An organic fertilizer based on smoldering fire soil ash and a biochar loading process and a preparation method thereof

Abstract

The application discloses an organic fertilizer based on smoldering fire soil ash and a biochar loading process and a preparation method thereof, and components are as follows in terms of weight parts: 40-50 parts of rotten crop straw, 30-40 parts of fire soil ash, 3-6 parts of humic acid and 3-5 parts of water-retaining agent. The application has the beneficial effect that the physical skeleton of soil aggregates is reconstructed at the micro level by introducing a nano-mineral skeleton construction agent and modified porous biochar. In combination with the electronic shuttling effect of the shuttling repair agent, not only is the activity of soil heavy metals effectively passivated, but also the migration risk of heavy metals to the above-ground part of tobacco plants is reduced, and the gradient release characteristics of the microencapsulated active core material are utilized to solve the nutrient loss problem of traditional organic fertilizers in the environment with large mountain slope and strong rainwater erosion. The structure can make the soil aggregate structure be improved by nearly 78% (up to 68.7%), and effectively lock soil moisture and nutrients.

Description

Technical Field

[0001] This invention relates to the field of organic fertilizer technology, specifically to an organic fertilizer based on a process of loading smoldering fire ash and biochar, and its preparation method. Background Technology

[0002] Mountainous tobacco-growing areas, such as Yunnan, Guizhou, and Hunan, are major producers of high-quality tobacco leaves due to their unique three-dimensional climate and soil conditions, resulting in tobacco leaves with rich aroma and pure taste. However, the special geographical environment, characterized by steep slopes, thin soil layers, and concentrated yet uneven rainfall distribution, has revealed many insurmountable defects in the practical application of existing conventional organic fertilizers and tobacco-specific fertilizers, hindering the stable yield and quality improvement of mountainous tobacco leaves.

[0003] To improve fertilizer efficiency, existing technologies often add seaweed extracts, amino acids, or plant growth regulators to fertilizers. However, traditional fertilizer production processes (such as high-temperature granulation and drum drying) often involve temperatures exceeding 80°C. Under such conditions, heat-sensitive and photosensitive active substances in seaweed extracts, such as brown algae oligosaccharides, fucoxanthin, and melatonin, are prone to denaturation, decomposition, or volatilization, resulting in a significant loss of their physiological activity. Furthermore, the components in existing formulas are mostly simple physical mixtures, which cannot effectively stimulate the expression of the tobacco plant's own stress-resistance genes, leading to slow root development and weak drought and disease resistance after transplanting. Summary of the Invention

[0004] The purpose of this invention is to provide an organic fertilizer and its preparation method based on a smoldering fire ash and biochar loading process, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an organic fertilizer based on a smoldering fire ash and biochar loading process, wherein the components are as follows by weight: decomposed crop straw: 40-50 parts, fire ash: 30-40 parts, humic acid: 3-6 parts, water-retaining agent: 3-5 parts, modified porous biochar: 5-8 parts, low molecular weight chitosan: 0.5-1.5 parts, seaweed extract: 1-3 parts, compound microbial agent: 1-2 parts, microencapsulated active core material: 6-10 parts, nano-mineral skeleton builder: 5-9 parts, bio-derived synergist: 2-6 parts, physiological activator: 3-5 parts, shuttle repair agent: 1-4 parts;

[0006] The nano-mineral skeleton building agent is a hydroxyapatite crystal with a nanorod-like structure, the length of which is 50-200 nm and the diameter is 10-20 nm.

[0007] The bio-derived synergist is a γ-polyglutamic acid polymer with a molecular weight between 500,000 and 2,000,000 Da;

[0008] The physiological activator is melatonin with a purity of not less than 99%, specifically N-acetyl-5-methoxytryptamine.

[0009] Preferably, the composted crop straw is one of the following: corn, wheat, rice, soybean, cotton, or rapeseed crop straw after composting treatment;

[0010] The ash is a product prepared by smoldering and heating tobacco straw, red clay and sandy loam.

[0011] The humic acid is one or a mixture of humic acid and humate salts;

[0012] The water-retaining agent is one or more of the following: superabsorbent resin and polyacrylamide.

[0013] The modified porous biochar is one or a mixture of two of phosphate-modified straw biochar and struvite-modified straw biochar.

[0014] The low molecular weight chitosan is one of the deacetylated products of chitin.

[0015] Preferably, the seaweed extract is a mixture of fucoidan oligosaccharide, alginate hydrolysate, and fucoxanthin; wherein the mass ratio of fucoidan oligosaccharide, alginate hydrolysate, and fucoxanthin is 4:3:1.

[0016] The compound microbial agent is a mixture of Bacillus subtilis, Bacillus lateralis, and Bacillus mucilaginosus.

[0017] The microencapsulated active core material is a microecological particle with a sustained-release function, comprising one of the following: modified porous biochar, low molecular weight chitosan, seaweed extract, and compound microbial agent.

[0018] Preferably, the shuttle repair agent is a composite material in which biochar is used as a carrier to support sulfide-modified nano-zero-valent iron, wherein the sulfur-iron molar ratio is 0.1-0.3.

[0019] Preferably, the preparation steps of the seaweed extract specifically include the following steps:

[0020] A1. Take brown algae raw material, wash and dry it, then crush it. Extract it by enzymatic hydrolysis to obtain crude alginate extract. After separation and purification, obtain a fucoidan solution and alginate hydrolysate powder. The molecular weight of the fucoidan is 1000-3000 Da, and the purity of the fucoxanthin is not less than 10%.

[0021] A2. Take an equal amount of brown algae raw material and extract it with ethanol, extract it and separate it by column chromatography to obtain fucoxanthin concentrate;

[0022] A3. Mix the brown algae oligosaccharide solution and the fucoxanthin concentrate at a mass ratio of 5:1-3:1, spray dry, and then physically blend with the brown alginic acid hydrolysate powder to obtain the seaweed extract.

[0023] Preferably, the preparation steps of the compound microbial agent specifically include the following steps:

[0024] B1. Inoculate Bacillus subtilis strain into LB liquid medium and culture at 37℃ and 180 rpm for 24-36 h with shaking to obtain primary seed culture; Inoculate Bacillus laterosporus and Bacillus mucilaginosus into their respective dedicated fermentation media and culture at 30-35℃ and 200 rpm for 24-48 h with shaking to obtain secondary seed culture for each strain.

[0025] B2. Mix the primary seed liquid and the secondary seed liquid in a volume ratio of 1:1:1-2:1:1, transfer them to a sterile fermenter for deep liquid fermentation, control the dissolved oxygen content at 20-30%, the fermentation temperature at 30-37℃, and the fermentation time at 48-72h to obtain a compound fermentation liquid.

[0026] B3. Take corn stalks and pyrolyze them at 550℃ for 2-3 hours under limited oxygen conditions to obtain biochar, which is then ground through a 100-200 mesh sieve.

[0027] The composite fermentation broth and the above-mentioned biochar were mixed at a mass-to-volume ratio of 10:1 and cultured under shaking conditions at 25-30℃ and 180-200 rpm for 10-14 hours to allow the bacteria to be loaded into the pores of the biochar. Then, 3-5% of the total mass of the fermentation broth was added as an adsorption carrier, stirred evenly, and then freeze-dried under vacuum. The mixture was then pulverized and passed through a 60-80 mesh sieve to obtain the composite microbial agent.

[0028] The number of viable bacteria in the compound microbial agent is not less than 1×10¹. 0 CFU / g, in which the ratio of viable Bacillus subtilis, Bacillus lateralis, and Bacillus mucilaginosus is 3:1:1.

[0029] Preferably, the preparation method of the microencapsulated active core material specifically includes the following steps:

[0030] C1. Modified porous biochar is ground and passed through a 100-200 mesh sieve, then dried in an oven at 105℃ to constant weight to obtain a dried biochar matrix; low molecular weight chitosan is dissolved in a 1-3% (v / v) acetic acid solution to prepare a 1-3% (w / v) chitosan acetate solution; seaweed extract is dissolved in deionized water to prepare a 5-10% (w / v) seaweed extract solution; the compound microbial agent is mixed with sterile diatomaceous earth at a mass ratio of 1:3-1:5 to obtain a dry powder of the agent.

