不同尾矿含量盆栽小麦生长结实和重金属富集状况

采用盆栽试验方法，研究了不同尾矿含量对小麦生产结实及重金属富集的影响。结果表明，当尾矿含量达到30％-45％时，小麦的营养生长（根、茎、叶）和生殖生长（穗长、盆组产量、单株产量、百粒重）都显著降低；小麦根系、茎杆和种子中Ni和Co的含量都随土壤中Ni和Co含量增大而增大，而Cu的富集有选择性，当尾矿Cu含量达到30％以后小麦器官中Cu的含量不再增加；无论是Ni和Co还是Cu含量，总的分布趋势是小麦根部累积量最大，其次是茎叶部，种子中含量最少。进一步分析表明，当土壤中尾矿含量达到30％～45％后，小麦种子中Ni、Co、Cu含量就严重超过食用标准，因此，受尾矿污染的农地不应采用农作复垦。

Accumulations of Heavy Metal in Wheat Plant and the Growth Status Under Pot Experiment with Different Contents of Tailings

The accumulations of Ni, Co and Cu in wheat plant (spring wheat, Longchun No.23) and their effects on the growth of the wheat plant under different contents of tailings were discussed in the present study bu using pot experiments. Nine levels, tailings contents in each level were 0%, 5%, 15%, 30%, 45%, 60%, 75%, 90%, and 100%, respectively, and three replicates in each level were designed. The tailings were chosen from Jinchuan Non-ferrous Metal Limited Company, located in Northwest of China. 60 grains of wheat were sowed in every pot and preserved 30 individuals respectively a month later. The vegetative growth and reproduction of the wheat were investigated and observed during the whole growing season. The contents of Ni, Co and Cu in plant body and soil were determined with ICP-AES. The results indicated that there were significant declines in both vegetative and reproductive growth of wheat when tailings content in soil reached 30%~45%. Concentrations of Ni and Co in roots, stalks and seeds increased with their concentrations increasing in soil, but concentrations of Cu represented selective accumulation when the tailings contents reached 30%. The general distribution pattern of Ni, Co and Cu in wheat organs followed the order: root > stalk > seed. Further analysis suggested, concentrations of Ni, Co, and Cu in seed severely exceeded safe standard for food when the content of tailings in soil was beyond 30%~45%. So, agricultural reclaim is not suitable for farmland polluted by tailings, since Ni, Co and Cu in tailings affect growth and seed setting of crops.