Effects Of Four Amendments On The Forms Transfor-mation Of Added Cd In Four Soils And The Biological Effects Of Cabbage In Alluvial Soil In Hunan Province

Soil is the human survival and development of material basis, however, in recent years with the rapid development of industry and agriculture, the accelerated urbanization process, especially in heavy metal contaminated soil pollution is serious, has become a worldwide environmental problem, has aroused attention. In view of this, this article alluvial soil, Quaternary red clay, red limestone, granite and red cabbage for the study pots, pots with indoor training and testing the combination of 4 different amendments (slaked lime, calcium magnesium phosphate, slaked lime+cow dung, Chinese milk vetch) Cultivated on the lake different forms of added Cd in Soil transformation and bioavailability. The results showed that:(1) Alluvial soil, red soil of the original limestone soil Cd chemical forms of heavy metals to iron and manganese oxides Cd> Cd-based carbonate; Quaternary red clay in the iron and manganese oxides Cd> Cd is exchangeable Main; granite in red by the organic bound Cd> Mn oxidation state of Cd> Cd-based carbonate bond.(2) Cd into the soil outside the stationary source after a certain time, four different types of soil in farming, the proportion of different forms of Cd some changes have occurred, compared with the control soil, but mainly in the form of exchangeable Cd. Alluvial soil, Quaternary red clay, red limestone and granite, respectively, red soil exchangeable Cd from 15.0%to 45.7%,18.2%to 45.0%,12.0% to 39.0%,14.0%to 32.3%.(3) The results show that four kinds of amendments(slaked lime, calcium magnesium phosphate, slaked lime+cow dung, Chinese milk vetch) can significantly reduce exchangeable-Cd contents in the Alluvial soil, Quaternary red clay, red limestone and granite red soil that after culturing 30 days indoor. It can promote the cadmium form inversion from exchangeable-Cd to Fe-Mn oxide, carbonate combination, organic fraction and Residual cadmium.(4) Soil Conditioners can effectively decreasing the Cd contamination in the alluvial soil on the cadmium uptake of Chinese cabbage, slaked lime+cow dung, lime can significantly improve the growth status of Chinese cabbage, Chinese milk vetch organic amendments severely inhibited the growth of Chinese cabbage, compared with the original soil, calcium magnesium phosphate on the growth status of Chinese cabbage is not obvious. For this reason, the amendments on the restoration of heavy metal there are still some limitations and potential risks, mainly in the repair of inorganic and organic amendments effects not only the kinds of heavy metal ions, but also by crop, soil type and environmental factors in the constraints.