Water-soluble fertilizer prepared based on EPG water and fertilizer gathering and absorbing technology

Abstract

The invention provides a water-soluble fertilizer prepared based on an EPG water and fertilizer aggregation and absorption technology, and relates to the technical field of fertilizers, the water-soluble fertilizer comprises the following components by weight: 0.1-0.5 part of Ectoin, 0.05-0.2 part of polyglutamic acid with a low polymerization degree, 0.05-0.2 part of polyglutamic acid with a high polymerization degree, and 0.05-0.2 part of gamma-aminobutyric acid. In the invention, the cyclic amino acid derivative enhances the retention of water around cells and reduces the loss of water penetrating through cell walls, thereby maintaining the water balance of plants in pressure environments such as drought and the like. In addition, the composition inhibits the generation of free radicals through the anti-oxidation effect, and delays the aging process of plants. Different polymerization degrees of polyglutamic acid ensure immediate and lasting nutrient release, low-polymerization-degree polyglutamic acid quickly acts on crops to improve the initial growth speed, and high-polymerization-degree polyglutamic acid ensures continuous supply to avoid nutrient interruption.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to a water-soluble fertilizer prepared based on EPG water-fertilizer aggregation technology. Background Art

[0002] Water-soluble fertilizers refer to fertilizers that can be completely dissolved in water. They are a widely used method of fertilization in modern agriculture. The main purpose of this type of fertilizer is to provide nutrients directly to crops through irrigation systems (such as drip irrigation and sprinkler irrigation), ensuring that the nutrients can be quickly and evenly absorbed by the crops.

[0003] However, existing water-soluble fertilizer technology mainly focuses on providing nutrients directly to crops, but often ignores the specific adaptation needs of crops under different environmental pressures. For example, under extreme climatic conditions, traditional water-soluble fertilizers are difficult to effectively protect crops from stress, resulting in rapid evaporation of water and loss of nutrients before they are fully absorbed, which not only reduces the utilization efficiency of fertilizers, but also limits the maximum potential of crop growth. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a water-soluble fertilizer prepared based on EPG water-fertilizer aggregation technology.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme: a water-soluble fertilizer prepared based on EPG water-fertilizer aggregation technology, the water-soluble fertilizer comprises the following components by weight:

[0006] 0.1-0.5 parts of ectoine, 0.05-0.2 parts of low-polymerization degree polyglutamic acid, 0.05-0.2 parts of high-polymerization degree polyglutamic acid, 0.05-0.2 parts of γ-aminobutyric acid, 20-50 parts of potassium sulfate, 20-50 parts of calcium nitrate, 1-3 parts of mycorrhizal fungi, and 1-5 parts of sodium alginate.

[0007] Preferably, the molecular weight of the low-polymerization polyglutamic acid is ≤20 kDa.

[0008] Preferably, the molecular weight of the high-polymerization polyglutamic acid is ≥1000 kDa.

[0009] The present invention provides a method for preparing a water-soluble fertilizer based on EPG water-fertilizer aggregation technology, comprising the following steps:

[0010] S1, batching and mixing: weigh ectoine, low-polymerization polyglutamic acid, high-polymerization polyglutamic acid, γ-aminobutyric acid, potassium sulfate, calcium nitrate, mycorrhizal fungi and sodium alginate with an electronic balance; put them into the mixing tank, operate in a sealed environment and maintain the internal dry state; use a paddle stirrer, stir at a speed of 230-500rpm, use a circulating water jacket to control the temperature at 25-35°C, and control the humidity to no more than 10%; continue stirring for 15-30 minutes to make the particles fully and evenly distributed and mix the base material in powder form; after the operation is completed, a preliminary mixture of ingredients is obtained;

[0011] S2, microbial inoculation operation: in the preliminary mixture of ingredients, an inert atmosphere is provided, and a gas with an oxygen content of 8-12% is introduced; the mycorrhizal fungus spore suspension is sprayed into the mixing tank, the stirring speed during spraying is 150-300 rpm, the temperature in the tank is 30-33° C., and the spraying is continued for 30-60 min, so that the mycorrhizal fungus spores are uniformly adsorbed on the surface of the previous powder; after the operation is completed, an inoculated microbial mixture is obtained;

