Preparation method of sugarcane leaf filter mud compost improved by combined function bacteria and rice husk carbon and application thereof

Abstract

The present application relates to the technical field of sugarcane industry waste resource utilization and organic fertilizer, and is a preparation method and application of sugarcane leaf and filter mud compost modified by adding composite functional strains and rice husk carbon, wherein the sugarcane leaf and filter mud are used as main raw materials. Through the synergistic effect of the strains and the rice husk carbon, the carbon and nitrogen conversion efficiency in the composting process is strengthened, the composting maturity and nutrient content are improved, and efficient resource utilization of sugarcane industry waste is realized.

Description

Technical Field

[0001] This invention relates to the field of resource utilization of sugarcane industry waste and organic fertilizer technology, specifically a method for preparing sugarcane leaf filter mud compost improved by the combined use of compound functional bacteria and rice husk charcoal, and its application. Background Technology

[0002] The sugarcane sugar industry is one of my country's important strategic industries. Taking major producing areas such as Guangxi as an example, a large amount of by-products such as sugarcane leaves and filter mud are generated annually during sugarcane harvesting and sugar production, amounting to nearly ten million tons. Currently, the main methods for handling these by-products are field stockpiling, simple return to the field, or low-value utilization. These methods suffer from problems such as extensive processing and low utilization efficiency, which not only waste resources but may also exacerbate soil acidification, fertility decline, and non-point source pollution risks. At the same time, the long-term reliance on chemical fertilizers in major producing areas to pursue high yields and high sugar content easily leads to problems such as soil compaction, decreased organic matter content, and acidification. There is an urgent need to achieve green efficiency through organic fertilizer substitution and soil improvement. With the promotion of step-by-step mechanized harvesting, the amount of sugarcane leaves has further increased, and the contradictions of "difficult to collect, difficult to store and transport, difficult to process," high risks of stockpiling, and low utilization rate of sugarcane leaves have become more prominent.

[0003] Sugarcane leaves are mainly composed of cellulose, hemicellulose and lignin. They have a high lignin content and a dense structure. Directly returning them to the field or using conventional composting results in slow decomposition and difficulty in rapidly releasing nutrients within a short period, which can lead to a long decomposition period and insufficient product maturity.

[0004] Filter mud has a high moisture content and is rich in organic matter and nutrients such as nitrogen and phosphorus, making it a potential source of organic fertilizer. However, during composting or fermentation, it is prone to ammonium nitrogen accumulation and ammonia release, resulting in off-odors and nitrogen volatilization losses. Simultaneously, the high moisture content can lead to insufficient aeration and localized anaerobic conditions, affecting temperature rise and composting stability. Co-fermentation of sugarcane leaves and filter mud in an aerobic manner can regulate the carbon-nitrogen ratio and moisture content to some extent, but it still faces key bottlenecks such as limited degradation of sugarcane leaf lignocellulose, easy nitrogen loss from filter mud, and insufficient humification.

[0005] While existing technologies have been reported to improve the composting process through methods such as turning and temperature control, adding single-function microbial agents, or biochar, they generally suffer from several drawbacks: single microbial agents have limited target sites, making it difficult to simultaneously achieve synergistic degradation of lignin "cell wall breaking" and cellulose / hemicellulose hydrolysis; ammonia generated during composting is difficult to effectively fix, leading to both nitrogen loss and odor problems; and while biochar, when used alone, can improve the porosity of the compost pile and adsorb some ammonium nitrogen to a certain extent, its effect on enhancing microbial activity is limited and it lacks matching optimization with functional microbial communities. Therefore, there is an urgent need for a combined enhancement technology for sugarcane leaf-filter mud systems that balances efficient degradation of lignocellulose and nitrogen retention, shortens the composting cycle, and improves the degree of humification. Summary of the Invention

[0006] To address the problems of slow lignocellulose degradation, large nitrogen loss, long composting cycle, and low maturity in existing filter mud-sugarcane leaf compost, this invention provides a method for preparing sugarcane leaf filter mud compost improved by the combined use of compound functional bacteria and rice husk charcoal: using sugarcane leaves and filter mud as the main raw materials, adding compound functional bacteria and rice husk charcoal, and then aerobic fermenting to obtain the compost; the raw materials are prepared in the following weight ratio: sugarcane leaves: filter mud: compound functional bacteria: rice husk charcoal = 30~50: 20~40: 1~5: 3~5.

