A foliar fertilizer with high nitrogen utilization rate and a preparation method thereof

Abstract

The application belongs to the field of fertilizers, and particularly relates to a high-nitrogen-fertilizer utilization rate foliar fertilizer and a preparation method thereof. Glycidyl methacrylate is used to prepare a polymer, and then polyarginine is used to modify the polymer to obtain a composite matrix. Part of the composite matrix is combined with 3,4,9,10-perylenetetracarboxylic dianhydride to obtain a photosensitive matrix. The photosensitive matrix is used as a ligand, metal ions are combined with the ligand to form a complex, and the complex is compounded with the composite matrix and soluble compounds of nutrient elements to obtain the foliar fertilizer. The high-nitrogen-fertilizer utilization rate foliar fertilizer can promote photosynthesis of plants, promote root growth, and improve nitrogen absorption and utilization of plants.

Description

Technical Field

[0001] The invention belongs to the field of fertilizers, and in particular relates to a foliar fertilizer with high nitrogen fertilizer utilization rate and a preparation method thereof. Background Art

[0002] Rice field ecosystems are not only the foundation of food production, but also an important carrier of biodiversity conservation. They occupy an important position in the global biogeochemical cycle and agricultural carbon sink. Diversified planting patterns can significantly improve the stability and productivity of the ecosystem. Higher species diversity not only helps to improve rice field productivity, but also enhances the system's adaptability to environmental changes. When biological activities and organic matter cycles in rice field ecosystems are insufficient to provide the nutrients needed for crop growth, appropriate fertilization becomes a necessary measure. Fertilization is a key means to quickly and effectively supplement crop nutrients, promote rice plant growth, and increase grain yield. However, different fertilization methods have different effects on crop growth and soil carbon, nitrogen, and phosphorus cycles. Traditional single fertilization methods may lead to inefficient nutrient utilization and even environmental pollution.

[0003] Traditional fertilization methods mainly involve applying carbon, nitrogen, phosphorus, and potassium to the roots. Besides the roots, leaves are the most important nutrient absorption organs and also play a key role in nutrient absorption and utilization. Foliar fertilization sprays the nutrients required by plants directly onto the leaf surface, effectively improving nutrient absorption efficiency. Compared with root fertilization, it has a faster absorption rate and higher utilization rate. The effectiveness of foliar fertilizer application depends on the crop leaves' ability to absorb and transport nutrients. Whether nutrients can smoothly enter the mesophyll cells is a key factor in determining the efficiency of nutrient absorption and utilization by the leaves. At the same time, different functional types of foliar fertilizers will also have a significant impact on the growth characteristics of crops and the characteristics of plant communities. While optimizing nutrient supply, they can also regulate crop physiological processes and improve overall production efficiency.

[0004] Nitrogen fertilizer application contributes as much as 30% to 50% to increased grain production, making it the most effective way to boost grain output. Current demand for nitrogen fertilizer is high, but its utilization rate (NUE) is far lower than in developed countries in Europe and the United States. To improve this situation, precise regulation of aboveground crop growth, such as foliar spraying of plant growth regulators, biostimulants, organic acids, sugars, and nutrients, is an important approach to promoting nutrient uptake by crop roots, reducing fertilizer usage, and improving NUE. However, existing foliar fertilizer products generally suffer from low technical content, poor quality, and substandard nutrient content. Therefore, improving foliar fertilizer preparation techniques and product functionality, scientifically enhancing NUE in rice paddy ecosystems, improving nutrient cycling in rice paddies, and promoting the sustainable development of biodiversity-based agriculture have become crucial research topics. Summary of the Invention

[0005] The present invention mainly provides a foliar fertilizer with high nitrogen utilization rate, strong affinity with plants, and easy absorption. The technical solution is as follows:

[0006] A method for preparing a foliar fertilizer with high nitrogen fertilizer utilization rate comprises the following steps: preparing a polymer using glycidyl methacrylate, and then modifying it using polyarginine to obtain a composite matrix; combining a portion of the composite matrix with 3,4,9,10-perylenetetracarboxylic dianhydride to obtain a photosensitive matrix; using the photosensitive matrix as a ligand, combining metal ions with the ligand to form a complex; and compounding the complex with the composite matrix and a soluble compound of nutrient elements to obtain the foliar fertilizer.

