Nitrous oxide (N2O) is the most important greenhouse gas produced by agricultural soils and is a byproduct of microbial nitrification and denitrification processes. The N2O emission rates depend on soil, climatic and management factors. The objectives of this study were i) to evaluate N2O emissions during a barley crop period and its subsequent barley-maize interperiod, under two management systems, and ii) to relate the N2O flux rates with soil mineral N content, waterfilled pore space (WFPS) and soil temperature.