Abstract:Abstract: Soil salinization has become one of the key constraints for the sustainable development of global agriculture. Mulch-drip irrigation with a suitable irrigation regime can effectively alleviate soil salinity in crop root zones and increase crop yield. In this study, in order to understand the response of soil water and salt transport and crop growth to different drip irrigation regimes, an agro-hydrological model (Agro-Hydrological & chemical and Crop systems simulator, AHC) was calibrated and validated based on the field-observed data in 2020 and 2021 in the upper Yellow River Basin. Then, the calibrated and validated AHC model was used to simulate the soil water and salt dynamics and crop growth under different irrigation and soil salinization scenarios. The results showed that the AHC model could reasonably simulate the change tendency of the measured soil water, salt transport, and crop growth processes. The R2, Root Mean Square Error (RMSE) and Mean Relative Error (MRE) values of soil water content and salt concentration in the calibration period were 0.75-0.83, 0.02-0.06 cm3/cm3, –1.7%-14.0% and 0.55-0.83, 1.55-3.40 g/L, –15.1%-–0.3%, respectively. The above three indicators of soil water content and salt concentration in the validation period were 0.58-0.77, 0.04-0.06 cm3/cm3, –1.0%-12.3% and 0.50-0.70, 1.49-3.48 g/L, –15.0%-6.2%, respectively. Meanwhile, the R2 of LAI, dry biomass and plant height were more than 0.85, the MRE of LAI, dry biomass and plant height were in the range of –20.9%-12.8%, the RMSE of LAI, dry biomass and plant height were in the range of 0.24-0.96, 1.48-1.99 t/hm2, 11.49-38.58 cm. In addition, the scenario analysis results showed that soil salinization, matric potential, and salt-leaching irrigation all had great effects on the irrigation regime, water consumption, yield, and water use efficiency. The mulched drip irrigation with –25 kPa and –15 kPa matric potentials combined with salt-leaching was recommended for maize in slightly and moderately saline soils, respectively. For slightly saline soils, the average salt stress coefficient, maize yield, and water use efficiency of –25 kPa matric potential with salt-leaching irrigation scenario were higher than those of –25 kPa matric potential without salt-leaching scenario, respectively. For moderately saline soils, the average salt stress coefficient and maize yield of –15 kPa matric potential with salt-leaching irrigation scenario were 25.2% and 31.1% higher than those of –15 kPa matric potential without salt-leaching scenario, respectively. This study can provide scientific evidence for soil water and salt regulation and irrigation management in HID and other irrigation districts with similar conditions.