[0012] S3, biological fermentation process: the inoculated microbial mixture is subjected to closed fermentation, a stainless steel fermentation tank is used, sterilized by high-pressure steam for 30-60 minutes and pure oxygen is introduced to make the dissolved oxygen 30-50%; the stirring speed is 200-400rpm, the temperature is 25-32°C, the humidity is 50-60%, and the fermentation period is 48-72h; sampling is performed at regular intervals, and the concentration of microbial metabolites is measured by an ultraviolet spectrophotometer, and the change of ion concentration is monitored by a conductivity meter; after the fermentation is completed, a fermentation product base is obtained;

[0013] S4, post-fermentation treatment: heat inactivation is performed in the fermentation product base material; heating to 60-80°C through a plate heat exchanger and maintaining for 10-20 minutes; then using a centrifuge at a speed of 5000-8000 rpm to separate the solid and liquid, and using a filter membrane to intercept the residual solid phase; transferring the separated clear liquid to a neutralization tank, adjusting the pH to 6.0-7.0 and stirring for 20-40 minutes; after the neutralization process is completed, the supernatant is taken to obtain a stable fermentation product;

[0014] S5, dissolving and mixing: stirring the fermentation product with a magnetic stirrer at a speed of 400-600 rpm, and adding double deionized pure water in batches to maintain the solid content at 10-20%; maintaining the solution at a temperature of 35-45° C. for 30-50 minutes to promote the dissolution of sodium alginate, potassium sulfate and calcium nitrate; and obtaining a uniform solution;

[0015] S6, bubble dissolution introduction: inject microbubbles into the uniform solution, and pass the solution at a pressure of 10-30 kPa using an ultrasonic microporous aeration device; the ultrasonic frequency is 20-30 kHz so that the gas forms 30-100 μm microbubbles in the solution; the dissolved oxygen value is controlled at 5-10 mg / L for 20-40 min to allow the gas to fully contact the liquid phase and increase the intermolecular transfer rate; after the operation is completed, a high gas-liquid contact solution is obtained;

[0016] S7, polymerization reaction: introducing an ultraviolet light source and a 5-15 Hz magnetic field into the high gas-liquid contact solution, and adding ammonium persulfate and N,N'-methylenebisacrylamide as initiating components; the temperature is 40-50° C., and the stirring is 50-100 rpm; obtaining a polymerization reaction mixture;

[0017] S8, high-pressure spray granulation preparation: adjusting the viscosity and solid content of the polymerization reaction mixture; evaporating under reduced pressure at 50-60° C. by a rotary evaporator to make the solid content reach 25-35%; monitoring the viscosity online, if the viscosity exceeds 200-300 mPa·s, adding pure water, if it is insufficient, extending the evaporation time; obtaining the spray granulation liquid;

[0018] S9, pressure spray granulation: the spray granulation liquid is pumped into the top of the spray drying tower at a pressure of 5-10 MPa, and atomized into droplets smaller than 50 μm through a 0.5-1.0 mm nozzle; the hot air enters the tower at 120-160°C and leaves the tower at 60-90°C, and the spiral air flow distributor makes the droplets evenly suspended to obtain wet particles, thereby obtaining a wet particle product;

[0019] S10, rapid drying of particles: the wet particle product is treated in a through-flow hot air drying furnace; the total drying time is 20-40 minutes until the moisture content is reduced to 1-5%, and dry fertilizer particles are obtained after the operation is completed;

[0020] S11, particle cooling and packaging: the dried fertilizer particles are introduced into a cooling drum, and 5-15°C cold air is evenly circulated to reduce the particle temperature to 20-30°C; after cooling, a vibrating screen is used to remove non-standard particles larger than 2mm and smaller than 0.5mm; and finished fertilizer is obtained.

