鄂西秭归地区土壤高镉背景成因及其对农作物的影响  

Causes of high cadmium background of soil and its influence on cropsin Zigui area,western Hubei Province

作　　者：代许可 寇磊 蒋达源 潘泓宇 黄黎粤 谭向前 Dai Xuke;Kou Lei;Jiang Dayuan;Pan Hongyu;Huang Liyue;Tan Xiangqian(Seventh Geological Brigade of Hubei Geological Bureau,Yichang 443000,China)

机构地区：[1]湖北省地质局第七地质大队,湖北宜昌443000

出　　处：《资源环境与工程》2025年第2期183-190,共8页Resources Environment & Engineering

基　　金：秭归县土地质量地球化学评价(MSDZ202308)。

摘　　要：土壤中重金属Cd可以通过食物链对人类健康造成安全风险,给农业种植活动带来负面影响。选取鄂西秭归县农业种植活动集中的南部三镇(九畹溪镇、杨林桥镇、两河口镇)为研究区,系统采集表层土壤样、岩石剖面样、土壤形态样、农作物及根系土壤样等样品,分析样品中Cd的含量及形态特征,探讨土壤中Cd的来源、生物可利用性及其对农业种植活动的影响。结果表明,研究区表层土壤中Cd含量为0.07~54.46 mg/kg,平均值为0.53 mg/kg,是湖北省土壤Cd背景值(0.31 mg/kg)的1.71倍,为明显富集状态;表层土壤Cd高值区与二叠系地层在空间分布上相吻合,且二叠系岩石Cd含量普遍较高,因此地质背景是导致表层土壤高镉的主要原因之一;表层土壤中Cd以易利用形态为主,中等利用形态次之,尤其是离子交换态比例较大,对当地农业种植活动造成潜在威胁;区内脐橙、茶叶、白菜、玉米、水稻等典型农作物食用部分的Cd含量普遍处在食品安全限值内,个别玉米样品出现Cd超标问题,可能存在农作物安全风险,但风险总体可控。建议适当改良秭归地区高镉土壤,从根本上降低其污染风险。Heavy metal Cd in soil can cause safety risks to human health through the food chain and bring negative effects to agricultural planting activities.Three towns(Jiuwanxi Town,Yanglinqiao Town and Lianghekou Town)in the south of Zigui County,western Hubei Province,where agricultural planting activities are concentrated,were selected as the research areas.Surface soil samples,rock profile samples,soil morphology samples,crop and root soil samples were systematically collected to analyze the content and form characteristics of Cd,and to explore the source and bioavailability of Cd in soil and its impact on agricultural planting activities.The results show that the content of Cd in surface soil is 0.07 to 54.46 mg/kg,with an average value of 0.53 mg/kg,which is 1.71 times the background value of Hubei Province(0.31 mg/kg),which is obviously enriched.The high-value area of Cd in surface soil is spatially consistent with the Permian strata,and the Cd content of the Permian rock is generally high,so the geological background is one of the main reasons for the high Cd in surface soil.Cd in surface soil is mainly in the form of easy utilization,followed by the medium utilization form,especially the proportion of ion exchange state is large,which poses a potential threat to local agricultural planting activities.The Cd content in the edible parts of typical crops such as navel orange,tea,Chinese cabbage,corn and rice in the area is generally within the food safety limit,some corn samples have the problem of Cd exceeding the standard,and there may be crop safety risks,but the risks are generally controllable.It is recommended to properly improve high-cadmium soil in Zigui area to fundamentally reduce its pollution risk.

关 键 词：表层土壤 高镉背景 二叠系地层 生物可利用性 秭归县 

分 类 号：P596[天文地球—地球化学] S153[天文地球—地质学]