A method for preparing organic fertilizer based on cow dung and cassava residue

Abstract

This application relates to a method for preparing organic fertilizer based on cow dung and cassava residue in the field of organic solid waste resource utilization. The method includes the following steps: pretreatment of cow dung and cassava residue; mixing cow dung and cassava residue evenly according to a set ratio to obtain a mixture, and incorporating a compound microbial agent into the mixture; wherein the moisture content of the mixture is 55-60%, the carbon-nitrogen ratio is 25-30:1, and the compound microbial agent includes Bacillus amyloliquefaciens, Bacillus subtilis, Bacillus thermophilus, and intermediate thermophilic actinomycetes; and employing an intelligent turning system to perform segmented aerobic fermentation of the mixture in a segmented fermentation tank. This method for preparing organic fertilizer enables the synergistic resource utilization of cow dung and cassava residue, reduces environmental pollution, improves production efficiency, meets the needs of large-scale production, and produces high-quality organic fertilizer that is nutrient-balanced, highly active, pollution-free, and meets relevant national standards.

Description

Technical Field

[0001] This application relates to the field of resource utilization and treatment of organic solid waste, and in particular to a method for preparing organic fertilizer based on cow dung and cassava residue. Background Technology

[0002] With the rapid development of animal husbandry and agricultural product processing, the discharge of cow manure and cassava residue has been increasing year by year. Cow manure, as a major waste product of animal husbandry, is rich in nutrients such as protein, cellulose, and minerals, making it a high-quality raw material for preparing organic fertilizer. However, cow manure has a high water content and slow decomposition speed, and fermentation alone easily produces foul odors. Furthermore, nutrients are easily lost during fermentation, and improper handling can cause soil, water, and air pollution. Cassava residue is a major byproduct of cassava processing into starch and alcohol. It contains a large amount of organic matter such as cellulose and starch, is widely available, and is inexpensive. However, when fermented alone, cassava residue has an unbalanced carbon-nitrogen ratio, low fermentation efficiency, and is prone to rotting and spoilage, making it difficult to use directly as a raw material for organic fertilizer.

[0003] Currently, while some organic fertilizer preparation technologies employ co-fermentation of livestock and poultry manure with crop straw and waste residue, these methods have several shortcomings: First, the raw material ratio is unreasonable, and the synergistic effect of cow manure and cassava residue is not fully utilized, resulting in a long fermentation cycle (usually 20-30 days) and incomplete decomposition. This leads to "secondary fermentation" after application to farmland, causing root and seedling burn. Second, the microbial agents used are mostly single strains or simple mixed strains, with limited ability to decompose cellulose and lignin, making it difficult to quickly degrade recalcitrant components in the raw materials. Fermentation efficiency and organic fertilizer quality need improvement. Third, the fermentation process often relies on manual turning or traditional mechanical turning, making it impossible to precisely control key parameters such as fermentation temperature, humidity, and oxygen content. This results in unstable fermentation processes, unbalanced organic fertilizer nutrients, and high manual labor intensity with low automation, hindering large-scale production. Fourth, the fermentation process generates severe odor emissions, polluting the surrounding environment and failing to meet environmental protection requirements.

[0004] Therefore, this invention is proposed. Summary of the Invention

[0005] The main objective of this invention is to provide a method for preparing organic fertilizer based on cow dung and cassava residue, aiming to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, this invention proposes a method for preparing organic fertilizer based on cow dung and cassava residue, comprising the following steps: S1. Pre-treatment of cow dung and cassava residue; S2. Mix cow dung and cassava residue evenly according to a set ratio to obtain a mixture, and mix the mixture with a compound microbial agent; wherein, the moisture content of the mixture is 55-60%, the carbon-nitrogen ratio is 25-30:1, and the compound microbial agent includes Bacillus amyloliquefaciens, Bacillus subtilis, Bacillus thermophilus, and intermediate thermophilic actinomycetes; S3. An intelligent turning and turning system is adopted to carry out segmented aerobic fermentation of the mixture in a segmented fermentation tank.

[0007] In some embodiments of the present invention, the intelligent turning and turning system includes a detection module, an intelligent controller, and an execution module; the intelligent controller has built-in preset parameters required for fermentation, can receive real-time detection data sent by the detection module, compare the real-time detection data with the preset parameters, automatically generate control commands and send them to the execution module to complete the turning and turning fermentation operation of the mixture.

