Composite chelating clear liquid type water-soluble fertilizer based on gamma-aminobutyric acid and preparation method of composite chelating clear liquid type water-soluble fertilizer

Abstract

The invention relates to the field of fertilizers, in particular to a gamma-aminobutyric acid-based composite chelated clear liquid type water-soluble fertilizer and a preparation method thereof, and the gamma-aminobutyric acid-based composite chelated clear liquid type water-soluble fertilizer is prepared from the following components in parts by mass: 50 to 55 parts of microcapsule suspension, 2 to 4 parts of 5-amino acetyl propylene, 0.4 to 0.6 part of modified surfactant, 0.1 to 0.3 part of nano silicon dioxide and 42 to 44 parts of deionized water. Compared with the prior art, through a compounding technology of environment response microcapsule entrapped stress-resistant factors and a multifunctional auxiliary agent, stress targeted fertilizer supply and pesticide-fertilizer function fusion are realized, the nutrient utilization efficiency and crop resistance are greatly improved, meanwhile, the bottleneck of long-term stable storage of a liquid fertilizer is broken through, and the application prospect is wide. The method has a wide application prospect in the fields of large-scale flight control agriculture and green low-carbon planting.

Description

Technical Field

[0001] The present invention relates to the field of fertilizers, in particular to a gamma-aminobutyric acid-based composite chelated liquid-type water-soluble fertilizer and a preparation method thereof. Background Art

[0002] Water-soluble fertilizers, a key branch of liquid fertilizers, use water as a medium to achieve highly homogenized nitrogen, phosphorus, potassium, and trace elements. Their core technology lies in the compounding of refined raw materials, such as ammonium polyphosphate, to create a stable system with balanced nutrients and excellent solubility. This fertilizer, with its rapid absorption of ionic nutrients, significantly improves utilization efficiency. It is particularly well-suited for integrated water and fertilizer precision control systems, enabling on-demand supply through drip and sprinkler irrigation, providing a core platform for water and fertilizer conservation and intelligent management in modern agriculture.

[0003] In the existing technology, the formula of traditional water-soluble fertilizers is prone to precipitation, clogging the nozzles of drip irrigation and aerial spraying equipment, resulting in uneven fertilization and frequent malfunctions. In addition, its nutrient release is passive and lacks an anti-adversity response mechanism. Its utilization rate decreases under stresses such as high temperature and waterlogging. At the same time, when mixed with pesticides, flocculation often occurs due to ion antagonism, forcing the fertilizer to be applied in batches, reducing work efficiency. In addition, chemical chelating agents are difficult to degrade, causing heavy metal residues and soil compaction risks. In addition, the liquid system has poor stability and the storage period is generally less than 6 months, exacerbating storage losses.

[0004] Therefore, according to the above-mentioned related technologies, it is urgent to develop a γ-aminobutyric acid-based composite chelated liquid type water-soluble fertilizer and a preparation method thereof. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to propose a γ-aminobutyric acid composite chelated clear liquid water-soluble fertilizer and a preparation method thereof, so as to solve the problems of precipitation blockage, single function, drug-fertilizer antagonism and environmental risks in the prior art.

[0006] Based on the above purpose, the present invention provides a γ-aminobutyric acid-based composite chelated liquid-type water-soluble fertilizer and a preparation method thereof.

[0007] The invention relates to a γ-aminobutyric acid composite chelated liquid water-soluble fertilizer, which is characterized by being composed of the following components in parts by mass: 50-55 parts of a microcapsule suspension, 2-4 parts of 5-aminoacetpropylene, 0.4-0.6 parts of a modified surfactant, 0.1-0.3 parts of nano-silicon dioxide, and 42-44 parts of deionized water.

[0008] Preferably, the microcapsule suspension is prepared as follows: Step A1: Add modified poly (N-isopropylacrylamide) to deionized water, heat to 3-5°C, stir for 25-35 minutes at 700-900 rpm to obtain a colloid; Step A2: Add the sodium alginate solution to a flask, heat it to 20-30°C, add the colloid and the chelating mother liquor, stir and mix, place in a high-pressure homogenizer, emulsify for 8-12 minutes at a speed of 4500-5500 rpm to obtain an emulsion; Step A3: Add 2% calcium chloride crosslinker solution to the flask, cool to 5-8°C, add the emulsion, react for 20-40 minutes, rotate at 80-120 rpm, and centrifuge to obtain a microcapsule suspension; By modifying the isopropyl groups in poly (N-isopropylacrylamide) at high temperatures, they undergo severe dehydration and shrinkage, leading to the collapse of the polymer network. Simultaneously, in an alkaline environment, the degree of ionization of the carboxyl groups in sodium alginate increases, generating strong electrostatic repulsion that expands the molecular chain. The synergistic effect of the two opens the microcapsule wall structure, instantly releasing γ-aminobutyric acid and zinc-boron complexes, thereby achieving a precise response mechanism to the environment. Preferably, the mass ratio of the sodium alginate solution, colloid and chelating mother liquor in step A2 is 0.27-0.28:1:2.2-2.3; The mass ratio of the 2% calcium chloride crosslinker solution to the emulsion in step A3 is 1:5.1-5.3.

