A bio-organic fertilizer prepared by microbial fermentation and a preparation method thereof

Abstract

The present application relates to the technical field of bio-organic fertilizer preparation, and particularly relates to a bio-organic fertilizer prepared by microbial fermentation and a preparation method thereof, which is prepared by fermentation of raw materials and compound microbial strains, wherein the raw materials include livestock and poultry manure, crop straw, industrial organic waste residue and a humification agent, and the compound microbial strains are a ternary combination of bacillus subtilis, bacillus mycoides and saccharomyces cerevisiae, or a quaternary combination of bacillus subtilis, bacillus mycoides, saccharomyces cerevisiae and bacillus mucilaginosus. The present application adopts a multi-element compound strain combination and optimizes the ratio, and the synergistic effect of each strain is significant, which greatly improves the organic matter degradation efficiency and effective nutrient activation capacity, and compared with single strain, the microbial activity is stronger, and the nutrient supply capacity of the fertilizer is better.

Description

Technical Field

[0001] This invention relates to the field of bio-organic fertilizer preparation technology, specifically to a bio-organic fertilizer prepared by microbial fermentation and its preparation method. Background Technology

[0002] With the promotion of the concept of sustainable agricultural development, bio-organic fertilizers have become an important alternative to traditional chemical fertilizers due to their ability to improve soil structure and enhance crop quality. However, current bio-organic fertilizer preparation technologies still face many problems that urgently need to be solved. Regarding the application of microbial strains, existing technologies mostly use single strains or simple combinations of strains, lacking in-depth optimization of the synergistic metabolic mechanisms of the strains, resulting in low organic matter degradation efficiency and poor activation of effective nutrients. In terms of raw material ratios, there is a common problem of unreasonable combinations of livestock and poultry manure, crop straw, and industrial organic waste, leading to an imbalance in the carbon-nitrogen ratio. This affects both the efficiency of microbial fermentation and the difficulty in achieving a balanced supply of nutrients. Furthermore, a large amount of industrial organic waste is not effectively utilized, resulting in resource waste and environmental pressure.

[0003] At the fermentation process level, existing technologies are mostly extensive operations, lacking precise control over key parameters such as fermentation temperature and turning frequency. This results in incomplete fertilizer decomposition, posing a risk of pathogen residues and potentially affecting crop growth due to uncomposted components. Furthermore, traditional preparation methods have long production cycles and poor product versatility, making it difficult to adapt to different soil conditions and crop needs. Additionally, some products suffer from insufficient decomposition and low viable microbial counts, resulting in limited soil improvement and minimal crop growth promotion effects. These shortcomings fail to meet the demands of modern agriculture for efficient, safe, and multifunctional bio-organic fertilizers. Therefore, there is an urgent need to develop a bio-organic fertilizer preparation technology with strong raw material adaptability, optimized processes, and excellent overall performance. Summary of the Invention

[0004] The primary objective of this invention is to provide a bio-organic fertilizer prepared by microbial fermentation and its preparation method.

[0005] A further objective of this invention is to provide a bio-organic fertilizer prepared by microbial fermentation, which is prepared by fermentation of raw materials and compound microbial strains. The raw materials include livestock and poultry manure, crop straw, industrial organic waste residue and composting agent. The compound microbial strains are a ternary combination of Bacillus subtilis, Bacillus megaterium phosphate-solubilizing and Saccharomyces cerevisiae, or a quaternary combination of Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, Saccharomyces cerevisiae and Bacillus mucilaginosus.

[0006] Preferably, the proportions of the raw materials by weight are: 45-65 parts of livestock and poultry manure, 15-30 parts of crop straw, 15-20 parts of industrial organic waste residue, and 5 parts of composting agent.

[0007] Preferably, when the compound microbial strain is a ternary combination, the mass ratio of Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, and Saccharomyces cerevisiae is 3:2:1; when it is a quaternary combination, the mass ratio of Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, Saccharomyces cerevisiae, and Bacillus mucilaginosus is 3-5:2-3:1-2:1-2.

[0008] Preferably, the livestock and poultry manure is one of pig manure, chicken manure, or cow manure.

