A tea tree cultivation method for increasing the content of tea polyphenols in tea leaves

Abstract

This invention discloses a tea tree cultivation method for increasing the content of tea polyphenols in tea leaves, relating to the field of tea cultivation technology. The tea tree cultivation method of this invention includes the following steps: (1) Before the spring tea buds sprout, a soil conditioner is applied to the soil between the tea tree rows; the soil conditioner comprises the following raw materials by weight percentage: 20-30% cake fertilizer, 15-25% decomposed biogas residue, 2-7% microbial inoculant, 10-15% phosphate rock powder, 10-15% potassium magnesium sulfate, 1-2% zinc sulfate, 1-2% manganese sulfate, 3-5% sulfur powder, and 10-20% auxiliary components; (2) After tea tree pruning, at the initial stage of tea tree budding, and after each tea picking, a water-soluble foliar fertilizer is sprayed onto the tea tree canopy; the water-soluble foliar fertilizer contains ≥1.2g / L of selenium and ≥100g / L of silicon. Implementing this invention can significantly increase the content of tea polyphenols in tea leaves.

Description

Technical Field

[0001] This invention relates to the field of tea cultivation technology, and in particular to a method for cultivating tea trees to increase the content of tea polyphenols in tea leaves. Background Technology

[0002] Tea polyphenols are among the most important functional and quality-enhancing components of tea. Their content directly determines the flavor intensity, astringency, and health benefits of tea. They not only determine the color, aroma, and taste of tea, but also possess significant antioxidant, anti-tumor, lipid-lowering, and blood sugar-lowering effects. In recent years, with increasing attention to healthy eating, the market demand for teas with high polyphenol content has continued to grow. How to effectively increase the polyphenol content in tea has become a crucial technical challenge for the tea industry. The accumulation of tea polyphenols is influenced by various factors, including tea variety, growing environment, soil characteristics, and cultivation management practices. Among these, soil environment and leaf nutrient regulation are the most critical and controllable factors. Increasing the polyphenol content of fresh leaves is key to improving the quality and economic benefits of finished tea.

[0003] Existing technologies for increasing the polyphenol content of fresh tea leaves mainly include three categories: tea variety selection, root fertilization, and foliar fertilizer application. However, all of these methods have limitations and cannot meet the demands of large-scale and efficient production. The first method involves screening or hybridizing tea varieties to cultivate high polyphenol content. This method is time-consuming, costly, and difficult to apply rapidly in existing tea gardens. The second method, existing root fertilization techniques, mainly apply compound fertilizers containing nitrogen, phosphorus, and potassium to the soil. The core function of these fertilizers is to meet the nutritional needs of tea trees, promoting branch and leaf sprouting and root development. However, as a secondary metabolite of tea trees, the synthesis of tea polyphenols is not closely related to the supply of nitrogen, phosphorus, and potassium, resulting in a very limited promoting effect of these fertilizers on polyphenol synthesis and an insignificant increase in yield. Moreover, excessive application of these fertilizers can easily lead to soil compaction and environmental pollution. For the third method, traditional foliar fertilizers are generally general-purpose foliar fertilizers. These fertilizers are primarily formulated with nitrogen, which promotes leaf growth, and are not very effective at increasing the polyphenol content in fresh leaves; they may even dilute the concentration of polyphenols within cells. Therefore, there is an urgent need to develop a highly efficient method to increase the polyphenol content in tea leaves. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a tea tree cultivation method that can significantly increase the content of tea polyphenols in tea leaves.

[0005] To address the aforementioned technical problems, this invention provides a tea tree cultivation method for increasing the polyphenol content in tea leaves, comprising the following steps: (1) Before the spring tea buds sprout, apply a soil conditioner to the soil between the tea tree rows; the soil conditioner includes the following raw materials by weight percentage: 20-30% cake fertilizer, 15-25% decomposed biogas residue, 2-7% microbial inoculant, 10-15% phosphate rock powder, 10-15% potassium magnesium sulfate, 1-2% zinc sulfate, 1-2% manganese sulfate, 3-5% sulfur powder and 10-20% auxiliary components; (2) Water-soluble foliar fertilizer is sprayed on the canopy of tea trees after pruning, at the early stage of tea tree budding, and after each tea picking; the water-soluble foliar fertilizer contains ≥1.2g / L of selenium and ≥100g / L of silicon.

[0006] As an improvement to the above technical solution, the following steps are also included: after the first tea picking of summer tea is completed, apply soil conditioner to the soil between the tea tree rows again.

[0007] As an improvement to the above technical solution, in step (1), the spring tea buds sprout between January and February of each year; The method for applying soil conditioner is as follows: dig trenches between tea tree rows, with a depth of 15-20cm, and evenly sprinkle the soil conditioner into the trenches at a rate of 150-200kg / acre, then cover with soil and water.

[0008] As an improvement to the above technical solution, the microbial agent includes one or more of phosphate-solubilizing bacteria, potassium-solubilizing bacteria, and nitrogen-fixing bacteria.

