在31年的长期定位试验研究基础上，分析了5个不同施肥处理下土壤重金属Cu、Zn、Cd、Pb的含量变化及其分级特征。施肥处理包括CK、NP、M、MNP (等N) 及HMNP（高氮)。结果表明，不同施肥处理Cu、Zn含量差异显著，尤其NP处理大幅度提高了土壤中锌的含量。而不同处理对Cd、Pb含量影响不大。5个不同施肥处理下的Cu、Zn、Cd、Pb均以残留态的含量为主，平均占总量为44.4%、45.6%、35.4%以及80.3%。不同施肥处理影响了重金属在各个形态间的分配比例和顺序。Cu、Zn的各个形态的含量表现为残留态>碳酸盐结合态>铁锰氧化态>有机态含量>可交换态，Pb的各形态分配顺序与Cu、Zn完全不同，依次为残留态＞有机态＞可交换态＞酸盐结合态＞铁锰氧化态，不同施肥处理影响到各个形态分配的量。不同施肥处理对Cd的形态分配影响较大。在长期NP、MNP施肥下，Cd的含量高低依次为残留态＞有机态＞铁锰氧化态＞碳酸盐结合态＞可交换态，而在其它施肥处理下，Cd的含量高低依次为残留态＞碳酸盐结合态＞有机态＞铁锰氧化态＞可交换态。
The content and chemical fractionations of heavy metals Cu, Zn, Cd and Pb in five different treatments were studied based on the 31-year long-term localized fertilization on Shajiang Black Soil. The fertilizer treatments included CK, NP, M, MNP (equal nitrogen) and HMNP (high nitrogen). The results showed that the heavy metal contents of Cu, Zn were significantly different under different fertilizer treatments, especially, the NP treatment improved total soil Cu content to an extent of 85%. However, fertilizer treatments had no significant influence on the total contents of Cd and Pb. Among the chemical fractionations, the residual form of Cu, Zn, Cd and Pb was the main fractionation of the heavy metals in the soil in despite of different fertilizations, and accounting for 44.4%, 45.6%, 35.4% and 80.3% of their total content respectively. Fertilizer treatments affected the distribution of total heave mental to fractionations and their sequence. The contents of Cu and Zn in different fractionations showed the order from high to low as residual form, carbonate form, Fe-Mn oxide form, organic form and exchangeable form. The contents of different Pb showed the sequence as residual form, organic form, exchangeable form, carbonate form and Fe-Mn oxide form, totally different with those of Cu, Zn. Fertilizer treatments affected the amount of different fractions. However, the sequence of different forms of Cd was significantly affected by fertilizer treatments. Under the long-term fertilization of NP、MNP, the sequence of the fractionations of Cd from high to low was residual form, organic form, Fe-Mn oxide form, carbonate form and exchangeable form. However, the other treatments showed the sequence as residual form, carbonate form, organic form, Fe-Mn oxide form, and exchangeable form.