摘要
福建沿海地区土壤Pb含量远高于我国其他地区及全国背景值,其对农产品安全、生态环境的影响值得关注。本文采集该地区典型耕作区58套土壤-水稻样品,查明Pb、Cd等重金属元素含量特征及其关键控制因素。研究表明从水稻根→茎叶→稻谷,重金属元素含量和富集系数呈现明显的下降趋势,有害重金属As、Pb的递减速率远大于植物营养元素Cu、Zn,指示水稻根部对重金属元素具有一定的阻截作用。土壤-稻谷间Pb具有显著正相关性,显示土壤Pb是稻谷Pb的重要来源;稻谷Pb含量与土壤有机碳呈负相关关系,与土壤p H值呈弱负相关关系,说明富含有机碳、相对碱性的土壤环境可降低土壤Pb的生物有效性,减少稻谷对土壤Pb的吸收富集。土壤理化条件对稻谷Cd富集系数有显著影响,富含有机碳、Al2O3、Fe2O3、Ca O、Mg O、S的土壤条件有利于阻断稻谷对土壤Cd的吸收,降低土壤Cd污染的生态风险。本项研究为开展水田土壤重金属污染治理修复、预测稻谷食用安全提供了依据。
Lead content of soil in coastal areas of Fujian Province is higher than that of soil in other areas and in the background level of China,and is therefore of significant influence on food safety and the ecological environment. Based on Pb and Cd contents of 58 suites of soil and rice samples, the characteristic of content and its influencing factors are discussed. Results show that the concentrations and BCF values of heavy metals decrease rapidly from root to stem leaf to rice,and concentrations of toxic elements like arsenic and lead decrease more obviously than those of plant nutrients such as copper and zinc,indicating that rice root has a barrier effect for toxic element uptake. Lead content of rice is positively correlated with that of soil,indicating the soil is the main source of lead in rice. Lead content of rice is negatively correlated with organic carbon contents and p H of soil. This indicates that the abundance of organic carbon and neutral-alkaline soil conditions may reduce bioavailability of lead in soils. The bio-concentration factor of cadmium has a good correlation with physicochemical conditions of soil. Abundance of organic carbon,Al2O3,Fe2O3,Ca O,Mg O and S can hinder the uptake of cadmium by rice and reduce its ecorisk. This research provides the foundation for restoring paddy fields polluted by heavy metals and contributes in predicting the impact of heavy metal pollution of soil on the safety of rice.
出处
《岩矿测试》
CAS
CSCD
北大核心
2016年第3期295-301,共7页
Rock and Mineral Analysis
基金
国土资源部公益性行业科研专项经费项目<典型红壤区农业生态地质研究>课题二"典型地质环境区红壤化过程地球化学特征研究"(201411091-2)
关键词
水稻
土壤
重金属含量
富集系数
影响因素
福建沿海地区
rice
soil
heavy metal content
BCF
influencing factors
coastal areas in Fujian Province
