Methods, systems, and methods of use thereof for increasing free amino acid content of tea leaves

Abstract

The application discloses a method and system for improving the content of free amino acids in tea leaves and a use method thereof, and relates to the technical field of tea tree cultivation and tea quality improvement. The method comprises the following steps: S1, arranging a light frequency conversion covering net above a tea tree canopy, wherein the light frequency conversion covering net comprises a net-shaped base material and a light conversion functional layer loaded on the net-shaped base material; the light conversion functional layer comprises an ultraviolet-blue light light conversion path and / or a green light-red light light conversion path; the ultraviolet-blue light light conversion path is used for absorbing 280-400 nm ultraviolet light and emitting 430-470 nm blue light; the green light-red light light conversion path is used for absorbing ultraviolet light, blue light and / or 500-570 nm green light and emitting 620-680 nm red light; and S2, applying a purple non-sulfur photosynthetic bacterial preparation into the rhizosphere soil of the tea tree within a time window of 1-15 days before or 1-15 days after the arrangement of the light frequency conversion covering net; the purple non-sulfur photosynthetic bacteria are selected from Rhodopseudomonas and / or Rhodobacter. The application realizes the synergistic occurrence of canopy light quality regulation and rhizosphere microorganism nitrogen metabolism promotion.

Description

Technical Field

[0001] This invention relates to the field of tea tree cultivation and tea quality improvement technology, and in particular to a method, system and application method for increasing the content of free amino acids in tea. Background Technology

[0002] Free amino acids are crucial quality components that determine the freshness and flavor harmony of tea. Theanine accounts for approximately 40%-70% of the total free amino acids in tea plants. It is primarily synthesized in the roots of the tea plant from ethylamine and glutamic acid via theanine synthase, and then transported to the above-ground parts. Increasing the free amino acid content in fresh leaves often involves measures such as shading, optimizing nitrogen fertilizer supply, increasing the application of organic fertilizers, and using foliar nutrients.

[0003] Existing shading and covering technologies mainly affect tea tree metabolism by reducing light intensity. Traditional black nets, silver-gray nets, or ordinary shade nets are difficult to precisely optimize the light quality structure of the tea tree canopy. Excessive shading may also lead to a decrease in photosynthetic rate, weak buds and leaves, increased disease risk, and yield fluctuations. Ordinary agricultural films or covering nets are also difficult to convert spectral components such as ultraviolet and green light into blue and red light, which are more conducive to nitrogen metabolism in tea trees.

[0004] Furthermore, existing shading and microbial agent application methods rely heavily on manual experience. They typically cannot dynamically and formulaically adjust the height of the shading net, the duration of shading, the amount of water replenishment, and the application time and amount of purple non-sulfur photosynthetic bacteria preparations based on real-time blue and red light photon flux ratios below the shading net, relative soil moisture content in the rhizosphere, canopy temperature and humidity, weather forecasts, and the number of days remaining before harvest. They also lack control methods that correlate the above environmental and phenological data with measured quality indicators (total free amino acids, theanine, phenol-amino acid ratio) during the harvest period and use them for closed-loop calibration. This results in fluctuations in the quality improvement effect of the same shading material or the same microbial agent formula in different seasons and different tea gardens. Summary of the Invention

[0005] To address the technical problems existing in the prior art, embodiments of the present invention provide a method, system, and method of using it for increasing the free amino acid content of tea. The technical solution is as follows: A method for increasing the free amino acid content in tea leaves, the method comprising: S1. A light frequency conversion covering net is laid above the tea tree canopy. The light frequency conversion covering net includes a mesh substrate and a light conversion functional layer loaded on the mesh substrate. The light conversion functional layer includes an ultraviolet-blue light conversion path and / or a green-red light conversion path. The ultraviolet-blue light conversion path is used to absorb 280-400 nm ultraviolet light and emit 430-470 nm blue light. The green-red light conversion path is used to absorb ultraviolet light, blue light and / or 500-570 nm green light and emit 620-680 nm red light. S2. Within a time window of 1-15 days before or after the deployment of the optical frequency conversion coverage network, apply a purple non-sulfur photosynthetic bacteria preparation to the rhizosphere soil of the tea trees; the purple non-sulfur photosynthetic bacteria are selected from the genus Rhodopseudomonas (…). Rhodopseudomonas ) and / or Rhodophytes ( Rhodobacter ).

[0006] Optionally, in S1, the mesh substrate is selected from one or more of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyolefin elastomer, polylactic acid, and bio-based polyester. And / or, the unit area mass of the mesh substrate is 20-180 g / m². 2 ; And / or, the light-converting functional layer is loaded onto the mesh substrate by means of blending and drawing light-converting masterbatch, surface coating, lamination or impregnation curing; And / or, the ultraviolet-blue light conversion pathway and the green-red light conversion pathway coexist in the same light conversion functional layer or exist in different layers of the composite film layer; And / or, the ultraviolet-blue light conversion pathway includes an ultraviolet-blue light conversion component, wherein the ultraviolet-blue light conversion component is selected from rare earth europium (Eu). 3+ Eu 2+ One or more of the following: doped aluminate phosphors, rare earth europium doped silicate phosphors, and rare earth europium organic complexes; And / or, the green-to-red light conversion pathway includes a green-to-red light conversion component, wherein the green-to-red light conversion component is selected from nitrogen-doped carbon dots, manganese (Mn) 4+ ) doped fluoride phosphors, rare earth praseodymium (Pr 3+ One or more of the organic complexes.

[0007] Optionally, the light-converting component is free of cadmium, lead, mercury, and hexavalent chromium, and / or has a solubility of less than 0.1 g / L in water at 25°C; And / or, the mass fraction of the light-converting component in the optical frequency conversion coverage network is 0.05%-8.00%; And / or, the shading rate of the optical frequency conversion coverage network is 15%-55%; And / or, the transmittance of the optical frequency conversion coverage network at 400-700 nm is 45%-85%; And / or, the mesh size of the optical frequency conversion coverage mesh is 0.5-8.0 mm; And / or, a ventilation gap is formed between the optical frequency conversion covering net and the top surface of the tea tree canopy, and the height of the ventilation gap is 10-80 cm; And / or, after the optical frequency conversion coverage network is deployed, the sum of the 400-500 nm blue light photon flux and the 600-700 nm red light photon flux measured on the horizontal plane of the canopy accounts for 55%-85% of the 400-700 nm visible light photon flux; And / or, the optical frequency conversion coverage net is laid 10-80 cm above the canopy 7-35 days before the tea tree shoots are harvested.

[0008] Optionally, in S2, the purple non-sulfur photosynthetic bacteria are selected from Rhodopseudomonas palustris (… Rhodopseudomonas palustris ), capsular red bacteria ( Rhodobacter capsulatus ), spherical red bacteria ( Rhodobacter sphaeroides One or more of the following; And / or, the purple non-sulfur photosynthetic bacteria preparation is selected from liquid bacterial agents, solid bacterial agents, or granular bacterial agents; And / or, the effective viable count of the purple non-sulfur photosynthetic bacteria preparation: for liquid preparations, not less than 1.0 × 10⁻⁶. 8 CFU / mL, for solid or granular inoculants, not less than 1.0 × 10⁻⁶. 8 CFU / g; And / or, when using liquid inoculant, the dosage of the undiluted inoculant is 30-450 L / hm. 2 Dilute 50-500 times before application; And / or, when using solid or granular inoculants, the application rate is 15-300 kg / hm². 2 ; And / or, the purple non-sulfur photosynthetic bacteria preparation is applied to the rhizosphere soil of tea trees by ring trench application, strip trench application, drip irrigation application, or rhizosphere hole application, with an application depth of 5-15 cm. And / or, the purple non-sulfur photosynthetic bacteria preparation further includes a protective carrier and a rhizosphere colonization promoting component; the protective carrier is selected from one or more of humic acid, fulvic acid, alginate, bentonite, attapulgite, peat moss, biochar, starch, and maifanite powder; the rhizosphere colonization promoting component is selected from one or more of molasses, seaweed oligosaccharide, chitosan oligosaccharide, phosphate, and magnesium sulfate; And / or, for three days before and three days after the application of the purple non-sulfur photosynthetic bacteria preparation, do not apply urea with a nitrogen content greater than 46%, nitrogen fertilizer containing nitrate nitrogen, agricultural fungicides, hydrogen peroxide and / or sodium hypochlorite to the application area.

