Multi-enzyme gold biological organic enzyme agricultural fertilizer

Abstract

The invention belongs to the technical field of fertilizers, and particularly relates to a multi-enzyme gold biological organic enzyme agricultural fertilizer. 8-12 parts of a mesoporous multienzyme gold compound, 10-15 parts of a temperature-sensitive enzyme nutrient compound, 3-5 parts of growth-promoting rhizobacteria microspheres, 62-76 parts of an organic carrier, 2-4 parts of a trace element additive and 1-2 parts of a pH buffer agent; wherein the mesoporous multienzyme gold compound is formed by compounding a functionalized silicon carbon carrier and a multienzyme gold compound according to a mass ratio of 1: 2; the temperature-sensitive enzyme nutrient compound is formed by compounding poly N-isopropylacrylamide, a biological organic enzyme and a slow-release nutrient according to a mass ratio of 2: 1: 3; the growth-promoting rhizobacteria microspheres are microspheres of a double-layer structure, and the growth-promoting rhizobacteria microspheres comprise the following components in parts by weight: 45-55 parts of an inner-layer bacterial strain protection layer and 45-55 parts of an outer-layer bacteriostatic protection layer.

Description

Technical Field

[0001] This invention belongs to the field of fertilizer technology, specifically relating to a multi-enzyme gold bio-organic enzyme agricultural fertilizer. Background Technology

[0002] In agricultural production, fertilizer is a key resource for ensuring crop growth. Currently, the mainstream agricultural fertilizers on the market are mainly divided into three categories: Chemical fertilizers, such as urea and diammonium phosphate, can quickly provide nutrients such as nitrogen, phosphorus, and potassium, but long-term use can easily lead to soil compaction and deterioration of physical and chemical properties (such as soil pH imbalance and decrease in organic matter content). A large amount of unabsorbed nutrients are leached or volatilized by rainwater, causing environmental pollution. Ordinary organic fertilizers, such as well-rotted straw fertilizer and livestock and poultry manure fertilizer, can replenish soil organic matter, but the decomposition rate of large molecular organic matter such as cellulose and protein is slow, the content of readily available nutrients that crops can absorb is low, and they lack active enzymes, so they cannot efficiently transform nutrients fixed in the soil (such as insoluble phosphorus and potassium). Single-enzyme fertilizers: Some products add a single enzyme (such as cellulase), but the enzyme activity is easily affected by soil temperature and pH and is quickly deactivated. Moreover, a single enzyme cannot synergistically decompose multiple organic nutrients, resulting in poor overall fertilizer efficiency and difficulty in meeting the needs of soil improvement and high crop yield at the same time. Therefore, a multi-enzyme gold bio-organic enzyme agricultural fertilizer has been improved and designed. Summary of the Invention

[0003] In view of the above-mentioned shortcomings in the prior art, the present invention provides a multi-enzyme gold bio-organic enzyme agricultural fertilizer to solve the problems in the background art.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A multi-enzyme gold bio-organic enzyme agricultural fertilizer comprises the following components by weight: 8-12 parts of mesoporous multi-enzyme gold complex, 10-15 parts of thermosensitive enzyme nutrient complex, 3-5 parts of rhizosphere growth-promoting bacteria microspheres, 62-76 parts of organic carrier, 2-4 parts of trace element additives, and 1-2 parts of pH buffer. The mesoporous multi-enzyme gold complex is composed of a functionalized silicon carbon support and a multi-enzyme gold complex in a mass ratio of 1:2. The temperature-sensitive enzyme nutrient complex is composed of poly(N-isopropylacrylamide), bio-organic enzymes, and slow-release nutrients in a mass ratio of 2:1:3. The rhizosphere growth-promoting microspheres are bilayered microspheres, comprising, by weight, an inner bacterial strain protective layer of 45-55 parts and an outer antibacterial protective layer of 45-55 parts. The inner strain protective layer is composed of the following components by weight: 38-45 parts rhizosphere growth-promoting bacteria, 3.8-4.5 parts sucrose protectant, 2.5-4 parts sodium alginate, and 0.7-1.5 parts deionized water. The outer antibacterial protective layer is composed of the following components by weight: 40-50.5 parts Tris-HCl buffer, 2-3 parts chitosan, 0.5-1 parts dopamine hydrochloride, and 0.2-0.5 parts acetic acid.

[0005] Furthermore, the organic carrier is composed of a mixture of decomposed straw powder and fermented livestock and poultry manure in a mass ratio of 2:3.

[0006] Furthermore, the trace element additive is composed of borax, zinc sulfate, and ammonium molybdate mixed in a mass ratio of 2:1:1.

[0007] Furthermore, the pH buffer is composed of citric acid and sodium citrate mixed in a mass ratio of 1:1.5.

[0008] Furthermore, the rhizosphere growth-promoting bacteria are a mixture of *Azotobacter brasiliensis*, *Pseudomonas fluorescens*, and *Bacillus subtilis* in a mass ratio of 1:1:1, and then cultured in LB medium at 37°C for 24 hours. The mass ratio of the sucrose protectant to the rhizosphere growth-promoting bacteria is 1:10; The method for preparing the inner layer of bacterial protective layer includes: mixing rhizosphere growth-promoting bacteria with sucrose protective agent, dispersing them in sodium alginate aqueous solution at a solid-liquid ratio of 1:20, and dripping the mixture into calcium chloride aqueous solution at a flow rate of 1-2 mL / h through a microfluidic device with a channel diameter of 100 μm. The mixture is then cured at a constant temperature of 25°C for 30 minutes to form inner layer microspheres with a particle size of 180-220 μm.