[0009] Preferably, the crop straw is one of wheat straw, corn straw, or rice straw.

[0010] Preferably, the industrial organic waste residue is one of brewer's grains, monosodium glutamate residue, or papermaking black liquor treatment residue.

[0011] Preferably, the inoculation amount of the compound microbial strain is 1.0%-3.2% of the total mass of the raw materials.

[0012] A method for preparing the aforementioned bio-organic fertilizer includes the following steps: (1) Raw material pretreatment: Dry livestock and poultry manure to 53%-65% moisture content and remove impurities; crush crop straw to 1-3 cm particle size, or soak it in 0.8%-1.0% alkaline solution for 1.5-2 hours, rinse it with water until neutral, and then dry it to 52%-53% moisture content; dry industrial organic waste residue to 43%-48% moisture content and crush it to 0.8-2 cm particle size; (2) Mixed inoculation: Mix the pretreated raw materials with the composting agent evenly, and spray the activated compound microbial strains that have been soaked in sterile water at 30°C for 2-3 hours evenly into the mixture. The amount of sterile water added is 5 times the mass of the strains. Stir until the material is uniform, and control the total moisture content of the material to be 54%-65% and the pH value to be 6.8-7.8. Glucose can be added optionally. (3) Fermentation treatment: Transfer the mixture into the fermentation tank, pile it up to a height of 90 cm, maintain the fermentation temperature at 48℃-63℃, turn the pile every 1-2 days, and ferment for 8-16 days. Segmented temperature control can be used. (4) Post-fermentation and aging: After fermentation, the material is transferred to the aging field, piled up to a height of 55 cm, covered with shade cloth, and ventilated or turned over regularly. After aging for 6-12 days, biological organic fertilizer is obtained.

[0013] Preferably, the segmented temperature control is as follows: the temperature is maintained at 53°C in the early stage of fermentation and at 63°C in the later stage of fermentation.

[0014] Preferably, the amount of glucose added during mixed inoculation is 0.5% of the total mass of the raw materials.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses a combination of multiple composite microbial strains with optimized ratios. The synergistic effect of each strain is significant, greatly improving the degradation efficiency of organic matter and the activation capacity of effective nutrients. Compared with single strains, the microbial activity is stronger and the fertilizer's nutrient supply capacity is better.

[0016] 2. This invention optimizes the ratio of livestock and poultry manure, crop straw and industrial organic waste residue, and achieves precise control of carbon-nitrogen ratio. This ensures efficient microbial fermentation and realizes the resource utilization of industrial waste, which not only reduces production costs but also alleviates environmental pressure and broadens the application range of raw materials.

[0017] 3. This invention employs a process combining segmented fermentation, precise temperature control, and scientific turning, effectively improving fertilizer decomposition, thoroughly killing pathogens, avoiding adverse effects on crops from uncomposted components, and shortening the production cycle while increasing production efficiency. Fourth, the prepared bio-organic fertilizer is rich and balanced in nutrients, with sufficient organic matter and available phosphorus and potassium. After application, it can significantly increase soil organic matter content, improve soil structure, promote crop root development and plant growth, and enhance crop resistance and quality.

[0018] 4. The technical solution of this invention has a reasonable parameter range and strong universality, which can be adapted to different raw material combinations and production conditions. Even under extreme parameter combinations, it can still stably produce high-quality fertilizer, providing a reliable guarantee for large-scale production and diversified application. It fully meets the application needs of modern agriculture for efficient, safe and environmentally friendly bio-organic fertilizers, and has significant economic, social and environmental benefits. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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. Example

[0020] Raw material ratio: 50 parts pig manure, 25 parts wheat straw, 20 parts brewer's grains, and 5 parts composting agent.

[0021] The compound microbial strain consisted of Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, and Saccharomyces cerevisiae, in a mass ratio of 3:2:1, with each strain containing 2.0 × 10⁻⁶ microorganisms. 9 CFU per gram, 1.5 × 10 9 CFU per gram, 1.0 × 10 9 Each gram of CFU is inoculated at a rate of 1.0% of the total mass of the raw materials.

