土壤中Cu、Cd植物有效性模型的建立与检验

Establishment and Test of Statistical Model for Phytoavailability of Copper and Cadmium in Soils

选择我国代表性土壤中的黑土、暗棕壤、棕壤、黄棕壤、砖红壤、赤红壤、红壤、黄壤、紫色土、灰钙土、潮土和水稻土等12个土类的57个土壤样品为建模对象,以0.1 mol/L HCl提取的Cu、Cd含量表征土壤中重金属的植物有效性含量,利用多元线性回归的方法建立土壤中Cu、Cd植物有效性与土壤理化性质的统计模型,并选取南昌地区不同类型企业周边的蔬菜-土壤样品为模型验证对象,检验模型的适用性。研究结果表明,采用权重离子冲量的形式可同时表征复合污染土壤中Cu、Cd的植物有效性:lgwI植物=0.995 lgwI土+0.153 lgP速效+0.084lgSOM-0.058pH-0.365(r=0.875,F=42.570,n=57,P<0.001),即土壤中Cu、Cd的植物有效态含量与土壤中重金属全量、有机质含量、速效磷含量呈正相关,与土壤pH呈负相关。独立于模型的土壤-蔬菜样品中Cu、Cd含量的实测值与模型的预测值之间呈极显著的正相关关系(r=0.864,n=75,P<0.001),验证了模型的可靠性。

A statistical model were established for phytoavailability of Cu and Cd in different kinds of soils with 57 soil samples belonging to 12 soil classes,namely black soil,dark brown soil,brown soil,yellow brown soil,latosol,latosolic red soil,red soil,zheltozem,purple soil,light sierozem,alluvial soil and paddy soil.The phytoavailable contents of Cu and Cd in the tested soils were extracted by 0.1 mol/L HCl and the phytoavailability of Cu and Cd against soil physicochemical properties was analyzed with multiple regression method.Then,the statistical model was tested by the red soil-vegetable system in the adjacent area of Nanchang.The results indicated that weight ion impulse（I） could express the phytoavailability of Cu and Cd in combination contamination soils：lgwIplant=0.995 lgwIsoil＋0.153 lgPavailable ＋0.084 lgSOM-0.058pH-0.365（r=0.875,F=42.570,n=57,P0.001）.There was significant positive correlation between wIplant and physico chemical properties（such as wI soil,P available and SOM（soil organic matter） and negative correlation with pH.The predicted content of phytoavailability of Cu and Cd in the tested samples had significant correlation with the actual content,and the main driving factors were the total content of Cu and Cd,SOM,pH and P available（r=0.864,n=75,P0.001）.