黎塘岩溶区铁锰结核背景下的土壤诊断

Soil Diagnosis of Fe-Mn Nodules Background in Litang Karst

对黎塘岩溶区铁锰结核背景下的土壤进行了诊断分析。结果表明:①土壤呈中性,A层土壤有机质、阳离子交换量(CEC)、全氮、有效氮、全磷、有效磷、全钾含量及养分等级普遍高于B层,全钾、有效磷养分等级均为Ⅰ,属甚缺乏,已成为土壤养分限制的主要因子;②与广西土壤元素背景值相比较,A层土壤重金属元素Cr(Ⅵ)、Pb、Co、Zn的含量偏高,Ni、Cu的含量偏少;B层土壤重金属元素Cr(Ⅵ)、Pb、Zn、Co、Ni的含量偏高,Cu含量偏少;土壤重金属污染评价结果说明A层土壤重金属污染因子为Cr(Ⅵ)、Pb、Co和Zn,对应污染等级为中污染、轻污染、轻污染和轻污染;B层土壤重金属污染因子为Cr(Ⅵ)、Co、Pb、Zn和Ni,对应的污染等级为中污染、中污染、轻污染、轻污染和轻污染;A、B层土壤综合污染等级均为中污染。

Soil of Fe-Mn nodules background in Litang karst were diagnosised. The results showed that （1）pH value of soil were neutral, organic matter,CEC, total N, available N, total P, available P,total K content and fertility grades in A layer soil was higher than that of B layer, total K and available P index were Ⅰ , which was very lack and became the main restrictions factor. （2）Compared with background values of elements in Guangxi soil, heavy metal contents of Cr （VI）, Pb, Co, Zn were high and Ni, Cu were low in A layer soil, while contents of Cr （Ⅵ）, Pb, Zn , Co, Ni were high and Cu was low in B layer soil,The pollution index of heavy metals in the soil showed that pollution factors in A layer soil were Cr （ Ⅵ ）, Pb, Co and Zn, it＇s pollution grade were medium, light, light, light ; while pollution factors in B layer soil were Cr （Ⅵ）, Co, Pb, Zn and Ni, it＇s pollution grade were medium, medium, light,light,light, the comprehensive pollution grade was medium in A,B layer soil.