitation is cumulated Naivasha D.O. = agro-humid period (AHP), during agro-humid period in mm Station no. Altitude AEZ min. 40 days Subzone: 9036002 1900m UM 5 = grass growing period only (s/vs) + vu

Year Year Rainfall / c.& leg. gr.p. January February March April May June July August September October November December 1st AHP 2nd AHP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 mm days mm days 1930 30/31 1931 31/32 1932 32/33 1933 33/34 1934 34/35 1935 00 0 00000g 36 108 136 162 175 183 234 284 314 314 314 00000000gggggggg 35/36 314 110 -- 1936 gg g gg129 28 45 72 184 222 238 254 263 270 ggggggggggggggggggggg 36/37 270 90 -- 1937 00 0 0000g 51 160 183 213 222 356 356 445 467 518 531 614 630 30 31 37 0000gggggggg 37/38 667 160 -- 1938 gg g 0000033 49 68 108 135 137 151 161 gggg00ggggggggggggg0 38/39 161 80 -- 1939 00 0 000000gggg0000000gggggggg00000000 39/40 - - - - 1940 00 0 gg39 37 56 94 127 225 330 386 391 398 g 00000000000000000000 40/41 398 90 -- 1941 00 0 000gggg43 72 120 178 249 258 262 gg00000000000gggggg 41/42 262 70 -- 1942 gg g 000gg34 48 92 141 142 199 200 213 244 247 g 000gggg0000000000 42/43 247 100 -- 1943 00 0 0000000048 98 127 131 135 170 172 173 221 235 23 26 53 74 106 128 133 138 0000000 43/44 235 100 138 80 1944 00 0 00000ggggggggg28 33 77 77 32 42 45 ggggg62 72 87 155 191 191 191 44/45 122 70 191 70 1945 00 0 0000000gg52 56 93 115 136 155 164 170 g 46 74 79 156 159 191 195 208 gggggg0 45/46 170 80 208 80 1946 00 0 00000778 781 846 876 907 966 976 997 1006 1010 g 0035 47 54 107 128 134 154 174 226 269 275 291 310 gg 46/47 1010 100 310 130 1947 gg g ggg70 71 120 127 212 320 371 430 444 455 456 g 37 77 81 5 gggggggggggggg 47/48 456 90 -- 1948 00 0 0000000054 80 91 101 116 133 gg00ggg55 63 91 97 122 142 165 188 193 ggg 48/49 133 60 193 90 1949 00 0 000000030 117 122 125 205 226 226 246 246 ggggg000000000000 49/50 246 90 -- 1950 00 0 000ggg33 105 107 116 127 138 143 158 168 187 197 ggg39 39 136 147 163 164 gggg000 50/51 197 110 164 60 1951 00 0 000029 93 152 262 363 363 374 440 458 458 g 0 ggggggggggggggggg 51/52 458 100 -- 1952 gg 0 000000gg86 160 193 205 206 g 000000 0gggggggggg0 52/53 206 50 -- 1953 00 0 00000040 54 113 231 231 238 ggggg00gggggg40 70 109 126 143 149 g 0 53/54 238 60 149 60 1954 00 0 00000046 125 149 199 260 309 356 376 385 385 0 gggggggggggggggg 54/55 385 100 -- 1955 00 g ggggggg42 131 152 155 159 ggg 28 54 19 73 83 107 119 143 178 203 220 239 247 gggg 55/56 159 70 247 110 1956 gg g gggggggg0000000000000000000000000 56/57 - - - - 1957 57/58 1958 58/59 1959 000 0000g 35 65 73 86 113 113 ggggggg 59/60 113 60 1960 gg g ggg35 94 140 171 198 246 259 259 286 286 g 000050 50 90 106 106 146 155 160 ggggggg 60/61 286 100 160 80 1961 gg 0 00050 66 97 183 194 227 232 235 00000gggggg30 88 146 339 422 422 462 540 61/62 235 80 634 110 1962 629 634 634 gggggg 000 0ggggggggggg 62/63 -- 1963 gg g ggggggg62 212 226 253 344 383 383 383 000000000000028 73 152 185 226 63/64 383 80 235 70 1964 234 235 0 0033 52 61 106 168 211 272 272 283 ggggggggg000gggggggggg 64/65 283 80 -- 1965 gg g gg00000g 90 121 141 146 146 0 ggggggggggggggggggg 65/66 146 50 -- 1966 gg 0 000038 69 81 147 275 289 290 gggg0000066 124 124 154 161 172 205 261 291 318 322 323 0 66/67 290 70 323 120 1967 00 0 00000gg41 92 177 206 211 233 250 257 260 326 341 3 51 52 54 0 30 38 72 129 137 154 186 207 gg 67/68 396 150 207 80 1968 000053 110 43 80 86 168 199 337 344 346 00000000000ggggg48 54 84 131 138 140 68/69 346 80 140 60 1969 00 0 0000ggggg88 98 127 135 147 ggg00000000000ggggg 69/70 147 50 -- 1970 gg g ggggg93 166 170 193 199 249 285 296 331 333 359 359 gggg41 50 83 103 110 113 139 152 gg00 70/71 359 120 152 80 1971 00 0 000000028 60 85 222 234 242 g 0031 32 41 46 113 117 129 135 159 234 272 273 280 305 307 334 354 71/72 242 80 354 150 1972 gg 0 gggg000000gg29 80 92 94 ggggggggg53 85 114 137 149 156 g 0 72/73 94 40 156 60 1973 0000gggg0086 127 178 185 211 238 240 245 0000000ggggggggggg 73/74 245 80 -- 1974 gg 0 00000g 94 212 223 237 251 290 291 320 365 403 411 435 1 4 45 76 78 91 ggggggggg 74/75 435 120 91 60 1975 g 0 0 0000ggg58 115 126 157 170 171 gggg49 24 48 51 76 82 112 156 169 194 194 gggg0 75/76 171 60 194 100 1976 00 0 0000000gggg34 44 54 102 137 148 151 gg38 60 85 85 88 00000000 76/77 151 70 88 50 1977 00 0 000000105 151 205 316 335 336 339 gggggggggggg30 77 111 168 186 203 229 259 77/78 339 70 340 120 1978 260 333 335 340 g 34 21 95 222 261 278 348 406 421 421 g 00000gg32 50 81 111 124 129 156 171 186 gg58 93 78/79 421 90 186 90 1979 99 119 171 274 290 292 g 49 58 104 120 129 ggggggggggggg00000 79/80 (129) (50) -- 1980 00 0 000 67 110 126 194 233 279 297 308 347 349 349 0000000000ggggg0 80/81 (349) (110) -- 1981 00 0 000030 176 201 304 318 352 379 384 384 0 ggggggggggggggggggg 81/82 384 90 -- 1982 gg g ggg000g 43 99 114 131 210 210 225 231 g 000037 64 75 83 84 129 176 221 259 346 390 407 411 82/83 231 80 411 130 1983 gg g ggg0000067 103 105 105 0 41 100 100 116 139 g 1 46 78 78 105 140 151 197 211 250 256 261 00 83/84 139 50 261 120 1984 00 0 0000000gggg00000ggggggg0000043 85 166 187 187 84/85 - - 187 50 1985 g 0 g ggg0062 115 185 209 231 286 294 294 317 317 317 344 346 000000000000000 85/86 346 130 -- 1986 0 g g gggggg33 43 161 183 183 192 207 224 229 g 0000ggggggggggggg 86/87 229 90 -- 1987 g 0 0 0000gggggg40 112 243 243 270 294 297 324 gggg0000ggggg00 87/88 324 80 -- 1988 00 0 000ggg 0000000gggggggggg0000000 88/89 -- 1989 00 0 0000gg41 51 88 144 179 186 215 224 224 0 g 37 76 84 93 135 139 169 00g 89/90 224 (90) (169) (70) 1990 gg g 0052 31 71 89 236 266 274 000000gggg00053 76 116 135 139 90/91 274 (60) (139) (50) no AH cd. 49 49 50 50 50 45 45 41 35 23 14 9 8 7 9 16 23 28 34 36 40 41 41 33 35 36 35 36 32 36 35 34 37 38 42 43 Median rain- 246 88 AHP cd. 4 4 3 2 2 7 8 12 18 28 37 42 42 43 41 36 29 24 18 17 13 12 12 19 19 18 19 18 22 18 18 19 16 14 10 9 fall in AHPs #### 5954 %AHP/val.y. 8% 8% 6% 4% 4% 13% 15% 23% 34% 55% 73% 82% 84% 86% 82% 69% 56% 46% 35% 32% 25% 23% 23% 37% 35% 33% 35% 33% 41% 33% 34% 36% 30% 27% 19% 17% 66% reliab. of 224 - median AHP rainf. in AHPs 60%-reliable 80 - Martin Mueller 2010 length of AHP 4 4 26 26

First rainy season: Av. mid of April - July Middle rains & second rainy season: Av. end of Aug. - begin of Dec Years of usable records: 51 1) Years of usable records: 54 1)

