Preparation method and application of pesticide-fertilizer integrated eutectic gel carrier

Abstract

The invention relates to the field of pesticide-fertilizer integrated carrier materials, in particular to a preparation method and application of a pesticide-fertilizer integrated deep-eutectic gel carrier. A deep-eutectic solvent composed of urea, choline chloride and unsaturated fatty acid is used for dissolving pesticide, and through ring-opening polymerization of lipoic acid, the pesticide-fertilizer integrated deep-eutectic gel carrier is obtained. The preparation process is simple and efficient, raw materials are renewable, rapid, low in cost and suitable for large-scale industrial production, in addition, the pesticide-fertilizer integrated carrier has excellent pH and oxidation-reduction response release performance, the utilization rate of pesticide and fertilizer can be effectively increased, and the pesticide-fertilizer integrated carrier is suitable for large-scale industrial production. Environmental pollution caused by loss of pesticides and fertilizers is reduced, and the method has important application prospects in the field of plant nutrition and protection.

Description

Technical Field

[0001] The present invention belongs to the field of integrated medicine and fertilizer carrier materials, and particularly relates to a preparation method and application of an integrated medicine and fertilizer eutectic gel carrier. Background Art

[0002] In modern agricultural production, pesticides and fertilizers play a vital role in improving crop yield and quality. However, traditional pesticide and fertilizer formulations often face challenges in practical application, such as leaching, volatilization, and decomposition, leading to their substantial loss into the surrounding environment and posing a serious threat to ecosystems and human health. Furthermore, due to differences in chemical properties, release mechanisms, and compatibility between pesticides and fertilizers, most formulations struggle to effectively integrate them, hindering their synergistic effects. To address these challenges, encapsulating pesticides and fertilizers in hydrogels has been widely recognized as an effective strategy for constructing integrated pesticide and fertilizer carriers. Hydrogels are a class of soft materials formed by cross-linking hydrophilic polymers. Due to their unique structure, high adsorption capacity, excellent water retention, unique stimuli-responsive properties, and good biocompatibility, they are widely used in agriculture, biomedicine, industry, and environmental protection. Currently, a variety of polymers have been used to construct hydrogel carriers, including chitosan, cellulose, alginate, lignin, poly (N-isopropylacrylamide), and polyvinyl alcohol. While these hydrogel carriers have improved pesticide and fertilizer utilization and soil water retention to a certain extent, they still face challenges such as complex preparation processes, high costs, limited functionality, poor drug solubility, and insufficient temperature tolerance, which limit their large-scale industrial production and practical application. Therefore, developing a simple, green, and precise controlled release and efficient and stable integrated drug and fertilizer delivery system remains a significant challenge.

[0003] The emergence of eutectic gels provides a potential solution to the above challenges. In 2003, Abbott et al. first discovered that by mixing specific hydrogen bond acceptors and hydrogen bond donors in a certain proportion, a liquid mixture with a melting point lower than that of a single component can be obtained, which was named a eutectic solvent. Thanks to its advantages such as low vapor pressure, high thermal stability, excellent solubility, simple preparation process, low cost, and good biocompatibility, eutectic solvents are gradually becoming an ideal dispersion medium for constructing eutectic gels. Compared with hydrogels, eutectic gels exhibit more excellent properties in terms of environmental stability, conductivity and processability, and have been widely used in energy storage, catalysis, flexible electronic materials, biomedicine and environmental protection. In addition, the eutectic gel has the following three characteristics, making it an ideal material for constructing integrated drug and fertilizer carriers: 1) The high polarity of the eutectic solvent is conducive to the dissolution and encapsulation of pesticides and fertilizers; 2) The preparation process is simple, the raw material cost is low, and the environmental stability is good, which is suitable for large-scale production and meets the requirements of green and sustainable agricultural development; 3) The controllable and reversible dynamic bonds give it excellent controlled release performance, rapid self-healing performance and reprocessing performance, which can meet the needs of different practical application scenarios.

