Nucleotide-containing slow-release fertilizer and preparation method thereof
By pretreating and modifying zeolite powder and combining it with polyvinyl alcohol to form a core-shell structure, the problem of rapid decomposition of nucleotides in fertilizers is solved, achieving the slow release and long-term promotion of plant growth of nucleotides, thus meeting the comprehensive nutritional needs of crops.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- MEIHEKOU FULLKONG FERTILIZER
- Filing Date
- 2026-02-06
- Publication Date
- 2026-05-08
AI Technical Summary
Existing technologies make it difficult to stably load nucleotides into fertilizer systems, leading to their rapid decomposition or loss in the soil and failing to achieve a long-term effect of promoting plant growth.
By pretreating and surface-modifying zeolite powder to form a core-shell structure, and combining it with polyvinyl alcohol to form a dual physical barrier, the release rate of nucleotides is regulated. Fertilizer enhancers are added to enhance adsorption performance, forming a multi-level filtration barrier structure to achieve a slow-release effect.
It effectively prevents the rapid loss and degradation of nucleotides, achieves long-term synergy between chemical nutrition and biological stimulation, promotes root development and crop resistance, and meets the nutritional needs of different growth stages.
Smart Images
Figure SMS_1 
Figure SMS_2
Abstract
Description
Technical Field
[0001] This invention relates to the field of agricultural fertilizer technology, specifically to a slow-release fertilizer containing nucleotides and its preparation method. Background Technology
[0002] Chemical fertilizers are a crucial material foundation for ensuring food security, but conventional compound fertilizers release nutrients rapidly and have low utilization rates, easily leading to resource waste and environmental pollution. Controlled-release fertilizers, which delay nutrient release through physical or chemical means, are an important way to improve fertilizer utilization. Currently, controlled-release technology mainly focuses on the controlled release of macroelements such as nitrogen, phosphorus, and potassium, while research on the stability and controlled release of bioactive substances (such as amino acids, humic acid, and alginic acid) that play an important regulatory role in plant growth is relatively limited.
[0003] Nucleotides, as an important class of bioactive substances, participate in various physiological and biochemical processes in plants, promoting root development, enhancing photosynthesis, improving crop resistance, and enhancing quality. However, due to their small molecular weight and high water solubility, nucleotides are easily decomposed by microorganisms or leached away by water when directly applied to soil, making it difficult for them to exert a lasting effect throughout the crop growth cycle and limiting their application in actual agricultural production. How to stably load nucleotides into fertilizer systems has become a key challenge in improving the technological content and functionality of fertilizers.
[0004] In existing technologies, although there have been attempts to simply mix active substances with fertilizers or load them onto porous materials (such as zeolite and bentonite) through physical adsorption, these methods generally suffer from problems such as weak binding force, low loading capacity, and uncontrollable release. The active substances quickly become ineffective after being released in large quantities in a short period of time, and cannot achieve long-term stimulation.
[0005] In summary, the present invention provides a slow-release fertilizer containing nucleotides and a method for preparing the same, in order to solve the technical problems mentioned above. Summary of the Invention
[0006] The purpose of this invention is to provide a slow-release fertilizer containing nucleotides and its preparation method. The slow-release fertilizer prepared by this invention can not only provide crops with abundant nutrients and promote their growth, but also improve the crops' tolerance to drought and meet the comprehensive nutritional needs of crops at different growth stages. Meanwhile, the fertilizer efficiency enhancer can effectively prevent the rapid loss and degradation of nucleotides, and achieve long-term synergy between chemical nutrition and biostimulation.
[0007] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a method for preparing a slow-release fertilizer containing nucleotides, comprising the following steps: by weight, mixing and stirring 30-40 parts of urea, 10-12 parts of potassium sulfate, 5-10 parts of superphosphate, 10-15 parts of potassium nitrate, 10-20 parts of diammonium phosphate, 5-8 parts of fertilizer enhancer, 1-3 parts of amino acids and 2-4 parts of trace elements for 20-30 minutes; after stirring, grinding the resulting mixture and passing it through a 50-80 mesh sieve, then adding 3-8 parts of polyvinyl alcohol, stirring for 20-30 minutes and granulating to obtain the slow-release fertilizer containing nucleotides.
