The results showed that the entire pollution indexes of heavy metals in the field that had been irrigated with sewage and conventional farmlands were obviously higher than that of other fields.

• 结果表明,污水灌溉区和常规农业生产区的重金属综合污染指数明显高于其他典型区域,揭示了污水灌溉和农药、化肥的施用是土壤中重金属污染的主要来源。