[0022] Preparation steps: Raw material pretreatment: Pig manure is naturally sun-dried to 58% moisture content, and impurities such as stones and plastics are removed; wheat straw is crushed to a particle size of 3 cm, soaked in 1.0% sodium hydroxide solution for 2 hours, rinsed with water until neutral, and sun-dried to 52% moisture content; brewer's grains are dried to 48% moisture content and crushed to a particle size of 2 cm.

[0023] Mixed inoculation: Mix the pretreated pig manure, wheat straw, brewer's grains and composting agent evenly, and spray the activated compound microbial inoculum evenly into the mixture. The inoculum activation conditions are soaking in sterile water at 30℃ for 2 hours, and the amount of sterile water added is 5 times the mass of the inoculum. Stir until the material is homogeneous, and control the total moisture content of the material to 58% and the pH value to 7.0.

[0024] Fermentation treatment: Transfer the mixture into a fermentation tank, pile it up to a height of 90 cm, and maintain the fermentation temperature at 58°C after natural heating. Turn the pile once a day and ferment for 10 days.

[0025] Post-fermentation aging: After fermentation, the material is transferred to the aging field, piled up to a height of 55 cm, covered with a shade cloth, and naturally aged for 7 days. During this period, the pile is turned over once every 2 days to finally obtain biological organic fertilizer. Example

[0026] Based on the technical solution of Example 1, to improve the synergy of the strains and the efficiency of effective nutrient activation, strain optimization and process fine-tuning were carried out, and the raw materials and step parameters were optimized as follows: Raw material ratio: 45 parts pig manure, 30 parts wheat straw, 20 parts brewer's grains, and 5 parts composting agent.

[0027] Compound microbial strain: Based on the strain in Example 1, Bacillus mucilaginosus was added to form a quaternary strain combination with a mass ratio of 3:2:1:1. The bacterial content of each strain was 2.0 × 10⁻⁶. 9 CFU per gram, 1.5 × 10 9 CFU per gram, 1.0 × 10 9 CFU per gram, 1.5 × 10 9 For each gram of CFU, the inoculation amount was adjusted to 1.5% of the total mass of the raw materials to verify the compatibility and effectiveness of the increased inoculation amount.

[0028] Preparation steps: Raw material pretreatment: Pig manure is naturally sun-dried to 58% moisture content to remove impurities such as stones and plastics; wheat straw is crushed to a particle size of 2 cm, soaked in 1.0% sodium hydroxide solution for 2 hours, rinsed with water until neutral, and sun-dried to 52% moisture content; brewer's grains are dried to 48% moisture content and crushed to a particle size of 2 cm. By optimizing the straw particle size, the contact area between the inoculum and the raw materials is increased.

[0029] Mixed inoculation: The pretreated pig manure, wheat straw, brewer's grains and composting agent are mixed evenly. The activated compound microbial strains are evenly sprayed into the mixture. The activation conditions of the strains are the same as in Example 1. Stir until the materials are uniform, control the total moisture content of the materials to 60% and the pH value to 7.0, and fine-tune the moisture content to adapt to the synergistic metabolic needs of the quaternary strains.

[0030] Fermentation treatment: Transfer the mixture into the fermentation tank, pile it up to a height of 90 cm, and maintain the fermentation temperature at 60°C after natural heating. Turn the pile once a day for the first 5 days, and turn it once every 2 days for the next 5 days. The fermentation time is 10 days. Optimize the turning frequency to balance fermentation efficiency and energy consumption.

[0031] Post-fermentation aging: After fermentation, the material is transferred to the aging field, piled up to a height of 55 cm, covered with a shade cloth, and naturally aged for 8 days. During this period, the pile is turned over once every 2 days to finally obtain biological organic fertilizer. Example

[0032] Based on the technical solution of Example 2, and considering the potential for improvement in raw material types and production cycle, raw material expansion and process optimization are carried out to achieve a dual improvement in raw material adaptability and production efficiency. The parameters are as follows: Raw material ratio: 55 parts chicken manure, 20 parts corn stalks, 20 parts monosodium glutamate residue, and 5 parts composting agent. By replacing the core raw materials, the compatibility of different livestock and poultry manure, straw, and industrial waste residues is verified, and the application range of raw materials is expanded.

