Amino acid water-soluble fertilizer and its production process

Abstract

The application discloses an amino acid water-soluble fertilizer and a production process thereof, and relates to the technical field of water-soluble fertilizers. The amino acid water-soluble fertilizer uses free amino acids as an organic nitrogen source and combines with medium element calcium to improve crop quality. The amino acid water-soluble fertilizer has low formula cost, high absorption rate, promotes the synergistic effect of nutrient elements, is suitable for crop growth, is simple to use, and has high cost performance. The amino acid water-soluble fertilizer uses amino acids and calcium as raw materials, has the characteristics of wide applicability, high output-input ratio and easy market promotion. The product is fully water-soluble, environmentally friendly and safe, can regulate the physiological function of crops, increase yield and amino acid content, improve quality, and has remarkable economic benefits. In addition, the amino acid water-soluble fertilizer realizes efficient resource utilization by activating the carboxyl group of castor oil acid and combining with fucoidan polysaccharide enzyme oligosaccharide to construct microcapsules.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of water-soluble fertilizers, in particular to an amino acid water-soluble fertilizer and a production process thereof. BACKGROUND

[0002] With the increasing requirements of modern agriculture on crop quality, yield and environmental friendliness, water-soluble fertilizers have been widely used in modern agriculture, especially in facility agriculture and efficient agriculture, due to their efficient, precise fertilization and easy absorption and utilization.

[0003] However, traditional water-soluble fertilizers mainly rely on inorganic nitrogen sources or simple organic nitrogen compounds. Although inorganic nitrogen fertilizers have a quick effect, they are prone to leaching and volatilization, have a low utilization rate, and long-term overuse can lead to soil acidification and salinization, and can increase the risk of nitrate accumulation in agricultural products. Some water-soluble fertilizers containing amino acids are usually added as auxiliary components (such as synergists or chelating agents), and the content is low, which cannot fully play the core role of free amino acids as high-quality organic nitrogen sources. Free amino acids can be directly absorbed and utilized by crops, and have the advantages of stimulating crop growth, enhancing stress resistance and improving quality, but the existing products still have deficiencies in using free amino acids as the main nitrogen source and scientifically matching other nutrient elements to realize synergistic absorption.

[0004] In addition, water-soluble fertilizers containing microbial agents or biological stimulants (such as seaweed extracts, oligosaccharides and betaine) have good biological activity, can promote crop rooting, improve nutrient absorption efficiency and enhance stress resistance. However, these biological active ingredients are easily inactivated during the production, storage and application of fertilizers, resulting in unstable effects or even complete loss. Conventional physical mixing or simple embedding technology cannot provide sufficient protection.

[0005] In summary, it is of great practical significance to develop an amino acid water-soluble fertilizer which can efficiently provide organic nitrogen sources, significantly improve the utilization rate of secondary nutrients and the cost performance, effectively protect and deliver biological active ingredients, realize multi-stage efficient utilization of functional materials, and has excellent comprehensive performance, feasible production process, controllable cost and simple application, to meet the needs of modern agricultural production for quality improvement and efficiency increase, and green and sustainable development. Therefore, it is urgent to develop a new type of amino acid water-soluble fertilizer and its production process to overcome the above-mentioned defects of the prior art. SUMMARY

[0006] The application aims to provide an amino acid water-soluble fertilizer and a production process thereof to solve the problems in the prior art.

[0007] To solve the above technical problems, the present application provides the following technical solutions: on the one hand, an amino acid water-soluble fertilizer, comprising a water-soluble fertilizer and a bacterial microcapsule, wherein the water-soluble fertilizer comprises the following components at the following concentrations: 100-200 g / L amino acid, 30-50 g / L calcium chloride, 3-5 g / L diatomite, 10-20 g / L potassium fulvate, 3-6 g / L magnesium sulfate heptahydrate, 0.5-1 g / L boric acid, and the balance being water;

[0008] The amino acid is composed of polyglutamic acid, methionine, cystine, lysine, tryptophan, phenylalanine, threonine, valine, leucine and isoleucine at a mass ratio of 10-15:2-4:8-9:5-8:0.1-1:2-5:0.5-2:7.5-8.2:1-3:4-7.

