Organic-inorganic compound fertilizer containing functional microorganism and its production method

Abstract

The application relates to an organic-inorganic compound fertilizer containing functional microorganisms and a production method thereof, and relates to the technical field of fertilizers. The 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 mass fractions: 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 yeast extract and 30-40 parts of modified active carbon carriers. The production method comprises the following steps: preparing the inorganic core layer, preheating the inorganic core layer, spraying the organic coating layer material to coat the surface, and obtaining a preliminary product with the organic coating layer; coating the functional microorganism outer layer material on the surface of the organic coating layer of the preliminary product, low-temperature drying and screening, and obtaining the organic-inorganic compound fertilizer containing the functional microorganisms. The application has the effects of improving the slow-release effect of the fertilizer and the survival rate of the microorganisms.

Description

TECHNICAL FIELD

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

[0002] With the advancement of agricultural modernization, the problems of soil degradation and environmental pollution caused by excessive use of traditional fertilizers have become increasingly prominent, and the development of green and efficient fertilizers has become an inevitable trend for sustainable agricultural development. Organic-inorganic compound fertilizers have become a research hotspot in the field of fertilizers by combining the long-acting nature of organic fertilizers with the quick-acting nature of inorganic fertilizers, and have the dual advantages of soil improvement and nutrient supplementation. However, existing compound fertilizers generally have defects such as spatial and temporal mismatch between nutrient release and crop demand, and single function of microorganisms, which are difficult to meet the needs of precision agriculture.

[0003] The introduction of functional microorganisms provides a new way to improve the performance of compound fertilizers. For example, functional strains such as nitrogen-fixing bacteria, phosphorus-dissolving bacteria, and potassium-dissolving bacteria can improve nutrient utilization rate through biological transformation, and antagonistic strains can inhibit soil-borne diseases and enhance crop stress resistance. However, functional microorganisms face multiple challenges during fertilizer production and storage: high-temperature granulation process can easily damage the activity of the strains, high-salt environment of inorganic nutrients can inhibit microbial metabolism, and organic acids produced during the composting process of organic fertilizers can also damage the strains. In addition, traditional carrier materials such as peat and straw have poor adsorption, making it difficult to effectively protect the survival rate of microorganisms in complex environments. Low survival rate of microorganisms leads to poor functional stability and unstable fertilizer efficiency, making it difficult to achieve long-term and sustainable ecological benefits, and thus needs to be improved. SUMMARY

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

[0005] The organic-inorganic compound fertilizer containing functional microorganisms and the production method thereof provided by the present application adopt the following technical solutions:

[0006] In a first aspect, the present application provides an organic-inorganic compound fertilizer containing functional microorganisms, which adopts the following technical solutions:

[0007] An organic-inorganic compound fertilizer containing functional microorganisms, comprising an inorganic core layer, an organic coating layer, and a functional microorganism outer layer, wherein the functional microorganism outer layer comprises the following components in mass fraction:

[0008] Compound functional microorganisms 10-15 parts

[0009] Synergistic growth-promoting microorganisms 5-10 parts

[0010] Trehalose 2-3 parts

[0011] Mannitol 1-2 parts

[0012] Sodium alginate 10-15 parts

[0013] Chitosan 8-10 parts

[0014] Yeast extract 2-4 parts

[0015] Modified activated carbon carrier 30-40 parts.

[0016] The fertilizer realizes the synergistic effect of microorganism protection and nutrient slow release through the triple structure design of inorganic core layer-organic coating layer-functional microorganism outer layer; the inorganic core layer provides available nutrients; the organic coating layer delays the rapid release of inorganic nutrients and blocks the direct damage of high salt in the inorganic core layer to the microorganism, and the porous structure can also promote the colonization of microorganisms and provide energy for metabolism; the complex functional microorganism and the synergistic growth-promoting microorganism form a symbiotic network through metabolic complementation, secrete extracellular enzymes and antibiotics, and enhance the soil nutrient activation and disease inhibition capacity; sodium alginate and chitosan are ionically cross-linked to form a pH-responsive microcapsule, and its three-dimensional network structure allows nutrient diffusion and shields the damage of the external high-salt environment to the microorganism; trehalose and mannitol act as glassing protective agents to stabilize the cell membrane of the microorganism by forming an amorphous matrix; the modified activated carbon carrier can adsorb and fix the microorganism after modification, and at the same time provide a micro-anaerobic environment to promote denitrification; the nucleotides and amino acids in the yeast extract serve as a nutrient reserve for the microorganism, maintaining cell metabolic activity during storage; the functional microorganism outer layer cooperates through physical embedding, chemical protection and biological function to maintain the activity of the microorganism during production and long-term storage, and through carrier adsorption and microcapsule controlled release mechanism, the release period of nutrients is prolonged, realizing the dual improvement of long-acting and microbial function of the fertilizer.

[0017] Preferably, the complex functional microorganism includes Enterobacter cloacae, Pseudomonas and Bacillus licheniformis.

[0018] The indole acetic acid secreted by Enterobacter cloacae can stimulate crop root growth and expand nutrient absorption area; Pseudomonas secretes acid phosphatase and glucosidase to convert insoluble phosphorus in the soil into available state, and at the same time releases potassium ions in mica and feldspar through potassium channel protein; 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 the microcapsule, regulate extracellular enzyme secretion through quorum sensing signals, and enhance stress resistance; in addition, the exopolysaccharide produced by Enterobacter cloacae and the alginate secreted by Pseudomonas together form a biofilm wrapped in the outer layer of the microorganism, which synergistically resists high-salt environment and improves the survival rate of the microorganism.

