A microbial fertilizer special for soybean and a preparation method thereof

Abstract

The application discloses a special microbial bacterial fertilizer for soybean, which is prepared from the following raw materials in a mass ratio: amino acid, ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, copper sulfate pentahydrate, calcium chloride, sodium molybdate decahydrate, end-amino hyperbranched polymer, compound microbial agent and sodium borate decahydrate, wherein the mass ratio of the amino acid, ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, copper sulfate pentahydrate, calcium chloride, sodium molybdate decahydrate, end-amino hyperbranched polymer, compound microbial agent and sodium borate decahydrate is 6-18:1-2:1-2:1-2:1-2:0.1-1:1-2:1-3:1-2:1-2. The application further discloses a preparation method of the special microbial bacterial fertilizer for soybean. In the process of foliar spraying, the special microbial bacterial fertilizer for soybean is easy to form a special film, thereby delaying the waste of the fertilizer, reducing the erosion of the foliar fertilizer, greatly increasing the film forming strength of the end-amino hyperbranched polymer and the chelate product, protecting the plants, resisting pests and reducing the use of the special microbial bacterial fertilizer for soybean.

Description

Technical Field

[0001] This invention relates to the field of soybean foliar fertilizer technology, and in particular to a soybean-specific microbial fertilizer and its preparation method. Background Technology

[0002] As my country's fourth largest grain crop and also used for oilseeds, soybeans play a vital role in promoting rural economic development, increasing farmers' income, and ensuring national food security. With increasing research into plant nutrient absorption mechanisms, the importance of foliar fertilizers has become increasingly apparent. Foliar fertilizers bypass the root system, entering the plant directly through stomata on the leaf surface, where they are absorbed and utilized for plant metabolism. This reduced nutrient transport distance minimizes losses caused by root absorption and ensures nutrients reach the appropriate functional parts directly, resulting in rapid fertilizer effectiveness. Therefore, foliar fertilizers offer high utilization rates and can quickly supplement nutrition and improve crop quality.

[0003] In soybean cultivation, the proper application of foliar fertilizer can protect soybeans from pests and diseases; however, improper use of foliar fertilizer can also cause damage. If foliar fertilizer damage occurs on plants, the primary factor is likely the foliar fertilizer itself, involving three main aspects:

[0004] a. Phytotoxicity caused by different foliar fertilizer structures: Generally, foliar fertilizers that are highly water-soluble, inorganic, have small molecular weight, or contain heavy metals are prone to causing phytotoxicity; for example, most arsenic preparations, Bordeaux mixture, lime sulfur mixture, and other inorganic copper and inorganic sulfur preparations are prone to causing phytotoxicity such as leaf spots, withered leaves, scorching, and deformities.

[0005] b. Phytotoxicity caused by improper use of foliar fertilizers: such as misuse of foliar fertilizers, improper mixing of foliar fertilizers, excessive dosage, uneven application, short intervals, and application during the sensitive period of plants, can all easily cause phytotoxicity.

[0006] c. Phytotoxicity caused by problems with the quality of foliar fertilizers: such as excessive impurities, inaccurate dosage of additives and adjuvants, which affect emulsification performance or spray quality, or even change physicochemical properties, are also causes of phytotoxicity.

[0007] Soil physicochemical properties, such as sandy soil, infertile soil, and soil with low organic matter content, can lead to pesticide damage due to weak soybean growth and poor resistance to adverse conditions. In particular, the soil in these fields has poor adsorption of foliar fertilizers, making it more susceptible to pesticide damage when herbicides or insecticides and fungicides are applied. Currently, common methods for treating pesticide damage include spraying water to dilute and reduce the concentration of foliar fertilizers and spraying growth regulators. However, these methods are time-consuming and have limited effectiveness, especially for soybeans with severe pesticide damage.

[0008] However, with the development of research, more and more evidence shows that soybean crops can also absorb organic amino acids, and that amino acids can chelate with micronutrients, making micronutrients easier to absorb and greatly improving fertilizer utilization. Numerous studies have proven that amino acids can increase soybean yield and quality, enhance crop resistance, and improve the ecological environment. However, the low chelation rate between amino acids and micronutrients limits the development and application of amino acid fertilizers to some extent. In addition, they are very easy to fall off the surface of soybean crops after spraying, so the expected goals of increasing yield and quality are not achieved. Summary of the Invention

[0009] Based on the technical problems existing in the background technology, the present invention proposes a soybean-specific microbial fertilizer and its preparation method.

