Microbial organic fertilizer for promoting growth and disease resistance and preparation method thereof

Abstract

This invention belongs to the field of functional fertilizer technology, specifically relating to a growth-promoting and disease-resistant microbial organic fertilizer and its preparation method. The method includes the following steps: preparation of a disease-resistant organic complex; pretreatment of the fermentation substrate; and composting fermentation preparation of the organic liquid fertilizer. This invention uses scandium ions as rare-earth coordination centers and resaegus pinnatifida as an organic ligand, and prepares the disease-resistant organic complex through an alkaline activation-assisted alcohol-thermal coordination method. The scandium ions in this complex can stimulate cell growth and enhance the biological activity of defense enzymes in crops. The resaegus pinnatifida ligand itself has electron shuttle function and can participate in redox signal transduction within the crop. The complex formed after coordination with scandium ions can effectively activate defense enzymes in wheat, including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT). The synergistic effect of both significantly improves wheat's resistance to sheath blight, powdery mildew, and leaf rust.

Description

Technical Field

[0001] This invention belongs to the field of functional fertilizer technology, specifically relating to a growth-promoting and disease-resistant microbial organic fertilizer and its preparation method. Background Technology

[0002] Wheat is one of the most widely planted and highest-yielding grain crops globally. Throughout its growth cycle, it is susceptible to various soil-borne and seed-borne diseases, among which root rot caused by Fusarium, sheath blight caused by Rhizoctonia, powdery mildew, and Fusarium head blight are particularly serious. For a long time, the control of these diseases has mainly relied on chemical fungicides and seed dressings. However, the overuse of chemical agents has not only led to increasing pathogen resistance and a continuous decline in control efficacy, but has also severely damaged the beneficial microbial community structure in the rhizosphere soil, causing soil microecological imbalance and triggering a series of problems such as pesticide and veterinary drug residues and environmental pollution. Utilizing organic fertilizers as a carrier and introducing active components with growth-promoting and disease-resistant functions to develop multifunctional microbial organic fertilizers that combine nutrient supply, growth promotion, and disease control has become an important technical approach to reduce chemical inputs and ensure stable and increased crop yields.

[0003] However, existing growth-promoting and disease-resistant fertilizer products and related technologies still have several significant shortcomings. Firstly, in terms of growth-promoting and disease-resistant functional materials, most commonly used ones are simple combinations of conventional plant growth regulators and common trace elements, or a few rare earth complexes that have been widely reported. These complexes have limited room for innovation in composition and relatively simple mechanisms of action, making it difficult to simultaneously achieve multiple disease-resistant functions such as inducing systemic resistance in plants and enhancing physical defense barriers. Furthermore, in terms of functional microorganisms, the strains used are mostly concentrated in a few strains commonly used in agricultural production, such as Bacillus and yeast. There is a lack of specific strain combinations that can efficiently degrade complex organic substrates, transform special biomass, and eliminate toxic components, resulting in low fermentation efficiency, poor adaptability to unconventional organic raw materials, and a limited range of usable raw materials. This, in turn, limits the ways to prepare highly efficient growth-promoting and disease-resistant fertilizers. The functions of the prepared products are often relatively simple, and the growth-promoting and disease-resistant effects fail to form a good synergy, resulting in poor overall performance. Summary of the Invention

[0004] To address the aforementioned technical deficiencies, this invention presents a growth-promoting and disease-resistant microbial organic fertilizer and its preparation method. The prepared growth-promoting and disease-resistant microbial organic fertilizer can effectively improve the growth-promoting and disease-resistant capabilities of crops such as wheat, meeting the comprehensive needs of modern agricultural green and efficient production.

[0005] A method for preparing a growth-promoting and disease-resistant microbial organic fertilizer includes the following steps:

[0006] S1: Preparation of disease-resistant organic complexes

[0007] A scandium chloride solution and an activated resazurin alkaline alcohol solution were prepared. The scandium chloride solution was added to the activated resazurin alkaline alcohol solution under stirring. The precipitate was collected, washed, freeze-dried, and then pulverized to obtain the disease-resistant organic complex.

[0008] S2: Pretreatment of fermentation substrate

[0009] The prickly nightshade is dried and chopped to obtain prickly nightshade segments. The empty fruit clusters of oil palm are crushed to obtain crushed oil palm empty fruit clusters. Then, the prickly nightshade segments, crushed oil palm empty fruit clusters and sheep manure are spread out, and while turning and mixing, a sophorolipid solution is added to adjust the moisture content to obtain a mixed fermentation substrate.

[0010] S3: Composting and fermentation preparation of organic liquid fertilizer

[0011] The culture solutions of *Bacillus brevis*, *Termitomyces vulgaris*, and *Enterococcus avium* were mixed evenly to obtain a mixed bacterial solution. The mixed bacterial solution was sprayed onto the mixed fermentation substrate, and urea, superphosphate, potassium sulfate, calcium carbonate, zinc sulfate, and ferrous sulfate were added and stirred evenly. After fermentation, fermented material was obtained. The fermented material was extracted with purified water and filtered twice to obtain organic liquid fertilizer. Disease-resistant organic compound, guar gum, xanthan gum, and glucose were added to the organic liquid fertilizer and stirred evenly to obtain a growth-promoting and disease-resistant microbial organic fertilizer.