[0009] Further, the preparation method of the bacterial microcapsule is as follows:

[0010] (1) 100 g of ricinoleic acid is mixed with a 0.5 mol / L NHS / DMF solution, stirred at 25°C for 30 min, then fucoidan is added, the mass ratio of fucoidan to ricinoleic acid being 5:3-5, and 0.1 mol / L EDC / DMF solution is added as a catalyst, and the reaction is carried out at 45°C under 0.1 MPa nitrogen protection for 4 h to generate ricinoleic acid-fucoidan, and the reaction solution is concentrated by dialysis to a solid content of 40% to prepare a wall material solution;

[0011] (2) Azotobacter and Pseudomonas fluorescens are compounded at a viable bacterial number ratio of 3:0.5-2.5, and a culture solution is added to prepare a bacterial suspension; then 5-8 g / L of brown algal polyphenol, 20-30 g / L of betaine and 40-50 g / L of trehalose are added to the bacterial suspension, stirred for 5 min to prepare a mixed core material solution; the mixed core material solution is added to the wall material solution, the mass ratio of the core material to the wall material being 1:2, and 0.8% of glyceryl monostearate based on the total mass of the core material and the wall material is added as an emulsifying agent for emulsification, freezing, drying and dehydration to obtain the bacterial microcapsule.

[0012] Further, in step (1), the molar ratio of NHS to the carboxyl group of ricinoleic acid is 1.2:1.

[0013] Further, in step (1), the molar ratio of EDC to the carboxyl group of ricinoleic acid is 1:1.

[0014] Further, in step (1), the dialysis step is as follows: the reaction solution is purified by a 3500 Da molecular weight cut-off dialysis bag, and the dialysis external solution is replaced every 4 h.

[0015] Further, the dialysis external solution is a phosphate buffer with a pH of 7.0 and a concentration of 0.05 mol / L.

[0016] Further, the specific steps of emulsification, freezing, drying and dehydration in step (2) are as follows: emulsification is formed under high-speed shearing at 8000 rpm to form an emulsion with a particle size of 30 mu m, the emulsion is sprayed into a-40 DEG C cold trap at a pressure of 0.4 MPa through an atomizer, and the liquid droplets are instantaneously frozen; then, the emulsion is frozen and dried in a vacuum freeze dryer under the conditions of a temperature of-50 DEG C and a vacuum degree of 0.02 MPa for 24 h.

[0017] Further, the viable bacterial concentration of the bacterial suspension in step (2) is 6x10 9 CFU / mL.

[0018] In another aspect, a production process of an amino acid water-soluble fertilizer comprises the following process steps: adding amino acids, water, potassium fulvic acid and diatomite according to a formula, heating to 40 DEG C, stirring for 0.5 h, then adding calcium chloride, magnesium sulfate heptahydrate and boric acid, stirring for 1 h to obtain a water-soluble fertilizer, and finally adding a bacterial microcapsule containing 0.08 times the mass of the water-soluble fertilizer.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] The free amino acid is used as an organic nitrogen source in the present application, which is one of the key fertilizer sources for improving crop quality; the ratio of the free amino acid and the medium element is designed, the content of the medium element is higher, the cost is lower, the absorption and utilization rate is further improved, the absorption of the various nutrient elements is promoted and synergistic effect is achieved, compared with the use of organic fertilizer and inorganic fertilizer alone, the present application is more suitable for crop growth, the use method is simple, and the cost performance is high.

[0021] The present application is carefully prepared from amino acid and calcium raw materials according to a certain ratio. It has the characteristics of full water solubility, environmental protection and safety. After use, it can adjust the physiological function of crops, increase yield, improve the content of amino acid in crops, improve crop quality and economic benefit.

[0022] In the present application, the carboxyl group of castor oil acid is activated and combined with oligosaccharides obtained by enzymatic hydrolysis of fucoidan, which is used as a wall material to emulsify and encapsulate the bacterial community of Azotobacter chroococcum and Pseudomonas fluorescens, ingredients such as phloroglucinol, betaine and trehalose, and form microcapsules; castor oil acid is a protective agent during storage and is decomposed to be a colonization inducer during use, which realizes efficient utilization of resources through ingenious function transformation. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0024] In order to more clearly illustrate the method provided by the present application, the following examples are provided for further illustration. In the following examples, the test methods for each index of the amino acid water-soluble fertilizer prepared are as follows:

[0025] Growth: 5m 2 Soil as an experimental plot, each plot evenly distributed 5 pakchoi, every 5d for one fertilization, each plot of 400ml of amino acid water-soluble fertilizer, a total of 30d cultivation, observation of soil hardening, measured the average height of pakchoi.

