Cd Hg Pb胁迫下不同作物可食部分重金属含量及累积特征研究

采用微区土培试验方法,研究了甘肃省3类10种主要栽培作物在Cd、Hg、Pb重度污染土壤上,作物可食部分对重金属的吸收富集能力,并根据食品安全国家标准(GB 2762—2012),采用单因子指数法对农产品质量安全进行评价。结果表明:不同类型作物对重金属的吸收与富集能力有显著性差异,对Cd富集能力表现为蔬菜类油料作物粮食作物,对Hg、Pb富集能力表现为蔬菜类粮食作物油料作物;同一作物(除玉米和大豆外)对不同重金属吸收能力表现为CdPbHg。经综合评价,在对甘肃地区pH值大于8.0的重金属重度污染土壤进行种植业结构调整时,Cd污染耕地可优先选择种植玉米,Hg污染耕地可优先选择种植玉米和油菜,Pb污染耕地可优先选择种植玉米和大豆。

Heavy metal content and accumulation characteristics in the edible parts of different crops under Cd, Hg, and Pb stress

The test method of micro area soil cultivation was used in this research to investigate absorption and accumulation ability of heavy metals in the edible parts of 10 common types of cultivated crops, including three main crop classes, planted in soil heavily polluted by Cd, Hg, or Pb. Furthermore, the quality and safety of agricultural products were evaluated using a single factor index method, according to National food safety standard of China(GB 2762-2012). The results showed that there were significant differences in the absorption capacity of different types of heavy metals in different crops. The trend of accumulation ability of Cd showed as vegetables > oil crops > food crops; for Hg and Pb, it was vegetables > food crops > oil crops. The absorption ability of the same crop(except corn and soybean) for different heavy metals was in the order of Cd > Pb > Hg. This comprehensive evaluation suggested that corn was preferable for Cd-polluted farmland, corn and rapeseed for Hg-polluted farmland, and corn and soybeans for Pb-polluted farmland. This information is helpful for adjusting the crop planting structure in Gansu Province.