[0009] Optionally, the method further includes: S3. During the covering period, maintain the relative soil moisture content of the tea tree rhizosphere at 50%-85% of field capacity. And / or, the method is used to increase the theanine content in tea and / or reduce the phenol-to-amino acid ratio; And / or, the method is used to increase the total free amino acid content or theanine content in raw materials of green tea, white tea, yellow tea or famous teas.

[0010] A system for increasing the free amino acid content of tea leaves, the system comprising: (1) Optical frequency conversion covering mesh, which includes a mesh substrate and a light conversion functional layer loaded on the mesh substrate, wherein the light conversion functional layer includes an ultraviolet-blue light conversion path and / or a green-red light conversion path, wherein the ultraviolet-blue light conversion path is used to absorb 280-400 nm ultraviolet light and emit 430-470 nm blue light, and the green-red light conversion path is used to absorb ultraviolet light, blue light and / or 500-570 nm green light and emit 620-680 nm red light; (2) A support and fixing component for laying the optical frequency conversion coverage net above the tea tree canopy, the support and fixing component including at least two of the following: support rod, horizontal pull rope, pressure film rope, ground anchor and adjustable height connector; (3) Purple non-sulfur photosynthetic bacteria preparation, wherein the purple non-sulfur photosynthetic bacteria are selected from the genus Rhodopseudomonas ( Rhodopseudomonas ) and / or Rhodophytes ( Rhodobacter ).

[0011] Optionally, the optical frequency conversion coverage net is a recyclable roll-up coverage net; And / or, the edge of the optical frequency conversion coverage mesh is provided with at least one of the following: tear-resistant reinforcing strip, breathable and moisture-wicking zone, and positioning and fixing holes; And / or, the support and fixing components create a ventilation gap of 10-80cm between the optical frequency conversion covering net and the top surface of the tea tree canopy; And / or, the purple non-sulfur photosynthetic bacteria preparation is packaged in conjunction with the light frequency conversion covering net; And / or, the purple non-sulfur photosynthetic bacteria are selected from Rhodopseudomonas palustris (… Rhodopseudomonas palustris ), capsular red bacteria ( Rhodobacter capsulatus ), spherical red bacteria ( Rhodobacter sphaeroides One or more of the following; And / or, the purple non-sulfur photosynthetic bacteria preparation is selected from liquid bacterial agents, solid bacterial agents, or granular bacterial agents; And / or, the effective viable count of the purple non-sulfur photosynthetic bacteria preparation: for liquid preparations, not less than 1.0 × 10⁻⁶. 8 CFU / mL, for solid or granular inoculants, not less than 1.0 × 10⁻⁶. 8 CFU / g; And / or, the system is used to increase the theanine content in tea and / or reduce the phenol-to-ammonia ratio.

[0012] Optionally, the system further includes: (4) Intelligent monitoring and control module, wherein the intelligent monitoring and control module includes: (i) A data acquisition unit, comprising: a spectral sensor located below the optical frequency conversion coverage network, a soil moisture sensor located in the rhizosphere soil layer, a canopy temperature and humidity sensor located in the ventilation gap, and a meteorological data interface; (ii) Data processing unit; and (iii) Prescription output unit; The data processing unit generates the regulatory prescription according to the following rules: (a) When the sum of the photon flux of 400-500nm blue light and 600-700nm red light below the optical frequency conversion cover net accounts for less than 55% of the photon flux of 400-700nm visible light, a prescription is output to reduce the height of the optical frequency conversion cover net or replace it with an optical frequency conversion cover net with higher light conversion efficiency. (b) When the ratio is higher than 85%, or the canopy temperature in the ventilation gap is higher than the preset upper limit, output a prescription to increase the height of the optical frequency conversion coverage network, shorten the coverage time, or increase the ventilation gap; (c) When the relative water content of the rhizosphere soil is less than 50% of the field capacity, apply the prescription of purple non-sulfur photosynthetic bacteria preparation after replenishing water to reach 50%-85% of the field capacity. (d) When the relative moisture content of the rhizosphere soil is higher than 85% of the field capacity, or the forecast of rainfall in the next 24 hours is higher than the preset threshold, output a prescription to postpone the application of bacteria or reduce the amount applied with water. The prescription output unit outputs at least one of the following: the height of the optical frequency conversion coverage net, the coverage duration, the amount of water replenishment, and the application time of the purple non-sulfur photosynthetic bacteria preparation.

[0013] Optionally, the detection band of the spectral sensor is 350-800 nm, and it outputs at least one of the following: 400-500 nm blue light photon flux, 600-700 nm red light photon flux, and 400-700 nm total visible light photon flux. And / or, the soil moisture sensor is placed in the 5-20 cm rhizosphere soil layer; And / or, the meteorological data interface receives at least one of rainfall, maximum temperature, minimum temperature and solar radiation forecast; And / or, the data processing unit further includes a prescription prediction model, which is a supervised regression model; And / or, the prescription prediction model is selected from one of gradient boosting regression tree, random forest regression, support vector regression and single hidden layer artificial neural network; And / or, the input to the prescription prediction model is a feature vector, which includes: the proportion of the sum of blue and red light photon fluxes below the optical frequency conversion coverage network to the visible light photon flux, the average daily canopy temperature, the average daily canopy relative humidity, the relative moisture content of the rhizosphere soil, the tea variety code, the phenological stage code, the number of days covered, the number of days remaining before harvest, the application amount of purple non-sulfur photosynthetic bacteria preparation, and at least one of the following for the next 3 days: rainfall, maximum temperature, and solar radiation forecast. And / or, the output of the prescription prediction model is the predicted value of theanine content, total free amino acid content and phenol-amino acid ratio of fresh leaves at the harvesting period; And / or, the prescription prediction model is obtained by cross-validation training using the feature vector of the historical covering season and the measured theanine content, total free amino acid content, and phenol-amino acid ratio of the corresponding harvest period as training samples; And / or, the data processing unit maps each candidate control action to a corresponding component in the feature vector on the set of feasible control actions consisting of the optical frequency conversion coverage net deployment height, coverage start date, coverage end date, purple non-sulfur photosynthetic bacteria preparation application amount, and rhizosphere moisture target value. The optical frequency conversion coverage net deployment height corresponds to the ratio of the sum of blue and red light photon flux below the coverage net to the visible light photon flux. The coverage start date and coverage end date correspond to the number of days covered and the number of days remaining before harvest. The purple non-sulfur photosynthetic bacteria preparation application amount and the rhizosphere moisture target value correspond to the purple non-sulfur photosynthetic bacteria preparation application amount component and the rhizosphere soil relative moisture content component in the feature vector, respectively. Then, taking the theanine content predicted by the prescription prediction model as the target, and under the condition that the phenol-to-ammonia ratio is not higher than the preset upper limit and the canopy temperature and rhizosphere relative moisture content meet the preset constraints, the optimal combination of control actions is selected as the prescription output. And / or, after each tea-picking season, the data processing unit updates the prescription prediction model with the measured theanine content, total free amino acid content, and phenol-amino acid ratio of that season. And / or, when the prediction error of the prescription prediction model exceeds a preset threshold in the most recent tea-picking season, the data processing unit reverts to generating a control prescription based on the rules.

[0014] The system is used by first applying the purple non-sulfur photosynthetic bacteria preparation according to step S2, then setting up the light frequency conversion covering net according to step S1, and maintaining the relative water content of the tea tree rhizosphere soil at 50%-85% of field capacity during the covering period.

[0015] The beneficial effects of the technical solutions provided by the embodiments of the present invention include at least the following: This invention discloses a method and system for synergistically enhancing the free amino acid content in tea leaves using a light frequency conversion covering net and photosynthetic bacteria. The method involves deploying a light frequency conversion covering net above the tea tree canopy. The covering net comprises a mesh substrate and a light-converting functional layer loaded thereon. The light-converting functional layer has ultraviolet-blue light conversion pathways and / or green-red light conversion pathways, respectively used to convert 280-400 nm ultraviolet light into 430-470 nm blue light, and ultraviolet light, blue light, and / or 500-570 nm green light into 620-680 nm red light. Simultaneously, 1-15 days before or after covering, an effective viable bacteria count of not less than 1.0 × 10⁻⁶ is applied to the rhizosphere of the tea trees. 8 CFU / mL (liquid) or 1.0 × 10 8 A CFU / g (solid, granular) purple non-sulfur photosynthetic bacteria preparation, which maintains the rhizosphere relative water content at 50%-85% of field capacity during mulching, synergistically promotes canopy light quality regulation and rhizosphere microbial nitrogen metabolism, thereby increasing the total free amino acid content and theanine content of tea shoots. This method is applicable to improving the freshness and quality of green tea, white tea, yellow tea, and other premium tea raw materials.

