Effect of antecedent soil moisture conditions on emissions and isotopologue distribution of N2O during denitrification

► Antecedent soil moisture conditions affected denitrification. The N2+N2O fluxes and the N2/N2O ratios were higher in soils which were preincubated under dry conditions when compared to soils preincubated under wet conditions. ► The observed time patterns of N2O and N2 suggested a nonhomogeneous distribution of nitrate and denitrifier activity in the incubated soil. ► The time courses of δ15N-N2O, δ18O-N2O and Site Preference (SP) varied in line with the observed N2O and N2 emissions supporting the existence of multipools of nitrate. ► Isotopic fractionation modelling of the δ15N of emitted N2O, during the time series confirmed it being derived from multipools of nitrate. ► Manipulating the timing of fertiliser application according to antecedent moisture conditions could be a potential mitigation measure for soil N2O emissions.