[0009] As an improvement to the above technical solution, the cake fertilizer includes one or more of rapeseed cake fertilizer, peanut cake fertilizer, and soybean cake fertilizer.

[0010] As an improvement to the above technical solution, the auxiliary components include zeolite powder and diatomaceous earth, wherein the weight percentage of zeolite powder in the soil conditioner is 5-10%, and the weight percentage of diatomaceous earth in the soil conditioner is 5-10%.

[0011] As an improvement to the above technical solution, step (2) includes the following steps: Step (2.1): Before the spring tea sprouts and after applying soil conditioner to the soil between the tea tree rows, prune the tea trees. 3 to 7 days after pruning, spray the tea tree canopy with water-soluble foliar fertilizer for the first time. Step (2.2): After pruning the tea tree in step (2.1), when the new shoots of the tea tree have sprouted to the stage of one bud and one leaf at the beginning of unfolding, spray the tea tree canopy with water-soluble foliar fertilizer for the second time. Step (2.3): Spray water-soluble foliar fertilizer on the tea tree canopy 3 to 7 days after each tea picking.

[0012] As an improvement to the above technical solution, in steps (2.1), (2.2) and (2.3), the water-soluble foliar fertilizer is diluted 3 to 12 times at a dosage of 300 to 600 ml / mu and then sprayed on the canopy of the tea trees.

[0013] As an improvement to the above technical solution, the water-soluble foliar fertilizer contains 1.2~2g / L of selenium, 100~150g / L of silicon, and has a pH value of 6.5~7.5.

[0014] As an improvement to the above technical solution, the tea tree variety is the Yunnan large-leaf variety.

[0015] Implementing this invention has the following beneficial effects: This embodiment, based on the physiological characteristics of tea trees and the mechanism of tea polyphenol synthesis, firstly improves the rhizosphere environment by applying a specially formulated soil conditioner to the soil between tea tree rows before spring tea budding, promoting the absorption of elements required for tea polyphenol synthesis. Secondly, after tea tree pruning, at the early stage of budding, and after each tea harvest, a water-soluble foliar fertilizer with a selenium content ≥1.2 g / L and a silicon content ≥100 g / L is sprayed onto the tea tree canopy to further regulate the synthesis and metabolism of tea polyphenols in the tea leaves. This embodiment, by applying a specially formulated soil conditioner and water-soluble foliar fertilizer at specified times, can simultaneously optimize the rhizosphere environment and leaf metabolic pathways of tea tree growth, creating a suitable rhizosphere environment for tea tree growth and providing the nutrients required for tea polyphenol synthesis, thus significantly increasing the tea polyphenol content in tea leaves. Furthermore, the combination of soil conditioner and water-soluble foliar fertilizer significantly reduces the amount of conventional compound fertilizer used in tea tree cultivation, reducing soil compaction and environmental pollution. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in further detail below. This invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this invention.

[0017] Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Raw materials whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0018] This embodiment discloses a tea tree cultivation method for increasing the content of tea polyphenols in tea leaves, including the following steps: (1) Before the spring tea buds sprout, apply a soil conditioner to the soil between the tea tree rows; the soil conditioner includes the following raw materials by weight percentage: 20-30% cake fertilizer, 15-25% decomposed biogas residue, 2-7% microbial inoculant, 10-15% phosphate rock powder, 10-15% potassium magnesium sulfate, 1-2% zinc sulfate, 1-2% manganese sulfate, 3-5% sulfur powder and 10-20% auxiliary components; preferably, the tea tree is a mature tea tree, that is, a tea tree planted for 5-30 years. During this period, the tea tree's tea polyphenol synthesis enters its peak period, which is the core stage of tea picking, and the fresh leaves are of the best quality; (2) Water-soluble foliar fertilizer is sprayed on the canopy of tea trees after pruning, at the early stage of tea tree budding, and after each tea picking; the water-soluble foliar fertilizer contains ≥1.2g / L of selenium and ≥100g / L of silicon.

[0019] It is worth noting that this implementation method, based on the physiological characteristics of tea trees and the mechanism of tea polyphenol synthesis, firstly improves the rhizosphere environment by applying a specific soil conditioner to the soil between tea tree rows before spring tea budding, promoting the absorption of elements required for tea polyphenol synthesis. Secondly, after tea tree pruning, at the early stage of budding, and after each tea harvest, a water-soluble foliar fertilizer with a selenium content ≥1.2 g / L and a silicon content ≥100 g / L is sprayed onto the tea tree canopy to further regulate the synthesis and metabolism of tea polyphenols in the tea leaves. This implementation method, by applying a specifically formulated soil conditioner and water-soluble foliar fertilizer at designated times, can simultaneously optimize the rhizosphere environment and leaf metabolic pathways of tea tree growth, creating a suitable rhizosphere environment for tea tree growth and providing the nutrients required for tea polyphenol synthesis, thus significantly increasing the tea polyphenol content in tea leaves.

