广西三江县土壤硒含量分布特征及其影响因素研究

Distribution Characteristics of Soil Selenium Content and Its Influencing Factors in Sanjiang County, Guangxi

以广西三江县土壤为研究对象,采集了表层土壤样2751件和土壤垂向剖面样180件,测定了土壤中硒的含量。利用多元统计分析、地统计学法、GIS空间分析技术和Pearson相关性分析法研究了土壤硒的含量特征和影响因素。结果表明:研究区表层土壤硒平均含量为0.63 mg/kg,变化范围为0.10~14.41 mg/kg。研究区土壤硒资源丰富,足硒和富硒土壤面积为95.87%。土壤硒含量的分布主要受到地质背景的控制,不同成土母岩形成的表层土壤硒含量存在较大差异,寒武系以黑色岩系为母质的土壤硒含量最高,平均含量达2.58 mg/kg,变化范围为0.31~14.41 mg/kg。不同土壤类型中,黄壤硒含量最高,平均含量达0.75 mg/kg,变化范围为0.24~2.07 mg/kg,水稻土硒含量最低,平均含量为0.51 mg/kg;不同土地利用类型土壤硒含量差异较大,除水田为基本自然状态以外,其余地类均呈现富集。研究区表层土壤硒含量总体上受控于深层土壤硒含量,成土过程中表层土壤硒含量发生了次生富集。同时土壤pH、Corg、P、S、Al_(2)O_(3)、TFe_(2)O_(3)含量和CIA等对土壤硒含量的分布也有一定的影响。

Taking the soil of Sanjiang County in Guangxi as the research object, 2,751 samples of surface soil and 180 soil vertical profile samples were collected to determine the content of selenium in soil. The characteristics and influencing factors of soil selenium content were studied by using multivariate statistical analysis, geostatistical method, GIS spatial analysis technique and Pearson correlation analysis. The results showed that the average selenium content in the surface soil of the study area was 0.63 mg/kg and varied from 0.10 to 14.41 mg/kg. The soil is rich in selenium resources, and the area of selenium-full and selenium-rich soil was up to 95.87%. The distribution of selenium content in the soil is controlled by the geological background. The selenium content of the surface soil formed by different parent rocks is quite different. The Cambrian has the highest selenium content in soil with black rock series as parent material, with an average content of 2.58 mg/kg, the variation range is 0.31-14.41 mg/kg. Among different soil types, yellow soil has the highest selenium content, with an average content of 0.75 mg/kg, varying from 0.24 to 2.07 mg/kg, and paddy soil has the lowest selenium content, with an average content of 0.51 mg/kg. The soil selenium content of different land use types is quite different. Except for paddy fields, which are the basic natural state, all other land types are enriched. The selenium content of the surface soil in the study area is generally controlled by the selenium content of the deep soil, and the selenium content of the surface soil has secondary enrichment during the soil formation process. At the same time, soil pH, Corg, P, S, Al_(2)O_(3), TFe_(2)O_(3)and CIA also have a certain influence on the distribution of soil selenium content.