The North China Plain (NCP) is a major food producing region in China. Overexploitation of groundwater for irrigation and overapplication of nitrogen (N) fertilizer have contributed to increased food production but have also resulted in water shortages and groundwater contamination. This paper reviews potential conflicts between strategies that ensure water security, food security, and water pollution reduction in the NCP. It outlines some agriculture-related strategies for resolving water shortages. Besides water saving and N saving technologies, policies such as fallow tillage, a water transfer project accounting for the recovery of groundwater level, and N management limiting N input in farmland are discussed. In particular, there are conflicts between the strategies for recovering shallow groundwater and releasing N from the unsaturated zone to the aquifer in the piedmont plain because a large amount of N is stored in the thick unsaturated zone. A transition from food-oriented strategies to sustainable development management of resources and the environment is necessary. To benefit from synergies and avoid tradeoffs between water security, food security, and clean water in the NCP, we must combine water and N management, groundwater level and water quantity control, socioeconomic issues, and climate change.

The North China Plain (NCP) is one of the major grain production areas in China where the groundwater level has declined rapidly in recent years because of irrigation. To alleviate the pressure on water resources, in 2016, the government developed and implemented a reasonable subsidy policy, known as the Winter Fallow Policy (WFP), to fallow cultivated land in a selected pilot area in the funnel region (Heilonggang region, HR). In the present study, a large-scale household survey was conducted across the NCP groundwater overexploitation region (OR) to evaluate the possible impact of the WFP on groundwater and food security. Our survey results indicated that the education level of decision makers, the dependency ratio of farmers, laborers per cultivated area, and the magnitude of the importance of water-saving in agriculture of decision makers have significant impacts on farmers' willingness to fallow. The average ecological compensation (EC) was 8781 CNY/ha (1358 USD/ha) and varied from 6932 to 10816 CNY/ha (1072–1673 USD/ha) in different counties. Winter wheat fallow in semiarid, dry subhumid and humid areas can save approximately 4642, 3325 and 1906 m³/ha, respectively, of groundwater in the OR. In the HR, a fallow area of 0.31×10⁶ ha is recommended for maintaining the current groundwater table, and an area of 0.42×10⁶ ha is recommended for restoring or recovering groundwater resources; these areas are greater than the existing fallow area and will reduce wheat yields, accounting for 1.55% and 2.08%, respectively, of national wheat production. Thus, EC standards should be determined based on local commodity price standards and modified based on annual changes in local conditions. Furthermore, the winter fallow acreage should be expanded in the HR to maintain the groundwater table.

The increasing dependency on groundwater, especially in irrigated regions, has highlighted the notable place of groundwater resources within the water-food-energy nexus (WFEN). This role is particularly relevant in the Haihe River basin of China, a globally representative area that is experiencing rapid aquifer depletion. The winter wheat (Triticum aestivum L.) fallow strategy may have the potential to limit withdrawal in this region. Based on information from multiple sources, this paper proposed six kinds of fallow schemes—under the same triple-cropping system consisting of winter wheat and summer maize (Zea mays L.) followed by fallow and summer maize in two years (WW–SM/F–SM) but with different irrigation schemes—as scenarios to conduct detailed simulation by a modified Soil and Water Assessment Tool (SWAT) model. Then, the water balance components of the shallow aquifer and soil profile (2 m) under different scenarios were analyzed to quantify the variations in hydrological processes caused by changes in cropping system and pumping intensity. Furthermore, through 17 indices that could quantitatively describe the changes related to the WFEN, the effects of seasonal fallow schemes on shallow groundwater drawdown mitigation, grain yield reduction, and energy consumption savings were evaluated. Based on these evaluation outcomes, linear programming was used to optimize the fallow schemes at the subbasin scale. As a result, to satisfy the constraint of stopping groundwater drawdown as well as improving water and energy productivities, the minimum reduction in the annual average winter wheat yield would be 55% compared with the basic scenario, while the summer maize yield would remain basically stable. Under the optimized fallow scheme pattern, 66% of the well-irrigated cropland should adopt the WW–SM/F–SM system with two irrigation applications for winter wheat and a rain-fed scheme for summer maize; additionally, 24% of the well-irrigated cropland should adopt the WW–SM/F–SM system with one irrigation application for winter wheat and a rain-fed scheme for summer maize, and the recommended fallow schemes for the other 10% of well-irrigated cropland varied spatially. Compared to the basic scenario, the optimized fallow scheme pattern could decrease shallow groundwater exploitation by 36.5 × 10⁸ m³ a⁻¹ (i.e., to realize shallow groundwater equilibrium), reduce the diesel consumption of agricultural machines and electricity consumption of pumping wells by 32% and 90%, respectively, and save energy costs by approximately 873 yuan ha⁻¹. These results could provide a quantitative reference for policy-making in this watershed and serve as a typical case for similar areas that wish to implement fallow strategies to achieve groundwater sustainability.