Amino acid organic fertilizer application method for improving sensory evaluation quality of tobacco leaves

Abstract

The application discloses an amino acid organic fertilizer application method for improving sensory evaluation quality of tobacco leaves, and relates to the tobacco planting technical field, and comprises the following steps: soil diagnosis is carried out before transplanting, and the total amount of the amino acid organic fertilizer is adjusted according to the diagnosis result; the amino acid organic fertilizer is divided into base fertilizer, fertilizer application in the rosette stage and fertilizer application in the vigorous growth period according to the growth period of tobacco plants, and the proportion is 60-65%, 20-25% and 15-20% of the total amount in sequence; the application of the amino acid fertilizer is stopped after the present budding stage, and 2-3 times of 0.2% potassium dihydrogen phosphate solution is sprayed on the leaves; the mixed solution of chelated zinc and borax is applied in the vigorous growth period and is used for foliar spraying. The application improves the absorption and utilization rate of functional components of the fertilizer, stabilizes and enhances the quality and flavor of the tobacco leaves, makes the sensory evaluation quality of the cured tobacco leaves reach the high-quality tobacco leaf standard, and provides technical support for high-end cigarette raw material supply.

Description

Technical Field

[0001] This invention relates to the field of tobacco planting technology, and in particular to a method for applying amino acid organic fertilizer to improve the sensory evaluation quality of tobacco leaves. Background Technology

[0002] In tobacco cultivation, improving the sensory evaluation quality of cured tobacco leaves has always been a key research focus. Tobacco quality is influenced by various factors, among which soil fertility and fertilization management play a crucial role. Traditional fertilization methods often rely heavily on chemical fertilizers. While the long-term, excessive use of chemical fertilizers has ensured tobacco yield to some extent, it has also brought many drawbacks. On the one hand, the overuse of chemical fertilizers leads to soil compaction, disrupting the soil's aggregate structure and reducing soil aeration and permeability, thus affecting tobacco root growth and nutrient absorption. On the other hand, relying solely on chemical fertilizers cannot meet the balanced nutritional needs of tobacco during growth, resulting in an imbalance in the internal chemical composition of the tobacco leaves. This, in turn, affects the sensory evaluation quality of cured tobacco leaves, with issues such as insufficient aroma and a rough taste being particularly prominent. With consumers' increasing demands for tobacco quality and the growing awareness of sustainable agricultural development, finding a fertilization method that can both improve the soil environment and enhance tobacco leaf quality is urgently needed. Amino acid organic fertilizer, as a novel type of fertilizer, is gradually gaining attention. Amino acids are the basic building blocks of proteins; their small molecular weight allows for direct absorption by crops, and they possess functions such as repairing cell damage and detoxification. Simultaneously, the slow nutrient supply of amino acid organic fertilizer facilitates stable nutrient absorption by tobacco during growth, promoting the accumulation of sugars and nutrients, which theoretically has a positive impact on improving the sensory evaluation quality of cured tobacco leaves. However, current research on the application methods of amino acid organic fertilizer in tobacco cultivation lacks systematic analysis and suffers from the following shortcomings: 1. Traditional methods often employ single-application basal fertilization or simple multi-application topdressing, failing to accurately match the varying needs of tobacco plants at key growth stages for amino acid nitrogen forms, resulting in insufficient absorption and utilization of functional components; 2. The soil-fertilizer interaction mechanism is lacking; 3. Traditional methods typically focus only on the functions of amino acids themselves, without systematically designing micronutrient application schemes; 4. The lack of standardized application procedures leads to significant fluctuations in the total amount of aroma compounds in cured tobacco leaves when the same amino acid organic fertilizer is applied in different production areas, severely restricting its industrial applicability. How to scientifically and rationally apply amino acid organic fertilizer to maximize its effectiveness in improving tobacco quality has become an urgent problem to be solved. Summary of the Invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, the present invention provides a method for applying amino acid organic fertilizer to improve the sensory evaluation quality of tobacco leaves, comprising: Before transplanting, conduct soil diagnosis and adjust the total amount of amino acid organic fertilizer according to the soil diagnosis results. Apply amino acid organic fertilizer in stages during the tobacco plant's growth period: apply basal fertilizer 7 days before transplanting, accounting for 60%–65% of the total amount; apply topdressing during the seedling stage 25–30 days after transplanting, accounting for 20%–25% of the total amount; and apply topdressing during the vigorous growth stage 45–50 days after transplanting, accounting for 15%–20% of the total amount. After the tobacco plants begin to bud, stop applying amino acid organic fertilizer and instead spray the leaves with a 0.2% potassium dihydrogen phosphate solution 2-3 times, with a 7-day interval between each application.

