Abstract:An indoor incubation under 30 ℃ and 65% water holding capacity was conducted to study how different split applications, in the circumstances of equal nitrogen amount, respectively affected N2O emission. Four treatments were designed, including one-time application (S1, 200 mg/kg nitrogen fertilizer was applied to the soil at one time), two separate applications (S2, 200 mg/kg nitrogen fertilizer equally distributed into the soil), three separate applications (S3, 200 mg/kg nitrogen fertilizer was divided into three different times: 80, 60 and 60 mg/kg), and control (CK, no fertilization). The results showed that the application of nitrogen fertilizer significantly promoted N2O emission in soil. Under the same nitrogen application rate, different application times significantly resulted in differences of soil pH, which would further affect the N2O accumulation emission. The more times of applications, the greater the degree of soil acidification, so the less cumulated amount of N2O emissions. Therefore, under the condition of the same amount of nitrogen, soil acidification, N2O emissions, nitrate nitrogen accumulation and fertilizer costs should be comprehensively considered in determining the reasonable split applications.