[0010] A soybean-specific microbial fertilizer comprises the following raw materials: amino acids, ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, copper sulfate pentahydrate, calcium chloride, sodium molybdate decahydrate, terminal amino hyperbranched polymer, compound microbial agent, and sodium borate decahydrate; the mass ratio of amino acids, ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, copper sulfate pentahydrate, calcium chloride, sodium molybdate decahydrate, terminal amino hyperbranched polymer, compound microbial agent, and sodium borate decahydrate is 6-18:1-2:1-2:1-2:1-2:0.1-1:1-2:1-3:1-2:1-2.

[0011] Preferably, the compound microbial agent includes: Bacillus amyloliquefaciens, Lactobacillus rhamnosus, and Streptococcus lactis.

[0012] Preferably, the concentration of Bacillus amyloliquefaciens is 1-3 × 10⁻⁶. 9 cfu / g, Lactobacillus rhamnosus concentration is 1-3×10 9 cfu / g, lactic acid streptococcus concentration is 3-5×10 7 cfu / g.

[0013] The above-mentioned method for preparing soybean-specific microbial fertilizer includes the following steps:

[0014] S1. Mix amino acids with water evenly, and add ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, and copper sulfate pentahydrate in sequence while stirring. Adjust the pH of the system to 6-6.5, heat to 65-75℃, stir for 1-2 hours, shear emulsify, and grind to obtain prechelated material a.

[0015] S2. Mix amino acids with water evenly, adjust the pH of the system to 4-5, add calcium chloride, shear emulsify, and grind to obtain prechelated material b.

[0016] S3. Mix prechelated material a and prechelated material b evenly, add sodium molybdate decahydrate while stirring, stir at high speed for 1-2 hours, add terminal amino hyperbranched polymer and compound bacterial agent, adjust the pH of the system to 2.5-3.2, add sodium borate decahydrate and continue stirring for 1-2 hours, cool to 45-55℃, stir at high speed for 1-2 hours to obtain soybean-specific microbial fertilizer.

[0017] Preferably, the mass ratio of the amino acid used in S1 to the amino acid used in S2 is 5-15:1-3.

[0018] Preferably, in S1, the amino acids are mixed evenly with water and then added to a reaction vessel preheated to 45-55°C.

[0019] Preferably, in S1, a colloid mill is used for shear grinding, and the grinding time is 2-4 hours.

[0020] Preferably, in S2, the temperature is maintained at 50-60°C during the shear emulsification process.

[0021] Preferably, in step S2, the grinding time is 1-2 hours.

[0022] Preferably, in step S3, water cooling is used to lower the temperature to 45-55°C.

[0023] Beneficial effects:

[0024] (1) This invention proposes a microbial foliar fertilizer that is easy to use, highly targeted, and shows results in a short time. It quickly solves the problem of pesticide damage to plants by selective absorption technology, allowing plants to grow healthily. At the same time, it changes the pesticide residue in the soil around the plants, providing a good soil environment for the healthy growth of plants.

[0025] (2) In this invention, ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, and copper sulfate pentahydrate are compounded and pre-chelated with amino acids, calcium chloride is pre-chelated with amino acids, and then sodium molybdate is mixed with the chelation products of the first two steps. The chelates formed by each element are stable and do not have poor compatibility. Moreover, by controlling the pH value of each step of the reaction, the precipitation of metal cations can be effectively avoided, and the presence of a large number of hydrogen ions can be avoided, which is not conducive to the chelation reaction. The soybean-specific microbial fertilizer obtained by this invention can improve fertilizer utilization and crop nutrient conversion rate, thereby producing a synergistic effect in nutrient absorption and significantly increasing yield and quality.

[0026] (3) The present invention adds a terminal amino hyperbranched polymer. Due to its large amount of internal cavity structure, it can provide a rich cavity structure as a carrier for the compound bacterial agent. By adjusting the pH value of the system to 2.5-3.2, the -NH2 on its surface can be converted into -NH3. +Then it chelates with borate, resulting in excellent stability. This invention enhances the enzymatic function of exogenous microorganisms, which not only promotes the formation of a good growth environment for plants and improves enzyme activity, but also has a strong adhesion effect on the leaf surface during spraying, resulting in increased yield and improved quality.

