Study On Accumulation Of Five Heavy Metals In Crops And Soil In Different Levels

Soil heavy metal pollu ting has not only restrict the substainable development of economy and society, but also bring severe risk to human health. There is importantly significance to learn the accumulation of crops’edible part and the effect on crop’s yields. In thesis, heavy metals (Cr、Pb、Cd、As and Hg) concentrations in three crops and according soil (latosol) were investigated in a field experiment to explore their accumulation in crops’edible parts and effect on yields, which can provide scientific evidences for soil pollution abatement. The main results of the study are shown below.(1) Under different metal-specific treatments, the bioconcentration capacity of rice to five metals had the following orders:Cd>Hg>As>Cr>Pb. Heavy metal concentrations in rice increased with the addition of metal level, respectively. After harvest, available-metal and total metal concentrations in paddy soil were increased with the addition of heavy metal level, respectively. As for the yield, reduced amplitude of the rice yields followed the orders:Cr>As>Pb. Whereas, in the Hg and Cd groups, the rice yields were increased by11.7%and7.5%, respectively, compared to the control.(2) Under different metal-specific treatments, the bioconcentration capacity of pakchoi to five metals followed in orders:Cd>As>Cr>Hg>Pb. Heavy metal concentrations in pakchoi edible part were increased with the addition of metal level, respectively. After harvest, available-metal and total metal concentrations in pakchoi soil were increased with the addition of heavy metal level, respectively. In the As and Cr groups, compared with the control, the pakchoi yields reduced by24.1%and24.8%, respectively. While in the Pb group, the pakchoi yields were increased by5.6%. compared to the control. Hg and Cd treatments have no significant influence on the pakchoi yields.(3) Under different metal-specific treatments, the bioconcentration capacity of carrot to five metals followed in orders:Cd>Hg>Cr> As> Pb. Heavy metal concentrations in carrot edible part increased with the raising of feed metal, respectively. After harvest, available-metal and total metal concentrations in carrot soil increased with the addition of heavy metal level, respectively. In general, reduced amplitude of the carrot yields followed the orders:Cr>Pb>Cd>As>Hg. As、Pb and Cr treatments have no significant influence on the carrot yields. In the Cl level Hg treatment, compared with the control, the carrot yields increased by7.8%. While in the C1and C2level Cd treatments, the pakchoi yields were reduced by5.2%and 15.7%, respectively.