[0008] Furthermore, the preparation method of the fertilizer efficiency enhancer includes the following steps: Step 1: Disperse β-cyclodextrin evenly in an 85-90wt% ethanol aqueous solution at a mass ratio of 1:10-15. Then add 0.3-0.5 times the amount of 3-aminopropyltriethoxysilane to the β-cyclodextrin, mix well, adjust the pH of the reaction system to 4.5-5.5, react at 50-60℃ for 3-4 hours, and then filter, wash and dry to obtain modified cyclodextrin. Step 2: Disperse the functionalized zeolite powder evenly in N,N-dimethylformamide at a dosage ratio of 20-40 g / L. While stirring, add modified cyclodextrin, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine. React at 35-45℃ for 15-25 h. Then, filter, wash, and vacuum dry the reaction solution sequentially. Next, soak the obtained solid material in a nucleotide aqueous solution with a concentration of 30-40 g / L and a mass of 4-6 times its weight for 10-20 h. After filtration, dry the solid material. The mass ratio of functionalized zeolite powder, modified cyclodextrin, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine is 2-4:1:5-10:0.5-1.5.
[0009] Furthermore, the functionalized zeolite powder is prepared by the following method: silane coupling agent is uniformly dispersed in N,N-dimethylformamide at a dosage ratio of 20-30 g / L, then succinic anhydride with a mass of 1.5-2 times that of the silane coupling agent is added, and the mixture is stirred for 3-4 hours. Then, modified zeolite powder with a mass of 3-5 times that of the succinic anhydride and deionized water with a volume of 15-25% of N,N-dimethylformamide are added. The mixture is stirred for another 4-6 hours and then centrifuged. The resulting solid material is washed alternately with ethanol and deionized water 2-3 times and then vacuum dried.
[0010] Furthermore, the silane coupling agent is selected from any one of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.
[0011] Furthermore, the modified zeolite powder is prepared by the following method: pretreated zeolite powder is uniformly dispersed in an ethanol aqueous solution with a mass of 20-30 times that of the pretreated zeolite powder and a concentration of 40-60 wt%. Then, a tetraethyl orthosilicate solution with a mass of 0.5-0.8 times that of the pretreated zeolite powder is added dropwise. The pH of the reaction system is adjusted to 9-11, and the mixture is magnetically stirred for 3-5 hours under a closed system at room temperature. The reaction solution is then subjected to centrifugation, washing, drying, and grinding to obtain the final product. The mass ratio of tetraethyl orthosilicate, ethanol, and water in the tetraethyl orthosilicate solution is 3-5:20-30:5-10, and its pH is 3.5-4.
[0012] Furthermore, the pretreated zeolite powder is prepared by the following method: zeolite powder with a particle size of 100-200 mesh is washed with deionized water, and then centrifuged at a speed of 2000-4000 r / min for 10-20 min; after repeating the washing process 3-5 times, it is dried and ground to obtain the final product.
[0013] Furthermore, the amino acid is any one of glutamic acid, aspartic acid, threonine, and arginine.
[0014] Furthermore, the trace element is any one of EDTA-Fe, EDTA-Mn, EDTA-Zn, and EDTA-Cu.
[0015] Furthermore, the nucleotide is any one of 5'-guanine monophosphate disodium salt, 5'-adenine nucleotide disodium salt, or 5'-cytosine monophosphate disodium salt.
[0016] Secondly, the present invention provides a slow-release fertilizer containing nucleotides, which is prepared by the preparation method described above.
[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention effectively removes impurities from the surface and internal pore structure of zeolite powder through pretreatment, increasing its specific surface area and improving its adsorption capacity. Then, a silica film is coated onto the surface of the pretreated zeolite powder, forming a core-shell structure with zeolite powder as the "core" and nano-silica as the "shell." Zeolite powder, as a porous carrier, possesses dual functions of physical adsorption and ion exchange, effectively retaining nitrogen, slowly releasing nutrients, and improving soil water retention and aeration. The silica film layer on its surface not only effectively controls the pore size of the zeolite powder, thus regulating the release rate of subsequently adsorbed nucleotides and achieving the effect of slow-release nucleotides, but also provides abundant silanol groups on its surface, offering numerous reaction sites for subsequent robust grafting and modification of cyclodextrin. Finally, cyclodextrin was "grafted" into functionalized zeolite powder through a chemical reaction, forming a multi-level core-shell structure with zeolite powder as the core, silica film as the second outermost layer, and cyclodextrin as the outermost layer. The introduction of cyclodextrin significantly enhanced the adsorption performance of the prepared fertilizer enhancer. At the same time, it synergistically formed a multi-level "filtration barrier" structure with zeolite powder and silica, achieving further regulation of nucleotide release efficiency and a good sustained-release effect. This effectively prevents the rapid loss and degradation of nucleotides, realizing the long-term synergy between chemical nutrition and biostimulation.