[0026] Microbial survival: after one week of fertilization, the soil sample in the pakchoi root zone was dug out, the peripheral soil of the root system was shaken off, and the soil sample close to the root surface was taken as the rhizosphere soil. The plate gradient dilution method was used to determine the number of microorganisms. The beef extract peptone agar medium was used to determine the bacteria. Three soil samples were taken from each treatment area, and the average data was measured.

[0027] Microcapsule storage condition: the microcapsules containing bacteria of the examples and the comparative examples were stored at 25℃ and 60% humidity in the dark for 3 months, and then the amino acid water-soluble fertilizer was prepared. The plate gradient dilution method was used to determine the number of microorganisms in the fertilizer after 3 months. The beef extract peptone agar medium was used to determine the bacteria. Three samples were taken respectively, and the average data was measured to calculate the survival rate of azotobacter and pseudomonas fluorescens. Then the microcapsules stored for 3 months were mixed with the water-soluble fertilizer to test the growth condition.

[0028] Example 1: a production process of an amino acid water-soluble fertilizer, comprising the following process steps:

[0029] (1) the Flavobacterium RC2-3mut strain is inoculated in a liquid culture medium, and seed liquid is obtained by culturing at 30℃ under 200rpm shaking bed for 24h; then the seed liquid is inoculated in a fermentation culture medium at an inoculation amount of 10wt%, and is fermented in a 5L fermenter, and is cultured at 30℃ under 200rpm for 72h; the fermentation liquid is centrifuged at 4℃ and 10000rpm for 5min, the supernatant is discarded, and the precipitate is dissolved with 5 times the volume of 20mM, pH8.0 Tris-HCl solution; the cells are broken by ultrasonic wave under the protection of ice bath at 800w for 10min, and are centrifuged at 4℃ and 10000rpm for 5min; the supernatant is obtained, and fucoidanase is obtained; the liquid culture medium comprises fucoidan 10g / L, proteose peptone 10g / L and ammonium nitrate 5g / L, and is prepared with membrane filtered seawater, and the pH is natural; the fermentation culture medium comprises fucoidan 1% (mass fraction in the culture medium), beef extract 2% (mass fraction in the culture medium), and is prepared with membrane filtered seawater, and the pH is natural; a PBS buffer solution with pH=8.0 and a concentration of 24mM is prepared, fucoidan with a molecular weight of 5000 is dissolved in the above buffer solution to prepare a 1wt% fucoidan solution; a PBS buffer solution with pH=8.0 and a concentration of 24mM is prepared, and fucoidanase is dissolved in the above buffer solution to prepare a fucoidanase solution with an active concentration of 1000U / mL; 1mL of the fucoidanase solution with an active concentration of 1000U / mL is added into 10mL of the 1wt% fucoidan solution, and the reaction is carried out at 30℃ in a water bath pot under 100rpm for 2h, and the reaction is terminated by water bath at 100℃ for 10min; after cooling, the supernatant is obtained by centrifugation at 8000rpm for 10min; the oligosaccharide with a molecular weight less than 100kDa is filtered out by using an ultrafiltration membrane system, and is freeze-dried at-40℃ for 2h to obtain fucoidan oligosaccharide; 100g of ricinoleic acid is dissolved in 500mL of anhydrous DMF, and is mixed with 0.5mol / L of an NHS / DMF solution, and the molar ratio of NHS to the carboxyl group of ricinoleic acid is 1.2:1; then the carboxyl group is activated by stirring at 25℃ for 30min, and the stirring speed is 120rpm; then fucoidan oligosaccharide is added, and the mass ratio of fucoidan oligosaccharide to ricinoleic acid is 5:3; 0.1mol / L of an EDC / DMF solution is added as a catalyst, and the molar ratio of EDC to the carboxyl group of ricinoleic acid is 1:1; the reaction is carried out at 45℃ under 0.1MPa nitrogen protection for 4h to generate ricinoleic acid-fucoidan oligosaccharide; the reaction liquid is purified by using a dialysis bag with a molecular weight cut-off of 3500Da, and the outer liquid of dialysis is a phosphate buffer solution with pH=7.0 and a concentration of 0.05mol / L; the outer liquid of dialysis is replaced every 4h; the wall material solution is prepared by concentrating to a solid content of 40%;