[0020] It is worth noting that the tea tree cultivation method in this embodiment is based on conventional soil fertilization and pest and disease management in tea gardens. Conventional soil fertilization in tea gardens mainly involves applying compound fertilizers containing nitrogen, phosphorus, potassium, and other elements. By adopting the tea tree cultivation method of this embodiment, the use of soil conditioners and water-soluble foliar fertilizers can significantly reduce the amount of compound fertilizer used in conventional soil fertilization in tea gardens, thereby reducing soil compaction and environmental pollution. In some embodiments, the amount of conventional soil fertilization can be reduced to 50% to 60% of the original amount using this tea tree cultivation method.

[0021] In addition, in step (1), before the spring tea buds sprout, a soil conditioner is applied to the soil between the tea tree rows. The soil conditioner improves the soil's physical, chemical, and biological properties by adjusting the soil pH, creating a suitable rhizosphere environment for tea tree growth and providing the nutrients required for tea polyphenol synthesis. The soil conditioner includes the following raw materials by weight percentage: 20-30% cake fertilizer, 15-25% decomposed biogas residue, 2-7% microbial inoculant, 10-15% phosphate rock powder, 10-15% potassium magnesium sulfate, 1-2% zinc sulfate, 1-2% manganese sulfate, 3-5% sulfur powder, and 10-20% auxiliary components. Among them, the oilseed cake in the soil conditioner is an organic fertilizer processed from the residue after oil extraction from oilseed crops. It mainly contains nitrogen, phosphorus, potassium and trace elements. Oilseed cake helps to reduce the ratio of tea polyphenols and amino acids in tea, and improves the fresh taste of tea. Well-rotted biogas residue can increase the organic carbon content of the soil, improve the soil structure and reduce soil compaction. Microbial agents can activate insoluble nutrients in the soil. Inorganic components such as phosphate rock powder, potassium magnesium alum, zinc sulfate, manganese sulfate and sulfur powder can provide the mineral elements required for the synthesis of tea polyphenols. Among them, zinc has a significant promoting effect on the accumulation of tea polyphenols.

[0022] Well-rotted biogas residue is formed from the solid matter remaining after the fermentation of organic matter through composting. It is rich in organic matter, humic acid, trace nutrients, various amino acids, enzymes, and beneficial microorganisms, effectively improving soil quality. It also contains nitrogen, phosphorus, and potassium, meeting the needs of crop growth. This fertilizer has a high nutrient content, rich in organic matter and humic acid, thus improving soil structure. Long-term application of biogas residue fertilizer can loosen the soil, increase fertility, improve permeability, and prevent soil compaction. However, it should be noted that uncomposted biogas residue will compete with crops for oxygen in the soil, affecting root development; therefore, this implementation method requires the use of well-composted biogas residue.

[0023] To further explain, after tea tree pruning, during the early stages of bud break, and after each tea harvest, the new tissues of the tea tree are metabolically active, and the stomata and cuticle of the leaves have strong absorption capacity. This implementation method applies water-soluble foliar fertilizer at these three key time points. Through the synergistic effect of selenium and the penetrating component silicon, it can activate the tea tree's defense response and secondary metabolism, directly promoting the synthesis and accumulation of tea polyphenols, while simultaneously improving the absorption and utilization efficiency of the foliar fertilizer, thereby significantly increasing the tea polyphenol content in the tea leaves. Specifically, after tea tree pruning and after each tea harvest, water-soluble foliar fertilizer is sprayed onto the tea tree canopy. At this time, the tea tree is in a state of wound repair and re-germination, and its hormone levels and metabolic flow undergo drastic changes. Spraying water-soluble foliar fertilizer at this time can reserve sufficient precursor substances for the germination of new buds and leaves, and guide metabolic flow towards the synthesis of defensive secondary metabolites such as tea polyphenols. In addition, when tea trees are in the early stages of budding, water-soluble foliar fertilizer can be sprayed on the canopy. At this time, the new shoots of the tea trees are just beginning to grow and cell division is vigorous. This is the golden period for the synthesis and accumulation of tea polyphenols. Supplementing nutrition at this time can directly participate in the synthesis process and maximize the initial content of tea polyphenols in the new leaves.

[0024] Specifically, the water-soluble foliar fertilizer in this embodiment contains ≥1.2g / L of selenium and ≥100g / L of silicon. Selenium can activate polyphenol oxidase in tea plants, thereby increasing the content of tea polyphenols in tea leaves. If the selenium content is lower than 1.2g / L, the effect of increasing the content of tea polyphenols in tea leaves will be poor.

[0025] To further explain, this implementation method, based on the tea tree growth cycle and the synthesis pattern of tea polyphenols, determines the optimal time and dosage ratio for soil improvement and foliar regulation, achieving a precise match between technical measures and the physiological needs of tea trees, and can effectively increase the content of tea polyphenols in tea leaves.

