Soil conditioner based on ash and organic matter and preparation method thereof

Abstract

The invention belongs to the technical field of soil improvement, and particularly relates to a soil conditioner based on ash and organic matter and a preparation method of the soil conditioner. The preparation method of the soil conditioner based on the ash and the organic matter comprises the following steps: S1, pretreating the ash and the organic matter; s2, mixing the ash and organic matter, and then sequentially adding a microbial agent and a binder to form a first mixture; s3, the first mixture is stacked, the surface of the first mixture is covered with a breathable film, the breathable film is opened every second preset time within the first preset time range for pile turning, then aging is conducted for third preset time, then crushing and granulation are conducted, and the soil conditioner is formed. Therefore, according to the soil conditioner prepared by the preparation method disclosed by the invention, the ash and the organic matters are subjected to synergistic fermentation modification, and the pore structure of the ash is coupled with the organic matters for humification to form a composite water-retaining matrix, so that the volume weight of soil can be reduced, the organic matters of the soil are increased, nitrogen is immobilized, heavy metals are passivated, and vegetation recovery is promoted.

Description

Soil conditioner based on ash and organic matter and its preparation method Technical Field

[0001] This disclosure belongs to the field of soil improvement technology, and specifically relates to a soil conditioner based on ash and organic matter and its preparation method. Background Technology

[0002] Site closure refers to systematic engineering measures implemented to eliminate environmental safety hazards, block the migration of pollutants, and restore the ecological function of a waste disposal site or a resource extraction site after it has reached its designed service life and its original operational function has been terminated.

[0003] There are two main existing improvement schemes. One is to use soil replacement, which involves transporting high-quality soil from other places to cover the surface of the enclosure to meet the needs of plant growth. However, this scheme has problems such as high transportation costs, large resource consumption, and complex engineering. The other is to apply organic fertilizer, which improves soil properties by supplementing organic matter. However, this can easily lead to poor soil water retention and unstable aggregate structure. Some organic fertilizers also pose a risk of heavy metal contamination, which in turn affects the survival of green plants and the safety of the ecological environment. Summary of the Invention

[0004] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a soil conditioner based on ash and organic matter and its preparation method.

[0005] In a first aspect, this disclosure provides a method for preparing a soil conditioner based on ash and organic matter, comprising: S1, pretreating the ash and organic matter; S2, mixing the ash and organic matter, and then sequentially adding a microbial agent and a binder to form a first mixture; S3, piling up the first mixture, covering the surface of the first mixture with a breathable membrane, opening the breathable membrane and turning the pile at second preset time intervals within a first preset time range, then aging for a third preset time, and then crushing and granulating to form the soil conditioner.

[0006] In one embodiment of this disclosure, step S1 specifically includes: S11, sieving the ash residue to remove impurities; S12, crushing the organic matter to a first preset particle size.

[0007] In one embodiment of this disclosure, in step S2, the preset ratio of ash, organic matter, microbial agent and binder is: 60%-80%: 15%-30%: 3%-8%: 2-8%.

[0008] In one embodiment of this disclosure, after the first mixture is formed in step S2, water is added to adjust the humidity of the first mixture to a preset humidity.

[0009] In one embodiment of this disclosure, the detailed method of "stacking the first mixture" in step S3 is as follows: the first mixture is stacked in a fermentation tank, the fermentation tank having a depth of 1.2-1.5m perpendicular to the working surface and a width of 2.5-3.0m parallel to the working surface.

[0010] In one embodiment of this disclosure, the detailed method of "opening the breathable membrane for turning the mixture at a second preset time interval" in step S3 is as follows: opening the breathable membrane at a second preset time interval, detecting the actual temperature of the first mixture, turning the mixture, and adjusting the temperature of the first mixture to a preset temperature.

[0011] In one embodiment of this disclosure, the first preset time is 15-20 days; and / or, the second preset time is 0.5-1.5 days; and / or, the third preset time is 4-6 days.

[0012] In one embodiment of this disclosure, the preset temperature is 50-65°C.

[0013] In one embodiment of this disclosure, the microbial agent includes at least: nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and lignin-degrading bacteria.

[0014] Secondly, this disclosure provides a soil conditioner, which is prepared using the soil conditioner preparation method based on ash and organic matter as described in any of the above embodiments.

