Agroecological practices improve soil fertility and maize (Zea mays L.) yield under semi-deciduous forest conditions

Abstract

Agroecology is considered effective at improving soil fertility and crop yields. However, its effectiveness in increasing maize productivity within Ghana’s semi-deciduous forest zone remains insufficiently validated by empirical evidence. This knowledge gap is important, especially in the context of persistent soil fertility degradation and declining maize yields across the region. Thus, the present study evaluated the effects of agroecological practices, namely, mulching, reduced tillage, crop rotation and relay cropping, on soil nitrogen availability and maize yield in the semi-deciduous forest zone during the 2023 and 2024 cropping seasons. Agroecological practices significantly (p < 0.001) affected soil ammonium concentration (NH4+-N) (44%), microbial biomass carbon (MBC) (38%), soil organic carbon (SOC) (42%), total nitrogen (TN) (22%) and nitrate (NO3− -N) concentration (18%). Compared to the reference farm, reduced tillage and mulching consistently resulted in improved biomass yield (>95%) and maize grain yield (>90%) across the three cropping seasons. Maize grain yield exhibited a strong positive and significant correlation with soil NH4+-N (p < 0.05, r = 0.90), SOC (p < 0.001, r = 0.89), TN (p < 0.01, r = 0.8) and MBC (p < 0.05, r = 0.89) concentrations. Reduced tillage and mulching could enhance soil and crop productivity in deciduous maize-cropping systems.