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通过室内土培试验,研究了不同浓度处理水平的Cd、Pb、Cu、Zn、As几种重金属对玉米Zea mays和高粱Sorghum vulgare成苗过程的影响。结果表明,在土壤环境质量二级标准上限值处,复合重金属对玉米、高粱的苗长和根长抑制均达到了极显著程度,当超过土壤环境质量三级标准后根长几乎被完全抑制。同时发现,玉米和高粱生理生化指标的变化与土壤重金属浓度之间存在一定的相关性。生长在铅锌尾矿和矿毒水污染土壤中的玉米和高粱受毒害作用也极其显著,高粱的抗性比玉米强。以酶活性为参考指标,可以将土壤环境质量二级标准上限值拟设定为土壤中5种重金属对玉米和高粱产生明显生理毒性效应的临界浓度值。
The effects of Cd, Pb, Cu, Zn, As on the seedling growth of Zea mays and Sorghum vulgare were studied by indoor soil culture experiments. The results showed that at the upper limit of secondary standard of soil environmental quality, the composite heavy metals inhibited the seedling length and root length of maize and sorghum to a very significant extent. When the soil environmental quality exceeded the third grade standard, the root length was almost completely inhibited . At the same time, it was found that there was a certain correlation between the changes of physiological and biochemical indexes of maize and sorghum and the concentration of soil heavy metals. The toxic effects of corn and sorghum grown in the soils polluted by lead-zinc mine tailings and mineral water are also significant. Sorghum is more resistant than corn. Taking enzyme activity as a reference index, the upper limit of secondary standard of soil environmental quality could be set as the critical concentration value of five kinds of heavy metals in soil which have obvious physiological and toxicological effects on corn and sorghum.