Novel amino acid leaf fertilizer and preparation method thereof

Abstract

The invention relates to a novel amino acid foliar fertilizer and a preparation method thereof, and belongs to the technical field of agricultural fertilizers. The method aims at solving the technical problems that in the prior art, the amino acid conversion rate is low, product stability is poor, and severe conditions such as strong acid and strong alkali are possibly used. The method comprises the following steps: mixing soybean meal, fish meal and saccharomyces cerevisiae thalli to form a compound protein raw material, performing two-stage crushing and degreasing, performing step-by-step enzymolysis by adopting a compound enzyme preparation compounded by alkaline protease and flavourzyme, performing enzyme deactivation, and performing ultrafiltration by adopting a ceramic membrane to obtain purified amino acid hydrolysate, and mixing the hydrolysate with a composite trace element mixed solution formed by EDTA-Fe, EDTA-Zn, boric acid, ammonium molybdate and citric acid, adding humic acid, a seaweed extract and an organic silicon penetrant, and carrying out high-speed shearing, filtering and vacuum degassing to finally obtain the product. The method is mainly used for producing the amino acid foliar fertilizer which is high in free amino acid content, good in stability and easy to absorb by plants.

Description

Novel amino acid foliar fertilizer and its preparation method Technical Field

[0001] This invention belongs to the field of agricultural fertilizer technology, specifically relating to a novel amino acid foliar fertilizer and its preparation method. Background Technology

[0002] In the field of amino acid foliar fertilizer production, traditional processes have long faced problems such as low amino acid conversion rates, poor product stability, and environmental pollution. Existing technologies mainly rely on enzymatic hydrolysis or strong acid hydrolysis processes using single protein raw materials, which significantly restricts the improvement of product quality. For example, patent CN111436525A (application number CN202010189404.5) proposes a feed processing method integrating fermentation and enzymatic hydrolysis, which uses plant protein (20–30%), starch (50–65%), and dietary fiber (15–20%) as raw materials, and carries out fermentation and enzymatic hydrolysis by adding a compound bacterial liquid of lactobacillus, Bacillus, and yeast. Although this method simplifies the process, it is not optimized for the degree of free amino acids, and the metabolites of the compound bacterial strain are complex, resulting in a final product with a free amino acid content of only 78–85 g / L, and the presence of incompletely degraded large molecular peptides, which are prone to precipitation and stratification during storage.

[0003] The drawbacks of strong acid hydrolysis processes are even more pronounced. For example, patent application CN2024119537765 – Preparation method of amino acid foliar fertilizer based on animal hair extraction – while optimizing raw material utilization through byproduct resource utilization (residue to biochar, waste liquid to amino acid recovery), its core strong acid hydrolysis step still suffers from the inherent defects of traditional processes: firstly, heat-sensitive amino acids are severely degraded. In a high-temperature, highly acidic environment, tryptophan is almost completely destroyed, and the loss rate of cystine, threonine, etc. reaches 18%-22%, resulting in the proportion of essential amino acids in the product being less than 35%, and a significant decrease in nutritional balance. Secondly, there is a high risk of salt byproduct accumulation - during the neutralization process, sulfuric acid reacts with potassium hydroxide and ammonia to produce salts such as potassium sulfate and ammonium sulfate. Even after ion exchange desalination, the residual salt content in the hydrolysate is still 3%-5%, which can easily lead to soil salinization in the long term. Especially in the closed environment of facility agriculture, it will significantly reduce soil permeability and crop root absorption capacity. Thirdly, there are high process costs and environmental pressures - on the one hand, ion exchange resins need to be regenerated regularly, consuming a large amount of acid and alkali reagents and generating high-salt wastewater, increasing subsequent treatment costs by 20%-30%; on the other hand, the initial investment and maintenance costs of acid-resistant reactors and vacuum desalination equipment are high, which is difficult for small and medium-sized production enterprises to bear, and the risk of strong acid leakage places strict requirements on operational safety.

[0004] This demonstrates that current amino acid foliar fertilizer preparation technology suffers from systemic defects, severely hindering product performance improvement and industrial application. The primary problem lies in the limited selection of raw materials. For example, using only plant protein (soybean meal) or animal protein (fishmeal) as the hydrolysis matrix fails to leverage the complementary amino acid profiles of plant and animal proteins, resulting in an incomplete essential amino acid profile in the final product and limiting its nutritional value. Secondly, mainstream hydrolysis processes have significant drawbacks: while strong acid hydrolysis can achieve high protein conversion rates, it irreversibly destroys heat-sensitive amino acids such as tryptophan and serine under high-temperature, strong-acid conditions (e.g., 110 ℃ / 7 mol / L HCl), causing an essential amino acid loss rate exceeding 40%. Conversely, conventional enzymatic hydrolysis processes, due to the limited enzyme types and lack of segmented control, result in 12-18% of unhydrolyzed macromolecular peptides remaining, reducing the yield of free amino acids. Third, low purification efficiency has become a key bottleneck. Effective pretreatment methods are generally lacking before membrane separation, allowing unhydrolyzed colloids, lipid impurities, and cell debris to directly enter the ultrafiltration system, causing membrane fouling and resulting in a target product recovery rate of less than 70%. Simultaneously, residual impurities exacerbate the risk of precipitation during storage. Finally, the lack of technical expertise in the compounding process leads to stability degradation. The direct addition of trace elements and functional additives (such as humic acid) triggers phase separation. Coupled with the lack of pre-chelation and stepwise dispersion processes, the product generally exhibits high precipitation rates and significantly increased turbidity after three months of accelerated storage at 40 °C, severely impacting commercial applications. These deficiencies collectively form a technical predicament of raw material limitations, hydrolytic degradation, inefficient purification, and unstable compounding, urgently requiring breakthroughs through systematic process innovation. Summary of the Invention

[0005] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0006] Another objective of this invention is to provide a novel method for preparing amino acid foliar fertilizer, which can efficiently produce amino acid foliar fertilizer with high free amino acid content and good stability under mild conditions.

[0007] To achieve these objectives and other advantages of the present invention, a novel method for preparing amino acid foliar fertilizer is provided, comprising the following steps: S1: mixing soybean meal, fish meal, and brewer's yeast cells in a mass ratio of 6-10:3-5:1 to form a composite protein raw material; S2: subjecting the composite protein raw material to a two-stage pulverization process, first pulverizing to 15-25 mesh, then refining to 70-90 mesh, to obtain a specific surface area of ​​not less than 0.8 m². 2 / g of raw material powder; S3: Degrease the raw material powder, sterilize the degreased raw material by high-pressure steam at 115-125 ℃ for 18-22 min, add water to the sterilized raw material to adjust the solid-liquid ratio to 1:3-5 g / mL, and adjust the pH of the mixture to 8.0-9.0; S4: Add 0.7%-0.9% of the total dry weight of the raw material compound enzyme preparation to the pH-adjusted mixture, and carry out the enzymatic hydrolysis reaction at 52-58 ℃ and 140-160 r / min for 5-7 h. Add the compound enzyme preparation once at the 2nd and 4th hours after the start of the enzymatic hydrolysis reaction, with the addition amount being 0.08%-0.12% of the total dry weight of the raw material; wherein, the compound enzyme preparation is composed of alkaline protease and flavor protease at an enzyme activity unit ratio of 2.5-3.5:1; S5: Heat the enzymatically hydrolyzed material to 80-90 ℃ and maintain it for 12-18 minutes. S6: EDTA-Fe, EDTA-Zn, boric acid, ammonium molybdate, and citric acid are mixed and stirred at 40-50 °C for 25-35 min to form a composite trace element mixture. S7: The amino acid hydrolysate and the composite trace element mixture are mixed and stirred at 40-50 °C for 50-70 min. Humic acid, seaweed extract, and organosilicon penetrant are added to the mixture after reaction, and shearing and stirring at 2800-3200 r / min at 30-40 °C for 15-25 min. S8: The sheared and stirred mixture is filtered sequentially through a 180-220 mesh filter cloth and a 0.4-0.5 μm filter membrane. The filtered liquid is degassed under a vacuum of -0.075 to -0.085 MPa for 12-18 minutes. The amino acid foliar fertilizer was obtained by min.

[0008] Preferably, in step S1, the brewer's yeast cells are pretreated by the following method before being mixed: the brewer's yeast cells are mixed with a sodium hydroxide solution with a mass concentration of 0.8%-1.2% at a mass ratio of 1:8-12, soaked at 45-55 ℃ for 30-50 min, and the soaked mixture is circulated 3-5 times by a high-pressure homogenizer at a pressure of 60-80 MPa. The homogenized slurry is then subjected to solid-liquid separation, and the solid components are collected as pretreated brewer's yeast cells for mixing.

[0009] Preferably, in step S3, the raw material powder is degreased, specifically including: mixing the raw material powder with n-hexane at a temperature of 50-70 ℃ at a mass ratio of 1:3-5, and performing a first-stage degreasing treatment for 40-80 min under the conditions of stirring speed of 100-200 r / min and temperature of 50-70 ℃; performing solid-liquid separation on the mixture after the first-stage degreasing treatment and collecting the solid phase; adding 1.5-2.5 times its mass of hot water at a temperature of 75-85 ℃ to the collected solid phase, stirring evenly to form a suspension, maintaining the temperature of the suspension at 55-65 ℃, and centrifuging at a speed of 2500-3500 r / min for 10-20 min to perform a second-stage degreasing treatment, separating and removing the upper floating oil and the middle aqueous phase, and collecting the bottom solid phase as the degreased raw material.

[0010] Preferably, the separation and removal of the upper floating oil and the intermediate aqueous phase specifically includes: allowing the centrifuged material to stand for 5-15 minutes to allow it to stably separate into an upper floating oil, an intermediate aqueous phase, and a bottom solid phase in a container; using a skimming device to remove the upper floating oil at a temperature of 40-60 ℃; removing the intermediate aqueous phase by inserting a pipette into the container; transferring the remaining bottom solid phase after removing the aqueous phase to a Buchner funnel and filtering it under a vacuum of -0.06 to -0.08 MPa for 3-8 minutes to obtain a degreased and dehydrated solid raw material.