[0027] (4) During the foliar spraying process, the present invention can easily form a special film, delay the waste of fertilizer, reduce the erosion of foliar fertilizer, and the combination of HBP-NH2 and chelated products greatly increases the film strength, protects the plants, resists pests, and reduces the use of soybean-specific microbial fertilizer. Attached Figure Description

[0028] Figure 1 This is a comparison chart of the chelation rates of soybean-specific microbial fertilizers obtained in Example 5 and Comparative Examples 1-2.

[0029] Figure 2 This is a comparison chart of the change rates of various morphological indicators in Example 5, Comparative Example 1, and Comparative Example 2 at the full grain stage.

[0030] Figure 3 This is a comparison chart of antioxidant indicators and chlorophyll content between Example 5, Comparative Example 1, Comparative Example 2, and the blank control group.

[0031] Figure 4 This is a comparison chart of the rate of change of production indicators for Example 5, Comparative Example 1, and Comparative Example 2. Detailed Implementation

[0032] The technical solution of the present invention will now be described in detail through specific embodiments.

[0033] Example 1

[0034] A soybean-specific microbial fertilizer comprises the following raw materials: 6 kg glycine, 1 kg ferrous sulfate heptahydrate, 1 kg manganese sulfate monohydrate, 1 kg zinc sulfate heptahydrate, 1 kg copper sulfate pentahydrate, 0.1 kg calcium chloride, 1 kg sodium molybdate decahydrate, 1 kg terminal amino hyperbranched polymer, 1 kg compound microbial agent, and 1 kg sodium borate decahydrate.

[0035] The compound microbial agent includes: a concentration of 1×10 9 Bacillus amyloliquefaciens at a concentration of 1×10⁻⁶ CFU / g 9 Lactobacillus rhamnosus at a concentration of 3 × 10⁻⁶ CFU / g 7 CFU / g of lactic acid streptococci.

[0036] The above-mentioned method for preparing soybean-specific microbial fertilizer includes the following steps:

[0037] S1. Mix 5 kg of amino acids with 20 kg of water evenly and add them to a reaction vessel preheated to 45°C. While stirring, add ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, and copper sulfate pentahydrate in sequence. Adjust the pH of the system to 6-6.5, heat to 65°C, stir for 1 hour, emulsify by high-speed shearing, and then send it to a colloid mill for high-speed shearing grinding for 2 hours to obtain prechelated material a.

[0038] S2. Mix 1 kg of amino acids with 5 kg of water evenly, adjust the pH of the system to 4-5, add calcium chloride, emulsify by high-speed shearing at 50°C, and send it to a colloid mill for high-speed shearing and grinding for 1 hour to obtain pre-chelated material b.

[0039] S3. Mix prechelated material a and prechelated material b evenly, add sodium molybdate decahydrate while stirring, stir at high speed for 1 hour, add terminal amino hyperbranched polymer and compound bacterial agent, adjust the pH of the system to 2.5-3.2, add sodium borate decahydrate and continue stirring for 1 hour, cool down to 45℃ by water cooling, stir at high speed for 1 hour to obtain soybean-specific microbial fertilizer.

[0040] Example 2

[0041] A soybean-specific microbial fertilizer comprises the following raw materials: 18 kg glycine, 2 kg ferrous sulfate heptahydrate, 2 kg manganese sulfate monohydrate, 2 kg zinc sulfate heptahydrate, 2 kg copper sulfate pentahydrate, 1 kg calcium chloride, 2 kg sodium molybdate decahydrate, 3 kg terminal amino hyperbranched polymer, 2 kg compound microbial agent, and 2 kg sodium borate decahydrate.

[0042] The compound microbial agent includes: a concentration of 3×10 9 Bacillus amyloliquefaciens at a concentration of 3 × 10⁻⁶ CFU / g 9 Lactobacillus rhamnosus at a concentration of 5 × 10⁻⁶ CFU / g 7 CFU / g of lactic acid streptococci.

[0043] The above-mentioned method for preparing soybean-specific microbial fertilizer includes the following steps:

[0044] S1. Mix 15kg of amino acids with 40kg of water evenly and add them to a reaction vessel preheated to 55℃. While stirring, add ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, and copper sulfate pentahydrate in sequence. Adjust the pH of the system to 6-6.5, raise the temperature to 75℃, stir for 2 hours, emulsify by high-speed shearing, and then send it to a colloid mill for high-speed shearing grinding for 4 hours to obtain prechelated material a.

