Efficient fermentation preparation method of microbial fertilizer

Abstract

The invention discloses an efficient fermentation preparation method of a microbial fertilizer, and belongs to the technical field of microbial fertilizers, and the method mainly comprises the following steps: crushing organic wastes to a proper particle size, mixing the crushed organic wastes with livestock and poultry manure, a mineral carrier, humic acid substances and a microbial agent, and adjusting the water content to form a fermentation base material; the method comprises the following steps: adding a complex enzyme preparation into a base material, inoculating a microbial inoculum composed of multiple functional microorganisms, adding a sugar-containing substance, carrying out stage temperature-controlled aerobic fermentation, and carrying out regular turning to obtain a completely decomposed material; and finally, granulating the decomposed material, and carrying out coating treatment by adopting a protective solution, so as to obtain the granular microbial fertilizer. Compared with the prior art, the method has the advantages that the conversion efficiency of organic matters and the activity of functional microorganisms are remarkably improved; the activity of the fungicide is effectively protected, nutrient release is delayed, and the final product has the comprehensive advantages of lasting fertilizer efficiency, crop growth promotion and soil improvement.

Description

Technical Field

[0001] This invention relates to the field of microbial fertilizer technology, and in particular to a highly efficient fermentation preparation method for microbial fertilizer. Background Technology

[0002] The efficient fermentation preparation of microbial fertilizers is a key step in improving their product quality and field application effects. Existing technologies typically involve pretreatment of organic materials (such as livestock manure and crop straw), inoculation with specific functional microbial agents, fermentation and maturation under certain conditions, and subsequent granulation and preservation. To improve fermentation efficiency, common practices include adding exogenous enzymes to promote organic matter degradation, using staged temperature control to guide microbial community succession, and using various carriers or encapsulation materials to process the fermentation products to protect microbial activity. However, how to achieve a comprehensive improvement from fermentation efficiency to product stability through synergistic optimization of material compatibility and process parameters remains a key direction for technological improvement in this field.

[0003] Among the existing technologies, CN120574093A discloses a bio-improving fertilizer for saline-alkali soil. It modifies cyclodextrin with amino acid surfactants and grafts it onto attapulgite to construct an organic-inorganic composite carrier, aiming to improve the tolerance of the microbial agent in saline-alkali environments and its ability to adsorb and fix sodium ions. While this technology has achieved beneficial results in specific application scenarios, its carrier construction method is relatively complex, and the technical solution focuses on solving specific problems in saline-alkali soil improvement, thus its universality needs to be strengthened. Another publication, CN120463570A, discloses a selenium-containing compound microbial fertilizer containing arbuscular mycorrhizal fungi. It utilizes selenium-rich straw, livestock manure, and yeast as multi-form selenium sources, relying on mycorrhizal fungi to promote selenium absorption and translocation. This technology focuses on the biofortification function of selenium, but its core lies in the coupling of selenium with specific mycorrhizae. It does not provide a systematic solution on how to optimize fermentation and protection processes to ensure the long-term coexistence and activity stability of multiple functional strains in the compound microbial fertilizer.

[0004] In summary, existing technologies for microbial fertilizer preparation still face several common challenges. First, the efficiency and stability of the fermentation process need improvement; insufficient organic matter conversion or poor control of dominant microbial populations can affect the quality of subsequent products. Second, the functional microorganisms in the finished fertilizer are easily deactivated by environmental stress during storage, transportation, and soil application; maintaining their high survival rate through economical and effective protection strategies is a pain point in the industry. Finally, many technical solutions focus only on achieving a single functional goal (such as for saline-alkali land or selenium-rich products), lacking an integrated preparation process that can comprehensively consider fermentation efficiency, microbial activity protection, and nutrient slow-release performance. Therefore, there is an urgent need in this field for a microbial fertilizer preparation method that can achieve efficient fermentation, ensure the long-term stability of microbial activity, and has broad applicability. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention aims to provide a highly efficient fermentation preparation method for microbial fertilizers that can improve fermentation efficiency, effectively ensure the activity of microbial agents, and enhance product stability.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] A highly efficient fermentation preparation method for microbial fertilizer is as follows:

[0008] Step 1: Mix the crushed corn stalks with pig manure, vermiculite, brewer's yeast, attapulgite soil, humic acid, and calcium humate, and adjust the moisture content to form a fermentation substrate;

[0009] Step 2: Add compound enzyme to the fermentation substrate of Step 1, inoculate with Bacillus mucilaginosus, Bacillus subtilis and Bacillus amyloliquefaciens and add sugar-containing substances, mix evenly and then transfer to fermentation to obtain mature material.

