Special organic fertilizer for preventing and controlling tobacco black shank and preparation method thereof

Abstract

The invention discloses a special organic fertilizer for preventing and controlling tobacco black shank and a preparation method thereof.The special organic fertilizer is prepared from corn straw, rice husk charcoal, a biological leavening agent, limonin, salicylic acid, plant ash, shrimp shell powder and soluble potassium silicate, and the biological leavening agent is tarlaromyces flavus powder; the preparation process comprises the following steps: acidizing the prawn shell powder, crushing and fermenting the corn straws, the rice husk charcoal and the acidized prawn shell powder, increasing the activity of the tarlaromyces flavus powder by using limonin and salicylic acid, carrying out secondary fermentation, and finally granulating and drying. The growth and development of tobacco root systems are promoted, the stress resistance of the tobacco is enhanced, and the occurrence of soil-borne diseases is reduced, so that the yield of the tobacco is increased. Meanwhile, the tobacco absorbs more comprehensive and balanced nutrients, and the internal quality of the tobacco leaves is improved.

Description

Technical Field

[0001] This invention relates to the field of organic fertilizer preparation technology, specifically to a special organic fertilizer for controlling tobacco black shank disease and its preparation method. Background Technology

[0002] Tobacco black shank, also known as tobacco black root or black stem disease, is an important soil-borne fungal disease of tobacco caused by Phytophthora infestans. It mainly infects the roots and base of the stems of tobacco plants, forming black, sunken lesions, hence the name "black shank".

[0003] Currently, chemical agents are mainly used to control tobacco black shank disease in production, such as phenylamides, fosetyl-aluminum, and dichlorvos. However, the large-scale, long-term, and repeated use of the same fungicide or several systemic fungicides with similar mechanisms of action easily leads to drug resistance in the tobacco black shank pathogen, resulting in decreased efficacy and increased pesticide dosage. Simultaneously, with the long-term use of chemical pesticides, pesticide residues and environmental pollution problems are becoming increasingly serious. Furthermore, long-term use of chemical pesticides reduces the population density of soil microorganisms suitable for tobacco plant growth, affecting the balance of the soil microbial community and impacting the growth and development of tobacco plants to varying degrees. On the other hand, tobacco is a leaf-based economic crop with specific requirements for the appearance and internal quality of tobacco leaves. Chemical residues, pathogen resistance, and the impact on cigarette safety limit the large-scale use of chemical agents and are also detrimental to tobacco leaf exports. Therefore, providing a bio-organic fertilizer that can both control tobacco black shank disease and meet the nutritional requirements for tobacco growth is of great significance for achieving ecological control and improving tobacco quality. Summary of the Invention

[0004] The purpose of this invention is to provide an organic fertilizer for the prevention and control of tobacco black shank disease and its preparation method, so as to solve the problems in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: An organic fertilizer for controlling tobacco black shank disease, wherein the raw materials of the organic fertilizer, by weight, consist of 30-50 parts corn stalks, 3-10 parts rice husk charcoal, 0.5-1.5 parts bio-fermentation agent, 0.2-0.5 parts limonene, 0.2-0.5 parts salicylic acid, 10-20 parts wood ash, 10-20 parts shrimp shell powder, and 5-15 parts soluble potassium silicate, wherein the bio-fermentation agent is *Bacillus thuringiensis* powder.

[0006] The raw materials of the aforementioned organic fertilizer, calculated by weight, consist of 35-45 parts corn stalks, 5-8 parts rice husk charcoal, 0.7-1.2 parts bio-fermentation agent, 0.3-0.4 parts limonene, 0.3-0.4 parts salicylic acid, 12-18 parts wood ash, 12-18 parts shrimp shell powder, and 7-13 parts soluble potassium silicate. The bio-fermentation agent is *Bacillus thuringiensis* powder.

[0007] Specifically, the raw materials of the aforementioned organic fertilizer, calculated by weight, consist of 40 parts corn stalks, 6.5 parts rice husk charcoal, 1 part bio-fermentation agent, 0.35 parts limonene, 0.35 parts salicylic acid, 14-16 parts wood ash, 15 parts shrimp shell powder, and 10 parts soluble potassium silicate. The bio-fermentation agent is Bacillus thuringiensis powder.

[0008] The bacterial content in the aforementioned *Bryophytum comosum* powder is 1.0-3.0 × 10⁻⁶. 10 cfu / g.

