A method for producing organic fertilizer with low carbon and high efficiency by cascade oxygen supply composting

Abstract

This invention discloses a method for low-carbon and high-efficiency organic fertilizer production through tiered oxygen supply composting. This invention uses a compound microbial agent as its core, achieving simultaneous breakthroughs in compost maturity and fertilizer efficiency. By precisely delivering targeted compound microbial agents in stages and coupling them with a tiered oxygen supply strategy, this invention directionally regulates the structure and function of the microbial community, significantly improving organic matter conversion efficiency and the degree of humification. The final product shows a significant increase in organic matter content of 31%, and the seed germination index increases from 71% to 89%, demonstrating its excellent effects in thorough composting and eliminating phytotoxicity. In pot experiments, the biomass of maize plants increased by approximately 97%, further verifying the significant promoting effect of high-quality DOM (dominant organic matter) formed by functional microbial agents on fertilizer efficiency.

Description

Technical Field

[0001] This invention relates to the field of biotechnology, and in particular to a method for producing organic fertilizer in a low-carbon and efficient manner through tiered oxygen supply composting. Background Technology

[0002] Livestock and poultry manure composting is a key technology for realizing the resource utilization of agricultural waste and promoting sustainable agricultural development. Currently, the mainstream composting processes mainly include two categories: aerobic composting and anaerobic fermentation composting. However, both have certain technical limitations in practical applications. One root cause lies in the lack of precise control over the composition, activity, and succession patterns of the functional microbial community—the core driver of the composting process. While aerobic composting promotes organic matter decomposition through continuous oxygen supply, a single oxygen supply mode is difficult to match the dynamic needs of complex microbial communities at different stages, leading to problems such as high energy consumption, severe nitrogen loss, and large greenhouse gas emissions. It also results in low organic matter and dissolved organic matter (DOM) content in the compost product and slow fertilizer effect. Although anaerobic fermentation composting can retain organic matter and increase DOM content to some extent, anaerobic microbial metabolism easily accumulates intermediate harmful products such as volatile fatty acids, which are toxic to crops. Furthermore, the products often require secondary aerobic stabilization treatment, increasing process complexity and cost.

[0003] To overcome the aforementioned bottlenecks, existing technologies largely focus on process and equipment innovation through physicochemical methods. For example, in aerobic composting, oxygen-enriched ventilation, free radical enhancement, or intelligent oxygen supply systems are used to optimize oxygen distribution; anaerobic fermentation explores dry fermentation or anaerobic-aerobic coupling processes to improve gas production or degradation efficiency. However, most of these improvements fail to systematically introduce and regulate core functional microbial agents, resulting in limited effectiveness. While intelligent oxygen supply systems can improve oxygen transfer efficiency, if they cannot synchronize with the metabolic rhythm of the target microorganisms, they will still lead to energy waste and increased emissions. The mass transfer and start-up challenges faced by anaerobic dry fermentation are essentially closely related to the lack of efficient, customized inoculants to quickly establish a stable community. Therefore, how to integrate and dominantly utilize compound microbial agents in the process has become the key to breaking through the bottlenecks of existing technologies. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a method for producing organic fertilizer in a low-carbon and efficient manner through tiered oxygen supply composting.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A method for low-carbon and efficient production of organic fertilizer through tiered oxygen supply composting includes the following steps:

[0007] (1) Mix poultry and livestock manure with mushroom residue, adjust the moisture content, and obtain mixed manure;

[0008] (2) Place the mixed manure in a container, cover it with a film for composting, and measure the composting temperature regularly. Based on the composting temperature, the composting process is divided into four stages. When the temperature first exceeds 45℃ after the start of composting, it is the early stage of composting, and the oxygen supply is adjusted to low. When the temperature is below 55℃, it is the middle stage of composting, and the oxygen supply is adjusted to high. When the temperature is below 45℃ after the middle stage of composting, it is the late stage of composting, and the oxygen supply is adjusted to low. 3 to 10 days before the end of composting is the final stage of composting, and the oxygen supply is adjusted to high. The interval between supplying oxygen to the pile and stopping the oxygen supply is 15 to 120 minutes.

