A method for preparing a microbial fertilizer using medicinal plant residues

Abstract

This invention discloses a method for preparing microbial fertilizer using medicinal plant residues, belonging to the field of microbial fertilizer technology. The method includes: pretreating the medicinal plant residues and adjusting their moisture content and nutrient balance to obtain a material to be detoxified; sampling and preparing an aqueous extract during aerobic fermentation; selecting at least two indicators from maturity and phytotoxicity, salt content, and inhibitory marker residues to set release thresholds; ending fermentation when the thresholds are reached in a single sampling to obtain a detoxification matrix; cooling the detoxification matrix; contacting the aqueous extract or leaching with a porous adsorption carrier to adsorb residual inhibitory components to form a pre-adsorption carrier; loading and immobilizing bacterial agents to obtain microbial carrier bacteria; granulating the detoxification matrix and enriching the carrier bacteria on the surface of the particles; and drying to obtain microbial fertilizer. This invention achieves controllable detoxification and improves the colonization and storage stability of the microorganisms.

Description

Technical Field

[0001] This invention relates to the field of microbial fertilizer technology, and in particular to a method for preparing microbial fertilizer using medicinal plant residues. Background Technology

[0002] In recent years, the resource utilization of medicinal plant residues and the preparation process of microbial fertilizers have been rapidly integrated. The mainstream route takes aerobic fermentation as the core, and is equipped with online or offline monitoring of process parameters such as pile temperature gradient, ventilation and oxygen supply level, moisture content, pH, carbon-nitrogen ratio, ammonia nitrogen, volatile organic acids, and humification index. Combined with unit operations such as turning, watering, buffering and conditioning and granulation fixation, the matrix is ​​stabilized and the microbial agent is carried out.

[0003] For medicinal plant residues, the release and transformation of water-soluble salts and inhibitory metabolites during fermentation are dynamically coupled. Existing processes mostly use fermentation time or a single maturity signal as the endpoint criterion, and have not formed a release threshold system that simultaneously covers maturity and phytotoxicity characterization indicators, salt characterization indicators and inhibitory marker residue characterization indicators, resulting in a lack of repeatable quantitative basis for determining the completion of detoxification. Summary of the Invention

[0004] In view of this, this application provides a method for preparing microbial fertilizer using medicinal plant residues.

[0005] According to one aspect of this disclosure, a method for preparing microbial fertilizer using medicinal plant residues is provided, comprising: Step 1, pretreating the medicinal plant residues and adjusting their moisture content and nutrient balance to obtain a material to be detoxified; Step 2, subjecting the material to be detoxified to aerobic fermentation, and taking samples to prepare an aqueous extract during the fermentation process, detecting release indicators and setting corresponding preset release thresholds; before the start of fermentation, determining a combination of release criteria for determining the completion of detoxification from the release indicators, and keeping it unchanged during the fermentation process; monitoring the pile operating parameters during fermentation, and executing control actions to maintain aerobic fermentation and promote the completion of detoxification to end the fermentation, obtaining a detoxification matrix; Step 3, ... Step 4: Cool the detoxification substrate to a set temperature to obtain a substrate for planting; Step 5: Provide a porous adsorption carrier, and contact the porous adsorption carrier with an aqueous extract prepared from the detoxification substrate, or with a leaching solution obtained by rinsing the detoxification substrate with water and collecting the filtrate, so that the porous adsorption carrier first adsorbs the residual inhibitory components in the detoxification substrate to obtain a pre-adsorption carrier; Step 6: Load and fix functional microbial agents on the surface and pores of the pre-adsorption carrier to obtain a microbial protective micro-zone carrier bacteria; Step 7: Use the detoxification substrate as the main material for granule molding, and allow the microbial protective micro-zone carrier bacteria to form an enriched distribution in the surface area of ​​the granules, and treat under drying conditions to obtain microbial fertilizer.

[0006] In a preferred embodiment of the microbial fertilizer preparation method of the present invention, the medicinal plant residue is a residue from a single medicinal plant source, or a residue generated from the same prescription formula.

[0007] In a preferred embodiment of the microbial fertilizer preparation method of the present invention, the materials used to adjust the moisture content and nutrient balance in step one include carbon-regulating and bulking materials and moisture-regulating materials; the carbon-regulating and bulking materials are selected from at least one of straw powder, sawdust, rice husk powder, corn cob powder and wheat bran; the moisture-regulating materials are at least one of clean water and recycled fermentation liquid.

[0008] As a preferred embodiment of the microbial fertilizer preparation method of the present invention, the release indicators include maturity and phytotoxicity characterization indicators, salinity characterization indicators, and residual inhibitory marker characterization indicators; the release judgment indicator combination consists of at least two of the release indicators; the control actions include at least: turning the pile when the pile temperature exceeds 65°C; adding alkaline buffer conditioning material when the pH is below 6.0; replenishing water when the moisture content is below 40%; and stopping the replenishment of conditioning material containing inorganic salts to the pile and extending the aerobic stability period when the salinity characterization indicator is electrical conductivity EC and the electrical conductivity EC is higher than the salinity characterization threshold.

[0009] As a preferred embodiment of the microbial fertilizer preparation method of the present invention, the aqueous extract is prepared at a solid-liquid ratio of 1:10 (g:mL), shaken at 25℃ for 30 min, and then filtered; the maturity and phytotoxicity characterization index is the germination index GI, which is obtained by dark incubation of the same variety and batch of seeds at 25℃ for 48 h.