[0015] One of the beneficial effects of this disclosure is that the soil conditioner preparation method is based on ash and organic matter. First, both are pretreated to avoid stratification and clumping when directly mixed, which could lead to difficulties in subsequent granulation and prevent effective synergistic effects after application to the soil. Then, the ash and organic matter are mixed, and microbial agents and binders are added sequentially. This avoids osmotic pressure stress that might occur from direct contact between the microbial agents and the high-concentration binder solution, and ensures that the binder evenly coats all the ash and organic matter, thus forming a first mixture. The first mixture is then piled up, and a breathable membrane is covered on its surface to allow continuous oxygen penetration into the pile. To maintain microbial activity and ensure timely removal of carbon dioxide produced during fermentation, preventing excessively high carbon dioxide concentrations inside the compost pile from inhibiting microorganisms; simultaneously, within a certain first preset time range, the ventilated membrane is opened and the compost pile is turned over at second preset time intervals, thereby turning the oxygen-rich first mixture into the interior of the compost pile and turning the anaerobic first mixture from inside the compost pile to the surface, ensuring continuous aerobic fermentation; then, after a third preset aging time, the temperature of the compost pile naturally drops to the ambient temperature, allowing the intermediate products produced by fermentation to further aggregate and stabilize; finally, the compost is crushed and granulated to obtain a soil conditioner with regular particles, facilitating uniform application and improving fertilization precision.

[0016] Thus, the soil conditioner prepared by the method disclosed herein uses a combination of microbial agents and binders, which enables the ash and organic matter to undergo synergistic fermentation and modification. The pore structure of the ash is coupled with the humification of organic matter to form a composite water-retaining matrix, thereby reducing soil bulk density, increasing soil organic matter, retaining nitrogen, passivating heavy metals, and promoting vegetation restoration. Attached Figure Description

[0017] Embodiments of this disclosure are illustrated in conjunction with the accompanying drawings, which are included and form part of this specification, and together with their description, serve to explain the principles of this disclosure.

[0018] Figure 1 is a flowchart of a method for preparing a soil conditioner based on ash and organic matter according to an embodiment of the present disclosure; Figure 2 is a flowchart of a method for preparing a soil conditioner based on ash and organic matter according to another embodiment of the present disclosure. Detailed Implementation

[0019] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0020] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0021] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0022] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0024] In this article, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, rather than to define the absolute position of these related parts.

[0025] In this article, "first," "second," etc., are used only to distinguish one another, and not to indicate degree of importance, order, or prerequisite for each other.

[0026] In this document, terms such as “equal” and “same” are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use.

[0027] Site closure refers to systematic engineering measures implemented to eliminate environmental safety hazards, block the migration of pollutants, and restore the ecological function of a waste disposal site or a resource extraction site after it has reached its designed service life and its original operational function has been terminated.

[0028] There are two main existing improvement schemes. One is to use soil replacement, which involves transporting high-quality soil from other places to cover the surface of the enclosure to meet the needs of plant growth. However, this scheme has problems such as high transportation costs, large resource consumption, and complex engineering. The other is to apply organic fertilizer, which improves soil properties by supplementing organic matter. However, this can easily lead to poor soil water retention and unstable aggregate structure. Some organic fertilizers also pose a risk of heavy metal contamination, which in turn affects the survival of green plants and the safety of the ecological environment.

[0029] Therefore, this disclosure provides a soil conditioner based on ash and organic matter and its preparation method. The preparation method of the soil conditioner based on ash and organic matter of this disclosure includes: S1, pretreating ash and organic matter; S2, mixing ash and organic matter, and then sequentially adding microbial inoculants and binders to form a first mixture; S3, piling up the first mixture, covering the surface of the first mixture with a breathable membrane, opening the breathable membrane and turning the pile at second preset time intervals within a first preset time range, then aging for a third preset time, and then crushing and granulating to form the soil conditioner.

