The behavior of nitrous oxide (N2O) in fertilized soil was studied in terms of soil fluxes, the production rates at various depths and the turnover in soil. The diffusive losses of N2O to the atmosphere calculated from soil N2O profile compared favorably with the flux directly determined with a closed chamber technique. The estimate of N2O production rates at several depths demonstrated that the sites of N2O production was only near the soil surface. The calculated residence time of N2O in the entire soil column studied was only 1.4 hour during active emission period and less than 1 day even in the later period having trace N2O emission. The prolonged N2O emission observed after the active phase was due likely to a lasting N2O production rather than a supply from the soil N2O reservoir. The results suggested that most N2O in soil was emitted quite promptly to the atmosphere after its production. A minor role of soil as an N2O reservoir is emphasized from the viewpoint of the origin of groundwater N2O.
N2O emissionfertilized soildiffusionsoil N2O production and turnovergroundwater