Agricultural and forestry waste high-temperature aerobic composting method

Abstract

The application discloses a kind of high-temperature aerobic composting methods of agricultural and forestry wastes, specific steps are as follows: high-carbon, high-nitrogen agricultural and forestry wastes, inorganic nitrogen source are mixed, the soluble carbon-nitrogen ratio of mixture is adjusted to (5~20):1, inoculates first-stage composite inoculant, is placed in nano intelligent molecular film aerobic composting system and is fermented, implements intelligent ventilation program.Second-stage composite inoculant is supplemented in composting high-temperature stage, and third-stage composite inoculant is supplemented in cooling stage.The application supplements different composite inoculants in different stages, improves the degradation efficiency of heap;Intelligent air blowing is carried out in combination with sensor data and air blowing system, and a plurality of parameters are detected in real time, soluble carbon-nitrogen ratio is fitted and calculated, and is controlled between (5~20):1.The highest proportion of forestry waste in the application can reach 90%, composting rotting cycle can be shortened to 40~60 days, lignocellulose degradation rate is >50%, organic matter is 30-60%, total nutrient is >2%, seed germination index is >90%, and can be used as high-quality organic fertilizer or substrate raw material.

Description

Technical Field

[0001] This invention belongs to the field of organic solid waste resource utilization technology, specifically relating to a high-temperature aerobic composting method for agricultural and forestry waste. Background Technology

[0002] Large quantities of organic waste generated from forestry and agricultural activities (such as sawdust, dead branches, straw, and rice husks) generally have a high carbon-to-nitrogen ratio (>60:1, reaching as high as 450:1), leading to insufficient nitrogen for microbial growth during composting. This results in difficulties in raising the compost temperature and a prolonged maturation period. Existing technologies often adjust the total carbon-to-nitrogen ratio of the mixture to 25-30:1 by adding livestock manure or inorganic nitrogen sources (such as urea) to promote microbial metabolism and compost temperature rise. However, this method only focuses on the static adjustment of the initial carbon-to-nitrogen ratio of the entire material, neglecting the dynamic impact of water-soluble organic carbon and nitrogen content and the carbon-to-nitrogen ratio, which can be directly utilized by microorganisms, on the succession of the microbial community. High-temperature aerobic composting of agricultural and forestry waste is essentially a microbially driven biotransformation process, and the growth and reproduction of core functional microbial communities (bacteria, fungi, and actinomycetes) exhibit significantly different adaptability to different carbon-to-nitrogen ratios.

[0003] The composting process of agricultural and forestry waste is essentially a multi-stage biotransformation reaction driven by microorganisms. The dominant functional microbial groups (bacteria, fungi, and actinomycetes) at different temperature stages show significant differences in their adaptability to the carbon-nitrogen ratio. For example, bacteria, as the dominant microbial group in the early stage of composting (mesothermal stage 20~45℃), have a suitable carbon-nitrogen ratio of (5~10):1. They mainly degrade simple sugars, proteins, and other easily soluble organic matter, and generate heat through fermentation to drive the temperature of the compost pile. Fungi gradually accumulate in the mesothermal-high temperature transition stage (45~55℃), with a suitable carbon-nitrogen ratio of (10~20):1. They can secrete extracellular enzymes such as cellulase and ligninase to decompose complex carbohydrates and lignin-like recalcitrant substances. Actinomycetes dominate in the high temperature stage (55~70℃), with a suitable carbon-nitrogen ratio of (10~15):1. They mainly participate in the synthesis of humus and the stabilization of the compost pile structure. The succession of the aforementioned microbial community depends on the dynamic balance of the carbon-nitrogen ratio in the compost pile. When the carbon-nitrogen ratio is too high (>35:1), the lignin degradation efficiency of fungi decreases by more than 30%, and the composting cycle is extended by 15-20 days. When the carbon-nitrogen ratio is too low (<20:1), excessive bacterial proliferation leads to ammonia nitrogen loss of more than 25%, resulting in nitrogen waste and air pollution. Therefore, precise control of the carbon-nitrogen ratio is not only a prerequisite for initiating composting but also the key to maintaining efficient metabolism of the microbial community.