[0010] Step 3: Granulate the composted material obtained in Step 2 to form granules, and then spray the granules with a protective solution to obtain the microbial fertilizer.

[0011] Preferably, the efficient fermentation preparation method of the microbial fertilizer is as follows, in parts by weight:

[0012] Step 1: Select 400-500 parts of corn stalks, crush them to a particle size of 1-10mm, and mix them with 300-400 parts of pig manure, 60-90 parts of vermiculite, 20-40 parts of brewing yeast, 50-80 parts of attapulgite, 70-100 parts of humic acid, and 1-10 parts of calcium humate. Stir until uniform, and adjust the moisture content of the mixture to 38-45% by spraying water through atomization to form a fermentation substrate.

[0013] Step 2: Add 1-10 parts of compound enzyme to the fermentation substrate prepared in Step 1, then inoculate with 30-40 parts of Bacillus mucilaginosus, 15-25 parts of Bacillus subtilis and 15-30 parts of Bacillus amyloliquefaciens and add 30-45 parts of sugar-containing substance. Stir for 5-15 minutes and then transfer to the fermentation chamber for fermentation to obtain the decomposed material.

[0014] Step 3: After fermentation is complete, the composted material prepared in Step 2 is fed into a rotary granulator to produce particles with a diameter of 3-8 mm using the disc granulation method. The particles are then placed in a fluidized bed coating machine, with the inlet air temperature set to 40-50℃ and the air volume to 1-2 m³ / h. 3 Spray the protective solution evenly onto the granules at a rate of 80-150 mL / min for 10-30 minutes. The mass ratio of the protective solution to the granules is 0.5-2:8-12.

[0015] The complex enzyme is composed of cellulase, xylanase and papain in a mass ratio of 0.5-2:0.5-2:0.3-0.8.

[0016] In step 2, the fermentation is carried out by turning the pile every 1-3 days, with a fermentation cycle of 20-28 days. The fermentation temperature is set at 30-35℃ in the early stage of fermentation, 45-50℃ in the middle stage of fermentation, and 40-45℃ in the later stage of fermentation.

[0017] The protective solution is prepared as follows: weigh 3-8 parts of the protective substance, add 80-120 parts of water, stir for 10-20 minutes to obtain the protective solution.

[0018] The protective substance is at least one of 2-hydroxypropyl-β-cyclodextrin, sodium alginate, gum arabic, sodium carboxymethyl cellulose, konjac glucomannan, methyl-β-cyclodextrin, and γ-polyglutamic acid.

[0019] Preferably, the protective substance is composed of 2-hydroxypropyl-β-cyclodextrin and sodium alginate in a mass ratio of 1-3:2-4.

[0020] More preferably, the protective substance is composed of 2-hydroxypropyl-β-cyclodextrin, sodium alginate, and γ-polyglutamic acid in a mass ratio of 1-3:2-4:0.2-0.6.

[0021] The sugar-containing substance is at least one of pectin, glucose, sucrose, fructose, and cellulose.

[0022] Step 3 can also be prepared using the following method:

[0023] After fermentation, the composted material prepared in step 2 is fed into a rotary granulator to produce particles with a diameter of 3-8 mm using the disc granulation method. The particles are then placed in a fluidized bed coating machine, where a protective solution is sprayed evenly onto the particles. The mass ratio of the protective solution to the particles is 0.5-2:8-12, the spray rate is 80-150 mL / min, the inlet air temperature is set to 35-40℃ for 0-5 minutes, and the air volume is 1-1.3 m³ / min. 3 / min, rapidly wetting the particle surface; inlet air temperature 43-48℃, air volume 1.3-1.8m³ / min; 5-15 minutes. 3 / min, to promote initial curing of the film; 15-20 minutes, inlet air temperature 40-45℃, air volume 0.8-1.2m³ / min. 3 The microbial fertilizer is obtained by drying slowly at a rate of / min to avoid cracking of the membrane.

[0024] This invention incorporates calcium humate and a complex enzyme, along with an organic-inorganic composite carrier and sugar-containing substances, to guide microbial community succession through a stepped, temperature-controlled fermentation process. Finally, granulation and coating are used to protect microbial activity. Overall, it synergistically optimizes mass transfer, enzymatic hydrolysis, and microecology, aiming to achieve efficient organic matter conversion, dominant microbial colonization, and long-term functional release.

