Method and device for preparing environment-friendly covering layer by utilizing agricultural byproducts and wastes

Abstract

The invention relates to a method and a device for preparing an environment-friendly covering layer by utilizing agricultural byproducts and wastes, a product and application. The method comprises the following steps: crushing and mixing livestock manure, plant waste rich in lignocellulose and amaranthus hypochondriacus residues, inoculating a specific complex microbial inoculant, sequentially performing controllable aerobic fermentation and compacted and sealed anaerobic fermentation, adding mineral and plant source insecticidal components, and finally forming and drying to obtain the environment-friendly covering layer. According to the method and the special device, the waste can be efficiently converted into a special product with triple functions of increasing the fertility, biologically killing insects and creating a rhizosphere micro-aerobic environment; the covering layer is particularly suitable for planting grain amaranth, and can effectively promote growth, inhibit soil-borne diseases and improve the yield and quality by quantitatively covering the root zone in the seedling stage or the middle growth stage of the grain amaranth, and resource utilization and high-value utilization of agricultural waste are achieved.

Description

Technical Field

[0001] This invention relates to the field of agricultural waste resource utilization and green planting technology, and more specifically, it relates to a method and apparatus for preparing an environmentally friendly covering layer using agricultural by-products and waste. Background Technology

[0002] With the development of agriculture, the large-scale generation and improper disposal of livestock manure and agricultural processing waste have become serious environmental problems. Traditional treatment methods such as dumping, landfilling, or simple composting not only occupy land but also easily produce foul odors, breed mosquitoes and flies, and pollute water and air. On the other hand, in crop cultivation, especially amaranth, which has special requirements for its growing environment, chemical fertilizers and pesticides are generally relied upon to ensure yield. This has led to a series of problems such as soil compaction, ecological imbalance, and agricultural product residues, which are not conducive to the development of smart agriculture. Existing organic mulches or fertilizers, such as ordinary straw mulch or farmyard manure, have relatively limited functions. Straw mulch mainly serves to retain moisture and suppress weeds, but it degrades slowly and may compete for soil nitrogen in the early stages of decomposition, affecting crop growth. Ordinary compost mainly provides nutrients but lacks the ability to control specific pests and diseases, and it cannot actively regulate the rhizosphere microenvironment. As a high-value crop, amaranth's root system is highly sensitive to soil aeration and soil-borne diseases. Conventional fertilization and mulch management methods cannot meet its comprehensive needs for continuous nutrient supply, root disease prevention, and a suitable oxygen environment in the root zone. Therefore, it is necessary to develop a technology that can simultaneously realize the high-value utilization of agricultural waste and the green and precise cultivation of crops, transforming waste into specialized materials with multiple functions such as soil improvement, nutrient supply, pest and disease control, and microenvironment regulation, which has important environmental and economic significance. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method and apparatus for preparing an environmentally friendly covering layer using agricultural by-products and waste, so as to solve the problems existing in the above-mentioned background technology.

[0004] The above-mentioned technical objective of this invention is achieved through the following technical solution: a method for preparing an environmentally friendly covering layer using agricultural by-products and waste, comprising: Step S1, Raw material pretreatment: Livestock manure and plant waste are crushed separately. The plant waste includes a first component and a second component. The first component is a material rich in lignocellulose, and the second component is a plant material rich in specific trace elements produced during the production or processing of amaranth seeds. Step S2, Activation of the compound microbial agent: Mix the compound solid microbial agent with the activation solution and activate at 30-35℃ for 20-40 minutes; the compound solid microbial agent contains anaerobic acid-producing bacteria, lignocellulose-degrading bacteria and biocontrol actinomycetes; Step S3, Mixing and Aerobic Fermentation: Mix the pretreated livestock manure, the first component material, and the second component material according to the preset dry weight ratio. Add 3%-5% of the activated compound microbial agent, which accounts for 3%-5% of the total dry weight of the mixture. Adjust the moisture content of the mixture to 55%-65%. After stirring evenly, transport it to a sealed fermentation container and carry out one aerobic fermentation at 40-50℃ for 5-7 days. During the one aerobic fermentation, mechanical stirring and compressed air aeration are performed every 22-26 hours, each lasting 10-20 minutes. Step S4, Functional Enhancement and Anaerobic Fermentation: After the first aerobic fermentation, add 1%-2% of mineral additives and 0.5%-1% of plant-derived insecticidal active ingredients to the material according to its total dry weight. After mixing evenly, transfer the material to a sealed anaerobic fermentation container, compact the material, and then carry out a second anaerobic fermentation at 35-40℃ for 10-15 days under completely sealed conditions. Step S5, Shaping and Drying: Remove the material that has completed the secondary anaerobic fermentation and shape it into a pre-determined semi-finished covering layer through physical pressing. Then, dry it at room temperature until the moisture content is less than 30% to obtain the finished environmentally friendly covering layer.

[0005] Optionally, the livestock manure is selected from one or more of cow manure, sheep manure, and poultry manure, and the particle size is controlled to be 5-15mm after crushing; the first component material is selected from one or more of crop straw, rice husk, wheat husk, and sawdust, and the particle size is controlled to be 3-10mm after crushing; the second component material is selected from one or more of amaranth straw, amaranth leaves, and amaranth processing residue, and the particle size is controlled to be 3-8mm after crushing.

[0006] Optionally, in step S2, the activating solution is a brown sugar aqueous solution with a mass percentage concentration of 2%-5%; in the composite solid microbial agent, the anaerobic acid-producing bacteria are lactic acid bacteria, the lignocellulose-degrading bacteria are thermophilic Bacillus stearothermophilus, and the biocontrol actinomycetes are Streptomyces flavus.