[0045] S2. Mix 3 kg of amino acids with 15 kg of water evenly, adjust the pH of the system to 4-5, add calcium chloride, emulsify by high-speed shearing at 60℃, and send it to a colloid mill for high-speed shearing and grinding for 2 hours to obtain pre-chelated material b.

[0046] S3. Mix prechelated material a and prechelated material b evenly, add sodium molybdate decahydrate while stirring, stir at high speed for 2 hours, add terminal amino hyperbranched polymer and compound bacterial agent, adjust the pH of the system to 2.5-3.2, add sodium borate decahydrate and continue stirring for 2 hours, cool down to 55℃ by water cooling, stir at high speed for 2 hours to obtain soybean-specific microbial fertilizer.

[0047] Example 3

[0048] A soybean-specific microbial fertilizer comprises the following raw materials: 12 kg glycine, 1.5 kg aspartic acid, 1 kg glutamic acid, 1.7 kg ferrous sulfate heptahydrate, 1.2 kg manganese sulfate monohydrate, 1.7 kg zinc sulfate heptahydrate, 1.2 kg copper sulfate pentahydrate, 0.7 kg calcium chloride, 1.2 kg sodium molybdate decahydrate, 2.5 kg terminal amino hyperbranched polymer, 1.3 kg compound microbial agent, and 1.8 kg sodium borate decahydrate.

[0049] The compound microbial agent includes: a concentration of 1.5 × 10⁻⁶. 9 Bacillus amyloliquefaciens at a concentration of 2.5 × 10⁻⁶ CFU / g. 9 Lactobacillus rhamnosus CFU / g at a concentration of 3.5 × 10⁻⁶ 7 CFU / g of lactic acid streptococci.

[0050] The above-mentioned method for preparing soybean-specific microbial fertilizer includes the following steps:

[0051] S1. Mix glycine with 25 kg of water evenly and add it to a reaction vessel preheated to 52°C. While stirring, add ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, and copper sulfate pentahydrate in sequence. Adjust the pH of the system to 6-6.5, raise the temperature to 68°C, stir for 100 min, emulsify by high-speed shearing, and then send it to a colloid mill for high-speed shearing grinding for 2.5 h to obtain prechelated material a.

[0052] S2. Mix aspartic acid, glutamic acid and 8kg of water evenly, adjust the pH of the system to 4-5, add calcium chloride, emulsify by high-speed shearing at 58℃, and send it to a colloid mill for high-speed shearing and grinding for 80min to obtain prechelated material b.

[0053] S3. Mix prechelated material a and prechelated material b evenly, add sodium molybdate decahydrate while stirring, stir at high speed for 100 min, add terminal amino hyperbranched polymer and compound bacterial agent, adjust the pH of the system to 2.5-3.2, add sodium borate decahydrate and continue stirring for 70 min, cool down to 52℃ by water cooling, stir at high speed for 70 min to obtain soybean-specific microbial fertilizer.

[0054] Example 4

[0055] A soybean-specific microbial fertilizer comprises the following raw materials: 7 kg glycine, 1 kg glutamic acid, 1.5 kg aspartic acid, 1.3 kg ferrous sulfate heptahydrate, 1.8 kg manganese sulfate monohydrate, 1.3 kg zinc sulfate heptahydrate, 1.8 kg copper sulfate pentahydrate, 0.3 kg calcium chloride, 1.8 kg sodium molybdate decahydrate, 1.5 kg terminal amino hyperbranched polymer, 1.7 kg compound microbial agent, and 1.2 kg sodium borate decahydrate.

[0056] The compound microbial agent includes: a concentration of 2.5 × 10⁻⁶. 9 Bacillus amyloliquefaciens at a concentration of 1.5 × 10⁻⁶ CFU / g. 9 Lactobacillus rhamnosus CFU / g at a concentration of 4.5 × 10⁻⁶ 7 CFU / g of lactic acid streptococci.

