Method for preparing organic fertilizer by decomposing excrement and medicine residues through compound strains

Abstract

The invention discloses a method for preparing an organic fertilizer by decomposing excrement and medicine residues through a compound strain, and relates to the field of organic waste treatment and resource utilization, and the method comprises the following steps: S1, screening and compounding of the compound strain; s2, raw material pretreatment; s3, inoculation and fermentation; s4, carrying out post-treatment; according to the invention, the screened and compounded compound bacterial strain contains multiple functional microorganisms to form a multi-enzyme synergistic effect system, so that the decomposition efficiency of complex organic matters such as cellulose, lignin and protein in the excrement and the medicine residues is remarkably improved, the fermentation period is greatly shortened, the treatment efficiency of wastes is improved, and the energy consumption and the time cost are reduced; by optimizing fermentation conditions and process parameters, the prepared organic fertilizer is rich in various nutrient elements such as nitrogen, phosphorus, potassium and the like, high in organic matter content, rich in microbial flora and metabolites such as amino acid, polysaccharide, enzyme and the like, and capable of effectively improving the soil structure, improving the soil fertility and enhancing the water and fertilizer retention capacity of soil.

Description

Technical Field

[0001] The invention relates to organic waste treatment and resource utilization technology, and in particular to a method for preparing organic fertilizer by decomposing feces and medicinal residues using a composite bacterial strain. Background Art

[0002] With the rapid development of modern agriculture, animal husbandry, and the traditional Chinese medicine industry, the generation of wastes such as livestock and poultry manure and traditional Chinese medicine residues has increased dramatically. Due to the complex composition of these wastes (e.g., high concentrations of ammonia nitrogen in manure and plant secondary metabolites such as tannins and alkaloids in traditional Chinese medicine residues), improper disposal not only consumes significant land resources but also causes environmental pollution problems such as soil contamination, water eutrophication, and air pollution. Furthermore, the long-term excessive use of chemical fertilizers has led to increasingly prominent problems such as soil structure damage, decreased fertility, and reduced agricultural product quality. Therefore, the development of green, environmentally friendly, and highly efficient organic fertilizers to replace some chemical fertilizers has become an urgent need for sustainable agricultural development.

[0003] Traditional organic fertilizer production methods, such as natural composting, rely on environmental microorganisms and suffer from drawbacks such as long fermentation cycles, low maturity, and unstable product quality, making it difficult to meet the demand for high-quality organic fertilizers in modern agriculture. While fermentation using microbial agents has improved to some extent, the effectiveness of a single strain is limited, making it difficult to fully and efficiently decompose the complex organic matter in feces and medicinal residues. The resulting organic fertilizer's nutrient content and efficiency still need to be improved. Therefore, developing a method that can quickly and efficiently decompose feces and medicinal residue waste to produce a highly fertile, multifunctional organic fertilizer is of great practical significance. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing organic fertilizer by decomposing feces and medicinal residues using a composite bacterial strain, so as to solve the problems in the prior art that traditional composting relies on environmental microorganisms, resulting in low fermentation efficiency, single-strain bacterial agents are difficult to fully decompose complex organic matter, and cannot efficiently convert livestock and poultry feces and medicinal residue waste into high-quality organic fertilizer, making it difficult to meet the needs of modern agriculture for fertilizers with balanced nutrients and diverse functions.

[0005] In order to achieve the above object, the present invention provides the following technical solution: a method for preparing organic fertilizer by decomposing feces and medicinal residues using a composite bacterial strain, comprising the following steps:

[0006] S1. Isolating and screening Bacillus subtilis, Bacillus licheniformis, Trichoderma viride, Aspergillus niger, and Saccharomyces cerevisiae from mature compost, and compounding Bacillus subtilis, Bacillus licheniformis, Trichoderma viride, Aspergillus niger, and Saccharomyces cerevisiae in a volume ratio of 3:2:2:1:1 to obtain a composite strain solution;

[0007] Among them, Bacillus subtilis (producing β-glucanase) and Trichoderma viride (secreting exocellulase) form a cellulose degradation chain; Aspergillus niger (acidic protease) cooperates with Bacillus licheniformis (thermostable lipase) to achieve simultaneous protein-lipid decomposition; Saccharomyces cerevisiae regulates pH through metabolites (ethanol, organic acids) to activate lignin peroxidase activity;