Chances for the right growing periods: M. mat. maize 5 gr. p. of at least 120 days = 10 % of the seasons M. mat. maize 6 gr. p. of at least 120 days = 11 % of all seasons E. mat. sorghum 14 gr. p. of at least 100 days = 28 % of all seasons E. mat. sorghum 9 gr. p. of at least 100 days = 17 % of all seasons E. mat. beans 22 gr. p. of at least 90 days = 43 % of all seasons E. mat. beans 11 gr. p. of at least 90 days = 20 % of all seasons V.e.mat. barley 33 gr. p. of at least 80 days = 65 % of all seasons V.e.mat. barley 16 gr. p. of at least 80 days = 30 % of all seasons

Existential risks: No cereal growing period in a year or more: 3 times = 5,4 % of the years WATBAL run specifications by B. Hornetz 2) 2 or more consecutive rainy seasons without the min. AHP of 50 d.: 3 times in 54 years ISUM ESUM ELIM OLIM STOCK RE IR No grass growing period in a season: 3 times = 2,7 % of the seasons 1 2,4 2,4 0,4 1 180 0,9 25 No grass growing period in a year or more: never = 0 % of the years � 1,5 1,2 0,2 1 180 0,9 15 rainfall scenario: DISCON

1) valid = no significant gaps in the records 2) AHP = Agro-humid period ~ growing period for cereals and legumes; GGP = grass growing period ( ) figures in brackets means: no data at the beginning or end of the rainy season NAKURU GROUP 29

TABLE 5: CLIMATIC YIELD POTENTIALS OF SELECTED ANNUAL CROPS 1) in UM 5 (s/vs) + vu (calc. for station 9036002 Naivasha D.O. with locally dominating ando-luvic Phaeozems)

First rainy season Middle rains and (av. start mid of April till July) Second rainy season 3)

Total Total Yield Estim. crop Estim. crop Potential average failures average failures (in % Crop variety yield out Crop variety yield out of Opti- 2) 2) (kg/ha) of 10 (kg/ha) of 10 mum) seasons seasons Very good (80 – 100 %) Foxtail millet (ISe 285) 2190 0 Finger millet (Ekalakala) 1970 0 Good Sorghum (KARI Mtama 1) 2390 0 (60 – 80 %) Cowpeas (Kunde 1) 820 0 Dolichos beans (Kat/DL-2) 2190 0 Soyabeans (Gazelle) 980 0 Barley (Bima) 1440 0 Barley (Karne) 2110 0 Barley (Tumaini) 1940 0 Wheat (Africa Mayo) 1500 0 Wheat (Ngiri, Kenya see Fair Tembo) 1850 0 (40 – 60 %) Wheat (KS Mamba) 1440 0 next Wheat (Kenya Kongoni) 1800 0 Triticale (T65, T74, T62) 1710 0 page Beans (Rosecoco) 910 1 Beans (Red Haricot) 510 1 Sunflower (H 8998) 1600 0 Poor Maize (KH-500-44A) 2510 2 (20 – 40 %)

TABLE 5: CONTINUATION

Middle rains to 2nd rainy season Second rainy season (av. start August till November) (av. start mid of October till January)

Total Total Yield Estim. crop Estim. crop Potential average failures average failures (in % Crop variety yield out Crop variety yield out of Opti- 2) 2) (kg/ha) of 10 (kg/ha) of 10 mum) seasons seasons Very good (80 – 100 %) Good Foxtail millet (ISe 285) 1830 0 (60 – 80 %) Finger millet (Ekalakala) 1320 0 Foxtail millet (ISe 285) 1260 0 Sorghum (KARI Mtama 1) 1610 0 Cowpeas (Kunde 1) 500 2 Fair Cowpeas (Kunde 1) 500 1 Dolichos beans (Kat/DL-2) 1410 1 (40 – 60 %) Dolichos beans (Kat/DL-2) 1440 0 Finger millet (Ekalakala) 1120 1 Soyabeans (Gazelle) 660 1 Sorghum (KARI Mtama 1) 1360 1

Maize (KH 500-44A) 1890 3 910 3 Barley (Bima) 920 3 Barley (Karne) 840 3 Barley (Karne) 1140 3 Barley (Tumaini) 650 3 Barley (Tumaini) 1000 3 Wheat (Africa Mayo) Wheat (Africa Mayo) 810 3 Wheat (Ngiri, Kenya Tembo) Poor 780 3 Wheat (Ngiri, Kenya Wheat (KS Mamba) (20 – 40 %) 610 3 Tembo) 1090 3 Wheat (Kenya Kongoni) 760 3 Wheat (KS Mamba) 850 3 Triticale (T65, T74, T62) 720 3 Wheat (Kenya Kongoni) 1060 3 Sunflower (H 8998) 750 3 Triticale (T65, T74, T62) 1010 3 Soyabeans (Gazelle) 480 3 Sunflower (H 8998) 1070 3

SOIL DISTRIBUTION, FERTILITY AND MAJOR CHARACTERISTICS

Nakuru District is part of the central Rift Valley and includes several lake Nakuru, Elmenteita and Naivasha. In addition, three extinct volcanoes rise above the volcanic plains and uplands, i.e. Menengai, Longonot and Suswa. East and west of the plains, escarpments mark the transition to higher plains and footridges. The Mau escarpment is the most imposing scarp. The underlying rock is volcanic but varies according to its age. In some areas, there are geysers where hydrothermal energy may be developed for generation of electricity (Hells Gate in the Naivasha area). On the volcanoes, soils of units MP1, PvP1 and Lava occur, lava fields may be included. Smaller areas are occupied by soils of units MV4, MV2 and MV5 with inclusions of lava vents and have moderate to high fertility (apart of the rocky land). A variety of soils occur on the hills and minor scarps. The most extensive areas are those of unit HV1. In addition, unit HPC with a humic topsoil occurs. Associated with the escarpment are a number of plateaus on either side of the Rift Valley. Unit LP1, of high fertility, occurs frequently. Unit LuP1, of high fertility too, is found in large areas, and also unit LsB1 of moderate to high or variable fertility. Northeast of Nakuru, unit LPC with a very thick humic topsoil occurs. Some of the higher ground in the Rift Valley has been described as uplands. In the Molo area, the northeast and west of Nakuru, units UP2, LvP1, PvP2, PvP3 and RPA of high fertility are common. Uni UV2 of variable fertility is associated with the hills. Smaller areas are composed of soils of units UBP1 with a humic topsoil and BP1 of low to moderate fertility. Lacustrine plains are common around the lakes. Here, the soils of unit P1U1 have a low fertility. Associated with this unit are soils of unit P1PC, of moderate to high fertility. They may have a humic topsoil. Smaller areas of the volcanic plains, south of Longonot and Suswa are composed of unit PvP4. Bottomlands occur within some of the plateaus, e.g. unit BP1 of low to moderate fertility. In the extreme north of Nakuru District, some areas with unit BV1 of moderate to high fertility are found.

LEGEND TO THE SOIL MAP OF NAKURU GROUP OF DISTRICTS

1 Explanation of first character physiography( )

M Mountains and Major Scarps H Hills and Minor Scarps L Plateaus and high-level Structural Plains Ls Step-faulted floor of the Rift Valley Lu Plateau/Upland Transitions R Volcanic Footridges U Uplands, Upper, Middle and Lower Levels Pv Volcanic Plains PI Lacustrine Plains B Bottomlands

2 Explanation of second character (lithology): Plant nutrients in parent material: B Basic and Ultra-basic Igneous Rocks (basalts, nepheline phonolites; older basic tuffs included) very many to many BP - do - with influence of volcanic ash predominant very many P Pyroclastic rocks many (to few) U Undifferentiated Basement System Rocks (predominantly Gneisses) few (to many) V Undifferentiated or Various igneous rocks many V+ -do - with volcanic ash admixture many NAKURU GROUP 33

3 Soil descriptions

MP1 Somewhat excessively drained, shallow to moderately deep, brown to dark brown, firm and slightly smeary, strongly calcareous, stony to gravelly clay loam; in many places saline and/or sodic and with inclusions of lava fields: ando-calcaric REGOSOLS, partly lithic phase

MV2 Well drained, very deep, dark reddish brown to dark brown, very friable and smeary, clay loam to clay, with a thick acid humic topsoil; in places shallow to moderately deep and rocky: humic ANDOSOLS, partly lithic phase

MV5 Well drained, shallow to moderately deep, dark reddish brown to dark brown, friable, rocky and bouldery, clay loam to clay; in places with a humic topsoil: nito-chromic CAMBISOLS; with haplic PHAEOZEMS, lithic phase, LITHOSOLS, eutric REGOSOLS and Rock Outcrops

HPC Complex of: well drained, deep to very deep, dark brown to greyish brown, friable and smeary clay loam, with a thick humic topsoil: mollic ANDOSOLS and: somewhat excessively drained, shallow, dark brown to brown, friable and slightly smeary, rocky and stony, clay loam: ando-eutric CAMBISOLS, lithic and stony phase; with Rock Outcrops

HV1 Well drained, shallow, dark reddish brown, friable, strongly calcareous, bouldery or stony, loam to clay loam; in many places saline: LITHOSOLS; with calcic XEROSOLS, lithic, bouldery and saline phase and Rock Outcrops

HVC Complex of: well drained to moderately well drained, shallow to moderately deep, dark brown, firm, stony, clay loam to clay; in places with a humic topsoil: eutric REGOSOLS, partly lithic phase; with verto-luvic PHAEOZEMS, partly lithic phase