[0004] In the composting process of agricultural and forestry waste, the carbon and nitrogen forms actually available to microorganisms are not the total carbon and nitrogen of the compost, but rather small molecules of water-soluble organic carbon and some inorganic carbon, and small molecules of water-soluble organic nitrogen and inorganic nitrogen. Furthermore, current mainstream monitoring methods are generally based on elemental analysis to detect total carbon and nitrogen content, which cannot reflect the real-time dynamics of water-soluble effective components. This leads to lagging control strategies, an inability to match the dynamic nutritional needs of microorganisms, and limitations on further improvements in fermentation efficiency and compost product quality. For example, in the early stages of composting, insufficient water-soluble carbon and nitrogen content results in a low degradation rate of lignocellulose. Even if the total carbon-to-nitrogen ratio is within the theoretical range, microbial growth may still be limited due to nutrient deficiency. At high temperatures, with the rapid decomposition of organic matter, the concentration of water-soluble carbon and nitrogen may rise or fall sharply in a short period, leading to an imbalance in the carbon-to-nitrogen ratio that cannot be monitored in a timely manner.

[0005] Therefore, it is necessary to develop a new composting method that adjusts parameters according to different stages of composting, to solve the technical problem that traditional composting parameter control is not adapted to changes in the actual nutritional needs of microorganisms, and to achieve precise composting and high-value utilization of agricultural and forestry waste. Summary of the Invention

[0006] To address the aforementioned problems in existing technologies, this invention provides a high-temperature aerobic composting method for agricultural and forestry waste. This method involves adding different microbial agents at different stages of composting, collecting real-time parameters of the compost pile using sensors for temperature, humidity, conductivity, pH, and oxygen concentration, calculating the soluble carbon-to-nitrogen ratio, and implementing intelligent ventilation control to improve the composting efficiency and quality of high-carbon, low-nitrogen waste.

[0007] To achieve the above objectives, the present invention proposes the following technical solution:

[0008] A method for high-temperature aerobic composting of agricultural and forestry waste, the method comprising the following steps:

[0009] (1) Raw material pretreatment: After crushing the high-carbon agricultural and forestry waste, mix it with the high-nitrogen agricultural and forestry waste and inorganic nitrogen source, adjust the soluble carbon-nitrogen ratio of the mixture to (5~20):1, and the moisture content to 55%~60%. Inoculate the obtained mixture with the first-stage compound microbial agent, stir thoroughly, and obtain the initial mixture of compost.

[0010] Preferably, the high-carbon agricultural and forestry waste includes one or more of sawdust, fruit shells, dead branches, and straw. The high-nitrogen agricultural and forestry waste includes one or more of oilseed cake and livestock manure. The high-carbon agricultural and forestry waste is generally crushed to a particle size of (3~12) mm, wherein the proportion of material with a particle size ≤8 mm is greater than 75%. The inorganic nitrogen source includes one or both of urea and ammonium sulfate.

[0011] Preferably, the soluble carbon-nitrogen ratio of the mixture is controlled at (10~20):1.

[0012] (2) High-temperature aerobic fermentation of nano-membrane and phased addition of microbial agents: The initial mixture of compost is piled in an aerobic composting system covered by a nano-intelligent molecular membrane for aerobic fermentation. The system is equipped with sensors for temperature, humidity, conductivity, pH and oxygen concentration to collect the parameters of the pile in real time. The oxygen concentration, temperature and humidity of the pile are regulated by an intelligent ventilation program. The second stage of compound microbial agents is added during the high-temperature stage of composting and the third stage of compound microbial agents is added during the cooling stage.

[0013] (3) When the compost temperature is ≤40℃, it enters the post-composting stage.

