砂姜黑土中重金属Cu、Cd、Zn形态分布与土壤酶活性研究

采用小麦农田取样,对土壤中的重金属运用连续提取方法,研究了皖北砂姜黑土中Cu、Cd、Zn的化学形态特征及其与四种土壤酶(过氧化氢酶、脲酶、蔗糖酶、中性磷酸酶)活性间的关系。结果表明:在砂姜黑土中,残留态Cu、Cd、Zn在总量中所占比例很高,交换态、有机态、碳酸盐结合态含量明显低于残留态。在三种元素中,Zn的化学形态变化趋势最为一致,表现为残留态>碳酸盐结合态>铁锰结合态>有机态>交换态;砂姜黑土中交换态Cu、Cd、Zn对脲酶活性有显著抑制作用,有机态Cu、Cd、Zn对过氧化氢酶表现为一定程度的促进作用。因此,在砂姜黑土壤中,把交换态Cu、Cd、Zn和脲酶以及中性磷酸酶的活性共同作为评价土壤Cu、Cd、Zn污染程度的主要生化指标是可行的。

Relationship of Heavy Metal Forms and Distribution with Soil Enzyme Activities in Indicotic Black Soil

A successive extraction method was utilized to study the relations of chemical forms of copper,cadmium and zinc with four soil enzyme activities(calatase,urease,invertase,and neutral phosphatase) in Indicotic black soil(Cambisols).The result showed that the residual proportions of Cu,Cd and Zn to the total were quite high in the soils and that the contents of exchangeable organic and carbonate combined forms were lower than the residual form.Of the three elements,the Zn chemomorphosis change tendency was the most consistent,being that residual form>carbonate combined form>Fe-Mn oxide combined form>organic form>exchangeable form.It was found that the exchangeable form of Cu,Cd and Zn inhibited soil urease activities significantly in polluted soils,while the organic forms of Cu,Cd and Zn could inhibit invertase to some extent.