Effect of nitrogen fertilizer management and waterlogging on nitrous oxide emission from subtropical sugarcane soils

Considerable potential for N 2O emission from Australian sugarcane systems exists from high N fertilizer application rates and periodic waterlogging. To determine N 2O emissions, 2 experiments were conducted on ratooned sugarcane grown under field conditions. In the first experiment, crops received 0, 100 or 200 kg N ha −1 as single or split application. In the second experiment, a sub-set of the single N application plots was subjected to waterlogging. Higher N 2O emissions (350 μg–17 mg N 2O m −2 h −1) occurred during warm and wet months (November–February) and coincided with high availability of mineral N in top soil (10–500 mg N kg −1 soil). Lower emissions (