Organic-inorganic compound fertilizer containing functional microorganisms and production method of organic-inorganic compound fertilizer

Abstract

The invention relates to a functional microorganism-containing organic-inorganic compound fertilizer and a production method thereof, and relates to the technical field of fertilizers, the functional microorganism-containing organic-inorganic compound fertilizer comprises an inorganic core layer, an organic coating layer and a functional microorganism outer layer, the functional microorganism outer layer comprises the following components in parts by mass: 10-15 parts of compound functional microorganisms, 5-10 parts of synergistic growth-promoting microorganisms, 2-3 parts of trehalose, 1-2 parts of mannitol, 10-15 parts of sodium alginate, 8-10 parts of chitosan, 2-4 parts of a yeast extract and 30-40 parts of a modified activated carbon carrier. The production method comprises the following steps: preparing an inorganic core layer, preheating the inorganic core layer, and spraying and coating an organic coating layer material to obtain a primary product with an organic coating layer; and coating the surface of the organic coating layer of the primary product with a functional microorganism outer layer material, drying at low temperature, and screening to obtain the organic-inorganic compound fertilizer containing the functional microorganisms. The fertilizer has the effect of improving the slow release effect of the fertilizer and the survival rate of microorganisms.

Description

Technical Field

[0001] This application relates to the technical field of fertilizers, and in particular to an organic-inorganic compound fertilizer containing functional microorganisms and a production method thereof. Background Art

[0002] With the advancement of agricultural modernization, problems such as soil degradation and environmental pollution caused by the overuse of traditional chemical fertilizers have become increasingly prominent. Developing green and efficient fertilizers has become an inevitable trend for the sustainable development of agriculture. Organic-inorganic compound fertilizers combine the long-term effectiveness of organic fertilizers and the quick-acting nature of inorganic fertilizers, and have the dual advantages of improving soil and supplementing nutrients, and have become a research hotspot in the fertilizer field. However, existing compound fertilizers generally have defects such as the temporal and spatial misalignment of nutrient release and crop requirements, and single microbial functions, and it is difficult to meet the needs of precision agriculture.

[0003] The introduction of functional microorganisms provides a new idea for improving the performance of compound fertilizers. For example, functional strains such as nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, and potassium-solubilizing bacteria can improve nutrient utilization efficiency through biological transformation, while antagonistic strains can inhibit soil-borne diseases and enhance the stress resistance of crops. However, functional microorganisms face multiple challenges in the production and storage of fertilizers: the high-temperature granulation process is easy to damage the activity of strains, the high-salt environment of inorganic nutrients will inhibit microbial metabolism, and the organic acids generated during the composting process of organic fertilizers may also damage the strains. In addition, traditional carrier materials (such as peat and straw) have poor adsorption properties and are difficult to effectively protect the survival rate of microorganisms in complex environments. The low survival rate of microorganisms leads to poor functional stability and unstable fertilizer efficiency, and it is difficult to achieve long-term and continuous ecological benefits, so it needs to be improved. Summary of the Invention

[0004] In order to improve the survival rate of microorganisms, this application provides an organic-inorganic compound fertilizer containing functional microorganisms and a production method thereof.

[0005] An organic-inorganic compound fertilizer containing functional microorganisms and a production method thereof provided by this application adopt the following technical solutions: In the first aspect, an organic-inorganic compound fertilizer containing functional microorganisms provided by this application adopts the following technical solutions: An organic-inorganic compound fertilizer containing functional microorganisms includes an inorganic core layer, an organic coating layer, and a functional microorganism outer layer. The functional microorganism outer layer includes the following components in parts by mass: Compound functional microorganisms 10 - 15 parts Synergistic growth-promoting microorganisms 5 - 10 parts Trehalose 2 - 3 parts Mannitol 1 - 2 parts Sodium alginate 10 - 15 parts Chitosan 8 - 10 parts Yeast extract 2 - 4 parts 30 - 40 parts of modified activated carbon carrier.

[0006] Through the triple - structure design of the inorganic core layer - organic coating layer - functional microorganism outer layer, the fertilizer realizes the synergistic effect of microorganism protection and nutrient slow - release; the inorganic core layer provides quick - acting nutrients; the organic coating layer delays the rapid release of inorganic nutrients through coating and blocks the direct harm of high salt in the inorganic core layer to microorganisms. Its porous structure can also promote the colonization of microorganisms and provide energy for microbial metabolism; the composite functional microorganisms and synergistic growth - promoting microorganisms form a symbiotic network through metabolic complementarity, secrete extracellular enzymes and antibiotics, and enhance the ability of soil nutrient activation and disease inhibition; sodium alginate and chitosan form pH - responsive microcapsules through ionic cross - linking. Its three - dimensional network structure allows nutrient diffusion and shields the damage of the external high - salt environment to microorganisms; trehalose and mannitol, as vitrification protectants, stabilize the microbial cell membrane by forming an amorphous matrix; after modification, the modified activated carbon carrier can adsorb and immobilize microorganisms and provide a micro - anaerobic environment to promote denitrification; nucleotides and amino acids in yeast extract are used as microbial nutrient reserves to maintain cell metabolic activity during storage; the functional microorganism outer layer combines physical embedding, chemical protection and biological functions to keep microorganisms active during the production process and long - term storage, and extends the nutrient release period through the carrier adsorption and microcapsule controlled - release mechanism, achieving a double improvement in the long - term effectiveness of the fertilizer and microbial functions.

[0007] Preferably, the composite functional microorganisms include Enterobacter cloacae, Pseudomonas sp., and Bacillus licheniformis.

