浙江省余姚市土壤硒分布特征及影响因素研究
Distribution of Selenium and Its Influencing Factors in Soils of Yuyao, Zhejiang Province

基于余姚市土地质量地质调查项目，对余姚市全区进行1:5万土壤地球化学采样，并采用现代分析测试手段进行高精度土壤硒的富集、分布研究，对特色土地资源开发利用具有重要意义。通过对余姚市系统的采集并分析化验的4773件表层土壤样数据进行分布特征及影响因素的统计分析，并结合余姚市土壤地质背景，结果表明，余姚市总体Se含量分布规律为南高东低，山区相对平原区较高。土壤硒全量主要在0.065~3.33 mg/kg之间，平均值0.441 mg/kg，标准离差0.25，变异系数0.57。不同土壤类型中硒含量差异显著，其中黄壤 > 红壤 > 水稻土 > 潮土 > 盐土。成土母岩是影响土壤硒含量的主要因素，铁锰氧化物、有机质、土壤类型等理化性质对硒具有明显的富集作用，此外，余姚市土壤硒含量与海拔、土壤pH有明显的相关关系，与重金属元素无明显关系，人类活动与自然因素对土壤硒的富集有一定的影响。
Based on the geological survey project of land quality in Yuyao city, 1:50,000 soil geochemical sampling was carried out in the whole district of Yuyao city, and modern analysis and testing methods were used to study the enrichment and distribution of high-precision soil selenium, which is significant for the development and utilization of characteristic land resources. Through the statistical analysis of the distribution characteristics and influencing factors of 4773 surface soil samples collected and analyzed systematically in Yuyao city, and with the soil geological background of Yuyao city, the results show that the distribution of total Se content in Yuyao city is high in the south, low in the east, and relatively higher in mountainous area compared to plain area. The total amount of selenium content in soil is mainly between 0.065 and 3.33 mg/kg, with an average value of 0.441 mg/kg, a standard deviation of 0.25, and a coefficient of variation of 0.57. There are significant differences in selenium content among different soil types, in which yellow soil > red soil > paddy soil > tidal soil > saline soil. The parent rock is the main factor affecting soil selenium content. The physical and chemical properties of iron-manganese oxide, organic matter and soil type have obvious enrichment effect on selenium. In addition, the soil selenium content in Yuyao city is significantly correlated with altitude and soil pH, but has no obvious relationship with heavy metal elements, and human activities and natural factors has a certain impaction on soil selenium enrichment.