Lessons for appropriate soil management technology generation for the savannas and their application to the grain legume-cereal rotation system

摘要

There are many legume-based technologies capable of regenerating soil fertility but few are being adopted by farmers in West Africa. At the International Institute of Tropical Agriculture (IITA) we found that alley cropping and cover cropping systems are biologically sustainable but have low adoption by farmers in the medium term. Negative reactions by farmers stimulated us to consider grain legume rotations for soil fertilily maintenance, a decision that permitted a concentration of efforts by several disciplines on the same system. The immediate payoff was the generation of a large body of scientific information generated by a small number of researchers. Positive reactions of farmers has led to research at the farm level, focusing on the increases in maize yield due to the N benefits and the reduction in Striga bemonthica parasitism. A preliminary estimate of the impact can be calculated for Northern Nigeria where gross revenue from soybean-maize rotation is 50 to 70 percent higher than continuous maize cropping. Several research and development efforts are now underway testing soybean or cowpea rotation with maize.