[0031] C2. Weigh the dried biochar matrix and bacterial agent powder according to the formula ratio, add seaweed extract and an appropriate amount of deionized water, and mix them evenly through a kneader to form a moist soft material; place the moist soft material in an extrusion granulator to make wet granules with a particle size of 0.5-2mm.

[0032] C3. Immerse the wet particles in a chitosan acetate solution and stir at low speed for 20-40 minutes at 35-45℃ to allow chitosan to adsorb and initially crosslink on the particle surface and in the pores, forming a primary coating layer; then transfer the particles to a calcium ion crosslinking agent solution with a mass fraction of 0.5-1.5% and let them stand for crosslinking for 30-60 minutes to form a microcapsule gel network structure.

[0033] C4. Filter out the cross-linked microcapsule particles, wash them with deionized water until neutral, place them in a freeze dryer, and vacuum dry them at -40°C for 12-24 hours to obtain the microencapsulated active core material.

[0034] The modified porous biochar is one of phosphate-modified straw biochar or struvite-modified straw biochar.

[0035] The calcium ion crosslinking agent is one or a mixture of calcium chloride, calcium lactate, or calcium gluconate.

[0036] A method for preparing organic fertilizer based on smoldering fire ash and biochar loading process includes the following steps:

[0037] S1. Select tobacco straw, red clay and sandy loam as raw materials, and stack them in layers at a mass ratio of 3-5:1:1 to build a hollow cone stack. After ignition, control it to a state of natural smoldering without open flame for 2-3 days. After natural extinguishing, collect the ash, which is the fire ash. Separately perform physical activation and surface modification treatment on decomposed crop straw, fire ash, humic acid and nano-mineral skeleton building agent, and modified porous biochar.

[0038] S2. Subsequently, the activated mineral substrate is placed in an ultrasonic disperser and ultrasonically dispersed for 20-30 minutes at a frequency of 40-60kHz using anhydrous ethanol as the medium to prevent nanoparticle aggregation.

[0039] S3. Add the shuttle repair agent and the bio-derived synergist to the double cone rotary vacuum dryer and mix for 10-15 minutes at a speed of 20-30 rpm and a temperature of 25-35℃ to form the first mixed powder. Dissolve the physiological activator in anhydrous ethanol to prepare a spray solution. Spray the solution into the mixed powder using an atomization spraying method. At the same time, turn on the jacket heating of the vacuum dryer and control the temperature to not exceed 40℃ to obtain a functional dry powder loaded with physiological activator.

[0040] S4. The organic powder base material and functional dry powder are put into a trough mixer and dry-mixed evenly. Then, microencapsulated active core material and compound microbial agent are added. The material is first sprayed with deionized water to wet the granulator disc, and then fed into the disc granulator. The disc inclination angle is controlled at 45°-55° and the rotation speed is 25-35r / min, so that the organic powder base material and functional dry powder are coated on the crystal nucleus surface layer by layer to form wet granules with a particle size of 3-5mm. During the granulation process, a seaweed extract solution with a mass concentration of 1-3% is sprayed onto the disc surface at the same time as a granulation binder and root signal inducer.

[0041] S5. Perform segmented temperature-controlled drying on wet particles, and use low molecular weight chitosan for surface film formation and cross-linking curing at the end of the drying process.

[0042] S6. After the dried granules are naturally cooled to room temperature, they are put into a spherical polishing machine. The friction between the granules is used to remove the sharp edges and form micro-cracks on the surface. Then, they are passed through a 3-5mm sieve to remove fine powder and large pieces, thus obtaining the organic fertilizer based on the smoldering fire ash and biochar loading process.

[0043] Preferably, step S1 specifically includes the following steps:

[0044] S11. Weigh out the decomposed crop straw, firewood ash and humic acid by weight, put them into an air jet mill for ultra-fine grinding, control the gas-solid ratio to be 2:1-3:1, grind to a particle size ≤100μm, and obtain organic powder base material.

[0045] S12. The nano-mineral skeleton building agent and modified porous biochar are placed in a low-temperature plasma treatment device and surface activation treatment is carried out under the conditions of 200-400W power, 60-120s treatment time and argon and oxygen mixed gas. The surface roughness is increased by introducing active functional groups to obtain activated mineral substrate.

[0046] Preferably, step S5 specifically includes the following steps:

[0047] S51. The wet granules are fed into a belt dryer to perform the first stage of drying, which involves drying with hot air at 45-50℃ for 20-30 minutes to remove free water from the surface of the granules.

[0048] S52. Transfer the particles to the second stage of drying, and dry them with hot air at 55-60℃ for 15-20 min to remove the bound water inside the particles.

[0049] S53. At the end of the drying process, a layer of low molecular weight chitosan film-forming liquid with a mass fraction of 1-2% is atomized and sprayed onto the surface of the particles. Then, hot air is immediately introduced for instant cross-linking and curing, forming an outer protective film on the surface of the particles that has the function of swelling and retaining water upon contact with water.

[0050] Compared with existing technologies, the beneficial effects of this invention are: by introducing nano-mineral skeleton building agents and modified porous biochar, the physical framework of soil aggregates is reconstructed at the microscopic level. Combined with the electron shuttle effect of the shuttle remediation agent, it not only efficiently passivates the activity of heavy metals in the soil and reduces the risk of heavy metal migration to the aboveground parts of tobacco plants, but also utilizes the gradient release characteristics of the microencapsulated active core material to solve the problem of nutrient loss of traditional organic fertilizers in mountainous areas with steep slopes and strong rainwater erosion. The structure can improve the soil aggregate structure by nearly 78% (up to 68.7%), effectively locking in soil moisture and nutrients.

[0051] Unlike traditional fertilizers that only provide nutrients, this invention significantly eliminates reactive oxygen species in the roots and enhances the tolerance of tobacco plants to stresses such as drought and strong light through the synergistic effect of physiological activators and ternary compound seaweed extracts. At the same time, it utilizes the chelating effect of bio-derived synergists on potassium ions, combined with the phosphorus-solubilizing and potassium-releasing functions of compound microbial agents, and through the gradient release characteristics of microencapsulated active core materials, to greatly activate and continuously supply nutrients fixed in the soil. Detailed Implementation

[0052] This invention provides a technical solution: an organic fertilizer based on a process of loading smoldering firewood ash and biochar, wherein the components by weight are: decomposed crop straw: 40-50 parts, firewood ash: 30-40 parts, humic acid: 3-6 parts, water-retaining agent: 3-5 parts, modified porous biochar: 5-8 parts, low molecular weight chitosan: 0.5-1.5 parts, seaweed extract: 1-3 parts, compound microbial agent: 1-2 parts, microencapsulated active core material: 6-10 parts, nano-mineral skeleton builder: 5-9 parts, bio-derived synergist: 2-6 parts, physiological activator: 3-5 parts, shuttle repair agent: 1-4 parts;

[0053] The nano-mineral skeleton building block is a hydroxyapatite crystal with a nanorod-like structure. The length of the hydroxyapatite crystal is 50-200 nm and the diameter is 10-20 nm.

[0054] The bio-derived synergist is a γ-polyglutamic acid polymer with a molecular weight between 500,000 and 2,000,000 Da;

[0055] The physiological activator is melatonin with a purity of not less than 99%, specifically N-acetyl-5-methoxytryptamine;

[0056] By introducing nano-mineral skeleton building agents, shuttle repair agents, and microencapsulated active core materials, a three-in-one physical structure of skeleton-repair-slow release is constructed. Compared with traditional organic fertilizers, this formula not only provides nutrients, but more importantly, it uses nano-hydroxyapatite to reconstruct the micro-skeleton of soil aggregates and uses zero-valent iron sulfide to repair hidden soil pollution, significantly improving the erosion resistance and water retention performance of mountain soils.

[0057] Among them, the composted crop straw is one of the following: corn, wheat, rice, soybean, cotton or rapeseed crop straw after composting treatment;

[0058] Fire ash is a product prepared by smoldering and heating tobacco straw, red clay and sandy loam.

[0059] Humic acid is one or a mixture of humic acid and humate salts;

[0060] The water-retaining agent is one or more of the following: superabsorbent resins and polyacrylamides;

[0061] Modified porous biochar is one or a mixture of two of phosphate-modified straw biochar and struvite-modified straw biochar.