[0008] Indole - 3 - acetic acid secreted by Enterobacter cloacae can stimulate the growth of crop roots and expand the nutrient absorption area; Pseudomonas sp. secretes acid phosphatase and glucosidase to convert insoluble phosphorus in the soil into available forms, and at the same time releases potassium ions in mica and feldspar through potassium channel proteins; Bacillus licheniformis secretes lipopeptide antibiotics to inhibit the proliferation of soil - borne pathogens such as Fusarium oxysporum; the three strains form a micro - ecological network in the porous structure of the modified activated carbon carrier under the protection of microcapsules, regulate the secretion of extracellular enzymes through quorum - sensing signals, and enhance stress resistance; in addition, the extracellular polysaccharide produced by Enterobacter cloacae and alginic acid secreted by Pseudomonas sp. jointly form a biofilm, which wraps the outer layer of microorganisms, synergistically resists the high - salt environment, and improves the survival rate of microorganisms.

[0009] Preferably, the synergistic growth - promoting microorganisms include Bacillus subtilis, Trichoderma harzianum, and Lactobacillus plantarum.

[0010] The lipopeptide antibiotics secreted by Bacillus subtilis and the chitinase produced by Trichoderma harzianum form a synergistic antibacterial network to inhibit soil-borne pathogenic fungi such as Fusarium; Lactobacillus plantarum secretes lactic acid to lower the rhizosphere pH value and promote the iron activation efficiency of iron carrier-secreting bacteria such as Pseudomonas; the three strains form microecological niche differentiation in the mesoporous structure of the microcapsule and the modified activated carbon carrier: Bacillus subtilis occupies the microporous adsorption site to form a biofilm barrier, the hyphae of Trichoderma harzianum penetrate the carrier pores to secrete extracellular enzymes, and Lactobacillus plantarum colonizes on the carrier surface to regulate the microenvironment osmotic pressure, thereby improving the survival rate of microorganisms in complex environments and enhancing the performance of fertilizers.

[0011] Preferably, the preparation raw materials of the modified activated carbon carrier include activated activated carbon, acrylic acid and melamine.

[0012] Activated activated carbon has a rich mesoporous structure and a high specific surface area, providing physical colonization sites for microorganisms; the acrylic acid grafting reaction introduces carboxyl groups on the surface of activated carbon, improving the microbial loading capacity through electrostatic adsorption and enhancing the ion exchange ability for ammonium nitrogen; the melamine cross-linking reaction further forms a three-dimensional network structure containing amino groups, whose alkaline environment inhibits the proliferation of miscellaneous bacteria and can release fixed nutrients through protonation under acidic conditions; the density of carboxyl and amino groups on the surface of the modified carrier increases, and can form hydrogen bonds with carboxylate in the microcapsule, enhancing the embedding stability; its mesoporous structure can adsorb active substances to form an organic-inorganic complex, playing a slow-release role through physical retention and chemical chelation, thereby improving the microbial survival rate and slow-release performance of fertilizers.

[0013] Preferably, the modified activated carbon carrier is prepared by the following steps: Disperse the activated activated carbon in a solvent, add acrylic acid and ammonium persulfate, adjust the pH to acidic, remove oxygen by passing neutral gas, heat and stir for reaction, then wash and dry to obtain the preliminarily modified activated carbon; add the preliminarily modified activated carbon prepared above to an alkaline solution for ultrasonic dispersion, add melamine, heat and react, then wash to neutrality, dry, grind and sieve to obtain the modified activated carbon carrier.

[0014] The modified activated carbon carrier prepared according to the above steps has good adsorption performance, can effectively store microbial microcapsules, improve the survival rate of microorganisms, and enhance the slow-release performance of fertilizers through physical and chemical effects.

[0015] Preferably, the inorganic core layer includes ammonium phosphate, potassium nitrate and magnesium sulfate.

[0016] Ammonium phosphate provides high-concentration basic nutrients of nitrogen and phosphorus. Its ammonium nitrogen and orthophosphate dissociate rapidly in the soil to meet the nutrient requirements of crop seedlings. Potassium nitrate supplements potassium and regulates the soil redox potential, promoting the absorption of calcium and magnesium by the roots. Magnesium sulfate activates the activities of soil urease and phosphatase by providing magnesium ions, accelerating the mineralization of organic nitrogen and phosphorus. The difference in solubility of the three salts in water forms a gradient dissolution effect, resulting in a low initial release rate of nitrogen, phosphorus, and potassium. It acts synergistically with the cross-linked membrane of the organic coating layer to extend the slow-release period of nitrogen. The weak acidity of magnesium sulfate can neutralize the alkaline environment of potassium nitrate, forming a slightly acidic microdomain, inhibiting the proliferation of miscellaneous bacteria while promoting the secretion of siderophores by functional bacteria, and enhancing the survival rate of microorganisms near the high-salt core layer. At the same time, through the dual mechanisms of rapid nutrient startup and slow-release regulation, a dynamic balance between crop nutrient supply and microbial function is achieved.

[0017] Preferably, the raw materials for preparing the organic coating layer include decomposed animal manure, sodium lignosulfonate, modified starch-based materials, betaine, and polyglutamic acid.

[0018] The porous structure of decomposed animal manure and the modified starch-based material form a composite matrix that adsorbs and immobilizes functional microorganisms. Its natural humic acid chelates heavy metal ions and adjusts the soil pH to a neutral microdomain. Sodium lignosulfonate and starch are cross-linked through ester bonds to form a semi-permeable membrane, delaying the rapid release of inorganic nutrients and at the same time blocking the direct damage of the high-salt environment in the core layer to microorganisms. Betaine, as an osmoprotectant, maintains the integrity of the microbial cell membrane under dry or high-salt conditions. Polyglutamic acid regulates the hydrophilicity of the membrane by chelating calcium, magnesium and other ions, promoting the uniform diffusion of nutrients. The organic coating layer delays the release of the inorganic core layer and enhances the survival rate of microorganisms through the triple mechanisms of physical adsorption, chemical cross-linking, and biocompatibility.