[0030] The soil conditioner preparation method disclosed herein is based on ash and organic matter. First, both materials are pretreated to prevent stratification and clumping when directly mixed, which could lead to difficulties in subsequent granulation and prevent effective synergistic effects after application to the soil. Next, the ash and organic matter are mixed, and microbial agents and binders are added sequentially. This avoids osmotic pressure stress that might occur from direct contact between the microbial agents and the high-concentration binder solution, and ensures that the binder evenly coats all the ash and organic matter, thus forming a first mixture. The first mixture is then piled up, and its surface is covered with a breathable membrane to allow continuous oxygen entry into the pile, maintaining microbial activity. To ensure timely removal of carbon dioxide produced during fermentation and prevent excessively high carbon dioxide concentration inside the pile from inhibiting microbial activity, the following steps are taken: Simultaneously, within a predetermined first time interval, the ventilated membrane is opened and the pile is turned over at second predetermined time intervals. This allows the oxygen-rich first mixture to be turned into the pile, while simultaneously bringing the oxygen-deficient first mixture from the pile to the surface, ensuring continuous aerobic fermentation. After a third predetermined aging time, the pile temperature naturally decreases to ambient temperature, further stabilizing the intermediate products produced during fermentation. Finally, the mixture is crushed and granulated to obtain a soil conditioner with regular particles, facilitating even application and improving fertilization precision.

[0031] Thus, the soil conditioner prepared by the method disclosed herein uses a combination of microbial agents and binders, which enables the ash and organic matter to undergo synergistic fermentation and modification. The pore structure of the ash is coupled with the humification of organic matter to form a composite water-retaining matrix, thereby reducing soil bulk density, increasing soil organic matter, retaining nitrogen, passivating heavy metals, and promoting vegetation restoration.

[0032] The working principle of the soil conditioner preparation method based on ash and organic matter provided in this disclosure will be further explained below with reference to Figures 1 and 2.

[0033] Referring to Figure 1, in one embodiment, the method for preparing a soil conditioner based on ash and organic matter disclosed herein includes: S1, pretreating ash and organic matter; S2, mixing ash and organic matter, and then sequentially adding microbial inoculants and binders to form a first mixture; S3, piling up the first mixture, covering the surface of the first mixture with a breathable membrane, opening the breathable membrane for turning over at second preset time intervals within a first preset time range, then aging for a third preset time, and then crushing and granulating to form a soil conditioner.

[0034] In detail, the process begins with pretreatment of ash and organic matter. Ash refers to solid waste generated during industrial production, primarily from fuel combustion (such as coal and biomass) or mineral smelting. It is mainly composed of inorganic minerals, rich in mineral elements such as silicon, calcium, potassium, and aluminum, and has a loose, porous structure with high mechanical strength. Organic matter refers to waste from animal and plant remains, microbial metabolites, or organic waste (such as sludge and straw). It is carbon-based and contains organic compounds such as humus, cellulose, hemicellulose, and protein, which can increase soil fertility and bind small soil particles into stable, porous aggregates. The ash selected in this disclosure is coal ash and biomass ash, and the organic matter is municipal sludge, garden waste, or livestock manure. Its moisture content is ≤30%, with high humus content, strong water and fertilizer retention, and loose structure. The pores of the ash provide space for the organic matter to adhere, and the humus in the organic matter coats the ash particles. The organic matter solves the problem of poor water retention in the ash, while the ash solves the problem of the loose structure of the organic matter.

[0035] Secondly, the ash and organic matter are mixed, and then microbial agents and binders are added in sequence to form the first mixture. Specifically, the pretreated ash and organic matter are first dry-mixed evenly, then the composite microbial agent is added and mixed evenly, and finally the dissolved binder solution is sprayed while stirring. In this way, the osmotic pressure stress that may be caused by the microbial agent directly contacting the high-concentration binder solution can be avoided, and the binder is ensured to uniformly coat all solid particles, thereby forming the first mixture.

[0036] Finally, the first mixture is piled up for fermentation to maintain a high fermentation temperature. A breathable membrane is then placed over the pile to allow oxygen to continuously enter, maintaining microbial activity and ensuring that carbon dioxide produced during fermentation is promptly released. This prevents excessively high carbon dioxide concentration inside the pile from inhibiting microbial activity. The breathable membrane can be a polyolefin (PO) membrane, a polyester (PET) membrane, or a polyethylene (PE) mesh. The fermentation of the first mixture requires a stable moisture content. Too low a moisture content will inhibit microbial activity, leading to stagnation of organic matter degradation and insufficient activation of mineral elements in the ash slag. Too high a moisture content will easily create an anaerobic environment, producing foul odors and reducing the effectiveness of high-temperature sterilization. The breathable membrane can block the direct diffusion of water vapor, reducing moisture loss, and also forms a heat insulation layer, reducing the conduction of heat from inside the pile to the outside. Meanwhile, within the first preset time range, the breathable membrane is opened and the pile is turned over at second preset time intervals. Specifically, the bottom, middle and surface materials of the pile are fully mixed by turning, the oxygen-rich surface first mixture is turned into the interior, and the oxygen-deficient interior first mixture is turned to the surface. Furthermore, if the center of the pile is too hot, it will kill the microorganisms, while the low temperature at the edge will cause fermentation to stop. Therefore, by turning the pile at a preset frequency, oxygen is added to the piled first mixture, fermentation heat is dissipated, fermentation is made uniform, and local anaerobic and excessively high temperature are prevented.

