Amino acid water-soluble fertilizer containing nano-mimetic enzyme, preparation method and application thereof

Abstract

The invention discloses a kind of amino acid water-soluble fertilizer containing nano-mimetic enzyme and its preparation method and application, relate to the technical field of water-soluble fertilizer, the raw material of amino acid water-soluble fertilizer includes manganese tetraoxide, and the particle size of described manganese tetraoxide is 30-200nm; Preferably, water-soluble fertilizer particles are prepared into the structure of shell from inside to outside with manganese tetraoxide nanoparticles as core, polyglutamic acid / anionic polysaccharide, water-soluble film-forming material, dopamine / polyacrylamide in turn. The amino acid water-soluble fertilizer provided by the present invention improves the stability, adhesion and rainwater erosion resistance of amino acid water-soluble fertilizer, and is sprayed on crops by spraying or flying defense, effectively realizing the anti-lodging and yield increase of crops.

Description

Technical Field

[0001] The invention relates to the technical field of water-soluble fertilizers, and in particular to an amino acid water-soluble fertilizer containing a nano-mimetic enzyme, and a preparation method and application thereof. Background Art

[0002] At present, the amino acid water-soluble fertilizers on the market are mainly free amino acids, protein-degraded polypeptides or polymerized amino acids mixed with seaweed extract, humic acid and other substances. The utilization rate of amino acids is low, mainly because amino acids are good in water solubility, poor in adhesion, easy to lose after liquid surface spraying, and low in absorption ratio.

[0003] Nano-mimetic enzymes refer to materials with similar enzyme properties among nanomaterials. They are made of nanomaterials (inorganic or organic) with specific nanostructures and catalyze the biochemical reactions of substrates under physiological conditions. They follow the same enzyme kinetics and catalytic mechanisms. At the same time, the catalytic activity comes from the active center or electron transport structure it possesses. Nano-mimetic enzymes have been widely studied due to their high stability, low inactivation, low manufacturing cost, and fast catalytic speed.

[0004] Among the existing amino acid water-soluble fertilizer technologies, Chinese patent application CN113307676A provides a macadamia amino acid water-soluble fertilizer, whose raw materials include amino acid powder, polysaccharide polypeptide biological potassium, B2, sodium tetraborate, amino oligosaccharide, carbonase, diamine enzyme and water, which can promote the absorption of nutrients by macadamia trees. The fish protein amino acid water-soluble antibacterial fertilizer provided by Chinese patent application CN110452062A inhibits the reproduction of microbial pathogens through allicin and a variety of microorganisms. An amino acid enzyme biofertilizer provided by Chinese authorized patent CN103086784B contains agricultural amino acids, enzyme-containing materials, microbial organic fermentation materials made from plant seed meal as raw materials, and a mixture of inorganic fertilizers and trace elements. The enzyme-containing materials are protease, urease, phytase, chitinase, etc. As a newly developed nanomaterial, nano-mimetic enzymes are currently mainly used in the fields of medicine and pharmacy, and are rarely used in the agricultural field.

[0005] In summary, the development of an amino acid water-soluble fertilizer containing nanoenzymes, which has the characteristics of anti-wiper, slow release and high efficiency, will have broad market prospects. Summary of the invention

[0006] In view of the above shortcomings of the prior art, the present invention provides an amino acid water-soluble fertilizer containing nano-mimetic enzymes, a preparation method and application thereof, by using manganese tetraoxide as the core raw material of the amino acid water-soluble fertilizer, preparing it into a uniform and stable mixed liquid (or suspension) state, and spraying it on crops by spraying or aerial spraying, effectively achieving the anti-lodging and yield increase of crops. It is specifically achieved by the following technologies.

[0007] The amino acid water-soluble fertilizer containing nano-mimetic enzymes is characterized in that the amino acid water-soluble fertilizer is a suspension, and its raw materials include manganese tetraoxide, and the particle size of the manganese tetraoxide is 30-200nm.

[0008] The amino acid water-soluble fertilizer provided by the present invention, in addition to being able to add other raw materials commonly used in the industry, such as composite amino acids, biological enzymes, biological fermentation products and trace elements required by plants, the most important thing is that by adding manganese tetraoxide, the stress resistance of crops is achieved, including drought resistance, salt-alkali resistance, high temperature resistance, cold resistance and lodging resistance, and the like, indirectly improving the crop yield. Manganese tetraoxide, as a compound with a particle size of nanometer level (30-200nm), plays the role of mimicking enzymes in the amino acid water-soluble fertilizer of the present invention, and its working principle is that plants will produce a large amount of ROS under adverse stress, and manganese tetraoxide can catalyze the degradation of ROS, reduce the impact of adverse stress on plant growth, thereby increasing yield.

