Impact of tillage and N fertilization rate on soil N2O emissions in irrigated maize in a Mediterranean agroecosystem

•An increase in the fertilizer N rate increased N2O emissions in irrigated corn.•No-tillage significantly increased soil N2O emission at the highest N-fertilizer rate.•Denitrification was the main pathway under no-tillage for N2O emission.•The use 200 kg N ha−1 reduced the yield-scaled N2O emissions in the first out of three years.•The emission factor was much lower than 1% proposed by IPCC.