生活源再生水短期灌溉对表层农业土壤理化性质的影响

Effect of short-term irrigation on physicochemical characteristics of surface agricultural soil with reclaimed water from domestic sources

再生水灌溉农业是再生水资源化利用的重要途径。我国再生水灌溉农业起步较晚,相关基础性研究比较缺乏。以生活源再生水和农业土壤为研究对象,批次试验探讨短期灌溉对表层土壤性质的影响。结果表明:再生水灌溉对土壤pH值影响很小,但灌溉过程可以增加土壤有机质含量;土壤有机质呈现“升高—降低—趋稳”的变化趋势,代表了“再生水有机质补充”和“土壤有机质淋溶”的综合效应;灌溉后的土壤Ca^(2+),Na^(+)和K^(+)含量升高,其他离子含量变化甚微,推测再生水灌溉引发土壤次生盐渍化风险较低;再生水灌溉能够增加土壤AN和TP含量,这有助于改善土壤养分状况;灌溉前后土壤表面形貌差异不大。

Agricultural irrigation is an important way for the reutilization of reclaimed water.Currently,it lacks the related fundamental research on reclaimed water-irrigated agriculture in China.Reclaimed water from domestic sources and surface agricultural soil samples were selected,and batch experimental procedures were applied to investigate the relationship between irrigation process and soil properties.The results show:pH values of soil change little during the reaction,and organic matters contents in soil increase to some extent.The variation curve of organic matters contents in soil appears in the feature of“increased-decreased-stable”,which represents the comprehensive effect of“organic matters influx from reclaimed water”and“organic matters outflow from soil”.The concentrations of calcium ion,sodium ion and potassium ion increase,and those of other ions basically unchanged.It shows a low secondary risk of salinization in soil irrigated with reclaimed water.The contents increase of available nitrogen(AN)and total phosphorus(TP)in soil suggests that soil nutrients level might be improved via reclaimed water irrigation.The surface characteristics of soil samples before and after irrigation are similar.