[0025] To protect the activity and nutrients of microorganisms through coating, this invention employs a two-component system of protective components to achieve complementary effects. The encapsulating component enhances microscopic encapsulation, while the gelling film-forming component enhances particle surface adhesion and water retention. Together, they synergistically improve the microenvironment and reduce stress losses, thereby amplifying the field effects of functional bacteria by improving survival rate and sustained-release performance.

[0026] Furthermore, the addition of γ-polyglutamic acid in this invention is based on its excellent water retention, film-forming, and adhesion properties. γ-polyglutamic acid helps promote biofilm formation and optimize the moisture gradient within particles, enhances cell adhesion and stress resistance, thereby prolonging the microbial activity release period and stabilizing the dominant community, achieving a more lasting biological effect.

[0027] To address the coating effect, this invention further improves the process to solve the problems of activity loss and film defects in large-scale production. A stepped air inlet temperature control is employed to precisely regulate the film curing rhythm, thereby ensuring deep conversion while obtaining mechanically stable microbial fertilizer granules with well-preserved activity.

[0028] Compared with the prior art, the present invention has the following beneficial technical effects:

[0029] 1) This invention significantly improves the composting efficiency and quality of organic waste by optimizing material compatibility and dynamic temperature control during the fermentation stage. This method promotes the dominant colonization of functional microorganisms, achieves efficient conversion and stabilization of organic matter, and provides a highly active and high-quality composting substrate for subsequent preparation.

[0030] 2) This invention significantly enhances the stability of functional microorganisms in fertilizer products during storage and application by constructing a composite protection system. This system can effectively alleviate the stress of adverse external environments on the microorganisms, greatly reduce the rate of viable bacteria decay, and thus ensure that microbial fertilizers maintain high biological activity during both shelf life and field application.

[0031] 3) The microbial fertilizer granules obtained by this invention have good physical strength and structural stability. Their coating layer effectively regulates the release rate of nutrients and microbial agents, preventing rapid loss and achieving synergistic slow release of nutrients and microorganisms, which helps prolong fertilizer effectiveness and improve utilization. Detailed Implementation

[0032] Some material parameters and their sources:

[0033] Bacillus mucilaginosus, effective viable count: 2×10 9 CFU / g, commercially available product, accession number: ACCC 19749, China Agricultural Microbial Culture Collection Center;

[0034] Bacillus subtilis, effective viable count: 1×10 9 CFU / g, commercially available product, accession number: ACCC 62258, China Agricultural Microbial Culture Collection Center;

[0035] Bacillus amyloliquefaciens, effective viable count: 1×10⁻⁶ 9 CFU / g, commercially available product, preservation number: ACCC 60428, China Agricultural Microbial Culture Collection Center.

[0036] Saccharomyces cerevisiae, effective viable count: 2.4 × 10⁻⁶ 9 CFU / g, commercially available product, preservation number: ACCC 21429, China Agricultural Microbial Culture Collection Center.

[0037] Cellulase, activity: 100,000 U / g;

[0038] Xylanase, activity: 10000 U / g;

[0039] Papain, activity: 100,000 U / g;

[0040] Corn stalks (dry basis): cellulose 35%, hemicellulose 20%, lignin 8%.

[0041] Pig manure (fresh): 65% moisture, 2.0% total nitrogen (dry basis).

[0042] Vermiculite: Particle size: 2-4mm.

[0043] Attapulgite: Particle size: 200 mesh.

[0044] In the embodiments and comparative examples of this invention, all raw materials are commercially available products.

[0045] Example 1

[0046] A highly efficient fermentation preparation method for microbial fertilizer is as follows, in parts by weight:

[0047] Step 1: Select 450 parts of corn stalks, crush them to a particle size of 2-6mm, and mix them with 350 parts of pig manure, 75 parts of vermiculite, 28 parts of brewing yeast, 68 parts of attapulgite, 85 parts of humic acid and 5 parts of calcium humate. Stir until uniform, and adjust the moisture content of the mixture to 42% by atomizing water spray to form a fermentation substrate.

