Chicken manure aerobic fermentation method reinforced by phosphorus and potassium dissolving functional bacteria

Abstract

The application discloses a chicken manure aerobic fermentation method strengthened by phosphorus and potassium dissolving functional bacteria and relates to the harmless treatment technical field of livestock breeding wastes. Fresh broiler chicken manure is used as the only raw material, and any biomass auxiliary material is not needed, a batch feeding continuous fermentation mode is adopted, directional strengthening and scientific supplement of high-activity high-temperature-resistant phosphorus and potassium dissolving compound functional bacteria agents are adopted, high-temperature fermentation compost with a water content of 45-55% is used for fermentation starting, and the loading amount is controlled to be 70-80% of the effective volume of the tank body, so that rapid harmless treatment of the broiler chicken manure and efficient activation of phosphorus and potassium nutrients are realized, the fermentation efficiency and product quality are greatly improved, the energy consumption is reduced, and the method is suitable for the continuous manure treatment demand of large-scale farms.

Description

Technical Field

[0001] This invention relates to the technical field of harmless treatment of livestock and poultry breeding waste, specifically a method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria. Background Technology

[0003] Existing tank fermentation technologies often suffer from problems such as reliance on external heating for temperature maintenance, low start-up efficiency, and unreasonable control of feed volume and moisture, which further restrict fermentation efficiency and product quality.

[0004] Meanwhile, existing tank-type aerobic fermentation technology faces several bottlenecks in its application: First, current fermentation processes generally require the addition of biomass additives such as straw, mushroom compost, and sawdust to adjust the material's moisture content and carbon-nitrogen ratio, which not only increases processing costs and the difficulty of raw material procurement but also prolongs the pretreatment process, making it difficult to achieve direct fermentation of broiler manure as a single raw material; Second, the high-temperature fermentation environment (above 60℃) inside the tank places high demands on the heat resistance of the fermentation agents. Conventional agents are easily deactivated under the high-temperature environment inside the tank, making it difficult to maintain their effectiveness, resulting in low fermentation efficiency and insufficient degradation of organic matter; Third, existing processes have poor activation effects on phosphorus and potassium elements in chicken manure, as most of the phosphorus in chicken manure... Potassium exists in organic and mineral fixed forms, and the proportion of readily available phosphorus and potassium that plants can absorb and utilize is low, limiting the fertilizer efficiency and commercial value of fermentation products. Fourth, the temperature and oxygen control processes in the fermentation process have poor adaptability and cannot meet the dual requirements of harmless treatment and nutrient preservation and activation. Problems such as incomplete inactivation of pathogens, severe nutrient loss during high-temperature periods, and damage to the activity of functional bacteria often occur. Moreover, temperature maintenance largely depends on external heating, resulting in high energy consumption and poor stability under extreme low-temperature conditions. Fifth, existing technologies do not clearly define the selection of fermentation start-up materials and moisture requirements, nor do they standardize the range of material loading, which can easily lead to problems such as start-up failure, insufficient accumulation of metabolic heat, or insufficient fermentation space. Summary of the Invention

[0005] To address the shortcomings of existing tank-type aerobic fermentation technology, such as the need to add biomass additives, poor heat resistance of microbial agents, low activation efficiency of phosphorus and potassium nutrients, poor adaptability to fermentation processes, insufficient continuity, uneven moisture distribution of materials, and unreasonable replenishment of microbial agents, as well as the dependence on external heating for temperature maintenance, low start-up efficiency, and unscientific control of loading amount and start-up raw material moisture, this invention proposes a method for aerobic fermentation of chicken manure enhanced with phosphorus and potassium solubilizing functional bacteria. The specific technical solution is as follows: A method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria, the method comprising the following steps: (1) Take fresh broiler manure, remove hard debris such as metal, stones, and plastic. The original moisture content of the material is 70-80%, and the pH value is 6.5-7.5 to obtain fermentation raw materials; (2) After Bacillus subtilis, Bacillus megaterium and Bacillus mucilaginosus were activated by slant culture and cultured in seed liquid, they were mixed in proportion to prepare a compound bacterial agent; (3) Control the amount of material to 70-80% of the effective volume of the tank. The starter compost is fermented in advance. After fermentation on the second day, the fermentation temperature is stable. Every day, the fermentation raw materials obtained in step (1) are transported to the fermentation tank for dynamic replenishment. Every week, 0.05-0.1% of the weight of the fermentation raw materials is added to the compound microbial agent described in step (2). The starter compost, fermentation raw materials and compound microbial agent are mixed evenly. Each batch of newly added raw materials is fermented after 7 days to obtain chicken manure organic fertilizer.

[0006] Furthermore, the ratio of the number of viable bacteria of Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus is (1-3):1:1.

[0007] Furthermore, the ratio of the number of viable bacteria of Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus is 2:1:1.

[0008] Furthermore, in step (3), after the first batch of fermentation raw materials are put into the fermentation tank, a batch feeding and continuous fermentation mode is adopted. Fresh chicken manure is added daily, and the material in the tank is controlled to maintain a loading of 70-80%. Compound microbial agent is added once a week, and the amount of inoculation is controlled at 0.05-0.1% of the daily feed amount of fresh chicken manure.

[0009] Furthermore, in step (3), the ventilation volume inside the fermenter is controlled at 2000-3000 m3 / h, the main shaft stirring speed is set at 1.0-2.0 r / h, and the stirring pauses for 1 minute after every 9° rotation and for 5 minutes after every full rotation.