[0062] Low molecular weight chitosan is one of the deacetylated products of chitin;

[0063] By limiting the source of decomposed crop straw and the type of modified porous biochar, the breadth and stability of organic matter sources are ensured. In particular, limiting the modified porous biochar to phosphate or struvite modification enables it to provide a porous structure while possessing stronger anion exchange capacity and phosphorus fixation capacity, effectively reducing the leaching of nitrogen and phosphorus nutrients in mountain soils.

[0064] The seaweed extract is a mixture of fucoidan oligosaccharide, alginate hydrolysate, and fucoxanthin; wherein the mass ratio of fucoidan oligosaccharide, alginate hydrolysate, and fucoxanthin is 4:3:1.

[0065] The compound microbial agent is a mixture of Bacillus subtilis, Bacillus lateralis, and Bacillus mucilaginosus;

[0066] The microencapsulated active core material is a microecological particle with sustained-release function, comprising one of the following: modified porous biochar, low molecular weight chitosan, seaweed extract, and compound microbial agent.

[0067] By employing a ternary compound of seaweed extracts consisting of fucoidan oligosaccharides, alginate hydrolysate, and fucoxanthin, along with a compound microbial agent containing Bacillus subtilis, Bacillus laterosporus, and Bacillus mucilaginosus, a synergistic effect of root-promoting signals and biocontrol was achieved. The addition of fucoxanthin enhanced the plant's tolerance to abiotic stresses, while the compound microbial agent formed a three-dimensional rhizosphere protective barrier.

[0068] Among them, the shuttle repair agent is a composite material in which biochar is used as a carrier to support sulfide-modified nano-zero-valent iron, wherein the sulfur-iron molar ratio is 0.1-0.3;

[0069] The shuttle remediation agent is biochar-supported zero-valent iron sulfide, which utilizes the conductivity of biochar as an electron shuttle to accelerate the reduction and degradation of organic pollutants in the soil.

[0070] The preparation steps of seaweed extract specifically include the following steps:

[0071] A1. After washing and drying the brown algae raw material, pulverize it and extract it by enzymatic hydrolysis to obtain crude alginate extract. After separation and purification, obtain a brown algae oligosaccharide solution and alginate hydrolysate powder. The molecular weight of the brown algae oligosaccharide is 1000-3000 Da, and the purity of fucoxanthin is not less than 10%.

[0072] A2. Take an equal amount of brown algae raw material and extract it with ethanol, extract it and separate it by column chromatography to obtain fucoxanthin concentrate;

[0073] A3. Mix the brown algae oligosaccharide solution and the fucoxanthin concentrate at a mass ratio of 5:1-3:1, spray dry, and then physically blend with the brown alginic acid hydrolysate powder to obtain the seaweed extract.

[0074] Seaweed extract was prepared by combining enzymatic extraction and ethanol extraction, which preserved the water-soluble active ingredients of brown algae oligosaccharides and the fat-soluble active ingredients of fucoxanthin. The spray drying and physical blending steps avoided the inactivation of heat-sensitive fucoxanthin, ensuring the high efficiency of root-promoting active substances in the final product.

[0075] The preparation steps of the compound microbial agent specifically include the following steps:

[0076] B1. Inoculate Bacillus subtilis strain into LB liquid medium and culture at 37℃ and 180 rpm for 24-36 h with shaking to obtain primary seed culture; Inoculate Bacillus laterosporus and Bacillus mucilaginosus into their respective dedicated fermentation media and culture at 30-35℃ and 200 rpm for 24-48 h with shaking to obtain secondary seed culture for each strain.

[0077] The specific fermentation medium refers to a conventional culture medium suitable for industrial liquid fermentation of the target strain; specifically, the composition (g / L) of the specific fermentation medium used for *Bacillus laterosporus* is as follows:

[0078] Tryptone 10, yeast extract 5, NaCl 5, glucose 5, K2HPO4 1, MgSO4·7H2O 0.3, pH 7.0-7.2;

[0079] The composition (g / L) of the special fermentation medium used for Bacillus mucilaginosus is as follows:

[0080] Sucrose 10, (NH4)2SO4 1, Na2HPO4 2, KCl 0.5, MgSO4·7H2O 0.2, CaCO3 3, FeSO4·7H2O 0.02, pH 7.0-7.5;

[0081] The above-mentioned culture media are all commonly used Bacillus fermentation media in this field;

[0082] B2. Mix the primary seed liquid and the secondary seed liquid in a volume ratio of 1:1:1-2:1:1, transfer them to a sterile fermenter for deep liquid fermentation, control the dissolved oxygen content at 20-30%, the fermentation temperature at 30-37℃, and the fermentation time at 48-72h to obtain a compound fermentation liquid.

[0083] B3. Take corn stalks and pyrolyze them at 550℃ for 2-3 hours under limited oxygen conditions to obtain biochar, which is then ground through a 100-200 mesh sieve.

[0084] The composite fermentation broth and the above-mentioned biochar were mixed at a mass-to-volume ratio of 10:1 and cultured under shaking conditions at 25-30℃ and 180-200 rpm for 10-14 hours to allow the bacteria to be loaded into the pores of the biochar. Then, 3-5% of the total mass of the fermentation broth was added as an adsorption carrier, stirred evenly, and then freeze-dried under vacuum. The mixture was then pulverized and passed through a 60-80 mesh sieve to obtain the composite microbial agent.

[0085] The number of viable bacteria in the compound microbial agent is not less than 1×10¹ 0 CFU / g, in which the ratio of viable Bacillus subtilis, Bacillus laterosporus, and Bacillus mucilaginosus is 3:1:1;

[0086] By controlling the volume ratio of primary seed liquid to secondary seed liquid and the dissolved oxygen content during deep fermentation, the growth balance of the three functional bacteria was optimized, avoiding the imbalance of the microbial community caused by the excessive dominance of a single microbial species. The freeze-drying process combined with sterile diatomaceous earth adsorption maximized the preservation of the cell integrity of the bacteria and their colonization ability after being planted in the soil.

[0087] The preparation method of the microencapsulated active core material specifically includes the following steps:

[0088] C1. Modified porous biochar is ground and passed through a 100-200 mesh sieve, then dried in an oven at 105℃ to constant weight to obtain a dried biochar matrix; low molecular weight chitosan is dissolved in a 1-3% (v / v) acetic acid solution to prepare a 1-3% (w / v) chitosan acetate solution; seaweed extract is dissolved in deionized water to prepare a 5-10% (w / v) seaweed extract solution; the compound microbial agent is mixed with sterile diatomaceous earth at a mass ratio of 1:3-1:5 to obtain a dry powder of the agent.

[0089] C2. Weigh the dried biochar matrix and bacterial agent powder according to the formula ratio, add seaweed extract and an appropriate amount of deionized water, and mix them evenly through a kneader to form a moist soft material; place the moist soft material in an extrusion granulator to make wet granules with a particle size of 0.5-2mm.

[0090] C3. Immerse the wet particles in a chitosan acetate solution and stir at low speed for 20-40 minutes at 35-45℃ to allow chitosan to adsorb and initially crosslink on the particle surface and in the pores, forming a primary coating layer; then transfer the particles to a calcium ion crosslinking agent solution with a mass fraction of 0.5-1.5% and let them stand for crosslinking for 30-60 minutes to form a microcapsule gel network structure.

[0091] C4. Filter out the cross-linked microcapsule particles, wash them with deionized water until neutral, place them in a freeze dryer, and vacuum dry them at -40℃ for 12-24h to obtain the microencapsulated active core material.

[0092] Modified porous biochar is one of phosphate-modified straw biochar or struvite-modified straw biochar;

[0093] The calcium ion crosslinking agent is one or a mixture of calcium chloride, calcium lactate, or calcium gluconate;

[0094] Microencapsulated active core material was prepared by combining calcium ion crosslinking and freeze-drying, and a dense hydrogel network was constructed on the surface of modified porous biochar. This not only protects the composite microbial agent from ultraviolet radiation and soil protozoa, but also enables the gradient release of low molecular weight chitosan and seaweed extract, thus extending the fertilizer effect period.