[0033] Compound microbial strains: The quaternary strain combination of Example 2 was used, with the mass ratio adjusted to 4:2:1:1 to adapt to the nutrient characteristics of the new raw materials. The content of each strain was consistent with that of Example 2. The inoculation amount was adjusted to 2.0% of the total mass of the raw materials to further expand the range of inoculation amounts.

[0034] Preparation steps: Raw material pretreatment: Chicken manure was dried to a moisture content of 53%, and the moisture content was adjusted to suit the high nitrogen characteristics of chicken manure; corn stalks were crushed to a particle size of 1 cm, soaked in 0.8% sodium hydroxide solution for 1.5 hours, rinsed with water until neutral, and dried to a moisture content of 53%, optimizing the straw treatment concentration and time to improve degradation efficiency; monosodium glutamate residue was dried to a moisture content of 43%, crushed to a particle size of 0.8 cm, and the particle size of the waste residue was refined to enhance nutrient release.

[0035] Mixed inoculation: Mix the pretreated chicken manure, corn stalks, monosodium glutamate residue and composting agent evenly. Spray the activated compound microbial inoculum evenly into the mixture. The inoculum activation conditions are: soaking in sterile water at 30℃ for 2 hours. The amount of sterile water added is 5 times the mass of the inoculum. At the same time, add 0.5% glucose to improve the activation efficiency of the inoculum. Stir until the material is uniform and control the total moisture content of the material to 54% and the pH value to 6.8.

[0036] Fermentation process: The mixed materials are transferred into a fermentation tank and piled up to a height of 90 cm. A segmented fermentation process is adopted. In the first stage, the temperature is maintained at 53°C for 1 to 3 days to support the colonization of microorganisms. In the second stage, the temperature is maintained at 63°C for 4 to 8 days to enhance the degradation of organic matter and the killing of pathogens. The pile is turned over once a day. The total fermentation time is 8 days, which shortens the fermentation cycle and improves production efficiency.

[0037] Post-fermentation aging: After fermentation, the material is transferred to the aging field, piled up to a height of 55 cm, covered with a shade cloth, and ventilated regularly. After aging for 6 days, the final moisture content of the material is controlled at 18%, resulting in bio-organic fertilizer. Example

[0038] Based on the technical solution of Embodiment 3, the rationality and universality of the protection scope are verified by using extreme parameter combinations of the upper and lower limits of the protection scope of this invention. The parameters are as follows: Raw material ratio: 65 parts cow manure, 15 parts rice straw, 15 parts papermaking black liquor treatment residue, and 5 parts composting agent. Among them, 65 parts cow manure is the upper limit of the livestock and poultry manure ratio, 15 parts rice straw is the lower limit of the straw ratio, and 15 parts papermaking black liquor treatment residue is the intermediate value of industrial waste residue, to verify the suitability of extreme raw material ratios.

[0039] Compound microbial strains: The quaternary strain combination of Example 2 was used, with the mass ratio adjusted to 5:3:2:2, which is close to the upper limit of the strain ratio range. The content of each strain was consistent with that of Example 2. The inoculation amount was 3.2% of the total mass of raw materials, which is the upper limit of the inoculation amount range.

[0040] Preparation steps: Raw material pretreatment: Cow dung was dried to a moisture content of 65%, which is the upper limit of the material moisture range; rice straw was crushed to a particle size of 3 cm and used directly without soaking in alkali solution, simplifying the pretreatment steps to verify the degradation ability of the bacteria on untreated straw; papermaking black liquor treatment residue was dried to a moisture content of 48% and crushed to a particle size of 1.5 cm.

[0041] Mixed inoculation: Mix the pretreated cow manure, rice straw, papermaking black liquor treatment residue and composting agent evenly. Spray the activated compound microbial inoculum evenly into the mixture. The inoculum activation conditions are: soaking in sterile water at 30℃ for 3 hours. The amount of sterile water added is 5 times the mass of the inoculum. Stir until the material is homogeneous. Control the total moisture content of the material to 65% and the pH value to 7.8, with the pH value close to the upper limit of the range.

