Low-temperature-resistant and low-oxygen-resistant organic fertilizer leavening agent for plateau regions, preparation method and fermentation method

Abstract

The invention relates to the field of microbial fermentation, in particular to a low-temperature-resistant and low-oxygen-resistant organic fertilizer leavening agent for plateau regions, a preparation method and a fermentation method, and the low-temperature-resistant and low-oxygen-resistant organic fertilizer leavening agent comprises quaternary compound bacteria and a composite carrier, the quaternary compound bacteria are formed by compounding psychrophilic heat-producing bacillus, hypoxia-resistant saccharomycetes, bacillus coagulans and cold-resistant lactic acid bacteria; the composite carrier is prepared from the following raw materials in percentage by mass: 60 to 70 percent of corn straw powder, 5 to 10 percent of nano zero-valent iron, 3 to 5 percent of glycerol and the balance of sodium alginate-chitosan microspheres. The leavening agent is started to heat within 48 hours at the environment temperature of less than or equal to 5 DEG C; oxygen lt is dissolved; the interior of the 1 mg / L micro-aerobic and low-oxygen pile body is continuously metabolized; the effective fermentation activity is maintained in an outdoor-20 DEG C fluctuation environment.

Description

A low-temperature and low-oxygen resistant organic fertilizer fermentation agent for high-altitude areas, its preparation method and fermentation method Technical Field

[0001] This invention relates to the field of microbial fermentation, and more specifically, to a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for use in high-altitude areas, its preparation method, and its fermentation method. Background Technology

[0002] The unique geographical and climatic conditions of plateau regions present multiple technical challenges to organic fertilizer fermentation, primarily in terms of temperature, oxygen content, microbial activity, and fermentation processes. Regions like the Qinghai-Tibet Plateau (such as Aba County in western Sichuan) have an average altitude exceeding 3800 meters, an average annual temperature below 5℃, and atmospheric oxygen levels only 50-60% of those in plains areas. This extreme environment has a decisive impact on the traditional organic fertilizer fermentation process.

[0003] In low-temperature environments, when the temperature drops below 10℃, the enzyme activity of conventional fermentation microorganisms decreases sharply, the microbial metabolic rate slows down, fermentation is difficult to start, and the temperature rise is slow. The low temperature environment makes it difficult for the fermentation pile to reach and maintain a high temperature stage (above 50℃), resulting in a significant reduction in the efficiency of organic matter decomposition. Studies have shown that the protein decomposition capacity of room-temperature inoculants at 5℃ is only 20%-30% of that at room temperature. Furthermore, high-altitude areas are characterized by large diurnal temperature variations, with temperature fluctuations reaching 20-30℃. This temperature instability further exacerbates the instability of the microbial community structure, making the fermentation process difficult to sustain. This not only prolongs the fermentation cycle (from the conventional 15-20 days to 40-60 days) but may even prevent the normal fermentation process from being completed. It also leads to incomplete inactivation of pathogens and weed seeds, and the final product's maturity and nutrient content often fail to meet agricultural standards.

[0004] In terms of low-oxygen environments, the thin air in high-altitude areas directly reduces oxygen transport efficiency within the compost pile, restricts the respiration of aerobic microorganisms, leads to low organic matter decomposition efficiency, and prolongs the fermentation cycle. Aerobic fermentation requires a dissolved oxygen concentration of at least 5 mg / L, while under natural ventilation conditions in high-altitude areas, the oxygen concentration at the center of the compost pile is often below 1 mg / L. This hypoxic state promotes the dominance of anaerobic microorganisms, producing malodorous gases such as hydrogen sulfide and ammonia, while also causing the accumulation of organic acids and inhibiting the growth and reproduction of beneficial microorganisms.

[0005] Furthermore, the intense ultraviolet radiation and frequent freeze-thaw cycles at high altitudes exacerbate the fermentation difficulties. Ultraviolet radiation damages microbial cells, while repeated freeze-thaw cycles disrupt the pile structure, leading to uneven fermentation, frequent turning, heat loss, and microbial community imbalance. Traditional fermentation agents generally lack adaptability to such complex environments, making the development of specialized fermentation agents for the unique conditions of high-altitude regions urgently necessary.

