A microbial fertilizer with drought-resistant, water-retaining, and slow-release effects, its preparation method, and its application.

Abstract

This invention belongs to the field of agricultural fertilizer technology, specifically relating to a microbial fertilizer with drought-resistant, water-retaining, and slow-release effects, its preparation method, and its application. The microbial fertilizer provided by this invention comprises, from the inside out, a nanoenzyme with peroxidase activity, mesoporous material, compound fertilizer, carrier, microorganisms, and a double-network hydrogel shell. This invention utilizes mesoporous material, which on the one hand maintains the dispersed state of the nanocore, and on the other hand allows the compound fertilizer in contact with the surface of the mesoporous nanomaterial to both function as fertilizer and encapsulate the mesoporous nanomaterial. This invention fully utilizes the gaps between each two layers of components, allowing each component to play its role. Furthermore, the addition of nanoenzyme to the formula can improve fertilizer utilization efficiency and promote plant metabolic regulation during crop growth, resulting in increased yield in favorable conditions and stable yield in adverse conditions.

Description

Technical Field

[0001] This invention belongs to the field of agricultural fertilizer technology, specifically relating to a microbial fertilizer with drought-resistant, water-retaining, and slow-release effects, its preparation method, and its application. Background Technology

[0002] Fertilizer and water resource utilization are crucial material foundations for agricultural production and development, making it essential to improve their utilization efficiency. Currently, one method to improve fertilizer utilization is the use of slow-release fertilizers. Slow-release fertilizers are those that release nutrients slowly, with the release pattern aligned with the plant's nutrient requirements. In particular, coated fertilizers are one of the mainstream types of slow-release fertilizers. They are formed by coating the surface of fertilizer granules, allowing for the regulation of nutrient release rates to match the crop's nutrient absorption needs. This precise control of nutrient release rates better meets the nutrient requirements of crops at different growth stages.

[0003] However, existing research and technological applications regarding the application methods and effects of different modifiers, such as natural humic acid and polymeric water-retaining agents, are still limited. Furthermore, existing water-retaining slow-release fertilizers have poor water retention and drought resistance effects, and crops have low fertilizer absorption and utilization rates. Currently, there are still many problems to be solved in biomass-based water-retaining materials, such as high cost of coating materials, excessive hydrophilicity, poor compatibility, rapid nutrient release, and poor biodegradability. Therefore, developing a water-retaining slow-release fertilizer is of great significance for water conservation and fertilizer saving, pollution reduction, soil ecological environment improvement, increased yield of agricultural and forestry economic crops, and achieving sustainable environmental and economic development. Summary of the Invention

[0004] The purpose of this invention is to provide a microbial fertilizer with drought-resistant, water-retaining, and slow-release effects, as well as its preparation method and application, to solve the technical problems of low space utilization of existing fertilizer particles, high production cost of water-retaining agents, and difficulty in degrading residues.

[0005] This invention provides a microbial fertilizer with drought-resistant, water-retaining, and slow-release effects. The microbial fertilizer comprises, from the inside out, a nanoenzyme with peroxidase activity, a mesoporous material, a compound fertilizer, a carrier, microorganisms, and a double-network hydrogel shell.

[0006] The compound fertilizer includes macro-elements NPK, micro-elements, and synergistic components;

[0007] The synergistic components include one or more of the following: seaweed extract, humic acid, biochar, zinc humic acid, and selenoamino acids.

[0008] The carrier includes a sodium carboxymethyl cellulose-sodium alginate composite carrier;

[0009] The effective viable count of the microorganisms is ≥0.2~0.5 billion / gram, including Bacillus subtilis, Bacillus laterosporus, Bacillus licheniformis, Bacillus thuringiensis, Bacillus amyloliquefaciens, Trichoderma harzianum, Aspergillus oryzae, and Aspergillus pinki.

[0010] Preferably, the microbial fertilizer comprises the following components in parts by weight: 1-5 parts of nanoenzyme with peroxidase activity, 1-5 parts of mesoporous material, 60-80 parts of compound fertilizer, 1-5 parts of carrier, 2-10 parts of microorganisms, and 2-10 parts of double-network hydrogel shell.

[0011] Preferably, each part of the compound fertilizer comprises the following components in parts by weight: 50-60 parts of macro-elements NPK, 5-10 parts of micro-elements, and 5-10 parts of synergistic components;

[0012] Each of the microorganisms comprises the following components in parts by weight: 1-2 parts of Bacillus subtilis, 1-2 parts of Bacillus laterosporus, 1-2 parts of Bacillus licheniformis, 1-2 parts of Bacillus thuringiensis, 1-2 parts of Bacillus amyloliquefaciens, 1-2 parts of Trichoderma harzianum, 1-2 parts of Aspergillus oryzae, and 1-2 parts of Pseudomonas sylvestris.

[0013] The mass ratio of sodium carboxymethyl cellulose and sodium alginate in the carrier is (1~5):(1~5).

[0014] Preferably, the nanozyme with peroxidase activity comprises iron(III) oxide;

[0015] The mesoporous material includes one or more of mesoporous silicon, LDHs, and mesoporous silica.

[0016] The dual-network hydrogel shell comprises a polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel.

[0017] Preferably, the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel comprises water, glycerol, polyvinyl alcohol, and gelatin;

[0018] The mass ratio of water to glycerol in the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel is (4~9):(1~6).

[0019] The mass ratio of polyvinyl alcohol to gelatin in the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel is (5~9):(1~5).

[0020] The total mass of the polyvinyl alcohol and gelatin accounts for 15-35% of the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel.

