Field and laboratory studies of N_2O turnover in the saturated zone of hydromorphic soils of Northwest Germany. Ⅱ: Laboratory incubations to determine total denitrification and N_2O production

摘要

Groundwater N_2O concentrations and emissions to the atmosphere are closely related to denitrification dynamics in the saturated zone. In the shallow groundwater of hydromorphic soils redox conditions are generally favourable for denitrification which is often caused by the presence of fossil organic carbon and reduced sulphur compounds in the subsoil. The contribution of theses systems to N_2O emission to the atmosphere is poorly understood. The objective of this study was to determine the potential of hydromorphic soils to emit N_2O to the atmosphere. Samples from the saturated zone of hydromorphic soils were analyzed for denitrification, N_2O production and controlling parameters in the laboratory. NO_3- and N_2O-concentrations of the shallow ground water were measured in the field.