[0014] The first-stage compound microbial agent contains the following strains: Bacillus amyloliquefaciens (CGMCC No. 15834) and Bacillus sicca (CGMCC No. 30728) liquid inoculum, with a volume ratio of (1-3):(3-1), and a viable count of 1×10⁻⁶. 9 -1×10 11 CFU / g;

[0015] The second-stage compound microbial agent contains the following strains: *Saccharomyces cerevisiae* (CGMCC No. 15835) and *Penicillium sumatratum* (CGMCC No. 41238) liquid inoculum, with a volume ratio of (3-2):(2-3), and a viable count of 1×10⁻⁶. 10 -1×10 11 CFU / g;

[0016] The third-stage compound microbial agent contains the following strains: Aspergillus ryukyu (CGMCC No. 41237), Fomitopsis versicolor (CGMCC No. 41880), and Paecilomyces lilacinus (CGMCC No. 41239) in liquid form, with a volume ratio of (1-1.2):(2-2.5):(2-3), and a viable count of 1×10⁻⁶. 11 -1×10 12 CFU / g.

[0017] The addition amount of the compound microbial agent in the first, second, and third stages is (0.1~0.5)% of the total dry weight of the stockpile.

[0018] Furthermore, in step (2), after the temperature rises to 65°C and is maintained for 10 days, a second-stage compound microbial agent is added; when the compost temperature drops below 50°C, a third-stage compound microbial agent is added.

[0019] Furthermore, in step (2), during the aerobic fermentation process, the soluble carbon-nitrogen ratio of the mixture is tracked and monitored, and controlled within the range of (5~20):1, preferably between (10~20):1.

[0020] Soluble carbon-nitrogen ratio (SCN) is defined as the dynamic ratio of soluble organic carbon to soluble nitrogen based on microbial decomposition and assimilation efficiency. It is used to characterize the availability of carbon and nitrogen sources and the state of microbial metabolic balance in the composting system.

[0021] Since soluble organic carbon and soluble nitrogen are difficult to detect directly online during the composting process, this invention uses online measurable parameters such as temperature, humidity, electrical conductivity (EC), pH, and oxygen concentration to establish a real-time estimation model for the soluble carbon-nitrogen ratio, thereby achieving automated detection and control of the equipment.

[0022] The soluble carbon-to-nitrogen ratio estimation model is as follows:

[0023] SCN t ≈a×EC t +b×T t +c×M t +d×pH t +e×O 2t +k (1)

[0024] Where: SCN t EC represents the soluble carbon-to-nitrogen ratio at time t. t T represents the conductivity at time t, in mS / cm. t The temperature at time t, in °C; M t The humidity at time t, in %; pH t The pH value at time t; O 2t Let t be the oxygen concentration at time t, in units of %; a, b, c, d, and e are the model coefficients obtained by least squares fitting; and k is the fitting constant.

[0025] Soluble carbon-nitrogen ratio fitting calculation method: Using temperature, humidity, conductivity, pH, and oxygen concentration sensors of the composting system, the conductivity EC of the compost pile at time t is collected in real time. t Temperature T t Humidity M t pH t and oxygen concentration O 2t Substituting the parameters into the aforementioned preset estimation model, the soluble carbon-to-nitrogen ratio (SCN) of the composting system at time t is calculated through multiple linear fitting. t .

[0026] This invention targets a low-salt composting system for agricultural and forestry waste, limiting the range of each online parameter as follows: electrical conductivity EC t 0.1-3.0 mS / cm, temperature Tt 10-65℃, humidity M t pH: 40-65%, pH: 6.0-8.5, Oxygen concentration: 40-65%. 2t : 5-18%; the corresponding regression coefficients are: a∈[0.10,0.70], b∈[0.09,0.54], c∈[0.03,0.08], d∈[0.05,0.50], e∈[0.20,0.8].

[0027] Furthermore, the soluble carbon-nitrogen ratio (SCN) obtained from the fitting calculation was analyzed. t Real-time judgment is performed to control the SCN ratio to remain within the preset range of (5~20):1; if soluble carbon-to-nitrogen ratio SCN is detected... t If the ratio is >20:1 or <5:1, at least one parameter of the reaction system, namely the ventilation rate and oxygen concentration, should be adjusted in real time until the soluble carbon-to-nitrogen ratio (SCN) is reached. t Meets the preset range.