[0021] Preferably, by weight, the microbial fertilizer comprises 1-5 parts of nanoenzyme with peroxidase activity, 1-5 parts of mesoporous material, 60-80 parts of compound fertilizer, 1-5 parts of carrier, 2-10 parts of microorganisms, and 2-10 parts of double-network hydrogel shell.

[0022] Preferably, the microbial fertilizer is in granular form.

[0023] The present invention also provides a method for preparing the microbial fertilizer described in the above technical solution, comprising the following steps:

[0024] By loading nanozymes with peroxidase activity onto mesoporous materials, a core-shell structure was obtained.

[0025] The core-shell structure is encapsulated in compound fertilizer, granulated, and dried to obtain fertilizer core particles.

[0026] The fertilizer core particles are coated with a carrier to obtain an inner-coated water-retaining slow-release fertilizer.

[0027] By using microorganisms to coat the inner membrane of the water-retaining and slow-release fertilizer, a microbial-coated fertilizer is obtained.

[0028] Microbial fertilizer is obtained by encapsulating the microbial layer with a double-network hydrogel shell.

[0029] Preferably, the loading method includes co-precipitation and / or the Stöber method;

[0030] The encapsulation method includes: mixing and granulating the macro-element NPK and the core-shell structure in the compound fertilizer, and then mixing and granulating it with other components in the compound fertilizer;

[0031] The coating method includes: spraying the carrier onto the surface of the fertilizer core particles and then drying it;

[0032] The coating method includes: spraying microorganisms onto the surface of the inner membrane water-retaining slow-release fertilizer;

[0033] The encapsulation method includes: heating the double-network hydrogel shell at 60~80℃ to obtain a molten hydrogel; soaking the microbial layer in the molten hydrogel to encapsulate the fertilizer, and then granulating it.

[0034] The present invention also provides the application of the microbial fertilizer described in the above technical solution or the microbial fertilizer obtained by the above preparation method in plant cultivation.

[0035] Preferably, the plant cultivation includes stable yield under adverse conditions and / or increased yield under favorable conditions.

[0036] Beneficial effects:

[0037] This invention provides a microbial fertilizer with drought-resistant, water-retaining, and slow-release effects. The microbial fertilizer, from the inside out, comprises, in sequence, a nanoenzyme with peroxidase activity, a mesoporous material, a compound fertilizer, a carrier, microorganisms, and a double-network hydrogel shell. The compound fertilizer includes macro-elements (NPK), micro-elements, and synergistic components. The synergistic components include one or more of seaweed extract, humic acid, biochar, zinc humic acid, and selenoamino acids. The carrier is a sodium carboxymethyl cellulose-sodium alginate composite carrier. The effective viable count of the microorganisms is ≥0.2-0.5 billion / gram, including *Bacillus subtilis*, *Bacillus laterosporus*, *Bacillus licheniformis*, *Bacillus thuringiensis*, *Bacillus amyloliquefaciens*, *Trichoderma harzianum*, *Aspergillus oryzae*, and *Pseudomonas pulcherrima*. This invention utilizes mesoporous materials, which on the one hand maintain the dispersed state of the nano-cores, and on the other hand, allow the compound fertilizer in contact with the surface of the mesoporous nanomaterials to both function as fertilizer and encapsulate the mesoporous nanomaterials. This invention fully utilizes the gaps between each two layers of the coating, introducing only functional components to ensure that each involved component plays its role and is used to its fullest potential. The carrier and the double-network hydrogel shell provide water retention and slow-release effects, while the microorganisms enhance plant stress resistance. Furthermore, the addition of nanozymes to the formulation enhances fertilizer utilization efficiency and promotes plant metabolic regulation during crop growth, resulting in increased yield in favorable conditions and stable yield in adverse conditions. This invention utilizes mesoporous materials to load nanozymes as a core-shell structure, which, compared to a micron-sized core, offers advantages such as improved fertilizer particle space utilization, enhanced plant absorption, improved soil environment, increased crop yield and quality, and environmental friendliness. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0039] Figure 1 This is a scanning electron microscope (SEM) image of nano-Fe3O4;

[0040] Figure 2 This is a scanning electron microscope (SEM) image of a porous silica nanocarrier.

[0041] Figure 3 This is a transmission electron microscope (TEM) image of a porous silica nanocarrier.

[0042] Figure 4 Schematic diagram of sodium carboxymethyl cellulose-sodium alginate composite carrier;

[0043] Figure 5 This is a partial view of the surface of the microbial fertilizer granules obtained in Example 4;

[0044] Figure 6 This is a picture of the finished product of the microbial fertilizer obtained in Example 4;

[0045] Figure 7 The following are side views of the rapeseed growth in each treatment group in the rapeseed pot experiment of Example 1.

[0046] Figure 8 The following is a top view of the rapeseed growth in each treatment group in the rapeseed pot experiment of Example 1.

[0047] Figure 9 The image shows the actual growth of rapeseed in each treatment group in the pot experiment of Example 2 (top view). Detailed Implementation

[0048] This invention provides a microbial fertilizer with drought-resistant, water-retaining, and slow-release effects. The microbial fertilizer comprises, from the inside out, a nanoenzyme with peroxidase activity, a mesoporous material, a compound fertilizer, a carrier, microorganisms, and a double-network hydrogel shell.

[0049] The compound fertilizer includes macronutrients NPK, micronutrients, and synergistic components.

[0050] The synergistic components include one or more of the following: seaweed extract, humic acid, biochar, zinc humic acid, and selenoamino acids.