LPl Well drained, moderately deep to very deep, dark brown, friable and slightly smeary, clay loam to clay, with a humic topsoil: ando-luvic PHAEOZEMS

LP2 Imperfectly drained, deep, very dark greyish brown, mottled, firm clay, abruptly underlying a thick topsoil of friable silty clay loam: dystric and eutric PLANOSOLS

LPC Complex of: well drained, deep to very deep, very dark greyish brown to dark brown, friable and slightly smeary, clay loam, with a humic topsoil: ando-luvic PHAEOZEMS and: imperfectly drained, deep, very dark greyish brown to black, firm, moderately calcareous, cracking clay, with a humic topsoil: verto-luvic PHAEOZEMS NAKURU GROUP 34

LsB1 Well drained, moderately deep, dark reddish brown to reddish brown, friable to firm and slightly smeary, bouldery and stony, clay loam to clay; in places calcareous: ando-chromic CAMBISOLS, bouldery phase; with calcic XEROSOLS

LuP1 Well drained, deep to very deep, dark brown, friable and smeary, sandy clay to clay, with an acid humic topsoil: humic ANDOSOLS

LuP2 Well drained, deep to very deep, very dark greyish brown, friable and smeary, clay loam, with a thick humic topsoil: mollic ANDOSOLS

RB3 Well drained, extremely deep, dusky red to dark reddish brown, friable clay; with inclusions of well drained, moderately deep, dark red to dark reddish brown, friable clay over rock, pisoferric or petroferric material: eutric NITISOLS; with nito-chromic CAMBISOLS and chromic ACRISOLS, partly lithic, pisoferric or petroferric phase

RBA Association of: well drained, extremely deep, dark reddish brown, friable and in places slightly smeary clay, with an acid humic topsoil; on interfluves: humic to ando-humic NITISOLS and: well drained, shallow to moderately deep, dark reddish brown to dark brown, friable, clay loam to clay, with an acid humic topsoil; on valley sides: humic CAMBISOLS, partly lithic phase

RPA Association of: well drained, very deep, dark reddish brown, very friable and smeary, sandy clay loam to clay, with a thick humic topsoil; on interfluves : mollic ANDOSOLS and: well drained, shallow to moderately deep, dark brown to dark reddish brown, very friable and slightly smeary, clay loam to clay; on valley sides: ando-eutric CAMBISOLS, partly lithic phase

UB1 Well drained, extremely deep, dark reddish brown, friable clay; in places deep to very deep: eutric NITISOLS; with nito-chromic LUVISOLS

UBP1 Well drained, deep to very deep, dark reddish brown to dark red, firm clay; with inclusions of imperfectly drained, moderately deep, dark greyish brown clay: nito-ferric/chromic LUVISOLS; with gleyic LUVISOLS

UP2 Well drained, deep to very deep, dark reddish brown, friable and smeary, silty clay to clay, with a humic topsoil: mollic ANDOSOLS

UV1 Well drained, very deep, dark reddish brown to very dark greyish brown, friable and slightly smeary clay, with a humic topsoil: ando-luvic PHAEOZEMS NAKURU GROUP 35

UV2 Well drained, shallow, dark brown, friable, strongly calcareous, strongly saline and moderately sodic, stony loam; with a stone surface: calcaric REGOSOLS, stone-mantle and saline-sodic phase

UV+1 Moderately well drained, moderately deep, reddish brown to red, firm clay loam, with a humic topsoil: ando-luvic PHAEOZEMS

PvP1 Excessively drained to well drained, very deep, dark greyish brown to olive grey, stratified, calcareous, loose fine sand to very friable sandy loam or silt: ando-calcaric REGOSOLS

PvP2 Well drained, moderately deep to deep, brown to dark brown, very friable, loam to sandy clay loam: vitric ANDOSOLS

PvP3 Well drained, deep to very deep, daTk reddish brown to dark brown, friable, slightly gravelly loam to clay loam, with a humic topsoil: mollic ANDOSOLS

PvP4 Imperfectly drained, very deep, yellowish brown to olive grey, friable, slightly saline, slightly sodic, sandy loam to silt loam, with a brittle and strongly sodic deeper subsoil: gleyic SOLONETZ, saline and fragipan phase

PlPC Complex of: well drained, moderately deep to deep, dark brown, friable and slightly smeary, fine gravelly, sandy clay loam to sandy clay, with a humic topsoil: ando-haplic PHAEOZEMS and: imperfectly drained, moderately deep to deep, strong brown, mottled, firm and brittle, sandy clay to clay: gleyic CAMBISOLS, fragipan phase

PlU1 Imperfectly drained to poorly drained, very deep, dark greyish brown to dark brown, firm to very firm, slightly to moderately calcareous, slightly to moderately saline, moderately to strongly sodic, silt loam to clay; in many places with a humic topsoil: undifferentiated SOLONETZ, saline phase

BP1 Imperfectly drained to poorly drained, moderately deep, dark greyish brown, mottled, very firm, clay loam, abruptly underlying a topsoil of acid humic friable loam: humic PLANOSOLS

BV1 Imperfectly drained, deep, dark brown to olive grey, firm to very firm, clay soils of varying calcareousness, salinity and sodicity; in many places cracking: VERTISOLS and SOLONCHAKS, undifferentiated

Lava Excessively drained, exceedingly bouldery to stony, extremely rocky land: Boulders and Rock Outcrops NAKURU GROUP 36

NOTES for definitions (of underlined words) 1 mollic Nitisols and chromo-luvic Phaeozems: soils are equally important 2 mollic Nitisols, with chromo-luvic Phaeozems: Nitisols are prevalent 3 in places: in <30% of the area 4 in many places: in 30-50% of the area 5 predominantly: in >50% of the area 6 deeper subsoil: below 80 cm. NAKURU GROUP 37

3.2.4 FARM SURVEY IN NAKURU GROUP OF DISTRICTS

The Farm Survey (FS) of 2004 was carried out in four AEZs, covering UH 2, LH 2, LH 3 and UM 4 (Table 27). The data collected during the 2004 FS were on various agricultural aspects presented in Tables 28a-d, while cropping patterns results are presented in Tables 29a-d. Key results from the 2004 FS are as follows: The average total land size in Nakuru group of districts across the sample sites is low (1.73, 0.93, 1.89 ha). This is with the exception of UM 4 (Lengenet) which has an average of 3.0 ha per household in the sample, the whole location had 1.07 ha only per household (including non-farmers). The reduced land size could be attributed to increased population which has encouraged land subdivision. Nakuru group of districts, being a high potential area may have attracted migrants from surrounding more densely populated areas. Land is predominantly allocated to annual crops, pasture & fodder; less land is allocated for permanent crops in all the AEZs. For instance, in LH 2 and UM 4, only 0.04ha and 0.06 are allocated to permanent crops (fruits). In UH 2 and LH 3 it was more due to pyrethrum (today less). In UM 4, the average land allocated to permanent pasture and fodder is 1.49ha, the highest in all the AEZs. LH 2 has the lowest land size average for annual crops at 0.58ha per farm due to dense population. The main food crops grown in most of the AEZs are maize, beans, Irish potatoes, tomatoes and vegetables. Collard (Brassica oleracea var. sabellica) and peas were particular in UH 2, while finger millet and sorghum in UM 4. Maize and beans, cultivated both as cash and food crops, are the main crops as illustrated by the size of land on which they are cultivated. Annual and bi-annual crops are mainly cultivated during the first and middle rains. However, crops such as Irish potatoes, tomatoes, and kales are also grown during the 2nd rainy season on a reduced acreage in UH 2, LH 2 and LH 3. Pyrethrum was the main cash crop in UH 2 and LH 3 (up to 2005, before the burning of the factory) and fruits (avocados, oranges, bananas & mangoes) are the main perennial crops cultivated in Nakuru. These perennial crops were only reported in LH 2 and UM 4. Analysis of cultivated land shows that the first and middle rains are the most dependent ones for farming when compared with the second rainy season. There is more land under annual and semi-permanent crops in LH 3 (44.93ha per 30 farms) and UM 4 (37.62ha) than in UH 2 (18.83ha) and LH 2 (26.04ha). Dairy and goat/sheep farming is common in all the AEZs in Nakuru. UM 4 and UH 2 have the highest averages for dairy animals (4.6 resp. 3.7). Farmers in Nakuru seem to have embraced dairy farming and discarded the less profitable zebu since the later were reported in AEZ UM 4 only. This is backed up by high percentage of farmers keeping improved cattle. The average sheep/goat number per household is 5 in all the AEZs except in LH 2 which has an average of 3.7 sheep/goats. The stocking rate as number of livestock kept per ha in all the four sites is proportional to the land available for farming. Thus, dairy TLU/ha values range between 4.0 (UM 4) and 11.1 (LH 2). TLU/ha values for sheep/goat are between 0.54 (UM 4) and 2.75 (UH 2); it seems low but they are calculated additionally to cattle. Small farmers in Nakuru group of districts apply chemical fertilizer and use manure to improve soil quality. Whereas topdressing (of phosphates) is practiced in all the AEZs, use of nitrogen during planting is only reported in LH 2, and insecticides are used in UH 2 only. There is need for farmers to scale-up use of manure as a sustainable method of improving soil quality and reduce cost of production associated with purchase of chemical fertilizers. Whereas the majority of farmers in UM 4 and LH 2 use improved seed cultivars, more efforts need to be directed in AEZs UH 2 and LH 3, where less than half of the respondents do not use improved seeds.

