Organic fertilizer for promoting plant growth and improving soil and preparation method thereof

Abstract

The invention discloses an organic fertilizer for promoting plant growth and improving soil and a preparation method thereof, and belongs to the technical field of organic fertilizers. The organic fertilizer is prepared from the following raw materials: composted chicken manure, soybean meal, straw powder, sweet potato vines, humic acid, a compound microbial agent, rosmarinic acid and a stimulant. The compound microbial agent is prepared from madula angustifolia actinomycetes, pseudomonas stutzeri and bacillus velezensis, and the stimulant is a glucosamine sulfate solution. The rosmarinic acid, the glucosamine sulfate solution and the compound microbial agent are added into the organic fertilizer, the three components are compounded with the straw, the chicken manure and the like to form the organic fertilizer, and various substances have a synergistic effect, so that on one hand, the growth of Chinese cabbages is promoted, and the yield is increased; on the other hand, soil physicochemical properties are obviously improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic fertilizers, and particularly relates to an organic fertilizer for promoting plant growth and soil improvement and a preparation method thereof. Background Art

[0002] Chinese cabbage is a crop of the genus Brassica in the family Brassicaceae and is one of the vegetable crops with the largest cultivation area in China. In the traditional production of Chinese cabbage, excessive application of chemical fertilizers has caused multiple problems such as reduced quality of Chinese cabbage, degradation of vegetable field soil, and environmental pollution due to long-term, continuous, and high-dose application of chemical fertilizers.

[0003] As an important factor in agricultural production, nitrogen fertilizer plays a key role in increasing crop yields and farmers' incomes. However, the phenomenon of excessive nitrogen application has been widespread in actual agricultural production in China. Problems such as soil compaction and low soil nutrient utilization efficiency caused by excessive fertilization are not conducive to the sustainable and healthy development of vegetable production. At the same time, it will also cause serious accumulation of nitrates in the soil and crops, which is harmful to human health. Organic fertilizers are rich in humus and microorganisms, can restore the soil aggregate structure, enhance the water and fertilizer retention capacity. In addition, organic fertilizers slowly release nutrients, reduce nitrate accumulation, improve the quality of Chinese cabbage, and at the same time enhance the safety of Chinese cabbage, meeting the needs of consumers for green and organic agricultural products. This has made people increasingly interested in bio-organic fertilizers, considering them potential substitutes for traditional chemical fertilizers. Bio-organic fertilizers are made from natural materials such as plant and animal manure and cause much less harm to the environment. Soil is the basis of agricultural production, and protecting soil health and improving soil fertility are crucial for agricultural production.

[0004] Therefore, how to rationally apply bio-organic fertilizers to replace nitrogen fertilizer in the production of Chinese cabbage is an urgent problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide an organic fertilizer for promoting plant growth and soil improvement, which can effectively promote the growth of Chinese cabbage, increase the yield, and improve the physical and chemical properties of the soil.

[0006] To achieve the above technical purpose, the technical solution adopted by the present invention is as follows:

[0007] An organic fertilizer for promoting plant growth and soil improvement, comprising the following raw materials in parts by weight: 35 - 40 parts of decomposed chicken manure, 15 - 20 parts of soybean meal, 10 - 20 parts of straw powder, 10 - 14 parts of sweet potato vine, 8 - 10 parts of humic acid, 5 - 8 parts of compound microbial inoculant, 2 - 3 parts of rosmarinic acid, and 1 - 3 parts of stimulant.

[0008] Further, the stimulant is a glucosamine sulfate solution with a concentration of 5 mg / L.

[0009] Further, the compound microbial inoculum is Actinomadura chibaensis, Pseudomonas stutzeri, and Bacillus velezensis with a mass ratio of 1:1:1.