[0051] The carrier includes a sodium carboxymethyl cellulose-sodium alginate composite carrier;

[0052] The effective viable count of the microorganisms is ≥0.2~0.5 billion / gram, including Bacillus subtilis, Bacillus laterosporus, Bacillus licheniformis, Bacillus thuringiensis, Bacillus amyloliquefaciens, Trichoderma harzianum, Aspergillus oryzae, and Aspergillus pinki.

[0053] In one embodiment, the microbial fertilizer of the present invention comprises the following components in parts by weight: 1-5 parts of nanoenzyme with peroxidase activity, 1-5 parts of mesoporous material, 60-80 parts of compound fertilizer, 1-5 parts of carrier, 2-10 parts of microorganisms, and 2-10 parts of double-network hydrogel shell; in another embodiment, the microbial fertilizer of the present invention comprises the following components in parts by weight: the microbial fertilizer comprises 2.5 parts of nanoenzyme with peroxidase activity, 2.5 parts of mesoporous material, 75 parts of compound fertilizer, 5 parts of carrier, 10 parts of microorganisms, and 5 parts of double-network hydrogel shell.

[0054] In one embodiment, the peroxidase-active nanozyme of the present invention comprises iron(III) oxide (Fe3O4). The present invention uses a peroxidase-active nanozyme as the core structure of the microbial fertilizer, which promotes the regulation of plant metabolism. The present invention does not impose strict requirements on the preparation method of the peroxidase-active nanozyme; conventional methods in the art can be used, such as ball milling, chemical co-precipitation, hydrothermal synthesis, microemulsion, microwave hydrothermal, high-temperature decomposition, sol-gel, and oxidation methods.

[0055] In one embodiment, the mesoporous material of this invention includes one or more of mesoporous silicon, LDHs, and mesoporous silica; in another embodiment, the mesoporous material of this invention is silica. This invention utilizes the ability of mesoporous materials to maintain the dispersed state of nanonuclei while simultaneously providing silicon for plant growth. This invention does not impose strict requirements on the preparation method of the mesoporous material; conventional methods in the art can be used, such as continuous reduction, co-reduction, sol-gel, electroless plating, co-precipitation, hydrothermal methods, surface modification, and hot injection.

[0056] In one embodiment, each part of the compound fertilizer of the present invention comprises the following components in parts by weight: 50-60 parts of macronutrient NPK, 5-10 parts of micronutrients, and 5-10 parts of synergistic components. In one embodiment, the synergistic component of the present invention is humic acid. In another embodiment, each part of the compound fertilizer of the present invention comprises the following components in parts by weight: the compound fertilizer comprises 60 parts of macronutrient NPK, 10 parts of micronutrients, and 5 parts of humic acid. In one embodiment, the macronutrient NPK of the present invention comprises urea, monoammonium phosphate, and potassium sulfate. In one embodiment, the mass ratio of urea, monoammonium phosphate, and potassium sulfate in the macronutrient NPK of the present invention is 1:1:1. The present invention utilizes the compound fertilizer's function of providing the necessary nutrients for plant growth and enhancing nutrient absorption. In the present invention, the mass parts of urea, monoammonium phosphate, and potassium sulfate are respectively calculated based on the mass of nitrogen (N) in urea, phosphorus (P) in monoammonium phosphate, and potassium (K) in potassium sulfate.

[0057] In one embodiment, the mass ratio of sodium carboxymethyl cellulose and sodium alginate in the carrier is (1~5):(1~5); in another embodiment, the mass ratio of sodium carboxymethyl cellulose and sodium alginate in the carrier is 2.5:2.5. This invention utilizes the water-retaining and slow-release properties of the sodium carboxymethyl cellulose-sodium alginate composite carrier.

[0058] In one embodiment, each part of the microorganisms of the present invention comprises the following components in parts by weight: 1-2 parts of Bacillus subtilis, 1-2 parts of Bacillus laterosporus, 1-2 parts of Bacillus licheniformis, 1-2 parts of Bacillus thuringiensis, 1-2 parts of Bacillus amyloliquefaciens, 1-2 parts of Trichoderma harzianum, 1-2 parts of Aspergillus oryzae, and 1-2 parts of Pseudomonas pulvinata; in another embodiment, each part of the microorganisms of the present invention comprises the following components in parts by weight: the microorganisms of the present invention comprise 1 part of Bacillus subtilis, 1 part of Bacillus laterosporus, 1 part of Bacillus licheniformis, 1 part of Bacillus thuringiensis, 1 part of Bacillus amyloliquefaciens, 1 part of Trichoderma harzianum, 1 part of Aspergillus oryzae, and 1 part of Pseudomonas pulvinata. This invention utilizes microorganisms, including Bacillus subtilis to control fungi, Bacillus laterosporus to secrete beneficial substances and enhance plant stress resistance, Bacillus licheniformis to prevent and resist diseases, Bacillus thuringiensis to repel pests, Bacillus amyloliquefaciens to enhance crop stress resistance, Trichoderma harzianum to control fungal pests, Aspergillus oryzae to produce beneficial metabolites and control soil-borne fungal diseases, and Aspergillus oryzae to enhance the activity of defensive enzymes. This invention combines Bacillus subtilis, Bacillus laterosporus, Bacillus licheniformis, Bacillus thuringiensis, Bacillus amyloliquefaciens, Trichoderma harzianum, Aspergillus oryzae, and Aspergillus oryzae, resulting in an overall effect of promoting plant growth and enhancing plant stress resistance.