[0007] The composite functional bacteria are prepared by mixing highly efficient lignocellulose-degrading bacteria and nitrogen-fixing bacteria; the lignocellulose-degrading bacteria include *Phanerochaete chrysosporium* and *Trichoderma* strains. Trichoderma sp. LH-413; among which, Trichoderma sp. LH-413 is classified as belonging to the genus Trichoderma ( Trichoderma sp. The nitrogen-fixing bacteria are deposited at the China Center for Type Culture Collection (CCTCC), accession number CCTCC NO: M2023749; Azotobacter sp. The accession number is CICC 20024; the accession number is ATCC24725, and it was purchased from the China Industrial Microbial Culture Collection Center.

[0008] The method of the present invention includes the following steps: a. Raw material pretreatment: Chop / crush sugarcane leaves to a particle size ≤5 mm, dehydrate and loosen the filter mud, break up agglomerates if necessary, mix evenly, and adjust the initial moisture content to 55%~65% and the carbon-nitrogen ratio (C / N) to 22~28 by adding water to obtain loose and breathable compost base material; b. Strain preparation: The compound inoculum of lignocellulose-degrading bacteria and nitrogen-fixing bacteria were separately cultured until the activity of all three was ≥1×10⁻⁶. 9 After CFU / mL, the volume ratio of *Phanerochaete chrysosporium* was: Trichoderma sp. LH-413: Nitrogen-fixing bacteria Azotobacter sp.= A mixture of 3:3:2 yields a compound functional bacteria; c. Combined fermentation: Add compound functional bacteria and rice husk charcoal evenly to the compost base material, mix thoroughly and then carry out aerobic composting. During the composting process, control the aeration rate to 0.05-0.1 m³ / (m³·h). d. Composting management: Turn the compost pile every 3-7 days for the first 20 days, and every 7 days thereafter, shortening the total fermentation cycle to 45-48 days; during this period, maintain the high temperature of the compost pile above ≥55 ℃ for 10-15 days to achieve pathogen inactivation and full decomposition of organic matter.

[0009] As described above, the application of a sugarcane leaf filter mud compost improved by a combination of compound functional bacteria and rice husk charcoal in crop cultivation substrates or soil conditioners.

[0010] The various functional strains in the composite functional microbial strains rapidly proliferate in the composting environment and form a dominant microbial community, synergistically degrading the lignocellulose enriched in sugarcane leaves and the residual fiber and organic matter in the filter mud: lignocellulose-degrading bacteria (Phanerochaete chrysosporium and Trichoderma strains) Trichoderma sp. LH-413 secretes laccase, peroxidase, and other lignin-degrading enzymes, preferentially disrupting the lignin barrier of sugarcane leaves and increasing substrate accessibility; cellulose-degrading bacteria secrete cellulase, hemicellulase, etc., further hydrolyzing cellulose and hemicellulose, releasing usable carbon sources and accelerating the humification process; nitrogen-fixing bacteria ( Azotobacter sp. In the pores of rice husk charcoal and the moist microenvironment of filter mud, nitrogen in the air is fixed and converted into microbial assimilated nitrogen / organic nitrogen. Combined with the adsorption and fixation of NH3 / ammonium nitrogen by rice husk charcoal, the effective nitrogen loss caused by NH3 volatilization is reduced, thereby improving the nitrogen nutrition level of the compost product.

[0011] Rice husk char has a large specific surface area and well-developed pore structure, which can improve the aeration and water retention conditions of the compost pile and provide an attachment carrier and microenvironment for complex functional microorganisms. At the same time, rice husk char can adsorb and fix ammonia (NH3) and ammonium nitrogen generated during composting through pore adsorption and surface functional group action, reducing NH3 volatilization and nitrogen loss. In addition, its surface active sites can promote the polymerization and transformation of humic precursor substances, thereby further improving the degree of humification and quality of compost products.