[0012] Furthermore, the preparation of the disease-resistant organic complex in step S1 includes the following steps:

[0013] S1.1: Place scandium chloride in a container, add an aqueous ethanol solution with a volume fraction of 70-75%, and stir until the scandium chloride is completely dissolved to prepare a scandium chloride alcohol solution with a scandium ion concentration of 0.2-0.5 mol / L;

[0014] S1.2: Dissolve resamaritan in an 85-90% (v / v) aqueous ethanol solution to prepare a resamaritan alcohol solution with a concentration of 0.8-1 mol / L. Slowly add 1-2 mol / L NaOH aqueous solution to the resamaritan alcohol solution at a molar ratio of 1:(2-3) of resamaritan to NaOH. Stir at 150-200 rpm for 40-60 min to obtain an activated resamaritan alkaline alcohol solution.

[0015] S1.3: Under the conditions of stirring at 40-50℃ and 200-250rpm, scandium chloride solution is added to activated resveratrol basic alcohol solution, and then the reaction is continued to be stirred for 2-2.5h. The precipitate is collected by filtration, washed 2-3 times with distilled water, and then freeze-dried at -50 to -70℃. The precipitate is then pulverized through a 200-300 mesh sieve to obtain the disease-resistant organic complex.

[0016] Furthermore, the pretreatment of the fermentation substrate in step S2 includes the following steps:

[0017] S2.1: Dry the whole plant of Solanum nigrum until the moisture content is 50-70%, chop it into 1-5cm pieces with a chopper to obtain Solanum nigrum chopped pieces, put the empty fruit clusters of oil palm into a pulverizer, pulverize them through a 100-mesh sieve to obtain the pulverized empty fruit clusters of oil palm.

[0018] S2.2: On a clean plastic sheet, evenly spread the crushed empty fruit bunches of oil palm as the bottom layer, then evenly spread a layer of sheep manure on top, and finally evenly spread the cut segments of Solanum nigrum as the top layer. The mass ratio of crushed empty fruit bunches of oil palm, sheep manure and cut segments of Solanum nigrum is 1:(0.3-0.5):(0.5-0.7). Then, use an iron shovel to stir the three layers of materials from one side to the other, while adding sophoryl ester aqueous solution until they are mixed evenly to obtain the mixed fermentation substrate.

[0019] Furthermore, step S3, the composting and fermentation preparation of organic liquid fertilizer, includes the following steps:

[0020] S3.1: *Bacillus brevis*, *Termitomyces vulgaris*, and *Enterococcus avium* were cultured separately in culture media until the logarithmic growth phase, with a viable count of 1 × 10⁻⁶. 9 CFU / g was used to obtain soil brevicorbacterium, var. mutagenesis, and avian enterococcus. The soil brevicorbacterium, var. mutagenesis, and avian enterococcus were mixed evenly at a volume ratio of 1:(0.5-0.6):(0.3-0.4) to obtain a mixed bacterial solution.

[0021] S3.2: Spray mixed bacterial solution into the mixed fermentation substrate, and add urea, superphosphate, potassium sulfate, calcium carbonate, zinc sulfate and ferrous sulfate. Stir evenly and carry out composting fermentation. The fermentation time is 50-60 days. During the fermentation period, turn the compost every 7 days to obtain fermented material.

[0022] S3.3: Mix the fermented material with purified water at a mass ratio of 1:(5-6) and stir evenly. After soaking for 24-30 hours, filter to separate the solid residue and fermentation liquid. Then, use 21-32 thread count gauze to further filter the fermentation liquid to obtain organic liquid fertilizer. Based on the mass of organic liquid fertilizer, add 0.2-0.3% disease-resistant organic compound, 0.1-0.2% guar gum, 0.05-0.1% xanthan gum and 0.03-0.05% glucose to the organic liquid fertilizer. Stir at a stirring speed of 200-300 rpm for 25-30 minutes to obtain a growth-promoting and disease-resistant microbial organic fertilizer.

[0023] Further, in step S1.3, the volume ratio of scandium chloride solution to activated resamarium alkaline alcohol solution is 1:(1.3-1.5).

[0024] Furthermore, in step S2.2, the mass concentration of the sophorolipid aqueous solution is 0.3-0.5%, and the final moisture content of the mixture after adding the sophorolipid aqueous solution is 55-65%.

[0025] Furthermore, the *Bacillus brevis* in step S3.1 is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC1.3103 and cultured on CM0002 nutrient gravy agar; *Termitomyces vulgaris* is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC1.8372 and cultured on tryptophan-soybean agar; and *Enterococcus avium* is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC1.2505 and cultured on MRS medium.

[0026] Further, in step S3.2, based on the mass of the mixed fermentation substrate, the mixed bacterial solution accounts for 0.8-1%, urea accounts for 1.5-2%, superphosphate accounts for 2-2.5%, potassium sulfate accounts for 1.5-2%, calcium carbonate accounts for 1-1.5%, zinc sulfate accounts for 0.1-0.2%, and ferrous sulfate accounts for 0.1-0.2%.