[0008] In some embodiments of the present invention, the execution module includes a tumbling mechanism and a ventilation device, both of which are electrically connected to the intelligent controller.

[0009] In some embodiments of the present invention, the turning and turning mechanism is equipped with an integrated microbial agent synchronous spraying device.

[0010] In some embodiments of the present invention, the ventilation device includes a fish raft-type ventilation pipe disposed at the bottom of a segmented fermentation tank and a high-pressure centrifugal fan connected to the fish raft-type ventilation pipe.

[0011] In some embodiments of the present invention, the detection module includes a temperature sensor, a humidity sensor, and an oxygen sensor, each of which is embedded in the mixture.

[0012] In some embodiments of the present invention, a set of sensors is provided in the surface layer, middle layer and bottom layer of the mixture.

[0013] In some embodiments of the present invention, the intelligent turning and throwing system is also equipped with an audible and visual alarm.

[0014] In some embodiments of the present invention, a conditioning agent is added during the staged fermentation process of the mixture.

[0015] In some embodiments of the present invention, after the mixture has completed segmented aerobic fermentation, it is sequentially crushed, sieved, dried, granulated, cooled, and packaged to obtain the finished product.

[0016] This invention optimizes the mixing ratio of cow dung and cassava residue, fully leveraging their complementary advantages of high nitrogen and high carbon content to achieve optimal microbial fermentation parameters such as carbon-nitrogen ratio and moisture content. By screening highly efficient compound microbial agents with synergistic effects of multiple strains, the decomposition capacity of recalcitrant components like cellulose and lignin in the raw materials is enhanced. Furthermore, a precise and intelligent turning and control strategy is designed to automate the monitoring and regulation of key parameters throughout the fermentation process. Ultimately, this method achieves the efficient resource utilization of both cow dung and cassava residue, successfully producing high-quality organic fertilizer with balanced nutrient composition, high beneficial bacteria activity, no harmful residues, and no pollution. Simultaneously, this method significantly shortens the fermentation cycle to 10-15 days, substantially reducing labor costs and effectively minimizing odor and pollutant emissions during fermentation. It fully meets the needs of large-scale, standardized organic fertilizer production, addressing the industry pain point that existing technologies cannot simultaneously balance efficiency, quality, and environmental protection. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. In the drawings: Figure 1 This is a schematic diagram illustrating the implementation of the organic fertilizer preparation method based on cow dung and cassava residue of the present invention. Detailed Implementation

[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. It should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0019] my country is a traditional agricultural powerhouse and also the country with the largest amount of agricultural waste in the world. With the continuous intensification and large-scale development of cattle farming in my country, cattle excrement, containing foul-smelling gases, nitrogen, phosphorus, and other harmful substances, has seriously polluted the environment and water sources, making manure treatment a crucial issue for the livestock industry. Cow manure is an excellent biomass resource, containing various mineral elements such as carbon, nitrogen, calcium, and phosphorus. Domestic researchers have explored various methods to treat cow manure, achieving its harmless disposal while maximizing its biomass advantages. Composting is one of the simple and effective ways to utilize agricultural waste in a resource-efficient and harmless manner.

[0020] Cassava residue is a byproduct of starch or ethanol production. Every year, a large amount of cassava residue resources generated in my country cannot be effectively utilized. These wastes contain large amounts of starch, lignocellulose (including hemicellulose, cellulose, and lignin), and small amounts of cyanide, which, when left in the environment, pollute water bodies and living environments. Currently, the main applications of cassava residue in China are: producing single-cell protein; as animal feed, but its use as animal feed, especially for monogastric animals, is limited due to the presence of toxic substances such as cyanide; and cultivating edible fungi. Cassava residue is mostly composed of carbohydrates, with an organic matter content exceeding 90% (on a dry matter basis). It contains a relatively high amount of crude fiber, low crude protein, and a high carbon-to-nitrogen ratio. However, these methods only solve part of the cassava residue disposal problem, leaving a large amount unresolved.