[0007] Optionally, in step S4, the mineral additive is diatomaceous earth with a specific surface area greater than 30 m² / g or phosphate rock powder pulverized to a mesh size of 200 or higher; the plant-derived insecticidal active ingredient is selected from matrine extract, azadirachtin extract, or the residue after extraction thereof.

[0008] Optionally, in step S4, the compaction process brings the bulk density of the material to 0.6-0.8 g / cm³; the top of the anaerobic fermentation container is equipped with an exhaust valve, which is connected to a biogas collection or combustion treatment device.

[0009] Optionally, the physical pressing method in step S5 can be any one of roller pressing, ring die pressing, or flat plate pressing to form the material into particles with a particle size of 3-10mm, strips with a cross-sectional side length of 10-30mm, or sheets with a thickness of 20-50mm; the drying is carried out under normal temperature, light-proof and ventilated conditions until the moisture content of the finished covering layer is less than 30%.

[0010] An apparatus for implementing the above-described method of preparing an environmentally friendly covering layer using agricultural by-products and waste includes: The raw material pretreatment unit, the mixing and aerobic fermentation unit, the anaerobic fermentation unit, and the molding and drying unit are connected in sequence; the raw material pretreatment unit includes at least a first crusher for crushing livestock manure and a second crusher for crushing plant waste. The mixing and aerobic fermentation unit includes a mixer, a closed aerobic fermentation tank, and a first conveying mechanism; the mixer is equipped with water and bacterial agent addition ports; the closed aerobic fermentation tank is a vertical or horizontal tank, with a rotatable stirring paddle and a microporous aeration disc at the bottom of the tank, a jacket for introducing heat medium on the tank wall, and an exhaust gas outlet connected to a deodorization device at the top; the first conveying mechanism is a closed screw conveyor or belt conveyor, used to convey the material in the mixer to the closed aerobic fermentation tank. The anaerobic fermentation unit includes an anaerobic fermentation chamber and a second conveying mechanism. The anaerobic fermentation chamber is a sealed chamber with an insulation layer and temperature sensor on the walls. A vertically movable hydraulic compaction plate is installed at the top of the chamber. A sealable feed inlet and a valved exhaust pipe are located at the top of the chamber. A pneumatically or hydraulically driven discharge gate is located at the bottom of the chamber. The second conveying mechanism is used to transport the material output from the sealed aerobic fermenter to the feed inlet of the anaerobic fermentation chamber. The molding and drying unit includes a molding machine and a drying chamber that are connected to the unloading gate of the anaerobic fermentation chamber; the molding machine is a roller granulator, a ring die briquetting machine or a flat plate press; the drying chamber is equipped with ventilation facilities.

[0011] An environmentally friendly covering layer prepared according to the above-mentioned method for preparing an environmentally friendly covering layer using agricultural by-products and waste.

[0012] An application method based on the environmentally friendly covering layer prepared above involves uniformly spreading the covering layer on the surface of the root zone of amaranth at a rate of 1500-2500 kg / ha during the seedling stage or mid-growth stage, with a thickness of 2-5 cm.

[0013] In summary, the present invention has the following beneficial effects: 1. The prepared environmentally friendly covering layer is an innovative, multifunctional material. It is not a simple physical mixture, but rather a stable humus complex formed through targeted bio-fermentation, reconstructing the macromolecular organic matter in the raw materials into a bio-fermentation process. This simultaneously achieves long-lasting fertilization and soil improvement. The humus produced during fermentation can complex nutrients, enabling slow release and providing sustained fertility, avoiding the drawbacks of rapid loss of nutrients from chemical fertilizers. Its porous structure significantly enhances soil water retention and moisture retention, improves soil aggregate structure, and fundamentally alleviates soil compaction. Furthermore, the endobiotic functional bacteria (such as Streptomyces flavus) within the environmentally friendly covering layer produce antibiotic-like substances during fermentation, which, in conjunction with external... The plant-derived insecticidal components (matrine and azadirachtin) added to the product form a synergistic protective zone in the rhizosphere, inhibiting and repelling soil-borne pathogens and underground pests, reducing dependence on chemical pesticides. It also intelligently regulates the rhizosphere microenvironment. The product's unique physicochemical structure and the internal enrichment of facultative / anaerobic microorganisms actively consume oxygen at the root-soil interface after mulching, creating a localized micro-aerobic to anaerobic reducing environment. This environment not only effectively inhibits the activity of aerobic pathogens (such as Fusarium and Rhizoctonia), precisely addressing root rot and other problems that amaranth is susceptible to, but also acts as a mild stress, stimulating the crop's root resistance mechanism.

[0014] 2. During the preparation of the environmentally friendly covering layer, the processing residue of amaranth itself is specially added, namely the second component. The residue is rich in specific trace elements that amaranth absorbs and accumulates from the soil during its growth, such as high levels of potassium, calcium, iron, and zinc. Through fermentation, these are returned to the soil, achieving an efficient closed loop of nutrients in the crop-waste-crop system. This specifically supplements the elements that amaranth is most likely to lack or needs. At the same time, by controlling the molding process, the product can be made into granules of different sizes or specific shapes. After being laid, it can form a loose, breathable, and moisture-retaining physical covering layer above the roots. This covering layer buffers drastic changes in soil temperature and humidity, providing a stable environment for the temperature- and humidity-sensitive roots of amaranth. It has a synergistic effect, with the triple functions of fertilization, pest control, and micro-oxygenation not isolated but working synergistically in the rhizosphere of amaranth. Healthy roots enhance nutrient absorption, and a good microenvironment inhibits diseases, reducing the depletion of nutrients and root damage caused by pests and diseases, thus forming a virtuous cycle of healthy soil, strong roots, and high yield and quality. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the preparation method steps of the present invention. Detailed Implementation