Sustainable agriculture offers solutions to some of these aforementioned problems observed in Nakuru group of districts: These can be summarized as follows: • Improved soil fertility: Conventional farming methods rely on artificial fertilizers to maintain fertility. Sustainable agriculture uses a range of techniques to maintain and improve soil fertility: organic fertilizers, mulching, cover crops, agro-forestry, crop rotation and multiple cropping. Farmers in the Nakuru group, especially in AEZs UH 2, should be encouraged to intercrop maize and beans as this has the potential to optimize yield and improve soil fertility. • Better pest control: Conventional farming uses chemical pesticides to control pests. These are expensive and often result in the emergence of new pests or the resurgence of the very pests they are trying to control. Although use of insecticides was only reported in UH 2, farmers should be encouraged to adopt integrated pest management approaches: a combination of natural enemies, crop rotations and mixtures and biological NAKURU GROUP 38 control methods. These methods cost less than the pesticides, and do not result in pest resurgence. • Controlling erosion: Sustainable agriculture includes a plethora of techniques to conserve precious topsoil and prevent it from being washed or blown away (in particular Andosols). These include using contour bunds, contour planting, check-dams, gully plugs, and maintaining cover crops or mulch to protect the soil from heavy rainfall. • Water conservation: Water is scarce in much of Kenya, and drought is never far away. Sustainable agriculture conserves water in the soil through a variety of methods. Fortunately, many of these are the same as those used to control soil erosion. Because it conserves water and uses a variety of crops instead of just one, sustainable agriculture is less risky than conventional mono cropping: it is more likely to produce food for the farm family even during a drought. Although Nakuru group of districts is broadly a high potential area, farmers in UM 4 should be encouraged to cultivate drought resistant crops which optimize rain water. In addition, rain water harvesting techniques should be promoted to enable farmers cope with un reliable rainfall. • Reliance on local inputs: Farmers often do not realize the value of the inputs they have immediately to hand. They include manure from their animals (which very often is wasted in conventional systems), vegetation from roadsides and the field boundaries (used as mulch or to make compost), and local varieties of crops (many of which are ideally adapted to local conditions but which have been half-forgotten in the rush to adopt modern varieties). Farmers need to be encouraged to use these local inputs as this will not only reduce the cost of production but also reduce the negative effects of artificial inputs on the environment. • Indigenous knowledge: An important local input is the people’s own knowledge. Local people are experts on the plants, animals, soils and ecosystems they are surrounded by and on which they depend. Sustainable agriculture draws on this wealth of knowledge, and encourages local people to use it, test it, and promote what works best. • Local organizations and initiative: Equally important are the energy and capacity of local people to organize and cooperate to solve their own problems. Unlike conventional extension agencies, organizations that promote sustainable agriculture spend at least as much time in helping farmers organize as they do in teaching farming technologies. Ironically, many sustainable agriculture approaches are very similar to the techniques traditionally used by farmers before the advent of “modern” farming. That does not mean, though, that sustainable agriculture turns its back on modern inputs or ideas. Many types of sustainable agriculture use modern high-yielding crop varieties and artificial fertilizers wherever appropriate.

TABLE 27: FARM SURVEY SITES (Representative of the Dominating Agro-Ecological Zones, Subzones and Units)

Agro-Ecological Unit District No. in Farm Survey Sites 2004 Kenya AEZone Subzone Soil Unit vl i or Kuresoi Division, Tulwet Location, Soliat 103 UH 2 two LuP 1 Sublocation vl/l or Njoro Division, Njoro Location, Njoro 104 LH 2 two UP 2 Sublocation Nakuru Naivasha Division, Naivasha East Location, 105 LH 3 (l/vl) LP 1 Mununga Sublocation (l) or Rongai Division, Lengenet Location, 106 UM 4 two PvP 2 Lengenet Sublocation

Tables 28 a - d ASSETS, LAND USE, FARMING INTENSITY AND INPUTS see main Volume Southern Rift Valley Province Tables 29 a - d: CROPPING PATTERN see main Volume Southern Rift Valley Province NAKURU GROUP 39 NAKURU GROUP 40

3.2.5 INTRODUCTION TO THE ACTUAL LAND USE SYSTEMS AND POTENTIAL INTENSIFICATION BY BETTER FARM MANAGEMENT IN TYPICAL AGRO- ECOLOGICAL SUBZONES

In order to realize the main task of the farm management, a question targeting specifically the inputs used by farmers and resultant increase in yields was included in the Small Farm Survey questionnaire that was conducted. In each survey area the purposively sampled 30 farmers were divided into 3 groups: one group applying low inputs, a second one medium inputs, and a third one high inputs. The difference between these groups shows the amount of yields that can be realistically achieved by the farmers practicing better farm management. The column with the yield potential finally shows figures under optimal soil conditions, water supply, crop husbandry and pest control, which is the ultimate goal of any farmer.

More detailed information can be found together with calculations of profitability in the Farm Management Guidelines of each district. But the tables found there are not yet correlated with the relevant and most suited Agro-Ecological Units, which are necessary for the calculation of expected yields and the amount of inputs. Hopefully this will be done in future, made possible by the information of this handbook. The amount of fertiliser per soil unit is described in MURIUKI & QURESHI: Fertiliser Use Manual, KARI 2001. For more details, see Chapter 3.2.6.

In terms of aerial expanse, the dominant Zones in which field data were collected from in the Nakuru Group of Districts are: UH 2, LH 2, LH 3 and UM 4. An additional important reference material is “Small Holder Farming Handbook for Self-employment”. First published in 1997 by Information Research and Communication Centre (IRACC) & Marketing Support Services Ltd, Nairobi.

The picture given by the tables is a bit too positive if we compare it with the chapter Agricultural Statistics. The farmers selected are good ones and some high figures reflect some hopes. NAKURU GROUP 41

Subzone UH 2 vl i or two of the Wheat-Pyrethrum Zone

This is the Pyrethrum-Wheat Zone with a very long cropping season and intermediate rains separable into two variable cropping seasons as typified by Kuresoi Division, Tulwet Location, Soliat Sub-location. The predominant soil type in this subzone is the well drained, deep to very deep, dark brown, friable and smeary, sandy clay, with an acidic humic topsoil: humic ANDOSOLS. The annual average rainfall is 1100-1400 mm. The first rainy season can expect more than 500 – 800 mm in 10 out of 15 seasons; the middle rains and second rainy season > 200 – 300 mm. The 60% reliability of the growing periods during the st1 and 2nd seasons is more than 200 and 70 – 100 days, respectively.

This Subzone is in the still frost-free lower parts of Zone UH 2 and well suited for the production of a variety of crops. During the first rainy season and the middle rains until the 2nd rainy season, the following food crops are grown in order of importance: maize, Irish potatoes and collards. Pyrethrum is the main cash crop grown but declining. In the second rainy season, the crop mix in order of importance comprises of: Irish potatoes, peas, cabbages and collards (see Table 29a). These crops could as well fall under the category of high value crops for farmers since most of them are sold in outside markets as far as the capital city Nairobi. There were no perennial crops reported being grown by farmers in this subzone.

It is encouraging to note that most farmers in this Subzone reported using P2O5 nutrient-based fertilisers to improve the soil fertility and hence crop production. It is surprising that no farmer reported applying N-based fertiliser as a soil replenishment strategy in this Subzone (see Table 28a). Nitrogen is among the major nutrients essential for plant growth. It is a vital constituent of protein and protoplasm and therefore necessary for biomass increase and reproduction in plants. The characteristic symptom of N deficiency is chlorosis of the lower leaves. The data shown in Table 30 are responses from farmers operating at three different production levels in their farming enterprise. The essence of these data is to demonstrate the incremental increase in yield that is expected should farmers optimize their use of fertiliser or manure application under the humic ANDOSOLS dominant soil type. NAKURU GROUP 42

TABLE 30: INCREASE OF YIELDS BY BETTER FARM MANAGEMENT IN AGRO- ECOLOGICAL UNIT1) UH 2 vl i or two, LuP 1

Subzone: vl i or two, lower part; Soil Unit: LuP 1 Survey Area 103 (Soliat) AEZ: UH 2 WHEAT-PYRETHRUM ZONE Subzone: (Periods in days2): 1st rainy season 200 or more, 2nd rainy season >90 days) Crop, Yields3) vl i or two Unit with predom. Soil: RB 2 = well drained deep to very deep humic ANDOSOL and Inputs Reliable rainfall: 1st rainy season and middle rains: 2nd rainy season: > 250 mm in at least 10 out > 770 mm in at least 10 out of 15 years of 15 years Farmers in Prod. Level Farmers in Prod. Level Maize local II= III= AEU I= low II= med.4) III= high5) AEU Pot.6) I= low monocropped med.4) high5) Pot.6) Yields3) kg/ha ------Fertiliser7): N kg/ha ------

P2O5 kg/ha ------K2O kg/ha ------Manure t/ha ------Hybrid maize Maize is Yields3) kg/ha 3500 7000 9000 11000 grown Fertiliser7): from the N kg/ha - - - first rainy

