Using Reclaimed Water for Agricultural and Landscape Irrigation in China: a Review

Suffering from severe water scarcity, China has been using wastewater for irrigating cereal, fiber, and vegetable crops as well as landscapes, for decades. During this time, both quantities and qualities have been enhanced from raw wastewater to secondary and even tertiary treated wastewater. Currently, approximately one-third of the reclaimed water is used for agricultural irrigation. Moreover, 34, 12, 23 and 2% of the reclaimed water is used in the sector of recreation/environment, miscellaneous urban use, industry, and groundwater recharge, respectively. Extensive research has been conducted concerning irrigation with reclaimed water, including the responses of crops and risk assessments of the environment, soils, groundwater, and human exposure. A positive response to reclaimed water irrigation on crop growth and yield with acceptable product qualities was found as a resulted of exposure of the additional nutrient constituents of reclaimed water. These findings were generally supported, although reductions in crop yield and quality and the ornamental performance of landscapes and soil deterioration were occasionally reported in the literature. More reclaimed water is expected to be used for agricultural and landscape irrigation as the conventional water supply is becoming increasingly limited. The increasing concern of environmental risk caused by irrigation with reclaimed water and its complexity requires continuous monitoring and more research on the negative influences resulting from reclaimed water irrigation. Copyright (c) 2017 John Wiley & Sons, Ltd.