[0019] Preferably, the raw materials for preparing the modified starch-based material include hydroxypropyl starch, humic acid, and potassium fulvate.

[0020] The three-dimensional network structure formed by hydroxypropyl starch after etherification reaction provides mechanical support. Its hydroxyl and carboxyl groups are cross-linked with the aromatic ring structure of humic acid and potassium fulvate through hydrogen bonds to form a semi-permeable membrane, delaying the dissolution rate of inorganic nutrients. Humic acid is embedded in the starch matrix through π-π conjugation. Its rich carboxylic acid groups chelate iron, aluminum and other ions in the fertilizer, inhibiting the fixation of phosphate and enhancing the release rate of phosphorus. The low-molecular-weight humic acid fragments of potassium fulvate penetrate into the starch micropores and adsorb ammonium nitrogen through ion exchange to form a slow-release system with dynamic balance. After further cross-linking the modified starch-based material with sodium lignosulfonate and combining with the osmoprotective effect of betaine, the survival rate of microorganisms is enhanced. The biostimulation effect of humic acid and potassium fulvate promotes microorganisms to secrete extracellular polysaccharides, forming a composite protective layer with the microcapsule, and enhancing the stability of the organic coating layer and the slow-release effect through cation bridging in the soil.

[0021] Preferably, the mass ratio of the hydroxypropyl starch, humic acid and potassium fulvate is 1:1.2:(0.3 - 0.5).

[0022] The modified starch-based material prepared according to the above mass ratio can effectively improve the slow-release effect of the fertilizer and the survival rate of microorganisms.

[0023] In a second aspect, the present application provides a production method of an organic-inorganic compound fertilizer containing functional microorganisms, adopting the following technical solution: A production method of an organic-inorganic compound fertilizer containing functional microorganisms, comprising the following steps: Mix and stir the inorganic core layer, granulate, dry and screen to obtain the inorganic core layer; preheat the inorganic core layer, spray and coat the organic coating layer material to obtain a preliminary product with an organic coating layer; coat the functional microorganism outer layer material on the surface of the organic coating layer of the preliminary product, dry at low temperature and screen to obtain an organic-inorganic compound fertilizer containing functional microorganisms.

[0024] The organic-inorganic compound fertilizer containing functional microorganisms prepared according to the above steps has a good slow-release effect, the microorganisms have a high survival rate, can play their performance for a long time, and improve the utilization rate of nutrients.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: 1. Through the triple-structure design of the inorganic core layer - organic coating layer - functional microorganism outer layer, the synergistic effect of microorganism protection and nutrient slow release is realized; the inorganic core layer provides quick-acting nutrients; the organic coating layer delays the rapid release of inorganic nutrients through coating and blocks the direct damage of the high salt in the inorganic core layer to microorganisms, and its porous structure can also promote the colonization of microorganisms and provide energy for microbial metabolism; the composite functional microorganisms and synergistic growth-promoting microorganisms form a symbiotic network through metabolic complementarity, secrete extracellular enzymes and antibiotics, and enhance the ability of soil nutrient activation and disease inhibition; sodium alginate and chitosan form a pH-responsive microcapsule through ionic cross-linking, and its three-dimensional network structure allows nutrient diffusion and can shield the damage of the external high-salt environment to microorganisms; trehalose and mannitol, as vitrification protectants, stabilize the microbial cell membrane by forming an amorphous matrix; the modified activated carbon carrier can adsorb and fix microorganisms after modification, and at the same time provide a micro-anaerobic environment to promote denitrification; nucleotides and amino acids in yeast extract are used as microbial nutrient reserves to maintain cell metabolic activity during storage; the functional microorganism outer layer combines physical embedding, chemical protection and biological functions to keep the microorganisms active during the production process and long-term storage, and extends the nutrient release period through the carrier adsorption and microcapsule controlled-release mechanism, realizing the dual improvement of the long-term effectiveness of the fertilizer and the microbial function.

[0026] 2. The activated activated carbon has a rich mesoporous structure and a high specific surface area, providing physical colonization sites for microorganisms; the acrylic acid grafting reaction introduces carboxyl groups on the surface of the activated carbon, enhancing the microbial loading capacity through electrostatic adsorption and simultaneously enhancing the ion exchange capacity for ammonium nitrogen; the melamine cross-linking reaction further forms a three-dimensional network structure containing amino groups, whose alkaline environment inhibits the proliferation of miscellaneous bacteria and can release the fixed nutrients through protonation under acidic conditions; the density of carboxyl and amino groups on the surface of the modified carrier increases, enabling the formation of hydrogen bonds with carboxylate ions in the microcapsules and enhancing the embedding stability; its mesoporous structure can adsorb active substances to form an organic-inorganic complex, which plays a slow-release role through physical interception and chemical chelation, thereby improving the microbial survival rate and slow-release performance of the fertilizer.