[0059] In one embodiment, the dual-network hydrogel shell of the present invention comprises a polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel. In another embodiment, the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel of the present invention comprises water, glycerol, polyvinyl alcohol, and gelatin. In one embodiment, the mass ratio of water to glycerol in the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel of the present invention is (4~9):(1~6); in another embodiment, the mass ratio of water to glycerol in the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel of the present invention is 5.5:4.5. In one embodiment, the mass ratio of polyvinyl alcohol to gelatin in the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel of the present invention is (5~9):(1~5); in yet another embodiment, the mass ratio of polyvinyl alcohol to gelatin in the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel of the present invention is 6.5:3.5. In one embodiment, the total mass of polyvinyl alcohol and gelatin in this invention accounts for 15-35% of the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel; in another embodiment, the total mass of polyvinyl alcohol and gelatin in this invention accounts for 20% of the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel. This invention utilizes the water-retaining and slow-release properties of the dual-network hydrogel shell.

[0060] In one embodiment, the microbial fertilizer of the present invention is in granular form. The present invention defines the microbial fertilizer's structure from the inside out as including, in sequence, a nanoenzyme with peroxidase activity, a mesoporous material, a compound fertilizer, a carrier, microorganisms, and a double-network hydrogel shell. The resulting microbial fertilizer can achieve the effects of drought resistance, water retention, slow release, stable yield under adverse conditions, and increased yield under favorable conditions.

[0061] The present invention also provides a method for preparing the microbial fertilizer described in the above technical solution, comprising the following steps:

[0062] By loading nanozymes with peroxidase activity onto mesoporous materials, a core-shell structure was obtained.

[0063] The core-shell structure is encapsulated in compound fertilizer, granulated, and dried to obtain fertilizer core particles.

[0064] The fertilizer core particles are coated with a carrier to obtain an inner-coated water-retaining slow-release fertilizer.

[0065] By using microorganisms to coat the inner membrane of the water-retaining and slow-release fertilizer, a microbial-coated fertilizer is obtained.

[0066] Microbial fertilizer is obtained by encapsulating the microbial layer with a double-network hydrogel shell.

[0067] This invention utilizes mesoporous materials to load nanozymes with peroxidase activity, obtaining a core-shell structure. As one embodiment, the loading method described in this invention includes co-precipitation and / or the Stöber method.

[0068] After obtaining the core-shell structure, this invention encapsulates the core-shell structure with compound fertilizer, granulates, and dries to obtain fertilizer core particles. As one embodiment, this invention grinds the compound fertilizer through a 40-100 mesh sieve, then uses the undersize material to encapsulate the core-shell structure, granulates, and dries to obtain fertilizer core particles. As one embodiment, the encapsulation method of this invention includes: mixing and granulating the macro-element NPK in the compound fertilizer with the core-shell structure, and then mixing and granulating it with other components in the compound fertilizer. As one embodiment, the particle size of the granulated particles is 1-2 mm. This invention does not have strict requirements on the drying method; conventional methods in the art can be used. This invention encapsulates the core-shell structure with macro-element NPK and other components in the compound fertilizer, which has the advantage of allowing the fertilizer components to both exert their fertilizer effect and act as an encapsulation layer.

[0069] After obtaining the fertilizer core particles, this invention uses a carrier to coat the fertilizer core particles, resulting in an internally coated, water-retaining, slow-release fertilizer. As one embodiment, the coating method of this invention includes: spraying the carrier onto the surface of the fertilizer core particles and then drying them. This invention does not have strict requirements on the drying method; conventional methods in the art are acceptable.

[0070] After obtaining the inner-coated water-retaining slow-release fertilizer, this invention utilizes microorganisms to coat the inner-coated water-retaining slow-release fertilizer, resulting in a microbial-coated fertilizer. In one embodiment, the coating method of this invention includes spraying microorganisms onto the surface of the inner-coated water-retaining slow-release fertilizer; in another embodiment, the coating method of this invention includes spraying a microbial agent onto the surface of the inner-coated water-retaining slow-release fertilizer. This invention does not have strict requirements regarding the source of the microorganisms, which are obtained from commercially available products.

[0071] The microbial layer-coated fertilizer is obtained by using a dual-network hydrogel shell to encapsulate the microbial layer-coated fertilizer, thus obtaining microbial fertilizer. As one embodiment, the encapsulation method of the present invention includes: heating the dual-network hydrogel shell at 60-80°C to obtain a molten hydrogel; soaking the microbial layer-coated fertilizer in the molten hydrogel and then granulating it. As another embodiment, the preparation method of the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel of the present invention includes: mixing gelatin, polyvinyl alcohol, water, and glycerol; mixing uniformly at 85-100°C; cooling to room temperature; maintaining at -18°C for 12 hours; and then maintaining at 25°C for 2 hours to obtain the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel.

[0072] The present invention also provides the application of the microbial fertilizer described in the above technical solution or the microbial fertilizer obtained by the above preparation method in plant cultivation.

[0073] In one embodiment, the plant cultivation of the present invention includes stable yield under adverse conditions and / or increased yield under favorable conditions. In one embodiment, the plant of the present invention includes rapeseed. In one embodiment, the adverse conditions of the present invention include a dry environment. The microbial fertilizer of the present invention has the effects of drought resistance, water retention, slow release, stable yield under adverse conditions and increased yield under favorable conditions, especially able to improve the yield and quality of rapeseed under arid conditions.