[0021] Preferably, in step S2, the mycorrhizal fungus spore suspension is mixed with sterile water, an inorganic nitrogen source and phosphate in a mixing ratio of 1:1:0.2.

[0022] Preferably, in step S4, the pore size of the filter membrane is 0.2-0.45 μm.

[0023] Preferably, in step S10, the hot air temperature of the hot air drying furnace is 70-100° C., and the air flow is 0.5-1.5 m / s.

[0024] Preferably, in step S7, the intensity of the ultraviolet light source is 800 μW / cm 2 .

[0025] 1. Compared with the prior art, in the present invention, the cyclic amino acid derivatives enhance the retention of water around the cells and reduce the water loss through the cell wall, thereby maintaining the water balance of the plant in stressful environments such as drought. In addition, this component inhibits the production of free radicals through antioxidant effects and delays the aging process of plants. The different polymerization degrees of polyglutamic acid ensure immediate and lasting nutrient release. Low-polymerization polyglutamic acid quickly acts on crops and increases the initial growth rate, while high-polymerization polyglutamic acid ensures continuous supply and avoids nutrient interruptions. The addition of aminobutyric acid enhances the adaptability of plants to low-oxygen environments, while activating the synthesis of endogenous hormones, promoting cell activity, and enhancing the overall health and growth potential of crops. The synergistic effect of these components not only improves the overall effectiveness of the fertilizer, but also provides conditions for crops to grow stably in a variety of environments.

[0026] 2. Compared with the prior art, the present invention uses an inert atmosphere and precise oxygen content control during microbial inoculation and biological fermentation to improve the survival rate and activity of mycorrhizal fungi, which not only enhances the biological activity of the fertilizer, but also improves the nutrient recycling capacity in the soil. The subsequent post-fermentation treatment ensures the stability and safety of the product through thermal inactivation and reduces potential risks to the environment. The high-pressure spray granulation and rapid drying technology are used to optimize the physical form of the fertilizer and improve its solubility and utilization rate in the soil.

[0027] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 The present invention proposes a preparation step diagram of a method for preparing a water-soluble fertilizer based on EPG water-fertilizer aggregation technology. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Example 1, a water-soluble fertilizer prepared based on EPG water-fertilizer aggregation technology, the water-soluble fertilizer prepared based on EPG water-fertilizer aggregation technology includes the following components in parts by weight:

[0032] 0.5 parts of ectoine, 0.2 parts of low-polymerization degree polyglutamic acid, 0.2 parts of high-polymerization degree polyglutamic acid, 0.05 parts of gamma-aminobutyric acid, 50 parts of potassium sulfate, 30 parts of calcium nitrate, 2 parts of mycorrhizal bacteria, and 2 parts of sodium alginate.

[0033] In this embodiment, the molecular weight of the low-polymerization polyglutamic acid is ≤20 kDa.

[0034] In this embodiment, the molecular weight of the high-polymerization degree polyglutamic acid is ≥1000 kDa.

[0035] The present invention provides a method for preparing a water-soluble fertilizer based on EPG water-fertilizer aggregation technology, comprising the following steps:

[0036] S1, batching and mixing: weigh ectoine, low-polymerization polyglutamic acid, high-polymerization polyglutamic acid, γ-aminobutyric acid, potassium sulfate, calcium nitrate, mycorrhizal fungi and sodium alginate with an electronic balance; put them into the mixing tank, operate in a sealed environment and maintain the internal dry state; use a paddle stirrer, stir at a speed of 500 rpm, use a circulating water jacket to control the temperature at 35°C, and control the humidity to no more than 10%; continue stirring for 30 minutes to make the particles fully and evenly distributed and mix the base material in powder form; after the operation is completed, a preliminary mixture of ingredients is obtained;