[0021] While existing technologies have attempted to combine cow dung with cassava residue for organic fertilizer preparation, significant technical shortcomings remain, failing to meet the demands for efficient, high-quality, and large-scale production. For example, one method for preparing cow dung fertilizer using cow dung, cassava residue, and fish bone meal as raw materials involves adding only a single antagonistic bacteria for fermentation without combining it with a multi-strain synergistic compound microbial agent. This results in slow decomposition of recalcitrant components such as cellulose and lignin, with a fermentation cycle of 25–35 days, far longer than the 7–12 days of this invention. Furthermore, this method lacks any intelligent control mechanisms, relying entirely on manual experience to control turning and ventilation. This makes it difficult to precisely control fermentation temperature, humidity, and oxygen content, leading to uneven fermentation and incomplete decomposition. Consequently, the nutrient content of the organic fertilizer fluctuates significantly, beneficial bacteria activity is insufficient, and the fertilizer effect is difficult to guarantee consistently. For example, another type of organic fertilizer and its preparation method involves adding a variety of complex auxiliary materials in addition to cow dung and cassava residue. This not only increases the cost of raw material procurement and processing but also makes the preparation process cumbersome, which is not conducive to large-scale promotion. More importantly, this method does not optimize the ratio of cow dung's high nitrogen content and cassava residue's high carbon content, and fails to reasonably control the carbon-nitrogen ratio of the mixture. As a result, the advantages of the two cannot be complemented, the fermentation efficiency is low, and it is difficult to achieve efficient resource utilization of these two wastes, cow dung and cassava residue. It also cannot fundamentally solve the problems of environmental pollution and poor fertilizer efficiency of traditional fermentation processes.

[0022] Addressing numerous technical challenges prevalent in existing organic fertilizer preparation processes, including lengthy fermentation cycles, incomplete material decomposition leading to secondary fermentation after application to farmland and subsequent root and seedling burn, easy loss or volatilization of core nutrients such as nitrogen, phosphorus, and potassium during fermentation, reliance on manual labor or traditional machinery resulting in low automation, high labor intensity, and susceptibility to operational errors, as well as the generation of large amounts of malodorous gases and excessive pollutant emissions during fermentation, this invention provides a highly efficient organic fertilizer preparation method based on the synergistic aerobic fermentation of cow dung and cassava residue using a trough-type turning and turning process. This method mixes cow dung, cassava residue, and highly efficient compound microbial agents in a specific ratio and performs efficient aerobic fermentation using an intelligent trough-type fermentation facility to produce stabilized and harmless organic fertilizer.

[0023] This application discloses a method for preparing organic fertilizer based on cow dung and cassava residue. For example... Figure 1 As shown, the method for preparing this organic fertilizer includes the following steps: S1. Pre-treatment of cow dung and cassava residue.

[0024] S2. Mix cow dung and cassava residue evenly according to a set ratio to obtain a mixture, and mix in a compound microbial agent; wherein, the moisture content of the mixture is 55-60%, the carbon-nitrogen ratio is 25-30:1, and the compound microbial agent includes Bacillus amyloliquefaciens, Bacillus subtilis, Bacillus thermophilus, and intermediate thermophilic actinomycetes.

[0025] S3. An intelligent turning and turning system is adopted to carry out segmented aerobic fermentation of the mixture in a segmented fermentation tank.

[0026] By using the organic fertilizer preparation method in this technical solution, cow manure and cassava residue are first pretreated. Then, cow manure, cassava residue, well-rotted organic fertilizer return material, and high-efficiency compound microbial agent are mixed in a specific ratio. Based on the characteristics that cow manure is rich in nutrients such as nitrogen, phosphorus, and potassium, and cassava residue is rich in organic matter such as cellulose and hemicellulose, the two are mixed in an optimized ratio to complement each other's advantages. This optimizes the raw material ratio so that parameters such as carbon-nitrogen ratio, moisture content, pH, and material porosity of the mixture reach the optimal range for microbial fermentation. Combined with a high-efficiency compound microbial agent scientifically formulated from multiple functional strains, the decomposition capacity of recalcitrant components is enhanced, fermentation efficiency is improved, and the activity of organic fertilizer is increased. In practice, it is necessary to simultaneously control four objectives: nutrient balance, moisture content, structural porosity, and pH buffering. Sticky fresh cow manure and loose cassava residue are mixed in a 1:1 weight ratio. The cassava residue particles expand the cow manure to form a "sponge" for oxygen supply, and the carbon-nitrogen ratio naturally falls into the ideal range of 25-30:1 and the pH is adjusted to 6.5-8.0. If the moisture content of the raw materials fluctuates, a formula of 2 parts fresh cow manure, 2 parts cassava residue, and 1 part decomposed organic fertilizer return material is used. The dry return material instantly locks the moisture content at 55%-60%, and at the same time, the "native" microbial community is introduced to accelerate the start-up. Then, an intelligent trough fermentation facility consisting of an intelligent turning system and segmented fermentation tanks is used for efficient aerobic fermentation to produce high-quality organic fertilizer that is nutrient-balanced, highly active, pollution-free, and meets relevant national standards. At the same time, it realizes the synergistic resource utilization of cow manure and cassava residue, reduces environmental pollution, improves production efficiency, and meets the needs of large-scale production. Ultimately, while achieving stable and harmless organic fertilizer production, it solves the environmental pollution problem of cow manure and cassava residue, turning waste into treasure and having significant environmental benefits.