[0030] (2) the Azospirillum and Pseudomonas fluorescens are compounded according to the ratio of live bacteria of 3:0.5, and are added into a culture solution to obtain a bacterial suspension, and the live bacteria concentration is 6×10 9CFU / mL; then 5 g / L of brown algae polyphenol, 20 g / L of betaine, and 40 g / L of trehalose were added to the bacterial suspension, and the mixture was stirred at a speed of 60 rpm for 5 min to obtain a mixed core material solution; the mixed core material solution was added to the wall material solution, and the mass ratio of the core material to the wall material was 1:2; then 0.8% of glyceryl monostearate based on the total mass of the core material and the wall material was added as an emulsifying agent to form an emulsion with a particle size of 30 μm under high-speed shearing at 8000 rpm; the emulsion was sprayed into a-40 ℃ cold trap at a pressure of 0.4 MPa by a atomizer, and the droplets were instantaneously frozen; then the bacterial microcapsules were obtained by freeze-drying in a vacuum freeze-drier at a temperature of-50 ℃ and a vacuum degree of 0.02 MPa for 24 h; the components of the culture solution include 0.5 wt% of rhamnolipid, 0.1 wt% of sodium glutamate, and 5 wt% of starch, and the rest is a PBS buffer solution with a pH of 7.0 and a concentration of 100 mM; the components of the culture solution include 0.5 wt% of rhamnolipid, 0.1 wt% of sodium glutamate, and 5 wt% of starch, and the rest is a PBS buffer solution with a pH of 7.0 and a concentration of 100 mM;

[0031] (3) The components are as follows: 180 g / L of amino acids, 35 g / L of calcium chloride, 3 g / L of diatomite, 10 g / L of potassium fulvate, 3 g / L of magnesium sulfate heptahydrate, 1 g / L of boric acid, and the rest is water; the amino acids, water, potassium fulvate, and diatomite are weighed, heated to 40 ℃, and stirred for 0.5 h; then the calcium chloride, magnesium sulfate heptahydrate, and boric acid are added and stirred for 1 h to obtain a water-soluble fertilizer; finally, 0.08 times the mass of the water-soluble fertilizer is added to the bacterial microcapsules; the amino acids include polyglutamic acid, methionine, cystine, lysine, tryptophan, phenylalanine, threonine, valine, leucine, and isoleucine at a mass ratio of 10:3:8:7:1:3:1:8:2:5.

[0032] Example 2: A production process of an amino acid water-soluble fertilizer, which includes the following process steps:

[0033] (1) The same method as in Example 1 was used to prepare fucoidan oligosaccharide; 100 g of ricinoleic acid was dissolved in 500 mL of anhydrous DMF, and a mixture of 0.5 mol / L of NHS / DMF solution was added, the molar ratio of NHS to the carboxyl group of ricinoleic acid being 1.2:1, then the carboxyl group was activated at 25°C for 30 min with stirring at a speed of 120 rpm; then fucoidan oligosaccharide was added, the mass ratio of fucoidan oligosaccharide to ricinoleic acid being 5:4, and 0.1 mol / L of EDC / DMF solution was added as a catalyst, the molar ratio of EDC to the carboxyl group of ricinoleic acid being 1:1, and the reaction was carried out at 45°C under the protection of 0.1 MPa of nitrogen for 4 h to form ricinoleic acid-fucoidan oligosaccharide, and the reaction solution was purified by a dialysis bag with a molecular weight cutoff of 3500 Da, the external solution being a phosphate buffer solution with a pH of 7.0 and a concentration of 0.05 mol / L, the external solution being replaced every 4 h, and the concentrated solution was obtained by concentrating to a solid content of 40% to obtain a wall material solution;

