Search

• Precipitation events trigger the pulse N 2 O emissions. • All sizes of precipitation events significantly increase cumulative N 2 O emissions. • Cumulative N 2 O emission after precipitation events parabolically varied with precipitation event sizes. • N addition amplifies the response of cumulative N 2 O emissions to precipitation events. • Precipitation event size plus long-term N addition led to substantial differences in N 2 O emissions. Precipitation events and nitrogen (N) addition play important roles in regulating nitrous oxide (N 2 O) emissions in semi-arid grassland ecosystems. The effects of precipitation events, long-term N addition, and their interaction on N 2 O emissions, however, remain largely unclear. We conducted a mesocosm experiment to examine how long-term N addition (0 and 10 g N m−2 yr−1, from 2011 to 2020) affects N 2 O emission responses to a gradient of manipulated precipitation events (0, 5, 10, 20, and 50 mm). The precipitation events had pulsing effects on N 2 O emissions due to the stimulation of microbial activity and substrate availability. Precipitation events significantly parabolically increased cumulative N 2 O emissions. Long-term N addition substantially enhanced cumulative N 2 O emissions response to precipitation events. The precipitation events and long-term N addition synergistically improved cumulative N 2 O emissions. The water-filled pore space and ammonium nitrogen content were the most important factors driving the temporal dynamics and accumulation of N 2 O emissions following the precipitation events and long-term N addition. Our study indicates that N addition affects the N 2 O emissions responses to precipitation events, which are essential for understanding the response of N 2 O emissions to global change. [ABSTRACT FROM AUTHOR]