[0027] In some embodiments of the present invention, the pH value of the mixture can be adjusted within the range of 6.5-8 to provide a neutral to slightly alkaline environment suitable for microbial fermentation.

[0028] In some embodiments of the present invention, the pretreatment of cow dung and cassava residue includes impurity removal, solid-liquid separation and particle size adjustment through scientific pretreatment processes.

[0029] In some embodiments of the present invention, such as Figure 1 As shown, impurity removal, solid-liquid separation, and particle size adjustment can be accomplished through the front-end processing system.

[0030] In one embodiment of the present invention, the front-end processing system includes a solid-liquid separation device, which is used to separate materials with high water content into solid and liquid components, and then a transmission system is used to transfer the materials to a segmented fermentation tank.

[0031] In some embodiments of the present invention, such as Figure 1 As shown, the segmented fermentation tank includes a pretreatment zone, a high-temperature degradation zone, and a composting zone.

[0032] In this invention, the material processed by the front-end processing system can be transported to the pretreatment zone of the segmented fermentation tank. In the pretreatment zone, the carbon-nitrogen ratio and moisture content of the mixture are adjusted to the optimal range for microbial fermentation, giving full play to the complementary advantages of high nitrogen in cow manure and high carbon in cassava residue, thereby improving fermentation efficiency and organic fertilizer quality. Specifically, the moisture content of the mixture can be adjusted to 55-60%, the pH value to 6.5-8, and the C / N ratio to 25:1.

[0033] In some embodiments of the present invention, such as Figure 1 As shown, the intelligent turning and turning system includes a detection module, an intelligent controller, and an execution module. The intelligent controller has built-in preset parameters required for fermentation, can receive real-time detection data sent by the detection module, compare the real-time detection data with the preset parameters, automatically generate control commands, and send them to the execution module to complete the turning and turning fermentation operation of the mixture.

[0034] In this invention, all components such as the detection module, intelligent controller, and execution module can be existing equipment and can be obtained through market procurement. The control program of the intelligent controller can be conventionally programmed according to the fermentation parameters of this invention, without the need to develop new control algorithms. The overall system structure is simple, the operation is stable, and the degree of automation is high.

[0035] Furthermore, the intelligent controller can be a PLC controller with built-in preset parameters, such as thresholds for temperature, humidity, oxygen content, turning frequency, turning time, and ventilation volume. It can receive real-time detection data sent by the detection module, analyze and process the real-time detection data through the built-in intelligent algorithm, compare it with the preset thresholds, automatically generate control commands, and send them to the execution module.

[0036] In this invention, the intelligent algorithm is designed with reference to the control logic of similar intelligent fermentation equipment and optimized in combination with the characteristics of the fermentation process of this invention. It can fine-tune the parameter thresholds according to the weight of the mixture to be fermented and the type of raw materials, thereby improving the accuracy of control.

[0037] Furthermore, the intelligent controller has data storage, display, and alarm functions, and can store all parameter data during the fermentation process, facilitating later traceability and process optimization.

[0038] In some embodiments of the present invention, the alarm function can be achieved using an audible and visual alarm. When a parameter is detected to exceed a preset threshold, an audible and visual alarm is automatically issued to remind staff to troubleshoot the fault in a timely manner.