[0011] Preferably, the process involves pre-treating the enzyme-inactivated material before ultrafiltration, followed by filtration using a ceramic membrane ultrafiltration system. The pre-treatment includes: cooling the enzyme-inactivated material to 35-45°C; adding purified water at 30-40°C (15%-25% of the material mass) to the cooled material and mixing at 80-120 r / min for 5-15 min to obtain a diluted material; transferring the diluted material to a shearing tank and performing high-speed shearing at 30-40°C and 5000-7000 r / min for 8-15 min; filtering the high-speed sheared material through a 100-150 mesh sieve and collecting the filtrate as the material to be ultrafiltered into the ceramic membrane ultrafiltration system.

[0012] Preferably, a vibrating screen combined with countercurrent flushing is used to filter the material after high-speed shearing. Specifically, this includes: pumping the high-speed sheared material into a vibrating screen equipped with an ultrasonic vibration device, the screen containing a 100-150 mesh stainless steel screen; activating the ultrasonic vibration device, setting the ultrasonic frequency to 20-40 kHz and the amplitude to 5-15 μm, allowing the material to pass through the screen under vibration conditions for filtration, and collecting the filtrate passing through the screen; simultaneously, pumping a portion of the collected filtrate back to the back of the screen through a countercurrent flushing pipeline, the countercurrent flushing flow rate being set to 5%-15% of the feed flow rate, using the filtrate flow to continuously back-flush the screen channels; and inputting the filtrate collected after vibrating screening and countercurrent flushing as the material to be ultrafiltered into the ceramic membrane ultrafiltration system.

[0013] Preferably, in step S6, EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate are mixed and stirred with citric acid at 40-50 °C for 25-35 min. Specifically, this includes: weighing citric acid, EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate according to the total mass of the composite protein raw materials; wherein the amount of citric acid is 4.0%-6.0% of the total mass of the composite protein raw materials, the amount of EDTA-Fe is 2.5%-3.5% of the total mass of the composite protein raw materials, the amount of EDTA-Zn is 1.5%-2.5% of the total mass of the composite protein raw materials, the amount of boric acid is 1.0%-2.0% of the total mass of the composite protein raw materials, and the amount of ammonium molybdate is 0.15%-0.25% of the total mass of the composite protein raw materials; dissolving citric acid in water at a temperature of 40-50 °C... Prepare a citric acid solution with a mass concentration of 15%-25% in deionized water at ℃; first add EDTA-Fe to the citric acid solution, and mix and stir for 8-12 min at 40-50 ℃ and a stirring speed of 200-300 r / min; then add EDTA-Zn, and continue mixing and stirring for 8-12 min at the same temperature and stirring conditions; finally add boric acid and ammonium molybdate, maintain the temperature at 40-50 ℃ and the stirring speed at 200-300 r / min, and mix and stir for another 8-12 min to form the composite trace element mixture.

[0014] Preferably, step S7 specifically includes: weighing humic acid, seaweed extract, and organosilicon penetrant according to the total mass of the composite protein raw materials; wherein the amount of humic acid weighed is 1.0%-2.0% of the total mass of the composite protein raw materials, the amount of seaweed extract weighed is 0.5%-1.0% of the total mass of the composite protein raw materials, and the amount of organosilicon penetrant weighed is 0.2%-0.4% of the total mass of the composite protein raw materials; mixing the amino acid hydrolysate with the composite trace element mixture at a volume ratio of 3.5-4.5:1, and reacting at 40-50 ℃ with a stirring speed of 150-250 r / min for 50-70 min to obtain a first mixture, and adjusting the temperature of the first mixture to 30-35 ℃; mixing the weighed humic acid with deionized water at a temperature of 30-35 ℃ at a mass ratio of 1:3-5, and stirring at a speed of 800-1200 r / min for 10-20 minutes. The humic acid pre-dispersion solution was obtained by mixing the weighed seaweed extract with deionized water at 30-35 ℃ at a mass ratio of 1:2-4 and stirring at 400-600 r / min for 5-15 min. The humic acid pre-dispersion solution was added to the first mixture after temperature adjustment and dispersed at 30-35 ℃ and 300-500 r / min for 10-20 min to obtain the second mixture. The seaweed extract pre-dispersion solution was added to the second mixture and dispersed at 30-35 ℃ and 300-500 r / min for 10-20 min. Finally, the weighed organosilicon penetrant was added, and the temperature of the mixture was maintained at 30-35 ℃ and sheared and stirred at 2800-3200 r / min for 15-25 min. During the shearing process, the temperature of the mixture was controlled not to exceed 40 ℃ by circulating water cooling.

[0015] Preferably, after shearing and stirring at a speed of 2800-3200 r / min for 15-25 min, a maturation treatment is also included. The maturation treatment specifically includes: transferring the sheared and stirred mixture into a maturation tank equipped with a slow stirring device, and continuously stirring and maturing at a temperature of 25-30 ℃ and a stirring speed of 30-60 r / min for 18-36 h; in the last 2-4 h of the maturation process, slowly cooling the mixture to 10-15 ℃ at a rate of 0.5-1.0 ℃ / min.

[0016] A novel amino acid foliar fertilizer is prepared by the method described above.

[0017] The present invention has at least the following beneficial effects: the method of the present invention can achieve efficient conversion of protein raw materials under mild conditions through a compound enzyme stepwise hydrolysis and membrane purification process to obtain hydrolysate with high free amino acid content; through optimized raw material pretreatment and stepwise compounding process, the stable coexistence and uniform dispersion of nutrients in the product are ensured; the final amino acid foliar fertilizer product not only has high clarity and good stability, and is not prone to stratification and precipitation during long-term storage, but is also easier for plant leaves to absorb and utilize. Detailed Implementation

[0018] The present invention will now be described in further detail so that those skilled in the art can implement it based on the description.

[0019] A novel method for preparing amino acid foliar fertilizer, which can efficiently produce amino acid foliar fertilizer with high free amino acid content and good stability under mild conditions.

[0020] To achieve these objectives and other advantages of the present invention, a novel method for preparing amino acid foliar fertilizer is provided, comprising the following steps: S1: mixing soybean meal, fish meal, and brewer's yeast cells in a mass ratio of 6-10:3-5:1 to form a composite protein raw material; S2: subjecting the composite protein raw material to a two-stage pulverization process, first pulverizing to 15-25 mesh, then refining to 70-90 mesh, to obtain a specific surface area of ​​not less than 0.8 m². 2 / g of raw material powder; S3: Degrease the raw material powder, sterilize the degreased raw material by high-pressure steam at 115-125 ℃ for 18-22 min, add water to the sterilized raw material to adjust the solid-liquid ratio to 1:3-5 g / mL, and adjust the pH of the mixture to 8.0-9.0; S4: Add 0.7%-0.9% of the total dry weight of the raw material compound enzyme preparation to the pH-adjusted mixture, and carry out the enzymatic hydrolysis reaction at 52-58 ℃ and 140-160 r / min for 5-7 h. Add the compound enzyme preparation once at the 2nd and 4th hours after the start of the enzymatic hydrolysis reaction, with the addition amount being 0.08%-0.12% of the total dry weight of the raw material; wherein, the compound enzyme preparation is composed of alkaline protease and flavor protease at an enzyme activity unit ratio of 2.5-3.5:1; S5: Heat the enzymatically hydrolyzed material to 80-90 ℃ and maintain it for 12-18 minutes. S6: EDTA-Fe, EDTA-Zn, boric acid, ammonium molybdate, and citric acid are mixed and stirred at 40-50 °C for 25-35 min to form a composite trace element mixture. S7: The amino acid hydrolysate and the composite trace element mixture are mixed and stirred at 40-50 °C for 50-70 min. Humic acid, seaweed extract, and organosilicon penetrant are added to the mixture after reaction, and shearing and stirring at 2800-3200 r / min at 30-40 °C for 15-25 min. S8: The sheared and stirred mixture is filtered sequentially through a 180-220 mesh filter cloth and a 0.4-0.5 μm filter membrane. The filtered liquid is degassed under a vacuum of -0.075 to -0.085 MPa for 12-18 minutes. The amino acid foliar fertilizer was obtained by min.

[0021] This invention utilizes a composite protein raw material, formulated from soybean meal, fish meal, and brewer's yeast cells in a specific ratio. After a two-stage pulverization process to increase the specific surface area, the mixture undergoes defatting and sterilization to create suitable conditions for subsequent enzymatic hydrolysis. A composite enzyme preparation, composed of alkaline protease and flavor protease in a specific ratio, is used and added stepwise during the hydrolysis process. This achieves efficient and targeted hydrolysis of the protein under mild temperature and pH conditions, significantly improving the conversion rate of free amino acids. After hydrolysis, the hydrolysate is purified using ceramic membrane ultrafiltration with a specific molecular weight cutoff, effectively removing incompletely hydrolyzed macromolecular peptides and impurities, resulting in a high-purity amino acid hydrolysate. Subsequently, the amino acid hydrolysate is systematically mixed with a pre-chelated trace element mixture, and functional additives such as humic acid and seaweed extract are added stepwise for high-speed shear dispersion. Finally, the mixture undergoes precision filtration and vacuum degassing to construct a stable and homogeneous composite system where all nutrients coexist. This method avoids harsh conditions such as strong acids and alkalis throughout the process. Under a mild process environment, it not only achieves efficient utilization of raw materials and high yield of amino acids, but also ensures that the final foliar fertilizer product has high clarity, good storage stability, and nutrients that are easily absorbed by plants.

[0022] In another technical solution, in step S1, the brewer's yeast cells are pretreated by the following method before being mixed: the brewer's yeast cells are mixed with a sodium hydroxide solution with a mass concentration of 0.8%-1.2% at a mass ratio of 1:8-12, and soaked at 45-55 ℃ for 30-50 min. The soaked mixture is then circulated 3-5 times by a high-pressure homogenizer at a pressure of 60-80 MPa. The homogenized slurry is then subjected to solid-liquid separation, and the solid components are collected as pretreated brewer's yeast cells for mixing.