P2O5 kg/ha 20 40 50 season to K2O kg/ha - - - the 2nd Manure t/ha 4 10 12 r.s. (late mat.) Maize local intercropped with beans Yields3) kg/ha ------Fertiliser7): - - - N kg/ha ------

P2O5 kg/ha ------K2O kg/ha ------Manure t/ha ------Maize hybrid intercropped with beans Yields3) kg/ha - - - - Fertiliser7): - - - - N kg/ha - - - -

P2O5 kg/ha - - - - K2O kg/ha - - - Manure t/ha - - - -

NOTES: 1)Source: Interview of 30 farmers (if possible 10 in each level) 2004 by Divisional and Field staff 2)Figures of these cereals growing periods should be reached or surpassed in 6 out of 10 years; growing periods may be considered longer due to immediately following second rainy season by middle rains. Then the second growing period is shorter than the given figures 3)Achieved average yields with average rainfall 4)Farmers with medium inputs 5)Farmers with high inputs of Fertiliser, insecticides, soil and water conservation 6)Potential yield according to crop list and local climate of this Agro-Ecological Unit if soils are optimally fertilized, plus optimal crop management 7)Fertiliser applications are averaged at 20 % of pure nutrient NAKURU GROUP 43

Subzone LH 3 vl/l or two of the Wheat/Maize-Barley Zone

This is the Wheat/Maize-Barley Zone with a very long to long cropping season separable into two variable cropping seasons as exemplified by Njoro Division, Njoro Location, Njoro Sub-location. The dominant soil type in this subzone is the well drained, deep to very deep, dark reddish brown, friable and smeary, silty clay to clay, with a humic topsoil: mollic ANDOSOLS. The annual average rainfall is 850-1100 mm. The first rainy season can expect more than 250 – 300 mm in 10 out of 15 seasons; the middle rains and second rainy season > 350 – 500 mm. The 60% reliability of the growing periods during the 1st and 2nd seasons is more than 90 and 150 – 160 days, respectively.

The crops grown during the first rainy season in order of importance are: maize as pure stand, maize and bean intercrop, beans as pure stand, Irish potatoes, tomatoes and kales. The irish potatoes, tomatoes and kales are high value crops sold in nearby markets and also far markets like Nairobi city. During the second rainy season, farmers reported growing only the high value crops, i.e. Irish potatoes, tomatoes and kales (see Table 29b). The perennial crops reported being grown by farmers in this subzone include: avocado, oranges and bananas.

It is very encouraging to note that farmers in this subzone are utilising fertilisers in improving soil fertility to boost crop production as can be appreciated from Table 28b. If this trend continues and farmers can sustain it, significant yield increases in the staple maize crop can be realized as shown in Table 31 under the prevalent soil type of mollic ANDOSOLS. As can be seen from Table 31, the farmers reported attaining slightly more maize under the intercrop system. This could be as a result of additional benefits accruing from nitrogen fixation by the accompanying bean legume under the intercrop. NAKURU GROUP 44

TABLE 31: INCREASE OF YIELDS BY BETTER FARM MANAGEMENT IN AGRO- ECOLOGICAL UNIT1) LH 3 vl/l or two, UP 2

Subzone: vl/l or two, Soil Unit: UP 2 Survey Area 104 (Njoro) AEZ: LH 3 WHEAT/MAIZE-BARLEY ZONE 2) st nd Crop Yields3) Subzone: vl/l or two (Periods in days : 1 rainy season 90 or more, 2 rainy season >60 days) and Inputs Unit with predom. Soil: UP 2 = well drained deep to deep mollic ANDOSOLS Reliable rainfall: 1st rainy season & middle rains: 2nd rainy season: > 200 mm in at least 10 out > 600 mm in at least 10 out of 15 years of 15 years Farmers in Prod. Level Farmers in Prod. Level Maize local II= III= AEU I= low II= med.4) III= high5) AEU Pot.6) I= low monocropped med.4) high5) Pot.6) Yields3) kg/ha ------Fertiliser7): N kg/ha ------

P2O5 kg/ha ------K2O kg/ha ------Manure t/ha ------

Hybrid maize Maize is Yields3) kg/ha 5000 7500 10500 14000 - - - grown Fertiliser7): - - - only N kg/ha 10 30 40 - - - during the

P2O5 kg/ha 10 20 40 - - - first rainy K2O kg/ha 5 5 20 - - - season + Manure t/ha 5 8 12 - - - middle rains Maize local intercropped with beans Yields3) kg/ha ------Fertiliser7): - - - N kg/ha ------

P2O5 kg/ha ------K2O kg/ha ------Manure t/ha ------

Maize hybrid Maize is intercropped grown with only beans during the Yields3) kg/ha 6000 8000 11000 15000 first rainy Fertiliser7): season N kg/ha 10 30 40 plus

P2O5 kg/ha 10 20 40 middle K2O kg/ha 5 5 20 rains Manure t/ha 5 8 12

NOTES: 1)Source: Interview of 30 farmers (if possible 10 in each level) 2004 by Divisional and Field staff 2)Figures of these cereals growing periods should be reached or surpassed in 6 out of 10 years; growing periods may be considered longer due to immediately following second rainy season by middle rains. Then the second growing period is shorter than the given figures. High yielding varieties H 6213 and KH 600-24A 3)Achieved average yields with average rainfall 4)Farmers with medium inputs 5)Farmers with high inputs of Fertiliser, insecticides, soil and water conservation 6)Potential yield according to crop list and local climate of this Agro-Ecological Unit if soils are optimally fertilized, plus optimal crop management 7)Fertiliser applications are averaged at 20 % of pure nutrient NAKURU GROUP 45

Subzone LH 3 (l/vl) of the Wheat/Maize-Barley Zone

This is the Wheat/Maize-Barley Zone with a (weak) long to very long cropping season as found in Naivasha Division, Naivasha East Location, Mununga Sub-location. The dominant soil type in this subzone is the well drained, moderately deep to very deep, dark brown, friable and slightly smeary, clay loam to clay, with a humic topsoil: ando-luvic PHAEOZEMS. The annual average rainfall is 850-950 mm. The first rainy season can expect more than 230 – 250 mm in 10 out of 15 seasons; the middle rains and second rainy season > 350 – 450 mm. The 60% reliability of the growing periods during the 1st and 2nd seasons is more than 90 and 130 – 140 days, respectively. Therefore both seasons and the middle rains are taken together to cultivate the late maturing maize.

The crops grown by farmers during the first rainy season in order of importance include” maize pure stand, maize and beans intercrop, beans pure stand, Irish potatoes, onions and pyrethrum as the only cash crop. The second rainy season crops comprise of: Irish potatoes, onions and beans. The Irish potato is both a household food crop and high value income generating. It is sold in nearby markets and also transported as far as Nairobi, the capital. There were no perennial crops reported being grown by farmers in this subzone.

It is strange that the farmers in this subzone are not applying the much needed nitrogen based fertiliser, may be due to the still very good soil. Nitrogen is among the major nutrients essential for plant growth. It is a vital constituent of protein and protoplasm and therefore necessary for biomass increase and reproduction in plants. The characteristic symptom of N deficiency is chlorosis of the lower leaves.

Farmers are however making deliberate efforts to apply P2O5-based fertilisers to the soil in order to increase crop yields. (see Table 28c). Phosphorus is involved in plant energy relations and in the structure of nucleic acids and is available to plants in the form of hydrated ortho-phosphate in the soil solution. Purple or bronze leaves are common deficiency symptoms, appearing first on lower leaf tips and progressing along leaf margins until the entire leaf is discolored. Phosphorus fertilisers are generally applied and incorporated before sowing as their mobility in soils is limited. An example of the expected yield increases for the staple maize crop under three different farm production levels is illustrated in Table 32 under the dominating ando-luvic PHAEOZEMS soil type. Like in the previous similar subzone, farmers reported slightly more maize yields intercropped with beans than under pure stand. The plausible reason for this inter alia is the residual effects of nitrogen fixation from the bean legume when intercropped. NAKURU GROUP 46

TABLE 32: INCREASE OF YIELDS BY BETTER FARM MANAGEMENT IN AGRO- ECOLOGICAL UNIT1) LH 3 (l/vl), LP 1

Subzone: (l/vl), Soil Unit: LP 1 Survey Area 105 (Mununga) AEZ: LH 3 WHEAT/MAIZE-BARLEY ZONE 2) st nd Crop, Yields3) Subzone:(l/vl) (Periods in days : 1 rainy season 90 or more, 2 rainy season >130 days) and Inputs Unit with predom. Soil: LP 1 = well drained moderately deep to deep ando-luvic PHAEOZEMS Reliable rainfall: 1st rainy season: > 240 mm in at 2nd rainy season: > 220 mm in at least 10 out least 10 out of 15 years, + middle rains > 500 mm of 15 years Farmers in Prod. Level Farmers in Prod. Level Maize local II= III= AEU I= low II= med.4) III= high5) AEU Pot.6) I= low monocropped med.4) high5) Pot.6) Yields3) kg/ha ------Fertiliser7): N kg/ha ------

P2O5 kg/ha ------K2O kg/ha ------Manure t/ha ------Hybrid maize Maize is Yields3) kg/ha 3000 4500 8000 10000 - - - grown Fertiliser7): - - - only N kg/ha ------during the

P2O5 kg/ha 10 30 40 - - - first rainy K2O kg/ha - 4 15 - - - season + Manure t/ha 4 8 10 - - - middle r. Maize local intercropped with beans Yields3) kg/ha ------Fertiliser7): - - - N kg/ha ------

P2O5 kg/ha ------K2O kg/ha ------Manure t/ha ------Maize hybrid Maize is intercropped grown with only beans during the Yields3) kg/ha 3500 5000 8900- 12000 first rainy Fertiliser7): - - - season N kg/ha - - - plus

P2O5 kg/ha 10 30 40 middle r. K2O kg/ha - 4 15 into 2nd Manure t/ha 4 8 10 rainy s.