[0016] First, the present invention does not simply block light, but rather uses light frequency conversion to directionally regulate the light spectrum received by the canopy, thereby maintaining photosynthetic capacity while moderately reducing strong light stress. Second, this invention constructs a technical chain of canopy light quality regulation - rhizosphere nitrogen metabolism promotion - new shoot amino acid accumulation; Third, this invention clarifies key parameters such as coverage height, coverage time, light conversion band, shading rate, viable bacteria count, application rate, water management and agricultural restrictions, and has strong feasibility. Fourth, the present invention can use an intelligent monitoring and control module to regulate the covering, watering and bacterial application processes in a prescription and closed-loop manner according to rules and prescription prediction models, thereby reducing quality fluctuations caused by differences in human experience. Fifth, this invention is applicable to the production of high-end green tea, white tea, and famous teas, and helps to reduce reliance on high-nitrogen fertilization and heavy shading. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating the method provided in an embodiment of the present invention; Figure 2This is a schematic diagram of the structure of the optical frequency conversion coverage network provided in this embodiment of the invention, which is deployed above the tea tree canopy. Figure 3 This is a schematic diagram of the optical frequency conversion coverage network and its spectral conversion characteristics provided in an embodiment of the present invention; wherein, Figure 3 (a) is a schematic diagram of the structural composition of the optical frequency conversion coverage network. Figure 3 (b) is a schematic diagram of the spectral distribution before and after optical frequency conversion; Figure 4 This is a schematic diagram of the rhizosphere inoculation method for the purple non-sulfur photosynthetic bacteria preparation provided in this embodiment of the invention; Figure 5 This is a schematic diagram of the synergistic mechanism between canopy light quality regulation and rhizosphere photosynthetic bacteria provided in an embodiment of the present invention; Figure 6 This is a flowchart of the intelligent monitoring and prescription control module provided in Embodiment 6 of the present invention. It shows that: data from a spectral sensor, soil moisture sensor, canopy temperature and humidity sensor, meteorological data interface, and phenological and harvesting period data are collected by the data acquisition unit into inputs such as blue and red light photon flux, rhizosphere moisture, canopy temperature and humidity, weather forecast, and remaining days before harvesting; the data processing unit generates a prescription based on a rule-based decision engine and by calling a prescription prediction model (using threshold judgment, random forest, support vector regression, or neural network, and trained or calibrated with the total free amino acid content, theanine, and phenol-amino acid ratio measured during the harvesting period); the prescription output unit outputs control suggestions such as the height of the covering net and the number of covering days, the time and amount of fungal agent application, water replenishment amount, and rhizosphere moisture target; and the measured quality data during the harvesting period is fed back for model calibration. 1-Tea tree canopy; 2-Light frequency conversion covering net; 3-Support rod; 4-Horizontal rope; 5-Filling rope; 6-Ground anchor; 7-Ventilation gap; 8-Ultraviolet light; 9-Green light; 10-Blue light; 11-Red light; 12-Mesh substrate; 13-Light conversion component; 14-Tea tree rhizosphere soil; 15-Purple non-sulfur photosynthetic bacteria preparation; 16-Circular application trench; 17-Absorbing root; 18-Rhizosphere beneficial microbial functional zone; 19-Canopy nitrogen metabolism enhancement pathway; 20-Free amino acid accumulation pathway; 21-Data acquisition unit; 22-Spectral sensor; 23-Soil moisture sensor; 24-Canopy temperature and humidity sensor; 25-Meteorological data interface; 26-Data processing unit (executes rule decision engine and calls prescription prediction model); 27-Prescription prediction model; 28-Prescription output unit; 29-Prescription for covering net height and covering days; 30-Prescription for inoculant application time and dosage. Detailed Implementation

[0019] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0020] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0021] This invention belongs to the technical fields of tea tree cultivation, rhizosphere microbial regulation in tea gardens, functional covering materials, intelligent agricultural monitoring and regulation, and tea quality improvement. Specifically, it relates to a method and system for synergistically increasing the free amino acid content of tea leaves using a light frequency conversion covering net and purple non-sulfur photosynthetic bacteria, which is particularly suitable for the targeted improvement of the freshness and crispness of green tea, white tea, and other premium tea raw materials.

[0022] Rhodopseudomonas spp. ( Rhodopseudomonas ) and Rhodophytes ( Rhodobacter Purple non-sulfur photosynthetic bacteria have potential applications in rhizosphere microecological regulation, root promotion, and small molecule metabolite formation. However, existing tea garden microbial agents are mostly used as single soil improvement measures, lacking matching designs with canopy light quality regulation measures, making it difficult to form a synergistic system that combines aboveground light quality-induced nitrogen metabolism with underground rhizosphere nitrogen supply and absorption promotion.

[0023] This invention aims to solve the problems that ordinary shading can only reduce light intensity but cannot optimize the ratio of blue and red light; to solve the problem that the application of microbial agents alone is disconnected from the photosynthetic and nitrogen metabolism processes of the tea tree canopy, resulting in unstable quality-promoting effects; to solve the problem that the covering height, covering duration, rhizosphere moisture, and application time and amount of microbial agents rely on manual experience and are difficult to match with real-time environmental and phenological data for prescription matching; and to solve the problem that in the production of high-end green tea and white tea, the over-reliance on high-nitrogen fertilization or heavy shading leads to an inability to balance quality, yield, and ecological risks.

[0024] To address the aforementioned issues, this invention employs a synergistic technical approach of canopy light quality regulation and rhizosphere purple non-sulfur photosynthetic bacteria promoting nitrogen metabolism: First, a light frequency conversion covering net is deployed before the harvesting of tea shoots to directionally convert some of the ultraviolet and green light received in the canopy into blue and red light; second, a purple non-sulfur photosynthetic bacteria preparation is applied to the rhizosphere soil; and third, water management and agricultural restrictions are used to improve the survival and functional expression of the preparation in the rhizosphere.

[0025] In the optimized system, the intelligent monitoring and control module collects canopy spectrum, rhizosphere moisture, canopy temperature and humidity and meteorological data. Based on the rule decision engine and prescription prediction model, it outputs prescription suggestions for the height of the covering net, the duration of covering, the amount of water replenishment and the time and amount of microbial agent application; ultimately promoting the accumulation of free amino acids and theanine in new shoots.

[0026] In one embodiment of the present invention, a method for increasing the free amino acid content and reducing the phenol-amino acid ratio in tea is provided, comprising: S1, deploying a light frequency conversion covering net above the tea tree canopy, the light frequency conversion covering net comprising a mesh substrate and a light conversion functional layer loaded on the mesh substrate, the light conversion functional layer comprising an ultraviolet-blue light conversion pathway and / or a green-red light conversion pathway, wherein the ultraviolet-blue light conversion pathway is used to absorb 280-400 nm ultraviolet light and emit 430-470 nm blue light, and the green-red light conversion pathway is used to absorb ultraviolet light, blue light and / or 500-570 nm green light and emit 620-680 nm red light; S2, applying a purple non-sulfur photosynthetic bacteria preparation to the rhizosphere soil of the tea tree within a time window of 1-15 days before or after deploying the light frequency conversion covering net, wherein the purple non-sulfur photosynthetic bacteria are selected from the genus Rhodopseudomonas and / or the genus Rhodophyton. Furthermore, during the covering period, the relative moisture content of the rhizosphere soil of the tea trees is maintained at 50%-85% of field capacity. This invention also provides a system for implementing the above method and its usage, the system comprising a light frequency conversion covering net, support and fixing components, and a purple non-sulfur photosynthetic bacteria preparation, and may further include an intelligent monitoring and control module.