[0009] The poultry and livestock manure mentioned in step (1) is at least one of chicken manure, cow manure, and pig manure.

[0010] The mushroom residue mentioned in step (1) is the culture medium waste after the harvesting of edible fungi.

[0011] The dry weight ratio of poultry and livestock manure to mushroom residue in step (1) is 1.5:1.

[0012] The container mentioned in step (2) is a compost bin.

[0013] The low oxygen supply mentioned in step (2) refers to controlling the ventilation rate to 0.005–0.05 L·kg. -1 DM·min -1 That is, the aeration volume per kilogram of compost per minute is 0.005 to 0.05 L; preferably 0.05 L / kg. -1 DM·min -1 .

[0014] The high oxygen supply mentioned in step (2) refers to controlling the ventilation rate at 0.35–0.5 L·kg⁻¹. -1 DM·min -1 That is, the aeration volume per kilogram of compost per minute is 0.35 to 0.5 L; preferably 0.5 L / kg. -1 DM·min -1 .

[0015] The temperature mentioned in step (2) is the average temperature obtained by measuring the temperature at the center, surface and in between of the compost.

[0016] An organic fertilizer obtained through tiered oxygen supply composting is prepared using the method described above.

[0017] The application of organic fertilizer obtained through tiered oxygen supply composting in promoting plant growth.

[0018] The present invention has the following advantages and effects compared with the prior art:

[0019] (1) Using compound microbial agents as the core, this invention achieves a simultaneous breakthrough in compost maturity and fertilizer efficiency. By precisely delivering targeted compound microbial agents in stages and coupling them with a tiered oxygen supply strategy, this invention directionally regulates the structure and function of the microbial community, greatly improving the efficiency of organic matter conversion and the degree of humification. The organic matter content in the final product increased significantly by 31%, and the seed germination index increased from 71% to 89%, demonstrating its excellent effect in thorough decomposition and elimination of plant toxicity. In pot experiments, the biomass of corn plants increased by about 97%, further verifying the significant promoting effect of high-quality DOM formed by functional microbial agents on fertilizer efficiency.

[0020] (2) Through the synergistic effect of metabolic guidance and precise oxygen supply by compound microbial agents, carbon and nitrogen emission reduction and retention are achieved at the source. The functional microbial agents added in this invention can guide carbon and nitrogen to beneficial transformation pathways. Combined with staged oxygen supply control, the generation of greenhouse gases such as methane and nitrous oxide and the volatilization loss of nitrogen are effectively suppressed. Compared with traditional aerobic composting, the total greenhouse gas emissions are reduced by 45.8%, carbon loss is reduced by 47.5%, and nitrogen loss is reduced by 28.9%. While achieving efficient composting, outstanding environmental benefits are also achieved.

[0021] (3) The process has strong universality, and the modular design of the microbial agent and oxygen supply strategy facilitates industrial application. The compound microbial agent formula and matching oxygen supply scheme provided by this invention can be flexibly adjusted according to different livestock and poultry manure raw materials. The operation logic is clear and it is easy to integrate with existing facilities. This "microbial agent-oxygen supply" synergistic system provides a high-efficiency, stable, and low-cost waste resource utilization technology path for large and medium-sized farms and organic fertilizer plants, and has significant potential for industrial promotion. Attached Figure Description

[0022] Figure 1 These are the experimental results of different experimental groups in Example 1.

[0023] Figure 2 These are the experimental results of different experimental groups in Example 2.

[0024] Figure 3 These are the experimental results of different experimental groups in Example 3.

[0025] Figure 4 These are the experimental results of different experimental groups in Example 4.

[0026] Figure 5 These are the experimental results of different experimental groups in Example 5.

