A method for reducing chlorine content in soil and tobacco leaves under high-chlorine soil conditions

Abstract

This invention discloses a method for reducing the chlorine content in soil and tobacco leaves under high-chlorine soil conditions, belonging to the field of tobacco planting technology. The method for reducing the chlorine content in soil and tobacco leaves under high-chlorine soil conditions provided by this invention includes the following steps: seedling raising, land preparation, transplanting tobacco seedlings, growth, tobacco leaf harvesting, and tobacco leaf curing; the growth process includes the seedling establishment stage, the crowning stage, the vigorous growth stage, and the budding stage; a mixture of potassium humate and fermented soybean milk is applied after transplanting the seedlings, during the crowning stage, and at the budding stage. This invention, by combining potassium humate with fermented soybean milk solution and applying the mixture after transplanting the seedlings, during the crowning stage, and at the budding stage, can not only effectively reduce the chlorine content in the soil but also reduce the chlorine content in the cured tobacco leaves while improving the quality of tobacco growth, thereby enhancing the quality of the tobacco leaves.

Description

Technical Field

[0001] This invention belongs to the field of soil improvement and tobacco technology, and particularly relates to a method for reducing the chlorine content of soil and tobacco leaves under high-chlorine soil conditions. Background Technology

[0002] In modern agricultural production, excessively high chlorine levels in soil often negatively impact crop growth, particularly tobacco cultivation. High-chlorine soil not only affects tobacco root development but also leads to excessively high chlorine levels in tobacco leaves, thus affecting leaf quality and even reducing market value. To address the problem of high-chlorine soil, farmland soil improvement technology has been a key focus of agricultural research. Traditional methods, such as applying solid amendments like gypsum and aluminum salts, can reduce soil chlorine levels in the short term, but these methods are typically costly, their effects are not sustainable, and they can easily have negative environmental impacts.

[0003] Potassium humate, as an important organic mineral fertilizer, has a strong soil-improving effect. It can chemically react with ions in the soil, altering the soil's physicochemical properties and promoting the absorption of nutrients and the excretion of harmful substances. In view of this, existing technologies have proposed methods to reduce chloride ion content in tobacco leaves using potassium humate. For example, patent CN118252082A discloses a tobacco cultivation method that involves applying potassium humate fertilizer on days 27-33, 42-48, and 57-63 after transplanting, at a rate of 4-6 kg / mu each time. However, this patent also uses chloride ion channel inhibitors to reduce chloride ion absorption to a more suitable level, and the amount of potassium humate fertilizer used is relatively large.

[0004] Therefore, there is an urgent need for a method that requires a small amount of potassium humate and can effectively reduce the chlorine content in soil and tobacco leaves under high-chlorine conditions to solve the above problems. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a method for reducing the chlorine content in soil and tobacco leaves under high-chlorine soil conditions.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for reducing the chlorine content of soil and tobacco leaves under high-chlorine soil conditions, comprising the following steps: seedling raising, land preparation, transplanting of tobacco seedlings, growth, tobacco leaf harvesting, and tobacco leaf curing;

[0008] The growth process includes the seedling stage (10-15 days after transplanting), the seedling stage (25-30 days after transplanting), the vigorous growth stage (50-55 days after transplanting), and the budding stage (85-95 days after transplanting).

[0009] A mixture of potassium humate and fermented soybean milk was applied after transplanting the tobacco seedlings, at the seedling stage, and at the budding stage.

[0010] Technical Principle: This invention combines potassium humate with fermented soybean milk solution and applies the mixture after transplanting tobacco seedlings, during the rosette stage, and at the budding stage. Potassium humate, a humic acid fertilizer, has multiple benefits, including increasing soil organic matter content, improving soil structure, enhancing soil permeability and water retention, and reducing salt accumulation. Fermented soybean milk, rich in nitrogen, phosphorus, potassium, amino acids, and oligosaccharides, significantly enhances soil enzyme activity and fertility, while also increasing beneficial microbial communities and further optimizing the soil environment. By combining potassium humate with fermented soybean milk, this invention effectively increases soil organic matter content, improves soil structure and permeability, reduces salt accumulation, effectively lowers chlorine content in the soil, and promotes tobacco growth. This improves tobacco growth quality while reducing chlorine content in cured tobacco leaves, thereby enhancing the quality of the tobacco leaves.

[0011] Furthermore, the potassium fulvate contains 52% fulvic acid by mass and 20% potassium oxide by mass; the potassium fulvate is mineral-derived potassium fulvate, and as an example, mineral-derived potassium fulvate purchased from Xinjiang Shuanglong Humic Acid Co., Ltd. can be used.

[0012] Furthermore, the fermented soy milk is obtained by soaking soybeans and water at a ratio of 1:4 (kg:L) at room temperature for 8 hours, then grinding them into soy milk, and finally sealing and storing it in a cool and ventilated place for 6 days of fermentation.

[0013] Furthermore, the fermented soy milk has a water content of 90%; the fermented soy milk contains 67.43% organic matter, 35.07% carbohydrates, 1.46% phosphorus, and 1.41% potassium.

[0014] Furthermore, the seedling raising process involves rinsing the tobacco seeds with distilled water, disinfecting them with potassium permanganate, rinsing them again with distilled water, and then placing the seeds in a seedling tray containing substrate for floating seedling raising.

[0015] Furthermore, the potassium permanganate has a mass concentration of 0.2% and a disinfection time of 5–10 minutes.

[0016] Furthermore, the substrate is sterilized.

[0017] Furthermore, the land preparation involves: plowing the soil to a depth of 20-30cm, exposing it to the sun for 6-10 days, setting the ridge height at 0.5m, the row spacing at 1.2m, and the plant spacing at 0.6m; and digging pits at fixed intervals, with a pit diameter of 25-30cm and a depth of 18-20cm.