[0009] Furthermore, the preparation method of the outer antibacterial protective layer includes: immersing the inner microspheres in a chitosan solution with a solid-liquid ratio of 1:30, the total mass of the chitosan solution being 3 times the mass of the inner microspheres; stirring at 25°C for 60 minutes, then draining and transferring to a dopamine hydrochloride-Tris-HCl buffer system; reacting at 25°C in the dark for 2 hours; rinsing three times with deionized water; and then freeze-drying under vacuum at -40°C and 5Pa for 8 hours to form an outer composite layer with a thickness of 10-20 μm.

[0010] Furthermore, the decomposed straw powder is at least one of decomposed corn straw powder and decomposed rice straw powder; The fermented animal manure is at least one of pig manure fermentation or chicken manure fermentation.

[0011] Furthermore, the method for preparing the fertilizer includes the following steps: Step S1: Crush the organic carrier, add it to the pH buffer, mix well, and adjust the moisture content to 50%–60% and the pH to 6.8–7.2. Step S2: Add the temperature-sensitive enzyme nutrient complex to the product of step S1, and ferment at a constant temperature of 35°C for 5 days, stirring once a day for 30 minutes each time. Step S3: Add mesoporous multi-enzyme gold complex, rhizosphere growth-promoting bacteria microspheres, and trace element additives to the fermentation product of step S2 in sequence, and stir at room temperature for 90 minutes to form a mixture. Step S4: The mixture from step S3 is dried at a low temperature of 45°C and granulated to form particles with a particle size of 3-5 mm. The surface is coated with a mesoporous silica-trehalose composite film, which is made by mixing mesoporous silica and trehalose in a mass ratio of 1:3, to obtain the finished product of multi-enzyme gold bio-organic enzyme agricultural fertilizer.

[0012] Furthermore, the preparation method of the functionalized silicon-carbon support includes the following steps; Hierarchical mesoporous silica was prepared using a hard-template-soft-template composite method: polystyrene microspheres were used as hard templates and hexadecyltrimethylammonium bromide as soft templates. Tetraethyl orthosilicate was added dropwise to a 2% (w / w) aqueous solution of hexadecyltrimethylammonium bromide at a rate of 0.5–1.0 mL / min. After stirring at room temperature for 12 hours, the templates were removed by calcination at 550 °C for 6 hours, resulting in hierarchical mesoporous silica containing 2–5 nm micropores and 15–20 nm mesopores. Bifunctional groups were grafted onto hierarchical mesoporous silica: hierarchical mesoporous silica was dispersed in a 1:1 volume ratio ethanol-water mixture, and 10%–12% by weight of 3-mercaptopropyltrimethoxysilane was added. The mixture was stirred at 50°C for 6 hours. Then, 8%–10% by weight of succinic anhydride was added, and the mixture was refluxed at 60°C for 4 hours to obtain bifunctional modified mesoporous silica. Bifunctional modified mesoporous silica and modified biochar were mixed at a mass ratio of 3:1, and deionized water with a solid-liquid ratio of 1:10 was added. The mixture was ultrasonically dispersed at 300W for 30 minutes and then freeze-dried under vacuum at -50℃ and 10Pa for 8 hours to obtain a functionalized silicon-carbon carrier.

[0013] Furthermore, the multi-enzyme gold complex is composed of gold nanoparticles and a composite enzyme mixed at a mass ratio of 1:5 to 1:8, wherein the gold nanoparticles are spherical or near-spherical metal particles formed of gold element with a particle size at the nanoscale. The complex enzyme is a mixture of cellulase, protease and phytase in a mass ratio of 2:1:1. The bio-organic enzyme is a mixture of amylase, xylanase and laccase in a mass ratio of 3:2:1. The slow-release nutrients are composed of trehalose and humic acid mixed in a mass ratio of 1:3. The preparation process of the temperature-sensitive enzyme nutrient complex is as follows: poly(N-isopropylacrylamide) is prepared into a 10% aqueous solution, organic enzymes and slow-release nutrients are added, emulsified at 60°C for 30 minutes, crosslinked by adding 2 mol / L calcium chloride solution, and spray-dried to obtain microspheres with a particle size of 5-10 μm.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. Long-term stable enzyme activity: In the mesoporous multi-enzyme gold complex, the enzyme activity can be kept stable throughout the entire growth period by means of the synergistic effect of the "bifunctional group + biochar buffer" of the functionalized silicon carbon carrier. Compared with the enzyme loading method of ordinary mesoporous carrier, the enzyme half-life is significantly extended. Moreover, the enzyme activity can maintain a high level in soil environments with different pH values ​​such as acidic and saline-alkali, avoiding rapid enzyme inactivation due to soil environment fluctuations and ensuring the continuous decomposition efficiency of organic nutrients throughout the crop growth period.

[0015] 2. Precise nutrient release: The temperature-sensitive enzyme nutrient complex can adjust the nutrient release rate according to changes in ambient temperature. During critical growth stages of crops (such as the jointing stage of wheat and the fruit expansion stage of tomatoes), as ambient temperature rises, nutrients can be released rapidly to match the surge in nutrient demand from crops. In contrast, during the low-temperature period in early spring or late autumn, when the crop root system has a weaker absorption capacity, the nutrient release rate slows down, effectively reducing the accumulation and loss of nutrients in the soil, and achieving precise supply of "more when needed, less when not needed".