[0016] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0017] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0018] In this invention, unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. The terms "vertical," "horizontal," "left," "right," "above," "below," and similar expressions are for illustrative purposes only and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] This invention provides a method for preparing an environmentally friendly covering layer using agricultural by-products and waste, such as... Figure 1 As shown, it includes: Step S1, Raw material pretreatment: Livestock manure and plant waste are crushed separately. The plant waste includes a first component and a second component. The first component is a material rich in lignocellulose, and the second component is a plant material rich in specific trace elements produced during the production or processing of amaranth seeds. Step S2, Activation of the compound microbial agent: Mix the compound solid microbial agent with the activation solution and activate at 30-35℃ for 20-40 minutes; the compound solid microbial agent contains anaerobic acid-producing bacteria, lignocellulose-degrading bacteria and biocontrol actinomycetes; Step S3, Mixing and Aerobic Fermentation: Mix the pretreated livestock manure, the first component material, and the second component material according to the preset dry weight ratio. Add 3%-5% of the activated compound microbial agent, which accounts for 3%-5% of the total dry weight of the mixture. Adjust the moisture content of the mixture to 55%-65%. After stirring evenly, transport it to a sealed fermentation container and carry out one aerobic fermentation at 40-50℃ for 5-7 days. During the one aerobic fermentation, mechanical stirring and compressed air aeration are performed every 22-26 hours, each lasting 10-20 minutes. Step S4, Functional Enhancement and Anaerobic Fermentation: After the first aerobic fermentation, add 1%-2% of mineral additives and 0.5%-1% of plant-derived insecticidal active ingredients to the material according to its total dry weight. After mixing evenly, transfer the material to a sealed anaerobic fermentation container, compact the material, and then carry out a second anaerobic fermentation at 35-40℃ for 10-15 days under completely sealed conditions. Step S5, Shaping and Drying: Remove the material that has completed the secondary anaerobic fermentation and shape it into a pre-determined semi-finished covering layer through physical pressing. Then, dry it at room temperature until the moisture content is less than 30% to obtain the finished environmentally friendly covering layer.

[0021] Furthermore, the livestock manure is selected from one or more of cow manure, sheep manure, and poultry manure, and the particle size is controlled to be 5-15mm after crushing; the first component material is selected from one or more of crop straw, rice husk, wheat husk, and sawdust, and the particle size is controlled to be 3-10mm after crushing; the second component material is selected from one or more of amaranth straw, amaranth leaves, and amaranth processing residue, and the particle size is controlled to be 3-8mm after crushing.

[0022] Further, in step S2, the activating solution is a brown sugar aqueous solution with a mass percentage concentration of 2%-5%; in the compound solid bacterial agent, the anaerobic acid-producing bacteria are lactic acid bacteria, the lignocellulose-degrading bacteria are thermophilic Bacillus stearothermophilus, and the biocontrol actinomycetes are Streptomyces flavus.

[0023] Further, in step S4, the mineral additive is diatomaceous earth with a specific surface area greater than 30 m² / g or phosphate rock powder pulverized to a mesh size of 200 or higher; the plant-derived insecticidal active ingredient is selected from matrine extract, azadirachtin extract, or the residue after extraction thereof.

[0024] Furthermore, in step S4, the compaction process brings the bulk density of the material to 0.6-0.8 g / cm³; the top of the anaerobic fermentation vessel is equipped with an exhaust valve, which is connected to a biogas collection or combustion treatment device.

[0025] Furthermore, the physical pressing method in step S5 is to use any one of roller pressing, ring die pressing or flat plate pressing to make the material into particles with a particle size of 3-10mm, strips with a cross-sectional side length of 10-30mm or sheets with a thickness of 20-50mm; the drying is carried out under normal temperature, light-proof and ventilated conditions until the moisture content of the finished covering layer is less than 30%.

[0026] In the specific preparation process, this process is the optimal embodiment. In step S1 of the preparation method, the purpose of this step is to physically process the raw materials to a particle size suitable for fermentation and to achieve the scientific formulation of the raw materials. In the selection of raw materials, livestock manure is used as the main nitrogen source, microbial carbon source and fermentation substrate. Cow manure is preferred because its carbon-to-nitrogen ratio is relatively moderate (about 25:1) and its cellulose content is high, which is conducive to forming a porous structure of the covering layer. Sheep manure and poultry manure can also be used, but attention should be paid to adjusting the subsequent ratio to balance the carbon-to-nitrogen ratio. In the selection of the first component, since it needs to be rich in lignocellulose as the main carbon source and physical framework, straw, rice husks and other materials provide a large amount of cellulose and hemicellulose. During the fermentation process, some of them are degraded into humus, while the undegraded parts form the physical support for the formation of the covering layer, giving it good air permeability and shape retention. The second component is amaranth residue, which serves as a functional trace element carrier and a specific compatible ingredient. Amaranth has a strong ability to absorb and accumulate potassium, calcium, and certain trace elements. These elements exist in organic form in its residues, such as straw and leaves. Reusing these residues achieves a closed-loop cycle of nutrients and targeted supplementation. During the crushing process, hammer mills or shear mills are used to crush the raw materials separately. Manure is crushed to a particle size of 5-15mm to ensure uniform mixing and fermentation efficiency. Plant materials are crushed to a particle size of 3-10mm; too fine a particle size affects aeration, while too coarse a particle size hinders microbial contact and subsequent shaping. After crushing, high-moisture manure can be preliminarily dehydrated or mixed with dry plant material and spread out to ensure a more uniform moisture content for precise moisture control in subsequent step S3.