[0010] In a preferred embodiment of the microbial fertilizer preparation method of the present invention, the salt content characterization index is electrical conductivity EC, which is measured at 25°C; the sampling and testing frequency for the preparation of the aqueous extract is once every 2 to 4 days.

[0011] As a preferred embodiment of the microbial fertilizer preparation method of the present invention, wherein: the inhibitory marker corresponding to the inhibitory marker residue characterization index is at least one of total polyphenols, total saponins and total alkaloids, and the initial content of the inhibitory marker after obtaining the material to be detoxified in step one is used as the relative reduction calculation benchmark.

[0012] In a preferred embodiment of the microbial fertilizer preparation method of the present invention, the porous adsorption carrier is selected from at least one of biochar, zeolite, and bentonite, with a particle size of 0.2–2 mm; the contact conditions between the porous adsorption carrier and the aqueous extract or leaching liquid are: a solid-liquid ratio of 1:8–1:20 (g:mL), a temperature of 20–35°C, and a contact time of 30–180 min; and the pre-adsorption endpoint is determined by a decrease of ≥20% in the concentration of the inhibitory marker residue characterization index in the liquid phase after contact relative to the liquid phase before contact.

[0013] As a preferred embodiment of the microbial fertilizer preparation method of the present invention, the functional microbial agent includes at least Bacillus spp.; an immobilized binding system is used during loading, the immobilized binding system being selected from at least one of alginate, starch gum, and lignin sulfonate; after loading, it is incubated at 25-35°C for 12-72 hours, and the stable colonization criterion is that the change rate of the effective viable bacteria count on the surface and in the pores of the carrier does not exceed 20% in two tests at 24-hour intervals at the end of incubation.

[0014] As a preferred embodiment of the microbial fertilizer preparation method of the present invention, the obtained microbial fertilizer simultaneously meets the following indicators: effective viable bacteria count ≥ 1× CFU / g, germination index GI≥90%, electrical conductivity EC≤3.0mS / cm, pH 5.5~8.5, moisture content not higher than 30%.

[0015] The beneficial effects of this invention are as follows: during the aerobic fermentation process, samples are taken to prepare an aqueous extract. Preset release thresholds are set for at least two of the following indicators: maturity and phytotoxicity characterization indicators, salinity characterization indicators, and residual inhibitory marker characterization indicators. A combination of release criteria for determining the completion of detoxification is also predetermined. During the fermentation period, the working parameters of the pile are monitored simultaneously, and control actions such as turning the pile, adding water, and buffering are performed. When each indicator in the combination reaches its respective threshold in the same sampling test, the detoxification is triggered and the fermentation ends. This results in a detoxification matrix with controllable detoxification, stable physicochemical state, and easy subsequent cooling and immobilization of microbial agents. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart of a method for preparing microbial fertilizer using medicinal plant residues.

[0018] Figure 2 This is a comparison chart showing the retention rate of effective viable bacteria after 60 days of storage at room temperature.

[0019] Figure 3 This is a comparison chart of the pre-adsorption endpoint criterion and the stable colonization criterion. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0021] This application provides a method for preparing microbial fertilizer using medicinal plant residues, the overall process of which is as follows: Figure 1As shown, the process includes: Step 1, pretreating the medicinal plant residues and adjusting their moisture content and nutrient balance to meet aerobic fermentation conditions, obtaining the material to be detoxified. This material is used to improve the porosity and moisture content of the compost pile and reduce detoxification fluctuations caused by localized anaerobic conditions and uneven maturation. Step 2, aerobic fermentation of the material to be detoxified is carried out, and samples are taken during the fermentation process to prepare an aqueous extract. Release indicators are detected and corresponding release thresholds are set. The release indicators include maturity and phytotoxicity characterization indicators, salinity characterization indicators, and residual inhibitory marker characterization indicators, which are used to convert the detoxification completion determination into a verifiable quantitative boundary. Before fermentation begins, the release indicators are used to determine the release threshold. A set of release criteria is defined for determining the completion of detoxification. This set of criteria comprises at least two categories of release indicators and remains constant throughout the fermentation process. This reduces release deviations caused by changes in the determination criteria between different batches. During fermentation, the pile's operating parameters are monitored, and control actions are executed to maintain aerobic fermentation and promote detoxification. This stabilizes the pile temperature, pH, and salinity release rhythm, reducing interference from operating condition drift on the release determination. When each release indicator in the set reaches its respective release threshold in the same sampling test, detoxification is determined to be complete, and fermentation ends, yielding the detoxified matrix. This ensures that maturity, salinity, and residual... The remaining inhibitory components converge synchronously under the same release conditions, reducing the risk of phytotoxicity and salt stress caused by insufficient composting; Step 3: Cool the detoxification substrate to a set temperature to obtain a substrate for planting, which is used to match the temperature window of subsequent inoculant loading with the tolerance range of the bacteria, reducing the adverse effects of heat stress on activity maintenance; Step 4: Provide a porous adsorption carrier, which is then contacted with an aqueous extract prepared from the detoxification substrate, or with a filtrate obtained by rinsing the detoxification substrate with water and collecting the filtrate, so that the porous adsorption carrier first adsorbs the residual inhibitory components in the detoxification substrate, obtaining a pre-adsorption carrier, which is used to reduce the liquid content before inoculant contact. The fifth step involves loading and fixing functional microbial agents onto the surface and pores of the pre-adsorbed carrier to obtain protective micro-zone carrier bacteria, which are used to form a relatively stable microenvironment within the carrier pores, improving colonization stability and storage retention rate. The sixth step involves using the detoxification matrix as the main material for particle shaping, and enriching the protective micro-zone carrier bacteria in the surface area of ​​the particles. After drying, microbial fertilizer is obtained, which is used to form a bacterial distribution morphology on the particle surface that is more conducive to contact with the external matrix, and to balance the retention of live bacteria and the particle shaping strength under controlled moisture content conditions.