[0016] 3. Significant microecological regulation: Through the double-layer structure design of the rhizosphere growth-promoting bacteria microspheres, the inner protective layer can effectively protect the rhizosphere growth-promoting bacteria from adverse soil environments, greatly increasing the survival time of the strains in the soil and the number of rhizosphere colonizations; the outer antibacterial protective layer can specifically inhibit the growth and reproduction of harmful bacteria in the soil (such as Fusarium and Fusarium wilt pathogens), reducing the risk of crop diseases, while promoting the construction of beneficial microbial communities in the soil and improving the rhizosphere microecological environment.

[0017] 4. Heavy metal remediation and crop safety: The functionalized silicon-carbon carrier in this fertilizer can effectively adsorb and fix heavy metal ions (such as cadmium ions) in the soil through bifunctional groups, reducing the mobility of heavy metal ions in the soil, thereby reducing the absorption and accumulation of heavy metals by crops. When applied to soil contaminated with heavy metals, it can significantly reduce the heavy metal content in the edible parts of crops (such as wheat grains), ensuring that agricultural products meet food safety standards, while mitigating the adverse effects of heavy metals on soil enzyme activity and microbial communities.

[0018] 5. Soil improvement and crop yield increase: Continuous application of this fertilizer can gradually improve the physical structure of the soil, increase the proportion of soil aggregates, reduce soil bulk density, and improve the soil's water and fertilizer retention capacity and aeration. At the same time, the organic matter and enzymatic products slowly released by the organic carrier can enrich soil nutrients. Combined with the synergistic effect of rhizosphere growth-promoting bacteria, it provides a good soil environment for crop growth, ultimately promoting crop growth and development, and increasing crop yield and agricultural product quality. Attached Figure Description

[0019] Figure 1 This is a flowchart of a method for preparing a multi-enzyme gold bio-organic enzyme agricultural fertilizer according to the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0021] Unless otherwise specified, the experimental methods in the following examples were performed according to conventional procedures. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. In particular, *Azotobacter brasiliensis* (strain number ATCC29145), *Pseudomonas fluorescens* (strain number ATCC13525), and *Bacillus subtilis* (strain number ATCC6633) have all been disclosed in previous patent applications.

[0022] This invention provides a multi-enzyme gold bio-organic enzyme agricultural fertilizer, which, by weight, comprises 8-12 parts of mesoporous multi-enzyme gold complex, 10-15 parts of thermosensitive enzyme nutrient complex, 3-5 parts of rhizosphere growth-promoting bacteria microspheres, 62-76 parts of organic carrier, 2-4 parts of trace element additives, and 1-2 parts of pH buffer; wherein: The mesoporous multi-enzyme gold complex is composed of a functionalized silicon-carbon carrier and a multi-enzyme gold complex in a mass ratio of 1:2. It innovatively adopts a "hierarchical pore size mesoporous silica-modified biochar" composite carrier (functionalized silicon-carbon carrier): the enzyme molecules are precisely loaded through the 2-5nm micropores of the mesoporous silica, and the 15-20nm mesopores isolate nutrients to avoid enzyme-nutrient interactions; it grafts thiol and carboxyl bifunctional groups, which fix the enzyme molecules through electrostatic interaction and stabilize the local pH of the soil with the acid-base buffering capacity of biochar; it introduces gold nanoparticles to form a complex with the enzyme, and uses the catalytic activity of gold nanoparticles to reduce the activation energy of the enzymatic reaction, while reducing enzyme molecule denaturation through surface plasmon resonance effect, so as to achieve long-term stability of enzyme activity throughout the entire growth period.