[0027] In step S2, the purpose is to revive and pre-cultivate the functional microbial community so that it is in a highly active state when it is introduced into the main fermentation. The microbial agent consists of: anaerobic acid-producing bacteria, preferably *Lactobacillus plantarum*, which can rapidly produce organic acids such as lactic acid and acetic acid in the anaerobic environment at the beginning and end of aerobic fermentation, reduce the pH of the material, inhibit harmful microorganisms, and create a favorable environment for other microbial communities; lignocellulose-degrading bacteria, preferably *Bacillus stearothermophilus*, which is a thermophilic bacterium and has the highest activity in the 40-50℃ aerobic fermentation in the subsequent step S3. It can secrete cellulase and hemicellulase, effectively decompose hard raw materials such as straw, promote the humification process, and release heat to maintain the fermentation temperature; and biocontrol actinomycetes, preferably *Streptomyces flavus*, whose metabolites include antibiotic substances such as jinggangmycin and polyoxin, which have broad-spectrum antibacterial activity. During the fermentation process, it colonizes the material and eventually becomes the dominant beneficial microbial community in the product, exerting a continuous biocontrol effect in the rhizosphere after application. During the microbial agent activation process, a 2%-5% (w / w) brown sugar aqueous solution is heated to 30-35℃ to serve as the activation solution. Brown sugar provides an easily accessible carbon source. The compound solid microbial agent is mixed with the activation solution in a specific ratio (usually 3-5% of the dry weight of the material), with a mass ratio of microbial agent to liquid of approximately 1:1.5. The mixture is then allowed to stand or slowly stirred at 30-35℃ for 20-40 minutes. A slightly turbid solution with gentle bubbles indicates that the microbial community has regained its metabolic activity.

[0028] In the implementation of step S3, this step is the key stage for rapid heating of materials, initial degradation, and killing of pathogens and weed seeds; Mixing process: In a twin-shaft paddle mixer, the raw materials are added according to the dry weight ratio of (livestock manure): (first component): (second component) = (5-7): (2-4): (1-2). This ratio ensures that the initial carbon-nitrogen ratio (C / N) is within the ideal fermentation range of 25-30:1. Then, all the activating agents are added, and water is sprayed to adjust the total moisture content to 55%-65%. Too low a moisture content restricts microbial activity, while too high a moisture content leads to anaerobic digestion and odor. Aerobic fermentation control: Transfer the mixture into a closed aerobic fermentation tank; Temperature control: Hot water or steam is introduced through the tank wall jacket to rapidly raise the temperature of the material to 40-50℃ within 24-48 hours and maintain this temperature range for 5-7 days. This temperature range is the optimal working range for thermophilic functional bacteria, which can efficiently degrade organic matter and effectively sterilize. Oxygen and agitation control: Compressed air is introduced through a microporous aeration disc located at the bottom of the tank, and the aeration rate is maintained at 0.1-0.3 m³ air / (m³ material·min); at the same time, the agitator (5a) is started every 22-26 hours and run for 10-20 minutes at a speed of 2-10 rpm; this intermittent operation mode of aeration + agitation can ensure the aerobic needs of microorganisms while avoiding excessive loss of moisture and heat caused by continuous strong ventilation; the exhaust gas at the top of the tank is treated by a deodorization device such as a biological filter or chemical scrubbing before being discharged.

[0029] When the mixed material turns brownish-brown, loses its original fecal odor, emits a fermented earthy aroma, and the temperature begins to decrease naturally and slowly, it indicates that the main stage of aerobic fermentation is complete.

[0030] During the implementation of step S4, this step aims to introduce additional functions and give the product the potential to create a micro-oxygen environment by stabilizing materials in an anaerobic environment and enriching anaerobic / facultative bacteria. Transfer the aerobic fermented material to a homogenizing silo or add it via a conveyor, along with the following ingredients: Mineral additives, such as diatomaceous earth, added at 1-2%, can adsorb nutrients and functional components in fermentation products due to their porous structure, acting as a slow-release carrier and physically damaging some of the insect's body surface; phosphate rock powder (200 mesh or finer) can supplement medium-quantity elements such as phosphorus and calcium. Plant-derived insecticidal active ingredients, such as matrine extract residue or azadirachtin extract, are added at a rate of 0.5-1%. These natural compounds have contact, stomach poison, or repellent effects and produce a synergistic effect with biocontrol actinomycetes. After addition, the mixed material is transported to the anaerobic fermentation chamber for anaerobic fermentation. Compaction and sealing: Activate the hydraulic compaction plate on the top of the silo to compact the material to a bulk density of 0.6-0.8 g / cm³ at a pressure of 0.2-0.5 MPa. This operation removes most of the air from the material gaps, ensuring a strictly anaerobic environment. Then close the inlet and valves to ensure a complete seal. During fermentation, appropriate controls are implemented. The insulation layer of the silo and the built-in auxiliary heating device maintain the internal temperature at 35-40℃ for 10-15 days of static fermentation. Under these conditions, anaerobic / facultative bacteria such as lactic acid bacteria become active, further decomposing residual organic matter and producing more organic acids and bioactive substances, resulting in a more porous and stable material structure. The trace amounts of biogas produced during fermentation are discharged through the exhaust pipe and can be collected and utilized or safely burned. When the fermented material is uniformly dark brown, has a loose texture that crumbles easily, and has a distinct sour aroma without any putrid smell.

[0031] During the implementation of step S5, this step determines the application form and storage stability of the final product; In the molding step, the material from step S4 is physically pressed into shape by feeding it into a roller pellet mill, ring die briquetting machine, or flat blister press. The molding state can include: granules: 3-10mm in diameter, suitable for mechanized spreading or hole application; strips or flakes: 10-30mm in cross-sectional side length or 20-50mm in thickness, suitable for manual laying or inter-row covering. The molding pressure helps to form micropores inside the granules without excessively damaging their structural strength. In the optimal implementation, the molded shape is strips or flakes to ensure the effectiveness of fertilization. After molding, the product enters the drying chamber and is dried at room temperature (20-30℃), in the dark, under natural or forced ventilation conditions. The drying goal is to reduce the moisture content to below 30%. This moisture content can ensure the survival of functional microorganisms (especially spores) in the product, prevent mold growth during storage, and ensure that the product has suitable weight and spreadability. After drying, the finished product is obtained and can be stored in bags.