[0004] Furthermore, the total nitrogen content of the amino acid organic fertilizer is ≥8%, and the proportion of amino acid nitrogen in the total nitrogen content is ≥60%.

[0005] Furthermore, the soil diagnostics include: measuring the soil's pH value, organic matter content, and cation exchange capacity.

[0006] Furthermore, the adjustment of the total amount of amino acid organic fertilizer based on the soil diagnostic results includes: When the soil pH value is ≥6.5, the total amount of the amino acid organic fertilizer should be 25-30 kg / mu. When the soil pH value is between 5.5 and 6.5, the total amount of the amino acid organic fertilizer should be 30-35 kg / mu. When the soil pH value is <5.5, the total amount of the amino acid organic fertilizer should be 20-25 kg / mu, and 50-80 kg / mu of quicklime should be added to adjust the soil pH value to 5.8-6.2.

[0007] Furthermore, the step of adjusting the total amount of amino acid organic fertilizer based on soil diagnostic results also includes: When the soil organic matter content is <15g / kg and the cation exchange capacity is <10cmol / kg, the total amount of the amino acid organic fertilizer used shall be increased by 10%. When the soil organic matter content is >25g / kg and the cation exchange capacity is >15cmol / kg, the total amount of the amino acid organic fertilizer used is reduced by 15%.

[0008] Furthermore, the application of the base fertilizer involves distributing the amino acid organic fertilizer in strips at a rate of 60% to 65% of the total amount in the ridged tobacco field, with an application depth of 15-20 cm, and simultaneously applying 50-80 kg / mu of decomposed rapeseed cake fertilizer. During the basal stage, 20% to 25% of the total amount of amino acid organic fertilizer should be applied in a circular trench, with a trench depth of 10-15cm and a distance of 10cm from the stem base. The recommended topdressing method involves mixing 15%–20% of the total amount of amino acid organic fertilizer with 0.3–0.5 kg / mu of potassium sulfate, then diluting the mixture with 500 times its volume of water for root irrigation.

[0009] Furthermore, this also includes: Yu Wang regularly spraying a mixture of chelated zinc and borax on the leaves of tobacco plants once a week for a total of 3 times.

[0010] Furthermore, the dosage of the chelated zinc is 0.5-0.8 kg / mu, the dosage of the borax is 0.3-0.5 kg / mu, and the spraying concentration of the mixture is 0.05% zinc and 0.02% boron.

[0011] Furthermore, this also includes: collecting tobacco leaf samples from the middle of the soil (0-20cm) at the transplanting, vigorous growth, and maturity stages, respectively, and testing the soil pH, available zinc content, and soluble boron content, as well as the nitrate content and total free amino acid content of the tobacco leaves.

[0012] Furthermore, when the nitrate content of tobacco leaves during the vigorous growth period is >450mg / kg, the amount of amino acid organic fertilizer topdressing should be reduced by 10% to 15%; when the total amount of free amino acids in tobacco leaves during the vigorous growth period is <120μg / g, a mixture of chelated zinc and borax should be sprayed on the leaves once.