[0037] S2, microbial inoculation operation: in the preliminary mixture of ingredients, an inert atmosphere is used to protect the mixture, and a 12% oxygen content gas is introduced; the mycorrhizal fungus spore suspension is sprayed into the mixing tank, the stirring speed during the spraying is 300 rpm, the temperature in the tank is 33°C, and the spraying is continued for 60 minutes, so that the mycorrhizal fungus spores are uniformly adsorbed on the surface of the previous powder; after the operation is completed, the inoculated microbial mixture is obtained;

[0038] S3, biological fermentation process: the inoculated microbial mixture is fermented in a closed manner, using a stainless steel fermenter, sterilized by high-pressure steam for 60 minutes and introduced with pure oxygen to make the dissolved oxygen 50%; the stirring speed is 400 rpm, the temperature is 25°C, the humidity is 60%, and the fermentation period is 72 hours; sampling is performed at regular intervals, and the concentration of microbial metabolites is measured by an ultraviolet spectrophotometer, and the change of ion concentration is monitored by a conductivity meter; after the fermentation is completed, the fermentation product base is obtained;

[0039] S4, post-fermentation treatment: heat inactivation is performed in the fermentation product base; heating is performed to 60°C by a plate heat exchanger and maintained for 10 minutes; then the solid and liquid are separated by a centrifuge at a speed of 8000 rpm, and the residual solid phase is intercepted by a filter membrane; the separated clear liquid is transferred to a neutralization tank, the pH is adjusted to 7.0 and stirred for 40 minutes; after the neutralization process is completed, the supernatant is taken to obtain a stable fermentation product;

[0040] S5, dissolving and mixing: stirring the fermentation product with a magnetic stirrer at a speed of 600 rpm, and adding double deionized pure water in batches to maintain the solid content at 20%; maintaining the solution at a temperature of 45°C for 50 minutes to promote the dissolution of sodium alginate, potassium sulfate and calcium nitrate; obtaining a uniform solution;

[0041] S6, bubble dissolution introduction: microbubble injection is performed on the uniform solution, and an ultrasonic microporous aeration device is used to pass the solution at a pressure of 30 kPa; the ultrasonic frequency is 30 kHz to form 100 μm microbubbles in the solution; the dissolved oxygen value is controlled at 10 mg / L and lasts for 40 minutes to allow the gas to fully contact the liquid phase and increase the intermolecular transfer rate; after the operation is completed, a high gas-liquid contact solution is obtained;

[0042] S7, polymerization reaction: introducing an ultraviolet light source and a 15 Hz magnetic field into the high gas-liquid contact solution, and adding ammonium persulfate and N,N'-methylenebisacrylamide as initiating components; the temperature is 50°C, and the stirring is 100 rpm; and a polymerization reaction mixture is obtained;

[0043] S8, preparation for high-pressure spray granulation: adjusting the viscosity and solid content of the polymerization reaction mixture; evaporating under reduced pressure at 50°C by a rotary evaporator to make the solid mass fraction reach 35%; monitoring the viscosity online, if the viscosity exceeds 200mPa·s, adding pure water, if it is insufficient, extending the evaporation time; obtaining the spray granulation liquid;

[0044] S9, pressure spray granulation: the spray granulation liquid is pumped into the top of the spray drying tower at a pressure of 10MPa, and atomized into droplets smaller than 50μm through a 1.0mm nozzle; the hot air enters the tower at 160℃ and leaves the tower at 90℃, and the spiral air flow distributor makes the droplets evenly suspended to obtain wet particles, thus obtaining a wet particle product;

[0045] S10, rapid drying of particles: the wet particle product is treated in a through-flow hot air drying furnace; the total drying time is 40 minutes and the moisture content is reduced to 3%. After the operation is completed, dry fertilizer particles are obtained;

[0046] S11, particle cooling and packaging: the dried fertilizer particles are introduced into the cooling drum, and 15°C cold air is evenly circulated to reduce the particle temperature to 30°C; after cooling, a vibrating screen is used to remove non-standard particles larger than 2mm and smaller than 0.5mm; and finished fertilizer is obtained.