[0032] In Example 1, a granular covering layer was prepared using cow dung and wheat straw as the main materials. The raw materials selected were 1000 kg of fresh cow dung (70% moisture content), 400 kg of dry wheat straw, and 100 kg of dry amaranth straw. The raw materials were pretreated by draining the cow dung to a moisture content of about 60% and then crushing it to 10 mm. The wheat straw and amaranth straw were crushed to 5-8 mm respectively. Subsequently, microbial activation was performed by taking 50 kg of compound microbial agent (Lactobacillus plantarum: Bacillus thermophilus: Streptomyces flavus = 2:1.2:1) and activating it with 75 kg of 3% brown sugar water at 32°C for 30 minutes. Mixing and aerobic fermentation: The pretreated raw materials are mixed at a dry weight ratio (approximately 6:3:1), and microbial agents are added. The moisture content is adjusted to 60%, and aerobic fermentation is carried out at 45±2℃ for 6 days, with stirring and aeration for 15 minutes every 24 hours. Functional enhancement and anaerobic fermentation are carried out by adding 15kg of diatomaceous earth and 7.5kg of matrine residue to the mixture, mixing and transferring to an anaerobic chamber and compacting to a density of 0.72g / cm³. It is then sealed and fermented at 37±2℃ for 13 days. Molding and drying are carried out by ring die granulation (Φ6mm), and drying at room temperature with ventilation to a moisture content of 28%, yielding approximately 920kg of finished product, thus achieving an environmentally friendly covering layer.

[0033] In Example 2, a sheet-like covering layer was prepared using chicken manure and rice husks as the main materials. The raw materials used were 600 kg of dry chicken manure (30% moisture content), 300 kg of rice husks, and 150 kg of dry amaranth processing waste residue. The raw materials were pretreated by crushing them to the corresponding particle size range (chicken manure 10-15 mm, rice husks 3-5 mm, waste residue 3-5 mm). Microbial agents were added, and fermentation was carried out simultaneously. The amount and activation of the microbial agents were the same as in Example 1. The aerobic fermentation parameters were adjusted to 48℃ and maintained for 5 days. Before anaerobic fermentation, 12 kg of 200-mesh phosphate rock powder and 6 kg of azadirachtin extract were added. Anaerobic fermentation was carried out at 38℃ for 12 days. During the molding and drying process, the sheets were pressed into 30 mm thick sheets using a flatbed press and dried to a moisture content of 25%. The sheet-like product is easy to lay directly and is particularly suitable for seedbeds or ridge covering, while also having a high phosphorus and calcium content.

[0034] An apparatus for implementing the above-described method of preparing an environmentally friendly covering layer using agricultural by-products and waste includes: The raw material pretreatment unit, the mixing and aerobic fermentation unit, the anaerobic fermentation unit, and the molding and drying unit are connected in sequence; the raw material pretreatment unit includes at least a first crusher for crushing livestock manure and a second crusher for crushing plant waste. The mixing and aerobic fermentation unit includes a mixer, a closed aerobic fermentation tank, and a first conveying mechanism; the mixer is equipped with water and bacterial agent addition ports; the closed aerobic fermentation tank is a vertical or horizontal tank, with a rotatable stirring paddle and a microporous aeration disc at the bottom of the tank, a jacket for introducing heat medium on the tank wall, and an exhaust gas outlet connected to a deodorization device at the top; the first conveying mechanism is a closed screw conveyor or belt conveyor, used to convey the material in the mixer to the closed aerobic fermentation tank. The anaerobic fermentation unit includes an anaerobic fermentation chamber and a second conveying mechanism. The anaerobic fermentation chamber is a sealed chamber with an insulation layer and temperature sensor on the walls. A vertically movable hydraulic compaction plate is installed at the top of the chamber. A sealable feed inlet and a valved exhaust pipe are located at the top of the chamber. A pneumatically or hydraulically driven discharge gate is located at the bottom of the chamber. The second conveying mechanism is used to transport the material output from the sealed aerobic fermenter to the feed inlet of the anaerobic fermentation chamber. The molding and drying unit includes a molding machine and a drying chamber that are connected to the unloading gate of the anaerobic fermentation chamber; the molding machine is a roller granulator, a ring die briquetting machine or a flat plate press; the drying chamber is equipped with ventilation facilities.