[0019] Preferably, the synergistic growth promoting microorganisms include Bacillus subtilis, Trichoderma harzianum and Lactobacillus plantarum.

[0020] 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 reduces the rhizosphere pH value by secreting lactic acid, thereby promoting the iron element activation efficiency of iron carrier secretion bacteria such as Pseudomonas; the three strains form micro-niche differentiation in the mesoporous structure of the microcapsule and the modified activated carbon carrier: Bacillus subtilis occupies the micropore 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 surface of the carrier to regulate the microenvironment osmotic pressure, thereby improving the survival rate of microorganisms in complex environments and improving the performance of fertilizers.

[0021] Preferably, the raw materials for preparing the modified activated carbon carrier include activated activated carbon, acrylic acid and melamine.

[0022] The activated activated carbon has abundant mesoporous structure and 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, thereby improving the loading capacity of microorganisms through electrostatic adsorption and enhancing the ion exchange capacity for ammonium nitrogen; the melamine cross-linking reaction further forms a three-dimensional network structure containing amino groups, and the alkaline environment thereof inhibits the proliferation of miscellaneous bacteria, and in acidic conditions, the amino groups can be protonated to release fixed nutrients; the density of carboxyl and amino groups on the surface of the modified carrier is improved, which can form hydrogen bonds with carboxylate in the microcapsule, thereby enhancing the embedding stability; the mesoporous structure can adsorb active substances to form organic-inorganic complexes, thereby playing a slow-release role through physical entrapment and chemical chelation, thereby improving the survival rate of microorganisms and the slow-release performance of fertilizers.

[0023] Preferably, the modified activated carbon carrier is prepared by the following steps:

[0024] The activated activated carbon is dispersed in a solvent, acrylic acid and ammonium persulfate are added, the pH value is adjusted to be acidic, oxygen is removed by passing a neutral gas, and then heating and stirring are performed for reaction, followed by washing, drying, ultrasonic dispersion of the preliminary modified activated carbon prepared above in an alkaline solution, addition of melamine, heating for reaction, washing to neutral, drying, grinding and sieving, to obtain the modified activated carbon carrier.

[0025] The modified activated carbon carrier prepared according to the above steps has good adsorption performance, can effectively store microcapsules of microorganisms, improve the survival rate of microorganisms, and improve the slow-release performance of fertilizers through physical and chemical effects.

[0026] Preferably, the inorganic core layer includes ammonium phosphate, potassium nitrate and magnesium sulfate.

[0027] Ammonium phosphate provides high concentration of nitrogen and phosphorus basic nutrients, its ammonium nitrogen and orthophosphate are quickly dissociated in the soil to meet the needs of crop seedling stage; potassium nitrate supplements potassium and adjusts the soil oxidation-reduction potential, promotes the absorption of calcium and magnesium by roots; magnesium sulfate activates soil urease and phosphatase activity by providing magnesium ions, and accelerates the mineralization of organic nitrogen and phosphorus; the solubility difference of the three salts in water forms a gradient dissolution effect, which makes the initial release rate of nitrogen, phosphorus and potassium low, and cooperates with the cross-linked membrane of the organic coating layer to prolong the slow-release period of nitrogen; the weak acidity of magnesium sulfate can neutralize the alkaline environment of potassium nitrate, forming a micro-acidic micro-domain, which inhibits the proliferation of miscellaneous bacteria while promoting the secretion of siderophores of functional bacteria, and improves the survival rate of microorganisms near the high-salt core layer; at the same time, through the dual mechanism of nutrient rapid start and slow-release regulation, the dynamic balance of crop nutrient supply and microbial function is realized.

[0028] Preferably, the preparation raw materials of the organic coating layer include mature animal manure, sodium lignosulfonate, modified starch-based material, betaine and polyglutamic acid.

[0029] The porous structure of the mature animal manure and the modified starch-based material form a composite matrix to adsorb and fix functional microorganisms, and the natural humic acid chelates heavy metal ions and adjusts the soil pH to a neutral micro-domain; sodium lignosulfonate and starch are cross-linked by ester bonds to form a semi-permeable membrane, which delays the rapid release of inorganic nutrients, and at the same time blocks the direct damage of the high-salt environment of the core layer to microorganisms; betaine acts as an osmoprotectant to maintain the integrity of the microbial cell membrane under dry or high-salt conditions, and polyglutamic acid regulates the hydrophilicity of the membrane by chelating calcium, magnesium and other ions to promote the uniform diffusion of nutrients; the organic coating layer delays the release of the inorganic core layer through the triple mechanism of physical adsorption, chemical cross-linking and biocompatibility, and improves the survival rate of microorganisms.

[0030] Preferably, the preparation raw materials of the modified starch-based material include hydroxypropyl starch, humic acid and potassium fulvate.

[0031] The three-dimensional network structure formed by the etherification of hydroxypropyl starch provides mechanical support, and the hydroxyl and carboxyl groups cross-link with the aromatic ring structure of humic acid and potassium fulvate through hydrogen bonds to form a semi-permeable membrane, which delays the dissolution rate of inorganic nutrients; humic acid is embedded in the starch matrix through π-π conjugation, and its abundant carboxyl groups chelate iron, aluminum and other ions in the fertilizer to inhibit the fixation of phosphate and improve the release rate of phosphorus; the low molecular weight humic acid fragments of potassium fulvate penetrate into the micropores of starch and adsorb ammonium nitrogen through ion exchange, forming a dynamic equilibrium slow-release system; after further cross-linking of the modified starch-based material and sodium lignosulfonate, combined with the osmoprotective effect of betaine, the survival rate of microorganisms is improved; the biological stimulation effect of humic acid and potassium fulvate promotes the secretion of exopolysaccharides by microorganisms, forming a composite protective layer with microcapsules, and enhancing the stability of the organic coating layer in the soil through cation bridging, improving the slow-release effect.