[0018] Furthermore, the transplanting of tobacco seedlings involves: after 40-45 days of seedling cultivation, selecting healthy seedlings with uniform growth and transplanting them into tobacco ponds with high-chlorine soil. A mixture of potassium humate and fermented soybean milk is applied to the ponds at a rate of 75-225 kg / hm². 2 At the same time, the roots were irrigated with a mixture of potassium humate and fermented soybean milk;

[0019] The mass concentration of potassium humate in the mixture of potassium humate and fermented soy milk is 0.03-0.05%, and the mass concentration of fermented soy milk is 1-3%.

[0020] This invention improves microbial activity and soil available potassium content by applying a mixture of potassium humate and fermented soybean milk during the seedling stage (40-45 days). Using a mixture with a concentration of potassium humate and fermented soybean milk within the aforementioned range during transplanting ensures a high survival rate for tobacco seedlings. Excessive potassium humate concentration increases soil salinity, causing osmotic stress on tobacco roots and affecting their normal physiological functions. Insufficient potassium humate concentration has poor soil improvement effects and fails to meet the potassium requirements of tobacco growth, thus hindering normal growth and development. Conversely, excessive fermented soybean milk concentration leads to excessive organic matter content in the soil, increasing soil viscosity and density, which is detrimental to tobacco root growth and development. Insufficient fermented soybean milk concentration fails to provide sufficient organic matter and nutrients to the soil, limiting its effectiveness in soil improvement and tobacco growth. During the transplanting and seedling raising process, the amount of potassium humate and fermented soybean milk mixture should not be too high to avoid excessive chloride ions and organic matter in the soil, which can damage the tobacco root system.

[0021] Furthermore, the root irrigation method is as follows: use a wooden stick with a sharpened end and a diameter of 5cm to make a hole at a vertical angle of 30° near the root of the tobacco plant, then irrigate the root with a mixture of potassium humate and fermented soybean milk, and immediately seal the hole with soil after irrigation to prevent evaporation and moisture loss.

[0022] Furthermore, the liquid organic fertilizer is applied during the seedling stage, 10-15 days after transplanting, at a rate of 900 kg / hm². 2 .

[0023] Furthermore, the liquid organic fertilizer contains N≥6%, P2O5≥2%, and K2O≥12% (mass content); the liquid organic fertilizer originates from Yunnan Provincial Microbial Fermentation Engineering Research Center Co., Ltd.

[0024] Furthermore, the aforementioned seedling stage is as follows: 25–30 days after transplanting, apply a mixture of potassium humate and fermented soybean milk to the tobacco plants at a rate of 300–450 kg / hm². 2 At the same time, the roots were irrigated with a mixture of potassium humate and fermented soybean milk;

[0025] The mass concentration of potassium humate in the mixture of potassium humate and fermented soy milk is 0.06-0.1%, and the mass concentration of fermented soy milk is 4-6%.

[0026] This invention involves applying a mixture of potassium humate and fermented soybean milk during the seedling stage. Fermented soybean milk helps optimize the physical, chemical, and biological properties of the soil, increasing soil organic matter and nutrient levels, while also increasing the number and types of bacteria in the soil. Potassium humate helps increase soil organic matter content, improve soil structure, enhance soil permeability and water retention, and reduce salt accumulation. Using a mixture of potassium humate and fermented soybean milk within the aforementioned concentration range during the seedling stage ensures a balanced nutrition for tobacco plant growth. Excessive potassium humate concentration will inhibit tobacco plant growth, while insufficient concentration will fail to meet the plant's nutrient needs. Excessive fermented soybean milk concentration will lead to soil salt accumulation, while insufficient concentration will fail to provide adequate nitrogen nutrition. The application rate of the potassium humate and fermented soybean milk mixture during the seedling stage should be maintained within the aforementioned range; insufficient application will not meet the plant's growth needs, while excessive application will cause soil compaction and other problems.

[0027] Furthermore, the root irrigation method during the seedling stage is the same as that during transplanting and seedling raising, and will not be repeated here.

[0028] Furthermore, the liquid organic fertilizer is applied during the vigorous growth period, 50-55 days after transplanting, at a rate of 600 kg / hm². 2 .

[0029] Furthermore, the mass concentration of potassium humate in the mixture of potassium humate and fermented soybean milk applied during the budding stage is 0.1-0.3%, and the mass concentration of fermented soybean milk is 6-8%; the application time is 85-95 days after transplanting, and the application rate is 450-600 kg / hm². 2 The application site is the lower leaf surface of the tobacco plant.

[0030] This invention involves applying a mixture of potassium humate and fermented soybean milk during the budding stage. The fermented soybean milk helps provide tobacco plants with various amino acids and trace elements, promoting plant growth, while the potassium humate enhances soil fertility and improves plant resistance. Using a mixture of potassium humate and fermented soybean milk within the aforementioned concentration range during the budding stage ensures normal growth and development of the tobacco plants. Excessive potassium humate concentration can lead to soil salinization, affecting nutrient absorption by the tobacco plants; insufficient concentration cannot meet the plants' potassium requirements, thus hindering growth. Conversely, excessive fermented soybean milk concentration can cause overly moist soil, affecting root respiration; insufficient concentration cannot meet the plants' needs for amino acids and trace elements, also impacting growth. The application rate of the potassium humate and fermented soybean milk mixture during the budding stage should be maintained within the aforementioned range. Insufficient application will result in insufficient nutrient absorption, affecting yield and quality; excessive application will waste nutrients and may even harm the plants.

[0031] Furthermore, the tobacco leaves are harvested when the leaves are light yellow, at a maturity level of 70% or higher, with more than 2 / 3 of the main vein turning white, and the pubescence has mostly fallen off.

[0032] Furthermore, the method for reducing the chlorine content in soil and tobacco leaves under high-chlorine soil conditions specifically includes:

[0033] A. Seedling raising: Rinse the tobacco seeds with distilled water, then disinfect them with 0.2% potassium permanganate for 5-10 minutes; then rinse the seeds three times with distilled water, and then place the seeds in a seedling tray containing the disinfected substrate for floating seedling raising;

[0034] B. Land preparation: Plow the soil to a depth of 20-30cm, expose it to the sun for 6-10 days, raise the ridges to a height of 0.5m, with a row spacing of 1.2m and a plant spacing of 0.6m; dig pits at fixed intervals, with a pit diameter of 25-30cm and a depth of 18-20cm.