[0027] Figure 6 These are the experimental results of different experimental groups in Example 6. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0029] Unless otherwise specified in the following implementation plan, the test conditions are generally as per standard test conditions or the test conditions recommended by the reagent company. Unless otherwise specified, all materials and reagents used are commercially available.

[0030] Example 1: Production of Chicken Manure Organic Fertilizer Using a Cascaded Oxygen Supply Method

[0031] 1.1 Experimental Methods

[0032] (1) Composting pretreatment:

[0033] Chicken manure and mushroom residue (waste culture medium after edible fungi harvest) were mixed separately and then mixed at a mass ratio of 1.5:1 (dry weight), adjusting the moisture content to 55% and the carbon-nitrogen ratio to 30.

[0034] (2) Different composting processes:

[0035] Aerobic group (CK): Constant ventilation is used. The composting materials are placed in the compost bin and covered with a film.

[0036] Tiered oxygen supply treatment group (T1~T6): Place the composting raw materials into a composting box equipped with an intelligent ventilation system and cover it with a membrane. Set two sets of oxygen supply conditions: high oxygen supply and low oxygen supply. Refer to Table 1 for specific conditions. Divide the composting process into four stages according to the composting temperature. When the temperature is above 45℃ in the early stage of composting, adjust to low oxygen supply; when the temperature is below 55℃ in the middle stage of composting, adjust to high oxygen supply; when the temperature is below 45℃ in the later stage of composting, adjust to low oxygen supply; and when the temperature is above 5 days before the end of composting, adjust to high oxygen supply. The interval between supplying and stopping oxygen to the pile is 30 minutes, and the total composting time is 30 days.

[0037] Tiered oxygen supply and bacteria group (T7): The oxygen supply conditions are the same as those of group T4. The difference is that 0.1wt% of compound microbial agent (Guangzhou Weiliwang Biotechnology Co., Ltd., commercial name Fermentation Helper, effective live bacteria count >10 billion / g) is applied before, during and after composting.

[0038] Table 1. Oxygen flow rates of each treatment group in Example 1

[0039]

[0040] Note: L·kg -1 DM·min -1 This refers to the aeration volume per kilogram of compost per minute.

[0041] Gas and solid samples were collected every 5 days during the composting process to measure indicators such as carbon and nitrogen loss rate, organic matter content, GI, and total greenhouse gases (CH4, CO2, N2O).

[0042] 1.2 Methods for detecting and calculating carbon and nitrogen loss rates in composting

[0043] The carbon and nitrogen loss rate is calculated based on the total weight, organic carbon or total nitrogen content, and moisture content before and after composting. The calculation formula is as follows:

[0044]

[0045] L: Carbon or nitrogen loss rate of the stack (%)

[0046] M1: Initial total weight of compost (g);

[0047] M2: Total weight at the end of composting (g);

[0048] T1: Total organic carbon or total nitrogen content (%) of each treatment at the beginning of composting;

[0049] T2: Total organic carbon or total nitrogen content (%) of each treatment at the end of composting;

[0050] ω1: Initial moisture content (%) of each treatment in composting;

[0051] ω2: Moisture content (%) of each treatment at the end of composting.

[0052] 1.3 Greenhouse Gas Collection and Measurement Methods

[0053] Sampling method: Gas samples were collected using static chamber technology. A static chamber of the same size as the composting reactor was placed upside down above the composting reactor. At half the height of the side of the sampling chamber and centered, 100 mL of gas was drawn using a syringe and then detected by gas chromatography (Agilent 7890 B). A flame ionization detector was used to measure CH4 and CO2 at 200 °C, and an electron capture detector was used to measure N2O at 350 °C. For intermittent oxygen supply, samples were collected for 30 minutes during the oxygen supply period and at the oxygen supply interval, with one sample collected every 6 minutes. For continuous oxygen supply, one sample was collected every 6 minutes for 30 minutes.

