茶园土壤类型对铁观音茶叶稀土元素分布和组成的影响

为探明铁观音茶的质量安全状况,追溯隐患来源,对福建安溪县不同土壤茶园的铁观音茶叶进行稀土元素的分布、组成、迁移和富集能力进行研究。结果表明,安溪县红壤、黄红壤、黄壤茶园稀土组成均以镧、铈、钕、钇为主,但具体组成特征各异。3种类型土壤茶园铁观音茶叶片、叶柄稀土元素组成均以钇、镧、铈、钕4种元素为主,且含量均以第3叶第2叶第1叶叶柄。同种土壤类型茶园铁观音茶树不同部位叶片的稀土元素组成特征类似,但叶与叶柄对稀土元素的吸收能力不同。土壤类型对茶叶稀土元素的累积有显著影响,黄红壤茶园的茶叶稀土元素含量要显著低于红壤、黄壤茶园的(P0.05)。土壤与茶叶中稀土元素组成的相关系数为0.886～0.985,P 0.001,表明二者稀土元素组成密切相关。因此,铁观音茶叶中稀土元素累积、分布与茶园土壤类型有显著相关性。

Effects of Soil Types in Tea Garden on Distribution and Composition of Rare Earth Elements in Tieguanyin

In order to verify the quality safety of Tieguanyin tea, and trace the source of hidden danger, the distribution, composition, transfer and enrichment capacity of rare earth elements in leaves of Tieguanyin planted in 3 types of soil in Anxi County, Fujian Province were studied. The results showed that all of tea and soil types were dominant by La, Ce, Nd and Y, but the composition characters of rare earth elements in soils were different, and the contents of rare earth elements in tea were in the order of the third leaf > the second leaf > the first leaf > leaf stalk. The composition of rare earth elements were similar in leaves at different position planted in the same garden, which were different from leaf stalk. There was significant influence of soil type on accumulation of rare earth elements in tea. The contents of rare earth elements in tea from yellow-red soil were significantly lower than those from red soil and yellow soil (P<0.05). The correlation coefficient of composition of rare earth elements between tea and soil were 0.886-0.985 (P<0.001), which indicated the composition of rare earth elements in tea was significantly positively correlated with soil types. Therefore, the accumulation and distribution of rare earth elements in Tieguanyin tea had significant relation with soil type of tea garden.