Diversification and intensification of smallholder farming through intercropping with grain legumes in northern Tanzania

Sustainable intensification and diversification of crop production is key to meeting higher future food demands while mitigating environmental impact of agriculture in smallholder farms. One way to achieve this is cereal-legume intercropping, as legumes incorporated into cereal-based systems have the ability to increase availability of nitrogen (N) from biological nitrogen (N2) fixation. Other benefits associated with legumes inclusion includes the availability of legume grain yield, reduction in occurrence of pests and diseases, extended ground cover, better rooting ability, improved soil fertility in the long-term and the eventual increase in total yields. Productivity of intercrops depends on the balance between intra- and inter-specific competitions. This thesis focused on fine-tuning maize-legume intercropping systems in different agro-ecological zones, by working towards striking a balance between maximizing the benefits of inclusion of pigeonpea and lablab in maize systems, and minimizing potential disadvantages emanating from their competition with maize. A combination of farm surveys, on-farm trials and crop growth modelling were used on smallholder farms in northern Tanzania....