[0054] The formulas for calculating the emission rates of CH4, CO2, and N2O are as follows:

[0055] 60 1000

[0056] In the formula:

[0057] E a Emission rates of greenhouse gases (CH4, CO2, N2O), in mg·kg-1 DM·h -1 ;

[0058] P: Atmospheric pressure at the measured altitude, in atm;

[0059] V: Static box volume, in L;

[0060] M: Molecular weight of different gases, in g·mol⁻¹ -1 ;

[0061] R: Ideal gas constant 0.08206, unit L·atm·mol -1 ·K -1 ;

[0062] T: Static chamber temperature, in K;

[0063] m: Weight of dry matter in the initial mixture, in kg DM;

[0064] Static compost change rate within the container, unit: ppmv·min -1 ;

[0065] 60: The conversion factor from min to h;

[0066] 1000: the conversion factor from g to mg.

[0067] The cumulative emissions of CH4, CO2, and N2O during oxygen supply are calculated by multiplying the average gas emission rate of two consecutive times by the number of days between the two gas emissions. This gives the cumulative gas emission for a given time period, which is then summed up sequentially.

[0068] 1.4 Determination of Termination Germination Index (GI)

[0069] The test was conducted using plump radish seeds, following the method in Appendix F of NY / T 525-2021.

[0070] 1.5 Determination of biomass in potted plant experiments

[0071] The compost was applied to corn pots, with 8g of organic fertilizer (dry weight) applied to each pot. Urea, superphosphate and potassium chloride were added to supplement nitrogen, phosphorus and potassium elements, so that each treatment had 150mg / kg N, 120mg / kg P2O5 and 150mg / kg KCl. The plants were planted under natural conditions using conventional field management methods. Plant biomass was measured after the corn was harvested. The experimental period was 35 days.

[0072] 1.6 Experimental Results

[0073] The experimental results are shown in Table 2. It can be seen that the above technical solution significantly improves the quality and fertilizer efficiency of compost through the synergistic effect of tiered oxygen supply and microbial agents. Compared with traditional constant aerobic composting (CK), the treatment groups (T1-T6) using only tiered oxygen supply have achieved preliminary improvements. Among them, the optimal group T4 has an organic matter content of 40%, which is 25.0% higher than CK (32%).

[0074] Furthermore, the phased application of compound microbial agents (T7 treatment) is the core of the technological breakthrough. Compared with the T4 group, which only optimized oxygen supply, the compound microbial agent drove a comprehensive leap in key indicators: organic matter content increased by 42%, carbon loss decreased to 25.25% (a total reduction of 47.9% compared to the control), greenhouse gas emissions were further reduced, and seed germination index increased to 89%. Crucially, the compound microbial agent directly brought about a qualitative change in ultimate fertilizer efficiency, increasing potted plant biomass by 29.7% to 260.12 g / pot.

[0075] The above data shows that tiered oxygen supply optimizes the physical environment, while compound microbial agents play a leading role in biological processes such as organic matter conversion, carbon and nitrogen retention, and product safety. Ultimately, this achieves a synergistic breakthrough in composting's "carbon preservation, emission reduction, and quality improvement," constituting the biological core of this patented solution.

[0076] Table 2. Composting indexes of chicken manure organic fertilizer and biological indexes in pot experiment in Example 1

[0077]

[0078] Example 2: Production of Pig Manure Organic Fertilizer Using a Cascaded Oxygen Supply Method

[0079] Organic fertilizer was produced using pig manure according to the method in Example 1. The difference was that pig manure and straw were used as a compound compost during the pretreatment, and the oxygen supply conditions of the T7 treatment group were modified to be the same as those of the T3 treatment group. The amount of each microbial agent added was adjusted from 0.1% to 0.05%, while the other conditions remained the same.

[0080] The experimental results are shown in Table 3. It can be seen that the technical advantages of this method were further verified in the pig manure composting examples. Compared with constant oxygen supply (CK), the treatment groups using only tiered oxygen supply (T1-T6) have achieved significant improvement. Among them, the organic matter content of the T3 group was 49 g / kg, which was 22.5% higher than that of CK.

