Abstract:In order to explore the suitable irrigation method of brackish water for winter wheat, field experiments were carried out with different cycle irrigation methods and four single irrigation quota (40mm(I1), 60mm (I2), 80mm (I3) and 100mm (I4)) at jointing, heading and filling stages. There were four cycle irrigation treatments, that was, freshfreshfresh, brackishfreshfresh, freshbrackishfresh and freshfreshbrackish, the salt content of brackish water was 10dS/m. The AquaCrop model was used to calibrate and verify soil water and salt and winter wheat growth and production under salt water cycle irrigation. The salty cycle irrigation scheme was optimized through irrigation scenario simulation. The results showed that the AquaCrop model could simulate the soil water and salt status, the biomass and grain yield of winter wheat under salt water rotation irrigation. The RMSE of soil water, soil salinity, canopy cover, accumulative evapotranspiration, biomass and grain yield were 1.06%~2.09%, 0.03~0.27dS/m, 4.2%~11.0%, 14.95~52.17mm, 0.57~0.86t/hm2 and 0.28t/hm2 during calibration, respectively. The RMSE of final biomass and grain yield were 0.51t/hm2 and 0.33t/hm2 when verifying. Respectively, the coefficient of determination (R2) of each index was greater than 0.70, and the consistency index (d) was greater than 0.75. The calibrated model was used to simulate the grain yield under 64 salt water rotation irrigation scenarios, and the salt water rotation irrigation scheme was optimized: when the salt water content was 2~14dS/m, the range of single irrigation amount needed for 95% and 90% of the maximum yield by one irrigation of salt water at heading stage or filling stage was 79.3~93.1mm and 66.1~79.9mm, 79.6~90.8mm and 67.0~78.1mm, respectively, when salt water was irrigated at both heading stage and filling stage, the single irrigation amount was 80.4~102.6mm and 67.3~89.5 mm, respectively.