[0009] Preferably, the raw materials also include a first material, water and an adhesive for adhering to the surface of crop plants, the first material is one or more of polyglutamic acid and anionic polysaccharides, the first material is coated on the surface of the manganese tetraoxide, and the adhesive is coated on the surface of the first material; the adhesive is dopamine and / or polyacrylamide.

[0010] When the amino acid water-soluble fertilizer of the present invention is applied in farmland, in order to make the manganese tetraoxide and other substances in the amino acid water-soluble fertilizer more firmly adhere to the surface of crop plants and accelerate the absorption of manganese tetraoxide by the plants, a certain amount of adhesive (dopamine, polyacrylamide and other materials) can be added to the water-soluble fertilizer. These adhesives are evenly distributed on the surface of the manganese tetraoxide nanoparticles to form a shell structure, thereby promoting the relatively firm attachment of the manganese tetraoxide nanoparticles, thereby improving the adhesion and rainwater erosion resistance of the amino acid water-soluble fertilizer.

[0011] Because manganese tetraoxide is easy to agglomerate in solution, it will affect the uniformity and stability of the entire amino acid water-soluble fertilizer. In addition, manganese tetraoxide and adhesive (dopamine, polyacrylamide, etc.) are both positive charges. Because like repels like, the shape of the core (manganese tetraoxide)-shell (adhesive) space structure formed is irregular, which will also affect the adhesion and stability of amino acid water-soluble fertilizer to a certain extent. Therefore, in order to improve the stability of manganese tetraoxide and adhesive overall structure, in addition to adding adhesive, the first material is also added to the raw material. The first material is composed of negatively charged polyglutamic acid and / or anionic polysaccharides (such as seaweed polysaccharides, etc.), and its effect is to first form a negatively charged shell on the positively charged nano manganese tetraoxide surface, and then coat the positively charged adhesive outside the negatively charged shell. That is, the particle structure of the amino acid water-soluble fertilizer finally formed is "core (manganese dioxide nanoparticles, positively charged) - shell (first material, polyglutamic acid and / or anionic polysaccharides, etc., negatively charged) - shell (adhesive, positively charged)" from the inside to the outside.

[0012] Polyglutamic acid is a raw material that is easily purchased on the market. It is a high molecular polymer formed by glutamic acid through α-amino and γ-carboxyl groups to form peptide bonds. By increasing the proline and peroxidase content in crop plants, it achieves outstanding effects in increasing crop yields and resisting stress. More importantly, polyglutamic acid and anionic polysaccharides, as negatively charged materials, can form a very stable core-shell structure with the manganese oxide nanoparticles at the core and the adhesive at the outer layer.

[0013] Further preferably, the raw material of the amino acid water-soluble fertilizer also includes a pH regulator, and the pH value of the amino acid water-soluble fertilizer is 8.0-9.0; and the adhesive is dopamine.

[0014] pH adjusters can be selected from tris(hydroxymethyl)aminomethane, borax-sodium carbonate buffer system, etc., which are used to adjust the pH value of amino acid water-soluble fertilizer. When dopamine is used as an adhesive, it is necessary to adjust the pH value of the amino acid water-soluble fertilizer to alkaline so that dopamine self-polymerizes under alkaline conditions to form polydopamine. Polydopamine uses its own adhesiveness to wrap the internal "core (manganese tetraoxide nanoparticles) - shell (first material)" structure to form a nanofilm, so that the above internal structure wrapped by polydopamine can adhere more firmly to the surface of crop plants.

[0015] More preferably, the raw material of the amino acid water-soluble fertilizer also includes a second material; the amount of manganese tetraoxide, the first material, the second material and the adhesive is (8-12): (6-10): (9-15): (10-14);

[0016] The second material is a water-soluble film-forming material and a cross-linking agent; the first material is coated on the surface of the manganese tetraoxide, the second material is coated on the surface of the first material, and the adhesive is coated on the surface of the second material.

[0017] During daily storage, manganese tetraoxide is also susceptible to ultraviolet degradation. Therefore, in order to extend the shelf life of amino acid water-soluble fertilizer, it is also necessary to use a second material (water-soluble film-forming material), which is used to further form a film layer between the shell layer (first material) and the shell (adhesive) to protect the nano manganese tetraoxide from ultraviolet degradation. That is, the particle structure of the amino acid water-soluble fertilizer finally formed is a structure of "core (manganese tetraoxide nanoparticles) - shell (first material polyglutamic acid, anionic polysaccharide, etc.) - shell (second material water-soluble film-forming material) - shell (adhesive dopamine, polyacrylamide, etc.)" from the inside to the outside.

[0018] More preferably, the usage ratio of trimanganese tetraoxide, the first material, the second material and the adhesive is 5:4:6:6.