[0035] C. Transplanting tobacco seedlings: After 40-45 days of seedling cultivation, select healthy and vigorous seedlings with uniform growth and transplant them into tobacco ponds with high-chlorine soil. In advance, dilute a mixture of potassium humate and fermented soybean milk into the soil and apply it to the ponds at a rate of 75-225 kg / hm². 2 Using a sharpened wooden stick about 5cm in diameter, a hole was drilled at a 30° angle near the base of the tobacco plant. A mixture of potassium humate and fermented soybean milk was then poured into the roots. The hole was immediately sealed with soil to prevent evaporation and moisture loss. The mass concentration of potassium humate in the mixture of potassium humate and fermented soybean milk used for both the application in the pond and the root irrigation was 0.03-0.05%, and the mass concentration of fermented soybean milk was 1-3%.

[0036] D. Seedling recovery period: 10-15 days after transplanting, apply 900 kg / hm² of liquid organic fertilizer diluted with water. 2 ;

[0037] E. Seedling stage: 25-30 days after transplanting, apply a mixture of potassium humate and fermented soybean milk to the tobacco plants at a rate of 300-450 kg / hm². 2 Using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Irrigate the roots with a mixture of potassium humate and fermented soybean milk. Immediately after irrigation, seal the hole with soil to prevent evaporation and moisture loss. The mass concentration of potassium humate in the mixture of potassium humate and fermented soybean milk applied to the tobacco plant and used for root irrigation is 0.06-0.1%, and the mass concentration of fermented soybean milk is 4-6%.

[0038] F. Vigorous growth period: 50-55 days after transplanting, apply 600 kg / hm² of liquid organic fertilizer diluted with water to the tobacco plants for the second time. 2 ;

[0039] G. Budding stage: 85-95 days after transplanting, prune and remove side shoots from the tobacco plants, and spray the lower leaves with a mixture of potassium humate and fermented soybean milk at a rate of 450-600 kg / hm². 2 The mass concentration of potassium humate in the mixture of potassium humate and fermented soybean milk is 0.1-0.3%, and the mass concentration of fermented soybean milk is 6-8%.

[0040] H. Tobacco leaf harvesting: When the tobacco leaves are light yellow, more than 70% mature, the main vein turns more than 2 / 3 white, and the pubescence has basically fallen off, they can be harvested.

[0041] J. Tobacco leaf curing: Curing is carried out according to local high-quality curing techniques.

[0042] Compared with the prior art, the present invention has the following advantages and technical effects:

[0043] Root irrigation with fermented soybean milk has a significant positive impact on the physical, chemical, and biological properties of tobacco-growing soil. On the one hand, soybean milk irrigation during the rosette stage helps optimize the physical, chemical, and biological properties of the soil, increasing organic matter and nutrient levels, while also increasing the number and types of bacteria in the soil. On the other hand, soybean milk irrigation effectively promotes the accumulation of dry matter in tobacco plants and improves the sensory quality of tobacco leaves. This invention utilizes a mixed solution of potassium humate and fermented soybean milk for root irrigation and foliar spraying during the cultivation process to reduce the chlorine content in the soil and tobacco leaves under high-chlorine soil conditions, which is of great significance for improving the quality of tobacco raw materials and soil quality. Detailed Implementation

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0045] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] In this embodiment of the invention, room temperature refers to "25±2℃".

[0047] The tobacco variety used in the embodiments and comparative examples of this invention is the Honghua Dajinyuan from Midu, Yunnan.

[0048] In the following examples and comparative examples, potassium humate was purchased from Xinjiang Shuanglong Humic Acid Co., Ltd., with a humic acid content of 52% and a potassium oxide content of 20%. Fermented soybean milk was prepared by soaking soybeans and water at a ratio of 1:4 (kg:L) at room temperature for 8 hours, then grinding them into soy milk. The soy milk was then sealed and stored in a cool, ventilated place and fermented for 6 days. The fermented soy milk had a water content of 90%, and contained 67.43% organic matter, 35.07% carbohydrates, 1.46% phosphorus, and 1.41% potassium.

[0049] In the following comparative examples, both the compound microbial fertilizer and the tobacco-specific compound fertilizer are from Dali Prefecture Tobacco Company.

[0050] Unless otherwise specified, all raw materials used in the embodiments of this invention were purchased through commercial channels.

[0051] Example 1

[0052] A method for reducing the chlorine content in soil and tobacco leaves under high-chlorine soil conditions includes the following steps:

[0053] A. Seedling raising: Rinse the tobacco seeds with distilled water, then disinfect them with 0.2% potassium permanganate for 10 minutes; then rinse the seeds three times with distilled water, and then place the seeds in a seedling tray containing disinfected substrate for floating seedling raising;

[0054] B. Land preparation measures: The soil is plowed to a depth of 25cm, exposed to the sun for 7 days, the ridge height is 0.5m, the row spacing is 1.2m, and the plant spacing is 0.6m; pits are dug at fixed intervals, with a pit diameter of 25cm and a depth of 20cm;

[0055] C. Transplanting tobacco seedlings: After 41 days of seedling cultivation, select healthy and vigorous seedlings with uniform growth and transplant them into tobacco ponds with high-chloride soil. Beforehand, dilute a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.03% and fermented soybean milk concentration of 1%) in the soil at a rate of 75 kg / hm². 2 Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.03%, and the mass concentration of fermented soybean milk is 1%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0056] D. Seedling recovery period: 12 days after transplanting, apply liquid organic fertilizer diluted with water (N≥6%, P2O5≥2%).