[0081] Building upon the optimized tiered oxygen supply, the phased application of low-dose compound microbial agents (T7 treatment) was the key driver for achieving the final efficacy breakthrough. Compared to the T3 group, which only optimized oxygen supply, the introduction of the compound microbial agent led to a comprehensive improvement in indicators: organic matter content increased by 4.1% to 51 g / kg, carbon loss decreased by 12.7% to 22.98%, and greenhouse gas emissions decreased by 6.6% to 96.36 mg / kg DM. More importantly, the compound microbial agent significantly improved the product's biosafety and final fertilizer efficiency: seed germination index reached 94% (20.5% higher than CK), and biomass increased to 201.16 g / pot (40.1% higher than CK).

[0082] This embodiment demonstrates that tiered oxygen supply can improve basic conditions in different raw materials, while the compound microbial agent dominates the core biological processes of deep humification, decomposition of harmful substances, and activation of fertilizer potential in the complex system of pig manure composting. This is the fundamental guarantee that the technical solution has broad adaptability and high efficiency.

[0083] Table 3. Composting Indicators and Biological Indicators of Pig Manure Organic Fertilizer in Example 2

[0084]

[0085] Example 3: Production of cow manure organic fertilizer using a tiered oxygen supply method

[0086] Organic fertilizer was produced using cow dung according to the method in Example 1, except that cow dung and straw were used as a compound compost during pretreatment, and the oxygen supply conditions of the T7 treatment group were modified to be the same as those of the T3 treatment group. The amount of each microbial agent added was adjusted from 0.1% to 0.05%, while the other conditions remained the same.

[0087] The experimental results are shown in Table 4. It can be seen that the technical advantages of this method were further verified in the cow manure composting examples. Compared with constant oxygen supply (CK), the treatment groups using only tiered oxygen supply (T1-T6) have achieved significant results. Among them, the organic matter content of the T4 group was 45 g / kg, which was 25.0% higher than that of CK.

[0088] The application of 0.5% compound microbial inoculant (T7 treatment) in stages was the core of achieving the final technological breakthrough. Compared with the T4 group, which only optimized oxygen supply, the compound inoculant drove a comprehensive improvement and synergistic optimization of various indicators: organic matter content increased by 8.9% to 49 g / kg, carbon loss was further reduced by 10.6% to 15.31%, and greenhouse gas emissions were reduced by 8.1% to 84.03 mg / kg DM. Crucially, the compound inoculant led to a leap in the biotransformation depth and agronomical value of the compost products: seed germination index reached 96% (24.7% higher than the control), and biomass increased to 184.3 g / pot (53.4% ​​higher than the control).

[0089] This embodiment demonstrates that tiered oxygen supply is an important physical optimization method, while the compound microbial agent plays an irreplaceable core biological role in cow manure compost, a high-fiber raw material. By directionally regulating microbial metabolism, it achieves efficient humification while significantly improving product safety and fertilizer efficacy, ensuring the versatility and high efficiency of the technical solution in different raw material systems.

[0090] Table 4. Composting Indicators and Biological Indicators of Cow Dung Organic Fertilizer in Example 3 (Pot Experiment)

[0091]

[0092] Example 4: Production of Chicken Manure Organic Fertilizer via Tank Composting with Cascaded Oxygen Supply

[0093] Organic fertilizer was produced according to the method of Example 1, except that the composting bin was replaced with a composting tank with a ventilation device, and the amount of each microbial agent added in the T7 treatment group was adjusted from 0.1% to 0.08%, while all other conditions were the same.

[0094] The experimental results are shown in Table 5. It can be seen that the applicability of the technical solution was verified in the tank composting process examples. Compared with constant oxygen supply (CK), the use of only tiered intelligent ventilation (T1-T6) has achieved significant optimization in a closed environment. Among them, the organic matter content of group T4 is 45 g / kg, which is 12.5% ​​higher than that of CK.