[0022] Preferably, the medicinal plant residue is a residue from a single medicinal plant source, or a residue generated from the same prescription formulation, which is used to reduce the changes in the inhibitory component profile caused by differences in raw material sources, making it easier to maintain consistency between the release threshold and the judgment index combination.

[0023] Preferably, the materials used to adjust the moisture content and nutrient balance in step one include carbon-regulating and loosening materials and moisture-regulating materials; the carbon-regulating and loosening materials are selected from at least one of straw powder, sawdust, rice husk powder, corn cob powder, and wheat bran; the moisture-regulating materials are at least one of clean water and recycled fermentation liquid, used to supplement moisture while improving the aeration of the pile and facilitating the stable progress of the fermentation process.

[0024] Preferably, the control actions include at least: turning the pile when the pile temperature exceeds 65°C; adding alkaline buffer conditioning material when the pH is below 6.0; replenishing water when the moisture content is below 40%; and stopping the replenishment of conditioning material containing inorganic salts to the pile and extending the aerobic stability period when the salinity characterization index is electrical conductivity EC and the electrical conductivity EC is higher than the salinity characterization threshold. This is used to suppress fermentation instability caused by high temperature, acidification, water loss and salt accumulation, and reduce the probability of the physicochemical indicators of the detoxification substrate exceeding the limits.

[0025] Preferably, the aqueous extract is prepared at a solid-liquid ratio of 1:10 (g:mL), shaken at 25℃ for 30 min, and then filtered; the maturity and phytotoxicity characterization index is the germination index GI, which is obtained by dark incubating the same batch of seeds of the same variety at 25℃ for 48 h, to unify the sampling and detection standards and improve the comparability and threshold traceability between batches.

[0026] Preferably, the salinity characterization index is electrical conductivity EC, which is measured at 25°C; the sampling and testing frequency for preparing the aqueous extract is once every 2 to 4 days, which is used to form a sufficient density of process monitoring points during the critical stage of fermentation and reduce the lag in release judgment.

[0027] Preferably, the inhibitory marker corresponding to the inhibitory marker residue characterization index is at least one of total polyphenols, total saponins, and total alkaloids. The initial content of the inhibitory marker after obtaining the material to be detoxified in step one is used as the relative decrease calculation benchmark to convert the difference in the initial level of different raw materials into a relative convergence criterion, which facilitates stable control of the detoxification endpoint.

[0028] Preferably, the porous adsorption carrier is selected from at least one of biochar, zeolite, and bentonite, with a particle size of 0.2–2 mm. The contact conditions between the porous adsorption carrier and the aqueous extract or leaching liquid are: a solid-liquid ratio of 1:8–1:20 (g:mL), a temperature of 20–35°C, and a contact time of 30–180 min. The pre-adsorption endpoint is defined as a decrease of ≥20% in the concentration of the inhibitory marker relative to the liquid phase before contact, which forms a verifiable pre-adsorption completion boundary and reduces the risk of bacterial inhibition due to insufficient carrier adsorption.

[0029] Preferably, the functional microbial agent includes at least Bacillus microorganisms; an immobilization binding system is used during loading, the immobilization binding system being selected from at least one of alginate, starch gum, and lignin sulfonate; after loading, it is incubated at 25-35°C for 12-72 hours, and the stability colonization criterion is that the change rate of the effective viable bacteria count on the surface and in the pores of the carrier at the end of the incubation does not exceed 20% in two tests at 24-hour intervals, which is used to transform the colonization stability into a measurable boundary and reduce the storage degradation caused by short-term decline.

[0030] Preferably, the obtained microbial fertilizer simultaneously meets the following criteria: effective viable bacteria count ≥ 1× CFU / g, germination index GI≥90%, electrical conductivity EC≤3.0mS / cm, pH 5.5~8.5, moisture content not higher than 30%, used to simultaneously constrain the activity of live bacteria, phytotoxicity and salinity levels and control storage moisture conditions during the factory process, thereby improving product consistency.