[0006] Currently, several research directions have emerged for technologies related to organic fertilizer fermentation, but fermentation agent technologies specifically designed for the unique environment of high-altitude regions remain relatively scarce. There are three main technical directions: development of low-temperature resistant microbial agents, optimization of fermentation processes, and design of specialized equipment.

[0007] Regarding low-temperature resistant microbial agents, patent CN106399193A discloses a microbial agent for low-temperature fermentation of organic fertilizer, primarily suitable for large-scale livestock and poultry farms in northern regions that process manure to produce organic fertilizer under harsh winter conditions. It consists of Bacillus subtilis WEI-62, Bacillus licheniformis WEI-67, Bacillus amyloliquefaciens WEI-79, Enterococcus faecium WEI-89, and Candida albicans WEI-107. This agent claims to achieve rapid temperature rise for organic fertilizer fermentation at temperatures ranging from -30℃ to -10℃, shortening the composting time. However, this technology clearly ignores the limitations imposed by the low-oxygen environment of high altitudes on the activity of aerobic bacteria, and the strain formulation mainly targets the single factor of low temperature; therefore, its effectiveness in practical applications at high altitudes may be significantly reduced.

[0008] Patent CN106244475A proposes a low-temperature resistant composting fermentation agent with deodorizing function, containing eight microorganisms including Saccharomyces cerevisiae, Candida maltose, and Bacillus subtilis. This agent attempts to achieve rapid temperature rise under low-temperature conditions through the combination of thermophilic and mesophilic bacteria. However, its complex microbial composition may lead to competition and inhibition among microbial communities in practical applications, and it also fails to fully consider the impact of the low-oxygen environment at high altitudes.

[0009] Regarding fermentation technology, patent CN202510708396.3 describes a low-temperature fermentation method for organic fertilizer. This method attempts to achieve rapid fermentation at low temperatures by controlling the oxygen supply and the composition of the compound microbial agent. The method employs a staged aeration strategy: the aeration rate is 0.8-1.2 m³ / h·t during days 1-5 of fermentation, increasing to 1.5-2.0 m³ / h·t during days 6-10. This approach considers the oxygen requirements of microorganisms at different growth stages to some extent; however, the low-pressure environment of high-altitude areas may render the aeration rate calculation standard invalid, and continuous aeration increases the risk of heat loss.

[0010] Patent CN201710533527 proposes a method for manufacturing facultative anaerobic fermentation agents and organic fertilizers, attempting to combine the advantages of aerobic and anaerobic fermentation. This method controls the pile height (≥1.5m) to allow aerobic fermentation in the upper layer and anaerobic fermentation in the lower layer, creating a spontaneous facultative anaerobic environment. While this design is theoretically innovative, the oxygen gradient between the upper and lower layers of the pile may be more pronounced in the low-oxygen environment of high altitudes, potentially exacerbating the problem of uneven fermentation.

[0011] In terms of equipment, the NCS intelligent molecular membrane fermentation system employs high-temperature aerobic fermentation technology. Leveraging the unique properties of its intelligent molecular membrane, it provides a solution for livestock and poultry manure treatment in high-altitude areas. The system's molecular membrane exhibits excellent one-way permeability, allowing water vapor and air to pass through while preventing rainwater penetration. The inner layer is resistant to acid and alkali corrosion, effectively isolating odors and retaining nitrogen in the material to some extent. For cold regions, the membrane's unique heat-insulating properties prevent internal heat loss. However, this equipment solution is costly and does not fundamentally address the issue of microbial adaptability.

