Abstract:Sewage irrigation in rice-wheat rotation likely lead to more nitrogen (N) loss via ammonia (NH3) volatilization and nitrous oxide ((N2O) emission. A stimulated lysimeter study was conducted to evaluate the impacts of sewage irrigation with different nitrogen (N) concentration irrigation on NH3 volatilization, (N2O emission and crop yield. The four treatments received equal optimal N input (225 kg/hm2 in rice season and 150 kg/hm2 in wheat season from urea fertilizer were 1) clean water irrigation as the control (CK), 2) sewage irrigation with low N concentration (SI-L), 3) sewage irrigation with medium N concentration (SI-M) and 4) sewage irrigation with high N concentration (SI-H). Results in rice season showed that NH3 volatilization and(N2O emission increased with the N concentration of irrigated sewage, and the determination coefficient (R2) were 0.895 and 0.998, respectively. Sewage irrigation significantly increased the NH3 volatilization by 19.7% – 40.8% compared with the control, and the SI-H treatment significantly increased the (N2O emission by 68.8%. Sewage irrigation did not increase the rice grain yield. Data in the wheat season suggested that NH3 volatilization and (N2O emission also increased with the N concentration of irrigated sewage, and the determination coefficient (R2) were 0.939 and 0.980, respectively. Herein, 20.2% higher NH3 volatilization compared with the control was measured in the SI-H treatment. The SI-M and SI-H treatments significantly increased the(N2O emission in wheat season by 64.9% and 120.3%, respectively. The SI-H treatment significantly increased the wheat production by 46.7%. The results suggest that NH3volatilization and (N2O emission must be considered when sewage irrigation was occurred in paddy field and more rational water and N fertilizer management should be adopted when paddy soil was explored to treat sewage water.