[0010] Furthermore, the Actinomadura chibaensis is purchased from the China General Microbiological Culture Collection Center, with a preservation number of CGMCC 4.6236 and an original preservation date of March 9, 2008; the Pseudomonas stutzeri is purchased from the China Center for Type Culture Collection, with a preservation number of CCTCC AB 2012149 and an original preservation date of June 11, 2012; the Bacillus velezensis is purchased from the China Center for Type Culture Collection, with a preservation number of CCTCC AB 2012100 and an original preservation date of May 14, 2012.

[0011] Furthermore, the preparation method of the compound microbial inoculum is as follows:

[0012] Cultivate Actinomadura chibaensis, Pseudomonas stutzeri, and Bacillus velezensis in seed media at temperatures of 28°C, 30°C, and 35°C for 48 hours respectively, and then inoculate them into LB medium at an inoculation amount of 5% respectively, and cultivate until the bacterial concentration OD 600 = 3.0 to obtain three kinds of bacterial solutions. Mix the three kinds of bacterial solutions evenly according to the mass ratio of 1:1:1, and freeze-dry them into freeze-dried powder to obtain the compound microbial inoculum.

[0013] Further, the sweet potato vines are dried sweet potato vines. After the dried sweet potato vines are crushed, they are passed through a 60-mesh sieve.

[0014] A preparation method of an organic fertilizer for promoting plant growth and soil improvement is prepared by the following steps:

[0015] (1) Raw material mixing:

[0016] Mix the decomposed chicken manure, soybean meal, straw powder, and sweet potato vines evenly, and then add humic acid, sprinkle it while stirring, stir for 20

[0017] minutes until uniform, and finally add the compound microbial inoculum, rosmarinic acid, and stimulant and stir until uniform;

[0018] (2) Moisture adjustment and fermentation:

[0019] Adjust the mixture obtained in step (1) to a water content of 45 - 55%, pile it into a fermentation pile with a height of 1 - 1.5 meters, cover it with a breathable film, and ferment for two weeks. During this period, turn the pile over every 3 days;

[0020] (3) Granulation and drying:

[0021] Air-dry the fermented materials in step (2) until the water content reaches 18-20%, granulate them using a disk granulator, control the particle size to be 3-5 mm, then dry the granules using a dryer until the water content ≤ 10%, and naturally cool to room temperature to obtain the final product of organic fertilizer granules.

[0022] Furthermore, the application of the organic fertilizer of the present invention in Chinese cabbage cultivation.

[0023] All raw materials used in the present invention are commercially available.

[0024] The organic fertilizer of the present invention is added with a compound microbial inoculant, which is composed of Actinomadura chibaensis, Pseudomonas stutzeri, and Bacillus velezensis. Among them, Pseudomonas stutzeri secretes organic acids and phosphatases, converts insoluble phosphorus in the soil into soluble phosphorus for plant absorption, and induces systemic resistance, activates the plant immune system, and enhances disease resistance; Bacillus velezensis secretes growth-promoting substances, produces hormones such as indole acetic acid and gibberellin, promotes seed germination and root growth, can also dissolve insoluble phosphorus and potassium in the soil, improves nutrient availability, and at the same time helps plants resist stresses such as drought by synthesizing osmoprotectants such as proline. In addition, it secretes exopolysaccharides to promote the formation of soil aggregates, enhance air permeability and water retention; Actinomadura chibaensis can decompose complex organic substances, decompose plant residues by secreting cellulase, chitinase, etc., release nutrients such as nitrogen and phosphorus that can be utilized by plants. In addition, it produces the growth hormone indole acetic acid, stimulates the development of plant roots, enhances the nutrient absorption ability, and also has the ability of biological nitrogen fixation, which can convert nitrogen in the atmosphere into ammonium nitrogen and can be directly absorbed by plants. The compounding of the three strains has a synergistic effect, promotes plant growth, accelerates the decomposition of organic matter, promotes the formation of humus, and improves soil structure.