[0028] Furthermore, the method for determining the model coefficients is as follows:

[0029] (a) Collect multiple sets of samples from different raw materials and different fermentation stages during the composting process, and simultaneously record the online detection parameters corresponding to each set of samples: temperature T, humidity M, electrical conductivity EC, pH, and oxygen concentration O2. At the same time, use standard laboratory methods to detect the soluble carbon and soluble nitrogen content of each set of samples, and calculate the measured value of the soluble carbon-nitrogen ratio (SCN) corresponding to each set of samples.

[0030] (b) Using each online detection parameter as the independent variable and the measured value of soluble carbon-nitrogen ratio (SCN) as the dependent variable, a multiple linear fitting model was constructed: SCN = a×EC + b×T + c×M + d×pH + e×O2+k;

[0031] (c) The least squares method is used to fit the multivariate linear fitting model and the coefficients a, b, c, d, e and constant k are obtained to minimize the error between the model estimate and the measured SCN value.

[0032] In this invention, the preservation information for each strain is as follows:

[0033] Bacillus amyloliquefaciens was screened from decaying camellia oleifera shells and deposited at the China General Microbiological Culture Collection Center on May 31, 2018, with accession number CGMCC No. 15834.

[0034] The yeast 'Jiemenmeier' was screened from rotten camellia shells and deposited at the China General Microbiological Culture Collection Center on May 31, 2018, with accession number CGMCC No. 15835.

[0035] Aspergillus ryukyu was screened in a high-temperature (≥65℃) composting system of Camellia oleifera shells and was deposited at the China General Microbiological Culture Collection Center on May 22, 2024, with accession number CGMCC No.41237.

[0036] The fungus *Coriolus versicolor*, selected from decaying *Pinus massoniana* stumps, was deposited on April 8, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 41880.

[0037] Penicillium sumatrae, screened in a high-temperature (≥65℃) composting system for walnut husks, was deposited at the China General Microbiological Culture Collection Center on May 22, 2024, with accession number CGMCC No. 41238.

[0038] Bacillus sicca, screened in a high-temperature (≥65℃) composting system of Camellia oleifera shells, was deposited at the China General Microbiological Culture Collection Center on May 22, 2024, with accession number CGMCC No. 30728.

[0039] Purple lilac, screened in a high-temperature (≥65℃) composting system of camellia shells, was deposited at the China General Microbiological Culture Collection Center on May 22, 2024, with accession number CGMCC No.41239.

[0040] As a preferred embodiment, in step (2), the intelligent ventilation program is as follows: continuous ventilation at the beginning of composting, with an air volume of 3-5 m³ / h. 3 / ton is used for rapid heating and initiation of aerobic fermentation; when the temperature reaches 65℃ and is maintained for 10 days, intermittent ventilation is used, with ventilation time of 10~15 minutes per hour, and the rest of the time it is turned off; when the temperature drops below 50℃, continuous ventilation is resumed until the compost temperature is ≤40℃, and the compost enters the post-composting stage.

[0041] As a preferred embodiment, the aerobic composting system is covered with a 0.2-0.8 μm microporous nanomembrane, with an oxygen permeability ≥8000 g / (m³). 2 •24h), CO2 and NH3 retention rates ≥95%.

[0042] Compared with the prior art, the beneficial effects of this invention are as follows:

[0043] This invention is applicable to the efficient composting treatment of agricultural and forestry waste characterized by high carbon and low nitrogen (such as sawdust, dead branches, and fruit shells), and can significantly improve composting efficiency. This invention abandons the traditional static control mode of total carbon-to-nitrogen ratio, using the soluble carbon-to-nitrogen ratio available to microorganisms as the control index, regulating it to (5~20):1, which better matches the dynamic nutritional needs of microorganisms and greatly improves control precision. It adopts a "stage-by-stage + type-by-type" approach to supplement compound microbial agents, adapting to the metabolic characteristics of dominant microbial communities at different fermentation stages of composting, and specifically enhancing organic matter degradation and humic substance synthesis. Combined with nano-membrane sealed fermentation and intelligent ventilation programs, it achieves coordinated and precise control of oxygen supply, temperature, and carbon-to-nitrogen ratio, improving microbial decomposition efficiency.