[0023] Due to their dense cell wall structure, brewer's yeast cells often experience incomplete hydrolysis when directly involved in enzymatic hydrolysis, as the contents are difficult for proteases to fully contact. Furthermore, residual cell wall fragments can obstruct subsequent filtration and increase the turbidity of the final product. By mixing the yeast cells with a sodium hydroxide solution of a specific concentration and soaking them at a suitable temperature, followed by multiple high-pressure cyclic shearing processes using a high-pressure homogenizer, the physical integrity of the cell wall can be effectively disrupted, promoting the release of intracellular substances. This treatment makes the yeast cells more readily acted upon by proteases during subsequent enzymatic hydrolysis, while simultaneously converting previously difficult-to-process large-molecule cell wall substances into soluble or easily separable small-molecule components. This significantly improves enzymatic hydrolysis efficiency, reduces solid residue, ensures smooth filtration, and helps improve the clarity and stability of the final product.

[0024] In another technical solution, step S3 involves degreasing the raw material powder, specifically including: mixing the raw material powder with n-hexane at a temperature of 50-70 ℃ at a mass ratio of 1:3-5, and performing a first-stage degreasing treatment for 40-80 min under the conditions of stirring speed of 100-200 r / min and temperature of 50-70 ℃; performing solid-liquid separation on the mixture after the first-stage degreasing treatment and collecting the solid phase; adding 1.5-2.5 times its mass of hot water at a temperature of 75-85 ℃ to the collected solid phase, stirring evenly to form a suspension, maintaining the temperature of the suspension at 55-65 ℃, and centrifuging at a speed of 2500-3500 r / min for 10-20 min to perform a second-stage degreasing treatment, separating and removing the upper floating oil and the middle aqueous phase, and collecting the bottom solid phase as the degreased raw material.

[0025] The lipids in soybean meal and fishmeal, both components of a complex protein feedstock, differ in morphology and properties. Using a single degreasing method is often insufficient for complete removal, and residual lipids are prone to oxidative rancidity during subsequent high-temperature sterilization and storage. This can not only produce unpleasant odors but also encapsulate protein particles, hindering enzymatic hydrolysis. By employing n-hexane for a first-stage extraction degreasing process at a suitable temperature, most of the free and bound non-polar oils in the raw material are effectively dissolved and removed. Subsequently, the degreased solid phase is washed with hot water to form a suspension. Centrifugation at a specific temperature further reduces the viscosity of residual lipids and alters their aggregation state, efficiently separating polar lipids, phospholipids, and any remaining solvent. This two-step degreasing process achieves thorough and clean lipid removal from the complex feedstock, providing a foundation of low-impurity, homogeneous raw materials for subsequent processes, thus helping to ensure the pure flavor and storage stability of the final product.

[0026] In another technical solution, the separation and removal of the upper floating oil and the intermediate aqueous phase specifically includes: allowing the centrifuged material to stand for 5-15 minutes to allow it to stably separate into an upper floating oil, an intermediate aqueous phase, and a bottom solid phase in a container; using a skimming device, removing the upper floating oil at a temperature of 40-60 ℃; removing the intermediate aqueous phase by inserting a pipette into the container; transferring the remaining bottom solid phase after removing the aqueous phase to a Buchner funnel, and filtering it under a vacuum of -0.06 to -0.08 MPa for 3-8 minutes to obtain a degreased and dehydrated solid raw material.

[0027] Centrifugation often results in a mixed transition layer at the phase interfaces of the material, leading to incomplete removal of oils and water. This results in significant fluctuations in the residual oil and water content in the solid raw materials, potentially affecting the uniformity of subsequent high-pressure steam sterilization and making it difficult to precisely control the solid-liquid ratio in the enzymatic hydrolysis system, ultimately negatively impacting the stability of the final product. By allowing the centrifuged material to stand for a period, it stably separates into clear layers of oil, water, and solids within a container. Then, at a suitable temperature, a skimming device is used to remove the upper layer of oil, followed by suction of the intermediate water phase using a pipette. Finally, the remaining bottom solid phase is dehydrated by vacuum filtration. This series of phase-by-phase separation steps, combined with vacuum enhancement, achieves efficient, clear, and thorough separation of oils, water, and solids. This ensures that the raw materials entering subsequent sterilization and enzymatic hydrolysis processes have a uniform and stable low-oil, low-water state, providing a reliable guarantee for precise control of process parameters and consistency of the final product.

[0028] In another technical solution, the material after enzyme inactivation undergoes a pretreatment before ultrafiltration, followed by filtration using a ceramic membrane ultrafiltration system. The pretreatment includes: cooling the material after enzyme inactivation to 35-45°C; adding purified water at 30-40°C (15%-25% of the material mass) to the cooled material and stirring at 80-120 r / min for 5-15 min to obtain diluted material; transferring the diluted material to a shearing tank and performing high-speed shearing at 30-40°C and 5000-7000 r / min for 8-15 min; filtering the high-speed sheared material through a 100-150 mesh sieve and collecting the filtrate as the material to be ultrafiltered into the ceramic membrane ultrafiltration system.

[0029] Materials after enzyme inactivation often contain incompletely hydrolyzed colloidal proteins, fine particles, and large peptide fragments. If directly subjected to ceramic membrane ultrafiltration, these substances readily deposit rapidly on the membrane surface and within the pores, leading to severe concentration polarization and irreversible fouling. This results in a rapid decline in ultrafiltration flux, requiring frequent cleaning and maintenance, shortening membrane lifespan, and causing fluctuations in product yield. By first appropriately lowering the material temperature, then adding a certain proportion of purified water for dilution and gentle stirring, the viscosity and initial contaminant concentration of the system are effectively reduced. Subsequently, the diluted material is transferred to a shear tank for high-speed shearing, utilizing high-intensity shear force to disrupt the stability of colloids and disperse potentially aggregated particles. Finally, the sheared material is filtered through a relatively large-mesh sieve, pre-removing most of the larger particles that could cause physical clogging. This series of pretreatment steps significantly reduces the load on the subsequent ceramic membrane ultrafiltration process, enabling the membrane separation process to maintain a more stable and efficient operating state, extending the lifespan of the membrane module, and contributing to a more stable and higher product yield.

[0030] In another technical solution, a combination of vibrating screening and countercurrent flushing is used to filter materials subjected to high-speed shearing. Specifically, this includes: pumping the high-speed sheared material into a vibrating screen equipped with an ultrasonic vibration device, the screen containing a 100-150 mesh stainless steel screen; activating the ultrasonic vibration device, setting the ultrasonic frequency to 20-40 kHz and the amplitude to 5-15 μm, allowing the material to pass through the screen under vibration conditions for filtration, and collecting the filtrate; simultaneously, pumping a portion of the collected filtrate back to the back of the screen through a countercurrent flushing pipeline, with the countercurrent flushing flow rate set to 5%-15% of the feed flow rate, using the filtrate flow to continuously back-flush the screen channels; and inputting the filtrate collected after vibrating screening and countercurrent flushing as the material to be ultrafiltered into the ceramic membrane ultrafiltration system.

[0031] Materials processed by high-speed shearing often have high viscosity. The colloids and fine particles they contain easily form a paste-like coating on the screen surface when flowing through a static screen, clogging the screen openings. This leads to a sharp increase in filtration resistance and a rapid decrease in filtration flow, requiring frequent shutdowns for manual cleaning or screen replacement, impacting continuous production efficiency. By pumping the material into a vibrating screen equipped with an ultrasonic vibration device, ultrasonic vibration is activated during the screening process. The high-frequency, low-amplitude mechanical waves generated by this vibration continuously act on the screen and material, effectively breaking down particle adhesion and bridging on the screen surface and keeping the screen openings clear. Simultaneously, a portion of the collected filtrate is piped to the back of the screen for online countercurrent flushing. The shear force of the fluid itself continuously and directionally flushes the screen channels, promptly removing particles stuck in the openings. This synergistic effect of vibration and countercurrent flushing achieves self-cleaning of the filtration process, significantly reducing the risk of screen clogging and ensuring the filtration process can operate stably and continuously for extended periods, thereby improving the overall production efficiency and reliability of the process.

[0032] In another technical solution, in step S6, EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate are mixed and stirred with citric acid at 40-50 °C for 25-35 min. Specifically, this includes: weighing citric acid, EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate according to the total mass of the composite protein raw materials; wherein the amount of citric acid is 4.0%-6.0% of the total mass of the composite protein raw materials, the amount of EDTA-Fe is 2.5%-3.5% of the total mass of the composite protein raw materials, the amount of EDTA-Zn is 1.5%-2.5% of the total mass of the composite protein raw materials, the amount of boric acid is 1.0%-2.0% of the total mass of the composite protein raw materials, and the amount of ammonium molybdate is 0.15%-0.25% of the total mass of the composite protein raw materials; dissolving citric acid in water at a temperature of 40-50 °C... Prepare a citric acid solution with a mass concentration of 15%-25% in deionized water at ℃; first add EDTA-Fe to the citric acid solution, and mix and stir for 8-12 min at 40-50 ℃ and a stirring speed of 200-300 r / min; then add EDTA-Zn, and continue mixing and stirring for 8-12 min at the same temperature and stirring conditions; finally add boric acid and ammonium molybdate, maintain the temperature at 40-50 ℃ and the stirring speed at 200-300 r / min, and mix and stir for another 8-12 min to form the composite trace element mixture.

[0033] When multiple trace elements are chelated with citric acid simultaneously, the differences in reaction rates and binding abilities between different metal ions and citric acid can lead to competition and inhibition, resulting in insufficient chelation of some elements and poor homogeneity of the pre-chelate system. This, in turn, affects the stable presence of trace elements in the final product and their effective absorption by crops. By defining the precise ratio of each component relative to the raw materials and adopting a sequential step-by-step addition method: first, EDTA-Fe and citric acid solution are mixed and stirred under suitable conditions for a period of time to achieve initial chelation; then EDTA-Zn is added and stirring continues; finally, boric acid and ammonium molybdate are added to complete the mixing. This order of addition, which provides independent and sufficient reaction time windows for different metal ions, effectively reduces mutual interference between different ions and optimizes the overall chelation reaction process. The resulting composite trace element mixture exhibits better homogeneity and stability, laying a good foundation for subsequent compounding with amino acid hydrolysate and helping to improve the bioavailability and storage stability of nutrients in the final product.

