褐土中镉的化学形态及其对植物的毒性研究

通过土培试验研究了褐土中不同有机质处理(即去除有机质与未去除土壤按1∶1、1∶2、1∶3混合)对外源镉的化学形态及其植物毒性的影响,以期为镉污染土壤的防治和修复提供依据。结果表明,在外源添加镉浓度相同时,不同有机质处理对土壤中镉的植物毒性影响不显著。土壤中弱酸提取态的镉含量随着镉浓度的升高而增大,残渣态的镉含量随镉浓度的升高而减小;可还原态的镉占总量的百分比随镉浓度升高变化不大,均在28%左右;可氧化态的镉占总量百分比最小,最高为2.62%。除残渣态外,土壤中其他3种形态的镉与其植物毒性显著相关(R2≥0.70)。

Fractions and Phytotoxicity of Cadmium in Cinnamon Soil

Through cinnamon soil culture experiment,the effects of organic matter treatments(mixture soil with removal and remained organic matter by ratios of 1∶1,1∶2 and 1∶3) on chemical form of exogenous Cd and its phytotoxicity were studied to provide basis for the control and regulation of cadmium contaminated soil.The results showed that the impact of different organic matter processing were little on Cd phytotoxity under the same added Cd condition.Weak acid soluble fraction Cd in soil increased with added Cd increasing,while residual fraction Cd decreased with added Cd increasing.The persentage of reducible fraction Cd changed little with added Cd increasing,remained about 28%.The persentage of oxidable fraction Cd was lowest,at most reached 2.62%.Except residual fraction Cd,the other three forms of Cd had significant correlation with phytotoxity(R2≥0.70).