[0048] Step 2: Add 5 parts of compound enzyme to the fermentation substrate prepared in Step 1, then inoculate with 35 parts of Bacillus mucilaginosus, 20 parts of Bacillus subtilis, and 22 parts of Bacillus amyloliquefaciens, and add 38 parts of sucrose. After stirring for 10 minutes, transfer to the fermentation chamber for fermentation. Turn the pile over every 2 days to maintain an aerobic environment. The fermentation cycle is 22 days. Set the fermentation temperature to 35℃ for 0-5 days, 48℃ for 6-15 days, and 42℃ for 16-22 days to obtain the decomposed material.

[0049] Step 3: After fermentation is complete, the composted material prepared in Step 2 is fed into a rotary granulator to produce 5mm diameter granules using the disc granulation method. The granules are then placed in a fluidized bed coating machine, with the inlet air temperature set to 45℃ and the air volume to 1.5m³. 3 The protective solution is sprayed evenly onto the granules at a rate of 120 mL / min for 20 minutes. The mass ratio of the protective solution to the granules is 1:10, thus obtaining the microbial fertilizer.

[0050] The complex enzyme is composed of cellulase, xylanase, and papain in a mass ratio of 1:1:0.5.

[0051] The protective solution is prepared as follows: by weight, weigh 5 parts of the protective substance, add 100 parts of water, stir for 15 minutes to obtain the protective solution.

[0052] The protective substance is 2-hydroxypropyl-β-cyclodextrin.

[0053] Example 2

[0054] The efficient fermentation preparation method of a microbial fertilizer is basically the same as that in Example 1, except that the protective substance is sodium alginate.

[0055] Example 3

[0056] The efficient fermentation preparation method of a microbial fertilizer is basically the same as that in Example 1, except that the protective substance is gum arabic.

[0057] Example 4

[0058] The efficient fermentation preparation method of a microbial fertilizer is basically the same as that in Example 1, except that the protective substance is sodium carboxymethyl cellulose.

[0059] Example 5

[0060] The efficient fermentation preparation method of a microbial fertilizer is basically the same as that in Example 1, except that the protective substance is konjac glucomannan.

[0061] Example 6

[0062] The efficient fermentation preparation method of a microbial fertilizer is basically the same as that in Example 1, except that the protective substance is methyl-β-cyclodextrin.

[0063] Example 7

[0064] The efficient fermentation preparation method of a microbial fertilizer is basically the same as that in Example 1, except that the protective substance is composed of 2-hydroxypropyl-β-cyclodextrin and sodium alginate in a mass ratio of 2:3.

[0065] Example 8

[0066] The efficient fermentation preparation method of a microbial fertilizer is basically the same as that in Example 1, except that the protective substance is composed of gum arabic and sodium carboxymethyl cellulose in a mass ratio of 2:3.

[0067] Example 9

[0068] The efficient fermentation preparation method of a microbial fertilizer is basically the same as that in Example 1, except that the protective substance is composed of 2-hydroxypropyl-β-cyclodextrin, sodium alginate and γ-polyglutamic acid in a mass ratio of 2:3:0.4.

[0069] Example 10

[0070] The efficient fermentation preparation method of a microbial fertilizer is basically the same as that in Example 9, except that the preparation method in step 3 is different.

[0071] Step 3: After fermentation, the composted material prepared in Step 2 is fed into a rotary granulator to produce 5mm diameter granules using the disc granulation method. The granules are then placed in a fluidized bed coating machine, where a protective solution is sprayed evenly onto the granules at a spray rate of 120mL / min. The mass ratio of the protective solution to the granules is 1:10. The inlet air temperature is set to 35℃ and the air volume to 1.2m³ / min for the first 0-5 minutes.3 / min, rapidly wetting the particle surface; 5-15 minutes, inlet air temperature 45℃, air volume 1.5m³ / min. 3 / min, to promote initial curing of the film; 15-20 minutes, inlet air temperature 42℃, air volume 1.0m³ / min. 3 The microbial fertilizer is obtained by drying slowly at a rate of / min to avoid cracking of the membrane.

[0072] The protective solution is the same as in Example 9.

[0073] Comparative Example 1

[0074] A highly efficient fermentation preparation method for microbial fertilizer is basically the same as that in Example 1, except that the protective substance is replaced with an equal amount of water.

[0075] Test Example 1

[0076] Microbial fertilizer effective viable bacteria count and survival rate test

[0077] Microbial fertilizers used in the implementation and comparative experiments were selected and placed in a constant temperature and humidity chamber at 40℃ and 75% relative humidity to start an accelerated aging experiment, with an experimental period of 30 days.