[0026] In one embodiment, the tea cultivation method for increasing the polyphenol content in tea leaves further includes the following step: after the first harvest of summer tea leaves, applying a soil conditioner again to the soil between the tea tree rows. By applying the soil conditioner again after the first harvest of summer tea leaves, the polyphenol content of subsequent autumn tea can be effectively increased. If the soil conditioner is only applied to the soil between the tea tree rows before the spring tea buds sprout, although the polyphenol content of spring and summer tea can be increased, the polyphenol content of autumn tea will decrease, making it difficult to ensure consistent tea quality across seasons.

[0027] In one implementation, in step (1), the spring tea buds sprout between January and February of each year; specifically, it can be early January, mid-January, late January, early February, mid-February, or late February.

[0028] In one implementation, the soil conditioner is applied before the spring tea buds sprout and after the first harvest of summer tea leaves as follows: dig trenches between the tea tree rows, with a depth of 15-20cm, and evenly sprinkle the soil conditioner into the trenches at a rate of 150-200kg / acre, then cover with soil and water.

[0029] This embodiment involves applying a soil conditioner between tea rows at specific times, before spring tea budding and / or after the first summer tea harvest. This is beneficial for increasing tea yield and enhancing the polyphenol content in the tea leaves. The soil conditioner dosage is 150-200 kg / mu (approximately 115-120 kg / acre), which effectively increases the polyphenol content within this range. In some optional embodiments, a higher dosage (170-200 kg / acre) can be used before spring tea budding, while a lower dosage (150-170 kg / acre) can be used after the first summer tea harvest.

[0030] In one embodiment, the microbial agent includes one or more of phosphate-solubilizing bacteria, potassium-solubilizing bacteria, and nitrogen-fixing bacteria. These microbial agents, such as phosphate-solubilizing bacteria, potassium-solubilizing bacteria, and nitrogen-fixing bacteria, can activate insoluble nutrients in the soil.

[0031] Oilseed cake is made from the residue after pressing oil from oilseed crops such as soybeans, peanuts, and rapeseed. Its components include nitrogen, phosphorus, potassium, and various trace elements, classifying it as a comprehensive organic fertilizer. In one embodiment, the oilseed cake includes one or more of rapeseed oilseed cake, peanut oilseed cake, and soybean oilseed cake. Preferably, rapeseed oilseed cake is used, as it helps reduce the ratio of tea polyphenols to amino acids, enhancing the fresh and crisp taste of tea.

[0032] In one embodiment, the auxiliary components include zeolite powder and diatomaceous earth, wherein the weight percentage of zeolite powder in the soil conditioner is 5-10%, and the weight percentage of diatomaceous earth in the soil conditioner is 5-10%. The zeolite powder and diatomaceous earth mainly function to adsorb and release saturated soil and improve its physical structure.

[0033] Specifically, for soils that are too acidic (pH<4.0), the proportion of zeolite powder and diatomaceous earth in the soil conditioner can be appropriately increased; for soils that are poor in organic matter, the amount of organic components (rapeseed cake fertilizer, decomposed biogas residue and microbial inoculants) in the soil conditioner can be increased.

[0034] In one implementation, step (2) includes the following steps: Step (2.1): Before the spring tea buds sprout and after applying a soil conditioner to the soil between the tea tree rows, prune the tea trees. 3-7 days after pruning, spray the tea tree canopy with water-soluble foliar fertilizer for the first time. It should be noted that the pruning of the tea trees in step (2.1) refers to simply leveling the tea tree canopy, with a pruning height of 2-5cm, removing protruding branches and leaves on the picking surface to facilitate subsequent tea picking. In this embodiment, the first spraying of water-soluble foliar fertilizer is carried out before the spring tea buds sprout and after applying a soil conditioner to the soil between the tea tree rows. Specifically, the tea trees can be pruned on the same day as the application of the soil conditioner in spring or 2-5 days thereafter. Step (2.2): After pruning the tea tree in step (2.1), when the new shoots of the tea tree have sprouted to the stage of one bud and one leaf at the beginning of unfolding, spray the tea tree canopy with water-soluble foliar fertilizer for the second time. Step (2.3): Spray water-soluble foliar fertilizer on the tea tree canopy 3 to 7 days after each tea picking.

[0035] In this embodiment, water-soluble foliar fertilizer is sprayed onto the tea tree canopy 3-7 days after pruning and 3-7 days after each tea picking. Spraying water-soluble foliar fertilizer during this period provides sufficient precursor substances for the germination of new buds and leaves, and guides metabolic flow towards the synthesis of defensive secondary metabolites such as tea polyphenols.

[0036] In this embodiment, after pruning the tea tree, when the new shoots have sprouted to the stage of one bud and one leaf just beginning to unfold, a second application of water-soluble foliar fertilizer is made to the tea tree canopy. Specifically, tea leaves are usually picked when the new shoots of the tea tree sprout to one bud and two leaves, one bud and three leaves, or one bud and four leaves. In this embodiment, water-soluble foliar fertilizer is sprayed after pruning the tea tree and when the new shoots sprout to one bud and one leaf (i.e., the early stage of sprouting). At this time, the new shoots of the tea tree have just begun to grow and cell division is vigorous. This is the golden period for the synthesis and accumulation of tea polyphenols. Supplementing with water-soluble foliar fertilizer at this time can directly participate in the synthesis process and effectively increase the content of tea polyphenols in the tea leaves.