[0013] This invention provides a method for applying amino acid organic fertilizer to improve the sensory evaluation quality of tobacco leaves. By constructing a graded application model of amino acid organic fertilizer based on soil pH, and dynamically adjusting the fertilizer dosage in conjunction with organic matter and cation exchange capacity, it effectively reduces the ineffective mineralization rate of amino acids, improves fertilizer utilization, enhances soil fertility, promotes plant growth, and reduces environmental risks. Through a three-stage application pattern of 60%–65% basal fertilizer, 20%–25% during the rosette stage, and 15%–20% during the vigorous growth stage, it precisely matches the nitrogen absorption needs of tobacco plants, improving amino acid utilization. After the budding stage, the application of amino acid fertilizer is stopped and replaced with potassium dihydrogen phosphate to avoid the degradation of aroma precursors (such as carotenoids) caused by nitrogen excess in the later stage, thereby improving the retention rate of aroma substances. Through the synergistic effect of amino acids with zinc and boron, the plant's stress resistance and growth development are enhanced, and the conversion efficiency of aroma substances is improved. This invention improves the absorption and utilization rate of fertilizer functional components through multi-dimensional regulation of dynamic supply, soil adaptation, synergistic effect and quality monitoring, and steadily enhances the quality and flavor of tobacco leaves. It ensures that the sensory evaluation quality of flue-cured tobacco leaves consistently meets the standards of high-quality tobacco leaves, providing technical support for the supply of raw materials for high-end cigarettes. Attached Figure Description

[0014] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic flowchart of an amino acid organic fertilizer application method for improving the sensory evaluation quality of tobacco leaves, provided in one embodiment of this application. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0017] It should be understood that although the terms first, second, third, etc., may be used to describe the acquisition modules in the embodiments of the present invention, these acquisition modules should not be limited to these terms. These terms are only used to distinguish the acquisition modules from each other.

[0018] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0019] It should be noted that the directional terms such as "upper," "lower," "left," and "right" used in the embodiments of the present invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. Furthermore, in the context, it should be understood that when it is mentioned that an element is formed "upper" or "lower" of another element, it can not only be formed directly "upper" or "lower" of the other element, but also indirectly "upper" or "lower" of the other element through an intermediate element.

[0020] refer to Figure 1 This invention provides a method for applying amino acid organic fertilizer to improve the sensory evaluation quality of tobacco leaves, comprising: Step S101: Conduct soil diagnosis before transplanting, and adjust the total amount of amino acid organic fertilizer according to the soil diagnosis results. Specifically, soil diagnosis should be conducted before transplanting tobacco plants: the soil pH value, organic matter content, and cation exchange capacity should be measured. The total amount of amino acid organic fertilizer used will be adjusted according to the soil diagnostic results, including: When the soil pH value is ≥6.5, the total amount of the amino acid organic fertilizer should be 25-30 kg / mu. When the soil pH value is between 5.5 and 6.5, the total amount of the amino acid organic fertilizer should be 30-35 kg / mu. When the soil pH value is <5.5, the total amount of the amino acid organic fertilizer should be 20-25 kg / mu, and 50-80 kg / mu of quicklime should be added to adjust the soil pH value to 5.8-6.2. The soil pH value in this neutral range is more conducive to the activity of soil microorganisms and the release of nutrients.

[0021] Therefore, a graded application model for amino acid organic fertilizer based on soil pH was established. For acidic soils, directly applying the conventional application rate will cause ineffective mineralization of free amino acids and exacerbate soil acidification. This embodiment reduces the risk of soil acidification, increases the pH of acidic soil, improves the living environment of microorganisms, promotes amino acid mineralization, and reduces the ineffective mineralization rate of amino acids by reducing fertilizer application and neutralizing with quicklime. This improves the nitrogen availability of organic fertilizer. For example, a comparative experiment was conducted in the Yunnan red soil tobacco area with a soil pH of 5.2 and an organic matter content of 18.6 g / kg. Using the application method provided in this embodiment, the ineffective mineralization rate of amino acids can be reduced from the conventional 55%–60% to 30%–35%.

[0022] In addition, a dual-factor correction coefficient for soil organic matter content and cation exchange capacity was introduced to synergistically correct the total amount of amino acid organic fertilizer used. When the soil organic matter content is <15g / kg and the cation exchange capacity is <10cmol / kg, the total amount of the amino acid organic fertilizer used shall be increased by 10%. When the soil organic matter content is >25g / kg and the cation exchange capacity is >15cmol / kg, the total amount of the amino acid organic fertilizer used is reduced by 15%.