[0009] The aforementioned method for preparing organic-specific fertilizer is carried out according to the following steps: (1) Acidification treatment of shrimp shell powder: Take shrimp shell powder, wash it and dry it at 60-80℃ for 5-8h, soak it in dilute hydrochloric acid with a mass fraction of 4-6% at room temperature for 18-24h, filter it after reaction, wash it with water until neutral, and then dry it at 60-80℃ for 12-14h to obtain acidified shrimp shell powder. (2) Primary fermentation: Crush corn stalks, rice husk charcoal, and acidified shrimp shell powder to a particle size of <2cm, add water to make the moisture content reach 55-65%, use turning and stirring fermentation, raise the temperature to 60-70℃, maintain for 4-6 days, and obtain primary fermented product; (3) Activation of biological fermentation agent: Take the yellow blue bromide powder and inoculate it into LB liquid medium, add limonene and salicylic acid, activate at 28-32℃ for 28-36h to obtain biological fermentation broth; (4) Secondary fermentation: Reduce the temperature of the pile of primary fermentation material to 30-40℃, add activated biological fermentation liquid and mix well. Use static fermentation, maintain the temperature at 30-38℃ and the humidity at 45-55%, and ferment for 8-10 days. During this period, monitor the number of bacteria to ensure that the biocontrol bacteria become the dominant species and obtain secondary fermentation material. (5) Granulation: Add wood ash and soluble potassium silicate to the secondary fermentation product, adjust the pH to 6.0-7.5, transfer to a granulator for granulation, and then send to a dryer for drying. The moisture content is controlled below 5% to obtain organic fertilizer.

[0010] In the aforementioned step (1), the shrimp shell powder is acidified: the shrimp shell powder is washed and dried at 70℃ for 6-7 hours, soaked in 5% dilute hydrochloric acid at room temperature for 20-22 hours, filtered after reaction, washed with water until neutral, and then dried at 70℃ for 13 hours to obtain the acidified shrimp shell powder.

[0011] In step (2) above, the first fermentation is carried out by crushing corn stalks, rice husk charcoal, and acidified shrimp shell powder to a particle size of <2cm, adding water to make the moisture content reach 60%, and fermenting by turning and tossing, raising the temperature to 65℃ and maintaining it for 5 days to obtain the first fermented product.

[0012] In step (3) above, the bio-fermentation agent is activated: the yellow blue bromide powder is inoculated into LB liquid medium, the mass ratio of yellow blue bromide powder to LB liquid medium is 1:500, and limonene and salicylic acid are added. The mixture is activated at 30°C for 32 hours to obtain the activated bio-fermentation liquid.

[0013] In the aforementioned step (4), the secondary fermentation is carried out by lowering the temperature of the primary fermentation material pile to 33-38℃, adding activated biological fermentation liquid and mixing it, using static fermentation, maintaining a temperature of 33-38℃ and a humidity of 47-52%, fermenting for 8-9 days, monitoring the number of bacteria during the period to ensure that the biocontrol bacteria become the dominant species, and obtaining the secondary fermentation material.

[0014] Specifically, in the aforementioned step (4), the secondary fermentation is as follows: after the primary fermentation, the temperature of the primary fermentation material pile is reduced to 35°C, biological fermentation liquid is added and mixed, static fermentation is adopted, the temperature is maintained at 35°C and the humidity is 50%, and the fermentation lasts for 9 days. During this period, the number of bacteria is monitored to ensure that the biocontrol bacteria become the dominant species and the secondary fermentation material is obtained.

[0015] Compared with traditional chemical fertilizers, this invention has the following beneficial effects: (1) Using rice husk charcoal can increase the porosity of organic fertilizer, so that the nutrients of organic fertilizer can be released into the soil quickly and fully, while adsorbing harmful substances. In combination with the use of biological antibacterial agents, it can effectively reduce the incidence of diseases such as tobacco black shank.

[0016] (2) Limonene and salicylic acid effectively enhance the activity of the yellow blue fungus powder, effectively inhibit black shank disease, increase tobacco endogenous hormones to improve the disease resistance of black shank disease, and limonene and salicylic acid can also effectively resist the erosion of other harmful insects, including aphids, whiteflies, spider mites, thrips, as well as underground pests such as cutworms and wireworms.