[0037] In one embodiment, in steps (2.1), (2.2) and (2.3), the water-soluble foliar fertilizer is diluted 3 to 12 times at a dosage of 300 to 600 ml / mu and then sprayed on the canopy of the tea trees.

[0038] Further explanation: In steps (2.1), (2.2), and (2.3), the dosage of water-soluble foliar fertilizer is controlled at 300-600 ml / mu. Within this dosage range, it is beneficial to increase the content of tea polyphenols in tea leaves. Specifically, after diluting the water-soluble fertilizer with clean water, it is sprayed on the leaves using a sprayer, ensuring that both sides of the leaves are evenly moistened without dripping. The spraying time should preferably be chosen on cloudy days or in the evening of sunny days to avoid the fertilizer solution evaporating too quickly.

[0039] To further explain, water-soluble foliar fertilizer can be applied by drone spraying or manual spraying. In some embodiments, when using drone spraying, the water-soluble foliar fertilizer can be diluted 8 to 12 times before spraying. In some embodiments, when using manual spraying, the water-soluble foliar fertilizer can be diluted 3 to 10 times before spraying.

[0040] In one embodiment, the tea tree variety is the Yunnan Large-Leaf variety. The Yunnan Large-Leaf variety is a collective term for arborescent large-leaf tea tree varieties unique to Yunnan Province, including 12 nationally or provincially recognized superior varieties such as Mengku Large-Leaf, Fengqing Large-Leaf, and Menghai Large-Leaf. The tea-picking season for the Yunnan Large-Leaf variety generally begins from March to April each year and can continue until October to November. After the first harvest, a second harvest can be made after an interval of 15-25 days, and so on, with several to more than ten harvests per year. In this embodiment, after each harvest, a water-soluble foliar fertilizer is sprayed onto the surface of the tea tree. This provides sufficient precursor substances for the germination of new buds and leaves and guides metabolic flow towards the synthesis of defensive secondary metabolites such as tea polyphenols, ensuring that the tea polyphenol content in each batch of tea is within a high range, thus guaranteeing the consistency of tea quality.

[0041] In one embodiment, the water-soluble foliar fertilizer contains 1.2-2 g / L of selenium, 100-150 g / L of silicon, and has a pH of 6.5-7.5. Selenium and silicon content within these ranges is beneficial for significantly increasing the content of tea polyphenols in tea leaves.

[0042] It is worth noting that the water-soluble foliar fertilizer used in this embodiment can be a commercially available water-soluble foliar fertilizer, as long as it meets the requirements of a selenium content of 1.2~2g / L and a silicon content of 100~150g / L. In some embodiments, selenium-enriched foliar silicon fertilizer from Tieren Environmental Protection can be used. The pH value of the water-soluble foliar fertilizer can be adjusted during use to ensure that the pH value is within the range of 6.5~7.5. Alternatively, existing methods for preparing selenium-enriched foliar silicon fertilizer can also be used to formulate a foliar fertilizer with a selenium content of 1.2~2g / L and a silicon content of 100~150g / L.

[0043] In some optional embodiments, selenium powder is used as the selenium source and quartz sand is used as the silicon source to prepare water-soluble foliar fertilizer. The preparation method of water-soluble foliar fertilizer in this embodiment includes the following steps: (1) After uniformly mixing selenium powder with oxides (including zinc oxide and / or copper oxide) at a mass ratio of 1:(1.5~2.5), calcining the mixture for 20~30 minutes in an oxidizing atmosphere at 350℃~700℃ to vaporize the selenium and combine it with oxygen to generate selenium oxide, thereby removing impurities from the selenium powder; the calcined material is then cooled and crushed to obtain a calcined mixture. Specifically, the calcined material is crushed and passed through an 80~120 mesh sieve, and the undersize material is collected to obtain the calcined mixture; (2) The calcined mixture, quartz sand, flux, and stabilizer are thoroughly mixed in a mixer to form a selenium-containing glass precursor material. In some embodiments, the selenium-containing glass precursor material comprises the following raw materials by mass percentage: 1.5%~3.5% calcined mixture, 64%~75% quartz sand, 15%~25% flux, and 3%~8% stabilizer. Quartz sand provides the glass framework and silicon element; in some embodiments, potassium carbonate can be used as the flux, which decomposes into potassium oxide at high temperatures, significantly reducing the glass melting temperature; boron oxide can be used as the stabilizer; furthermore, the raw materials of the selenium-containing glass precursor material may also contain 0~0.5% clarifying agent, specifically, nitrates can be used as clarifying agents to help eliminate bubbles at high temperatures and obtain a uniform glass melt. Preferably, the particle size of the calcined mixture, quartz sand, and flux is 80~120 mesh.

[0044] (3) Place the selenium-containing glass precursor material into a high-temperature resistant crucible and heat it until the material is completely melted. The heating temperature is 1200℃~1400℃ to form a uniform glass melt.