[0012] The beneficial effects of this invention are: 1. This invention employs a composite functional microbial strain consisting of highly efficient lignin-degrading bacteria, cellulose-degrading bacteria, and a nitrogen-fixing bacterium, which is added in combination with rice husk charcoal. The composite functional microbial strain destroys the lignin-cellulose structure and accelerates the degradation of cellulose, hemicellulose, and lignin by secreting lignin-degrading enzymes and cellulases. At the same time, the nitrogen-fixing bacteria fix atmospheric nitrogen and promote the conversion of nitrogen into microbial assimilated nitrogen / organic nitrogen. The rice husk charcoal adsorbs and fixes ammonia gas generated during composting and provides a colonization carrier, thereby achieving a synergistic effect of "promoting degradation - nitrogen fixation and supplementation - ammonia absorption and nitrogen retention," overcoming the functional limitations of single microbial strains or single biochar. 2. By efficiently degrading sugarcane leaf lignocellulose and promoting humification through compound functional microorganisms, and by adsorbing and fixing ammonia released from the decomposition of filter mud with rice husk charcoal and working together with nitrogen-fixing bacteria to improve nitrogen retention, the composting fermentation cycle of this invention is shortened to 45-48 days. The total degradation rate of lignocellulose can reach up to 48%, the total nitrogen content reaches 3.1%, the humic acid content reaches 12.5%, the seed germination index reaches 92%, the product has no odor, and the heavy metal content meets the NY / T 1978-2022 standard. The compost quality is significantly better than that of traditional compost. 3. It enables the efficient resource utilization of sugarcane industry waste such as sugarcane leaves and filter mud, reduces environmental pollution, and the prepared compost can improve soil fertility and promote crop growth, which meets the needs of sustainable agricultural development. Attached Figure Description

[0014] Figure 1 This is a schematic diagram showing the changes in cellulose and total nitrogen content in filter mud and sugarcane leaf compost.

[0015] Figure 2 This diagram illustrates the changes in humic acid content and seed germination rate in filter mud and sugarcane leaf compost. Detailed Implementation

[0016] To better understand the content of this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below. The invention will be further explained below with reference to the embodiments, but this should not be construed as limiting the invention.

[0017] In the following embodiments, the bacterial strains were first streaked on the corresponding agar plates and then expanded in liquid culture medium. Microscopic examination of each bacterial culture revealed no contamination and an activity ≥1×10⁻⁶. 9 Once the concentration of CFU / mL is reached, it can be used for the preparation of mixed bacterial strains.

[0018] Comparative Examples

[0019] This embodiment does not add compound functional microorganisms or rice husk charcoal, but uses traditional composting methods, with the following steps: a. Raw material pretreatment: Take 35 parts sugarcane leaves and 25 parts filter mud. Chop / crush the sugarcane leaves to a particle size ≤5 mm. Dehydrate and loosen the filter mud. After mixing evenly, adjust the initial moisture content to 60% and C / N ratio to 25 to obtain compost base material. b. Fermentation: The compost base material is directly subjected to aerobic composting, maintaining an aeration rate of 0.075 m³ / (m³·h). The compost is turned over once every 5 days for the first 20 days, and once every 7 days thereafter, with a total fermentation cycle of 48 days.

[0020] The compost product was measured to be yellowish-brown with a slight odor, pH 7.9, electrical conductivity 3.4 mS / cm, seed germination index 62%, total lignocellulose degradation rate 20%, total nitrogen content 1.9%, and humic acid content 5.8%. The overall effect was far inferior to that of the embodiments of the present invention.