[0027] 3. The three-dimensional network structure formed after the etherification reaction of hydroxypropyl starch provides mechanical support. Its hydroxyl and carboxyl groups are cross-linked with the aromatic ring structures of humic acid and potassium fulvate through hydrogen bonds to form a semi-permeable membrane, delaying the dissolution rate of inorganic nutrients; humic acid is embedded in the starch matrix through π-π conjugation. Its abundant carboxylic acid groups chelate metal ions such as iron and aluminum in the fertilizer, inhibiting the fixation of phosphates and increasing the release rate of phosphorus; the low-molecular-weight humic acid fragments of potassium fulvate penetrate into the starch micropores and adsorb ammonium nitrogen through ion exchange to form a slow-release system with dynamic equilibrium; after the modified starch-based material is further cross-linked with sodium lignosulfonate and combined with the osmotic protection effect of betaine, the survival rate of microorganisms is improved; the biostimulation effect of humic acid and potassium fulvate promotes microorganisms to secrete extracellular polysaccharides, which form a composite protective layer with microcapsules. In the soil, the stability of the organic coating layer is enhanced through cation bridging, improving the slow-release effect. Specific embodiments

[0028] The embodiments of the present application disclose an organic-inorganic compound fertilizer containing functional microorganisms and its production method. The raw materials used in the present application can be obtained from commercially available raw materials except as otherwise specified. The following further elaborates on the present application in conjunction with the embodiments: Raw material description: The oxidant is potassium hydroxide, acrylic acid (CAS No.: 79-10-7), melamine (CAS No.: 108-78-1), trehalose (CAS No.: 99-20-7), mannitol (CAS No.: 69-65-8), sodium alginate (CAS No.: 9005-38-3), chitosan (CAS No.: 9012-76-4), yeast extract (CAS No.: 8013-01-2), hydroxypropyl starch (CAS No.: 9049-76-7), humic acid (CAS No.: 1415-93-6). Potassium humate is purchased from Shandong Anquan Chemical Technology Co., Ltd. The decomposed animal manure selected is decomposed chicken manure, sodium lignosulfonate (CAS No.: 8061-51-6), betaine (CAS No.: 107-43-7), polyglutamic acid (CAS No.: 25513-46-6).

[0029] Example 1 Preparation of modified activated carbon carrier Mix activated carbon and the oxidant according to a mass ratio of 1:3, add deionized water and ultrasonicate for 30 min, with a solid-liquid ratio of 1:10. Under nitrogen protection, activate at 800 °C for 2 h, perform pickling and neutralization with 10% hydrochloric acid and then dry to obtain high-porosity activated carbon; add the high-porosity activated carbon to 20% hydrogen peroxide aqueous solution, with a solid-liquid ratio of 1:10, stir at 80 °C at a speed of 200 rpm for 4 h, wash with water until neutral, and dry at 60 °C to constant weight to obtain activated activated carbon; Disperse 61.2 g of activated activated carbon in deionized water, with a solid-liquid ratio of 1:10, add 18.36 g of acrylic acid and 0.4 g of ammonium persulfate, adjust the pH to 4, purge with nitrogen to remove oxygen, then stir and react at 60 °C at a speed of 200 rpm for 6 h, wash with ethanol, and dry at 60 °C to constant weight to obtain preliminarily modified activated carbon; add the preliminarily modified activated carbon prepared above to 0.1 mol / L sodium hydroxide aqueous solution for ultrasonic dispersion, with a solid-liquid ratio of 1:10, add 8 g of melamine, react at 70 °C for 4 hours, wash with water until neutral, dry at 60 °C to constant weight, grind and pass through a 100-mesh sieve to obtain the modified activated carbon carrier.

[0030] Preparation of functional microorganism outer layer material Cultivate 10 g of composite functional microorganisms and 5 g of synergistic growth-promoting microorganisms to the logarithmic growth phase respectively, with the viable cell count being 1*10 9 CFU / g. The composite functional microorganisms are composed of Enterobacter cloacae, Pseudomonas sp., and Bacillus licheniformis with a mass ratio of 1:2:2. The synergistic growth-promoting microorganisms are composed of Bacillus subtilis, Trichoderma harzianum, and Lactobacillus plantarum with a mass ratio of 2:1:1. Centrifuge to collect the bacterial cells, resuspend with sterile saline, and adjust the concentration to 3×10 9CFU / mL to obtain a resuspension for standby; Disperse 10 g of sodium alginate into 500 mL of deionized water to prepare a sodium alginate solution; Disperse 8 g of chitosan into 800 mL of 1% acetic acid solution to prepare a chitosan solution.

[0031] Disperse 2 g of trehalose and 1 g of mannitol into 100 mL of deionized water, add it to the resuspension to obtain a mixed solution; Add the mixed solution to the sodium alginate solution, stir while adding at a speed of 200 rpm, and finish adding within 30 min to obtain a microbial sodium alginate mixed solution; Add the microbial sodium alginate mixed solution to 2 L of liquid paraffin containing 5% Span 80, disperse it at a speed of 5000 rpm for 20 min to obtain an emulsion, add 650 mL of 3% calcium chloride aqueous solution to the emulsion, stir and react at a speed of 5000 rpm for 60 min, wash with petroleum ether after centrifugation to obtain a preliminarily embedded microcapsule.

[0032] Disperse the preliminarily embedded microcapsules into the chitosan solution, stir at a speed of 5000 rpm for 30 min, wash with deionized water after centrifugation to obtain microcapsules; Immerse the microcapsules in 200 mL of physiological saline solution containing 2 g of yeast extract, after soaking for 2 h, freeze-dry at -20 °C to obtain functional microbial microcapsules; Disperse the functional microbial microcapsules and 30 g of modified activated carbon carrier into deionized water, with a solid-liquid ratio of 1:3, stir at a speed of 200 rpm for 1 h to obtain a functional microbial outer layer material.

