KE I33o. 06 Land evaluation in Kakamega District. A qualitative and quantitative land evaluation : for Soy and Lumakanda Locations, West Kenya. Part 1: Text. Rene PM van Dongen & Joris Frenke! University of Utrecht Faculty of Geographical Sciences April 1390 •* : ;' " Scanned from original by ISRIC - World Soil Information, as ICSU World Data Centre for Soils. The purpose is to make a safe depository for endangered documents and to make the accrued information available for consultation, following Fair Use Guidelines. Every effort is taken to respect Copyright of the materials within the archives where the identification of the Copyright holder is clear and, where feasible, to contact the originators. For questions please contact soil.isricfflwur.nl indicating the item reference number concerned. 32? 'Listen Ocol my old friend. The ways of your ancestors are good, their customs are solid and not hollow. They are not thin, not easily breakable. They can not be blown away by the winds because their roots reach deep into the soil.' Okot p'Bitek 'Song of Lawino1 ? ! CONTENTS. pag. ACKNOWLEX3DEMENTS , 5 IJST OF FIGURES AND TABLES 6 LIST OF MAPS AND APPENDICES IN PART 2 8 CHAPTER I: LAND EVALUATION IN KAKAMEGA DISTRICT. 1. 1 Introduction to Land Evaluation in Kakamega District 11 CHAPTER 2: GENERAL DESCRIPTION OF THE RESEARCH AREA. 2. 1 Physical Geographical Land Unit Mapping. 17 2. 1. 1 Introduction. 17 2. 1. 2 Climate and Agro-Ecological Zones 18 2. 1. 3 Geology 22 2. 1. 4 Land use ,. 22 2. 1. 5 The physical-geographical landunit map 23 2. 1. 5. 1 Source maps 23 2. 1. 5. 2 Description of the physical-geographical landunits 23 CHAPTER 3: METHODS. 3. 1 The Nested Analysis of variance (N. A. V) 25 3. 1. 1 Introduction. 25 3. 1. 2 Sampling method. 25 3. 1. 3 Method of calculation. 25 3. 2 Methods of Soil Mapping 27 3. 2. 1 Introduction. 27 3. 2. 2 Describing the soil profiles 28 3. 3 Methods of Land Evaluation: 32 3. 3. 1 Introduction. 32 3. 3. 2 The Qualitative KSS model 33 3. 3. 3 Quantitative land evaluation: the WOFOST model 39 3. 3. 3. 1 Introduction. 39 3. 3. 3. 2 The model structure 39 4 pag. CHAPTER 4 RESULTS. 4. 1 Results from Nested Analysis 48 4. 1. 1 Analysis of variance results 48 4. 1. 2 The amount of variance 50 4. 1. 3 Conclusions 51 4. 2 Results of infiltration experiments 51 4. 2. 1 Description of the results 51 4. 2. 2 Effect of Land Management 52 4. 2. 3 Adaptations of the results for use in WDFOST. 52 4. 3 Results from pF-experiments 54 4. 4 Soil Profile Descriptions 56 4. 4. 1 Introduction. 56 4. 4. 2 Classifications 56 4. 4. 3 Major Classification Units 58 4. 4. 4 Soil Genesis 60 4. 4. 5 Legend of the DIDC-Soil Map 63 4. 4. 6 Comparison between LBDA (1985) and DIDC (1989) maps 66 CHAPTER 5 RESULTS OF THE LAND EVALUATION. 5. 1 Introduction. 70 5. 2 Results of the KSS Model 70 5. 3 Input in the WDFOST Model 73 5. 4 Results of the WOFOST Model 78 5. 5 Some conclusions » 86 5. 6 Differences between the Land Evaluation systems 88 CHAPTER 6 CONCLUSIONS 89 REFERENCES 94 PART 2: CONTENTS. PART 2 pag. MAPS 1-45 APPENDICES 46-165 Acknowledcrements. For all the help during our stay and fieldwork in Kenya and during the preparations and the computation in Holland, we highly appreciate the help of the following persons: In Kenya: Mr T.R Okuku, Mr E. O. Nyanja, Daniel, drs. G. Franck, drs. W. Hoenderdos (all from the D. I. D. C. -Rakamega). Mr J.N. Qureshi, Mr P. O. S. Oduor (National Agricultural Laboratories), Mr Dürr (F. U. R. P. -Nairobi ) and the people of the L. B. D. A. in Kisumu; In Holland: Dr H. Th. Riezebos, Dr J. J. Sterkenburg, Prof. Dr J. Hinderink, Prof. Dr. P.A Burrough (all University of Utrecht), Dr J. Wolf (S.O. W.-Wageningen), Dr B. H. Janssen (L.U. W. ), Dr E. M.A. Smaling- and Dr W. Andriesse (Stiboka-Wageningen) and Dr W. G. Sombroek and Dr. V. W. P. van Engelen (I.S.RI.C -Wageningen). And last but not least all the friends in Soy and environs: Mr Gerrit Noordam, Mr Philip Wakaba, John Mburu, Grace Kalekye Masalai and her children, Barnabas Koech, Paul Kiprotich, Francis Juma, Eluid Karanja, Zakayo Mwachi, Mr M. Wamachali and all the people of the extension program in Liquyani and all the people of Soy Country Club for so kindly giving us the ' laboratory' and other facilities! Zeist, April 1990 Joris Frenkel René van Dongen LIST OF FIGURES AND TABLES FIGURES: Fig. 1. 1 Position of Kakamega District with South-West Kenya. Fig. 1. 2 Position of Western Province within Kenya. Fig. 1. 3 Position of Soy and Lumakanda Locations within Kakamega District. Fig. 1. 