[0021] Example 1 (Lignocellulose-degrading bacteria only) This embodiment only adds lignin-degrading bacteria (Phanerochaete chrysosporium + Trichoderma sp. LH-413 in the compound microbial agent) to verify the limitations of a single degrading bacterial species and to highlight the synergistic degradation advantages of the compound microbial agent. The steps are as follows: a. Raw material pretreatment: Take 38 parts sugarcane leaves and 28 parts filter mud. Crush the sugarcane leaves to a particle size ≤ 5 mm and dehydrate and loosen the filter mud. After mixing evenly, adjust the initial moisture content to 62% and C / N ratio to 26 to obtain compost base material. b. Fermentation treatment: Add 2 parts of lignocellulose degrading bacteria (no nitrogen-fixing bacteria, no rice husk char) to the compost base material, mix thoroughly and then carry out aerobic composting, maintaining an aeration rate of 0.08 m³ / (m³·h). c. Compost management: Turn the compost pile every 5 days for the first 20 days, and every 7 days thereafter. The total fermentation cycle is 48 days, during which a high temperature period (≥55 ℃) is maintained for 11 days.

[0022] The compost product was measured to be dark brown with no obvious odor, pH 7.3, electrical conductivity 2.7 mS / cm, and seed germination index 79%. The total degradation rate of lignocellulose was 32% (it could only destroy the lignin barrier of sugarcane leaves, lacking synergistic effects of cellulose-degrading bacteria and nitrogen-fixing bacteria, resulting in limited degradation efficiency); the total nitrogen content was 1.7% (there were no nitrogen fixation or supplementation measures, and no nitrogen retention measures, leading to severe volatilization and loss of ammonium nitrogen from the filter mud); and the humic acid content was 8.6% (the degree of humification was average), highlighting the functional limitations of a single degradation strain.

[0023] Example 2 (only nitrogen-fixing bacteria group added) This embodiment only adds nitrogen-fixing bacteria (Azotobacter sp.) to verify the limitations of a single nitrogen-fixing bacterial species and to highlight the synergistic degradation advantages of the compound bacterial agent. The steps are as follows: a. Raw material pretreatment: Take 38 parts sugarcane leaves and 28 parts filter mud. Crush the sugarcane leaves to a particle size ≤ 5 mm and dehydrate and loosen the filter mud. After mixing evenly, adjust the initial moisture content to 62% and C / N ratio to 26 to obtain compost base material. b. Fermentation treatment: Add 2 parts of nitrogen-fixing bacteria (without lignocellulose-degrading bacteria and without rice husk char) to the compost base material, mix thoroughly and then carry out aerobic composting, maintaining an aeration rate of 0.08 m³ / (m³·h). c. Compost management: Turn the compost pile every 5 days for the first 20 days, and every 7 days thereafter. The total fermentation cycle is 48 days, during which a high temperature period (≥55℃) is maintained for 10 days.

[0024] The compost product was measured to be yellowish-brown, odorless, with a pH of 7.4, an electrical conductivity of 2.6 mS / cm, and a seed germination index of 75%. The total degradation rate of lignocellulose was 25% (it could only slightly promote natural degradation through metabolites, lacked a highly efficient degradation enzyme system, and had poor degradation effect on sugarcane leaf lignocellulose). The total nitrogen content was 2.3% (it had a prominent nitrogen fixation function, making up for some of the nitrogen volatilization loss in the filter mud, but lacked degrading bacteria to synergistically improve compost quality). The humic acid content was 7.1% (low degree of humification), further confirming that a single bacterial species cannot simultaneously address degradation and nutrient retention.

[0025] Example 3 (only the compound functional bacterial strain group was added) This embodiment only adds a compound functional microbial strain to verify its single degradation and humification effects, excluding the interference of nitrogen retention by rice husk charcoal. The steps are as follows: a. Raw material pretreatment: Take 35 parts sugarcane leaves and 25 parts filter mud. Chop / crush the sugarcane leaves to a particle size ≤5 mm. Dehydrate and loosen the filter mud. After mixing evenly, adjust the initial moisture content to 60% and C / N ratio to 25 to obtain compost base material. b. Fermentation treatment: Add 3 parts of compound functional bacteria (without rice husk charcoal) to the compost base material, mix thoroughly and then carry out aerobic composting, maintaining an aeration rate of 0.075 m³ / (m³·h); c. Composting management: Turn the compost every 4 days for the first 20 days, and every 7 days thereafter. The total fermentation cycle is 48 days, during which a high temperature period (≥55 ℃) is maintained for 11 days.