[0004] Based on this, the present invention utilizes a low eutectic solvent composed of urea, choline chloride and unsaturated fatty acids to dissolve pesticides, and through the ring-opening polymerization of lipoic acid, a one-pot method is used to prepare a low eutectic gel carrier for integrated medicine and fertilizer. These gel carriers have simple preparation processes, renewable raw materials, rapid production, low cost, and can be produced on a kilogram scale. In addition, thanks to the presence of dynamic disulfide bonds and non-covalent bonds in the system, the gel carrier can respond to different pH values ​​and redox stimuli to achieve controlled release of pesticides and urea, showing excellent biological activity and plant nutrition. The present invention proposes a simple and efficient method for preparing a large-scale integrated medicine and fertilizer carrier, which provides a new approach to improving the utilization rate of pesticides and fertilizers in actual agricultural production and reducing environmental pollution, and has important research significance and practical value. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the above-mentioned prior art and provide a simple and efficient method for preparing a eutectic gel carrier for integrated fertilizer and medicine. The gel carrier not only has pH / redox dual-responsive controlled release properties, but also exhibits excellent biological activity and can provide essential nutrients to plants.

[0006] The purpose of the present invention is achieved through the following technical solutions: A method for preparing a medicine-fertilizer integrated eutectic gel carrier, the method comprising the following steps: ① After mixing choline chloride, urea, and unsaturated fatty acids in a certain proportion, heating and stirring at 60-90°C to form a homogeneous transparent liquid, a three-component deep eutectic solvent is obtained; then, the pesticide molecules are added to the solvent and ultrasonically treated until completely dissolved to obtain a pesticide solution; ② Add lipoic acid to the reactor, heat at 120-140°C and mechanically stir until completely melted, then add the solution in step ① dropwise to the system and continue the reaction for 20-40 minutes; ③ Slowly add the metal chloride solution dropwise to the mixed solution in step ②, continue the reaction for 10 to 30 minutes, transfer it to polytetrafluoroethylene molds of different shapes and sizes, and place it at room temperature for 24 to 48 hours to obtain a low-melting gel carrier for integrated fertilizer and medicine.

[0007] Wherein, the unsaturated fatty acid is one or more of acrylic acid, itaconic acid and maleic acid.

[0008] The pesticide is an active ingredient of an insecticide or fungicide that does not contain a double bond structure and is resistant to high temperatures, specifically including one or more of fipronil, prochloraz, tebuconazole, imidacloprid, pyraclostrobin, dinotefuran, thiamethoxam, and chlorantraniliprole.

[0009] Wherein, the metal chloride is one or more of ferric chloride, aluminum chloride, zinc chloride and calcium chloride.

[0010] The solvent used to dissolve the metal chloride is one or more of acetone, methanol, ethanol and ether.

[0011] Wherein, the molar ratio of the choline chloride, urea and unsaturated fatty acid is 1:(1-2):(0.5-1).

[0012] Among them, the proportions of various raw materials in the integrated drug-fertilizer eutectic gel carrier are: 64-94.5 parts by weight of lipoic acid, 5-30 parts by weight of low eutectic solvent, 0.25-5 parts by weight of pesticide molecules, and 0.25-1 part by weight of metal chloride.

[0013] The gel carrier is in the form of flakes or spheres, and has a particle size range of 1-5 mm.

[0014] The pesticide carrier is used for pH and redox response controlled release of pesticides and urea.

[0015] Compared with the prior art, the present invention has the following beneficial effects: First, the present invention uses a low eutectic solvent composed of urea, choline chloride and unsaturated fatty acids to dissolve pesticides, and prepares an integrated low eutectic gel carrier for pesticides and fertilizers in a one-pot method through ring-opening polymerization of lipoic acid, which solves the problems of difficulty in synergizing pesticides and fertilizers, difficulty in intelligent release, poor environmental stability and insufficient biocompatibility in existing fertilizer and pesticide reduction and efficiency improvement strategies.