[0007] Furthermore, the nutrient elements include phosphorus, potassium and calcium, and may or may not contain one or more of magnesium, iron, zinc, boron, aluminum, manganese, copper or sulfur; and the degree of polymerization of the polyarginine is 2 to 10.

[0008] Furthermore, 1 to 5 parts of the complex are compounded with 120 to 200 parts of the composite matrix, 60 to 100 parts of nutrient elements and water to obtain foliar fertilizer, based on parts by mass.

[0009] Further, the following steps are included:

[0010] a. Under nitrogen atmosphere, vinyl acetate and glycidyl methacrylate were dissolved in N,N-dimethylformamide, azobisisobutyronitrile was added, and the mixture was reacted at 60-80°C for 6-8 hours. The reaction was terminated, cooled to room temperature, precipitated with n-hexane, and filtered and dried to obtain a polymer;

[0011] b. Then, the polymer and polyarginine are added to N,N-dimethylformamide, and then 4-dimethylaminopyridine and dicyclohexylcarbodiimide are added. The reaction is carried out at room temperature for 10 to 16 hours. After the reaction is terminated, the composite matrix is ​​precipitated with n-hexane, filtered and dried to obtain the composite matrix.

[0012] c. Mix a portion of the composite matrix with 3,4,9,10-perylenetetracarboxylic dianhydride and imidazole, react at 160-170°C for 18-24 hours under a nitrogen atmosphere, cool to room temperature, add equal volumes of ethanol and concentrated hydrochloric acid, react for 8-12 hours, collect the precipitate, elute and purify to obtain a photosensitive matrix;

[0013] d. The photosensitive matrix and the soluble zinc salt are dispersed in an aqueous solution of ethanol, and the mixture is fully mixed and reacted at 50-70° C. until the ethanol evaporates. After cooling to room temperature, stirring is continued for 20-40 minutes. The precipitate is collected, washed thoroughly, and dried to obtain a complex.

[0014] e. Compounding the foliar fertilizer base, the composite base and the nutrient elements to obtain the foliar fertilizer.

[0015] Furthermore, the mass ratio of vinyl acetate to glycidyl methacrylate in step a is 2.5-3.5:1; the mass ratio of vinyl acetate to azobisisobutyronitrile in step a is 80-100:1.

[0016] Furthermore, the mass ratio of the polymer in step b to polyarginine is 6 to 8:1; the mass ratio of the polyarginine in step b to 4-dimethylaminopyridine is 10 to 13:1; and the mass ratio of the 4-dimethylaminopyridine in step b to dicyclohexylcarbodiimide is 1:2 to 3.

[0017] Furthermore, in step c, the mass ratio of the composite matrix to 3,4,9,10-perylenetetracarboxylic dianhydride is 2-3:1; and the mass ratio of 3,4,9,10-perylenetetracarboxylic dianhydride to imidazole in step c is 1:8-10.

[0018] Furthermore, the mass ratio of the soluble zinc salt to the photosensitive matrix in step d is 0.8 to 2:1.

[0019] Furthermore, the soluble zinc salt in step d includes one or more of zinc chloride, zinc nitrate, and zinc acetate.

[0020] A foliar fertilizer with high nitrogen fertilizer utilization rate prepared by the above preparation method.

[0021] By adopting the above scheme, the method of the present invention has the following advantages:

[0022] 1. The present invention combines polymers with amino acids to evenly disperse the amino acids in foliar fertilizers, and binds the amino acids to reduce their activity, preventing them from being destroyed in subsequent treatments. After application, the consumption of amino acids by microorganisms in the air is reduced, thereby promoting the absorption and utilization of nitrogen by plants.

[0023] 2. The present invention combines polyarginine with zinc ions to form an organic complex, which can significantly increase the solubility of zinc ions, making them more easily absorbed by plants and avoiding element loss. The combined force of the complex and the encapsulation of the ligands create a sustained-release effect, preventing damage to plants caused by a transient surge in zinc ions. Zinc ions also synergize with nitrogen in amino acids, promoting nitrogen absorption and further optimizing the quality of foliar fertilizers.

[0024] 3. The present invention combines a photosensitizer with a matrix to artificially capture and convert solar energy, solving the problem of natural conditions limiting the efficiency of photosynthesis. It increases the chlorophyll content of plants, enhances photosynthesis, and improves the light absorption efficiency of plants. It can also optimize the morphology of plant roots, enhance root activity and root absorption area, thereby enhancing the absorption and utilization of nitrogen nutrients by rice and improving the utilization rate of nitrogen in basal fertilizers.

