Cd Accumulation And Transfer In Wheat And Pepper Grown In Typical Soils In China

Cd is a kind of cumulative toxic elements,and due to its high mobility in soil,it can enter the food chain easily through be absorbing by plant roots,and eventually poses a threat to human health through food chain enrichment.In China,farmland soil heavy metal pollution is serious,the safety of production is difficult to guarantee.And it is lack of systematic and quantitative study in farmland system research of heavy metal biological effectiveness.According to the present situation,this study ues 19 typical farmland soils in China,through pot experiment to investigate accumulation and translocation of Cd from soil to different parts of plant(wheat and pepper)in CK,Low level Cd(0.3 mg/kg,pH<7.5;0.6 mg/kg,pH>7.5)and High level Cd(0.6 mg/kg,pH<7.5;1.2 mg/kg,pH>7.5).Results showed that the Cd content in wheat and pepper was in order of roots>stems>grains(fruits)for all tested soils,and there were significant correlations among the Cd concentrations in root,stem and grain(fruit)tissues.In the enrichment and transfer process of soil-crop systems,the roots of the accumulation of Cd content is far greater than the transfer to the stem and the content of grain(fruit).Determination of the basic physical and chemical properties of the tested soil,soil total Cd content and the bioavailability of Cd(EDTA and HNO3 extraction),using correlation analysis,multiple linear regression analysis to build accumulated quantitative relation models in soil properties,soil total Cd,EDTA-and HNO3-extractable Cd and Cd content of edible parts of crops.Results showed that the best prediction model in wheat and pepper are both builded basing on EDTA-extractable Cd.