新疆若羌县绿洲带土壤硒含量的空间分布及影响因素分析

Spatial distribution of selenium and its influencing factors in soils of oasis zone in Ruoqiang County, Xinjiang

为研究若羌县土壤Se含量、分布特征与土壤性质的关系,在研究区采集434个表层土壤样品,分析了若羌县土壤Se含量及其影响因素.结果表明,若羌县表层土壤Se含量变幅为0.06—0.47 mg·kg-1,平均值为0.18 mg·kg-1,总体属于中等、边缘及缺硒土壤,不存在硒中毒土壤.不同土壤类型中草甸土Se含量最高(0.23 mg·kg-1),盐土最低(0.13 mg·kg-1).成土母质以洪积物发育的土壤Se含量最高(0.25 mg·kg-1),湖积物最低(0.14 mg·kg-1).不同土地利用方式下,水田土壤Se含量最高(0.32 mg·kg-1).研究区土壤MgO、有机碳Corg、黏粒含量、TN和铁锰氧化物是影响土壤Se含量的主要因素.

To evaluate selenium content and distribution,and to study its relationship with soil properties,434 topsoil samples were collected.The results showed that selenium content ranged from 0.06 to 0.47 mg·kg-1 with average of 0.18 mg·kg-1.On the whole,the selenium level belonged to medium,marginal or deficient,with no Se-poisoning.Among soil types,meadow soil had the highest Se content(0.23 mg·kg-1),while saline soil had the lowest Se content(0.13 mg·kg-1).Among soil parent materials,the highest content was recorded in diluvial deposit with an average Se content by 0.25 mg·kg-1,while lake deposit was the lowest with an average by 0.14 mg·kg-1.In terms of land use,paddy soil had the highest Se content(0.32 mg·kg-1).MgO,Corg,clay contents,TN,iron and manganese oxides were the main factors,which affected soil selenium content.