东莞地区土壤环境质量基本特征

东莞市土壤环境质量较好,土壤中重金属铅、汞、镉、铬和砷虽有所累积,但大多都在《国家土壤环境质量标准》二级以下,仅汞和砷在三角洲平原前缘局部地带达到污染级．由于三角洲平原土壤有机质及养分含量较高,质地粘重,并有盐分累积,耕作方式常采用水旱轮作,从而减少了土壤中重金属的积累,也减少了植物对重金属的吸收．

The Basic Feature of Soil Circumstance Quality in Dongguan City

The soil circumstance quality in Dongguan city is better. The soil accumulates heavy metals including,plumbum, mercury,cadmium ,arsenic and chromium .But most of them are under the "National Soil Circumstance Quality Standard" second level,only mercury and arsenic in front part belt of delta plain achieve the pollution level. The content of organic matter and nutrient in soil is higher,and also cohesive texture ,further more it accumulates saltnity . So the cultivation manner often use water or drought in turn. And then it will decrease the accumulation of heavy metals in soil,and it will also decrease heavy metals absorbing of plants.