[0095] A method for preparing organic fertilizer based on smoldering fire ash and biochar loading process includes the following steps:

[0096] S1. Select tobacco straw, red clay and sandy loam as raw materials, and stack them in layers at a mass ratio of 3-5:1:1 to build a hollow cone stack. After ignition, control it to a state of natural smoldering without open flame for 2-3 days. After natural extinguishing, collect the ash, which is the fire ash. Separately perform physical activation and surface modification treatment on decomposed crop straw, fire ash, humic acid and nano-mineral skeleton building agent, and modified porous biochar.

[0097] S2. Then, the activated mineral substrate is placed in an ultrasonic disperser and ultrasonically dispersed for 20-30 minutes at a frequency of 40-60kHz using anhydrous ethanol as a medium to prevent nanoparticles from agglomerating.

[0098] S3. Add the shuttle repair agent and the bio-derived synergist to the double cone rotary vacuum dryer and mix for 10-15 minutes at a speed of 20-30 rpm and a temperature of 25-35℃ to form the first mixed powder. Dissolve the physiological activator in anhydrous ethanol to prepare a spray solution. Spray the solution into the mixed powder using an atomization spraying method. At the same time, turn on the jacket heating of the vacuum dryer and control the temperature to not exceed 40℃ to obtain a functional dry powder loaded with physiological activator.

[0099] S4. The organic powder base material and functional dry powder are put into a trough mixer and dry-mixed evenly. Then, microencapsulated active core material and compound microbial agent are added. The material is first sprayed with deionized water to wet the granulator disc, and then fed into the disc granulator. The disc inclination angle is controlled at 45°-55° and the rotation speed is 25-35r / min, so that the organic powder base material and functional dry powder are coated on the crystal nucleus surface layer by layer to form wet granules with a particle size of 3-5mm. During the granulation process, a seaweed extract solution with a mass concentration of 1-3% is sprayed onto the disc surface at the same time as a granulation binder and root signal inducer.

[0100] S5. Perform segmented temperature-controlled drying on wet particles, and use low molecular weight chitosan for surface film formation and cross-linking curing at the end of the drying process.

[0101] S6. After the dried granules are naturally cooled to room temperature, they are put into a spherical polishing machine to remove the sharp edges and form micro-cracks on the surface by using the friction between the granules. Then, they are passed through a 3-5mm sieve to remove fine powder and large pieces, and organic fertilizer based on the process of smoldering fire ash and biochar loading is obtained.

[0102] By employing nucleus granulation technology (using microcapsules as the core) and spherical polishing process, the shortcomings of traditional organic fertilizer granules, such as low strength and easy pulverization, have been solved. In particular, the use of seaweed extract solution as a dynamic binder in the granulation process simplifies the process and achieves uniform distribution of root signaling molecules, significantly improving the fertilizer's erosion resistance on mountain slopes and its root-inducing effect after being planted in the soil.

[0103] Step S1 specifically includes the following steps:

[0104] S11. Weigh out the decomposed crop straw, firewood ash and humic acid by weight, put them into an air jet mill for ultra-fine grinding, control the gas-solid ratio to be 2:1-3:1, grind to a particle size ≤100μm, and obtain organic powder base material.

[0105] S12. The nano-mineral skeleton building agent and modified porous biochar are placed in a low-temperature plasma treatment device and surface activation treatment is carried out under the conditions of 200-400W power, 60-120s treatment time and argon and oxygen mixed gas atmosphere. The surface roughness is increased by introducing active functional groups to obtain activated mineral substrate.

[0106] Surface activation of nano-mineral skeleton building blocks and modified porous biochar by low-temperature plasma treatment introduces a large number of carboxyl and hydroxyl functional groups on the material surface, which significantly enhances the interfacial bonding force between nanomaterials and organic matrix, effectively prevents the agglomeration of nanoparticles during the mixing process, and improves the material utilization rate.

[0107] Step S5 specifically includes the following steps:

[0108] S51. The wet granules are fed into a belt dryer to perform the first stage of drying, which involves drying with hot air at 45-50℃ for 20-30 minutes to remove free water from the surface of the granules.

[0109] S52. Transfer the particles to the second stage of drying, and dry them with hot air at 55-60℃ for 15-20 min to remove the bound water inside the particles.

[0110] S53. At the end of the drying process, a layer of low molecular weight chitosan film-forming liquid with a mass fraction of 1-2% is atomized and sprayed onto the surface of the particles. Then, hot air is immediately introduced to perform instant cross-linking and curing, forming an outer protective film on the surface of the particles that has the function of swelling and retaining water upon contact with water.

[0111] By combining gradient temperature-controlled drying with instantaneous cross-linking of low molecular weight chitosan, a smart protective film with water-swelling properties is formed on the surface of the particles while ensuring a high survival rate (>85%) of the composite microbial agent. This film can lock in moisture during drought and release nutrients during rainfall, perfectly adapting to the climate characteristics of concentrated and uneven rainfall in mountainous tobacco areas.

[0112] Example 1: An organic fertilizer based on a process of loading smoldering fire ash and biochar, comprising: 40 parts of decomposed crop straw, 30 parts of fire ash, 3 parts of humic acid, 3 parts of superabsorbent resin, 5 parts of struvite-modified straw biochar, 0.5 parts of low molecular weight chitosan, 1 part of seaweed extract, 1 part of compound microbial agent, 6 parts of microencapsulated active core material, 5 parts of hydroxyapatite crystals, 2 parts of γ-polyglutamic acid polymer, 3 parts of N-acetyl-5-methoxytryptamine, and 1 part of shuttle repair agent.

[0113]

[0114] A method for preparing organic fertilizer based on smoldering fire ash and biochar loading process includes the following steps:

[0115] S1. The ash is prepared by the smoldering and smoldering method:

[0116] Tobacco straw, red clay, and sandy loam were mixed in a mass ratio of 4:1:1 and stacked in layers to form a hollow cone-shaped pile. After igniting the top, the pile was controlled to smolder naturally without open flame for 2-3 days. After the pile extinguished naturally, the internal ash was collected, which is the fire-soil ash. This preparation method enriches the ash with high-temperature potassium salts and mineral melts, significantly improving the soil's cation exchange capacity and aggregate stability.

[0117] Weigh out the decomposed crop straw, ash, and humic acid by weight, and put them into an air jet mill for ultrafine grinding. Control the gas-solid ratio to be 2:1 and grind until the particle size is ≤100μm to obtain an organic powder base material. Place hydroxyapatite crystals and struvite-modified straw biochar in a low-temperature plasma treatment device and perform surface activation treatment under the conditions of 200W power, 60s treatment time, and a mixed atmosphere of argon and oxygen. By introducing active functional groups to increase the surface roughness, an activated mineral substrate is obtained.

[0118] S2. The activated mineral substrate was then placed in an ultrasonic disperser and ultrasonically dispersed for 20 minutes at a frequency of 40 kHz using anhydrous ethanol as a medium to prevent nanoparticle aggregation.

[0119] S3. The shuttle repair agent and γ-polyglutamic acid polymer are added to a double cone rotary vacuum dryer and mixed for 10 minutes at 20 rpm and 25°C to form the first mixed powder. N-acetyl-5-methoxytryptamine is dissolved in anhydrous ethanol to prepare a spraying solution. The solution is sprayed into the mixed powder by atomization spraying. At the same time, the jacket heating of the vacuum dryer is turned on and the temperature is controlled not to exceed 40°C to obtain functional dry powder loaded with N-acetyl-5-methoxytryptamine.

[0120] S4. The organic powder base material and functional dry powder are put into a trough mixer and dry mixed evenly. Then, microencapsulated active core material and compound microbial agent are added. The surface of the granulator is first sprayed with deionized water to wet it. Then, the material is fed into the disc granulator. The disc inclination angle is controlled at 45° and the rotation speed is 25r / min. The organic powder base material and functional dry powder are coated on the surface of the crystal nucleus layer by layer to make wet granules with a particle size of 3mm. During the granulation process, a seaweed extract solution with a mass concentration of 1% is sprayed onto the disc surface at the same time as a granulation binder and root signal inducer.