[0025] The organic fertilizer of the present invention also contains rosmarinic acid and glucosamine sulfate. Among them, rosmarinic acid, as a natural plant extract, contains abundant plant growth hormones, which can stimulate plant cell division and root development, thus promoting the overall growth of plants and increasing yields. At the same time, it has strong antioxidant properties, can scavenge free radicals in plants, and reduce oxidative stress damage. In addition, rosmarinic acid can serve as an energy source for soil microorganisms, promote the proliferation of beneficial microorganisms, enhance soil fertility. When the microbial fertilizer is used in combination with rosmarinic acid, the content of soluble phosphorus in the soil can be increased, and the nutrient absorption efficiency can be optimized. Rosmarinic acid has natural antibacterial and insecticidal properties, and its presence in compost can inhibit the growth of pathogenic bacteria, reduce the dependence on chemical pesticides, and thus maintain the soil ecological balance. Adding it to the organic fertilizer can reduce the risk of plants being invaded by pathogenic bacteria and pests. Glucosamine sulfate can stimulate plant cell division and elongation, accelerate seedling growth, make the crop leaves greener and thicker, and improve the photosynthesis efficiency. Glucosamine sulfate can promote the proliferation of beneficial microorganisms in the soil, accelerate the decomposition of organic matter and release nutrients, thus improving the soil structure, enhancing air permeability and water retention capacity, and creating better conditions for root growth. As a natural organic substance, glucosamine sulfate is non-toxic, has dual regulatory functions of medicine effect and fertilizer effect, can reduce the dependence on chemical pesticides and fertilizers, and can also effectively solve the problem of soil compaction.

[0026] Each of the other components selected in the present invention also has its own functions. Chicken manure and cow manure provide a high nitrogen content and promote leaf growth; soybean meal and straw powder increase the carbon-nitrogen ratio and prolong the fertilizer effect; microbial inoculants accelerate the decomposition of organic matter; humic acid enhances the water and fertilizer retention capacity of the soil.

[0027] Beneficial effects

[0028] The organic fertilizer of the present invention contains various beneficial microorganisms, rosmarinic acid, glucosamine sulfate and other components. The organic fertilizer obtained by compounding the above specific substances can, on the one hand, dissolve phosphorus, potassium and other compounds that are difficult for plants to absorb in the soil, promote plant nutrient absorption, improve the soil organic matter content, increase the soil aggregate structure, improve the soil water and fertilizer retention capacity, significantly improve the physical and chemical properties of the soil, and improve the fertilizer utilization rate; on the other hand, it can promote the growth of Chinese cabbage and increase the yield.

[0029] A large amount of agricultural waste is used in the preparation process of the organic fertilizer of the present invention, which not only solves the environmental pollution of agricultural waste but also utilizes it as resources, having both environmental and economic benefits. Specific embodiments

[0030] The technical solutions of the present invention will be further described below in conjunction with specific embodiments, but not limited thereto.

[0031] Example 1

[0032] An organic fertilizer for promoting plant growth and soil improvement, comprising the following raw materials in parts by weight: 35 parts of decomposed chicken manure, 15 parts of soybean meal, 10 parts of straw powder, 10 parts of sweet potato vines, 8 parts of humic acid, 5 parts of compound microbial inoculum, 2 parts of rosmarinic acid, and 1 part of stimulant.

[0033] The stimulant is a glucosamine sulfate solution with a concentration of 5 mg / L.

[0034] The compound microbial inoculum is Actinomadura chibaensis, Pseudomonas stutzeri, and Bacillus velezensis with a mass ratio of 1:1:1.

[0035] The preservation number of Actinomadura chibaensis is CGMCC 4.6236; the preservation number of Pseudomonas stutzeri is CCTCC AB 2012149; the preservation number of Bacillus velezensis is CCTCC AB 2012100.

[0036] The preparation method of the compound microbial inoculum is as follows:

[0037] Actinomadura chibaensis, Pseudomonas stutzeri, and Bacillus velezensis are respectively cultured in a seed medium at temperatures of 28 °C, 30 °C, and 35 °C for 48 h, and then inoculated into an LB medium at an inoculation amount of 5% respectively, and cultured until the bacterial concentration OD 600 = 3.0 to obtain three kinds of bacterial solutions. The three kinds of bacterial solutions are mixed evenly according to a mass ratio of 1:1:1 and freeze-dried into a freeze-dried powder to obtain a compound microbial inoculum.

