Effect of Nitrogen Fertiliser Application on Maize Yield Across Agro-Ecological Regions and Soil Types in Zimbabwe: A Meta-analysis Approach

Abstract

Accurate nitrogen (N) fertilisation increases crop yields and minimises environmental pollution in maize based production systems. In this study we report on a meta-analysis of the effects of N fertilisation on maize yield using observations from 53 studies conducted in Zimbabwe since the 1950s for possible refinement of fertiliser recommendations. We assessed the response of maize to: 100 kgN ha−1 compared to the control using the weighted mean yield difference approach. Application of N fertiliser significantly (p 100 kgN ha−1 (> 1.5 fold of recommended blanket rate) in mineral form in loam soils under good management in areas that receive 600–1000 mm year−1 rainfall whilst rates of < 30 kgN ha−1 (< 50% of recommended rate) can be relied upon for positive yield response in small holder areas that receive < 600 mm rainfall year−1.