[0037] The first mixture after fermentation is aged for a third preset time, allowing the pile temperature to naturally drop to ambient temperature to avoid "burning the seedlings." At the same time, it is still covered with a breathable membrane to prevent gas escape and moisture loss, making the moisture distribution inside and outside the pile more even. Some intermediate products (such as ammonia) produced in the later stage of fermentation are further transformed, allowing the humus to further aggregate and stabilize, reducing the plant toxicity of the product. In this way, the number of microorganisms adapted to high temperatures decreases, while microorganisms adapted to medium and low temperatures and with more functional properties (such as nitrogen-fixing bacteria and actinomycetes) become the dominant species, making the product more adaptable after being applied to the soil.

[0038] Referring to Figure 2, in one embodiment, step S1 of this disclosure specifically includes: S11, sieving the ash residue to remove impurities; S12, crushing the organic matter to a first preset particle size.

[0039] Specifically, this disclosure involves sieving ash residue to remove impurities. As industrial solid waste, ash residue is prone to contamination with various impurities during collection, storage, and transportation. Coal ash may contain plastic film, fiber impurities, etc. If these impurities enter subsequent processes, they will lead to uneven mixing of ash residue and organic waste. Harmful impurities (such as metal fragments and non-degradable plastics) cannot be degraded after being applied to the soil, affecting vegetation growth and even causing secondary pollution. Coarse screening can be used to remove large-diameter impurities such as large stones, coal gangue, and metal blocks to avoid clogging or damaging subsequent crushing equipment. Then, fine screening is used to remove medium-diameter impurities such as plastic residue and small stones, ensuring that the ash residue entering the mixing process has a preliminary uniform particle size, guaranteeing that its particle size is ≤2mm.

[0040] Subsequently, the organic matter is crushed to a first preset particle size. Since the organic matter consists of municipal sludge, garden waste, or livestock manure, the particle size varies greatly. Straw can reach tens of centimeters in length, sludge forms flocculent aggregates, and livestock manure contains lumps. Furthermore, their physical forms differ significantly; straw is highly resilient, and sludge is highly viscous. When directly mixed with ash, large straw particles tend to float, lumps of manure agglomerate, and ash settle, resulting in stratification and insufficient contact between the two materials, leading to localized imbalances during subsequent fermentation. Appropriate crushing equipment is selected based on the type of organic waste (shear crushing for straw, extrusion crushing for sludge) to uniformly crush the organic matter to the first preset particle size, eliminating large-particle agglomerates and making the organic matter into uniform fragments or powder, thereby increasing the degradation rate, shortening the subsequent fermentation cycle, and ensuring sufficient coupling between ash and organic matter. Specifically, the first preset particle size in this disclosure is ≤5mm.

[0041] In addition, in one embodiment, after aging, the first mixture is crushed and granulated to a second preset particle size of 3-5 mm. Through mechanical crushing and homogenization, the clumps of material after fermentation and aging are broken up, so that the first mixture is evenly dispersed. Then, it is physically extruded or bonded to form a granular product with a particle size of 3-5 mm and a suitable strength and porosity, thereby improving the application efficiency and uniformity and avoiding imbalance in local improvement effects.

[0042] Referring to Figures 1 and 2, in one embodiment, in step S2 of this disclosure, the preset ratio of ash, organic matter, microbial agent and binder is: 60%-80%: 15%-30%: 3%-8%: 2-8%.

[0043] In detail, the ash and slag ratio should be 60-80%. If it is below 60%, the soil conditioner will not have sufficient structural support, and if it is above 80%, it will result in insufficient organic matter and microbial content, thus reducing its effectiveness.