[0008] S2. Grinding the livestock and poultry manure and the Chinese medicinal residues to a particle size of less than 5 mm, increasing the specific surface area and improving the contact efficiency of the bacterial flora, and uniformly mixing the livestock and poultry manure and the Chinese medicinal residues in a mass ratio of 3:1 to 5:1 to obtain a mixed material, adjusting the water content of the mixed material to 50%-60% and the carbon-nitrogen ratio to 25:1-30:1 to obtain a pretreated material;

[0009] S3. Inoculate the composite bacterial strain solution into the pretreated material at a rate of 3%-5% by mass of the mixed material, stir thoroughly and pile into a pile, set ventilation ducts at the bottom of the pile, and control the pile temperature between 50°C and 65°C through periodic ventilation and turning to avoid excessive temperature causing microbial death and nutrient loss. Ferment for 15-20 days;

[0010] S4. After the fermentation material is aged, it is sieved to remove undecomposed impurities and bulk materials to obtain a finished organic fertilizer with uniform particles, which is then packaged with moisture-proof and breathable packaging materials.

[0011] Furthermore, in step S2, the moisture content of the mixture is adjusted by adding water or dry straw powder, and the carbon-nitrogen ratio is adjusted by adding nitrogen-containing substances or carbon-containing substances.

[0012] Furthermore, in step S3, the height of the stack is 1.2-1.5 m, and the width is 1.5-2.0 m.

[0013] Furthermore, in step S3:

[0014] During the initial 0-5 days of fermentation, the pile should be turned once a day to ensure uniform heating of the materials and promote microbial growth. When the pile temperature reaches above 55°C and remains above 55°C for 3 days, the turning time should be changed to every 2-3 days.

[0015] The ventilation frequency is 0.5-1 hour every 1-2 days to ensure the oxygen supply during the fermentation process and promote the growth and metabolism of aerobic microorganisms.

[0016] Furthermore, the aging treatment time in step S4 is 7-10 days.

[0017] Furthermore, in step S4, after the undecomposed impurities and bulk materials are removed by screening, trace elements and / or beneficial microbial agents are added, and the trace elements and / or beneficial microbial agents are fully mixed with the organic fertilizer.

[0018] Furthermore, the trace elements include at least one of zinc, boron, and iron.

[0019] Furthermore, the beneficial microbial inoculant includes at least one of nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, and potassium-solubilizing bacteria.

[0020] Furthermore, the livestock and poultry manure is selected from at least one of pig manure, cow manure, and chicken manure.

[0021] Furthermore, the traditional Chinese medicine residue is derived from the waste after processing traditional Chinese medicinal materials and includes at least one of honeysuckle, astragalus membranaceus, and licorice.

[0022] Compared with the prior art, the method for preparing organic fertilizer by decomposing manure and medicine residue with a composite strain provided by the present invention has the following beneficial effects:

[0023] 1. The composite strain screened and compounded contains a variety of functional microorganisms, forming a multi-enzyme synergistic action system, which significantly improves the decomposition efficiency of complex organic substances such as cellulose, lignin, and protein in manure and medicine residue, greatly shortens the fermentation cycle, improves the waste treatment efficiency, and reduces energy consumption and time cost;

[0024] 2. By optimizing the fermentation conditions and process parameters, the prepared organic fertilizer is rich in various nutrient elements such as nitrogen, phosphorus, and potassium, has a high organic matter content, and also contains rich microbial flora and metabolites such as amino acids, polysaccharides, and enzymes, which can effectively improve the soil structure, increase the soil fertility, enhance the soil water and fertilizer retention capacity, promote plant growth, and improve the quality of agricultural products;

[0025] 3. By converting livestock and poultry manure and traditional Chinese medicine residue into high-value-added organic fertilizer, the resource utilization of manure and medicine residue waste is realized, the environmental pollution caused by waste is reduced, the waste treatment cost is lowered. At the same time, the produced organic fertilizer can replace part of chemical fertilizers, reduce the dependence of agricultural production on chemical fertilizers, reduce the agricultural production cost, and has significant economic and environmental benefits;