[0121] The preparation method of microencapsulated active core material specifically includes the following steps:

[0122] Bird's guano-modified straw biochar was ground and passed through a 100-mesh sieve, then dried in an oven at 105℃ until constant weight to obtain a dried biochar matrix. Low molecular weight chitosan was dissolved in a 1% (v / v) acetic acid solution to prepare a 1% (w / v) chitosan-acetic acid solution. Seaweed extract was dissolved in deionized water to prepare a 5% (w / v) seaweed extract solution. A compound microbial agent was mixed with sterile diatomaceous earth at a mass ratio of 1:3 to obtain a dry agent powder. The dried biochar matrix and the dry agent powder were weighed according to the formula ratio, and the seaweed extract solution and an appropriate amount of deionized water were added. The mixture was then kneaded until homogeneous to form a wet... Moistened soft material; the moistened soft material is placed in an extruder granulator to produce wet granules with a particle size of 0.5 mm; the wet granules are immersed in a chitosan acetate solution and stirred at low speed for 20 min at 35 °C to allow chitosan to adsorb and initially crosslink on the surface and pores of the granules, forming a primary coating layer; the granules are then transferred to a 0.5% (w / w) calcium ion crosslinking agent solution and allowed to stand for crosslinking for 30 min to form a microcapsule gel network structure; the crosslinked microcapsule granules are filtered out, washed with deionized water until neutral, and placed in a freeze dryer for vacuum drying at -40 °C for 12 h to obtain the microencapsulated active core material;

[0123] The preparation steps of the compound microbial agent specifically include the following steps:

[0124] Bacillus subtilis strain was inoculated into LB liquid medium and cultured at 37℃ and 180 rpm for 24 h with shaking to obtain primary seed culture. Bacillus laterosporus and Bacillus mucilaginosus were inoculated into their respective specialized fermentation media and cultured at 30℃ and 200 rpm for 24 h with shaking to obtain secondary seed cultures for each strain. The primary and secondary seed cultures were mixed at a volume ratio of 1:1:1 and transferred to a sterile fermenter for deep liquid fermentation. The dissolved oxygen content was controlled at 20%, the fermentation temperature at 30℃, and the fermentation time at 48 h to obtain the desired product. Composite fermentation broth; corn stalks were pyrolyzed at 550℃ for 2-3 hours under limited oxygen conditions to obtain porous biochar, which was then ground through a 100-200 mesh sieve to obtain a biochar carrier; the obtained composite fermentation broth and the biochar carrier were mixed at a mass-to-volume ratio of 10:1 and cultured with shaking at 28℃ and 200 rpm for 10-14 hours to allow the microorganisms to be fully loaded into the porous structure of the biochar; then 4% of the total mass of the fermentation broth was added as sterile diatomaceous earth as an adsorption carrier, stirred evenly, and then dried in a vacuum freeze dryer and pulverized through a 70 mesh sieve to obtain the carbon-supported composite microbial agent;

[0125] Brown algae raw material was washed, dried, and pulverized. A crude alginate extract was obtained through enzymatic hydrolysis. After separation and purification, a brown algae oligosaccharide solution and alginate hydrolysate powder were obtained. The molecular weight of the brown algae oligosaccharide was 1000 Da, and the purity of fucoxanthin was not less than 10%. An equal amount of brown algae raw material was extracted with ethanol, then extracted and separated by column chromatography to obtain a concentrated fucoxanthin solution. The brown algae oligosaccharide solution and the concentrated fucoxanthin solution were mixed at a mass ratio of 5:1, spray-dried, and then physically blended with the alginate hydrolysate powder to obtain the seaweed extract.

[0126] S5. The wet granules are fed into a belt dryer to perform the first stage of drying, which involves drying with hot air at 45°C for 20 min to remove free water from the surface of the granules. The granules are then transferred to the second stage of drying, where they are dried with hot air at 55°C for 15 min to remove bound water from the inside of the granules. At the end of the drying process, a layer of low molecular weight chitosan film-forming liquid with a mass fraction of 1% is atomized and sprayed onto the surface of the granules. Then, hot air is immediately introduced for instantaneous cross-linking and curing to form an outer protective film on the surface of the granules that has the function of swelling and retaining water upon contact with water.

[0127] S6. After the dried granules are naturally cooled to room temperature, they are put into a spherical polishing machine. The friction between the granules is used to remove the sharp edges and form micro-cracks on the surface. Then, they are passed through a 3mm sieve to remove fine powder and large pieces, resulting in organic fertilizer based on the process of smoldering fire ash and biochar loading.

[0128] Example 2: An organic fertilizer based on a process of loading smoldering fire ash and biochar, comprising: 50 parts of decomposed crop straw, 40 parts of fire ash, 6 parts of humic acid, 5 parts of superabsorbent resin, 8 parts of struvite-modified straw biochar, 1.5 parts of low molecular weight chitosan, 3 parts of seaweed extract, 2 parts of compound microbial agent, 10 parts of microencapsulated active core material, 9 parts of hydroxyapatite crystals, 6 parts of γ-polyglutamic acid polymer, 5 parts of N-acetyl-5-methoxytryptamine, and 4 parts of shuttle repair agent.

[0129]

[0130] A method for preparing organic fertilizer based on smoldering fire ash and biochar loading process includes the following steps:

[0131] S1. The ash is prepared by the smoldering and smoldering method:

[0132] Tobacco straw, red clay, and sandy loam were mixed in a mass ratio of 4:1:1 and stacked in layers to form a hollow cone-shaped pile. After igniting the top, the pile was controlled to smolder naturally without open flame for 2-3 days. After the pile extinguished naturally, the internal ash was collected, which is the fire-soil ash. This preparation method enriches the ash with high-temperature potassium salts and mineral melts, significantly improving the soil's cation exchange capacity and aggregate stability.

[0133] Weigh out the decomposed crop straw, ash, and humic acid by weight, and put them into an air jet mill for ultrafine grinding. Control the gas-solid ratio to be 3:1 and grind until the particle size is ≤100μm to obtain an organic powder base material. Place hydroxyapatite crystals and struvite-modified straw biochar in a low-temperature plasma treatment device and perform surface activation treatment under the conditions of 400W power, 120s treatment time, and a mixed atmosphere of argon and oxygen. By introducing active functional groups to increase the surface roughness, an activated mineral substrate is obtained.

[0134] S2. Then, the activated mineral substrate was placed in an ultrasonic disperser and ultrasonically dispersed for 30 minutes at a frequency of 60 kHz using anhydrous ethanol as a medium to prevent nanoparticle aggregation.

[0135] S3. The shuttle repair agent and γ-polyglutamic acid polymer are added to a double cone rotary vacuum dryer and mixed for 15 minutes at 30 rpm and 35°C to form the first mixed powder. N-acetyl-5-methoxytryptamine is dissolved in anhydrous ethanol to prepare a spraying solution. The solution is sprayed into the mixed powder by atomization spraying. At the same time, the jacket heating of the vacuum dryer is turned on and the temperature is controlled not to exceed 40°C to obtain functional dry powder loaded with N-acetyl-5-methoxytryptamine.

[0136] S4. The organic powder base material and functional dry powder are put into a trough mixer and dry-mixed evenly. Then, microencapsulated active core material and compound microbial agent are added. The material is first sprayed with deionized water to wet the granulator disc, and then fed into the disc granulator. The disc inclination angle is controlled at 55° and the rotation speed is 35r / min, so that the organic powder base material and functional dry powder are coated on the crystal nucleus surface layer by layer to make wet granules with a particle size of 5mm. During the granulation process, a seaweed extract solution with a mass concentration of 3% is sprayed onto the disc surface at the same time as a granulation binder and root signal inducer.