[0044] The proportion of organic matter should be 15-30%. If the organic matter is too low, there will be insufficient humus to form an effective aggregate structure, and it will not be able to make up for the shortcomings in water and fertilizer retention, resulting in poor soil improvement. If the organic matter is too high, it will increase costs and introduce too many impurities. At the same time, after high proportion of organic matter is fermented or applied to the soil, it requires a lot of oxygen for microbial degradation. If the oxygen supply is insufficient, an anaerobic environment is easily formed, leading to the decomposition of organic matter. It will also lead to an imbalance in the carbon-nitrogen ratio (C / N), and microorganisms will compete with plants for nitrogen during decomposition.

[0045] The proportion of microbial inoculants should be 3%-8%, and the microbial inoculants need to reach a certain concentration (live bacteria count ≥ 2 × 10⁻⁶). 8 Only when the proportion of functional bacteria (CFU / g) is low can a dominant microbial community be formed, which can quickly decompose refractory components such as cellulose and lignin. When the proportion is too low, the functional microbial community cannot occupy the ecological niche, resulting in low degradation efficiency and causing the fermentation process to stagnate. When the functional microbial community metabolizes excessively, it will quickly consume the oxygen in the fermentation system. Even if oxygen is supplied by turning the pile, it cannot meet the respiratory needs of the microbial community, resulting in the formation of an anaerobic environment in some parts of the pile.

[0046] The binder ratio is 2-8%. The binder needs to bind the loose ash particles, organic waste debris, and sealing soil matrix particles together to form an effective complex. If the ratio is too low, the binder cannot cover the surface of the ash and organic matter particles, and the physical adsorption and chemical complexation are insufficient, making it difficult to form an effective complex and unable to suppress the flying of ash dust and organic matter. Excessive binder will form an over-crosslinked bonding network, filling the internal pores of the first mixture, resulting in the loss of soil aeration and permeability, and forming a compacted structure.

[0047] Correspondingly, the total of ash, organic matter, microbial agents and binders is 100%, and the proportions of each can be adjusted by those skilled in the art according to the given range, and this disclosure does not impose any limitations.

[0048] Furthermore, in one embodiment, the adhesive of this disclosure has a viscosity ≥500 mPa·s. This adhesive is a mixture of modified starch and sodium carboxymethyl cellulose (CMC-Na), both of which are natural or semi-synthetic polymers, environmentally friendly, and do not affect the soil microbial community. The modified starch provides initial viscosity and a carbon source, while sodium carboxymethyl cellulose (CMC-Na) provides strong hydrophilicity and ion exchange capacity. The blend of the two forms a gel complex with superior performance. Simultaneously, both raw materials are widely available and inexpensive. Optionally, the adhesive may also use sodium alginate, polyacrylamide (PAM), chitosan, etc., which also have binding and water-retaining functions.

[0049] Referring to Figures 1 and 2, in one embodiment, after the first mixture is formed in step S2 of this disclosure, water is added to adjust the humidity of the first mixture to a preset humidity.

[0050] In detail, this disclosure adjusts the humidity of the first mixture to a preset humidity of 45-55%. Since the natural moisture content of ash is low (e.g., fly ash 5%-10%) or is in powder form, and the moisture content of organic matter fluctuates greatly (e.g., straw 15%-25%, sludge 60%-80%), when the two are directly mixed, the imbalance of humidity can easily lead to dust from ash and clumps of organic matter, resulting in uneven mixing and affecting the subsequent fermentation effect.

[0051] The moisture content of the first mixture is adjusted to 45%-55% to form a water film on the surface of the ash and organic particles, which enhances the adsorption between particles, avoids dust and stratification, and provides the water required for the metabolism of microorganisms during subsequent fermentation.

[0052] Referring to Figures 1 and 2, in one embodiment, the detailed method of "stacking the first mixture" in step S3 of this disclosure is as follows: the first mixture is stacked in a fermentation tank, the depth of the fermentation tank perpendicular to the working surface is 1.2-1.5m, and the width of the fermentation tank parallel to the working surface is 2.5-3.0m. The fermentation tank for trough fermentation is usually constructed of reinforced concrete.

[0053] Thus, this disclosure adopts a trough fermentation, with the fermentation trough being long and narrow, set on the working surface. Its depth perpendicular to the working surface is 1.2-1.5m, its width parallel to the working surface is 2.5-3.0m, and its length can be 20-50m. The trough is equipped with a fence and a removable breathable membrane to cover it, forming a semi-closed and controllable environment to avoid interference from external temperature and humidity fluctuations on fermentation. Conventional open-air windrow fermentation is greatly affected by environmental fluctuations and is prone to insufficient temperature and uneven oxygen supply.