[0027] In a preferred embodiment of the present invention, a method for synergistically increasing the free amino acid content of tea leaves using a light frequency conversion covering network and photosynthetic bacteria is provided, comprising the following steps: S1. 7-35 days before the harvesting of new tea shoots, a light frequency conversion covering net is laid 10-80 cm above the tea tree canopy. The light frequency conversion covering net includes a mesh substrate and a light conversion functional layer loaded on the mesh substrate. The light conversion functional layer has at least one of the ultraviolet-blue light conversion pathway and / or green-red light conversion pathway. The ultraviolet-blue light conversion pathway is used to absorb 280-400 nm ultraviolet light and emit 430-470 nm blue light. The green-red light conversion pathway is used to absorb ultraviolet light, blue light and / or 500-570 nm green light and emit 620-680 nm red light. S2. Within a time window of 1-15 days before or after the deployment of the optical frequency conversion coverage network, apply a purple non-sulfur photosynthetic bacteria preparation to the rhizosphere soil of the tea trees; the purple non-sulfur photosynthetic bacteria is Rhodopseudomonas spp. ( Rhodopseudomonas ) and / or Rhodophytes ( Rhodobacter The effective viable count of the purple non-sulfur photosynthetic bacteria preparation is not less than 1.0 × 10⁻⁶ bacteria in the liquid preparation. 8 CFU / mL, for solid or granular inoculants, not less than 1.0 × 10⁻⁶. 8 CFU / g; S3. During the covering period, maintain the relative soil moisture content of the tea tree rhizosphere at 50%-85% of field capacity. S4. Harvest new tea shoots according to the standards for processing tea.

[0028] Optionally, the mesh substrate is selected from one or more of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyolefin elastomer, polylactic acid, and bio-based polyester, and the unit area mass of the mesh substrate is 20-180 g / m². 2 .

[0029] Optionally, the light conversion functional layer is loaded onto the mesh substrate by means of blending and drawing light conversion masterbatch, surface coating, lamination or impregnation curing; the ultraviolet-blue light conversion pathway and the green-red light conversion pathway exist simultaneously in the same light conversion functional layer or exist separately in different layers of the composite film.

[0030] Optionally, the ultraviolet-blue light conversion pathway is composed of an ultraviolet-blue light conversion component, wherein the ultraviolet-blue light conversion component is selected from rare earth europium (Eu). 3+ Eu 2+ The green-to-red light conversion pathway is composed of a green-to-red light conversion component, which is selected from nitrogen-doped carbon dots and manganese (Mn) doped phosphors, rare earth europium-doped silicate phosphors, and rare earth europium organic complexes, or a combination of two or more of these components. 4+ ) doped fluoride phosphors, rare earth praseodymium (Pr 3+ The light-converting components are one or more combinations of organic complexes; none of the light-converting components contain cadmium, lead, mercury, or hexavalent chromium, and their solubility in water at 25°C is less than 0.1 g / L; the mass fraction of the light-converting components in the optical frequency conversion coverage network is 0.05%-8.00%.

[0031] Optionally, the basis weight of the mesh substrate is 20-180 g / m². 2 Within the specified range, the shading rate of the optical frequency conversion covering mesh is 15%-55%, the transmittance of visible light at 400-700 nm is 45%-85%, and the mesh aperture is 0.5-8.0 mm.

[0032] Optionally, a ventilation gap is formed between the optical frequency conversion covering net and the top surface of the tea tree canopy, and the height of the ventilation gap is 10-80 cm.

[0033] Optionally, after the optical frequency conversion coverage network is deployed, on a clear morning between 10:00 and 12:00, on the horizontal plane of the canopy, the sum of the blue light photon flux of 400-500 nm and the red light photon flux of 600-700 nm is measured using a 350-800 nm range spectroradiometer, and is found to account for 55%-85% of the visible light photon flux of 400-700 nm.

[0034] Optionally, the purple non-sulfur photosynthetic bacteria are selected from Rhodopseudomonas palustris (… Rhodopseudomonas palustris ), capsular red bacteria ( Rhodobacter capsulatus ), spherical red bacteria ( Rhodobacter sphaeroides One or more combinations of )

[0035] Optionally, the purple non-sulfur photosynthetic bacteria preparation is a liquid, solid, or granular inoculum; when it is a liquid inoculum, the dosage of the stock solution is 30-450 L / hm. 2 (Equivalent to 2-30 L / mu), dilute 50-500 times before application; when using solid or granular inoculants, the application rate is 15-300 kg / hm. 2 (equivalent to 1-20 kg / mu).

[0036] Optionally, the purple non-sulfur photosynthetic bacteria preparation further includes a protective carrier and a rhizosphere colonization promoting component; the protective carrier is selected from one or more combinations of humic acid, fulvic acid, alginate, bentonite, attapulgite, peat moss, biochar, starch, and maifanite powder; the rhizosphere colonization promoting component is selected from one or more combinations of molasses, seaweed oligosaccharide, chitosan oligosaccharide, phosphate, and magnesium sulfate.

[0037] Optionally, the purple non-sulfur photosynthetic bacteria preparation is applied to the rhizosphere soil of tea trees by means of ring trench application, strip trench application, drip irrigation application, or rhizosphere hole application, with an application depth of 5-15 cm.

[0038] Optionally, for a total of 6 days, including the first 3 days and the last 3 days after the application of the purple non-sulfur photosynthetic bacteria preparation, urea with a nitrogen content greater than 46%, nitrogen fertilizer containing nitrate nitrogen, agricultural fungicides, hydrogen peroxide, and sodium hypochlorite shall not be applied to the application area.

[0039] Optionally, the method is used to increase the total amount of free amino acids or theanine content in raw materials of green tea, white tea, yellow tea or famous teas.

[0040] In a preferred embodiment of the present invention, a tea tree free amino acid enhancement system is provided, comprising three parts: a light frequency conversion covering net, a support and fixing component, and a purple non-sulfur photosynthetic bacteria preparation. The light frequency conversion covering net includes a mesh substrate and a light-converting functional layer loaded on the mesh substrate. The light-converting functional layer has at least one of an ultraviolet-blue light conversion pathway and / or a green-red light conversion pathway. The support and fixing component includes two or more combinations of support rods, horizontal pull ropes, pressure film ropes, ground anchors, and adjustable height connectors. The light frequency conversion covering net is positioned above the tea tree canopy, creating a 10-80 cm ventilation gap between the light frequency conversion covering net and the top surface of the tea tree canopy. The effective viable count of the purple non-sulfur photosynthetic bacteria preparation is not less than 1.0 × 10⁻⁶ for liquid bacteria. 8 CFU / mL, for solid or granular inoculants, not less than 1.0 × 10⁻⁶. 8 CFU / g.

[0041] Optionally, the optical frequency conversion covering net is a recyclable roll-up covering net with tear-resistant reinforcing strips, breathable and moisture-wicking zones, and positioning and fixing holes on the edges; the purple non-sulfur photosynthetic bacteria preparation is packaged together with the optical frequency conversion covering net.

[0042] Optionally, it also includes an intelligent monitoring and control module, which includes a data acquisition unit, a data processing unit, and a prescription output unit; The data acquisition unit includes a spectral sensor located below the cover net, a soil moisture sensor located in the 5-20 cm rhizosphere soil layer, a canopy temperature and humidity sensor located in the ventilation gap, and a meteorological data interface. The spectral sensor has a detection band of 350-800 nm and outputs at least 400-500 nm blue light photon flux, 600-700 nm red light photon flux, and 400-700 nm visible light total photon flux. The meteorological data interface receives rainfall, maximum temperature, minimum temperature, and solar radiation forecasts for the next 1-7 days. The data processing unit generates control prescriptions according to the following rules: (a) When the sum of the photon flux of 400-500 nm blue light and 600-700 nm red light below the cover net is less than 55% of the photon flux of 400-700 nm visible light, a prescription is output to reduce the height of the cover net or replace it with a cover net with higher light conversion efficiency; (b) When the ratio is higher than 85%, or the canopy temperature in the ventilation gap is higher than the preset upper limit, a prescription is output to increase the height of the cover net, shorten the covering time, or increase the ventilation gap; (c) When the relative moisture content of the rhizosphere soil is lower than 50% of the field capacity, a prescription is output to first replenish water to reach 50%-85% of the field capacity before applying the purple non-sulfur photosynthetic bacteria preparation; (d) When the relative moisture content of the rhizosphere soil is higher than 85% of the field capacity, or the rainfall forecast for the next 24 hours is higher than the preset threshold, a prescription is output to postpone the application of bacteria or reduce the amount applied with water. The prescription output unit outputs at least one of the following: the height of the covering net, the duration of the covering, the amount of water replenishment, and the application time of the purple non-sulfur photosynthetic bacteria preparation.