[0010] Furthermore, in step (3), starting from the seventh day after feeding, the fermented chicken manure organic fertilizer at the bottom of the fermentation tank is discharged daily. The discharged fermented organic fertilizer is odorless and loose, with a moisture content controlled at 30-35%. After natural cooling, the organic fertilizer can be used directly as organic fertilizer, or it can be further decomposed for 30 days to become high-quality chicken manure organic fertilizer.

[0011] Furthermore, in step (3), the composting to be started is compost that is fermenting at high temperature, with a moisture content controlled at 45-55%.

[0012] Furthermore, in step (3), the fermentation tank is a vertical high-temperature aerobic fermentation tank, which can realize segmented fermentation, consisting of three areas from top to bottom: a heating zone, a high-temperature harmless zone, and a composting and fertilizer preservation zone.

[0013] Furthermore, the fermentation time of the raw materials in the heating zone is between 0 and 24 hours, and the temperature inside the tank is between 25 and 60°C; the fermentation time of the raw materials in the high-temperature harmless treatment zone is between 24 and 96 hours, and the temperature inside the tank is between 60 and 70°C; the fermentation time of the raw materials in the composting and fertilizer preservation zone is between 96 and 168 hours, and the temperature inside the tank is stable at 45 and 55°C.

[0014] The beneficial technical effects of this invention are as follows: using fresh broiler manure as the sole raw material, without adding any biomass additives, and adopting a batch-feeding continuous fermentation mode, the invention optimizes the material distribution and moisture gradient within the tank through targeted enhancement and scientific supplementation of highly active, high-temperature resistant phosphorus and potassium solubilizing compound functional bacteria, combined with a staged temperature and oxygen control fermentation process in a vertical fermenter; at the same time, it is clear that the temperature inside the tank is mainly maintained by the metabolic heat generated by the decomposition of chicken manure, and in extreme special circumstances (such as winter), hot air can be introduced for auxiliary heating; the fermentation start-up uses high-temperature fermentation compost with a moisture content of 45-55%, and the loading amount is controlled at 70-80% of the effective volume of the tank, achieving rapid and harmless treatment of broiler manure and efficient activation of phosphorus and potassium nutrients, significantly improving fermentation efficiency and product quality, reducing energy consumption, and meeting the continuous manure treatment needs of large-scale farms. Detailed Implementation

[0015] Preferred embodiments of the present invention are described below. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0016] This invention proposes an aerobic fermentation method for chicken manure enhanced with phosphorus- and potassium-solubilizing functional bacteria. Fresh broiler manure is used as the sole fermentation raw material, without the addition of biomass additives. A batch-feeding continuous fermentation mode is adopted, and inoculation is enhanced by phosphorus- and potassium-solubilizing compound functional bacteria. Combined with the staged temperature and oxygen control fermentation process of a vertical high-temperature aerobic fermenter, the continuous harmless treatment and resource utilization of broiler manure can be achieved.

[0017] Fresh broiler manure is pre-processed by removing hard debris such as stones, metal, and plastic. The initial moisture content of the material is 70-80%, and the pH value is adjusted to 6.5-7.5, resulting in raw material for fermentation. Removing hard debris mitigates equipment operation risks. Furthermore, the initial organic matter content of the raw material is 42.5%, total nitrogen 4.1%, total phosphorus 5.2%, and total potassium 3.2%. Its own carbon-nitrogen ratio, organic matter, and nutrient reserves can fully support the full-cycle growth and metabolism of heat-resistant phosphorus- and potassium-solubilizing bacteria and indigenous fermentation microorganisms. No additional straw, mushroom compost, sawdust, or other auxiliary materials are needed to adjust the carbon-nitrogen ratio, simplifying the pretreatment process, reducing raw material procurement and processing costs, and meeting the on-site treatment needs of large-scale farms.

[0018] The selection of fresh raw materials avoids problems such as anaerobic putrefaction, excessive growth of pathogens, nitrogen volatilization and loss, and degradation of organic matter caused by prolonged storage of feces. It ensures the activity and uniformity of the fermentation substrate and avoids problems such as contamination by miscellaneous bacteria, nutrient dilution, and poor material uniformity caused by the introduction of auxiliary materials. It provides a stable and high-quality substrate environment for the rapid colonization and proliferation of functional bacteria.

[0019] The initial moisture content of the pretreated raw material is 78%, which is the optimal range for the growth and metabolism of aerobic fermentation microorganisms. This moisture content meets the water requirements for the growth and reproduction of microbial cells, and avoids the problems of insufficient material porosity, anaerobic fermentation, and slow temperature rise caused by excessively high moisture content, as well as the inhibition of microbial metabolic activity caused by excessively low moisture content. After being put into the tank, the pretreated fresh chicken manure can help the functional bacteria to quickly colonize and multiply after inoculation. At the same time, the initial moisture content of 78% is consistent with the original moisture value of most fresh chicken manure, eliminating the need for additional water replenishment or dehydration processes, making it more convenient to use and effectively reducing the labor and material costs of moisture adjustment. The initial moisture content is perfectly suited to the moisture gradient design of the batch fermentation tank. The surface layer of fresh chicken manure has a moisture content of 70-80%, which gradually decreases as the material migrates downwards and the fermentation process progresses. Finally, the moisture content of the bottom layer is stable at 30-35%, eliminating the need for additional dehydration and drying treatment. At the same time, it precisely matches the moisture requirements of microorganisms in the three stages of heating zone, high-temperature harmless treatment zone, and composting and fertilizer preservation zone, ensuring the process stability of each fermentation stage.