[0026] The compost product was measured to be dark brown and odorless, with a pH of 7.2, an electrical conductivity of 2.5 mS / cm, a seed germination index of 83%, a total lignocellulose degradation rate of 45% (the lignin-degrading bacteria and cellulose-degrading bacteria in the compound functional strain synergistically secreted degradation enzymes, significantly accelerating the decomposition of sugarcane leaf lignocellulose and promoting humification), a total nitrogen content of 2.2% (due to the lack of rice husk charcoal, the ammonia (NH3) released from the decomposition of the filter mud lacked effective adsorption and fixation, and ammonium nitrogen was easily converted and volatilized, resulting in low nitrogen retention; although nitrogen-fixing bacteria could supplement some nitrogen, it was difficult to completely offset the volatilization loss), and a humic acid content of 11.0% (the strain promoted the conversion of organic matter into humus). This indicates that the compound functional strain can significantly promote the degradation and humification of lignocellulose, but it needs to be combined with rice husk charcoal to enhance ammonia absorption and nitrogen retention.

[0027] Example 4 (with only rice husk charcoal added) In this embodiment, only rice husk charcoal was added to verify its single adsorption and nitrogen retention efficiency, excluding the influence of microbial strains on degradation. The steps are as follows: a. Raw material pretreatment: Take 35 parts sugarcane leaves and 25 parts filter mud. Chop / crush the sugarcane leaves to a particle size ≤5mm. Dehydrate and loosen the filter mud. After mixing evenly, adjust the initial moisture content to 60% and C / N ratio to 25 to obtain compost base material. b. Fermentation treatment: Add 3 parts rice husk charcoal (without adding compound functional bacteria) to the compost base material, mix thoroughly and then carry out aerobic composting, maintaining an aeration rate of 0.075 m³ / (m³·h); c. Compost management: Turn the compost pile every 3 days for the first 20 days, and every 7 days thereafter. The total fermentation cycle is 48 days, during which a high temperature period (≥55 ℃) is maintained for 10 days.

[0028] The compost product was measured to be dark brown and odorless, with a pH of 7.1, an electrical conductivity of 2.4 mS / cm, a seed germination index of 78%, a total lignocellulose degradation rate of 28% (significantly better than the 20% in the unadded group, mainly due to the natural degradation of the compost and the aeration effect of rice husk charcoal), a total nitrogen content of 2.6% (the nitrogen source in the filter mud is easily ammonified and volatilized in the form of NH3 during fermentation; rice husk charcoal has a significant adsorption and fixation effect on the ammonia (NH3) generated during composting, reducing nitrogen loss caused by NH3 volatilization, thus demonstrating a significant nitrogen retention effect), and a humic acid content of 8.8% (due to the lack of added compound functional bacteria, the humification promotion effect is limited). This indicates that rice husk charcoal alone can achieve ammonia absorption and nitrogen retention, but its effect on the deep degradation of lignocellulose and the enhancement of humification is relatively insufficient.

[0029] Example 5 (Low bacterial strain + low rice husk charcoal group) This embodiment uses a low-dose combination of microbial inoculum and rice husk charcoal to verify the basic synergistic effect. The steps are as follows: a. Raw material pretreatment: Take 35 parts sugarcane leaves and 25 parts filter mud. Chop / crush the sugarcane leaves to a particle size ≤5 mm. Dehydrate and loosen the filter mud. After mixing evenly, adjust the initial moisture content to 60% and C / N ratio to 25 to obtain compost base material. b. Combined fermentation: Add 1 part of compound functional bacteria and 3 parts of rice husk charcoal to the compost base material, mix thoroughly and then carry out aerobic composting, maintaining an aeration rate of 0.075 m³ / (m³·h). c. Composting management: Turn the compost every 5 days for the first 20 days, and every 7 days thereafter. The total fermentation cycle is 48 days, during which a high temperature period (≥55 ℃) is maintained for 12 days.