[0017] (3) Acidification treatment of shrimp shell powder can increase the chitin content, stimulate plant resistance, promote the reproduction of beneficial bacteria, and promote tobacco growth. Shrimp shell powder and wood ash contain a large amount of calcium and potassium. Using shrimp shell powder and wood ash can not only effectively supplement the calcium and potassium content of the soil and effectively supplement the soil nutrients, but also shrimp shell powder and wood ash themselves have a certain antibacterial effect, so they can also effectively inhibit the occurrence of black shank disease.

[0018] (4) Soluble potassium silicate is absorbed by tobacco roots, and the silicic acid produced is transported to the plant surface with water. The silicic acid combines with organic matter such as pectic acid and polysaccharide uronic acid to form an insoluble silicic acid mixture deposit, which fills and strengthens the structure of the cell wall. The thickened and silicified cell wall can effectively resist the invasion of black shank disease.

[0019] (5) The organic fertilizer of the present invention promotes the growth and development of tobacco roots, enhances the tobacco's resistance to adverse conditions, and reduces the occurrence of soil-borne diseases by improving the soil environment and providing sufficient nutrients, thereby increasing the yield of tobacco. At the same time, the tobacco absorbs more comprehensive and balanced nutrients, and the intrinsic quality of the tobacco leaves is improved. Detailed Implementation

[0020] The embodiments of the present invention will be described in further detail below with reference to the examples. These examples are for illustrative purposes only and should not be construed as limiting the scope of the invention. Unless otherwise specified, all reagents used in this invention are commercially available.

[0021] Example 1 Organic fertilizer ingredient ratio: The mixture consists of 40 kg of corn stalks, 6.5 kg of rice husk charcoal, 1 kg of *Auricularia auricula-judae* mycelium powder, 0.3 kg of limonene, 0.3 kg of salicylic acid, 15 kg of wood ash, 15 kg of shrimp shell powder, and 10 kg of soluble potassium silicate.

[0022] Organic fertilizer preparation process: (1) Acidification treatment of shrimp shell powder: Take shrimp shell powder, wash it and dry it at 70℃ for 6.5h, soak it in dilute hydrochloric acid with a mass fraction of 5% at room temperature for 20-22h, filter it after reaction, wash it with water until neutral, and then dry it at 70℃ for 13h to obtain acidified shrimp shell powder. (2) Primary fermentation: Corn stalks, rice husk charcoal, and acidified shrimp shell powder are crushed to a particle size of <2cm, and water is added to make the moisture content reach 60%. The fermentation is carried out by turning and tossing, and the temperature is raised to 65℃ and maintained for 5 days to obtain the primary fermented product. (3) Activation of biological fermentation agent: Take the yellow blue bromide powder and inoculate it into LB liquid medium. The mass ratio of yellow blue bromide powder to LB liquid medium is 1:500. Add limonene and salicylic acid and activate at 30℃ for 32h to obtain activated biological fermentation liquid. (4) Secondary fermentation: After the primary fermentation, the temperature of the primary fermentation material pile is reduced to 35°C, biological fermentation liquid is added and mixed, static fermentation is adopted, the temperature is maintained at 35°C and the humidity is 50%, and the fermentation is carried out for 9 days. During the period, the number of bacteria is monitored to ensure that the biocontrol bacteria become the dominant species and the secondary fermentation material is obtained. (5) Granulation: Add wood ash and soluble potassium silicate to the secondary fermentation product, adjust the pH to 6.0-7.5, transfer to a granulator for granulation, and then send to a dryer for drying. The moisture content is controlled below 5% to obtain organic fertilizer.

[0023] Example 2 Organic fertilizer ingredient ratio: 50 kg of corn stalks, 3 kg of rice husk charcoal, 1.5 kg of biological fermentation agent, 0.2 kg of limonene, 0.5 kg of salicylic acid, 10 kg of wood ash, 20 kg of shrimp shell powder, and 15 kg of soluble potassium silicate.