[0038] The sweet potato vines are dry sweet potato vines. After the dry sweet potato vines are crushed, they are passed through a 60-mesh sieve.

[0039] A preparation method of an organic fertilizer for promoting plant growth and soil improvement is prepared by the following steps:

[0040] (1) Raw material mixing:

[0041] Mix the decomposed chicken manure, soybean meal, straw powder, and sweet potato vines evenly, and then add humic acid, sprinkle it while stirring, stir for 20

[0042] minutes until uniform, and finally add the compound microbial inoculum, rosmarinic acid, and stimulant and stir until uniform;

[0043] (2) Adjusting moisture and fermentation:

[0044] Adjust the mixture obtained in step (1) to a water content of 45-55%, pile it into a fermentation pile with a height of 1-1.5 meters, cover it with a breathable film, and ferment for two weeks, turning the pile over every 3 days during this period;

[0045] (3) Granulation and drying:

[0046] Dry the fermented materials from step (2) until the water content reaches 18 - 20%, granulate using a disc granulator, control the particle size to be 3 - 5 mm, then dry the granules using a dryer until the water content ≤ 10%, and naturally cool to room temperature to obtain the final product organic fertilizer granules.

[0047] Example 2

[0048] An organic fertilizer for promoting plant growth and soil improvement, comprising the following raw materials in parts by weight: 38 parts of decomposed chicken manure, 18 parts of soybean meal, 15 parts of straw powder, 12 parts of sweet potato vine, 9 parts of humic acid, 6 parts of compound microbial inoculant, 2 parts of rosmarinic acid, and 2 parts of stimulant.

[0049] The stimulant is a glucosamine sulfate solution with a concentration of 5 mg / L.

[0050] The compound microbial inoculant is Actinomadura chibaensis, Pseudomonas stutzeri, and Bacillus velezensis with a mass ratio of 1:1:1.

[0051] The preservation number of Actinomadura chibaensis is CGMCC 4.6236; the preservation number of Pseudomonas stutzeri is CCTCC AB 2012149; the preservation number of Bacillus velezensis is CCTCC AB 2012100.

[0052] The preparation method of the compound microbial inoculant is as follows:

[0053] Culture Actinomadura chibaensis, Pseudomonas stutzeri, and Bacillus velezensis in seed media at temperatures of 28 °C, 30 °C, and 35 °C for 48 h respectively, inoculate into LB medium at an inoculation amount of 5% respectively, and culture until the bacterial concentration OD 600 = 3.0 to obtain three kinds of bacterial solutions, mix the three kinds of bacterial solutions evenly according to the mass ratio of 1:1:1, and freeze-dry into freeze-dried powder to obtain the compound microbial inoculant.

[0054] The sweet potato vine is dry sweet potato vine. After the dry sweet potato vine is crushed, it is passed through a 60-mesh sieve.

[0055] A preparation method of an organic fertilizer for promoting plant growth and soil improvement is prepared by the following steps:

[0056] (1) Raw material mixing:

[0057] Mix the decomposed chicken manure, soybean meal, straw powder, and sweet potato vine evenly, then add humic acid, sprinkle it while stirring, stir for 20

[0058] minutes until uniform, and finally add the compound microbial inoculant, rosmarinic acid, and stimulant and stir until uniform;

[0059] (2) Adjust moisture and ferment:

[0060] Adjust the water content of the mixture obtained in step (1) to 45 - 55%, stack it into a fermentation pile with a height of 1 - 1.5 meters, cover it with a breathable film, and ferment for two weeks. During this period, turn the pile over every 3 days;

[0061] (3) Granulation and drying:

[0062] Dry the fermented material in step (2) until the water content reaches 18 - 20%, granulate it using a disc granulator, control the particle size to be 3 - 5 mm, and then use a dryer to dry the particles until the water content ≤ 10%, and naturally cool to room temperature to obtain the final product organic fertilizer particles.

