凤凰县土壤—农作物系统中Cd含量及迁移富集特征  

Cd in the soil-crop system in Fenghuang County:Content and migration and enrichment characteristics

作　　者：肖凯琦 徐宏根[1] 戴亮亮 李毅 李凯 XIAO Kai-Qi;XU Hong-Gen;DAI Liang-Liang;LI Yi;LI Kai(Changsha General Survey of Natural Resources Center,China Geological Survey,Changsha 410625,China)

机构地区：[1]中国地质调查局长沙自然资源综合调查中心,湖南长沙410625

出　　处：《物探与化探》2024年第4期1136-1145,共10页Geophysical and Geochemical Exploration

基　　金：中国地质调查局地质调查项目(ZD20220214)。

摘　　要：为了研究湘西州凤凰县土壤—农作物系统中重金属元素迁移富集特征,依托土地质量地球化学调查项目,系统采集了当地主要的120组农作物及根系土样品(50件猕猴桃,36件水稻,34件玉米),农作物样品测试As、Cd、Cr、Cu、Hg、Pb和Zn共7项指标,根系土样品测试pH值、Mn、Se、As、Cd、Cr、Cu、Hg、Ni、Pb、Zn和理化性质等共18项指标,分析研究区内土壤和农作物籽实重金属含量特征,采用多元线性回归、相关性分析等方法,开展Cd在土壤—农作物系统中迁移富集特征的研究。结果表明,研究区土壤以弱酸性为主,土壤中Cd含量高于湖南省背景值,Cr、Ni和Cu高值区主要分布于西南和东南部,Cd与pH呈西高东低的分布趋势。农作物籽实中重金属元素富集系数最高的元素为Cd、Zn和Cu,研究区土壤—农作物中Cd的迁移主要受土壤pH与质地影响,pH值越高,质地越细,Cd迁移能力越弱,此外其迁移能力一定程度上还受土壤中Mn、CaO和总碳含量影响。区域内猕猴桃重金属富集系数较低,适宜推广生产。To investigate the migration characteristics of heavy metals in the soil-crop system of Fenghuang County,Xiangxi Tujia and Miao Autonomous Prefecture,this study systematically collected 120 groups of local staple crop and root-soil samples(50 for kiwi fruit,36 for rice,and 34 for corn).Agricultural crop samples were tested for seven indicators,including As,Cd,Cr,Cu,Hg,Pb,and Zn.Root soil samples were tested for 18 indicators,including pH,Mn,Se,As,Cd,Cr,Cu,Hg,Ni,Pb,Zn,and physicochemical properties.The test results were used to analyze the heavy metal contents of soil and crop seeds in the study area.Furthermore,the migration and enrichment of Cd in the soil-crop system were examined through multiple linear regression and correlation analysis.The results are as follows:(1)The study area is dominated by weakly acidic soil,with Cd content higher than the background value in Hunan Province.The high-value zones of Cr,Ni,and Cu are primarily distributed in the southwestern and southeastern portions of the study area.The Cd and pH in the soil show higher values in the west and lower values in the east;(2)In crop seeds,the three heavy metals with the highest enrichment coefficients are Cd,Zn,and Cu.The migration of Cd in the soil-crop system of the study area is principally influenced by soil pH and texture.A higher pH value and finer texture correspond to weaker migration of Cd.Additionally,Cd migration is affected to some extent by the contents of Mn,CaO,and total organic carbon in the soil.The relatively low heavy metal enrichment coefficient of kiwi fruit in the study area makes kiwi fruit suitable for production promotion.

关 键 词：凤凰 土壤 农作物 迁移 影响因素 

分 类 号：X53[环境科学与工程—环境工程] X825