M. J. Goss, S. Blagodatsky and A. Unc, In: Encyclopedia of Soils in the Environment (Second Edition), edited by M. J. Goss and M. Oliver, Volume 1, 2023, Pages 261-269, Academic Press
https://doi.org/10.1016/B978-0-12-822974-3.00282-2
Denitrification is the transformation of plant available nitrogen (N) to gaseous forms that can return N to the atmospheric pool. Nitrous oxide, N2O, an important greenhouse gas is formed during both aerobic and anaerobic processes but the concentration of oxygen in the soil determines which processes predominate. The varied nature and uncertainties within the pathways, together with the range of gaseous products makes quantification of losses from soil particularly difficult. Fertilizer N accounts for about 43% of global N2O releases to the atmosphere from agriculture. The chapter summarizes the fundamental processes of N-transformation that generate gaseous forms of N.