[0027] A growth-promoting and disease-resistant microbial organic fertilizer is prepared by the above-mentioned method for preparing a growth-promoting and disease-resistant microbial organic fertilizer.

[0028] The beneficial effects are as follows: 1. This invention uses scandium ions as rare earth coordination centers and resaegus pinnatifida as an organic ligand to prepare a disease-resistant organic complex via an alkaline activation-assisted alcohol-thermal coordination method. The scandium ions in this complex can stimulate cell growth and enhance the bioactivity of defense enzymes in crops. The resaegus pinnatifida ligand itself has electron shuttle function and can participate in redox signal transduction within crops. The complex formed after coordination with scandium ions can effectively activate defense enzymes in wheat, including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT). The synergistic effect of both significantly improves wheat's resistance to sheath blight, powdery mildew, and leaf rust.

[0029] 2. This invention employs three specific bacterial strains with complementary functions for synergistic fermentation to prepare organic liquid fertilizer. This process efficiently transforms mixed fermentation substrate into a liquid fertilizer rich in bioactive substances, significantly promoting the growth and development of crops such as wheat. *Bacillus brevis* has a strong ability to degrade cellulose and pectin, efficiently decomposing complex polysaccharides in empty fruit clusters of oil palm and *Solanum nigrum* during the high-temperature stage of composting, releasing small-molecule nutrients that can be absorbed and utilized by plants. *Termite mutata* can convert livestock waste such as sheep manure into nutrient molecules. Furthermore, its β-glucosidase, in conjunction with rhamnosidase produced by *Enterococcus avium*, effectively degrades solanine in *Solanum nigrum* during fermentation. The three bacterial agents, compounded in a specific volume ratio, work synergistically, playing a leading role in different stages of composting fermentation. The resulting organic liquid fertilizer not only contains inorganic nutrients such as nitrogen, phosphorus, potassium, and trace elements, but is also rich in bioactive components such as humic acid, free amino acids, and microbial metabolites. After application, these active substances can sustainably improve the rhizosphere microecological environment of crops, promote the proliferation of beneficial bacteria, enhance root vitality, and promote crop growth.

[0030] 3. This invention uses a combination of three organic materials—Solanum nigrum, sheep manure, and hollow fruit clusters of oil palm—as a fermentation substrate. This achieves resource utilization of waste while endowing the organic liquid fertilizer with unique nutrient characteristics and biological activity. Solanum nigrum, as an invasive plant, has a large biomass and wide distribution; using it as a fertilizer raw material can achieve the ecological governance goal of "turning a pest into a treasure." This application utilizes rhamnosidase produced by Enterococcus avium to effectively degrade solanine, converting the abundant organic nitrogen in Solanum nigrum into readily available nutrients beneficial to crops such as wheat. Sheep manure contains abundant organic matter and trace elements; after treatment with *Terminus mutata*, it can promote the composting and humification process, improving the maturity and nutrient availability of the organic fertilizer product. Hollow fruit clusters of oil palm have a high cellulose content. With the assistance of sophorolipids, the three materials achieve uniform mixing and full penetration, forming an organic fertilizer substrate with excellent physicochemical properties after composting and fermentation. The resulting liquid fertilizer, obtained through extraction, combines readily available nutrients and organic matter. Organic liquid fertilizer prepared using this as a fermentation substrate can significantly improve crop growth. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the preparation method of growth-promoting and disease-resistant microbial organic fertilizer used in embodiments of the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that the *Bacillus brevis* in the following examples is deposited at the China General Microbiological Culture Collection Center (CGMCC) under accession number CGMCC1.3103 and cultured on CM0002 nutrient gravy agar; *Termitomyces vulgaris* is deposited at the China General Microbiological Culture Collection Center (CGMCC) under accession number CGMCC1.8372 and cultured on tryptophan-soybean agar; and *Enterococcus avium* is deposited at the China General Microbiological Culture Collection Center (CGMCC) under accession number CGMCC1.2505 and cultured on MRS medium.

[0034] Example 1

[0035] A growth-promoting and disease-resistant microbial organic fertilizer and its preparation method, such as Figure 1 As shown, it includes the following steps:

[0036] S1: Preparation of disease-resistant organic complexes

[0037] S1.1: Place scandium chloride in a container, add 70% (v / v) ethanol aqueous solution and stir until scandium chloride is completely dissolved to prepare a scandium chloride alcohol solution with a scandium ion concentration of 0.2 mol / L;

[0038] S1.2: Dissolve reamarine in an 85% (v / v) aqueous ethanol solution to prepare a reamarine alcohol solution with a concentration of 0.8 mol / L. Slowly add 1 mol / L NaOH aqueous solution to the reamarine alcohol solution at a molar ratio of 1:2 (reamarine to NaOH). Stir at 150 rpm for 40 min to obtain an activated reamarine alkaline alcohol solution.