[0020] After pretreatment to remove hard impurities, the uniformity and flowability of the material are greatly improved, making it perfectly compatible with the hydraulic stirring system and high-pressure ventilation system inside the tank. On the one hand, it avoids problems such as uneven mixing, local clumping, ventilation short circuits, and anaerobic dead zones caused by hard impurities. It ensures that the material inside the tank is fully mixed and in contact with the inoculated compound functional bacteria and the introduced oxygen, greatly improving mass transfer and oxygen transfer efficiency. This promotes the rapid metabolism and decomposition of organic matter by aerobic microorganisms, continuously generating metabolic heat. The temperature inside the tank is mainly maintained by the metabolic heat of the chicken manure itself, with auxiliary heating only required in extreme low-temperature environments, significantly reducing fermentation energy consumption. On the other hand, it ensures the precise implementation of the staged temperature and oxygen control process, ensuring that the ventilation volume, stirring speed, and temperature control of the heating zone, high-temperature harmless treatment zone, and composting and fertilizer preservation zone are completely in line with the process settings. It ensures that the high temperature above 60℃ is maintained for more than 72 hours, completely inactivating pathogens and parasite eggs. At the same time, it enables phosphorus and potassium solubilizing bacteria to continuously secrete extracellular enzymes and activate phosphorus and potassium nutrients, ultimately compressing the continuous fermentation cycle to 7 days and greatly improving the efficiency of manure treatment.

[0021] The phosphorus- and potassium-solubilizing compound functional bacterial agent used in this invention is composed of Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus. All three strains are thermotolerant and can maintain metabolic activity at high temperatures of 60-70℃. The compound bacterial agent has an effective viable count of... The high viable bacterial count ensures rapid colonization and continuous function of the strains within the tank. Among them, *Bacillus subtilis* rapidly decomposes organic matter and increases the fermentation temperature rise rate, while also possessing phosphorus-solubilizing capabilities; *Bacillus megaterium* is a highly efficient organic phosphorus-degrading strain that decomposes insoluble organic phosphorus in chicken manure, converting it into readily available phosphorus that plants can absorb; and *Bacillus mucilaginosus* is a highly efficient potassium-solubilizing strain that decomposes silicate minerals, releasing fixed potassium, and simultaneously secretes extracellular polysaccharides, enhancing the fertilizer's water and fertilizer retention capacity. The three strains work synergistically, continuously performing organic matter degradation and phosphorus and potassium solubilization throughout the entire tank fermentation cycle. Adapting to the high-temperature, high-shear fermentation environment within the tank, and working in synergy with composting startup, they further improve fermentation startup efficiency.

[0022] In existing technologies, Bacillus subtilis, yeast, and lactic acid bacteria are typically selected as functional strains in compound inoculants to achieve chicken manure fermentation. This patent does not simply replace conventional strains; rather, it addresses problems in existing tank fermentation technologies such as the lack of targeted phosphorus and potassium solubilization functions, poor compatibility of strains with the high-temperature aerobic tank fermentation environment, insufficient stability in continuous fermentation, and low activation efficiency of phosphorus and potassium nutrients. Specific advantages are as follows: Bacillus megaterium can secrete large amounts of extracellular enzymes such as acid phosphatase, alkaline phosphatase, and phytase, which can efficiently decompose insoluble organic phosphorus and fixed phosphorus minerals such as calcium phosphate / iron aluminum phosphate in chicken manure, directly converting them into readily available phosphorus that can be absorbed and utilized by plants. In contrast, yeast and lactic acid bacteria in the paper can only achieve weak dissolution of phosphorus through metabolic acid production, and they do not have the ability to secrete extracellular enzymes for targeted phosphorus solubilization. Their organic phosphorus mineralization efficiency is extremely low, and they cannot achieve deep activation of phosphorus in chicken manure.

[0023] Bacillus mucilaginosus, also known as silicate bacteria, is a dedicated potassium-solubilizing bacterium. It can efficiently release potassium fixed in chicken manure by secreting extracellular polysaccharides, organic acids, and other substances, thereby disrupting the crystal lattice structure of silicate / aluminosilicate minerals. It also has the function of phosphorus solubilization and releasing trace elements. In contrast, yeast and lactic acid bacteria lack the biological ability to decompose mineral lattices. Their activation of potassium can only achieve weak dissolution through metabolic acid production, and their potassium-solubilizing efficiency is less than 1 / 10 that of Bacillus mucilaginosus, making it completely impossible to achieve efficient release of fixed potassium.

