Abstract/Summary

Ammonia (NH3) volatilization, nitrous oxide (N2O) emission and mineral nitrogen leaching from paddy fields are closely related to nitrogen fertilizer application. Excessive nitrogen fertilizer application has exacerbated adverse environmental effects, including global warming, atmospheric haze and groundwater pollution. Reducing the nitrogen application rate could alleviate negative environmental effects, but simultaneously brings risks of yield reduction. Biofertilizers, also known as microbial fertilizers, utilize microorganisms to improve the effectiveness of concurrent nitrogen fertilizers and have been shown to help mitigate the adverse effects of nitrogen fertilizer while ensuring rice yield. This study, which is one of the first field-scale trials of N2O-mitigating biofertilizers, focused on a typical paddy field in East China and investigated 9 treatments that combined mineral nitrogen fertilizer and N2O-mitigating biofertilizer applications to investigate yield and nitrogen loss effects over three years. The results showed reducing nitrogen combined with the N2O-mitigating biofertilizers increased rice yield by up to 26%, and simultaneously reduced N2O emission, mitigated nitrogen leaching loss, and had no significant impact on NH3 volatilization and methane (CH4) emissions. This is an important result and suggests that wider-scale adoption of N2O-mitigating biofertilizers could help reduce the environmental footprint of rice production whilst maintaining, or even improving, rice yield.