[0063] Example 3

[0064] An organic fertilizer for promoting plant growth and soil improvement, comprising the following raw materials in parts by weight: 40 parts of decomposed chicken manure, 20 parts of soybean meal, 20 parts of straw powder, 14 parts of sweet potato vines, 10 parts of humic acid, 8 parts of compound microbial inoculant, 3 parts of rosmarinic acid, and 3 parts of stimulant.

[0065] The stimulant is a glucosamine sulfate solution with a concentration of 5 mg / L.

[0066] The compound microbial inoculant is Actinomadura chibaensis, Pseudomonas stutzeri, and Bacillus velezensis with a mass ratio of 1:1:1.

[0067] The preservation number of Actinomadura chibaensis is CGMCC 4.6236; the preservation number of Pseudomonas stutzeri is CCTCC AB 2012149; the preservation number of Bacillus velezensis is CCTCC AB 2012100.

[0068] The preparation method of the compound microbial inoculant is as follows:

[0069] Culture Actinomadura chibaensis, Pseudomonas stutzeri, and Bacillus velezensis in a seed medium at temperatures of 28 °C, 30 °C, and 35 °C for 48 hours respectively, inoculate them into an LB medium at an inoculation amount of 5% respectively, and culture until the bacterial concentration OD 600 = 3.0 to obtain three kinds of bacterial solutions, mix the three kinds of bacterial solutions evenly according to a mass ratio of 1:1:1, and freeze-dry them into freeze-dried powder to obtain the compound microbial inoculant.

[0070] The sweet potato vines are dry sweet potato vines. After the dry sweet potato vines are crushed, they are passed through a 60-mesh sieve.

[0071] A preparation method of an organic fertilizer for promoting plant growth and soil improvement is prepared by the following steps:

[0072] (1) Raw material mixing:

[0073] Mix the decomposed chicken manure, soybean meal, straw powder and sweet potato vines evenly, then add humic acid, sprinkle it in while stirring, stir for 20 minutes until it is evenly mixed, and finally add the composite microbial agent, rosmarinic acid and stimulant and stir until it is evenly mixed;

[0074] (2) Adjusting water content and fermentation:

[0075] The mixture obtained in step (1) is adjusted to have a moisture content of 45-55%, and piled into a fermentation pile with a height of 1-1.5 meters, covered with a breathable film, and fermented for two weeks, during which the pile is turned over every 3 days;

[0076] (3) Granulation and drying:

[0077] The fermented material in step (2) is aired to a moisture content of 18-20%, granulated by a disc granulator, the particle size of which is controlled to be 3-5 mm, and then dried by a dryer to a moisture content of ≤10%, and naturally cooled to room temperature to obtain the final product, organic fertilizer granules.

[0078] Comparative Example 1

[0079] Compared with Example 3, this comparative example is the same as Example 3 except that only Actinomycetes Madura chibaensis is used in the preparation process of the composite microbial agent. The other raw materials and steps are the same as those in Example 3.

[0080] Comparative Example 2

[0081] Compared with Example 3, this comparative example is the same as Example 3 except that only Pseudomonas stutzeri is used in the preparation process of the composite microbial agent. The other raw materials and steps are the same as those in Example 3.

[0082] Comparative Example 3

[0083] Compared with Example 3, this comparative example is the same as Example 3 except that only Bacillus Velezii is used in the preparation process of the composite microbial agent. The other raw materials and steps are the same as those in Example 3.

[0084] Comparative Example 4

[0085] Compared with Example 3, this comparative example is the same as Example 3 except that rosmarinic acid is not added during the preparation process. The other raw materials and steps are the same as those of Example 3.