[0012] In summary, most existing fermentation agents are optimized only for a single temperature factor, neglecting the complex environmental pressures of high-altitude regions, such as low oxygen, strong ultraviolet radiation, and large diurnal temperature variations. The adaptive mechanisms of microorganisms under complex stresses are complex; strains that are simply resistant to low temperatures may not function properly in low-oxygen environments. Furthermore, existing agents often employ a strategy of targeted domestication of ambient-temperature strains rather than isolating native strains from the unique high-altitude environment, thus limiting their genetic adaptability to the extreme high-altitude conditions. Summary of the Invention

[0013] The purpose of this invention is to provide a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for use in high-altitude areas, which can start heating within 48 hours at an ambient temperature of ≤5℃; continuously metabolize within a micro-oxygen and low-oxygen pile with dissolved oxygen <1 mg / L; and maintain effective fermentation activity in an open-air environment with fluctuating temperatures of -20℃.

[0014] Another objective of this invention is to provide a method for preparing a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for use in plateau regions, which is simple and quick to operate.

[0015] The third objective of this invention is to provide a fermentation method using a low-temperature and low-oxygen resistant organic fertilizer fermentation agent suitable for high-altitude regions.

[0016] The technical problem solved by this invention is achieved by the following technical solution.

[0017] On one hand, embodiments of the present invention provide a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for use in plateau areas, comprising a quaternary compound bacteria and a composite carrier; the quaternary compound bacteria are composed of psychrophilic thermogenic Bacillus, low-oxygen resistant yeast, coagulant Bacillus, and psychrophilic lactic acid bacteria; the composite carrier, by mass percentage, comprises the following raw materials: 60-70% corn straw powder, 5-10% nano-zero valent iron, 3-5% glycerol, and the balance being sodium alginate-chitosan microspheres.

[0018] In some embodiments of the present invention, the composite carrier comprises the following raw materials by mass percentage: 65% corn stalk powder, 8% nano-zero valent iron, 4% glycerol, and 23% sodium alginate-chitosan microspheres.

[0019] In some embodiments of the present invention, the number of viable bacteria in the fermentation agent is greater than 5 × 10⁻⁶. 8 CFU / g. The average particle size of the nano-zero valent iron is 30-50 nm.

[0020] Secondly, embodiments of the present invention provide a method for preparing a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for use in plateau areas, comprising the following steps: psychrophilic thermogenic Bacillus, low-oxygen resistant yeast, Bacillus coagulans, and psychrophilic lactic acid bacteria are respectively cultured to a concentration of 1-2 × 10⁻⁶. 9 The bacterial solutions were prepared at CFU / mL. The bacterial solutions were mixed to obtain a composite bacterial solution. Corn straw powder, nano-zero valent iron, glycerol, and sodium alginate-chitosan microspheres were mixed to obtain a composite carrier. The composite bacterial solution was sprayed onto the composite carrier. The mixture was dried until the moisture content was less than 10% to obtain the fermentation agent.

[0021] In some embodiments of the present invention, the volume ratio of each bacterial liquid is 4:7:1:3, and the drying temperature is 25-30°C.

[0022] Thirdly, embodiments of the present invention provide a fermentation method using a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for plateau regions, comprising the following steps: preparing a fermentation base material with a C / N ratio of (26-30):1, and adjusting the moisture content of the fermentation base material to 55-60%; inoculating with a fermentation agent; fermenting the pile and covering the surface of the pile with straw; when the temperature inside the pile is higher than 65°C, turning the pile until fermentation is complete.

[0023] In some embodiments of the present invention, the inoculum amount of the fermenting agent is 0.5-1% of the dry weight of the fermentation substrate.

[0024] In some embodiments of the present invention, the fermentation substrate includes at least one of cow dung, sheep dung, urea, rapeseed meal, and straw.

[0025] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: The fermentation agent provided by the present invention, in the quaternary compound bacteria, includes: hypoxia-tolerant yeast: it can still metabolize sugars to produce organic acids under DO<0.5 mg / L conditions, improve the microenvironment pH and inhibit pathogens; Bacillus coagulans: it has both mesophilic activity and cellulose degradation ability, and takes over to dominate the decomposition of organic matter after the pile temperature rises to 25°C; and cold-resistant lactic acid bacteria: it secretes lactic acid to lower the local pH, and works with yeast to form an "acid-oxygen dual-regulation" microecology, enhancing the system's stress resistance.