[0057] The above-mentioned method for preparing soybean-specific microbial fertilizer includes the following steps:

[0058] S1. Glycine, glutamic acid and 35 kg of water are mixed evenly and added to a reaction vessel preheated to 48°C. Ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate and copper sulfate pentahydrate are added sequentially while stirring. The pH of the system is adjusted to 6-6.5. The temperature is raised to 72°C and stirred for 80 min. After high-speed shear emulsification, it is sent to a colloid mill for high-speed shear grinding for 3.5 h to obtain prechelated material a.

[0059] S2. Mix aspartic acid with 12kg of water evenly, adjust the pH of the system to 4-5, add calcium chloride, emulsify by high-speed shearing at 52℃, and send it to a colloid mill for high-speed shearing and grinding for 100min to obtain prechelated material b.

[0060] S3. Mix prechelated material a and prechelated material b evenly, add sodium molybdate decahydrate while stirring, stir at high speed for 80 minutes, add terminal amino hyperbranched polymer and compound bacterial agent, adjust the pH of the system to 2.5-3.2, add sodium borate decahydrate and continue stirring for 110 minutes, cool down to 48℃ by water cooling, stir at high speed for 110 minutes to obtain soybean-specific microbial fertilizer.

[0061] Example 5

[0062] A soybean-specific microbial fertilizer comprises the following raw materials: 10 kg glycine, 2 kg threonine, 1.5 kg ferrous sulfate heptahydrate, 1.5 kg manganese sulfate monohydrate, 1.5 kg zinc sulfate heptahydrate, 1.5 kg copper sulfate pentahydrate, 0.5 kg calcium chloride, 1.5 kg sodium molybdate decahydrate, 2 kg terminal amino hyperbranched polymer, 1.5 kg compound microbial agent, and 1.5 kg sodium borate decahydrate.

[0063] The compound microbial agent includes: a concentration of 2×10 9Bacillus amyloliquefaciens at a concentration of 2 × 10⁻⁶ CFU / g 9 Lactobacillus rhamnosus at a concentration of 4 × 10⁻⁶ CFU / g 7 CFU / g of lactic acid streptococci.

[0064] The above-mentioned method for preparing soybean-specific microbial fertilizer includes the following steps:

[0065] S1. Mix glycine with 30kg of water evenly and add it to a reaction vessel preheated to 50℃. While stirring, add ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, and copper sulfate pentahydrate in sequence. Adjust the pH of the system to 6-6.5, heat to 70℃, stir for 90min, emulsify by high-speed shearing, and then send it to a colloid mill for high-speed shearing grinding for 3h to obtain prechelated material a.

[0066] S2. Mix threonine with 10kg of water evenly, adjust the pH of the system to 4-5, add calcium chloride, emulsify by high-speed shearing at 55℃, and send it to a colloid mill for high-speed shearing and grinding for 90min to obtain pre-chelated material b.

[0067] S3. Mix prechelated material a and prechelated material b evenly, add sodium molybdate decahydrate while stirring, stir at high speed for 90 minutes, add terminal amino hyperbranched polymer and compound bacterial agent, adjust the pH of the system to 2.5-3.2, add sodium borate decahydrate and continue stirring for 90 minutes, cool down to 50℃ by water cooling, stir at high speed for 90 minutes to obtain soybean-specific microbial fertilizer.

[0068] Comparative Example 1

[0069] A soybean-specific microbial fertilizer comprises the following raw materials: 10 kg glycine, 2 kg threonine, 1.5 kg ferrous sulfate heptahydrate, 1.5 kg manganese sulfate monohydrate, 1.5 kg zinc sulfate heptahydrate, 1.5 kg copper sulfate pentahydrate, 0.5 kg calcium chloride, 1.5 kg sodium molybdate decahydrate, 1.5 kg compound microbial agent, and 1.5 kg sodium borate decahydrate.

[0070] The compound microbial agent includes: a concentration of 2×10 9 Bacillus amyloliquefaciens at a concentration of 2 × 10⁻⁶ CFU / g 9 Lactobacillus rhamnosus at a concentration of 4 × 10⁻⁶ CFU / g 7 CFU / g of lactic acid streptococci.

[0071] The above-mentioned method for preparing soybean-specific microbial fertilizer includes the following steps:

[0072] S1. Mix glycine with 30kg of water evenly and add it to a reaction vessel preheated to 50℃. While stirring, add ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, and copper sulfate pentahydrate in sequence. Adjust the pH of the system to 6-6.5, heat to 70℃, stir for 90min, emulsify by high-speed shearing, and then send it to a colloid mill for high-speed shearing grinding for 3h to obtain prechelated material a.