[0044] The high-temperature aerobic composting method for agricultural and forestry waste of this invention can shorten the composting cycle to 40-60 days, with forestry waste accounting for up to 90%, lignocellulose degradation rate >50%, and the final product has a pH of 6.5-8.0, organic matter of 30-60%, total nutrients >2%, moisture <30%, and seed germination index >90%, and can be used as a high-quality organic fertilizer or substrate raw material. Detailed Implementation

[0045] The technical solution of the present invention will be further explained and illustrated below through specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0046] Instructions for microbial preservation:

[0047] 1. Trametes versicolor YLDF-3, accession number CGMCC No.41880, accession date April 8, 2025, depositary institution: China General Microbiological Culture Collection Center; its sequence comparison results are shown in Table 1.

[0048] Table 1. Sequence comparison results of YLDF-3

[0049]

[0050] 2. *Bacillus amyloliquefaciens* was deposited at the China General Microbiological Culture Collection Center (CGMCC) on May 31, 2018, with accession number CGMCC No. 15834 (disclosed in patent CN 109136122A); *Saccharomyces guillemmayri* was deposited at the CGMCC on May 31, 2018, with accession number CGMCC No. 15835 (disclosed in patent CN 109136122A); *Aspergillus ryukinensis* was deposited at the CGMCC on May 22, 2024, with accession number CGMCC No. 41237 (disclosed in patent CN 119242451A); *Penicillium sumatratum* was deposited at the CGMCC on May 22, 2024, with accession number CGMCC No. 41238 (disclosed in patent CN 119242451A). The following are patent information disclosed in patent CN 119242451 A: Bacillus sicca was deposited at the China General Microbiological Culture Collection Center (CGMCC) on May 22, 2024, with accession number CGMCC No. 30728; and the following are patent information disclosed in patent CN 119242451 A: Paecilomyces lilacinus was deposited at the same center on May 22, 2024, with accession number CGMCC No. 41239.

[0051] Example 1:

[0052] Camellia oleifera branches and leaves, camellia oleifera fruit shells, camellia oleifera cake, walnut shells, torreya nut bark, pine wood, and pine bark are crushed, with a particle size controlled at 3-12mm and the proportion of materials ≤8mm being >75%. Urea is added to adjust the soluble carbon-nitrogen ratio of the mixture to 20. The initial soluble carbon-nitrogen ratio can be calculated by testing the soluble carbon and soluble nitrogen content in the sample. At 0.1wt% of the total dry weight of the stockpile, a first-stage compound liquid microbial agent (Bacillus amyloliquefaciens (CGMCC No. 15834) and Bacillus thuringiensis (CGMCC No. 30728) in a volume ratio of 3:2, with a viable count of 1×10⁻⁶, is added. 11 Adjust the moisture content to 55-60% (CFU / g) and stir well.

[0053] The mixture is placed into an aerobic fermentation tank covered by a (0.2~0.8μm) intelligent molecular membrane, and initial continuous air is blown in at a volume of 3-5 m³ / h. 3 / ton; after the pile temperature rises to 65℃ and is maintained for 10 days, add 0.1wt% of the second-stage compound microbial agent (Yeastra meyerii (CGMCC No. 15835) and Penicillium sumatrae (CGMCC No. 41238) liquid microbial agent, with a volume ratio of 3:2 and a viable count of 1×10⁻⁶. 10(CFU / g), switch to intermittent ventilation, ventilating for 10-15 minutes per hour, and shutting off the rest of the time; when the pile temperature drops below 50℃, add 0.2wt% of the total dry weight of the pile material, containing the third-stage compound microbial agent (Aspergillus ryukyu CGMCC No. 41237, Fungia versicolor CGMCC No. 41880, and Paecilomyces lilacinus GMCC No. 41239), at a volume ratio of 1.2:2.5:2.5, with a viable count of 1×10⁻⁶. 12 (CFU / g), restore continuous blasting until the reactor temperature ≤40℃.

[0054] During composting, parameters are collected by online sensors and used to calculate the soluble carbon-to-nitrogen ratio in real time using an estimation model, controlling it within the range of (5~20):1. Composting is completed on day 60, with an organic matter content of 59.2%, a C / N ratio of 16.8, a lignocellulose degradation rate of 54.3%, total nutrients (N+P2O5+K2O) of 4.6%, moisture content of 26%, pH of 7.3, and a seed germination index of 145%.