[0025] 4. The composite matrix of the present invention has both hydrophobic segments and hydrophilic segments, which can be used as an active agent on the leaf surface to improve the wettability of foliar fertilizer on the leaf surface, and can also improve the dispersibility between raw materials in aqueous solution and improve the fluidity of foliar fertilizer.

[0026] 5. The foliar fertilizer of the present invention is in liquid form, and the composite matrix formed by the polymer and amino acid has a strong adhesion ability to the leaves and good affinity with the leaf surface. The fertilizer nutrients are more easily absorbed by the plants, solving the problem that solid compound fertilizers are difficult to absorb and have poor effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A comparison chart of the effects of foliar fertilizer on nitrogen accumulation in rice in various embodiments;

[0028] Figure 2 A comparison chart of the effects of foliar fertilizer on the agronomic utilization rate of nitrogen in rice in various embodiments;

[0029] Figure 3 A comparison chart of the effects of foliar fertilizers on the physiological utilization rate of nitrogen in rice according to various embodiments;

[0030] Figure 4 A comparison chart of the effects of foliar fertilizers on nitrogen absorption and utilization efficiency of rice in various embodiments; DETAILED DESCRIPTION

[0031] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0032] Example 1: (1) Under a nitrogen atmosphere, 21 g of vinyl acetate and 8.5 g of glycidyl methacrylate were dissolved in 250 mL of N,N-dimethylformamide, and 0.3 g of azobisisobutyronitrile was added. The mixture was reacted at 70° C. for 7 h, then terminated, cooled to room temperature, precipitated with n-hexane, and filtered and dried to obtain a polymer.

[0033] (2) Then, 1.2 g of polymer and 0.2 g of polyarginine were added to 20 mL of N,N-dimethylformamide, and then 0.02 g of 4-dimethylaminopyridine and 0.04 g of dicyclohexylcarbodiimide were added. The reaction was allowed to proceed at room temperature for 16 h. After the reaction was terminated, the composite matrix was precipitated with n-hexane and filtered and dried to obtain the composite matrix.

[0034] (3) 1 g of the composite matrix was mixed with 0.5 g of 3,4,9,10-perylenetetracarboxylic dianhydride and 4 g of imidazole, and the mixture was reacted at 160°C for 20 h under a nitrogen atmosphere. After cooling to room temperature, 35 mL of ethanol and 35 mL of concentrated hydrochloric acid were added and the mixture was reacted for 10 h. The precipitate was collected and purified by elution to obtain a photosensitive matrix;

[0035] (4) Disperse 0.4 g of the photosensitive matrix and 0.5 g of zinc chloride in 75 mL of a 50% ethanol aqueous solution, mix thoroughly and react at 70°C until the ethanol evaporates. After cooling to room temperature, continue stirring for 40 min. Collect the precipitate, wash thoroughly, and then dry to obtain a complex.

[0036] (5) 2.5 g of the complex was mixed with 80 g of the composite matrix, 20 g of phosphorus pentoxide, 20 g of potassium oxide and 377.5 g of water to prepare a foliar fertilizer.

[0037] Example 2: (1) Under a nitrogen atmosphere, 29 g of vinyl acetate and 8.5 g of glycidyl methacrylate were dissolved in 250 mL of N,N-dimethylformamide, and 0.3 g of azobisisobutyronitrile was added. The mixture was reacted at 70° C. for 7 h, then terminated, cooled to room temperature, precipitated with n-hexane, and filtered and dried to obtain a polymer.

[0038] (2) Then, 1.2 g of polymer and 0.2 g of polyarginine were added to 20 mL of N,N-dimethylformamide, and then 0.02 g of 4-dimethylaminopyridine and 0.04 g of dicyclohexylcarbodiimide were added. The reaction was allowed to proceed at room temperature for 16 h. After the reaction was terminated, the composite matrix was precipitated with n-hexane and filtered and dried to obtain the composite matrix.

