土壤铜镉的植物可利用性评估模型

Statistical Model for Phytoavailability of Copper and Cadmium in Soils

文章选择12种土类共57个不同土体为研究对象,分析了土壤的基本理化性质(pH、有机质、速效磷、阳离子代换量和粘粒含量)和土壤中铜、镉全量。利用SPSS13.0统计软件预测了土壤铜、镉的植物可利用性与土壤理化性质的相关模型,发现土壤中镉的植物可利用态含量与土壤中全镉、有机质、速效磷和阳离子代换量呈正相关,与土壤pH呈负相关关系。与镉不同,在考虑铜的植物可利用性时,必须考虑镉的影响。结合离子冲量和生态风险指数法的优点,采用加权离子冲量的形式可有效地表征土壤中铜镉复合污染的植物可利用性(lgωI植物=0.995 lgωI土-0.058 pH+0.084 lgSOM+0.153 lgP速效-0.365)。并且说明铜镉复合污染的植物可利用性主要受到土壤中重金属含量、pH、有机质和速效磷的影响。

Physicochemical properties including pH,organic matter（OM）,available phosphorus content,CEC and clay content as well as total Cu and Cd of 57 soil samples which belonged to 12 soil types were analyzed.Statistical model for phytoavailability of Cu and Cd in different soils with soil physicochemical properties was predicted by using SPSS 13.0 software.Results indicated there was positive correlation between Cd phytoavailability and parts of physicochemical properties including total Cd,OM,available phosphorus and CEC while negative correlation between Cd phytoavailability and pH.Besides that,the phytoavailability of Cu was affected by soil Cd significantly.Statistical model expressed by weight ion impulse has significant relation between phytoavailability of Cu-Cd compound contamination and physicochemical properties in different soils,combined with the advantage of ion impulse and Hakanson ecological risk index.Phytoavailability of heavy metals compound contamination was affected by the content of heavy metals,pH,SOM and available phosphorus content significantly.