Effects of Returning Biochar Straw and Reducing Nitrogen on Soil Microbial Composition and Metabolic Function Raw sequence reads

Given the potential adverse effects of direct nutrient addition on soil C pools, there is an urgent need to identify alternative fertilization and field management practices that can replace direct fertilization while enhancing C sequestration. This study conducted a long-term field experiment in Shenyang croplands, where straw and biochar application are logistically feasible, to investigate whether straw-derived biochar combined with N fertilization can mitigate environmental losses caused by excessive fertilizer application. A two-factor experimental design was employed. These findings confirm that biochar combined with moderate N reduction (N60) enhances soil C storage, nutrient efficiency, and ecological stability, offering a sustainable agricultural strategy for climate mitigation.