The present research project entitled: “Exploring options to enhance biological nitrogen fixation and yield of soybean and common bean in smallholder farming systems of Rwanda” is implemented within the framework of the N2Africa project: Putting nitrogen fixation to work for smallholder farmers in Africa. We hypothesise that successful nitrogen fixation and productivity of legumes in the field depend on the interaction between legume genotypes and rhizobium genotypes as influenced by environment and management. Based on the role of common bean and soybean in the farmers diet and income generation, and considering the growth of the population, the decrease in soil fertility and cost of nitrogen (N) fertilizers, the cultivation of legumes can play an important role in sustaining agricultural productivity given legumes’ ability to fix nitrogen, which can help to reduce the need for nitrogen-based fertilizers.
The present PhD project will evaluate the factors affecting the competition for nodules occupancy and survival of introduced rhizobia in soils, and will unravel the causal factors limiting the success in nitrogen fixation and grain yield increases in common bean and soybean across various environmental conditions of Rwanda via field trials and laboratory work.