[0034] (2) The Azospirillum and Pseudomonas fluorescens were mixed at a ratio of 3:1.5 by viable cell count, and a bacterial suspension was prepared by adding a culture solution, the viable cell concentration being 6×10 9 CFU / mL; then 7 g / L of brown algal polyphenol, 25 g / L of betaine, and 45 g / L of trehalose were added to the bacterial suspension, stirring was carried out at a speed of 60 rpm for 5 min to obtain a mixed core material solution; the mixed core material solution was added to the wall material solution, the mass ratio of the core material to the wall material being 1:2, and 0.8% of glycerol monostearate based on the total mass of the core material and the wall material was added as an emulsifier to form an emulsion with a particle size of 30 μm under high-speed shearing at 8000 rpm, the emulsion was sprayed into a cold trap at -40°C by a nebulizer at a pressure of 0.4 MPa, and the liquid droplets were instantaneously frozen; then the bacterial microcapsules were obtained by freeze-drying in a vacuum freeze-dryer at a temperature of -50°C and a vacuum degree of 0.02 MPa for 24 h; the culture solution comprised rhamnolipid 0.5 wt%, sodium glutamate 0.1 wt%, starch 5 wt%, and the rest was a PBS buffer solution with a pH of 7.0 and a concentration of 100 mM;

[0035] (3) The following components were prepared at the following concentrations: 180 g / L of amino acids, 35 g / L of calcium chloride, 3 g / L of diatomite, 10 g / L of potassium fulvate, 3 g / L of magnesium sulfate heptahydrate, 1 g / L of boric acid, and the rest being water; the amino acids, water, potassium fulvate, and diatomite were weighed, heated to 40°C, and stirred for 0.5 h, then the calcium chloride, magnesium sulfate heptahydrate, and boric acid were added, and stirring was carried out for 1 h to obtain a water-soluble fertilizer; finally, 0.08 times the mass of the water-soluble fertilizer was added to the bacterial microcapsules, wherein the amino acids comprised polyglutamic acid, methionine, cystine, lysine, tryptophan, phenylalanine, threonine, valine, leucine, and isoleucine at a mass ratio of 10:3:8:7:1:3:1:8:2:5.

[0036] Example 3; a production process for an amino acid water-soluble fertilizer, comprising the following process steps:

[0037] (1) The same method as in Example 1 was used to prepare fucoidan; 100 g of ricinoleic acid was dissolved in 500 mL of anhydrous DMF, and a 0.5 mol / L NHS / DMF solution was added to mix, with the molar ratio of NHS to ricinoleic acid carboxyl being 1.2:1, then the carboxyl group was activated at 25℃ for 30 min with a stirring speed of 120 rpm; then fucoidan was added, with the mass ratio of fucoidan to ricinoleic acid being 5:3, and 0.1 mol / L EDC / DMF solution was added as a catalyst, with the molar ratio of EDC to ricinoleic acid carboxyl being 1:1, and the reaction was carried out at 45℃ under 0.1 MPa of nitrogen protection for 4 h to generate ricinoleic acid-fucoidan, and the reaction solution was purified by a molecular weight cutoff dialysis bag with a cutoff molecular weight of 3500 Da, with the dialysis outer solution being a phosphate buffer solution with a pH of 7.0 and a concentration of 0.05 mol / L, the dialysis outer solution was replaced every 4 h, and the solution was concentrated to a solid content of 40% to obtain a wall material solution;

[0038] (2) Azospirillum and Pseudomonas fluorescens were mixed at a ratio of 3:2.5 by viable cell count, and a culture solution was added to obtain a bacterial suspension, with a viable cell concentration of 6×10 9 CFU / mL; then 8 g / L of brown algal polyphenol, 30 g / L of betaine, and 50 g / L of trehalose were added to the bacterial suspension to obtain a mixed core material solution, which was stirred at a speed of 60 rpm for 5 min; the mixed core material solution was added to the wall material solution, with a core material to wall material mass ratio of 1:2, and 0.8% of glycerol monostearate based on the total mass of the core material and the wall material was added as an emulsifier to form an emulsion with a particle size of 30 μm under high-speed shearing at 8000 rpm; the emulsion was sprayed into a -40℃ cold trap by a nebulizer at a pressure of 0.4 MPa, and the droplets were instantaneously frozen; then the bacterial microcapsules were obtained by freeze-drying in a vacuum freeze-drier at a temperature of -50℃ and a vacuum degree of 0.02 MPa for 24 h; the culture solution comprised rhamnolipid 0.5 wt%, sodium glutamate 0.1 wt%, and starch 5 wt%, with the remainder being a PBS buffer solution with a pH of 7.0 and a concentration of 100 mM;