[0016] Secondly, in the preparation method of the integrated low-melting eutectic gel carrier for medicine and fertilizer provided by the present invention, the raw materials used are cheap and environmentally friendly, and the preparation process is simple and efficient, which is suitable for large-scale industrial production and has great application potential in actual agricultural production.

[0017] Third, the integrated low-melting gel carrier of pesticides and fertilizers prepared by the present invention has dual response release characteristics of pH and redox, which can achieve precise control of the release and mutual synergy of pesticides and fertilizers, effectively improve the utilization rate of pesticides and fertilizers, and reduce environmental pollution caused by loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an optical photograph of the integrated medicine-fertilizer eutectic gel carrier provided in Example 1 of the present invention.

[0019] Figure 2 This is the weight change curve of the integrated medicine-fertilizer eutectic gel carrier at 60°C provided in Example 1 of the present invention.

[0020] Figure 3 This is the stress-strain curve of the integrated medicine-fertilizer eutectic gel carrier provided in Example 1 of the present invention.

[0021] Figure 4 Release curves of imidacloprid (A) and urea (B) at different pH values ​​for the integrated drug-fertilizer eutectic gel carrier provided in Example 1 of the present invention.

[0022] Figure 5 Release curves of imidacloprid (A) and urea (B) from the integrated drug-fertilizer eutectic gel carrier provided in Example 1 of the present invention in the presence or absence of glutathione.

[0023] Figure 6 The acute toxicity of the integrated drug-fertilizer eutectic gel carrier provided in Example 1 of the present invention and the commercial imidacloprid wettable powder after treating aphids.

[0024] Figure 7 The height and root length (A), as well as the fresh weight and dry weight (B) of wheat after 14 days of treatment with the integrated drug-fertilizer eutectic gel carrier provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are also within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0027] In view of the defects of the existing technology, the present invention uses for the first time a low eutectic solvent composed of urea, choline chloride and unsaturated fatty acids to dissolve pesticides, and through the ring-opening polymerization of lipoic acid, constructs an integrated low eutectic gel carrier for pesticides and fertilizers, which solves the inherent defects of traditional pesticide and fertilizer preparations and expands the application scope of the integrated pesticide and fertilizer carrier.

[0028] Urea, thioctic acid, acrylic acid, itaconic acid, maleic acid, fipronil, prochloraz, tebuconazole, imidacloprid, pyraclostrobin, dinotefuran, thiamethoxam, and chlorantraniliprole were all purchased from Shanghai Aladdin Reagent Co., Ltd.; choline chloride, ferric chloride, aluminum chloride, and zinc chloride were all purchased from Beijing Inokai Technology Co., Ltd.

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work. Example 1

[0030] In this example, acrylic acid was used as the unsaturated fatty acid, imidacloprid was used as the model pesticide molecule, and ferric chloride was used as the cross-linking agent to prepare a eutectic gel carrier for pesticide and fertilizer integration. The specific preparation method is as follows: ① 1.26 g of choline chloride, 0.81 g of urea, and 0.49 g of acrylic acid were mixed, heated at 80°C, and stirred to form a homogeneous transparent liquid to obtain a three-component deep eutectic solvent. 0.38 g of imidacloprid was then added to the solvent and sonicated until completely dissolved to obtain an imidacloprid solution. ② Add 9.8 g of lipoic acid to a 50 mL beaker, heat at 120°C and mechanically stir until completely melted, then add the solution from step ① dropwise to the system and continue the reaction for 30 min; ③ Slowly add 0.064 g of ferric chloride in acetone solution to the mixed solution in step ②, continue the reaction for 20 minutes, transfer it to a sheet polytetrafluoroethylene mold with a particle size of 1-5 mm, and place it at room temperature for 48 hours to obtain a low-melting eutectic gel carrier for medicine and fertilizer. Example 2