[0009] Preferably, the chelating mother solution preparation steps are as follows: Add γ-aminobutyric acid, salicylic acid and methyl jasmonate to deionized water, heat to 40-50°C, stir and react for 25-35 minutes at a speed of 250-350 rpm, add 10% citric acid solution, adjust the pH to 4.8-5.2, heat to 55-65°C, add zinc sulfate and boric acid, react for 1-3 hours at a speed of 300-500 rpm, and after the reaction is complete, cool to 20-30°C and filter to obtain a chelating mother liquor; By using γ-aminobutyric acid as a stress signal molecule, the crop glutamate decarboxylase pathway is activated, the cell osmotic balance is maintained under high temperature, and the activity of alcohol dehydrogenase is enhanced during waterlogging; at the same time, the targeting of boron elements mainly acts on the reproductive growth stage, zinc ions directly activate the key enzymes for pollen tube elongation, and boric acid strengthens the cross-linking of cell wall pectin. Through a dual-trigger mechanism, the stress-resistant substances can quickly reach the site of action, thereby improving the bioavailability conversion rate and increasing yield and stress resistance benefits.

[0010] Preferably, the mass ratio of the gamma-aminobutyric acid, salicylic acid, methyl jasmonate, zinc sulfate and boric acid is 1:0.18-0.19:0.12-0.13:0.3-0.32:0.08-0.12.

[0011] Preferably, the modified poly N-isopropylacrylamide is prepared as follows: Step B1: Add chitosan to 1% acetic acid solution, heat to 40-50°C, stir for 1-3 hours, add epichlorohydrin, heat to 55-65°C, react for 50-70 minutes, add 10% NaOH solution, adjust the pH to 6.8-7.2, purify, and dry to obtain epoxy-activated chitosan; Step B2: Under a nitrogen atmosphere, N-isopropylacrylamide, 4-cyano-4-(phenylthiocarbonyl)valeric acid and an initiator azobisisobutyronitrile are added to anhydrous ethanol, the temperature is raised to 55-65°C, the reaction is carried out for 3-5 hours, epoxy-activated chitosan and a crosslinker N,N'-methylenebisacrylamide are added, the temperature is raised to 68-72°C, the reaction is carried out for 10-14 hours, and after the reaction is complete, the temperature is lowered to 20-30°C, the precipitate is filtered, washed and dried to obtain modified poly N-isopropylacrylamide; The mass ratio of the chitosan, 1% acetic acid solution and epichlorohydrin is 1:23-27:0.23-0.27; The mass ratio of the N-isopropylacrylamide, 4-cyano-4-(phenylthiocarbonyl)valeric acid, initiator, epoxy-activated chitosan and crosslinking agent is 1:4.8-5.2:0.23-0.27:0.04-0.06:0.008-0.012.

[0012] Preferably, the preparation method of the modified surfactant is as follows: Step C1: Under a nitrogen atmosphere, add allyl polyoxyethylene ether and a platinum catalyst to hydrogenated silicone oil, raise the temperature to 80-100°C, stir and react for 3-5 hours, cool to 50-70°C, add chloropropyltrimethoxysilane, react for 2-4 hours, and distill under reduced pressure to obtain chloropropyl polyether silicone oil; Step C2: adding chloropropyl polyether silicone oil to isopropyl alcohol solvent, adding trimethylamine aqueous solution, heating to 30-40°C, stirring and reacting for 12-14 hours, and after the reaction is complete, performing vacuum distillation, recrystallization, and adjusting the pH to 5.5-6.5 to obtain a modified surfactant; A flexible skeleton is formed by the siloxane bonds of the silicone main chain in the modified surfactant, reducing the intermolecular forces. At the same time, the polyether blocks in the allyl polyoxyethylene ether are directionally arranged at the gas-liquid interface to reduce the surface tension. In addition, the permanent positive charge carried by the quaternary ammonium salt group in the modified surfactant has a strong adsorption force and can adsorb the negatively charged pathogen cell membrane. Its hydrophobic alkyl chain can pierce the phospholipid bilayer, causing the leakage of cell contents. At the same time, the silicone chain improves the permeability of the drug solution, making it easier for the quaternary ammonium salt to reach the pathogen target.

[0013] Preferably, in step C1, the mass ratio of allyl polyoxyethylene ether, platinum catalyst, hydrogenated silicone oil and chloropropyltrimethoxysilane is 1:0.0012-0.0013:0.36-0.38:0.48-0.52; The mass ratio of the chloropropyl polyether silicone oil to the trimethylamine aqueous solution in step C2 is 1:0.32-0.34.

