Aminobutyric acid synergistic fertilizer and preparation method thereof

Abstract

The invention discloses an aminobutyric acid synergistic fertilizer and a preparation method thereof, and belongs to the technical field of fertilizers. The synergistic fertilizer comprises the following raw materials in parts by weight: 80-90 parts of fertilizer effect particles and 20-40 parts of a coating solution. The coating solution is prepared by the following steps: adding modified chitosan into an acetic acid solution with the volume concentration of 1%, and uniformly stirring at 300-500r / min to obtain the coating solution, and a preparation method of the modified chitosan comprises the following steps: adding chitosan into a citric acid solution, stirring until the chitosan is dissolved, then adding epoxy chloropropane, stirring at 400r / min for 4 hours, then adding humic acid, and stirring for 0.5 hour to obtain a mixed solution; dropwise adding the mixed solution into a 0.2 mol / L NaOH solution, stirring for 12 hours, eluting residual NaOH in a product with distilled water, drying at 80 DEG C for 12 hours, taking out, and grinding into powder, so as to obtain the modified chitosan. The aminobutyric acid synergistic fertilizer prepared by the invention has excellent slow release performance.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizers, and in particular relates to an aminobutyric acid synergistic fertilizer and a preparation method thereof. Background Art

[0002] Fertilizers contribute 40%-60% to crop yields. Fertilizer application is an important measure to ensure food security, but the fertilizer utilization rate has long been around 30%-45%.

[0003] As an active substance, synergistic fertilizer can increase the absorption of nutrients by crops through methods such as nitrogen fixation, and can also play a certain regulatory role in the growth of crops. It is usually added to conventional fertilizers, which can appropriately reduce the amount of fertilizer applied and improve the utilization rate of fertilizers.

[0004] GABA (usually γ-aminobutyric acid) is a synergistic fertilizer that can regulate nitrogen metabolism in plants and promote nitrogen absorption and transport. GABA can accelerate starch decomposition by activating amylase, increase the absorption and utilization of amino acids to maintain seed growth, and reduce oxidative damage by enhancing antioxidant enzyme defense, thereby improving crop resistance. It has broad application prospects.

[0005] Patent CN114276181 B announced a multifunctional fertilizer synergist composed of polyglutamic acid of different molecular weights. The patented synergist consists of the following components by weight: 50-400 parts of low molecular weight poly-γ-glutamic acid (1KD-10KD), 50-500 parts of medium molecular weight poly-γ-glutamic acid (10KD-300KD), 100-500 parts of high molecular weight poly-γ-glutamic acid (300KD-1500KD), 100-500 parts of ultra-high molecular weight poly-γ-glutamic acid (1500KD-8000KD), 20-50 parts of aminobutyric acid, 1-10 parts of DCD, and 1-10 parts of NBPT. The fertilizer synergist has obvious growth-promoting and stress-resistant functions. However, the synergistic fertilizer prepared by the patent and the prior art still has the problem of poor performance such as slow release. Summary of the invention

[0006] In order to solve the problem that the synergistic fertilizer prepared by the prior art in the background technology still has poor performance such as slow release, the present invention provides an aminobutyric acid synergistic fertilizer and a preparation method thereof.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] A GABA synergistic fertilizer comprises the following raw materials in parts by weight: 80-90 parts of fertilizer granules and 20-40 parts of coating solution.

[0009] Furthermore, the fertilizer granules are prepared by the following steps:

[0010] Dissolve γ-aminobutyric acid and glycine in water to obtain a mixed solution a; dissolve nitrogen, phosphorus and potassium fertilizers and trace elements in water to obtain a mixed solution b; add the mixed solution a to the mixed solution b, stir, and then perform spray drum granulation to obtain fertilizer granules, and control the particle size of the fertilizer granules to be 2.5-3 mm.

[0011] Among them, the dosage ratio of γ-aminobutyric acid, glycine and water is 40-60g:20-30g:160mL; the dosage ratio of nitrogen, phosphorus and potassium fertilizers, trace elements and water is 1.5-1.7kg:5-8g:2L; the volume ratio of mixed solution a and mixed solution b is 1:12.5.