[0024] The Bacillus megaterium and Bacillus mucilaginosus selected in this patent are both thermoresistant Bacillus species that can form spores in a high-temperature environment of 60-70℃ to resist extreme stress. When the temperature is suitable, they germinate rapidly and maintain high metabolic activity, and can continuously and stably perform their functions during the entire 7-day fermentation cycle (especially in the high-temperature harmless zone). In contrast, yeast and lactic acid bacteria are non-stress-resistant microorganisms without spore protection. When the ambient temperature exceeds 55℃, they will undergo large-scale inactivation and death. In the high-temperature environment of 60-70℃ for more than 72 hours in this patent, they basically cannot survive, let alone continuously perform their metabolic functions. Furthermore, this patent is a fully aerobic fermentation system that continuously supplies oxygen through a high-pressure vortex ventilation system. Both Bacillus megaterium and Bacillus mucilaginosus are strict aerobic bacteria, exhibiting the strongest metabolic activity and fastest proliferation rate in a sufficiently oxygenated environment, allowing them to quickly colonize the material and form a dominant bacterial community. In contrast, yeast is a facultative anaerobic and lactic acid bacteria is an anaerobic. Their growth and metabolism are significantly inhibited in a continuously aerobic environment, resulting in a slow proliferation rate and weak colonization ability. Consequently, they cannot form a stable dominant bacterial community in the aerobic fermentation system and are unable to exert their effects continuously.

[0025] The specific methods for activating the bacterial slant culture are as follows: Specialized culture media were prepared according to the characteristics of the strains, dispensed into test tubes, and autoclaved at 121℃ for 20 minutes. The media were then cooled and solidified on slant agar, with the pH controlled between 6.5 and 7.5 to suit the fermentation environment. *Bacillus subtilis* and *Bacillus megaterium* were cultured on general nutrient agar (NA) medium (1000 mL distilled water system), containing 10.0 g peptone, 3.0 g beef extract, 5.0 g sodium chloride, and 18.0 g agar, with a pH of 7.0-7.2. *Bacillus mucilaginosus* was cultured on a silicate bacteria-specific medium (1000 mL distilled water system), containing 10.0 g sucrose, 0.5 g dipotassium hydrogen phosphate, 0.2 g magnesium sulfate, 0.1 g calcium chloride, 0.2 g sodium carbonate, and 18.0 g agar, with a pH of 7.0-7.5.

[0026] Inside the clean bench, using an inoculation loop that has been sterilized by flaming and cooled, take one loop of the preserved bacterial culture (one loop for slant culture, one loop for glycerol culture). The bacterial suspension was streaked in a zigzag pattern on the surface of an agar slant, with aseptic technique applied throughout to prevent contamination. *Bacillus subtilis* and *Bacillus megaterium* were incubated at 37°C for 12-18 hours to obtain morphologically uniform single colonies; *Bacillus mucilaginosus* was incubated at 30°C for 48-72 hours, and single colonies with clear transparent zones and viscous colonies were selected. To match the high-temperature fermentation environment of chicken manure at 60-70°C, the initial cultured single colonies were transferred to fresh agar slant, and *Bacillus subtilis* / *Bacillus megaterium* were incubated at 60°C for 24 hours, and *Bacillus mucilaginosus* was incubated at 55°C for 72 hours. This process was repeated for three generations to retain stable strains that exhibited normal growth under high temperatures and strong spore-forming ability.

[0027] The specific methods for scaling up the above seed culture are as follows: 1. Primary seed culture (shake flask) for scale-up Bacillus subtilis and Bacillus megaterium were cultured in NB nutrient broth (1000 mL distilled water system) containing 10.0 g peptone, 3.0 g beef extract, and 5.0 g sodium chloride, with a pH of 7.0-7.2. Bacillus mucilaginosus was cultured in agar-free silicate broth (1000 mL distilled water system) with the same formulation as its slant culture medium (agar-free), with a pH of 7.0-7.5. After aliquoting into Erlenmeyer flasks, the media were autoclaved at 121°C for 20 min and then cooled to room temperature before use.

[0028] Inside the clean bench, use an inoculation loop to take one loopful of activated and qualified slant culture and inoculate it into a 500mL Erlenmeyer flask containing 100mL of sterile liquid culture medium. Inoculate each strain separately to prevent cross-contamination.

[0029] Bacillus subtilis and Bacillus megaterium were cultured at 180-220 r / min and 37℃ for 12-16 h. The termination conditions were that the bacterial cells entered the late logarithmic growth phase, the spore formation rate was ≥30%, and there were no contaminating bacteria. Bacillus mucilaginosus was cultured at 160-180 r / min and 30℃ for 24-48 h. The termination conditions were that the bacterial solution was viscous, the bacterial cells were in the logarithmic growth phase, spores began to form, and there were no contaminating bacteria.

[0030] Secondary seed culture (seed tank) scale-up culture The culture medium formula is consistent with the primary seed culture medium of the corresponding strain. It is prepared according to the effective volume of the seed tank, sterilized by high-pressure steam at 121℃ for 30 minutes, and cooled to the inoculation temperature. The tank is kept under positive pressure and sterile throughout the process.

[0031] Bacillus subtilis was cultured at 37℃, with the temperature raised to 55℃ for 4 hours at the end of the incubation period. The aeration rate in the container was 1:0.8-1:1.2 VVM, the stirring speed was 150-200 r / min, and the culture time was 12-18 hours. The termination criterion was a viable count ≥5.0 × 10⁻⁶. 9 CFU / mL, spore formation rate ≥80% and free of contaminating bacteria; Bacillus megaterium culture parameters consistent with Bacillus subtilis; Bacillus mucilaginosus cultured at 30℃, with the final temperature increased to 50℃ for acclimatization for 6 hours, aeration rate of 1:0.6-1:0.8 VVM, stirring speed of 120-150 r / min, cultured for 36-48 hours, with viable cell count as the termination criterion. The spore formation rate is ≥70% and there are no other bacteria.

