Cd-Pb复合污染在土壤-烟草系统中生态效应的研究

Ecological Effect of Combined Cd-Pb Pollution on Soil-tobacco System

通过盆栽实验研究了复合污染对烟草生长的影响,以及重金属复合污染物在土壤-烟草系统中迁移、累积规律。结果表明:元素交互作用特别是Cd、Pb两元素复合作用影响了烟草的正常生长发育,株高比对照减少了17.70 cm,达到极显著性水平(p<0.01),烟草减产38.44%,而五元复合污染对烟草的生长影响很小。Cd元素在H5不同处理重金属处理的烟草叶部累积的浓度大小顺序为:五元素>两元素>单元素,而对Pb元素则表现为:单元素>两元素>五元素,特征刚好与Cd元素相反。元素交互作用时,Pb元素的存在促进了烟草对Cd元素的吸收,而Cd元素却抑制了烟草对Pb元素的吸收;Cd、Pb元素大部分集中于烟草的茎叶,尤其是Cd元素比Pb元素更易向地上部迁移。

A potted experiment was carried out to investigate t he effects of combined pollution, migration and accumulation of heavy metals in soil-tobacco systems. The results showed that normal growth of tobacco in single element treatment and Cd-Pb treatment was seriously affected. The crop was 17.70 cm shorter in height and 38.44% less in yield than that in controlled trials. And there was significant decrease （p〈0.01）., The normal growth of tobacco in the five-heavy metals treatment was not affected clearly. In terms of distribution of Cd in the leaf of tobacco, the treatments were in the order： 〉 Cd-Pb treatment 〉single element treatment. In terms of distribution of Pb in the leaf of tobacco, the order of the treatments was contrary to that of Cd. In the two elements treatment or the five elements treatment, the presence of Pb stimulated the plant to absorb Cd, but the presence of Cd inhibited the absorption of Pb by tobacco. Moreover, the elements of Cd and Pb tended to be accumulated in the aerial parts of tobacco, while Cd was more mobile than Pb to migrate upward.