The mechanism by which temperature sensitivity (TS) of soil N 2 O emissions is increased by agricultural management with application of nitrogen fertilizer (AMN) is unclear. We hypothesized that a higher TS of N 2 O emission induced by AMN is the result of the faster growth of specific microorganisms in response to faster nitrogen (N) mineralization at higher temperatures. To test this hypothesis, we used reciprocal transplants to separate the contributions of abiotic and microbial components to the TS of N 2 O emissions in an arable soil receiving organic and inorganic fertilizers and its neighboring natural grassland soil treated with two levels of N. N 2 O sources were separated with acetylene, and the abundances of N 2 O-producing microbes were assessed by quantifying the copy numbers of the associated functional genes. Compared with natural soil, only changes in abiotic properties increased the Q 10 (the factor by which the rate increases with a 10 °C rise in temperature) by 105.7%, while changes in both abiotic and the microbiome increased the Q 10 by 225.2%. Higher TS of N 2 O emission in the arable soil induced by a microbiome shift was associated with faster N mineralization, increased proportion of nitrification-N 2 O emission, and faster growth of ammonia-oxidizing bacteria at higher temperatures. Addition of ammonium nitrate further enhanced the TS of N 2 O emissions, the proportion of nitrification-N 2 O emission, and the increased extent of the growth of ammonia-oxidizing bacteria in the soil with AMN compared to the natural grassland soil. Substrate-driven growth of ammonia-oxidizing bacteria with higher substrate preference contributes significantly to the higher TS of N 2 O emission caused by AMN. [ABSTRACT FROM AUTHOR]