[0034] In another technical solution, step S7 specifically includes: weighing humic acid, seaweed extract, and organosilicon penetrant according to the total mass of the composite protein raw materials; wherein the amount of humic acid weighed is 1.0%-2.0% of the total mass of the composite protein raw materials, the amount of seaweed extract weighed is 0.5%-1.0% of the total mass of the composite protein raw materials, and the amount of organosilicon penetrant weighed is 0.2%-0.4% of the total mass of the composite protein raw materials; mixing the amino acid hydrolysate with the composite trace element mixture at a volume ratio of 3.5-4.5:1, and reacting at 40-50 ℃ with a stirring speed of 150-250 r / min for 50-70 min to obtain a first mixture, and adjusting the temperature of the first mixture to 30-35 ℃; mixing the weighed humic acid with deionized water at a temperature of 30-35 ℃ at a mass ratio of 1:3-5, and stirring at a speed of 800-1200 r / min for 10-20 minutes. The humic acid pre-dispersion solution was obtained by mixing the weighed seaweed extract with deionized water at 30-35 ℃ at a mass ratio of 1:2-4 and stirring at 400-600 r / min for 5-15 min. The humic acid pre-dispersion solution was added to the first mixture after temperature adjustment and dispersed at 30-35 ℃ and 300-500 r / min for 10-20 min to obtain the second mixture. The seaweed extract pre-dispersion solution was added to the second mixture and dispersed at 30-35 ℃ and 300-500 r / min for 10-20 min. Finally, the weighed organosilicon penetrant was added, and the temperature of the mixture was maintained at 30-35 ℃ and sheared and stirred at 2800-3200 r / min for 15-25 min. During the shearing process, the temperature of the mixture was controlled not to exceed 40 ℃ by circulating water cooling.

[0035] In the compounding process of amino acid foliar fertilizer preparation, if the mixing ratio of amino acid hydrolysate and trace element mixture is not clearly defined, or if the addition amount and dispersion method of macromolecular organic adjuvants such as humic acid and seaweed extract lack clear specifications, it is easy to cause uneven distribution of components in the system, poor homogeneity of the mixture, and possible stratification or precipitation after long-term storage. By clarifying the volume ratio between amino acid hydrolysate and compound trace element mixture, and accurately weighing each functional adjuvant according to the total mass of compound protein raw materials, a quantitative basis for system construction is provided. Furthermore, humic acid and seaweed extract are first pre-dispersed with deionized water to prepare well-dispersed pre-dispersed solutions, which are then added sequentially to the reaction mixture of amino acids and trace elements under gentle stirring conditions. Finally, an organosilicon penetrant is introduced and subjected to high-speed shear stirring. This stepwise pre-dispersion and orderly introduction process enables viscous or solid adjuvant components to achieve full and fine dispersion and integration in the liquid phase, thereby forming a homogeneous and stable compound nutrient system, significantly improving the physical stability and storage reliability of the product.

[0036] In another technical solution, after shearing and stirring at a speed of 2800-3200 r / min for 15-25 min, a maturation treatment is also included. The maturation treatment specifically includes: transferring the sheared and stirred mixture into a maturation tank equipped with a slow stirring device, and continuously stirring and maturing at a temperature of 25-30 ℃ and a stirring speed of 30-60 r / min for 18-36 h; in the last 2-4 h of the maturation process, slowly cooling the mixture to 10-15 ℃ at a rate of 0.5-1.0 ℃ / min.

[0037] After mixing amino acids, trace elements, humic acid, seaweed extract, and other components, direct subsequent processing may not allow the molecular interactions between the components to reach a sufficient balance, easily leading to fluctuations in the physicochemical properties of the product during the initial storage period, resulting in slight turbidity or precipitation. The maturation mechanism of this invention involves transferring the mixture to a maturation tank equipped with a slow-speed stirring device, and conducting continuous, slow stirring at a relatively mild temperature for an extended period. This provides conditions for sufficient adjustment and binding of the molecules in the system through weak interactions such as hydrogen bonds, van der Waals forces, and coordination bonds. Subsequently, at the end of the maturation period, the system temperature is gradually reduced at a programmed, slow rate, which helps to "fix" the established stable dispersion and binding state. This maturation and programmed cooling process effectively promotes the aging and stabilization of the composite system, significantly improving the physical homogeneity and long-term storage stability of the final foliar fertilizer product.

[0038] Example 1: A method for preparing a novel amino acid foliar fertilizer, comprising the following steps: S1: Mixing soybean meal, fish meal, and brewer's yeast cells in a mass ratio of 6:3:1 to form a composite protein raw material; S2: Performing a two-stage pulverization process on the composite protein raw material, first pulverizing to 20 mesh, then refining to 80 mesh, to obtain a specific surface area of ​​0.8 m². 2 / g of raw material powder; S3: Degrease the raw material powder, sterilize the degreased raw material by high-pressure steam at 121 ℃ for 20 min, add water to the sterilized raw material to adjust the solid-liquid ratio to 1:4 g / mL, and adjust the pH of the mixture to 8.5; wherein, the degreasing treatment method is as follows: mix the raw material powder with n-hexane at 60 ℃ at a mass ratio of 1:4, and carry out the first-stage degreasing treatment for 60 min under the conditions of stirring speed of 150 r / min and temperature of 60 ℃; separate the solid and liquid phases of the mixture after the first-stage degreasing treatment, and collect the solid phase as the degreased raw material; S4: add 0.8% of the total dry weight of the raw material compound enzyme preparation to the pH-adjusted mixture, and carry out the enzymatic hydrolysis reaction for 6 min under the stirring conditions of 55 ℃ and 150 r / min. h, the compound enzyme preparation is added once at the 2nd and 4th hour after the start of the enzymatic hydrolysis reaction, with the addition amount being 0.1% of the total dry weight of the raw materials; wherein, the compound enzyme preparation is composed of alkaline protease and flavor protease in an enzyme activity unit ratio of 3:1; S5: the enzymatically hydrolyzed material is heated to 85 ℃ and held for 15 min for enzyme inactivation treatment, and the enzyme-inactivated material is filtered using a ceramic membrane ultrafiltration system with a molecular weight cutoff of 500 Da, and the filtrate is collected to obtain amino acid hydrolysate; the enzyme-inactivated material is filtered using a ceramic membrane ultrafiltration system, specifically as follows: the material temperature is lowered to 40-45 ℃, and the enzyme-inactivated and cooled material is filtered using a ceramic membrane ultrafiltration system with a molecular weight cutoff of 500 Da. The ultrafiltration operating parameters are as follows: the feed pressure is controlled at 0.25-0.35 MPa, the membrane surface flow rate is maintained at 2.5-3.5 m / s, and the operating temperature is maintained at 40-45 ℃. At ℃, constant volume dialysis and filtration are performed by continuously adding purified water until the conductivity of the filtrate is lower than 800 μS / cm; then, a concentration operation is performed to concentrate it to about 1 / 3 of the original material volume, and all the filtrate is collected as amino acid hydrolysate.

[0039] S6: EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate are simultaneously mixed and stirred with citric acid at 45 °C for 30 min to form a composite trace element mixture. Citric acid, EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate are weighed according to the total mass of the composite protein raw materials. The amount of citric acid is 5.0% of the total mass of the composite protein raw materials, EDTA-Fe is 3.0%, EDTA-Zn is 2.0%, boric acid is 1.5%, and ammonium molybdate is 0.2%. S7: The amino acid hydrolysate and the composite trace element mixture are mixed at a volume ratio of 4:1 and stirred at 45 °C for 60 min. Humic acid, seaweed extract, and organosilicon penetrant are added to the resulting mixture, and the mixture is sheared and stirred at 3000 r / min at 35 °C for 20 min. min; wherein, based on the total mass of the composite protein raw materials, humic acid, seaweed extract, and organosilicon penetrant are weighed separately; the amount of humic acid is 1.5% of the total mass of the composite protein raw materials, the amount of seaweed extract is 0.8% of the total mass of the composite protein raw materials, and the amount of organosilicon penetrant is 0.3% of the total mass of the composite protein raw materials; S8: the mixture after shearing and stirring is filtered sequentially through a 200-mesh filter cloth and a 0.45μm filter membrane, and the filtered liquid is degassed for 15 min under a vacuum of -0.08MPa to obtain the amino acid foliar fertilizer.

[0040] The effects of the ratio of the compound enzyme (2:1, 3:1, 4:1), enzymatic hydrolysis temperature (45 ℃, 55 ℃, 65 ℃), and chelation time (10 min, 30 min, 50 min) on the free amino acid content and stability were investigated. The results showed that the free amino acid content of Example 1 was 152.3 g / L, and after storage at 40 ℃ for 3 months, the precipitation rate was 0.48%, the turbidity was 8.5 NTU, the amino acid retention rate was 98.5%, and the zinc retention rate was 97.8%.

[0041] When the ratio of the complex enzyme was adjusted from 3:1 in Example 1 to 2:1, the free amino acid content decreased to about 142 g / L, the precipitation rate increased to 1.5% after storage, and the amino acid retention rate decreased to about 94%. When the ratio was adjusted to 4:1, the amino acid content increased slightly to about 155 g / L, but due to the imbalance of the enzyme system, the complexity of the hydrolysis products increased, the precipitation rate increased to 1.8%, and the turbidity increased to 15.5 NTU.

[0042] Regarding the enzymatic hydrolysis temperature, when the temperature was reduced from 55 °C in Example 1 to 45 °C, insufficient enzyme activity caused the amino acid content to drop to about 138 g / L, the precipitation rate increased to 1.2%, and the amino acid retention rate decreased to about 95%. When the temperature was increased to 65 °C, although the initial hydrolysis rate accelerated, some heat-sensitive amino acids were degraded, and the amino acid content was about 146 g / L. Moreover, the high temperature promoted the dissolution of impurities, and the precipitation rate increased to 1.8% after storage, and the turbidity reached 15.0 NTU.

[0043] The effect of chelation time was as follows: when the time was shortened from 30 min in Example 1 to 10 min, the chelation of trace elements was insufficient, and the free amino acid content was basically maintained at about 148 g / L. However, after storage, the zinc retention rate decreased to about 92%, and the precipitation rate increased to 1.1%. When the time was extended to 50 min, the amino acid content did not increase significantly (about 151 g / L), while the long-term heating caused slight aging of the system, the precipitation rate increased slightly to 0.9%, and the energy consumption increased.

