华北平原地下水压采区冬小麦种植综合效应探讨

Evaluating the comprehensive effects of planting winter wheat in thegroundwater depletion regions in the North China Plain

华北平原冬小麦-夏玉米一年两熟种植模式为维护国家粮食安全发挥了重要作用。但冬小麦生长期正处于华北平原降水较少的干旱季节,实现高产依赖于灌溉,是华北平原地下水超采的主导因素之一。随着国家地下水限采政策的实施,在地下水超采区如何稳定冬小麦的种植面积和产量是面临的一个重要问题。本文通过综述以往研究并结合典型地点田间试验结果,从冬小麦种植可减少休闲期土壤蒸发损失、具有的深根系系统可充分利用土壤储水、可利用微咸水替代淡水灌溉、通过限水灌溉发展优质麦生产、冬春形成覆盖层美化和防沙尘效应等方面论述了华北平原种植冬小麦的优势,提出华北平原冬小麦生产需要转变传统高耗水高产量理念,充分发挥冬小麦抗旱、耐盐能力强的特点,在不实施大规模压缩冬小麦种植面积条件下,通过冬小麦限水灌溉和微咸水利用满足对地下水压采需求,充分发挥华北平原冬小麦种植冬春防风沙、美化环境的生态功能,同时满足区域口粮安全的保障功能。

The traditional annual double cropping system of winter wheat and summer maize in the North China Plain(NCP) can take the full advantage of regional climate resources, and has played an important role in maintaining national food security. However, high winter wheat production depends on irrigation, which is one of the leading factors for groundwater over-exploitation in the NCP. With the implementation of the national groundwater extraction restriction policy, how to develop winter wheat in groundwater over-extraction areas is becoming an important issue. Based on long-term field experimental data and literatures, this paper discussed aspects such as reducing soil evaporation loss during fallow period, brackish water resources utilization, deficit irrigation to improve quality, and effective cover formation in winter and spring seasons by planting winter wheat. The production of winter wheat in the groundwater depletion regions in the NCP would involve a change from the traditional practice of applying adequate irrigation water for high yield to using limited irrigation for higher quality and higher water use efficiency. The planting of winter wheat can reduce soil evaporation and fully use the rainfall resources during winter and spring seasons. Winter wheat can also form an effective coverage to reduce soil erosion and green the rural areas. By applying reduced irrigation based on the irrigation water availability in a region, winter wheat can still maintain a stable yield due to its deep root characteristics which can efficiently absorb the deep soil water stored during the summer rainy season. Under reduced irrigation, the quality of winter wheat can be improved, which provides the opportunity to grow high-quality winter wheat in the NCP. In the low plain of the NCP, where shallow saline water is abundant, irrigation for winter wheat by fresh water can be replaced by the shallow saline water. Growing winter wheat based on the irrigation water availability in the NCP has the benefits of wind erosion protection, beautification of the rural environment, and meeting regional food security.