[0039] (3) The following components were mixed at the following concentrations: 180 g / L amino acids, 35 g / L calcium chloride, 3 g / L diatomite, 10 g / L potassium fulvate, 3 g / L magnesium sulfate heptahydrate, 1 g / L boric acid, and the balance being water; the amino acids, water, potassium fulvate, and diatomite were weighed and heated to 40℃, and stirred for 0.5 h; then the calcium chloride, magnesium sulfate heptahydrate, and boric acid were added, and stirred for 1 h to obtain a water-soluble fertilizer; finally, 0.08 times the mass of the water-soluble fertilizer was added to the bacterial microcapsules; the amino acids comprised polyglutamic acid, methionine, cystine, lysine, tryptophan, phenylalanine, threonine, valine, leucine, and isoleucine at a mass ratio of 10:3:8:7:1:3:1:8:2:5.

[0040] Comparative Example 1; Comparative Example 1 differs from Example 2 in that steps (1) (2) are changed to: (1) mix 2.0% chitosan acetic acid solution with pH = 5.0 and 3.5% fucoidan aqueous solution with pH = 6.8 at a volume ratio of 3:2, stir at 500 rpm in a 45°C water bath for 30 min to form a uniform milky white colloid, then add 0.5% glycerol as a plasticizer, continue stirring for 10 min to prepare a composite colloid; cool the composite colloid to 25°C, add 1.0% sodium tripolyphosphate solution at a rate of 2 ml / min, the volume of the sodium tripolyphosphate solution is one sixth of the total volume of the colloid, while maintaining the stirring speed at 300 rpm, after dripping, stand for 60 min to crosslink to obtain an elastic gel block;

[0041] (2) mix Azospirillum brasilense and Pseudomonas fluorescens at a ratio of 3:1.5 by viable cell number, add to the culture solution to prepare a bacterial suspension, the viable cell concentration is 6 x 10 9 CFU / mL; then add 7 g / L brown algal polyphenol, 25 g / L betaine, and 45 g / L trehalose to the bacterial suspension, stir at 60 rpm for 5 min to prepare a mixed core material solution, then uniformly disperse into the composite gel; granulate through a screw extruder with a 30 μm aperture template, collect the wet granules and transfer to a freeze dryer, sublimate and dehydrate at -50°C and a vacuum degree of 10 Pa for 24 h to obtain bacterial-containing microcapsules; the components of the culture solution include rhamnolipid 0.5 wt%, sodium glutamate 0.1 wt%, and starch 5 wt%, and the rest is PBS buffer solution with pH = 7.0 and a concentration of 100 mM. The remaining steps are the same as in Example 2.

[0042] Comparative Example 2; Comparative Example 2 differs from Example 2 in that step (2) is changed to: add Azospirillum brasilense to the culture solution to prepare a bacterial suspension, the viable cell concentration is 6 x 10 9 CFU / mL; then add 7 g / L brown algal polyphenol, 25 g / L betaine, and 45 g / L trehalose to the bacterial suspension, stir at 60 rpm for 5 min to prepare a mixed core material solution; add the mixed core material solution to the wall material solution, the mass ratio of core material to wall material is 1:2, then add 0.8% glyceryl monostearate as an emulsifying agent to the total mass of the core material and wall material, emulsify at a high speed of 8000 rpm to form an emulsion with a particle size of 30 μm, the emulsion is sprayed into a -40°C cold trap by an atomizer at a pressure of 0.4 MPa, the liquid droplets are instantaneously frozen; then freeze-dry in a vacuum freeze dryer at a temperature of -50°C and a vacuum degree of 0.02 MPa for 24 h to obtain bacterial-containing microcapsules; the components of the culture solution include rhamnolipid 0.5 wt%, sodium glutamate 0.1 wt%, and starch 5 wt%, and the rest is PBS buffer solution with pH = 7.0 and a concentration of 100 mM. The remaining steps are the same as in Example 2.

