不同土壤下苋菜镉吸收规律及其阈值研究  

Absorption Rules and Threshold Value of Amaranth Cadmium under Different Soil Types

作　　者：王小蒙[1] 郑向群[1] 丁永祯[1] 郑顺安 师荣光[1] 成卫民[1] 姚秀荣[1] 

机构地区：[1]农业部环境保护科研监测所,天津300191 [2]农业部农业生态与资源保护总站,北京100125

出　　处：《环境科学与技术》2016年第10期1-8,共8页Environmental Science & Technology

基　　金：国家国家自然科学基金(41371463);公益性行业(农业)科研专项(200903015);农业生态环境项目

摘　　要：以中国20种典型土壤和苋菜为研究对象,通过盆栽实验揭示不同土壤类型和不同浓度镉污染对苋菜镉累积的相关规律,寻求符合叶菜类卫生标准的土壤镉污染阈值。结果表明:土壤的理化性质不同,不同浓度镉处理对苋菜生长表现出多样性,或促进(盐碱土、黄棕壤和黄绵土)、或抑制(黑钙土和棕漠土)或没有显著影响(黄壤和红壤)。同种土壤条件下,苋菜可食部位镉含量随镉处理浓度增加而升高,而同一浓度处理下,则受土壤pH影响较大。当pH<7.5时,随着pH的上升,重金属含量则随之降低。通过土壤理化性质与苋菜富集系数之间的回归方程,可得出符合国家食品卫生标准的土壤镉污染建议阈值,分别为0.3 mg/kg(pH<6.5)、0.8 mg/kg(6.5<pH<7.5)和1.2mg/kg(pH>7.5)。根据计算出的阈值,可以为叶菜类蔬菜种植区选择和污染农田土壤的治理提供科学依据。With 20 kinds of typical soils and amaranth as the study objective, pot experiment was done to reveal relevant Cd accumulation law of amaranth under different soil types and different concentrations of cadmium, to determine soil cadmium contamination thresholds in line with green vegetable production requirements. Results showed that different physical and chemical properties of the soil led to different concentrations of Cd on the growth performance of the diversity of amaranth, or promoting （saline-alkali soil, yellow brown soil, loess soil） or inhibition （Chemozem, browr~ desert soils） or no significant effect （yellow soil, red soil）. Under the same kind of soil conditions, amaranth edible parts of the cadmium content increased with increasing concentrations of cadmium, while at the same concentrations, affected by soil pH. When pH 〈7.5, as the pH rises, the heavy metal content will also be gradually reduced. By regression equations of soil physical and chemical properties and amaranth enrichment factor, proposal thresholds for soil cadmium can be drawn in line with national food hygiene standards, that is, 0.3 mg/kg at pH 〈6.5, 0.8 mg/kg at 6.5 〈pH 〈7.5, 1.2 mg/kg at pH 〉 7.5. The predicted threshold value of Cd in soil can be reference for the growing areas of leafy vegetable and determination of the target of soil pollution control.

关 键 词：苋菜 镉 土壤类型 阈值 

分 类 号：X53[环境科学与工程—环境工程]