[0031] In this example, itaconic acid was used as the unsaturated fatty acid, tebuconazole was used as the model pesticide molecule, and ferric chloride was used as the cross-linking agent to prepare a pesticide-fertilizer eutectic gel carrier. The specific preparation method is as follows: ① Mix 2.42 g of choline chloride, 1.04 g of urea, and 1.12 g of itaconic acid, heat at 90°C, and stir to form a homogeneous transparent liquid to obtain a three-component deep eutectic solvent. Then, add 0.77 g of tebuconazole to the solvent and sonicate until completely dissolved to obtain a tebuconazole solution. ② Add 9.8 g of lipoic acid to a 50 mL beaker, heat at 140°C and mechanically stir until completely melted, then add the solution from step ① dropwise to the system and continue the reaction for 40 min; ③ Slowly add 0.15 g of ferric chloride ethanol solution to the mixed solution in step ②, continue the reaction for 30 minutes, transfer it to a spherical polytetrafluoroethylene mold with a particle size of 1-5 mm, and place it at room temperature for 24 hours to obtain a low-melting gel carrier for integrated medicine and fertilizer. Example 3

[0032] In this example, maleic acid was used as the unsaturated fatty acid, dinotefuran was used as the model pesticide molecule, and aluminum chloride was used as the cross-linking agent to prepare a pesticide-fertilizer eutectic gel carrier. The specific preparation method is as follows: ① 1.90 g of choline chloride, 0.41 g of urea, and 1.19 g of maleic acid were mixed, heated at 60°C, and stirred to form a homogeneous transparent liquid to obtain a three-component deep eutectic solvent. 0.56 g of dinotefuran was then added to the solvent and sonicated until completely dissolved to obtain a dinotefuran solution. ② Add 9.8 g of lipoic acid to a 50 mL beaker, heat at 130°C and mechanically stir until completely melted, then add the solution from step ① dropwise to the system and continue the reaction for 30 min; ③ Slowly add 0.14 g of aluminum chloride methanol solution to the mixed solution in step ②, continue the reaction for 30 min, transfer it to a spherical polytetrafluoroethylene mold with a particle size of 1-5 mm, and place it at room temperature for 36 h to obtain a low-melting eutectic gel carrier for medicine and fertilizer. Example 4

[0033] In this example, maleic acid was used as the unsaturated fatty acid, pyraclostrobin was used as the model pesticide molecule, and zinc chloride was used as the cross-linking agent to prepare a pesticide-fertilizer eutectic gel carrier. The specific preparation method is as follows: ① 1.26 g of choline chloride, 0.81 g of urea, and 0.49 g of maleic acid were mixed, heated at 60°C, and stirred to form a homogeneous transparent liquid to obtain a three-component deep eutectic solvent. 0.38 g of pyraclostrobin was then added to the solvent and sonicated until completely dissolved to obtain a pyraclostrobin solution. ② Add 9.8 g of lipoic acid to a 50 mL beaker, heat at 130°C and mechanically stir until completely melted, then add the solution from step ① dropwise to the system and continue the reaction for 30 min; ③ Slowly add 0.064 g of zinc chloride ether solution to the mixed solution in step ②, continue the reaction for 20 minutes, transfer it to a sheet polytetrafluoroethylene mold with a particle size of 1-5 mm, and place it at room temperature for 48 hours to obtain a low-melting eutectic gel carrier for medicine and fertilizer. Example 5

[0034] In this example, maleic acid was used as the unsaturated fatty acid, fipronil was used as the model pesticide molecule, and calcium chloride was used as the cross-linking agent to prepare a eutectic gel carrier for pesticide and fertilizer integration. The specific preparation method is as follows: ① 0.85 g of choline chloride, 0.22 g of urea, and 0.49 g of maleic acid were mixed, heated at 80°C, and stirred to form a homogeneous transparent liquid to obtain a three-component deep eutectic solvent. 0.12 g of fipronil was then added to the solvent and sonicated until completely dissolved to obtain a fipronil solution. ② Add 9.8 g of lipoic acid to a 50 mL beaker, heat at 130°C and mechanically stir until completely melted, then add the solution from step ① dropwise to the system and continue the reaction for 30 min; ③ Slowly add 0.058 g of calcium chloride in acetone solution to the mixed solution in step ②, continue the reaction for 10 to 30 minutes, transfer it to a sheet polytetrafluoroethylene mold with a particle size of 1 to 5 mm, and place it at room temperature for 48 hours to obtain a low-melting eutectic gel carrier for medicine and fertilizer. Example 6