[0057] K2O≥12%) 900 kg / hm 2 ;

[0058] E. Seedling stage: 28 days after transplanting, apply a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.06% and fermented soybean milk concentration of 4%) to the tobacco plants at a rate of 300 kg / hm². 2 Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.06%, and the mass concentration of fermented soybean milk is 4%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0059] F. Vigorous growth period: 52 days after transplanting, apply 600 kg / hm² of liquid organic fertilizer diluted with water to the tobacco plants for the second time. 2 ;

[0060] G. Budding stage: 90 days after transplanting, prune and remove side shoots from the tobacco plants, and spray the lower leaves with a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.1% and fermented soybean milk concentration of 6%) at a rate of 450 kg / hm². 2 ;

[0061] H. Tobacco leaf harvesting: When the tobacco leaves are light yellow, about 70% mature, the main vein turns white for more than 2 / 3 of the time, and the hairs have mostly fallen off, they can be harvested.

[0062] J. Tobacco leaf curing: Curing is carried out according to local high-quality curing techniques.

[0063] Example 2

[0064] A method for reducing the chlorine content in soil and tobacco leaves under high-chlorine soil conditions includes the following steps:

[0065] A. Seedling raising: Rinse the tobacco seeds with distilled water, then disinfect them with 0.2% potassium permanganate for 10 minutes; then rinse the seeds three times with distilled water, and then place the seeds in a seedling tray containing disinfected substrate for floating seedling raising;

[0066] B. Land preparation measures: plow the soil to a depth of 30cm, expose it to the sun for 10 days, ridge height is 0.5m, row spacing is 1.2m, plant spacing is 0.6m; dig pits at fixed intervals, with a pit diameter of 30cm and a depth of 20cm;

[0067] C. Transplanting tobacco seedlings: After 45 days of seedling cultivation, select healthy and vigorous seedlings with uniform growth and transplant them into tobacco ponds with high-chloride soil. Beforehand, dilute a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.04% and fermented soybean milk concentration of 2%) in the soil at a rate of 150 kg / hm². 2 Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.04%, and the mass concentration of fermented soybean milk is 2%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0068] D. Seedling recovery period: 15 days after transplanting, apply liquid organic fertilizer diluted with water (N≥6%, P2O5≥2%).

[0069] K2O≥12%) 900 kg / hm 2 ;

[0070] E. Seedling stage: 30 days after transplanting, apply a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.08% and fermented soybean milk concentration of 5%) to the tobacco plants at a rate of 375 kg / hm². 2 Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.08%, and the mass concentration of fermented soybean milk is 5%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0071] F. Vigorous growth period: 55 days after transplanting, apply 600 kg / hm² of liquid organic fertilizer diluted with water to the tobacco plants for the second time. 2 ;

[0072] G. Budding stage: 85 days after transplanting, prune and remove side shoots from the tobacco plants, and spray the lower leaves with a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.15% and fermented soybean milk concentration of 7%) at a rate of 525 kg / hm².2 ;

[0073] H. Tobacco leaf harvesting: When the tobacco leaves are light yellow, about 70% mature, the main vein turns white for more than 2 / 3, and the pubescence has basically fallen off, they can be harvested.

[0074] J. Tobacco leaf curing: Curing is carried out according to local high-quality curing techniques.

[0075] Example 3

[0076] A method for reducing the chlorine content in soil and tobacco leaves under high-chlorine soil conditions includes the following steps:

[0077] A. Seedling raising: Rinse the tobacco seeds with distilled water, then disinfect them with 0.2% potassium permanganate for 10 minutes; then rinse the seeds three times with distilled water, and then place the seeds in a seedling tray containing disinfected substrate for floating seedling raising;

[0078] B. Land preparation measures: plow the soil to a depth of 30cm, expose it to the sun for 10 days, ridge height is 0.5m, row spacing is 1.2m, plant spacing is 0.6m; dig pits at fixed intervals, with a pit diameter of 27cm and a depth of 20cm;

[0079] C. Transplanting tobacco seedlings: After 45 days of seedling cultivation, select healthy and vigorous seedlings with uniform growth and transplant them into tobacco ponds with high-chloride soil. Beforehand, dilute a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.05% and fermented soybean milk concentration of 3%) in the soil at a rate of 225 kg / hm². 2 Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.05%, and the mass concentration of fermented soybean milk is 3%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0080] D. Seedling recovery period: 10 days after transplanting, apply liquid organic fertilizer diluted with water (N≥6%, P2O5≥2%).

[0081] K2O≥12%) 900 kg / hm 2 ;

[0082] E. Seedling stage: 25 days after transplanting, apply a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.1% and fermented soybean milk concentration of 5%) to the tobacco plants at a rate of 375 kg / hm². 2Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.1%, and the mass concentration of fermented soybean milk is 5%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0083] F. Vigorous growth period: 55 days after transplanting, apply 600 kg / hm² of liquid organic fertilizer diluted with water to the tobacco plants for the second time. 2 ;

[0084] G. Budding stage: 92 days after transplanting, prune and remove side shoots from the tobacco plants, and apply a foliar spray of a mixture of potassium humate and fermented soybean milk to the roots (the mass concentration of potassium humate in the mixture is 0.2%, and the mass concentration of fermented soybean milk is 8%), at a rate of 600 kg / hm². 2 ;

[0085] H. Tobacco leaf harvesting: When the tobacco leaves are light yellow, about 70% mature, the main vein turns white for more than 2 / 3, and the pubescence has basically fallen off, they can be harvested.

[0086] J. Tobacco leaf curing: Curing is carried out according to local high-quality curing techniques.

[0087] Comparative Example 1

[0088] A. Seedling raising: Rinse the tobacco seeds with distilled water, then disinfect them with 0.2% potassium permanganate for 10 minutes; then rinse the seeds three times with distilled water, and then place the seeds in a seedling tray containing disinfected substrate for floating seedling raising;

[0089] B. Land preparation measures: plow the soil to a depth of 30cm, expose it to the sun for 10 days, ridge height is 0.5m, row spacing is 1.2m, plant spacing is 0.6m; dig pits at fixed intervals, with a pit diameter of 30cm and a depth of 20cm;

[0090] C. Transplanting tobacco seedlings: After 40 days of seedling cultivation, select healthy seedlings with uniform growth and transplant them into the tobacco pond in a standardized manner. Apply compound microbial fertilizer (N, P2O5, and K2O content of 5%, 5%, and 15% respectively) at 240 kg / hm² to the pond. 2 480 kg / hm² of tobacco-specific compound fertilizer (N, P₂O₅, and K₂O content of 10%, 10%, and 24%, respectively) 2 .

