Biological production and consumption of nitrous oxide in soils

Nitrous oxide (N₂O) may be produced in the soil by both abiotic and biotic processes, with the contributions from biotic processes being more significant. The major direct, biotic sources of N₂O are denitrification and nitrification, although nitrifying bacteria also make an indirect contribution, because the NO₃^- produced may be subject to denitrification. N₂O is both produced and consumed by the process of denitrification, and the balance between production and consumption determines net N₂O production. In this paper, the biological processes of N₂O production, the approaches to determining the contributions from these different sources, and the way in which the different interacting processes influence overall N₂O emission are outlined.