Ziyuan Kexue (Jan 2023)
Spatiotemporal evolution of water footprint and water-saving potentials of crop production in Shaanxi Province during 1989-2019
Abstract
[Objective] Shaanxi Province is an important grain, oil, and fruit production base in China, but most part of the province is located in the semi-arid zone. Limited water resources are the biggest constraint to the sustainable development of local economy and society. Quantitative evaluation of water consumption and water-saving potentials in crop production is crucial for water resource-adapted agricultural development and green and high-efficiency water-saving. [Methods] Based on the spatiotemporal evolution characteristics of the annual blue water footprint (irrigation water consumption) and green water footprint (effective precipitation consumption) of growing 10 major crops under irrigated and rainfed conditions in Shaanxi Province from 1989 to 2019, the engineering water-saving potential and real water-saving potential of crop production in typical years were deduced. [Results] The results show that: (1) The consumptive water footprint per yield of all crops in Shaanxi Province showed an overall downward trend in the 30-year study period, and the water footprint of individual crops had visible differences between cities. The provincial average unit consumptive water footprint of apple production decreased by 91.3%; the difference of consumptive water footprint of wheat production between cities reached 3.41 m3/kg. At the same time, the grey water footprint of apple and rapeseed production showed an increasing trend. (2) The total consumptive water footprint of crop production was 16.055 billion m3/a in 2019, slightly decreased by 1.8% from 1989. Corn, wheat, and apple production contributed more than 80% of the total consumptive water footprint of provincial crop production. (3) The water-saving potential, blue water saving potential, and green water saving potential of crop production in Shaanxi Province were 62%, 68%, and 49%, respectively. [Conclusion] There is a great potential of agricultural water-saving in Shaanxi Province. There are two preliminary suggestions: (1) Combining technology and management measures to accelerate agricultural water-saving and efficiency; (2) Accelerate scientific and accurate fertilization to reduce environmental pressure.
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