嵊县几种主要土壤硒的状况及有效度评价

STUDIES ON THE STATUS AND AVAILABILITY OF SELENIUM IN SOILS IN SHENXAN,ZHEJIANG PROVINCE

测定了嵊县６种主要类型土壤剖面的全硒，有效硒，粘粒组分中的硒以及表土的有机态硒。土壤全硒变化在６５－８９８μｇ／ｋｇ．有机态硒为８－１４３μｇ／ｋｇ，约占全硒１３％－２７％。有效硒（Ｏｌｓｅｎ法浸提）２９－１５３μｇ／ｋｇ，占全硒２１％－５２％。粘粒中硒含量一般比相应土壤高１．１５－１０．０９倍，影响土壤中硒含量、剖面分布及有效度的因素主要是有机质、粘粒及土壤交换性酸，嵊县不同土壤间硒的有效度变异很大，反映了母质、景观和生物等因素的深刻影响。

rofiles of six important types of soil,representing about 70% of the cultivated soil areain Shenxian,were collected to study the status and availability of selenium and its implica-tions for some Se deficiency related diseases in animals in this region.Total Se content in this region varied greatly from soil to soil.However,the total Se con-tent of soils from white muscular disease area is generally lower than the critical value(Se100 to 150 μg/kg)found in soils from a Keshan diseaseregion in China. NaHCO_3-extractableSe contents,ranging from 29-153μg/kg,accounted for 21%-52%of the total Se. The oer-centage of available Se of total Se is higher than the value(5%-10%)commonly observedin soils from the Keshan disease region. Factos affecting Se availability in soils included or-ganic matter content,clay content and exchangeable acidity. Low Se soils in this region weremainly associated with low Se content in parent materical or with loss of selenium during soildevelopment.