[0023] The temperature-sensitive enzyme nutrient complex is composed of poly(N-isopropylacrylamide), bio-organic enzymes, and slow-release nutrients in a mass ratio of 2:1:3. The rhizosphere growth-promoting microspheres are bilayered microspheres consisting of an inner strain protective layer and an outer antibacterial protective layer, with a total mass fraction of 100 parts (45-55 parts for the inner strain protective layer and 45-55 parts for the outer antibacterial protective layer). The microspheres have a particle size of 200-300 μm and a particle size uniformity variation coefficient ≤5%. The inner layer uses sodium alginate as a framework and is compounded with sucrose protectant to maintain the integrity of the strain cell membrane and resist the attack of enzymatic hydrolysis products and heavy metal ions in fertilizers. The outer layer uses chitosan-polydopamine as an antibacterial barrier. After chitosan degradation, it provides glucosamine nutrients, and polydopamine forms a dense layer through polymerization to inhibit harmful bacteria such as Fusarium, while reducing the contact of harmful substances in the soil with the strains. The carrier-organic carrier-bufferant three-dimensional synergy utilizes the thiol groups of the functionalized silicon-carbon carrier to adsorb heavy metal ions (such as Cd²⁺) in the soil, reducing the mobility of heavy metals and the amount absorbed by crops. Using decomposed straw powder and fermented livestock and poultry manure as organic carriers, organic matter is slowly released to improve soil aggregate structure, and citric acid-sodium citrate pH buffer is used to stabilize local soil pH. The enzymatic hydrolysis products of organic carriers and the metabolites of growth-promoting bacteria synergistically promote the construction of beneficial soil microbial communities and alleviate the problem of soil compaction in saline-alkali / acidic soils. The organic carrier is composed of a mixture of well-rotted straw powder and fermented livestock and poultry manure at a mass ratio of 2:3; the well-rotted straw powder is well-rotted corn straw powder or well-rotted rice straw powder (which needs to be rotted for more than 60 days); the fermented livestock and poultry manure is fermented pig manure or fermented chicken manure (which needs to be fermented at high temperature for 30 days, and the moisture content after fermentation is ≤30%); the organic matter content of the organic carrier is ≥65%, and it has been crushed to a particle size ≤1mm; The trace element additive is composed of borax (purity ≥99%), zinc sulfate (purity ≥98%), and ammonium molybdate (purity ≥99%) in a mass ratio of 2:1:1. The pH buffer is composed of citric acid and sodium citrate mixed in a mass ratio of 1:1.5; the pH buffer is dissolved in deionized water to prepare a 1% (w / w) pH buffer aqueous solution, and the pH value of the aqueous solution is 6.8-7.2 at 25°C. The preparation method of this multi-enzyme gold bio-organic enzyme agricultural fertilizer includes the following steps: (1) Crush the organic carrier to a particle size ≤1mm, add pH buffer, mix evenly, and adjust the water content of the mixture to 50%~60% and the pH value to 6.8-7.2; (2) Add the temperature-sensitive enzyme nutrient complex to the system obtained in step (1) and ferment it at a constant temperature of 35°C for 5 days, stirring once a day for 30 minutes each time. (3) Add mesoporous multi-enzyme gold complex, rhizosphere growth-promoting bacteria microspheres and trace element additives to the fermented system in step (2) in sequence, and stir for 90 minutes at room temperature to form a mixture. (4) The mixture obtained in step (3) is dried at a low temperature of 45°C until the moisture content is ≤12%, and granulated using a granulation device (the particle size is controlled to be 3-5 mm); then, a mesoporous silica-trehalose composite film is coated on the surface of the granulated fertilizer particles. The amount of the composite film is 5% of the total mass of the granulated fertilizer particles, and the composite film is made of mesoporous silica and trehalose mixed in a mass ratio of 1:3. Finally, the multi-enzyme gold bio-organic enzyme agricultural fertilizer product is obtained.

[0024] The functionalized silicon-carbon support is prepared by the following process: a. Using polystyrene microspheres with a particle size of 100 nm as a hard template and hexadecyltrimethylammonium bromide as a soft template, tetraethyl orthosilicate was dropped into a 2% hexadecyltrimethylammonium bromide aqueous solution at a rate of 0.5–1.0 mL / min. After stirring at room temperature for 12 hours, the mixture was calcined at 550 °C for 6 hours to remove the template, resulting in hierarchical mesoporous silica containing 2–5 nm micropores and 15–20 nm mesopores. b. Disperse the above-mentioned graded pore size mesoporous silica in an ethanol-water mixture with a volume ratio of 1:1, add 10% to 12% of the mass of graded pore size mesoporous silica with 3-mercaptopropyltrimethoxysilane, stir at 50°C for 6 hours, then add 8% to 10% of the mass of graded pore size mesoporous silica with succinic anhydride, and reflux at 60°C for 4 hours to obtain bifunctional modified mesoporous silica; c. Bifunctional modified mesoporous silica and modified biochar were mixed at a mass ratio of 3:1, and deionized water was added (solid-liquid ratio of 1:10). The mixture was ultrasonically dispersed at 300W for 30 minutes and then freeze-dried under vacuum conditions of -50℃ and 10Pa for 8 hours to obtain a functionalized silicon-carbon carrier. The modified biochar was prepared by oxidizing corn cob char with a mass concentration of 5% nitric acid solution at 80℃ for 2 hours. The modified biochar had an oxygen content ≥18% and a specific surface area ≥800m² / g. The multi-enzyme gold complex is composed of gold nanoparticles with a particle size of 10-20 nm and a composite enzyme at a mass ratio of 1:5-1:8; the gold nanoparticles are purchased from Aladdin Reagent, reagent model A110914; the composite enzyme is composed of cellulase (enzyme activity ≥800 U / g), protease (enzyme activity ≥600 U / g), and phytase (enzyme activity ≥500 U / g) at a mass ratio of 2:1:1. The minimum critical temperature of dissolution (LCST) of the poly-N-isopropylacrylamide is 32°C. This poly-N-isopropylacrylamide is prepared by the following process: N-isopropylacrylamide monomer and crosslinking agent N,N'-methylenebisacrylamide are mixed at a mass ratio of 100:1. Ammonium persulfate initiator, accounting for 0.5% of the mass fraction of the mixture, is added. The mixture is reacted at 60°C for 6 hours, purified by dialysis, and then freeze-dried to obtain poly-N-isopropylacrylamide. Using poly-N-isopropylacrylamide (PNIPAM) with a minimum critical temperature of dissolution (LCST = 32°C) as a temperature-sensitive carrier, it achieves "low-temperature gelation slow release (<32°C, matching the weak absorption period of crops) and high-temperature dissolution rapid release (≥32°C, matching the key growth period of crops)". It is compounded with amylase, xylanase, and other biological organic enzymes to form a synergistic enzymatic hydrolysis system with cellulase and protease in the mesoporous multi-enzyme gold complex. This accelerates the decomposition of the organic carrier while controlling the release of nutrients, ensuring synchronous "controlled release-enzymatic hydrolysis" and avoiding nutrient supply lag.

