Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Water Res. 2022 Sep 1;223:119028. doi: 10.1016/j.watres.2022.119028. Epub 2022 Aug 28.
Precipitation can affect the residence time of nitrogen compounds, and temperature can influence nitrogen transformation in soil. Therefore, we hypothesized that climate factors can affect the emissions of NO, an important greenhouse gas produced via nitrogen transformation, by influencing the migration and transformation of nonpoint source nitrogen in soil. To test this hypothesis and quantify the effect of climate factors on NO emissions, the SWAT model and the modified SWAT-NO coupler were used to study the effect of climate factors on the migration and transformation of nonpoint source nitrogen and NO emissions in an agricultural watershed from 2009 to 2018. Temperature affected NO emissions more significant than precipitation, and NO emissions increased with temperature and reached a plateau when the average monthly temperature was 23.0 °C. The NO emissions first increased rapidly with precipitation due to the increase in moisture. However, when the average monthly precipitation reached 78.8 mm, the NO emissions began to decrease because the residence time of nitrogen compounds in soil were reduced due to fast removal via runoff, which inhibits NO emissions. Under the context of climate change with three scenarios (RCP2.6, RCP4.5, RCP8.5), temperature would increase gradually while precipitation would not change significantly from 2021 to 2080, as a result, the changes would increase NO emissions by 6.7%, 32.3%, and 70.7%, respectively. This study quantifies the feedback of NO emissions to climate change in croplands, providing a scientific basis for climate change mitigation and agricultural management.
降水会影响氮化合物的停留时间，而温度会影响土壤中的氮转化。因此，我们假设气候因素可以通过影响土壤中非点源氮的迁移和转化来影响作为重要温室气体之一的氮转化产生的一氧化二氮（NO）排放。为了验证这一假设并量化气候因素对 NO 排放的影响，本研究采用 SWAT 模型和改进的 SWAT-NO 耦合模型，从 2009 年到 2018 年，研究了气候因素对农业流域非点源氮迁移转化和 NO 排放的影响。温度对 NO 排放的影响比降水更为显著，NO 排放随温度升高而增加，当平均月气温达到 23.0°C 时达到峰值。NO 排放最初因水分增加而迅速随降水增加，然而，当平均月降水量达到 78.8mm 时，由于氮化合物在土壤中的停留时间因快速通过径流而减少，从而抑制了 NO 排放，NO 排放开始减少。在三种情景（RCP2.6、RCP4.5、RCP8.5）下的气候变化背景下，2021 年至 2080 年期间，温度将逐渐升高，而降水变化不明显，因此，这些变化将分别使 NO 排放增加 6.7%、32.3%和 70.7%。本研究量化了农田中 NO 排放对气候变化的反馈，为气候变化缓解和农业管理提供了科学依据。