[0032] Preferably, the mass ratio of the hydroxypropyl starch, humic acid and potassium fulvate is 1:1.2:(0.3-0.5).

[0033] The modified starch-based material prepared according to the mass ratio can effectively improve the slow-release effect of the fertilizer and the survival rate of the microorganisms.

[0034] In a second aspect, the present application provides a production method of an organic-inorganic compound fertilizer containing functional microorganisms, which adopts the following technical scheme:

[0035] The production method of the organic-inorganic compound fertilizer containing functional microorganisms comprises the following steps:

[0036] 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 to coat the inorganic core layer to obtain a preliminary product with an organic coating layer; the functional microorganism outer layer material is coated on the surface of the organic coating layer of the preliminary product, and the product is dried at low temperature and sieved to obtain the organic-inorganic compound fertilizer containing functional microorganisms.

[0037] The organic-inorganic compound fertilizer containing functional microorganisms prepared according to the above steps has good slow-release effect, high survival rate of microorganisms, and can long-term play the performance and improve the nutrient utilization rate.

[0038] In summary, the present application has at least one of the following beneficial technical effects:

[0039] 1. Through the triple structure design of 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 available nutrients; the organic coating layer delays the rapid release of inorganic nutrients and blocks the direct damage of high salt in the inorganic core layer to the microorganisms, and the porous structure of the organic coating layer can promote the colonization of microorganisms and provide energy for the metabolism of microorganisms; the compound functional microorganisms and the synergistic growth microorganisms form a symbiotic network through metabolic complementation, secrete extracellular enzymes and antibiotics, and enhance the soil nutrient activation and disease inhibition capacity; sodium alginate and chitosan are ionically crosslinked to form a pH-responsive microcapsule, and the three-dimensional network structure allows nutrient diffusion and shields the damage of the external high-salt environment to the microorganisms; trehalose and mannitol act as glassification protective agents to stabilize the cell membrane of the microorganisms by forming an amorphous matrix; the modified activated carbon carrier can adsorb and fix the microorganisms, and at the same time provide a micro-anaerobic environment to promote denitrification; nucleotides and amino acids in the yeast extract serve as nutrient reserves for the microorganisms, maintaining the metabolic activity of the cells during storage; the functional microorganism outer layer cooperates with physical embedding, chemical protection and biological function to maintain the activity of the microorganisms during the production process and long-term storage, and prolongs the nutrient release period through carrier adsorption and microcapsule controlled release mechanism, realizing the dual improvement of long-acting property of the fertilizer and the function of the microorganisms.

[0040] 2. The activated activated carbon has abundant mesoporous structure and 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, improving the loading capacity of microorganisms through electrostatic adsorption, and enhancing the ion exchange capacity for ammonium nitrogen; the melamine crosslinking reaction further forms a three-dimensional network structure containing amino groups, which inhibits the proliferation of miscellaneous bacteria in an alkaline environment, and can release fixed nutrients under acidic conditions through protonation; the surface carboxyl and amino density of the modified carrier is improved, which can form hydrogen bonds with carboxylate in the microcapsule, enhancing the embedding stability; the mesoporous structure can adsorb active substances to form organic-inorganic complexes, playing a slow-release role through physical entrapment and chemical chelation, thereby improving the survival rate of microorganisms and slow-release performance of the fertilizer.

[0041] 3. The three-dimensional network structure of hydroxypropyl starch formed after etherification provides mechanical support, and the hydroxyl and carboxyl groups crosslink with the aromatic ring structure of humic acid and potassium fulvate through hydrogen bonds, forming a semi-permeable membrane to delay the dissolution rate of inorganic nutrients; humic acid is embedded in the starch matrix through π-π conjugation, and its abundant carboxyl groups chelate iron, aluminum and other ions in the fertilizer, inhibiting the fixation of phosphate and improving the release rate of phosphorus; the low molecular weight humic acid fragments of potassium fulvate penetrate into the pores of starch, adsorbing ammonium nitrogen through ion exchange, forming a dynamic balance slow-release system; after the modified starch-based material is further crosslinked with sodium lignosulfonate, combined with the osmoprotective effect of betaine, the survival rate of microorganisms is improved; the biological stimulation effect of humic acid and potassium fulvate promotes the secretion of extracellular polysaccharides by microorganisms, forming a composite protective layer with microcapsules, and enhancing the stability of the organic coating layer in soil through cation bridging, improving the slow-release effect. DETAILED DESCRIPTION

[0042] The present application discloses an organic-inorganic compound fertilizer containing functional microorganisms and a production method thereof. The raw materials used in the present application can be obtained through commercial raw materials, except for special instructions. The present application will be further described in detail in combination with the following examples:

[0043] Raw material description: oxidizing agent 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 fulvate purchased from Shandong Anquan Chemical Technology Co., Ltd., mature animal manure selected as mature chicken manure, sodium lignosulfonate (CAS No. 8061-51-6), betaine (CAS No. 107-43-7), polyglutamic acid (CAS No. 25513-46-6).

