中国主要粮食作物的生产水足迹量化及评价

明确作物消耗单位水量所提供的营养物质差异对于引导节水型膳食结构和农业种植规划具有重要意义,水足迹为进行上述分析提供了有效的指标。本文基于水足迹理论,在量化中国大陆主要粮食作物重量、能量和蛋白质水足迹的基础上,评价了各作物间及区域间三种水足迹的差异性,探讨了粮食作物消费结构调整对生产端水资源消耗产生的影响。结果显示:各作物生产水足迹差异显著并且具有明显的区域分布特征,东北地区、黄淮海地区作物重量水足迹均较低,表明上述地区的水分利用效率较高;5种粮食作物中,玉米和小麦具有较低的能量水足迹,而大豆具有较低的蛋白质水足迹,表明在耗水量相同的情况下,玉米和小麦较其他作物能提供更多的能量,大豆能提供更多的蛋白质;不同粮食作物消费结构下的农业用水差异显著,通过调整作物消费结构,可以达到显著的节水效果。本研究结果可为解决未来粮食生产水危机提供一个潜在途径。

Quantification and evaluation of water footprint of major grain crops in China

Guaranteeing water resources and food security are the main challenge that China faces today. To explore the diversity of nutrient supply of different crops in the case of consuming the same volume of water will contribute to establishing the water saving diet pattern and cropping structure. Based on the water footprint(WF)theory, the multidimensional water footprint of five major grain crops are analyzed by assessing the WF per unit weight, per unit energy, and per unit protein of those crops. Through scenario analysis, the water saving benefits of adjustments to the dietary consumption structure is evaluated. The results show that Northeastern and Huang-Huai-Hai Region have a relatively low WF which indicates that those regions have high weight water use efficiency. Among the five grain crops,wheat and maize have relative small energy water footprint. Soybean has a relative small protein water footprint. It indicates that wheat and maize will consume less water than other crops when provide the same energy. Soybean will consume less water than other crops when provide the same protein. Scenario analysis of adjustments to the grain crops structure proves that it is feasible to reach the objective of water saving benefit in agriculture through changing crop consumption structure. The conclusion will act as a reference for a water-conserving dietary pattern,and provide a potential solution for future water resource crises faced by grain production.