[0032] This patent employs a batch-feed continuous fermentation mode, where materials continuously migrate downwards within the tank, and the accompanying hydraulic stirring system generates mechanical shearing force. The spore structure of Bacillus megaterium and Bacillus mucilaginosus can resist mechanical shearing damage, allowing them to rapidly colonize fresh materials during continuous feeding. Only weekly replenishment of the inoculant is needed to maintain system stability. In contrast, yeast and lactic acid bacteria lack spore protection, and mechanical shearing easily causes cell rupture and death. During continuous fermentation, the bacterial population rapidly declines, requiring frequent and large-scale replenishment of the inoculant, with the highest addition reaching 0.5%, which is 5-10 times the amount used in this patent. This results in extremely poor fermentation stability and significantly increased processing costs.

[0033] The batch-feeding continuous fermentation mode adopted in this invention can accurately adapt to the continuous manure production needs of large-scale farms. The specific fermentation system design is as follows: the material layer height in the vertical high-temperature aerobic fermentation tank is stably maintained at 2.4 meters, corresponding to 70-80% of the effective volume of the tank. This ensures sufficient fermentation space and effectively concentrates the metabolic heat generated by the decomposition of chicken manure, avoiding the problems of insufficient material leading to heat loss and excessive material leading to insufficient fermentation space. The surface layer is always fresh chicken manure (70-80% moisture content). With the daily operation of the stirring device, the fresh chicken manure on the surface gradually migrates downwards, and fresh chicken manure is replenished daily, maintaining the material volume at 70-80%. Due to differences in the fermentation process, a clear moisture gradient forms from top to bottom within the tank, decreasing from 70-80% in the surface layer of fresh chicken manure to approximately 35% in the bottom layer of fermenting chicken manure. The compost used to initiate fermentation has a moisture content controlled between 45-55%, a range optimal for microbial growth and metabolism, facilitating rapid initiation of the fermentation process and promoting the rapid colonization and proliferation of functional bacteria. This reasonable moisture gradient precisely matches the growth and metabolic needs of microorganisms at different fermentation stages, effectively improving fermentation efficiency. The complete fermentation cycle of fresh chicken manure within the tank is approximately 7 days. After 7 days of phased high-temperature fermentation, the material is discharged from the bottom outlet of the tank. At this point, the discharged material has undergone harmless treatment, is odorless, loose, and has a moisture content of 30-35%. After 30 days of composting and maturation, it becomes high-quality tank-grown chicken manure organic fertilizer.

[0034] This invention optimizes the inoculation and replenishment methods of the microbial agent, balancing fermentation effect and cost control: During the initial fermentation start-up, a compound functional microbial agent is added at 0.05%~0.1% of the weight of the raw materials to be fermented. Combined with high-temperature fermentation compost with a moisture content of 45~55% as the starting substrate, this ensures rapid colonization and proliferation of the strains in the material, quickly initiating the fermentation process. In the continuous production stage, the highly active functional microbial community remaining in the tank can be fully utilized. It is not necessary to inoculate the microbial agent in full with each replenishment; only weekly replenishment of the compound microbial agent is required, with the inoculation amount controlled at 0.05%~0.1%. This maintains the high activity of the fermentation system, effectively reducing the cost of microbial agent use while ensuring the stability of the fermentation effect.

[0035] The phased temperature- and oxygen-controlled fermentation process of this invention is precisely designed for the environmental characteristics, material moisture gradient distribution, and microbial growth and metabolic characteristics of continuous fermentation in batches in tanks. It also fully considers temperature maintenance, start-up methods, and material loading requirements: During the heating phase, optimized ventilation and stirring parameters, combined with the advantages of starting compost with a moisture content of 45-55%, provide a suitable growth environment for functional bacteria, promoting their rapid colonization and proliferation. Simultaneously, the metabolic heat generated by chicken manure decomposition allows the material to rapidly heat to above 60°C within 24 hours. In extreme low-temperature environments, hot air can be introduced for auxiliary heating, significantly shortening the fermentation start-up time and preventing start-up failure due to excessively low temperatures; during the high-temperature harmless treatment phase… Under the premise of ensuring a sustained high temperature of over 60℃ for more than 72 hours to completely inactivate pathogens and parasite eggs in the material, sufficient oxygen and a suitable growth environment are provided for the thermophilic phosphorus- and potassium-solubilizing bacteria by stably controlling the ventilation volume and stirring frequency. During this stage, the high temperature is mainly maintained by the metabolic heat generated by the continuous decomposition of chicken manure, without the need for additional auxiliary heating, thus reducing energy consumption and achieving simultaneous harmless treatment and nutrient activation. During the composting and fertilizer preservation period, the temperature inside the tank is gradually reduced to effectively reduce nitrogen volatilization and loss, promote the composting process of the material, and further increase the number of viable functional bacteria and the content of readily available nutrients. The temperature inside the tank is still maintained by the metabolic heat generated by the decomposition of the remaining organic matter, ensuring the quality of the bio-organic fertilizer of the fermentation product.