[0033] Prepare an organic coating layer material Disperse 20 g of hydroxypropyl starch, 24 g of humic acid and 6 g of potassium fulvate into 250 mL of deionized water, stir and mix at 80 °C at a speed of 200 rpm for 30 min to obtain a starch mixed solution, spray-dry the starch mixed solution, with an inlet air temperature of 160 - 180 °C and an outlet air temperature of 80 - 90 °C to obtain a modified starch-based material; Mix the above-prepared modified starch-based material, 50 g of well-rotted chicken manure, 30 g of sodium lignosulfonate, 5 g of betaine, 3 g of polyglutamic acid and 120 mL of deionized water, stir at a speed of 200 rpm to obtain an organic coating layer material.

[0034] Prepare an organic-inorganic compound fertilizer containing functional microorganisms Mix ammonium phosphate, potassium nitrate, and magnesium sulfate in the inorganic core layer in a mass ratio of 1:1:1, stir the mixture at a speed of 60 rpm for 30 min, perform disk granulation, and then dry it at 60°C until the water content is less than 5%. After screening, the inorganic core layer is obtained; preheat the inorganic core layer to 50°C, feed it into a coating machine, spray and coat the organic coating layer material, and control the coating weight gain at 10% to obtain a preliminary product with an organic coating layer; coat the functional microorganism outer layer material on the surface of the organic coating layer of the preliminary product through fluidized bed coating, dry it at a low temperature of 30°C for 2 h, and after screening, obtain an organic-inorganic compound fertilizer containing functional microorganisms.

[0035] Example 2 Prepare a modified activated carbon carrier Mix activated carbon and an oxidizing agent in a mass ratio of 1:3, add deionized water and ultrasonicate for 30 min, with a solid-liquid ratio of 1:10. Under nitrogen protection, activate at 800°C for 2 h, perform pickling and neutralization with 10% hydrochloric acid and then dry to obtain highly porous activated carbon; add the highly porous activated carbon to a 20% hydrogen peroxide aqueous solution, with a solid-liquid ratio of 1:10, stir at a speed of 200 rpm at 80°C for 4 h, wash with water until neutral, and dry at 60°C to constant weight to obtain activated activated carbon; Disperse 61.2 g of activated activated carbon in deionized water, with a solid-liquid ratio of 1:10, add 18.36 g of acrylic acid and 0.4 g of ammonium persulfate, adjust the pH to 4, remove oxygen by passing nitrogen, stir and react at a speed of 200 rpm at 60°C for 6 h, wash with ethanol, and dry at 60°C to constant weight to obtain preliminarily modified activated carbon; add the preliminarily modified activated carbon prepared above to a 0.1 mol / L sodium hydroxide aqueous solution for ultrasonic dispersion, with a solid-liquid ratio of 1:10, add 8 g of melamine, react at 70°C for 4 hours, wash with water until neutral, dry at 60°C to constant weight, grind, and pass through a 100-mesh sieve to obtain a modified activated carbon carrier.

[0036] Prepare a functional microorganism outer layer material Cultivate 15 g of composite functional microorganisms and 10 g of synergistic growth-promoting microorganisms to the logarithmic growth phase respectively, with a viable count of 1*109 CFU / g. The composite functional microorganisms are composed of Enterobacter cloacae, Pseudomonas sp., and Bacillus licheniformis in a mass ratio of 1:2:2, and the synergistic growth-promoting microorganisms are composed of Bacillus subtilis, Trichoderma harzianum, and Lactobacillus plantarum in a mass ratio of 2:1:1. Centrifuge to collect the bacterial cells, resuspend them with sterile physiological saline, and adjust the concentration to 3×10 9 CFU / mL to obtain a resuspension for standby; disperse 15 g of sodium alginate in 500 mL of deionized water to prepare a sodium alginate solution; disperse 10 g of chitosan in 800 mL of 1% acetic acid solution to prepare a chitosan solution.

[0037] Disperse 3 g of trehalose and 2 g of mannitol into 100 mL of deionized water, add it to the resuspension to obtain a mixed solution; add the mixed solution to the sodium alginate solution, stir while adding at a speed of 200 rpm, and finish adding within 30 min to obtain a microbial sodium alginate mixed solution; add the microbial sodium alginate mixed solution to 2 L of liquid paraffin containing 5% Span 80, disperse it at a speed of 5000 rpm for 20 min to obtain an emulsion, add 650 mL of an aqueous calcium chloride solution with a mass concentration of 3% to the emulsion, stir and react at a speed of 5000 rpm for 60 min, wash with petroleum ether after centrifugation to obtain a preliminarily embedded microcapsule.

[0038] Disperse the preliminarily embedded microcapsule into the chitosan solution, stir at a speed of 5000 rpm for 30 min, wash with deionized water after centrifugation to obtain a microcapsule; soak the microcapsule in 200 mL of a physiological saline solution containing 4 g of yeast extract, after soaking for 2 h, freeze-dry at -20 °C to obtain a functional microbial microcapsule; disperse the functional microbial microcapsule and 40 g of modified activated carbon carrier into deionized water with a solid-liquid ratio of 1:3, stir at a speed of 200 rpm for 1 h to obtain a functional microbial outer layer material.

[0039] Prepare an organic coating layer material Disperse 18.52 g of hydroxypropyl starch, 22.22 g of humic acid, and 9.26 g of potassium fulvate into 250 mL of deionized water, stir and mix at 80 °C at a speed of 200 rpm for 30 min to obtain a starch mixed solution, spray-dry the starch mixed solution with an inlet air temperature of 160 - 180 °C and an outlet air temperature of 80 - 90 °C to obtain a modified starch-based material; mix the above-prepared modified starch-based material, 50 g of well-rotted chicken manure, 30 g of sodium lignosulfonate, 5 g of betaine, 3 g of polyglutamic acid, and 120 mL of deionized water, stir at a speed of 200 rpm to obtain an organic coating layer material.

