以干旱区绿洲金昌城郊耕作土壤为供试土壤,采用全量分析法和Tessier五步连续提取法研究了六个典型土壤剖面重金属Cu、Zn和Ni的总量以及形态纵向分布规律。结果表明:重金属Cu和Ni表聚现象明显,表层至下,其浓度先减少后稳定,两种元素在剖面中的迁移距离相近,基本在45cm附近;Cu和Ni化学行为相似,反映了Cu和Ni来源相同;Zn的总量分布没有明显的规律性。在土壤剖面中,Cu、Ni有形态变化层位,0-45cm有机态Cu〉残渣态Cu〉铁-锰氧化态Cu,碳酸盐态Cu〉可交换态Cu;Ni的铁-锰氧化态〉有机态,残渣态,碳酸盐态〉可交换态;45cm后Cu、Ni主要以残渣态存在;Zn在所有土层中均以残渣态为主要赋存形态。研究土壤Cu、Ni的总量及形态分布主要受人为活动影响,Zn主要受成土母岩影响。
Six profiles of tillage soils of Jinchang urban were chosen to study the vertical distribution of total contents and specialtion of Cu, Zn and Ni. The results showed that the upper layer was enriched in Cu and Ni, but their concentrations decreased with soil depth increasing firstly and then reached a steady level. The transfer depth of Cu and Ni reached 45 centimeters down profiles. Actions of the distribution and transfer of total contents of Cu, Ni indicated they came from the same source. There was not apparent law for total content of Zn distribution in tillage soil . For specialtion distribution of Cu and Ni there were different in layers. However ration of Cu in organic matter and in residual fraction varied drasticallv as well as Ni in Fe - Mn oxides and in residual fraction varied drastically. From 0 to 45 centimeters, contents of Cu in organic matter was more than in residual fraction and concentration in Fe - Mn Oxides bound forms of Ni was more than in residual fraction . But they were found predominantly in residual fraction in original soil layers. In all soil layers Zn was mainly existed in residual fraction layers.