[0042] Fermentation treatment: Transfer the mixed materials into the fermentation tank, pile them up to a height of 90 cm, maintain the fermentation temperature at 48°C, which is the lower limit of the fermentation temperature range, turn the pile twice a day to adapt to the aeration requirements of materials with extreme ratios, and ferment for 16 days, which is the upper limit of the fermentation time range.

[0043] Post-fermentation aging: After fermentation, the material is transferred to the aging field, piled up to a height of 55 cm, covered with a shade cloth, ventilated once a day, and aged for 12 days to finally obtain biological organic fertilizer.

[0044] Comparative Example 1: Raw material ratio: exactly the same as in Example 1.

[0045] Complex microbial strain: Contains only Bacillus subtilis, with a bacterial count of 2.0 × 10⁻⁶. 9 CFU per gram, inoculation dose 1.0%.

[0046] Preparation steps: exactly the same as in Example 1.

[0047] Comparative Example 2: Raw material ratio: 70 parts pig manure, 10 parts wheat straw, 15 parts brewer's grains, and 5 parts composting agent. The 70 parts pig manure exceeds the range of livestock and poultry manure ratio of this invention, and the 10 parts wheat straw is below the range of straw ratio of this invention.

[0048] Composite microbial strains: completely consistent with Example 1.

[0049] Preparation steps: exactly the same as in Example 1.

[0050] Comparative Example 3: Raw material ratio: completely consistent with Example 2.

[0051] Composite microbial strains: completely consistent with Example 2.

[0052] Preparation steps: The raw material pretreatment is the same as in Example 2. After mixing and inoculation, it is naturally fermented with temperature fluctuations between 30 and 45 degrees Celsius. The pile is not turned over throughout the process. The fermentation time is 10 days and the post-ripening and aging time is 3 days. The post-ripening time is lower than the lower limit of the scope of this invention.

[0053] Comparative Example 4: Raw material ratio: 65 parts chicken manure, 30 parts corn stalks, 5 parts composting agent, no industrial organic waste residue.

[0054] Composite microbial strains: completely consistent with Example 3.

[0055] Preparation steps: completely consistent with Example 3.

[0056] Comparative Example 5: Raw material ratio: 60 parts pig manure, 40 parts wheat straw, no industrial waste residue, no composting agent, no compound bacteria.

[0057] Complex microbial strains: None; rely on natural fermentation by environmental microorganisms.

[0058] Preparation steps: The raw materials are simply mixed and piled up for fermentation, then naturally turned over. The fermentation time is 30 days, without any post-ripening or aging steps.

[0059] Comparative Example 6: Raw material ratio: completely consistent with Example 2.

[0060] The compound microbial strain is a binary combination of Bacillus subtilis and Bacillus megaterium in a mass ratio of 3:2, with an inoculation amount of 1.5%, which is a simple combination of strains in existing technologies.

[0061] Preparation steps: The raw material pretreatment is the same as in Example 2. After mixing and inoculation, fermentation is carried out at a constant temperature of 58°C for 10 days, with the pile turned over once a day. After aging for 8 days, it is a simple combination of existing fermentation and aging processes.

[0062] Performance testing and results analysis: Test metrics and methods: The performance testing methods of this invention are all formulated in accordance with the relevant national standards for bio-organic fertilizers (NY884-2012), and the key testing steps are specified as follows: (1) The organic matter content was determined by the potassium dichromate titration method, using 0.8 mol / L potassium dichromate solution and concentrated sulfuric acid for heating digestion, followed by ferrous sulfate titration to calculate the content; (2) The effective phosphorus content was determined by the sodium bicarbonate extraction method for molybdenum and antimony, and the absorbance of the extract was measured at a wavelength of 700 nm after color development. (3) The effective potassium content was determined by ammonium acetate extraction flame photometry, and the content was measured by flame photometer after extraction. (4) The number of viable microorganisms was determined by plate counting using LB medium and incubated at 37°C for 24-48 hours. (5) pH value was measured by potentiometric method. Fertilizer and carbon dioxide-free distilled water were mixed at a ratio of 1:10, and the mixture was allowed to stand for 30 minutes before being measured with a pH meter. (6) Seed germination rate: Wheat seeds were used as the test object. The germination method was carried out by filter paper in petri dish. The seeds were cultured for 7 days under constant temperature of 25℃ and 12 hours of light per day. The germination rate was calculated. (7) Soil improvement effect: Select barren soil (organic matter content ≤10g / kg), apply fertilizer according to the conventional fertilizer application rate, plant wheat, and measure the increase in soil organic matter, wheat plant height (plant height measured to the growth point) and fresh weight of single plant after a 30-day growing period. (8) The degree of decomposition was determined by the germination index method. Germination index = (germination rate of seeds in the fertilized group × average root length) / (germination rate of seeds in the control group × average root length) × 100. A germination index ≥ 85 was considered to be fully decomposed. (9) The pathogen kill rate was determined by plate counting method. The number of Escherichia coli in the samples before and after fermentation (cultured on eosin methylene blue medium) was measured and the kill rate was calculated.

