Nitrogen-rich organic soils under warm well-drained conditions are global nitrous oxide emission hotspots

Nitrous oxide (N(2)O) is a powerful greenhouse gas and the main driver of stratospheric ozone depletion. Since soils are the largest source of N(2)O, predicting soil response to changes in climate or land use is central to understanding and managing N(2)O. Here we find that N(2)O flux can be predicted by models incorporating soil nitrate concentration (NO(3)(−)), water content and temperature using a global field survey of N(2)O emissions and potential driving factors across a wide range of organic soils. N(2)O emissions increase with NO(3)(−) and follow a bell-shaped distribution with water content. Combining the two functions explains 72% of N(2)O emission from all organic soils. Above 5 mg NO(3)(−)-N kg(−1), either draining wet soils or irrigating well-drained soils increases N(2)O emission by orders of magnitude. As soil temperature together with NO(3)(−) explains 69% of N(2)O emission, tropical wetlands should be a priority for N(2)O management.