[0026] 4. By adding trace elements and beneficial microorganisms, the organic fertilizer has multiple functions such as nitrogen fixation, phosphorus solubilization, and potassium solubilization, improves the availability of nutrients in the soil, enhances the stress resistance of plants, reduces the occurrence of pests and diseases, and is conducive to the sustainable development of agriculture. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0028] Figure 1 Process flow chart of the method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain provided by an embodiment of the present invention. Detailed implementation manners

[0029] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] Embodiment 1:

[0031] Please refer to Figure 1 , a method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain, comprising the following steps:

[0032] S1. Screening and compounding of the composite strain: Bacillus subtilis, Bacillus licheniformis, Trichoderma viride, Aspergillus niger and Saccharomyces cerevisiae are isolated and screened from mature compost. After identification and performance testing, they are compounded according to a volume ratio of 3:2:2:1:1 to prepare a composite strain bacterial liquid;

[0033] Specifically, the following means can be adopted to achieve it:

[0034] Select a compost sample with a maturity ≥ 60% (calculated according to the humification coefficient), and the sampling depth is 30 cm below the center of the compost pile;

[0035] Adopt the dilution coating method, culture at 37 °C for 48 hours in an LB solid medium (containing 100 μg / mL cycloheximide to inhibit fungi), and pick single colonies; use a potato dextrose agar (PDA) medium (containing 50 μg / mL streptomycin to inhibit bacteria) to culture at 28 °C for 5 days, and select colonies with strong mycelial growth;

[0036] Adjust the concentration of each strain to an equal volume ratio using a hemocytometer (Bacillus subtilis 3×10 8 CFU / mL, Bacillus licheniformis 2×10 8 CFU / mL, and the remaining strains are adjusted according to the ratio);

[0037] S2. Pretreatment of raw materials: Collect pig feces and honeysuckle medicinal residues, remove impurities and then crush them to a particle size < 5 mm, mix them according to a mass ratio of pig feces:medicinal residues = 4:1, adjust the water content to 55%, and the carbon-nitrogen ratio to 28:1;

[0038] Pig manure is rich in nitrogen and medium in phosphorus, with a relatively low cellulose content. Honeysuckle residue is rich in lignin and phenolic compounds. They are mixed at a mass ratio of 4:1 to balance the carbon-nitrogen ratio. By pulverizing (particle size <5 mm), the specific surface area is increased to promote the contact efficiency of strains.

[0039] Bacillus subtilis and Trichoderma viride preferentially degrade the lignin-cellulose complex in the residue (Trichoderma viride secretes exocellulase, and Bacillus subtilis produces β-glucanase); Aspergillus niger and Bacillus licheniformis decompose proteins (Aspergillus niger produces acid protease) and lipids (Bacillus licheniformis produces thermotolerant lipase) in pig manure; Saccharomyces cerevisiae metabolizes to produce ethanol and organic acids, activates lignin peroxidase, and accelerates the degradation of phenolic substances.

[0040] S3. Inoculation and fermentation: The compound strain liquid is inoculated into the material at 4% of the mass of the mixed material, stirred evenly, and then piled into a strip stack. Ventilation pipes are set at the bottom. In the first 5 days, ventilate for 1 hour and turn the pile once a day. After the temperature reaches 55°C and is maintained for 3 days, ventilate for 1 hour and turn the pile once every 2 days. The fermentation cycle is 18 days.

[0041] S4. Post-treatment: After fermentation, age for 8 days, screen to remove impurities, add appropriate amounts of zinc and boron trace elements, nitrogen-fixing bacteria, and phosphorus-solubilizing bacteria, mix evenly, and then package.

