Nitrogen Fertilization Does Not Impact CH 4 and N 2 O Emissions in Restored Agricultural Wetlands

The team found that N fertilization at rates up to 200% of the commonly applied rate (80 kg N ha) lowered grain yields and did not improve plant aboveand below-ground biomass production. Additionally, the fertilization did not change plant contribution to soil-dissolved organic carbon pools and CH4 emissions, demonstrated by two C-CO2 pulse labeling experiments in the field. Ultimately, N fertilization did not affect total annual CH4 and N2O emissions. This study suggests that N availability is not the limiting factor that regulates CH4 and N2O emissions in these restored degraded peat soils. Management other than N fertilization may determine the effectiveness of rice cultivation as a regional solution to mitigate greenhouse gas emissions in the Delta.