[0039] (3) 1 g of the composite matrix was mixed with 0.5 g of 3,4,9,10-perylenetetracarboxylic dianhydride and 4 g of imidazole, and the mixture was reacted at 160°C for 20 h under a nitrogen atmosphere. After cooling to room temperature, 35 mL of ethanol and 35 mL of concentrated hydrochloric acid were added and the mixture was reacted for 10 h. The precipitate was collected and purified by elution to obtain a photosensitive matrix;

[0040] (4) Disperse 0.4 g of the photosensitive matrix and 0.5 g of zinc chloride in 75 mL of a 50% ethanol aqueous solution, mix thoroughly and react at 70°C until the ethanol evaporates. After cooling to room temperature, continue stirring for 40 min. Collect the precipitate, wash thoroughly, and then dry to obtain a complex.

[0041] (5) 2.5 g of the complex was mixed with 80 g of the composite matrix, 20 g of phosphorus pentoxide, 20 g of potassium oxide and 377.5 g of water to prepare a foliar fertilizer.

[0042] Example 3: (1) Under a nitrogen atmosphere, 21 g of vinyl acetate and 8.5 g of glycidyl methacrylate were dissolved in 250 mL of N,N-dimethylformamide, and 0.3 g of azobisisobutyronitrile was added. The mixture was reacted at 70° C. for 7 h, then terminated, cooled to room temperature, precipitated with n-hexane, and filtered and dried to obtain a polymer.

[0043] (2) Then, 1.5 g of polymer and 0.2 g of polyarginine were added to 20 mL of N,N-dimethylformamide, and then 0.02 g of 4-dimethylaminopyridine and 0.04 g of dicyclohexylcarbodiimide were added. The reaction was allowed to proceed at room temperature for 16 h. After the reaction was terminated, the composite matrix was precipitated with n-hexane and filtered and dried to obtain the composite matrix.

[0044] (3) 1 g of the composite matrix was mixed with 0.5 g of 3,4,9,10-perylenetetracarboxylic dianhydride and 4 g of imidazole, and the mixture was reacted at 160°C for 20 h under a nitrogen atmosphere. After cooling to room temperature, 35 mL of ethanol and 35 mL of concentrated hydrochloric acid were added and the mixture was reacted for 10 h. The precipitate was collected and purified by elution to obtain a photosensitive matrix;

[0045] (4) Disperse 0.4 g of the photosensitive matrix and 0.5 g of zinc chloride in 75 mL of a 50% ethanol aqueous solution, mix thoroughly and react at 70°C until the ethanol evaporates. After cooling to room temperature, continue stirring for 40 min. Collect the precipitate, wash thoroughly, and then dry to obtain a complex.

[0046] (5) 2.5 g of the complex was mixed with 80 g of the composite matrix, 20 g of phosphorus pentoxide, 20 g of potassium oxide and 377.5 g of water to prepare a foliar fertilizer.

[0047] Example 4: (1) Under a nitrogen atmosphere, 21 g of vinyl acetate and 8.5 g of glycidyl methacrylate were dissolved in 250 mL of N,N-dimethylformamide, and 0.3 g of azobisisobutyronitrile was added. The mixture was reacted at 70° C. for 7 h, then terminated, cooled to room temperature, precipitated with n-hexane, and filtered and dried to obtain a polymer.

[0048] (2) Then, 1.2 g of polymer and 0.2 g of polyarginine were added to 20 mL of N,N-dimethylformamide, and then 0.02 g of 4-dimethylaminopyridine and 0.04 g of dicyclohexylcarbodiimide were added. The reaction was allowed to proceed at room temperature for 10 h. After the reaction was terminated, the composite matrix was precipitated with n-hexane and filtered and dried to obtain the composite matrix.

[0049] (3) 1 g of the composite matrix was mixed with 0.5 g of 3,4,9,10-perylenetetracarboxylic dianhydride and 4 g of imidazole, and the mixture was reacted at 160°C for 20 h under a nitrogen atmosphere. After cooling to room temperature, 35 mL of ethanol and 35 mL of concentrated hydrochloric acid were added and the mixture was reacted for 10 h. The precipitate was collected and purified by elution to obtain a photosensitive matrix;

[0050] (4) Disperse 0.4 g of the photosensitive matrix and 0.5 g of zinc chloride in 75 mL of a 50% ethanol aqueous solution, mix thoroughly and react at 70°C until the ethanol evaporates. After cooling to room temperature, continue stirring for 40 min. Collect the precipitate, wash thoroughly, and then dry to obtain a complex.

