Abstract:NH3 volatilization and N2O emission under different fertilization of a salined flavo-aquic soil in Hetao Irrigation Area studied through the static chamber gas chromatography and in situ field determination, the different fertilization included 1) CK, farmer conventional fertilization, 2) B, bentonite + CK, 3) C, biochar + CK, and 4) HA, humic acid + CK. The results showed that: compared with CK, B fertilization significantly reduced the cumulative emission of soil N2O by 30.9% and decreased nitrogen loss by 31.5%, but there were no significant difference between the other fertilization and CK in N2O cumulative emission. The NH3 volatilization rate of each treatment reached the peak value in 3—5 days after fertilization, and then gradually tended to be stable. Compared with CK, B, C, and HA treatments significantly reduced total amount of soil NH3 volatilization by 56.0%, 41.2% and 49.0%, and decreased nitrogen loss rate by 56.0%, 41.2% and 52.1%, respectively. Soil temperature and air temperature were significantly positively correlated with soil N2O emission; Soil water content ranged from 151.2 g/kg to 203.3 g/kg in maize growth period in which soil moisture content and soil N2O emission were positively correlated. B fertilization significantly reduced soil NH3 volatilization and N2O emission, and increased crop yield by 11.1% compared to CK, which indicate it is the more reasonable fertilization.