[0024] Organic fertilizer preparation process: (1) Acidification treatment of shrimp shell powder: Take shrimp shell powder, wash it and dry it at 80℃ for 8 hours. Soak it in dilute hydrochloric acid with a mass fraction of 6% at room temperature for 18 hours. After the reaction, filter it, wash it with water until neutral, and then dry it at 80℃ for 12 hours to obtain acidified shrimp shell powder. (2) Primary fermentation: Corn stalks, rice husk charcoal, and acidified shrimp shell powder are crushed to a particle size of <2cm, and water is added to make the moisture content reach 65%. The fermentation is carried out by turning and stirring, and the temperature is raised to 60℃ and maintained for 6 days to obtain the primary fermented product. (3) Activation of biological fermentation agent: Take the yellow blue bromide powder and inoculate it into LB liquid medium. The mass ratio of yellow blue bromide powder to LB liquid medium is 1:500. Add limonene and salicylic acid and activate at 32℃ for 28h to obtain biological fermentation liquid. (4) Secondary fermentation: The temperature of the pile of primary fermentation material is reduced to 30°C, activated biological fermentation liquid is added and mixed, static fermentation is adopted, the temperature is maintained at 30°C and the humidity is 45-, and fermentation is carried out for 8 days. During the period, the number of bacteria is monitored to ensure that the biocontrol bacteria become the dominant species and the secondary fermentation material is obtained. (5) Granulation: Add wood ash and soluble potassium silicate to the secondary fermentation product, adjust the pH to 6.0-7.5, transfer to a granulator for granulation, and then send to a dryer for drying. The moisture content is controlled below 5% to obtain organic fertilizer.

[0025] Example 3 Organic fertilizer ingredient ratio: 30 kg of corn stalks, 10 kg of rice husk charcoal, 0.5 kg of biological fermentation agent, 0.5 kg of limonene, 0.2 kg of salicylic acid, 20 kg of wood ash, 10 kg of shrimp shell powder, and 5 kg of soluble potassium silicate.

[0026] Organic fertilizer preparation process: (1) Acidification treatment of shrimp shell powder: Take shrimp shell powder, wash it and dry it at 60℃ for 5 hours. Soak it in dilute hydrochloric acid with a mass fraction of 4% at room temperature for 24 hours. After the reaction, filter it, wash it with water until neutral, and then dry it at 60℃ for 14 hours to obtain acidified shrimp shell powder. (2) Primary fermentation: Corn stalks, rice husk charcoal, and acidified shrimp shell powder are crushed to a particle size of <2cm, and water is added to make the moisture content reach 55%. The mixture is turned and fermented, and the temperature is raised to 70℃ and maintained for 4 days to obtain the primary fermented product. (3) Activation of biological fermentation agent: Take the yellow blue bromide powder and inoculate it into LB liquid medium. The mass ratio of yellow blue bromide powder to LB liquid medium is 1:500. Add limonene and salicylic acid and activate at 28℃ for 36h to obtain biological fermentation liquid. (4) Secondary fermentation: The temperature of the pile of primary fermentation material is reduced to 40°C, activated biological fermentation liquid is added and mixed, static fermentation is adopted, the temperature is maintained at 38°C and the humidity is 55%, and fermentation is carried out for 10 days. During the period, the number of bacteria is monitored to ensure that the biocontrol bacteria become the dominant species and the secondary fermentation material is obtained. (5) Granulation: Add wood ash and soluble potassium silicate to the secondary fermentation product, adjust the pH to 6.0-7.5, transfer to a granulator for granulation, and then send to a dryer for drying. The moisture content is controlled below 5% to obtain organic fertilizer.

[0027] Example 4 Organic fertilizer ingredient ratio: The ingredients, by weight, are: 45 kg corn stalks, 7 kg rice husk charcoal, 0.9 kg bio-fermentation agent, 0.25 kg limonene, 0.5 kg salicylic acid, 12 kg wood ash, 18 kg shrimp shell powder, and 9 kg soluble potassium silicate.