[0086] Comparative Example 5

[0087] Compared with Example 3, this comparative example has the same raw materials and steps as Example 3 except that the stimulant glucosamine sulfate solution is not added during the preparation process.

[0088] Comparative Example 6

[0089] Compared with Example 3, this comparative example is the same as Example 3 except that rosmarinic acid and stimulant glucosamine sulfate solution are not added during the preparation process, and the other raw materials and steps are the same as Example 3.

[0090] Performance Testing

[0091] Planting experiment

[0092] The planting experiment was carried out in the company's experimental base. The tested variety was Beijing New No. 3. The cultivation method of Chinese cabbage was high-ridge cultivation, with a ridge height of 20 cm, a plant spacing of 60 cm × 46 cm, and a planting density of 3,000 plants per mu. 10 treatment groups were set up in the experiment: applying the organic fertilizers of Examples 1-3, Comparative Examples 1-6 respectively and no fertilization (control group). The fertilization amount of each treatment group was 1,500 kg per mu. Each treatment group had 3 replicates, totaling 30 plots. The plot area was 5 m × 6 m, and they were arranged in a randomized block design. Two weeks before transplanting, all fertilizers were applied as a one-time base fertilizer, and the field management measures such as irrigation during the Chinese cabbage growth season and field pest and disease control were the same. It was sown on August 10, 2023 and harvested on November 3, 2023.

[0093] Collection and determination of Chinese cabbage:

[0094] During the Chinese cabbage harvest period, 6 Chinese cabbage plants were randomly selected from each experimental plot. Among them, 4 plants were used for the determination of plant height and plant width, and the yield was calculated according to the total mass of the 4 Chinese cabbages. For the leaf heads of the other 2 Chinese cabbages, 1 / 4 of each was taken and homogenized with a blender to determine the quality of the Chinese cabbage. Among them, the soluble sugar content was determined by the anthrone-sulfuric acid colorimetric method, the soluble protein content was determined by the Coomassie brilliant blue G250 colorimetric method, and the nitrate content was determined by the phenoldisulfonic acid colorimetric method. The results of the above determination data are shown in Table 1.

[0095] Table 1 Results of agronomic traits, yield and quality of Chinese cabbage

[0096]

[0097] It can be seen from the data in Table 1 that after applying the organic fertilizers of Examples 1-3 of the present invention, the plant height, plant width and yield of Chinese cabbage were significantly increased, and the quality of Chinese cabbage was further improved. After applying the organic fertilizers of Comparative Examples 1-6 with changed formulation compositions, the agronomic traits, yield and quality of Chinese cabbage all decreased to varying degrees. Therefore, the three kinds of bacteria, Actinomadura madurae, Pseudomonas stutzeri, Bacillus velezensis, rosmarinic acid and glucosamine sulfate in the present invention are all core components of the present invention, and the effect will be weakened if any one is missing.

[0098] Collection and determination of soil samples:

[0099] During the harvesting period of Chinese cabbage, the 5-point sampling method was used to collect soil samples from the 0-20 cm soil layer in the test areas of each treatment group with a soil drill, and the soil organic matter, ammonium nitrogen, available phosphorus, and available potassium were measured. Among them, the organic matter content was measured by the external heating potassium dichromate oxidation method, the soil ammonium nitrogen content was measured by a continuous flow analyzer after extraction with 1 mol / L KCl solution, the soil available phosphorus content was measured by colorimetry after extraction with 0.5 mol / L NaHCO3, and the soil available potassium content was measured by a flame photometer after extraction with 1 mol / L NH4OAc solution. The results of the above measurement data are shown in Table 2.

