Effects Of Organic Materials On The Bioavailability Of Pb And Zn In Vegetable Soil

This paper selects 4 kinds of organic materials,such as corn stalks,deer manure,municipal sludge and microbial fertilizer,and studies the bioavailability of heavy metals Pb and Zn in the soil of a greenhouse and the impact of each classification form in Changchun.Pot experiments were conducted to investigate the influence of pakchoi on the absorption of heavy metals Pb and Zn.The main conclusions are as follows:(1)The content of DTPA-Pb in soil decreased with the increase of organic material addition,and was significantly lower than the control group.JG,LF,WN treatment groups DTPA-Zn contents in soil is presented to reduce with the increase of adding amount of organic material as the steady trend,after the JF treatment groups had DTPA-Zn content in the soil with decreaseed with the increase of adding amount of organic material.(2)After adding organic materials,the content of DTPA-Pb in soil decreased with the extension of curing time,and in the curing time of the 90 d,and the content of DTPA-Pb in soil was significantly lower than that in the blank experiment.DTPA-Zn content in the soil as the curing time to extend the present different change trend,but at the curing time of the 90 d,besides JG1 and JG2 treatment group,DTPA-Zn content in soil were significantly lower than DTPA-Zn content in the soil of curing 30 d.(3)After the addition of 4 kinds of organic materials to curing 90 d,the residue state of Pb in the soil increased significantly,and the reducible state of Pb and oxidation state of Pb content decreased significantly.However,the changes of Zn in soil were not obvious.Only WN2,WN3 and JF2 and JF3 treatment groups showed a significant increase in residual Zn content in soil.(4)After adding organic material,compared with the black experiment,the content of Pb in plant were significantly decreased,among them,the content of Pb in plant of LF3,WN3 and JF3 treatment group were the lowest,but the content of Pb in the plant of JF2 and JF3 treatment group were no significant difference,showed that 5% microbial fertilizer can achieve the best effect;The content of Pb in the JG treatment group was independent of the addition.(5)The content of Pb and Zn in the plant were significantly positively correlated with Pb and Zn in soil(p<0.05),which showed a significant negative correlation with the residue state in soil(p<0.05).The content of Zn in the plant was significantly positively correlated with the sum of the acid-extractable Zn,reducible state of Pb and oxidation state of Pb,which was significantly positive correlation(p<0.01).Showed that can reduce the absorption of Pb and Zn by reducing Pb and Zn in soil.