[0023] Amino acid organic fertilizer itself contains abundant organic matter. Through reasonable fertilization, the organic matter content of the soil can be gradually increased to improve soil fertility. Soils with high organic matter content usually have better fertilizer retention capacity and microbial activity. Soils with high cation content can adsorb more cations. When the organic matter content and cation content of the soil are too high, the total amount of amino acid organic fertilizer should be appropriately reduced to avoid nutrient excess. By adjusting the application amount of amino acid organic fertilizer through organic matter content and cation exchange capacity, it can be ensured that nitrogen and other nutrients in the fertilizer are effectively adsorbed and retained by the soil, reducing nutrient leaching and avoiding fertilizer waste. This solves the problem of fertilizer imbalance caused by ignoring the differences in soil fertilizer retention capacity in traditional methods.

[0024] Therefore, the amino acid organic fertilizer graded application model based on soil pH, combined with the synergistic correction of organic matter content and cation exchange capacity, can significantly improve fertilizer utilization, improve soil fertility, promote plant growth, and reduce environmental risks.

[0025] Step S102: Apply amino acid organic fertilizer in stages during the tobacco plant's growth period: apply basal fertilizer 7 days before transplanting, accounting for 60%–65% of the total amount; apply topdressing during the seedling stage 25–30 days after transplanting, accounting for 20%–25% of the total amount; apply topdressing during the vigorous growth stage 45–50 days after transplanting, accounting for 15%–20% of the total amount. Specifically, the total nitrogen content of amino acid organic fertilizer should be ≥8%. High nitrogen content provides sufficient nitrogen for plant growth. Amino acid nitrogen should account for ≥60% of the total nitrogen content. Amino acid nitrogen is one of the main forms of nitrogen acquisition by plants, and a high proportion of amino acid nitrogen means that the nitrogen in the fertilizer is more easily absorbed by plants, improving fertilizer utilization efficiency. Base fertilizer should be applied 7 days before transplanting tobacco seedlings. Apply the amino acid organic fertilizer in strips, distributing 60%–65% of the total amount, in the raised tobacco field at a depth of 15–20 cm. Simultaneously apply 50–80 kg / mu of well-rotted rapeseed cake fertilizer. Amino acid organic fertilizer mainly provides readily available nitrogen and other amino acid nutrients, while well-rotted rapeseed cake fertilizer provides more comprehensive nutrients such as organic matter and slow-release nutrients. The combination of the two provides rich and balanced nutrition for the early growth of tobacco seedlings, promotes the decomposition and nutrient release of the amino acid organic fertilizer, improves fertilizer utilization efficiency, optimizes the soil environment, promotes robust root development of tobacco seedlings, and enhances the stress resistance of tobacco seedlings. Topdressing during the rosette stage should be carried out 25-30 days after transplanting, using 20%-25% of the total amount of amino acid organic fertilizer applied in a circular trench. The trench should be 10-15cm deep and 10cm away from the stem base. During the rosette stage, the number of leaves increases and the root system begins to extend deeper into the soil and around the plant. This is a critical period for tobacco growth, and the demand for nutrients gradually increases. To ensure that the plant can smoothly enter the vigorous growth period, a circular trench should be dug around the plant at a distance of 10cm from the stem base and a depth of 10-15cm. The distance from the stem base can be adjusted according to the tobacco variety and soil conditions, and the trench depth can be adjusted according to the soil texture and the distribution of tobacco roots. After evenly applying amino acid organic fertilizer in the trench, cover it with soil. Circular trench application can directly apply fertilizer to the absorption range of the root system, improve fertilizer utilization, promote root growth and expansion, and provide sufficient nutrients to the plants in the rosette stage when their nutrient demand increases. Topdressing during the vigorous growth period should be carried out 45-50 days after transplanting. Mix 15%-20% of the total amount of amino acid organic fertilizer with 0.3-0.5 kg / mu of potassium sulfate, and then dilute with 500 times the amount of water for root irrigation. The vigorous growth period refers to the stage from the end of the crowning stage to the beginning of the budding stage, which is the fastest growth stage for tobacco. The number and volume of leaves of the plants increase rapidly, and the demand for nutrients also increases significantly. Potassium can promote the root system's resistance to stress and enhance the root system's absorption efficiency of nutrients and water. Combined with amino acid organic fertilizer, it promotes the accumulation of dry matter, improves the combustibility and aroma quality of tobacco leaves. The application of potassium sulfate can ensure that tobacco obtains sufficient potassium during the vigorous growth period, thereby improving the quality of tobacco leaves. Applying the amino acid organic fertilizer and potassium sulfate solution to the soil through root irrigation can accurately deliver fertilizer to the area around the tobacco roots, improve fertilizer utilization, and reduce the diffusion and loss of nutrients in the soil.