[0055] During composting, the soluble carbon-to-nitrogen ratio is calculated in real time using the following fitting method:

[0056] Using sensors for temperature, humidity, conductivity, pH, and oxygen concentration in the composting system, the conductivity EC at time t is collected in real time. t Temperature T t Humidity M t pH t and oxygen concentration O 2t Substituting the parameters into the preset soluble carbon-nitrogen ratio estimation model, the soluble carbon-nitrogen ratio (SCN) of the composting system at time t is obtained through multiple linear fitting. t ;

[0057] The estimation model is: SCN t ≈a×EC t +b×T t +c×M t +d×pH t +e×O 2t +k

[0058] Where a, b, c, d, and e are model coefficients obtained by least squares fitting; k is a fitting constant with a value range of [-5, 8].

[0059] The method for determining the model coefficients is as follows:

[0060] (a) Collect multiple sets of samples from different raw materials and different fermentation stages during the composting process, and simultaneously record the online detection parameters corresponding to each set of samples: temperature T, humidity M, electrical conductivity EC, pH, and oxygen concentration O2. At the same time, use standard laboratory methods to detect the soluble carbon and soluble nitrogen content of each set of samples, and calculate the measured value of the soluble carbon-nitrogen ratio (SCN) corresponding to each set of samples.

[0061] (b) Using each online detection parameter as the independent variable and the measured value of soluble carbon-nitrogen ratio (SCN) as the dependent variable, a multiple linear fitting model was constructed: SCN = a×EC + b×T + c×M + d×pH + e×O2+k;

[0062] (c) The least squares method is used to fit the multivariate linear fitting model and the coefficients a, b, c, d, e and constant k are obtained to minimize the error between the model estimate and the measured SCN value.

[0063] The general ranges for the low-salt system of agricultural and forestry waste are: a∈[0.10,0.70], b∈[0.09,0.54], c∈[0.03,0.08], d∈[0.05,0.50], e∈[0.20,0.8].

[0064] The model coefficients in this embodiment have been calculated and fitted, with a=0.12, b=0.22, c=0.04, d=0.4, e=0.28, and k=0.2. Online parameter control range: EC t 0.1~3.0 mS / cm, T t 10~65℃, M t 40~65%, pH t 6.0~8.5, O 2t 5~18%, ensure SCN t The ratio remains stable at 5 to 20:1.

[0065] During the experiment, the soluble carbon-nitrogen ratio (SCN) obtained from the fitting calculation was... t Real-time judgment is performed to control the SCN ratio to remain within the preset range of (5~20):1; if soluble carbon-to-nitrogen ratio SCN is detected... t If the ratio is >20:1 or <5:1, at least one parameter of the reaction system, namely the ventilation rate and oxygen concentration, should be adjusted in real time until the soluble carbon-to-nitrogen ratio (SCN) is reached. t Meets the preset range.

[0066] Example 2:

[0067] The main materials are sawdust, rice straw and stalks. Oilseed cake and ammonium sulfate are added to adjust the soluble carbon-nitrogen ratio to 15. The first stage of microbial agents (Bacillus amyloliquefaciens (CGMCC No. 15834) and Bacillus sicca (CGMCC No. 30728) in a volume ratio of 2:1) are added. The remaining fermentation, ventilation and microbial agent addition procedures are the same as in Example 1.

[0068] The model coefficients in this embodiment were calculated and fitted, with a=0.1, b=0.24, c=0.03, d=0.1, e=0.35, and k=-1. Online parameter control range: EC t 0.1~3.0 mS / cm, T t 10~65℃, M t 40~65%, pH t 6.0~8.5, O 2t 5~18%, ensure SCN t The ratio remains stable at 5 to 20:1.

[0069] The composting process takes about 50 days. The C / N ratio of the compost product is 17.1:1, the organic matter content is 57.8%, the seed germination index is 91%, the total nutrients are 4.0%, the moisture content is 27%, and the pH is 7.1.