[0044] Example 2: A method for preparing a novel amino acid foliar fertilizer, which differs from Example 1 in that, in step S1, the brewer's yeast cells are pretreated by the following method before being mixed: the brewer's yeast cells are mixed with a 1.0% sodium hydroxide solution at a mass ratio of 1:10, soaked at 50 °C for 40 min, and the soaked mixture is circulated 4 times by a high-pressure homogenizer at a pressure of 70 MPa. The homogenized slurry is then subjected to solid-liquid separation, and the solid components are collected as pretreated brewer's yeast cells for mixing.

[0045] Example 3 describes a method for preparing a novel amino acid foliar fertilizer. The difference from Example 1 is that in step S3, the raw material powder is degreased using the following method: The raw material powder is mixed with n-hexane at 60°C at a mass ratio of 1:4, and a first-stage degreasing treatment is performed for 60 min at a stirring speed of 150 r / min and a temperature of 60°C. The mixture after the first-stage degreasing treatment is then subjected to solid-liquid separation, and the solid phase is collected. Two times the mass of hot water at 80°C is added to the collected solid phase, and after stirring until a suspension is formed, the temperature of the suspension is maintained at 60°C, and centrifuged at 3000 r / min for 15 min to separate and remove the upper floating oil and the middle aqueous phase. The bottom solid phase is collected as the degreased raw material.

[0046] Separating and removing the upper floating oil and the intermediate aqueous phase specifically includes: allowing the centrifuged material to stand for 5-15 minutes to allow it to stably separate into an upper floating oil, an intermediate aqueous phase, and a bottom solid phase in a container; using a skimming device, removing the upper floating oil at a temperature of 40-60 ℃; removing the intermediate aqueous phase by inserting a pipette into the container; transferring the remaining bottom solid phase after removing the aqueous phase to a Buchner funnel, and filtering it under a vacuum of -0.06 to -0.08 MPa for 3-8 minutes to obtain the degreased and dehydrated solid raw material.

[0047] Example 4 describes a method for preparing a novel amino acid foliar fertilizer, which differs from Example 1 in that it involves pre-treating the enzyme-inactivated material before ultrafiltration, followed by filtering the enzyme-inactivated material using a ceramic membrane ultrafiltration system. The pre-treatment includes: cooling the temperature of the enzyme-inactivated material to 40°C; adding purified water at 35°C to the cooled material at 20% of the material's mass, and stirring and mixing at 100 r / min for 10 min to obtain a diluted material; transferring the diluted material to a shearing tank and performing high-speed shearing treatment at 35°C and 6000 r / min for 10 min; filtering the high-speed sheared material through a 120-mesh sieve, and collecting the filtrate as the material to be ultrafiltered into the ceramic membrane ultrafiltration system.

[0048] The material after high-speed shearing is filtered using a combination of vibrating screening and countercurrent flushing. Specifically, the process includes: pumping the high-speed sheared material into a vibrating screen equipped with an ultrasonic vibration device, which has a built-in 120-mesh stainless steel screen; activating the ultrasonic vibration device, setting the ultrasonic frequency to 30 kHz and the amplitude to 10 μm, allowing the material to pass through the screen under vibration, and collecting the filtrate; simultaneously, pumping a portion of the collected filtrate back to the back of the screen through a countercurrent flushing pipeline, with the countercurrent flushing flow rate set to 5%-15% of the feed flow rate, using the filtrate flow to continuously back-flush the screen channels; and inputting the filtrate collected after vibrating screening and countercurrent flushing into the ceramic membrane ultrafiltration system as the material to be ultrafiltered.

[0049] Example 5 describes a method for preparing a novel amino acid foliar fertilizer, which differs from Example 1 in that, in step S6, EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate are mixed and stirred with citric acid at 45 °C for 30 min. Specifically, this includes: weighing citric acid, EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate according to the total mass of the composite protein raw materials; the amount of citric acid weighed is 5.0% of the total mass of the composite protein raw materials, the amount of EDTA-Fe weighed is 3.0% of the total mass of the composite protein raw materials, the amount of EDTA-Zn weighed is 2.0% of the total mass of the composite protein raw materials, the amount of boric acid weighed is 1.5% of the total mass of the composite protein raw materials, and the amount of ammonium molybdate weighed is 0.2% of the total mass of the composite protein raw materials; dissolving citric acid in deionized water at 45 °C to prepare a 20% citric acid solution; adding EDTA-Fe to the citric acid solution first, and mixing and stirring at 45 °C and a stirring speed of 250 r / min for 10 minutes. min; then add EDTA-Zn, and continue mixing and stirring for 10 min under the same temperature and stirring conditions; finally add boric acid and ammonium molybdate, maintain the temperature at 45 ℃ and the stirring speed at 250 r / min, and mix and stir for another 10 min to form the composite trace element mixture.

[0050] Example 6: A method for preparing a novel amino acid foliar fertilizer, differing from Example 1 in that step S7 specifically includes: weighing humic acid, seaweed extract, and organosilicon penetrant according to the total mass of the composite protein raw materials; the amount of humic acid weighed is 1.5% of the total mass of the composite protein raw materials, the amount of seaweed extract weighed is 0.8% of the total mass of the composite protein raw materials, and the amount of organosilicon penetrant weighed is 0.3% of the total mass of the composite protein raw materials; mixing the amino acid hydrolysate with the composite trace element mixture at a volume ratio of 4.0:1, and reacting at 45 ℃ with a stirring speed of 200 r / min for 60 min to obtain a first mixture, adjusting the temperature of the first mixture to 35 ℃; mixing the weighed humic acid with deionized water at 35 ℃ at a mass ratio of 1:4, and stirring at a speed of 1000 r / min for 15 min to obtain a humic acid pre-dispersion; mixing the weighed seaweed extract with deionized water at 35 ℃ at a mass ratio of 1:3, and stirring at 500 r / min... Stirring at a speed of 10 r / min for 10 min yields a pre-dispersion of seaweed extract. The humic acid pre-dispersion is added to the first mixture after temperature adjustment, and dispersed at 35 ℃ and a stirring speed of 400 r / min for 15 min to obtain a second mixture. The seaweed extract pre-dispersion is then added to the second mixture, and dispersed at 35 ℃ and a stirring speed of 400 r / min for another 15 min. Finally, the weighed organosilicon penetrant is added, the temperature of the mixture is maintained at 35 ℃, and sheared and stirred at a speed of 3000 r / min for 20 min. During the shearing process, the temperature of the mixture is controlled to not exceed 40 ℃ by circulating water cooling.

[0051] Example 7 describes a method for preparing a novel amino acid foliar fertilizer, which differs from Example 6 in that, after shearing and stirring at 3000 r / min for 20 min, a maturation treatment is included. The maturation treatment specifically includes: transferring the sheared and stirred mixture into a maturation tank equipped with a slow stirring device, and continuously stirring and maturing at 30 ℃ and a stirring speed of 40 r / min for 25 h; and during the last 3 h of the maturation process, slowly cooling the mixture to 10 ℃ at a rate of 0.8 ℃ / min.

[0052] Example 8: A method for preparing a novel amino acid foliar fertilizer, comprising the following steps: S1: Soybean meal, fish meal, and brewer's yeast cells are mixed in a mass ratio of 6:3:1 to form a composite protein raw material; the brewer's yeast cells are pretreated before mixing by the following method: the brewer's yeast cells are mixed with a 1.0% sodium hydroxide solution in a mass ratio of 1:10, soaked at 50 °C for 40 min, and the soaked mixture is circulated four times by a high-pressure homogenizer at a pressure of 70 MPa. The homogenized slurry is then subjected to solid-liquid separation, and the solid component is collected as the pretreated brewer's yeast cells for mixing; S2: The composite protein raw material is subjected to a two-stage pulverization process, first pulverized to 20 mesh, then refined to 80 mesh, to obtain a specific surface area of ​​0.8 m². 2 / g of raw material powder; S3: Degrease the raw material powder, sterilize the degreased raw material with high pressure steam at 121 ℃ for 20 min, add water to the sterilized raw material to adjust the solid-liquid ratio to 1:4 g / mL, and adjust the pH value of the mixture to 8.5; The raw material powder is degreased by the following method, specifically including: mixing the raw material powder with n-hexane at 60 ℃ at a mass ratio of 1:4, and performing a first-stage degreasing treatment for 60 min at a stirring speed of 150 r / min and a temperature of 60 ℃; performing solid-liquid separation on the mixture after the first-stage degreasing treatment, and collecting the solid phase; adding 2.0 times its mass of hot water at a water temperature of 80 ℃ to the collected solid phase, stirring evenly to form a suspension, maintaining the temperature of the suspension at 60 ℃, and centrifuging at a speed of 3000 r / min for 15 min to separate and remove the upper floating oil and the middle aqueous phase, and collecting the bottom solid phase as the degreased raw material.

[0053] Separating and removing the upper floating oil and the intermediate aqueous phase specifically includes: allowing the centrifuged material to stand for 5-15 minutes to allow it to stably separate into an upper floating oil, an intermediate aqueous phase, and a bottom solid phase in a container; using a skimming device, removing the upper floating oil at a temperature of 40-60 ℃; removing the intermediate aqueous phase by inserting a pipette into the container; transferring the remaining bottom solid phase after removing the aqueous phase to a Buchner funnel, and filtering under a vacuum of -0.06 to -0.08 MPa for 3-8 minutes to obtain a degreased and dehydrated solid raw material; S4: adding 0.8% of the total dry weight of the raw material compound enzyme preparation to the pH-adjusted mixture, and carrying out the enzymatic hydrolysis reaction at 55 ℃ and 150 r / min stirring conditions. h, the compound enzyme preparation is added once at the 2nd and 4th hour after the start of the enzymatic hydrolysis reaction, and the amount added is 0.1% of the total dry weight of the raw materials; wherein, the compound enzyme preparation is composed of alkaline protease and flavor protease in an enzyme activity unit ratio of 3:1; S5: the enzymatically hydrolyzed material is heated to 85 °C and held for 15 min for enzyme inactivation treatment, and the enzyme-inactivated material is filtered using a ceramic membrane ultrafiltration system with a molecular weight cutoff of 500 Da, and the filtrate is collected to obtain amino acid hydrolysate; wherein, the step of pre-treatment of the enzyme-inactivated material before ultrafiltration and then filtering the enzyme-inactivated material using a ceramic membrane ultrafiltration system includes: cooling the temperature of the enzyme-inactivated material to 40 °C; adding purified water at 35 °C to the cooled material, the amount added is 20% of the material mass, and stirring and mixing at 100 r / min for 10 min to obtain diluted material; the diluted material is transferred to a shearing tank and heated at 35 °C at 6000 The material is subjected to high-speed shearing at a rotation speed of r / min for 10 minutes; the material after high-speed shearing is filtered through a 120-mesh sieve, and the filtrate is collected as the material to be ultrafiltered and input into the ceramic membrane ultrafiltration system.