[0054] The elongated structure of the fermentation tank is adapted to mechanical turning, which can fully mix the bottom, middle and top layers of materials, break up the stratification and caking, and make the ash and organic matter evenly mixed.

[0055] Referring to Figures 1 and 2, in one embodiment, the detailed method of "opening the breathable membrane and turning the mixture at every second preset time interval" in step S3 of this disclosure is as follows: opening the breathable membrane at every second preset time interval, detecting the actual temperature of the first mixture, turning the mixture, and adjusting the temperature of the first mixture to the preset temperature.

[0056] In detail, the breathable membrane is opened at every second preset time interval. Then, a temperature sensor is used to detect the actual temperature of the first mixture inside the fermentation tank. The temperature sensor can be a probe type, inserted into the accumulated first mixture, and the collected data is transmitted to a server. To improve the accuracy of temperature detection, multiple detection points can be set. Specifically, along the depth direction of the fermentation tank, three detection positions are set: surface (10-20cm), middle (50-80cm), and deep (120-150cm). Along the length direction of the fermentation tank, three detection positions are set: both ends and the middle. Each detection position detects along the depth. The middle layer is the core heat-generating zone of fermentation, the deep layer is prone to oxygen deficiency and low temperature, and the surface layer is easily affected by environmental interference. Data from these three layers can reflect the vertical temperature gradient, ensuring no detection blind spots. This also adapts to long, narrow tanks, detecting temperature differences in the first mixture within the fermentation tank along its length, avoiding incomplete local fermentation.

[0057] In the initial stage of fermentation in the fermentation tank, the temperature of the pile needs to be rapidly raised to 55℃ to activate microbial metabolism. By strengthening insulation, heat loss is reduced, which in turn assists microbial heat production and shortens the heating cycle. Specifically, the outside of the tank is wrapped with thick insulation cotton to reduce heat conduction to the outside and to reduce the frequency of turning the pile to avoid heat loss due to frequent turning. During the main fermentation period, the pile temperature needs to be maintained at 50-65℃ for the first preset time. By balancing insulation and heat dissipation, local overheating or cooling is avoided, while ensuring the oxygen required for aerobic microbial metabolism. When the temperature is below 50℃, the frequency of turning the pile is reduced. When the temperature is between 50-65℃, the pile is turned once a day to ensure both oxygen supply and even heat distribution. When the temperature is above 65℃, the frequency of turning the pile is increased. Mechanical turning removes excess heat and breaks up material clumps. If the temperature is too high, some areas of the breathable membrane can be opened or water can be sprayed to supplement moisture. Natural ventilation or water evaporation can help dissipate heat, maintain microbial activity, and prevent fermentation stagnation caused by high temperature.

[0058] Referring to Figures 1 and 2, in one embodiment, the first preset time of this disclosure is 15-20 days; and / or, the second preset time is 0.5-1.5 days; and / or, the third preset time is 4-6 days.

[0059] Specifically, the initial fermentation time for this trough fermentation is 15-20 days. The initial fermentation period is 0-5 days, during which, under preset humidity and microbial inoculants, organic matter begins to decompose rapidly, producing small-molecule organic matter and heat. The porous surface of the ash begins to adsorb these newly formed small-molecule organic matter (such as organic acids and sugars) and microbial cells, forming preliminary complexes. The main fermentation stage, the main fermentation period mentioned above, is 5-15 days. Under the action of microbial inoculants, the organic matter enters a deep humification stage, decomposing recalcitrant components such as lignin and cellulose. Simultaneously, new and more stable humic substances (including humic acid and fulvic acid) are synthesized through microbial metabolism. The humic acid and other substances produced during humification have functional groups (-COOH, -OH) that interact with metal ions (such as CaO) on the surface of the ash particles. 2+ Fe 3 Al 3+ During this process, complexation or bridging occurs, and simultaneously, the binder forms a hydrated gel network under these temperature and humidity conditions, encapsulating and binding the ash and organic matter particles. Ultimately, the rigid pores of the ash are filled and cemented together by the colloidal humus produced by humification and the binder gel, forming a stable composite structure that maintains the air permeability of the ash while significantly improving its water and fertilizer retention capacity.

[0060] Meanwhile, the second preset time for turning over the pile can be 0.5-1.5 days, and the third preset time for aging can be 4-6 days. This disclosure does not impose any restrictions.

