Synergistic effect of biofilm-forming biofertilizers and ameliorants for enhancing fertilizer efficiency and maize agronomic traits on acidic soils

Acidic soils present significant challenges to maize productivity by limiting phosphorus availability and increasing toxicity risks from aluminum (Al) and iron (Fe).This study investigates the synergistic effect of biofilm-forming biofertilizers (BF) and organic ameliorants (OA) in improving soil fertility, enhancing nutrient availability, and maximizing maize growth and yield in acidic soils.A factorial randomized block design with three replications was employed, where the first factor included four treatments: control, BF only, OA only, and a combination of BF and OA.The second factor involved the application rate of inorganic NP fertilizers (IF) at 100%, 80%, 60%, and 40% of the recommended dose.Growth parameters, grain yield, and soil fertility indicators were assessed.The results revealed that the synergistic application of BF and OA significantly improved maize height and grain yield, particularly when integrated with reduced NP fertilizer rates.The highest maize height (222.33 cm) and grain yield (10.09 t ha) were achieved with the application of 1.200 g ha BF and 2 t ha OA.Furthermore, BF and OA application reduced NP fertilizer dependency by 40% without compromising yield, demonstrating enhanced fertilizer use efficiency.A strong positive correlation (R = 0.92) was observed between soil fertility improvements and maize grain yield, with BF and OA contributing 45% to yield enhancement.These findings highlight the effectiveness of biofilm-forming biofertilizers and ameliorants as sustainable solutions for improving maize productivity and soil health in acidic-stressed environments.