[0043] Optionally, the data processing unit further includes a prescription prediction model, which is a supervised regression model selected from one of gradient boosting regression tree, random forest regression, support vector regression, and single hidden layer artificial neural network. The input to the prescription prediction model is a feature vector, which includes: the ratio of the sum of blue and red light photon flux below the canopy to the visible light photon flux, the average daily canopy temperature, the average daily canopy relative humidity, the relative water content of the rhizosphere soil, the tea variety code, the phenological stage code, the number of days covered, the number of days remaining before harvest, the application rate of purple non-sulfur photosynthetic bacteria preparation, and the forecasts for rainfall, maximum temperature, and solar radiation in the next 3 days; the output of the prescription prediction model is the predicted values ​​of theanine content, total free amino acid content, and phenol-amino acid ratio in fresh leaves at the harvest period; The prescription prediction model is obtained by cross-validation training using the feature vector of the historical covering season and the measured theanine content, total free amino acid content, and phenol-amino acid ratio of the corresponding harvest period as training samples. The data processing unit takes the theanine content predicted by the prescription prediction model as the target, and selects the optimal combination of the corresponding control actions on the set of feasible control actions consisting of the height of the covering net, the start date of covering, the end date of covering, the amount of purple non-sulfur photosynthetic bacteria preparation applied and the target value of rhizosphere moisture. Under the condition that the phenol-to-amylene ratio is not higher than the preset upper limit and the canopy temperature and the relative water content of the rhizosphere meet the preset constraints. After each tea-picking season ends, the data processing unit updates the prescription prediction model with the measured theanine content, total free amino acid content, and phenol-amino acid ratio of that season. When the prediction error of the prescription prediction model in the most recent tea-picking season exceeds a preset threshold, the data processing unit reverts to generating a regulation prescription based on the rules.

[0044] Optionally, apply the purple non-sulfur photosynthetic bacteria preparation according to step S2, then set up the light frequency conversion covering net according to step S1, and maintain the relative water content of the tea tree rhizosphere soil at 50%-85% of field capacity during the covering period.

[0045] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0046] Unless otherwise specified, the experimental methods described in the following embodiments are conventional experimental methods well known to those skilled in the art, and are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Where specific conditions are not specified in the experimental methods, they are generally operated under conventional conditions.

[0047] Unless otherwise specified, all materials and reagents described in the following examples are commercially available.

[0048] Example 1: Strain source and preparation of purple non-sulfur photosynthetic bacteria

[0049] Source of bacterial strain (reliable source): The purple non-sulfur photosynthetic bacteria used in the embodiments of this invention are preferably *Rhodopseudomonas palustris* (…). Rhodopseudomonas palustris Type strain ATH 2.1.6 T This is a standard (type) strain that is available to the public.

[0050] (1) Public access and identification: Available through the Japan National Institute for Biological Resources (NITE) under NBRC 100419 T Obtained, or via the German Culture Collection (DSMZ) under DSM 123 T The 16S rRNA gene sequence has been obtained and is registered in GenBank (accession number AB498818), which can be used to confirm the identity of the strain upon arrival.

[0051] (2) Naming Tip: ATCC 17001 must not be used as a naming convention. R. palustris (According to the current classification, this collection is) R. rutila ); DSMZ currently uses the name Rhodopseudomonas pseudopalustris Log in to DSM 123, but it is... R. palustris The true type strain is used, therefore the application document also provides the strain designation ATH 2.1.6. TTo eliminate ambiguity, it was matched with 16S Registry Number AB498818.

[0052] (3) Commercial field inoculants: Rhodopseudomonas capsulatum ( Rhodobacter capsulatus DSM 1710 T ), spherical red bacteria ( Rhodobacter sphaeroides DSM 158 T The type strain of *Rhodopseudomonas palustris* can also be obtained from DSMZ as an alternative strain. Those skilled in the art can verify through simple experiments that the method of this invention and the above-mentioned strains can achieve interaction with *Rhodopseudomonas palustris* (…). Rhodopseudomonas palustris The same and similar effects will not be elaborated here.

[0053] Rhodopseudomonas palustris was inoculated into modified PYE medium (5 g / L glucose, 2 g / L yeast extract, 1 g / L K₂HPO₄, 0.2 g / L MgSO₄·7H₂O, 0.5 g / L NaCl, 1 g / L L-glutamate, pH 6.8-7.2) and cultured at 28-32℃ and 120-200 lx under weak light or intermittent light conditions for 72-120 h until the logarithmic growth phase was reached, with the expected OD₀... 660 ≥1.5.

[0054] Inoculate the activated bacterial solution into the expansion medium at an inoculation rate of 1%-10% (v / v) and culture until the effective viable count is not less than 1.0 × 10⁻⁶. 8 CFU / mL.

[0055] Add one or more of the following components to the expanded culture culture: molasses (0.5%-2.0%), seaweed oligosaccharide (0.1%-0.5%), magnesium sulfate (0.05%-0.2%), and dipotassium hydrogen phosphate (0.05%-0.2%) as protective and colonization promoting components, and mix well to obtain a liquid bacterial agent.

[0056] When preparing solid or granular bacterial agents, the above-mentioned bacterial solution is mixed with humic acid, biochar, attapulgite, alginate, or maifanite powder, and then dried at low temperature (25-40℃, air-flow drying) or extruded and granulated to ensure that the viable cell count is not less than 1.0 × 10⁻⁶. 8 CFU / g.

[0057] Example 2: A method for synergistic enhancement of high-end green tea in spring

[0058] Select mature tea gardens with uniform tree vigor and management level as the treatment subjects. 20 days before the expected harvest, dig a 5-15 cm deep circular application trench near the drip line projection of the tea trees, applying an effective viable bacteria count of no less than 1.0 × 10⁻⁶. 8 CFU / mL of Rhodopseudomonas palustris ( Rhodopseudomonas palustrisThe liquid inoculant should be diluted 100-300 times before application. The dosage of the undiluted inoculant is 75-225 L / hm². 2 (equivalent to 5-15 L / acre), after application, cover with soil and water appropriately.

[0059] 3-7 days after the application of the microbial agent, a light frequency conversion covering net is erected 20-50 cm above the tea tree canopy. This covering net uses a blend of polyethylene (PE) and ethylene-vinyl acetate copolymer (EVA) as the mesh substrate, and the light conversion functional layer contains an ultraviolet-blue light conversion component (Eu). 2+ Doped aluminate phosphor) and green-to-red light conversion component (Mn 4+ (Doped with fluorosilicate phosphor). The covering mesh has a shading rate of 25%-40%, a visible light transmittance of 55%-75% at 400-700 nm, a mesh aperture of 1.0-5.0 mm, and a unit area mass of 60-100 g / m². 2 .

[0060] During the covering period, maintain the relative soil moisture content in the rhizosphere at 60%-80% of field capacity. After 10-25 days of covering, harvest fresh leaves according to the standard of one bud and one leaf or one bud and two leaves at the initial unfolding stage for high-end green tea.

[0061] Example 3: A method for synergistic enhancement of white tea raw materials

[0062] The difference from Example 2 is that the optical frequency conversion covering net has a shading rate of 15%-30%, a visible light transmittance of 65%-85%, and a unit area mass of 40-80 g / m². 2 To avoid excessively inhibiting the expansion and withering adaptability of white tea buds and leaves; the covering position is 30-80 cm above the tea tree canopy, and the covering time is 7-20 days; the purple non-sulfur photosynthetic bacteria preparation uses solid granular inoculants with an effective viable count of not less than 1.0 × 10⁻⁶. 8 CFU / g, the carrier is a mixture of humic acid, biochar, attapulgite and alginate; applied by trenching, into the root zone and between rows, at a rate of 30-150 kg / hm. 2 (Equivalent to 2-10 kg / mu), application depth 5-12 cm.

[0063] Example 4: Fabrication and Spectral Testing of Optical Frequency Conversion Coverage Network

[0064] Using polyethylene (PE), polypropylene (PP), or ethylene-vinyl acetate copolymer (EVA) as the base resin, the ultraviolet-blue light conversion component (Eu) is... 2+ Doped aluminate phosphor, with an average particle size of 5-10 μm, and green-to-red light conversion component (Mn 4+A light-converting masterbatch is prepared by mixing doped fluorosilicate phosphor (average particle size 3-8 μm), antioxidant (hindered phenol, 0.1%-0.3%), light stabilizer (HALS, 0.2%-0.5%), and dispersant (calcium stearate, 0.3%-0.8%) at a total light-converting component mass fraction of 0.05%-8.00%.

