茶树与茶园土壤的铅含量及分布特征

Lead Concentration and Distribution Pattern in the Tea Plants (Camellia sinensis) and Soils of Different Tea Gardens

采用火焰原子分光光度法,对不同茶园的茶树树体及其土壤样品的铅含量及其分布进行测定。探讨树体及土壤中铅的分布状况,并以富集系数(BAF)为指标对茶树吸收累积铅的能力进行评价。结果表明,茶树新梢与树体铅含量平均值分别为2.26mg/kg和9.43mg/kg;茶树各部位铅含量顺序为:侧根(15.37mg/kg)>主根(11.74mg/kg)>叶片(8.50mg/kg)>生产枝(7.25mg/kg)>骨干枝(4.28mg/kg),其中根系和叶片吸收累积的铅约占树体的60.42%和7.16%。当土壤全铅和有效态铅含量分别在25.88～55.63mg/kg和5.21～25.93mg/kg范围内时,不同茶园茶树的各部位铅含量及铅分布率均呈极显著差异,茶树体内铅含量与土壤铅含量之间相关性并不显著,说明除茶园土壤的铅来源之外,茶树中铅还有其他吸收累积渠道。

In order to understand the content and distribution pattern of lead （Pb） in several tea gardens, and further evaluated the absorb and accumulate ability of tea, Pb content in tea plants （Camellia sinensis） and soils were investigated by the FAAS method. Pb concentration in newly shoots and tea plants were 2.26 mg/kg and 9.43 mg/kg, respectively. Pb content in different tea plant components showed the order as ： side root （15.37 mg/kg） ~ main root （11.74 mg/kg） leaves （8.50 mg/kg）~production branch （7.25 mg/kg）~main branch （4.28 mg/kg）. Compared with other components, Pb accumulation in roots and leaves accounted for 60.42 % and 7.16 of total Pb accumulation in a single plant. Pb concentration and distribution in tea plants were sig- nificantly different in different tea gardens when soil total Pb and available Pb concentration were 25.88--55.63 mg/kg and 5.21--25.93 mg/kg, respectively. However, insignificant correlation was observed between Pb content in tea plants and the soils, implying that there might be some other Pb sources besides the soil.