[0051] (5) 2.5 g of the complex was mixed with 80 g of the composite matrix, 20 g of phosphorus pentoxide, 20 g of potassium oxide and 377.5 g of water to prepare a foliar fertilizer.

[0052] Example 5: (1) Under a nitrogen atmosphere, 21 g of vinyl acetate and 8.5 g of glycidyl methacrylate were dissolved in 250 mL of N,N-dimethylformamide, and 0.3 g of azobisisobutyronitrile was added. The mixture was reacted at 70° C. for 7 h, then terminated, cooled to room temperature, precipitated with n-hexane, and filtered and dried to obtain a polymer.

[0053] (2) Then, 1.2 g of polymer and 0.2 g of polyarginine were added to 20 mL of N,N-dimethylformamide, and then 0.02 g of 4-dimethylaminopyridine and 0.04 g of dicyclohexylcarbodiimide were added. The reaction was allowed to proceed at room temperature for 16 h. After the reaction was terminated, the composite matrix was precipitated with n-hexane and filtered and dried to obtain the composite matrix.

[0054] (3) 1.5 g of the composite matrix was mixed with 0.5 g of 3,4,9,10-perylenetetracarboxylic dianhydride and 4 g of imidazole, and the mixture was reacted at 160° C. for 20 h under a nitrogen atmosphere. After cooling to room temperature, 35 mL of ethanol and 35 mL of concentrated hydrochloric acid were added and the mixture was reacted for 10 h. The precipitate was collected and purified by elution to obtain a photosensitive matrix;

[0055] (4) Disperse 0.4 g of the photosensitive matrix and 0.5 g of zinc chloride in 75 mL of a 50% ethanol aqueous solution, mix thoroughly and react at 70°C until the ethanol evaporates. After cooling to room temperature, continue stirring for 40 min. Collect the precipitate, wash thoroughly, and then dry to obtain a complex.

[0056] (5) 2.5 g of the complex was mixed with 80 g of the composite matrix, 20 g of phosphorus pentoxide, 20 g of potassium oxide and 377.5 g of water to prepare a foliar fertilizer.

[0057] Example 6: (1) Under a nitrogen atmosphere, 21 g of vinyl acetate and 8.5 g of glycidyl methacrylate were dissolved in 250 mL of N,N-dimethylformamide, and 0.3 g of azobisisobutyronitrile was added. The mixture was reacted at 70° C. for 7 h, then terminated, cooled to room temperature, precipitated with n-hexane, and filtered and dried to obtain a polymer.

[0058] (2) Then, 1.2 g of polymer and 0.2 g of polyarginine were added to 20 mL of N,N-dimethylformamide, and then 0.02 g of 4-dimethylaminopyridine and 0.04 g of dicyclohexylcarbodiimide were added. The reaction was allowed to proceed at room temperature for 16 h. After the reaction was terminated, the composite matrix was precipitated with n-hexane and filtered and dried to obtain the composite matrix.

[0059] (3) 1 g of the composite matrix was mixed with 0.5 g of 3,4,9,10-perylenetetracarboxylic dianhydride and 4 g of imidazole, and the mixture was reacted at 160°C for 20 h under a nitrogen atmosphere. After cooling to room temperature, 35 mL of ethanol and 35 mL of concentrated hydrochloric acid were added and the mixture was reacted for 10 h. The precipitate was collected and purified by elution to obtain a photosensitive matrix;

[0060] (4) Disperse 1 g of the photosensitive matrix and 0.5 g of zinc chloride in 75 mL of a 50% ethanol aqueous solution, mix thoroughly and react at 70°C until the ethanol evaporates. After cooling to room temperature, continue stirring for 40 min. Collect the precipitate, wash thoroughly, and then dry to obtain a complex.

[0061] (5) 2.5 g of the complex was mixed with 80 g of the composite matrix, 20 g of phosphorus pentoxide, 20 g of potassium oxide and 377.5 g of water to prepare a foliar fertilizer.

[0062] Example 7: (1) Under a nitrogen atmosphere, 21 g of vinyl acetate and 8.5 g of glycidyl methacrylate were dissolved in 250 mL of N,N-dimethylformamide, and 0.3 g of azobisisobutyronitrile was added. The mixture was reacted at 70° C. for 7 h, then terminated, cooled to room temperature, precipitated with n-hexane, and filtered and dried to obtain a polymer.