[0054] The material after high-speed shearing is filtered using a combination of vibrating screening and countercurrent flushing. Specifically, the process includes: pumping the high-speed sheared material into a vibrating screen equipped with an ultrasonic vibration device, the screen containing a 120-mesh stainless steel screen; activating the ultrasonic vibration device, setting the ultrasonic frequency to 30 kHz and the amplitude to 10 μm, allowing the material to pass through the screen under vibration, and collecting the filtrate; simultaneously, pumping a portion of the collected filtrate back to the back of the screen through a countercurrent flushing pipeline, with the countercurrent flushing flow rate set to 5%-15% of the feed flow rate, using the filtrate flow to continuously back-flush the screen channels; and inputting the filtrate collected after vibrating screening and countercurrent flushing as the material to be ultrafiltered into the ceramic membrane ultrafiltration system; S6: mixing EDTA-Fe, EDTA-Zn, boric acid, ammonium molybdate, and citric acid at 45°C. Mix and stir at ℃ for 30 min to form a composite trace element mixture; wherein, based on the total mass of the composite protein raw materials, citric acid, EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate are weighed respectively; the amount of citric acid is 5.0% of the total mass of the composite protein raw materials, the amount of EDTA-Fe is 3.0% of the total mass of the composite protein raw materials, the amount of EDTA-Zn is 2.0% of the total mass of the composite protein raw materials, the amount of boric acid is 1.5% of the total mass of the composite protein raw materials, and the amount of ammonium molybdate is 0.2% of the total mass of the composite protein raw materials; EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate are mixed and stirred with citric acid at 45 ℃ for 30 min, specifically including: dissolving citric acid in deionized water at 45 ℃ to prepare a 20% citric acid solution; adding EDTA-Fe to the citric acid solution first, and mixing and stirring at 45 ℃ and a stirring speed of 250 r / min for 10 min. min; then add EDTA-Zn, and continue mixing and stirring for 10 min under the same temperature and stirring conditions; finally add boric acid and ammonium molybdate, maintain the temperature at 45 ℃ and the stirring speed at 250 r / min, and mix and stir for another 10 min to form the composite trace element mixture; S7: mix the amino acid hydrolysate and the composite trace element mixture at a volume ratio of 4:1, stir and react at 45 ℃ for 60 min, add humic acid, seaweed extract and organosilicon penetrant to the mixture after reaction, and shear and stir at 3000 r / min at 35 ℃ for 20 min; wherein, according to the total mass of the composite protein raw materials, humic acid, seaweed extract and organosilicon penetrant are weighed respectively; the amount of humic acid is 1.5% of the total mass of the composite protein raw materials, the amount of seaweed extract is 0.8% of the total mass of the composite protein raw materials, and the amount of organosilicon penetrant is 0.3% of the total mass of the composite protein raw materials; the volume ratio is 4.A 0:1 amino acid hydrolysate was mixed with the composite trace element mixture and reacted at 45 °C with a stirring speed of 200 r / min for 60 min to obtain a first mixture. The temperature of the first mixture was adjusted to 35 °C. Humic acid was weighed and mixed with deionized water at 35 °C at a mass ratio of 1:4 and stirred at 1000 r / min for 15 min to obtain a humic acid pre-dispersion. Seaweed extract was weighed and mixed with deionized water at 35 °C at a mass ratio of 1:3 and stirred at 500 r / min for 10 min to obtain a seaweed extract pre-dispersion. The humic acid pre-dispersion was added to the first mixture after temperature adjustment and dispersed at 35 °C with a stirring speed of 400 r / min for 15 min to obtain a second mixture. The seaweed extract pre-dispersion was added to the second mixture and dispersed at 35 °C with a stirring speed of 400 r / min for another 15 min. min; finally, add the weighed organosilicon penetrant, maintain the temperature of the mixture at 35 ℃, and shear and stir at 3000 r / min for 20 min. During the shearing process, the temperature of the mixture is controlled not to exceed 40 ℃ by circulating water cooling; S8: filter the sheared and stirred mixture sequentially through a 200-mesh filter cloth and a 0.45μm filter membrane, and degas the filtered liquid under a vacuum of -0.08MPa for 15 min to obtain the amino acid foliar fertilizer; after shearing and stirring at 3000 r / min for 20 min, a maturation treatment is also included. The maturation treatment specifically includes: transferring the sheared and stirred mixture into a maturation tank equipped with a slow stirring device, and continuously stirring and maturing at 30 ℃ and a stirring speed of 40 r / min for 25 h; in the last 3 h of the maturation process, slowly cool the mixture to 10 ℃ at a rate of 0.8 ℃ / min.

[0055] Comparative Example 1 uses the method of Example 1, except that a single alkaline protease is used for enzymatic hydrolysis.

[0056] Comparative Example 2 uses the method of Example 1, except that a single flavor protease is used for enzymatic hydrolysis.

[0057] Comparative Example 3 uses the method of Example 1, except that the raw material powder is not degreased.

[0058] Comparative Example 4 uses the method of Example 1, except that it does not contain brewer's yeast cells, that is, the raw material powder is a mixture of soybean meal and fish meal in a mass ratio of 6:3.

[0059] Comparative Example 5 uses the method of Example 1, except that it does not contain fish meal and brewer's yeast cells, i.e., the raw material powder is soybean meal.

[0060] Comparative Example 6 describes a method for preparing an amino acid foliar fertilizer, which uses a strong acid hydrolysis method instead of the compound enzymatic hydrolysis process in Example 1. The method includes the following steps: First, soybean meal, fish meal, and brewer's yeast cells are mixed at a mass ratio of 6:3:1 to form a compound protein raw material. This material is then pulverized to 80 mesh using a double-stage grinding process to obtain raw material powder. This raw material powder is then mixed with a 7 mol / L hydrochloric acid solution at a solid-liquid ratio of 1:4 g / mL and placed in an acid-resistant reactor. Under nitrogen protection at 110±2 ℃, hydrolysis is continued for 10 hours. After hydrolysis, the material is cooled to below 50 ℃. A 40% potassium hydroxide solution is added to adjust the pH to 3.0, and the mixture is allowed to stand for 2 hours to remove protein residue. Then, 25% ammonia water is used to adjust the pH to 6.0. Subsequently, the neutralized liquid is subjected to activated carbon decolorization and ion exchange desalination treatment to obtain an amino acid hydrolysate. The subsequent steps are the same as in Example 1: the hydrolysate and the complex trace element mixture are mixed at a volume ratio of 4:1, humic acid, seaweed extract and organosilicon penetrant are added, and the mixture is subjected to high-speed shearing, filtration and vacuum degassing to obtain the foliar fertilizer product.

[0061] Comparative Example 7 uses the method of Example 1, except that 1.0% of the total dry weight of the raw materials of the compound enzyme preparation is added to the pH-adjusted mixture, and the enzymatic hydrolysis reaction is carried out at 55 °C and 150 r / min for 6 h. Other operations are the same as in Example 1.

[0062] Experiment 1: Amino Acid Detection. Accurately weigh 1.000 g of foliar fertilizer sample and dilute to 50 mL with 0.02 mol / L hydrochloric acid solution. Filter the solution through a 0.22 μm aqueous filter membrane and perform pre-column derivatization. The derivatization was performed using an automated program with o-phthalaldehyde (OPA) and 9-fluorenylmethoxycarbonyl chloride (FMOC-Cl). Gradient elution separation was then performed using a C18 column with an HPLC system equipped with a UV / fluorescence detector. The content of 17 common protein-derived free amino acids (including aspartic acid, glutamic acid, lysine, and tryptophan) was quantitatively determined using the external standard method.

[0063] The formula for calculating the total amount of free amino acids (g / L) is: the sum of the concentrations (g / L) of each individual amino acid.

[0064] The formula for calculating the percentage of essential amino acids (%) is: (sum of the concentrations of the eight essential amino acids (lysine, tryptophan, phenylalanine, methionine, threonine, isoleucine, leucine, and valine) / total free amino acids) × 100%.

[0065] The results are shown in Table 1.

[0066] Table 1 Amino acid detection results Table 1 shows that the total free amino acid content and the proportion of essential amino acids in the amino acid foliar fertilizer prepared using the optimized process of this invention both increased stepwise with the improvement of the process. In Examples 1 to 8, the free amino acid content gradually increased from 152.3 g / L to 157.2 g / L, and the proportion of essential amino acids increased from 40.0% to 48.0%, indicating that the composite raw materials and key steps such as stepwise enzymatic hydrolysis and chelation worked synergistically to effectively improve the release efficiency and nutritional balance of amino acids. In contrast, the total amino acid content and the proportion of essential amino acids in all comparative examples were significantly lower, confirming the negative impact of defective processes such as single enzymes, missing raw materials, or strong acid hydrolysis on the amino acid composition and content of the product.

[0067] II. Storage Stability 1. Experimental Design: Stability test conditions: (40±2) ℃, relative humidity (75±5)%, simulating the harsh environment of long-term storage.

[0068] Testing time points: initial (0 months) and endpoint (3 months).

[0069] 2. Detection method for sedimentation rate: Take 10.0 mL of sample, centrifuge at 4000 r / min for 15 minutes, measure the volume of sediment, and calculate the percentage.

