Our recent publication in Agriculture, Ecosystems and Environment examines nitrogen balances in smallholder maize systems in western Kenya. While other regions in the tropics have seen increases in food production over the past fifty years, per capita yields in sub-Saharan Africa (SSA) have stagnated or even declined. In response the African Green Revolution (AGR) marches forward, with the aim of giving farmers in SSA access to improved maize seed, mineral fertilizers, and legume rotation technologies. In theory, any of these inputs could in isolation, improve yields.
We used a combination of farmer interviews, on-farm harvests, and biomass modeling to calculate input-output balances on 24 working farms. We found that high yielding farms are more responsive to mineral N additions and low-yielding farms are more responsive to N added through legume rotations. This suggests that legume technologies are especially important for improving soil conditions to the point where they become responsive to mineral fertilizers and can support high yields.
Check out the full text publication on Kate's ResearchGate profile.
Dr. Kate Tully
Kate is an Assistant Professor of Agroecology at the University of Maryland.