[0039] S1.3: Under the conditions of stirring at 40℃ and 200 rpm, scandium chloride solution was added to activated resazurin basic alcohol solution, with a volume ratio of scandium chloride solution to activated resazurin basic alcohol solution of 1:1.3. The reaction was then stirred for 2 hours. The precipitate was collected by filtration, washed twice with distilled water, and then freeze-dried at -70℃. The precipitate was then pulverized through a 200-mesh sieve to obtain the disease-resistant organic complex.

[0040] S2: Pretreatment of fermentation substrate

[0041] S2.1: Dry the whole plant of Solanum nigrum until the moisture content is 50%, chop it into 1-5cm pieces with a chaff cutter to obtain Solanum nigrum chopped pieces, place the empty fruit clusters of oil palm in a pulverizer, pulverize them through a 100-mesh sieve to obtain the pulverized empty fruit clusters of oil palm.

[0042] S2.2: On a clean plastic sheet, evenly spread the crushed empty fruit bunches of oil palm as the bottom layer, then evenly spread a layer of sheep manure on top, and finally evenly spread the cut segments of Solanum nigrum as the top layer. The mass ratio of crushed empty fruit bunches of oil palm, sheep manure and cut segments of Solanum nigrum is 1:0.3:0.5. Then, use an iron shovel to stir the three layers of materials from one side to the other, while adding a sophorolipid aqueous solution until they are evenly mixed. The mass concentration of the sophorolipid aqueous solution is 0.3%. After adding the sophorolipid aqueous solution, the final moisture content of the mixture is 55%, thus obtaining the mixed fermentation substrate.

[0043] S3: Composting and fermentation preparation of organic liquid fertilizer

[0044] S3.1: *Bacillus brevis*, *Termitomyces vulgaris*, and *Enterococcus avium* were cultured separately in culture media until the logarithmic growth phase, with a viable count of 1 × 10⁻⁶. 9 CFU / g, obtained soil brevicorbacterium, termite variant, and enterococcus avianus bacterial solutions, mixed in a volume ratio of 1:0.5:0.3 to obtain a mixed bacterial solution;

[0045] S3.2: Spray mixed bacterial solution into the mixed fermentation substrate, and add urea, superphosphate, potassium sulfate, calcium carbonate, zinc sulfate and ferrous sulfate. Based on the mass of the mixed fermentation substrate, the mixed bacterial solution accounts for 0.8%, urea accounts for 1.5%, superphosphate accounts for 2%, potassium sulfate accounts for 1.5%, calcium carbonate accounts for 1%, zinc sulfate accounts for 0.1% and ferrous sulfate accounts for 0.1%. Stir evenly and carry out composting fermentation. The fermentation time is 50 days. During the fermentation period, the compost is turned over every 7 days to obtain fermented material.

[0046] S3.3: Mix the fermentation material with purified water at a mass ratio of 1:5 and stir evenly. After soaking for 24 hours, filter to separate the solid residue and fermentation liquid. Then, use 21-count or 32-count gauze to further filter the fermentation liquid to obtain organic liquid fertilizer. Based on the mass of organic liquid fertilizer, add 0.2% disease-resistant organic compound, 0.1% guar gum, 0.05% xanthan gum and 0.03% glucose to the organic liquid fertilizer. Stir at 200 rpm for 25 minutes to obtain a growth-promoting and disease-resistant microbial organic fertilizer.

[0047] Example 2

[0048] A growth-promoting and disease-resistant microbial organic fertilizer and its preparation method, such as Figure 1 As shown, it includes the following steps:

[0049] S1: Preparation of disease-resistant organic complexes

[0050] S1.1: Place scandium chloride in a container, add 72% (v / v) ethanol aqueous solution and stir until scandium chloride is completely dissolved to prepare a scandium chloride alcohol solution with a scandium ion concentration of 0.3 mol / L.

[0051] S1.2: Dissolve resamarimine in an 88% (v / v) aqueous ethanol solution to prepare a resamarimine alcohol solution with a concentration of 0.9 mol / L. Slowly add 1.5 mol / L NaOH aqueous solution to the resamarimine alcohol solution at a molar ratio of 1:2.5 for resamarimine to NaOH. Stir at 180 rpm for 50 min to obtain an activated resamarimine alkaline alcohol solution.

[0052] S1.3: Under the conditions of stirring at 45℃ and 225 rpm, scandium chloride solution was added to activated resazurin basic alcohol solution, with a volume ratio of scandium chloride solution to activated resazurin basic alcohol solution of 1:1.4. The reaction was then stirred for 2.2 h. The precipitate was collected by filtration, washed three times with distilled water, and then freeze-dried at -60℃. The precipitate was then pulverized through a 200-mesh sieve to obtain the disease-resistant organic complex.