[0014] The preparation method of the γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer comprises the following steps: Step S1: adding 5-aminolevulinic acid to deionized water, heating to 25-35°C, adding a modified surfactant, and sonicating for 10-20 minutes to complete the reaction to obtain a mixed solution; Step S2: adding the microcapsule suspension to the mixed solution, heating to 20-30° C., stirring for 40-50 minutes at a speed of 150-250 rpm, adding nano-silica, stirring and reacting for 15-25 minutes at a speed of 150-250 rpm, adding 0.5 mol / L citric acid solution, adjusting the pH to 6.5-7.0, standing for 5-15 minutes, and filtering to obtain a water-soluble fertilizer; The surface of nano-silica is rich in silanol groups, which self-assemble into a three-dimensional network structure through hydrogen bonds in the solution. Through this network, microcapsules and ionic nutrients are anchored in the grid gaps. The steric effect can effectively inhibit the collision and agglomeration caused by Brownian motion. In addition, under pH 6.5-7.0, the surface of nano-silica carries a negative charge, which can repel negatively charged microcapsules through Coulomb repulsion, thereby preventing aggregation caused by electrostatic adsorption. Preferably, the mass ratio of 5-aminolevulinic acid to modified surfactant in step S1 is 1:1.6-1.7; The mass ratio of the microcapsule suspension, the mixed solution and the nano-silicon dioxide in step S2 is 1.1-1.2:1:0.004-0.005.

[0015] Beneficial effects of the present invention: The present invention provides a clear liquid water-soluble fertilizer based on a γ-aminobutyric acid composite chelate. Compared with the existing technology, the present invention realizes the integration of adversity-targeted fertilizer supply and pesticide fertilizer functions through the technology of encapsulating stress-resistant factors in environmentally responsive microcapsules and compounding multifunctional adjuvants, greatly improving nutrient utilization efficiency and crop resistance, while breaking through the bottleneck of long-term stable storage of liquid fertilizers. It has broad application prospects in large-scale aerial spraying agriculture and green and low-carbon planting. DETAILED DESCRIPTION

[0016] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0017] Example 1: The steps for preparing the chelating mother solution are as follows: Add 100 g of γ-aminobutyric acid, 18 g of salicylic acid and 12 g of methyl jasmonate to 200 mL of deionized water, heat to 40 ° C, stir and react for 35 minutes at a speed of 250 rpm, add 10% citric acid solution, adjust the pH to 4.8-5.2, heat to 65 ° C, add 30 g of zinc sulfate and 8 g of boric acid, react for 1 hour at a speed of 500 rpm. After the reaction is completed, cool to 20 ° C, filter, and obtain the chelating mother liquor.

[0018] Example 2: The steps for preparing the chelating mother solution are as follows: Add 100 g of γ-aminobutyric acid, 18.5 g of salicylic acid and 12.5 g of methyl jasmonate to 200 mL of deionized water, heat to 45 ° C, stir and react for 30 min at a speed of 300 rpm, add 10% citric acid solution, adjust the pH to 4.8-5.2, heat to 60 ° C, add 31 g of zinc sulfate and 10 g of boric acid, react for 2 h at a speed of 400 rpm. After the reaction is completed, cool to 25 ° C, filter, and obtain the chelating mother liquor.

[0019] Example 3: The steps for preparing the chelating mother solution are as follows: Add 100 g of γ-aminobutyric acid, 19 g of salicylic acid and 13 g of methyl jasmonate to 200 mL of deionized water, heat to 50 ° C, stir and react for 25 min at a speed of 350 rpm, add 10% citric acid solution, adjust the pH to 4.8-5.2, heat to 55 ° C, add 32 g of zinc sulfate and 12 g of boric acid, react for 3 h at a speed of 300 rpm, and when the reaction is complete, cool to 30 ° C and filter to obtain a chelating mother liquor.

[0020] Example 4: The preparation steps of modified poly (N-isopropylacrylamide) are as follows: S1: Add 10 g of chitosan to 230 g of 1% acetic acid solution, heat to 40 ° C, stir for 3 h, add 2.3 g of epichlorohydrin, heat to 55 ° C, react for 70 min, add 10% NaOH solution, adjust the pH to 6.8-7.2, purify, and dry to obtain epoxy-activated chitosan; S2: Under a nitrogen atmosphere, 100 g of N-isopropylacrylamide, 480 g of 4-cyano-4-(phenylthiocarbonyl)valeric acid and 23 g of initiator azobisisobutyronitrile were added to 1000 mL of anhydrous ethanol, heated to 55 ° C, and reacted for 5 h. 4 g of epoxy-activated chitosan and 0.8 g of cross-linker N, N'-methylenebisacrylamide were added, heated to 68 ° C, and reacted for 14 h. After the reaction was completed, the temperature was lowered to 20 ° C, the precipitate was filtered, washed and dried to obtain modified poly N-isopropylacrylamide.