[0070] Turbidity: Measured directly using a portable turbidimeter.

[0071] Total free amino acids: determined by HPLC (pre-column derivatization), and the retention rate was calculated after 3 months.

[0072] Effective zinc content: After filtering the sample through a 0.45 μm filter membrane, the zinc content in the filtrate was determined by atomic absorption spectrometry, and the retention rate was calculated.

[0073] pH value: Measured using a precision pH meter, the absolute difference from the initial value is calculated.

[0074] 3. The changes in each indicator after storage at 40 ℃ for 3 months are shown in Table 2 below.

[0075] Table 2 Stability test results Table 2 shows that the optimized process of this invention significantly improves the storage stability of the foliar fertilizer. With the gradual improvement of the process (Examples 1 to 8), after 3 months of accelerated storage at 40℃, the precipitation rate decreased from 0.48% to 0.20%, the turbidity decreased from 8.5 NTU to 3.0 NTU, the retention rates of amino acids and zinc were close to 99%, and the pH change was minimal. This indicates that the steps of compound degreasing, membrane purification, and ordered compounding effectively eliminated unstable factors. In contrast, the stability of the comparative examples was poor, especially Comparative Example 6, which used strong acid hydrolysis, with a precipitation rate as high as 2.80%, a turbidity of 45.0 NTU, and a key component retention rate of less than 90%, highlighting the inherent defects of traditional vigorous processes.

[0076] III. Survey on the Incidence of Late Blight in Tomatoes: Survey Design and Timing: The experiment used appropriately replicated plots to conduct a systematic survey during the natural peak period of late blight disease incidence in tomatoes. A second survey was conducted 10 days after the last application of foliar fertilizer.

[0077] Sampling and grading methods: A diagonal five-point sampling method was used, with five plants continuously surveyed at each point. The total number of plants and the number of diseased plants were recorded. Disease severity grading was based on a 0-4 standard: Grade 0, no lesions; Grade 1, lesion area <5% of leaf area; Grade 2, lesion area 6%-25%; Grade 3, lesion area 26%-50%; Grade 4, lesion area >50%.

[0078] Calculate the incidence rate (number of diseased plants / total number of plants surveyed × 100%) and the disease index ([∑(number of diseased leaves × corresponding disease level)] / (total number of leaves surveyed × highest disease level) × 100).

[0079] Data recording and processing: Record the survey data of each community and calculate the average incidence rate and disease index of each treatment group.

[0080] Table 3 Results of Disease Incidence Survey Table 3 shows that the foliar fertilizer prepared according to this invention can significantly reduce the incidence of late blight in tomatoes. With process optimization (Examples 1 to 8), the incidence rate of tomatoes gradually decreased from 35.5% to 22.5%, and the disease index decreased from 20.1 to 12.1, indicating that the product's effect on inducing crop disease resistance continued to enhance. In contrast, comparative examples using defective processes such as single enzymatic hydrolysis, incomplete defatting, incomplete raw materials, or strong acid hydrolysis showed significantly higher incidence rates and disease indices, with the strong acid process (Comparative Example 6) performing the worst. The results indicate that the complete synergistic process system of this invention is significantly superior to traditional or single-improvement methods in enhancing crop disease resistance.

[0081] IV. Tomato Field Yield Trial 1. Experimental Design Experimental Location and Time: The experiment was conducted in the spring of 2024 (March-July) at a standardized vegetable experimental base. The test soil was sandy loam with a pH of 6.8 and an organic matter content of 1.5%. The previous crop was corn.

[0082] The tested variety was Jinpeng No. 1, a tomato variety that is mainly cultivated locally and sensitive to nutrients.

[0083] Experimental treatments: A randomized block design was used, with each treatment replicated three times. The plot size for each treatment was 10 m². 2 (2.5 m × 4 m), with 1 m wide isolation rows set between the small sections to prevent fertilizer solution drift and interference.

[0084] Treatment group: Amino acid foliar fertilizers prepared in the examples and comparative examples.

[0085] Commercially available control group: Sprayed with a certain brand of amino acid foliar fertilizer with a high market share (labeled as having ≥100g / L of free amino acids).

[0086] Blank control group: sprayed with an equal amount of water.

[0087] Field management: Except for the different foliar fertilization treatments, the planting density, irrigation, pest and disease control (using the same pesticides) and agricultural operations of all plots were strictly kept consistent in order to control a single variable.

[0088] 2. Application method, spraying time and frequency: Foliar spraying should be carried out during the three key nutrient-demanding stages of the entire growth period, namely the seedling stage (15 days after transplanting), the initial flowering stage (when 50% of the first cluster of flowers is open), and the fruit enlargement stage (10 days after the second cluster of fruits sets).

[0089] Application concentration and dosage: Dilute each foliar fertilizer product for each treatment 800 times, i.e., take 1.25 mL of the stock solution and dilute it with water to 1 L. Use a backpack electric sprayer (with a fan-shaped mist nozzle) to spray evenly, ensuring that both sides of the leaves are evenly covered with the pesticide, just enough to moisten the leaves without dripping. The application rate for each spray is 100 mL / m². 2 Converted to each community (20 m) 2 Apply 2 L of diluted solution each time.

[0090] Spraying conditions: Choose a sunny, windless afternoon after 4 PM to avoid high temperatures and strong sunlight causing rapid evaporation of the spray droplets, which could scorch the leaves or hinder absorption. If it rains within 24 hours after spraying, re-spray after the rain.

[0091] 3. Method for determining the index: Leaf chlorophyll content: On the 7th day after the last spray, 5 plants were randomly selected from each plot, and the SPAD value of the third fully unfolded functional leaf from the top of the plant (avoiding the midrib) was measured using a handheld chlorophyll meter (SPAD-502Plus). Three points were measured for each leaf and the average value was taken.

[0092] Fruit weight and yield: During the fruit ripening period, 20 uniformly sized, red-ripe fruits were collected from each plot using a five-point sampling method. The fruits were weighed using an electronic balance, and the average fruit weight was calculated. At the same time, yield was calculated by zone and yield per unit area.

[0093] Vitamin C content of fruit: The vitamin C content of the above-mentioned fruit samples was determined by titration with 2,6-dichlorophenolindophenol.

[0094] The results are shown in Table 4 below.

[0095] Table 4 Results of Tomato Field Yield Trial Table 4 shows that the foliar fertilizer of this invention can effectively promote tomato growth and improve fruit quality and yield. With the optimization of the preparation process (Examples 1 to 8), the chlorophyll content (SPAD value) of tomato leaves increased from 44.1 to 47.5, the single fruit weight increased from 162g to 176g, the yield increased from 5.50kg to 6.20kg, and the vitamin C content also increased from 17.8mg / 100g to 19.8mg / 100g, showing a positive gain for the system. Conversely, the relevant indicators of each comparative example and the commercially available control group were significantly lagging behind, with the blank control group showing the worst performance. This confirms that the complete process system of this invention has significant advantages in improving crop photosynthetic capacity, yield, and nutritional quality.

[0096] V. Cucumber Field Trial: The experimental design and application methods were the same as those for the tomato trial. A randomized block design was adopted, with 16 treatments including each embodiment of the present invention, each comparative example, commercially available amino acid foliar fertilizer, and a water-based blank control. Each treatment was replicated three times. The corresponding foliar fertilizer diluted 800 times was sprayed at the cucumber seedling stage, the initial flowering stage, and the peak fruiting stage. The investigated and measured indicators included: the SPAD value of functional leaves (indicating relative chlorophyll content) 7 days after the last spraying, the average weight of a single fruit and the yield per unit area at the marketable fruit harvest stage, the vitamin C content of the fruit, and the incidence and disease index of downy mildew, the main leaf disease of cucumber (the investigation was conducted 15 days after the last spraying at the peak of disease occurrence, and the grading standard referred to the 0-4 level method of the tomato trial). The experimental results are shown in Table 5 below.

[0097] Table 5. Results of field experiments on cucumber yield, quality, and disease occurrence. Table 5 shows that the foliar fertilizer of this invention significantly improved the growth, development, yield, quality, and disease resistance of cucumbers. With the optimization of the preparation process (Examples 1 to 8), the chlorophyll content of cucumber leaves, single cucumber weight, yield, and vitamin C content of fruits all showed a systematic increase, while the incidence and disease index of downy mildew significantly decreased. Among them, Example 8 performed best, with a yield of 9.05 kg and the incidence rate reduced to 18.0%. In contrast, all indicators of the comparative examples, the commercially available control group, and the blank control group were comprehensively inferior, further verifying the comprehensive advantages of the complete process system of this invention in promoting healthy crop growth and enhancing stress resistance.

[0098] VI. Strawberry Field Trial: The experimental design and application principles were the same as before: a randomized block design was adopted, with 16 treatments including each embodiment of the present invention, each comparative example, commercially available amino acid foliar fertilizer, and a water-based blank control, with each treatment replicated three times. The corresponding foliar fertilizer diluted 800 times was sprayed after the strawberry seedlings had established themselves, at the initial flowering stage, and at the fruit enlargement stage. The investigated and measured indicators included: SPAD value of functional leaves (representing relative chlorophyll content) 7 days after the last spray, average single fruit weight and yield per unit area at the marketable fruit harvest, soluble solids content of the fruit (TSS, measured using a handheld refractometer), and the incidence and disease index of gray mold, a major strawberry disease (investigated 15 days after the last spray during the peak disease occurrence period, with grading standards referring to the 0-4 level method used in tomato experiments). The experimental results are shown in Table 6 below.

[0099] Table 6. Results of strawberry field trials on yield, quality, and disease occurrence. Table 6 shows that the foliar fertilizer of this invention significantly improves the growth, development, fruit quality, and disease resistance of strawberries. With the optimization of the preparation process (Examples 1 to 8), the chlorophyll content of strawberry leaves, single fruit weight, yield, and soluble solids content of fruit all systematically increased, while the incidence and disease index of gray mold significantly decreased. Example 8 showed the best results, with a yield of 7.65 kg and an incidence rate of only 12.0%. All indicators of the comparative examples, the commercially available control group, and the blank control group were comprehensively inferior, which further confirms that the synergistic and complete process system of this invention has universal and significant advantages in improving the comprehensive agronomic traits of various crops.

