Modeling changes in farming systems with the adoption of improved fallows in southern Mali

Agricultural production in the Koutiala region, southern Mali, is based on cash sources (cotton and groundnut), cereal sources (maize, sorghum, millet), and a store of wealth (livestock). In these low-input farming systems, crop production is seriously constrained by soil fertility decline. Research is being conducted in the region to investigate the potential of improved fallows planted to leguminous agroforestry tree species to improve soil fertility and crop production. This paper examines the potential for the adoption of this technology on di€erent household groups using linear programming-based modeling. The model revealed that an improved fallow would be an interesting venture only if fodder has a market value and if maize yields equal to or higher than the regional average yield of 2500 kg haÿ1 can be achieved. Improved fallows are not ®nancially attractive to farmers if they do not produce bene®ts other than soil fertility improvement measured in terms of crop yield. Any subsidy program which would prevent farmers from cutting the fodder, as secondary output before the end of the planned fallow length, would not have adoption potentials. A special fallow installation loan program, similar to the one that cotton enjoys, would make the venture viable. # 2000 Elsevier Science Ltd. All rights reserved.