[0065] After mixing the light-converting masterbatch with the base resin in a certain proportion, the mixture is made into a mesh material through melt extrusion, drawing, and warp knitting processes; the resulting mesh material is then shaped, edge-reinforced, fitted with positioning holes, and wound up.

[0066] Spectral testing conditions: On a clear morning between 10:00 and 12:00, at a distance of 20-50 cm from the horizontal plane of the canopy directly below the cover net, take three consecutive measurements using a 350-800 nm range spectroradiometer and average them. A typical set of data: Below the cover net, the relative photon flux of blue light at 400-500 nm is approximately 30%, green light at 500-600 nm is approximately 14%, red light at 600-700 nm is approximately 33%, and ultraviolet light (<400 nm) is <1%; that is, blue light + red light ≈ 63%, falling within the 55%-85% range.

[0067] Example 5: Evaluation of Collaborative Processing Effect

[0068] To verify the synergistic effect of this invention, five treatments were set up: Group A was conventional tea garden management (no covering, no application of bacteria); Group B was covered with ordinary shade netting; Group C was covered with light frequency conversion netting only; Group D was treated with only purple non-sulfur photosynthetic bacteria preparation; and Group E was covered with light frequency conversion netting and simultaneously treated with purple non-sulfur photosynthetic bacteria preparation (this invention). Treatments A, C, D, and E constituted a two-factor fully crossover design of "covering netting (without / without) × purple non-sulfur photosynthetic bacteria preparation (without / without)" to test the interaction (synergistic) effect of the two factors; Group B served as a control for conventional shading. The tea tree variety, age, fertilization level, and harvesting standards were consistent with field management for each treatment. Each treatment had three replicate plots, with each plot area ≥ 30 m². 2 Protected lanes are set up between the small lanes.

[0069] Fresh leaf samples were collected during the harvesting period to determine: total free amino acids (GB / T 8314), theanine (HPLC), tea polyphenols (GB / T 8313), phenol-to-amino acid ratio (tea polyphenols / free amino acids), chlorophyll, and the activities of nitrate reductase (NR), glutamine synthase (GS), and glutamate synthase (GOGAT). Simultaneously, rhizosphere soil samples were collected to determine alkaline nitrogen, ammonium nitrogen, and microbial biomass nitrogen (MBN). Data are expressed as mean ± standard deviation. One-way ANOVA combined with Duncan's multiple comparisons (α=0.05) was used to compare the differences among the five treatments; different lowercase letters in the same column indicated significant differences between treatments (P<0.05). Then, two-way ANOVA was performed on A, C, D, and E to test the interaction effect of the "covering net × inoculant" to determine synergy.

[0070] Experimental results: The experimental results are shown in Tables 1 and 2.

[0071] Table 1 Fresh Leaf Quality Indicators

[0072] Note: Different lowercase letters in the same column indicate significant differences (P<0.05, Duncan).

[0073] Table 2. Nitrogen metabolism enzyme activities and rhizosphere nitrogen indices

[0074] Note: NR - nitrate reductase, GS - glutamine synthase, GOGAT - glutamate synthase, MBN - microbial biomass nitrogen; the meanings of the letters are the same as in Table 1.

[0075] As shown in Table 1, the total free amino acid content and theanine content of fresh leaves in group E (this invention) were significantly higher than those in the other treatments (P<0.05). Compared with group A, the total free amino acid content in group E increased by approximately 59.5%, while the content increased by approximately 30.3% and 9.5% respectively in group C (covering net only) and group D (applying only fungicide), and the sum of their increases (approximately 39.8%) was significantly less than the actual increase in group E (approximately 59.5%). Theanine showed the same trend (group E increased by approximately 89.7% compared to group A, which was higher than the sum of the individual increases of groups C and D, approximately 69.2%). This indicates that the effect of the covering net and the fungicide is synergistic rather than simply additive.

[0076] Compared directly with single treatments, the total free amino acid content in group E was approximately 22.4% higher than in group C and approximately 45.7% higher than in group D; group E also had the lowest phenol-to-amino acid ratio (approximately 4.15), exhibiting the best freshness and quality. Two-way ANOVA analysis of treatments A, C, D, and E showed a significant interaction effect between the "covering net × inoculant" treatment (P<0.05), statistically confirming their synergistic effect.

[0077] Mechanistically, rhizosphere alkaline nitrogen, ammonium nitrogen, and microbial biomass nitrogen significantly increased in the inoculant treatments (groups D and E), while there was no significant difference between the netting treatment (group C) and the conventional control (group A). ​​This indicates that the increase in available nitrogen in the underground parts and the microbial nitrogen pool is mainly contributed by purple non-sulfur photosynthetic bacteria. Simultaneously, the activities of NR, GS, and GOGAT, reflecting canopy nitrogen assimilation capacity, increased in both netting and inoculant treatments, reaching their highest level in group E. This forms a synergistic effect of "light quality optimization inducing nitrogen assimilation in the aboveground parts - inoculant promoting nitrogen supply and absorption in the underground parts." However, those skilled in the art will understand that the above mechanism is a commonly accepted explanation in the field, deduced by the inventors based on the technical effects, but the technical effects of this invention do not depend on a specific mechanism.

[0078] Example 6: Intelligent Monitoring and Prescription Adjustment Module

[0079] Data acquisition specifications: An intelligent monitoring and control module is added to the basis of Example 2 or 3. A spectral sensor is placed below the canopy net, 20-50 cm above the horizontal plane of the canopy, detecting wavelengths of 350-800 nm and outputting the total photon flux of 400-500 nm blue light, 600-700 nm red light, and 400-700 nm visible light. A soil moisture sensor is buried in the 5-20 cm rhizosphere soil layer, outputting volumetric water content and converting it to relative water content (percentage of field capacity). A canopy temperature and humidity sensor is placed in the ventilation gaps, outputting canopy temperature and relative humidity. A meteorological data interface receives rainfall, maximum temperature, minimum temperature, and solar radiation forecasts for the next 1-7 days. The sampling interval for each sensor is 5-10 minutes, and the data are aggregated into averages on hourly and daily scales.

[0080] Feature vector definition: Let the feature vector be x = [r_BR, T, RH, θ, V, S, d_cov, d_rem, P3,Tmax3, Rs, M_dose], where r_BR is the proportion of blue and red light (the percentage of blue light + red light photon flux to visible light photon flux, %); T and RH are the daily average canopy temperature (°C) and relative humidity (%), respectively; θ is the rhizosphere relative water content (the percentage of field capacity, %); V is the tea variety code (categorical variable, unique heat code); S is the phenological stage code (e.g., fish leaf stage / one bud and one leaf / one bud and two leaves, ordinal code); d_cov is the number of days covered; d_rem is the number of days remaining before harvest; and M_dose is the application rate of purple non-sulfur photosynthetic bacteria preparation (L·hm). -2 P3, Tmax3, and Rs represent the cumulative rainfall (mm), maximum temperature (°C), and solar radiation (MJ·m³) for the next 3 days, respectively. -2 ·d -1 ).

[0081] Rule-based decision engine (quantified thresholds): (a) r_BR < 55% → Reduce the cover net height by 10 cm, or replace with a cover net with higher light conversion efficiency; (b) r_BR > 85% or T > 30℃ (preset upper limit, adjustable according to variety) → Increase the cover net height by 10 cm, shorten the cover duration, or increase the ventilation gap; (c) θ < 50%FC → Replenish water to 50%-85%FC before applying bacteria; (d) θ > 85%FC or 24-hour rainfall forecast > 10 mm → Delay bacteria application for 1-3 days or reduce the amount of water applied by 30%-50%; (e) d_rem enters the preset pre-harvest window (e.g., ≤ 3 days) → Stop water replenishment and prepare to remove the net. The above thresholds are configurable parameters, and the default values ​​are as above.

[0082] Machine learning prescription model (reproducible): Gradient boosting regression tree is selected as the primary model (random forest regression, support vector regression, or single-hidden-layer artificial neural network are alternatives). Using feature vector x as input, it regresses and predicts the theanine content Y1, total free amino acid content Y2, and phenol-amino acid ratio Y3 at the harvest period. Training samples are from historical "coverage season × plot" records. Each sample consists of x and the measured Y1, Y2, and Y3 for the corresponding harvest period. See Table 3 for an example of the sample structure. A sample size of ≥40 is recommended, using 5-fold cross-validation for training. Root mean square error (RMSE) and coefficient of determination (R²) are used as the benchmarks. 2 The algorithm evaluates the features using mean absolute error (MAE) and outputs feature importance (for identifying key variables such as r_BR and θ). A set of example performance metrics: 5-fold cross-validation R for Y1. 2 Approximately 0.74 mg / g, RMSE approximately 1.3 mg / g -1 (Example value).

