A research team has found that soil type strongly determines how agricultural microbial communities process added carbon and nitrogen and whether denitrification releases nitrous oxide (N₂O) or converts it to harmless dinitrogen (N₂). Across five major Chinese farmland soils, pH and nitrate availability were the main factors shaping bacterial communities, but the presence of shared core microorganisms did not reliably predict N₂O emissions. Fluvo-aquic soil showed the most complete denitrification and the lowest relative N₂O production, whereas acidic red soil had limited denitrification capacity.
Agricultural soils are a major source of anthropogenic N₂O, a powerful greenhouse gas generated largely through microbial nitrogen transformations. During denitrification, microorganisms progressively reduce nitrate to N₂O and ultimately N₂, with the balance between these gases influenced by soil pH, carbon availability, nutrient status and microbial functions. Previous studies have examined how individual practices, including fertilization, irrigation, nitrification inhibitors and biochar application, affect N₂O emissions. However, farmland soils differ substantially in their physicochemical properties and microbial communities, meaning that identical carbon and nitrogen inputs may produce sharply different outcomes. Comparative evidence explaining these soil-dependent responses has remained limited, complicating the development of broadly effective agricultural mitigation practices.
A study (DOI: 10.48130/nc-0026-0006) published in Nitrogen Cycling on 21 April 2026 by Xiaojun Zhang's team, Shanghai Jiao Tong University, reports that physicochemical constraints and microbial functional differences jointly regulate denitrification, causing carbon and nitrogen inputs to alter N₂O and N₂ production differently among soil types.
Click here to see more...