[0021] Example 5: The preparation steps of modified poly N-isopropylacrylamide are as follows: S1: Add 10 g of chitosan to 250 g of 1% acetic acid solution, heat to 45 ° C, stir for 2 h, add 2.5 g of epichlorohydrin, heat to 60 ° C, react for 60 min, add 10% NaOH solution, adjust the pH to 6.8-7.2, purify, and dry to obtain epoxy-activated chitosan; S2: Under a nitrogen atmosphere, 100 g of N-isopropylacrylamide, 500 g of 4-cyano-4-(phenylthiocarbonyl)valeric acid and 25 g of initiator azobisisobutyronitrile were added to 1000 mL of anhydrous ethanol, heated to 60 ° C, and reacted for 4 h. 5 g of epoxy-activated chitosan and 1 g of cross-linking agent N, N'-methylenebisacrylamide were added, heated to 70 ° C, and reacted for 12 h. After the reaction was completed, the temperature was lowered to 25 ° C, the precipitate was filtered, washed and dried to obtain modified poly N-isopropylacrylamide.

[0022] Example 6: The steps for preparing modified poly (N-isopropylacrylamide) are as follows: S1: Add 10 g of chitosan to 270 g of 1% acetic acid solution, heat to 50 ° C, stir for 1 hour, add 27 g of epichlorohydrin, heat to 65 ° C, react for 50 minutes, add 10% NaOH solution, adjust the pH to 6.8-7.2, purify, and dry to obtain epoxy-activated chitosan; S2: Under a nitrogen atmosphere, 100 g of N-isopropylacrylamide, 520 g of 4-cyano-4-(phenylthiocarbonyl)valeric acid and 27 g of initiator azobisisobutyronitrile were added to 1000 mL of anhydrous ethanol, heated to 65 ° C, and reacted for 3 h. 6 g of epoxy-activated chitosan and 1.2 g of cross-linking agent N, N'-methylenebisacrylamide were added, heated to 72 ° C, and reacted for 10 h. After the reaction was completed, the temperature was lowered to 30 ° C, the precipitate was filtered, washed and dried to obtain modified poly N-isopropylacrylamide.

[0023] Example 7: The steps for preparing the microcapsule suspension are as follows: S1: Add 100 g of modified poly (N-isopropylacrylamide) to 200 mL of deionized water, heat to 3°C, and stir for 35 min at 700 rpm to obtain a colloid; S2: Add 27 g of sodium alginate solution to a flask, heat to 20°C, add 100 g of colloid and 220 g of chelating mother liquor, stir and mix, place in a high-pressure homogenizer, emulsify for 8 min at a speed of 5500 rpm to obtain an emulsion; S3: Add 100 g of 2% calcium chloride crosslinker solution into the flask, cool to 5°C, add 510 g of emulsion, react for 40 min, rotate at 80 rpm, and centrifuge to obtain microcapsule suspension.

[0024] Example 8: The steps for preparing the microcapsule suspension are as follows: S1: Add 100 g of modified poly (N-isopropylacrylamide) to 200 mL of deionized water, heat to 4°C, and stir for 30 min at 800 rpm to obtain a colloid; S2: Add 27.5 g of sodium alginate solution to a flask, heat to 25°C, add 100 g of colloid and 225 g of chelating mother liquor, stir and mix, place in a high-pressure homogenizer, emulsify for 10 min at a speed of 5000 rpm to obtain an emulsion; S3: Add 100 g of 2% calcium chloride crosslinker solution into the flask, cool to 6°C, add 520 g of emulsion, react for 30 min, rotate at 100 rpm, and centrifuge to obtain microcapsule suspension.

[0025] Example 9: The steps for preparing the microcapsule suspension are as follows: S1: Add 100 g of modified poly (N-isopropylacrylamide) to 200 mL of deionized water, heat to 5°C, and stir for 25 min at 900 rpm to obtain a colloid; S2: Add 28 g of sodium alginate solution to a flask, heat to 30°C, add 100 g of colloid and 230 g of chelating mother liquor, stir and mix, place in a high-pressure homogenizer, emulsify for 8 min at a speed of 5500 rpm to obtain an emulsion; S3: Add 100 g of 2% calcium chloride crosslinker solution into the flask, cool to 8°C, add 530 g of emulsion, react for 20 min, rotate at 120 rpm, and centrifuge to obtain microcapsule suspension.

[0026] Example 10: The preparation method of the modified surfactant is as follows: S1: Under a nitrogen atmosphere, 100 g of allyl polyoxyethylene ether and 0.12 g of platinum catalyst were added to 36 g of hydrogenated silicone oil, the temperature was raised to 80°C, and the mixture was stirred and reacted for 5 h. The temperature was then lowered to 50°C, 48 g of chloropropyltrimethoxysilane was added, the mixture was reacted for 4 h, and vacuum distillation was performed to obtain chloropropyl polyether silicone oil. S2: Add 100 g of chloropropyl polyether silicone oil to 200 mL of isopropanol solvent, add 32 g of trimethylamine aqueous solution, heat to 30°C, stir and react for 14 hours. After the reaction is complete, distill under reduced pressure, recrystallize, and adjust the pH to 5.5-6.5 to obtain a modified surfactant.