[0100] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A method for preparing a novel amino acid foliar fertilizer, characterized in that, Includes the following steps: S1: Mix soybean meal, fish meal, and brewer's yeast cells in a mass ratio of 6-10:3-5:1 to form a composite protein raw material; S2: Perform a two-stage grinding process on the composite protein raw material, first grinding to 15-25 mesh, then refining to 70-90 mesh, to obtain a specific surface area of ​​not less than 0.8 m². 2 / g of raw material powder; S3: Degrease the raw material powder, sterilize the degreased raw material by high-pressure steam at 115-125 ℃ for 18-22 min, add water to the sterilized raw material to adjust the solid-liquid ratio to 1:3-5 g / mL, and adjust the pH of the mixture to 8.0-9.0; S4: Add 0.7%-0.9% of the total dry weight of the raw material compound enzyme preparation to the pH-adjusted mixture, and carry out the enzymatic hydrolysis reaction at 52-58 ℃ and 140-160 r / min for 5-7 h. Add the compound enzyme preparation once at the 2nd and 4th hour after the start of the enzymatic hydrolysis reaction, and the amount added is 0.08%-0.12% of the total dry weight of the raw material; wherein, the compound enzyme preparation is composed of alkaline protease and flavor protease at an enzyme activity unit ratio of 2.5-3.5:1; S5: Heat the enzymatically hydrolyzed material to 80-90 ℃ and maintain it for 12-18 minutes. S6: Enzyme inactivation treatment was performed. The material after enzyme inactivation was filtered using a ceramic membrane ultrafiltration system with a molecular weight cutoff of 500 Da, and the filtrate was collected to obtain amino acid hydrolysate. S7: EDTA-Fe, EDTA-Zn, boric acid, ammonium molybdate, and citric acid were mixed and stirred at 40-50 °C to form a composite trace element mixture. S8: The amino acid hydrolysate and the composite trace element mixture were mixed and stirred at 40-50 °C for 50-70 min. Humic acid, seaweed extract, and organosilicon penetrant were added to the mixture after reaction, and sheared and stirred at 2800-3200 r / min at 30-40 °C for 15-25 min. S9: The sheared and stirred mixture was filtered sequentially through a 180-220 mesh filter cloth and a 0.4-0.5 μm filter membrane. The filtered liquid was degassed under a vacuum of -0.075 to -0.085 MPa for 12-18 minutes. The amino acid foliar fertilizer was obtained by min.

2. The preparation method of the novel amino acid foliar fertilizer according to claim 1, characterized in that, In step S1, the brewer's yeast cells are pretreated before being mixed by the following method: the brewer's yeast cells are mixed with a sodium hydroxide solution with a mass concentration of 0.8%-1.2% at a mass ratio of 1:8-12, and soaked at 45-55 ℃ for 30-50 min. The soaked mixture is then circulated 3-5 times by a high-pressure homogenizer at a pressure of 60-80 MPa. The homogenized slurry is then subjected to solid-liquid separation, and the solid components are collected as pretreated brewer's yeast cells for mixing.

3. The preparation method of the novel amino acid foliar fertilizer according to claim 1, characterized in that, In step S3, the raw material powder is degreased, specifically including: mixing the raw material powder with n-hexane at a temperature of 50-70 ℃ at a mass ratio of 1:3-5, and performing a first-stage degreasing treatment for 40-80 min under the conditions of stirring speed of 100-200 r / min and temperature of 50-70 ℃; performing solid-liquid separation on the mixture after the first-stage degreasing treatment and collecting the solid phase; adding 1.5-2.5 times its mass of hot water at a temperature of 75-85 ℃ to the collected solid phase, stirring evenly to form a suspension, maintaining the temperature of the suspension at 55-65 ℃, and centrifuging at a speed of 2500-3500 r / min for 10-20 min to perform a second-stage degreasing treatment, separating and removing the upper floating oil and the middle aqueous phase, and collecting the bottom solid phase as the degreased raw material.

4. The preparation method of the novel amino acid foliar fertilizer according to claim 3, characterized in that, Separating and removing the upper floating oil and the intermediate aqueous phase specifically includes: allowing the centrifuged material to stand for 5-15 minutes to allow it to stably separate into an upper floating oil, an intermediate aqueous phase, and a bottom solid phase in a container; using a skimming device, removing the upper floating oil at a temperature of 40-60 ℃; removing the intermediate aqueous phase by inserting a pipette into the container; transferring the remaining bottom solid phase after removing the aqueous phase to a Buchner funnel, and filtering it under a vacuum of -0.06 to -0.08 MPa for 3-8 minutes to obtain the degreased and dehydrated solid raw material.

5. The method for preparing the novel amino acid foliar fertilizer according to claim 1, characterized in that, The process involves pre-treating the enzyme-inactivated material before ultrafiltration, followed by filtration using a ceramic membrane ultrafiltration system. The pre-treatment includes: cooling the enzyme-inactivated material to 35-45°C; adding purified water at 30-40°C (15%-25% of the material's mass) to the cooled material and mixing at 80-120 r / min for 5-15 min to obtain a diluted material; transferring the diluted material to a shearing tank and subjecting it to high-speed shearing at 5000-7000 r / min for 8-15 min at 30-40°C; and filtering the high-speed sheared material through a 100-150 mesh sieve, collecting the filtrate as the material to be ultrafiltered and inputting it into the ceramic membrane ultrafiltration system.

6. The method for preparing the novel amino acid foliar fertilizer according to claim 5, characterized in that, The material after high-speed shearing is filtered using a combination of vibrating screening and countercurrent flushing. Specifically, the process includes: pumping the high-speed sheared material into a vibrating screen equipped with an ultrasonic vibration device, the screen containing a 100-150 mesh stainless steel screen; activating the ultrasonic vibration device, setting the ultrasonic frequency to 20-40 kHz and the amplitude to 5-15 μm, allowing the material to pass through the screen under vibration, and collecting the filtrate; simultaneously, pumping a portion of the collected filtrate back to the back of the screen through a countercurrent flushing pipeline, with the countercurrent flushing flow rate set to 5%-15% of the feed flow rate, using the filtrate flow to continuously back-flush the screen channels; and inputting the filtrate collected after vibrating screening and countercurrent flushing as the material to be ultrafiltered into the ceramic membrane ultrafiltration system.

7. The method for preparing the novel amino acid foliar fertilizer according to claim 1, characterized in that, In step S6, EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate are mixed and stirred with citric acid at 40-50 °C for 25-35 min. Specifically, this includes: weighing citric acid, EDTA-Fe, EDTA-Zn, boric acid, and ammonium molybdate according to the total mass of the composite protein raw materials; wherein the amount of citric acid is 4.0%-6.0% of the total mass of the composite protein raw materials, the amount of EDTA-Fe is 2.5%-3.5% of the total mass of the composite protein raw materials, the amount of EDTA-Zn is 1.5%-2.5% of the total mass of the composite protein raw materials, the amount of boric acid is 1.0%-2.0% of the total mass of the composite protein raw materials, and the amount of ammonium molybdate is 0.15%-0.25% of the total mass of the composite protein raw materials; dissolving citric acid in a solution at a temperature of 40-50 °C... Prepare a citric acid solution with a mass concentration of 15%-25% in deionized water at ℃; first add EDTA-Fe to the citric acid solution, and mix and stir for 8-12 min at 40-50 ℃ and a stirring speed of 200-300 r / min; then add EDTA-Zn, and continue mixing and stirring for 8-12 min at the same temperature and stirring conditions; finally add boric acid and ammonium molybdate, maintain the temperature at 40-50 ℃ and the stirring speed at 200-300 r / min, and mix and stir for another 8-12 min to form the composite trace element mixture.

8. The method for preparing the novel amino acid foliar fertilizer according to claim 1, characterized in that, Step S7 specifically includes: weighing humic acid, seaweed extract, and organosilicon penetrant according to the total mass of the composite protein raw materials; wherein the amount of humic acid weighed is 1.0%-2.0% of the total mass of the composite protein raw materials, the amount of seaweed extract weighed is 0.5%-1.0% of the total mass of the composite protein raw materials, and the amount of organosilicon penetrant weighed is 0.2%-0.4% of the total mass of the composite protein raw materials; mixing the amino acid hydrolysate with the composite trace element mixture at a volume ratio of 3.5-4.5:1, and reacting at 40-50℃ with a stirring speed of 150-250 r / min for 50-70 min to obtain a first mixture, and adjusting the temperature of the first mixture to 30-35℃; mixing the weighed humic acid with deionized water at a temperature of 30-35℃ at a mass ratio of 1:3-5, and stirring at a speed of 800-1200 r / min for 10-20 minutes. The humic acid pre-dispersion solution was obtained by mixing the weighed seaweed extract with deionized water at 30-35 ℃ at a mass ratio of 1:2-4 and stirring at 400-600 r / min for 5-15 min. The humic acid pre-dispersion solution was added to the first mixture after temperature adjustment and dispersed at 30-35 ℃ and 300-500 r / min for 10-20 min to obtain the second mixture. The seaweed extract pre-dispersion solution was added to the second mixture and dispersed at 30-35 ℃ and 300-500 r / min for 10-20 min. Finally, the weighed organosilicon penetrant was added, and the temperature of the mixture was maintained at 30-35 ℃ and sheared and stirred at 2800-3200 r / min for 15-25 min. During the shearing process, the temperature of the mixture was controlled not to exceed 40 ℃ by circulating water cooling.

9. The method for preparing the novel amino acid foliar fertilizer according to claim 8, characterized in that, After shearing and stirring at 2800-3200 r / min for 15-25 min, a maturation process is also included. The maturation process specifically includes: transferring the sheared and stirred mixture into a maturation tank equipped with a slow stirring device, and continuously stirring and maturing at 25-30 ℃ and a stirring speed of 30-60 r / min for 18-36 h; in the last 2-4 h of the maturation process, slowly cooling the mixture to 10-15 ℃ at a rate of 0.5-1.0 ℃ / min.

10. A novel amino acid foliar fertilizer, characterized in that, It is prepared by the method of any one of claims 1-9 for the preparation of the novel amino acid foliar fertilizer.

Images