[0025] The bio-organic enzyme is composed of amylase (enzyme activity ≥1200U / g), xylanase (enzyme activity ≥1000U / g), and laccase (enzyme activity ≥600U / g) in a mass ratio of 3:2:1. The slow-release nutrient group is composed of trehalose and humic acid mixed at a mass ratio of 1:3, wherein the humic acid is purchased from Sinopharm Group and has an organic matter content of ≥90%. The preparation process of the temperature-sensitive enzyme nutrient complex is as follows: First, poly(N-isopropylacrylamide) is dissolved in deionized water to prepare a 10% (w / w) poly(N-isopropylacrylamide) aqueous solution; then, the aqueous solution is mixed with bio-organic fertilizer and slow-release nutrients, emulsified at 60°C for 30 minutes, and a 2 mol / L calcium chloride solution is added dropwise. The solution is then dried using a spray drying device (inlet air temperature 120°C, outlet air temperature 60°C) to obtain temperature-sensitive enzyme nutrient complex microspheres with a particle size of 5-10 μm. The inner strain protective layer consists of 38-45 parts rhizosphere growth-promoting bacteria, 3.8-4.5 parts sucrose protectant, 2.5-4 parts sodium alginate, and 0.7-1.5 parts deionized water (all by weight). The rhizosphere growth-promoting bacteria were prepared by mixing *Azotobacter brasiliensis* (strain number ATCC29145), *Pseudomonas fluorescens* (strain number ATCC13525), and *Bacillus subtilis* (strain number ATCC6633) in a mass ratio of 1:1:1, with a viable count ≥10¹ after mixing. 0 CFU / g; verified by co-culturing in LB medium at 37°C for 24 hours, the colony coverage of this mixed strain was ≥95% (no antagonistic effect). The mass ratio of the sucrose protectant to the rhizosphere growth-promoting bacteria is 1:10, and the survival rate of the strains after low-temperature freeze-drying is ≥90%. The sodium alginate is prepared by dissolving it in deionized water to prepare a sodium alginate aqueous solution with a mass concentration of 2.0% ± 0.2%; the viscosity of this sodium alginate aqueous solution (mass concentration of 1%) is 100-300 mPa·s at 25℃; the preparation process of the inner layer strain protective layer is as follows: rhizosphere growth promoters, sucrose protectant, sodium alginate and deionized water are mixed (solid-liquid ratio of 1:20), and the mixture is dripped into a calcium chloride aqueous solution with a mass concentration of 3.0% ± 0.3% (the amount of calcium chloride aqueous solution is 1.5-2 times the total mass of the inner layer mixture) through a microfluidic device with a channel diameter of 100 μm at an injection flow rate of 1-2 mL / h, and solidified at 25℃ for 30 ± 5 minutes to obtain inner layer microspheres with a particle size of 180-220 μm; the compressive strength of the inner layer microspheres is ≥0.2 MPa; The outer antibacterial protective layer is composed of 40-50.5 parts Tris-HCl buffer, 2-3 parts chitosan, 0.5-1 parts dopamine hydrochloride, and 0.2-0.5 parts acetic acid (all by weight). The concentration of the Tris-HCl buffer solution was 0.05 mol / L, and the pH value was 8.5 ± 0.2. The chitosan was prepared by dissolving it in a 1% (w / w) aqueous solution of acetic acid (the chitosan concentration in the solution was 1%). The degree of deacetylation of the chitosan was ≥85%, and the viscosity of the chitosan solution at 25°C was 50-100 mPa·s. The chitosan was purchased from Aladdin, reagent type C106783. The dopamine hydrochloride is prepared by dissolving dopamine hydrochloride in deionized water to prepare an aqueous solution with a mass concentration of 0.5% ± 0.05%; after polymerization, this aqueous solution exhibits an inhibition rate of ≥90% against Fusarium oxysporum, the pathogen of tomato wilt. The preparation process of the outer antibacterial protective layer is as follows: the inner microspheres are immersed in chitosan solution (solid-liquid ratio of 1:30, total mass of chitosan solution is 3 times the total mass of inner microspheres), stirred at 25℃ for 60 minutes, then removed and drained of surface liquid; the drained inner microspheres are transferred into dopamine hydrochloride-Tris-HCl buffer system and reacted at 25℃ in the dark for 2±0.5 hours; after removal, they are rinsed 3 times with deionized water and freeze-dried at -40℃ and 5Pa vacuum for 8 hours to form an outer composite layer with a thickness of 10-20μm; Verification of the total mass of the outer antibacterial protective layer: The upper limit of the mass of each component is 50.5 parts (Tris-HCl buffer) + 3 parts (chitosan) + 1 part (dopamine hydrochloride) + 0.5 parts (acetic acid) = 55 parts; the lower limit of the mass is achieved by adjusting the amount of Tris-HCl buffer to 42.3 parts, so that 42.3 parts (Tris-HCl buffer) + 2 parts (chitosan) + 0.5 parts (dopamine hydrochloride) + 0.2 parts (acetic acid) = 45 parts, ensuring that the total mass of the outer and inner layers is 100 parts; Furthermore, the adsorption capacity of the thiol groups of the bifunctional modified mesoporous silica for cadmium ions (Cd²⁺) is ≥50 mg / g.

[0026] Furthermore, the microporous region (2-5 nm) of the graded-pore-size mesoporous silica is used to load the complex enzyme, the mesoporous region (15-20 nm) is used to load the slow-release nutrients, and the blockage rate of the mesoporous channels is <5%.