[0019] Further preferably, the second material is zein hydrolyzed polypeptide and sodium tripolyphosphate. Zein is a mixture of 25-45kDa protein with an average molecular weight, and has good film-forming, antibacterial and UV-resistant functions. By degrading zein into small molecule zein hydrolyzed polypeptide (water-soluble film-forming material), it can prevent the adverse effects of ultraviolet rays, release manganese tetraoxide nanoparticles slowly, and improve the overall stability of amino acid water-soluble fertilizer. The role of sodium tripolyphosphate (cross-linking agent) is to polymerize zein hydrolyzed polypeptide and firmly wrap it on the surface of the shell (first material polyglutamic acid, anionic polysaccharide, etc.).

[0020] Generally, the hydrolyzed zein polypeptide can be obtained by dissolving zein in an aqueous solution of NaOH, stirring and reacting at 50-70° C. for 4-10 hours, and then drying. In addition, other common hydrolysis methods can also be used to achieve the hydrolysis of zein.

[0021] More preferably, the mass ratio of the zein hydrolyzed polypeptide to sodium tripolyphosphate is (8-12):(1-3).

[0022] More preferably, the mass ratio of the zein hydrolyzed polypeptide to sodium tripolyphosphate is 6:1.

[0023] Preferably, the particle size of the trimanganese tetraoxide is 40-60 nm. By further controlling the particle size of the trimanganese tetraoxide within 40-60 nm, the transport efficiency of the trimanganese tetraoxide in the plant body can be improved, thereby improving its utilization rate. Generally, the particle size of the trimanganese tetraoxide can be controlled to the required nanometer level by ball mill grinding or the like.

[0024] The present invention also provides a method for preparing the above-mentioned amino acid water-soluble fertilizer containing nano-mimetic enzymes, comprising the following steps:

[0025] S1. Take the first material and add it into water to stir and dissolve, then add manganese tetraoxide and homogenize until the mixture is translucent;

[0026] S2, adding the second material to the mixed solution obtained in step S1, and continuing to stir until the second material is completely dissolved;

[0027] S3, adding an adhesive to the mixed solution obtained in step S2 while stirring until the adhesive is completely dissolved, and finally adding the pH adjuster, and continuing to stir to obtain a finished amino acid water-soluble fertilizer.

[0028] In the above preparation method, the stirring and homogenizing mentioned are set using conventional parameters, such as the stirring speed is set to 24-40r / min, and the homogenizing is set to 2500-3500r / min, 60-85min. There are no requirements for the stirring and homogenizing temperature conditions, and only the conventional outdoor temperature is required. In short, as long as all the raw materials can be stirred and dissolved, or the purpose of homogenization can be achieved, the corresponding parameters can be used directly without too many restrictions.

[0029] When used, the amino acid water-soluble fertilizer containing the nano-mimetic enzyme provided by the present invention can be fertilized by spraying or aerial spraying.

[0030] Preferably, when the amino acid water-soluble fertilizer is applied by spraying, it is diluted with water at a volume ratio of 1:(300-600) during the crop reproductive growth period to prepare an amino acid water-soluble fertilizer working solution, and sprayed at 15-30 L / mu each time, and applied 1-3 times a season;

[0031] When the above amino acid water-soluble fertilizer is applied by aerial spraying, it is diluted with water at a volume ratio of 1:(20-40) during the crop reproductive growth period to prepare an amino acid water-soluble fertilizer working solution, which is sprayed at 1-2L / mu each time, and applied 1-3 times a season.

[0032] Compared with the prior art, the present invention is beneficial in that:

[0033] 1. The present invention provides an amino acid water-soluble fertilizer containing nano manganese tetraoxide mimic enzyme, which is sprayed on crops by spraying or aerial spraying, effectively achieving the lodging resistance and yield increase of crops;

[0034] 2. By selecting dopamine, polyacrylamide and other raw materials to attach to the surface of manganese tetraoxide nanoparticles, the adhesion and rainwater resistance of amino acid water-soluble fertilizer are improved;

[0035] 3. By adopting a variety of different film-forming / shell-forming materials, not only the stability of the amino acid water-soluble fertilizer is improved, the shelf life of the amino acid water-soluble fertilizer is extended, but also the slow release of manganese tetroxide nanoparticles can be formed to extend the continuous effective period of the amino acid water-soluble fertilizer. In addition, by selecting special film-forming / shell-forming materials (such as polyglutamic acid, etc.), the synergistic effect can further increase crop yields and improve crop resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the particle size distribution diagram of the nano slow-release particles in the amino acid water-soluble fertilizer containing nanoenzymes prepared in Example 1. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0038] In order to meet the standard requirements of NY 1429-2010 for amino acid water-soluble fertilizers (free amino acid content ≥ 10%), before the following test examples, compound amino acid powder was additionally added to the amino acid water-soluble fertilizer products provided in the following examples and comparative examples. The method of use is to add 125g / kg of compound amino acid powder to the amino acid water-soluble fertilizer products and dissolve them by conventional stirring (36r / min). The compound amino acid powder was purchased from Sichuan Mianzhu Ruiyang Biotechnology Co., Ltd., the product model is P80, the main components are 17 kinds of free amino acids, and the free amino acid content is 80%.

