摘要： 采用传统统计和地统计相结合的方法,对70 hm²城郊公路边菜田土壤和韭菜中重金属空间变异特征进行了研究。结果表明,土壤Cu,Zn,Pb和Cd总量一般随距公路距离的增加呈降低的趋势,但其含量均未达到对土壤和作物构成潜在威胁的二级超标水平。韭菜可食部分Pb含量总体上也随距公路距离的增加呈降低的趋势,距南边公路往北280 m和距西边公路往东90 m范围内韭菜可食部分Pb含量普遍超标。韭菜可食部分Pb含量普遍超标主要与土壤中Pb含量和韭菜叶片吸收尾气Pb有关;自南边公路往北和自西边公路往东韭菜可食部分Pb含量空间变异的差异,可能与树木遮挡差异对尾气Pb运动影响范围的不同有关。

关键词: 城郊公路, 菜田土壤, 韭菜, 重金属, 空间变异

Abstract: Spatial variability of heavy metals in soils and Chinese leeks in a vegetable production area of 70 ha beside highway of suburb was studied using traditional statistics and geo-statistics.The results showed that the contents of soil total Cu,Zn,Pb and Cd tended to decrease with increasing distance away from highway,but their contents were below the 2nd criteria of environmental quality standard for soils,indicating no potential threat to the plants and environment in this study area.The contents of Pb in edible Chinese leek parts also decreased with increasing distance away from highway,with the percentage of edible Chinese leek samples beyond the criteria of national Chinese leek sanitary quality being 86%-100% within 280 m from the highway locating in south of the study area to north and 75% within 90 m from the highway locating in west of the study area to east,respectively.The contents of Pb in most edible Chinese leek samples beyond national Chinese leek sanitary quality probably resulted from total Pb in soils and Pb uptake by Chinese leek from the tail gases emitted by automobiles.Difference in spatial distribution of Pb in edible Chinese leek parts from the highway locating in south of the study area to north and from the highway locating in west of the study area to east was caused by different tree shelter with different range of movement for the tail gases emitted by automobiles.

Key words: Highway of suburb, Soils in vegetable field, Chinese leek, Heavy metals, Spatial variability

中图分类号: 

• S633.3