Sources and priming of nitrous oxide production across a range of moisture contents in a soil with high organic matter

Adding nitrogen fertilizers to agricultural soils contributes to increasing concentrations of nitrous oxide (N2O) in the atmosphere. However, the impacts of N addition on soil organic matter (SOM) turnover, SOM availability, and the ensuing SOM‐derived N2O emissions remain elusive. Within this context, the net change in direction and rate of SOM‐derived N2O production triggered by added N is termed the N2O priming effect. This incubation study examined the sources and priming of N2O production as a function of urea addition and multiple moisture contents in a soil with high SOM (55 g organic C kg−1). We assessed four water‐filled pore space (WFPS) conditions: 28, 40, 52, and 64%. Relative to controls receiving no N, urea addition increased N2O production by 2.6 times (P