Abstract:
【Objective】 The comprehensive evaluation index method of soil fertility was used to evaluate the soil pH, organic matter and content of medium and micro nutrients of tea gardens in Pu’er City, so as to provide scientific guidance for the management of soil nutrient and the enhancement of tea quality in the region. 【Method】 A total of 40 representative soil samples were collected from 4 typical tea planting areas in Pu’er City. Soil pH, organic matter and the available contents of medium and micro nutrients(calcium, magnesium, iron, manganese, copper and zinc) were determined. The membership function model was used to calculate the integrated fertility index(IFI), and a comprehensive evaluation of the soil nutrient characteristics and the quality of soil fertility in the tea gardens in Pu’er City was carried out. 【Result】 Soil of tea gardens in Pu’er City was generally acidic, with pH varying from 4.0 to 5.8, and the average value was 4.8.The contents of soil organic matter, available calcium, available magnesium, available iron, available manganese, available copper and available zinc were 4.9-41.6 g/kg, 87.7-2351.9 mg/kg, 56.9-272.2 mg/kg, 40.3-107.3 mg/kg, 2.8-64.8mg/kg, 0.3-2.9 mg/kg, and 0.5-5.2 mg/kg, with averages of 23.4 g/kg, 853.8 mg/kg, 134.5 mg/kg, 77.8 mg/kg, 38.3mg/kg, 1.2 mg/kg and 2.7 mg/kg, respectively. The average contents of these nutrients have reached the suitable levels, but there were large spatial variations among different tea gardens. Among them,95.0% of organic matter in surface soil of tea gardens, 55.0% of available calcium content in tea gardens and 62.5% of available magnesium content in tea gardens reached suitable levels and above, and more than 95% of soil in tea gardens had suitable contents of available iron, available magnesium, available copper and available zinc for tea tree growth. The IFI ranged from 0.59 to 1.00, with an average of 0.83, indicating that the overall soil nutrient status was generally fine. The IFI was extremely significantly positively correlated with organic matter, available magnesium, available manganese, available copper and available zinc(
P<0.01). 【Conclusion】 The soil pH and organic content of tea gardens in Pu’er City are suitable for the cultivation of high-yield and high-quality tea trees. However, the current situation is that there are deficiencies in medium nutrients, including available calcium and available magnesium, excessive levels of micro nutrients such as iron, manganese, copper, zinc, and unbalanced spatial distribution of nutrients. Therefore, it is necessary to optimize fertilization and implement scientific and precise fertilization practices, appropriately control inputs of micro nutrients, and strengthen soil testing and formulated fertilization in tea gardens, so as to maintain high-yield and high-quality production in tea gardens in Pu’er City.