[0070] Example 3:

[0071] The crushed sawdust, hickory shells, walnut peels and torreya bark were mixed in a 4:1 ratio. Chicken manure and urea were added to adjust the soluble carbon-nitrogen ratio to 10. The dosage and ratio of the microbial agent were the same as in Example 1. After the pile temperature was raised to 65°C and maintained for 10 days, the intermittent blowing ratio was adjusted to 10min / 50min (on / off), and the blowing was continued until the pile temperature was ≤40°C.

[0072] The model coefficients in this embodiment were calculated and fitted, with a=0.15, b=0.19, c=0.033, d=0.06, e=0.29, and k=-1.5. Online parameter control range: EC t 0.1~3.0 mS / cm, T t 10~65℃, M t 40~65%, pH t 6.0~8.5, O 2t 5~18%, control SCN t The ratio remains stable at 5 to 20:1.

[0073] The composting period was 48 days, and the final product had an organic matter content of 56.5%, a lignin degradation rate of 59%, a total nutrient content of 5.5%, and ammonia nitrogen loss that was 85% lower than that of the traditional control.

[0074] Comparative Example 1:

[0075] Using the same materials and operating conditions as in Example 1, only the first-stage compound liquid microbial agent was added; the second and third-stage microbial agents were not added subsequently. The results showed that the fermentation and maturation period reached 95 days, the lignocellulose degradation efficiency was only 18%, and the ammonia volatilization was more than 80% higher than in Example 1.

[0076] Comparative Example 2:

[0077] Using the same materials and operating conditions as in Example 1, the third-stage compound microbial agent was not added when the pile temperature dropped below 50°C. Results showed that after 85 days of composting, the lignocellulose degradation rate was only 22.9%, and the efficiency of humus synthesis decreased significantly in the later stages.

[0078] Comparative Example 3

[0079] Using the same materials and operating conditions as in Example 1, continuous blower air (air volume 3-5m³) was used throughout the process. 3 / ton), without implementing intelligent ventilation procedures. The results showed that the composting period was 88 days, the lignocellulose degradation efficiency was only 19%, and the compost product was not fully decomposed.

[0080] Comparative Example 4

[0081] Using the same materials as in Example 3, the initial soluble carbon-to-nitrogen ratio was adjusted to 25:1, and the total carbon-to-nitrogen ratio was 35:1. The remaining procedures for adding microbial agents and ventilation were the same as in Example 3. The results showed that the composting period was 77 days, the organic matter degradation was slow, and the lignocellulose degradation rate was only 27.3%.

[0082] Comparative Example 5

[0083] Using the same materials as in Example 3, the initial soluble carbon-nitrogen ratio was adjusted to 5, and the total carbon-nitrogen ratio to 15. The addition of other microbial agents and the ventilation procedure were the same as in Example 3. The results showed that the composting period was 69 days. The rapid temperature rise in the early stage led to a large loss of nitrogen, and the composting was slow in the later stage. The degradation rate of lignocellulose was only 22.8%.

[0084] Given that there are numerous embodiments of the present invention, and the raw materials and quantities involved can be selected within a limited range according to actual needs, and that the experimental data for each embodiment are extensive and numerous, it is not suitable to list and describe them one by one here. However, the content to be verified and the final conclusions obtained in each embodiment are similar. Therefore, the verification content of each embodiment will not be described one by one here.

[0085] The above description is merely a detailed explanation of preferred embodiments and principles of the present invention. For those skilled in the art, there may be changes in specific implementation methods based on the ideas provided by the present invention, and these changes should also be considered within the scope of protection of the present invention.

