Vertical Distribution of Available Heavy Metal in Vegetable Soil

Vertical distribution of diverse available heavy metal elements in vegertable soil profile ( 0 ~ 2m ) was studied with different extractants. The results indicated that the content of available heavy metal in soil decreased with the increase the depth. This regularity adequately showed that the external factors were the important resources of available heavy metal, for example the atmospheric deposition, fertilizer application, pesticides and so on. The content of one single element in deeper layer was still high in individual region, it maybe the soil was influenced by heavy metal mineralization.