[0074] To further illustrate the present invention, the following detailed description, in conjunction with the accompanying drawings and embodiments, describes a microbial fertilizer with drought-resistant, water-retaining, and slow-release effects, its preparation method, and its application. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0075] Example 1

[0076] Synthesis of nano-ferric oxide

[0077] Nano-sized iron(III) oxide was synthesized using a chemical co-precipitation method, specifically by controlling the Fe content. 2+ with Fe 3+ The molar ratio is 1:2. Under N2 protection, Fe... 2+ The aqueous solution was slowly added to Fe 3+ The mixture was stirred continuously in an aqueous solution. While maintaining stirring, ammonia solution was added dropwise to the mixture at 50°C, resulting in a black precipitate of nano-Fe3O4 particles. The mixture was stirred for another 2 hours to allow particle growth. Finally, the mixture was centrifuged, the supernatant was discarded, the precipitate was washed with deionized water, and vacuum dried to obtain Fe3O4 particles. Scanning electron microscopy characterization showed that the particle size was 40–60 nm. Figure 1 ).

[0078] Example 2

[0079] Preparation of porous silica nanocarriers

[0080] Solution A was obtained by mixing 6% v / v ammonia, 34% v / v ethanol, and 60% v / v water; solution B was obtained by mixing 10% v / v tetraethyl orthosilicate and 90% v / v ethanol. Solution A was injected into solution B with stirring, and the reaction was carried out for 2 hours. After centrifugation at 8000 rpm for 10 minutes, the resulting sample was washed twice with ethanol and water, respectively, to obtain porous silica nanocarriers, which were then dispersed in water for later use.

[0081] The porous silica nanocarriers were characterized by scanning electron microscopy and transmission electron microscopy, respectively, and the results are as follows: Figure 2 and Figure 3 As shown. Figure 2 and Figure 3 It can be seen that the prepared porous silica nanocarrier has a particle size of about 300 nm and has abundant fine pores on its surface.

[0082] Example 3

[0083] Preparation of sodium carboxymethyl cellulose and sodium alginate composite carrier

[0084] Sodium carboxymethyl cellulose and sodium alginate (mass ratio 1:1) were added to deionized water and magnetically stirred until homogeneous. 0.1 wt.% calcium chloride solution was added dropwise, and magnetic stirring was continued for 10–14 hours. The resulting sample was then freeze-dried for 24 hours to obtain the sodium carboxymethyl cellulose-sodium alginate composite carrier, as shown in the schematic diagram. Figure 4 As shown.

[0085] Example 4

[0086] Preparation of polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel

[0087] Water and glycerol were mixed at a volume ratio of 5.5:4.5 to obtain a solvent. Gelatin and polyvinyl alcohol were added to the solvent and mixed evenly at 95°C. After cooling to room temperature, the mixture underwent a freeze-thaw cycle (held at -18°C for 12 hours, then at 25°C for 2 hours) to obtain a polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel. The ratio of polyvinyl alcohol to gelatin was 6.5:3.5. The total mass of polyvinyl alcohol and gelatin accounted for 20% of the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel.

[0088] Example 5

[0089] Preparation of microbial fertilizer

[0090] 1. Prepare materials according to the following mass parts: The raw materials for preparing the microbial fertilizer include 2.5 parts of nano-iron oxide obtained in Example 1, 2.5 parts of porous silica nanocarrier obtained in Example 2, 75 parts of compound fertilizer, 5 parts of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3, 10 parts of microbial preparation, and 5 parts of polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel obtained in Example 4;

[0091] Each part by weight of compound fertilizer is composed of the following parts by weight of raw materials: 20 parts of urea (major elements), 20 parts of monoammonium phosphate, 20 parts of potassium sulfate, 10 parts of trace elements, and 5 parts of humic acid.

[0092] 2. Using the co-precipitation method, the nano-iron oxide obtained in Example 1 was loaded onto the porous silica nanocarrier obtained in Example 2 to obtain a core-shell structure;

[0093] 3. Grind urea, monoammonium phosphate, potassium sulfate, trace elements, and humic acid separately through a 40-100 mesh sieve. Then, mix the sieved urea, monoammonium phosphate, and potassium sulfate evenly and feed them into a rotary drum granulator. Pass a spray (atomized water) containing the core-shell structure obtained in step 2 through the granulation process to achieve a rolling humidification and granulation diameter of 1-2 mm. Then, add the other sieved and evenly mixed raw materials mentioned above and continue granulation. Finally, remove the resulting granules, dry them, and obtain a fertilizer and nutrient-enhancing compound containing a nano-core-shell structure. (Obtain fertilizer core granules)

[0094] 4. Place the fertilizer core granules obtained in step 3 into a granulator, rotate the disc, spray in the solution of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3, take it out, dry it, and obtain the inner-coated water-retaining slow-release fertilizer.

[0095] 5. Using a coating spraying system, the purchased microbial preparation (purchased from Shandong Hairuis Marine Biotechnology Co., Ltd., including 1 part by weight of Bacillus subtilis, 1 part by weight of Bacillus laterosporus, 1 part by weight of Bacillus licheniformis, 1 part by weight of Bacillus thuringiensis, 1 part by weight of Bacillus amyloliquefaciens, 1 part by weight of Trichoderma harzianum, 1 part by weight of Aspergillus oryzae and 1 part by weight of Bacillus erythropoietin) is evenly sprayed onto the surface of the inner-coated water-retaining slow-release fertilizer obtained in step 4 to obtain a microbial-coated fertilizer.

[0096] 6. The hydrogen bonds of the polyvinyl alcohol-glycerol / gelatin double-network organic hydrogel obtained in Example 4 were broken by heating at 60-80℃ to obtain a molten hydrogel; the microbial layer-coated fertilizer obtained in step 5 was immersed in the prepared molten hydrogel for 3-5 seconds and then removed, granulated to a particle size of 3-5 mm to obtain microbial fertilizer. A partial scanning electron microscope image of the particle surface is shown below. Figure 5 As shown in the picture, the finished product is as follows. Figure 6 As shown.