[0063] All tests were conducted with three parallel samples, and the average value was taken as the final result. The testing process was repeatable, and the data was authentic and reliable.

[0064] The test results are shown in Table 1 below: Table 1: sample Organic matter content Available phosphorus Available potassium viable bacteria count pH value Germination rate Germination Index Increase in soil organic matter Wheat plant height fresh weight of wheat Pathogen kill rate Example 1 42.3% 185.6 mg / kg 210.3 mg / kg <![CDATA[12.5×10 8 CFU / g]]> 7.0 91.2% 90.5% 8.2g / kg 28.6cm 3.25g / plant 92.3% Example 2 45.6% 220.8 mg / kg 245.1 mg / kg <![CDATA[18.3×10 8 CFU / g]]> 6.9 94.5% 95.2% 9.5g / kg 32.1cm 3.86g / plant 95.6% Example 3 48.2% 235.4 mg / kg 260.7 mg / kg <![CDATA[20.1×10 8 CFU / g]]> 6.8 96.3% 97.8% 10.3g / kg 35.4cm 4.23g / plant 97.2% Example 4 40.5% 178.2 mg / kg 195.6 mg / kg <![CDATA[15.8×10 8 CFU / g]]> 7.2 89.7% 88.3% 7.6g / kg 26.8cm 2.98g / plant 90.5% Comparative Example 1 35.1% 120.3 mg / kg 150.2 mg / kg <![CDATA[4.2×10 8 CFU / g]]> 7.3 82.5% 75.6% 4.3g / kg 22.3cm 2.15g / plant 78.2% Comparative Example 2 38.2% 145.6 mg / kg 170.5 mg / kg <![CDATA[8.7×10 8 CFU / g]]> 7.5 85.1% 80.2% 5.1g / kg 24.5cm 2.42g / plant 82.3% Comparative Example 3 36.5% 130.8 mg / kg 160.3 mg / kg <![CDATA[7.3×10 8 CFU / g]]> 7.4 83.2% 78.9% 4.7g / kg 23.1cm 2.28g / plant 75.6% Comparative Example 4 39.8% 160.5 mg / kg 185.2 mg / kg <![CDATA[9.5×10 8 CFU / g]]> 7.1 88.6% 85.3% 6.2g / kg 26.3cm 2.85g / plant 88.4% Comparative Example 5 28.6% 85.2 mg / kg 120.7 mg / kg <![CDATA[2.1×10 8 CFU / g]]> 7.6 75.3% 65.8% 3.1g / kg 19.8cm 1.86g / plant 62.5% Comparative Example 6 37.6% 152.4 mg / kg 178.6 mg / kg <![CDATA[9.2×10 8 CFU / g]]> 7.2 84.8% 81.5% 5.5g / kg 24.8cm 2.53g / plant 83.7% Based on the test data above, the bio-organic fertilizers prepared in each embodiment of the present invention exhibit excellent performance in all performance indicators, and their overall effect is significantly better than the corresponding prior art and combinations of prior art solutions in each comparative example. Even though Example 4 uses an extreme combination of the upper and lower limits of the parameter range of the present invention, its performance indicators are still far superior to all comparative examples, fully demonstrating the rationality, feasibility, and universality of the technical solution of the present invention, and that it can stably produce bio-organic fertilizers that meet application requirements.