[0100] Table 2 Soil physical and chemical properties

[0101]

[0102] As can be seen from the data in Table 2, the physical and chemical properties of the soil were improved after applying the organic fertilizer of the embodiment of the present invention. Specifically, applying the organic fertilizer of the present invention can increase the contents of soil ammonium nitrogen, available phosphorus, available potassium, and organic matter. Ammonium nitrogen is an important mineralized nitrogen in the soil, which can be directly or converted into nitrate nitrogen and absorbed and utilized by plants. It is an important measure of soil fertility and an important nitrogen source for crop growth. As can be seen from the data in Table 2, after applying the organic fertilizer of the present invention, the soil ammonium nitrogen content increased significantly; available phosphorus can reflect the total amount of phosphorus that can be released currently and in the future. As can be seen from Table 2, after applying the organic fertilizer of the present invention and planting Chinese cabbage, there is still a large amount of phosphorus reserves in the soil; available potassium is also an important indicator of soil fertility. As can be seen from the data in Table 2, after applying the organic fertilizer of the present invention, the available potassium content in the soil increased significantly compared with the blank control. From the above data, it can be seen that the organic fertilizer of the present invention can improve the physical and chemical properties of the soil.

[0103] It should be noted that the above embodiments are only some embodiments of the preferred ways to implement the present invention, rather than all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

Claims

1. An organic fertilizer for promoting plant growth and soil improvement, characterized in that: The invention comprises the following raw materials in parts by weight: 35-40 parts of decomposed chicken manure, 15-20 parts of soybean meal, 10-20 parts of straw powder, 10-14 parts of sweet potato vine, 8-10 parts of humic acid, 5-8 parts of composite microbial agent, 2-3 parts of rosmarinic acid and 1-3 parts of stimulant.

2. The organic fertilizer for promoting plant growth and soil improvement according to claim 1, characterized in that: The stimulant is a glucosamine sulfate solution with a concentration of 5 mg / L.

3. The organic fertilizer for promoting plant growth and soil improvement according to claim 1, characterized in that: The composite microbial agent comprises Actinomyces chibaensis, Pseudomonas stutzeri and Bacillus velez in a mass ratio of 1:1:

1.

4. The organic fertilizer for promoting plant growth and soil improvement according to claim 3, characterized in that: The deposit number of the Actinomycetes Madura chibae is CGMCC4.6236; the deposit number of the Pseudomonas stutzeri is CCTCC AB2012149; and the deposit number of the Bacillus velez is CCTCC AB 2012100.

5. The organic fertilizer for promoting plant growth and soil improvement according to claim 3, characterized in that: The preparation method of the composite microbial agent is as follows: Chiba Actinomyces, Pseudomonas stutzeri, and Bacillus velezensis were cultured in seed culture medium at 28°C, 30°C, and 35°C for 48 h, respectively, and inoculated into LB culture medium at a 5% inoculum, and cultured until the bacterial concentration OD 600 =3.0 to obtain three bacterial liquids, which were evenly mixed in a mass ratio of 1:1:1, and freeze-dried into freeze-dried powder to obtain a composite microbial agent.

6. The organic fertilizer for promoting plant growth and soil improvement according to claim 1, characterized in that: The sweet potato vines are dry sweet potato vines, which are crushed and passed through a 60-mesh sieve.

7. A method for preparing an organic fertilizer for promoting plant growth and improving soil according to any one of claims 1 to 6, characterized in that: Prepared by the following steps: (1) Raw material mixing: Mix the decomposed chicken manure, soybean meal, straw powder and sweet potato vines evenly, then add humic acid, sprinkle it in while stirring, stir for 20 minutes until it is evenly mixed, and finally add the composite microbial agent, rosmarinic acid and stimulant and stir until it is evenly mixed; (2) Adjusting water content and fermentation: The mixture obtained in step (1) is adjusted to have a moisture content of 45-55%, and piled into a fermentation pile with a height of 1-1.5 meters, covered with a breathable film, and fermented for two weeks, during which the pile is turned over every 3 days; (3) Granulation and drying: The fermented material in step (2) is aired to a moisture content of 18-20%, granulated by a disc granulator, the particle size of which is controlled to be 3-5 mm, and then dried by a dryer to a moisture content of ≤10%, and naturally cooled to room temperature to obtain the final product, organic fertilizer granules.

Images