Does pre-plant N fertiliser location affect soil mineral N and nitrous oxide emissions from irrigated cotton at Gunnedah?

Abstract

Key findings •• Changing the pre-plant N fertiliser from the non-irrigated side of the plant bed to the irrigated side of the plant bed did not affect soil mineral nitrogen (N), plant growth or cotton lint yield. •• The pattern of nitrous oxide (N2O) emissions after the first irrigation event differed according to N fertiliser placement treatment, but the total amount of N2O released was the same. •• Pre-plant N fertiliser placement did affect N2O emitted after the second irrigation (with water-run N), with more lost from the irrigated, non-fertilised side of the hill. •• The cumulative N2O losses summed over all the measurement events showed no treatment differences resulting from pre-plant N fertiliser location, indicating that there is no agronomic or environmental benefit to changing N fertiliser location.