[0091] D. Seedling stage: 28 days after transplanting, apply liquid organic fertilizer diluted with water (N≥6%, P2O5≥2%).

[0092] K2O≥12%) 750kg / hm 2 ;

[0093] E. Vigorous growth period: 55 days after transplanting, apply 750 kg / hm² of liquid organic fertilizer to the tobacco plants as a second application. 2 ;

[0094] F. Budding stage: 90 days after transplanting, the tobacco plants are topped and pruned.

[0095] G. Tobacco leaf harvesting: When the tobacco leaves are light yellow, about 70% mature, the main vein turns white for more than 2 / 3, and the pubescence has basically fallen off, they can be harvested.

[0096] H. Tobacco leaf curing: Curing is carried out according to local high-quality curing techniques.

[0097] The chlorine content in fresh tobacco leaves and first-cured tobacco leaves after harvesting in Examples 1-3 and Comparative Example 1 was determined, and the results are shown in Table 1.

[0098] Table 1 Chlorine content (%)

[0099] deal with Fresh tobacco leaves First-cured tobacco leaves Example 1 1.22 0.77 Example 2 1.05 0.49 Example 3 0.82 0.38 Comparative Example 1 1.44 0.98

[0100] As shown in Table 1, after repeated application of the mixture of potassium humate and fermented soybean milk in Examples 1-3 of the present invention, the chlorine content of fresh tobacco leaves and uncured tobacco leaves was reduced. In Example 1, the chlorine content of fresh tobacco leaves and uncured tobacco leaves was reduced by 0.22% and 0.21% respectively compared with Comparative Example 1. In Example 2, the chlorine content of fresh tobacco leaves and uncured tobacco leaves was reduced by 0.39% and 0.49% respectively compared with Comparative Example 1. In Example 3, the chlorine content of fresh tobacco leaves and uncured tobacco leaves was reduced by 0.62% and 0.60% respectively compared with Comparative Example 1.

[0101] Sensory evaluations were conducted on the first-cured tobacco leaves of Examples 1-3 and Comparative Example 1, in accordance with industry standard YC / T138-1998. The sensory evaluation results are shown in Table 2.

[0102] Table 2 Sensory evaluation results

[0103]

[0104] As shown in Table 2, after repeated application of the mixture of potassium humate and fermented soybean milk in Examples 1-3 of this invention, the sensory evaluation grades of the newly cured tobacco leaves were higher, especially the impurities and combustibility were significantly improved. The impurities and combustibility of Example 1 were 1.5 points higher than those of Comparative Example 1; the impurities and combustibility of Example 2 were 2 points and 1.5 points higher than those of Comparative Example 1, respectively; and the impurities and combustibility of Example 3 were 2.5 points and 2 points higher than those of Comparative Example 1, respectively.

[0105] The water-soluble chlorine content in soils at different growth stages of field experiments 1-3 and Comparative Example 1 was measured, and the results are shown in Table 3.

[0106] Table 3 Soil water-soluble chlorine content (mg / kg) at different growth stages in the field

[0107] deal with 0d 30d 60d 90d 120d Example 1 51.24 46.49 43.38 38.66 32.79 Example 2 51.24 45.77 42.53 37.48 30.46 Example 3 51.24 45.16 38.35 33.23 25.37 Comparative Example 1 51.24 48.37 45.68 43.49 40.31

[0108] As shown in Table 3, after repeated application of the mixture of potassium humate and fermented soybean milk in Examples 1-3 of this invention, the water-soluble chlorine content in the soil at different growth stages in the field of Examples 1-3 all decreased to varying degrees. At a growth period of 120 days, the chlorine content in Example 1 was 7.52 mg / kg lower than that in Comparative Example 1, the chlorine content in Example 2 was 9.85 mg / kg lower than that in Comparative Example 1, and the chlorine content in Example 3 was 14.94 mg / kg lower than that in Comparative Example 1.

[0109] Example 4

[0110] A method for reducing the chlorine content in soil and tobacco leaves under high-chlorine soil conditions includes the following steps:

[0111] A. Seedling raising: Rinse the tobacco seeds with distilled water, then disinfect them with 0.2% potassium permanganate for 7 minutes; then rinse the seeds with distilled water 3 times, and then put the seeds into a seedling tray containing disinfected substrate for floating seedling raising;

[0112] B. Land preparation measures: The soil is plowed to a depth of 25cm, exposed to the sun for 10 days, the ridge height is 0.5m, the row spacing is 1.2m, and the plant spacing is 0.6m; pits are dug at fixed intervals, with a pit diameter of 30cm and a depth of 20cm;

[0113] C. Transplanting tobacco seedlings: After 44 days of seedling cultivation, select healthy and vigorous seedlings with uniform growth and transplant them into tobacco ponds with high-chloride soil. Beforehand, dilute a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.05% and fermented soybean milk concentration of 1%) in the soil at a rate of 75 kg / hm². 2 Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.05%, and the mass concentration of fermented soybean milk is 1%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0114] D. Seedling recovery period: 15 days after transplanting, apply liquid organic fertilizer diluted with water (N≥6%, P2O5≥2%).