[0039] In this invention, intelligent fermentation using an intelligent controller is the core component. It employs an intelligent turning system composed of a detection module, an intelligent controller, and an execution module to ferment the mixture in stages. By monitoring key parameters during the fermentation process in real time, such as temperature, humidity, and oxygen content, it achieves precise and automated control of turning frequency, ventilation volume, temperature, and humidity. This effectively solves the problems of inaccurate parameter control, high manual labor intensity, and unstable fermentation results in traditional fermentation methods, shortens the fermentation cycle, and greatly improves the degree of decomposition and the quality of organic fertilizer.

[0040] In some embodiments of the present invention, the execution module includes a turning and throwing mechanism and a ventilation device. Both the turning and throwing mechanism and the ventilation device are electrically connected to the intelligent controller. The turning and throwing mechanism and the ventilation device can receive the control commands of the intelligent controller and complete the corresponding operations.

[0041] In some embodiments of the present invention, the turning mechanism can be a chain plate turning machine. The chain plate-turning tooth composite structure can completely break up the agglomerates, increase the porosity of the pile by 10%, and reduce the oxygen supply dead zone.

[0042] In this invention, based on the principle of adaptability of organic fertilizer fermentation equipment, a trough fermentation system is selected to be paired with an intelligent chain plate turning machine, which is suitable for large-scale continuous production, less affected by weather, and can achieve precise control of fermentation parameters.

[0043] Furthermore, the turning frequency and turning time of the turning mechanism can be automatically controlled by an intelligent controller.

[0044] In some embodiments of the present invention, the turning and turning mechanism is equipped with an integrated microbial agent synchronous spraying device.

[0045] In this invention, the use of a microbial agent synchronous spraying device allows for the simultaneous mixing or turning of materials and the addition of microbial agents in the pretreatment area of ​​a segmented fermentation tank, ensuring thorough mixing of the microbial agents and materials and solving the problems of uneven manual application and significant loss of microbial agent activity.

[0046] In some embodiments of the present invention, the ventilation device includes a fish raft-type ventilation duct disposed at the bottom of the segmented fermentation tank and a high-pressure centrifugal fan connected to the fish raft-type ventilation duct; wherein the high-pressure centrifugal fan has a suction air volume of 3000 m³ / h. 3 / h.

[0047] Furthermore, two high-pressure centrifugal fans can be installed, with one fan in operation and the other on standby. The PLC controller adjusts the oxygen supply in a closed loop based on temperature and oxygen content to ensure an oxygen concentration of ≥10%, thus solving the problem that the equipment hardware cannot meet the basic requirements of aerobic fermentation.

[0048] In some embodiments of the present invention, the detection module includes a temperature sensor, a humidity sensor, and an oxygen sensor, each of which is embedded in the mixture.

[0049] Furthermore, all sensors are waterproof, corrosion-resistant, and high-temperature resistant.

[0050] In some embodiments of the present invention, a set of sensors is provided in the surface layer, middle layer and bottom layer of the mixture.

[0051] Furthermore, in each layer of the mixture, one of each type of sensor can be set in an array at intervals of 0.6m. For example, in the middle layer of the mixture, one temperature sensor can be set in an array at intervals of 0.6m.

[0052] In this invention, by setting various sensors at intervals on the surface, middle and bottom layers of the mixture, temperature, humidity and oxygen content data during the fermentation process can be collected in real time, ensuring the accuracy and reliability of the collected data.

[0053] This invention employs an intelligent turning system integrating multiple sensors, intelligent controllers, and actuators, enabling real-time monitoring and precise control of key parameters such as temperature, humidity, oxygen content, and turning frequency during fermentation, thus achieving efficient segmented fermentation.

[0054] This invention employs an intelligent turning and turning system, which enables fully automated and precise control of the fermentation process. It can monitor and adjust key parameters such as fermentation temperature, humidity, oxygen content, and turning frequency in real time, avoiding human error, ensuring stable fermentation, and ensuring that the organic fertilizer is balanced and thoroughly decomposed. This avoids root and seedling burn caused by "secondary fermentation." At the same time, it reduces human intervention, lowers labor costs by more than 80%, and facilitates large-scale production.