[0026] Therefore, the application method provided in this embodiment breaks through the traditional base fertilizer-based model. Based on the nitrogen metabolism characteristics of tobacco plants at different growth stages, the optimal amino acid ratio of base fertilizer and topdressing is determined. Through a three-stage distribution of 60%–65% base fertilizer, 20%–25% topdressing during the seedling stage, and 15%–20% topdressing during the vigorous growth stage, the nitrogen absorption curve of tobacco plants is precisely matched (60% of nitrogen requirement during transplanting and 35% during the vigorous growth stage). This increases the amino acid utilization rate from the conventional 40% to 65%–70%, ensuring the efficient utilization of functional components. It also reduces the amino acid supply intensity during the tobacco plant's flower bud differentiation period (50–60 days after transplanting) by 40%–50%, effectively avoiding the degradation of aroma substances caused by nitrogen excess in the later stages.

[0027] Furthermore, this embodiment designs a foliar synergistic spraying scheme of amino acids, chelated zinc, and borax. Yu Wang sprayed a mixture of chelated zinc and borax on the leaves of tobacco plants three times a week. The dosage of chelated zinc was 0.5-0.8 kg / mu, and the dosage of borax was 0.3-0.5 kg / mu. The spraying concentration of the mixture was 0.05% zinc and 0.02% boron. Amino acids provided nitrogen and carbon sources, chelated zinc provided zinc, and borax provided boron. The synergistic effect of these three substances can optimize the nutritional balance in the plant, providing necessary nutritional support for the activity of phenylalanine ammonia-lyase (PAL) and 4-coumaric acid-CoA ligase (4CL), thus prolonging the peak duration of PAL enzyme activity. Within 5-7 days, the expression level of 4CL enzyme in the phenylpropane metabolic pathway was increased by 2.1-2.5 times. PAL enzyme and 4CL enzyme are key enzymes in the phenylpropane metabolic pathway. Prolonging the duration of the peak activity of PAL enzyme and increasing the expression level of 4CL enzyme can enable plants to carry out phenylpropane metabolism more efficiently over a longer period of time, synthesizing more secondary metabolites, thereby enhancing the plant's stress resistance and growth. Furthermore, the synergistic effect of zinc, boron, and amino acids controls the ratio of free amino acids (FAA) to total phenols to reach a balanced state, that is, the nitrogen metabolism and secondary metabolism in the plant reach a balanced state, promoting the synthesis pathway of aroma substances such as cephalosporin, improving the conversion efficiency of aroma substances, thereby enhancing the aroma of tobacco leaves and reducing the irritation of tobacco leaves. For example, in a comparative experiment in the red soil tobacco region of Yunnan, the above-mentioned chelated zinc and borax mixture was used for foliar spraying, which increased the PAL enzyme activity of tobacco leaves from the conventional 12-15 U / g to 28-32 U / g 7 days after spraying, an increase of 80% to 100% compared with the conventional treatment. The ratio of FAA to total phenol content in the leaves was controlled at 1:2.5-3.0, which promoted the synthesis efficiency of cephalosporin-like compounds by 35% to 40%. This achieved enzyme activity activation and optimization of metabolic pathways, and improved the conversion efficiency of aroma substances.

[0028] Step S103: After the tobacco plants have budded, stop applying amino acid organic fertilizer and instead spray the leaves with a 0.2% potassium dihydrogen phosphate solution 2-3 times, with an interval of 7 days between each spray.