[0047] In this embodiment, in step S2, the mycorrhizal fungus spore suspension is mixed with sterile water, an inorganic nitrogen source and phosphate in a mixing ratio of 1:1:0.2.

[0048] In this embodiment, in step S4, the pore size of the filter membrane is 0.45 μm.

[0049] In this embodiment, in step S10, the hot air temperature of the hot air drying furnace is 100° C., and the air flow is 1.5 m / s.

[0050] In this embodiment, in step S7, the intensity of the ultraviolet light source is 800 μW / cm 2 .

[0051] Example 2, a water-soluble fertilizer prepared based on EPG water-fertilizer aggregation technology, the water-soluble fertilizer prepared based on EPG water-fertilizer aggregation technology comprises the following components in parts by weight:

[0052] 0.2 parts of ectoine, 0.1 parts of low-polymerization degree polyglutamic acid, 0.1 parts of high-polymerization degree polyglutamic acid, 0.05 parts of gamma-aminobutyric acid, 50 parts of potassium sulfate, 30 parts of calcium nitrate, 2 parts of mycorrhizal fungi, and 2 parts of sodium alginate.

[0053] In this embodiment, the molecular weight of the low-polymerization polyglutamic acid is ≤20 kDa.

[0054] In this embodiment, the molecular weight of the high-polymerization polyglutamic acid is ≥1000 kDa.

[0055] The present invention provides a method for preparing a water-soluble fertilizer based on EPG water-fertilizer aggregation technology, comprising the following steps:

[0056] S1, batching and mixing: weigh ectoine, low-polymerization polyglutamic acid, high-polymerization polyglutamic acid, γ-aminobutyric acid, potassium sulfate, calcium nitrate, mycorrhizal fungi and sodium alginate with an electronic balance; put them into the mixing tank, operate in a sealed environment and maintain the internal dry state; use a paddle stirrer, stir at a speed of 300rpm, use a circulating water jacket to control the temperature at 30°C, and control the humidity to no more than 10%; continue stirring for 25 minutes to make the particles fully and evenly distributed and mix the base material in powder form; after the operation is completed, a preliminary mixture of ingredients is obtained;

[0057] S2, microbial inoculation operation: in the preliminary mixture of ingredients, an inert atmosphere is provided and a 10% oxygen content gas is introduced; the mycorrhizal spore suspension is sprayed into the mixing tank, the stirring speed is 200 rpm during the spraying, the temperature in the tank is 30°C, and the spraying is continued for 30 minutes, so that the mycorrhizal spores are uniformly adsorbed on the surface of the previous powder; after the operation is completed, the inoculated microbial mixture is obtained;

[0058] S3, biological fermentation process: the inoculated microbial mixture is fermented in a closed manner, using a stainless steel fermenter, sterilized by high-pressure steam for 60 minutes and introduced with pure oxygen to make the dissolved oxygen 35%; the stirring speed is 400 rpm, the temperature is 25°C, the humidity is 60%, and the fermentation period is 48 hours; sampling is performed at regular intervals, and the concentration of microbial metabolites is measured by an ultraviolet spectrophotometer, and the change of ion concentration is monitored by a conductivity meter; after the fermentation is completed, the fermentation product base is obtained;

[0059] S4, post-fermentation treatment: heat inactivation is performed in the fermentation product base; heating is performed to 80°C by a plate heat exchanger and maintained for 15 minutes; then the solid and liquid are separated by a centrifuge at a speed of 5000 rpm, and the residual solid phase is intercepted by a filter membrane; the separated clear liquid is transferred to a neutralization tank, the pH is adjusted to 7.0 and stirred for 40 minutes; after the neutralization process is completed, the supernatant is taken to obtain a stable fermentation product;

[0060] S5, dissolving and mixing: stirring the fermentation product with a magnetic stirrer at a speed of 500 rpm, and adding double deionized pure water in batches to maintain the solid content at 20%; maintaining the solution at a temperature of 45°C for 50 minutes to promote the dissolution of sodium alginate, potassium sulfate and calcium nitrate; obtaining a uniform solution;