[0036] The phosphorus- and potassium-solubilizing compound functional bacterial agent used in this invention is composed of Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus. All three strains are thermotolerant and can maintain metabolic activity at high temperatures of 60-70℃. The compound bacterial agent has an effective viable count of... The high viable bacterial count ensures rapid colonization and continuous function of the strains within the tank. Among them, *Bacillus subtilis* rapidly decomposes organic matter and increases the fermentation temperature rise rate, while also possessing phosphorus-solubilizing capabilities; *Bacillus megaterium* is a highly efficient organic phosphorus-degrading strain that decomposes insoluble organic phosphorus in chicken manure, converting it into readily available phosphorus that plants can absorb; and *Bacillus mucilaginosus* is a highly efficient potassium-solubilizing strain that decomposes silicate minerals, releasing fixed potassium, and simultaneously secretes extracellular polysaccharides, enhancing the fertilizer's water and fertilizer retention capacity. The three strains work synergistically, continuously performing organic matter degradation and phosphorus and potassium solubilization throughout the entire tank fermentation cycle. Adapting to the high-temperature, high-shear fermentation environment within the tank, and working in synergy with composting startup, they further improve fermentation startup efficiency. Example 1

[0037] Fresh broiler manure from large-scale broiler farms was collected, and hard debris such as stones and metals were removed. After testing, the raw material had an initial organic matter content of 42.5%, total nitrogen of 4.1%, total phosphorus of 5.2%, total potassium of 3.2%, and an initial moisture content of 78%. No biomass additives were required, and it was ready to be used as the raw material for fermentation.

[0038] Thermoresistant Bacillus subtilis, Bacillus megaterium, and Bacillus mucilage were activated separately by slant culture and then cultured in seed liquid. They were then mixed at a viable cell count ratio of 2:1:1 to prepare a compound microbial agent. The effective viable cell count of the compound microbial agent was 1.2 × 10⁻⁶. 10 CFU / g.

[0039] Compost undergoing high-temperature fermentation was selected as the start-up material, with its moisture content controlled at 50% (within the suitable range of 45-55%). This was then fed into the fermentation tank as the start-up substrate. A batch-feeding continuous fermentation mode was adopted, with the raw materials to be fermented being transported into the fermentation tank via a closed tipping bucket elevator. The loading volume was controlled at 75% of the tank's effective volume (within the range of 70-80%), corresponding to a material layer height of 2.4 meters. During the initial fermentation, a compound microbial agent was added at 0.08% of the weight of the raw materials to be fermented. The start-up compost, raw materials to be fermented, and microbial agent were mixed evenly using the tank's hydraulic stirring system, ensuring uniform distribution of the microbial agent within the materials. After entering continuous production, fresh chicken manure with a moisture content of approximately 75% was added daily to maintain a stable material layer height of 2.4 meters and a loading volume of 75%. The material was moved downwards daily by the stirring device. A compound microbial agent was added weekly at an inoculation rate of 0.08% to maintain the high activity of the fermentation system.

[0040] The material inside the tank exhibits a clear moisture gradient from top to bottom. The surface layer of fresh chicken manure has a moisture content of approximately 75%, the initial compost layer has a moisture content of 50%, and the bottom layer of fermenting chicken manure has a moisture content of approximately 35%. The fermentation cycle of fresh chicken manure in the tank is approximately 7 days, with specific stage controls as follows: ① Heating Zone (material layer height inside the tank is between 2.0-2.4m, continuous fermentation time is between 0-24h): Control the temperature inside the tank of this material layer at 45-55℃, and the ventilation volume at 2900m³ / h. 3 The main shaft stirring speed is 2.0 r / h, with a 1-minute pause after every 9° rotation and a 5-minute pause after each full rotation. Utilizing the high temperature advantage of the composting start-up and the metabolic heat generated by chicken manure decomposition, the temperature inside the tank reaches 55.2℃ after 24 hours of fermentation, and the effective viable bacteria count increases to 8.5 × 10⁻⁶. 8 CFU / g.

[0041] ② High-temperature harmless treatment period (material layer height inside the tank is between 0.8-2.0m, continuous fermentation time is between 24-96h): control the temperature inside the tank to be stable at 65-68℃, and the ventilation volume is 2900m³ / h. 3 The main shaft stirring speed is 2.0 r / h, and the stirring start / stop mode is the same as that of the heating zone. During this stage, the high temperature is maintained by the metabolic heat generated from the continuous decomposition of chicken manure. The temperature remains above 60℃ for 72 hours, completely inactivating pathogens and parasite eggs. Simultaneously, phosphorus- and potassium-solubilizing bacteria continue to function. After 96 hours of fermentation, the organic matter content of the material decreases to 41.3%, and the effective viable bacteria count increases to 1.1 × 10⁻⁶. 9CFU / g. ③ Composting and fertilizer retention period (material layer height in the tank is between 0-0.8m, continuous fermentation time is between 96-168h): control the temperature inside the tank to gradually decrease to 50-55℃, and the ventilation volume is 2000m³ / h. 3 / h, the main shaft stirring speed is 2.0r / h, and the stirring start and stop mode remains unchanged; at this stage, the material completes the decomposition and humification, and the functional bacteria further increase the number of effective live bacteria and the content of readily available nutrients in the material, while reducing nitrogen loss. The temperature inside the tank is maintained by the metabolic heat generated by the decomposition of the remaining organic matter. When fermentation reaches 168h, the fermentation process inside the tank is completed, and the material is discharged from the bottom outlet.

