Objective  Correlation between the soil properties and the quality of Duobei tea grown on the land was studied for improvements on plantation operation and product quality.

  Method   Soils at 9 Duobei tea planting areas were sampled to determine the pH and contents of metals, organic matters, available phosphorus, alkali hydrolysis nitrogen, and available potassium as well as the activities of sucrase, urease, and catalase. Sensory evaluation and chemical analysis on the teas were conducted. Correlation between the soil properties and the quality and antioxidant activity of Duobei tea grown on a same locality was analyzed.

  Result  The contents of organic matters and available phosphorus in the soil at the 9 planting areas reached the first-grade fertility standard, but the available nitrogen and potassium were generally low. Among the various lots, Field #7 showed the highest soil quality with 45.57g·kg⁻¹ on organic matters, 46.90 mg·kg⁻¹ on alkali hydrolyzed nitrogen, 14.81 mg·kg⁻¹ on available phosphorus, 157.00 mg·kg⁻¹ on available potassium, and 4.68 on pH. Judged being "tender, fresh, strong and mellow" on sensory quality and highly desirable on nutritional composition, the Duobei teas from Field #1, #2, and #7 deemed those areas the choice locations to produce premium grade products. And, the tea from Field #7 showed the greatest in vitro antioxidant capacity among all. A correlation analysis on the soil properties and tea quality revealed that the land with more organic matters, alkali hydrolysis nitrogen, urease, and invertase would likely to grow teas of higher nutritional and sensory quality but heightened soil pH, available phosphorus, and catalase activity in soil could bring about negative results.

  Conclusion  It appeared that application of nitrogen and potassium, control on phosphorus, and enrichment on organic matters in plantation soil could considerably improve the quality of Duobei tea produced.