[0083] Table 3 Training Sample Structure

[0084] Note: Only some feature fields are listed to illustrate the training sample structure. For the complete feature vector, please refer to the definition of feature vector x in the previous section of this embodiment. The net height is retained as an operation record field and is not used as a model input feature. The actual input of the model is its corresponding spectral measurement value r_BR.

[0085] Prediction → Prescription Mapping (Constrained Optimization): Construct a set of feasible control actions, such as net height ∈ {20, 30, 40, 50} cm, coverage end date ∈ {2 days, 4 days, 6 days before harvest}, and inoculant application rate ∈ {75, 150, 225 L·hm⁻²}. -2}, rhizosphere water target θ ∈{0.60, 0.70, 0.80}FC. For each candidate action combination, its corresponding features are substituted into the model to predict Y1 and Y3. The combination that maximizes Y1 under the constraints "Y3≤preset upper limit of phenol-ammonia ratio, canopy temperature≤upper limit, θ∈[0.50, 0.85]FC" is selected as the output prescription.

[0086] Example: In a spring green tea plot, 12 days remain before harvest, measured r_BR = 52% (<55%), T = 26℃, θ = 44%FC (<50%), variety Fuding Dabai, phenological stage one bud and one leaf, d_cov = 6 days, and expected rainfall of 3 mm in the next 3 days. The rule engine first determines: θ < 50% → replenish water to 70%FC before applying fungicide; r_BR < 55% → lower the net height. Through constraint optimization on the above feasible set, the model gives the optimal prescription: net height 30 cm, coverage ending 4 days before harvest, and fungicide application rate 150 L·hm². -2 θ =0.70FC, corresponding to a predicted theanine Y1 ≈ 20.5 mg·g -1 The phenol-to-amino acid ratio Y3≈4.6 (satisfies the constraint).

[0087] Online updates and drift rollback: After each tea-picking season, the measured samples Y1, Y2, and Y3 from that season are refilled into the sample library and the model is retrained or incrementally updated. In tea gardens lacking historical data, the above-mentioned rule engine is first run for one tea-picking season to accumulate samples. Drift monitoring is set up: When the model's prediction error in the most recent tea-picking season (such as the MAE of Y1) exceeds a preset threshold, it automatically rolls back to the rule engine to generate a prescription, and the model is activated again after the samples are replenished. This intelligent monitoring and control module does not change the basic steps S1-S4 of the method, but is only used to improve the matching and stability of the covering, watering, and fungicide application parameters under different tea garden conditions.

[0088] Mechanism of action explanation: The light frequency conversion coverage network converts some ultraviolet and green light into blue and red light, improving the effective spectral utilization efficiency of the tea tree canopy. Blue light participates in processes related to stomatal regulation, chloroplast development, and nitrogen metabolism in leaves; red light is beneficial for photosynthetic carbon assimilation and material accumulation, providing energy and a carbon skeleton basis for amino acid synthesis.

[0089] Purple non-sulfur photosynthetic bacteria form a beneficial microbial functional zone in the rhizosphere soil. By promoting the accumulation of available nitrogen and small-molecule nitrogenous metabolites in the rhizosphere, producing root-promoting substances, and improving the rhizosphere microenvironment, they enhance the root system's ability to absorb nitrogen and small-molecule organic nitrogen.

[0090] Theanine is mainly synthesized in the roots of tea trees from ethylamine and glutamate by theanine synthase and then transported to the above-ground shoots. This invention optimizes canopy light quality to induce enhanced activity of nitrogen metabolism-related enzymes and simultaneously enhances rhizosphere nitrogen supply and root absorption capacity, thus creating a synergistic effect between nitrogen absorption, transport, assimilation, and amino acid synthesis.

[0091] Those skilled in the art will understand that the above mechanism is a currently more readily accepted explanation in the art, derived by the inventors from the technical effects of the present invention, but the technical effects of the present invention do not depend on this specific mechanism.

[0092] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for increasing the free amino acid content in tea leaves, characterized in that, The method includes: S1. A light frequency conversion covering net is laid above the tea tree canopy. The light frequency conversion covering net includes a mesh substrate and a light conversion functional layer loaded on the mesh substrate. The light conversion functional layer includes an ultraviolet-blue light conversion path and / or a green-red light conversion path. The ultraviolet-blue light conversion path is used to absorb 280-400 nm ultraviolet light and emit 430-470 nm blue light. The green-red light conversion path is used to absorb ultraviolet light, blue light and / or 500-570 nm green light and emit 620-680 nm red light. S2. Within a time window of 1-15 days before or after the deployment of the optical frequency conversion coverage network, apply a purple non-sulfur photosynthetic bacteria preparation to the rhizosphere soil of the tea trees; the purple non-sulfur photosynthetic bacteria are selected from the genus Rhodopseudomonas (…). Rhodopseudomonas ) and / or Rhodophytes ( Rhodobacter ).

2. The method according to claim 1, characterized in that, In S1, the mesh substrate is selected from one or more of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyolefin elastomer, polylactic acid, and bio-based polyester. And / or, the unit area mass of the mesh substrate is 20-180 g / m². 2 ; And / or, the light-converting functional layer is loaded onto the mesh substrate by means of blending and drawing light-converting masterbatch, surface coating, lamination or impregnation curing; And / or, the ultraviolet-blue light conversion pathway and the green-red light conversion pathway coexist in the same light conversion functional layer or exist in different layers of the composite film layer; And / or, the ultraviolet-blue light conversion pathway includes an ultraviolet-blue light conversion component, wherein the ultraviolet-blue light conversion component is selected from rare earth europium (Eu). 3+ Eu 2+ One or more of the following: doped aluminate phosphors, rare earth europium doped silicate phosphors, and rare earth europium organic complexes; And / or, the green-to-red light conversion pathway includes a green-to-red light conversion component, wherein the green-to-red light conversion component is selected from nitrogen-doped carbon dots, manganese (Mn) 4+ ) doped fluoride phosphors, rare earth praseodymium (Pr 3+ One or more of the organic complexes.

3. The method according to claim 2, characterized in that, The light-converting component is free of cadmium, lead, mercury, and hexavalent chromium, and / or has a solubility of less than 0.1 g / L in water at 25°C; And / or, the mass fraction of the light-converting component in the optical frequency conversion coverage network is 0.05%-8.00%; And / or, the shading rate of the optical frequency conversion coverage network is 15%-55%; And / or, the transmittance of the optical frequency conversion coverage network at 400-700 nm is 45%-85%; And / or, the mesh size of the optical frequency conversion coverage mesh is 0.5-8.0 mm; And / or, a ventilation gap is formed between the optical frequency conversion covering net and the top surface of the tea tree canopy, and the height of the ventilation gap is 10-80 cm; And / or, after the optical frequency conversion coverage network is deployed, the sum of the 400-500 nm blue light photon flux and the 600-700 nm red light photon flux measured on the horizontal plane of the canopy accounts for 55%-85% of the 400-700 nm visible light photon flux; And / or, the optical frequency conversion coverage net is laid 10-80 cm above the canopy 7-35 days before the tea tree shoots are harvested.

4. The method according to claim 1, characterized in that, In S2, the purple non-sulfur photosynthetic bacteria are selected from Rhodopseudomonas palustris (… Rhodopseudomonas palustris ), capsular red bacteria ( Rhodobacter capsulatus ), spherical red bacteria ( Rhodobacter sphaeroides One or more of the following; And / or, the purple non-sulfur photosynthetic bacteria preparation is selected from liquid bacterial agents, solid bacterial agents, or granular bacterial agents; And / or, the effective viable count of the purple non-sulfur photosynthetic bacteria preparation: for liquid preparations, not less than 1.0 × 10⁻⁶. 8 CFU / mL, for solid or granular inoculants, not less than 1.0 × 10⁻⁶. 8 CFU / g; And / or, when using liquid inoculant, the dosage of the undiluted inoculant is 30-450 L / hm. 2 Dilute 50-500 times before application; And / or, when using solid or granular inoculants, the application rate is 15-300 kg / hm². 2 ; And / or, the purple non-sulfur photosynthetic bacteria preparation is applied to the rhizosphere soil of tea trees by ring trench application, strip trench application, drip irrigation application, or rhizosphere hole application, with an application depth of 5-15 cm. And / or, the purple non-sulfur photosynthetic bacteria preparation further includes a protective carrier and a rhizosphere colonization promoting component; the protective carrier is selected from one or more of humic acid, fulvic acid, alginate, bentonite, attapulgite, peat moss, biochar, starch, and maifanite powder; the rhizosphere colonization promoting component is selected from one or more of molasses, seaweed oligosaccharide, chitosan oligosaccharide, phosphate, and magnesium sulfate; And / or, for three days before and three days after the application of the purple non-sulfur photosynthetic bacteria preparation, do not apply urea with a nitrogen content greater than 46%, nitrogen fertilizer containing nitrate nitrogen, agricultural fungicides, hydrogen peroxide and / or sodium hypochlorite to the application area.