[0035] In this example, itaconic acid was used as the unsaturated fatty acid, prochloraz was used as the model pesticide molecule, and ferric chloride was used as the cross-linking agent to prepare a pesticide-fertilizer eutectic gel carrier. The specific preparation method is as follows: ① 1.25 g of choline chloride, 0.27 g of urea, and 0.87 g of itaconic acid were mixed, heated at 80°C, and stirred to form a homogeneous transparent liquid to obtain a three-component deep eutectic solvent. 0.25 g of prochloraz was then added to the solvent and ultrasonicated until completely dissolved to obtain a prochloraz solution. ② Add 9.8 g of lipoic acid to a 50 mL beaker, heat at 140°C and mechanically stir until completely melted, then add the solution from step ① dropwise to the system and continue the reaction for 30 min; ③ Slowly add 0.126 g of ferric chloride in acetone solution to the mixed solution in step ②, continue the reaction for 20 minutes, transfer it to a sheet polytetrafluoroethylene mold with a particle size of 1-5 mm, and place it at room temperature for 36 hours to obtain a low-melting gel carrier for integrated fertilizer and medicine. Example 7

[0036] In this example, acrylic acid was used as the unsaturated fatty acid, thiamethoxam and chlorantraniliprole were used as model pesticide molecules, and ferric chloride was used as a cross-linking agent to prepare a eutectic gel carrier for pesticides and fertilizers. The specific preparation method is as follows: ① After mixing 1.26 g of choline chloride, 0.81 g of urea, and 0.49 g of acrylic acid, the mixture was heated at 80°C with stirring to form a homogeneous transparent liquid, thereby obtaining a three-component deep eutectic solvent. Subsequently, 0.23 g of thiamethoxam and 0.15 g of chlorantraniliprole were added to the solvent and sonicated until completely dissolved, thereby obtaining a mixed solution of thiamethoxam and chlorantraniliprole. ② Add 9.8 g of lipoic acid to a 50 mL beaker, heat at 120°C and mechanically stir until completely melted, then add the solution from step ① dropwise to the system and continue the reaction for 30 min; ③ Slowly add 0.064 g of ferric chloride in acetone solution to the mixed solution in step ②, continue the reaction for 20 minutes, transfer it to a spherical polytetrafluoroethylene mold with a particle size of 1-5 mm, and place it at room temperature for 48 hours to obtain a low-melting gel carrier for integrated fertilizer and medicine.

[0037] Comparative Example 1 To demonstrate the importance of deep eutectic solvents, this comparative example uses water as the dispersion medium and urea as the fertilizer to prepare a lipoic acid-based hydrogel carrier. The specific preparation method is as follows: First, 0.3 g of sodium hydroxide and 0.7 g of urea were dissolved in 10 mL of deionized water, stirred evenly, and then 3 g of lipoic acid was slowly added; then, the mixture was heated and stirred at 60°C for 2 h, and the mixed solution was transferred to a spherical polytetrafluoroethylene mold with a particle size of 1-5 mm. Then, it was heated at a constant temperature of 50°C for 1 h and finally cooled to room temperature to obtain a lipoic acid-based hydrogel carrier.