[0012] Furthermore, the nitrogen, phosphorus and potassium fertilizer includes the following raw materials in parts by weight: 25-30 parts of urea, 5-13 parts of potassium sulfate, 10-15 parts of monoammonium phosphate, and 10-15 parts of ammonium chloride.

[0013] Furthermore, the trace elements are a mixture of zinc sulfate heptahydrate, manganese sulfate, and ammonium molybdate in a mass ratio of 1:1:1.

[0014] Further, the coating solution is prepared by the following steps:

[0015] The modified chitosan is added into an acetic acid solution with a volume concentration of 1%, and stirred evenly at 300-500 r / min to obtain a coating solution.

[0016] The dosage ratio of the modified chitosan to the acetic acid solution with a volume concentration of 1% is 20-45 g: 90-110 mL.

[0017] Further, the modified chitosan is prepared by the following steps:

[0018] Add chitosan to 0.3 mol / L citric acid solution, stir until chitosan is dissolved, then add epichlorohydrin, stir at 400 r / min for 4 hours, then add humic acid, stir at 500 r / min for 0.5 hour to obtain a mixed solution; drop the mixed solution into 0.2 mol / L NaOH solution, stir for 12 hours, elute the residual NaOH in the product with distilled water, dry at 80°C for 12 hours, take out and grind into powder to obtain modified chitosan.

[0019] Among them, the dosage ratio of chitosan, 0.3 mol / L citric acid solution, epichlorohydrin, and humic acid is 3g:50mL:2mL:3g; the volume ratio of the mixed solution to 0.2 mol / L NaOH solution is 1:1.

[0020] A method for preparing an aminobutyric acid synergistic fertilizer comprises the following steps:

[0021] The fertilizer particles are placed in a spray drum granulator, and the coating solution is coated on the surface of the fertilizer particles while the particles are rotating. The particles are dried in an oven at 30°C to obtain aminobutyric acid enhanced fertilizers. The particle size of the slow-release fertilizer particles is controlled to be 4-6 mm.

[0022] Beneficial effects of the present invention:

[0023] 1. The present invention uses modified chitosan as a coating agent for fertilizer-effective particles. The modified chitosan contains humic acid. Chitosan is a natural high-molecular polysaccharide with good film-forming and adhesion properties. Humic acid has good sustained-release properties. When chitosan and humic acid are combined, a dense protective film is formed to embed the fertilizer-effective particles inside. This embedding structure can slow down the release rate of fertilizer nutrients, so that the nutrients are gradually released in the soil for continuous absorption and utilization by crops.

[0024] 2. Humic acid has strong ion exchange and adsorption capacity, which can + , Ca 2+ The humic acid and chitosan compounds combine with harmful ions to form water-insoluble clusters or complexes. These clusters or complexes are relatively stable in the soil and are not easily absorbed by plants, thus effectively reducing the salt concentration in the soil. The reduction in salt concentration is conducive to plants to better absorb water and nutrients, reducing the adverse effects of salt stress on plant growth, so that the GABA fertilizer has the ability to alleviate saline-alkali land stress; and humic acid and chitosan themselves have good antibacterial properties, so that the GABA fertilizer also has bactericidal properties, expanding the application scenarios of the fertilizer.

[0025] 3. The fertilizer granules of the present invention contain γ-aminobutyric acid and glycine. γ-aminobutyric acid mainly promotes growth by regulating signal transduction and metabolic pathways in plants, while glycine is more of a supplementary source of amino acids to meet the growth needs of plants. When the two act together, a synergistic effect can be produced, further promoting the growth and development of plants. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The chitosan in the present invention has a molecular weight of 60 KDa and a deacetylation degree of 90%, which is purchased from Shanghai Yuanye Biotechnology Co., Ltd.; humic acid is purchased from Sinopharm Group Co., Ltd.; and glycine is food-grade glycine, which is purchased from Henan Siyuan Biotechnology Co., Ltd.

