广西荔浦市土壤硒分布特征及影响因素

Distribution characteristics and influencing factors of soil selenium in Lipu,Guangxi

基于广西荔浦土地质量地球化学评价项目,对荔浦市表层土壤硒分布特征和影响因素进行了分析研究。荔浦市土壤硒全量变化范围为0.10~1.09 mg/kg,平均值为0.44 mg/kg,高于全国土壤硒的平均含量,富硒土壤面积占研究区总面积的63.57%。成土母质中,全硒含量以石炭系鹿寨组硅质岩母质发育土壤为最高,平均值为0.673 mg/kg。土壤类型中,红壤全硒含量最高,平均值为0.643 mg/kg;洪积土全硒含量最低,平均值为0.283 mg/kg。不同的土地利用类型对土壤硒含量有一定的影响,林地全硒含量最高,平均值为0.613 mg/kg;水田全硒含量最低,平均值为0.391 mg/kg。此外,土壤的有机质、 pH值与硒含量分别存在着正、负相关关系,很大程度上控制着土壤硒含量分布特征。

Based on the geochemical investigation project of land quality in Lipu,Guangxi,the distribution characteristics and influencing factors of selenium in topsoil in the whole city are analyzed and studied.The results show that the total amount of soil selenium in Lipu ranged from 0.10 to 1.09 mg/kg,with an average value of 0.44 mg/kg,which is higher than the average content of soil selenium in China.The area of selenium rich soil is accounted for 63.57%of the total area of the city.In the soil forming parent material,the total selenium content is the highest in the siliceous rock parent material developed soil of Carboniferous Luzhai Formation,with an average value of 0.673 mg/kg.Among the soil types,the total selenium content of red soil is the highest,with an average value of 0.643 mg/kg,and that of proluvial soil is the lowest,with an average value of 0.283 mg/kg.Different land-use types have certain effects on soil selenium content.The total selenium content of forest land is the highest,with an average value of 0.613 mg/kg,and that of paddy field is the lowest,with an average value of 0.391 mg/kg.In addition,there are negative and positive correlations between soil pH value,organic matter and selenium content,which control the distribution characteristics of soil selenium content to a great extent.