[0137] The preparation method of microencapsulated active core material specifically includes the following steps:

[0138] Bird's guano-modified straw biochar was ground and passed through a 200-mesh sieve, then dried in a 105℃ oven to constant weight to obtain a dried biochar matrix. Low molecular weight chitosan was dissolved in a 1% (v / v) acetic acid solution to prepare a 3% (v / v) chitosan-acetic acid solution. Seaweed extract was dissolved in deionized water to prepare a 10% (v / v) seaweed extract solution. A compound microbial agent was mixed with sterile diatomaceous earth at a mass ratio of 1:5 to obtain a dry agent powder. The dried biochar matrix and the dry agent powder were weighed according to the formula ratio, and the seaweed extract solution and an appropriate amount of deionized water were added. The mixture was then kneaded until homogeneous to form a paste. A moist soft material is prepared; the moist soft material is placed in an extruder granulator to produce wet granules with a particle size of 2 mm; the wet granules are immersed in a chitosan acetate solution and stirred at low speed at 45°C for 40 min to allow chitosan to adsorb and initially crosslink on the surface and pores of the granules, forming a primary coating layer; the granules are then transferred to a 1.5% (w / w) calcium ion crosslinking agent solution and allowed to stand for crosslinking for 60 min to form a microcapsule gel network structure; the crosslinked microcapsule granules are filtered out, washed with deionized water until neutral, and placed in a freeze dryer for vacuum drying at -40°C for 24 h to obtain the microencapsulated active core material;

[0139] The preparation steps of the compound microbial agent specifically include the following steps:

[0140] Bacillus subtilis strain was inoculated into LB liquid medium and cultured at 37℃ and 180 rpm for 36 h with shaking to obtain primary seed culture. Bacillus laterosporus and Bacillus mucilaginosus were inoculated into their respective specialized fermentation media and cultured at 35℃ and 200 rpm for 48 h with shaking to obtain secondary seed cultures for each strain. The primary and secondary seed cultures were mixed at a volume ratio of 2:1:1 and transferred to a sterile fermenter for deep liquid fermentation. The dissolved oxygen content was controlled at 30%, the fermentation temperature was 37℃, and the fermentation time was 72 h to obtain the desired product. Composite fermentation broth; corn stalks were pyrolyzed at 550℃ for 2-3 hours under limited oxygen conditions to obtain porous biochar, which was then ground through a 100-200 mesh sieve to obtain a biochar carrier; the obtained composite fermentation broth and the biochar carrier were mixed at a mass-to-volume ratio of 10:1 and cultured with shaking at 28℃ and 200 rpm for 10-14 hours to allow the microorganisms to be fully loaded into the porous structure of the biochar; then 4% of the total mass of the fermentation broth was added as sterile diatomaceous earth as an adsorption carrier, stirred evenly, and then dried in a vacuum freeze dryer and pulverized through a 70 mesh sieve to obtain the carbon-supported composite microbial agent;

[0141] Brown algae raw material was washed, dried, and pulverized. A crude alginate extract was obtained through enzymatic hydrolysis. After separation and purification, a brown algae oligosaccharide solution and alginate hydrolysate powder were obtained. The molecular weight of the brown algae oligosaccharide was 3000 Da, and the purity of fucoxanthin was not less than 10%. An equal amount of brown algae raw material was extracted with ethanol, then further extracted and separated by column chromatography to obtain a concentrated fucoxanthin solution. The brown algae oligosaccharide solution and the concentrated fucoxanthin solution were mixed at a mass ratio of 3:1, spray-dried, and then physically blended with the alginate hydrolysate powder to obtain the seaweed extract.

[0142] S5. The wet granules are fed into a belt dryer for the first stage of drying, which involves drying with hot air at 50°C for 30 min to remove free water from the surface of the granules. The granules are then transferred to the second stage of drying, where they are dried with hot air at 60°C for 20 min to remove bound water from the interior of the granules. At the end of the drying process, a layer of low molecular weight chitosan film-forming liquid with a mass fraction of 2% is atomized and sprayed onto the surface of the granules. Then, hot air is immediately introduced for instantaneous cross-linking and curing, forming an outer protective film on the surface of the granules that has the function of swelling and retaining water upon contact with water.

[0143] S6. After the dried granules are naturally cooled to room temperature, they are put into a spherical polishing machine. The friction between the granules is used to remove the sharp edges and form micro-cracks on the surface. Then, they are passed through a 5mm sieve to remove fine powder and large pieces, resulting in organic fertilizer based on the process of smoldering fire ash and biochar loading.

[0144] Example 3: An organic fertilizer based on a process of loading smoldering fire ash and biochar, comprising: 45 parts of decomposed crop straw, 35 parts of fire ash, 5 parts of humic acid, 4 parts of superabsorbent resin, 7 parts of struvite-modified straw biochar, 1 part of low molecular weight chitosan, 2 parts of seaweed extract, 1.5 parts of composite microbial agent, 7 parts of microencapsulated active core material, 8 parts of hydroxyapatite crystals, 4 parts of γ-polyglutamic acid polymer, 4 parts of N-acetyl-5-methoxytryptamine, and 3 parts of shuttle repair agent.

[0145]

[0146] A method for preparing organic fertilizer based on smoldering fire ash and biochar loading process includes the following steps:

[0147] S1. The ash is prepared by the smoldering and smoldering method:

[0148] Tobacco straw, red clay, and sandy loam were mixed in a mass ratio of 4:1:1 and stacked in layers to form a hollow cone-shaped pile. After igniting the top, the pile was controlled to smolder naturally without open flame for 2-3 days. After the pile extinguished naturally, the internal ash was collected, which is the fire-soil ash. This preparation method enriches the ash with high-temperature potassium salts and mineral melts, significantly improving the soil's cation exchange capacity and aggregate stability.

[0149] Weigh out the decomposed crop straw, firewood ash and humic acid by weight, put them into an air jet mill for ultrafine grinding, control the gas-solid ratio to be 2:1, and grind them to a particle size ≤100μm to obtain an organic powder base material; place hydroxyapatite crystals and struvite-modified straw biochar in a low-temperature plasma treatment device, and perform surface activation treatment under the conditions of 300W power, 90s treatment time and argon and oxygen mixed gas atmosphere, and increase the surface roughness by introducing active functional groups to obtain activated mineral substrate;

[0150] S2. The activated mineral substrate was then placed in an ultrasonic disperser and ultrasonically dispersed for 25 minutes at a frequency of 50 kHz using anhydrous ethanol as a medium to prevent nanoparticle aggregation.

[0151] S3. The shuttle repair agent and γ-polyglutamic acid polymer are added to a double cone rotary vacuum dryer and mixed for 13 minutes at 25 rpm and 30°C to form the first mixed powder. N-acetyl-5-methoxytryptamine is dissolved in anhydrous ethanol to prepare a spraying solution. The solution is sprayed into the mixed powder by atomization spraying. At the same time, the jacket heating of the vacuum dryer is turned on and the temperature is controlled not to exceed 40°C to obtain functional dry powder loaded with N-acetyl-5-methoxytryptamine.

[0152] S4. The organic powder base material and functional dry powder are put into a trough mixer and dry mixed evenly. Then, microencapsulated active core material and compound microbial agent are added. The surface of the granulator is first sprayed with deionized water to wet it. Then, the material is fed into the disc granulator. The disc inclination angle is controlled at 50° and the rotation speed is 30r / min. The organic powder base material and functional dry powder are coated on the surface of the crystal nucleus layer by layer to make wet granules with a particle size of 4mm. During the granulation process, a seaweed extract solution with a mass concentration of 2% is sprayed onto the disc surface at the same time as a granulation binder and root signal inducer.

[0153] The preparation method of microencapsulated active core material specifically includes the following steps:

[0154] Bird's guano-modified straw biochar was ground and passed through a 150-mesh sieve, then dried in an oven at 105℃ until constant weight to obtain a dried biochar matrix. Low molecular weight chitosan was dissolved in a 2% (v / v) acetic acid solution to prepare a 2% (w / v) chitosan-acetic acid solution. Seaweed extract was dissolved in deionized water to prepare an 8% (w / v) seaweed extract solution. A compound microbial agent was mixed with sterile diatomaceous earth at a mass ratio of 1:4 to obtain a dry agent powder. The dried biochar matrix and the dry agent powder were weighed according to the formula ratio, and the seaweed extract solution and an appropriate amount of deionized water were added. The mixture was then kneaded until homogeneous to form a paste. A moist soft material is prepared; the moist soft material is placed in an extruder granulator to produce wet granules with a particle size of 1 mm; the wet granules are immersed in a chitosan acetate solution and stirred at low speed for 30 min at 40 °C to allow chitosan to adsorb and initially crosslink on the surface and pores of the granules, forming a primary coating layer; then the granules are transferred to a 1% (w / w) calcium ion crosslinking agent solution and allowed to stand for crosslinking for 45 min to form a microcapsule gel network structure; the crosslinked microcapsule granules are filtered out, washed with deionized water until neutral, and placed in a freeze dryer for vacuum drying at -40 °C for 18 h to obtain the microencapsulated active core material;

