土地利用方式对土壤重金属含量的影响分析(英文)

分别采集旱地、水稻田和基地0～20cm表层土,对不同种植作物土壤中的Cr、Cu、As、Pb、Zn含量及污染状况进行分析研究。Cr、Cu、As、Pb、Zn含量用等离子体发射光谱法ICP-AES测定,pH值测定采用Lp115型pH计,土壤污染状况采用内梅罗指数法进行评价。对比研究分析结果表明,全部土壤样品中As的含量低于陕西和全国的平均值,低于半数土样中Cr的含量高于陕西或全国平均值,超过半数以上的土样中Cu、Zn的含量高于陕西或全国平均值,所有土样中Pb含量高于陕西或全国平均值。单因子污染指数法和综合污染指数法研究分析表明,以国家二级标准为评价标准,研究区土壤未受污染,土壤为清洁,土壤质量完全符合农作物生长条件,对农产品质量不构成威胁。与陕西省自然背景平均值相比,可以看出Cu、Zn、Pb3种重金属元素高于陕西省自然背景平均值,Cr、As2种重金属元素低于陕西省自然背景平均值,土壤受到了轻度污染,说明评价标准的不同,评价结果存在明显差异。农田土壤样品重金属元素污染现象与土壤利用类型明显相关。土壤中As的含量为玉米地水稻土荒地,Cr、Cu、Zn的含量为玉米地荒地水稻土,Pb的含量为水稻土玉米地荒地。可见,旱地相对水田更易积累重金属元素Cr、Cu、Zn、As。

Effects of Land Use Patterns on Soil Heavy Metal Contents

Through sampling in farmland and analysis in laboratory,the contents and the pollution level of Cr,Cu,As,Pb,Zn in different soils were studied. The comparative result showed that the As in all soil samples are lower than the mean value of Shaanxi and whole nation,the Cr in lower half soil samples are higher than the mean value of Shaanxi and whole nation,the Cu and Zn in majority soil samples are higher than the mean value of Shaanxi and whole nation,and the Pb in all soil samples is higher than the mean value of Shaanxi and whole nation. The single factor pollution index and multi-factor pollution index method were used to evaluate the soil pollution. According to Soil Environmental Quality Standard,the studied soils were at unpolluted degrees,the soils were clear,the quality of soil adapt to the crop growth,and not affect the quality of agricultural product.