[0045] (4) Pour the molten glass into the mold and cool it to obtain a solid selenium-rich silicate glass.

[0046] (5) The selenium-rich silicate glass is coarsely crushed and then placed in a ball mill with a predetermined amount of deionized water for wet ball milling. During or after the ball milling process, a certain amount of organosilicon surfactant and chelating agent are added. Specifically, the surface of the ball-milled glass micropowder has high activity and is prone to agglomeration and precipitation. Through the synergistic effect of organosilicon surfactant and chelating agent, the agglomeration of glass micropowder can be effectively prevented, so that the glass micropowder is stably dispersed in water, so that the product achieves high water solubility, and improves the leaf spreading performance and absorption efficiency of the product, significantly improving nutrient utilization. Preferably, the organosilicon surfactant can be modified methyltrisiloxane; the chelating agent can be disodium EDTA and / or citric acid; disodium EDTA can stably complex various metal ions, prevent the formation of insoluble substances, and ensure the clarity of the solution; citric acid has both chelating and pH adjustment functions. Preferably, the amount of chelating agent added is 0.05%~0.15% of the total mass of the finished fertilizer, and the amount of organosilicon surfactant added is 0.1%~0.3% of the total mass of the finished fertilizer.

[0047] (6) Pass the ball-milled slurry through a 400-600 mesh sieve to remove large particles. The slurry collected is the foliar fertilizer concentrate. Add deionized water to the foliar fertilizer concentrate to the target mass and adjust the pH value to 6.5-7.5 to obtain water-soluble foliar fertilizer.

[0048] It is worth noting that traditional selenium-containing foliar fertilizers are generally prepared using a solution mixing method. For example, selenite or selenite is used as the selenium source to create nano-selenium sol, which is then mixed with silica sol to produce selenium-containing foliar silicon fertilizer. Selenium-containing foliar silicon fertilizers prepared using this method have poor stability; selenium and silicon elements are prone to separation or precipitation during use or after long-term storage. Furthermore, the selenium release rate of selenium-containing foliar silicon fertilizers prepared using traditional methods is relatively fast. When the selenium content in the fertilizer is too high, spraying it onto the tea surface can easily lead to localized selenium toxicity. The water-soluble foliar fertilizer prepared using the method described in this embodiment allows selenium atoms to directly enter and become part of the silicate glass network structure at high temperatures, forming a single, homogeneous selenium-silicon glass body. This avoids the separation of selenium and silicon elements during use, slows down the selenium release rate, prevents localized selenium toxicity, prolongs fertilizer effectiveness, and improves selenium utilization. Applying the water-soluble foliar fertilizer prepared in this embodiment to tea cultivation is beneficial to further increase the content of tea polyphenols in tea leaves.

[0049] In one embodiment, taking the preparation of 1 ton of water-soluble foliar fertilizer as an example, to ensure the silicon content of the finished product is 100-150 g / L, the total silicon mass needs to be 100-150 kg. When using quartz sand as the silicon source, the theoretical feed amount of quartz sand is 214.3-321.4 kg, and the actual feed amount needs to be increased by 5%-10% to avoid impurities in the quartz sand or losses during the preparation process. Optionally, the actual feed amount of quartz sand can be controlled at 230-350 kg. To ensure the selenium content of the finished product is 1.2-2 g / L, the theoretical feed amount of selenium powder is 1.2-2 kg. To compensate for the loss of selenium powder due to high-temperature volatilization, the actual feed amount of selenium powder needs to be increased by 10%-30%. Optionally, the actual feed amount of selenium powder can be controlled at 1.5-2.5 kg.

[0050] The technical solution of the present invention will be further described below through embodiments and comparative examples.

[0051] Example 1 This embodiment provides a tea tree cultivation method to increase the polyphenol content in tea leaves. The method involves conducting an experiment in a Pu'er tea producing area in Yunnan Province, selecting mature tea gardens of the "Yunnan Large Leaf" variety with consistent growth conditions. The experiment includes the following steps: (1) Before the spring tea buds sprout (early February), dig trenches between the tea tree rows, with a depth of 15cm. Spread the soil conditioner evenly into the trenches at a rate of 180kg / mu, then cover with soil and water. The soil conditioner includes the following raw materials by weight percentage: rapeseed cake fertilizer 25%, decomposed biogas residue 20%, microbial inoculant 5%, phosphate rock powder 12%, potassium magnesium sulfate 13%, zinc sulfate 2%, manganese sulfate 1%, sulfur powder 4%, zeolite powder 8%, and diatomaceous earth 10%. (2) Spray water-soluble foliar fertilizer (2.1) The day after applying soil conditioner between tea tree rows, prune the tea trees to a height of 2-5cm to level the tea tree canopy. On the third day after pruning, spray the tea tree canopy with water-soluble foliar fertilizer for the first time. The amount of water-soluble foliar fertilizer is 500ml / mu, diluted 10 times before spraying. (2.2) After pruning the tea trees in step (2.1), when the new shoots of the tea trees sprout to the stage of one bud and one leaf initial unfolding, spray the tea tree canopy with water-soluble foliar fertilizer for the second time; the amount of water-soluble foliar fertilizer is 500ml / mu, diluted 10 times before spraying. (2.3) On the third day after each tea picking, water-soluble foliar fertilizer was sprayed on the canopy of the tea trees. The amount of water-soluble foliar fertilizer was 400 ml / mu, diluted 10 times before spraying.