[0044] Example 1

[0045] Preparation of modified activated carbon carrier

[0046] The activated carbon and the oxidizing agent were mixed in a mass ratio of 1:3, deionized water was added and ultrasonicated for 30 min, the solid-liquid ratio was 1:10, and the activated carbon was activated at 800°C for 2h under nitrogen protection. After acid washing and neutralization with 10% hydrochloric acid, the activated carbon was dried to obtain high porosity activated carbon. The high porosity activated carbon was added to a 20% hydrogen peroxide aqueous solution, the solid-liquid ratio was 1:10, and the mixture was stirred at 200 rpm at 80°C for 4h. After washing to neutral and drying at 60°C to constant weight, the activated activated carbon was obtained.

[0047] The activated activated carbon was dispersed in deionized water, the solid-liquid ratio was 1:10, 18.36g of acrylic acid and 0.4g of ammonium persulfate were added, the pH was adjusted to 4, and the mixture was stirred at 200 rpm at 60°C for 6h after oxygen removal by nitrogen. After washing with ethanol and drying at 60°C to constant weight, the preliminary modified activated carbon was obtained. The preliminary modified activated carbon prepared above was ultrasonically dispersed in 0.1 mol / L sodium hydroxide aqueous solution, the solid-liquid ratio was 1:10, 8g of melamine was added, and the mixture was reacted at 70°C for 4h. After washing to neutral and drying at 60°C to constant weight, the mixture was ground and sieved through a 100 mesh sieve to obtain the modified activated carbon carrier.

[0048] Preparation of functional microbial outer material

[0049] 10g of the composite functional microorganism and 5g of the synergistic growth-promoting microorganism were respectively cultured to the logarithmic growth phase, and the viable bacterial count was 1*10 9CFU / g, the complex functional microorganism was composed of Enterobacter cloacae, Pseudomonas and Bacillus licheniformis with a mass ratio of 1:2:2, the synergistic growth promoting microorganism was composed of Bacillus subtilis, Trichoderma harzianum and Lactobacillus plantarum with a mass ratio of 2:1:1, the bacterial cells were collected by centrifugation, resuspended with sterile normal saline, and adjusted to a concentration of 3x10 9 CFU / mL, to obtain a resuspension solution for standby; 10 g of sodium alginate was dispersed in 500 mL of deionized water to prepare a sodium alginate solution; 8 g of chitosan was dispersed in 800 mL of 1% acetic acid solution to prepare a chitosan solution.

[0050] 2 g of trehalose and 1 g of mannitol were dispersed in 100 mL of deionized water and added to the resuspension solution to obtain a mixed solution; the mixed solution was added to the sodium alginate solution and stirred at a speed of 200 rpm while adding, and the addition was completed within 30 min to obtain a microorganism sodium alginate mixed solution; the microorganism sodium alginate mixed solution was added to 2 L of liquid paraffin containing 5% Span 80 and dispersed at a speed of 5000 rpm for 20 min to obtain an emulsion, 650 mL of a calcium chloride aqueous solution with a mass concentration of 3% was added to the emulsion, and the emulsion was stirred at a speed of 5000 rpm for 60 min, then washed with petroleum ether after centrifugation to obtain preliminary embedded microcapsules.

[0051] The preliminary embedded microcapsules were dispersed in the chitosan solution and stirred at a speed of 5000 rpm for 30 min, then washed with deionized water after centrifugation to obtain microcapsules; the microcapsules were soaked in 200 mL of a normal saline solution containing 2 g of yeast extract, soaked for 2 h, and then freeze-dried at -20°C to obtain functional microorganism microcapsules; the functional microorganism microcapsules and 30 g of modified activated carbon carriers were dispersed in deionized water with a solid-liquid ratio of 1:3, and stirred at a speed of 200 rpm for 1 h to obtain a functional microorganism outer layer material.

[0052] Preparation of an organic coating layer material

[0053] 20 g of hydroxypropyl starch, 24 g of humic acid, and 6 g of potassium fulvic acid were dispersed in 250 mL of deionized water, stirred at a speed of 200 rpm at 80°C for 30 min to obtain a starch mixed solution, and the starch mixed solution was spray dried with an inlet temperature of 160-180°C and an outlet temperature of 80-90°C to obtain a modified starch-based material; the modified starch-based material prepared above, 50 g of decomposed chicken manure, 30 g of sodium lignosulfonate, 5 g of betaine, 3 g of polyglutamic acid, and 120 mL of deionized water were mixed and stirred at a speed of 200 rpm to obtain an organic coating layer material.

[0054] Preparation of an organic-inorganic compound fertilizer containing functional microorganisms

[0055] The ammonium phosphate, potassium nitrate and magnesium sulfate of the inorganic core layer are mixed in a mass ratio of 1:1:1, stirred at a speed of 60 rpm for 30 min, and then granulated and dried at 60°C until the water content is less than 5%. After screening, the inorganic core layer is preheated to 50°C and sent to a coating machine. The organic coating layer material is sprayed and coated, and the coating weight is controlled at 10%. A preliminary product with an organic coating layer is obtained. The functional microorganism outer layer material is coated on the surface of the organic coating layer of the preliminary product by fluidized bed coating, and dried at a low temperature of 30°C for 2 h. After screening, an organic-inorganic compound fertilizer containing functional microorganisms is obtained.