[0053] S2: Pretreatment of fermentation substrate

[0054] S2.1: Dry the whole plant of Solanum nigrum until the moisture content is 60%, chop it into 1-5cm pieces with a chopper to obtain Solanum nigrum chopped pieces, put the empty fruit clusters of oil palm into a pulverizer, pulverize them through a 100-mesh sieve to obtain the pulverized material of empty fruit clusters of oil palm;

[0055] S2.2: On a clean plastic sheet, evenly spread the crushed empty fruit bunches of oil palm as the bottom layer, then evenly spread a layer of sheep manure on top, and finally evenly spread the cut segments of Solanum nigrum as the top layer. The mass ratio of crushed empty fruit bunches of oil palm, sheep manure and cut segments of Solanum nigrum is 1:0.4:0.6. Then, use an iron shovel to stir the three layers of materials from one side to the other, while adding a sophorolipid aqueous solution until they are evenly mixed. The mass concentration of the sophorolipid aqueous solution is 0.4%. After adding the sophorolipid aqueous solution, the final moisture content of the mixture is 60%, thus obtaining the mixed fermentation substrate.

[0056] S3: Composting and fermentation preparation of organic liquid fertilizer

[0057] S3.1: *Bacillus brevis*, *Termitomyces vulgaris*, and *Enterococcus avium* were cultured separately in culture media until the logarithmic growth phase, with a viable count of 1 × 10⁻⁶. 9 CFU / g, obtained soil brevicorbacterium, termite variant, and enterococcus avianus bacterial solutions, mixed in a volume ratio of 1:0.55:0.35 to obtain a mixed bacterial solution;

[0058] S3.2: Spray mixed bacterial solution into the mixed fermentation substrate, and add urea, superphosphate, potassium sulfate, calcium carbonate, zinc sulfate and ferrous sulfate. Based on the mass of the mixed fermentation substrate, the mixed bacterial solution accounts for 0.9%, urea 1.8%, superphosphate 2.2%, potassium sulfate 1.8%, calcium carbonate 1.2%, zinc sulfate 0.15% and ferrous sulfate 0.15%. Stir evenly and carry out composting fermentation. The fermentation time is 55 days. During the fermentation period, the compost is turned over every 7 days to obtain fermented material.

[0059] S3.3: Mix the fermented material with purified water at a mass ratio of 1:5.5 and stir evenly. After soaking for 28 hours, filter to separate the solid residue and fermentation liquid. Then, use 21-count or 32-count gauze to further filter the fermentation liquid to obtain organic liquid fertilizer. Based on the mass of organic liquid fertilizer, add 0.25% disease-resistant organic compound, 0.15% guar gum, 0.08% xanthan gum and 0.04% glucose to the organic liquid fertilizer. Stir at 250 rpm for 28 minutes to obtain a growth-promoting and disease-resistant microbial organic fertilizer.

[0060] Example 3

[0061] A growth-promoting and disease-resistant microbial organic fertilizer and its preparation method, such as Figure 1 As shown, it includes the following steps:

[0062] S1: Preparation of disease-resistant organic complexes

[0063] S1.1: Place scandium chloride in a container, add 75% (v / v) ethanol aqueous solution and stir until scandium chloride is completely dissolved to prepare a scandium chloride alcohol solution with a scandium ion concentration of 0.5 mol / L.

[0064] S1.2: Dissolve reamarine in a 90% (v / v) aqueous ethanol solution to prepare a reamarine alcohol solution with a concentration of 1 mol / L. Slowly add 2 mol / L NaOH aqueous solution to the reamarine alcohol solution at a molar ratio of 1:3 (reamarine to NaOH). Stir at 200 rpm for 60 min to obtain an activated reamarine alkaline alcohol solution.

[0065] S1.3: Under the conditions of stirring at 50℃ and 250rpm, scandium chloride solution was added to activated resazurin basic alcohol solution, with a volume ratio of scandium chloride solution to activated resazurin basic alcohol solution of 1:1.5. The reaction was then stirred for 2.5h. The precipitate was collected by filtration, washed three times with distilled water, and then freeze-dried at -50℃. The precipitate was then pulverized through a 300-mesh sieve to obtain the disease-resistant organic complex.

[0066] S2: Pretreatment of fermentation substrate

[0067] S2.1: Dry the whole plant of Solanum nigrum until the moisture content is 70%, chop it into 1-5cm pieces with a chopper to obtain Solanum nigrum chopped pieces, put the empty fruit clusters of oil palm into a grinder and grind them through a 100-mesh sieve to obtain the crushed material of empty fruit clusters of oil palm;

[0068] S2.2: On a clean plastic sheet, evenly spread the crushed empty fruit bunches of oil palm as the bottom layer, then evenly spread a layer of sheep manure on top, and finally evenly spread the cut segments of Solanum nigrum as the top layer. The mass ratio of crushed empty fruit bunches of oil palm, sheep manure and cut segments of Solanum nigrum is 1:0.5:0.7. Then, use an iron shovel to stir the three layers of materials from one side to the other, while adding a sophorolipid aqueous solution until they are evenly mixed. The mass concentration of the sophorolipid aqueous solution is 0.5%. After adding the sophorolipid aqueous solution, the final moisture content of the mixture is 65%, thus obtaining the mixed fermentation substrate.

