Study on Soil Nutrients and Tea Quality of Ancient Tea Arboretum and Modern Terrace Tea Garden in Jingmai Mountain

To improve soil management and enhance tea quality for tea garden, it is one of important approaches that the effects of ancient tea garden tea plant cultivation pattern on tea garden soil and tea quality are studied. The representative forest, ancient tea arboretum and modern terrace tea garden were selected in Jingmai Mountain in Yunnan Province. The soil pH, cation exchange capacity (CEC), soil organic matter (SOM), the total and available nutrients of nitrogen, phosphorus and potassium (NPK) and available Cu, Zn and Mn contents of forest and tea garden soils (0-20, ＞20-40 cm) and the tea component of a bud and two leaves: water extraction, tea polyphenols, amino acid, caffeine, 7 kinds of poly-phenols monomer substance and mineral elements calcium (Ca), magnesium(Mg), ferrum(Fe), copper (Cu), zinc (Zn), manganese (Mn) content were determined by the forest soil and tea of modern terrace tea garden as control. The results showed that: compared with modern terraced tea garden, the soil moisture content of ancient tea garden increased by 46.8%, and the soil pH value was significantly lower than that of modern terraced tea garden, but the soil acidification trend of ancient tea garden was not obviously. The soil CEC, SOM, total nitrogen (TN), total phosphorus (TP), available phosphorus (Olsen-P) and available Zn, Mn contents of ancient tea garden were significantly higher than these of modern terraced tea garden. Tea amino acid, caffeine, gallic catechins (EGC) and mineral elements Ca, Mg, Fe, Cu, Zn, Mn contents of ancient tea garden were significantly higher than these of modern terraced tea garden. However, compared with the tea of modern terraced tea garden, the tea water extract, tea poly-phenols, catechins (C), epicatechin (EC) contents and the ratios of poly-phenol to amino acid of ancient tea garden were significantly reduced by 8.2%, 7.7%, 39.2%, 22.8% and 32.4%, respectively. Moreover, tea gallic acid (GA) was detected only in the ancient tea tree. Tea garden soil CEC, SOM, TN, alkali-hydrolyzale nitrogen, TP and Olsen-P was significantly correlated with tea mineral elements Ca, Mg, Fe, Cu, Zn, Mn content, but there were no significant correlation between tea garden soil characteristics and tea water extract, tea poly-phenols, amino acid, caffeine and poly-phenols monomer substance. The soil fertility degradation phenomenon did not happen in ancient tea garden. Tea plant and forest intercropping mode of ancient tea garden is the base of sustainable utilization of soil fertility and tea quality formation, and it is favorable to form fitting environment conditions for tea plant growth, improve tea amino acids and caffeine content and reduce the ratios of poly-phenol to amino acid.