[0115] K2O≥12%) 900 kg / hm 2 ;

[0116] E. Seedling stage: 30 days after transplanting, apply a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.08% and fermented soybean milk concentration of 4%) to the tobacco plants at a rate of 300 kg / hm². 2Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.08%, and the mass concentration of fermented soybean milk is 4%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0117] F. Vigorous growth period: 53 days after transplanting, apply 600 kg / hm² of liquid organic fertilizer diluted with water to the tobacco plants for the second time. 2 ;

[0118] G. Budding stage: 90 days after transplanting, prune and remove side shoots from the tobacco plants, and spray the lower leaves with a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.2% and fermented soybean milk concentration of 6%) at a rate of 450 kg / hm². 2 ;

[0119] H. Tobacco leaf harvesting: When the tobacco leaves are light yellow, about 70% mature, the main vein turns white for more than 2 / 3, and the pubescence has basically fallen off, they can be harvested.

[0120] J. Tobacco leaf curing: Curing is carried out according to local high-quality curing techniques.

[0121] Example 5

[0122] A method for reducing the chlorine content in soil and tobacco leaves under high-chlorine soil conditions includes the following steps:

[0123] A. Seedling raising: Rinse the tobacco seeds with distilled water, then disinfect them with 0.2% potassium permanganate for 8 minutes; then rinse the seeds with distilled water 3 times, and then put the seeds into a seedling tray containing disinfected substrate for floating seedling raising;

[0124] B. Land preparation measures: The soil is plowed to a depth of 28cm, exposed to the sun for 10 days, with a ridge height of 0.5m, a row spacing of 1.2m, and a plant spacing of 0.6m; pits are dug at fixed intervals, with a pit diameter of 28cm and a depth of 20cm;

[0125] C. Transplanting tobacco seedlings: After 40 days of seedling cultivation, select healthy and vigorous seedlings with uniform growth and transplant them into tobacco ponds with high-chlorine soil. Beforehand, dilute a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.05% and fermented soybean milk concentration of 2%) in the soil at a rate of 150 kg / hm². 2 Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.05%, and the mass concentration of fermented soybean milk is 2%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0126] D. Seedling recovery period: 13 days after transplanting, apply liquid organic fertilizer diluted with water (N≥6%, P2O5≥2%).

[0127] K2O≥12%) 900 kg / hm 2 ;

[0128] E. Seedling stage: 30 days after transplanting, apply a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.1% and fermented soybean milk concentration of 5%) to the tobacco plants at a rate of 375 kg / hm². 2 Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.1%, and the mass concentration of fermented soybean milk is 5%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0129] F. Vigorous growth period: 55 days after transplanting, apply 600 kg / hm² of liquid organic fertilizer diluted with water to the tobacco plants for the second time. 2 ;

[0130] G. Budding stage: 90 days after transplanting, prune and remove side shoots from the tobacco plants, and spray the lower leaves with a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.3% and fermented soybean milk concentration of 7%) at a rate of 525 kg / hm². 2 ;

[0131] H. Tobacco leaf harvesting: When the tobacco leaves are light yellow, about 70% mature, the main vein turns white for more than 2 / 3, and the pubescence has basically fallen off, they can be harvested.

[0132] J. Tobacco leaf curing: Curing is carried out according to local high-quality curing techniques.

[0133] Example 6

[0134] A method for reducing the chlorine content in soil and tobacco leaves under high-chlorine soil conditions includes the following steps:

[0135] A. Seedling raising: Rinse the tobacco seeds with distilled water, then disinfect them with 0.2% potassium permanganate for 9 minutes; then rinse the seeds with distilled water 3 times, and then put the seeds into a seedling tray containing disinfected substrate for floating seedling raising;

[0136] B. Land preparation measures: The soil is plowed to a depth of 29cm, exposed to the sun for 9 days, with a ridge height of 0.5m, a row spacing of 1.2m, and a plant spacing of 0.6m; pits are dug at fixed intervals, with a pit diameter of 30cm and a depth of 20cm;

[0137] C. Transplanting tobacco seedlings: After 45 days of seedling cultivation, select healthy seedlings with uniform growth and transplant them into tobacco ponds with high-chlorine soil. Beforehand, dilute a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.05% and fermented soybean milk concentration of 3%) in the soil at a rate of 225 kg / hm². 2 Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk into the root zone (the mass concentration of potassium humate in the solution is 0.05%, and the mass concentration of fermented soybean milk is 3%). Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0138] D. Seedling recovery period: 14 days after transplanting, apply liquid organic fertilizer diluted with water (N≥6%, P2O5≥2%).

[0139] K2O≥12%) 900 kg / hm 2 ;

[0140] E. Seedling stage: 30 days after transplanting, apply a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.1% and fermented soybean milk concentration of 6%) to the tobacco plants at a rate of 450 kg / hm². 2 Then, using a sharpened wooden stick about 5cm in diameter, make a hole at a 30° angle near the base of the tobacco plant. Pour a well-mixed solution of potassium humate and fermented soybean milk (the mass concentration of potassium humate in the solution is 0.1%, and the mass concentration of fermented soybean milk is 6%) into the roots. Immediately after pouring, seal the hole with soil to prevent evaporation and moisture loss.

[0141] F. Vigorous growth period: 53 days after transplanting, apply 600 kg / hm² of liquid organic fertilizer diluted with water to the tobacco plants for the second time. 2 ;

[0142] G. Budding stage: 92 days after transplanting, prune and remove side shoots from the tobacco plants, and spray the lower leaves with a mixture of potassium humate and fermented soybean milk (potassium humate concentration of 0.3% and fermented soybean milk concentration of 8%) at a rate of 600 kg / hm². 2 ;

[0143] H. Tobacco leaf harvesting: When the tobacco leaves are light yellow, about 70% mature, the main vein turns white for more than 2 / 3, and the pubescence has basically fallen off, they can be harvested.

[0144] J. Tobacco leaf curing: Curing is carried out according to local high-quality curing techniques.

