Leguminous pre- and post-crops such as groundnut increased the yield of a food crop and
provided enough marketable produce itself to increase a farmer's income significantly. The
residues also helped maintain levels of soil organic carbon and nitrogen in soil. Analysis
suggested a good price for the secondary crop to be key, however, as is sufficient water to
grow it and availability of or tenure on the land for a farmer to be willing to invest. Hedgerow
intercropping boosted soil fertility but did not increase incomes sufficiently, monocropping
was profitable but yields and soil fertility declined rapidly. Monocropping remains popular
with farmers with little land or without tenure, however. Nrfixation was sufficient to
match offtake in a moderately yielding food-crop in these systems; more intensive production
requires additional input. Overall leguminous secondary cropping has the least against it
of the improved cropping systems investigated and probably stands the best chance of being
adopted by farmers in the region.