[0035] In a specific embodiment, the preparation device is sequentially connected along the material processing direction, including a raw material pretreatment unit, a mixing and aerobic fermentation unit, an anaerobic fermentation unit, and a molding and drying unit. The materials (livestock manure and plant waste) enter from the inlet of the pretreatment unit and pass through crushing, mixing, two-step fermentation, molding, and drying in sequence. Finally, the finished product with a covering layer is obtained from the outlet of the molding and drying unit. The units are connected by a closed conveying device to control the diffusion of dust and odor and to realize the automatic flow of materials. The core function of the raw material pretreatment unit is to crush raw materials of different properties to a predetermined particle size, creating conditions for uniform mixing and efficient fermentation, including: The first crusher is used to crush livestock manure with high moisture content. It is preferred to use a low-speed, high-torque twin-shaft shear crusher. Its two rotating shafts equipped with staggered blades rotate in opposite directions. Through shearing and tearing action, the tangled manure is crushed into particles of 5-15mm. The feed inlet is equipped with a grid to prevent large foreign objects from entering. The second crusher is used to crush dry plant waste (straw, rice husks, etc.). It is preferably a hammer crusher. The high-speed rotating hammers interact with the toothed plate to beat and grind the plant material to a particle size of 3-10mm. The crusher is equipped with screens of different aperture sizes, and the output particle size can be controlled by changing the screens. At the discharge points of the first and second crushers, a metering belt scale or a volumetric feeder can be configured as needed to accurately control the various raw materials to enter the next unit according to the preset ratio. The mixing and aerobic fermentation unit is the core area for achieving material homogenization, inoculation with microorganisms, and aerobic fermentation. The mixing machine, preferably a twin-shaft paddle mixer, has paddles mounted on two parallel shafts at a certain angle. During operation, it generates a combined axial and radial motion, ensuring that manure and plant materials with significant differences in specific gravity and particle size are highly uniformly mixed in a short time (usually 2-5 minutes). The machine cover has a microbial agent addition port for connecting to a microbial agent activation tank or directly adding solid microbial agents. A spray water inlet is connected to a flow meter and atomizing nozzles, which can automatically spray clean water based on feedback from an online moisture sensor to precisely adjust the moisture content to 55%-65%. The closed-loop aerobic fermenter is a vertical or horizontal cylindrical sealed pressure vessel. The main body is made of carbon steel with a corrosion-resistant lining or stainless steel. The tank wall is jacketed, through which hot water, steam, or heat transfer oil can be circulated as a heat medium to heat and maintain the temperature of the materials inside, ensuring precise control of the fermentation temperature at 40-50℃. A variable-speed rotating agitator, typically an anchor-type or frame-type with a scraper, is located at the center of the tank. The rotation speed can be adjusted within the range of 2-10 rpm. Low-speed operation avoids damaging the material structure while achieving agitation, preventing crust formation, and promoting uniform moisture and temperature. Microporous aeration is evenly distributed at the bottom of the tank. The aeration disc, made of engineering plastic or ceramic, is connected to an external blower and can uniformly supply oxygen to the deep layers of the material in the form of microbubbles. The aeration rate can be intermittently controlled according to the program settings. Temperature and humidity sensors are installed inside the tank, and the data is transmitted to the central control room in real time. The top of the tank has an exhaust outlet, which is connected to a biological filter deodorization device or a chemical scrubbing tower to purify and discharge waste gases such as ammonia and hydrogen sulfide produced during fermentation. The first conveying mechanism adopts a closed screw conveyor or a corrosion-resistant belt conveyor to stably and leak-free transport the uniformly mixed wet material in the mixer to the top feed inlet of the aerobic fermentation tank. The anaerobic fermentation unit is a key piece of equipment for creating a strictly anaerobic environment for materials, enabling functional enhancement and deep fermentation, including: The anaerobic fermentation chamber is a vertical cylindrical or square sealed chamber with a double-layered wall structure. The inner layer is made of corrosion-resistant metal, the outer layer is made of carbon steel, and the middle layer is filled with an insulation layer made of polyurethane foam to maintain a constant temperature (35-40℃) inside the chamber. The inner wall of the chamber is smooth, and the bottom is designed to be conical or inclined for easy unloading. A hydraulic compaction plate, i.e. a compaction device, is installed at the top of the chamber and is driven by a hydraulic station outside the chamber. The compaction plate has an area slightly smaller than the cross-section of the silo body, and its edges are equipped with sealing strips. During operation, the compaction plate descends vertically, applying an adjustable pressure of 0.2-0.5 MPa to the input material, uniformly compacting it to a bulk density of 0.6-0.8 g / cm³, effectively removing air from the gaps between the materials. A feed inlet with a quick-opening cap is located at the top of the silo, connecting to the second conveying mechanism. A pneumatically or hydraulically driven fan-shaped discharge door is located at the bottom of the silo body, providing good sealing performance and a large opening force. An exhaust pipe with a vacuum / pressure safety valve is located on the top of the silo. The pipe is sequentially connected to a condenser (to remove moisture), a gas-liquid separator, and a biogas flare or gas storage tank to safely handle trace amounts of combustible gas produced during fermentation. The second conveying mechanism also adopts a closed conveyor to send the material discharged from the aerobic fermentation tank, which has been initially mixed with mineral additives and plant-derived insecticides during the conveying process, into the anaerobic fermentation chamber. An additive feeding hopper can be set above the conveyor to realize online addition and mixing. The forming and drying unit shapes the fermented material into the final product and adjusts its moisture content. This includes: selecting a forming machine based on product shape requirements; for granulation, a ring die granulator is used. Loose material is extruded through small holes in the ring die and cut into cylindrical granules by a cutter. The granule diameter (3-10mm) can be controlled by changing the ring die; for block or flake production, a roller briquetting machine or a flat-plate tablet press is used, forming the material through a mold. A drying chamber is a well-ventilated room or belt dryer. The chamber is equipped with multiple layers of perforated trays or a low-speed mesh belt on which the formed products are laid flat. Stable airflow is provided by natural convection fans or low-power dehumidifiers. Drying is carried out at room temperature (20-30℃) and in the dark until the product moisture content is below 30%. The drying chamber can be connected to a humidity monitoring system to automatically determine the drying endpoint. In the specific implementation process, after the system is started, the crushed raw materials are fed into the mixer according to the formula, mixed with the bacterial agent and water, and then conveyed into the aerobic fermentation tank to complete the fermentation process of temperature control, aeration, and stirring. After fermentation, the material is conveyed into the anaerobic fermentation chamber, where it is compacted, sealed, and fermented at a constant temperature. After fermentation is complete, the discharge door is opened, and the material enters the molding machine (forming), and then it is dried in the drying chamber to the qualified moisture content, and packaged to obtain the finished product.

