TY - PRO AU - Freeman,H.A. AU - CIMMYT|EARO AU - Dimes,J. AU - Mwangi,W.M. ED - Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico) TI - Economic analysis of maize response to nitrogen: Exploring opportunities for targeting smallholder fertilizer use SN - 92-9146-065-6 PY - 1999/// CY - Addis Ababa (Ethiopia) PB - CIMMYT*EARO KW - Fertilizer application KW - Fertilizers KW - AGROVOC KW - Innovation adoption KW - Input output analysis KW - Kenya KW - Maize KW - Plant production KW - Production factors KW - Semiarid zones KW - Zea mays KW - Nitrogen fertilizers KW - CIMMYT N2 - Many soils in maize-based systems in semi-arid areas of Eastern Kenya have severe soil nutrient deficiencies, particularly nitrogen, that limit maize productivity. Despite decades of recommendations on the use of inorganic fertilizer, many farmers either do not use the input or apply very small quantities on crops. This study estimates nitrogen response function using maize yield data from a cropping system simulator, APSIM. The objective is to identify opportunities for smallholder farmers to increase the returns from the limited investments they are willing to make in inorganic fertilizer. Estimates of economic optima and marginal productivity suggest that targeting of nitrogen by cultivar and soil types will increase maize productivity. The study suggests the need for changes in research strategy and content of extension messages if progress is to be made on soil fertility management research in sub-Saharan Africa ER -