[0029] Specifically, during the budding stage, the focus of tobacco growth shifts from leaves and stems to flower buds. However, the main economic value of tobacco lies in the leaves, not the flower buds. Continuing to apply amino acid organic fertilizer after the budding stage may lead to nutrient overload. Excessive nitrogen can promote excessive bud development, affecting the quality of the tobacco leaves. Foliar spraying with potassium dihydrogen phosphate can quickly replenish phosphorus and potassium in tobacco leaves, promoting leaf thickening and maturation, improving leaf quality, and enhancing the tobacco's resistance to adverse conditions. Spraying 2-3 times ensures that the tobacco leaves continuously receive sufficient phosphorus and potassium throughout the maturation process, avoiding problems caused by insufficient or excessive fertilization in a single application. A 7-day interval allows sufficient time for the tobacco leaves to absorb and utilize the sprayed nutrients, preventing excessively high nutrient concentrations that could burn the leaves due to short intervals. At the same time, foliar spraying reduces nutrient loss and improves fertilizer utilization.

[0030] Furthermore, this embodiment establishes a full-process quality control chain. Tobacco leaf samples from the middle of the soil (0-20cm) are collected at the transplanting, vigorous growth, and maturity stages. The test indicators include: soil pH, available zinc content (mg / kg), soluble boron content (mg / kg), nitrate content (mg / kg), and total free amino acid content (μg / g) of tobacco leaves. When the nitrate content of tobacco leaves during the vigorous growth stage is >450mg / kg, the amount of amino acid organic fertilizer topdressing is reduced by 10% to 15%. When the total free amino acid content is <120μg / g, a mixture of chelated zinc and borax is sprayed on the leaves once more. This achieves dynamic feedback regulation to ensure that the total amount of aroma substances in the cured tobacco leaves is ≥380μg / g, of which cephalosporin-like compounds account for ≥45%, and the total sensory evaluation score is ≥85 points, thus achieving standardization of the final product.

[0031] A comparative experiment was conducted in the Yunnan red soil tobacco-growing area with a soil pH of 5.2 and an organic matter content of 18.6 g / kg. Using the application method provided in this embodiment, the content of carotenoid degradation products, such as β-damascone, in the flue-cured tobacco leaves reached 86.4 μg / g, which is 27.3% higher than that of conventional fertilization. Carotenoid degradation products can enhance the aroma, improve the taste, and increase the flavor of tobacco leaves. Referring to the standard document YC / T 138-1998 "Sensory Evaluation Methods for Tobacco and Tobacco Products", the "aroma quantity" index score in the sensory evaluation of flue-cured tobacco leaves in this embodiment increased from 6.0 points to 8.0 points, and the "irritation" score increased from 5.0 points to 7.0 points, with a full score of 9.0 points. The coefficient of variation of the total amount of aroma substances among different plots decreased from 17.3% to 6.8%, which simultaneously improved the stability of tobacco leaf quality and industrial adaptability.

[0032] This invention provides a method for applying amino acid organic fertilizer to improve the sensory evaluation quality of tobacco leaves. By constructing a graded application model of amino acid organic fertilizer based on soil pH, and dynamically adjusting the fertilizer dosage in conjunction with organic matter and cation exchange capacity, it effectively reduces the ineffective mineralization rate of amino acids, improves fertilizer utilization, enhances soil fertility, promotes plant growth, and reduces environmental risks. Through a three-stage application pattern of 60%–65% basal fertilizer, 20%–25% during the rosette stage, and 15%–20% during the vigorous growth stage, it precisely matches the nitrogen absorption needs of tobacco plants, improving amino acid utilization. After the budding stage, the application of amino acid fertilizer is stopped and replaced with potassium dihydrogen phosphate to avoid the degradation of aroma precursors (such as carotenoids) caused by nitrogen excess in the later stage, thereby improving the retention rate of aroma substances. Through the synergistic effect of amino acids with zinc and boron, the plant's stress resistance and growth development are enhanced, and the conversion efficiency of aroma substances is improved. This invention improves the absorption and utilization rate of fertilizer functional components through multi-dimensional regulation of dynamic supply, soil adaptation, synergistic effect and quality monitoring, and steadily enhances the quality and flavor of tobacco leaves. It ensures that the sensory evaluation quality of flue-cured tobacco leaves consistently meets the standards of high-quality tobacco leaves, providing technical support for the supply of raw materials for high-end cigarettes.

