| There is a long history of tea producing in Yunnan, where the cultivated areas and yields rank the forefront nationally with low quality. In this article, the author surveyed and sampled the soil in tea gardens of Yunnan province in order to determine the factors that restrain the improvement of tea quality through lab analysis and statistic analysis. At the same time, according to dependent factors as Cu or Zn, pot experiment was conducted to study the influence on the tea quality by the nutrient Cu and the nutrient Zn. Experiment results as following:1ã€In the soil nutrients of tea garden, the average value of p H and organic matter is 4.55 g/kgã€27.12g/kg respectively; the average value of Alkaline hydrolysis nitrogen, available phosphorus, and available potassium is: 90.12 mg / kg, 171.2 mg / kg, 90.24mg/kg respectively; the average value of exchangeable calcium, exchangeable magnesium was 773.69 mg / kg, 138.51 mg / kg respectively; the average value of available iron, available Mn, available Cu, and effective zinc is 80.45mg/kg, 50.54mg/kg, 0.8 mg / kg, 1.9 mg / kg respectively.2ã€85% p H and 83% organic matter can achieve high levels of quality, yield and efficiency in tea garden. In terms of quality, yield and efficiency, 60% alkali hydrolysable nitrogen, 58% available phosphorus, and 67.09% available potassium can achieve high levels. So can 80.92% exchangeable calcium, 100% exchange of magnesium, 100% available iron, 91.48% available Mn, 45.18% available Cu and47.12% Zn. Therefore, the dependent factors in improving the quality of Yunnan tea are: Copper nutrition and zinc nutrition.3ã€The tea sensory qualities are improved after fertilizing Cu, from trabs, aroma, liquor color, flavor, to tea-leaf. Within a certain scope of fertilizing Cu, it can remarkably improve the content of the tea water extract, free amino acid, soluble sugar, tea polyphenol, caffeine and catechins(in two ways as soil application and foliar application). Considering excessive copper on tea will decrease the contents and harm to tea, soil and even endanger human health, the optimal level of soil application of Cu marks 6 mg / kg. At this time of water extract, free amino acid, soluble sugar, tea polyphenols, catechin, caffeine, tea amino acid content were:45.11%, 3.66%, 2.57%, 24.55% and 13.89% and 2.96%, 1.56% respectively; the optimal level of foliar spraying copper marks 300 mg / kg. At this time of water extract, free amino acid, soluble sugar, tea polyphenols, catechin, caffeine, tea amino acid content were:46.66% and 3.71% and 2.73%, 25.66%, 14.12% and 3.12% and 1.68% respectively.4ã€The sensory quality of tea after application of zinc nutrition: the rope, aroma, soup color, taste, leaf base are better than the control. The amount of applied zinc fertilizer can also significantly improve the tea water extract, free amino acid, soluble sugar, tea polyphenol, caffeine and catechins content(soil application and foliar application). In order to improve the quality of tea and fertilizer utilization point of view, based on the relationship between the tea quality indexes and the quality of tea, obtains the soil Zn and optimal level of 12 mg / kg. At this time of water extract, free amino acid, soluble sugar, tea polyphenols, catechin, caffeine, tea amino acid content were:46.12%, 3.30% and 2.91%, 24.52%, 14.11% and 3.02% and 1.68%; optimal levels of foliar application of Zn was 600 mg / kg. At this time of water extract, free amino acid, soluble sugar, tea polyphenols, catechin, caffeine, tea amino acid content were:47.12%., 3.36% and 3.01% and 25.00%, 14.09%, 3.13% and 1.83%. |
