Meta-Analysis Study on the Role of Biochar on Soil Nitrogen Cycling

Soil nitrogen cycling is intricately related to soil physicochemical properties, enzymatic activity, and microbial vitality. Biochar, containing various elements such as carbon, nitrogen, and phosphorus, possesses a porous structure with strong adsorption capabilities. This characteristic renders it useful for ameliorating acidic soils, influencing soil nitrogen cycling, and mitigating greenhouse gas emissions. To quantitatively analyze the diverse impacts of different biochar on soil nitrogen cycling, this study collected 155 relevant articles and conducted a meta-analysis. The results indicate that biochar can elevate the pH by 4.60% for acidic soils and significantly increase soil organic carbon content by 64.60%. Additionally, biochar enhances the abundance of the nitrogen functional gene amoA-AOB by 25.58%, promoting ammonia oxidation, increasing N2 emissions by 15.70%, reducing NH3 emissions by 16.39%, and decreasing N2O emissions by 9.62%. The findings suggest that adding biochar to soil facilitates thorough nitrogen element cycling, thereby reducing greenhouse gas emissions. Incorporating biochar into soil management practices is recommended to enhance carbon sequestration and foster a more sustainable and efficient nitrogen cycle, contributing to improved soil health and reduced greenhouse gas emissions.