[0043] Comparative Example 3; Comparative Example 3 differs from Example 2 in that step (2) is changed to: Pseudomonas fluorescens is added to a culture solution to obtain a bacterial suspension, the viable bacterial concentration being 6x10 9 CFU / mL; 7 g / L of brown algal polyphenol, 25 g / L of betaine, and 45 g / L of trehalose are added to the bacterial suspension, and the mixture is stirred at a speed of 60 rpm for 5 min to obtain a mixed core material solution; the mixed core material solution is added to the wall material solution, the mass ratio of the core material to the wall material being 1:2, and 0.8% of glycerol monostearate based on the total mass of the core material and the wall material is further added as an emulsifying agent to form an emulsion with a particle size of 30 μm under high-speed shearing at 8000 rpm; the emulsion is sprayed into a cold trap at -40°C by a nebulizer at a pressure of 0.4 MPa, and the droplets are instantaneously frozen; then, the bacterial microcapsules are obtained by freeze-drying in a vacuum freeze-drying machine at a temperature of -50°C and a vacuum degree of 0.02 MPa for 24 h; the culture solution comprises rhamnolipid 0.5 wt%, sodium glutamate 0.1 wt%, and starch 5 wt%, and the rest is a PBS buffer solution with a pH of 7.0 and a concentration of 100 mM; and the remaining steps are the same as in Example 2.

[0044] Comparative Example 4

[0045] Comparative Example 4 differs from Example 2 in that urea is used instead of amino acid; and the remaining steps are the same as in Example 2.

[0046] Effect Example

[0047] The performance analysis results of the aqueous amino acid fertilizer of one of Examples 1 to 3 and Comparative Examples 1 to 4 of the present application are shown in Tables 1 and 2 below.

[0048] Table 1: Fertilizer test data before microcapsule storage

[0049]

[0050] Table 2: Fertilizer test data after three months of storage

[0051]

[0052] The present application constructs microcapsules containing Azotobacter and Pseudomonas fluorescens by activating the carboxyl group of ricinoleic acid and enzymatic hydrolysis of fucoidan oligosaccharides. Ricinoleic acid acts as a protective agent during storage and as a colonization inducer during use, achieving efficient resource utilization. During storage, the dense hydrophobic film formed by ricinoleic acid on the surface of the microcapsules effectively isolates external moisture and oxygen penetration, and the combination of trehalose ensures that the bacterial community maintains a high survival activity during long-term storage, protecting the effective factors from oxidation and failure. The use of amino acids forms a hydrated gel network with water retention capacity, and by designing the ratio of amino acids and microcapsules, the amino acids can effectively buffer the influence of external humidity fluctuations on the internal bacterial bodies. When the fertilizer is applied to the soil, the environmental microbial enzymes begin to decompose ricinoleic acid, and its products act as precursors of jasmonic acid signals, effectively stimulating Azotobacter to secrete a large amount of extracellular polysaccharide to form a biofilm, greatly improving its colonization ability on the surface of crop roots. The released Pseudomonas fluorescens has the ability to dissolve soil-insoluble phosphorus, and cooperates with Azotobacter to significantly improve the efficiency of crop nitrogen and phosphorus nutrient acquisition. Polyglutamic acid exhibits excellent water retention and fertilizer retention properties in the soil, forming a water and fertilizer release zone around the roots, greatly improving the absorption and utilization of water and nutrients by crops.

[0053] Example 4

[0054] The same method as in Example 2 was used to prepare the microcapsules containing bacteria, and the process of amino acid water-soluble fertilizer was the same as in Example 2, but the ratio of amino acid and calcium chloride was changed. The effect of the formula design of amino acid and calcium chloride on crops can be known, as shown in Table 3:

[0055] Table 3 Effect of formula design of amino acid and calcium chloride on crops

[0056]

[0057] In the present application, there is a synergistic relationship between amino acid (nitrogen source) and calcium chloride (calcium source). Calcium chloride can stabilize the cell wall structure and promote the transport and absorption of amino acids. Through formula design, the optimal nutrient ratio under this fertilizer system is achieved, thereby optimizing crop growth.