[0042] In view of the characteristics of pig manure (high nitrogen and low fiber) and honeysuckle residue (high lignin and containing phenolic substances), they are mixed at a mass ratio of 4:1 and the carbon-nitrogen ratio is adjusted to 28:1. A composite enzyme system is formed by Bacillus subtilis (producing β-glucanase) and Trichoderma viride (secreting exocellulase) to synergistically degrade the lignin-cellulose complex in the residue. At the same time, Aspergillus niger (acid protease) decomposes pig manure proteins, and Bacillus licheniformis (thermotolerant lipase) degrades lipids; in the initial stage of fermentation, turn the pile and ventilate every day to quickly inactivate pathogenic bacteria. Saccharomyces cerevisiae metabolizes to produce acid to activate lignin peroxidase and accelerate phenolic detoxification; in post-treatment, add zinc, boron, and nitrogen-fixing / phosphorus-solubilizing bacterial agents to directionally improve the phosphorus activity and anti-cracking properties of tomato organic fertilizer, achieving the synergistic effect of "double degradation of lignin-phenol + targeted phosphorus supplementation".

[0043] After testing, the total content of nitrogen, phosphorus, and potassium in the organic fertilizer prepared by the above method reaches 5.5%, the organic matter content reaches 45%, and the number of beneficial microorganisms reaches 1.5×10 8 cfu / g; in the tomato planting experiment, compared with applying ordinary chemical fertilizers, the tomato yield increased by 15% after applying this organic fertilizer, the vitamin C content of the fruit increased by 12%, and the taste was better.

[0044] Example 2:

[0045] Please refer to Figure 1 , a method for preparing organic fertilizer by decomposing feces and residue with a composite strain, including the following steps:

[0046] S1. Screening and compounding of the composite strain: same as Example 1;

[0047] S2. Raw material pretreatment: Collect cow dung and astragalus residue, crush them to a particle size of <5 mm, then mix them according to the mass ratio of cow dung: residue = 5:1, adjust the water content to 52%, and the carbon-nitrogen ratio to 26:1;

[0048] S3. Inoculation and fermentation: The inoculation amount of the composite strain liquid is 3% of the mass of the mixed materials. The ventilation and turning methods are the same as in Example 1, and the fermentation period is 16 days;

[0049] S4. Post-treatment: Aging for 7 days, adding iron trace elements and potassium-solubilizing bacteria after screening, and then packaging.

[0050] In view of the characteristics of cow dung (high fiber, low nitrogen) and astragalus residue (containing saponins and polysaccharides), by mixing them in a mass ratio of 5:1 and adjusting the carbon-nitrogen ratio to 26:1, Trichoderma viride (secreting endoglucanase) and Aspergillus niger (cellobiase) are used to synergistically degrade the dominant cellulose in cow dung. At the same time, Bacillus licheniformis can thermally decompose astragalus saponins at high temperature, and Saccharomyces cerevisiae metabolizes polysaccharides to generate mannan to improve soil structure; in the fermentation stage, high-frequency turning in the first 3 days and intermittent ventilation in the later period are adopted to maintain medium-temperature fermentation at 50 - 55 °C to ensure efficient conversion of saponins; in post-treatment, iron elements and potassium-solubilizing bacteria are added to directionally improve the potassium absorption and disease resistance of cucumbers, realizing the synergistic effect of "fiber-saponin double degradation + targeted potassium supplementation".

[0051] After detection, the total content of nitrogen, phosphorus and potassium in the organic fertilizer prepared by the above method is 5.2%, the organic matter content is 43%, and the number of beneficial microorganisms is 8 8 1.2×10 per gram. When applied in cucumber cultivation, compared with conventional fertilization, the disease resistance of cucumbers is significantly enhanced, the incidence of downy mildew is reduced by 20%, and the yield is increased by 12%.

[0052] In summary, the method for preparing organic fertilizer by decomposing feces and residues with the composite strain provided by the present invention can flexibly adjust the raw material ratio and strain combination according to the physical and chemical properties of different wastes (such as carbon-nitrogen ratio, fiber content, etc.), and can be adapted to the combination of various livestock and poultry manures and traditional Chinese medicine residues, improving the versatility and resource utilization efficiency of the process;

[0053] The composite strain remains highly active during the high-temperature fermentation stage (50 -  65 °C), and its degradation ability for complex substrates (such as lignin and saponins) is stable, avoiding fermentation interruption or efficiency decline caused by temperature fluctuations;

[0054] By differentially adding trace elements (such as zinc and iron) and functional microbial agents (such as potassium-solubilizing bacteria), special organic fertilizers for specific crops (such as fruits, vegetables, grains) can be developed directionally to meet the needs of precision agriculture;

[0055] During the fermentation process, natural anti-nutritional factors or toxic substances in the raw materials are effectively removed through microbial metabolism (such as phenolic degradation and saponin conversion), reducing the potential risks to the soil ecology after the application of organic fertilizers.