[0061] S6, bubble dissolution introduction: microbubble injection is performed on the uniform solution, and an ultrasonic microporous aeration device is used to pass the solution at a pressure of 30 kPa; the ultrasonic frequency is 30 kHz to form 100 μm microbubbles in the solution; the dissolved oxygen value is controlled at 10 mg / L and lasts for 40 minutes to allow the gas to fully contact the liquid phase and increase the intermolecular transfer rate; after the operation is completed, a high gas-liquid contact solution is obtained;

[0062] S7, polymerization reaction: introducing an ultraviolet light source and a 15 Hz magnetic field into the high gas-liquid contact solution, and adding ammonium persulfate and N,N'-methylenebisacrylamide as initiating components; the temperature is 50°C, and the stirring is 100 rpm; and a polymerization reaction mixture is obtained;

[0063] S8, preparation for high-pressure spray granulation: adjusting the viscosity and solid content of the polymerization reaction mixture; evaporating under reduced pressure at 50°C by a rotary evaporator to make the solid mass fraction reach 35%; monitoring the viscosity online, if the viscosity exceeds 200mPa·s, adding pure water, if it is insufficient, extending the evaporation time; obtaining the spray granulation liquid;

[0064] S9, pressure spray granulation: the spray granulation liquid is pumped into the top of the spray drying tower at a pressure of 10MPa, and atomized into droplets smaller than 50μm through a 1.0mm nozzle; the hot air enters the tower at 160℃ and leaves the tower at 90℃, and the spiral air flow distributor makes the droplets evenly suspended to obtain wet particles, thus obtaining a wet particle product;

[0065] S10, rapid drying of particles: the wet particle product is treated in a through-flow hot air drying furnace; the total drying time is 40 minutes and the moisture content is reduced to 3%. After the operation is completed, dry fertilizer particles are obtained;

[0066] S11, particle cooling and packaging: the dried fertilizer particles are introduced into the cooling drum, and 15°C cold air is evenly circulated to reduce the particle temperature to 30°C; after cooling, a vibrating screen is used to remove non-standard particles larger than 2mm and smaller than 0.5mm; and finished fertilizer is obtained.

[0067] In this embodiment, in step S2, the mycorrhizal fungus spore suspension is mixed with sterile water, an inorganic nitrogen source and phosphate in a mixing ratio of 1:1:0.2.

[0068] In this embodiment, in step S4, the pore size of the filter membrane is 0.45 μm.

[0069] In this embodiment, in step S10, the hot air temperature of the hot air drying furnace is 100° C., and the air flow is 1.5 m / s.

[0070] In this embodiment, in step S7, the intensity of the ultraviolet light source is 800 μW / cm 2 .

[0071] Experimental methods:

[0072] The dissolution experiment referred to the second method of 0931 of the fourth part of the Chinese Pharmacopoeia 2020 edition. 900 ml of aqueous solution was used as the dissolution medium, the rotation speed was 50 rpm, sampling was performed at 5 and 10 minutes, and a reversed-phase chromatographic column with C18 as the filler was used. Water-methanol (70:30) was used as the mobile phase, the detection wavelength was 262 nm, the flow rate was 1 ml / min, and the column temperature was 25°C. The detection was carried out to determine the solubility.

[0073] The sustained-release performance test uses a constant-temperature water bath to simulate the soil environment, places the fertilizer sample in the corresponding solution, takes samples at fixed intervals, and uses a UV spectrophotometer to detect the change in dissolved nutrient concentration to obtain the sustained-release duration. The particle compressive strength test uses a single-particle crushing strength meter to gradually apply force to a single fertilizer particle until the particle breaks, and records the maximum bearing capacity before breaking.

[0074] The nitrogen utilization rate test is carried out through potted experiments. Under the same fertilizer application conditions, the ratio of nitrogen absorption by the aboveground parts of crops to the total nitrogen applied is measured within a fixed period.

