内蒙古武川县土壤硒分布特性研究

Distribution Patterns of Soil Se in Wuchuan County,Inner Mongolia, China

北方农牧交错带是我国重要的生态类型区,也是我国典型缺硒区,对于该地区土壤硒含量和分布进行研究,有利于生产优质农产品和保障人体健康。对代表性农牧交错带——内蒙古武川县进行了等距离、大密度采样,并对采集到的237个土壤样品进行测定分析,探讨海拔高度、p H和土壤有机质对于土壤硒含量的影响。研究表明,武川县境内土壤表层全硒含量变幅为0.020~0.711 mg kg^(-1),几何平均值为0.141 mg kg^(-1),远低于全国平均水平,其中71.7%以上属于低硒土壤,土壤含硒<0.175 mg kg^(-1)。各乡镇中,二份子乡土壤硒的几何平均值最高,为0.174 mg kg^(-1),壕赖山乡最低,为0.104 mg kg^(-1)。对于不同利用方式的土壤,武川县草地土壤硒水平最高,其次是耕地和林地。对于武川县境内土壤,p H对土壤全硒含量无显著影响,而土壤有机质和海拔高度与土壤硒含量则呈显著正相关关系。研究表明,今后还应结合更多的地质和土壤特性以及植物吸收过程,全面、准确的分析硒在土壤-植物系统中的迁移转化特征。

Farming-grazing transitional zon e is an important ecosystem in Northern China, where there is lack of Selenium（Se） element in soil. High quality agricultural production and protection of human health have been promoted by the investigation of soil Se content and distribution in the region. In this study, a typical farming-grazing transitional zone, i.e., Wuchuan County, was selected to take 237 soil samples within the County and analyze soil Se content and the relationship between altitude, p H and soil organic matter. The results found that in surface（0- 20cm） soil of Wuchuan County, total Se content ranged from 0.020 to 0.711 mg kg^（-1）, with the geometric mean of 0.141 mg kg^（-1）, far below the national mean value of China. More than 71.7% of the county land was low Se（ 0.175 mg kg^（-1））.Among all the towns in the county, Erfenzi Town had the highest geometric mean value of total Se（0.174 mg kg^（-1）） and Haolaishan Town has the lowest value of 0.104 mg kg^（-1）. For all land-uses, grassland soil had the highest Se content,followed by farmland and forestry. Soil total Se content had a significant positive correlation between soil organic matter and altitude, but no relationship between soil organic matter and p H. More studies should be carried in the future on plant uptake of Se and the relationship between geological and soil properties, and completely and accurately analyze the migration and transformation characteristics of Se within soil-plant system.