开封黑岗口引黄灌区稻麦轮作下农田土壤剖面重金属分布特征  

Vertical distribution characteristics of heavy metals in agricultural soil profiles under rice-wheat system in Heigangkou Yellow River Irrigation Region

作　　者：陈志凡[1,2] 王岩松[1,2] 段海静[1,2] 赵子楠[1,2] 

机构地区：[1]河南大学环境科学研究所 [2]河南大学环境与规划学院,开封475004

出　　处：《中国生态农业学报》2012年第4期480-487,共8页Chinese Journal of Eco-Agriculture

基　　金：河南省教育厅自然科学研究计划项目(2010B610004)资助

摘　　要：引黄灌区是我国重要的农业生产基地,其土壤重金属赋存状况直接关系到农业的可持续发展。本研究以黑岗口引黄灌区开封北郊稻麦轮作下农田土壤为研究对象,采集了耕作层（0-15 cm与15-30 cm）与剖面（0-100 cm）土壤样品,对其土壤剖面主要性质与重金属Pb、Cd、Cu和Zn的积累特征进行了分析。结果表明：（1）长期引黄灌溉及稻麦轮作下,开封北郊农业土壤主要性质在剖面上表现出明显的分异特征：总有机碳（TOC）与全氮（TN）含量主要分布在耕作层土壤,而30 cm以下的土层其含量明显降低;全磷（TP）含量在各土壤层中无明显差异;在部分土壤剖面中CaCO3呈现出明显的淀积层。（2）耕作层（0-30 cm）土壤中重金属Pb、Cu、Zn的含量与研究区背景值相当,而Cd含量显著高于背景值。除少部分剖面含量超标外,Cd、Pb、Cu、Zn的平均含量均未超出WHO限值,且远低于我国农业土壤环境质量标准。因子分析源解析表明：引黄灌区土壤中Pb、Cu和Zn具有相似的来源和迁移特性,而Cd的来源和迁移特性具有特殊性,它可能与当地的化肥施用等农业活动有关。（3）土壤剖面中Cu和Zn具有明显的表聚现象,Pb的表聚作用不明显,而Cd在剖面各层土壤含量具有较大变异性,这与重金属的自身属性、土壤剖面性质和当地的耕作条件有较大相关性。（4）Cu和Zn在土壤剖面主要以有机结合态和残余态形式存在;Pb的残余态、有机态以及铁锰氧化态含量也较高,且Pb的全量与有机结合态含量百分比变化呈现出一定的相似性;而Cd具有较高的碳酸盐结合态和离子交换态,表明Cd在土壤中具有较强的移动性,预示Cd的潜在健康风险较高。Yellow River Irrigation Region（YRIR） is one of China＇s important grain production bases.The contents and chemical forms of heavy metals in the agricultural soils of the region are related to sustainable agricultural development.The distribution of main soil properties [total organic carbon（TOC）,total nitrogen（TN）,total phosphorus（TP） and CaCO3] and heavy metals（Pb,Cd,Cu and Zn） in the agricultural soils of YRIR were investigated using 45 soil samples.Five soil profiles（in the 0-100 cm soil layer） and arable soils（in the 0-15 cm and 15-30 cm soil layers） were collected from agricultural lands under rice-wheat rotation system in the northern suburb of Kaifeng.The region belongs to the Heigangkou YRIR,which is sufficiently representative of the YRIR.The chemical forms of heavy metals were analyzed by sequential extraction and the concentrations determined with ICP-AES and ICP-MS.Results showed that under long-term irrigation and rice-wheat rotation system,there were variations in the basic soil prop-erties in the study area at different soil depths.For example,the contents of TOC and TN primarily accumulated in the 0-30 cm depth of arable soils.These were clearly higher than those in the 30-100 cm soil layer.TP content was not remarkably different at different soil depths.Obvious CaCO3 alluvial horizons were also noted in some soil profiles.In the 0-30 cm depth of arable soils,Pb,Cu and Zn contents were similar to that of background soil value.However,Cd content was evidently higher than that of background soil value.Also the average content of the heavy metals was still within WHO threshold,and far below that of China for agricultural soil quality.Factor analysis showed that the sources and transfer characteristics of Pb,Cu and Zn were similar.Cd sources and transfer characteristics were distinct from those of other heavy metals,which was attributed to fertilizer broadcasting and other agricultural factors.While surface accumulation of total Cu and Zn in the soil profiles was obvious,P

关 键 词：开封北郊 引黄灌区 土壤剖面 重金属 稻麦轮作 

分 类 号：X53[环境科学与工程—环境工程]