[0069] S3: Composting and fermentation preparation of organic liquid fertilizer

[0070] S3.1: *Bacillus brevis*, *Termitomyces vulgaris*, and *Enterococcus avium* were cultured separately in culture media until the logarithmic growth phase, with a viable count of 1 × 10⁻⁶. 9 CFU / g, obtained soil brevicorbacterium, termite variant, and enterococcus avianus bacterial solutions, mixed evenly at a volume ratio of 1:0.6:0.4 to obtain mixed bacterial solutions;

[0071] S3.2: Spray mixed bacterial solution into the mixed fermentation substrate, and add urea, superphosphate, potassium sulfate, calcium carbonate, zinc sulfate and ferrous sulfate. Based on the mass of the mixed fermentation substrate, the mixed bacterial solution accounts for 1%, urea accounts for 2%, superphosphate accounts for 2.5%, potassium sulfate accounts for 2%, calcium carbonate accounts for 1.5%, zinc sulfate accounts for 0.2% and ferrous sulfate accounts for 0.2%. Stir evenly and carry out composting fermentation. The fermentation time is 60 days. During the fermentation period, the compost is turned over every 7 days to obtain fermented material.

[0072] S3.3: Mix the fermentation material with purified water at a mass ratio of 1:6 and stir evenly. After soaking for 30 hours, filter to separate the solid residue and fermentation liquid. Then, use 21-count or 32-count gauze to further filter the fermentation liquid to obtain organic liquid fertilizer. Based on the mass of organic liquid fertilizer, add 0.3% disease-resistant organic compound, 0.2% guar gum, 0.1% xanthan gum and 0.05% glucose to the organic liquid fertilizer. Stir at 300 rpm for 30 minutes to obtain a growth-promoting and disease-resistant microbial organic fertilizer.

[0073] Comparative Example 1

[0074] A method for preparing a growth-promoting and disease-resistant microbial organic fertilizer differs from Example 1 in that, in Comparative Example 1, the disease-resistant organic compound was not added in step S3.3, while the remaining steps were the same.

[0075] Comparative Example 2

[0076] A method for preparing a growth-promoting and disease-resistant microbial organic fertilizer differs from Example 1 in that, in Comparative Example 2, the mixed fermentation substrate is replaced with an equal mass of organic matrix, which is composed of straw and sheep manure in a mass ratio of 2:3. The remaining steps are the same.

[0077] Comparative Example 3

[0078] A method for preparing a growth-promoting and disease-resistant microbial organic fertilizer differs from Example 1 in that, in Comparative Example 3, the mixed bacterial solution in step S3.2 is replaced with an equal mass of composite bacterial solution. The composite bacterial solution consists of yeast and Bacillus subtilis in a 1:1 volume ratio, with a viable count of 10 in each solution. 9 CFU / g, the remaining steps are the same.

[0079] Experiment 1: Prepare experimental farmland soil (organic matter 20.56 g / kg; available nitrogen 81.26 mg / kg; available phosphorus 51.65 mg / kg; available potassium 113.32 mg / kg; pH 7.86), divide it into 21 equal portions and pot them, each pot containing 20 kg of soil. The pot diameter is 40 cm and the height is 25 cm. Divide the soil into 7 groups of 3 portions each. Sow wheat evenly, 10 grains per pot. Maintain soil moisture at 70-80% of field capacity during routine management.

[0080] The growth-promoting and disease-resistant microbial organic fertilizers prepared in Examples 1-3 and Comparative Examples 1-3, and commercially available 12-element liquid fertilizers (micronutrients ≥20g, mesonutrients ≥100g) were diluted to an EC value of 1.5ms / cm. These were sprayed on the corresponding wheat groups during the greening-jointing stage and the heading-early grain-filling stage. The spraying method involved spraying the upper and lower stems and leaves of the wheat with a sprayer, applying 200mL per group. Sheath blight was investigated in each group during the jointing stage, and powdery mildew and leaf rust were investigated during the heading stage. Disease severity was determined based on the percentage of affected leaf area to total leaf area: Level 1: Affected area less than 5% of total area; Level 2: Affected area 5%–10% of total area; Level 3: Affected area 10%–20% of total area; Level 4: Affected area 20%–40% of total area; Level 5: Affected area 40%–60% of total area; Level 6: 60%–80%.

[0081] Wheat growth status: Count the number of wheat ears in each pot, cut off the ears, then pull out all the roots, wash and air-dry them, and weigh the dried root system. Then rub off the wheat grains, weigh the grains, and calculate the average value for each pot in each group, as shown in Table 1.

[0082] Table 1: Growth of the experimental wheat

[0083]

[0084] As can be seen from the data in Table 1 (Examples 1-3), the growth-promoting and disease-resistant microbial organic fertilizers prepared in Examples 1-3 have a good growth-promoting and disease-resistant effect on wheat. Compared with commercially available liquid fertilizers, they have more comprehensive functions and better effects.

[0085] As can be seen from the data of Comparative Example 1, without the addition of disease-resistant organic compound to the growth-promoting and disease-resistant microbial organic fertilizer, the wheat disease level reached level 4. This proves that the synergistic coordination of scandium ions and azadirachtin in the disease-resistant organic compound prepared by this invention can significantly improve the wheat's resistance to sheath blight, powdery mildew and leaf rust.

