Conclusion
Research on legume in eastern Africa has facilitated the selection of different species for different environments. The choice of these legume species has been based on characteristics such as ease of establishment, high biomass production, N-fi xation, seed production, tolerance to biotic and abiotic stresses and alternative uses. Case studies on the use of legumes have shown improvements in both soil fertility and crop yields under legumes. However, lack of publication of fi ndings hinders effective dissemination of legume technologies in this region. There is need to address in more detail, certain aspects that are likely to affect the widespread adop-tion of legume technologies. In particular, there is need to identify niches for these legumes in both space and time; assessing their ability to fi x N under on-farm condi-tions and to demonstrate immediate benefi ts such as substantial increase of food crops, fodder and wood products and cash to the farm. Whereas a lot of research has been done on legumes in east Africa, it has focused on yields under different agro-ecological zones with scanty information on the contribution of the legumes to bio-logical N-fi xation. There is need therefore for more studies to focus on unexplored areas such as the contribution of the legumes to biological nitrogen fi xation as well as other non-N benefi ts such as the contribution of the legume to soil organic matter and other soil physical properties. Profi tability of green manure technologies, returns to labour (residue management, weed suppression), farmers’ perceptions and potential for adoption need further assessment. As such there is need to carry out more detailed characterization of green manures niches inorder to understand both the spatial and temporal niches of the legumes on farmers fi elds. Issues of seed availability, quality and markets also need to be addressed if sustainability of the legume based soil fertility improvement technologies is to be achieved.