[0073] S2. Mix threonine with 10kg of water evenly, adjust the pH of the system to 4-5, add calcium chloride, emulsify by high-speed shearing at 55℃, and send it to a colloid mill for high-speed shearing and grinding for 90min to obtain pre-chelated material b.

[0074] S3. Mix prechelated material a and prechelated material b evenly, add sodium molybdate decahydrate while stirring, stir at high speed for 90 minutes, add compound microbial agent, adjust the pH of the system to 2.5-3.2, add sodium borate decahydrate and continue stirring for 90 minutes, cool down to 50℃ using water cooling treatment, stir at high speed for 90 minutes to obtain soybean-specific microbial fertilizer.

[0075] Comparative Example 2

[0076] A soybean-specific microbial fertilizer comprises the following raw materials: 10 kg glycine, 2 kg threonine, 1.5 kg ferrous sulfate heptahydrate, 1.5 kg manganese sulfate monohydrate, 1.5 kg zinc sulfate heptahydrate, 1.5 kg copper sulfate pentahydrate, 0.5 kg calcium chloride, 1.5 kg sodium molybdate decahydrate, 2 kg terminal amino hyperbranched polymer, 1.5 kg compound microbial agent, and 1.5 kg sodium borate decahydrate.

[0077] The compound microbial agent includes: a concentration of 2×10 9 Bacillus amyloliquefaciens at a concentration of 2 × 10⁻⁶ CFU / g 9 Lactobacillus rhamnosus at a concentration of 4 × 10⁻⁶ CFU / g 7 CFU / g of lactic acid streptococci.

[0078] The above-mentioned method for preparing soybean-specific microbial fertilizer includes the following steps:

[0079] S1. Glycine, threonine and 40kg water are mixed evenly. Ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, copper sulfate pentahydrate and calcium chloride are added in sequence under stirring. High-speed shear emulsification is carried out at 55℃. Then it is sent to a colloid mill for high-speed shear grinding for 4.5h to obtain prechelated material.

[0080] S2. Continue stirring the prechelated material, add sodium molybdate decahydrate while stirring, stir at high speed for 90 minutes, add terminal amino hyperbranched polymer and compound bacterial agent, adjust the pH of the system to 2.5-3.2, add sodium borate decahydrate and continue stirring for 90 minutes, cool down to 50℃ using water cooling treatment, stir at high speed for 90 minutes to obtain soybean-specific microbial fertilizer.

[0081] The chelation rate of the soybean-specific microbial fertilizers obtained in Example 5 and Comparative Examples 1-2 was determined. Since amino acid metal ion chelates are poorly soluble in organic solvents, while free metal ions are readily soluble, the amino acid metal ion chelates form an inner complex salt structure through coordination bonds, exhibiting good stability. However, the stability constant of the EDTA-M complex is much larger than that of the amino acid metal chelate. Therefore, the metal element in the sample can be directly determined using organic solvent precipitation and EDTA complexometric titration to calculate the chelation rate. The specific operation is as follows:

[0082] Wash the Erlenmeyer flask thoroughly and rinse it with distilled water. Add 3 drops of orange dimethylformate solution to the sample. The solution will turn wine red. Perform a pre-titration with 0.02 mol / L EDTA solution to find the titration endpoint. After the titration is completed, the solution should turn yellow, and this should be used as a reference for the titration endpoint.

[0083] Take 12.5 mL of the sample into a clean 250 mL volumetric flask, dilute to volume with distilled water, and mix well. Take 25 mL of the diluted liquid into a clean 250 mL Erlenmeyer flask, and add 3 drops of diformate orange indicator. Titrate with 0.02 mol / L EDTA solution. Record the volume of solution consumed, V0.

[0084] Take 12.5 mL of the solution and place it into six clean 50 mL centrifuge tubes. Add 25 mL of 95% ethanol to each tube, stir thoroughly in a 40 °C water bath for 5 min, and let stand for 10 min. Centrifuge at 4800 rpm for 15 min. Discard the supernatant, redissolve the precipitate with distilled water, and pour the redissolved solution from two tubes into a 250 mL Erlenmeyer flask. Shake well, add 3 drops of orange diformate indicator, and titrate with 0.02 mol / L EDTA solution. Calculate the volume of solution consumed, V1.

