我国土壤中硒的淋溶

A PRELIMINARY STUDY ON LEACHING OF SELENIUM IN THE SOILS OF CHINA

对我国8种典型土壤中硒淋溶迁移的研究表明,硒的淋溶与土壤PH呈正相关关系,与土壤中粘粒含量,Al_2O_3等倍半氧化物的含量、土壤硒的吸附系数呈负相关关系。受这些因素影响,不同土壤硒的淋溶强度不同。本文计算了天然降雨条件下不同土壤中硒的淋溶率。结果表明,土壤硒淋溶率受有机质等土壤理化性质的影响,变化范同为0.35—2.22％,其顺序为:紫色土>褐土>暗棕壤>黑钙土>黑土>红壤、砖红壤>灰钙土。比较我国低硒—克山病病带土壤与足硒—非病带土壤的硒淋溶率的差异,病带土壤中硒的淋溶率显著大于非病带土壤,这可能是病带土壤硒低的原因之一。

It has been shown by study on eight typical soils of China that leaching of Se is positively related to pH, negatively related to content of clay particals, A12O3, R2O3and Se-absorption coefficient in soils. These factors result in the differences of Se leaching in various soils. The percentage of Se leaching in different soils was estimated according to the precipitation condition in local area respectively. It is shown that percentage of Se leaching is affected by physical and chemical parameter of soil such as organic matter etc.,and ranged from 0.35% to 2.22%, in the order as: purplish soil>drab soil>dark brown earth>chernozem>black soil>red earth = laterit soil>sierozem. Comparing the leaching of Se in Se deficient soil-Keshan disease area with Se sufficient soil-disease free area, Se leaching in soil is signifcantly higher in low Se area than that in non-disease area. Therefore, this may be one of the causation for low level of Se in soils of Keshan disease belt