[0095] The application of a low-dose compound microbial agent (T7 treatment) at a stage of 0.08% was key to achieving the final leap in efficacy. Compared to the T4 group, which only optimized ventilation, the introduction of the compound microbial agent brought about a systemic breakthrough in indicators: organic matter content increased by 6.7% to 48 g / kg, and carbon loss was further reduced by 9.7% to 21.32%. Especially in terms of greenhouse gas emission reduction, the compound microbial agent showed a stronger source control effect, significantly reducing emissions by 21.0% to 54.32 mg / kg DM. More importantly, the compound microbial agent significantly improved the product's biosafety and ultimate fertilizer efficiency in the closed system: the seed germination index reached 94% (23.7% higher than CK), and biomass increased to 274.4 g / pot (81.4% higher than CK).

[0096] This embodiment demonstrates that in the tank-type process, tiered oxygen supply solves the gas exchange problem, while the compound microbial agent dominates the core biotransformation process in a closed environment. By strengthening the microbial metabolic network, it achieves efficient carbon retention and deep emission reduction while ensuring the high safety and fertility of the products, providing an indispensable biological core for modern composting equipment.

[0097] Table 5. Composting indexes of chicken manure organic fertilizer and biological indexes in pot experiment in Example 4

[0098]

[0099] Example 5: Production of Chicken Manure Organic Fertilizer Using a Step-by-Step Oxygen Supply Method with Different Oxygen Supply Intervals

[0100] Organic fertilizer was produced using the same method as the T4 treatment group in Example 1, except that the oxygen supply interval was adjusted from 30 min to 15-180 min. The specific settings are shown in Table 6.

[0101] The experimental results are shown in Table 6. It can be seen that the tiered oxygen supply method with intervals of 30-120 minutes, as employed in this technical solution, demonstrates significant advantages in optimizing the composting process and improving product quality. Experimental data show that within the range of 30-minute intervals (T2 group) to 120-minute intervals (T4 group), all treatment groups exhibited good composting effects.

[0102] Group T2 (30-minute interval) performed best, with an organic matter content of 46%, a carbon loss of only 25.25%, a nitrogen loss of 41.30%, a total greenhouse gas emission of 75.23 mg / kg DM, and a seed germination index of 89%. Compared with Group T1 (15-minute interval), Group T2 reduced carbon loss by 30.2% and greenhouse gas emissions by 38.6%.

[0103] Within the optimal range of 30-120 minutes, groups T3 (60 minutes) and T4 (120 minutes) maintained good overall performance, with organic matter contents of 41% and 42%, and germination indices of 90% and 85%, respectively, both significantly better than group T5 (180 minutes). This result indicates that an oxygen supply interval of 30-120 minutes can ensure sufficient oxygen supply to the compost pile while avoiding nutrient loss due to excessive ventilation, achieving an ideal balance between oxygen supply efficiency and compost quality.

[0104] In summary, the 30-120 minute oxygen supply interval range determined by this patent, through the synergistic effect of optimized oxygen supply strategy and microbial agent, effectively reduces carbon and nitrogen loss and greenhouse gas emissions, while improving the maturity and nutrient content of compost products, providing a reliable technical solution for the production of high-quality organic fertilizer.

[0105] Table 6. Detection results of chicken manure organic fertilizer composting using different oxygen supply intervals in Example 5.

[0106]

[0107] Example 6: Production of Chicken Manure Organic Fertilizer Using a Cascaded Oxygen Supply Method at Different Composting Stages

[0108] Organic fertilizer was produced using the same method as the T4 treatment group in Example 1, except that the temperature during the composting stage was adjusted to different conditions, as detailed in Table 7.

[0109] The experimental results are shown in Table 7. It can be seen that this technical scheme (T4 treatment group) achieved a significant breakthrough in compost quality and emission reduction by optimizing the temperature segmentation nodes of the tiered oxygen supply. Compared with other temperature control schemes, the T4 group, under the reasonable temperature ratios of the early (>45℃), middle (<55℃), and late (<45℃) stages of composting, achieved an organic matter content of 46%, a carbon loss of only 25.25%, a nitrogen loss of 41.30%, a total greenhouse gas emission of 75.23 mg / kg DM, and a seed germination index of 89%.