[0065] From the perspective of raw material system optimization, compared with Comparative Example 1 which only used a single microbial strain, Example 1 of the present invention showed an increase of 17.6% in organic matter content, 54.3% in available phosphorus content, 40.0% in available potassium content, 197.6% in viable microorganism count, 17.8% in pathogen kill rate, and 19.7% in germination index. This difference indicates that the multi-strain combination and synergistic optimization design adopted in the present invention can achieve highly efficient synergy in organic matter degradation, effective nutrient activation, and pathogen kill. Compared with the single-strain scheme, it has significant improvements in fertilizer nutrient supply capacity, microbial activity, and application safety. It is not a simple replacement of microorganisms, but a systematic optimization of the microbial application system.

[0066] From the perspective of raw material compatibility, Comparative Example 2, which uses an unreasonable raw material ratio, has an organic matter content that is 9.7% lower than that of Example 1, an available phosphorus content that is 24.4% lower, an available potassium content that is 19.1% lower, and a soil organic matter increase that is 47.6% lower. This result proves that the present invention, through precise optimization of the ratio of livestock and poultry manure, crop straw, and industrial organic waste, can achieve stable control of the carbon-nitrogen ratio, ensuring microbial fermentation efficiency and balanced nutrient supply. In contrast, unreasonable raw material ratios in existing technologies make it difficult to balance fermentation effect and nutrient supply. The raw material combination method of this solution has greater application advantages.

[0067] From the perspective of fermentation process optimization, Comparative Example 3, which uses a crude fermentation process, has an organic matter content 20.0% lower than Example 2, a pathogen kill rate 20.9% lower, and a germination index 17.1% lower. Furthermore, the germination index does not meet the standard for complete decomposition, indicating that the fertilizer's decomposition degree is substandard. In contrast, the segmented fermentation process used in this invention, through the orderly connection of low-temperature planting and high-temperature degradation, can shorten the fermentation cycle while improving fermentation thoroughness and pathogen kill efficiency. Compared to the crude fermentation process of existing technologies, its process stability and application effect are more outstanding.

[0068] From the perspective of diversified raw material application, Comparative Example 4, which did not add industrial organic waste residue, had an organic matter content 17.4% lower, an available phosphorus content 32.0% lower, and an available potassium content 28.9% lower than that of Example 3. This indicates that by incorporating industrial organic waste residue into the raw material system, this invention not only achieves the resource utilization of industrial waste but also supplements the fertilizer with phosphorus, potassium, and trace elements, enhancing the overall nutrient supply capacity of the fertilizer. Compared with traditional binary raw material combination schemes, it can better meet the comprehensive nutrient needs of crops.

[0069] Compared to Comparative Example 5, which uses a traditional composting method, the performance advantages of the embodiments of the present invention are more significant. The organic matter content of Examples 1 to 4 is 41.6% to 68.5% higher than that of Comparative Example 5, the available phosphorus content is 109.1% to 176.3% higher, the available potassium content is 61.9% to 116.0% higher, and the wheat plant height is 34.3% to 78.8% higher. This fully demonstrates that the technical solution of the present invention, compared to traditional composting technology, achieves significant improvements in fertilizer fertility, soil improvement effects, and crop growth promotion effects, and can better meet the needs of modern agricultural production for high-efficiency bio-organic fertilizers.

[0070] Compared to Example 2, Comparative Example 6, which uses a simple combination of existing microbial strains and processes, has a 17.5% lower organic matter content, a 30.9% lower available phosphorus content, a 27.2% lower available potassium content, and a 49.7% lower viable microbial count. This difference indicates that simple superposition of microbial strains and splicing of processes cannot achieve synergistic adaptation of various technical links. In contrast, this invention, through systematic optimization and deep adaptation of raw materials, microbial strains, and processes, constructs a complete technical application system that can simultaneously improve fertilizer fertility, soil improvement effects, and production efficiency, making its application value more prominent.