Claims

1. A method for high-temperature aerobic composting of agricultural and forestry waste, characterized in that, The method includes the following steps: (1) After crushing the high-carbon agricultural and forestry waste, mix it with the high-nitrogen agricultural and forestry waste and inorganic nitrogen source, adjust the soluble carbon-nitrogen ratio of the mixture to (5~20):1, and the moisture content to 55%~60%. Inoculate the obtained mixture with the first-stage compound microbial agent, stir thoroughly, and obtain the initial mixture for composting. (2) The initial mixture of compost is placed in an aerobic composting system covered by a nano-intelligent molecular membrane for aerobic fermentation; the system is equipped with temperature, humidity, conductivity, pH and oxygen concentration sensors to collect the parameters of the compost pile in real time; the oxygen concentration, temperature and humidity of the compost pile are regulated by an intelligent ventilation program; a second-stage compound microbial agent is added during the high-temperature stage of composting and a third-stage compound microbial agent is added during the cooling stage; (3) When the compost temperature is ≤40℃, it enters the post-composting stage; The first-stage compound microbial agent contains the following strains: a mixed liquid agent of Bacillus amyloliquefaciens (CGMCC No. 15834) and Bacillus sicca (CGMCC No. 30728), with a volume ratio of (1-3):(3-1) and a viable count of 1×10⁻⁶. 9 -1×10 11 CFU / g; The second-stage compound microbial agent contains the following strains: a mixed liquid agent of *Saccharomyces cerevisiae* (CGMCC No. 15835) and *Penicillium sumatraense* (CGMCC No. 41238), with a volume ratio of (3-2):(2-3) and a viable count of 1×10⁻⁶. 10 -1×10 11 CFU / g; The third-stage compound microbial agent contains the following strains: a mixed liquid agent of Aspergillus ryukyu (CGMCC No. 41237), F. yunnanensis (CGMCC No. 41880), and Pseudomonas lilacinus (CGMCC No. 41239), with a volume ratio of (1-1.2):(2-2.5):(2-3), and a viable count of 1×10⁻⁶. 11 -1×10 12 CFU / g.

2. The method for high-temperature aerobic composting of agricultural and forestry waste according to claim 1, characterized in that, In step (1), the high-carbon agricultural and forestry waste includes one or more of sawdust, fruit shells, dead branches, and straw; the high-nitrogen agricultural and forestry waste includes one or more of oilseed cake and livestock manure; and the inorganic nitrogen source includes one or two of urea and ammonium sulfate.

3. The method for high-temperature aerobic composting of agricultural and forestry waste according to claim 1 or 2, characterized in that, In step (1), high-carbon agricultural and forestry waste is crushed to a particle size of 3-12 mm, of which the proportion of material with a particle size ≤8 mm is greater than 75%.

4. The method for high-temperature aerobic composting of agricultural and forestry waste according to claim 1, characterized in that, In step (2), the aerobic fermentation process controls the soluble carbon-to-nitrogen ratio to be (5~20):1; The soluble carbon-nitrogen ratio is calculated in real time using the following fitting method: Using sensors for temperature, humidity, conductivity, pH, and oxygen concentration in the composting system, the conductivity EC at time t is collected in real time. t Temperature T t Humidity M t pH t and oxygen concentration O 2t Substituting the parameters into the preset soluble carbon-nitrogen ratio estimation model, the soluble carbon-nitrogen ratio (SCN) of the composting system at time t is obtained through multiple linear fitting. t ; The estimation model is: SCN t ≈a×EC t +b×T t +c×M t +d×pH t +e×O 2t +k Where a, b, c, d, and e are model coefficients obtained by least squares fitting; the range of each parameter is: conductivity EC t 0.1-3.0 mS / cm, temperature T t 10-65℃, humidity M t 40-65%, pH t 6.0-8.5, Oxygen concentration O 2t : 5-18%; The coefficients take the following values: a∈[0.10,0.70], b∈[0.09,0.54], c∈[0.03,0.08], d∈[0.05,0.50], e∈[0.20,0.8]; k is the fitting constant.

5. The method for high-temperature aerobic composting of agricultural and forestry waste according to claim 1, characterized in that, In step (2), after the composting temperature rises to 65°C and is maintained for 10 days, the second-stage compound microbial agent is added; when the composting temperature drops below 50°C, the third-stage compound microbial agent is added.

6. The method for high-temperature aerobic composting of agricultural and forestry waste according to claim 1, characterized in that, In step (3), the amount of the first-stage compound microbial agent, the second-stage compound microbial agent, and the third-stage compound microbial agent added is 0.1~0.5% of the total dry weight of the stockpile.

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