西南岩溶区果园土壤—作物系统重金属元素迁移特征与污染评价  

Migration characteristics and pollution evaluation of heavy metal elements in orchard soil-crop system in karst area of southwestern China

作　　者：宁静 马一奇 杨慧[1,4] 马洋 黎永生 姚蓉 黄超 徐灿 NING Jing;MA Yi-qi;YANG Hui;MA Yang;LI Yong-sheng;YAO Rong;HUANG Chao;XU Can(Institute of Karst Geology,Chinese Academy of Geological Sciences/Key Laboratory of Karst Dynamics in Guangxi,Ministry of Natural Resources,Guilin,Guangxi 541004,China;College of Environmental Science and Engineering,Guilin University of Technology,Guilin,Guangxi 541006,China;Kunming General Survey Center for Natural Resources,China Geological Survey,Kunming,Yunnan 650111,China;International Research Center on Karst under the Auspices of United Nations Educational,Scientific and Cultural Organization,Guilin,Guangxi 541004,China;Guangxi Branch of China Academy of Science and Technology Development,Nanning,Guangxi 530022,China;Cold Groundwater Research Institute,Heilongjiang University,Harbin,Heilongjiang 150080,China;College of Water Resources and Electric Engineering,Heilongjiang University,Harbin,Heilongjiang 150080,China)

机构地区：[1]中国地质科学院岩溶地质研究所/自然资源部广西岩溶动力学重点实验室,广西桂林541004 [2]桂林理工大学环境科学与工程学院,广西桂林541006 [3]中国地质调查局昆明自然资源综合调查中心,云南昆明650111 [4]联合国教科文组织国际岩溶研究中心,广西桂林541004 [5]中国科技开发院广西分院,广西南宁530022 [6]黑龙江大学寒区地下水研究所,黑龙江哈尔滨150080 [7]黑龙江大学水利电力学院,黑龙江哈尔滨150080

出　　处：《南方农业学报》2023年第4期1106-1118,共13页Journal of Southern Agriculture

基　　金：广西重点研发计划项目(桂科AB22035004);广西科技基地和人才专项(桂科AD20297090);桂林市重点研发计划项目(2020010403);桂林市科学研究与技术开发计划项目(2020010905)。

摘　　要：【目的】分析西南岩溶地区地质高背景下土壤—作物系统的重金属迁移富集关系及其潜在生态风险,为岩溶区土壤合理开发利用和粮食安全生产提供科学依据。【方法】选取广西较典型的岩溶区果园和撂荒地作为研究区,同时采集不同母质的土壤进行对比,对果园和撂荒地内植物的根、茎、叶、果实及土壤剖面(0~100 cm)中的8种重金属元素[镉(Cd)、铬(Cr)、砷(As)、汞(Hg)、铅(Pb)、铜(Cu)、锌(Zn)和镍(Ni)]含量进行研究,并分别采用单因子污染指数、地累积指数、生物富集系数及相关分析等方法对土壤及作物的生态风险进行评价。【结果】研究区土壤中重金属元素Cd、Cr、Cu、Pb、Ni和Zn含量平均值均超广西土壤元素背景值,其中,Cd和Zn含量分别是广西土壤元素背景值的7.7和5.4倍。地累积指数结果表明,果园剖面土壤的Cd存在中度至重度污染,Zn的最大值存在中度污染;撂荒地剖面土壤的Cd存在中度污染,Zn存在无污染至中度污染。果园土壤剖面中Cd、Cu、Ni和Zn 4种元素最大迁移率均出现在50~60 cm处,撂荒地土壤中Ni和Cd元素最大迁移率出现在30~40 cm处,Cu和Zn元素最大迁移率则出现在60~80 cm处。果园和撂荒地土壤的Cd活化率最高,具有较强活性。果园中7种重金属元素的作物污染指数排序为Pb(22.09)>Ni(20.84)>Zn(3.24)>As(2.77)>Cr(1.43)>Cu(0.21)>Cd(0.01)。比较作物根、茎、叶和果实的生物富集系数,发现所有元素含量均在根系部位最大;果实中As元素的生物富集系数最高,为0.07。除As和Pb 2个元素外,其他元素(Cu、Cd、Zn、Ni和Cr)的生物富集系数最小值均出现在果实。研究区内土壤和果实中同一种重金属元素含量之间无显著相关性(P>0.05),即土壤重金属元素含量不会影响作物重金属元素含量。【结论】研究区土壤中Cd和Zn的超标率较高,存在Cd污染现象;与土壤相比,研究区作物果实中Cd和Zn的生物富�【Objective】This paper analyzed the heavy metal migration and enrichment relationship of soil-crop system and its potential ecological risk under the geological high background of karst area in southwestern China,so as to provide scientific basis for the rational development and utilization of soil,and food security and production in karst area.【Method】Orchards and wastelands in the relatively typical karst areas of Guangxi were selected as the study areas.Soils with different matrices were collected for comparative studies.The contents of eight heavy metal elements[cadmium(Cd),chromium(Cr),arsenic(As),mercury(Hg),lead(Pb),copper(Cu),zinc(Zn),and nickel(Ni)]in roots,stems,leaves,fruits,and soil profiles(0-100 cm)of the plants in the orchards and wastelands were investigated and evaluated for the ecological risks of the soil and the crops by using the single factor contamination index method,the geoaccumulation index,the bioconcentration coefficient,and the correlation analysis respectively.【Result】The average values of heavy metal elements Cd,Cr,Cu,Pb,Ni and Zn in the soils of the study area exceeded the Guangxi background values of the soil elements,of which the contents of Cd and Zn were 7.7 and 5.4 times as much as the Guangxi background values of the soil elements.The results of the geoaccumulation index showed that the Cd in the orchard soil profile was moderately to severely polluted,and the maximum value of Zn was also moderately polluted;the Cd in the wasteland profile was moderately polluted,and the Zn was non-polluted to moderately polluted.The maximum mobility of 4 elements,Cd,Cu,Ni and Zn,in the soil profile of the orchard appeared at 50-60 cm.The maximum mobility of Ni and Cd,Cu and Zn in the soil profile of the wasteland appeared at 30-40 cm and 60-80 cm respectively.Cd had the highest activation rate in orchard and wasteland soils with strong activity.The ranking of crop contamination indexes for the 7 heavy metal elements in the orchard was Pb(22.09)>Ni(20.84)>Zn(3.24)>As(2.77)>Cr(1.43)

关 键 词：重金属污染评价 岩溶区 土壤—作物系统 迁移富集 

分 类 号：S154.1[农业科学—土壤学]