[0075] In the moisture absorption test, the fertilizer particles are placed at a relative humidity of 60% and a temperature of 25°C for 24 hours, and the difference in sample mass before and after moisture absorption is recorded. The moisture absorption characteristics are evaluated by the mass increase ratio.

[0076] The finished fertilizers prepared in Examples 1-2 were tested, wherein Comparative Example 1 was a commercially available product, and the test results were as follows:

[0077] Table 1 Performance test data

[0078] Performance Indicators Comparative Example 1 Example 1 Example 2 Dissolution (%) 70 85 90 Sustained release duration (h) 12 24 30 Particle compressive strength (N) 20 30 35 Nitrogen utilization rate (%) 50 65 68 Moisture absorption rate (%) 10 5 4

[0079] As can be seen from Table 1, compared with Comparative Example 1, Examples 1-2 have higher solubility, longer sustained-release duration, better particle compressive strength, higher nitrogen utilization rate and lower moisture absorption rate, and are superior to the prior art in terms of overall fertilizer efficiency and storage stability.

Claims

1. A water-soluble fertilizer prepared based on EPG water-fertilizer aggregation technology, characterized in that: The water-soluble fertilizer comprises the following components by weight: 0.1-0.5 parts of ectoine, 0.05-0.2 parts of low-polymerization degree polyglutamic acid, 0.05-0.2 parts of high-polymerization degree polyglutamic acid, 0.05-0.2 parts of γ-aminobutyric acid, 20-50 parts of potassium sulfate, 20-50 parts of calcium nitrate, 1-3 parts of mycorrhizal fungi, and 1-5 parts of sodium alginate.

2. The water-soluble fertilizer prepared based on the EPG water-fertilizer aggregation technology according to claim 1 is characterized in that: The molecular weight of the low-polymerization polyglutamic acid is ≤20 kDa.

3. The water-soluble fertilizer prepared based on the EPG water-fertilizer aggregation technology according to claim 1 is characterized in that: The molecular weight of the high-polymerization polyglutamic acid is ≥1000kDa.

