镍对玉米和水稻污染效应及累积规律的研究

Pollution Effects and Accumulation Rules of Nickel in Corn and Rice

通过盆栽试验,分别探讨了镍在砂壤水稻土中对水稻和在草甸黑土中对玉米的污染效应和累积规律。结果表明,镍对水稻的毒害作用主要表现为生物量和有效分蘖下降,对玉米的毒害作用主要表现为生物量下降和穗重量降低。水稻和玉米各器官对镍的累积量随土壤中镍投加量的增加而增大,其分布规律为根>>茎叶>>子粒。分别以食品卫生标准和作物减产10%为依据,确定了镍在砂壤水稻土中对水稻和在草甸黑土中对玉米的毒性临界含量。

The pollution effects and accumulation rules of nickel were studied in the sandy loam paddy soil for rice and in the meadow soil for corn by pot experiments. The phytotoxicity of nickel in the soils presented both the decreasing of biomass and effective tiller for rice and the decreasing of biomass and weight of grain＇ s ear for corn. The nickel content in the tissues of the two plants increased with the increasing doses of nickel in soils. The accumulation rules of nickel in the two plants were all root〉〉stem and leaf〉〉grain. Comparing with rice, there was higher ability in the absorption and transformation of nickel from soil into corn. In addition, the critical concentrations of nickel phytotoxicity for both rice in the sandy loam paddy soil and corn in the meadow soil were determined based on the food standard of nickel （ 1 mg· kg^-1 ）and the reduction 10% of crop yield. According to the standard of the food limit quantity, the critical concentrations of nickel were 69 mg· kg^-1 （ total ）and 3.2 mg· kg^-1 （ available ）in the sandy loam paddy soil and 26 mg· kg^-1 （ total ）and 1.3 mg· kg^-1 （ available ）in the meadow soil, respectively. However, according to the standard of the reduction 10% of crop yield, the critical concentrations of nickel were 143 mg· kg^-1 〈（total） and 9.0 mg· kg^-1 （ available ）in the sandy loam paddy soil and 188 mg· kg^-1 （ total）and 39 mg· kg^-1 （ available ）in the meadow soil, respectively.