富硒土地资源研究进展与评价方法  

Research Progress of Selenium-enriched Land Resources and Evaluation Methods

作　　者：周国华[1] ZHOU Guo-hua(Key Laboratory of Geochemical Exploration of Ministry of Natural Resources,Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang 065000,China)

机构地区：[1]自然资源部地球化学探测技术重点实验室,中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000

出　　处：《岩矿测试》2020年第3期319-336,共18页Rock and Mineral Analysis

基　　金：中国地质调查局地质调查项目“珠江下游及浙江基本农田土地质量地球化学调查与应用示范”(DD2016320)。

摘　　要：硒是重要的生命必需元素,开发富硒农产品是提升我国人体硒摄入水平的安全有效途径,富硒土地资源评价与利用规划是土地质量地球化学调查成果服务于特色农产品发展与脱贫攻坚的重要切入点。本文评述了近年来在土壤和作物硒含量、土壤硒成因来源、土壤硒赋存形态及其生物有效性影响因素、土壤-作物系统硒吸收运移、硒与重金属镉等元素之间的相互作用等调查研究成果。针对我国土壤硒背景值约0.20mg/kg,远低于世界土壤背景值0.40mg/kg,整体上处于低硒水平的实际情况,认为采用0.40mg/kg Se作为富硒土壤标准具有较强的科学依据;多数情况下土壤硒主要来源于成土地质背景,部分地区与人为活动密切有关;富硒土壤可分为地质高背景、次生富集作用、人为输入及其多种作用的叠加成因,元素地球化学性质决定了硒与镉等重金属元素共生的普遍性;土壤硒成因来源以及pH、Eh、有机质、铁铝氧化物等土壤理化条件决定了硒和重金属赋存形态与生物有效性,进而影响到富硒土地的可利用性,成为制定富硒土壤地方标准的理论基础与考虑因素;不同作物种类对硒吸收富集能力不同,筛选适应当地农田生态环境、富硒低镉的农作物具有实际意义;现有的部分富硒农产品标准未充分考虑人体补硒目的,并存在标准间协调性差等问题,急需加强富硒农产品标准的制定。本文提出,富硒土地资源评价不仅需要考虑土壤硒和重金属含量,而且需综合土壤硒成因来源及其生物有效性、土壤-作物系统硒迁移累积、硒与重金属镉等元素之间的相互作用机制,以及当地气候、土壤和景观条件下作物种植的适宜性,依据富硒土地资源可利用性进行分类分区、科学规划和合理种植管理。同时建议,为满足富硒土地资源调查评价与可利用性分析、富硒农产品健康效应研究的需要,需要加BACKGROUND:Selenium is an important,essential element of life.The development of selenium-enriched agricultural products is a safe and effective way to increase the level of human selenium intake in China.The evaluation and utilization planning of selenium-enriched land resources are important aspects of land quality geochemical surveys,to serve the development of characteristic agricultural products and to overcome poverty.OBJECTIVES:To improve the methodology for selenium-enriched land assessment and to develop more effective and safe land-use planning methods.METHODS:The research results on selenium content in soil and crops,the origin of soil selenium,the soil selenium occurrence and its bioavailability factors,the soil-crop system selenium absorption and transport,and the interaction between selenium and heavy metal cadmium were reviewed in this article.RESULTS:The geochemical background of selenium in top soils in China was 0.2mg/kg,significantly lower than the average in world soils(0.4mg/kg).Generally,the soils had a low selenium level,and it was believed that the use of 0.40mg/kg selenium as a selenium-enriched soil standard had a strong scientific basis.Selenium in soils was mostly from a geological setting,however,in some cases anthropogenic activities may be an important source of soil selenium.The genetic mechanism of selenium-enriched soils can be categorized as high geological background,weathering accumulation and anthropogenic input as well as a multi-factor combination.The association of selenium with cadmium and other heavy metals was pervasive because of similar geochemical behavior and geological origin.The species and bio-availability of selenium in soils were mainly controlled by its source and soil physic-chemical properties such as pH,Eh,and contents of organic matter,iron oxides and aluminum oxides.In turn,these factors affect the availability of selenium-enriched land and became the theoretical basis and considerations for formulating local standards for selenium-enriched soil.The accum

关 键 词：富硒土地资源评价 土壤硒背景值 硒来源与富硒土壤成因 硒形态与生物有效性 富硒农产品 评价标准 

分 类 号：X142[环境科学与工程—环境科学]