Optimizing irrigation strategies to increase water utilization efficiency and achieve higher yield is vital for balancing groundwater use and improving food security during water shortage in the North China Plain (NCP). Based on a 16-year field experiment (2003–2018) using seven irrigation schedules from W0M0 to W4M3 (numbers are irrigation times in wheat (W) and maize (M) season, 75 mm each) in the winter wheat–summer maize double cropping system, we analyzed annual total water consumption (ET_a) and groundwater table change in terms of net groundwater depletion, annual total grain yield, water productivity (WP), irrigation water productivity (IWP) and marginal benefit of the whole wheat–maize system. Relationship between yield or WP and irrigation or ET_a were also revealed. Results showed that (1) total ET_a increased as irrigation input increased, ranging from 427.3 mm (Rainfed, W0M0) to 891.0 mm (W4M3). Soil water storage contributed nearly 30% to ET_a for winter wheat under water deficit conditions. Pre-sowing soil water storage played an important role in improving the annual yield and WP of both wheat and maize by promoting germination, seedling emergence and root growth; (2) the rainfed treatment (W0M0) was best for mitigating the groundwater table decline (0.1 m yr^-1), followed by W1M1 (0.5 m yr^-1) and W2M1 (0.8 m yr^-1). Groundwater table decline in M2W2 almost overlapped the observed data at the station (1.1 m yr^-1). In W3M2, the farmers’ traditional practice, the groundwater table declined by 1.4 m yr^-1, obviously over exploitation, while W4M2 and W4M3 declined by almost 2.0 m yr^-1; (3) the relationship between total annual yield and irrigation (or ET_a) followed a quadratic curve. Total annual yield significantly increased from W0M0 to M1W1 (25%) to M2M1 (5%) and then kept stable. Average annual WP decreased as irrigation increased, from 2.4 kg m^-3 (W0M0) to 1.6 kg m^-3 (W4M3). Average annual IWP and marginal benefit also declined as irrigation increased. These results over 16 years indicated that the W2M1 is the most balanced irrigation regime for wheat– maize rotation to mitigate groundwater decline, maintain grain production, and improve water use efficiency in the NCP.

优化灌溉策略以提高水资源利用效率和实现更高产量对于在华北平原 (NCP) 缺水期间平衡地下水使用和改善粮食安全至关重要。基于一项为期 16 年的田间试验（2003-2018），使用从 W0M0 到 W4M3 的七个灌溉计划（数字是小麦 (W) 和玉米 (M) 季节的灌溉时间，每个 75 毫米）在冬小麦 - 夏玉米双季灌溉中在种植系统中，我们分析_了地下水净消耗量、年粮食总产量、水生产力（WP）、灌溉水生产力（IWP）和全麦-玉米的边际效益等方面的年总耗水量（ETa）和地下水位变化系统。产量或 WP 与灌溉或ET _a之间的关系也被曝光了。结果表明 (1) 总ET _a随着灌溉输入的增加而增加，范围从 427.3 mm (Rainfed, W0M0) 到 891.0 mm (W4M3)。在缺水条件下，土壤蓄水对冬小麦的ET _a贡献了近 30% 。播前土壤蓄水通过促进发芽、出苗和根系生长，对提高小麦和玉米的年产量和可湿性起到重要作用；(2) 雨育处理 (W0M0) 最能缓解地下水位下降 (0.1 m yr ^-1 )，其次是 W1M1 (0.5 m yr ^-1 ) 和 W2M1 (0.8 m yr ^-1 )。M2W2 的地下水位下降几乎与该站的观测数据重叠（1.1 m yr^-1）。在农民的传统做法W3M2中，地下水位下降1.4 m yr ^-1，明显过度开采，而W4M2和W4M3下降近2.0 m yr ^-1；(3)年总产量与灌溉量(或ET _a )的关系呈二次曲线。年总产量从 W0M0 显着增加到 M1W1（25%）到 M2M1（5%），然后保持稳定。随着灌溉量的增加，年均 WP 减少​​，从 2.4 kg m ^-3 (W0M0) 减少到 1.6 kg m ^-3(W4M3)。随着灌溉量的增加，年平均 IWP 和边际收益也下降。这些超过 16 年的结果表明，W2M1 是小麦-玉米轮作最平衡的灌溉制度，可减轻地下水减少、维持粮食生产并提高 NCP 的用水效率。