[0040] Prepare an organic-inorganic compound fertilizer containing functional microorganisms Mix ammonium phosphate, potassium nitrate, and magnesium sulfate in the inorganic core layer according to a mass ratio of 1:1:1, stir and mix at a speed of 60 rpm for 30 min, pelletize by disk granulation and dry at 60 °C until the water content is lower than 5%, and obtain the inorganic core layer after screening; preheat the inorganic core layer to 50 °C, send it into a coating machine, spray and coat the organic coating layer material, and control the coating weight gain at 10% to obtain a preliminary product with an organic coating layer; coat the functional microbial outer layer material on the surface of the organic coating layer of the preliminary product through fluidized bed coating, dry at 30 °C for 2 h, and obtain an organic-inorganic compound fertilizer containing functional microorganisms after screening.

[0041] Example 3 Prepare a modified activated carbon carrier Mix activated carbon and an oxidant in a mass ratio of 1:3, add deionized water and ultrasonicate for 30 min with a solid-liquid ratio of 1:10. Under nitrogen protection, activate at 800 °C for 2 h, perform pickling and neutralization with 10% hydrochloric acid and then dry to obtain high-porosity activated carbon; add the high-porosity activated carbon to a 20% hydrogen peroxide aqueous solution with a solid-liquid ratio of 1:10, stir at 80 °C at a speed of 200 rpm for 4 h, wash with water until neutral, and dry at 60 °C to constant weight to obtain activated activated carbon; Disperse 61.2 g of activated activated carbon in deionized water with a solid-liquid ratio of 1:10, add 18.36 g of acrylic acid and 0.4 g of ammonium persulfate, adjust the pH to 4, purge with nitrogen to remove oxygen, and then stir and react at 60 °C at a speed of 200 rpm for 6 h. After washing with ethanol, dry at 60 °C to constant weight to obtain preliminarily modified activated carbon; add the preliminarily modified activated carbon prepared above to a 0.1 mol / L sodium hydroxide aqueous solution for ultrasonic dispersion with a solid-liquid ratio of 1:10, add 8 g of melamine, react at 70 °C for 4 hours, wash with water until neutral, dry at 60 °C to constant weight, grind and pass through a 100-mesh sieve to obtain a modified activated carbon carrier.

[0042] Prepare the outer material of functional microorganisms Cultivate 12.5 g of composite functional microorganisms and 7.5 g of synergistic growth-promoting microorganisms to the logarithmic growth phase with a viable cell count of 1×10⁹ CFU / g. The composite functional microorganisms are composed of Enterobacter cloacae, Pseudomonas sp., and Bacillus licheniformis in a mass ratio of 1:2:2, and the synergistic growth-promoting microorganisms are composed of Bacillus subtilis, Trichoderma harzianum, and Lactobacillus plantarum in a mass ratio of 2:1:1. Centrifuge to collect the cells, resuspend with sterile normal saline, and adjust the concentration to 3×10 9 CFU / mL to obtain a resuspended solution for standby; disperse 12.5 g of sodium alginate in 500 mL of deionized water to prepare a sodium alginate solution; disperse 9 g of chitosan in 800 mL of 1% acetic acid solution to prepare a chitosan solution.

[0043] Disperse 2.5 g of trehalose and 1.5 g of mannitol in 100 mL of deionized water, add to the resuspended solution to obtain a mixed solution; add the mixed solution to the sodium alginate solution and stir while adding at a speed of 200 rpm, and finish adding within 30 min to obtain a microbial sodium alginate mixed solution; add the microbial sodium alginate mixed solution to 2 L of liquid paraffin containing 5% Span 80 and disperse at a speed of 5000 rpm for 20 min to obtain an emulsion. Add 650 mL of a 3% calcium chloride aqueous solution to the emulsion and stir and react at a speed of 5000 rpm for 60 min. After centrifugation, wash with petroleum ether to obtain a preliminarily embedded microcapsule.

[0044] Disperse the preliminarily embedded microcapsules into the chitosan solution, stir at a speed of 5000 rpm for 30 min, wash with deionized water after centrifugation to obtain microcapsules; soak the microcapsules in 200 mL of physiological saline solution containing 3 g of yeast extract, after soaking for 2 h, freeze-dry at -20 °C to obtain functional microbial microcapsules; disperse the functional microbial microcapsules and 35 g of modified activated carbon carrier into deionized water, with a solid-liquid ratio of 1:3, stir at a speed of 200 rpm for 1 h to obtain the outer material of functional microorganisms.

[0045] Prepare the organic coating material Disperse 19.23 g of hydroxypropyl starch, 23.08 g of humic acid and 7.69 g of potassium fulvate into 250 mL of deionized water, stir and mix at a speed of 200 rpm at 80 °C for 30 min to obtain a starch mixture, spray-dry the starch mixture, with an inlet air temperature of 160 - 180 °C and an outlet air temperature of 80 - 90 °C to obtain a modified starch-based material; mix the above-prepared modified starch-based material, 50 g of well-rotted chicken manure, 30 g of sodium lignosulfonate, 5 g of betaine, 3 g of polyglutamic acid and 120 mL of deionized water, stir at a speed of 200 rpm to obtain the organic coating material.

