马铃薯种植区不同土壤类型镉赋存形态及风险评估  

Cadmium speciation and risk assessment of different soil types in potato planting area

作　　者：娄飞 符东顺 付天岭 蔡娜[1] 杨世梅 何腾兵[1,2] LOU Fei;FU Dong-shun;FU Tian-ling;CAI Na;YANG Shi-mei;HE Teng-bing(College of Agriculture,Guizhou University,Guiyang 550025,China;Institute of New Rural Development,Guizhou University,Guiyang 550025,China;College of Life Sciences,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学农学院,贵阳550025 [2]贵州大学新农村发展研究院,贵阳550025 [3]贵州大学生命科学学院,贵阳550025

出　　处：《南方农业学报》2020年第12期2901-2910,共10页Journal of Southern Agriculture

基　　金：国家自然科学基金项目(U1612442);贵州省科技基础条件平台建设项目(黔科合平台人才〔2019〕5701号)。

摘　　要：【目的】研究喀斯特马铃薯种植区土壤镉的赋存形态及农产品安全问题,为马铃薯种植区风险评估提供理论依据。【方法】以贵州省马铃薯主栽区域某县马铃薯及相应3种土壤类型(黄棕壤、棕壤和石灰土)为研究对象,采用CaCl2/BCR提取法测定土壤镉的赋存形态,以相关性和多因素方差分析探讨土壤pH、有机质、阳离子交换量(CEC)、总镉及其交互作用对镉赋存形态的影响;以富集系数和有效性评估土壤镉累积能力;采用地质累积指数法和潜在生态危害指数法比较土壤总镉和有效镉的生态风险。【结果】研究区域土壤总镉含量均值为1.394 mg/kg,变异系数为0.25;土壤镉分级提取的5种赋存形态中,弱酸态镉占总镉比例最大,达28%~58%,可还原态镉仅占4%~13%,其余3种形态介于二者之间。总镉对有效镉、弱酸态镉、可氧化态镉和残渣态镉等4种镉赋存形态均有极显著影响(P<0.01,下同),总镉与pH的交互作用对有效镉影响大于总镉和pH对有效镉的主效影响,而pH与有机质、pH与CEC交互影响弱于pH对有效镉的主效影响,土壤镉赋存形态的差异主要受总镉和土壤pH、有机质、CEC共同影响。种植区马铃薯块茎镉含量均值为0.086 mg/kg,富集系数为6%,有效性为15%。种植区土壤总镉地质累积指数(I_(geo))为2~3级,表明土壤处于中度污染至强污染,综合潜在生态风险指数(RI)为100.571~281.430,表明土壤处于轻微污染至中度污染。在马铃薯种植区3种土壤类型中,黄棕壤和棕壤pH均值分别为5.90和5.63,相对较低,但黄棕壤中有机质和CEC含量最低,黄棕壤马铃薯的镉有效性均值为17%,主要以弱酸态镉形态存在,有利于马铃薯吸收富集,其富集系数均值为7%,且其潜在风险均值为212.371。反之,石灰土中pH较高,为6.87,石灰土和棕壤中有机质和CEC较高,马铃薯富集能力较低,所以其镉活性较低,潜在风险较低。【结论】马铃薯种植�【Objective】To provide reasonable theoretical basis for risk assessment of potato growing areas,speciation of cadmium in soil of karst potato origin and Safety of agricultural products were studied.【Method】Potato and three soil types(yellow brown soil,brown soil and calcareous soil)in a main planting area of Guizhou were selected as the research objects.The speciations of cadmium in soil were determined by CaCl2/BCR extraction method.The effects of soil pH,organic matter,cation exchange capacity(CEC),total cadmium and their interaction on the occurrence forms of cadmium were discussed by correlation and multi-factor analysis of variance.The accumulation of cadmium in soil was evaluated by enrichment coefficient and availability.The ecological risks of total cadmium and available cadmium in soil were compared by using geological accumulation index and potential ecological hazard index.【Result】The average content of total cadmium in the soil was 1.394 mg/kg,and the coefficient of variation was 0.25.Among the five forms of soil cadmium,weak acid cadmium accounted for the largest proportion of total cadmium,accounting for 28%-58%,reducible cadmium only accounted for 4%-13%,and the other three forms were between the two.Total cadmium had extremely effects on effective cadmium,weak acid cadmium,oxidizable cadmium and residual cadmium(P<0.01,the same below).The interaction between total cadmium and pH had a greater effect on available cadmium than major effect of total cadmium and pH on available cadmium,while the interaction between pH and organic matter,pH and CEC was weaker than major effect of pH on available cadmium.The difference of occurrence forms of cadmium in soil was mainly influenced by total cadmium,soil pH,organic matter and CEC.The average content of cadmium in potato tubers was 0.086 mg/kg,the enrichment factor was 6%,and the availability was 15%.The total cadmium geological accumulation index(I_(geo))of the soil in the potato planting area was 2-3,indicating that the soil was in moderate to s

关 键 词：马铃薯 镉 赋存形态 有效性 土壤类型 风险评估 

分 类 号：S155[农业科学—土壤学] X825[农业科学—农业基础科学]