[0145] Comparative Example 2

[0146] A. Seedling raising: Rinse the tobacco seeds with distilled water, then disinfect them with 0.2% potassium permanganate for 6 minutes; then rinse the seeds with distilled water 3 times, and then put the seeds into a seedling tray containing disinfected substrate for floating seedling raising;

[0147] B. Land preparation measures: The soil is plowed to a depth of 20cm, exposed to the sun for 6 days, the ridge height is 0.5m, the row spacing is 1.2m, and the plant spacing is 0.6m; pits are dug at fixed intervals, with a pit diameter of 25cm and a depth of 18cm;

[0148] C. Transplanting tobacco seedlings: After 40 days of seedling cultivation, select healthy and vigorous seedlings with uniform growth and transplant them into tobacco ponds with high chloride soil. Apply compound microbial fertilizer (N, P2O5, and K2O content of 5%, 5%, and 15% respectively) at 240 kg / hm² to the ponds. 2 480 kg / hm² of tobacco-specific compound fertilizer (N, P₂O₅, and K₂O content of 10%, 10%, and 24%, respectively) 2 ;

[0149] D. Seedling stage: 23 days after transplanting, apply liquid organic fertilizer diluted with water (N≥6%, P2O5≥2%).

[0150] K2O≥12%) 750kg / hm 2 ;

[0151] E. Vigorous growth period: 53 days after transplanting, apply 750 kg / hm² of liquid organic fertilizer diluted with water to the tobacco plants for the second time. 2 ;

[0152] F. Budding stage: 93 days after transplanting, the tobacco plants are topped and pruned.

[0153] G. Tobacco leaf harvesting: When the tobacco leaves are light yellow, about 70% mature, the main vein turns white for more than 2 / 3, and the pubescence has basically fallen off, they can be harvested.

[0154] H. Tobacco leaf curing: Curing is carried out according to local high-quality curing techniques.

[0155] The chlorine content in the fresh tobacco leaves and first-cured tobacco leaves after harvesting in Examples 4-6 and Comparative Example 2 was determined, and the results are shown in Table 4.

[0156] Table 4 Chlorine content (%)

[0157] deal with Fresh tobacco leaves First-cured tobacco leaves Example 4 1.16 0.73 Example 5 0.95 0.54 Example 6 0.82 0.47 Comparative Example 2 1.33 0.91

[0158] As shown in Table 4, after repeated application of the mixture of potassium humate and fermented soybean milk in Examples 4-6 of the present invention, the chlorine content of both fresh tobacco leaves and uncured tobacco leaves decreased. In Example 4, the chlorine content of fresh tobacco leaves and uncured tobacco leaves decreased by 0.17% and 0.18% respectively compared with Comparative Example 2. In Example 5, the chlorine content of fresh tobacco leaves and uncured tobacco leaves decreased by 0.38% and 0.37% respectively compared with Comparative Example 2. In Example 6, the chlorine content of fresh tobacco leaves and uncured tobacco leaves decreased by 0.51% and 0.44% respectively compared with Comparative Example 2.

[0159] Sensory evaluations were conducted on the first-cured tobacco leaves of Examples 4-6 and Comparative Example 2, in accordance with industry standard YC / T138-1998. The sensory evaluation results are shown in Table 5.

[0160] Table 5 Sensory evaluation results

[0161]

[0162] As shown in Table 5, after repeated application of the mixture of potassium humate and fermented soybean milk in Examples 4-6 of this invention, the sensory evaluation grades of the newly cured tobacco leaves were higher, especially the impurities and combustibility were significantly improved. The impurities and combustibility of Example 4 were both 1.5 points higher than those of Comparative Example 2; the impurities and combustibility of Example 5 were 1.5 points and 2.0 points higher than those of Comparative Example 2, respectively; and the impurities and combustibility of Example 6 were both 2.0 points higher than those of Comparative Example 2.

[0163] The water-soluble chlorine content of soil at different growth stages in the fields of Examples 4-6 and Comparative Example 2 was measured, and the results are shown in Table 6.

[0164] Table 6. Soil water-soluble chlorine content (mg / kg) at different growth stages in the field.

[0165] deal with 0d 30d 60d 90d 120d Example 4 45.89 42.11 38.79 35.59 31.66 Example 5 45.89 40.67 36.81 33.48 28.32 Example 6 45.89 40.12 34.95 29.23 23.24 Comparative Example 2 45.89 43.78 41.62 39.49 36.31

[0166] As shown in Table 6, after multiple applications of the compound in Examples 4-6 of this invention, the water-soluble chlorine content in the soil at different growth stages in the field of Examples 4-6 decreased to varying degrees. At a field growth period of 120 days, the chlorine content in Example 4 was 4.65 mg / kg lower than that in Comparative Example 2, the chlorine content in Example 5 was 7.99 mg / kg lower than that in Comparative Example 2, and the chlorine content in Example 6 was 13.07 mg / kg lower than that in Comparative Example 2.

[0167] Comparative Example 3

[0168] The difference from Example 6 is that, C, transplanting tobacco seedlings: after 40 days of seedling cultivation, select healthy and vigorous tobacco seedlings with uniform growth and transplant them into tobacco ponds with high chloride soil. Apply 240 kg / hm² of compound microbial fertilizer (N, P₂O₅, and K₂O content of 5%, 5%, and 15% respectively) to the ponds in a single application. 2480 kg / hm² of tobacco-specific compound fertilizer (N, P₂O₅, and K₂O content of 10%, 10%, and 24%, respectively) 2 The rest is the same as in Example 6.

[0169] Comparative Example 4

[0170] The difference from Example 6 is that, in step D, the seedling stage: 23 days after transplanting, apply 750 kg / hm² of diluted liquid organic fertilizer (N≥6%, P2O5≥2%, K2O≥12%). 2 The rest is the same as in Example 6.

[0171] Comparative Example 5

[0172] The difference from Example 6 is that, F, budding stage: 93 days after transplanting, the tobacco plants are topped and pruned, otherwise the same as in Example 6.

[0173] The chlorine content in the fresh tobacco leaves and first-cured tobacco leaves of Comparative Examples 3-5 was determined, and the results are shown in Table 7.

