Abstract
A comprehensive long-term fertilizer trial programme for annual crops was established in 1985 at 70 sites in the high and medium rainfall areas of Kenya testing N and P, farmyard manure and other critical nutrients. Sites were selected according to their representativeness regarding soils and climate in agro-ecological units. The fertilizer trial programme included all major food crops typical for the respective area, both monocropped and intercropped in the case of cereals. Economic optimum fertilizer rates were calculated taking into account input/output price ratios and value-cost ratios. The majority of sites showed responses to N or P, only at one site response to both N and P with a significant interaction was found. Price elasticity of crops such as potatoes and cabbages was higher than that of maize or sorghum. Critical soil P levels were determined for maize at 13 ppm P for modified Olsen extract and 32 ppm P for Mehlich I extract. Variability of rainfall was found to greatly influence viability of fertilizer recommendations. First attempts to extrapolate fertilizer recommendations from areas of representativeness to areas with similar conditions by means of GIS and modelling approaches are discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Agricultural Information Centre (AIC) (1981) Major Crops Technical Handbook. Ministry of Agriculture, Nairobi
Allan AY (1988) Trial Design for FURP Phase II. In:FURP, 1990, pp 99–115 and Appendix 2
Bunting AH (1987) Agricultural Environments, Characterization, Classification and Mapping. CAB International, Wallingford. 335 p
FAO (1988) Fertilizer yearbook 1987, Vol. 37. FAO, Rome
FAO (1983) Maximizing fertilizer use efficiency. Fert. Plant Nutr. Bull. 6. FAO, Rome
FAO/UNESCO (1974) Soil map of the world (1:5,000,000), Vol. 1. Legend. UNESCO, Paris
FURP (1987) The Fertilizer Use Recommendation Project, Final Report. Annex I: Fertilizer trial documentation (FERDOC). Min of Agricultuie, Nairobi
FURP (1994) Fertilizer Use Recommendations, Volumes 1 to 24. Fertilizer Use Recommendation Project, Kenya Agricultural Research Institute, National Agricultural Research Laboratories, Nairobi.
Hills RC (1979) The structure of the inter-tropical convergence zone in equatorial Africa and its relationship to East African rainfall. Trans Inst Br Geogr 4: 329–352
Jaetzold R (1981) Klimageographie Ostafrika. Afrika Kartenwerk, Beiheft E-5, Berlin
Jaetzold R & Kutsch H (1982) Agro-ecological zones of the tropics with a sample from Kenya. Tropenlandwirtschaft 83: 15–34
Jaetzold R & Schmidt H (1983) Farm Management Handbook of Kenya. Volume II: Natural conditions and farm management information. Ministry of Agriculture, Nairobi
Janssen BH, Guiking FCT, Van der Eijk D, Smaling EMA, Wolf J & Van Reuler H (1990) A system for quantitative evaluation of the fertility of tropical soils (QUEFTS). Geoderma 46: 299–318
Keating BA, McCown RL, & Wafula BM (1992) Adjustment of nitrogen inputs in response to a seasonal forecast in a region of high climatic risk. Paper presented at the Int. Symposium on ‘Systems approaches for agricultural development’, Asian Institute of Technology, 2–6 December 1991
Monteith JL & Scott RK (1982) Weather and yield variation of crops. In: Blaxter & Fowden (eds) Food, Nutrition and Climate, pp 127–153.
Mudahar MS (1986) Fertilizer problems and policies in sub-Saharan Africa. In: Mokwunye AU & Vlek PLG (eds) Management of Nitrogen and Phosphorus Fertilizers in sub-Saharan Africa. Martinus Nijhoff, Dordrecht
Nadar HM & Faught WA (1984) Maize yield response to different levels of nitrogen and phosphorus fertilizer application. In: Dryland Farming Research in Kenya. E Afr Agric For J 44: 147–156
Nicholls N (1991) Advances in long-term weather forecasting. In: Muchow RC & Bellamy JA (eds) pp 427–444.
Nix HA (1985) Biophysical impacts: Agriculture. In: Kates et al. (eds) Climate impact assessment: Studies of the Interaction of Climate and Society, Chichester pp 105–130.
Roetter RP (1989) Analyse des Agroklimas und seiner Variabilität für ein Düngeranwendungs- und Bodenerhaltungsprojekt in einem tropischen Entwicklungsland. Diplomarbeit, Universität Trier
Roetter RP (1993) Simulation of the biophysical limitations to maize production under rainfed conditions in Kenya — Evaluation and application of the model WOFOST. Materialien zur Ostafrika-Forschung, Heft 12, Universität Trier
Roetter RP & Dreiser C (1994) Extrapolation of maize fertilizer trial results by using crop-growth simulation: Results for Murang'a District, Kenya. In: Fresco L O et al. (eds) The Future of the Land: Mobilising and Integrating Knowledge for Land Use Options, pp 249–260.
Rosenberg NJ, McKenney MS, Easterling WE & Lemon KM (1992) Validation of EPIC model simulations of crop responses to current climate and CO2 conditions: comparisons with census, expert judgment and experimental plot data. Agric For Meteorol 59: 35–51
Smaling EMA & van de Weg RF (1990) Using soil and climate maps and associated data sets to select sites for fertilizer trials in Kenya. Agric Ecosyst Environ 31: 263–274
Sombroek WG, Brown HMH & van der Pouw BJA (1982) The Exploratory Soil Map and Agro-climatic Zone Map of Kenya (1980), scale 1:1,000,000. Kenya Soil Survey E 1, Nairobi
Ssali H, Ahn PM & Mokwunye AU (1986) Fertility of soils of tropical Africa: a historical perspective. In: Mokwunye AU & Vlek PLG (eds) Management of Nitrogen and Phosphorus Fertilizers in sub-Saharan Africa. Martinus Nijhoff, Dordrecht
Stewart JI & Hash CT (1982) Impact of weather analysis on agricultural production and planning decisions for the semiarid areas of Kenya. J Appl Meteorol 21: 477–493
Van Diepen CA, Rappoldt C, Wolf F & van Keulen H (1988) Crop growth simulation model WOFOST documentation (version 4.1). Centre for World Food Studies, Wageningen
Van Diepen CA, Wolf J, van Keulen H and Rappold C (1989) WOFOST A simulation model for crop production. Soil Use Manage 5: 16–24
Van Keulen H, & Wolf J (eds) (1986) Modelling of agricultural production: weather, soils and crops. Simulation monographs, Wageningen
Vlek PLG (1990) The role of fertilizers in sustaining agriculture in sub-Saharan Africa. Fert Res 26: 327–339
Willems W (1989) El Nino und die ‘short rains’ in SE-Kenya — Saisonale Niederschlagsvorhersage für einen Trockenraum auf der Basis eines Modells für tägliche Niederschläge. Diplomarbeit, Universität Trier
World Bank (1994) Aide Memoire of NARP II preparation mission in Kenya, Nairobi
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Schnier, H.F., Recke, H., Muchena, F.N. et al. Towards a practical approach to fertilizer recommendations for food crop production in smallholder farms in Kenya. Nutr Cycl Agroecosyst 47, 213–226 (1996). https://doi.org/10.1007/BF01986276
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01986276