Nitrous Oxide Production From Soils in the Future

Abstract The increasing abundance of the greenhouse gas nitrous oxide (N2O) in the atmosphere is a global concern. Although it is well known that soils are a major source of atmospheric N2O, elucidation of the complexity of the underlying microbial and chemical production processes and the roles of biotic and abiotic factors is still needed. Land management practices, especially nitrogen (N) fertilization in agroecosystems, are important determinants of soil N2O production and its consequent contribution to climate change. Here, we summarize the known N2O production pathways that contribute to soil N2O production and the factors that control these pathways, highlight the importance of land management practices in controlling soil N2O production, and discuss management strategies to reduce soil N2O emissions. We also address the roles of climate change itself and adopted strategies to mitigate climate change on soil N2O emissions. Although management practices have been identified to reduce soil N2O emissions, understanding of how these management practices act in combination and whether they lead to additive or multiplicative reductions in N2O remains limited. Examination of the underlying mechanisms of soil N cycling and N2O production and collection of empirical data across multiple management practices and soil landscapes under conditions that reflect a changing climate will facilitate model development and identification of effective N2O mitigation strategies.