[0026] The combination of psychrophilic thermogenic bacteria, hypoxia-tolerant yeast, mesophilic relay bacteria, and acidification-regulating bacteria forms a dynamic functional relay chain that initiates at low temperatures, maintains low oxygen levels, enhances at mesophilic temperatures, and inhibits contaminating bacteria with acid, thus breaking through the limitations of single-strain functions.

[0027] Using corn stalk powder, nano-zero-valent iron, glycerol, and sodium alginate-chitosan microspheres as a composite carrier, the corn stalk powder possesses high water absorption and a naturally porous structure. This porous structure adsorbs bacterial cells and promotes aeration. Nano-zero-valent iron acts as an electron donor, promoting anaerobic respiration and enhancing the energy metabolism efficiency of microorganisms under low-oxygen conditions. Glycerol acts as a cryoprotectant, lowering the freezing point and maintaining the fluidity of the bacterial membrane, ensuring normal metabolism of psychrophilic bacteria at 0-15℃. Sodium alginate-chitosan microspheres encapsulate the bacterial cells, achieving sustained release and physical protection. The integration of nano-iron electron transport materials, biological antifreeze agents, a natural porous matrix, and sustained-release microcapsules into a single carrier achieves a three-in-one function: antifreeze preservation, conductive metabolism promotion, and sustained-release efficacy. This significantly improves the survival rate of the bacterial agent after storage and application in cold regions, with a 40-day survival rate >58%.

[0028] In summary, the fermentation agent provided by this invention can start heating within 48 hours at an ambient temperature of ≤5℃; continuously metabolize within a micro-oxygen and low-oxygen pile with dissolved oxygen <1mg / L; maintain effective fermentation activity in an open-air environment with fluctuating temperatures of -20℃; significantly shorten the fermentation cycle in plateau areas to within 20 days; and ensure a nitrogen retention rate of >70%. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to specific embodiments.

[0031] A low-temperature and low-oxygen resistant organic fertilizer fermentation agent for use in high-altitude areas includes a quaternary compound bacteria and a composite carrier; the quaternary compound bacteria are composed of psychrophilic thermogenic Bacillus, low-oxygen resistant yeast, Bacillus coagulans, and psychrophilic lactic acid bacteria; the composite carrier, by mass percentage, includes the following raw materials: 60-70% corn straw powder, 5-10% nano-zero valent iron, 3-5% glycerol, and the balance being sodium alginate-chitosan microspheres.

[0032] Among them, the psychrophilic and thermogenic Bacillus is Bacillus psychrophilus; the hypoxia-tolerant yeast is Phaffia rhodozyma; the coagulant Bacillus is Bacillus coagulans; and the psychrophilic lactic acid bacteria is Lacticaseibacillus paracasei. Preferably, the composite carrier, by mass percentage, includes the following raw materials: 65% corn straw powder, 8% nano-zero valent iron, 4% glycerol, and 23% sodium alginate-chitosan microspheres.

[0033] Among them, sodium alginate-chitosan microspheres are microspheres with sodium alginate as the shell and chitosan as the core. The sodium alginate-chitosan microspheres form a stable network structure through electrostatic cross-linking, thereby encapsulating the bacterial cells. Its sustained-release principle is as follows: the microsphere membrane acts as a physical barrier, which can regulate the diffusion rate and is also pH sensitive, exhibiting different degradation rates in different environments, thus enabling the continuous release of bacterial cells as the microsphere membrane slowly dissolves.

[0034] This carrier employs a dual encapsulation strategy: sodium alginate-chitosan microspheres form an inner structure through electrostatic cross-linking to encapsulate the bacteria, while a porous corn stalk network constructs an outer physical barrier. Antifreeze function is achieved by lowering the freezing point and maintaining cell membrane fluidity through glycerol; the slow-release process is synergistically regulated by microsphere membrane dissolution and diffusion through the pores of the corn stalk; and oxygen-conducting function is attributed to nano-zero-valent iron (nZVI) acting as an electron donor, promoting anaerobic metabolism in an aquatic environment while simultaneously regulating the local redox potential. These three elements synergistically construct an integrated protection-release-energy supply system, maintaining bacterial activity and function under freeze-thaw and low-oxygen conditions.