[0028] Organic fertilizer preparation process: (1) Acidification treatment of shrimp shell powder: Take shrimp shell powder, wash it and dry it at 75℃ for 7 hours. Soak it in dilute hydrochloric acid with a mass fraction of 4.5% at room temperature for 20 hours. After the reaction, filter it, wash it with water until neutral, and then dry it at 75℃ for 13 hours to obtain acidified shrimp shell powder. (2) Primary fermentation: Corn stalks, rice husk charcoal, and acidified shrimp shell powder are crushed to a particle size of <2cm, and water is added to make the moisture content reach 60%. The fermentation is carried out by turning and stirring, and the temperature is raised to 65℃ and maintained for 6 days to obtain the primary fermented product. (3) Activation of biological fermentation agent: Take the yellow blue bromide powder and inoculate it into LB liquid medium. The mass ratio of yellow blue bromide powder to LB liquid medium is 1:500. Add limonene and salicylic acid and activate at 29℃ for 33h to obtain biological fermentation liquid. (4) Secondary fermentation: The temperature of the pile of primary fermentation material is reduced to 36°C, activated biological fermentation liquid is added and mixed, static fermentation is adopted, the temperature is maintained at 35°C and the humidity is 48%, and fermentation is carried out for 9 days. During the period, the number of bacteria is monitored to ensure that the biocontrol bacteria become the dominant species and the secondary fermentation material is obtained. (5) Granulation: Add wood ash and soluble potassium silicate to the secondary fermentation product, adjust the pH to 6.0-7.5, transfer to a granulator for granulation, and then send to a dryer for drying. The moisture content is controlled below 5% to obtain organic fertilizer.

[0029] Example 5 Organic fertilizer ingredient ratio: The ingredients, by weight, are 35 kg of corn stalks, 4 kg of rice husk charcoal, 1.3 kg of biological fermentation agent, 0.4 kg of limonene, 0.3 kg of salicylic acid, 16 kg of wood ash, 13 kg of shrimp shell powder, and 7 kg of soluble potassium silicate.

[0030] Organic fertilizer preparation process: (1) Acidification treatment of shrimp shell powder: Take shrimp shell powder, wash it and dry it at 65℃ for 6 hours. Soak it in dilute hydrochloric acid with a mass fraction of 5.5% at room temperature for 22 hours. After the reaction, filter it, wash it with water until neutral, and then dry it at 65℃ for 12 hours to obtain acidified shrimp shell powder. (2) Primary fermentation: Corn stalks, rice husk charcoal, and acidified shrimp shell powder are crushed to a particle size of <2cm, and water is added to make the moisture content reach 60%. The fermentation is carried out by turning and stirring, and the temperature is raised to 70℃ and maintained for 6 days to obtain the primary fermented product. (3) Activation of biological fermentation agent: Take the yellow blue bromide powder and inoculate it into LB liquid medium. The mass ratio of yellow blue bromide powder to LB liquid medium is 1:500. Add limonene and salicylic acid and activate at 30℃ for 30h to obtain biological fermentation liquid. (4) Secondary fermentation: The temperature of the pile of primary fermentation material is reduced to 38°C, activated biological fermentation liquid is added and mixed, static fermentation is adopted, the temperature is maintained at 36°C and the humidity is 50%, and fermentation is carried out for 9 days. During the period, the number of bacteria is monitored to ensure that the biocontrol bacteria become the dominant species and the secondary fermentation material is obtained. (5) Granulation: Add wood ash and soluble potassium silicate to the secondary fermentation product, adjust the pH to 6.0-7.5, transfer to a granulator for granulation, and then send to a dryer for drying. The moisture content is controlled below 5% to obtain organic fertilizer.

[0031] Comparative Example 1: The difference compared to Example 1 is that rice husk charcoal is not used to increase the porosity of the fertilizer.

[0032] Comparative Example 2: The difference from Example 1 is that conventional Bacillus licheniformis is used for secondary fermentation, and limonene and salicylic acid are not added.

[0033] Comparative Example 3: The difference compared to Example 1 is that activated *Bacillus thymosa* powder is used for secondary fermentation, and limonene and salicylic acid are not added during the activation of the *Bacillus thymosa* powder.

[0034] Comparative Example 4: The difference compared to Example 1 is that conventional calcium oxide and potassium sulfate are used instead of shrimp shell powder and wood ash.

[0035] Comparative Example 5: The difference compared to Example 1 is that the shrimp shell powder used was not acidified.

[0036] Comparative Example 6: The difference compared to Example 1 is that soluble silica is not used.

[0037] Comparative Example 7: It is a commercially available traditional organic fertilizer, and its ingredients are 25-40 parts corn stalks, 10-25 parts livestock and poultry manure, 10-15 parts oil cake, 0.1-0.6 parts urea, and 0.1 parts composting agent.