4 Agricultural land per capita (ha. ). Fig. 1. 5 Population density per location in Kakamega District in 1988. Fig. 2. 1 Length of growing season in Soy and Lumakanda Locations. Fig. 2. 2 Rainfall in Kakamega District. Fig. 2. 3 Agro-Ecological zones in Kakamega District. Fig. 3. 1 Hierarchy of nested sampling scheme. Fig. 3. 2 Summary of a land evaluation procedure. Fig. 3. 3 Production levels within WOFOST. Fig. 3. 4 A summary of the model structure of WOFOST. Fig. 3. 5 Soil water balance in WOFOST. Fig. 3. 6 Stream model of the original program block controlling infiltration. Fig. 3. 7 Adjusted stream model of the program block controlling infiltration. Fig. 4. 1 Percentage of cumulative variance for N, K, pH-^O, P, CEC, Base Saturation and organic C percentage. Fig. 4. 2 Percentage of cumulative variance for theta (pF2), bulkdensity, percentage of clay, sand and pores. Fig. 4. 3 The determination of moisture content at field capacity. Fig. 4. 4 Classification of soils with an argic horizon in FAO (1989). Fig. 4. 5 Soil genesis along a slope. Fig. 5. 1 Supply of N and P along a slope in Sango. Fig. 5. 2 Increase in Base Saturation in topsoil in BLA transect. Fig. 5. 3 Monthly rainfall data for 1962 at Turbo Forest Station. Fig. 5. 4 Monthly rainfall data for 1983 at Turbo Forest Station. TABLES: Table 2. 1 Monthly rain and temperature data for meteorological stations in Soy and Lumakanda Locations. Table 3. 1 Terms in the analysis of variance. Table 3. 2 The landqualities in the KSS model. Table 3. 3 The ratings of the land qualities. Table 3. 4 Conversion tables for some Kenyan crops. Table 4. 1 Standard deviations for different parameters for different distance levels. Table 4. 2 Results from infiltration measurements. Table 4. 2a Fraction of rain not infiltrating, as depending on relative moisture content of the soil. Table 4. 3 Soil units in Soy and Lumakanda Locations: two methods compared. Table 4. 4 Summary of the most important soil chemical data. Table 4. 5 The Legend Units of the soil map in Soy and Lumakanda Locations. Adapted after Andriesse and van der Pouw, 1985. Table 4. 6 Comparison of LBDA map and DIDC map. Table 5. 1 Ratings of land qualities in Lumakanda location. Table 5. 2 Ratings of land qualities in Soy location. Table 5. 3 Suitability for crops in Lumakanda Location. Table 5. 4 Suitability for crops in Soy Location. Table 5. 5 Climatic input for WOFOST. Table 5. 6 The soil physical data used as input for WDFOST in Soy and Lumakanda Locations. Table 5. 7 Some general information about the origin of the soil chemical data in Soy and Lumakanda Locations. Table 5. 8 The supply of nutrients N, P and K in Soy and Lumakanda Locations. Table 5. 9 Amount of rainfall used by the different crops. Table 5. 10 Start of the growing season plus crop development indications for the evaluated cro p. Table 5. 11 The quantitative evaluation results for maize. Table 5. 12 Fertilizer requirements for maize production (as calculated by WDFOST) together with actual amounts of fertilizer given. Tables. 13 Nutrient Limited Yields for crops in Soy and Lumakanda Locations in wet season. Table 5.14 Nutrient Limited Yields for crops in Soy and Lumakanda Locations in the dry season. Table 5. 15 Fertilizer recommendations by W. A.R.C (1988). Table 5. 16 Fertilizer gift classes for beans and sunflower in Soy and Lumakanda Locations. Table 5. 17 Relative need for N, P and K for cassavA and sweet potato in Soy and Lumakanda Locations. Table 5. 18 'Fertilizer requirements for sorghum and millet in the dry season in Soy and Lumakanda Locations. Table 5. 19 The nutrient content of the most common fertilizers. LIST OF MAPS AND APPENDICES IN PART 2: LIST OF MAPS IN PART 2. FART 2: pag. Map 1. Geology of Soy and Lumakanda Locations 1 Map 2a. Land use in Soy Locations 2 Map 2b. Land use in Lumakanda Locations 3 Map 3. Physical Geographical Landunits in Soy and Lumakanda Locations 4 Map 4a. Position of soil profiles and gaugings in Forest Land Estate (BLA transect) 5 Map 4b. Position of soil profiles and gaugings in Selbourne Estate (BLB transect) 6 Map 4c. Position of soil profiles and gaugings in Sergoit Settlement scheme (BLC transect) 7 Map 4d. Position of soil profiles and gaugings in Sango Settlement scheme (VSE transect) 8 Map 4e. Position of soil profiles and gaugings in Mautuma Settlement scheme (VSN transect) 9 Map 4f. Position of soil profiles and gaugings in Lumakanda Settlement scheme (VSS transect) 10 Map 4g.