广东省揭西县土壤硒的分布特征及影响因素研究

Distribution of Soil Selenium and Its Influential Factors in Jiexi County,Guangdong Province

以揭西县土壤为研究对象,系统采集了332个表层土壤样品(0～20 cm)和86个深层土壤样品(> 150 cm)。运用Pearson相关分析、回归分析、地统计分析和GIS技术相结合的方法研究了揭西县土壤中全硒的分布特征和影响因素。结果表明,揭西县土壤全硒含量变幅为0.16～1.61 mg/kg,平均值为0.53 mg/kg,总体上以富硒土壤为主,不存在硒不足和硒过剩土壤。不同成土母质中,凝灰岩、花岗岩和页岩发育的土壤全硒含量较高,砂岩发育的土壤全硒含量较低。不同土地利用方式中,未利用地土壤全硒含量最高,其次是农用耕地,建设用地土壤全硒含量最低。Pearson相关分析和回归分析表明,土壤全硒含量与pH呈极显著负相关关系,与铁铝氧化物含量、有机碳含量及海拔高度呈极显著正相关关系。影响揭西县土壤全硒含量的主要因素是成土母质、土壤pH、有机碳、铁铝含量、海拔以及土地利用方式。

A total of 332 topsoil samples(0 – 20 cm) and 86 deep soil samples(> 150 cm) were collected in Jiexi County, Guangdong Province to study the characteristics of total selenium contents, spatial distribution and its influential factors by Pearson correlation analysis, regression analysis, geostatistical analysis and GIS technology. The results showed that the concentration of total selenium ranged from 0.16 to 1.61 mg/kg with a mean value of 0.53 mg/kg. The whole region was concentrated in the category of abundance of selenium content. Among the different types of parent materials, selenium contents were higher in soils developed from tuff, granite, and shale, while selenium concentrations were lower in soils developed from sandstone. Among the different land use types, the highest Se content was found in unused land, followed by agricultural arable land, and total selenium content was the lowest in construction land. Regression analysis and Pearson correlation analysis showed that soil total selenium content was significantly negatively correlated with pH, but significantly positively correlated with iron-aluminum oxide content, organic carbon content, and altitude. The parent material was the main influential factor of soil total selenium content in Jiexi County, while soil pH, organic carbon, iron and aluminum content, altitude, and land use type also had certain effects on the distribution and enrichment of soil total selenium content.