[0027] Furthermore, the functionalized silica-carbon support enables bifunctional modified mesoporous silica to maintain enzyme activity at ≥85% within a pH range of 4.5-9.5.

[0028] In the outer antibacterial protective layer of the rhizosphere growth-promoting bacteria microspheres, the amount of Tris-HCl buffer is 50.5 parts, the amount of chitosan is 3 parts, the amount of dopamine hydrochloride is 1 part, and the amount of acetic acid is 0.5 parts, with a total mass of 55 parts. In the corresponding inner strain protection layer, the amount of rhizosphere growth-promoting bacteria is 38 parts, the amount of sucrose protectant is 3.8 parts, the amount of sodium alginate is 2.5 parts, and the amount of deionized water is 0.7 parts, with a total mass of 45 parts.

[0029] Furthermore, the temperature-sensitive enzyme nutrient complex microspheres exhibit a nutrient release rate of ≥85% at temperatures ≥32℃ and a nutrient release rate of ≤15% at temperatures <15℃.

[0030] Furthermore, the decomposed straw powder is at least one of decomposed corn straw powder and decomposed rice straw powder; the livestock and poultry manure fermentation product is at least one of pig manure fermentation product and chicken manure fermentation product.

[0031] Furthermore, the thickness of the mesoporous silica-trehalose composite membrane described in step (4) is 5-10 μm; under the conditions of 80% relative humidity and 25℃, the composite membrane can make the hygroscopicity of the fertilizer ≤8% after 6 months of storage.

[0032] Example 1 (Applicable to wheat cultivation in cadmium-contaminated soil) Raw material preparation (by weight): Ten parts of mesoporous multi-enzyme gold complex: composed of 3.3 parts of functionalized silicon-carbon support and 6.7 parts of multi-enzyme gold complex; Thermosensitive enzyme nutrient complex 12 parts: composed of 4 parts poly-N-isopropylacrylamide, 2 parts bio-organic enzyme and 6 parts slow-release nutrients; Four portions of rhizosphere growth-promoting microspheres (divided into 100 parts by total weight): The inner layer of bacterial strain protective layer consists of 2.2 parts (calculated based on a ratio of 50 parts of the total inner layer mass): 2 parts of rhizosphere growth-promoting bacteria (calculated based on a ratio of 45 parts of the upper limit of rhizosphere growth-promoting bacteria in the inner layer), 0.2 parts of sucrose protectant, 0.018 parts of sodium alginate, and 0.002 parts of deionized water. The outer antibacterial protective layer consists of 1.8 parts (calculated based on a total outer layer mass of 50 parts, after slight adjustment): 1.62 parts Tris-HCl buffer (calculated based on a maximum outer layer Tris-HCl buffer mass of 50.5 parts), 0.09 parts chitosan, 0.03 parts dopamine hydrochloride, and 0.06 parts acetic acid. Organic carrier 65 parts: composed of 26 parts of decomposed corn stalk powder and 39 parts of fermented pig manure; Trace element additive (3 parts): composed of 1.5 parts borax, 0.75 parts zinc sulfate, and 0.75 parts ammonium molybdate; pH buffer 1.5 parts: composed of 0.6 parts citric acid and 0.9 parts sodium citrate; Preparation steps: ① Crush the organic carrier to a particle size of 0.8 mm, add pH buffer, and adjust the water content of the mixture to 55% and the pH value to 7.0; ② Add the temperature-sensitive enzyme nutrient complex to the above system and ferment at 35℃ for 5 days, stirring once a day for 30 minutes each time. ③ Add mesoporous multi-enzyme gold complex, rhizosphere growth-promoting bacteria microspheres, and trace element additives to the fermented system in sequence, and stir for 90 minutes at room temperature; ④ The mixed material is dried at 45℃ to a moisture content of 10%, and then granulated using a granulation device (with the particle size controlled at 4mm). Then, a mesoporous silica-trehalose composite film is coated on the surface of the granulated fertilizer particles. The amount of the composite film is 5% of the total mass of the granulated fertilizer particles, and the composite film is made by mixing mesoporous silica and trehalose in a mass ratio of 1:3.

[0033] Example 2 (Suitable for tomato cultivation in saline-alkali land) Raw material preparation (by weight): 12 parts of mesoporous multi-enzyme gold complex: composed of 4 parts of functionalized silicon carbon support and 8 parts of multi-enzyme gold complex; Thermosensitive enzyme nutrient complex 15 parts: composed of 5 parts poly-N-isopropylacrylamide, 2.5 parts bio-organic enzyme and 7.5 parts slow-release nutrients; Five portions of rhizosphere growth-promoting microspheres (divided into 100 parts by total weight): The inner layer of bacterial strain protective layer, 2.75 parts (calculated based on a ratio of 55 parts of total inner layer mass), consists of 2.475 parts of rhizosphere growth-promoting bacteria, 0.2475 parts of sucrose protectant, 0.022 parts of sodium alginate, and 0.0055 parts of deionized water. The outer antibacterial protective layer, 2.25 parts (calculated based on a total outer layer mass of 45 parts, after slight adjustment), consists of 2.025 parts Tris-HCl buffer, 0.135 parts chitosan, 0.0675 parts dopamine hydrochloride, and 0.0225 parts acetic acid. Organic carrier 62 parts: composed of 24.8 parts of decomposed rice straw powder and 37.2 parts of fermented chicken manure; Trace element additive (4 parts): composed of 2 parts borax, 1 part zinc sulfate and 1 part ammonium molybdate; pH buffer (2 parts): composed of 0.8 parts citric acid and 1.2 parts sodium citrate; Preparation steps: The preparation steps are the same as those in Example 1, except that the particle size is controlled to be 5 mm during granulation.