[0035] The fermentation agent contains more than 5 × 10⁶ viable bacteria. 8 CFU / g. The average particle size of nano-zero valent iron is 30-50 nm.

[0036] A method for preparing a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for use in high-altitude areas includes the following steps: psychrophilic thermogenic Bacillus, low-oxygen resistant yeast, Bacillus coagulans, and psychrophilic lactic acid bacteria are cultured separately to a concentration of 1-2 × 10⁻⁶. 9 The bacterial solutions, each with a CFU / mL concentration of viable bacteria, were mixed in a volume ratio of 4:7:1:3 to obtain a composite bacterial solution. Corn straw powder, nano-zero-valent iron, glycerol, and sodium alginate-chitosan microspheres were mixed to obtain a composite carrier. The composite bacterial solution was spray-inoculated onto the composite carrier. The mixture was then dried at 25-30℃ until the moisture content was less than 10%, thus obtaining the fermentation agent.

[0037] Thirdly, embodiments of the present invention provide a fermentation method using a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for plateau regions, comprising the following steps: preparing a fermentation substrate with a C / N ratio of (26-30):1, and adjusting the moisture content of the fermentation substrate to 55-60%; preferably, the C / N ratio is 29:1; inoculating the fermentation agent at 0.5-1% of the dry weight of the fermentation substrate; fermenting the pile, and covering the surface of the pile with straw for insulation; when the temperature inside the pile is higher than 65°C, turning the pile, without the need for daily turning, until fermentation is complete.

[0038] In some embodiments of the present invention, the fermentation substrate includes at least one of cow dung, sheep dung, urea, rapeseed meal, and straw. For high-altitude areas, the fermentation substrate is a mixture of sheep dung and rapeseed meal, with the rapeseed meal used to regulate the C / N ratio of the fermentation substrate.

[0039] The features and performance of the present invention will be further described in detail below with reference to the embodiments. Embodiment 1: Psychrophilic thermogenic Bacillus (Psychrophilic Bacillus SMHCC D10791, Shanghai Baocang Biotechnology Co., Ltd.), hypoxia-tolerant yeast (Rhodopseudomonas rubrum SHBCC D81594, Shanghai Baocang Biotechnology Center), Bacillus coagulans (Bacillus coagulans CAS68038-65-3, Jinan Huijinchuan Trading Co., Ltd.), and psychrophilic lactic acid bacteria (Lactobacillus casei SHBCC CD80590, Shanghai Baocang Biotechnology Center) were respectively cultured to a concentration of 1×10⁻⁶. 9 CFU / mL bacterial solutions, with each solution having the same viable cell concentration, were mixed in a volume ratio of 4:7:1:3 to obtain a composite bacterial solution. Corn straw powder, nano-zero-valent iron, glycerol, and sodium alginate-chitosan microspheres were mixed in a mass percentage ratio of 65:8:4:23 to obtain a composite carrier. The composite bacterial solution was spray-inoculated onto the composite carrier, ensuring a viable cell count of 5 × 10⁻⁶. 8 CFU / g; dry at 30℃ until the moisture content is less than 10% to obtain the fermentation agent.

[0040] Example 2: Psychrophilic thermogenic Bacillus, hypoxia-tolerant yeast, coagulant Bacillus, and psychrophilic lactic acid bacteria were cultured to a concentration of 1×10⁻⁶. 9 CFU / mL bacterial solutions, with each solution having the same viable cell concentration, were mixed in a volume ratio of 4:7:1:3 to obtain a composite bacterial solution. Corn straw powder, nano-zero-valent iron, glycerol, and sodium alginate-chitosan microspheres were mixed in a mass percentage ratio of 70:5:3:22 to obtain a composite carrier. The composite bacterial solution was spray-inoculated onto the composite carrier, ensuring a viable cell count of 5 × 10⁻⁶. 8 CFU / g; dry at 30℃ until the moisture content is less than 10% to obtain the fermentation agent.

