Abstract:In view of the contradiction between the declining of groundwater table and the demand of high yield, to clarify the yield and water use efficiency (WUE) of wheat-maize double cropping system in the different precipitation years under different irrigation scenarios, the results would provide important scientific decision-making basis to balance the sustainable of groundwater utilization and grain production. Based on the field experiment data, the crop biomass, LAI and soil water content under different irrigation treatments, the genetic parameters and parameters related with the soil water were calibrated and validated by using long-term meteorological data in the APSIM wheat-maize cropping model. Using the calibrated and validated APSIM model, the water deficit index (CWDI) was analyzed in different precipitation years, the crop yield, water use efficiency (WUE), and the irrigation water use efficiency (IWUE) of 8 irrigation scenarios under the dry, medium, and rainy years were simulated. The results showed that CWDI was high in each growth stage of wheat in different precipitation years, which indicated that water requirement of wheat in dry, medium, and rainy years was much higher than precipitation, especially from jointing to maturity stage. Maize was not affected by drought stress before tasseling, but was in medium or severe drought after tasseling. Considering both yield and water use efficiency in this region, when the total irrigation water was 225 mm (75 mm at wheat sowing + 75 mm at jointing + 75 mm at flowering), the total yield was high, and the WUE and IWUE was maximal. The average total yield and WUE were 17 357.6 kg/hm2 and 29.6 kg/(hm2·mm) in dry years, were 18 827.9 kg/hm2 and 25.9 kg/(hm2·mm) in the medium years, and were 19 685.2 kg/hm2 and 25.8 kg/(hm2· mm) in rainy years. Under this irrigation scenario, the yields of wheat and maize were high, and the WUE were also at the high level. So, this irrigation scenario was an important irrigation strategy and practice for water-grain trade-off in this region.