Estimation of ammonia emissions from rice fields under different N inputs in China

Abstract

Rice production is essential for ensuring food security. Nitrogen fertilizers applied in rice fields are prone to loss through NH3 emissions. We need to elucidate the responses of NH3 emissions to different N inputs. With a national dataset, we identified that N application rate, N application frequency, soil temperature, and soil silt fraction were the key driving factors of NH3 emissions. 190−210 kg N ha−1 was suitable for simultaneously reducing NH3 emissions and increasing rice yields. The model showed that under the actual N application rate and N application frequency of 3, national NH3 emissions were 0.852 Mt N each rice growing season, while national NH3 emission factor was 12.7 %. We developed a portable software to conveniently assess China's NH3 emissions from rice fields under different N inputs. The findings can help to optimize N inputs in rice fields to reduce NH3 emissions and improve ecosystem health and agricultural sustainability.