重庆东北脐橙主产区土壤重金属含量分析

研究区除As、Pb含量明显低于中国土壤元素背景值和三峡库区元素背景值外，其余重金属元素的含量均高于上述土壤背景值。这表明该区土壤中重金属含量相对较高，特别是其中Cd的富集系数最高，是造成研究区土壤重金属污染的主要因素，表明该区土壤受人类活动影响较大。根据土壤综合污染指数，与土壤分级标准相比较，该区土壤总体尚清洁，仅部分地区受到Cd轻度污染。

Analysis of Heavy Metals in Orchard Soil of the Major Navel Orange Production

Heavy metal elements of surface soil in the topsoil in navel orange producing area of Fengjie are analyzed. The results show that content of most heavy metal elements is higher than the background values of Chinese soil and Sanxia area except the content of As and Pb. The relatively higher content of heavy metal elements of surface soil in Fengjie area, especially the highest enrichment coefficient of Cd suggests that human activities have important influence on the soil in this area. Compared with soil synthetic pollution index and soil classification standard,although a few areas are slightly polluted, the surface soil in Fengjie area is still clean.