[0063] (2) Then, 1.2 g of polymer and 0.2 g of polyarginine were added to 20 mL of N,N-dimethylformamide, and then 0.02 g of 4-dimethylaminopyridine and 0.04 g of dicyclohexylcarbodiimide were added. The reaction was allowed to proceed at room temperature for 16 h. After the reaction was terminated, the composite matrix was precipitated with n-hexane and filtered and dried to obtain the composite matrix.

[0064] (3) 1 g of the composite matrix was mixed with 0.5 g of 3,4,9,10-perylenetetracarboxylic dianhydride and 4 g of imidazole, and the mixture was reacted at 160°C for 20 h under a nitrogen atmosphere. After cooling to room temperature, 35 mL of ethanol and 35 mL of concentrated hydrochloric acid were added and the mixture was reacted for 10 h. The precipitate was collected and purified by elution to obtain a photosensitive matrix;

[0065] (4) Disperse 0.4 g of the photosensitive matrix and 0.5 g of zinc chloride in 75 mL of a 50% ethanol aqueous solution, mix thoroughly and react at 50° C. until the ethanol evaporates. After cooling to room temperature, continue stirring for 40 min. Collect the precipitate, wash thoroughly, and then dry to obtain a complex.

[0066] (5) 2.5 g of the complex was mixed with 80 g of the composite matrix, 20 g of phosphorus pentoxide, 20 g of potassium oxide and 377.5 g of water to prepare a foliar fertilizer.

[0067] Example 8: (1) Under a nitrogen atmosphere, 21 g of vinyl acetate and 8.5 g of glycidyl methacrylate were dissolved in 250 mL of N,N-dimethylformamide, and 0.3 g of azobisisobutyronitrile was added. The mixture was reacted at 70° C. for 7 h, then terminated, cooled to room temperature, precipitated with n-hexane, and filtered and dried to obtain a polymer.

[0068] (2) Then, 1.2 g of polymer and 0.2 g of polyarginine were added to 20 mL of N,N-dimethylformamide, and then 0.02 g of 4-dimethylaminopyridine and 0.04 g of dicyclohexylcarbodiimide were added. The reaction was allowed to proceed at room temperature for 16 h. After the reaction was terminated, the composite matrix was precipitated with n-hexane and filtered and dried to obtain the composite matrix.

[0069] (3) 1 g of the composite matrix was mixed with 0.5 g of 3,4,9,10-perylenetetracarboxylic dianhydride and 4 g of imidazole, and the mixture was reacted at 160°C for 20 h under a nitrogen atmosphere. After cooling to room temperature, 35 mL of ethanol and 35 mL of concentrated hydrochloric acid were added and the mixture was reacted for 10 h. The precipitate was collected and purified by elution to obtain a photosensitive matrix;

[0070] (4) Disperse 0.4 g of the photosensitive matrix and 0.5 g of zinc chloride in 75 mL of a 50% ethanol aqueous solution, mix thoroughly and react at 70°C until the ethanol evaporates. After cooling to room temperature, continue stirring for 20 min. Collect the precipitate, wash thoroughly, and then dry to obtain a complex.

[0071] (5) 2.5 g of the complex was mixed with 80 g of the composite matrix, 20 g of phosphorus pentoxide, 20 g of potassium oxide and 377.5 g of water to prepare a foliar fertilizer.

[0072] Example 9: (1) Under a nitrogen atmosphere, 21 g of vinyl acetate and 8.5 g of glycidyl methacrylate were dissolved in 250 mL of N,N-dimethylformamide, and 0.3 g of azobisisobutyronitrile was added. The mixture was reacted at 70° C. for 7 h, then terminated, cooled to room temperature, precipitated with n-hexane, and filtered and dried to obtain a polymer.

[0073] (2) Then, 1.2 g of polymer and 0.2 g of polyarginine were added to 20 mL of N,N-dimethylformamide, and then 0.02 g of 4-dimethylaminopyridine and 0.04 g of dicyclohexylcarbodiimide were added. The reaction was allowed to proceed at room temperature for 16 h. After the reaction was terminated, the composite matrix was precipitated with n-hexane and filtered and dried to obtain the composite matrix.