[0085] Chelation rate = V1 ÷ V0 × 100%

[0086] like Figure 1As shown, Example 5 exhibits the highest chelation rate, exceeding 90%. The applicant believes this is because the present invention pre-chelates ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, and copper sulfate pentahydrate with glycine, while calcium chloride is pre-chelated with threonine. Then, sodium molybdate is mixed with the chelation products from the first two steps. The resulting chelates are stable and do not exhibit poor compatibility. Furthermore, controlling the pH value of each reaction step effectively prevents the precipitation of metal cations and avoids the presence of excessive hydrogen ions, which is detrimental to the chelation reaction. The present invention further employs a terminal amino hyperbranched polymer to chelate with borate, further enhancing the chelation rate.

[0087] Field trials were conducted at a soybean-specific microbial fertilizer obtained in Example 5 and Comparative Examples 1-2 at a planting base in Anhui Province. Details are as follows:

[0088] The soil type at the experimental site was alluvial soil, with a light loam texture. The soil physicochemical properties were as follows: pH = 8.5, organic matter 21.27 g / kg, available nitrogen 125.6 mg / kg, available phosphorus 18.59 mg / kg, and available potassium 191.45 mg / kg. The previous crop was corn, and the fertilizer application rate per mu (667 square meters) was 300 kg of organic fertilizer + 50 kg of compound fertilizer (15-15-15).

[0089] Xu Dou 14 was used as the experimental subject. This comparative experiment employed a completely randomized block design, with four groups (blank control group, Example 5 group, Comparative Example 1 group, and Comparative Example 2 group), each with three replicates. The plot area was 6m × 5m. Sowing was carried out in late May at a density of 36 seeds / m². 2 When the third compound leaf unfolds, the seedlings are thinned out, retaining 12 seedlings per square meter.

[0090] In Example 5, Comparative Example 1, and Comparative Example 2, foliar spraying was performed once each at the initial flowering, pod-forming, and grain-forming stages of soybeans. Each sample was sprayed with 50 mL (diluted 200 times) per acre, while the blank control group was sprayed with an equal amount of water. Other field management practices remained consistent and followed conventional methods.

[0091] During the full grain stage, morphological indicators such as soybean plant height, number of compound leaves, number of effective branches, number of main stem nodes, and number of pods per plant were measured. The middle leaf of the third fully unfolded compound leaf from the top of the soybean plant was taken to measure peroxidase activity, superoxide dismutase activity, and chlorophyll content.

[0092] The change rate of a certain indicator in a certain group is calculated as follows: (Value of the indicator in the group - Value of the indicator in the blank control group) ÷ Value of the indicator in the blank control group × 100%

[0093] like Figure 2 and Figure 3As shown, during the full grain stage, the morphological index change rate of the 5th group was the highest, and the peroxidase activity, superoxide dismutase activity and chlorophyll content were also the highest.

[0094] The applicant believes that this invention is due to its ability to easily form a special film during foliar spraying, thus delaying fertilizer waste and reducing the erosion caused by soybean-specific microbial fertilizers. The combination of terminal amino hyperbranched polymer (HBP-NH2) and chelated products effectively enhances the absorption of micronutrients by soybean plants and greatly increases film strength, protecting plants and resisting pests. Furthermore, the large number of hollow structures inside the terminal amino hyperbranched polymer provides abundant hollow structures as a carrier for the compound microbial agent. By enhancing the enzymatic function of exogenous microorganisms, it creates a favorable internal and external growth environment for soybean plants, improves enzyme activity, and further increases the chlorophyll content of leaves, thereby enhancing the accumulation of organic matter in the plants.

[0095] Nine soybean plants were randomly selected from each group at the full maturity stage to determine yield indicators such as the number of grains per plant, grain weight per plant, and weight of 100 grains.

[0096] The change rate of a certain indicator in a certain group is calculated as follows: (Value of the indicator in the group - Value of the indicator in the blank control group) ÷ Value of the indicator in the blank control group × 100%

[0097] like Figure 4 As shown, the yield indicators of Example 5 group and Comparative Examples 1-2 group were better than those of the blank control group, indicating that foliar fertilizer application to soybeans can significantly improve their yield traits; and the yield indicators of Example 5 group were better than those of the comparative examples group, confirming that the soybean-specific microbial fertilizer obtained by the present invention can improve fertilizer utilization and crop nutrient conversion rate, thereby producing a synergistic effect on nutrient absorption and significantly increasing yield and quality.

