小麦-玉米不同种植制度的耗水特征与产量响应

o address the water-grain contradiction faced by the traditional winter wheat-summer maize double cropping system in the groundwater funnel areas of the North China Plain, this study optimized irrigation regimes and explored alternative water-saving cropping patterns to identify suitable water-saving and grain-stabilizing cropping systems for the region. The study used conventional irrigated winter wheat-summer maize double cropping (WM-CK) as the control and established three other treatments: rainfed winter wheat-summer maize double cropping (WM-R), winter wheat/summer maize-spring maize relay cropping over two years (WMM), and spring maize monocropping (M). The yield, biomass, water use efficiency, and spatiotemporal dynamics of soil moisture were systematically analyzed across different cropping patterns. Results showed that compared with conventional irrigation, the average yield of rainfed winter wheat decreased by 27.1%, and the total yields over two consecutive years decreased by 17.1% and 4.5%, respectively. The total yield of the rainfed double cropping system over the rotation cycle was 10.8% lower than that of conventional irrigation. The total yields of the two-year-three-crop and one-year-one-crop systems were 27.2% and 51.4% lower than those of the traditional double cropping system, respectively. The cumulative soil water deficit in the conventionally irrigated double cropping fields reached 745.1 mm over two years. The rainfed cropping system reduced the soil water deficit by 59.4%. Compared with the traditional double cropping system, the two-year-three-crop and one-year-one-crop systems reduced the soil water deficit by 34.5% and 75.3%, respectively. Over the rotation cycle, the rainfed double cropping system consumed 416.3 mm less water than conventional irrigation and increased water use efficiency by 12.8%. The two-year-three-crop system consumed 493.3 mm less water than the conventionally irrigated double cropping system. However, due to the significant reduction in yield of the single spring maize crop in the second year, the water use efficiency did not increase significantly. In conclusion, both the rainfed cropping pattern and the two-year-three-crop system can effectively alleviate the problem of groundwater depletion with minimal yield loss, and can be considered as new cropping models for mitigating the water resource crisis and stabilizing grain production in the North China Plain.