[0046] Prepare the organic-inorganic compound fertilizer containing functional microorganisms Mix ammonium phosphate, potassium nitrate and magnesium sulfate in the inorganic core layer according to a mass ratio of 1:1:1, stir and mix at a speed of 60 rpm for 30 min, granulate by disk granulation and dry at 60 °C until the water content is lower than 5%, and obtain the inorganic core layer after screening; preheat the inorganic core layer to 50 °C, feed it into a coating machine, spray and coat the organic coating material, and control the coating weight gain at 10% to obtain a preliminary product with an organic coating layer; coat the outer material of functional microorganisms on the surface of the organic coating layer of the preliminary product by fluidized bed coating, dry at a low temperature of 30 °C for 2 h, and obtain the organic-inorganic compound fertilizer containing functional microorganisms after screening.

[0047] Example 4 Example 4 is based on Example 3. The difference between Example 4 and Example 3 is only that when preparing the modified activated carbon carrier in Example 4, the activated carbon is not modified, and the activated activated carbon is replaced with activated carbon.

[0048] Example 5 Example 5 is based on Example 3. The difference between Example 5 and Example 3 is only that acrylic acid is not added when preparing the modified activated carbon in Example 5.

[0049] Example 6 Example 6 is based on Example 3. The difference between Example 6 and Example 3 is only that melamine is not added when preparing the modified activated carbon in Example 6.

[0050] Example 7 Example 7 is based on Example 3. The only difference between Example 7 and Example 3 is that Lactobacillus plantarum is not added to the synergistic growth-promoting microorganisms in Example 7.

[0051] Example 8 Example 8 is based on Example 3. The only difference between Example 8 and Example 3 is that Trichoderma harzianum and Lactobacillus plantarum are not added to the synergistic growth-promoting microorganisms in Example 8.

[0052] Example 9 Example 9 is based on Example 3. The only difference between Example 9 and Example 3 is that the dosage of hydroxypropyl starch is 20.83 g, the dosage of humic acid is 25 g, and the dosage of potassium fulvate is 4.17 g in Example 9.

[0053] Example 10 Example 10 is based on Example 3. The only difference between Example 10 and Example 3 is that the dosage of hydroxypropyl starch is 17.86 g, the dosage of humic acid is 21.43 g, and the dosage of potassium fulvate is 10.71 g in Example 10.

[0054] Example 11 Example 11 is based on Example 3. The only difference between Example 11 and Example 3 is that potassium fulvate is not added when preparing the modified starch-based material in Example 11.

[0055] Comparative Example 1 Comparative Example 1 is based on Example 3. The only difference between Comparative Example 1 and Example 3 is that the synergistic growth-promoting microorganisms are not added in Comparative Example 1.

[0056] Comparative Example 2 Comparative Example 2 is based on Example 3. The only difference between Comparative Example 2 and Example 3 is that the modified activated carbon carrier is replaced with activated carbon in Comparative Example 2. Performance Detection Experiment

[0057] (1) Select "NY / T 1847-2010 General Technical Requirements for Quality Evaluation of Production Strains of Microbial Fertilizers" as the standard. Accelerate the aging of the test samples in a constant temperature incubator at 40 °C for 28 d. Test the viable bacteria counts before and after aging respectively, calculate the survival rate, test each test sample three times, and take the average value after measurement. The results are recorded in Table 1.

[0058] (2)Select "GB / T 23348-2009 Slow-release Fertilizers" as the standard. Weigh 10 g of the sample and put it into a small bag made of 100-mesh nylon screen. Place the small bag into a 250 mL glass bottle, add 200 mL of water, seal it with a lid, and place it in a biochemical constant temperature incubator at 25 °C. Take samples every day, test the nitrogen release amount with an automatic analyzer, and calculate the cumulative nitrogen release rate. The calculation formula is as follows: V = W n / W, where W n is the mass fraction of the nitrogen release amount measured on the nth day, and W is the mass fraction of the total nitrogen. Record the release rates at 60 d, 90 d, and 120 d in Table 1.

[0059] Table 1 Detection Results of Microbial Survival Rate and Slow-release Performance of Organic-inorganic Compound Fertilizers Containing Functional Microorganisms Test Results Survival Rate (%) Release Rate at 60d (%) Release Rate at 90d (%) Release Rate at 120d (%) Example 1 86.7 28.5 61.0 93.4 Example 2 87.2 28.8 61.5 94.2 Example 3 87.5 28.7 61.3 94.0 Example 4 77.3 42.6 75.2 88.6 Example 5 82.5 30.1 72.7 98.2 Example 6 83.8 29.4 69.8 96.9 Example 7 84.3 26.9 66.5 95.8 Example 8 82.1 25.4 67.6 96.3 Example 9 83.6 30.2 65.8 95.8 Example 10 84.5 25.8 67.2 96.7 Example 11 80.2 32.5 88.9 99.2 Comparative Example 1 75.6 25.3 50.8 75.2 Comparative Example 2 70.4 45.9 91.2 99.8 As can be seen from Table 1, the survival rates of Examples 1-3 are greater than 86.7%, the release amount at 60 d is less than 28.8%, and the release rate at 120 d is greater than 93.4%. It can be seen that the fertilizers prepared in this application have good microbial survival rates and slow-release performance.

[0060] As can be seen from Table 1, the differences between Examples 4, 5, 6 and Example 3 are only as follows: In Example 4, the activated carbon is not modified when preparing the modified activated carbon carrier; in Example 5, acrylic acid is not added when preparing the modified activated carbon; in Example 6, melamine is not added when preparing the modified activated carbon. Compared with Example 3, the performance of Examples 4, 5, 6 has decreased; this is because replacing or reducing the components of the modified activated carbon carrier will affect the performance balance between the components, and then affect the colonization of microorganisms, and further affect the slow-release effect and the microbial survival rate.