[0041] Example 3: Psychrophilic thermogenic Bacillus, hypoxia-tolerant yeast, coagulant Bacillus, and psychrophilic lactic acid bacteria were cultured to a concentration of 1×10⁻⁶. 9 CFU / mL bacterial solutions, with each solution having the same viable cell concentration, were mixed in a volume ratio of 4:7:1:3 to obtain a composite bacterial solution. Corn straw powder, nano-zero-valent iron, glycerol, and sodium alginate-chitosan microspheres were mixed in a mass percentage ratio of 60:5:3:32 to obtain a composite carrier. The composite bacterial solution was spray-inoculated onto the composite carrier, ensuring a viable cell count of 5 × 10⁻⁶. 8 CFU / g; dry at 30℃ until the moisture content is less than 10% to obtain the fermentation agent.

[0042] Example 4, based on the fermentation agent of Examples 1-3, was fermented according to the following parameters: using cow dung and rapeseed meal as raw materials, a fermentation substrate with a C / N ratio of 29:1 was prepared, and the moisture content of the fermentation substrate was adjusted to 60%; based on the dry weight of the fermentation substrate, 1% of the substrate weight was inoculated with the fermentation agent and mixed evenly; the inoculated fermentation substrate was piled into a 2m×1.5m×1m pile, and the surface of the pile was covered with 10cm thick straw for insulation; during the fermentation process, when the temperature inside the pile was higher than 65℃, the pile was turned over, but daily turning was not required. After 19 days of fermentation (with a temperature ≥50℃ for 5–7 days), the fermentation was completed when the appearance was dark brown, loose, odorless, and the germination index reached 70%, meeting the standard for maturity.

[0043] Comparative Example 1 uses a commercially available traditional fermentation agent (Jinan Nengjia Agricultural Technology Development Co., Ltd., high-temperature organic material fermentation agent) and ferments it according to the method in Example 4.

[0044] Example 1. The degradation rate of organic matter was detected by the gravimetric method (volatile solids determination method). The volatile solids (VS) content was calculated by measuring the mass change before and after high-temperature incineration fermentation, which indirectly reflects the degree of organic matter degradation.

[0045] The sample was dried at 105℃ to constant weight, and the total solids (TS) mass was obtained. The dried sample was placed in a muffle furnace at 550℃ for 4 hours and then cooled to obtain the ash mass. .

[0046] 2. The nitrogen retention rate was determined according to the method for determining total nitrogen content in Appendix D1 of NY / T 525-2021.

[0047] .

[0048] 3. The ammonia volatilization inhibition rate was determined using the double-layer sponge method: a sponge soaked in glycerol phosphate solution absorbed the volatilized ammonia (NH3), and the concentration of ammonium nitrogen was measured through the extract.

[0049] A bottomless PVC pipe (15 cm inner diameter, 15 cm height) was embedded in the organic fertilizer pile. The lower layer of sponge (5 cm from the bottom of the pipe) absorbed ammonia gas, while the upper layer of sponge isolated it from external interference. Sponge treatment: The sponge was soaked in glycerol phosphate solution (50 mL phosphoric acid + 40 mL glycerol to a final volume of 1 L) and covered with plastic film to prevent contamination. Sampling began 24 hours after fertilization, and the sponge was replaced every 24 hours. The sponge was then soaked in 300 mL of 1–2 mol / L KCl solution, shaken for 1 hour, and the extract was collected. The indophenol blue colorimetric method was used for determination.

[0050] , .

[0051] 4. Seed germination index was determined according to Appendix F of NY / T 525-2021. In this experiment, cucumber seeds were diluted 10 times according to the standard and cultured in a constant temperature incubator at 25℃ in the dark for 48 hours.

[0052] Seed germination index (%) = (germination rate of seeds treated with extract × root length) / (germination rate of seeds in control × root length) × 100.

[0053] The test results are shown in Table 1.