[0078] Viable cell count determination (plate count method): Samples were taken on day 0 and day 30. 1 g of sample was weighed and serially diluted in 99 mL of sterile water.

[0079] Inoculation and culture: 10 -5 The dilution was determined, and the sample was inoculated onto beef extract peptone agar plates and incubated at 37°C for 48 hours.

[0080] The number of viable bacteria at the end of the test and the initial number of viable bacteria were calculated using a colony counter, in units of CFU / g.

[0081] Survival rate = (number of viable bacteria at the end of the test / number of viable bacteria at the beginning) × 100%.

[0082] Each group was tested three times, and the average value was taken. The test results are shown in Table 1.

[0083] Table 1

[0084]

[0085] Test Example 2

[0086] Release stability test:

[0087] A 0.01 mol / L CaCl2 aqueous solution was used to simulate the salt ion intensity and calcium ion level in arid or semi-arid soils as a simulated soil solution.

[0088] 30g of each of the microbial fertilizers from the examples and comparative examples were selected, and the number of particles, n0, was counted. Each particle was placed in a conical flask containing 300mL of simulated soil solution. The conical flask was placed in a constant-temperature shaking incubator, with the temperature set at 25℃ and the rotation speed set at 60rpm (low-speed shaking simulates the slow erosion and infiltration of soil moisture). The number of particles, n, that remained unchanged (particles unable to pass through a 2mm sieve) was observed and recorded at 1h, 12h, 24h, and 48h after soaking. i Calculate the particle disintegration rate λ=(n0-n i ) / n0×100%.

[0089] Each group was tested three times, and the average value was taken. The relevant test data are summarized in Table 2.

[0090] Table 2

[0091]

[0092] This invention utilizes a fluidized bed process to construct a dense membrane on the particle surface, effectively blocking the direct attack of external extreme high temperature and high humidity environments on internal microorganisms. This protective layer not only acts as a physical barrier to slow down heat transfer, but also prevents spore-level strains from non-productive germination due to moisture absorption during storage by regulating the moisture balance of the internal microenvironment, thereby significantly extending the survival time of effective live bacteria.

[0093] Example 7 utilizes the molecular cavities of cyclodextrin to microscopically encapsulate spores, enhancing the thermal stability of the bacterial cells. Simultaneously, sodium alginate undergoes ion exchange with calcium ions released from the substrate, generating a calcium-alginate gel network in situ on the particle surface. This macromolecular cross-linked structure intercalates with the cyclodextrin inclusions, forming a multi-scale composite barrier that maintains bacterial count stability and significantly improves the particles' resistance to disintegration in aqueous solutions.

[0094] In Example 9, γ-polyglutamic acid, with its strong water-retention capacity and multi-functional molecular chains, filled the fine pores of the gel layer, enabling the membrane to transform from a loose network to a continuous and dense structure. This substance acts as a heat buffer at high temperatures and stabilizes the bacterial cell membrane through the biofilm effect in drought or saline environments. Experimental data show that the ternary system formed by γ-polyglutamic acid and the aforementioned components achieved a survival rate of 78.2%, demonstrating superior biocompatibility protection.

[0095] Example 10 precisely adjusted the water evaporation rate during film formation through stepped air intake temperature control. Initial low-temperature wetting ensured uniform spreading of the coating solution, mid-term medium-temperature curing initially built strength, and subsequent warm-up and slow drying eliminated thermal stress caused by rapid water loss within the film layer, preventing crack initiation. This defect-free interface structure significantly improved the physical properties of the coating layer, resulting in the lowest disintegration rate even under long-term scouring, achieving an optimal combination of viable bacterial protection and stable release.

Claims

1. A highly efficient fermentation preparation method for microbial fertilizer, characterized in that, The method is as follows: Step 1: Mix the crushed corn stalks with pig manure, vermiculite, brewer's yeast, attapulgite soil, humic acid, and calcium humate, and adjust the moisture content to form a fermentation substrate; Step 2: Add compound enzyme to the fermentation substrate of Step 1, inoculate with Bacillus mucilaginosus, Bacillus subtilis and Bacillus amyloliquefaciens and add sugar-containing substances, mix evenly and then transfer to fermentation to obtain mature material. Step 3: Granulate the composted material obtained in Step 2 to form granules, and then spray the granules with a protective solution to obtain the microbial fertilizer.