[0055] In some embodiments of this invention, conditioners are added during the staged fermentation process of the mixed material. Aerobic compost conditioners are classified into three categories: carbon source conditioners, physical conditioners, and functional conditioners. Carbon source conditioners, such as corn stalks, rice husks, and sawdust, need to be mixed with the main material in the required proportions before fermentation, pulverized to 1-5 cm, and the initial C / N ratio adjusted to 25:1-30:1, with a moisture content of 55%-65%. Physical conditioners, such as coarse sawdust and peanut shells, which are inert skeletal materials, should account for 10%-20% of the total volume to maintain the porosity of the compost pile and prevent collapse. Functional conditioners, such as lime (1%-2%) or superphosphate (approximately 4%), can be added when the pH deviates from 6.5-8.5. Composted return material and wood vinegar can be added at the beginning or during turning to inoculate microorganisms or improve quality. Combined with synergistic microbial agents and intelligent turning, efficient aerobic composting throughout the entire process can be ensured.

[0056] In this invention, the addition of conditioning agents and intelligent ventilation control during the fermentation process can effectively reduce odor emissions and pollution to the surrounding environment, thus meeting environmental protection requirements.

[0057] In some embodiments of the present invention, after the mixture has completed segmented aerobic fermentation, it is successively crushed, sieved, dried, granulated, cooled, and packaged to obtain the finished product.

[0058] The core purpose of the above post-processing is to process the decomposed material into finished organic fertilizer with uniform particles, acceptable moisture content, and easy storage, transportation, and application, thereby removing undecomposed particles and impurities and stabilizing the nutrients and activity of the organic fertilizer.

[0059] In some embodiments of the present invention, the crushing, screening, drying, granulation and cooling processes can be completed by a material sorting system, and the packaging can be completed by an automatic packaging system. The equipment for each step is selected to match the production scale to ensure that the quality of the finished product meets the standards.

[0060] In some embodiments of the present invention, a mixed strain of Bacillus amyloliquefaciens, Bacillus subtilis, Bacillus thermophilus, and intermediate thermophilic actinomycetes is used. All the bacterial agents used are independently isolated by Kangyang Microbiology Laboratory. Among them, Bacillus amyloliquefaciens, Bacillus subtilis, Bacillus thermophilus, and intermediate thermophilic actinomycetes can all be used as degradation agents. Bacillus subtilis as the main agent and Bacillus amyloliquefaciens as the auxiliary agent can be used as a deodorizing agent.

[0061] In some embodiments of the present invention, the total amount of compound microbial agent added is controlled at 0.3% to 0.5% (volume / mass) of the total wet weight of the stockpile, and the total number of effective viable bacteria in the liquid microbial agent needs to be ≥5.0 × 10⁻⁶. 8 CFU / mL is used to ensure rapid colonization of the pile. In terms of optimized proportions, functional groups are formed: a "deodorization and intermediate-temperature start-up group" and a "high-temperature degradation group." The final volume ratio is 40–45 parts Bacillus subtilis solution, 10–15 parts Bacillus amyloliquefaciens solution, 25–30 parts Bacillus thermophilus solution, and 10–15 parts intermediate thermophilic actinomycete solution. After mixing, the total viable count remains ≥5.0 × 10⁻⁶. 8 With a CFU / mL ratio, the deodorizing group accounts for 50%–60% and the high-temperature degradation group accounts for 35%–45%. This combination can achieve a synergistic effect of "degradation + deodorization" in composting, which can raise the temperature to 55°C within 24 hours, maintain the high-temperature period for 8–10 days, increase the cellulose degradation rate by more than 50%, and produce a germination index of >95% with no odor.

[0062] Bacillus amyloliquefaciens KY09 is deposited at the China Center for Type Culture Collection (CCTCC), Wuhan, China, on May 28, 2020, with accession number CCTCC No: M2020153.

[0063] Bacillus subtilis strain KY15 is deposited at the China Center for Type Culture Collection (CCTCC), Wuhan, China, on May 6, 2024, with accession number CCTCCNo: M2024865.

[0064] Geobacillus stearothermophilus KY14 is deposited at the China Center for Type Culture Collection (CCTCC), Wuhan, China, on May 6, 2024, with accession number CCTCC No: M2024864.

[0065] Intermediate thermophilic actinomycetes (classified as Thermoactinomyces intermedius KY-MS-1) The sample is deposited at the China Center for Type Culture Collection (CCTCC), located in Wuhan, China, on November 21, 2025, with accession number CCTCC No: M20252654.

