采用盆栽培育土壤的方式，通过修正的Tessier连续提取法(七步法)研究了N、P和K肥对外源Cd、Pb污染土壤重金属赋存形态的影响。结果表明，无论是原土还是添加外源性Cd、Pb的污染土壤，Pb基本被固定在残渣态和铁锰氧化物结合态，在外源Cd、Pb污染土壤中添加肥料可降低Pb的铁锰氧化物结合态等较稳定形态的赋存比例，提高生物可利用态的百分比，促进Pb向植物体系的迁移。原土中的Cd大部分处于生物可利用态，当外源性Cd污染进入土壤，离子交换态进一步增加，且土壤中Cd的浓度越大离子交换态所占的百分比越高。向中低浓度的Cd污染土加入肥料可增加离子交换态的赋存比例，提高土壤中Cd的活性；对更高浓度的Cd污染土，离子交换态已基本饱和，加入肥料对Cd的形态分布未有显著影响。添加肥料可促进土壤中外源性重金属Cd和Pb向植物体系迁移，为植物修复重金属污染土壤提供技术支持。%Pot experiments and soil incubation experiments were conducted to investigate the effects of chemical fertilizer added into soil on speciation transformation of exogenous Cd and Pb by the method of seven-step sequential extraction. As shown by the experimental results, Pb was fixed in carbonate-bound and Fe-Mn oxides-bound whatever the original soil or the contaminated soil added Cd and Pb exogenously. The percentage of CBD-Pb was reduced and the bioavailable state of Pb increased by adding chemical fertilizer. Chemical fertilizer can promote the migration of Pb to plant system. The percentage of biological available fractions of Cd was most in the original soil and increased further by adding Cd and Pb exogenously. And the concentration of Cd is higher in soil, the percentage of EXC-Cd is greater. It can increase the ratio of EXC-Cd and promote the migration of Cd by adding chemical fertilizer for low concentration of Cd pollution. It can promote the migration of Cd and Pb exogenously to plant system by adding chemical fertilizer.
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