The Influence On Distribution Of Heavy Meatals In Rice And Maize With Exposure Of Soil Heavy Meatals

Farmland heavy metal pollution directly affects the amount of food production and quality. In the heavy metal pollution of farmland in the light pollution, pollution, heavy pollution proportion accounted for more than 15%, which is important and difficult part of the pollution control.This study using pot experiment set five concentration gradient of Cd, Pb, Cr, Zn, respectively, to stress the rice, maize and studies four heavy metals in diverse conditions of rice, maize field managements, research of heavy metals in the crop distribution and accumulation traits of each part, in order to prediction, evaluation and repair of heavy metal contamination in order to provide basis for food satefy. The key outcomes were described as follows:1. The difference between heavy metal pollution levels had little effect on the growth of rice and maize. This study shows that heavy metal Pb, Zn, Cr, Cd in plants moderately severe pollution still can normal grow and develop. Through the research of heavy metals’ stress to rice and maize we found biological toxicity effect for different heavy metal tolerance in rice and corn,’9311’rice for zinc tolerance is poorer, corn ’zheng 958’ has poor tolerance of Cr.2.But different parts of the rice and corn for heavy metal Cd, Cr, Pb, Zn absorption and accumulation are various. Most of the heavy metals were stranded in the roots, a small part migrate to the ground. Heavy metal content of crops in vivo showed a dose-dependent manner, in a certain concentration range, with increasing concentrations of heavy metals increases, rice and corn each part of the heavy metal content, showing a good dose-content consistency. When the dose increased the damage of plant also increased.3.It turned out that with the augment of heavy metal, heavy metal enrichment of rice plants rised, but at high concentrations of heavy metal contaminatio, enrichment factor decreased in rice plants. And there was no significant difference between the height of rice plant and dry matter. It was demonstrated that the migration capacity of heavy metals in rice plant in the order is:Cd> Zn>Cr> Pb, in corn plant is:Zn> Cd> Cr> Pb.heavy metals in different parts of rice and corn plant showed enrichment capability root>stem>leaf>grain.4.And the content of heavy metals of aleurone layer in rice grain was significantly greater than that in endosperm. After processing into milled rice Cd content of brown rice can be reduced 3%～44, Cr content can be reduced 19%～80%, Pb content can be reduced 25%～38%. It can reduce the risk of heavy metal pollution of rice and reduce eating risk aversion after processing.