[0066] In this invention, a highly efficient compound microbial agent comprising Bacillus amyloliquefaciens, Bacillus subtilis, Bacillus thermophilus, and intermediate thermophilic actinomycetes is used. Compared with single strains or simple mixed strains, it has a stronger ability to decompose cellulose and lignin, can rapidly degrade the difficult-to-degrade components in raw materials, accelerate the fermentation speed, shorten the fermentation cycle, and at the same time improve the activity and fertilizer efficiency of organic fertilizer.

[0067] The organic fertilizer prepared using the method of the present invention has a pH value of 6.5 to 7.5 and a heavy metal content that meets the requirements of NY / T 525-2021 standard. After application, it can improve soil structure, increase soil organic matter content, enhance soil fertility, promote crop root growth, and improve crop yield and quality, thus having significant economic and social benefits.

[0068] The organic fertilizer prepared by this technical solution can be widely used in the planting of grain crops (wheat, corn, rice, etc.), cash crops (cotton, peanuts, soybeans, etc.), vegetables, fruit trees, flowers and other crops. It can be used as a base fertilizer or as a top dressing. After application, it can significantly improve soil fertility, promote crop growth, increase crop yield and quality, while reducing the amount of chemical fertilizer used and reducing agricultural non-point source pollution. It has broad application prospects.

[0069] The organic fertilizer prepared by the method of this invention can also be used as a high-quality seedling substrate, with significant advantages: First, it has a balanced and suitable nutrient composition, rich in nitrogen, phosphorus, potassium, and various trace elements, and is available in both fast-acting and slow-release forms, which can meet the growth needs of seedlings, promote the development of seedling roots and stems, and enhance stress resistance; Second, it has excellent physicochemical properties, with a loose texture, suitable porosity, and a stable pH value of 6.5-7.5, free of impurities and harmful organisms, which can prevent seedling rot and the breeding of pests and diseases, and is suitable for various seedling raising modes; Third, it is green, environmentally friendly, and low-cost, realizing the resource utilization of agricultural waste, and can replace topdressing during the seedling stage and traditional seedling substrates, reducing seedling raising costs; Fourth, it has wide adaptability and is easy to operate, and can be used for seedling raising of various crops. The particles are uniform, easy to store and transport, and can be used without additional processing; Fifth, it can improve the root foundation for seedling growth, and beneficial microorganisms can inhibit the growth of harmful bacteria, improve the transplant survival rate, and further expand the application scenarios of this technical solution.

[0070] Example 1 Screening of multiple strains with synergistic effects This embodiment uses cow dung and cassava residue as fermentation raw materials, and sets up a blank control, a single-strain inoculation group, and a compound microbial agent inoculation group. High-temperature aerobic fermentation was carried out under the same precise intelligent turning and control strategy for 25 days, and the composting effect and degradation capacity of each group were measured. The experimental groups were: CK group: natural fermentation, without inoculation of exogenous microbial agents; A group: inoculated with a single strain of Bacillus amyloliquefaciens; B group: inoculated with a single strain of Bacillus subtilis; C group: inoculated with a single strain of intermediate thermophilic actinomycetes; D group: inoculated with a single strain of thermophilic soil Bacillus; M group: inoculated with the A+B+C+D compound microbial agent screened in this invention. The initial carbon-nitrogen ratio, moisture content, pile density, and intelligent turning and control strategy were completely consistent for each group. The results showed that the degradation rate of cellulose and lignin in the compound microbial agent group M was significantly higher than that of each single-strain group and the blank control group, and far higher than the simple sum of the effects of each single strain; at the same time, the high-temperature duration was longer, the composting was more thorough, and the number of beneficial viable bacteria was higher. This invention demonstrates that there are significant synergistic degradation and symbiotic enhancement effects among the multiple strains screened in this invention, which can enhance the decomposition of recalcitrant components, realize the efficient resource utilization of cow manure and cassava residue, and prepare high-quality organic fertilizer with balanced nutrients, high activity of beneficial bacteria, no harmful residues, and no pollution.

