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| 北京大清河流域生态涵养区富硒土壤资源分布特征和来源解析 | |
| 引用本文： | 冯辉,张学君,张群,杜丽娜.北京大清河流域生态涵养区富硒土壤资源分布特征和来源解析[J].岩矿测试,2019,38(6):693-704. |
| 作者姓名： | 冯辉 张学君 张群 杜丽娜 |
| 作者单位： | 1. 北京市地质勘察技术院, 北京 100120;2. 中国地质科学院, 北京 100037 |
| 基金项目： | 北京政府公益性项目"北京生态涵养地区地质环境综合调查"（PXM2018-158307-000005） |
| 摘 要： | 北京是典型的硒缺乏地理分布区,但近些年研究成果表明局部地区土壤达到富硒水平,掌握该区富硒分布特征对于开展北京地区的富硒环境研究和开发利用富硒土地资源具有重要意义。本文以北京大清河流域生态涵养区1615km~2地球化学调查数据为基础,采用原子荧光光谱(AFS)等方法测定了研究区1297件表层土壤、25组玉米及对应根系土壤和15件岩石中Se等地球化学指标;利用相关分析、多元统计分析方法,结合GIS技术,研究土壤和农作物中硒含量特征、富硒成因来源以及土壤硒与碳铁磷等其他元素的关系,评价富硒土地的安全性。结果表明:研究区土壤硒含量区间为0.055～0.465mg/kg,背景值为0.257mg/kg,呈现富硒特征,厘定出360.4km~2富硒土地资源。当地种植的玉米硒含量变化范围为0.028～0.70mg/kg,几何均值为0.20mg/kg,80%的玉米样本为富硒农产品,且土壤富硒与作物富硒空间分布一致,指示土壤硒是作物体内硒的重要供给来源。研究认为,地质背景和成土母质是研究区富硒土地资源分布的主控因素,河流相沉积的暗色岩系是重要的土壤硒来源。富硒土地整体环境质量清洁安全,仅3.23km~2(面积占比0.2%)土壤重金属(镉汞铅)含量超风险管控值,在土地开发过程中需重点关注。 |
| 关 键 词： | 富硒土壤|岩石|富硒农作物|生态涵养区|分布特征|原子荧光光谱法 |
| 收稿时间： | 2019/5/27 0:00:00 |
| 修稿时间： | 2019/6/18 0:00:00 |
Distribution Characteristics and Sources Identification of Selenium-rich Soils in the Ecological Conservation Area of the Daqinghe River Watershed, Beijing |
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| FENG Hui,ZHANG Xue-jun,ZHANG Qun,DU Li-na.Distribution Characteristics and Sources Identification of Selenium-rich Soils in the Ecological Conservation Area of the Daqinghe River Watershed, Beijing[J].Rock and Mineral Analysis,2019,38(6):693-704. | |
| Authors: | FENG Hui ZHANG Xue-jun ZHANG Qun DU Li-na |
| Institution: | 1. Beijing Institute of Geo-Exploration Technology, Beijing 100120, China;2. Chinese Academy of Geological Sciences, Beijing 100037, China |
| Abstract: | BACKGROUND: Beijing is a typical geographical distribution area of selenium deficiency. However, some research results in recent years indicate that the soils in some areas reaches the level of selenium enrichment. It is important to study the characteristics of selenium distribution in these areas for the research of a selenium-rich environment in Beijing and the development of selenium-rich land resources. OBJECTIVES: To discuss the characteristics of selenium content in soil and crops, the source of selenium and the relationship between selenium in soil and other elements such as carbon, iron and phosphorus, and to evaluate the safety of selenium-rich land. METHODS: Samples of 1297 topsoil, 25 sets of corn and corresponding root soil and 15 rock samples were collected from an eco-conserving division of the Daqinghe River watershed. The content of selenium in these samples was determined by atomic fluorescence spectrometry. Methods of correlation analysis and multivariate statistical analysis and GIS technology were used to study the characteristics of selenium content in soil and crops, the source of selenium enrichment, and the relationship between soil selenium and other elements such as carbon, nitrogen, phosphorus and sulfur, and the safety of selenium-rich land was evaluated. RESULTS: The results showed that the soil selenium content ranged from 0.055 to 0.465mg/kg and that the background value was 0.257mg/kg, which show selenium-rich characteristics. 360.4km2 selenium-rich land resources was identified. The selenium content of corn ranged from 0.028 to 0.70mg/kg, and the geometric mean was 0.20mg/kg. 80% of the corn samples were selenium-rich products. The selenium-rich soil and the selenium-rich crops had the same spatial distribution, which indicated that the soil was an important source of selenium in crops. CONCLUSIONS: Geological background and soil parent material are the key control factors affecting the distribution of selenium-rich land resources. Dark rock series of fluvial deposition are a crucial source of selenium in soil. The overall environmental quality of selenium-rich land is clean and safe, and only 0.2% of the area (3.23km2) contains soil heavy metal (Cd, Hg, Pb) content, which exceeds the level of risk management control. Due to these findings, attention needs to be paid during selenium-rich land development. |
| Keywords: | selenium-rich soil|rock|selenium-rich crop|eco-conserving division|distribution characteristics|atomic fluorescence spectrometry |
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