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

Agricultural production in the Koutiala region, southern Mall, 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, c rop 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 fer tility and crop production. This paper examines the potential for the adopt ion of this technology on different household groups using linear programmi ng-based modeling. The model revealed that an improved fallow would be an i nteresting venture only if fodder has a market value and if maize yields eq ual to or higher than the regional average yield of 2500 kg ha(-1) can be a chieved. Improved fallows are not financially attractive to farmers if they do not produce benefits other than soil fertility improvement measured in terms of crop yield. Any subsidy program which would prevent farmers from c utting 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. (C) 2000 Elsevier Science Ltd. All rights reserved.