浙西石灰岩发育土壤镉的积累及其成土过程中镉的淋失特征  

Cadmium accumulation in soils developed from limestone and leaching characteristics of cadmium during development of the soils in western Zhejiang Province

作　　者：张爽 章明奎[1] ZHANG Shuang;ZHANG Mingkui(College of Environmental and Resource Sciences,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学环境与资源学院,杭州310058

出　　处：《浙江大学学报（农业与生命科学版）》2020年第5期591-598,共8页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：国家重点研发计划专项“农田地质高背景重金属污染机理研究”(2017YFD0800305)。

摘　　要：为了解石灰岩风化成土过程中镉的土壤地球化学特征,从浙西地区同时采集3类石灰土表层和剖面分层土样,开展石灰岩丘陵及其附近沟谷地带土壤镉的富集及土壤剖面中镉的垂直分布特征研究;以稳定元素锆为参照,采用物质质量平衡法分析成土过程中土壤镉的淋失特征,并与当地泥页岩发育的黄红壤进行比较。结果表明:石灰岩成土过程中土壤镉同时发生了明显淋失与强烈富集现象。由于石灰岩成土过程比较特殊,土壤中锆和镉呈现明显的富集;石灰岩丘陵及其附近沟谷地带土壤镉的富集量明显高于同一地区泥页岩发育的土壤。3种石灰土剖面土壤镉的垂直分布有明显差异,不同石灰土镉的化学形态也有差异。石灰岩风化过程中土壤镉的高淋失特征及含镉较高的石灰土的地表侵蚀可能是石灰岩分布区及附近地区土壤镉积累较高的主要原因。In order to understand the geochemical characteristics of soil cadmium(Cd)during weathering and soil formation of limestone,three types of limestone soils were sampled at the same time from western Zhejiang Province.The Cd enrichment in limestone hills and nearby valleys and the vertical distribution of Cd in the soil profiles were studied.The leaching characteristics of Cd during development of the soils were analyzed by mass balance method with reference to stable element zirconium(Zr),and the results were also compared with those of yellowish red soils developed from local shale.The results showed that the leaching and accumulation of Cd in the limestone soils occurred simultaneously.Because of the special soil-forming process of limestone,the enrichment of Zr and Cd in the soils was obvious,and the enrichment amounts of soil Cd in limestone hills and nearby valleys were obviously higher than that of shale-derived hilly soil in the same area.The vertical distribution of Cd in three kinds of limestone soils had obvious differences and the chemical forms of Cd in different limestone soils were also different.The high leaching characteristics of Cd in the soils during weathering of limestone and the surface erosion of the limestone soils with high Cd content may be the main reasons for the high Cd accumulation in the soils in the limestone distribution area and its vicinity.

关 键 词：石灰岩 镉 富集 淋失 地质高背景 

分 类 号：S151[农业科学—土壤学] X131.3[农业科学—农业基础科学]