[0052] Among them, the water-soluble foliar fertilizer has a selenium content of ≥1.2g / L, a silicon content of ≥100g / L, and a pH of 7.5.

[0053] Example 2 This embodiment provides a tea tree cultivation method to increase the content of tea polyphenols in tea leaves. The tea garden used in Example 2 is the same as that in Example 1, and the method includes the following steps: (1) Before the spring tea buds sprout (early February), dig trenches between the tea tree rows, with a depth of 15cm. Spread the soil conditioner evenly into the trenches at a rate of 200kg / mu, then cover with soil and water. The soil conditioner includes the following raw materials by weight percentage: rapeseed cake fertilizer 20%, decomposed biogas residue 25%, microbial agent 7%, phosphate rock powder 10%, potassium magnesium sulfate 15%, zinc sulfate 2%, manganese sulfate 2%, sulfur powder 3%, zeolite powder 9%, and diatomaceous earth 7%. (2) Spray water-soluble foliar fertilizer (2.1) The day after applying soil conditioner between tea tree rows, prune the tea trees to a height of 2-5cm to level the tea tree canopy. On the third day after pruning, spray the tea tree canopy with water-soluble foliar fertilizer for the first time. The amount of water-soluble foliar fertilizer is 500ml / mu, diluted 10 times before spraying. (2.2) After pruning the tea trees in step (2.1), when the new shoots of the tea trees sprout to the stage of one bud and one leaf at the beginning of the unfolding stage, spray the tea tree canopy with water-soluble foliar fertilizer for the second time; the amount of water-soluble foliar fertilizer is 600ml / mu, diluted 10 times before spraying. (2.3) On the third day after each tea picking, water-soluble foliar fertilizer was sprayed on the canopy of the tea trees. The amount of water-soluble foliar fertilizer was 400 ml / mu, diluted 10 times before spraying.

[0054] In Example 2, the water-soluble foliar fertilizer used was the same as that used in Example 1.

[0055] (3) After the first tea picking of summer tea is completed, soil conditioner is applied to the soil between the tea tree rows again. The soil conditioner formula used in step (3) is the same as the soil conditioner formula in step (1) of this embodiment, and the method of applying the soil conditioner is also the same. The difference is that the amount of soil conditioner used in step (3) is 150 kg / mu.

[0056] Comparative Example 1 This comparative example provides a tea tree cultivation method. The tea garden used in the comparative example 1 experiment is the same as that in example 1, that is, the comparative example is conducted in other areas of the same tea garden as example 1. The comparative example 1 only performs conventional soil fertilization (compound fertilizer) and pest and disease management, that is, the comparative example 1 does not apply soil conditioner and water-soluble foliar fertilizer.

[0057] Comparative Example 2 This comparative example provides a tea tree cultivation method, wherein the tea garden used in Comparative Example 2 is the same as that in Example 1, and includes the following steps: Before the spring tea buds sprout (early February), dig trenches between the tea tree rows, 15cm deep, and evenly spread the soil conditioner at a rate of 180kg / mu into the trenches, then cover with soil and water. The soil conditioner includes the following raw materials by weight percentage: rapeseed cake fertilizer 25%, decomposed biogas residue 20%, microbial inoculant 5%, phosphate rock powder 12%, potassium magnesium sulfate 13%, zinc sulfate 2%, manganese sulfate 1%, sulfur powder 4%, zeolite powder 8%, and diatomaceous earth 10%.

[0058] That is, this comparative example only applies soil conditioner, without spraying the water-soluble foliar fertilizer of Example 1.

[0059] Comparative Example 3 This comparative example provides a tea tree cultivation method, wherein the tea garden used in Comparative Example 3 is the same as that in Example 1, and includes the following steps: (1) Before the spring tea buds sprout (early February), dig trenches between the tea tree rows, with a depth of 15cm. Spread the soil conditioner evenly into the trenches at a rate of 180kg / mu, then cover with soil and water. Apply the soil conditioner between the tea tree rows. The soil conditioner includes the following raw materials by weight percentage: 25% rapeseed cake fertilizer, 20% decomposed biogas residue, 5% microbial inoculant, 12% phosphate rock powder, 13% potassium magnesium sulfate, 2% zinc sulfate, 1% manganese sulfate, 4% sulfur powder, 8% zeolite powder, and 10% diatomaceous earth. (2) On the third day after each tea picking, water-soluble foliar fertilizer was sprayed on the canopy of the tea trees. The amount of water-soluble foliar fertilizer was 400 ml / mu, diluted 10 times before spraying. The water-soluble foliar fertilizer used in Comparative Example 3 was the same as that used in Example 1.

