Will Maize-Based Cropping Systems Reduce Water Consumption without Compromise of Food Security in the North China Plain?

The winter wheat-summer maize double cropping system caused overexploitation of groundwater in the North China Plain; it is unsustainable and threatens food security and the overall wellbeing of humankind in the region. Finding water-saving cropping systems without compromising food security is a more likely solution. In this study, six alternative cropping systems' water conservation and food supply capacity were compared simultaneously. A combined water footprint method was applied to analyze the cropping systems' water consumption. The winter wheat-summer maize system had the largest water consumption (16,585 m(3)/ha on average), followed by the potato/spring maize, spinach-spring maize, rye-spring maize, vetch-spring maize, pea/spring maize, soybean||spring maize and mono-spring maize cropping systems. For the groundwater, the spinach-spring maize, pea/spring maize, soybean||spring maize systems showed a higher degree of synchronization between crop growth period and rainfall, which could reduce use of groundwater by 36.8%, 54.4% and 57.6%, respectively. For food supply capacity, the values for spinach-spring maize, pea/spring maize, soybean||spring maize systems were 73.0%, 60.8% and 48.4% of winter wheat-summer maize, respectively, but they showed a better feeding efficiency than the winter wheat-summer maize system. On the whole, spinach-spring maize may be a good option to prevent further decline in groundwater level and to ensure food security in a sustainable way.