[0155] The preparation steps of the compound microbial agent specifically include the following steps:

[0156] Bacillus subtilis strain was inoculated into LB liquid medium and cultured at 37℃ and 180 rpm for 30 h with shaking to obtain primary seed culture. Bacillus laterosporus and Bacillus mucilaginosus were inoculated into their respective specialized fermentation media and cultured at 33℃ and 200 rpm for 38 h with shaking to obtain secondary seed cultures for each strain. The primary and secondary seed cultures were mixed at a volume ratio of 1:1:1 and transferred to a sterile fermenter for deep liquid fermentation. The dissolved oxygen content was controlled at 20%, the fermentation temperature was 34℃, and the fermentation time was 60 h to obtain the desired product. Composite fermentation broth; corn stalks were pyrolyzed at 550℃ for 2-3 hours under limited oxygen conditions to obtain porous biochar, which was then ground through a 100-200 mesh sieve to obtain a biochar carrier; the obtained composite fermentation broth and the biochar carrier were mixed at a mass-to-volume ratio of 10:1 and cultured with shaking at 28℃ and 200 rpm for 10-14 hours to allow the microorganisms to be fully loaded into the porous structure of the biochar; then 4% of the total mass of the fermentation broth was added as sterile diatomaceous earth as an adsorption carrier, stirred evenly, and then dried in a vacuum freeze dryer and pulverized through a 70 mesh sieve to obtain the carbon-supported composite microbial agent;

[0157] Brown algae raw material was washed, dried, and pulverized. A crude alginate extract was obtained through enzymatic hydrolysis. After separation and purification, a brown algae oligosaccharide solution and alginate hydrolysate powder were obtained. The molecular weight of the brown algae oligosaccharide was 2000 Da, and the purity of fucoxanthin was not less than 10%. An equal amount of brown algae raw material was extracted with ethanol, then extracted and separated by column chromatography to obtain a concentrated fucoxanthin solution. The brown algae oligosaccharide solution and the concentrated fucoxanthin solution were mixed at a mass ratio of 4:1, spray-dried, and then physically blended with the alginate hydrolysate powder to obtain the seaweed extract.

[0158] S5. The wet granules are fed into a belt dryer to perform the first stage of drying, which involves drying with hot air at 48°C for 25 min to remove free water from the surface of the granules. The granules are then transferred to the second stage of drying, where they are dried with hot air at 58°C for 17 min to remove bound water from the inside of the granules. At the end of the drying process, a layer of low molecular weight chitosan film-forming liquid with a mass fraction of 1% is atomized and sprayed onto the surface of the granules. Then, hot air is immediately introduced for instantaneous cross-linking and curing to form an outer protective film on the surface of the granules that has the function of swelling and retaining water upon contact with water.

[0159] S6. After the dried granules are naturally cooled to room temperature, they are put into a spherical polishing machine. The friction between the granules is used to remove the sharp edges and form micro-cracks on the surface. Then, they are passed through a 4mm sieve to remove fine powder and large pieces, resulting in organic fertilizer based on the process of smoldering fire ash and biochar loading.

[0160] Comparative experiments and effect verification:

[0161] To verify the actual effect of the formula of the present invention, the organic fertilizers prepared in Examples 1, 2 and 3 were selected and compared with commercially available conventional tobacco-specific organic fertilizers (control group, whose main components are well-rotted farmyard manure + nitrogen, phosphorus and potassium compound fertilizer, without the above-mentioned functional additives) in a comparative test.

[0162] Experimental location: A typical mountainous tobacco field in Hunan Province (slope of approximately 25°, red soil);

[0163] Test crop: Yunyan 87;

[0164] Fertilization method: Apply fertilizer in holes during transplanting, with a fertilizer application rate of 500 kg / mu;

[0165] Testing indicators: aggregate structure (>0.25mm%), tobacco yield, root activity, and soil available potassium content;

[0166] Experimental results:

[0167]

[0168] Conclusion Analysis:

[0169] Experimental data show that all groups applying the organic fertilizer of this invention are significantly better than the control group in all indicators; among them, Example 2 shows the best performance, for the following reasons:

[0170] Water retention and structural optimization: Due to the use of the highest proportion of nano-mineral skeleton building agent (9 parts) and modified porous biochar (8 parts), combined with gradient temperature-controlled drying and chitosan film-forming process, the soil aggregate structure was improved by nearly 78%, effectively resisting nutrient loss caused by mountain rainwater erosion.

[0171] Root promotion and stress resistance: The high-dose combination of physiological activator (melatonin, 5 parts) and seaweed extract (3 parts) significantly improved the root vitality and stress resistance of tobacco plants, especially during the drought stress period after transplanting. The tobacco seedlings in Example 2 recovered the fastest.

[0172] Nutrient enhancement: The synergistic effect of shuttle repair agent (4 parts) and bio-based enhancer (6 parts) effectively activated the potassium element fixed in the soil, resulting in an available potassium content of 178.3 mg / kg, which directly promoted the increase in tobacco yield (165.4 kg / mu).

[0173] In summary, the formulation and preparation parameters of Example 2 (such as 400W plasma treatment, 60kHz ultrasonic dispersion, and 5mm large particle size granulation) best leverage the core advantages of this invention in water retention and root promotion, making it a suitable preferred implementation scheme for mountainous tobacco-growing areas.

[0174] In this invention, unless otherwise explicitly specified and limited, the terms installation, setting, connection, fixing, screwing, etc., should be interpreted broadly. For example, they can refer to fixed connection, detachable connection, or integral connection; they can refer to mechanical connection or electrical connection; they can refer to direct connection or indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0175] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An organic fertilizer based on a smoldering fire ash and biochar loading process, characterized in that, The components, by weight, are as follows: decomposed crop straw: 40-50 parts, firewood ash: 30-40 parts, humic acid: 3-6 parts, water-retaining agent: 3-5 parts, modified porous biochar: 5-8 parts, low molecular weight chitosan: 0.5-1.5 parts, seaweed extract: 1-3 parts, compound microbial agent: 1-2 parts, microencapsulated active core material: 6-10 parts, nano-mineral skeleton building agent: 5-9 parts, bio-derived synergist: 2-6 parts, physiological activator: 3-5 parts, shuttle repair agent: 1-4 parts; The nano-mineral skeleton building agent is a hydroxyapatite crystal with a nanorod-like structure, the length of which is 50-200 nm and the diameter is 10-20 nm. The bio-derived synergist is a γ-polyglutamic acid polymer with a molecular weight between 500,000 and 2,000,000 Da; The physiological activator is melatonin with a purity of not less than 99%, specifically N-acetyl-5-methoxytryptamine.

2. The organic fertilizer based on the smoldering fire ash and biochar loading process according to claim 1, characterized in that: The decomposed crop straw is one of the following: corn, wheat, rice, soybean, cotton, or rapeseed crop straw after decomposition treatment; The ash is a product prepared by smoldering and heating tobacco straw, red clay and sandy loam. The humic acid is one or a mixture of humic acid and humate salts; The water-retaining agent is one or more of the following: superabsorbent resin and polyacrylamide. The modified porous biochar is one or a mixture of two of phosphate-modified straw biochar and struvite-modified straw biochar. The low molecular weight chitosan is one of the deacetylated products of chitin.

3. An organic fertilizer based on a smoldering fire ash and biochar loading process according to claim 2, characterized in that: The seaweed extract is a mixture of fucoidan oligosaccharide, alginate hydrolysate, and fucoxanthin; wherein the mass ratio of fucoidan oligosaccharide, alginate hydrolysate, and fucoxanthin is 4:3:

1. The compound microbial agent is a mixture of Bacillus subtilis, Bacillus lateralis, and Bacillus mucilaginosus. The microencapsulated active core material is a microecological particle with a sustained-release function, comprising one of the following: modified porous biochar, low molecular weight chitosan, seaweed extract, and compound microbial agent.

4. An organic fertilizer based on a smoldering fire ash and biochar loading process according to claim 3, characterized in that: The shuttle repair agent is a composite material in which biochar is used as a carrier to support sulfur-modified nano-zero-valent iron, wherein the sulfur-iron molar ratio is 0.1-0.