[0028] Example 1

[0029] The modified chitosan of the present embodiment is prepared by the following steps:

[0030] Add 3 g of chitosan to 50 mL of 0.3 mol / L citric acid solution, stir until the chitosan is dissolved, then add 2 mL of epichlorohydrin, stir at 400 r / min for 4 h, then add 3 g of humic acid, stir at 500 r / min for 0.5 h to obtain a mixed solution; drop 50 mL of the mixed solution into 50 mL of 0.2 mol / L NaOH solution, stir for 12 h, elute the residual NaOH in the product with distilled water, dry at 80°C for 12 h, take out and grind into powder to obtain modified chitosan.

[0031] Example 2

[0032] The coating solution of this embodiment is prepared by the following steps:

[0033] 20 g of modified chitosan was added into 90 mL of acetic acid solution with a volume concentration of 1%, and stirred evenly at 300 r / min to obtain a coating solution.

[0034] The preparation steps of modified chitosan are the same as those in Example 1.

[0035] Example 3

[0036] The coating solution of this embodiment is prepared by the following steps:

[0037] 30 g of modified chitosan was added into 100 mL of acetic acid solution with a volume concentration of 1%, and stirred evenly at 400 r / min to obtain a coating solution.

[0038] The preparation steps of modified chitosan are the same as those in Example 1.

[0039] Example 4

[0040] The coating solution of this embodiment is prepared by the following steps:

[0041] 45 g of modified chitosan was added into 110 mL of acetic acid solution with a volume concentration of 1%, and stirred evenly at 500 r / min to obtain a coating solution.

[0042] The preparation steps of modified chitosan are the same as those in Example 1.

[0043] Comparative Example 1

[0044] The coating solution of this comparative example is prepared by the following steps:

[0045] 20 g of chitosan was added into 90 mL of acetic acid solution with a volume concentration of 1%, and stirred evenly at 300 r / min to obtain a coating solution.

[0046] Example 5

[0047] The fertilizer granules of this embodiment are made by the following steps:

[0048] Dissolve 40g of γ-aminobutyric acid and 20g of glycine in 160mL of water to obtain a mixture a; dissolve 1.5kg of nitrogen, phosphorus and potassium fertilizers and 5g of trace elements in 2L of water to obtain a mixture b; add 160mL of the mixture a to 2L of the mixture b, stir, and then perform spray drum granulation to obtain fertilizer granules, and control the particle size of the fertilizer granules to be 2.5mm.

[0049] The nitrogen, phosphorus and potassium fertilizer comprises the following raw materials in parts by weight: 25 parts of urea, 5 parts of potassium sulfate, 10 parts of monoammonium phosphate, and 10 parts of ammonium chloride.

[0050] The trace elements are a mixture of zinc sulfate heptahydrate, manganese sulfate, and ammonium molybdate in a mass ratio of 1:1:1.

[0051] Example 6

[0052] The fertilizer granules of this embodiment are made by the following steps:

[0053] Dissolve 50g of γ-aminobutyric acid and 25g of glycine in 160mL of water to obtain a mixture a; dissolve 1.5kg of nitrogen, phosphorus and potassium fertilizers and 5g of trace elements in 2L of water to obtain a mixture b; add 160mL of the mixture a to 2L of the mixture b, stir, and then perform spray drum granulation to obtain fertilizer granules, and control the particle size of the fertilizer granules to be 2.7mm.

[0054] The nitrogen, phosphorus and potassium fertilizer comprises the following raw materials in parts by weight: 28 parts of urea, 7 parts of potassium sulfate, 13 parts of monoammonium phosphate, and 13 parts of ammonium chloride.

[0055] The trace elements are a mixture of zinc sulfate heptahydrate, manganese sulfate, and ammonium molybdate in a mass ratio of 1:1:1.

[0056] Example 7

[0057] The fertilizer granules of this embodiment are made by the following steps:

[0058] Dissolve 60g of γ-aminobutyric acid and 30g of glycine in 160mL of water to obtain a mixture a; dissolve 1.5kg of nitrogen, phosphorus and potassium fertilizers and 5g of trace elements in 2L of water to obtain a mixture b; add 160mL of the mixture a to 2L of the mixture b, stir, and then perform spray drum granulation to obtain fertilizer granules, and control the particle size of the fertilizer granules to be 3mm.