[0038] Experiments were conducted on the above-described embodiments and comparative examples at the Fuding Dabai planting base in Fuquan City, Guizhou Province, using yellow loam soil. Each embodiment and comparative example involved transplanting 30 seedlings (approximately 60-70 days old), with a row spacing of 1.0m × 0.5m. Base fertilizer was applied before transplanting at a rate of 28 kg / mu, using deep application of cuttings. Topdressing was applied 15 days after transplanting, and a second topdressing was applied 35 days after the first, at a rate of 15 kg / mu. Topdressing was applied in two holes on both sides (25 ± 1 cm away from the tobacco plant). The soil physicochemical properties of the experimental field are shown in Table 1.

[0039] Table 1. Physicochemical properties of soil from the experimental field Experiment Example 1: Investigation of tobacco leaves' resistance to black shank disease The incidence and disease index of black shank disease were detected at the maturity stage of tobacco plants. The calculation method for the incidence of black shank disease is as follows: Incidence rate (%) = (Number of infected plants / Total number of plants surveyed) × 100 Number of diseased plants: refers to the number of tobacco plants in the survey sample that exhibit typical symptoms of tobacco black shank disease (such as black sunken lesions at the base of the stem, wilting of leaves, and plant death).

[0040] Disease index was determined according to the tobacco disease classification and survey methods in the Tobacco Industry Standard of the People's Republic of China: Grade 0: The entire plant is disease-free; Grade 1: Occasionally, there are chlorotic spots on the stem, or a few leaves wither on the side with stripes; Grade 2: Black streaks appear on the stem, but have not yet reached the top, or more than half of the leaves on the affected side wither; Grade 3: Black streaks on the stem reach the top of the plant, or more than 2 / 3 of the leaves on the diseased side wither; Grade 4: The diseased plant is basically dead.

[0041] Disease index = [∑(disease level × number of strains at this level) / (highest level × total number of strains)] × 100.

[0042] Prevention and control effect = (control disease index - treatment disease index) / control disease index × 100%.

[0043] The incidence and disease index of black shank disease in mature tobacco are shown in Table 2.

[0044] Table 2. Incidence and Disease Index of Tobacco Black Shank As can be seen from Table 2, the tobacco leaves cultivated using the organic fertilizer provided in Examples 1-5 of this invention have lower incidence and disease index of black shank disease than those in Comparative Examples 1-6. In particular, activated carbon can effectively increase the porosity of organic fertilizer, effectively adsorb harmful substances, and work synergistically with the *Bacillus thuringiensis* powder to effectively kill black shank disease. Limonene and salicylic acid can also significantly increase the antibacterial activity of *Bacillus thuringiensis* powder. The three work synergistically to achieve reliable control of tobacco black shank disease.

[0045] Experimental Example 2: Investigation of Agronomic Traits and Yield of Tobacco Leaves The tobacco plants grown in each embodiment and comparative example were investigated. At the tobacco maturity period, their height, number of leaves, maximum area of ​​functional leaves, and yield were measured. The average values ​​of height and number of leaves were taken, as shown in Table 3.

[0046] Table 2. Agronomical traits and yield of tobacco As can be seen from Table 3, the tobacco leaves cultivated using the organic fertilizer provided in Examples 1-5 of this invention have higher plant height, number of leaves, leaf area, and yield than those in Comparative Examples 1-6. This shows that the organic fertilizer prepared by this invention can significantly improve the quality and yield of tobacco while effectively controlling black shank disease.

Claims

1. An organic fertilizer specifically for controlling tobacco black shank disease, characterized in that: The raw materials of the organic special fertilizer, calculated by weight, consist of 30-50 parts corn stalks, 3-10 parts rice husk charcoal, 0.5-1.5 parts bio-fermentation agent, 0.2-0.5 parts limonene, 0.2-0.5 parts salicylic acid, 10-20 parts wood ash, 10-20 parts shrimp shell powder, and 5-15 parts soluble potassium silicate. The bio-fermentation agent is *Bacillus thuringiensis* powder.

2. The organic fertilizer according to claim 1, characterized in that: The raw materials of the organic fertilizer, calculated by weight, consist of 35-45 parts corn stalks, 5-8 parts rice husk charcoal, 0.7-1.2 parts bio-fermentation agent, 0.3-0.4 parts limonene, 0.3-0.4 parts salicylic acid, 12-18 parts wood ash, 12-18 parts shrimp shell powder, and 7-13 parts soluble potassium silicate. The bio-fermentation agent is *Bacillus thuringiensis* powder.