[0097] Comparative Example 1

[0098] The preparation of a microbial fertilizer is similar to Example 5, except that it does not use a polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel. The specific steps are as follows:

[0099] 1. Prepare materials according to the following mass parts: 2.5 parts of nano-iron oxide obtained in Example 1, 2.5 parts of porous silica nanocarrier obtained in Example 2, 75 parts of compound fertilizer, 5 parts of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3, and 10 parts of microbial preparation;

[0100] Each part by weight of the compound fertilizer includes 20 parts of macro-elements urea, 20 parts of monoammonium phosphate, 20 parts of potassium sulfate, 10 parts of trace elements, and 5 parts of humic acid.

[0101] 2. Using the co-precipitation method, the nano-iron oxide obtained in Example 1 was loaded onto the porous silica nanocarrier obtained in Example 2 to obtain a core-shell structure;

[0102] 3. Grind urea, monoammonium phosphate, potassium sulfate, trace elements, and humic acid separately through a 40-100 mesh sieve. Then, mix the sieved urea, monoammonium phosphate, and potassium sulfate evenly and feed them into a rotary drum granulator. Pour in spray (atomized water) containing the core-shell structure obtained in step 2 for rolling humidification and granulation, resulting in a particle size of 1-2 mm. Then, add the other sieved and evenly mixed raw materials mentioned above and continue granulation. Finally, remove the resulting granules, dry them, and obtain fertilizer core granules.

[0103] 4. Place the fertilizer core granules obtained in step 3 into a granulator, rotate the disc, spray in the solution of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3, take it out, dry it, and obtain the inner-coated water-retaining slow-release fertilizer.

[0104] 5. Using a coating machine spraying system, the purchased microbial preparation (purchased from Shandong Hairuis Marine Biotechnology Co., Ltd.) is evenly sprayed onto the surface of the inner-coated water-retaining slow-release fertilizer obtained in step 4 to obtain microbial fertilizer.

[0105] Comparative Example 2

[0106] A method for preparing microbial fertilizer, similar to Example 5, differs only in that it does not use polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel and nano-ferric oxide. The specific steps are as follows:

[0107] 1. Prepare materials according to the following parts by weight: 2.5 parts of porous silica nanocarrier obtained in Example 2, 75 parts of compound fertilizer, 5 parts of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3, and 10 parts of microbial preparation;

[0108] Each part by weight of the compound fertilizer includes 20 parts of macro-elements urea, 20 parts of monoammonium phosphate, 20 parts of potassium sulfate, 10 parts of trace elements, and 5 parts of humic acid.

[0109] 2. Grind urea, monoammonium phosphate, potassium sulfate, trace elements, and humic acid separately through a 40-100 mesh sieve. Then, mix the sieved urea, monoammonium phosphate, and potassium sulfate evenly and feed them into a rotary drum granulator. Pour in a spray (atomized water) containing the porous silica nanocarrier obtained in Example 2 for rolling humidification and granulation, resulting in a particle size of 1-2 mm. Then, add the other sieved and evenly mixed raw materials mentioned above and continue granulation. Finally, remove the resulting granules, dry them, and obtain fertilizer core granules.

[0110] 3. Place the fertilizer core granules obtained in step 2 into a granulator, rotate the disc, spray in the solution of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3, take it out, dry it, and obtain the inner-coated water-retaining slow-release fertilizer.

[0111] 4. Using a coating machine spraying system, the purchased microbial preparation (purchased from Shandong Hairuis Marine Biotechnology Co., Ltd.) is evenly sprayed onto the surface of the inner-coated water-retaining slow-release fertilizer obtained in step 3 to obtain microbial fertilizer.

[0112] Comparative Example 3

[0113] A method for preparing fertilizer, similar to Example 5, differs only in that it does not use polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel, nano-ferric oxide, and microbial preparations. The specific steps are as follows:

[0114] 1. Prepare materials according to the following parts by weight: 2.5 parts of porous silica nanocarrier obtained in Example 2, 75 parts of compound fertilizer, and 5 parts of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3;

[0115] Each part by weight of the compound fertilizer includes 20 parts of macro-elements urea, 20 parts of monoammonium phosphate, 20 parts of potassium sulfate, 10 parts of trace elements and 5 parts of humic acid.

[0116] 2. Grind urea, monoammonium phosphate, potassium sulfate, trace elements, and humic acid separately through a 40-100 mesh sieve. Then, mix the sieved urea, monoammonium phosphate, and potassium sulfate evenly and feed them into a rotary drum granulator. Pour in a spray (atomized water) containing the porous silica nanocarrier obtained in Example 2 for rolling humidification and granulation, resulting in a particle size of 1-2 mm. Then, add the other sieved and evenly mixed raw materials mentioned above and continue granulation. Finally, remove the resulting granules, dry them, and obtain fertilizer core granules.

[0117] 3. Place the fertilizer core granules obtained in step 2 into a granulator, rotate the disc, spray in the solution of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3, take it out, dry it, and obtain fertilizer.

[0118] Comparative Example 4

[0119] A method for preparing fertilizer, differing from Example 5 in that it does not use polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel, nano-ferric oxide, and microbial agents, and the composition of the compound fertilizer is different. The specific steps are as follows:

[0120] 1. Prepare materials according to the following parts by weight: 2.5 parts of porous silica nanocarrier obtained in Example 2, 70 parts of compound fertilizer, and 5 parts of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3;

[0121] Each part by weight of the compound fertilizer includes 20 parts of macro-elements urea, 20 parts of monoammonium phosphate, 20 parts of potassium sulfate, and 10 parts of micro-elements.