[0031] In the common process described in this application, medicinal plant residues are pulverized to 2-8 mm and mixed with carbon-regulating and bulking materials and moisture-containing conditioning materials to obtain the material to be detoxified. The moisture content and pH are then adjusted. The material to be detoxified undergoes aerobic fermentation, and the pile temperature, moisture content, pH, and electrical conductivity (EC) are recorded. During the fermentation process, the pile conditions are adjusted by turning the pile, adding water, and adding alkaline buffer conditioning materials. The composition of the release criteria combination and the preset release thresholds for each release criterion are determined before the start of fermentation of this batch based on the small-scale fermentation records of the same source raw materials and the results of the germination index (GI) and electrical conductivity (EC) measurements. Subsequent sampling and testing are conducted every 3 days. If all release criteria in the same sampling and testing simultaneously reach their respective thresholds, the release criteria will be determined. Fermentation was terminated at the preset release threshold to obtain a detoxification substrate. The detoxification substrate was then cooled to obtain a planting substrate. An aqueous extract of the planting substrate was prepared and contacted with a porous adsorption carrier. The pre-adsorption carrier was obtained by the relative decrease in the concentration of the inhibitory marker corresponding to the residual inhibitory marker in the liquid phase reaching the pre-adsorption endpoint criterion. Functional microbial agents and immobilized binding systems were applied to the pre-adsorption carrier and incubated. The change rate of effective viable bacteria was detected twice at 24-hour intervals to meet the stable planting criterion, thus obtaining the microbial protective micro-zone carrier bacteria. The detoxification substrate was shaped into granules, and the microbial protective micro-zone carrier bacteria were enriched and distributed on the surface of the granules. After drying, the microbial fertilizer was obtained, and the germination index (GI), conductivity (EC), pH, and effective viable bacteria count of the finished product were detected.

[0032] In this embodiment, the preset release threshold is determined by taking medicinal plant residues from the same prescription formula, preparing 10 kg of the material to be detoxified according to the same carbon-regulating and bulking material ratio and water content regulator dosage as in formal production, and conducting simultaneous small-scale fermentation. Aqueous extracts are prepared by sampling every 3 days, and the germination index (GI), electrical conductivity (EC), and the content of inhibitory markers corresponding to the residual characterization indicators of inhibitory markers are measured. The relative decrease is calculated based on the initial content obtained in step one after obtaining the material to be detoxified. When the germination index (GI) reaches no less than 90%, the electrical conductivity (EC) reaches no more than 3.0 mS / cm, and the relative decrease of the inhibitory markers reaches the predetermined target range and maintains a fluctuation of no more than 2 absolute percentage points between two adjacent samplings, this set of values ​​is written into the preset release threshold for this batch and used for triggering judgment during the same sampling in subsequent formal fermentation.

[0033] Example 1, Step 1: Medicinal plant residues are pulverized to 2-8 mm. 18 kg of straw powder, 10 kg of rice husk powder, and 6 kg of wheat bran are added as carbon-regulating and bulking materials based on a wet basis of 200 kg. A moisture-regulating material is added to achieve a moisture content of 58% and a pH of 6.9, yielding the material to be detoxified. Step 2: The material to be detoxified undergoes aerobic fermentation in windrows, with monitoring of pile conditions. Control actions include turning the pile when the temperature exceeds 65℃, adding alkaline buffering material when the pH is below 6.0, replenishing water when the moisture content is below 40%, and stopping the addition of inorganic salt-containing conditioning materials and extending the aerobic stabilization period when the conductivity (EC) exceeds the salinity threshold. Sampling and testing are conducted every 3 days. The release criteria are the germination index (GI), conductivity (EC), and total polyphenols. The preset release thresholds are: germination index (GI) not lower than 90%, conductivity (EC) not higher than 3.0 mS / cm, and a relative decrease in total polyphenols not less than 75%. The germination index (GI) is obtained from the same sampling and testing on the 18th day. The fermentation process was completed with a 96.8% reduction in I, an electrical conductivity EC of 2.10 mS / cm, and a relative decrease in total polyphenols of 77%, yielding a detoxifying matrix. Step three involved cooling the detoxifying matrix to 34℃ to obtain a substrate for colonization. Step four involved using biochar as a porous adsorption carrier with a particle size of 0.5–1.0 mm. The biochar and an aqueous extract prepared from the detoxifying matrix were contacted at a solid-liquid ratio of 1:12 at 30℃ for 120 min. A relative decrease of 31% in the total polyphenols in the liquid phase met the pre-adsorption endpoint criterion, resulting in a pre-adsorption carrier. Step five involved using Bacillus microorganisms as the functional microbial agent, with alginate as the immobilization binding system. Incubation at 30℃ for 36 h and two 24-h interval tests showed a change in the effective viable cell count of 12%, meeting the stable colonization criterion, thus obtaining a protective micro-area carrier. Step six involved shaping the detoxifying matrix into 3–5 mm particles and enriching the protective micro-area carrier bacteria on the surface of the particles. Drying at 45℃ to a moisture content of 28% yielded a microbial fertilizer with an effective viable cell count of 3.4 × 10⁻⁶ mS / cm. CFU / g, germination index GI 98.9%, electrical conductivity EC 1.95mS / cm, pH 7.1.