[0110] Compared to group T1, group T4 showed a 24.3% increase in organic matter content, a 16.2% decrease in carbon loss, and a 7.4% reduction in greenhouse gas emissions. Compared to group T3, although both groups had the same germination index, group T4 showed a significantly higher organic matter content (43.8%) and a 28.3% decrease in carbon loss, demonstrating the crucial role of segmented temperature control in promoting organic matter retention.

[0111] Experimental results show that the temperature segmentation scheme of "early stage >45℃, middle stage <55℃, and late stage <45℃" adopted in this patent can effectively coordinate the balance between microbial activity and organic matter decomposition. While ensuring the maturity of compost, it can significantly improve nutrient retention and reduce greenhouse gas emissions, providing an optimized temperature control strategy for high-quality compost production.

[0112] Table 7 shows the test results of chicken manure organic fertilizer composting at different composting stages in Example 6.

[0113]

[0114] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for low-carbon and high-efficiency production of organic fertilizer through tiered oxygen supply composting, characterized in that... Includes the following steps: (1) Mix poultry and livestock manure with mushroom residue, adjust the moisture content, and obtain mixed manure; (2) Place the mixed manure in a container, cover it with a film for composting, and measure the composting temperature regularly. Based on the composting temperature, the composting process is divided into four stages. When the temperature first exceeds 45℃ after the start of composting, it is the early stage of composting, and the oxygen supply is adjusted to low. When the temperature is below 55℃, it is the middle stage of composting, and the oxygen supply is adjusted to high. When the temperature is below 45℃ after the middle stage of composting, it is the late stage of composting, and the oxygen supply is adjusted to low. 3 to 10 days before the end of composting is the final stage of composting, and the oxygen supply is adjusted to high. The interval between supplying oxygen to the pile and stopping the oxygen supply is 15 to 120 minutes.

2. The method for low-carbon and high-efficiency organic fertilizer production through tiered oxygen supply composting according to claim 1, characterized in that: The poultry and livestock manure mentioned in step (1) is at least one of chicken manure, cow manure, and pig manure; The mushroom residue mentioned in step (1) is the culture medium waste after the harvesting of edible fungi.

3. The method for low-carbon and high-efficiency organic fertilizer production through tiered oxygen supply composting according to claim 1, characterized in that: The dry weight ratio of poultry and livestock manure to mushroom residue in step (1) is 1.5:

1.

4. The method for low-carbon and high-efficiency organic fertilizer production through tiered oxygen supply composting according to claim 1, characterized in that: The container mentioned in step (2) is a compost bin.

5. The method for low-carbon and high-efficiency organic fertilizer production through cascaded oxygen supply composting according to claim 1, characterized in that: The low oxygen supply mentioned in step (2) refers to controlling the ventilation rate to 0.005–0.05 L·kg. -1 DM·min -1 That is, the aeration volume per kilogram of compost per minute is 0.005 to 0.05 L.

6. The method for low-carbon and high-efficiency production of organic fertilizer through cascaded oxygen supply composting according to claim 1, characterized in that: The high oxygen supply mentioned in step (2) refers to controlling the ventilation rate at 0.35–0.5 L·kg⁻¹. -1 DM·min -1 That is, the aeration volume per kilogram of compost is 0.35 to 0.5 L per minute.

7. The method for low-carbon and high-efficiency organic fertilizer production through tiered oxygen supply composting according to claim 1, characterized in that: The temperature mentioned in step (2) is the average temperature obtained by measuring the temperature at the center, surface and in between of the compost.

8. An organic fertilizer obtained by cascade oxygen supply composting, prepared by the method described in any one of claims 1 to 7.

9. The application of the organic fertilizer obtained by tiered oxygen supply composting as described in claim 8 in promoting plant growth.

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