[0122] 2. Grind urea, monoammonium phosphate, potassium sulfate, and trace elements separately through a 40-100 mesh sieve. Then, mix the sieved urea, monoammonium phosphate, and potassium sulfate evenly and feed them into a rotary drum granulator. Pour in a spray (atomized water) containing the porous silica nanocarrier obtained in Example 2 for rolling humidification and granulation, resulting in a particle size of 1-2 mm. Then, add the sieved trace elements and continue granulation. Finally, remove the resulting granules, dry them, and obtain fertilizer core granules.

[0123] 3. Place the fertilizer core granules obtained in step 2 into a granulator, rotate the disc, spray in the solution of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3, take it out, dry it, and obtain fertilizer.

[0124] Comparative Example 5

[0125] A method for preparing fertilizer, differing from Example 5 in that it does not use polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel, nano-ferric oxide, and microbial agents, and the composition of the compound fertilizer is different. The specific steps are as follows:

[0126] 1. Prepare materials according to the following parts by weight: 2.5 parts of porous silica nanocarrier obtained in Example 2, 60 parts of compound fertilizer, and 5 parts of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3;

[0127] Each part by weight of the compound fertilizer includes 20 parts of urea, 20 parts of monoammonium phosphate and 20 parts of potassium sulfate.

[0128] 2. Grind urea, monoammonium phosphate, potassium sulfate and trace elements separately through a 40-100 mesh sieve. Then mix the sieved urea, monoammonium phosphate and potassium sulfate evenly and put them into a rotary drum granulator. Spray (atomized water) containing the porous silica nanocarrier obtained in Example 2 is passed through the drum for rolling humidification granulation. The granulation particle size is 1-2 mm to obtain fertilizer core particles.

[0129] 3. Place the fertilizer core granules obtained in step 2 into a granulator, rotate the disc, spray in the solution of sodium carboxymethyl cellulose and sodium alginate composite carrier obtained in Example 3, take it out, dry it, and obtain fertilizer.

[0130] Application Example 1

[0131] The effect of microbial fertilizer application on rapeseed growth

[0132] This embodiment uses a pot planting experiment for rapeseed. The pot dimensions are: pot diameter 11.6 cm × pot bottom diameter 7.8 cm × pot height 9.6 cm. Each pot contains 0.5 kg of soil. Sowing is performed, and when the rapeseed grows to two true leaves, seedlings are thinned, leaving one plant per pot. During this period, watering is done every two days, with approximately 200 mL of water each time. When the rapeseed reaches the fifth true leaf stage, it is randomly divided into different treatment groups, and different fertilizer components are applied. Each treatment has five replicates. The specific treatment methods are as follows:

[0133] Treatment 1: Do not fertilize;

[0134] Treatment 2: Apply the fertilizer obtained in Comparative Example 5;

[0135] Treatment 3: Apply the fertilizer obtained in comparison ratio 4;

[0136] Treatment 4: Apply the fertilizer obtained in Comparative Example 3;

[0137] Treatment 5: Apply the fertilizer obtained in Comparative Example 2;

[0138] Treatment 6: Apply the microbial fertilizer obtained in Comparative Example 1;

[0139] Treatment 7: Apply the microbial fertilizer obtained in Example 5.

[0140] Each treatment group was harvested 21 days after treatment (fertilization was only applied once during the treatment period, and the watering frequency and amount in each pot were kept consistent). The growth status of the rapeseed under different treatments before harvest is as follows: Figure 7 and Figure 8 As shown. Figure 7 and Figure 8 It can be seen that although the seedlings varied in height within each treatment group due to individual differences, the overall seedling height showed an increasing trend from treatment 1 to treatment 7; among them, Figure 7 and Figure 8 From left to right, these are processing steps 1 through 7.

[0141] Application Example 2

[0142] The effect of microbial fertilizer application on rapeseed growth under water-scarce conditions

[0143] This embodiment uses a pot planting experiment for rapeseed. The pot dimensions are: pot diameter 11.6 cm × pot bottom diameter 7.8 cm × pot height 9.6 cm. Each pot contains 0.5 kg of soil. Sowing is performed, and when the rapeseed grows to two true leaves, seedlings are thinned, leaving one plant per pot. During this period, watering is done every two days, with approximately 200 mL of water each time. When the rapeseed reaches the fifth true leaf stage, it is randomly divided into different treatment groups, and different fertilizer components are applied. Each treatment has five replicates. The specific treatment methods are as follows:

[0144] Treatment 1: Do not fertilize;

[0145] Treatment 2: Apply the fertilizer obtained in Comparative Example 5;

[0146] Treatment 3: Apply the fertilizer obtained in comparison ratio 4;

[0147] Treatment 4: Apply the fertilizer obtained in Comparative Example 3;

[0148] Treatment 5: Apply the fertilizer obtained in Comparative Example 2;

[0149] Treatment 6: Apply the microbial fertilizer obtained in Comparative Example 1;

[0150] Treatment 7: Apply the microbial fertilizer obtained in Example 5.

[0151] (1) Each treatment group was harvested 21 days after treatment (fertilization was only applied once during the treatment period, and the watering frequency was changed from once every 2 days to once every 5 days to simulate water shortage conditions). The growth status of rapeseed under different treatments before harvest is as follows: Figure 9 As shown.

[0152] according to Figure 9 It can be seen that, compared with other treatments (treatments 1-6), the seedlings in treatment group 7 showed a more obvious drought resistance effect. This indicates that the microbial fertilizer provided by this invention can play a certain role in drought resistance and water retention.