[0060] Specifically, fresh leaf samples from Examples 1, 2, and Comparative Examples 1 to 3 were simultaneously harvested during the one-bud-two-leaf stage of spring tea, summer tea, and autumn tea. The content of tea polyphenols in the fresh leaves of spring tea, summer tea, and autumn tea was detected, and the results are as follows: The average content of tea polyphenols in the fresh leaves of spring tea, summer tea, and autumn tea in Example 1 was 26.5%. The average content of tea polyphenols in the fresh leaves of spring tea, summer tea, and autumn tea in Example 2 was 31.1%. The average polyphenol content of fresh tea leaves in Comparative Example 1 (spring, summer, and autumn teas) was 11.6%. The average content of tea polyphenols in fresh leaves of spring tea, summer tea and autumn tea in Comparative Example 2 was 18.4%.

[0061] The average content of tea polyphenols in fresh leaves of spring tea, summer tea and autumn tea in Comparative Example 3 was 20.7%.

[0062] Therefore, it can be seen that the tea tree cultivation methods of Examples 1 and 2 can significantly increase the content of tea polyphenols in tea leaves.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for cultivating tea trees to increase the content of tea polyphenols in tea leaves, characterized in that, Includes the following steps: (1) Before the spring tea buds sprout, apply a soil conditioner to the soil between the tea tree rows; the soil conditioner includes the following raw materials by weight percentage: 20-30% cake fertilizer, 15-25% decomposed biogas residue, 2-7% microbial inoculant, 10-15% phosphate rock powder, 10-15% potassium magnesium sulfate, 1-2% zinc sulfate, 1-2% manganese sulfate, 3-5% sulfur powder and 10-20% auxiliary components; (2) Water-soluble foliar fertilizer is sprayed on the canopy of tea trees after pruning, at the early stage of tea tree budding, and after each tea picking; the water-soluble foliar fertilizer contains ≥1.2g / L of selenium and ≥100g / L of silicon.

2. The tea tree cultivation method for increasing the polyphenol content in tea leaves according to claim 1, characterized in that, It also includes the following steps: After the first harvest of summer tea leaves, a soil conditioner is applied again to the soil between the rows of tea trees.

3. The tea tree cultivation method for increasing the polyphenol content in tea leaves according to claim 1 or 2, characterized in that, In step (1), the spring tea buds sprout between January and February each year; The method for applying soil conditioner is as follows: dig trenches between tea tree rows, with a depth of 15-20cm, and evenly sprinkle the soil conditioner into the trenches at a rate of 150-200kg / acre, then cover with soil and water.

4. The tea tree cultivation method for increasing the polyphenol content in tea leaves according to claim 1, characterized in that, The microbial inoculant includes one or more of phosphate-solubilizing bacteria, potassium-solubilizing bacteria, and nitrogen-fixing bacteria.

5. The tea tree cultivation method for increasing the polyphenol content in tea leaves according to claim 4, characterized in that, The oilseed cake fertilizer includes one or more of rapeseed oilseed cake fertilizer, peanut oilseed cake fertilizer, and soybean oilseed cake fertilizer.

6. The tea tree cultivation method for increasing the polyphenol content in tea leaves according to claim 5, characterized in that, The auxiliary components include zeolite powder and diatomaceous earth, wherein the weight percentage of zeolite powder in the soil conditioner is 5-10%, and the weight percentage of diatomaceous earth in the soil conditioner is 5-10%.

7. The tea tree cultivation method for increasing the polyphenol content in tea leaves according to claim 3, characterized in that, Step (2) includes the following steps: Step (2.1): Before the spring tea sprouts and after applying soil conditioner to the soil between the tea tree rows, prune the tea trees. 3 to 7 days after pruning, spray the tea tree canopy with water-soluble foliar fertilizer for the first time. Step (2.2): After pruning the tea tree in step (2.1), when the new shoots of the tea tree have sprouted to the stage of one bud and one leaf at the beginning of unfolding, spray the tea tree canopy with water-soluble foliar fertilizer for the second time. Step (2.3): Spray water-soluble foliar fertilizer on the tea tree canopy 3 to 7 days after each tea picking.

8. The tea tree cultivation method for increasing the polyphenol content in tea leaves according to claim 7, characterized in that, In steps (2.1), (2.2) and (2.3), the water-soluble foliar fertilizer is diluted 3 to 12 times at a dosage of 300 to 600 ml / mu and then sprayed on the canopy of the tea trees.

9. The tea tree cultivation method for increasing the polyphenol content in tea leaves according to claim 1, characterized in that, The water-soluble foliar fertilizer contains 1.2-2 g / L of selenium, 100-150 g / L of silicon, and has a pH value of 6.5-7.

5.

10. The tea tree cultivation method for increasing the content of tea polyphenols in tea leaves according to claim 1, characterized in that, The tea tree variety mentioned is the Yunnan large-leaf variety.