[0056] Example 2

[0057] Preparation of modified activated carbon carrier

[0058] The activated carbon and oxidizing agent are mixed in a mass ratio of 1:3, and deionized water is added for ultrasonic treatment for 30 min. The solid-liquid ratio is 1:10. The mixture is activated at 800°C for 2 h under nitrogen protection. After acid washing and neutralization using 10% hydrochloric acid, the mixture is dried to obtain high-porosity activated carbon. The high-porosity activated carbon is added to a 20% hydrogen peroxide aqueous solution. The solid-liquid ratio is 1:10. The mixture is stirred at a speed of 200 rpm at 80°C for 4 h. After washing to neutral, the mixture is dried at 60°C until the weight is constant to obtain activated activated carbon.

[0059] The activated activated carbon is dispersed in deionized water. The solid-liquid ratio is 1:10. 18.36 g of acrylic acid and 0.4 g of ammonium persulfate are added. The pH is adjusted to 4. After oxygen removal by nitrogen, the mixture is stirred at a speed of 200 rpm at 60°C for 6 h. After washing with ethanol, the mixture is dried at 60°C until the weight is constant to obtain preliminary modified activated carbon. The preliminary modified activated carbon prepared above is added to a 0.1 mol / L sodium hydroxide aqueous solution and ultrasonically dispersed. The solid-liquid ratio is 1:10. 8 g of melamine is added. The mixture is reacted at 70°C for 4 h. After washing to neutral, the mixture is dried at 60°C until the weight is constant. After grinding, the mixture is sieved through a 100-mesh sieve to obtain a modified activated carbon carrier.

[0060] Preparation of functional microorganism outer layer material

[0061] 15 g of composite functional microorganisms and 10 g of synergistic growth-promoting microorganisms are respectively cultured to the logarithmic growth phase, with a viable bacterial count of 1*109 CFU / g. The composite functional microorganisms are composed of Enterobacter cloacae, Pseudomonas and Bacillus licheniformis in a mass ratio of 1:2:2. The synergistic growth-promoting microorganisms are composed of Bacillus subtilis, Trichoderma harzianum and Lactobacillus plantarum in a mass ratio of 2:1:1. The bacterial cells are collected by centrifugation, resuspended with sterile physiological saline, and adjusted to a concentration of 3*10 9CFU / mL, and obtain a resuspension solution for standby; 15 g of sodium alginate was dispersed into 500 mL of deionized water to prepare a sodium alginate solution; 10 g of chitosan was dispersed into 800 mL of 1% acetic acid solution to prepare a chitosan solution.

[0062] 3 g of trehalose and 2 g of mannitol were dispersed into 100 mL of deionized water and added to the resuspension solution to obtain a mixture; the mixture was added to the sodium alginate solution while stirring at a speed of 200 rpm, and the addition was completed within 30 min to obtain a microbial sodium alginate mixture; the microbial sodium alginate mixture was added to 2 L of liquid paraffin containing 5% Span 80 and dispersed at a speed of 5000 rpm for 20 min to obtain an emulsion; 650 mL of a 3% calcium chloride aqueous solution was added to the emulsion, and the reaction was stirred at a speed of 5000 rpm for 60 min; after centrifugation, the preliminary embedded microcapsules were washed with petroleum ether to obtain the preliminary embedded microcapsules.

[0063] The preliminary embedded microcapsules were dispersed into the chitosan solution and stirred at a speed of 5000 rpm for 30 min; after centrifugation, the microcapsules were washed with deionized water to obtain the microcapsules; the microcapsules were soaked in 200 mL of a physiological saline solution containing 4 g of yeast extract, and after soaking for 2 h, the functional microbial microcapsules were obtained by freeze-drying at -20℃; the functional microbial microcapsules and 40 g of modified activated carbon carrier were dispersed into deionized water at a solid-liquid ratio of 1:3, and stirred at a speed of 200 rpm for 1 h to obtain the functional microbial outer material.

[0064] Preparation of organic coating layer material

[0065] 18.52 g of hydroxypropyl starch, 22.22 g of humic acid, and 9.26 g of potassium fulvic acid were dispersed into 250 mL of deionized water, and the mixture was stirred at a speed of 200 rpm at 80℃ for 30 min to obtain a starch mixture; the starch mixture was spray-dried at an inlet temperature of 160-180℃ and an outlet temperature of 80-90℃ to obtain a modified starch-based material; the modified starch-based material prepared above, 50 g of decomposed chicken manure, 30 g of sodium lignosulfonate, 5 g of betaine, 3 g of polyglutamic acid, and 120 mL of deionized water were mixed and stirred at a speed of 200 rpm to obtain the organic coating layer material.

[0066] Preparation of organic-inorganic compound fertilizer containing functional microorganisms

[0067] The ammonium phosphate, potassium nitrate and magnesium sulfate of the inorganic core layer are mixed in a mass ratio of 1:1:1, stirred at a speed of 60 rpm for 30 min, and then granulated and dried at 60°C until the water content is less than 5%. After screening, the inorganic core layer is preheated to 50°C and sent to a coating machine. The organic coating layer material is sprayed and coated, and the coating weight is controlled at 10%. A preliminary product with an organic coating layer is obtained. The functional microorganism outer layer material is coated on the surface of the organic coating layer of the preliminary product by fluidized bed coating, and dried at 30°C for 2 h. After screening, an organic-inorganic compound fertilizer containing functional microorganisms is obtained.