[0071] Example 2 A mixture of cow dung and cassava residue at a wet weight ratio of 1:1 was used, without the addition of fish bone meal. The mixture was then inoculated with an optimized compound microbial agent (45 parts Bacillus subtilis, 15 parts Bacillus amyloliquefaciens, 30 parts Bacillus thermophilus, and 15 parts intermediate thermophilic actinomycetes, with a total inoculum of 0.5% v / w and a viable count ≥5×10⁻⁶). 8The compost was carried out under unified control with intelligent turning and turning (CFU / mL). Results: On day 11, the cellulose degradation rate was 53.1% and the lignin degradation rate was 36.9%. The high-temperature period lasted for 15 days, the maturity period was 20 days, the final product had a germination index of 98.6%, organic matter of 46.8%, total nutrients of 5.6%, and 3.1 × 10⁻⁶ live Bacillus bacteria. 8 CFU / g.

[0072] Comparative Example 1 Using the same raw materials of cow dung and cassava residue and intelligent turning and composting technology, with the addition of fish bone meal accounting for 5% of the total dry weight, and inoculation with only an equal amount of a single Bacillus amyloliquefaciens solution (0.5% v / w), the results showed: cellulose degradation rate of 33.6%, lignin degradation rate of 20.5%, high-temperature period of only 5 days, composting period extended to 42 days, final product germination index of 79.1%, organic matter of 39.2%, total nutrients of 4.2%, and viable bacteria count of only 8 × 10⁻⁶. 5 CFU / g.

[0073] Comparison Conclusion Compared to Comparative Example 1, Example 2 showed a 58% increase in cellulose degradation rate, an 80% increase in lignin degradation rate, a 22-day shorter composting period, and increases in organic matter and total nutrients by 19% and 33%, respectively, with a two-order-of-magnitude increase in viable bacteria count. This fully demonstrates that the present invention, through the synergistic combination of four bacteria forming a "deodorization-growth-high-temperature degradation" functional relay, completely overcomes the shortcomings of insufficient degradation capacity of single antagonistic bacteria, the tendency of fish bone meal to cause local pH abnormalities, and the single microbial community, achieving highly efficient conversion from raw materials to high-quality organic fertilizer with significant quantifiable synergistic effects.

[0074] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing organic fertilizer based on cow dung and cassava residue, characterized in that, Includes the following steps: S1. Pre-treatment of cow dung and cassava residue; S2. Mix cow dung and cassava residue evenly according to a set ratio to obtain a mixture, and mix the mixture with a compound microbial agent; wherein, the moisture content of the mixture is 55-60%, the carbon-nitrogen ratio is 25-30:1, and the compound microbial agent includes Bacillus amyloliquefaciens, Bacillus subtilis, Bacillus thermophilus, and intermediate thermophilic actinomycetes; S3. An intelligent turning and turning system is adopted to carry out segmented aerobic fermentation of the mixture in a segmented fermentation tank.

2. The method for preparing organic fertilizer according to claim 1, characterized in that, The intelligent turning and turning system includes a detection module, an intelligent controller, and an execution module. The intelligent controller has built-in preset parameters required for fermentation, can receive real-time detection data sent by the detection module, compare the real-time detection data with the preset parameters, automatically generate control commands, and send them to the execution module to complete the turning and turning fermentation operation of the mixture.

3. The method for preparing organic fertilizer according to claim 2, characterized in that, The execution module includes a tumbling mechanism and a ventilation device, both of which are electrically connected to the intelligent controller.

4. The method for preparing organic fertilizer according to claim 3, characterized in that, The turning and turning mechanism is equipped with an integrated microbial agent synchronous spraying device.

5. The method for preparing organic fertilizer according to claim 3, characterized in that, The ventilation device includes a fish raft-type ventilation pipe installed at the bottom of the segmented fermentation tank and a high-pressure centrifugal fan connected to the fish raft-type ventilation pipe.

6. The method for preparing organic fertilizer according to claim 2, characterized in that, The detection module includes a temperature sensor, a humidity sensor, and an oxygen sensor, each of which is embedded in the mixture.

7. The method for preparing organic fertilizer according to claim 6, characterized in that, A set of sensors is installed in each of the surface, middle and bottom layers of the mixture.

8. The method for preparing organic fertilizer according to claim 2, characterized in that, The intelligent turning and throwing system is also equipped with an audible and visual alarm.

9. The method for preparing organic fertilizer according to claim 1, characterized in that, Conditioning agents are added during the staged fermentation process of the mixture.

10. The method for preparing organic fertilizer according to claim 1, characterized in that, After the mixture completes segmented aerobic fermentation, it is successively crushed, sieved, dried, granulated, cooled, and packaged to obtain the finished product.

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