3. The organic fertilizer according to claim 1 or 2, characterized in that: The raw materials of the organic special fertilizer, calculated by weight, consist of 40 parts corn stalks, 6.5 parts rice husk charcoal, 1 part bio-fermentation agent, 0.35 parts limonene, 0.35 parts salicylic acid, 14-16 parts wood ash, 15 parts shrimp shell powder, and 10 parts soluble potassium silicate. The bio-fermentation agent is Bacillus thuringiensis powder.

4. The organic fertilizer according to any one of claims 1-3, characterized in that: The bacterial content of the *Bretschneidera sinensis* powder is 1.0-3.0 × 10⁻⁶. 10 cfu / g.

5. The method for preparing the organic-specific fertilizer according to any one of claims 1-4, characterized in that: The preparation method of the organic special fertilizer is carried out according to the following steps: (1) Acidification treatment of shrimp shell powder: Take shrimp shell powder, wash it and dry it at 60-80℃ for 5-8h, soak it in dilute hydrochloric acid with a mass fraction of 4-6% at room temperature for 18-24h, filter it after reaction, wash it with water until neutral, and then dry it at 60-80℃ for 12-14h to obtain acidified shrimp shell powder. (2) Primary fermentation: Crush corn stalks, rice husk charcoal and acidified shrimp shell powder to a particle size of <2cm, add water to make the moisture content reach 55-65%, use turning and stirring fermentation, raise the temperature to 60-70℃, maintain for 4-6 days to obtain primary fermented product; (3) Activation of biological fermentation agent: Take the yellow blue bromide powder and inoculate it into LB liquid medium, add limonene and salicylic acid, activate at 28-32℃ for 28-36h to obtain biological fermentation broth; (4) Secondary fermentation: Reduce the temperature of the pile of primary fermentation material to 30-40℃, add activated biological fermentation liquid and mix well. Use static fermentation, maintain the temperature at 30-38℃ and the humidity at 45-55%, and ferment for 8-10 days. During this period, monitor the number of bacteria to ensure that the biocontrol bacteria become the dominant species and obtain secondary fermentation material. (5) Granulation: Add wood ash and soluble potassium silicate to the secondary fermentation product, adjust the pH to 6.0-7.5, transfer to a granulator for granulation, and then send to a dryer for drying. The moisture content is controlled below 5% to obtain organic fertilizer.

6. The preparation method according to claim 5, characterized in that: In step (1), the shrimp shell powder is acidified: the shrimp shell powder is washed and dried at 70℃ for 6-7 hours, soaked in 5% dilute hydrochloric acid at room temperature for 20-22 hours, filtered after reaction, washed with water until neutral, and then dried at 70℃ for 13 hours to obtain the acidified shrimp shell powder.

7. The preparation method according to claim 5, characterized in that: In step (2), the first fermentation is carried out by crushing corn stalks, rice husk charcoal, and acidified shrimp shell powder into particles <2cm, adding water to make the moisture content reach 60%, and fermenting by turning and tossing, raising the temperature to 65℃ and maintaining it for 5 days to obtain the first fermented product.

8. The preparation method according to claim 5, characterized in that: In step (3), the bio-fermentation agent is activated: the yellow blue bromide powder is inoculated into LB liquid culture medium, the mass ratio of yellow blue bromide powder to LB liquid culture medium is 1:500, and limonene and salicylic acid are added. The mixture is activated at 30°C for 32 hours to obtain the activated bio-fermentation liquid.

9. The preparation method according to claim 5, characterized in that: In step (4), the secondary fermentation is carried out by lowering the temperature of the primary fermentation material pile to 33-38℃, adding activated biological fermentation liquid and mixing it, and using static fermentation to maintain the temperature at 33-38℃ and the humidity at 47-52% for 8-9 days. During this period, the number of bacteria is monitored to ensure that the biocontrol bacteria become the dominant species, and the secondary fermentation material is obtained.

10. The preparation method according to claim 9, characterized in that: In step (4), the secondary fermentation is carried out: after the primary fermentation, the temperature of the primary fermentation material is reduced to 35°C, the biological fermentation liquid is added and mixed, and static fermentation is carried out. The temperature is maintained at 35°C and the humidity is 50%. The fermentation lasts for 9 days, during which the number of bacteria is monitored to ensure that the biocontrol bacteria become the dominant species and the secondary fermentation material is obtained.

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