富硒土壤硒及微量元素特征

Characteristics of selenium and trace elements in selenium-rich soil

富硒土壤是特定地质条件下形成的,各地富硒土壤结构及形成不尽相同,对开发利用富硒土壤效果就不同。本文对两个地区的富硒土壤通过野外踏勘,周围环境调查,系统采集岩石、土壤,按照《生态地球化学评价样品分析技术要求》,分析土壤理化指标、常量元素、硒及微量元素等,查明土壤中硒主要来源,土壤微量元素分布特征与硒的相关性,以及土壤溶液微量元素分布特征等。结果发现甲地区土壤硒主要来源于荒岔沟组(Pt 1 h)含石墨变粒岩和含墨大理岩,富硒区的分布受含石墨变粒岩层和地形坡度控制;乙地区土壤硒主要来源于林家沟组顶部碳质板岩,受碳质板岩层控制。富硒土壤中As、Cd、Co、Cr、Cu、Mn、Mo、Ni、Zn均高于全国土壤平均值,其中Cd、Cu、Ni、Zn显著偏高;甲地区硒与Cr、Cu、Mo、Ni、Pb、TC正相关,与Mn负相关;乙地区硒与As、Ge、Mo、S、TC正相关,与Mn负相关。土壤溶液有益元素按其摩尔浓度大小排列为:Zn Cu Co Ni Mn Se Mo Ge,土壤溶液有害元素按其摩尔浓度大小排列为:Cr As Pb Cd Hg。在开发和利用富硒土壤有益元素同时注意重金属的污染,为发展富硒农产品产业提供基础数据。

Selenium-rich soil is formed under specific geological conditions,and the structure and formation of selenium-rich soil are different in different regions,so the effect on the exploitation and utilization of selenium-rich soil is different.In this paper,field surveys and environmental surveys were conducted on selenium-rich soils in two regions,systematically collecting rocks and soils,and soil physical and chemical indexes,major elements,selenium and trace elements of soil were analyzed according to Technical Requirements for Sample Analysis of Ecological Geochemical Evaluation,so as to find out the main source of selenium in soil and the correlation between distribution characteristics of trace elements and selenium,as well as the distribution characteristics of trace elements in soil solution.The results showed that the soil selenium in Region A mainly derived from the graphitic granulated rocks and marble of the Huangchagou(Pt 1 h),and the distribution of selenium in the area is controlled by the graphitic granulated rocks and the topographic slope.Soil selenium in Region B mainly comes from carbonaceous slate at the top of Linjiagou and is controlled by carbonaceous slate.The contents of As,Cd,Co,Cr,Cu,Mn,Mo,Ni and Zn in selenium-rich soil are higher than the national average values,and Cd,Cu,Ni and Zn were significantly higher.Selenium in Region A is positively correlated with Cr,Cu,Mo,Ni,Pb and TC,and negatively correlated with Mn.Selenium in Region B is positively correlated with As,Ge,Mo,S and TC,and negatively correlated with Mn.The beneficial elements in soil solution are arranged as Zn Cu Co Ni Mn Se Mo Ge and the harmful elements are arranged as Cr As Pb Cd Hg according to their molar concentration.Pay attention to the pollution of heavy metal while exploiting and utilizing beneficial elements in selenium-rich soil,providing basic data for the development of selenium-rich agricultural products industry.