[0059] The nitrogen, phosphorus and potassium fertilizer comprises the following raw materials in parts by weight: 30 parts of urea, 13 parts of potassium sulfate, 15 parts of monoammonium phosphate, and 15 parts of ammonium chloride.

[0060] The trace elements are a mixture of zinc sulfate heptahydrate, manganese sulfate, and ammonium molybdate in a mass ratio of 1:1:1.

[0061] Comparative Example 2

[0062] The fertilizer granules of this comparative example are made by the following steps:

[0063] Dissolve 60g of γ-aminobutyric acid in 160mL of water to obtain a γ-aminobutyric acid solution; dissolve 1.5kg of nitrogen, phosphorus and potassium fertilizers and 5g of trace elements in 2L of water to obtain a mixed solution b; add 160mL of the γ-aminobutyric acid solution to 2L of the mixed solution b, stir, and then perform spray drum granulation to obtain fertilizer granules, and control the particle size of the fertilizer granules to be 2.5mm.

[0064] The nitrogen, phosphorus and potassium fertilizer comprises the following raw materials in parts by weight: 25 parts of urea, 5 parts of potassium sulfate, 10 parts of monoammonium phosphate, and 10 parts of ammonium chloride.

[0065] The trace elements are a mixture of zinc sulfate heptahydrate, manganese sulfate, and ammonium molybdate in a mass ratio of 1:1:1.

[0066] Comparative Example 3

[0067] The fertilizer granules of this comparative example are made by the following steps:

[0068] Dissolve 60g of glycine in 160mL of water to obtain a glycine solution; dissolve 1.5kg of nitrogen, phosphorus and potassium fertilizers and 5g of trace elements in 2L of water to obtain a mixed solution b; add 160mL of the glycine solution to 2L of the mixed solution b, stir, and then perform spray drum granulation to obtain fertilizer granules, and control the particle size of the fertilizer granules to be 2.5mm.

[0069] The nitrogen, phosphorus and potassium fertilizer comprises the following raw materials in parts by weight: 25 parts of urea, 5 parts of potassium sulfate, 10 parts of monoammonium phosphate, and 10 parts of ammonium chloride.

[0070] The trace elements are a mixture of zinc sulfate heptahydrate, manganese sulfate, and ammonium molybdate in a mass ratio of 1:1:1.

[0071] Example 8

[0072] A GABA synergistic fertilizer comprises the following raw materials in parts by weight: 80 parts of fertilizer granules prepared in Example 5 and 20 parts of coating solution prepared in Example 2.

[0073] The fertilizer particles are placed in a spray drum granulator, and the coating solution is coated on the surface of the fertilizer particles while the particles are rotating. The particles are dried in an oven at 30°C to obtain aminobutyric acid enhanced fertilizers. The particle size of the slow-release fertilizer particles is controlled to be 4 mm.

[0074] Example 9

[0075] A GABA synergistic fertilizer comprises the following raw materials in parts by weight: 85 parts of fertilizer granules prepared in Example 6 and 30 parts of coating solution prepared in Example 3.

[0076] The fertilizer granules are placed in a spray drum granulator, and the coating solution is coated on the surface of the fertilizer granules while the granules are rotating. The granules are dried in an oven at 30°C to obtain aminobutyric acid enhanced fertilizers. The particle size of the slow-release fertilizer granules is controlled to be 5 mm.

[0077] Example 10

[0078] A GABA synergistic fertilizer comprises the following raw materials in parts by weight: 90 parts of fertilizer granules prepared in Example 7 and 40 parts of coating solution prepared in Example 4.

[0079] The fertilizer particles are placed in a spray drum granulator, and the coating solution is coated on the surface of the fertilizer particles while the particles are rotating. The particles are dried in an oven at 30°C to obtain aminobutyric acid enhanced fertilizers. The particle size of the slow-release fertilizer particles is controlled to be 6 mm.

[0080] Comparative Example 4

[0081] The raw materials and steps of this comparative example are the same as those of Example 8, except that the coating solution uses the raw materials prepared in Comparative Example 1.