[0086] As can be seen from the data of Comparative Example 2, Comparative Example 2 did not use the mixed fermentation material composed of Solanum nigrum, sheep manure, and empty fruit clusters of oil palm. Instead, it used straw and sheep manure, which significantly reduced the growth-promoting effect. This proves that the present invention uses a combination of three organic materials, Solanum nigrum, sheep manure, and empty fruit clusters of oil palm, as the fermentation substrate. While realizing the resource utilization of waste, it endows the organic liquid fertilizer with unique nutrient characteristics and biological activity. After composting and fermentation, it forms an organic fertilizer matrix with excellent physicochemical properties. The liquid fertilizer obtained by extraction has both fast-acting nutrients and organic matter. The organic liquid fertilizer prepared with this as the fermentation substrate can greatly improve the growth capacity of crops.

[0087] As can be seen from the data of Comparative Example 3, Comparative Example 3 did not use a mixed culture of *Bacillus brevis*, *Terminus mutata*, and *Enterococcus avium* for fermentation. Instead, it used commonly used yeast and *Bacillus subtilis*. The growth-promoting effect on wheat decreased significantly. This proves that the present invention uses three specific strains with complementary functions for synergistic fermentation to prepare organic liquid fertilizer. This can efficiently convert the mixed fermentation substrate into a liquid fertilizer rich in bioactive substances, sustainably improve the rhizosphere microecological environment of crops, promote the proliferation of beneficial bacteria, enhance root vitality, and promote crop growth.

[0088] Experiment 2: Take 3 portions of the mixed bacterial suspension prepared in Examples 1-3, and inoculate them into LB liquid medium containing α-solanine and α-carboxine at an inoculation rate of 1%, respectively. The content of α-solanine and α-carboxine is 750 μg / mL. Incubate at 37℃ and 200 rpm for 72 h. HPLC is used to determine the concentration of residual α-solanine and α-carboxine in each group of LB liquid medium, and the degradation rate is calculated. The data are recorded as shown in Table 2.

[0089] Table 2: Degradation rate of solanine by mixed bacterial culture

[0090]

[0091] As shown in Table 2, the degradation rate of solanine by the mixed bacterial solution prepared in the embodiments of this application reached over 95%, which proves that the mixed bacteria composed of *Bacillus spp.*, *Termitomyces vulgaris*, and *Enterococcus avium* have a good degradation rate of solanine.

[0092] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a growth-promoting and disease-resistant microbial organic fertilizer, characterized in that, Includes the following steps: S1: Preparation of disease-resistant organic complexes A scandium chloride solution and an activated resazurin alkaline alcohol solution were prepared. The scandium chloride solution was added to the activated resazurin alkaline alcohol solution under stirring. The precipitate was collected, washed, freeze-dried, and then pulverized to obtain the disease-resistant organic complex. S2: Pretreatment of fermentation substrate The prickly nightshade is dried and chopped to obtain prickly nightshade segments. The empty fruit clusters of oil palm are crushed to obtain crushed oil palm empty fruit clusters. Then, the prickly nightshade segments, crushed oil palm empty fruit clusters and sheep manure are spread out, and while turning and mixing, a sophorolipid solution is added to adjust the moisture content to obtain a mixed fermentation substrate. S3: Composting and fermentation preparation of organic liquid fertilizer The culture solutions of *Bacillus brevis*, *Termitomyces vulgaris*, and *Enterococcus avium* were mixed evenly to obtain a mixed bacterial solution. The mixed bacterial solution was sprayed onto the mixed fermentation substrate, and urea, superphosphate, potassium sulfate, calcium carbonate, zinc sulfate, and ferrous sulfate were added and stirred evenly. After fermentation, fermented material was obtained. The fermented material was extracted with purified water and filtered twice to obtain organic liquid fertilizer. Disease-resistant organic compound, guar gum, xanthan gum, and glucose were added to the organic liquid fertilizer and stirred evenly to obtain a growth-promoting and disease-resistant microbial organic fertilizer.

2. The method for preparing a growth-promoting and disease-resistant microbial organic fertilizer according to claim 1, characterized in that, Step S1, the preparation of the disease-resistant organic complex, includes the following steps: S1.1: Place scandium chloride in a container, add an aqueous ethanol solution with a volume fraction of 70-75%, and stir until the scandium chloride is completely dissolved to prepare a scandium chloride alcohol solution with a scandium ion concentration of 0.2-0.5 mol / L; S1.2: Dissolve resamaritan in an 85-90% (v / v) aqueous ethanol solution to prepare a resamaritan alcohol solution with a concentration of 0.8-1 mol / L. Slowly add 1-2 mol / L NaOH aqueous solution to the resamaritan alcohol solution at a molar ratio of 1:(2-3) of resamaritan to NaOH. Stir at 150-200 rpm for 40-60 min to obtain an activated resamaritan alkaline alcohol solution. S1.3: Under the conditions of stirring at 40-50℃ and 200-250rpm, scandium chloride solution is added to activated resveratrol basic alcohol solution, and then the reaction is continued to be stirred for 2-2.5h. The precipitate is collected by filtration, washed 2-3 times with distilled water, and then freeze-dried at -50 to -70℃. The precipitate is then pulverized through a 200-300 mesh sieve to obtain the disease-resistant organic complex.

