Response Of Pakchoi To Soil Cadmium Pollution And Its Relation With Soil Properties

Cadmium is a kind of typical pollutant, which is harmful to human health. Cadmium can be uptake from soil by plant, the amount of Cd uptake by plant depend on not only plant species but also soil properties. It's significant to protection of environment and human health that understand the fate of Cadmium in soil and distribution of Cd forms. Most studies show that soil properties have a correlate strongly with bioavailability of Cd such as pH. This study is to identify soil properties how to influence on the bioavailability of Cd with Tessier's sequential extraction program under different soil conditions. Some results have achieved as follow:1.Under pot culture condition, two rates of Cd applied to 9 soil types(1.0and5.0mg/kgsoil),toxic symptom and decrease of biomass of pakchoi have not shown significantly. At two soils applied 6 levels of Cdwhich range from 0 mg/kg-lOmg/kg, when the content of Cd uptake by pakchoi can achieve 197mg/kg DW, pakchoi still have nothing toxic symptom and significantly decrease biomass.2.With the rate of Cd applied to soils increasing, the uptake of potassiun and calcium increase can be comfirmed .The amount of manganese and magnesian uptake by pakchoi have not been effected. The amount of iron uptake by pakchoi is different under two soil types condition that the amount of iron uptake by pakchoi decrease with rate of Cd applied increase in acid soil and increase in alkaline soil. The amount of copper uptake by pakchoi improved in alkaline soil and reduced in acid soil with the rate of Cd increasing.3.0n the acid soil ,the distribution of chemical forms in pakchoi is NaCl-extractable-Cd>water-extractable-Cd > aetic acid- extractable-Cd > C2H5OH- extractable-Cd > HC1- extractable-Cd. NaCl-extractable-Cd and water- extractable-Cd are predominant forms in pakchoi.4.The regression model show that relation between the amount of uptake by pakchoi and rates of Cd according to the equations as followed; Y= -0.588 X2+10.862 X +5.692(alkaline soil); Y=-1.96X2+38.45X+8.68(acid soil)5.The regression model show that the relation between the amount of uptake by pakchoi and forms of Cd in different soils: Y=54. 892XF1+3. 547 (R=0. 779, R2=0. 607, P<0. 001 = . The model of Cd uptake by pakchoi and soil properties at 0mg Cd applied as followed: Y=3.10XoM-0. 508(R=0. 821,R2=0. 674). The model of Cd uptake by pakchoi and soil properties at ling Cd applied as followed: Y=-7. 973X?0. 077Xap-0. 368XAFEE+3. 184XOM+67. 271 (R=0.998, R2=0. 996) . at 5mg Cd: Y=-18. 696XPH+166. 745 (R=0. 841, R2=0. 707)-, the integrated model is : Y=7. 97XTcd-0. 047XFsi+2. 9019 (R=0. 8866, R2=0. 780)...