Combining Farmyard Manure with Mineral Nitrogen Fertilizer Boosts Maize Yields and Maintains Soil Health: Insights from Four Long-Term Experiments

Maize productivity in sub-Saharan Africa often falls below its potential due to soil fertility challenges. Researchers assessed the potential to counteract soil organic carbon (SOC) losses and yield declines using different organic resource treatments, with and without mineral nitrogen (N) fertilizer. While all treatments that received mineral N had similar yields in the first year, the application of farmyard manure (FYM) combined with mineral N was the only treatment that did not lose yields over the two decades, eventually outperforming all others. The results suggest that combining FYM with mineral N is the most effective of all tested strategies for simultaneously sustaining maize yields and SOC levels in similar tropical soils.