[0027] Example 11: The preparation method of the modified surfactant is as follows: S1: Under a nitrogen atmosphere, 100 g of allyl polyoxyethylene ether and 0.125 g of platinum catalyst were added to 37 g of hydrogenated silicone oil, the temperature was raised to 90°C, and the mixture was stirred and reacted for 4 h. The temperature was then lowered to 60°C, and 50 g of chloropropyltrimethoxysilane was added. The mixture was reacted for 3 h, and the mixture was distilled under reduced pressure to obtain chloropropyl polyether silicone oil. S2: Add 100 g of chloropropyl polyether silicone oil to 200 mL of isopropanol solvent, add 33 g of trimethylamine aqueous solution, heat to 35°C, stir and react for 13 hours. After the reaction is complete, distill under reduced pressure, recrystallize, and adjust the pH to 5.5-6.5 to obtain a modified surfactant.

[0028] Example 12: The preparation method of the modified surfactant is as follows: S1: Under a nitrogen atmosphere, 100 g of allyl polyoxyethylene ether and 0.13 g of platinum catalyst were added to 38 g of hydrogenated silicone oil, the temperature was raised to 100 ° C, and stirred for reaction for 3 h. The temperature was lowered to 70 ° C, 52 g of chloropropyltrimethoxysilane was added, and the reaction was carried out for 2 h. The mixture was distilled under reduced pressure to obtain chloropropyl polyether silicone oil; S2: Add 100 g of chloropropyl polyether silicone oil to 200 mL of isopropanol solvent, add 34 g of trimethylamine aqueous solution, heat to 40°C, stir and react for 12 hours. After the reaction is complete, distill under reduced pressure, recrystallize, and adjust the pH to 5.5-6.5 to obtain a modified surfactant.

[0029] Example 13: Preparation method of γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer S1: Add 100 g of 5-aminolevulinic acid to 500 mL of deionized water, heat to 25°C, add 160 g of modified surfactant, and sonicate for 20 min. The reaction is complete to obtain a mixed solution; S2: Add 110g of microcapsule suspension to 100g of the mixed solution, heat to 20°C, stir for 50min, rotate at 150rpm, add 0.4g of nano-silica, stir and react for 15min, rotate at 250rpm, add 0.5mol / L citric acid solution, adjust the pH to 6.5-7.0, let stand for 5min, filter, and obtain water-soluble fertilizer.

[0030] Example 14: Preparation method of γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer S1: Add 100 g of 5-aminolevulinic acid to 500 mL of deionized water, heat to 30°C, add 165 g of modified surfactant, and sonicate for 15 min. The reaction is complete to obtain a mixed solution. S2: Add 115g of microcapsule suspension to 100g of the mixed solution, heat to 25°C, stir for 45min, rotate at 200rpm, add 0.45g of nano-silica, stir and react for 20min, rotate at 200rpm, add 0.5mol / L citric acid solution, adjust the pH to 6.5-7.0, let stand for 10min, filter, and obtain water-soluble fertilizer.

[0031] Example 15: Preparation method of γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer S1: Add 100 g of 5-aminolevulinic acid to 200 mL of deionized water, heat to 35°C, add 170 g of modified surfactant, and sonicate for 10 min. The reaction is complete to obtain a mixed solution. S2: Add 120g of microcapsule suspension to 100g of the mixed solution, heat to 30°C, stir for 45min, rotate at 200rpm, add 0.5g of nano-silica, stir and react for 15min, rotate at 250rpm, add 0.5mol / L citric acid solution, adjust the pH to 6.5-7.0, let stand for 5min, filter, and obtain water-soluble fertilizer.

[0032] Comparative Example 1: Compared with Example 13, this comparative example only replaces the "modified surfactant" with the "silicone surfactant", and the remaining steps and parameters are the same. This comparative example will not be repeated, and finally a water-soluble fertilizer is obtained.

[0033] Comparative Example 2: Compared with Example 13, this comparative example only replaces the "microcapsule suspension" with the "chelating mother liquor", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally obtains a water-soluble fertilizer.

[0034] Comparative Example 3: Compared with Example 13, this comparative example replaces "nano silicon dioxide" with "fumed silica", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a water-soluble fertilizer is obtained.

[0035] Comparative Example 4: Compared with Example 13, this comparative example only replaces the temperature "5°C" in the microcapsule preparation step with "15°C", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a water-soluble fertilizer is obtained.

