湖北恩施地区土壤-植物系统中Se元素的 地球化学特征

在对恩施地区典型农业活动区——芭蕉、长平和鱼塘坝三地土壤中Se元素含量进行调查的基础上，通过与富Se土壤质量标准进行对比，发现除长平地区外，其余两地分别属于富Se和高Se地区，并通过土壤理化性质、形态分析和土壤中所生长的植物进行比较，初步研究了Se在土壤-植物体系中迁移转化的规律。结果表明：整体来看，鱼塘坝地区属于超富Se地区，植物中Se的含量也最高，长平地区属于非富Se地区，芭蕉地区则属于中等富Se地区；植物对Se的吸收受一定的土壤理化性质的影响，不同类型的植物对Se的吸收富集相差较大；形态分析研究表明，鱼塘坝地区土壤中生物可利用的Se含量较高，而芭蕉地区土壤中残渣态Se的比例较高，表现为Se的生物可利用性低于鱼塘坝地区。

Geochemical characteristics of selenium in the soil-plants system of Enshi area, Hubei Province

The survey of selenium content of soil in such typical agricultural areas as Bajiao, Changping and Yutangba was carried out. On the basis of the investigation and the comparison with the Se-rich soil quality standards, Bajiao and Yutangba were found to be Se-rich and highly Se-rich areas respectively. Based an investigation of the physical and chemical properties of soil, speciation and plants growing in the soil, the authors conducted a preliminary study of the migration and transformation of selenium in the soil-plant system. Three aspects of results have been obtained. First, the selenium content of soils and plants is quite high in Yutangba but rather low in Changping. Second, the physical and chemical properties of soil have a certain influence on the selenium absorption of plant, with different types of plants showing remarkable difference in the absorption and enrichment of selenium. Third, speciation analysis shows that the bioavailability of selenium in Yutangba soil is higher than that in Bajiao, while the Bajiao soil has a higher proportion of residual selenium, showing that its bioavailability of selenium is lower than that of Yutangba area.