[0030] The compost product was measured to be dark brown and odorless, with a pH of 7.2, an electrical conductivity of 2.6 mS / cm, a seed germination index of 86%, a total lignocellulose degradation rate of 39% (the compound functional microorganisms played a basic degradation role), a total nitrogen content of 2.7% (rice husk char adsorbed and fixed ammonia (NH3) and provided a microbial carrier, which, together with the nitrogen-fixing bacteria, improved nitrogen retention), and a humic acid content of 10.0% (the microbial agent promoted humification). All indicators were superior to the single-addition group, reflecting the synergistic effect between the compound functional microorganisms' "promoting degradation / nitrogen fixation" and the rice husk char's "ammonia absorption and nitrogen retention / carrier".

[0031] Example 6 (medium-sized bacterial strain + medium-sized rice husk charcoal group, preferred dosage) This embodiment uses a moderate dosage compound ratio to achieve a three-dimensional balance of degradation, nitrogen retention, and humification, resulting in the optimal overall effect. The steps are as follows: a. Raw material pretreatment: Take 35 parts sugarcane leaves and 25 parts filter mud. Chop / crush the sugarcane leaves to a particle size ≤5 mm. Dehydrate and loosen the filter mud. After mixing evenly, adjust the initial moisture content to 60% and C / N ratio to 25 to obtain compost base material. b. Combined fermentation: Add 3 parts of compound functional bacteria and 4 parts of rice husk charcoal to the compost base material, mix thoroughly and then carry out aerobic composting, maintaining an aeration rate of 0.075 m³ / (m³·h). c. Compost management: Turn the compost pile every 5 days for the first 20 days, and every 7 days thereafter. The total fermentation cycle is 48 days, during which a high temperature period (≥55℃) is maintained for 12 days.

[0032] The compost product was measured to be dark brown and odorless, with a pH of 7.3, an electrical conductivity of 2.6 mS / cm, a seed germination index of 92%, a total lignocellulose degradation rate of 46% (due to the efficient secretion of degradation enzymes by the compound functional microorganisms, resulting in synergistic degradation of lignin and cellulose), a total nitrogen content of 3.1% (due to the combined effect of NH3 adsorption and fixation by rice husk charcoal, nitrogen supplementation by nitrogen-fixing bacteria, and microbial assimilation and fixation, achieving high nitrogen retention), and a humic acid content of 12.5% ​​(due to a high degree of humification). It achieves a balance between degradation efficiency, ammonia absorption and nitrogen retention, and humification level, and its comprehensive performance far exceeds that of the single additive group and other compound groups.

[0033] Example 7 (Low bacterial strain + high rice husk charcoal group) This embodiment focuses on using a high amount of rice husk charcoal to enhance nitrogen retention and weaken the degradation effect of microorganisms. The steps are as follows: a. Raw material pretreatment: Take 35 parts sugarcane leaves and 25 parts filter mud. Chop / crush the sugarcane leaves to a particle size ≤5 mm. Dehydrate and loosen the filter mud. After mixing evenly, adjust the initial moisture content to 60% and C / N ratio to 25 to obtain compost base material. b. Combined fermentation: Add 2 parts of compound functional bacteria and 5 parts of rice husk charcoal to the compost base material, mix thoroughly and then carry out aerobic composting, maintaining an aeration rate of 0.075 m³ / (m³·h). c. Compost management: Turn the compost pile every 5 days for the first 20 days, and every 7 days thereafter. The total fermentation cycle is 48 days, during which a high temperature period (≥55 ℃) is maintained for 13 days.

[0034] The compost product was measured to be dark brown and odorless, with a pH of 7.2, an electrical conductivity of 2.6 mS / cm, a seed germination index of 87%, a total degradation rate of lignocellulose of 41% (the low amount of microbial agent limited the supply of degradation enzymes, resulting in a lower degradation rate than the optimal dosage group), a total nitrogen content of 3.0% (high rice husk charcoal dosage has a stronger ability to adsorb and fix NH3, and the ammonia absorption and nitrogen retention effect is more prominent), and a humic acid content of 10.6% (affected by insufficient microbial agent, the degree of humification is lower than the optimal dosage group). This indicates that rice husk charcoal mainly contributes to ammonia absorption and nitrogen retention, while the deep degradation and humification of lignocellulose still depend on the compound functional microbial strains.