[0036] Performance testing: Intelligent release efficiency test: Refer to NY / T1860.30-2016 test standard and use Boxun BIC-400 constant temperature and humidity chamber; 1. Take 1.0 g of each of the water-soluble fertilizers of Examples 13-15 and Comparative Examples 1-4, add them to 100 mL of deionized water, heat to 25° C., and disperse for 10 minutes to obtain a suspension; 2. Place 50 mL of the suspension in a constant temperature box, raise the temperature to 35.0 ± 0.5 ° C, leave it for 1 hour, take a sample, and filter and test; 3. Take another 50 mL of suspension and add 10 mL of 100 mmol / moL sodium bicarbonate buffer. Place in a thermostat, raise the temperature to 25.0 ± 0.5 °C, and let stand for 1 hour. Take a sample, filter it, and test it. 4. Take 1.0 g of each of the water-soluble fertilizers of Examples 13-15 and Comparative Examples 1-4, add 100 mL of hydrochloric acid solution with a pH of 2.0, and ultrasonically treat for 30 minutes. Centrifuge for 10 minutes, take the supernatant, and determine the γ-aminobutyric acid and Zn content in the supernatant. 2+ Concentration, as the 100% release benchmark value; 5. Release rate calculation:

[0037] C t : filtrate concentration at time t (mg / mL) V: total volume of suspension (100 mL) W: mass of microcapsule sample (1.00 g) C ∞ : Complete release control group concentration (mg / mL) Table 1 project <![CDATA[C ∞ (mg / mL)]]> Release rate at 35℃ (60min) (%) pH=8.0 Release rate (60min) (%) Example 13 85.2±0.8 91.5±1.2 90.8±1.0 Example 14 86.0±0.7 92.3±1.1 91.7±0.9 Example 15 85.8±0.9 91.8±1.3 90.5±1.1 Comparative Example 1 85.5±0.8 89.2±1.5 88.6±1.4 Comparative Example 2 84.3±1.0 43.6±2.5 42.1±2.8 Comparative Example 3 85.1±0.7 90.1±1.4 89.3±1.3 Comparative Example 4 84.7±0.9 62.7±2.1 60.3±2.3 Flying air defense compatibility test: Refer to NY / T 1860.22-2016 test standard and use droplet analyzer; 1. Test group: Take 20 g of each of the water-soluble fertilizers of Examples 13-15 and Comparative Examples 1-4, add 80 mL of deionized water, stir to dissolve, add 10 mL of 200 g / L glufosinate-ammonium mother solution to make the volume 100 mL, and let it stand for 5 min; Control group: Take 20g of commercially available EDTA chelated multi-element water-soluble fertilizer, add 80mL of deionized water, stir to dissolve, add 10mL of 200g / L glufosinate ammonium stock solution to make the volume 100mL, and let it stand for 5min; 2. The experimental group and the control group were added to the drone respectively. A 10m×10m target area was demarcated on the flat farmland. Water-sensitive paper with a size of 76×26mm and a spacing of 1m×1m was laid evenly along the center line for spraying. The drone was flown at an altitude of 2.5m, a speed of 5m / s, and a spray width of 4m. This was repeated three times. 3. Uniformity calculation: ; 4. Drift rate calculation: ; N out : Total number of droplets on water-sensitive paper 5 m outside the target area; N in : the total number of droplets in the target area; 5. Let the remaining liquid stand for 24 hours and classify it according to NY / T 1860.22-2016 standard: Grade A: no flocculation, no precipitation (light transmittance > 95%); Grade B: Slightly flocculated (transmittance 80%-95%); Grade C: Obvious precipitation or stratification (transmittance <80%).

[0038] Table 2 project CV (%) Drift rate (%) Mixing and grading of liquid medicine Example 13 12.3±0.8 8.9±0.6 A-level Example 14 11.5±0.7 8.7±0.5 A-level Example 15 12.1±0.9 9.1±0.7 A-level Comparative Example 1 18.7±1.2 32.5±1.4 Class B Comparative Example 2 13.2±0.9 9.5±0.8 C-level Comparative Example 3 12.9±1.0 9.3±0.6 Class B Comparative Example 4 14.6±1.1 10.8±0.9 A-level control group 38.5±2.3 41.2±2.0 C-level Long-term storage stability test: Refer to GB / T 36204-2018 test standard, using laser particle size analyzer and rotational viscometer; 1. Take 500 ml of each of the water-soluble fertilizers of Examples 13-15, Comparative Examples 1-4, and the commercially available EDTA-chelated multi-element water-soluble fertilizer of the control group, respectively, and divide them into 50 ml graduated cylinders, place them in a dark environment at 25 ° C, and store them for 6 months; 2. Gently rotate the measuring cylinder 5 times, let it stand for 2 hours, and read the volume V of the sediment at the bottom. 沉淀 ; Calculation of precipitation rate: ; 3. Place the water-soluble fertilizer in the measuring cylinder in a constant temperature box, raise the temperature to 40°C, and place it for 180 days. Take 1 mL of sample, dilute it 100 times with deionized water, and record the polydispersity index (PDI) value. 4. Take 10 mL of the aged sample and equilibrate it in a constant temperature water bath at 25°C for 30 minutes. Use a rotational viscometer to measure the viscosity (mPa·S). Take the average value of the three measurements and calculate the viscosity change rate before and after.