[0068] Example 3

[0069] Preparation of modified activated carbon carrier

[0070] The activated carbon and oxidizing agent are mixed in a mass ratio of 1:3, and deionized water is added for ultrasonic treatment for 30 min. The solid-liquid ratio is 1:10. The mixture is activated at 800°C for 2 h under nitrogen protection. After acid washing and neutralization using 10% hydrochloric acid, the mixture is dried to obtain high-porosity activated carbon. The high-porosity activated carbon is added to a 20% hydrogen peroxide aqueous solution. The solid-liquid ratio is 1:10. The mixture is stirred at 200 rpm for 4 h at 80°C. After washing to neutral, the mixture is dried at 60°C to constant weight to obtain activated activated carbon.

[0071] The activated activated carbon is dispersed in deionized water. The solid-liquid ratio is 1:10. 18.36 g of acrylic acid and 0.4 g of ammonium persulfate are added. The pH is adjusted to 4. After oxygen removal by nitrogen, the mixture is stirred at 200 rpm for 6 h at 60°C. After washing with ethanol, the mixture is dried to constant weight at 60°C to obtain preliminary modified activated carbon. The preliminary modified activated carbon prepared above is added to a 0.1 mol / L sodium hydroxide aqueous solution and ultrasonically dispersed. The solid-liquid ratio is 1:10. 8 g of melamine is added. The mixture is reacted at 70°C for 4 h. After washing to neutral, the mixture is dried to constant weight at 60°C. After grinding, the mixture is sieved through a 100-mesh sieve to obtain a modified activated carbon carrier.

[0072] Preparation of functional microorganism outer layer material

[0073] 12.5 g of complex functional microorganisms and 7.5 g of synergistic growth-promoting microorganisms are respectively cultured to the logarithmic growth phase, with a viable bacterial count of 1*109 CFU / g. The complex functional microorganisms are composed of Enterobacter cloacae, Pseudomonas and Bacillus licheniformis in a mass ratio of 1:2:2. The synergistic growth-promoting microorganisms are composed of Bacillus subtilis, Trichoderma harzianum and Lactobacillus plantarum in a mass ratio of 2:1:1. The bacterial cells are collected by centrifugation, resuspended with sterile physiological saline, and adjusted to a concentration of 3*10 9CFU / mL, and obtain the resuspension solution for standby; 12.5 g of sodium alginate was dispersed into 500 mL of deionized water to prepare a sodium alginate solution; 9 g of chitosan was dispersed into 800 mL of 1% acetic acid solution to prepare a chitosan solution.

[0074] 2.5 g of trehalose and 1.5 g of mannitol were dispersed into 100 mL of deionized water and added into the resuspension solution to obtain a mixture; the mixture was added into the sodium alginate solution and stirred at a speed of 200 rpm while adding, and the addition was completed within 30 min to obtain a microbial sodium alginate mixture; the microbial sodium alginate mixture was added into 2 L of liquid paraffin containing 5% Span 80 and dispersed at a speed of 5000 rpm for 20 min to obtain an emulsion, 650 mL of a calcium chloride aqueous solution with a mass concentration of 3% was added into the emulsion, and the reaction was stirred at a speed of 5000 rpm for 60 min, and after centrifugation, the preliminary embedded microcapsules were washed with petroleum ether to obtain the preliminary embedded microcapsules.

[0075] The preliminary embedded microcapsules were dispersed into the chitosan solution and stirred at a speed of 5000 rpm for 30 min, and after centrifugation, the microcapsules were washed with deionized water to obtain the microcapsules; the microcapsules were soaked in 200 mL of a physiological saline solution containing 3 g of yeast extract, and after soaking for 2 h, the functional microbial microcapsules were obtained by freeze-drying at -20℃; the functional microbial microcapsules and 35 g of a modified activated carbon carrier were dispersed into deionized water, the solid-liquid ratio was 1:3, and the mixture was stirred at a speed of 200 rpm for 1 h to obtain the functional microbial outer material.

[0076] Preparation of an organic coating layer material

[0077] 19.23 g of hydroxypropyl starch, 23.08 g of humic acid, and 7.69 g of potassium fulvic acid were dispersed into 250 mL of deionized water, and the mixture was stirred at a speed of 200 rpm at 80℃ for 30 min to obtain a starch mixture; the starch mixture was spray-dried, the inlet air temperature was 160-180℃, and the outlet air temperature was 80-90℃ to obtain a modified starch-based material; the modified starch-based material prepared above, 50 g of decomposed chicken manure, 30 g of sodium lignosulfonate, 5 g of betaine, 3 g of polyglutamic acid, and 120 mL of deionized water were mixed, and the mixture was stirred at a speed of 200 rpm to obtain the organic coating layer material.

[0078] Preparation of an organic-inorganic compound fertilizer containing functional microorganisms

[0079] The inorganic core layer ammonium phosphate, potassium nitrate and magnesium sulfate are mixed in a mass ratio of 1:1:1, stirred at a speed of 60 rpm for 30 min, and then granulated and dried at 60℃ until the water content is less than 5%, and then sieved to obtain the inorganic core layer; the inorganic core layer is preheated to 50℃, and then sent into a coating machine, and then the organic coating layer material is sprayed to coat, and the coating weight is controlled at 10%, to obtain a preliminary product with an organic coating layer; the functional microorganism outer layer material is coated on the surface of the organic coating layer of the preliminary product by fluidized bed coating, and then dried at 30℃ for 2h, and then sieved to obtain the organic-inorganic compound fertilizer containing functional microorganisms.

[0080] Example 4

[0081] Example 4 is based on Example 3, and the difference between Example 4 and Example 3 is only that in Example 4, the activated carbon is not modified when preparing the modified activated carbon carrier, and the activated carbon is replaced by activated carbon.