[0061] As can be seen from Table 1, the differences between Examples 7, 8 and Example 3 are only as follows: In Example 7, Lactobacillus plantarum is not added to the synergistic growth-promoting microorganisms; in Example 8, Trichoderma harzianum and Lactobacillus plantarum are not added to the synergistic growth-promoting microorganisms. Compared with Example 3, the performance of Examples 7, 8 has decreased; this is because reducing the types of synergistic growth-promoting microorganisms will affect the synergistic promotion effect between microorganisms, thereby affecting the survival rate and the slow-release effect.

[0062] As can be seen from Table 1, the differences between Examples 9, 10, 11 and Example 3 are only as follows: in Example 9, the mass ratio of hydroxypropyl starch, humic acid and potassium fulvate is 1:1.2:0.2; in Example 10, the mass ratio of hydroxypropyl starch, humic acid and potassium fulvate is 1:1.2:0.6; in Example 11, potassium fulvate is not added when preparing the modified starch-based material. Compared with Example 3, the performance of Examples 9, 10 and 11 has decreased. This is because the ratio and composition of the modified starch-based material are changed. Excessive or insufficient potassium fulvate will affect the synergistic effect with humic acid, affect the activity of microorganisms and the stability of the coating. The absence of potassium fulvate will further reduce the stability of the coating, thereby affecting the sustained-release effect.

[0063] As can be seen from Table 1, the difference between Comparative Example 1 and Example 3 is only that: no synergistic growth-promoting microorganisms are added. Compared with Example 3, the performance of Comparative Example 1 has decreased. This is because the lack of synergistic growth-promoting microorganisms will reduce the synergistic effect among microorganisms, the composite functional microorganisms lack protection, their activity decreases, and the regulatory effect of the synergistic growth-promoting microorganisms is absent, and the sustained-release effect is also affected.

[0064] As can be seen from Table 1, the difference between Comparative Example 2 and Example 3 is only that: in Comparative Example 2, the modified activated carbon carrier is replaced by activated carbon. Compared with Example 3, the performance of Comparative Example 2 has decreased. This is because replacing the modified activated carbon carrier with activated carbon reduces the effect of adsorbing microcapsules, the sites for microorganism colonization decrease, thereby reducing the auxiliary effect on the organic coating, and the coating is more likely to disintegrate, thus affecting the sustained-release effect.

[0065] This specific embodiment is only an interpretation of the present application, and it does not limit the present application. Through the above description, relevant staff can make various changes and modifications completely within the scope without deviating from the technical idea of this application. The technical scope of this application is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An organic-inorganic compound fertilizer containing functional microorganisms, characterized in that: It includes an inorganic core layer, an organic coating layer and a functional microbial outer layer, wherein the functional microbial outer layer includes the following components in parts by weight: 10-15 servings of composite functional microorganisms 5-10 servings of synergistic growth-promoting microorganisms 2-3 parts of trehalose 1-2 parts of mannitol 10-15 parts of sodium alginate Chitosan 8-10 parts 2-4 parts yeast extract 30-40 parts of modified activated carbon carrier.

2. The organic-inorganic compound fertilizer containing functional microorganisms according to claim 1, characterized in that: The composite functional microorganisms include Enterobacter cloacae, Pseudomonas and Bacillus licheniformis.

3. The organic-inorganic compound fertilizer containing functional microorganisms according to claim 2, characterized in that: The synergistic growth-promoting microorganisms include Bacillus subtilis, Trichoderma harzianum and Lactobacillus plantarum.

4. The organic-inorganic compound fertilizer containing functional microorganisms according to claim 1, characterized in that: The raw materials for preparing the modified activated carbon carrier include activated activated carbon, acrylic acid and melamine.

5. The organic-inorganic compound fertilizer containing functional microorganisms according to claim 4, characterized in that: The modified activated carbon support is prepared by the following steps: The activated carbon is dispersed in a solvent, acrylic acid and ammonium persulfate are added, the pH is adjusted to acidic, neutral gas is passed to deoxygenate, the mixture is heated and stirred for reaction, and then washed and dried to obtain preliminary modified activated carbon; the preliminary modified activated carbon prepared above is added to an alkaline solution for ultrasonic dispersion, melamine is added, the mixture is heated for reaction, washed to neutrality, dried, ground, and sieved to obtain a modified activated carbon carrier.

6. The organic-inorganic compound fertilizer containing functional microorganisms according to claim 1, characterized in that: The inorganic core layer includes ammonium phosphate, potassium nitrate and magnesium sulfate.

7. The organic-inorganic compound fertilizer containing functional microorganisms according to claim 1, characterized in that: The raw materials for preparing the organic coating layer include decomposed animal excrement, sodium lignin sulfonate, modified starch-based material, betaine and polyglutamic acid.

8. The organic-inorganic compound fertilizer containing functional microorganisms according to claim 7, characterized in that: The raw materials for preparing the modified starch-based material include hydroxypropyl starch, humic acid and potassium fulvic acid.

9. The organic-inorganic compound fertilizer containing functional microorganisms according to claim 8, characterized in that: The mass ratio of the hydroxypropyl starch, humic acid and potassium fulvic acid is 1:1.2:(0.3-0.5).

10. A method for producing an organic-inorganic compound fertilizer containing functional microorganisms as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: The inorganic core layer is mixed and stirred, granulated, dried, and sieved to obtain the inorganic core layer; The inorganic core layer is preheated, and the organic coating layer material is sprayed on the coating to obtain a preliminary product with an organic coating layer; the functional microbial outer layer material is coated on the surface of the organic coating layer of the preliminary product, and the product is sieved after low-temperature drying to obtain an organic-inorganic compound fertilizer containing functional microorganisms.