Synergistic Effects of Biochar with Phosphorus Fertilization on soil Biochemical Properties and Wheat Productivity

Purpose: Excessive fertilization is a growing concern due to its adverse impacts on soil health and the environment. This study assessed the impact of different feedstock-based biochar (BC) combined with reduced phosphorus (P) fertilization on soil biochemical characteristics and wheat crop growth. Methods: Farmyard manure biochar (FMB) and parthenium plant biochar (PPB) were each pyrolyzed at 400 and 600 ℃. These BCs, combined with P fertilizer, were first tested under incubation conditions over 84 days to monitor alkaline phosphatase (ALP), dehydrogenase (DEH), and microbial biomass. A subsequent greenhouse experiment evaluated soil nutrients, microbial activity, and wheat performance under same treatments. Results: Farmyard manure biochar produced at 600 ℃ (FMB600) consistently outperformed the rest. In incubation study, FMB600 raised soil ALP, DEH, and microbial biomass carbon (MBC) by 38%, 29%, and 8% respectively, while microbial biomass phosphorus (MBP) increased by 45%. In pot experiment, FMB600 increased nitrate nitrogen (NO₃–N), ammonium nitrogen (NH₄-N), and available P by 48%, 93%, and 96% respectively over unamended control (Ck). Soil organic carbon (SOC) and dissolved organic carbon (DOC) improved by approximately 32% and 87% respectively, along with meaningful gains in micronutrients (zinc, copper, and iron). Wheat plants showed stronger photosynthesis, transpiration, and stomatal conductance, with 37–74% higher P accumulation in roots and shoots. Grain protein, harvest index, and grain yield improved by 19% and 10% 54% respectively over Ck. Conclusions: Biochar-based fertilization offers a practical strategy for reducing chemical inputs while sustaining crop performance, supporting sustainable wheat production in arid agricultural systems.