Projected background nitrous oxide emissions from cultivable maize and rice farmland in China

Özet

Climate change is expected to have a major impact on agriculture in China. It affects agricultural backgroundnitrous oxide emissions (BNE) through warming or cooling and precipitation changes, but the related mechanisms remain poorly understood. Therefore, using projections of future climate derived from a multi-modelensemble under three representative concentration pathway scenarios (RCP2.6, RCP4.5, and RCP8.5), a gridbased spatial analysis was conducted to investigate the agricultural BNE by empirical statistical models andsimulated suitable cultivation areas of rice and maize in China for 2006–2100. The results indicated that thespatio-temporal variation of BNE was dominated by temperature and the interaction effect of temperature andprecipitation may also play an important role. Under the high-emission scenario (RCP8.5), the greater warmingcaused the potential BNE area of maize and rice to slightly migrate northward and the high-emission area wasconcentrated in southeastern China. The total BNE showed an increasing trend over time, from 120.59 ± 0.69to 142.42 ± 0.78 Gg N a−1during the 21st century, driven by the synthetic action of these climatic factors. Thefindings of this study may provide reference for predicting future agricultural BNE and formulating appropriatemeasures to mitigate global warming.