4. A method for preparing water-soluble fertilizer based on EPG water-fertilizer aggregation technology, characterized in that: The following steps are involved: S1, batching and mixing: weigh ectoine, low-polymerization polyglutamic acid, high-polymerization polyglutamic acid, γ-aminobutyric acid, potassium sulfate, calcium nitrate, mycorrhizal fungi and sodium alginate with an electronic balance; put them into the mixing tank, operate in a sealed environment and maintain the internal dry state; use a paddle stirrer, stir at a speed of 230-500rpm, use a circulating water jacket to control the temperature at 25-35°C, and control the humidity to no more than 10%; continue stirring for 15-30 minutes to make the particles fully and evenly distributed and mix the base material in powder form; after the operation is completed, a preliminary mixture of ingredients is obtained; S2, microbial inoculation operation: in the preliminary mixture of ingredients, an inert atmosphere is provided, and a gas with an oxygen content of 8-12% is introduced; the mycorrhizal fungus spore suspension is sprayed into the mixing tank, the stirring speed during spraying is 150-300 rpm, the temperature in the tank is 30-33° C., and the spraying is continued for 30-60 min, so that the mycorrhizal fungus spores are uniformly adsorbed on the surface of the previous powder; after the operation is completed, an inoculated microbial mixture is obtained; S3, biological fermentation process: the inoculated microbial mixture is subjected to closed fermentation, a stainless steel fermentation tank is used, sterilized by high-pressure steam for 30-60 minutes and pure oxygen is introduced to make the dissolved oxygen 30-50%; the stirring speed is 200-400rpm, the temperature is 25-32°C, the humidity is 50-60%, and the fermentation period is 48-72h; sampling is performed at regular intervals, and the concentration of microbial metabolites is measured by an ultraviolet spectrophotometer, and the change of ion concentration is monitored by a conductivity meter; after the fermentation is completed, a fermentation product base is obtained; S4, post-fermentation treatment: heat inactivation is performed in the fermentation product base material; heating to 60-80°C through a plate heat exchanger and maintaining for 10-20 minutes; then using a centrifuge at a speed of 5000-8000 rpm to separate the solid and liquid, and using a filter membrane to intercept the residual solid phase; transferring the separated clear liquid to a neutralization tank, adjusting the pH to 6.0-7.0 and stirring for 20-40 minutes; after the neutralization process is completed, the supernatant is taken to obtain a stable fermentation product; S5, dissolving and mixing: stirring the fermentation product with a magnetic stirrer at a speed of 400-600 rpm, and adding double deionized pure water in batches to maintain the solid content at 10-20%; maintaining the solution at a temperature of 35-45° C. for 30-50 minutes to promote the dissolution of sodium alginate, potassium sulfate and calcium nitrate; and obtaining a uniform solution; S6, bubble dissolution introduction: inject microbubbles into the uniform solution, and pass the solution at a pressure of 10-30 kPa using an ultrasonic microporous aeration device; the ultrasonic frequency is 20-30 kHz so that the gas forms 30-100 μm microbubbles in the solution; the dissolved oxygen value is controlled at 5-10 mg / L for 20-40 min to allow the gas to fully contact the liquid phase and increase the intermolecular transfer rate; after the operation is completed, a high gas-liquid contact solution is obtained; S7, polymerization reaction: introducing an ultraviolet light source and a 5-15 Hz magnetic field into the high gas-liquid contact solution, and adding ammonium persulfate and N,N'-methylenebisacrylamide as initiating components; The temperature is 40-50°C and the stirring speed is 50-100 rpm; a polymerization reaction mixture is obtained; S8, high-pressure spray granulation preparation: adjusting the viscosity and solid content of the polymerization reaction mixture; evaporating under reduced pressure at 50-60° C. by a rotary evaporator to make the solid content reach 25-35%; monitoring the viscosity online, if the viscosity exceeds 200-300 mPa·s, adding pure water, if it is insufficient, extending the evaporation time; obtaining the spray granulation liquid; S9, pressure spray granulation: the spray granulation liquid is pumped into the top of the spray drying tower at a pressure of 5-10 MPa, and atomized into droplets smaller than 50 μm through a 0.5-1.0 mm nozzle; the hot air enters the tower at 120-160°C and leaves the tower at 60-90°C, and the spiral air flow distributor makes the droplets evenly suspended to obtain wet particles, thereby obtaining a wet particle product; S10, rapid drying of particles: the wet particle product is treated in a through-flow hot air drying furnace; the total drying time is 20-40 minutes until the moisture content is reduced to 1-5%, and dry fertilizer particles are obtained after the operation is completed; S11, particle cooling and packaging: the dried fertilizer particles are introduced into a cooling drum, and 5-15°C cold air is evenly circulated to reduce the particle temperature to 20-30°C; after cooling, a vibrating screen is used to remove non-standard particles larger than 2mm and smaller than 0.5mm; and finished fertilizer is obtained.

5. The method for preparing water-soluble fertilizer based on EPG water-fertilizer aggregation technology according to claim 4 is characterized in that: In step S2, the mycorrhizal fungus spore suspension is mixed with sterile water, an inorganic nitrogen source and phosphate in a mixing ratio of 1:1:0.

2.

6. The method for preparing water-soluble fertilizer based on EPG water-fertilizer aggregation technology according to claim 4 is characterized in that: In step S4, the pore size of the filter membrane is 0.2-0.45 μm.

7. The method for preparing water-soluble fertilizer based on EPG water-fertilizer aggregation technology according to claim 4 is characterized in that: In step S10, the hot air temperature of the hot air drying furnace is 70-100° C., and the air flow is 0.5-1.5 m / s.

8. The method for preparing water-soluble fertilizer based on EPG water-fertilizer aggregation technology according to claim 4, characterized in that: In step S7, the intensity of the ultraviolet light source is 800 μW / cm 2 .

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