Legume technologies are often promoted to increase nutrition, livelihoods and soil fertility of sub-Saharan smallholder farmers. Differences between regions as agro-ecological potential, market access and off-farm income opportunities and differences between farmers in terms of resource endowment and livelihood strategy imply that blanket recommendations for legume technologies are unlikely to be effective. Identification of niches through detailed system characterization, with the use of a farm typology to deal with the enormous diversity in smallholder farms, is an opportunity to improve both recommendations and their targeting. Fine-tuning recommendations to the farm type level will probably improve adoption by farmers and make legume-based development projects more effective. The results of farm characterizations, covering diverse farm types in Mchinji and Salima district in central Malawi, were used to gain insights in the possibilities of legumes to increase nutrition, livelihoods and soil fertility.
Maize was the dominant staple food crop in both regions. Tobacco was a major cash crop in Mchinji, whereas cotton, tobacco and groundnuts were the most common cash crops in Salima. Although the area under legume cultivation was smaller in Mchinji than in Salima, groundnut had high adoption rates in both regions. Soyabean, beans and cowpea had low adoption rates and were allocated only very small areas. Farmers themselves defined the boundaries within which legumes can expand on their farm by food security and income. These were bordered and influenced by highly dynamic socio-economic, agronomic and biophysical factors. Although labour use efficiency of maize was generally higher than that of groundnut, legumes were economically more profitable than maize. Since maize is perceived as the main food security crop, the majority of the farmers indicated that legumes can only be expanded when domestic maize production is sufficient to satisfy household demand. Low resource endowed households were generally less food secure than medium or high resource endowed households and mentioned lack of cash for seeds and lack of land and labour as the major production constraints to expanding legume production. This indicates that targeting low resource endowed farmers who cannot be self-sufficient in maize production with legume technologies is unlikely to be successful. Although legumes did not have the potential to generate as high net benefits as tobacco or cotton, they were less risky in terms of possible negative net benefits and required less establishment costs. Therefore, cultivating legumes can be an option to generate some cash as well as to fortify diets with good quality protein for subsistence oriented farmers who are already self sufficient in maize production. Marketability of legumes other than groundnut was often a major constraint for market oriented farmers to expanding their production. Farmers of all types were less interested in the potential soil fertility benefits of legumes. Current contributions of legumes to soil fertility are likely to vary among farms and fields due to (1) probable variable rates in biological nitrogen fixation and biomass production, notably due to variable soil fertility within farms and the preferential allocation of legumes to less fertile fields and (2) differences in residue management to store nutrients over the dry season.