Long-term effects of cropping system on N2O emission potential

► Four experimental cropping systems differed two-fold in annual C inputs. ► A freeze-thaw induced flush in respiration from intact soil ceased within 48 h. ► Nitrous oxide emissions were highest from the system with lowest annual C input. ► Denitrification was the main source of N2O, as indicated by gaseous 15N losses. ► Gas diffusivity was a main driver of N2O, but interacted with cropping system.