Accumulative Characteristics Of Heavy Metals By Crops And Quality Safety Of Agricultural Products

Using both the field-survey method and the pot-culture experiments, contaminative situation of Cd, Pb, Cu and Zn in soils distributed around the Qingchengzi Pb-Zn Mining Area of Liaoning Province were investigated, and metal accumulation in maize (Zea mays L.), sorghum (Sorghum L.), soybean (Glycine max L.) and foxtail millet (Panicum miliaceum L.) was analyzed. Further experiments were carried out to examine the growth and development characteristics of two maize varieties Shendan 16 and Nongda 108 under conditions of a range of Cd concentrations as well as a combination of Pb, Cu and Zn. In addition, differences in assimilation of metals were delineated based on the four types of metals. Main results including: 1) Soil around Qingchengzi showed various degree of contamination with Cd, Pb, Cu and Zn and the order of contamination followed Cd>Zn>Pb>Cu, all higher than Class II of the soil environmental quality standard GB15618-1995. The magnitudes of concentration were 17.1, 1.38, 1.10 and 2.94 times that of the standard, respectively. 2) Accumulation of all four metals was consistently higher in roots than seeds for the plants investigated. 3) Significant differences of metal concentrations were also observed between Shendan 18 and Nongda108 in the roots, leaves, stems and seeds under conditions of a combination of Cd, Pb, Cu and Zn. Shendan showed obviously less accumulation of Cd than Nongda108.