[0034] Example 1 (Wheat cultivation in cadmium-contaminated soil): Focusing on heavy metal remediation and enzyme stability, the enzyme half-life (80 days) is 4.4 times that of ordinary mesoporous silica fertilizer (18 days), ensuring nutrient decomposition throughout the entire growth period; the soil Cd²⁺ adsorption rate (85.6%) is more than twice that of the control, making the Cd content of wheat grains (0.18 mg / kg) meet food safety standards, while the control exceeded the standard; at the same time, the yield per mu (560 kg) increased by 16.7% compared with ordinary mesoporous fertilizer, reflecting the dual value of "remediation + yield increase". Example 2 (Tomato cultivation in saline-alkali land): Focusing on temperature-sensitive controlled release and disease control, in a saline-alkali environment, the nutrient release rate (87%) of the fertilizer of this invention at 32℃ is close to that of ordinary temperature-sensitive fertilizer (90%), while also taking into account enzyme efficiency; the incidence of tomato wilt disease (2.8%) is only 1 / 8-1 / 9 of the control, significantly reducing the risk of disease; the single fruit weight (220g) and vitamin C content (28mg / 100g) are both higher than the control, achieving a synergistic effect of "controlled release + quality improvement". The enzymatic hydrolysis products of the mesoporous multi-enzyme gold complex provide "auxiliary absorption substrates" for temperature-sensitive controlled-release nutrients and provide carbon sources for growth-promoting bacteria. The temperature-sensitive controlled-release nutrients and enzymatic hydrolysis products work together to improve the rhizosphere environment and increase the colonization rate of growth-promoting bacteria. The metabolites of growth-promoting bacteria can enhance the heavy metal adsorption capacity of functionalized silicon-carbon carriers, and the heavy metals adsorbed by the carriers reduce their toxicity to enzymes and growth-promoting bacteria. Ultimately, a positive cycle of "stable enzyme activity → precise nutrient supply → survival and colonization of growth-promoting bacteria → heavy metal remediation → soil improvement" is formed, realizing the comprehensive efficacy of fertilizer in "quality improvement - yield increase - remediation - improvement".

[0035] The above are merely embodiments of the present invention. The circuits, electronic components, and modules involved are all prior art, fully achievable by those skilled in the art, and require no further explanation. The scope of protection in this application does not involve improvements to the software and methods. Commonly known structures and characteristics in the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all prior art in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the application.

Claims

1. A multi-enzyme gold bio-organic agro-fertilizer, characterized in that: The fertilizer comprises the following components by mass: 8-12 parts of mesoporous multi-enzyme gold complex, 10-15 parts of temperature-sensitive enzyme nutrient complex, 3-5 parts of rhizosphere growth-promoting bacteria microspheres, 62-76 parts of organic carrier, 2-4 parts of trace element additive, and 1-2 parts of pH buffer; The mesoporous multi-enzyme gold complex is formed by compounding a functionalized silicon-carbon carrier and a multi-enzyme gold complex at a mass ratio of 1:

2. The temperature-sensitive enzyme nutrient complex is formed by compounding poly-N-isopropyl acrylamide, biological organic enzyme and slow-release nutrient at a mass ratio of 2:1:

3. The rhizosphere growth-promoting bacteria microspheres are double-layer structure microspheres, and the rhizosphere growth-promoting bacteria microspheres comprise, by weight, 45-55 parts of inner-layer strain protection layer and 45-55 parts of outer-layer bacteriostatic protection layer. The inner-layer strain protection layer is composed of the following components by mass: 38-45 parts of rhizosphere growth-promoting bacteria, 3.8-4.5 parts of sucrose protective agent, 2.5-4 parts of sodium alginate, and 0.7-1.5 parts of deionized water. The outer-layer bacteriostatic protection layer is composed of the following components by mass: 40-50.5 parts of Tris-HCl buffer, 2-3 parts of chitosan, 0.5-1 part of dopamine hydrochloride, and 0.2-0.5 part of acetic acid.

2. A multi-enzyme gold bio-organic enzyme agricultural fertilizer as claimed in claim 1, characterized by: The organic carrier is formed by mixing composted straw powder and livestock and poultry manure ferment at a mass ratio of 2:

3.

3. The multi-enzyme gold bio-organic enzyme agricultural fertilizer as described in claim 1, characterized in that: The trace element additive is formed by mixing borax, zinc sulfate and ammonium molybdate at a mass ratio of 2:1:

1.

4. A multi-enzyme gold bio-organic enzyme agricultural fertilizer as claimed in claim 1, characterized by: The pH buffer is formed by mixing citric acid and sodium citrate at a mass ratio of 1:1.

5.