Subzone UM 4 (l) or two of the Maize-Sunflower Zone1)

This is the Maize-Sunflower Zone with a (weak) long cropping season separable into two variable cropping seasons as found in Rongai Division, Lengenet Location, Lengenet Sub-location. The dominant soil type in this subzone is the well drained, moderately deep to deep, brown to dark brown, very friable, loam to sandy clay loam: vitric ANDOSOLS. The annual average rainfall is 850-1000 mm. The first rainy season can expect more than 250 – 300 mm in 10 out of 15 seasons; the middle rains and second rainy season > 350 – 450 mm. The 60% reliability of the growing periods during the 1st and 2nd seasons is more than 70 and 140 – 150 days, respectively. But because the first rainy season is so short, it is agriculturally combined by the middle rains with the 2nd rainy season.

Farmers in this subzone reported growing the following crops during the first rainy season in order of importance: maize as pure stand, maize and beans intercrop, beans as pure stand, finger millet and sorghum. No crops were reported during the second rainy season (see Table 29d). The perennial crops grown are: oranges, bananas, mangoes and avocadoes. All these perennial crops are sold in nearby markets and as far as Nairobi by farmers for cash income.

There is no reported application of nitrogen-based fertilisers by farmers in this subzone (because the soil is still fertile in nitrogen). The use of P2O5-based fertilisers is however adequate in addition to farmyard manure. (see Table 28d).This non-application of nitrogen-based fertiliser to replenish partly the soil fertility is a worrying trend if food security is to be attained in this subzone. It should be noted that the continuous cultivation of maize every year without adding any nutrients to the soil is a recipe for poor and unproductive soil, which in the long run will culminate into food scarcity in this subzone. Soil fertility depletion in smallholder farms is the fundamental biophysical root cause of declining per capita food production and soil fertility replenishment should be considered as an investment in natural resource capital. By fundamental root cause, we mean that no matter how effectively other conditions are remedied, per capita food production will continue to decrease unless soil fertility depletion is effectively addressed. The way out of this worrying trend is for the farmers to urgently start investing in soil health. If this could be embraced, there is hope for a turn around in terms of increased crop yields. This can be seen from Table 33 depicting expected incremental maize yield under three farm management production levels on the dominant vitric ANDOSOL.

1) It was formerly named Sunflower-Maize Zone when sunflowers were a dominating cash crop, but now maize planting gives better returns and is more important. Food crops are now also cash crops. NAKURU GROUP 48

TABLE 33: INCREASE OF YIELDS BY BETTER FARM MANAGEMENT IN AGRO- ECOLOGICAL UNIT1) UM 4 (l) or two, PvP 2

Subzone: (l) or two, Soil Unit: PvP 2 Survey Area 106 (Lengenet) AEZ: UM 4 MAIZE-SUNFLOWER ZONE Subzone: (l) or two (Periods in days2): 1st rainy season 160 or more, 2nd rainy season >90 days) Crop, Yields3) Unit with predom. Soil: PvP 2 = well drained and moderately deep deep to deep vitric ANDOSOL and Inputs Reliable rainfall: 1st rainy season: > 250 mm in at 2nd rainy season: > 130 mm in at least 10 out of least 10 out of 15 years, + middle rains > 400 mm 15 years Farmers in Prod. Level Farmers in Prod. Level Maize local II= III= AEU I= low II= med.4) III= high5) AEU Pot.6) I= low monocropped med.4) high5) Pot.6) Yields3) kg/ha ------Fertiliser7): N kg/ha ------

P2O5 kg/ha ------K2O kg/ha ------Manure t/ha ------Hybrid maize Maize is Yields3) kg/ha 2550 5570 8000 11000 - - - grown Fertiliser7): - - - only N kg/ha ------during the

P2O5 kg/ha 5 30 40 - - - first rainy K2O kg/ha ------season + Manure t/ha 2 6 10 - - - middle r. Maize local intercropped with beans Yields3) kg/ha ------Fertiliser7): - - - N kg/ha ------

P2O5 kg/ha ------K2O kg/ha ------Manure t/ha ------Maize hybrid Maize is intercropped grown with only beans during the Yields3) kg/ha 3000 6500 9000 - first rainy Fertiliser7): - - - - season + N kg/ha - - - - middle

P2O5 kg/ha 5 35 40 - rains into K2O kg/ha - - - 2nd rainy Manure t/ha 2 8 10 - season

3.3.6 FERTILISER AND MANURE RECOMMENDATIONS FOR IMPORTANT AGRO-ECOLOGICAL UNITS

The Fertiliser Use Recommendation Project of the GTZ (FURP) from 1986 till 1992 had 2 trial sites in the former Nakuru District –one at Mau Summit in Agro-Ecological Zone UH 2 (Wheat-Pyrethrum Zone). This site is representing the very fertile mollic Andosols in the central and western parts of the district group around Molo, Rongai, Elburgon and Mau Narok; the soils have developed on ashes and pyroclastic rocks of recent volcanoes of the Rift Valley system. This soil type is also occurring in the neighbouring Narok, Kericho and Baringo Districts. Another trial site was established at Bahati in the AEZ LH 3 (Wheat/Maize- Barley Zone), representing the fertile humic Phaeozems in the Subukia Valley and around Nakuru Town; a strip of the soil type is stretching parallel to the escarpment of the Rift from Nakuru Town southwards to Gilgil and Naivasha –surrounding Lake Naivasha on its southern shore. Similar soils of the Phaeozem type are occurring in the southeastern corner of the district group–bordering Nyandarua- in AEZ UH 3, Wheat- Barley Zone; the soils are described by FURP data from neighbouring Njabini site in Nyandarua. In the utmost northeastern part 2 more soil units are running in from neighbouring Nyandarua: moderately fertile nito-chromic Luvisols north of Dundori in the AEZ UH 1 (Sheep-Dairy Zone), UH 2 (Pyrethrum-Wheat Zone) and LH 2 (Wheat/Maize-Pyrethrum Zone), described by FURP data from Charagita/Nyandarua. Small patches of very fertile ando-luvic Phaeozems are occurring in AEZ LH 3 (Wheat/Maize-Barley Zone) and UM 4 (Upper Sisal Zone); this soil unit is stretching into the neighbouring district groups of Nyandarua, Laikipia and Baringo and is described by FURP data from Ol Joro Orok/Nyandarua. Recommended rates of an Agro-Ecological Unit (AEU) increase towards the wetter subzones and decrease into the dry ones if the soil unit extends there (see small maps). Generally, we have tended to lower the rates due to the low financial base of the smallholder farmers. If a system could be put in place to give the starter fertiliser on credit, repayable with part of the money obtained from harvest, then higher rates would be used by the farmers. The optimum can be calculated from the yield functions in MURIUKI & QURESHI (2001)1. In the long run the optimal amount must be given to maintain the nutrient content. Some quantities for this can be seen in chapter 3.1 under the ‘General Remarks’ section. Higher application rate recommendations are given in the Smallholder Farming Handbook of the IRACC and MSS, Nairobi 1997, but the economic investment and risk is too high for the local farmers. A rural small credit system for the inputs could help a lot. Where scientific sources for quantifying the rates are lacking, some conclusions can be drawn from the difference of inputs and yields between the low and high production levels of the Farm Survey 2004. An empty column in the recommendation tables denoted as “Other Nutrients Recommended” does not mean that there is nothing to be done but it is because of lack of trial data. Symptoms of deficiencies and methods of addressing these can be found in MURIUKI & QURESHI (2001), Table 1&2, p.22-23. Finally it must be emphasized once more that fertilising alone will increase the yields only for some few years. The micronutrients that are not included in the fertiliser become exhausted very fast. Manuring almost up to the full return of the extracted nutrients is a must in order to have a stable agrobiological system for continuous sustainable production2. This advice is also valid for the fertile volcanic soils in the district, which still have a high nutrient content. Water is in some areas of the district group (LH 4, UM 4 and UM 5) a limiting factor to crop production. Therefore, soil and water conservation measures are necessary to increase water availability and to minimize the risk of fertiliser application; timely planting is essential. The area under irrigation with surface water and groundwater is increasing, particularly around Lake Naivasha where large farms and agrobusiness companies have been established within the last decades. Environmental aspects like uncontrolled extraction of water, pollution of ground- and seawater with agrochemicals and accumulation of salts in irrigated soils (“white desertification”) should be considered. NAKURU GROUP 50

