湖南省油菜主产区土壤养分含量与重金属污染风险评价

Evaluation on soil nutrients and heavy metals pollution risk in main producing areas of rapeseed in Hunan Province,China

在湖南省油菜主产区采集56个耕层土壤样品,测定土壤主要养分与有效态重金属含量,研究土壤肥力现状及其空间分布特征,并对土壤重金属污染风险进行综合评价。结果表明,湖南油菜主产区土壤pH呈弱酸性和微酸性,普遍缺乏有机质和氮、磷、钾、硼、硫、钼,还有约一半的土壤缺少钙和镁,而铁、锰、铜、锌元素丰富,土壤综合肥力等级评价结果为一般。镉轻度、中度和重度污染的样品分别占16.1%、1.8%和1.8%,但未发现铜、锌、铅、镍污染样本。据此认为,湖南省油菜生产中应合理补充有机质和氮、磷、钾、硼等元素,同时,部分地区还需采取降低镉有效性的改土措施。

In this study,56 topsoil samples were collected from the main producing areas of rapeseed in Hunan Province,and the contents of main nutrients and available heavy metals in these samples were determined to reveal the spatial distribution characteristics of soil fertility,as well as heavy metals pollution risk.The results showed that the soils in the main producing areas of rapeseed in Hunan Province were mainly mild acid and weak acid,and the deficiency of organic matter,nitrogen,phosphorus,potassium,boron,sulfur and molybdenum was common.About half of the soil samples were deficient in calcium and magnesium,yet were rich in iron,manganese,copper and zinc.The soil comprehensive fertility was rated average.Among all the samples,the lightly,moderately and seriously cadmium polluted samples accounted for 16.1%,1.8%and 1.8%,respectively,and no pollution risk of copper,zinc,lead and nickel was found.Therefore,organic matter,nitrogen,phosphorus,potassium,boron should be reasonably supplemented in the main producing areas of rapeseed in Hunan Province,and measures should be taken to reduce the availability of cadmium in certain areas.