[0082] Comparative Example 5

[0083] The raw materials and steps of this comparative example are the same as those of Example 8, except that the fertilizer granules are the material prepared in Comparative Example 2.

[0084] Comparative Example 6

[0085] The raw materials and steps of this comparative example are the same as those of Example 8, except that the fertilizer granules are the material prepared in Comparative Example 3.

[0086] Performance tests were performed on Examples 8 to 10 and Comparative Examples 4 to 6, and the test items were as follows:

[0087] 1. Sustained release: Determined by water dissolution rate method according to GB / T 23348-2009; 10 g of the synergistic fertilizer prepared in Examples 8 to 10 and Comparative Example 4 was weighed and put into a small bag made of 100-mesh nylon gauze, the small bag was put into a 250 mL glass bottle, 200 mL of water was added, the bottle was sealed with a cover, and placed in a 25°C biochemical constant temperature incubator, and samples were taken at 1, 7, 28, 36, and 42 days, and the nitrogen release was tested by an automatic analyzer, and the cumulative nitrogen release rate was calculated. The calculation formula is as follows: nitrogen release rate = Wn / W, where Wn is the mass fraction of the nitrogen release measured on the nth day, and W is the mass fraction of the total nitrogen. The test results are shown in Table 1.

[0088] 2. Soil improvement field experiment: The test site was selected in a high-cold area, and the soil organic matter content (0.85%) and soil salt content (0.37%) in the test soil were tested; rice planting was used for testing. In the experiment, the synergistic fertilizers prepared in Examples 8-10 and Comparative Example 4 were used for fertilization to ensure that the fertilizer content of the experimental products was the same, and 120 kg of fertilizer was applied per mu. The measurement results are shown in Table 2.

[0089] 3. Bactericidal performance: 2 kg of the synergistic fertilizer prepared in Examples 8-10 and Comparative Example 4 was dissolved in 10 L of water. The volume of the synergistic fertilizer per mu of land was 10 L. Referring to "GB / T17980.19-2000 Guidelines for Field Efficacy Tests of Pesticides (I) Control of Rice Leaf Diseases with Fungicides", the area of ​​each zone was 30 m2, 4 replicates were set, and the pesticide was applied twice, with an interval of 7 days between each application. The pesticide was investigated 7d and 14d after each application, respectively. The classification was carried out according to the relevant data investigation standard, the disease index was statistically calculated, and the prevention effect was calculated. The test results are shown in Table 3.

[0090] 4. Synergistic test: 200g of the synergistic fertilizer prepared by Example 8, Comparative Example 5 and Comparative Example 6 was dissolved in 1L of water, and a soil potted test of pakchoi was carried out in a greenhouse. A total of 30 pakchoi plants were planted. During the period of three leaves and one heart of pakchoi, the three synergistic fertilizers were evenly sprayed on the leaves of 10 pakchoi plants until they were wet. The second and third sprays were applied on the 5th and 10th days after the first spraying. One month after the third spraying, the pakchoi was harvested, and the fresh weight and dry weight of the aboveground part and root system of the pakchoi were measured. The test results are shown in Table 4.

[0091] Table 1

[0092] project 1d dissolution rate 7d dissolution rate 28d dissolution rate 56d dissolution rate 70d dissolution rate Example 8 1.5％ 6.4％ 35.6％ 74.4％ 96.8％ Example 9 1.2％ 6.1％ 35.1％ 74.1％ 96.5％ Example 10 1.1％ 5.9％ 34.2％ 73.8％ 96.1％ Comparative Example 4 2.3％ 8.4％ 37.8％ 80.2％ 98.4％

[0093] It can be seen from Table 1 that the dissolution rates of the enhanced fertilizers prepared in Examples 8 to 10 are all lower than that of Comparative Example 4, indicating that modified chitosan as a coating agent for fertilizer particles can effectively improve the sustained-release performance of the enhanced fertilizer.

[0094] Table 2

[0095]

[0096]

[0097] It can be seen from Table 2 that the use of the synergistic fertilizers prepared in Examples 8 to 10 has a significant improvement effect on the soil organic matter content and soil salt content, and the rice fruit setting rate is also significantly improved. The improvement effect of soil organic matter content, soil salt content and rice fruit setting rate are better than those of Comparative Example 4.