[0034] Example 2, Step 1: Medicinal plant residues were pulverized to 2-8 mm. Based on a wet basis of 200 kg, 16 kg of sawdust, 12 kg of corn cob powder, and 14 kg of straw powder were added, along with a moisture-regulating agent to achieve a moisture content of 57% and a pH of 6.8, thus obtaining the material to be detoxified. Step 2: Sampling and testing were conducted every 3 days. The release criteria were the germination index (GI), electrical conductivity (EC), and total saponins. The preset release thresholds were: germination index (GI) not lower than 90%, electrical conductivity (EC) not higher than 3.0 mS / cm, and a relative decrease in total saponins not less than 72%. On the 19th day, the same sampling and testing yielded a germination index (GI) of 95.6% and an electrical conductivity (EC) of 2.23 mS / cm. The total saponins decreased by 73% and fermentation ended to obtain the detoxification matrix; in step three, the detoxification matrix was cooled to 35℃ to obtain the substrate for planting; in step four, the porous adsorption carrier was zeolite with a particle size of 0.3-0.8 mm, and the solid-liquid ratio was 1:10, contacted at 25℃ for 150 min, resulting in a 27% relative decrease in the total saponins in the liquid phase to obtain the pre-adsorption carrier; in step five, the immobilization and binding system was starch glue, incubated at 28℃ for 48 h, with a change rate of 15%, to obtain the microbial protective micro-zone carrier bacteria; in step six, the detoxification matrix was shaped into 2-4 mm particles, and the microbial protective micro-zone carrier bacteria were enriched and distributed on the surface of the particles, dried to a moisture content of 26%, to obtain the microbial fertilizer, with an effective viable count of 3.0 × 10⁻⁶. CFU / g, germination index GI 97.6%, electrical conductivity EC 2.12 mS / cm, pH 7.2.

[0035] Example 3, Step 1: Medicinal plant residues are pulverized to 2-8 mm, and 16 kg of straw powder, 12 kg of rice husk powder, and 10 kg of corn cob powder are added based on 200 kg of wet substrate. A moisture-regulating agent is added to achieve a moisture content of 56% and a pH of 6.9 to obtain the material to be detoxified. Step 2: The release criteria are the germination index (GI) and electrical conductivity (EC). The preset release thresholds are a germination index (GI) of not less than 90% and an electrical conductivity (EC) of not more than 3.0 mS / cm. On the 16th day, a sample taken at the same time showed a germination index (GI) of 92.4% and an electrical conductivity (EC) of 2.60 mS / cm, at which point fermentation was terminated to obtain the detoxification substrate. Step 3: The detoxification substrate is cooled to 34℃ to obtain the planting substrate; Step 4: The porous adsorption carrier is a mixture of biochar and zeolite with a particle size of 0.4-1.0 mm. The solid-liquid ratio is 1:14, and the mixture is contacted at 32℃ for 90 min, resulting in a 24% relative decrease in total polyphenols in the liquid phase, thus obtaining a pre-adsorption carrier; Step 5: The immobilization and bonding system is alginate, incubated at 32℃ for 24 h, with a change rate of 18%, yielding the micro-carrier bacteria for bacterial protection; Step 6: The detoxification substrate is shaped into 3-5 mm particles, and the micro-carrier bacteria for bacterial protection are enriched and distributed on the surface of the particles. The particles are then dried to a moisture content of 27% to obtain microbial fertilizer. The finished product has an effective viable count of 2.6 × 10⁻⁶. CFU / g, germination index GI 95.0%, electrical conductivity EC 2.44 mS / cm, pH 7.0.

[0036] Example 4, Step 1: Medicinal plant residues are pulverized to 2-8 mm. 14 kg of sawdust, 16 kg of straw powder, and 8 kg of wheat bran are added to a wet substrate of 200 kg. A moisture-regulating agent is added to achieve a moisture content of 55% and a pH of 6.7 to obtain the material to be detoxified. Step 2: The release criteria are the germination index (GI) and total polyphenols. The preset release thresholds are a germination index (GI) of not less than 90% and a relative decrease in total polyphenols of not less than 76%. On the 17th day, a sample taken at the same time shows a germination index (GI) of 94.9% and a relative decrease in total polyphenols of 76%, at which point fermentation is terminated to obtain the detoxification matrix. Step 3: Detoxification. The substrate was cooled to 35℃ to obtain the planting substrate; in step four, the porous adsorption carrier was bentonite with a particle size of 0.2-0.6 mm, and the solid-liquid ratio was 1:16. It was contacted at 30℃ for 60 min, resulting in a 22% relative decrease in total polyphenols in the liquid phase, thus obtaining a pre-adsorption carrier; in step five, the immobilization and bonding system was lignin sulfonate, incubated at 30℃ for 48 h, with a change rate of 16%, yielding the microbial protective carrier bacteria; in step six, the detoxification substrate was shaped into 3-5 mm particles, and the microbial protective carrier bacteria were enriched and distributed on the surface of the particles. It was then dried to a moisture content of 27% to obtain microbial fertilizer, with a finished product having an effective viable count of 2.8 × 10⁻⁶. CFU / g, germination index GI 96.1%, electrical conductivity EC 2.80mS / cm, pH 6.9.