[0036] An environmentally friendly covering layer prepared according to the above-mentioned method for preparing an environmentally friendly covering layer using agricultural by-products and waste.

[0037] An application method based on the environmentally friendly covering layer prepared above involves uniformly spreading the covering layer on the surface of the root zone of amaranth at a rate of 1500-2500 kg / ha during the seedling stage or mid-growth stage, with a thickness of 2-5 cm.

[0038] In practical implementation, precise selection of the application time is crucial. Application should be done during the seedling stage, 15-25 days after emergence, when the seedlings are approximately 10-15cm tall, and between rows after the amaranth seedlings have been established. Application at this time helps to establish an early root zone. The slow-release nutrients provided by the mulch layer meet the critical needs of seedlings transitioning from heterotrophic to autotrophic growth; its biocontrol function establishes a barrier against pathogens and pests in the early stages, preventing damping-off, seedling blight, and damage from underground pests; the early formation of a microaerobic environment promotes root development and the cultivation of strong seedlings. Applying mulch during the mid-growth stage, when the plants are 20-30cm tall and in a rapid vegetative growth phase, is more commonly done before canopy closure. This stage is the peak period for amaranth's demand for fertilizer and water, and also a period of intense competition from soil-borne diseases and root systems. Mulching at this time provides a continuous supply of nutrients to meet the needs of rapid growth; the reducing microenvironment it creates effectively inhibits the outbreak of aerobic pathogens such as root rot; and physical mulching significantly suppresses weeds between rows, reducing nutrient competition.

[0039] The dosage range corresponds to the thickness range. For example, when the product is spread to a uniform thickness of about 3 cm, the dosage is usually around 2000 kg / ha. If the dosage is too low (less than 1500 kg / ha) or too thin (less than 2 cm), a continuous functional layer cannot be formed, resulting in poor moisture retention, weed suppression, and microenvironment regulation effects. If the dosage is too high (greater than 2500 kg / ha) or too thick (greater than 5 cm), it may excessively hinder soil gas exchange, and in extreme cases, it may even affect root respiration, which is also uneconomical. In practical applications, adjustments can be made within the above range: Sandy soils and arid regions: the upper limit of dosage (e.g., 2500 kg / ha) and the upper limit of thickness (e.g., 4-5 cm) should be used to enhance water retention capacity; Clay soils and rainy regions: the lower limit of dosage (e.g., 1500-1800 kg / ha) and the lower limit of thickness (e.g., 2-3 cm) should be used to prevent poor aeration; Fields with high incidence of diseases: the dosage can be appropriately increased to strengthen biological control and the effect of micro-oxygen environment.

[0040] This invention discloses a method and apparatus for preparing an environmentally friendly covering layer using agricultural by-products and waste. The prepared environmentally friendly covering layer is an innovative multifunctional material, not a simple physical mixture, but rather a stable humus complex reconstructed from macromolecular organic matter in the raw materials through targeted biological fermentation. This simultaneously achieves: long-lasting fertilization and soil improvement. The humus produced during fermentation can complex nutrients, enabling slow release and providing sustained fertility, avoiding the drawbacks of rapid loss of nutrients from heavy chemical fertilizer application. Its porous structure significantly enhances soil water retention and moisture retention capacity, improves soil aggregate structure, and fundamentally alleviates soil compaction. The endophytic functional bacteria (such as Streptomyces flavus) within the environmentally friendly covering layer produce antibiotic-like substances during fermentation, which, together with exogenously added plant-derived insecticidal components (matrine, azadirachtin), form a synergistic protective zone in the rhizosphere, inhibiting and repelling soil-borne pathogens and underground pests, reducing dependence on chemical pesticides. Furthermore, it allows for intelligent regulation of the rhizosphere microenvironment, resulting in a unique product. The physicochemical structure and the facultative / anaerobic microorganisms enriched within it can actively consume oxygen at the root-soil interface after mulching, creating a localized micro-aerobic to anaerobic reducing environment. This environment can not only effectively inhibit the activity of aerobic pathogens (such as Fusarium and Rhizoctonia) and precisely address root rot and other problems that amaranth is susceptible to, but also act as a mild stress to stimulate the crop's root resistance mechanism. In the process of preparing the environmentally friendly mulch layer, the processing residue of amaranth itself is specially added, namely the second component. The residue is rich in specific trace elements that amaranth absorbs and accumulates from the soil during its growth, such as high levels of potassium, calcium, iron, and zinc. Through fermentation, these are returned to the soil, achieving an efficient closed loop of nutrients in the crop-waste-crop system, and specifically supplementing the elements that amaranth is most likely to lack or require. At the same time, by controlling the molding process, the product can be made into granules of different sizes or specific shapes, which can form a loose, breathable, and moisture-retaining physical mulch layer above the roots after being laid. This covering layer buffers drastic changes in soil temperature and humidity, providing a stable environment for the temperature- and humidity-sensitive roots of amaranth. It has a synergistic effect, with the triple functions of fertilization, pest control, and micro-oxygenation not isolated but working synergistically in the rhizosphere of amaranth. Healthy roots enhance nutrient absorption, and a good microenvironment inhibits diseases, reducing the depletion of nutrients and root damage caused by pests and diseases, thus forming a virtuous cycle of healthy soil, strong roots, and high yield and quality.