[0174] Table 7 Chlorine content (%)

[0175] deal with Fresh tobacco leaves First-cured tobacco leaves Comparative Example 3 1.18 0.76 Comparative Example 4 1.26 0.85 Comparative Example 5 1.20 0.80

[0176] As shown in Table 7, since the mixed solution was not applied simultaneously at the transplanting seedling, seedling, and budding stages in Comparative Examples 3-5, the chlorine content of both fresh and newly cured tobacco leaves increased. The chlorine content of fresh and newly cured tobacco leaves in Comparative Example 3 increased by 0.36% and 0.29% compared to Example 6, respectively. The chlorine content of fresh and newly cured tobacco leaves in Comparative Example 4 increased by 0.44% and 0.38% compared to Example 6, respectively. The chlorine content of fresh and newly cured tobacco leaves in Comparative Example 5 increased by 0.38% and 0.33% compared to Example 6, respectively.

[0177] Sensory evaluations were conducted on the flue-cured tobacco leaves of Comparative Examples 3-5 according to industry standard YC / T 138—1998. The sensory evaluation results are shown in Table 8.

[0178] Table 8 Sensory Evaluation Results

[0179]

[0180]

[0181] As shown in Table 8, Comparative Examples 3-5 did not apply the mixed liquor simultaneously during the transplanting, seedling, and budding stages, resulting in lower sensory evaluation grades for the newly cured tobacco leaves. The off-gas and combustibility scores of Comparative Example 3 were 0.5 and 1.0 points lower than those of Example 6, respectively; the off-gas and combustibility scores of Comparative Example 4 were both 1.5 points lower than those of Example 6; and the off-gas and combustibility scores of Comparative Example 5 were 1.0 and 1.5 points lower than those of Example 6, respectively.

[0182] The water-soluble chlorine content in the soil at different growth stages of the field samples 3-5 was determined, and the results are shown in Table 9.

[0183] Table 9. Soil water-soluble chlorine content (mg / kg) at different growth stages in the field.

[0184] deal with 0d 30d 60d 90d 120d Comparative Example 3 45.89 41.34 37.06 34.25 29.58 Comparative Example 4 45.89 42.95 49.12 36.93 30.81 Comparative Example 5 45.89 41.79 38.57 35.36 30.16

[0185] As shown in Table 9, Comparative Examples 3-5 did not simultaneously apply the mixed solution during the transplanting, seedling, and budding stages of tobacco seedlings, and the water-soluble chlorine content in the soil increased to varying degrees at different growth stages in the field. At a field growth period of 120 days, the chlorine content in Comparative Example 3 was 6.34 mg / kg higher than that in Example 6, in Comparative Example 4 it was 7.57 mg / kg higher than that in Example 6, and in Comparative Example 5 it was 6.92 mg / kg higher than that in Example 6.

[0186] The above are merely preferred embodiments 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 scope of the technology 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 reducing the chlorine content of soil and tobacco leaves under high-chlorine soil conditions, characterized in that, The following steps are involved: Seedling raising, land preparation, transplanting tobacco seedlings, growth, tobacco harvesting, and tobacco curing; The growth process includes the seedling stage, the clustering stage, the vigorous growth stage, and the budding stage. A mixture of potassium humate and fermented soybean milk was applied after transplanting tobacco seedlings, at the seedling stage, and at the budding stage. The transplanted tobacco seedlings are prepared by: raising seedlings for 40-45 days, selecting healthy seedlings with uniform growth, and transplanting them into tobacco ponds with high-chlorine soil. A mixture of potassium humate and fermented soybean milk is applied to the ponds at a rate of 75-225 kg / hm². 2 Simultaneously, the roots are irrigated with a mixture of potassium humate and fermented soybean milk; the mass concentration of potassium humate in the mixture of potassium humate and fermented soybean milk is 0.03-0.05%, and the mass concentration of fermented soybean milk is 1-3%. The sowing period is 25-30 days after transplanting, during which a mixture of potassium humate and fermented soybean milk is applied to the tobacco plants at a rate of 300-450 kg / hm². 2 Simultaneously, the roots are irrigated with a mixture of potassium humate and fermented soybean milk; the mass concentration of potassium humate in the mixture of potassium humate and fermented soybean milk is 0.06-0.1%, and the mass concentration of fermented soybean milk is 4-6%. The potassium humate and fermented soybean milk mixture applied during the budding stage has a mass concentration of 0.1-0.3% and a fermented soybean milk mass concentration of 6-8%. Application is performed 85-95 days after transplanting at a rate of 450-600 kg / hm². 2 The application site is the lower leaf surface of the tobacco plant.

2. The method for reducing the chlorine content of soil and tobacco leaves under high-chlorine soil conditions according to claim 1, characterized in that, The seedling raising process involves rinsing tobacco seeds with distilled water, disinfecting them with potassium permanganate, rinsing them again with distilled water, and then placing the seeds in a seedling tray containing substrate for floating seedling raising.

3. The method for determining the chlorine content of soil and tobacco leaves under low-chlorine soil conditions according to claim 1, characterized in that, The land preparation process involves: plowing the soil to a depth of 20–30 cm, exposing it to the sun for 6–10 days, setting the ridge height at 0.5 m, the row spacing at 1.2 m, and the plant spacing at 0.6 m; and digging pits at fixed intervals, with a pit diameter of 25–30 cm and a depth of 18–20 cm.

4. The method for determining the chlorine content of soil and tobacco leaves under low-chlorine soil conditions according to claim 1, characterized in that, The application of liquid organic fertilizer during the seedling stage should be done 10-15 days after transplanting, at a rate of 900 kg / hm². 2 .

5. The method for reducing the chlorine content of soil and tobacco leaves under high-chlorine soil conditions according to claim 1, characterized in that, Liquid organic fertilizer should be applied during the vigorous growth period, 50-55 days after transplanting, at a rate of 600 kg / hm². 2 .

6. The method for reducing the chlorine content of soil and tobacco leaves under high-chlorine soil conditions according to claim 1, characterized in that, The tobacco leaves are harvested when the leaf surface is light yellow, the maturity is 70% or more yellow, the main vein has turned white for more than 2 / 3 of its length, and the pubescence has basically fallen off.

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