[0037] Example 5, Step 1: Medicinal plant residues were pulverized to 2-8 mm. 18 kg of straw powder, 10 kg of rice husk powder, and 12 kg of corn cob powder were added to a wet basis of 200 kg, along with a moisture-regulating agent to achieve a moisture content of 58% and a pH of 7.0, thus obtaining the material to be detoxified. Step 2: The release criteria were germination index (GI), electrical conductivity (EC), and total alkaloids. The preset release thresholds were: germination index (GI) not less than 90%, electrical conductivity (EC) not higher than 3.0 mS / cm, and a relative decrease in total alkaloids not less than 68%. On the 20th day, the same sample was taken and tested, and the germination index (GI) was 96.5%, electrical conductivity (EC) was 2.03 mS / cm, and the relative decrease in total alkaloids was 69%. Step 1: Fermentation yields a detoxifying substrate; Step 2: The detoxifying substrate is cooled to 34℃ to obtain a substrate for planting; Step 3: A porous adsorption carrier, a mixture of zeolite and bentonite with a particle size of 0.3–0.9 mm, is contacted at 35℃ for 120 min at a solid-liquid ratio of 1:12, resulting in a 26% relative decrease in total alkaloids in the liquid phase, thus obtaining a pre-adsorption carrier; Step 4: An immobilization and bonding system, a mixture of starch gum and lignin sulfonate, is incubated at 33℃ for 36 h, resulting in a 14% change rate, thus obtaining a microbial protective micro-zone carrier bacteria; Step 5: The detoxifying substrate is shaped into 2–4 mm particles, and the microbial protective micro-zone carrier bacteria are enriched and distributed on the surface of the particles. The particles are then dried to a moisture content of 25% to obtain a microbial fertilizer with an effective viable count of 3.2 × 10⁻⁶. CFU / g, germination index GI 98.1%, electrical conductivity EC 2.02 mS / cm, pH 7.2.

[0038] Example 6, Step 1: Medicinal plant residues were pulverized to 2-8 mm. 20 kg of straw powder, 12 kg of rice husk powder, and 6 kg of wheat bran were added to a wet basis of 200 kg, along with a moisture-regulating agent to achieve a moisture content of 59% and a pH of 7.1, thus obtaining the material to be detoxified. Step 2: The release criteria were germination index (GI), electrical conductivity (EC), and total polyphenols. The preset release thresholds were: germination index (GI) not less than 90%, electrical conductivity (EC) not higher than 3.0 mS / cm, and a relative decrease in total polyphenols not less than 80%. On the 18th day, the same sample was tested and found to have a germination index (GI) of 98.2%, an electrical conductivity (EC) of 1.84 mS / cm, and a relative decrease in total polyphenols of 8%. Step 1: 1% fermentation is completed to obtain a detoxification substrate; Step 3: The detoxification substrate is cooled to 33℃ to obtain a planting substrate; Step 4: A porous adsorption carrier, biochar with a particle size of 0.3–0.8 mm, is contacted at 33℃ for 150 min with a solid-liquid ratio of 1:15, resulting in a 39% relative decrease in total polyphenols in the liquid phase, thus obtaining a pre-adsorption carrier; Step 5: An immobilization and bonding system, alginate, is incubated at 30℃ for 60 h, with a change rate of 10%, yielding a microbial carrier bacteria; Step 6: The detoxification substrate is shaped into 3–5 mm particles, and the microbial carrier bacteria are enriched and distributed on the surface of the particles. The particles are then dried to a moisture content of 25% to obtain a microbial fertilizer with an effective viable count of 4.0 × 10⁻⁶. CFU / g, germination index GI 100.6%, electrical conductivity EC 1.73 mS / cm, pH 7.0.

[0039] Comparative Example 1: Step 1, the formulation of the material to be detoxified was the same as in Example 1; Step 2, aerobic fermentation was carried out in windrows, and the pile operating parameters were controlled and sampling was performed every 3 days. However, the completion of detoxification was determined by a fixed fermentation time of 12 days, after which the pile was removed from the ground. At the end of the fermentation, the same sampling test showed a germination index (GI) of 88.4%, an electrical conductivity (EC) of 3.43 mS / cm, and a relative decrease in total polyphenols of 53%, thus obtaining the detoxification matrix; Steps 3 to 6 were the same as in Example 1, and the effective viable count of the finished product was 2.1 × 10⁻⁶. CFU / g, germination index GI 86.5%, electrical conductivity EC 3.31mS / cm, pH 6.6.

[0040] Comparative Example 2: Steps one through three were the same as in Example 1; Step four: The porous adsorption carrier used biochar with a particle size of 0.5–1.0 mm. The biochar did not contact the aqueous extract or leaching liquid and did not form a pre-adsorption carrier; Step five: The functional microbial agent and the immobilized binding system alginate were loaded onto the porous adsorption carrier and incubated at 30°C for 36 h. The change rate of the effective viable bacteria count was 27% after two 24-hour intervals, which did not meet the stable colonization criterion; Step six was the same as in Example 1, and the initial effective viable bacteria count of the finished product was 2.6 × 10⁻⁶. CFU / g, germination index GI 98.4%, electrical conductivity EC 1.94 mS / cm, pH 7.1, effective viable count 0.9× after 60 days of storage at room temperature. CFU / g.

[0041] Comparative Example 3: Steps one through five are the same as in Example 1; Step six: The micro-carrier bacteria protecting the bacteria are mixed with the detoxification matrix and then formed into granules. The micro-carrier bacteria protecting the bacteria are approximately uniformly distributed inside and outside the granules and then dried. The effective viable count of the finished product is 2.9 × 10⁻⁶. CFU / g, germination index GI 98.6%, electrical conductivity EC 1.93 mS / cm, pH 7.1, effective viable bacteria count on the outer layer of the particles 2.3 × CFU / g and the effective viable bacteria count in the inner layer of the particles is 2.1× CFU / g.

[0042] The products of the above embodiments and comparative examples were tested for effective viable bacteria count, particle compressive strength, and effective viable bacteria retention rate after 60 days of storage at room temperature.

