土壤—农产品系统中重金属含量关系的影响因素分析

针对浙江省主要粮食、油料大宗作物以及蔬菜、茶叶等各类典型经济作物,选择典型种植区开展了农产品及根系土壤调查,根系土壤样测定了土壤有机质、酸碱度及十多种重金属元素含量,农产品样测定了十多种重金属元素含量。采用分类统计、相关分析、含量分布散点图等方法,研究了农产品与土壤中重金属含量关系。结果表明,作物种类是决定农产品重金属含量的最主要因素;农产品与土壤中重金属含量总体上具有共消长的趋势;土壤有机质、pH值是影响作物对土壤重金属吸收累积的重要环境因素;作物样品采集、加工和分析过程中沾污问题可能会对土壤-农产品重金属含量的相关性产生较大影响。

FACTORS AFFECTING HEAHY METAL CONCENTRATIONS IN THE SOIL-AGRICULTURAL PRODUCT SYSTEM

A systematic survey for the eatable parts of main and special crops and their rhizosphere soils was carried out. The soil samples were determined for organic matters, pH and over 10 of heavy metal elements; while vegetable samples were determined for over 10 of heavy metal elements. The relation of heavy metal element concentrations in the soils to those in the agro-products was analyzed by way of statistics, correlation analysis and X-Y plots. The results show that the bio-type is the key factor affecting the concentrations of heavy metal elements in agro-products. It is also shown that the concentrations of heavy metal elements in the soils and the agro-products are in the trend of co-increasing-decreasing. And the organic matters and pH in the soils are the important factors affecting crop's uptake of heavy metals from soil. Attention must be paid to the contamination of vegetable samples during sampling, processing and analyzing, which may result in incorrect conclusion.