Increasing Pigeon and Maize Yield in Malawi: Explorations in Smallholder Maize Management Practices.

Increasing maize production is critical for securing food availability and reducing starvation in Malawi since maize accounts for over 60% of total food production. Increasing soil fertility by adding fertilizers could enhance maize field productivity; but smallholder farmers in Malawi have little access to high-cost fertilizers. Additionally, the existent recommended fertilization rates do not account for spatial variations in soil properties. Therefore, fertilizer application may not be the most effective methods to increase maize yield in Malawi. The nitrogen-fixation legume in rotation with maize can be a practical way to increase soil fertility and maize production for smallholder farmers in Malawi. In this study, we chose pigeonpea (Cajanus cajan) in rotation with maize cultivation as an exemplary legume-maize cropping system to demonstrate a more effective way to increase soil fertility and maize yield. The objectives are 1) assess the effectiveness of pigeonpea with regard to increasing maize yield and 2) compare profitability among different maize management scenarios, including pigeonpea-maize system scenario and applying varied fertilization rate scenarios. We proposed to use the Systems Approach to Land Use Sustainability model to simulate soil nitrogen accumulation and maize yield under maize-pigeonpea management and under different fertilization rate (0~90 kgN/ha) scenarios. We have collected historical weather data for 10 weather stations in Malawi from both the Food and Agriculture Organization and the Modern-Era Retrospective Analysis for Research and Applications (MERRA). Soil data was collected from the most updated S-world database, developed by the Soil Geography and Landscape Group at Wageningen University. We expect that we pigeonpea would add 30 kg/ha-equivalent nitrogen to maize production fields. The most profitable cropping scenario would be maize-pigeonpea system.