3. The method for preparing a growth-promoting and disease-resistant microbial organic fertilizer according to claim 1, characterized in that, Step S2, the pretreatment of the fermentation substrate, includes the following steps: S2.1: Dry the whole plant of Solanum nigrum until the moisture content is 50-70%, chop it into 1-5cm pieces with a chopper to obtain Solanum nigrum chopped pieces, put the empty fruit clusters of oil palm into a pulverizer, pulverize them through a 100-mesh sieve to obtain the pulverized empty fruit clusters of oil palm. S2.2: On a clean plastic sheet, evenly spread the crushed empty fruit bunches of oil palm as the bottom layer, then evenly spread a layer of sheep manure on top, and finally evenly spread the cut segments of Solanum nigrum as the top layer. The mass ratio of crushed empty fruit bunches of oil palm, sheep manure and cut segments of Solanum nigrum is 1:(0.3-0.5):(0.5-0.7). Then, use an iron shovel to stir the three layers of materials from one side to the other, while adding sophoryl ester aqueous solution until they are mixed evenly to obtain the mixed fermentation substrate.

4. The method for preparing a growth-promoting and disease-resistant microbial organic fertilizer according to claim 3, characterized in that, Step S3, the composting and fermentation preparation of organic liquid fertilizer, includes the following steps: S3.1: *Bacillus brevis*, *Termitomyces vulgaris*, and *Enterococcus avium* were cultured separately in culture media until the logarithmic growth phase, with a viable count of 1 × 10⁻⁶. 9 CFU / g was used to obtain soil brevicorbacterium, var. mutagenesis, and avian enterococcus. The soil brevicorbacterium, var. mutagenesis, and avian enterococcus were mixed evenly at a volume ratio of 1:(0.5-0.6):(0.3-0.4) to obtain a mixed bacterial solution. S3.2: Spray mixed bacterial solution into the mixed fermentation substrate, and add urea, superphosphate, potassium sulfate, calcium carbonate, zinc sulfate and ferrous sulfate. Stir evenly and carry out composting fermentation. The fermentation time is 50-60 days. During the fermentation period, turn the compost every 7 days to obtain fermented material. S3.3: Mix the fermented material with purified water at a mass ratio of 1:(5-6) and stir evenly. After soaking for 24-30 hours, filter to separate the solid residue and fermentation liquid. Then, use 21-32 thread count gauze to further filter the fermentation liquid to obtain organic liquid fertilizer. Based on the mass of organic liquid fertilizer, add 0.2-0.3% disease-resistant organic compound, 0.1-0.2% guar gum, 0.05-0.1% xanthan gum and 0.03-0.05% glucose to the organic liquid fertilizer. Stir at a stirring speed of 200-300 rpm for 25-30 minutes to obtain a growth-promoting and disease-resistant microbial organic fertilizer.

5. The method for preparing a growth-promoting and disease-resistant microbial organic fertilizer according to claim 2, characterized in that, In step S1.3, the volume ratio of scandium chloride solution to activated resamarium alkaline alcohol solution is 1:(1.3-1.5).

6. The method for preparing a growth-promoting and disease-resistant microbial organic fertilizer according to claim 3, characterized in that, In step S2.2, the mass concentration of the sophorolipid aqueous solution is 0.3-0.5%, and the final moisture content of the mixture after adding the sophorolipid aqueous solution is 55-65%.

7. The method for preparing a growth-promoting and disease-resistant microbial organic fertilizer according to claim 3, characterized in that, The *Bacillus brevis* from step S3.1 was deposited at the China General Microbiological Culture Collection Center (CGMCC) under accession number CGMCC1.3103 and cultured on CM0002 nutrient gravy agar; *Termitomyces vulgaris* was deposited at the China General Microbiological Culture Collection Center (CGMCC) under accession number CGMCC1.8372 and cultured on tryptophan-soybean agar; *Enterococcus avium* was deposited at the China General Microbiological Culture Collection Center (CGMCC) under accession number CGMCC1.2505 and cultured on MRS medium.

8. The method for preparing a growth-promoting and disease-resistant microbial organic fertilizer according to claim 4, characterized in that, Step S3.2: Based on the mass of the mixed fermentation substrate, the mixed bacterial solution accounts for 0.8-1%, urea accounts for 1.5-2%, superphosphate accounts for 2-2.5%, potassium sulfate accounts for 1.5-2%, calcium carbonate accounts for 1-1.5%, zinc sulfate accounts for 0.1-0.2%, and ferrous sulfate accounts for 0.1-0.2%.

9. A microbial organic fertilizer that promotes growth and disease resistance, characterized in that, It is prepared by the method for preparing a growth-promoting and disease-resistant microbial organic fertilizer according to any one of claims 1-8.

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