Abstract: Abstract: A winter wheat-summer maize cropping system has been the dominant system on the North China Plain (NCP) during the past three decades, accounting for approximately 50% of wheat production and 35% of maize production in China. Nitrogen (N) supplied through fertilization is one of the main plant nutrients affecting plant growth and plays a powerful role in the promotion of crop production. Traditional N application rates adopted by farmers to achieve high crop production range from 550 to 600 kg/hm2 for the winter wheat-summer maize cropping system in this region, which exceeds the crop N requirement. Furthermore, 50%-80% of the fertilizer is applied at planting. The application of excess inorganic N fertilizer, the broadcasting of N on the soil surface in a few split applications and flooding irrigation on the NCP have resulted in not only a low nitrogen use efficiency, but also a series of environmental problems, such as gaseous N losses.Drip fertigation is an effective approach for improving fertilizer use efficiency, as well as ecological environment. One-year experiment (from June 15, 2015 to June 12, 2016) at a summer maize-winter wheat field in NCP was performed to quantify N2O emissions from maize and wheat fields and evaluate N2O mitigation efficiency of alternative irrigation and fertilization managements by using the static opaque chamber method. We measured N2O emissions under 5 treatments, including no N fertilizer use (CK), drip irrigation + N broadcasting (DN100%), fertigation (FN100%), fertigation with N reduced by 60% (FN40%) and farmers' traditional practice (FP100%). The cumulative N2O emission in wheat field was higher than that in maize field. The N2O peaks of maize were observed in jointing and tasseling stage, while that of wheat were observed in seedling and jointing stage. Compared with FP, the average N2O flux under the FN40% treatment was reduced by 70.8% and 66.7% and the cumulative N2O emissions by 58.7% and 66.3% in maize and wheat season, respectively; in addition,the annual cumulative N2O emissions were decreased by 62.9% and a stable grain yield was maintained. The emission factors under FN40% treatment were 0.06 and 0.01 for maize and wheat, respectively, which were significantly lower than other fertilization treatments. Both soil temperature and soil moisture could influence the N2O emissions in this study. However, there were different correlations in the different managements. This research indicates that N fertigation rates in a wheat-maize cropping system can be significantly reduced by 60% compared to FP100%, without negatively affecting grain yield, but decreasing N2O emissions.