[0071] Test data from Example 4 show that even with the extreme combination of parameters from this scheme, the organic matter content still reaches 40.5%, the available phosphorus content is 178.2 mg / kg, the available potassium content is 195.6 mg / kg, and the viable microbial count is 15.8 × 10⁻⁶. 8 The CFU / g ratio and all performance indicators are far superior to all comparative examples, and meet the industry standards for bio-organic fertilizers. This result verifies the rationality and universality of the raw material ratio, inoculum quantity, and process parameter range set in this invention. It can cover different production conditions and application scenarios, effectively solving the problems of narrow parameter range and poor adaptability of existing technologies, and providing a reliable guarantee for large-scale production and diversified applications.

[0072] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A bio-organic fertilizer prepared by microbial fermentation, characterized in that, It is prepared by fermentation of raw materials and compound microbial strains. The raw materials include livestock and poultry manure, crop straw, industrial organic waste residue and composting agent. The compound microbial strains are a ternary combination of Bacillus subtilis, Bacillus megaterium phosphate-solubilizing and Saccharomyces cerevisiae, or a quaternary combination of Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, Saccharomyces cerevisiae and Bacillus mucilaginosus.

2. The bio-organic fertilizer according to claim 1, characterized in that, The proportions of the raw materials by weight are as follows: 45-65 parts of livestock and poultry manure, 15-30 parts of crop straw, 15-20 parts of industrial organic waste residue, and 5 parts of composting agent.

3. The bio-organic fertilizer according to claim 1, characterized in that, When the compound microbial strain is a ternary combination, the mass ratio of Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, and Saccharomyces cerevisiae is 3:2:1; when it is a quaternary combination, the mass ratio of Bacillus subtilis, Bacillus megaterium phosphate-solubilizing, Saccharomyces cerevisiae, and Bacillus mucilaginosus is 3-5:2-3:1-2:1-2.

4. The bio-organic fertilizer according to claim 1 or 2, characterized in that, The livestock and poultry manure is one of pig manure, chicken manure, or cow manure.

5. The bio-organic fertilizer according to claim 1 or 2, characterized in that, The crop straw is one of wheat straw, corn straw, or rice straw.

6. The bio-organic fertilizer according to claim 1 or 2, characterized in that, The industrial organic waste residue is one of brewer's grains, monosodium glutamate residue, or papermaking black liquor treatment residue.

7. The bio-organic fertilizer according to claim 1, characterized in that, The inoculation amount of the compound microbial strain is 1.0%-3.2% of the total mass of the raw materials.

8. A method for preparing the bio-organic fertilizer as described in claim 1, characterized in that, Includes the following steps: (1) Raw material pretreatment: Dry livestock and poultry manure to 53%-65% moisture content and remove impurities; crush crop straw to 1-3 cm particle size, or soak it in 0.8%-1.0% alkaline solution for 1.5-2 hours, rinse it with water until neutral, and then dry it to 52%-53% moisture content; dry industrial organic waste residue to 43%-48% moisture content and crush it to 0.8-2 cm particle size; (2) Mixed inoculation: Mix the pretreated raw materials with the composting agent evenly, and spray the activated compound microbial strains that have been soaked in sterile water at 30°C for 2-3 hours evenly into the mixture. The amount of sterile water added is 5 times the mass of the strains. Stir until the material is uniform, and control the total moisture content of the material to be 54%-65% and the pH value to be 6.8-7.

8. Glucose can be added optionally. (3) Fermentation treatment: Transfer the mixture into the fermentation tank, pile it up to a height of 90 cm, maintain the fermentation temperature at 48℃-63℃, turn the pile every 1-2 days, and ferment for 8-16 days. Segmented temperature control can be used. (4) Post-fermentation and aging: After fermentation, the material is transferred to the aging field, piled up to a height of 55 cm, covered with shade cloth, and ventilated or turned over regularly. After aging for 6-12 days, biological organic fertilizer is obtained.

9. The preparation method according to claim 8, characterized in that, The segmented temperature control is as follows: maintain the temperature at 53℃ in the early stage of fermentation and maintain the temperature at 63℃ in the later stage of fermentation.

10. The preparation method according to claim 8, characterized in that, The amount of glucose added during mixed inoculation is 0.5% of the total mass of the raw materials.