5. The method according to claim 1, characterized in that, The method further includes: S3. During the covering period, maintain the relative soil moisture content of the tea tree rhizosphere at 50%-85% of field capacity. And / or, the method is used to increase the theanine content in tea and / or reduce the phenol-to-amino acid ratio; And / or, the method is used to increase the total free amino acid content or theanine content in raw materials of green tea, white tea, yellow tea or famous teas.

6. A system for increasing the free amino acid content of tea leaves, characterized in that, The system includes: (1) Optical frequency conversion covering mesh, which includes a mesh substrate and a light conversion functional layer loaded on the mesh substrate, wherein the light conversion functional layer includes an ultraviolet-blue light conversion path and / or a green-red light conversion path, wherein the ultraviolet-blue light conversion path is used to absorb 280-400 nm ultraviolet light and emit 430-470 nm blue light, and the green-red light conversion path is used to absorb ultraviolet light, blue light and / or 500-570 nm green light and emit 620-680 nm red light; (2) A support and fixing component for laying the optical frequency conversion coverage net above the tea tree canopy, the support and fixing component including at least two of the following: support rod, horizontal pull rope, pressure film rope, ground anchor and adjustable height connector; (3) Purple non-sulfur photosynthetic bacteria preparation, wherein the purple non-sulfur photosynthetic bacteria are selected from the genus Rhodopseudomonas ( Rhodopseudomonas ) and / or Rhodophytes ( Rhodobacter ).

7. The system according to claim 6, characterized in that, The optical frequency conversion coverage net is a recyclable roll-up coverage net; And / or, the edge of the optical frequency conversion coverage mesh is provided with at least one of the following: tear-resistant reinforcing strip, breathable and moisture-wicking zone, and positioning and fixing holes; And / or, the support and fixing components create a 10-80 cm ventilation gap between the optical frequency conversion covering net and the top surface of the tea tree canopy; And / or, the purple non-sulfur photosynthetic bacteria preparation is packaged in conjunction with the light frequency conversion covering net; And / or, the purple non-sulfur photosynthetic bacteria are selected from Rhodopseudomonas palustris (… Rhodopseudomonas palustris ), capsular red bacteria ( Rhodobacter capsulatus ), spherical red bacteria ( Rhodobacter sphaeroides One or more of the following; And / or, the purple non-sulfur photosynthetic bacteria preparation is selected from liquid bacterial agents, solid bacterial agents, or granular bacterial agents; And / or, the effective viable count of the purple non-sulfur photosynthetic bacteria preparation: for liquid preparations, not less than 1.0 × 10⁻⁶. 8 CFU / mL, for solid or granular inoculants, not less than 1.0 × 10⁻⁶. 8 CFU / g; And / or, the system is used to increase the theanine content in tea and / or reduce the phenol-to-ammonia ratio.

8. The system according to claim 6, characterized in that, The system also includes: (4) Intelligent monitoring and control module, wherein the intelligent monitoring and control module includes: (i) A data acquisition unit, comprising: a spectral sensor located below the optical frequency conversion coverage network, a soil moisture sensor located in the rhizosphere soil layer, a canopy temperature and humidity sensor located in the ventilation gap, and a meteorological data interface; (ii) Data processing unit; and (iii) Prescription output unit; The data processing unit generates the regulatory prescription according to the following rules: (a) When the sum of the photon flux of 400-500nm blue light and 600-700nm red light below the optical frequency conversion cover net accounts for less than 55% of the photon flux of 400-700nm visible light, a prescription is output to reduce the height of the optical frequency conversion cover net or replace it with an optical frequency conversion cover net with higher light conversion efficiency. (b) When the ratio is higher than 85%, or the canopy temperature in the ventilation gap is higher than the preset upper limit, output a prescription to increase the height of the optical frequency conversion coverage network, shorten the coverage time, or increase the ventilation gap; (c) When the relative water content of the rhizosphere soil is less than 50% of the field capacity, apply the prescription of purple non-sulfur photosynthetic bacteria preparation after replenishing water to reach 50%-85% of the field capacity. (d) When the relative moisture content of the rhizosphere soil is higher than 85% of the field capacity, or the forecast of rainfall in the next 24 hours is higher than the preset threshold, output a prescription to postpone the application of bacteria or reduce the amount applied with water. The prescription output unit outputs at least one of the following: the height of the optical frequency conversion coverage net, the coverage duration, the amount of water replenishment, and the application time of the purple non-sulfur photosynthetic bacteria preparation.

9. The system according to claim 8, characterized in that, The spectral sensor has a detection band of 350-800nm ​​and outputs at least one of the following: 400-500 nm blue light photon flux, 600-700 nm red light photon flux, and 400-700 nm total visible light photon flux. And / or, the soil moisture sensor is placed in the 5-20 cm rhizosphere soil layer; And / or, the meteorological data interface receives at least one of rainfall, maximum temperature, minimum temperature and solar radiation forecast; And / or, the data processing unit further includes a prescription prediction model, which is a supervised regression model; And / or, the prescription prediction model is selected from one of gradient boosting regression tree, random forest regression, support vector regression and single hidden layer artificial neural network; And / or, the input to the prescription prediction model is a feature vector, which includes: the proportion of the sum of blue and red light photon fluxes below the optical frequency conversion coverage network to the visible light photon flux, the average daily canopy temperature, the average daily canopy relative humidity, the relative moisture content of the rhizosphere soil, the tea variety code, the phenological stage code, the number of days covered, the number of days remaining before harvest, the application amount of purple non-sulfur photosynthetic bacteria preparation, and at least one of the following for the next 3 days: rainfall, maximum temperature, and solar radiation forecast. And / or, the output of the prescription prediction model is the predicted value of theanine content, total free amino acid content and phenol-amino acid ratio of fresh leaves at the harvesting period; And / or, the prescription prediction model is obtained by cross-validation training using the feature vector of the historical covering season and the measured theanine content, total free amino acid content, and phenol-amino acid ratio of the corresponding harvest period as training samples; And / or, the data processing unit maps each candidate control action to a corresponding component in the feature vector on the set of feasible control actions consisting of the optical frequency conversion coverage net deployment height, coverage start date, coverage end date, purple non-sulfur photosynthetic bacteria preparation application amount, and rhizosphere moisture target value. The optical frequency conversion coverage net deployment height corresponds to the ratio of the sum of blue and red light photon flux below the coverage net to the visible light photon flux. The coverage start date and coverage end date correspond to the number of days covered and the number of days remaining before harvest. The purple non-sulfur photosynthetic bacteria preparation application amount and the rhizosphere moisture target value correspond to the purple non-sulfur photosynthetic bacteria preparation application amount component and the rhizosphere soil relative moisture content component in the feature vector, respectively. Then, taking the theanine content predicted by the prescription prediction model as the target, and under the condition that the phenol-to-ammonia ratio is not higher than the preset upper limit and the canopy temperature and rhizosphere relative moisture content meet the preset constraints, the optimal combination of control actions is selected as the prescription output. And / or, after each tea-picking season, the data processing unit updates the prescription prediction model with the measured theanine content, total free amino acid content, and phenol-amino acid ratio of that season. And / or, when the prediction error of the prescription prediction model exceeds a preset threshold in the most recent tea-picking season, the data processing unit reverts to the rule described in claim 8 to generate a control prescription.

10. The method of using the system according to any one of claims 6-9, characterized in that, First, apply the purple non-sulfur photosynthetic bacteria preparation according to step S2 in claim 1, then set up the light frequency conversion covering net according to step S1 in claim 1, and maintain the relative water content of the tea tree rhizosphere soil at 50%-85% of field capacity during the covering period.

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