摘要：Atmospheric nitrogen (N) deposition has increased dramatically due to increased human activities since the industrial revolution. However, it is still unclear what the responses of soil nitrous oxide (N2O) is to long-term elevated N deposition in a temperate grassland. Here, we conducted anin situfield experiment to investigate these responses to long-term high N addition on a temperate steppe in Inner Mongolia, China, from April 2017 to October 2018. Soil N2O emissions significantly increased by long-term N addition, use of structural equation modeling (SEM) showed that topsoil (0-5 cm) NH4+-N content was the most important limiting factor for N2O emission. Our results indicate that long-term high N addition showed a significantly increase in N2O emission in this temperate grassland.