[0038] Comparative Example 2 To demonstrate the importance of lipoic acid ring-opening polymerization for the controlled-release performance of a carrier, this comparative example used chitosan (molecular weight: 100 kDa) as the gel backbone, a deep eutectic solvent composed of choline chloride, urea, and maleic acid as the dispersion medium, imidacloprid as the model pesticide molecule, and glutaraldehyde as the crosslinker to prepare a drug-fertilizer integrated eutectic gel carrier. The specific preparation method is as follows: ① After mixing 19.57 g of choline chloride, 5.05 g of urea, and 11.39 g of maleic acid, heating and stirring at 80°C to form a homogeneous transparent liquid, a three-component deep eutectic solvent was obtained. Then, 1.6 g of imidacloprid was added to the solvent and sonicated until completely dissolved, thereby obtaining an imidacloprid solution. ② Add 2 g of chitosan to the solution in step ①, heat at 80°C and mechanically stir until completely dissolved; ③ Slowly add 0.4 g of glutaraldehyde to the mixed solution in step ②, continue the reaction for 20 min, transfer it to a spherical polytetrafluoroethylene mold with a particle size of 1-5 mm, and place it at room temperature for 24 h to obtain a low-melting gel carrier for integrated fertilizer and medicine.

[0039] Comparison of gel carrier performance data of Examples 1-7 and Comparative Examples 1-2:

[0040] In the methods described in Examples 1-7 of the present invention, by changing the type of deep eutectic solvent, the mass ratio of lipoic acid to the deep eutectic solvent, the type of pesticide molecule, and the type of cross-linking agent, a drug-fertilizer integrated deep eutectic gel carrier can be obtained, and the carrier exhibits ideal mechanical properties, excellent pH and redox dual-responsive release performance, and high environmental stability.

[0041] In the preparation method described in Comparative Example 1, since the dispersion medium is replaced with water, and most pesticide molecules lack good water solubility, it is difficult to obtain a pesticide-fertilizer integrated gel carrier with high environmental stability. While the gel carrier described in Comparative Example 2 can achieve integrated pesticide and fertilizer, the lack of dynamic sulfur-sulfur bonds makes it difficult to achieve pH- and redox-responsive controlled release of the pesticide and fertilizer.

[0042] In summary, the integrated drug-fertilizer eutectic gel carriers described in Examples 1-7 of the present invention have significantly better environmental stability and controlled release performance than comparative examples 1-2 under specific composition conditions, exhibiting excellent pH and redox dual-responsive release performance and high environmental adaptability.

[0043] In order to further verify the beneficial effects of the present invention, the inventors conducted tests on the environmental stability, mechanical properties, release properties, insecticidal activity and plant nutrition effect of the gel carrier prepared in Example 1.

[0044] Environmental stability test 50 mg of gel carrier was placed in an oven at 60°C to test the change in carrier mass over time. Three replicates were set for each sample. The solvent loss rate of the gel carrier can be calculated using formula (1): (1).

[0045] in, W 0 and W t Represent the initial mass of the gel carrier and the mass after different drying times, respectively.

[0046] Release performance test 300 mg of gel support was immersed in 50 mL of phosphate buffer (10 mM, pH = 5, 7, 9) or glutathione (100 mM) at different pH values. At predetermined time intervals, 3 mL of solution was removed and 3 mL of solvent was added as a supplement. The concentrations of imidacloprid and urea were then determined by high-performance liquid chromatography and ultraviolet spectroscopy, respectively. All tests were repeated three times. The cumulative release rate (CRR) of the pesticide and urea can be calculated using formula (2): (2).

[0047] Among them, c t and v t are the concentrations of pesticide and urea and the volume of the removed solution at time t, respectively. v 0 (50 mL) is the total volume of the release solution, m 0 is the total weight of pesticide and urea in the gel carrier.

[0048] Insecticidal activity test Aphids were used as model pests to test the biological activities of 10% imidacloprid wettable powder and integrated fertilizer and pesticide eutectic gel carrier. This experiment used five soils with active ingredient concentrations of 3.125, 6.25, 12.5, 25.0 and 50.0 mg / kg, respectively. First, wheat seeds were planted in pots containing 120 g of nutrient soil, and the gel carrier was sprinkled on the soil surface; when the wheat seedlings grew to the 4-5 leaf stage, 20 aphids were inoculated in each pot, and the number of dead aphids was counted after 48 hours to calculate the mortality rate. 10% imidacloprid wettable powder was used as the control group, and deionized water was used as the blank control group. Each treatment was repeated three times. The median lethal concentration (LC50) was calculated using SPSS26 software. 50 ).