[0082] Example 5

[0083] Example 5 is based on Example 3, and the difference between Example 5 and Example 3 is only that in Example 5, the acrylic acid is not added when preparing the modified activated carbon.

[0084] Example 6

[0085] Example 6 is based on Example 3, and the difference between Example 6 and Example 3 is only that in Example 6, the melamine is not added when preparing the modified activated carbon.

[0086] Example 7

[0087] Example 7 is based on Example 3, and the difference between Example 7 and Example 3 is only that in Example 7, the Lactobacillus plantarum is not added in the synergistic growth-promoting microorganism.

[0088] Example 8

[0089] Example 8 is based on Example 3, and the difference between Example 8 and Example 3 is only that in Example 8, the Trichoderma harzianum and Lactobacillus plantarum are not added in the synergistic growth-promoting microorganism.

[0090] Example 9

[0091] Example 9 is based on Example 3, and the difference between Example 9 and Example 3 is only that in Example 9, the amount of hydroxypropyl starch is 20.83g, the amount of humic acid is 25g, and the amount of potassium fulvate is 4.17g.

[0092] Example 10

[0093] Example 10 is based on Example 3, the difference between Example 10 and Example 3 is only that the amount of hydroxypropyl starch used in Example 10 is 17.86 g, the amount of humic acid used is 21.43 g, and the amount of potassium fulvate used is 10.71 g.

[0094] Example 11

[0095] Example 11 is based on Example 3, the difference between Example 11 and Example 3 is only that no potassium fulvate is added when preparing the modified starch-based material in Example 11.

[0096] Comparative Example 1

[0097] Comparative Example 1 is based on Example 3, the difference between Comparative Example 1 and Example 3 is only that no synergistic growth-promoting microorganisms are added in Comparative Example 1.

[0098] Comparative Example 2

[0099] Comparative Example 2 is based on Example 3, the difference between Comparative Example 2 and Example 3 is only that the modified activated carbon carrier is replaced by activated carbon in Comparative Example 2.

[0100] Performance detection experiment

[0101] (1) Select "NY / T 1847-2010 Microbial Fertilizer Production Strain Quality Evaluation General Technical Requirements" as the standard, accelerate the aging of the sample in a 40°C constant temperature incubator for 28 days, test the viable count before and after aging, calculate the survival rate, test each sample three times, take the average value after measurement, and record the results in Table 1.

[0102] (2) Select "GB / T 23348-2009 Slow-Release Fertilizer" as the standard, weigh 10 g of the sample into a small bag made of 100-mesh nylon gauze, place the small bag into a 250 mL glass bottle, add 200 mL of water, seal with a lid, and place it in a 25°C biochemical incubator. Take samples every day, test the nitrogen release amount using an automatic analyzer, calculate the cumulative nitrogen release rate, and the calculation formula is as follows: V = W n / W, W n is the mass fraction of nitrogen release amount determined on the nth day, and W is the mass fraction of total nitrogen. Record the release rates at 60d, 90d, and 120d in Table 1.

[0103] Table 1 Microbial survival rate and slow-release performance detection results of organic-inorganic compound fertilizers containing functional microorganisms

[0104] Test results Survival rate (%) 60 d release rate (%) 90 d release rate (%) 120 d release rate (%) 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

[0105] From Table 1, the survival rate of Examples 1-3 is greater than 86.7%, the release amount at 60d is less than 28.8%, and the release rate at 120d is greater than 93.4%, so it can be seen that the fertilizer prepared in the application has good microbial survival rate and slow-release performance.

[0106] From Table 1, the difference between Examples 4, 5, 6 and Example 3 is that: in Example 4, the modified activated carbon carrier is prepared without modification of the activated carbon; in Example 5, the modified activated carbon is prepared without adding acrylic acid; in Example 6, the modified activated carbon is prepared without adding melamine; compared with Example 3, the performance of Examples 4, 5 and 6 has decreased; this is because the replacement or reduction of the components of the modified activated carbon carrier will affect the performance balance between the components, and then affect the colonization of the microorganisms, and then affect the slow-release effect and the survival rate of the microorganisms.

[0107] From Table 1, the difference between Examples 7, 8 and Example 3 is that: in Example 7, the synergistic growth-promoting microorganisms do not contain Lactobacillus plantarum; in Example 8, the synergistic growth-promoting microorganisms do not contain Trichoderma harzianum and Lactobacillus plantarum; compared with Example 3, the performance of Examples 7 and 8 has decreased; this is because reducing the types of synergistic growth-promoting microorganisms will affect the synergistic promotion between microorganisms, thereby affecting the survival rate and the slow-release effect.

[0108] From Table 1, the difference between Examples 9, 10, 11 and Example 3 is that: 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, the modified starch-based material is prepared without adding potassium fulvate; 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, and too much or too little potassium fulvate will affect the synergistic effect with humic acid, affect the activity of the microorganisms and the stability of the coating, and the absence of potassium fulvate will further reduce the stability of the coating, thereby affecting the slow-release effect.

[0109] From Table 1, the difference between Comparative Example 1 and Example 3 is 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 between microorganisms, the complex functional microorganisms lack protection, the activity decreases, and the lack of regulation of the synergistic growth-promoting microorganisms will also affect the slow-release effect.