______1 MURIUKI, A.W. & QURESHI, J.N. (2001): Fertiliser Use Manual.- Nairobi 2 China has parts with similar soils to Rift Valley Province and stabilized productivity there for hundreds of years by returning the kitchen waste as well as human and animal excrements to the fields. The organic material could be used together with the urea for biogas production first to reduce the hygienic and energy problems. This and the ecosan toilets (for enriched humus) could be a way to sustainability of agricultural production. NAKURU GROUP 51 NAKURU GROUP 52

TABLE 34a: FERTILISER AND MANURE RECOMMENDATIONS FOR THE AGRO-ECOLOGICAL UNITS of the Wheat/Pyrethrum Zone UH 2 vl i or two, the Wheat/Maize-Pyrethrum Zone LH 2 vl, the Wheat/Maize-Barley Zones LH 3 vl/l or two & (l/vl) and the Maize-Sisal Zones UM 4 (l) & (l/m) i; Soils UP 2, RPA, LuP 1, Pv P2 and Pv P3

Av. Exp. Yield Recommended Average Yield Average Yield Other Crop varieties and Fertiliser Rates Increase if this Increase if 5t/ Nutrients + Response- 1 Season curve Rate is Applied ha Manure are Recom- 2 kg/ha kg/ha ** kg/ha Applied mended First rainy season 1 4 Hybrid maize (H 625) 4100 + 19.3 P 75 P2O5 1448 200 kg Lime

Hybrid maize (H 625) & 2700 + 55.2 P - 50 P2O5 1910 - “ beans (GLP 2) or garden 0.34 P2 peas (local) Beans (GLP 2; 208 - - - “ intercropped with maize)

Garden Peas (local; 328 + 34.6 P - 20 P2O5 436 “ intercropped with maize) 0.64 P2 5 Potatoes (Roslin Tana) 5154 + 57.2 P 75 P2O5 4290 500 kg “

Cabbages (Copenhagen) 19190 + 926 P - 65 P2O5 32500 3600 kg “ 6.54 P2 Second rainy season2

Maize (H 625) 745 + 86.9 P - 45 P2O5 2330 - - 0.78 P2 - 0.28 NP

Maize (H 625) & beans 1072 + 23.2 P 75 P2O5 1740 - - (GLP 2) or garden peas (local)³ Garden peas (local) 57 - - - -

Semi-perennial crops Pyrethrum 300 1 teaspoon of 600 - 700 - - DSP per pl. hole, after 2 months 1 kg CAN or ASN per 80 m of row

Sources: muriuki, A.W. & qureshi, J.N.: Fertiliser Use Manual.- Nairobi 2001, p.116 - 117, and conclusions from the Farm Survey 2004; Information Research and Communication Centre (IRACC): Small Holder Farming Handbook for Self Employment.- Nairobi 1997, p. 183; KARI (Ed.): Fertilizer Use Recommendations. Vol. 17, Nakuru (& Narok) District.- Fertiliser Use Recommendation Project (FURP), Nairobi ca. 1997. The AEU of the trial site is underlined

1 The initial high yields of maize can probably be attributed to the application of farm yard manure at the start of the experiments (FURP, p. 1). 2 Cultivation of maize, beans, peas and other crops during the second season is in AEZones 4 not recommended due to unfavourable/unreliable rainfall; instead, farmers are advised to grow green manures or leave the land fallow for regeneration of natural fertility (FURP, p. 10). 3 Yields of maize were slightly improved later in the experiment due to N-fixation by the legumes (FURP, p. 10). 4 1.5 - 2.5 t/ha for meeting the decline of pH (FURP, p. 4). 5 Monitoring of soil fertility should continue every three to four years (FURP, p. 1) * data not available ** The actual conversion of the real nutrient content into commercial fertiliser can be seen in Annex table I, p. 37. NAKURU GROUP 53 NAKURU GROUP 54

TABLE 34b: FERTILISER AND MANURE RECOMMENDATIONS FOR THE AGRO-ECOLOGICAL UNITS of the Wheat/Maize- Pyrethrum Zone LH 2 vl/l or two, the Wheat/Maize-Barley Zone LH 3 vl/l and the Sunflower Zones UM 4 l/vl and UM 4 (l); Soils Ls B1, P1 PC & UB P1

Av. Exp. Yield + Recommended Average Yield Average Yield Other Crop varieties and Response-curve Fertiliser Increase if this Increase if 5t/ Nutrients Season Rates Rate is Applied ha Manure are Recom- Applied 6 mended 5 kg/ha kg/ha ** kg/ha First rainy season 3 Hybrid maize (H 625) 3306 + 7.24 N + 20 P2O5 530 400 kg Lime (1.5 - 35.5 P - 0.45 P2 2.5t/ha) ³ Hybrid maize (H 625) & 3512 + 16.2 N 40/50 ² - 75 N 650/810 - 1220 400 kg “ beans (GLP 2) (maize) (maize) 588 (beans) Second rainy season 4 Semi-perennial crops Pyrethrum (at higher 300 1 teaspoon of 600 - 700 - - places) DSP per pl. hole before planting, after 2 months 1 kg CAN or ASN per 80 m

Sources: muriuki, A.W. & qureshi, J.N.: Fertiliser Use Manual.- Nairobi 2001, p.116-117, and conclusions from the Farm Survey 2004; Information Research and Communication Centre (IRACC): Small Holder Farming Handbook for Self Employment.- Nairobi 1997, p. 183; KARI (Ed.): Fertilizer Use Recommendations. Vol. 17, Nakuru (& Narok) District.- Fertiliser Use Recommendation Project (FURP), Nairobi ca. 1997. The AEU of the trial site is underlined.

1 Intercropping maize with beans is more profitable at this site than monocropping maize (FURP, p. 14). 2 Application of N fertiliser depends on the yield level: with 75 kg N/ha yields range between 4 to 6 t/ha (FURP, p. 14). 3 In case of severe decline of pH in soil (FURP, p. 4). 4 No experiments performed during the second rainy season. 5 Soil tests are recommended regularly (every 3-4 years) to monitor soil pH, P, cations, N and organic C (MURIUKI/QURESHI, p. 116). 6 Farm yard manure should be applied regularly (every 3-4 years) (FURP, p. 4). * data not available ** The actual conversion of the real nutrient content into commercial fertiliser can be seen in Annex table I, p. 37. NAKURU GROUP 55 NAKURU GROUP 56

TABLE 34c: FERTILISER AND MANURE RECOMMENDATIONS FOR THE AGRO-ECOLOGICAL UNITS of the southeastern Wheat-Barley Zones UH 3 l/vl and UH 3 (l/vl); Soil LP 1

Av. Exp. Yield + Recommended Average Yield Average Yield Other Crop varieties and Response-curve Fertiliser Rates Increase if this Increase if 5t/ Nutrients Season 1 2 Rate is Applied ha Manure are Recom- Applied ³ mended 4 kg/ha kg/ha ** kg/ha First rainy season

Peas (local) 831 + 13.7 N + 74 25 N, 20 P2O5 2970 - - P - 0.43 P²

Potatoes (R. Tana) 14000 + 86.6 N + 75 N, 45 P2O5 17220 - - 327 P - 1.97 P²

Cabbages (Copenhagen) 23245 + 305 N 75 N, 75 P2O5 33430 - - - 1.66 N² + 383 P - 1.57 NP

Carrots (Royal 28130 + 125 N + 50 N, 25 P2O5 18725 12400 kg Chantenay) 499 P Second rainy season

Peas (local) 684 + 13.9 N + 25 N, 75 P2O5 3010 - - 35.5 P

Sources: muriuki, A.W. & qureshi, J.N.: Fertiliser Use Manual.- Nairobi 2001, p.121-123, and conclusions from the Farm Survey 2004; KARI (Ed.): Fertilizer Use Recommendations. Vol. 19, Nyandarua District.- Fertiliser Use Recommendation Project (FURP), Nairobi ca. 1997. The trial site is in UH 3 of neighbouring Nyandarua group of districts.1

1 The area is not suitable for maize cultivation due to high risk of frosts. Cultivation of maize and potatoes should avoid frost in sensitive stages of growth (FURP, p. 18). 2 N and P fertiliser should be applied together (MURIUKI/QURESHI, p. 122). 3 Regular application of organic fertiliser is recommended (MURIUKI/QURESHI, p. 122). 4 Soil tests are recommended regularly (every 3-4 years) to monitor soil pH, P, cations, N and organic C (MURIUKI/QURESHI, p. 122). * data not available ** The actual conversion of the real nutrient content into commercial fertiliser can be seen in Annex table I, p. 37. NAKURU GROUP 57 NAKURU GROUP 58

TABLE 34d: FERTILISER AND MANURE RECOMMENDATIONS FOR THE AGRO-ECOLOGICAL UNITS of the northeastern Sheep-Dairy Zone UH 1 vl i or two, the Wheat/Maize- Pyrethrum Zone LH 2 vl/l or two and the Wheat/Maize-Barley Zone LH 3 l/vl; Soil RB 3

Av. Exp. Yield + Average Yield Average Yield Other 1 Recommended Crop varieties and Response-curve Fertiliser Rates Increase if this Increase if 5t/ Nutrients Season Rate is Applied ha Manure are Recom- Applied 5 mended 6 kg/ha kg/ha ** kg/ha First rainy season Maize (Highland Comp.) 3078 + 7.01 N + - ³ - - Mg 7 4.66 P Maize (Highland Comp.) 2893 + 11.2 N - ³ - - “ & peas (local) ² (maize) Potatoes (Annet) - - - - “

Cabbages (Copenhagen) 43618 - 83.7 P + 75 P2O5 6425 2000 kg “ 1.98 NP Second rainy season 4 Semi-perennial crops Pyrethrum 300 1 teaspoon of 600 - 700 - - DSP per pl. hole before planting, after 2 months 1 kg CAN or ASN per 80 m Sources: muriuki, A.W. & qureshi, J.N.: Fertiliser Use Manual.- Nairobi 2001, p.121& 122, and conclusions from the Farm Survey 2004; Information Research and Communication Centre (IRACC): Small Holder Farming Handbook for Self Employment.- Nairobi 1997, p. 183; KARI (Ed.): Fertilizer Use Recommendations. Vol. 19, Nyandarua District.- Fertiliser Use Recommendation Project (FURP), Nairobi ca. 1997. The AEU of the trial site Charagita is underlined.