[0098] Table 3

[0099] It can be seen from Table 3 that the antibacterial effect of the enhanced fertilizers prepared in Examples 8 to 10 is higher than the antibacterial effect of the enhanced fertilizer prepared in Comparative Example 4.

[0100] Table 4

[0101]

[0102]

[0103] It can be seen from Table 4 that the enhanced fertilizer prepared in Example 8 can effectively promote the growth and development of pakchoi compared with the enhanced fertilizer prepared in Comparative Examples 5 and 6, indicating that there is a synergistic effect between γ-aminobutyric acid and glycine, and the simultaneous presence of the two can promote the growth and development of plants.

[0104] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0105] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A GABA synergistic fertilizer, characterized in that: The invention comprises the following raw materials in parts by weight: 80-90 parts of fertilizer-effective particles and 20-40 parts of coating solution.

2. The aminobutyric acid synergistic fertilizer according to claim 1, characterized in that: Fertilizer granules are made through the following steps: Dissolve γ-aminobutyric acid and glycine in water to obtain a mixed solution a; dissolve nitrogen, phosphorus and potassium fertilizers and trace elements in water to obtain a mixed solution b; add the mixed solution a to the mixed solution b, stir, and then perform spray drum granulation to obtain fertilizer granules, and control the particle size of the fertilizer granules to be 2.5-3 mm.

3. The aminobutyric acid synergistic fertilizer according to claim 1, characterized in that: The dosage ratio of γ-aminobutyric acid, glycine and water is 40-60g:20-30g:160mL; the dosage ratio of nitrogen, phosphorus and potassium fertilizers, trace elements and water is 1.5-1.7kg:5-8g:2L; the volume ratio of mixed solution a and mixed solution b is 1:12.

5.

4. The aminobutyric acid synergistic fertilizer according to claim 2, characterized in that: The nitrogen, phosphorus and potassium fertilizer includes the following raw materials in parts by weight: 25-30 parts of urea, 5-13 parts of potassium sulfate, 10-15 parts of monoammonium phosphate, and 10-15 parts of ammonium chloride.

5. The aminobutyric acid synergistic fertilizer according to claim 2, characterized in that: The trace elements are a mixture of zinc sulfate heptahydrate, manganese sulfate, and ammonium molybdate in a mass ratio of 1:1:

1.

6. The GABA synergistic fertilizer according to claim 1, characterized in that: The coating solution is prepared by the following steps: adding modified chitosan into an acetic acid solution with a volume concentration of 1%, and stirring evenly at 300-500r / min to obtain the coating solution.

7. The aminobutyric acid synergistic fertilizer according to claim 6, characterized in that: The dosage ratio of the modified chitosan to the acetic acid solution with a volume concentration of 1% is 20-45g:90-110mL.

8. The aminobutyric acid synergistic fertilizer according to claim 6, characterized in that: Modified chitosan is prepared by the following steps: Add chitosan to 0.3 mol / L citric acid solution, stir until chitosan is dissolved, then add epichlorohydrin, stir at 400 r / min for 4 h, then add humic acid, stir at 500 r / min for 0.5 h to obtain a mixed solution; drop the mixed solution into 0.2 mol / L NaOH solution, stir for 12 h, elute, dry at 80°C for 12 h, take out and grind to obtain modified chitosan.

9. The aminobutyric acid synergistic fertilizer according to claim 8, characterized in that: The dosage ratio of chitosan, 0.3 mol / L citric acid solution, epichlorohydrin, and humic acid is 3g:50mL:2mL:3g; the volume ratio of the mixed solution to 0.2 mol / L NaOH solution is 1:

1.

10. The method for preparing an aminobutyric acid synergistic fertilizer according to any one of claims 1 to 9, characterized in that: The following steps are involved: The fertilizer particles are placed in a spray drum granulator, and the coating solution is coated on the surface of the fertilizer particles while the particles are rotating. The particles are dried in an oven at 30°C to obtain aminobutyric acid enhanced fertilizers. The particle size of the slow-release fertilizer particles is controlled to be 4-6 mm.

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