[0056] The method for preparing organic fertilizers by decomposing feces and pharmaceutical residues provided by the present invention can effectively convert feces and pharmaceutical residues into high-quality organic fertilizers, with good application effects and promotion values. In practical applications, the process parameters can be appropriately adjusted and optimized according to different raw material sources and market demands to obtain the best economic and environmental benefits.

[0057] Only some exemplary embodiments of the present invention have been described by way of illustration. Undoubtedly, for those of ordinary skill in the art, the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the protection scope of the claims of the present invention.

Claims

1. A method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain, characterized in that, The following steps are involved: S1. Isolating and screening Bacillus subtilis, Bacillus licheniformis, Trichoderma viride, Aspergillus niger, and Saccharomyces cerevisiae from mature compost, and compounding Bacillus subtilis, Bacillus licheniformis, Trichoderma viride, Aspergillus niger, and Saccharomyces cerevisiae in a volume ratio of 3:2:2:1:1 to obtain a composite strain solution; S2. Grinding livestock and poultry manure and Chinese medicinal residues to a particle size of less than 5 mm, respectively, mixing the livestock and poultry manure and Chinese medicinal residues in a mass ratio of 3:1 to 5:1 to obtain a mixed material, and adjusting the water content of the mixed material to 50%-60% and the carbon-nitrogen ratio to 25:1-30:1 to obtain a pretreated material; S3, inoculating the composite bacterial strain liquid into the pretreated material at 3%-5% of the mass of the mixed material, stirring thoroughly and then piling into a pile, setting a ventilation duct at the bottom of the pile, and controlling the pile temperature between 50°C and 65°C through periodic ventilation and turning, and fermenting for 15-20 days; S4. After the fermentation material is aged, it is sieved to remove undecomposed impurities and bulk materials to obtain a finished organic fertilizer with uniform particles, which is then packaged with moisture-proof and breathable packaging materials.

2. The method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain according to claim 1, characterized in that, In step S2, the moisture content of the mixture is adjusted by adding water or dry straw powder, and the carbon-nitrogen ratio is adjusted by adding nitrogen-containing substances or carbon-containing substances.

3. The method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain according to claim 1, characterized in that, In step S3, the height of the stack is 1.2-1.5 m, and the width is 1.5-2.0 m.

4. A method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain according to claim 1, characterized in that, In the step S3: During the initial 0-5 days of fermentation, the pile should be turned once a day. When the pile temperature reaches above 55°C and remains above 55°C for 3 days, the turning time should be changed to once every 2-3 days. The ventilation frequency is 0.5-1 hour every 1-2 days.

5. A method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain according to claim 1, characterized in that, The aging treatment time in step S4 is 7-10 days.

6. The method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain according to claim 1, characterized in that, In step S4, after the undecomposed impurities and bulk materials are removed by screening, trace elements and / or beneficial microbial agents are added and the trace elements and / or beneficial microbial agents are fully mixed with the organic fertilizer.

7. A method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain according to claim 6, characterized in that, The trace elements include at least one of zinc, boron and iron.

8. A method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain according to claim 6, characterized in that, The beneficial microbial agent includes at least one of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and potassium-solubilizing bacteria.

9. The method for preparing organic fertilizer by decomposing feces and medicinal residues with a composite strain according to claim 1, characterized in that, The livestock and poultry manure is selected from at least one of pig manure, cow manure and chicken manure.

10. The method for preparing organic fertilizer by decomposing feces and medicinal residues using a composite bacterial strain according to claim 1, characterized in that: The traditional Chinese medicine residues are derived from waste after processing traditional Chinese medicines, and include at least one of honeysuckle, astragalus, and liquorice.

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