[0042] The fermentation products discharged from the bottom of the tank were odorless and loose. Testing revealed a moisture content of 32%, organic matter of 41.2%, total nitrogen of 3.8%, phosphorus pentoxide of 5.5%, potassium oxide of 3.3%, total nutrients of 12.6%, and an effective viable bacteria count of 1.2 × 10⁻⁶. 9 The product has the following characteristics: CFU / g, 100% mortality rate of roundworm eggs, 0 fecal coliforms / g, available phosphorus content of 3.2%, and available potassium content of 2.2%. After composting the product for 30 days, a high-quality canned chicken manure organic fertilizer is obtained, and all indicators fully meet the NY884-2012 standard for biological organic fertilizer. Example 2

[0043] Take fresh broiler manure from large-scale broiler farms, remove hard debris, and the initial organic matter content of the raw material is 41.8%, total nitrogen 4.0%, total phosphorus 5.1%, total potassium 2.7%, and initial moisture content 75%. No biomass additives are needed, and this is the raw material to be fermented.

[0044] Take fresh broiler manure from large-scale broiler farms, remove hard debris, and the initial organic matter content of the raw material is 41.8%, total nitrogen 4.0%, total phosphorus 5.1%, total potassium 2.7%, and initial moisture content 75%. No biomass additives are needed, and this is the raw material to be fermented.

[0045] Compost undergoing high-temperature fermentation was selected as the starter material, with its moisture content controlled at 45%, and fed into the fermentation tank as the starter substrate. A batch-feed continuous fermentation mode was adopted, feeding the fermentation tank until the filling volume reached 70% of the tank's effective volume, corresponding to a material layer height of 2.4 meters. A compound microbial agent was added at 0.05% of the weight of the raw material to be fermented. The starter compost, materials, and microbial agent were mixed evenly using a stirring system. Subsequently, fresh chicken manure with a moisture content of approximately 70% was added daily to maintain a stable material layer height of 2.4 meters and a filling volume of 70%. The material migrated downwards with the stirring device. A compound microbial agent was added weekly at an inoculation rate of 0.05% to ensure the stability of the fermentation system.

[0046] The fermentation cycle of fresh chicken manure in the tank is approximately 7 days. Combined with the continuous fermentation characteristics of batch feeding, the moisture content of the materials inside the tank is clearly defined: the surface layer of fresh chicken manure has a moisture content of about 70%, the initial composting moisture content is 45%, and the bottom layer of fermenting chicken manure has a moisture content of about 35%. The temperature inside the tank is mainly maintained by the metabolic heat of the chicken manure. During periods of low temperature in winter, auxiliary heating with hot air is activated to ensure that the temperature reaches the target. Specific stage control is as follows: ① Heating Zone (material layer height inside the tank is between 2.0-2.4m, continuous fermentation time is between 0-24h): Control the temperature inside the tank of this material layer at 45-55℃, and the ventilation volume at 3000m³ / h. 3 The main shaft stirring speed was 1.5 r / h, and the stirring start-stop mode was the same as in Example 1. Utilizing the high temperature advantage of starting composting and the metabolic heat generated by chicken manure decomposition, after 24 hours of fermentation, the temperature inside the tank rose to 66.1℃, and the effective viable bacteria count increased to 7.8 × 10⁻⁶. 8 CFU / g.

[0047] ② High-temperature harmless treatment zone (material layer height inside the tank is between 0.8-2.0m, continuous fermentation time is between 24-96h): The temperature inside the tank is controlled to be stable at 65-68℃, and the ventilation volume is 3000m³. 3 The main shaft stirring speed is 1.5 r / h, and the stirring start / stop mode is the same as that of the heating zone; it relies on the metabolic heat of chicken manure to maintain high temperature, without the need for additional auxiliary heating, and can maintain a high temperature above 60℃ for more than 72 hours, with the effective viable bacteria count increasing to 1.0 × 10⁶ after 96 hours. 9 CFU / g.

[0048] ③ Composting and Fermentation Zone (material layer height in tank between 0-0.8m, continuous fermentation time between 96-168h): Control the temperature inside the tank to gradually decrease to 45-50℃, and maintain a ventilation volume of 3000m³ / h. 3 The main shaft stirring speed is 1.5 r / h, and the stirring start / stop mode is the same as that of the heating zone; the temperature inside the tank is maintained by the metabolic heat of the remaining organic matter, and the material is discharged from the bottom outlet after 168 hours.

[0049] The discharged fermentation product had a moisture content of 31.2%. Analysis revealed 41.1% organic matter, 3.7% total nitrogen, 5.3% phosphorus pentoxide, 2.1% potassium oxide, 12.1% total nutrients, and 1.0 × 10⁻⁶ viable bacteria. 9 CFU / g, 100% mortality rate of roundworm eggs, 0 fecal coliforms / g, available phosphorus content 2.9%, available potassium content 2.1%; after 30 days of composting and decomposition, it becomes a high-quality tank-type chicken manure organic fertilizer, meeting the requirements of NY884-2012 standard.