2. The efficient fermentation preparation method for microbial fertilizer as described in claim 1, characterized in that, The method is as follows, by weight: Step 1: Select 400-500 parts of corn stalks, crush them to a particle size of 1-10mm, and mix them with 300-400 parts of pig manure, 60-90 parts of vermiculite, 20-40 parts of brewing yeast, 50-80 parts of attapulgite, 70-100 parts of humic acid, and 1-10 parts of calcium humate. Stir until uniform, and adjust the moisture content of the mixture to 38-45% by spraying water through atomization to form a fermentation substrate. Step 2: Add 1-10 parts of compound enzyme to the fermentation substrate prepared in Step 1, then inoculate with 30-40 parts of Bacillus mucilaginosus, 15-25 parts of Bacillus subtilis and 15-30 parts of Bacillus amyloliquefaciens and add 30-45 parts of sugar-containing substance. Stir for 5-15 minutes and then transfer to the fermentation chamber for fermentation to obtain the decomposed material. Step 3: After fermentation is complete, the composted material prepared in Step 2 is fed into a rotary granulator to produce particles with a diameter of 3-8 mm using the disc granulation method. The particles are then placed in a fluidized bed coating machine, with the inlet air temperature set to 40-50℃ and the air volume to 1-2 m³ / h. 3 Spray the protective solution evenly onto the granules at a rate of 80-150 mL / min for 10-30 minutes. The mass ratio of the protective solution to the granules is 0.5-2:8-12.

3. The efficient fermentation preparation method for microbial fertilizer as described in claim 1 or 2, characterized in that, Step 3 can also be prepared using the following method: After fermentation, the composted material prepared in step 2 is fed into a rotary granulator to produce particles with a diameter of 3-8 mm using the disc granulation method. The particles are then placed in a fluidized bed coating machine, where a protective solution is sprayed evenly onto the particles. The mass ratio of the protective solution to the particles is 0.5-2:8-12, the spray rate is 80-150 mL / min, the inlet air temperature is set to 35-40℃ for 0-5 minutes, and the air volume is 1-1.3 m³ / min. 3 / min, rapidly wetting the particle surface; inlet air temperature 43-48℃, air volume 1.3-1.8m³ / min; 5-15 minutes. 3 / min, to promote initial curing of the film; 15-20 minutes, inlet air temperature 40-45℃, air volume 0.8-1.2m³ / min. 3 The microbial fertilizer is obtained by drying slowly at a rate of / min to avoid cracking of the membrane.

4. The efficient fermentation preparation method of microbial fertilizer as described in claim 1 or 2, characterized in that, The complex enzyme is composed of cellulase, xylanase and papain in a mass ratio of 0.5-2:0.5-2:0.3-0.

8.

5. The efficient fermentation preparation method for microbial fertilizer as described in claim 1 or 2, characterized in that, The sugar-containing substance is at least one of pectin, glucose, sucrose, fructose, and cellulose.

6. The efficient fermentation preparation method of microbial fertilizer as described in claim 1 or 2, characterized in that, In step 2, the fermentation is carried out by turning the pile every 1-3 days, with a fermentation cycle of 20-28 days. The fermentation temperature is set at 30-35℃ in the early stage of fermentation, 45-50℃ in the middle stage of fermentation, and 40-45℃ in the later stage of fermentation.

7. The efficient fermentation preparation method of microbial fertilizer as described in claim 1 or 2, characterized in that, The protective solution is prepared as follows: weigh 3-8 parts of the protective substance, add 80-120 parts of water, stir for 10-20 minutes to obtain the protective solution.

8. The efficient fermentation preparation method of microbial fertilizer as described in claim 7, characterized in that, The protective substance is at least one of 2-hydroxypropyl-β-cyclodextrin, sodium alginate, gum arabic, sodium carboxymethyl cellulose, konjac glucomannan, methyl-β-cyclodextrin, and γ-polyglutamic acid.

9. The efficient fermentation preparation method of microbial fertilizer as described in claim 7, characterized in that, The protective substance is composed of 2-hydroxypropyl-β-cyclodextrin and sodium alginate in a mass ratio of 1-3:2-4.

10. The efficient fermentation preparation method of microbial fertilizer as described in claim 7, characterized in that, The protective substance is composed of 2-hydroxypropyl-β-cyclodextrin, sodium alginate, and γ-polyglutamic acid in a mass ratio of 1-3:2-4:0.2-0.6.

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