Study on the Content Changes of Zinc and Selenium in Tea and Differences in the Planting Soil

Selecting tea and soil from four tea gardens, Guiding, Duyun, Fenggang and Meitan, as test materials, we tested the content of zinc and selenium in different tea leaves and planting soils. We also studied the differences in zinc and selenium content in different soil types and depths, the differences in zinc and selenium content in new tea leaves (one bud two leaves) and leaves older than one year, and also the relationship between content in soil and leaves. With the increase in soil depth from 0-20 cm to 20-40 cm, the content of zinc increased from 2.0% to 18.0%, respectively, but the content of selenium did not change significantly. The content of zinc and selenium showed significant differences in different soils and soil depths in the same plots (Sig.< 0.01), but the differences exhibited no obvious regular change. The content of zinc and selenium in new tea leaves were 2.3 to 4.0 times and 1.2 to 3.0 times higher, respectively, than that in old leaves (greater than one year old). The content of zinc and selenium in new tea leaves had a positive correlation with the content in soil, and there was a positive correlation between zinc and selenium content in new leaves. Results showed that zinc and selenium came from pedogenic rock, and directly affected tea quality. Thus, the selection of a reasonable soil type is important in regards to high-quality tea and tea garden construction.