[0039] It should be noted that the amino acid water-soluble fertilizers provided in the following examples and comparative examples contain only common composite amino acid powders purchased on the market that can be used as raw materials for amino acid water-soluble fertilizers. The use of composite amino acid powders produced by other manufacturers will not affect the claimed stress resistance, yield-increasing and other effects of the amino acid water-soluble fertilizers provided by the present invention.

[0040] The amino acid water-soluble fertilizers provided in the following examples and comparative examples, if not otherwise specified, were prepared by the following method:

[0041] S1. Add the first material (polyglutamic acid or seaweed polysaccharide) into water and stir at room temperature (36 r / min) until the first material is dissolved, then add nano manganese tetraoxide (particle size 40-60 nm), and homogenize by conventional homogenization method (2900 r / min) for 75 min until the mixed solution becomes translucent, and then stop homogenization;

[0042] S2, adding the second material (water-soluble film-forming material, such as zein hydrolyzed polypeptide; and a cross-linking agent, such as sodium tripolyphosphate) to the translucent mixed solution obtained in step S1, and continuing to stir (36 r / min) until the second material is completely dissolved, using an electric diaphragm pump to control the addition time to about 25 min, and continuing to stir for 75 min after the addition is completed;

[0043] S3. Add an adhesive (such as dopamine or polyacrylamide) to the mixed solution obtained in step S2 while stirring (36 r / min) until the adhesive is completely dissolved; finally, add a pH adjuster (tris(hydroxymethyl)aminomethane) for polymerization, and use an electric diaphragm pump to control the addition time to about 8 minutes. After the addition is completed, continue stirring for 75 minutes, and continue stirring to obtain a finished amino acid water-soluble fertilizer.

[0044] If not otherwise specified, the amino acid water-soluble fertilizers provided in the following examples and comparative examples are prepared using the following method as the raw materials, nano manganese tetraoxide and zein hydrolyzed polypeptide.

[0045] Nano manganese tetraoxide: take manganese tetraoxide (purchased from Aladdin Reagent Company) and grind it in a ball mill until the average particle size is 40-60nm;

[0046] Zein hydrolyzed polypeptide: Zein was dissolved in a 0.2 mol / L NaOH aqueous solution, heated to 60° C., stirred for 8 hours, and freeze-dried (conventional drying method) to obtain a powder of zein hydrolyzed polypeptide.

[0047] The raw materials used in the following examples and comparative examples, such as manganese tetraoxide, zein, NaOH, sodium tripolyphosphate, dopamine, tris(hydroxymethyl)aminomethane and other reagents, were purchased from Aladdin Reagent Company.

[0048] Example 1

[0049] The amino acid water-soluble fertilizer containing nano-mimicking enzyme prepared in this embodiment has raw materials of 10g of nano manganese tetraoxide, 8g of the first material (polyglutamic acid), 10g of the second material (10g of zein hydrolyzed polypeptide and 2g of sodium tripolyphosphate), 12g of an adhesive (dopamine), 2g of a pH regulator (trishydroxymethylaminomethane) and 56g of water, and the pH value of the amino acid water-soluble fertilizer is 8.0-9.0. That is, the dosage of manganese tetraoxide, the first material, the second material and the adhesive is 5:4:6:6, and the dosage of zein hydrolyzed polypeptide and sodium tripolyphosphate is 5:1.

[0050] In the preparation method of the amino acid water-soluble fertilizer provided in this embodiment, step S2 specifically adds the zein hydrolyzed polypeptide to the translucent mixed solution obtained in step S1 and continues stirring (36r / min) until the zein hydrolyzed polypeptide is completely dissolved, and then sodium tripolyphosphate is added for cross-linking, and an electric diaphragm pump is used to control the addition time to about 25min, and stirring is continued for 75min after the addition is completed.

[0051] The microstructure of the amino acid water-soluble fertilizer provided in this embodiment is "core (manganese tetraoxide nanoparticles) - shell (first material polyglutamic acid, anionic polysaccharide, etc.) - shell (second material water-soluble film-forming material) - shell (adhesive dopamine, polyacrylamide, etc.)". The particle size distribution of the amino acid water-soluble fertilizer prepared in this embodiment was tested: 1 mL of the prepared amino acid water-soluble fertilizer solution was taken, and its average particle size was measured using the Malvern Nano-ZS nanoparticle size and Zeta potential analyzer. The test results are as follows: Figure 1 As shown, it can be clearly seen that the particle size of the nano slow-release particles in the prepared amino acid water-soluble fertilizer is 100-400nm, the average particle size is 208.7nm, and the PdI value is 0.330, indicating that the prepared nano slow-release particles have good uniformity and high quality.