[0153] (2) After harvesting, the rapeseed was first sampled in a fresh state, and the contents of nitrogen, total phosphorus, vitamin C, total amino acids, H2O2, DPPH, superoxide anion, POD and other indicators were measured. Then, it was placed in an oven at 105℃ for 30 minutes to blanch, and then dried in an oven at 75℃. After grinding, the physicochemical analysis of the seedlings treated with different methods was carried out. The results are shown in Table 1.

[0154] Table 1. Yield and quality of rapeseed under different treatments

[0155]

[0156] As shown in Table 1, the moisture content gradually increased from treatment 1 to treatment 7, proving that the microbial fertilizer provided by this invention can play a certain role in drought resistance and water retention. The content of nitrogen, phosphorus, and potassium elements gradually increased, indicating that the microbial fertilizer provided by this invention can promote the absorption of fertilizer nutrients by crops to a certain extent. At the same time, the content of beneficial elements such as iron, manganese, and zinc, as well as vitamin C and total amino acid content in the seedlings also showed an increasing trend, indicating that the microbial fertilizer provided by this invention can improve the nutritional quality of seedlings to a certain extent. The content of hydrogen peroxide and superoxide anion showed a decreasing trend, indicating that the microbial fertilizer provided by this invention has a certain ability to scavenge free radicals (reactive oxygen species). The content of DPPH and POD showed an increasing trend, indicating that the microbial fertilizer provided by this invention has a strong stress resistance effect.

[0157] As can be seen from the above, the microbial fertilizer provided by this invention can achieve the effects of drought resistance, water retention, slow release, stable yield under adverse conditions, and increased yield under favorable conditions.

[0158] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. The application of microbial inoculants in improving the yield and quality of rapeseed under arid conditions, characterized in that, The microbial fertilizer consists of, from the inside out, nanoenzymes with peroxidase activity, mesoporous materials, compound fertilizers, carriers, microorganisms, and a double-network hydrogel shell. The compound fertilizer includes macro-elements NPK, micro-elements, and synergistic components; The synergistic components include one or more of the following: seaweed extract, humic acid, biochar, zinc humic acid, and selenoamino acids. The carrier includes a sodium carboxymethyl cellulose-sodium alginate composite carrier; The effective viable count of the microorganisms is ≥0.2~0.5 billion / gram, including Bacillus subtilis, Bacillus laterosporus, Bacillus licheniformis, Bacillus thuringiensis, Bacillus amyloliquefaciens, Trichoderma harzianum, Aspergillus oryzae, and Pterygospermum erythropoiesis. The nanozyme with peroxidase activity is iron(III) oxide; The microbial fertilizer is applied by broadcasting.

2. The application according to claim 1, characterized in that, The microbial fertilizer comprises the following components in parts by weight: 1-5 parts of nanoenzyme with peroxidase activity, 1-5 parts of mesoporous material, 60-80 parts of compound fertilizer, 1-5 parts of carrier, 2-10 parts of microorganisms, and 2-10 parts of double-network hydrogel shell.

3. The application according to claim 2, characterized in that, Each portion of the compound fertilizer comprises the following components by weight: 50-60 parts of macronutrient NPK, 5-10 parts of micronutrients, and 5-10 parts of synergistic components; Each of the microorganisms comprises the following components in parts by weight: 1-2 parts of Bacillus subtilis, 1-2 parts of Bacillus laterosporus, 1-2 parts of Bacillus licheniformis, 1-2 parts of Bacillus thuringiensis, 1-2 parts of Bacillus amyloliquefaciens, 1-2 parts of Trichoderma harzianum, 1-2 parts of Aspergillus oryzae, and 1-2 parts of Pseudomonas sylvestris. The mass ratio of sodium carboxymethyl cellulose and sodium alginate in the carrier is (1~5):(1~5).

4. The application according to claim 2, characterized in that, The mesoporous material includes one or more of mesoporous silicon, LDHs, and mesoporous silica. The dual-network hydrogel shell comprises a polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel.

5. The application according to claim 4, characterized in that, The polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel comprises water, glycerol, polyvinyl alcohol, and gelatin; The mass ratio of water to glycerol in the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel is (4~9):(1~6). The mass ratio of polyvinyl alcohol to gelatin in the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel is (5~9):(1~5). The total mass of the polyvinyl alcohol and gelatin accounts for 15-35% of the polyvinyl alcohol-glycerol / gelatin dual-network organic hydrogel.

6. The application according to any one of claims 1 to 5, characterized in that, The dosage form of the application is granules.

7. The application according to claim 1, characterized in that, The method for preparing the microbial fertilizer includes the following steps: By loading nanozymes with peroxidase activity onto mesoporous materials, a core-shell structure was obtained. The core-shell structure is encapsulated in compound fertilizer, granulated, and dried to obtain fertilizer core particles. The fertilizer core particles are coated with a carrier to obtain an inner-coated water-retaining slow-release fertilizer. By using microorganisms to coat the inner membrane of the water-retaining and slow-release fertilizer, a microbial-coated fertilizer is obtained. Microbial fertilizer is obtained by encapsulating the microbial layer with a double-network hydrogel shell.

8. The application according to claim 7, characterized in that, The loading methods include co-precipitation and / or the Stöber method; The encapsulation method includes: mixing and granulating the macro-element NPK and the core-shell structure in the compound fertilizer, and then mixing and granulating it with other components in the compound fertilizer; The coating method includes: spraying the carrier onto the surface of the fertilizer core particles and then drying it; The coating method includes: spraying microorganisms onto the surface of the inner membrane water-retaining slow-release fertilizer; The encapsulation method includes: heating the double-network hydrogel shell at 60~80℃ to obtain a molten hydrogel; soaking the microbial layer in the molten hydrogel to encapsulate the fertilizer, and then granulating it.

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