[0050] The strain combination in this patent is not an independent technical feature, but rather forms a complete synergistic system with core processes such as "fermentation with a single raw material without auxiliary materials, continuous fermentation with batch feeding, staged temperature and oxygen control, and autonomous maintenance of tank temperature by metabolic heat." Specific advantages are as follows: This patent requires the material to be rapidly heated to above 60°C within 24 hours. Bacillus megaterium and Bacillus subtilis work together to rapidly decompose large molecular organic matter, protein, cellulose, etc. in chicken manure, releasing a large amount of metabolic heat, greatly improving the heating rate, perfectly matching the process requirements of the heating zone, and ensuring successful fermentation start-up even in extreme low temperature environments. This patent requires a sustained high temperature of over 60℃ for more than 72 hours to completely inactivate pathogens and parasite eggs. Bacillus megaterium and Bacillus mucilaginosus continuously metabolize under high temperature, maintaining stable metabolic heat within the tank without relying on external heating. Simultaneously, their metabolic products inhibit the growth of pathogens and putrefactive bacteria, creating a synergistic effect with high-temperature harmlessness, ultimately achieving a 100% mortality rate for Ascaris eggs and a fecal coliform count ≤100 CFU / g for harmlessness. Using fresh broiler manure as the sole raw material, without the need for any biomass additives, the system requires extremely high levels of ability from the bacterial strains to decompose organic matter and regulate the microenvironment. Bacillus megaterium and Bacillus mucilaginosus can efficiently decompose recalcitrant organic matter in chicken manure, autonomously adjusting the carbon-to-nitrogen ratio and pH value to a suitable fermentation range, making them suitable for fermentation systems without additives.

[0051] The fermentation product of this patent, after 7 days of in-tank fermentation and 30 days of maturation, has a total nutrient content (N+P2O5+K2O) ≥12% and an effective viable bacteria count ≥1.0×10⁻⁶. 9 With a CFU / g, all indicators are superior to the national standard NY884-2012 "Bio-organic Fertilizer", and it can be sold directly as a commercial bio-organic fertilizer. Bacillus megaterium and Bacillus mucilaginosus can not only solubilize phosphorus and potassium, but their metabolites can also promote crop root growth and enhance stress resistance. The fermentation products have the dual functions of nutrient supply and growth promotion and stress resistance. At the same time, their spore structure can ensure that the survival rate of live bacteria is high and the activity is stable during the storage of organic fertilizer, resulting in a long product shelf life.

[0052] Although the invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0053] The technical solution of the present invention has been described in conjunction with preferred embodiments. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions resulting from these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria, characterized in that: The method includes the following steps: (1) Take fresh broiler manure, remove hard debris such as metal, stones, and plastic. The original moisture content of the material is 70-80%, and the pH value is 6.5-7.5 to obtain fermentation raw materials; (2) After Bacillus subtilis, Bacillus megaterium and Bacillus mucilaginosus were activated by slant culture and cultured in seed liquid, they were mixed in proportion to prepare a compound bacterial agent; (3) The fermentation tank is pre-filled with starter compost that is fermenting at high temperature. The amount of material is controlled to be 70-80% of the effective volume of the tank. The starter compost is fermented in advance. After the fermentation temperature stabilizes on the second day, the fermentation raw materials obtained in step (1) are transported to the fermentation tank for dynamic replenishment every day. The compound microbial agent described in step (2) is added weekly at 0.05-0.1% of the weight of the fermentation raw materials. The starter compost, fermentation raw materials and compound microbial agent are mixed evenly. Each batch of newly added raw materials is fermented after 7 days to obtain chicken manure organic fertilizer.

2. The method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria according to claim 1, characterized in that: The ratio of viable counts of Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus is (1-3):1:

1.

3. The method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria according to claim 2, characterized in that: The ratio of viable bacteria mass of Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus is 2:1:

1.

4. The method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria according to claim 1, characterized in that: In step (3), after the first batch of fermentation raw materials are put into the fermentation tank, a batch feeding and continuous fermentation mode is adopted. Fresh chicken manure is added daily, and the material in the tank is controlled to maintain 70-80% of the loading amount. Compound microbial agent is added once a week, and the amount of inoculation is controlled at 0.05-0.1% of the daily feed amount of fresh chicken manure.

5. The method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria according to claim 1, characterized in that: In step (3), the ventilation volume in the fermentation tank is controlled at 2000-3000 m3 / h, the main shaft stirring speed is set at 1.0-2.0 r / h, and the stirring pauses for 1 minute after every 9° rotation and for 5 minutes after every full rotation.

6. The method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria according to claim 1, characterized in that: In step (3), starting from the seventh day after feeding, the fermented chicken manure organic fertilizer at the bottom of the fermentation tank is discharged daily. The discharged fermented organic fertilizer is odorless and loose, with a moisture content controlled at 30-35%. After natural cooling, the organic fertilizer can be used directly as organic fertilizer, or it can be further decomposed for 30 days to become high-quality chicken manure organic fertilizer.

7. The method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria according to claim 1, characterized in that: In step (3), the composting to be started is compost that is fermenting at high temperature, with a moisture content controlled at 45-55%.

8. The method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria according to claim 1, characterized in that: In step (3), the fermentation tank is a vertical high-temperature aerobic fermentation tank. The fermentation tank can realize segmented fermentation, which consists of three areas from top to bottom: heating zone, high-temperature harmless treatment zone and composting and fertilizer preservation zone.

9. The method for aerobic fermentation of chicken manure enhanced with phosphorus- and potassium-solubilizing bacteria according to claim 8, characterized in that: The fermentation time of the raw materials in the heating zone is between 0 and 24 hours, and the temperature inside the tank is between 25 and 60°C; the fermentation time of the raw materials in the high-temperature harmless treatment zone is between 24 and 96 hours, and the temperature inside the tank is between 60 and 70°C; the fermentation time of the raw materials in the composting and fertilizer preservation zone is between 96 and 168 hours, and the temperature inside the tank is stable at 45 and 55°C.