[0043] Table 1. Comparison of Product Test Results between Examples and Comparative Examples

[0044] serial number Initial viable bacterial count (CFU / g) Compressive strength of particles (N / particle) Effective viable bacteria count (CFU / g) after 60 days of storage at room temperature Retention rate of effective viable bacteria after 60 days of storage at room temperature (%) Example 1 3.4× 18.6 2.9× 85.3 Example 2 3.0× 17.9 2.5× 83.3 Example 3 2.6× 16.8 2.1× 80.8 Example 4 2.8× 16.5 2.2× 78.6 Example 5 3.2× 18.1 2.6× 81.3 Example 6 4.0× 19.4 3.0× 75 Comparative Example 1 2.1× 14.9 1.3× 61.9 Comparative Example 2 2.6× 16.2 0.9× 34.6 Comparative Example 3 2.9× 15.7 1.9× 65.5

[0045] Table 2. Comparison of Key Criteria and Differences between the Examples and Comparative Examples

[0046] serial number Release Judgment Indicator Combination Trigger or end fermentation days The pre-adsorption endpoint criterion corresponds to a relative decrease Rate of change corresponding to stable colonization criterion The surface region of the particles forms an enriched distribution. Example 1 Germination index (GI), electrical conductivity (EC), total polyphenols 18 31% 12% yes Example 2 Germination index (GI), electrical conductivity (EC), total saponins 19 27% 15% yes Example 3 Germination index (GI), electrical conductivity (EC) 16 24% 18% yes Example 4 Germination index (GI), total polyphenols 17 22% 16% yes Example 5 Germination index (GI), electrical conductivity (EC), total alkaloids 20 26% 14% yes Example 6 Germination index (GI), electrical conductivity (EC), total polyphenols 18 39% 10% yes Comparative Example 1 Germination index (GI), electrical conductivity (EC), total polyphenols 12 31% 12% yes Comparative Example 2 Germination index (GI), electrical conductivity (EC), total polyphenols 18 not applicable 27% yes Comparative Example 3 Germination index (GI), electrical conductivity (EC), total polyphenols 18 31% 12% no

[0047] Table 1 shows that the initial effective viable bacterial counts in Examples 1–6 were all around 2.6 × 10⁻⁶. ~4.0× The initial viable count of Comparative Example 1 was 2.1 × This indicates that under the same raw material conditions, the detoxification completion judgment triggered by the combination of release judgment indicators, combined with the pre-adsorption endpoint criterion and stable colonization criterion, makes the microbial carrier level of the finished product more stable, thereby obtaining a higher effective viable count starting point.

[0048] Table 1 further shows that the effective viable bacteria count retention rate of Examples 1-6 after 60 days of storage at room temperature was 75.0%-85.3%, compared to 61.9% for Comparative Example 1, 34.6% for Comparative Example 2, and 65.5% for Comparative Example 3. The comparison results of the retention rates are as follows: Figure 2 As shown; in Comparative Example 2, the retention rate decreased due to the lack of a pre-adsorption carrier. The comparison between the relative decrease corresponding to the pre-adsorption endpoint criterion and the change rate corresponding to the stable colonization criterion is as follows. Figure 3As shown, the relative decrease of the inhibitory markers corresponding to the pre-adsorption endpoint criterion is directly related to the subsequent colonization stability. The pre-adsorption carrier can reduce the continuous stress of inhibitory markers on the bacteria, making the effective viable bacteria count more stable during the storage stage.

[0049] As can be seen from the comparison in Table 2, Comparative Example 1 used a fixed fermentation time to end the fermentation. The number of days for triggering or ending fermentation was 12, and the combination of release criteria did not meet the preset release threshold in the same sampling. Correspondingly, the germination index GI and electrical conductivity EC related indicators in Table 1 deteriorated as a whole, which was reflected in the decrease in the number of effective viable bacteria and the retention rate. This shows that using the combination of release criteria to trigger the same sampling can end the fermentation when the detoxification completion reaches a consistent level, reducing the risk of phytotoxicity and saltiness caused by under-fermentation, and providing a more suitable substrate environment for subsequent planting.

[0050] Table 2 also shows that Comparative Example 3 did not form an enriched distribution in the surface area of ​​the particles. Even though the initial effective viable bacteria count was close to the range of the Examples, its effective viable bacteria count retention rate after 60 days of storage at room temperature was still lower than that of the Examples group, and the particle compressive strength was also lower than the typical level of the Examples group. This indicates that the enriched distribution of the micro-carrier bacteria in the surface area of ​​the particles can form more stable micro-ecological sites during the drying and storage stages, reduce the proportion of bacteria that are restricted or stressed inside the particles, and thus improve the storage stability and particle integrity of the finished product.

[0051] Combining Tables 1 and 2, Examples 1-6 achieved a high effective viable count and stable retention rate when all three criteria of release determination, pre-adsorption, and stable colonization were met. Comparative Examples 1-3 showed a repeatable downward trend in the corresponding indicators after deviating from the three key points of fermentation endpoint determination, pre-adsorption carrier formation, and surface enrichment distribution, which supports the comprehensive advantages of this scheme in terms of detoxification controllability, cell colonization stability, and finished product storage stability.

[0052] The above description is only a specific embodiment of this disclosure, but the protection scope of this disclosure is not limited thereto. The protection scope of this disclosure should be determined by the protection scope of the claims.

