Speaker
Description
Purpose: In several countries, invasive aquatic plants (IAP) have plagued most river systems, limiting their utilization. However, there is limited information on the conversion of this significant feedstock to biochar with agricultural value. Consequently, a field experiment was conducted to evaluate the influence of biochar from IAP (Arthropteris orientalis), its co-compost and mixtures on soil physicochemical properties and maize yields in Ghana in three consecutive cropping seasons. Methods: Experimental plots were treated with biochar at 2.5 t ha-1 (B2.5) and 5 t ha-1 (B5), co-composted biochar at 2 t ha-1 (CCB2) and 4 t ha-1 (CCB4), B2.5+CCB2, NPK fertilizer at 100%, B2.5+50%NPK, CCB2+50%NPK, and control in a randomised block design replicated three times. Results: Biochar and co-composted biochar significantly enhanced soil nitrogen, organic carbon, exchangeable cations, porosity, and maize yields. Across the three cropping seasons, CCB4 increased maize grain yield up to 125%. Levels of NO3--N and NH4+-N increased from 21 to 42 days after amendment (DAA) application, then declined at 63 DAA. However, the B2.5+CCB2 and NPK50%+B2.5 treatments generally caused a significant increase in NO3--N and NH4+-N at 63 DAA compared to the other treatments. The B5 treatment considerably decreased soil bulk density while enhancing soil porosity and water content. Principal component analysis revealed that soil organic carbon, pH, NO3--N, soil water content and bulk density were strongly linked with soil fertility and maize productivity under biochar amendments. Conclusions: Our findings demonstrate that CCB4 and B2.5+CCB2 are the most effective soil amendments for improving maize yields after two application seasons.