1 During the experimental period crops suffered from water logging in 50% of the years (FURP, p. 6); therefore there is a high risk of fertiliser application. The improvement of drainage measures in areas prone to water logging is recommended (MURIUKI/QURESHI, p. 121). 2 Peas did not produce any yield due to water logging (FURP, p. 7). 3 Maize responded very little to N and P fertiliser; therefore, application is not economical (FURP, p. 7). 4 No experiments performed during the second rainy season. 5 Although the organic matter content of the soil is generally high, periodic (5 years) application of organic fertilisers may be necessary in continuously cultivated fields (MURIUKI/QURESHI, p. 121). 6 Soil tests are recommended regularly (every 3-4 years) to monitor soil pH, P, cations, N and organic C (MURIUKI/QURESHI, p. 121). 7 Mg application is necessary to achieve a favourable Ca/Mg ratio (MURIUKI/QURESHI, p. 121).* data not available ** The actual conversion of the real nutrient content into commercial fertiliser can be seen in Annex table I, p. 37. NAKURU GROUP 59 NAKURU GROUP 60

TABLE 34e: FERTILISER AND MANURE RECOMMENDATIONS FOR THE AGRO-ECOLOGICAL UNITS of the northeastern Wheat/Maize-Pyrethrum Zone LH 2 vl/l or two, the Wheat/ Maize-Barley Zone LH 3 vl/l and the Maize-Sisal Zones UM 4 l/ vl or two, UM 4 (l) and UM 4 (l/m) i; Soil LPC

Av. Exp. Yield + Recommended Average Yield Average Yield Other Crop varieties and Response-curve Fertiliser Rates Increase if this Increase if 5t/ Nutrients Season 1 Rate is Applied ha Manure are Recom- Applied³ mended 5 kg/ha kg/ha ** kg/ha First rainy season Maize (H 614) 6899 - 1,2 - - -

Maize (H 614) & 6553 (maize) - 1,2 - - - green peas (local)/beans 71.5 + 2.59 N - (GLP 2) 0.03 N² (gr. peas) Potatoes (Roslin Tana) 27209 - 1,2 - - - Cabbages (Copenhagen) 62428 - 1,2 - 7800 kg -

Second rainy season 4 Semi-perennial crops Pyrethrum 300 1 teaspoon of 600 - 700 - - DSP per pl. hole before planting, after 2 months 1 kg CAN or ASN per 80 m

Sources: muriuki, A.W. & qureshi, J.N.: Fertiliser Use Manual.- Nairobi 2001, p.121-122, and conclusions from the Farm Survey 2004; Information Research and Communication Centre (IRACC): Small Holder Farming Handbook for Self Employment.- Nairobi 1997, p. 183; KARI (Ed.): Fertilizer Use Recommendations. Vol. 19, Nyandarua District.- Fertiliser Use Recommendation Project (FURP), Nairobi ca. 1997. Trial site with similar soils is Ol Joro Orok.

1 Responses of all crops tested were very low or insignificant to N and P fertiliser due to high natural fertility of the soils; therefore, applications of N and P is not recommended. As yields are high, nutrient removal may be high over the years, so that nutrient contents should be monitored every 3-4 years and compensated if necessary (FURP, p. 11-12). 2 Farmer´s fields next to the trial site were low in P levels, so that P application is recommended (MURIUKI/ QURESHI, p. 121). 3 Regular application of organic fertiliser is recommended to maintain favourable N and organic C (MURIUKI/ QURESHI, p. 121). 4 No experiments performed during the second rainy season. 5 Soil tests are recommended regularly (every 3-4 years) to monitor soil pH, P, cations, N and organic C (MURIUKI/QURESHI, p. 121). NAKURU GROUP 61 NAKURU GROUP 62

3.2.7 FINAL STATEMENTS

If we see the now densely settled higher parts of the Nakuru group of districts, it is impossible to believe that at the beginning of the last century it was almost all virgin land. But this shows also the problem: If population increase cannot be stopped, then the future will be ridden by hunger, poverty and insecurity. About 50% of the people are already below the poverty line. To settle up the last big farms and ranches would be no solution but increase the problems because the delivery of basic food stuffs to the town population would collapse. Intensification of agriculture is the immediate answer: Higher yields of the traditional crops andmore vegetables which give about 3-5 times more income (Table 35a & b) could earn the money for the basic needs of a rural family. Also emerging crops like Amaranth open perspectives for a reasonable income (Table 35b). We got in 2010 no specific data for costs of living, but other districts counted 200 000 - 350 000 KSh a year for a farmers family of five. For sustainability there must be also more efforts in soil care. Fertility of the volcanic soil was very good in the first years of cultivation. When it decreased fertiliser was put in. But the micronutrients were not given by this way. Organic manure is necessary because it contains everything the plants need. Where livestock delivers not enough, humans must supply it by themselves. Ecosan toilets, biodigesters and composters are a must if the future shall be less dangerous. To conserve the last forests is very essential too, not only for nature but also for men, first of all to secure the water supply. The loss of forests has already created a difficult situation.

TABLE 35 a: Projected Agricultural Incomes (Gross Margins)1) in Zone LH 2 of Nakuru North District with ando-chromic Cambisols

Area Crop Yield Price Gross Costs Interest Gross Margin KSh KSh Output KSh ca. KSh KSh 1 acre Maize & 20 b/a maize 2 000/b. maize 40 000 21 900 2) 3 000 27 100 = 67 750/ha beans 4 b/a beans 3 000/b. beans 12 000 38 200 with fam. labour 1 acre Irish 110 b/a 500/bag 55 000 26 750 3) 3 500 24 750 = 61 875/ha potatoes 36 300 with fam. labour 1 acre Cabbage 20 000 kg/a 10/kg 210 000 40 050 4) 5 000 164 950 176 650 with fam. labour 1 acre Carrots 80 bags/a 2 000/bag 160 000 29 340 5) 3 700 126 040 137 740 with fam. labour

LH 2 is the Wheat/Maize-Pyrethrum Zone, but here farms are too small and hilly for wheat; the gross margin of pyrethrum is about 40% lower than that of maize or potatoes.

1) Data supplied by Div. AO-Kabazi Div. Joseph G. Mwaniki. Prices 2009, coming years and details see the Farm Man. resp. Agribusiness Guidelines of the District Agr. Office. 2) 11 100 KSh could be transferred to family labour. 3) 11 550 KSh could be transferred to family labour. 4) 7 050 KSh could be transferred to family labour. Costs without transport to market. 5) 11 700 KSh could be transferred to family labour. Costs without transport to market. NAKURU GROUP 63

TABLE 35 b: Projected Agricultural Incomes (Gross Margins)1) in Zones LH 3 and UM 4 of Rongai District, with vitric and mollic Andosols

Gross Area Crop Yield Price output Costs Interest Gross Margin KSh KSh KSh KSh 1 ha Maize pure stand 50 bags/ha 2 300/bag 115 000 46 150 2) 7 350 61 500 KSh

40 b/ha maize 2 300/bag, 3) 1 ha Maize and beans 13 b/ha beans 4 500 b. beans 150 500 73 500 11 760 65 240 KSh 0.1 ha Tomatoes 1 920 kg /0.1 ha 15/kg 28 800 10 175 4) 1 625 17 000 KSh 5) 0.1 ha Kales or spinach 1 450 kg /0.1 ha 10/kg 14 500 8 285 6) 1 325 4 890 KSh 1 ha Irish potatoes 16 500 kg/ha 13.60/kg 224 400 102 720 7) 8 220 113 460 KSh 9) 1 ha Amaranth 2 500 kg/ha 50/kg 125 000 40 110 8) 3 210 82 680 KSh

Wheat is not economical to small farmers because of the high rental costs of machinery, esp. combine harvester.

1) Data supplied by DAO Rongai Nixon Kasembeli. Prices 2010, coming years and details see the annual Farm Management resp. Agribusiness Guidelines of the District Agr. Office. 2) 23 000 KSh could be transferred to family labour 3) 26 150 KSh could be transferred to family labour 4) 3 540 KSh could be transferred to family labour 5) Risky because of diseases and marketing difficulties 6) 3 405 KSh could be transferred to family labour 7) 21 350 KSh could be transferred to family labour 8) 18 450 KSh could be transferred to family labour 9) Prices rose in 2010