[0054] Table 1 Comparison of Implementation Results

[0055] As shown in Table 1, the embodiments of this invention achieve rapid and efficient fermentation of organic fertilizer in high-altitude and cold regions through innovative synergistic effects of microbial strains (low-temperature synergistic metabolism of Pharfia rubra and cold-resistant lactic acid bacteria), innovative carrier materials (nano-iron composite antifreeze carrier), and innovative process parameters (low-frequency dynamic temperature control strategy). Compared with existing technologies, this invention shortens the fermentation cycle by 40% in environments ranging from -15℃ to 5℃, increases the ammonia volatilization inhibition rate by 30%, and improves the seed germination index by 17.3%, demonstrating significant technological breakthroughs and application value.

[0056] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A low-temperature and low-oxygen resistant organic fertilizer fermentation agent for use in high-altitude areas, characterized in that, It includes a quaternary compound bacteria and a composite carrier; the quaternary compound bacteria are composed of psychrophilic thermogenic Bacillus, hypoxia-tolerant yeast, coagulant Bacillus, and psychrophilic lactic acid bacteria; the composite carrier, by mass percentage, includes the following raw materials: 60-70% corn straw powder, 5-10% nano-zero valent iron, 3-5% glycerol, and the balance is sodium alginate-chitosan microspheres.

2. The low-temperature and low-oxygen resistant organic fertilizer fermentation agent for plateau areas according to claim 1, characterized in that, The composite carrier comprises the following raw materials by mass percentage: 65% corn stalk powder, 8% nano-zero valent iron, 4% glycerol, and 23% sodium alginate-chitosan microspheres.

3. The low-temperature and low-oxygen resistant organic fertilizer fermentation agent for plateau areas according to claim 1, characterized in that, The fermentation agent contains more than 5 × 10⁶ viable bacteria. 8 CFU / g.

4. The low-temperature and low-oxygen resistant organic fertilizer fermentation agent for plateau areas according to claim 1, characterized in that, The average particle size of the nano-zero valent iron is 30-50 nm.

5. A method for preparing a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for plateau areas as described in any one of claims 1-4, characterized in that, Includes the following steps: Psychrophilic thermogenic Bacillus, hypoxia-tolerant yeast, Bacillus coagulans, and psychrophilic lactic acid bacteria were cultured to concentrations of 1-2 × 10⁻⁶. 9 The bacterial solutions were prepared at CFU / mL. The bacterial solutions were mixed to obtain a composite bacterial solution. Corn straw powder, nano-zero valent iron, glycerol, and sodium alginate-chitosan microspheres were mixed to obtain a composite carrier. The composite bacterial solution was sprayed onto the composite carrier. The mixture was dried until the moisture content was less than 10% to obtain the fermentation agent.

6. The method for preparing a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for plateau areas according to claim 5, characterized in that, The volume ratio of each bacterial culture is 4:7:1:

3.

7. The method for preparing a low-temperature and low-oxygen resistant organic fertilizer fermentation agent for plateau areas according to claim 5, characterized in that, The drying temperature is 25-30℃.

8. A fermentation method using the low-temperature and low-oxygen resistant organic fertilizer fermentation agent for plateau areas as described in any one of claims 1-4, characterized in that, Includes the following steps: Prepare a fermentation substrate with a C / N ratio of (26-30):1, and adjust the moisture content of the fermentation substrate to 55-60%; inoculate with a fermentation agent; ferment the pile and cover the surface of the pile with straw; when the temperature inside the pile is higher than 65℃, turn the pile over until fermentation is complete.

9. The fermentation method for a low-temperature and low-oxygen resistant organic fertilizer fermentation agent used in plateau areas according to claim 8, characterized in that, The amount of the starter culture is 0.5-1% of the dry weight of the fermentation substrate.

10. The fermentation method for a low-temperature and low-oxygen resistant organic fertilizer fermentation agent used in plateau areas according to claim 8, characterized in that, The fermentation substrate includes at least one of cow dung, sheep dung, urea, rapeseed meal, and straw.

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