5. The multi-enzyme gold bio-organic enzyme agricultural fertilizer as described in claim 1, characterized in that: The rhizosphere growth-promoting bacteria are formed by mixing Azospirillum brasilense, Pseudomonas fluorescens and Bacillus subtilis at a mass ratio of 1:1:1, and then culturing the mixture in LB medium at 37°C for 24 hours. The mass ratio of the sucrose protective agent to the rhizosphere growth-promoting bacteria is 1:

10. The preparation method of the inner-layer strain protection layer comprises the following steps: mixing the rhizosphere growth-promoting bacteria and the sucrose protective agent, dispersing the mixture in a sodium alginate aqueous solution at a solid-liquid ratio of 1:20, dropping the mixture into a calcium chloride aqueous solution through a microfluidic device with a channel diameter of 100 μm at a feeding flow rate of 1-2 mL / h, and solidifying the mixture at 25°C for 30 minutes to form inner-layer microspheres with a particle size of 180-220 μm.

6. The multi-enzyme gold bio-organic enzyme agricultural fertilizer as described in claim 1, characterized in that: The preparation method of the outer-layer bacteriostatic protection layer comprises the following steps: soaking the inner-layer microspheres in a chitosan solution at a solid-liquid ratio of 1:30, the total mass of the chitosan solution being 3 times the mass of the inner-layer microspheres, stirring the mixture at 25°C for 60 minutes, then taking out the mixture, draining the mixture, transferring the mixture into a dopamine hydrochloride-Tris-HCl buffer system, reacting the mixture at 25°C for 2 hours in the dark, washing the mixture with deionized water for 3 times, and vacuum freeze-drying the mixture at -40°C and 5 Pa for 8 hours to form an outer-layer composite layer with a thickness of 10-20 μm.

7. The multi-enzyme gold bio-organic enzyme agricultural fertilizer as described in claim 1, characterized in that: The composted straw powder is at least one of composted corn straw powder and composted rice straw powder. The livestock and poultry manure ferment is at least one of pig manure ferment and chicken manure ferment.

8. The multi-enzyme gold bio-organic enzyme agricultural fertilizer as described in claim 1, characterized in that: The preparation method of the fertilizer comprises the following steps: Step S1: crushing the organic carrier, adding the organic carrier into the pH buffer, mixing the mixture, adjusting the moisture content of the mixture to 50%-60% and the pH of the mixture to 6.8-7.2, and then uniformly mixing the mixture. Step S2, add the temperature-sensitive enzyme nutrient compound to the product of step S1, and ferment at a constant temperature of 35℃ for 5 days, with daily stirring for 30 minutes each time; Step S3, add the mesoporous multi-enzyme gold compound, rhizosphere growth-promoting bacteria microspheres, and trace element additives to the fermentation product of step S2 in sequence, stir at room temperature for 90 minutes, and form a mixture; Step S4, dry the mixture of step S3 at a low temperature of 45℃, granulate to form particles with a particle size of 3-5mm, and coat the surface with a mesoporous silica-trehalose composite film prepared by mixing mesoporous silica and trehalose at a mass ratio of 1:3, to obtain the multi-enzyme gold bio-organic enzyme agricultural fertilizer product.

9. The multi-enzyme gold bio-organic enzyme agricultural fertilizer as described in claim 1, characterized in that: The preparation method of the functionalized silicon-carbon carrier comprises the following steps: a. Hierarchical-pore mesoporous silica is prepared by a hard-template-soft-template composite method: polystyrene microspheres are used as the hard template, cetyltrimethylammonium bromide is used as the soft template, tetraethyl orthosilicate is added at a rate of 0.5-1.0mL / min into a 2% mass concentration aqueous solution of cetyltrimethylammonium bromide, stirring at room temperature for 12 hours, and then calcining at 550℃ for 6 hours to remove the template, to obtain hierarchical-pore mesoporous silica containing 2-5nm micropores and 15-20nm mesopores; b. Double-functional group grafting is performed on the hierarchical-pore mesoporous silica: the hierarchical-pore mesoporous silica is dispersed in a volume ratio of 1:1 of ethanol-water mixed solution, 3-mercaptopropyltrimethoxysilane is added at a mass fraction of 10%-12% of the mesoporous silica, and stirring is performed at 50℃ for 6 hours; then succinic anhydride is added at a mass fraction of 8%-10% of the mesoporous silica, and refluxing is performed at 60℃ for 4 hours, to obtain double-functional modified mesoporous silica; c. The double-functional modified mesoporous silica is mixed with modified biochar at a mass ratio of 3:1, deionized water is added at a solid-liquid ratio of 1:10, ultrasonic dispersion is performed at 300W for 30 minutes, and vacuum freeze-drying is performed at -50℃ and 10Pa for 8 hours, to obtain the functionalized silicon-carbon carrier.

10. The multi-enzyme gold bio-organic enzyme agricultural fertilizer as described in claim 1, characterized in that: The multi-enzyme gold compound is obtained by mixing nano-gold particles and composite enzymes at a mass ratio of 1:5-1:8, wherein the nano-gold particles are spherical or spherical-like metal particles formed by gold elements and having a particle size in the nanometer scale; The composite enzymes are obtained by mixing cellulase, protease, and phytase at a mass ratio of 2:1:1; The bio-organic enzymes are obtained by mixing amylase, xylanase, and laccase at a mass ratio of 3:2:1; The slow-release nutrients are obtained by mixing trehalose and humic acid at a mass ratio of 1:3; The preparation process of the temperature-sensitive enzyme nutrient compound is as follows: a 10% mass concentration aqueous solution of poly-N-isopropyl acrylamide is prepared, bio-organic enzymes and slow-release nutrients are added, emulsification is performed at 60℃ for 30 minutes, a 2mol / L calcium chloride solution is added for crosslinking, and spray drying is performed to obtain microspheres with a particle size of 5-10μm.

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