[0061] In one embodiment, the second preset time for turning the pile is 0.5-1.5 days. Specifically, during fermentation, the pile temperature needs to be raised and maintained at 50-65°C for a first preset time. By balancing heat preservation and heat dissipation, local overheating or cooling is avoided, while ensuring the oxygen required for aerobic microbial metabolism. When the temperature is <50°C, the frequency of turning the pile is reduced. When the temperature is 50-65°C, the pile is turned once a day to balance oxygen supply and heat distribution. When the temperature is >65°C, the frequency of turning the pile is increased to remove excess heat through mechanical turning and break up material clumps.

[0062] Meanwhile, the first preset time for trough fermentation can be 15-20 days, and the third preset time for aging can be 4-6 days, without any limitation in this disclosure.

[0063] In one embodiment, the third preset aging time of this disclosure is 4-6 days. Thus, as fermentation ends, the activity of high-temperature microorganisms decreases, and the system temperature gradually drops to room temperature. Through 4-6 days of aging and settling, the first mixture cools evenly, avoiding incomplete fermentation due to excessive cooling or excessive degradation due to excessive cooling. This is beneficial for further condensation and stabilization of humic substances, as well as the succession of microbial communities, forming a more balanced microbial community. If the cooling is too slow, the area can be gradually increased from a fully covered breathable membrane to a partially covered breathable membrane, and finally, the breathable membrane can be removed, thus gradually increasing the natural heat dissipation area.

[0064] Meanwhile, the first preset time for trough fermentation can be 15-20 days, and the second preset time for turning the pile can be 0.5-1.5 days. This disclosure does not impose any restrictions.

[0065] Referring to Figures 1 and 2, in one embodiment, the preset temperature of this disclosure is 50-65°C.

[0066] Thus, this disclosure controls the fermentation temperature of the first mixture at 50-65℃, which can inactivate pathogenic microorganisms (Salmonella, Escherichia coli) and parasite eggs carried by organic matter, while accelerating the oxidative decomposition of malodorous substances (hydrogen sulfide, ammonia), eliminating the risk of secondary pollution. At the same time, most of the mineral elements such as potassium, silicon, and calcium in the ash slag exist in the form of inert silicates (such as potassium feldspar and mica), which cannot be directly absorbed by plants. Cellulose and lignin in the organic matter are difficult to degrade and need to rely on the metabolic transformation of functional microorganisms. 50-65℃ is the optimal metabolic temperature for heat-resistant functional microbial groups. At this temperature, the activity of microbial enzymes is enhanced, and they can efficiently secrete organic acids such as oxalic acid and citric acid, break down the aluminosilicate lattice structure of the ash slag, release soluble potassium, silicon, and calcium ions, and accelerate the degradation of cellulose and lignin into small molecule organic matter, providing raw materials for the synthesis of humic substances. This temperature can also accelerate chemical complexation reactions to form a stable composite structure.

[0067] Referring to Figures 1 and 2, in one embodiment, the microbial agent of this disclosure includes at least: nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and lignin-degrading bacteria.

[0068] In detail, nitrogen-fixing bacteria (such as Azotobacter chrysotrichum) can convert gaseous nitrogen in the air into ammonium nitrogen that can be used by plants, and achieve biological nitrogen fixation through their nitrogenase system, directly increasing the nitrogen content of the soil.

[0069] Phosphate-solubilizing bacteria (such as Bacillus megaterium) can secrete organic acids (such as citric acid and oxalic acid) to dissolve insoluble phosphates in ash and soil, converting them into soluble phosphorus for plant absorption.

[0070] Lignin-degrading bacteria (such as *Procambarus chrysospora*) can secrete enzyme systems such as lignin peroxidase to decompose lignin and cellulose in organic waste that are difficult to degrade, transforming them into small molecules that are easily humified and providing carbon sources for other microorganisms.

[0071] Furthermore, the microbial agents disclosed herein may also include potassium-solubilizing bacteria and biocontrol bacteria. Potassium-solubilizing bacteria are functional microbial communities capable of producing metabolic products such as organic acids and enzymes, converting insoluble potassium (such as potassium feldspar, mica, and other silicate minerals) in ash slag into soluble potassium that plants can absorb, while simultaneously synergistically activating mineral elements such as silicon and calcium. These bacteria are resistant to fermentation temperatures of 50-65℃. Biocontrol bacteria are functional microbial communities capable of inhibiting plant pathogens (such as soil-borne fungi and bacteria) through antagonistic effects, inducing plant disease resistance, and improving soil microecological balance, thereby reducing the incidence of plant diseases in sealed soil.