[0058] It will be obvious to a person skilled in the art that, without departing from the spirit or essential characteristics of the application, the present application can be implemented in other specific forms. The present application is therefore considered in all its symmetrical and / or asymmetric aspects to be illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the description given above, and therefore all changes falling within the meaning and range of equivalency of the claims are therefore to be embraced therein. Any reference signs in the claims should not be construed as limiting the claims.

Claims

1. An amino acid water-soluble fertilizer comprising a water-soluble fertilizer and a bacterial-containing microcapsule, characterized in that, The water agent fertilizer comprises the following components in the following concentrations: 100-200 g / L amino acid, 30-50 g / L calcium chloride, 3-5 g / L diatomite, 10-20 g / L potassium fulvate, 3-6 g / L magnesium sulfate heptahydrate, 0.5-1 g / L boric acid, and the balance being water; The amino acid water-soluble fertilizer comprises the following process steps: adding amino acid, water, potassium fulvate and diatomite according to the formula, heating to 40°C, stirring for 0.5 h, then adding calcium chloride, magnesium sulfate heptahydrate and boric acid, stirring for 1 h to obtain the water agent fertilizer, and finally adding the bacterial microcapsules in an amount of 0.08 times the mass of the water agent fertilizer; The amino acid is composed of polyglutamic acid, methionine, cystine, lysine, tryptophan, phenylalanine, threonine, valine, leucine and isoleucine in a mass ratio of 10-15:2-4:8-9:5-8:0.1-1:2-5:0.5-2:7.5-8.2:1-3:4-7; The bacterial microcapsules comprise the following preparation steps: (1) 100 g of ricinoleic acid is mixed with 0.5 mol / L of an NHS / DMF solution, stirred at 25°C for 30 min, then fucoidan is added, the mass ratio of fucoidan to ricinoleic acid being 5:3-5, and 0.1 mol / L of an EDC / DMF solution is added as a catalyst, and the reaction is carried out at 45°C under 0.1 MPa of nitrogen protection for 4 h to generate ricinoleic acid-fucoidan, and the reaction solution is concentrated by dialysis to a solid content of 40% to obtain a wall material solution; (2) Azospirillum and Pseudomonas fluorescens are mixed at a ratio of 3:0.5-2.5 (viable bacteria number), and a bacterial suspension with a viable bacteria concentration of 6×10 9 CFU / mL is prepared; then 5-8 g / L of phlorofuco-phenone, 20-30 g / L of betaine, and 40-50 g / L of trehalose are added to the bacterial suspension, and stirred for 5 min to prepare a mixed core material solution; the mixed core material solution is added to a wall material solution, the mass ratio of the core material to the wall material is 1:2, and 0.8% of glyceryl monostearate is added as an emulsifier, and then emulsification, freezing, drying, and dehydration are performed to obtain bacterial microcapsules.

2. The amino acid water-soluble fertilizer according to claim 1, characterized in that, In step (1), the molar ratio of NHS to the carboxyl group of ricinoleic acid is 1.2:

1.

3. The amino acid water-soluble fertilizer according to claim 1, characterized in that, In step (1), the molar ratio of EDC to the carboxyl group of ricinoleic acid is 1:

1.

4. The amino acid water-soluble fertilizer according to claim 1, characterized in that, In step (1), the dialysis step is that the reaction solution is purified by a dialysis bag with a molecular weight cut-off of 3500 Da, and the dialysis external solution is changed every 4 h.

5. The amino acid water-soluble fertilizer according to claim 1, characterized in that, The dialysis external solution is a phosphate buffer with a pH of 7.0 and a concentration of 0.05 mol / L.

6. The amino acid water-soluble fertilizer according to claim 1, characterized in that, In step (2), the emulsification, freezing, drying and dehydration steps are as follows: the emulsion is formed by high-speed shearing at 8000 rpm to have a particle size of 30 μm, the emulsion is sprayed into a-40°C cold trap by an atomizer at a pressure of 0.4 MPa, and the liquid droplets are frozen instantaneously; then the emulsion is freeze-dried in a vacuum freeze-drying machine at a temperature of-50°C and a vacuum degree of 0.02 MPa for 24 h.

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