[0052] Example 2

[0053] Compared with Example 1, the amino acid water-soluble fertilizer containing nano-mimicking enzyme prepared in this embodiment has raw materials of 8g nano manganese tetraoxide, 10g of the first material (polyglutamic acid), 8g of the second material (zein hydrolyzed polypeptide and 3g of sodium tripolyphosphate), 10g of the adhesive (dopamine), 3g of the pH regulator (trishydroxymethylaminomethane) and 58g of water, and the pH value of the amino acid water-soluble fertilizer is 8.0-9.0. That is, the dosage of manganese tetraoxide, the first material, the second material and the adhesive is 8:10:11:10, and the dosage of zein hydrolyzed polypeptide and sodium tripolyphosphate is 8:3.

[0054] Example 3

[0055] The amino acid water-soluble fertilizer containing nano-mimicking enzyme prepared in this embodiment, compared with Example 1, has raw materials of 12g of nano manganese tetraoxide, 6g of the first material (polyglutamic acid), 12g of the second material (12g of zein hydrolyzed polypeptide and 1g of sodium tripolyphosphate), 14g of adhesive (dopamine), 1g of pH regulator (trishydroxymethylaminomethane) and 54g of water, and the pH value of the amino acid water-soluble fertilizer is 8.0-9.0. That is, the dosage of manganese tetraoxide, the first material, the second material and the adhesive is 12:6:13:14, and the dosage of zein hydrolyzed polypeptide and sodium tripolyphosphate is 12:1.

[0056] Example 4

[0057] The amino acid water-soluble fertilizer containing nano-mimetic enzymes prepared in this embodiment has the following differences from those in Example 1 in that the second material (zein hydrolyzed polypeptide and sodium tripolyphosphate) is not contained, and the amount of water is increased accordingly; that is, the raw materials only contain 10g of nano manganese tetraoxide, 8g of the first material (polyglutamic acid), 12g of an adhesive (dopamine), 2g of a pH regulator (tris(hydroxymethyl)aminomethane) and 68g of water.

[0058] The preparation method of the amino acid water-soluble fertilizer provided in this comparative example is:

[0059] S1. Add the first material (polyglutamic acid) to water and stir at room temperature (36 r / min) until the first material is dissolved, then add nano manganese tetraoxide (particle size 40-60 nm), and homogenize (2900 r / min) for 75 min using a conventional homogenization method until the mixed solution becomes translucent, and then stop homogenizing;

[0060] S2. Add an adhesive (e.g., dopamine) to the mixed solution obtained in step S1 while stirring (36 r / min) until the adhesive is completely dissolved; finally, add a pH adjuster (tris(hydroxymethyl)aminomethane) for polymerization, and use an electric diaphragm pump to control the addition time to about 8 minutes. After the addition is completed, continue stirring for 75 minutes, and continue stirring to obtain a finished amino acid water-soluble fertilizer.

[0061] The microstructure of the amino acid water-soluble fertilizer formed in this embodiment is "core (manganese tetraoxide nanoparticles) - shell (first material polyglutamic acid, anionic polysaccharide, etc.) - shell (adhesive dopamine, polyacrylamide, etc.)"

[0062] Example 5

[0063] The amino acid water-soluble fertilizer containing nano-mimicking enzymes prepared in this embodiment has the following differences from Example 1 in that the first material used is 8 g of seaweed polysaccharide (anionic polysaccharide) and the adhesive is 12 g of polyacrylamide. That is, the amount of manganese tetraoxide, the first material, the second material and the adhesive is 5:4:6:6, and the amount of zein hydrolyzed polypeptide and sodium tripolyphosphate is 5:1. The pH value of the amino acid water-soluble fertilizer is 8.0-9.0.

[0064] The preparation method of the amino acid water-soluble fertilizer provided in this embodiment is the same as that in Example 1.

[0065] Comparative Example 1

[0066] The amino acid water-soluble fertilizer containing nano-mimetic enzymes prepared in this comparative example is different from Example 1 in that the raw materials do not contain nano-manganese tetraoxide and the amount of water is increased; that is, the raw materials only contain 8g of the first material (polyglutamic acid), 10g of the second material (10g of zein hydrolyzed polypeptide and 2g of sodium tripolyphosphate), 12g of an adhesive (dopamine), 2g of a pH regulator (tris(hydroxymethyl)aminomethane) and 66g of water.

[0067] The preparation method of the amino acid water-soluble fertilizer provided in this comparative example is:

[0068] S1. Add the first material (polyglutamic acid) into water and stir at room temperature (36 r / min) until the first material is dissolved;

[0069] S2, adding the zein hydrolyzed polypeptide (water-soluble film-forming material) to the translucent mixed solution obtained in step S1, and continuing to stir (36 r / min) until the zein hydrolyzed polypeptide is completely dissolved, and then adding sodium tripolyphosphate for cross-linking, using an electric diaphragm pump to control the addition time to about 25 minutes, and continuing to stir for 75 minutes after the addition is completed;

[0070] S3. Add an adhesive (dopamine) to the mixed solution obtained in step S2 while stirring (36 r / min) until the adhesive is completely dissolved; finally, add a pH adjuster (tris(hydroxymethyl)aminomethane) for polymerization, and use an electric diaphragm pump to control the addition time to about 8 minutes. After the addition is completed, continue stirring for 75 minutes, and continue stirring to obtain a finished amino acid water-soluble fertilizer.