[0110] From Table 1, it can be seen that the difference between Comparative Example 2 and Example 3 is that the modified activated carbon carrier is replaced by activated carbon in Comparative Example 2, and the performance of Comparative Example 2 is lower than that of Example 3; this is because the effect of adsorbing microcapsules is reduced when the modified activated carbon carrier is replaced by activated carbon, the site for microbial colonization is reduced, and thus the auxiliary effect on the organic coating is reduced, the coating is more prone to disintegration, and thus the slow-release effect is also affected.

[0111] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application. Through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A method for producing an organic-inorganic compound fertilizer containing functional microorganisms, characterized in that: Includes the following steps: Activated carbon and potassium hydroxide were mixed at a mass ratio of 1:3, and deionized water was added. The mixture was sonicated for 30 min at a solid-liquid ratio of 1:

10. Under nitrogen protection, the mixture was activated at 800℃ for 2 h. After acid washing and neutralization with 10% hydrochloric acid, the mixture was dried to obtain high-porosity activated carbon. The high-porosity activated carbon was then added to a 20% hydrogen peroxide aqueous solution at a solid-liquid ratio of 1:

10. The mixture was stirred at 80℃ at 200 rpm for 4 h. After washing with water until neutral, the mixture was dried at 60℃ to constant weight to obtain activated carbon. 61.2g of activated carbon was dispersed in deionized water at a solid-liquid ratio of 1:

10. 18.36g of acrylic acid and 0.4g of ammonium persulfate were added, and the pH was adjusted to 4. After purging with nitrogen to remove oxygen, the mixture was stirred at 200rpm at 60℃ for 6 hours. After washing with ethanol, the mixture was dried at 60℃ to constant weight to obtain preliminary modified activated carbon. The preliminary modified activated carbon prepared above was added to 0.1mol / L sodium hydroxide aqueous solution and ultrasonically dispersed at a solid-liquid ratio of 1:

10. 8g of melamine was added, and the mixture was reacted at 70℃ for 4 hours. After washing with water to neutrality, the mixture was dried at 60℃ to constant weight, ground, and passed through a 100-mesh sieve to obtain the modified activated carbon carrier. 12.5g of compound functional microorganisms and 7.5g of synergistic growth-promoting microorganisms were cultured to the logarithmic growth phase, with a viable count of 1×10⁻⁶. 9 The CFU / g compound functional microorganisms consist of Enterobacter cloacae, Pseudomonas aeruginosa, and Bacillus licheniformis in a mass ratio of 1:2:2, while the synergistic growth-promoting microorganisms consist of Bacillus subtilis, Trichoderma harzianum, and Lactobacillus plantarum in a mass ratio of 2:1:

1. The bacterial cells were collected by centrifugation, resuspended in sterile physiological saline, and the concentration was adjusted to 3 × 10⁻⁶ CFU / g. 9 CFU / mL was used to obtain a resuspension for later use; 12.5g of sodium alginate was dispersed in 500mL of deionized water to prepare a sodium alginate solution; 9g of chitosan was dispersed in 800mL of 1% acetic acid solution to prepare a chitosan solution. 2.5 g trehalose and 1.5 g mannitol were dispersed in 100 mL of deionized water and added to the resuspension to obtain a mixture. The mixture was then added to a sodium alginate solution while stirring at 200 rpm for 30 min to obtain a microbial sodium alginate mixture. The microbial sodium alginate mixture was added to 2 L of liquid paraffin containing 5% Span 80 and dispersed at 5000 rpm for 20 min to obtain an emulsion. 650 mL of a 3% calcium chloride aqueous solution was added to the emulsion and stirred at 5000 rpm for 60 min. After centrifugation, the mixture was washed with petroleum ether to obtain preliminary encapsulated microcapsules. The pre-encapsulated microcapsules were dispersed in a chitosan solution and stirred at 5000 rpm for 30 min. After centrifugation, the microcapsules were washed with deionized water to obtain microcapsules. The microcapsules were then soaked in 200 mL of physiological saline solution containing 3 g of yeast extract for 2 h and freeze-dried at -20 °C to obtain functional microbial microcapsules. The functional microbial microcapsules and 35 g of modified activated carbon carrier were dispersed in deionized water at a solid-liquid ratio of 1:3 and stirred at 200 rpm for 1 h to obtain the functional microbial outer layer material. 19.23g of hydroxypropyl starch, 23.08g of humic acid, and 7.69g of potassium fulvate were dispersed in 250mL of deionized water and stirred at 200rpm for 30min at 80℃ to obtain a starch mixture. The starch mixture was then spray-dried at an inlet air temperature of 160-180℃ and an outlet air temperature of 80-90℃ to obtain a modified starch-based material. The modified starch-based material prepared above, 50g of decomposed chicken manure, 30g of sodium lignosulfonate, 5g of betaine, 3g of polyglutamic acid, and 120mL of deionized water were mixed and stirred at 200rpm to obtain an organic coating layer material. Ammonium phosphate, potassium nitrate, and magnesium sulfate in the inorganic core layer were mixed in a mass ratio of 1:1:1 and stirred at 60 rpm for 30 minutes. After disc granulation, the mixture was dried at 60°C until the moisture content was less than 5%. After sieving, the inorganic core layer was obtained. The inorganic core layer was preheated to 50°C and fed into a coating machine to spray an organic coating material. The weight gain of the coating was controlled at 10%, resulting in a preliminary product with an organic coating layer. The functional microbial outer layer material was then coated onto the surface of the organic coating layer of the preliminary product through fluidized bed coating. The mixture was dried at 30°C for 2 hours and then sieved to obtain an organic-inorganic compound fertilizer containing functional microorganisms.