[0035] Example 8 (High bacterial strain + low rice husk charcoal group) This embodiment emphasizes a high dosage of microbial strains to enhance degradation and humification effects, while weakening the nitrogen-retaining effect of rice husk charcoal. The steps are as follows: a. Raw material pretreatment: Take 35 parts sugarcane leaves and 25 parts filter mud. Chop / crush the sugarcane leaves to a particle size ≤5 mm. Dehydrate and loosen the filter mud. After mixing evenly, adjust the initial moisture content to 60% and C / N ratio to 25 to obtain compost base material. b. Combined fermentation: Add 5 parts of compound functional bacteria and 3 parts of rice husk charcoal to the compost base material, mix thoroughly and then carry out aerobic composting, maintaining an aeration rate of 0.075 m³ / (m³·h). c. Compost management: Turn the compost pile every 6 days for the first 20 days, and every 7 days thereafter. The total fermentation cycle is 48 days, during which a high temperature period (≥55 ℃) is maintained for 14 days.

[0036] The compost product was measured to be dark brown and odorless, with a pH of 7.4, an electrical conductivity of 2.8 mS / cm, a seed germination index of 88%, a total lignocellulose degradation rate of 48% (high bacterial count promotes enzyme secretion, resulting in more complete lignocellulose degradation), a total nitrogen content of 2.5% (low rice husk char content limits the adsorption and fixation of ammonia (NH3) generated during composting; under strong degradation / mineralization conditions, ammonification is enhanced, making NH3 more volatile and limiting nitrogen retention), and a humic acid content of 11.8% (high degree of humification). This indicates that the compound functional bacterial strain can significantly promote lignocellulose degradation and humification, but insufficient rice husk char content will limit the ammonia absorption and nitrogen retention effect.

[0037] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing sugarcane leaf filter mud compost improved by a combination of compound functional bacteria and rice husk charcoal, characterized in that, Sugarcane leaves and filter mud are used as the main raw materials, with the addition of compound functional bacteria and rice husk charcoal. The raw materials are prepared in the following weight ratio: sugarcane leaves: filter mud: compound functional bacteria: rice husk charcoal = 30~50: 20~40: 1~5: 3~5.

2. The preparation method according to claim 1, characterized in that, The composite functional bacteria are prepared by mixing lignocellulose-degrading bacteria and nitrogen-fixing bacteria; the lignocellulose-degrading bacteria include *Phanerochaete chrysosporium* and *Trichoderma* strains. Trichoderma sp. LH-413; among which, Trichoderma sp. LH-413 is classified as belonging to the genus Trichoderma ( Trichoderma sp. The nitrogen-fixing bacteria are deposited at the China Center for Type Culture Collection (CCTCC), accession number CCTCC NO: M2023749; Azotobacter sp. The accession number is CICC 20024.

3. The preparation method according to claim 1, characterized in that, Includes the following steps: a. Raw material pretreatment: Chop / crush sugarcane leaves to a particle size ≤ 5 mm, dehydrate and loosen the filter mud, break up agglomerates if necessary, mix evenly, and adjust the initial moisture content to 55%-65% and the carbon-nitrogen ratio (C / N) to 22-28 by adding water to obtain loose and breathable compost base material; b. Strain preparation: The compound inoculum of lignocellulose-degrading bacteria and nitrogen-fixing bacteria were separately cultured until the activity of all three was ≥1×10⁻⁶. 9 After CFU / mL, the volume ratio of *Phanerochaete chrysosporium* was: Trichoderma sp. LH-413: Nitrogen-fixing bacteria Azotobacter sp.= A mixture of 3:3:2 yields a compound functional bacteria; c. Combined fermentation: Add compound functional bacteria and rice husk charcoal evenly to the compost base material, mix thoroughly and then carry out aerobic composting. During the composting process, control the aeration rate to 0.05-0.1 m³ / (m³·h). d. Composting management: Turn the compost pile every 3-7 days for the first 20 days, and every 7 days thereafter; during this period, maintain the high temperature of the compost pile above 55°C for 10-15 days.

4. The use of compost prepared by any one of claims 1-3 in crop cultivation substrates or soil conditioners.

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