Ammonia emissions from paddy fields are underestimated in China.
Ammonia emissions from paddy fields are underestimated in China.
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DOI：
10.1016/j.envpol.2017.12.103
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发表时间：
2018-04
影响因子：
8.9
通讯作者：
Hongyuan Wang;Dan Zhang;Yitao Zhang;Limei Zhai;B. Yin;F. Zhou;Yucong Geng;Junting Pan;Jiafa L
中科院分区：
文献类型：
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作者：
Hongyuan Wang;Dan Zhang;Yitao Zhang;Limei Zhai;B. Yin;F. Zhou;Yucong Geng;Junting Pan;Jiafa L
中国经常使用过量的氮（N）肥料，并且大部分N可以作为氨（NH3）损失。然而，由于测量方法的不同以及气候等因素的影响，稻田NH3排放量的定量化存在较大的不确定性。本研究采用标准化方法，测定了一年三熟制（单季稻、双季稻和轮作）下的NH3排放量。测量时间为2年，在中国各地共进行了3131次观测。结果表明，在目前的农业生产方式下，NH3排放量占施氮量的17.7%（14.4-21.0%），比以前的估算值高出33.1%（10.6-52.6%）。施氮量是影响NH3排放速率的主导因素，NH3排放速率随施氮量的增加呈指数增加（p<0.001）。2013年，中国稻田的NH3排放总量估计为1.7 Tg N/年，是通过淋溶或径流流失的N的几倍。这表明，农田非点源污染的缓解措施不仅要考虑到氮流失到水中，而且要考虑到空气中，从而改善空气质量。
Excessive nitrogen (N) fertilizers are often used in China, and a large proportion of the N can be lost as ammonia (NH3). However, quantifying the NH3emission from paddy fields is always affected by large uncertainties due to different measuring methods and other factors such as climate. In this study, using a standardized method, we measured the NH3emissions in three typical annual rice cropping systems: single rice, double rice and rotation with other crops. The measurements were conducted for 2 years with a total of 3131 observations across China. Results showed that NH3emissions accounted for 17.7% (14.4–21.0%) of the N applied under current farm practice, which was 33.1% (10.6–52.6%) higher than previous estimates. Nitrogen application rate was the dominant factor influencing NH3emission rate, which exponentially increased with the N fertilizer rate (p< .001). Total NH3emissions from paddy fields were estimated at 1.7 Tg N yr−1in 2013 in China, several times the amount of N lost through leaching or runoff. This suggests that mitigation measures for non-point source pollution from cropland should take into account not only the N lost to water, but also to air, thereby improving air quality.