[0041] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing an environmentally friendly covering layer using agricultural by-products and waste, characterized in that, include: Step S1, Raw material pretreatment: Livestock manure and plant waste are crushed separately. The plant waste includes a first component and a second component. The first component is a material rich in lignocellulose, and the second component is a plant material rich in specific trace elements produced during the production or processing of amaranth seeds. Step S2, Activation of the compound microbial agent: Mix the compound solid microbial agent with the activation solution and activate at 30-35℃ for 20-40 minutes; the compound solid microbial agent contains anaerobic acid-producing bacteria, lignocellulose-degrading bacteria and biocontrol actinomycetes; Step S3, Mixing and Aerobic Fermentation: Mix the pretreated livestock manure, the first component material, and the second component material according to the preset dry weight ratio. Add 3%-5% of the activated compound microbial agent, which accounts for 3%-5% of the total dry weight of the mixture. Adjust the moisture content of the mixture to 55%-65%. After stirring evenly, transport it to a sealed fermentation container and carry out one aerobic fermentation at 40-50℃ for 5-7 days. During the one aerobic fermentation, mechanical stirring and compressed air aeration are performed every 22-26 hours, each lasting 10-20 minutes. Step S4, Functional Enhancement and Anaerobic Fermentation: After the first aerobic fermentation, add 1%-2% of mineral additives and 0.5%-1% of plant-derived insecticidal active ingredients to the material according to its total dry weight. After mixing evenly, transfer the material to a sealed anaerobic fermentation container, compact the material, and then carry out a second anaerobic fermentation at 35-40℃ for 10-15 days under completely sealed conditions. Step S5, Shaping and Drying: Remove the material that has completed the secondary anaerobic fermentation and shape it into a pre-determined semi-finished covering layer through physical pressing. Then, dry it at room temperature until the moisture content is less than 30% to obtain the finished environmentally friendly covering layer.

2. The method for preparing an environmentally friendly covering layer using agricultural by-products and waste according to claim 1, characterized in that, The livestock manure is selected from one or more of cow manure, sheep manure, and poultry manure, and the particle size is controlled to be 5-15mm after crushing; the first component material is selected from one or more of crop straw, rice husk, wheat husk, and sawdust, and the particle size is controlled to be 3-10mm after crushing; the second component material is selected from one or more of amaranth straw, amaranth leaves, and amaranth processing residue, and the particle size is controlled to be 3-8mm after crushing.

3. The method for preparing an environmentally friendly covering layer using agricultural by-products and waste according to claim 1, characterized in that, In step S2, the activating solution is a brown sugar aqueous solution with a mass percentage concentration of 2%-5%; in the compound solid bacterial agent, the anaerobic acid-producing bacteria are lactic acid bacteria, the lignocellulose-degrading bacteria are thermophilic Bacillus stearothermophilus, and the biocontrol actinomycetes are Streptomyces flavus.

4. The method for preparing an environmentally friendly covering layer using agricultural by-products and waste according to claim 1, characterized in that, In step S4, the mineral additive is diatomaceous earth with a specific surface area greater than 30 m² / g or phosphate rock powder pulverized to a mesh size of 200 or higher; the plant-derived insecticidal active ingredient is selected from matrine extract, azadirachtin extract or the residue after extraction thereof.

5. The method for preparing an environmentally friendly covering layer using agricultural by-products and waste according to claim 1, characterized in that, In step S4, the compaction process brings the bulk density of the material to 0.6-0.8 g / cm³; the top of the anaerobic fermentation container is equipped with an exhaust valve, which is connected to a biogas collection or combustion treatment device.

6. The method for preparing an environmentally friendly covering layer using agricultural by-products and waste according to claim 1, characterized in that, The physical pressing method in step S5 is to use any one of roller pressing, ring die pressing or flat plate pressing to make the material into particles with a particle size of 3-10mm, strips with a cross-sectional side length of 10-30mm or sheets with a thickness of 20-50mm; the drying is carried out under normal temperature, light-proof and ventilated conditions until the moisture content of the finished covering layer is less than 30%.

7. A preparation apparatus for implementing the method for preparing an environmentally friendly covering layer using agricultural by-products and waste as described in any one of claims 1-6, characterized in that, include: The raw material pretreatment unit, the mixing and aerobic fermentation unit, the anaerobic fermentation unit, and the molding and drying unit are connected in sequence. The raw material pretreatment unit includes at least a first crusher for crushing livestock manure and a second crusher for crushing plant waste; The mixing and aerobic fermentation unit includes a mixer, a closed aerobic fermentation tank, and a first conveying mechanism; the mixer is equipped with water and bacterial agent addition ports; the closed aerobic fermentation tank is a vertical or horizontal tank, with a rotatable stirring paddle and a microporous aeration disc at the bottom of the tank, a jacket for introducing heat medium on the tank wall, and an exhaust gas outlet connected to a deodorization device at the top; the first conveying mechanism is a closed screw conveyor or belt conveyor, used to convey the material in the mixer to the closed aerobic fermentation tank. The anaerobic fermentation unit includes an anaerobic fermentation chamber and a second conveying mechanism. The anaerobic fermentation chamber is a sealed chamber with an insulation layer and temperature sensor on the walls. A vertically movable hydraulic compaction plate is installed at the top of the chamber. A sealable feed inlet and a valved exhaust pipe are located at the top of the chamber. A pneumatically or hydraulically driven discharge gate is located at the bottom of the chamber. The second conveying mechanism is used to transport the material output from the sealed aerobic fermenter to the feed inlet of the anaerobic fermentation chamber. The molding and drying unit includes a molding machine and a drying chamber that are connected to the unloading gate of the anaerobic fermentation chamber; the molding machine is a roller granulator, a ring die briquetting machine or a flat plate press; the drying chamber is equipped with ventilation facilities.

8. An environmentally friendly covering layer prepared by a method for preparing an environmentally friendly covering layer using agricultural by-products and waste, as described in any one of claims 1-6.

9. An application method based on the environmentally friendly covering layer according to claim 8, characterized in that, During the seedling or mid-growth stage of amaranth, the covering layer is evenly spread on the surface of the root zone of the plant at a rate of 1500-2500 kg / ha, with a thickness of 2-5 cm.

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