石泉县中部地区土壤硒分布特征及影响因素

石泉县是我国富硒(Se)的重点地区，研究其土壤Se元素的分布特征及影响因素，对特色农业资源的开发利用具有重要意义。为开发富硒土地，以1个·km^-2的采样密度对石泉县研究区土壤的Se分布特征及其影响因素进行分析。结果表明：石泉县研究区表层土壤中Se含量为0.06～12.8 mg·kg^-1，平均值为0.678 mg·kg^-1，以足Se(0.175～0.40 mg·kg^-1)或富Se(0.40～3 mg·kg^-1)为主，其分布面积达到80.28%,Se中毒(>3mg·kg^-1)区域仅为3.83%，缺Se(<0.175 mg·kg^-1)面积仅为15.88%。成土母质是影响石泉县Se含量的主要因素，高Se土壤主要分布在以页岩、板岩为母质的古生代地层区；Se含量与主要重金属As、Cd、Cr、Cu、Hg、Ni、Zn、Pb等元素存在着较强的伴生关系；海拔、坡度等地形地貌因素对Se的含量无明显影响；另外，Se含量与p H存在一定正相关关系，...

Distribution of soil selenium in the middle of Shiquan County and its influential factors

Soil selenium (Se) is in level enrichment in Shiquan County,China.It is of great significance for the development and utilization of characteristic agricultural resources to study the distribution characteristics and influential factors of selenium elements.In order to stimulate the development of Serich agricultural resources,soil samples were collected with the sampling density of 1 sample·km;for surface soil,respectively,and then the spatial distribution of soil Se and its influential factors were studied.The results showed that the content of Se in the surface soil ranged from 0.06 to 12.8 mg·kg^-1with a mean of 0.678 mg·kg^-1.For the total region,about 80.28%soil of Se were sufficient and rich (0.175~0.40mg·kg^-1and 0.40~3 mg·kg^-1),while only 3.83%was poisoning (>3 mg·kg^-1),and only 15.88%was in deficiency(<0.175 mg·kg^-1).Among the different soil parent materials,the selenium enrichment area was mainly distributed in the Paleozoic strata stratigraphic zones with shale and slate as the parent material.Correlation analysis showed that the associated relationship was observed between Se and heavy metal (As,Cd,Cr,Cu,Hg,Ni,Zn and Pb) contents in surface soil.There was no significant correlation between elevation and slope with the surface soil selenium content.In addition,there was a certain positive correlation between the content of Se and p H,and it has a strong relationship with Mg,Al and Fe,but not signiftcant with K.