[0071] Comparative Example 2

[0072] The amino acid water-soluble fertilizer containing nano-mimetic enzymes prepared in this comparative example is different from Example 1 in that the raw materials do not contain the first material (polyglutamic acid) and the amount of water is increased; that is, the raw materials only contain 10g of nano manganese tetraoxide, 10g of the second material (10g of zein hydrolyzed polypeptide and 2g of sodium tripolyphosphate), 12g of an adhesive (dopamine), 2g of a pH regulator (tris(hydroxymethyl)aminomethane) and 62g of water.

[0073] The preparation method of the amino acid water-soluble fertilizer provided in this comparative example is:

[0074] S1. Take nano manganese tetraoxide and add it into water at room temperature while stirring (36 r / min), and homogenize it by conventional homogenization method (2900 r / min) for 75 min until the mixed solution becomes translucent, and then stop homogenization;

[0075] S2, adding the zein hydrolyzed polypeptide (water-soluble film-forming material) to the translucent mixed solution obtained in step S1, and continuing to stir (36 r / min) until the zein hydrolyzed polypeptide is completely dissolved, and then adding sodium tripolyphosphate for cross-linking, using an electric diaphragm pump to control the addition time to about 25 minutes, and continuing to stir for 75 minutes after the addition is completed;

[0076] S3. Add an adhesive (dopamine) to the mixed solution obtained in step S2 while stirring (36 r / min) until the adhesive is completely dissolved; finally, add a pH adjuster (tris(hydroxymethyl)aminomethane) for polymerization, and use an electric diaphragm pump to control the addition time to about 8 minutes. After the addition is completed, continue stirring for 75 minutes, and continue stirring to obtain a finished amino acid water-soluble fertilizer.

[0077] Comparative Example 3

[0078] The amino acid water-soluble fertilizer containing nano-mimicking enzyme prepared in this comparative example has the following differences from Example 1 in that the raw materials do not contain an adhesive (dopamine) and a pH regulator (tris(hydroxymethyl)aminomethane), and the amount of water is increased. That is, the raw materials only contain 10g of nano manganese tetraoxide, 8g of the first material (polyglutamic acid), 10g of the second material (10g of zein hydrolyzed polypeptide and 2g of sodium tripolyphosphate) and 70g of water.

[0079] The preparation method of the amino acid water-soluble fertilizer provided in this comparative example is:

[0080] S1. Add the first material (polyglutamic acid) to water and stir at room temperature (36 r / min) until the first material is dissolved, then add nano manganese tetraoxide (particle size 40-60 nm), and homogenize (2900 r / min) for 75 min using a conventional homogenization method until the mixed solution becomes translucent, and then stop homogenizing;

[0081] S2. Add the zein hydrolyzed polypeptide (water-soluble film-forming material) to the translucent mixed solution obtained in step S1 and continue stirring (36 r / min) until the zein hydrolyzed polypeptide is completely dissolved, then add sodium tripolyphosphate for cross-linking, use an electric diaphragm pump to control the addition time to about 25 min, and continue stirring for 75 min after the addition is completed to obtain a finished amino acid water-soluble fertilizer.

[0082] Test Example 1: Determination of stability of amino acid water-soluble fertilizer

[0083] The amino acid water-soluble fertilizer products prepared in the examples and comparative examples were tested for room temperature stability (25°C, 90 days), high temperature stability (54°C, 14 days), low temperature stability (4°C, 14 days) and pH stability. The pH stability was tested by mixing the amino acid water-soluble fertilizer with a pH value of 3 HCl solution or a pH value of 10 NaOH solution at a volume ratio of 1:100; and observing after standing at 25°C for 4 hours. The results are shown in Table 1 below.

[0084] Table 1 Amino Acid Water-soluble Fertilizer Stability Test Results

[0085] Group Name normal temperature high temperature Low temperature pH = 3 pH = 10 Example 1 clarify clarify clarify clarify clarify Example 2 clarify clarify clarify clarify clarify Example 3 clarify clarify clarify clarify clarify Example 4 clarify clarify clarify clarify clarify Example 5 clarify precipitation clarify clarify clarify Comparative Example 1 precipitation precipitation precipitation precipitation precipitation Comparative Example 2 precipitation precipitation precipitation precipitation precipitation Comparative Example 3 clarify clarify clarify precipitation clarify

[0086] The results in Table 1 above show that the amino acid water-soluble fertilizer containing nanozymes prepared in Examples 1-4 are stable under normal temperature, high temperature, low temperature, and acidic and alkaline conditions. Example 5 is stable under all conditions except high temperature.