[0098] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A soybean-specific microbial fertilizer, characterized in that, Its raw materials include: amino acids, ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, copper sulfate pentahydrate, calcium chloride, sodium molybdate decahydrate, amino-terminated hyperbranched polymer, compound bacterial agent, and sodium borate decahydrate; the mass ratio of amino acids, ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, copper sulfate pentahydrate, calcium chloride, sodium molybdate decahydrate, amino-terminated hyperbranched polymer, compound bacterial agent, and sodium borate decahydrate is 6-18:1-2:1-2:1-2:1-2:0.1-1:1-2:1-3:1-2:1-2; The following steps are used to prepare it: S1. Mix amino acids with water evenly, and add ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, and copper sulfate pentahydrate in sequence while stirring. Adjust the pH of the system to 6-6.5, heat to 65-75℃, stir for 1-2 hours, shear emulsify, and grind to obtain prechelated material a. S2. Mix amino acids with water evenly, adjust the pH of the system to 4-5, add calcium chloride, shear emulsify, and grind to obtain prechelated material b. S3. Mix prechelated material a and prechelated material b evenly, add sodium molybdate decahydrate while stirring, stir at high speed for 1-2 hours, add terminal amino hyperbranched polymer and compound bacterial agent, adjust the pH of the system to 2.5-3.2, add sodium borate decahydrate and continue stirring for 1-2 hours, cool to 45-55℃, stir at high speed for 1-2 hours to obtain soybean-specific microbial fertilizer.

2. The soybean-specific microbial fertilizer according to claim 1, characterized in that, The compound microbial agent includes: Bacillus amyloliquefaciens, Lactobacillus rhamnosus, and Streptococcus lactis.

3. The soybean-specific microbial fertilizer according to claim 2, characterized in that, The concentration of Bacillus amyloliquefaciens is 1-3 × 10⁻⁶. 9 cfu / g, Lactobacillus rhamnosus concentration is 1-3×10 9 cfu / g, lactic acid streptococcus concentration is 3-5×10 7 cfu / g.

4. A method for preparing soybean-specific microbial fertilizer as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Mix amino acids and water evenly, and while stirring, add ferrous sulfate heptahydrate, manganese sulfate monohydrate, zinc sulfate heptahydrate, and copper sulfate pentahydrate in sequence. Adjust the pH of the system to 6-6.5, heat to 65-75℃, stir for 1-2 hours, shear emulsify, and grind to obtain the pre-chelated material. a ; S2. Mix amino acids and water evenly, adjust the pH of the system to 4-5, add calcium chloride, shear emulsify, and grind to obtain the pre-chelated material. b ; S3, Prechelated material a Prechelated materials b Mix thoroughly, add sodium molybdate decahydrate while stirring, stir at high speed for 1-2 hours, add terminal amino hyperbranched polymer and compound bacterial agent, adjust the pH of the system to 2.5-3.2, add sodium borate decahydrate and continue stirring for 1-2 hours, cool to 45-55℃, stir at high speed for 1-2 hours to obtain soybean-specific microbial fertilizer.

5. The method for preparing soybean-specific microbial fertilizer according to claim 4, characterized in that, The mass ratio of amino acids used in S1 to those used in S2 is 5-15:1-3.

6. The method for preparing soybean-specific microbial fertilizer according to claim 4, characterized in that, In S1, amino acids are mixed evenly with water and then added to a reaction vessel preheated to 45-55℃.

7. The method for preparing soybean-specific microbial fertilizer according to claim 4, characterized in that, In S1, a colloid mill is used for shear grinding, and the grinding time is 2-4 hours.

8. The method for preparing soybean-specific microbial fertilizer according to claim 4, characterized in that, In S2, the temperature is maintained at 50-60℃ during the shear emulsification process.

9. The method for preparing soybean-specific microbial fertilizer according to claim 4, characterized in that, In S2, the grinding time is 1-2 hours.

10. The method for preparing soybean-specific microbial fertilizer according to claim 4, characterized in that, In S3, water cooling is used to lower the temperature to 45-55℃.

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