[0033] The above description is merely a preferred embodiment of the present invention. Those skilled in the art should understand that the scope of disclosure in this invention is not limited to the specific combination of the above-described technical features, but should also cover other technical solutions formed by any combination of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A method for applying amino acid organic fertilizer to improve the sensory evaluation quality of tobacco leaves, characterized in that, include: Before transplanting, conduct soil diagnosis and adjust the total amount of amino acid organic fertilizer according to the soil diagnosis results. The soil diagnosis includes measuring the soil pH, organic matter content, and cation exchange capacity. The adjustment of the total amount of amino acid organic fertilizer based on the soil diagnosis results includes: when the soil pH is ≥6.5, the total amount of amino acid organic fertilizer is 25-30 kg / mu; when the soil pH is 5.5 ≤ 6.5, the total amount of amino acid organic fertilizer is 30-35 kg / mu; when the soil pH is <5.5, the total amount of amino acid organic fertilizer is 20-25 kg / mu, with an additional 50-80 kg / mu of quicklime to adjust the soil pH to 5.8-6.2; when the soil organic matter content is <15 g / kg and the cation exchange capacity is <10 cmol / kg, the total amount of amino acid organic fertilizer is increased by 10%; when the soil organic matter content is >25 g / kg and the cation exchange capacity is >15 cmol / kg, the total amount of amino acid organic fertilizer is reduced by 15%. Apply amino acid organic fertilizer in stages during the tobacco plant's growth period: Apply basal fertilizer 7 days before transplanting, distributing 60%–65% of the total amount of amino acid organic fertilizer in strips on the raised tobacco field at a depth of 15–20 cm, and simultaneously applying 50–80 kg / mu of decomposed rapeseed cake fertilizer; apply topdressing 25–30 days after transplanting during the seedling stage, applying 20%–25% of the total amount of amino acid organic fertilizer in a ring trench, 10–15 cm deep and 10 cm away from the stem base; apply topdressing 45–50 days after transplanting during the vigorous growth stage, mixing 15%–20% of the total amount of amino acid organic fertilizer with 0.3–0.5 kg / mu of potassium sulfate and diluting the mixture with 500 times its volume of water for root irrigation; Yu Wang regularly sprayed a mixture of chelated zinc and borax on the leaves of tobacco plants once a week for a total of three times. Tobacco leaf samples were collected from the middle of the soil (0-20cm) at the transplanting, vigorous growth, and maturity stages. The soil pH, available zinc content, and soluble boron content were tested, as were the nitrate content and total free amino acid content of the tobacco leaves. When the nitrate content of tobacco leaves during the vigorous growth period is >450mg / kg, the amount of amino acid organic fertilizer top dressing should be reduced by 10% to 15%; when the total amount of free amino acids in tobacco leaves during the vigorous growth period is <120μg / g, the foliar spraying of a mixture of chelated zinc and borax should be increased by 1 time. After the tobacco plants begin to bud, stop applying amino acid organic fertilizer and instead spray the leaves with a 0.2% potassium dihydrogen phosphate solution 2-3 times, with a 7-day interval between each application.

2. The method for applying amino acid organic fertilizer to improve the sensory evaluation quality of tobacco leaves according to claim 1, characterized in that, The total nitrogen content of the amino acid organic fertilizer is ≥8%, and the proportion of amino acid nitrogen in the total nitrogen content is ≥60%.

3. The method for applying amino acid organic fertilizer to improve the sensory evaluation quality of tobacco leaves according to claim 1, characterized in that, The dosage of the chelated zinc is 0.5-0.8 kg / mu, the dosage of the borax is 0.3-0.5 kg / mu, and the spraying concentration of the mixture is 0.05% zinc and 0.02% boron.

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