[0087] The amino acid water-soluble fertilizers prepared in Comparative Examples 1 and 2 are unstable under various conditions. After analysis, the former reason may be that there is no nano manganese tetraoxide as the core, and the polymer generated by the subsequent reaction is irregular in shape and easily aggregates and precipitates. The latter reason may be that nano manganese tetraoxide is easy to agglomerate in the absence of polyglutamic acid encapsulation, and the structure of the formed nano slow-release particles is unstable, and then agglomeration precipitation occurs.

[0088] The amino acid water-soluble fertilizer containing nanoenzymes prepared in Comparative Example 3 is easily precipitated under acidic conditions of pH 3. This is because the isoelectric point of the zein hydrolyzed polypeptide is around pH 3, and it is easy to agglomerate and then precipitate without polydopamine wrapping.

[0089] Test Example 2: Determination of the ability of amino acid water-soluble fertilizer to withstand rainwater erosion

[0090] Take the amino acid water-soluble fertilizer prepared in the examples and comparative examples, add the composite amino acid powder and stir to form the corresponding test samples. The test samples corresponding to Examples 1-5 and Comparative Example 3 were respectively diluted with water at a volume ratio of 1:300 to prepare the test sample working solution, and lycopene was added as an indicator at a mass ratio of 1:100000 to each working solution, and sprayed on the surface of rice leaves (variety is Xiangdao Longxiangyou 4876).

[0091] After 30 minutes of spraying, a sprayer was used to simulate rainfall (hand sprayer flow rate 1L / min, spray height 1m from the leaf, 10min). Five leaves were randomly taken for each treatment, and 5cm of the middle of each leaf was taken for photography. The staining ratio was calculated using software, and the staining ratio was subjected to completely randomized single factor statistical analysis by statistical software. The results are shown in Table 2 below. In Table 2, different lowercase letters a and b indicate significant differences at the 5% confidence level. Comparative Examples 1 and 2 were not tested because they did not pass the stability test.

[0092] Table 2 Test results of the rainwater erosion resistance of amino acid water-soluble fertilizer containing nanozymes

[0093] Preparation method Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 3 Dyeing ratio 90.45％a 88.32％a 93.17％a 86.91％a 77.62％a 3.43％b

[0094] The results in Table 2 above show that the amino acid water-soluble fertilizers containing polydopamine layers have strong rainwater erosion resistance, all exceeding 85%. The amino acid water-soluble fertilizer of Example 5 has the second best rainwater erosion resistance, which is 77.62%, due to the use of polyacrylamide as an adhesive. The rainwater erosion resistance of Comparative Example 3 without an adhesive layer is very poor, only 3.43%. This shows that the polydopamine nanolayer has excellent adhesion and rainwater erosion resistance.

[0095] Test Example 3: Evaluation of the yield-increasing and lodging-resistance effects of amino acid water-soluble fertilizer

[0096] Take the amino acid water-soluble fertilizer prepared in the embodiment and comparative example, add the composite amino acid powder and stir to form the corresponding test sample. Taking Xiangdaolongxiangyou 4876 as the test variety, the test samples corresponding to Examples 1-5 and Comparative Example 3 were applied once at the rice break stage and the full heading stage, respectively, with the commercially available amino acid water-soluble fertilizer Guoguang Four High as control 1, and with clean water as control 2; Examples 1-5 and Comparative Example 3 were applied 50mL each time, and the commercially available amino acid water-soluble fertilizer Guoguang Four High of Control 1 was applied 30mL each time according to the recommended dose. Two treatment methods were adopted: 1.5L of water was added for drone flight spraying (the commercially available amino acid water-soluble fertilizer Guoguang Four High did not declare that it could be sprayed by drone flight, so drone flight spraying was not carried out) and 30L of water was added for manual spraying, each treatment was 2 acres, and the interval between each treatment was more than 10m. Comparative Examples 1 and 2 were not measured because they did not pass the stability test.

[0097] When the rice was mature, each experimental area used a 5-point sampling method and harvested 1m 2 The yield per mu of rice was calculated. A 50 cm × 50 cm square was used with a tape measure to measure the lodging area. The lodging rate was calculated based on the proportion of the lodging area to the experimental area. The results are shown in Table 3 below.

[0098] Table 3 Evaluation results of yield increase and lodging resistance of amino acid water-soluble fertilizer containing nanozymes

[0099]

[0100] 1. Analysis of production increase effect

[0101] Compared with the pure water control, the yield of the amino acid water-soluble fertilizer containing nanozymes prepared in Examples 1-5 is significantly different from that of the latter, indicating that the amino acid water-soluble fertilizer containing nanozymes can significantly increase the yield and has the effect of increasing production.

