BIOLOGICAL PRODUCTION AND CONSUMPTION OF NITROUS-OXIDE IN SOILS

Nitrous oxide (N2O) may be produced in the soil by both abiotic and bi otic processes, with the contributions from biotic processes being mor e significant. The major direct, biotic sources of N2O are denitrifica tion and nitrification, although nitrifying bacteria also make an indi rect contribution, because the NO, produced may be subject to denitrif ication. N2O is both produced and consumed by the process of denitrifi cation, and the balance between production and consumption determines net N2O production. In this paper, the biological processes of N2O pro duction, the approaches to determining the contributions from these di fferent sources, and the way in which the different interactings proce sses influence overall N2O emission are outlined. (C) Elsevier, Paris.