Maize Responses to Fertilizers in Ghana

This policy brief presents the findings of a comprehensive study conducted in Ghana to determine the fertilizer yield responses for maize in the rainfed production system. The aim of the study was to provide site-specific fertilizer recommendations that would enhance crop yield responses. The research analyzed experimental trial results from nearly 1,700 data points across various agroecological zones in Ghana, considering different fertilizer treatments. The findings revealed that current fertilizer use in Ghana is low, significantly impacting maize yields. The study demonstrated that a combination of 60-130 kg N ha–1, 60 kg P2O5 ha–1, and 20-60 kg K2O ha–1 resulted in the highest yields, ranging from 5 to 7 tons per hectare. Additionally, the research highlighted the importance of sulfur (S) in enhancing maize yields, indicating that NPK treatment in combination with S tended to produce higher average yields compared to NPK alone. The study also emphasized the need for differentiated fertilizer recommendations based on the varying yield responses observed within and between agroecological zones. Furthermore, it recommended the integration of micronutrients into fertilizer research programs to assess their response and determine appropriate application rates. Given the significant findings on sulfur fertilization, the policy brief suggests that the government should support further research to establish precise recommendations for the source, rate, timing, and placement of S fertilizers for specific sites. By implementing these recommendations, Ghana can enhance maize yields and address the persistent yield gap, contributing to increased food security and self-sufficiency.
Maize, Fertilizers, Production, Micronutrients