Contaminative Actuality And Analytic Study Of Cd In Agricultural Soils Of Guizhou Province

In this paper, the present situation of Cd in the agriculture soils of Guizhou Province was investigated and evaluated. That will provide some suggestions about how to improve the polluted soils of Cd, how to choose the places as planting organic foods and adjust the configuration of agriculture. The results showed that the distribution of Cd is asymmetrical in the agriculture soils of Guizhou Province, the highest coefficient of variation of Cd reached 110%. The single factor polluted index of Cd was 11.8, which overstepped out and away the level of heavy pollution. It could be seen that the soils had being polluted especially by Cd. It was more appropriately to choose 0.310mg/kg as the background concentration of Cd in the soils of Guizhou Province. The concentration of Cd in the soil sections reduced from the top down, Cd was enriched in the surface, which increased the risk of agricultural produce. It got the best extract condition of available Cd through orthogonal design, and under the experimental condition, the extract contents of available Cd were inverse ratio to pH, direct ratio to total contents of Cd. It was the first time that the paper combined the model of non-polluted evaluation to the geography information system and established the soils analytic system of Guizhou Province, which could directly and vividly educe the evaluated results including the evaluation of Cd element pollution and the evaluation of integrated polluted index and so on. That was an innovational point in the methods of environmental quality evaluation in soils.