[0102] The amino acid water-soluble fertilizer containing nanozymes prepared in Examples 1-4 has significant differences in yield compared with Comparative Example 3 and Control 1, indicating that polydopamine has a significant effect in resisting rain erosion, and polydopamine is wrapped outside the zein hydrolyzed polypeptide layer, which can significantly improve the yield-increasing effect of the amino acid water-soluble fertilizer containing nanozymes. Because it rained a little within 12 hours after application.

[0103] 2. Analysis of anti-lodging effect

[0104] The lodging rate of the amino acid water-soluble fertilizer containing nanozymes prepared by Examples 1-5 was 3.03%-22.89%, which was much lower than 83.49% of the clear water control, indicating that the amino acid water-soluble fertilizer containing nanozymes can greatly improve the lodging resistance of rice.

[0105] The lodging rates of the two fertilization methods of the amino acid water-soluble fertilizer containing nanozymes prepared in Comparative Example 3 were 78.36% and 75.23%, indicating that in the absence of an adhesive, the anti-lodging ability of the amino acid water-soluble fertilizer containing nanozymes decreased. Since it rained a little within 2 hours after fertilization, it is speculated that the rain washed away a large amount of the amino acid water-soluble fertilizer containing nanozymes without a dopamine outer layer, resulting in a significant decrease in the anti-lodging effect. The same phenomenon was also observed in the commercially available Guoguang Four High Group, with a lodging rate of 81.34%, which is close to the lodging rate of 83.49% in the clear water control group.

[0106] The above specific embodiments describe the implementation of the present invention in detail, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the claims and technical concept of the present invention, the technical solution of the present invention can be modified and changed in many simple ways, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. An amino acid water-soluble fertilizer containing nano-mimetic enzymes, characterized in that: The amino acid water-soluble fertilizer is a suspension, and its raw materials include manganese tetraoxide, and the particle size of manganese tetraoxide is 30-200nm; The raw materials also include the first material, the second material, water and the adhesive; the first material is one or more of polyglutamic acid and seaweed polysaccharide, and the amounts of manganese tetraoxide, the first material, the second material and the adhesive are (8-12):(6-10):(9-15):(10-14); the second material is zein hydrolyzed polypeptide and sodium tripolyphosphate in a mass ratio of (8-12):(1-3); the first material is coated on the surface of manganese tetraoxide, the second material is coated on the surface of the first material, and the adhesive is coated on the surface of the second material; The raw materials also include a pH regulator, and the pH value of the amino acid water-soluble fertilizer is 8.0-9.0; The adhesive is dopamine; The preparation method of the amino acid water-soluble fertilizer comprises the following steps: S1. Take the first material and add it into water to stir and dissolve, then add manganese tetraoxide and homogenize until the mixture is translucent; S2, adding the second material to the mixed solution obtained in step S1, and continuing to stir until the second material is completely dissolved; S3, adding an adhesive to the mixed solution obtained in step S2 while stirring until the adhesive is completely dissolved, and finally adding the pH adjuster, and continuing to stir to obtain a finished amino acid water-soluble fertilizer.

2. The amino acid water-soluble fertilizer containing nano-mimetic enzyme according to claim 1, characterized in that: The usage ratio of the trimanganese tetraoxide, the first material, the second material and the adhesive is 5:4:6:

6.

3. The amino acid water-soluble fertilizer containing nano-mimetic enzyme according to claim 1, characterized in that: The mass ratio of the zein hydrolyzed polypeptide to sodium tripolyphosphate is 6:

1.

4. The amino acid water-soluble fertilizer containing nano-mimetic enzyme according to claim 1, characterized in that: The particle size of the trimanganese tetraoxide is 40-60 nm.

5. The method for preparing the amino acid water-soluble fertilizer containing nano-mimetic enzyme according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Take the first material and add it into water to stir and dissolve, then add manganese tetraoxide and homogenize until the mixture is translucent; S2, adding the second material to the mixed solution obtained in step S1, and continuing to stir until the second material is completely dissolved; S3, adding an adhesive to the mixed solution obtained in step S2 while stirring until the adhesive is completely dissolved, and finally adding the pH adjuster, and continuing to stir to obtain a finished amino acid water-soluble fertilizer.

6. The use of the amino acid water-soluble fertilizer containing nano-mimetic enzymes according to any one of claims 1 to 4, characterized in that: Fertilization is carried out by spraying or aerial spraying.

7. The use of the amino acid water-soluble fertilizer containing nano-mimetic enzyme according to claim 6, characterized in that: When fertilizing by spraying, add water at a volume ratio of 1:(300-600) to make amino acid water-soluble fertilizer working solution during the crop reproductive growth period, spray at 15-30L / mu each time, and apply 1-3 times a season; When fertilizing by aerial spraying, during the reproductive growth period of crops, add water at a volume ratio of 1:(20-40) to make an amino acid water-soluble fertilizer working solution, spray it at a rate of 1-2L / mu each time, and apply it 1-3 times a season.

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