Synergetic Effects of Biochar and Biofertilizer on Corn Production under Greenhouse Conditions

Heavy reliance on synthetic nitrogen (N) fertilizers has resulted in soil degradation, declining soil productivity, and lower N use efficiency (NUE). Sustainable alternatives such as biochar (BC) and biofertilizers (BFs) offer promising solutions to enhance soil health and support yield improvement. This study investigates the individual and combined effects of BC and microbial BFs on soil properties, corn growth, and yield under controlled greenhouse conditions. A randomized experiment with seven treatments consisting of granular urea, BC, BFs, and their combinations were conducted using clay loam soil. Soil samples collected at four growth stages were analyzed for inorganic N forms, including ammonium-N (NH4+–N) and nitrate-N (NO3−–N), as well as organic matter (OM), phosphorus (P), potassium (K), and other physicochemical properties, while plant growth traits, chlorophyll content, biomass, and grain yield were measured. Treatments containing BC and/or BFs significantly increased soil OM and nutrient availability, including N, P, and K. In addition, these treatments improved plant height, leaf number, and chlorophyll concentration, resulting in 14–17% greater biomass and 14–19% higher yield compared to the control. Notably, the integrated application of BC, BFs, and 50% urea treatment increased yield and biomass by 25% and 28%, respectively, values comparable to full urea application, indicating that N fertilizer use can be reduced without compromising productivity. Overall, the results highlight strong synergistic benefits of BC and BFs for sustainable corn production.