[0039] Table 3 project Sedimentation rate (%) PDI Viscosity change rate (%) Example 13 0 0.18 ±0.02 +4.2 Example 14 0 0.16 ±0.01 +3.8 Example 15 0.05 ±0.01 0.19 ±0.02 +4.5 Comparative Example 1 0.10 ±0.02 0.25 ±0.03 +8.7 Comparative Example 2 0.30 ±0.05 0.31 ±0.04 +12.3 Comparative Example 3 8.5 ±0.3 0.48 ±0.05 +42.1 Comparative Example 4 0.15 ±0.03 0.28 ±0.03 +7.9 control group 12.7 ±0.5 0.72 ±0.08 +68.3 Data Analysis: As can be seen from Tables 1-3, the γ-aminobutyric acid composite chelated liquid water-soluble fertilizer prepared by the present invention has more excellent intelligent release performance, flying spray compatibility and long-term storage stability; In Comparative Example 1, the modified surfactant was replaced by a silicone surfactant, resulting in a decrease in release efficiency. The reason is that the ordinary silicone surfactant lacks the quaternary ammonium salt group and the synergistic effect with the silicone chain, and cannot adsorb pathogen cell membranes through positive charges, which weakens the antibacterial function. In addition, the polyether block is disordered, resulting in an increase in gas-liquid interfacial tension, reduced droplet uniformity, and increased drift rate. At the same time, the stability of the microcapsule structure is reduced, weakening the environmental response ability. In addition, its precipitation rate is 0.10%, and the viscosity change rate is +8.7%. The reason is that the flexible siloxane skeleton of the modified surfactant is missing, the intermolecular force is increased, and the particle aggregation is accelerated. In Comparative Example 2, the microcapsule suspension was replaced with a chelating mother liquor, resulting in the loss of its intelligent release function. The reason was the direct use of the chelating mother liquor and the lack of the poly (N-isopropylacrylamide) / sodium alginate composite structure, which made it impossible to trigger the capsule wall to open under adverse conditions. At the same time, nutrients were released only by passive diffusion, and γ-aminobutyric acid and zinc boron could not be delivered in a targeted manner. In addition, after mixing with the herbicide, obvious precipitation occurred. The reason was that the unencapsulated ionic nutrient Zn 2+ It has ion antagonism with glufosinate ammonium, causing flocculation and serious precipitation during storage. The reason is that the free metal ions zinc and boron gradually aggregate and settle during long-term storage. In Comparative Example 3, since nano-silica was replaced by fumed silica, the storage stability collapsed. The reason was that the density of silanol groups on the surface of fumed silica was low, and it could not form a three-dimensional hydrogen bond network to anchor the microcapsules. In addition, it had insufficient negative charge at pH = 6.5-7.0, and the Brownian motion of the molecules caused the microcapsules to collide and agglomerate. In addition, the stability of the mixed use of pesticides and fertilizers decreased because fumed silica had a weak anchoring ability for ionic nutrients and could not inhibit the antagonistic reaction with herbicides.

[0040] In Comparative Example 4, the intelligent response of the microcapsules failed because the cross-linking temperature rose to 15°C. This was because high-temperature cross-linking destroyed the structural integrity of the microcapsules. In addition, the temperature was too high during calcium chloride cross-linking, resulting in excessive shrinkage of the sodium alginate molecular chains and reduced porosity of the capsule wall. At the same time, poly (N-isopropylacrylamide) dehydrated prematurely at high temperatures and lost its temperature-responsive elasticity. In addition, its storage stability decreased because defects in the capsule wall caused partial rupture of the microcapsules, and leakage of the contents triggered secondary agglomeration.

[0041] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0042] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A water-soluble fertilizer based on a γ-aminobutyric acid composite chelate liquid, characterized in that: The invention is composed of the following components in parts by mass: 50-55 parts of microcapsule suspension, 2-4 parts of 5-aminoacetpropylene, 0.4-0.6 parts of modified surfactant, 0.1-0.3 parts of nano silicon dioxide and 42-44 parts of deionized water.

2. The γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer according to claim 1, characterized in that: The microcapsule suspension preparation steps are as follows: Step A1: Add modified poly (N-isopropylacrylamide) to deionized water, heat to 3-5°C, stir for 25-35 minutes at 700-900 rpm to obtain a colloid; Step A2: Add the sodium alginate solution to a flask, heat it to 20-30°C, add the colloid and the chelating mother liquor, stir and mix, place in a high-pressure homogenizer, emulsify for 8-12 minutes at a speed of 4500-5500 rpm to obtain an emulsion; Step A3: Add 2% calcium chloride crosslinker solution into the flask, cool to 5-8°C, add the emulsion, react for 20-40 minutes, rotate at 80-120 rpm, and centrifuge to obtain a microcapsule suspension.