Claims

1. A method for preparing microbial fertilizer using medicinal plant residues, characterized in that, include, Step 1: Pre-treat the medicinal plant residues and adjust their moisture content and nutrient balance to obtain the material to be detoxified; Step 2: The material to be detoxified is subjected to aerobic fermentation, and samples are taken during the fermentation process to prepare an aqueous extract. Release indicators are detected and corresponding preset release thresholds are set. Before the start of fermentation, a combination of release indicators for determining the completion of detoxification is determined from the release indicators and remains unchanged during this fermentation process. During the fermentation process, the working parameters of the pile are monitored, and control actions are executed to maintain aerobic fermentation and promote the completion of detoxification to end the fermentation, thereby obtaining the detoxification matrix. Step 3: Cool the detoxification substrate to a set temperature to obtain the substrate for planting; Step four: Provide a porous adsorption carrier and contact it with an aqueous extract prepared from the detoxification matrix, or with a leaching solution obtained by adding water to the detoxification matrix, so that the porous adsorption carrier first adsorbs the residual inhibitory components in the detoxification matrix to obtain a pre-adsorption carrier; Step 5: Load and fix the functional microbial agent onto the surface and pores of the pre-adsorbed carrier to obtain the micro-carrier bacteria for bacterial protection. Step six: Use the detoxification matrix as the main material for granulation and form it, and make the protective micro-carrier bacteria form an enriched distribution in the surface area of ​​the granules. Then, process it under drying conditions to obtain microbial fertilizer.

2. The method for preparing microbial fertilizer using medicinal plant residues according to claim 1, characterized in that, The medicinal plant residues are residues from a single medicinal plant source, or residues generated from the same prescription formulation.

3. The method for preparing microbial fertilizer using medicinal plant residues according to claim 1, characterized in that, The materials used in step one to adjust the moisture content and nutrient balance include carbon-regulating and bulking materials and moisture-regulating materials; the carbon-regulating and bulking materials are selected from at least one of straw powder, sawdust, rice husk powder, corn cob powder and wheat bran; the moisture-regulating materials are at least one of clean water and recycled fermentation liquid.

4. The method for preparing microbial fertilizer using medicinal plant residues according to claim 1, characterized in that, The release criteria include maturity and phytotoxicity characterization indicators, salinity characterization indicators, and residual inhibitory marker characterization indicators. The release determination index combination consists of at least two of the release indexes; The control actions include at least: turning the pile when the pile temperature exceeds 65°C; adding alkaline buffer conditioning material when the pH is below 6.0; replenishing water when the moisture content is below 40%; and stopping the replenishment of conditioning material containing inorganic salts to the pile and extending the aerobic stability period when the salinity characterization index is electrical conductivity EC and the electrical conductivity EC is higher than the salinity characterization threshold.

5. The method for preparing microbial fertilizer using medicinal plant residues according to claim 1, characterized in that, The aqueous extract was prepared at a solid-liquid ratio of 1:10 (g:mL), shaken at 25℃ for 30 min, and then filtered. The maturity and phytotoxicity characterization index was the germination index GI, which was obtained by dark incubating the same batch of seeds of the same variety at 25℃ for 48 h.

6. The method for preparing microbial fertilizer using medicinal plant residues according to claim 1, characterized in that, The salinity characterization index is electrical conductivity EC, which is measured at 25°C; the sampling and testing frequency for the preparation of the aqueous extract is once every 2 to 4 days.

7. The method for preparing microbial fertilizer using medicinal plant residues according to claim 1, characterized in that, The inhibitory markers corresponding to the residual characterization index of the inhibitory markers are at least one of total polyphenols, total saponins and total alkaloids, and the initial content of the inhibitory markers after obtaining the material to be detoxified in step one is used as the basis for calculating the relative decrease.

8. The method for preparing microbial fertilizer using medicinal plant residues according to claim 1, characterized in that, The porous adsorption carrier is selected from at least one of biochar, zeolite, and bentonite, with a particle size of 0.2–2 mm. The contact conditions between the porous adsorption carrier and the aqueous extract or leaching liquid are as follows: solid-liquid ratio of 1:8–1:20 (g:mL), temperature of 20–35℃, and contact time of 30–180 min. The pre-adsorption endpoint is defined as a decrease of ≥20% in the concentration of the inhibitory marker residue characterization index in the liquid phase after contact relative to the liquid phase before contact.

9. The method for preparing microbial fertilizer using medicinal plant residues according to claim 1, characterized in that, The functional microbial agent includes at least Bacillus spp.; an immobilization bonding system is used for loading, and the immobilization bonding system is selected from at least one of alginate, starch glue, and lignin sulfonate; after loading, it is incubated at 25-35℃ for 12-72h, and the stable colonization is determined by the change rate of the effective viable bacteria count on the surface and in the pores of the carrier not exceeding 20% ​​in two tests at 24h intervals at the end of incubation.

10. The method for preparing microbial fertilizer using medicinal plant residues according to claim 1, characterized in that, The resulting microbial fertilizer simultaneously meets the following criteria: effective viable bacteria count ≥ 1× CFU / g, germination index GI≥90%, electrical conductivity EC≤3.0mS / cm, pH 5.5~8.5, moisture content not higher than 30%.

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