[0049] Plant Nutrition Effect Test Wheat was used as the model plant in this experiment. All wheat seeds were disinfected with 0.05 wt% sodium hypochlorite and washed three times with deionized water. Plastic pots 8 cm in diameter and height were filled with 200 g of soil and treated with 2 g of a eutectic gel carrier for the integrated fertilizer and pesticide. Untreated soil served as a blank control. Ten wheat seeds were sown in the soil at a depth of 3 cm, and tap water was added to maintain moisture throughout the growing season. All plants were incubated in the laboratory at a temperature of 25 ± 1°C and a 12:12 h light:dark cycle for 14 days. Wheat height, root length, fresh weight, and dry weight were measured and analyzed. Three replicates were set up for each treatment.

[0050] The basic principles, main features and advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the appended claims rather than the above description. Therefore, it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure signs in the claims should not be regarded as limiting the claims involved.

[0051] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for preparing a medicine-fertilizer integrated eutectic gel carrier, characterized in that: The preparation method comprises the following steps: ① After mixing choline chloride, urea, and unsaturated fatty acids in a certain proportion, heating and stirring at 60-90°C to form a homogeneous transparent liquid, a three-component deep eutectic solvent is obtained; then, the pesticide molecules are added to the solvent and ultrasonically treated until completely dissolved to obtain a pesticide solution; ② Add lipoic acid to the reactor, heat at 120-140°C and mechanically stir until completely melted, then add the solution in step ① dropwise to the system and continue the reaction for 20-40 minutes; ③ Slowly add the metal chloride solution dropwise to the mixed solution in step ②, continue the reaction for 10 to 30 minutes, transfer it to polytetrafluoroethylene molds of different shapes and sizes, and place it at room temperature for 24 to 48 hours to obtain a low-melting gel carrier for integrated fertilizer and medicine.

2. The preparation method of the medicine-fertilizer integrated eutectic gel carrier according to claim 1, characterized in that: The unsaturated fatty acid is one or more of acrylic acid, itaconic acid and maleic acid.

3. The preparation method of the medicine-fertilizer integrated eutectic gel carrier according to claim 1, characterized in that: The pesticide is an active ingredient of an insecticide or fungicide that does not contain a double bond structure and is resistant to high temperatures, specifically including one or more of fipronil, prochloraz, tebuconazole, imidacloprid, pyraclostrobin, dinotefuran, thiamethoxam, and chlorantraniliprole.

4. The preparation method of the medicine-fertilizer integrated eutectic gel carrier according to claim 1, characterized in that: The metal chloride is one or more of ferric chloride, aluminum chloride, zinc chloride and calcium chloride.

5. The preparation method of the medicine-fertilizer integrated eutectic gel carrier according to claim 1, characterized in that: The solvent used to dissolve the metal chloride is one or more of acetone, methanol, ethanol and ether.

6. The preparation method of the medicine-fertilizer integrated eutectic gel carrier according to claim 1, characterized in that: The molar ratio of the choline chloride, urea and unsaturated fatty acid is 1:(1-2):(0.5-1).

7. The method for preparing the medicine-fertilizer integrated eutectic gel carrier according to claim 1, wherein: The proportions of the raw materials in the integrated medicine-fertilizer eutectic gel carrier are as follows: 64-94.5 parts by weight of lipoic acid, 5-30 parts by weight of a deep eutectic solvent, 0.25-5 parts by weight of pesticide molecules, and 0.25-1 part by weight of a metal chloride.

8. The method for preparing the medicine-fertilizer integrated eutectic gel carrier according to claim 1, wherein: The gel carrier is in the form of flakes or spheres, and has a particle size range of 1-5 mm.

9. An application of the integrated medicine-fertilizer eutectic gel carrier prepared according to claim 1, characterized in that: The pesticide carrier is used for pH and redox responsive controlled release of pesticides and urea.

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