Investigation of heavy metals' migration in soil-crop system in the suburban farmland zone of Changchun

For the purpose of studying heavy metals' migration in soil-crop system in farmland protection zone, an investigation is conducted in the suburban farmland protection zone of Changchun in September 2004. Samples of soil and corns are collected, and analyses of the soil samples and the content of heavy metal in corn roots, stems, leaves and seeds are respectively conducted. The results show that the content of all the heavy metals except Cd in the soil is much higher than that in the crops. And within the crops, the content of heavy metals in the roots and leaves are much higher than that in the stems and seeds. The distribution regularity of heavy metals within crops is roots> leaves> stems> seeds. In terms of the enrichment coefficient of all heavy metal elements, Cd is the highest, then Zn and Cu, with Pb and Cr being the lowest. And the roots have the largest enrichment coefficient of all the heavy metals.