[0074] (3) 1 g of the composite matrix was mixed with 0.5 g of 3,4,9,10-perylenetetracarboxylic dianhydride and 4 g of imidazole, and the mixture was reacted at 160°C for 20 h under a nitrogen atmosphere. After cooling to room temperature, 35 mL of ethanol and 35 mL of concentrated hydrochloric acid were added and the mixture was reacted for 10 h. The precipitate was collected and purified by elution to obtain a photosensitive matrix;

[0075] (4) Disperse 0.4 g of the photosensitive matrix and 0.5 g of zinc chloride in 75 mL of a 50% ethanol aqueous solution, mix thoroughly and react at 70°C until the ethanol evaporates. After cooling to room temperature, continue stirring for 40 min. Collect the precipitate, wash thoroughly, and then dry to obtain a complex.

[0076] (5) 0.5 g of the complex was mixed with 80 g of the composite matrix, 20 g of phosphorus pentoxide, 20 g of potassium oxide and 379.5 g of water to prepare a foliar fertilizer.

[0077] Example sample performance test:

[0078] Cultivate rice seedlings of the same size and growth in a rice seedling tray, transplant them to field crops when they have 3 leaves and 1 heart, and plant them at a conventional density. Apply 240 kg of pure nitrogen, 12 kg of pure phosphorus, and 72 kg of pure potassium per hectare throughout the entire growth period. Foliar fertilizer is sprayed at the heading stage and the grain filling stage of rice, with 400 L of diluted solution sprayed per hectare at each time. Clear water is used as a control example, and a no-fertilization blank control is set. Each embodiment is repeated 10 times and averaged. After the ripening period, the grain yield, plant nitrogen accumulation, nitrogen agronomic utilization rate, nitrogen physiological utilization rate, and nitrogen absorption utilization rate of rice are measured. Each sample is measured 3 times and averaged. The nitrogen content of the collected plants and soil was determined by an isotope mass spectrometer (Elementar). The agronomic nitrogen utilization rate was calculated by the formula (grain yield of the fertilized treatment - grain yield of the unfertilized treatment) / nitrogen application rate; the physiological nitrogen utilization rate was calculated by the formula (grain yield of the fertilized treatment - grain yield of the unfertilized treatment) / (total nitrogen accumulation of the fertilized plants - total nitrogen accumulation of the unfertilized plants); and (total nitrogen accumulation of the fertilized plants - total nitrogen accumulation of the unfertilized plants) / nitrogen application rate × 100%.

[0079] Here are the results:

[0080]

[0081]

[0082] Compared to Example 1, Example 2 had a higher vinyl acetate content and a naturally lower glycidyl methacrylate content. The resulting complex naturally contained less polyarginine and 3,4,9,10-perylenetetracarboxylic dianhydride, resulting in inferior growth of the treated rice plants compared to Example 1. Furthermore, the rice grain yield, nitrogen absorption and utilization rate, and agronomic utilization rate of Examples 3 and 5, which contained relatively lower levels of polyarginine and 3,4,9,10-perylenetetracarboxylic dianhydride, and Example 9, which had a significantly reduced complex content, were also inferior to those of Example 1. The rice plant growth of Example 6, which added a greater amount of photosensitive substrate, was significantly better than that of Example 1, with a particularly significant increase in grain yield and nitrogen fertilizer utilization rate. This suggests that the addition of 3,4,9,10-perylenetetracarboxylic dianhydride can increase plant photosynthesis and root growth, thereby improving nitrogen utilization in plants. The foliar fertilizer prepared using the method of the present invention is beneficial to plant growth and promotes nitrogen absorption and utilization in plants.

[0083] In Example 4, during the polymer-polyarginine complexation process, the reaction time was shorter, but the rice plant growth was not as good as in Example 1, possibly because the combination of the two was not yet complete. During the preparation of the complex, the rice plant growth in Example 7, which had a lower reaction temperature, was better, and the nitrogen fertilizer utilization rate was significantly increased. This may be because the ethanol evaporated more slowly at a lower temperature, resulting in a more complete and stable complexation and more uniform release of zinc ions, which improved nitrogen absorption and utilization in the plants. In Example 8, where the stirring time after room temperature was shorter, the plant growth did not change significantly, possibly because the reaction was relatively complete.