3. The γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer according to claim 2, characterized in that: The mass ratio of the sodium alginate solution, colloid and chelating mother liquor in step A2 is 0.27-0.28:1:2.2-2.3; The mass ratio of the 2% calcium chloride crosslinker solution to the emulsion in step A3 is 1:5.1-5.

3.

4. The γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer according to claim 2, characterized in that: The steps of preparing the chelating mother liquor are as follows: Add γ-aminobutyric acid, salicylic acid and methyl jasmonate to deionized water, heat to 40-50°C, stir and react for 25-35 minutes at a speed of 250-350 rpm, add 10% citric acid solution, adjust the pH to 4.8-5.2, heat to 55-65°C, add zinc sulfate and boric acid, react for 1-3 hours at a speed of 300-500 rpm. After the reaction is complete, cool to 20-30°C and filter to obtain a chelating mother liquor.

5. The γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer according to claim 4, characterized in that: The mass ratio of the gamma-aminobutyric acid, salicylic acid, methyl jasmonate, zinc sulfate and boric acid is 1:0.18-0.19:0.12-0.13:0.3-0.32:0.08-0.

12.

6. The γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer according to claim 2, characterized in that: The preparation steps of the modified poly N-isopropylacrylamide are as follows: Step B1: Add chitosan to 1% acetic acid solution, heat to 40-50°C, stir for 1-3 hours, add epichlorohydrin, heat to 55-65°C, react for 50-70 minutes, add 10% NaOH solution, adjust the pH to 6.8-7.2, purify, and dry to obtain epoxy-activated chitosan; Step B2: Under a nitrogen atmosphere, N-isopropylacrylamide, 4-cyano-4-(phenylthiocarbonyl)valeric acid and an initiator azobisisobutyronitrile are added to anhydrous ethanol, the temperature is raised to 55-65°C, the reaction is carried out for 3-5 hours, epoxy-activated chitosan and a crosslinker N,N'-methylenebisacrylamide are added, the temperature is raised to 68-72°C, the reaction is carried out for 10-14 hours, and after the reaction is complete, the temperature is lowered to 20-30°C, the precipitate is filtered, washed and dried to obtain modified poly N-isopropylacrylamide; The mass ratio of the chitosan, 1% acetic acid solution and epichlorohydrin is 1:23-27:0.23-0.27; The mass ratio of the N-isopropylacrylamide, 4-cyano-4-(phenylthiocarbonyl)valeric acid, initiator, epoxy-activated chitosan and crosslinking agent is 1:4.8-5.2:0.23-0.27:0.04-0.06:0.008-0.

012.

7. The γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer according to claim 1, characterized in that: The modified surfactant preparation method is as follows: Step C1: Under a nitrogen atmosphere, add allyl polyoxyethylene ether and a platinum catalyst to hydrogenated silicone oil, raise the temperature to 80-100°C, stir and react for 3-5 hours, cool to 50-70°C, add chloropropyltrimethoxysilane, react for 2-4 hours, and distill under reduced pressure to obtain chloropropyl polyether silicone oil; Step C2: Add chloropropyl polyether silicone oil to isopropyl alcohol solvent, add trimethylamine aqueous solution, heat to 30-40°C, stir and react for 12-14 hours. After the reaction is complete, perform vacuum distillation, recrystallize, and adjust the pH to 5.5-6.5 to obtain a modified surfactant.

8. The γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer according to claim 7, characterized in that: In step C1, the mass ratio of allyl polyoxyethylene ether, platinum catalyst, hydrogenated silicone oil and chloropropyltrimethoxysilane is 1:0.0012-0.0013:0.36-0.38:0.48-0.52; The mass ratio of the chloropropyl polyether silicone oil to the trimethylamine aqueous solution in step C2 is 1:0.32-0.

34.

9. The method for preparing a γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer according to any one of claims 1 to 8, characterized in that: The preparation steps are as follows: Step S1: adding 5-aminolevulinic acid to deionized water, heating to 25-35°C, adding a modified surfactant, and sonicating for 10-20 minutes to complete the reaction to obtain a mixed solution; Step S2: adding the microcapsule suspension to the mixed solution, heating to 20-30° C., stirring for 40-50 minutes at a speed of 150-250 rpm, adding nano-silica, stirring and reacting for 15-25 minutes at a speed of 150-250 rpm, adding 0.5 mol / L citric acid solution, adjusting the pH to 6.5-7.0, standing for 5-15 minutes, and filtering to obtain a water-soluble fertilizer.

10. The method for preparing a γ-aminobutyric acid composite chelated liquid type water-soluble fertilizer according to claim 9, characterized in that: The mass ratio of 5-aminolevulinic acid to modified surfactant in step S1 is 1:1.6-1.7; The mass ratio of the microcapsule suspension, the mixed solution and the nano-silicon dioxide in step S2 is 1.1-1.2:1:0.004-0.005.

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