从芜湖市三山区蔬菜基地采集82个农田土壤样品,测试其中的As、Zn、Pb、Cr、Ni、Co、Mn和Fe 8种金属总量和生物有效态含量,对蔬菜基地农田土壤含量特征及来源进行了分析。结果表明:蔬菜基地土壤中8种元素的含量均高于其土壤背景值,其中As(30.01 mg/kg)含量是其土壤背景值的2.83倍。与我国《土壤环境质量标准》中的2级标准(pH〉7.5)比较,蔬菜基地土壤中As污染较为普遍,超标率为75.61%,其它元素均未超标。Pb和Mn的活化率较高,对植物危害较大。Fe和Cr的活化率相对较低,对植物危害较小。主成分分析表明:土壤中的Pb、Co、Ni、Fe、Mn和Cr主要来源于成土母质,As和Zn主要来源于农业活动。
There were 82 soil samples collected from the vegetable base in Sanshan District of Wuhu City. The characteristics of contents and sources in the vegetable soil were analyzed in detail by testing total concentrations and bioavailable concentrations of 8 metal elements in soil. The results showed that the contenls of all metals were higher than their own background value in vegetable soil, and the content of As (30.01 mg/kg) was 2. 83 times of its background value of the corresponding heavy metal element in soil. There was about 75.61% of As in all the collected soil samples from the investigated sites which had overran the content for heavy metals of China Environmental Quality Standard for Soils (GB15618 -1995, Grade II). Contamination of As was relatively universal. All the other elements did not exceed the stipulated standards. The activation rate of Pb and Mn was quite high, and they did great harm to plants. The activation rate of Fe and Cr was relatively low,and they did less harm to plants. PCA showed that Pb,Co, Ni,Fe,Mn, Cr and Cu in the vegetable soil were mainly of geogenic origin, but As and Zn mainly from agricultural activities.