[0084] Those skilled in the art can make various other corresponding changes and deformations based on the technical solutions and concepts described above, and all of these changes and deformations should fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing foliar fertilizer with high nitrogen fertilizer utilization rate, characterized in that: The following steps are involved: A polymer is prepared using glycidyl methacrylate, which is then modified with polyarginine to obtain a composite matrix; a portion of the composite matrix is ​​combined with 3,4,9,10-perylenetetracarboxylic dianhydride to obtain a photosensitive matrix; the photosensitive matrix is ​​used as a ligand to combine metal ions with the ligand to form a complex; the complex is compounded with the composite matrix and a soluble compound of a nutrient element to obtain a foliar fertilizer. Specifically, the method comprises the following steps: a. dissolving vinyl acetate and glycidyl methacrylate in N,N-dimethylformamide under a nitrogen atmosphere, adding azobisisobutyronitrile, reacting at 60-80°C for 6-8 hours, terminating the reaction, cooling to room temperature, precipitating with n-hexane, and filtering and drying to obtain a polymer; b. Then, the polymer and polyarginine were added to N,N-dimethylformamide, followed by 4-dimethylaminopyridine and dicyclohexylcarbodiimide, and the reaction was carried out at room temperature for 10-16 hours. After the reaction was terminated, the composite matrix was precipitated with n-hexane, filtered and dried to obtain the composite matrix; c. Mix a portion of the composite matrix with 3,4,9,10-perylenetetracarboxylic dianhydride and imidazole, react at 160-170°C for 18-24 hours under a nitrogen atmosphere, cool to room temperature, add equal volumes of ethanol and concentrated hydrochloric acid, react for 8-12 hours, collect the precipitate, elute and purify to obtain a photosensitive matrix; d. The photosensitive matrix and the soluble zinc salt are dispersed in an aqueous solution of ethanol, and the mixture is fully mixed and reacted at 50-70°C until the ethanol evaporates. After cooling to room temperature, stirring is continued for 20-40 minutes. The precipitate is collected, washed thoroughly, and dried to obtain a complex. e. The foliar fertilizer matrix is ​​compounded with the composite matrix and nutrient elements to obtain foliar fertilizer.

2. The preparation method of the foliar fertilizer with high nitrogen fertilizer utilization rate according to claim 1, wherein The nutrient elements include phosphorus, potassium and calcium, and may or may not contain one or more of magnesium, iron, zinc, boron, aluminum, manganese, copper or sulfur; the degree of polymerization of the polyarginine is 2-10.

3. The preparation method of the foliar fertilizer with high nitrogen fertilizer utilization rate according to claim 1, wherein By weight, 1 to 5 parts of the complex are compounded with 120 to 200 parts of a composite matrix, 60 to 100 parts of nutrient elements and water to make 1000 parts to obtain a foliar fertilizer.

4. The preparation method of foliar fertilizer with high nitrogen fertilizer utilization rate according to claim 1, wherein The mass ratio of vinyl acetate to glycidyl methacrylate in step a is 2.5-3.5:1; the mass ratio of vinyl acetate to azobisisobutyronitrile in step a is 80-100:

1.

5. The preparation method of foliar fertilizer with high nitrogen fertilizer utilization rate according to claim 1, wherein The mass ratio of the polymer in step b to polyarginine is 6-8:1; the mass ratio of the polyarginine in step b to 4-dimethylaminopyridine is 10-13:1; and the mass ratio of the 4-dimethylaminopyridine in step b to dicyclohexylcarbodiimide is 1:2-3.

6. The preparation method of foliar fertilizer with high nitrogen fertilizer utilization rate according to claim 1, wherein In step c, the mass ratio of a portion of the composite matrix to 3,4,9,10-perylenetetracarboxylic dianhydride is 2-3:1; and the mass ratio of 3,4,9,10-perylenetetracarboxylic dianhydride to imidazole is 1:8-10.

7. The method for preparing foliar fertilizer with high nitrogen fertilizer utilization rate according to claim 1, wherein The mass ratio of the soluble zinc salt to the photosensitive matrix in step d is 0.8-2:

1.

8. The method for preparing foliar fertilizer with high nitrogen fertilizer utilization rate according to claim 1, wherein The soluble zinc salt in step d includes one or more of zinc chloride, zinc nitrate and zinc acetate.

9. A foliar fertilizer with high nitrogen fertilizer utilization rate prepared by the preparation method according to any one of claims 1 to 3.

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