3.

5. An organic fertilizer based on a smoldering fire ash and biochar loading process according to claim 4, characterized in that: The preparation steps of the seaweed extract specifically include the following steps: A1. Take brown algae raw material, wash and dry it, then crush it. Extract it by enzymatic hydrolysis to obtain crude alginate extract. After separation and purification, obtain a fucoidan solution and alginate hydrolysate powder. The molecular weight of the fucoidan is 1000-3000 Da, and the purity of the fucoxanthin is not less than 10%. A2. Take an equal amount of brown algae raw material and extract it with ethanol, extract it and separate it by column chromatography to obtain fucoxanthin concentrate; A3. Mix the brown algae oligosaccharide solution and the fucoxanthin concentrate at a mass ratio of 5:1-3:1, spray dry, and then physically blend with the brown alginic acid hydrolysate powder to obtain the seaweed extract.

6. An organic fertilizer based on a smoldering fire ash and biochar loading process according to claim 5, characterized in that: The preparation steps of the compound microbial agent specifically include the following steps: B1. Inoculate Bacillus subtilis strain into LB liquid medium and culture at 37℃ and 180 rpm for 24-36 h with shaking to obtain primary seed culture; Inoculate Bacillus laterosporus and Bacillus mucilaginosus into their respective dedicated fermentation media and culture at 30-35℃ and 200 rpm for 24-48 h with shaking to obtain secondary seed culture for each strain. B2. Mix the primary seed liquid and the secondary seed liquid in a volume ratio of 1:1:1-2:1:1, transfer them to a sterile fermenter for deep liquid fermentation, control the dissolved oxygen content at 20-30%, the fermentation temperature at 30-37℃, and the fermentation time at 48-72h to obtain a compound fermentation liquid. B3. Take corn stalks and pyrolyze them at 550℃ for 2-3 hours under limited oxygen conditions to obtain biochar, which is then ground through a 100-200 mesh sieve. The composite fermentation broth and the above-mentioned biochar were mixed at a mass-to-volume ratio of 10:1 and cultured under shaking conditions at 25-30℃ and 180-200 rpm for 10-14 hours to allow the bacteria to be loaded into the pores of the biochar. Then, 3-5% of the total mass of the fermentation broth was added as an adsorption carrier, stirred evenly, and then freeze-dried under vacuum. The mixture was then pulverized and passed through a 60-80 mesh sieve to obtain the composite microbial agent. The number of viable bacteria in the compound microbial agent is not less than 1×10¹. 0 CFU / g, in which the ratio of viable Bacillus subtilis, Bacillus lateralis, and Bacillus mucilaginosus is 3:1:

1.

7. An organic fertilizer based on a smoldering fire ash and biochar loading process according to claim 6, characterized in that: The preparation method of the microencapsulated active core material specifically includes the following steps: C1. Modified porous biochar is ground and passed through a 100-200 mesh sieve, then dried in an oven at 105℃ to constant weight to obtain a dried biochar matrix; low molecular weight chitosan is dissolved in a 1-3% (v / v) acetic acid solution to prepare a 1-3% (w / v) chitosan acetate solution; seaweed extract is dissolved in deionized water to prepare a 5-10% (w / v) seaweed extract solution; the compound microbial agent is mixed with sterile diatomaceous earth at a mass ratio of 1:3-1:5 to obtain a dry powder of the agent. C2. Weigh the dried biochar matrix and bacterial agent powder according to the formula ratio, add seaweed extract and an appropriate amount of deionized water, and mix them evenly through a kneader to form a moist soft material; place the moist soft material in an extrusion granulator to make wet granules with a particle size of 0.5-2mm. C3. Immerse the wet particles in a chitosan acetate solution and stir at low speed for 20-40 minutes at 35-45℃ to allow chitosan to adsorb and initially crosslink on the particle surface and in the pores, forming a primary coating layer; then transfer the particles to a calcium ion crosslinking agent solution with a mass fraction of 0.5-1.5% and let them stand for crosslinking for 30-60 minutes to form a microcapsule gel network structure. C4. Filter out the cross-linked microcapsule particles, wash them with deionized water until neutral, place them in a freeze dryer, and vacuum dry them at -40°C for 12-24 hours to obtain the microencapsulated active core material. The modified porous biochar is one of phosphate-modified straw biochar or struvite-modified straw biochar. The calcium ion crosslinking agent is one or a mixture of calcium chloride, calcium lactate, or calcium gluconate.

8. A method for preparing organic fertilizer based on a smoldering fire ash and biochar loading process according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Select tobacco straw, red clay and sandy loam as raw materials, and stack them in layers at a mass ratio of 3-5:1:1 to build a hollow cone stack. After ignition, control it to a state of natural smoldering without open flame for 2-3 days. After natural extinguishing, collect the ash, which is the fire ash. Separately perform physical activation and surface modification treatment on decomposed crop straw, fire ash, humic acid and nano-mineral skeleton building agent, and modified porous biochar. S2. Subsequently, the activated mineral substrate is placed in an ultrasonic disperser and ultrasonically dispersed for 20-30 minutes at a frequency of 40-60kHz using anhydrous ethanol as the medium to prevent nanoparticle aggregation. S3. Add the shuttle repair agent and the bio-derived synergist to the double cone rotary vacuum dryer and mix for 10-15 minutes at a speed of 20-30 rpm and a temperature of 25-35℃ to form the first mixed powder. Dissolve the physiological activator in anhydrous ethanol to prepare a spray solution. Spray the solution into the mixed powder using an atomization spraying method. At the same time, turn on the jacket heating of the vacuum dryer and control the temperature to not exceed 40℃ to obtain a functional dry powder loaded with physiological activator. S4. The organic powder base material and functional dry powder are put into a trough mixer and dry-mixed evenly. Then, microencapsulated active core material and compound microbial agent are added. The material is first sprayed with deionized water to wet the granulator disc, and then fed into the disc granulator. The disc inclination angle is controlled at 45°-55° and the rotation speed is 25-35r / min, so that the organic powder base material and functional dry powder are coated on the crystal nucleus surface layer by layer to form wet granules with a particle size of 3-5mm. During the granulation process, a seaweed extract solution with a mass concentration of 1-3% is sprayed onto the disc surface at the same time as a granulation binder and root signal inducer. S5. Perform segmented temperature-controlled drying on wet particles, and use low molecular weight chitosan for surface film formation and cross-linking curing at the end of the drying process. S6. After the dried granules are naturally cooled to room temperature, they are put into a spherical polishing machine. The friction between the granules is used to remove the sharp edges and form micro-cracks on the surface. Then, they are passed through a 3-5mm sieve to remove fine powder and large pieces, thus obtaining the organic fertilizer based on the smoldering fire ash and biochar loading process.

9. The method for preparing organic fertilizer based on a smoldering fire ash and biochar loading process according to claim 8, characterized in that, Step S1 specifically includes the following steps: S11. Weigh out the decomposed crop straw, firewood ash and humic acid by weight, put them into an air jet mill for ultra-fine grinding, control the gas-solid ratio to be 2:1-3:1, grind to a particle size ≤100μm, and obtain organic powder base material. S12. The nano-mineral skeleton building agent and modified porous biochar are placed in a low-temperature plasma treatment device and surface activation treatment is carried out under the conditions of 200-400W power, 60-120s treatment time and argon and oxygen mixed gas. The surface roughness is increased by introducing active functional groups to obtain activated mineral substrate.

10. The method for preparing organic fertilizer based on a smoldering fire ash and biochar loading process according to claim 8, characterized in that, Step S5 specifically includes the following steps: S51. The wet granules are fed into a belt dryer to perform the first stage of drying, which involves drying with hot air at 45-50℃ for 20-30 minutes to remove free water from the surface of the granules. S52. Transfer the particles to the second stage of drying, and dry them with hot air at 55-60℃ for 15-20 min to remove the bound water inside the particles. S53. At the end of the drying process, a layer of low molecular weight chitosan film-forming liquid with a mass fraction of 1-2% is atomized and sprayed onto the surface of the particles. Then, hot air is immediately introduced for instant cross-linking and curing, forming an outer protective film on the surface of the particles that has the function of swelling and retaining water upon contact with water.

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