[0072] Secondly, this disclosure provides a soil conditioner, which is prepared using the soil conditioner preparation method based on ash and organic matter as described in any of the above embodiments.

[0073] Specifically, this disclosure uses comparative experiments to verify the performance of the soil conditioner. The experimental group consists of the soil conditioner prepared according to the method of this disclosure based on ash and organic matter; control group 1 consists of a simple physical mixture of equal amounts of ash (70%) and organic matter (30%), without microbial agents or binders, and without fermentation; control group 2 consists of commercially available ordinary organic fertilizer, specifically a type of fermented chicken manure fertilizer; and control group 3 is a blank control group, consisting only of the original sealed soil.

[0074] In the experiment, three replicates were set up for each group, and the experiment was conducted in a test trench (1m×1m) simulating the slope closure, with the same application dosage of 30kg / m. 2 The soil was mixed into the 0-20cm soil layer, and then tall fescue was planted uniformly. Table 1 shows the soil test data of the comparative experiment disclosed in this paper.

[0075] Table 1

[0076] As shown in the table above, the soil conditioner disclosed herein can improve the physical and chemical properties of the soil, reduce soil bulk density, increase organic matter content, reduce nitrogen leaching rate, and increase the coverage rate after vegetation planting.

[0077] Thus, the soil conditioner prepared by the method disclosed herein uses a combination of microbial agents and binders, which enables the ash and organic matter to undergo synergistic fermentation and modification. The pore structure of the ash is coupled with the humification of organic matter to form a composite water-retaining matrix, thereby reducing soil bulk density, increasing soil organic matter, retaining nitrogen, passivating heavy metals, and promoting vegetation restoration.

[0078] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of this disclosure is defined by the appended claims.

Claims

1. A method for preparing a soil conditioner based on ash and organic matter, characterized in that, include: S1. Pre-treat the ash and organic matter; S2. Mix the ash and organic matter, then add microbial inoculant and binder in sequence to form a first mixture; S3. Stack the first mixture and cover the surface of the first mixture with a breathable membrane. Within a first preset time range, open the breathable membrane at second preset time intervals to turn the mixture over. Then, age it for a third preset time, and then crush and granulate it to form the soil conditioner.

2. The method for preparing a soil conditioner based on ash and organic matter according to claim 1, characterized in that, Step S1 specifically includes: S11, sieving the ash residue to remove impurities; S12, crushing the organic matter to a first preset particle size.

3. The method for preparing a soil conditioner based on ash and organic matter according to claim 1, characterized in that, In step S2, the preset ratio of ash, organic matter, microbial agent and binder is: 60%-80%: 15%-30%: 3%-8%: 2-8%.

4. The method for preparing a soil conditioner based on ash and organic matter according to claim 3, characterized in that, After the first mixture is formed in step S2, water is added to adjust the humidity of the first mixture to a preset humidity.

5. The method for preparing a soil conditioner based on ash and organic matter according to any one of claims 1 to 4, characterized in that, The detailed method for "stacking the first mixture" in step S3 is as follows: the first mixture is stacked in a fermentation tank, the fermentation tank having a depth of 1.2-1.5m perpendicular to the working surface and a width of 2.5-3.0m parallel to the working surface.

6. The method for preparing a soil conditioner based on ash and organic matter according to claim 5, characterized in that, The detailed method for "opening the breathable membrane for turning the mixture at a second preset time interval" in step S3 is as follows: open the breathable membrane at a second preset time interval, detect the actual temperature of the first mixture, turn the mixture, and adjust the temperature of the first mixture to the preset temperature.

7. The method for preparing a soil conditioner based on ash and organic matter according to claim 5, characterized in that, The first preset time is 15-20 days; and / or, the second preset time is: 0.5-1.5 days; and / or, the third preset time is 4-6 days.

8. The method for preparing a soil conditioner based on ash and organic matter according to claim 6, characterized in that, The preset temperature is 50-65℃.

9. The method for preparing a soil conditioner based on ash and organic matter according to claim 5, characterized in that, The microbial agent includes at least: nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and lignin-degrading bacteria.

10. A soil conditioner, characterized in that, The soil conditioner was prepared using the method described in any one of claims 1-9, which is based on ash and organic matter.

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