[0018] 2. This invention uses polyvinyl alcohol as a binder, which forms a mild gel layer upon contact with water in the soil. This gel layer, together with the microporous structure of the fertilizer enhancer, constitutes a dual physical barrier, slowing down the dissolution and diffusion rate of water-soluble nutrients. Because the nucleotides are protected and released slowly, they can continue to function throughout the crop's entire growth cycle. They can act as signaling molecules and energy substances, promoting root development, enhancing leaf photosynthesis, and improving the crop's tolerance to adverse conditions such as drought and low temperatures.
[0019] 3. This invention not only provides macronutrients such as nitrogen, phosphorus, and potassium, but also adds amino acid organic nitrogen and micronutrient chelates. Amino acids can be directly absorbed by crops, supplementing their organic carbon skeleton; micronutrients exist in EDTA chelated form, exhibiting good stability and high availability in the soil. The components work synergistically in the slow-release system to meet the comprehensive nutritional needs of crops at different growth stages. Detailed Implementation
[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0021] Example 1 A method for preparing a nucleotide-containing slow-release fertilizer includes the following steps: 30 parts by weight of urea, 10 parts by weight of potassium sulfate, 5 parts by weight of superphosphate, 10 parts by weight of potassium nitrate, 10 parts by weight of diammonium phosphate, 5 parts by weight of fertilizer enhancer, 1 part by weight of glutamic acid and 2 parts by weight of EDTA-Fe are mixed and stirred for 20 minutes; after stirring, the resulting mixture is ground and passed through a 50-mesh sieve, and then 3 parts by weight of polyvinyl alcohol (the polyvinyl alcohol in this example, as well as in examples 2 and 3, was purchased from Jiangsu Haian Petrochemical Plant, brand name PVA-4000) is added, and after stirring for 20 minutes, granulation is performed to obtain the nucleotide-containing slow-release fertilizer.
[0022] The preparation method of fertilizer efficiency enhancer includes the following steps: Step 1: Disperse β-cyclodextrin evenly in an 85wt% ethanol aqueous solution at a mass ratio of 1:10, then add 0.3 times the amount of 3-aminopropyltriethoxysilane to β-cyclodextrin, mix well, adjust the pH of the reaction system to 4.5, react at 50℃ for 4 hours, and then filter, wash and dry to obtain modified cyclodextrin. Step 2: Disperse the functionalized zeolite powder evenly in N,N-dimethylformamide at a dosage ratio of 20 g / L. While stirring, add modified cyclodextrin, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine. After reacting at 35°C for 25 h, filter, wash, and vacuum dry the reaction solution sequentially. Then, soak the obtained solid material in an aqueous solution of 5'-guanine nucleoside monophosphate disodium salt with a concentration of 30 g / L, four times its mass, for 10 h. After filtration, dry the material. The mass ratio of functionalized zeolite powder, modified cyclodextrin, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine is 2:1:5:0.5.
[0023] Functionalized zeolite powder is prepared by the following method: 3-aminopropyltriethoxysilane is uniformly dispersed in N,N-dimethylformamide at a dosage ratio of 20 g / L. Then, succinic anhydride with a mass of 1.5 times that of 3-aminopropyltriethoxysilane is added. After mixing and stirring for 3 hours, modified zeolite powder with a mass of 3 times that of succinic anhydride and deionized water with a volume of 15% of N,N-dimethylformamide are added. After stirring for another 4 hours, centrifugation is performed. The resulting solid material is washed twice alternately with ethanol and deionized water and then vacuum dried.
[0024] Modified zeolite powder is prepared by the following method: pretreated zeolite powder is uniformly dispersed in an ethanol aqueous solution with a concentration of 40 wt% and a mass of 20 times that of the pretreated zeolite powder, and then tetraethyl orthosilicate solution with a mass of 0.5 times that of the pretreated zeolite powder is added dropwise. The pH of the reaction system is adjusted to 9, and the mixture is magnetically stirred for 3 hours under a closed system at room temperature. The reaction solution is then subjected to centrifugation, washing, drying, and grinding to obtain the modified zeolite powder. The mass ratio of tetraethyl orthosilicate, ethanol, and water in the tetraethyl orthosilicate solution is 3:20:5, and its pH is 3.5.
[0025] The pretreated zeolite powder is prepared by the following method: 100-mesh clinoptilolite powder is washed with deionized water and then centrifuged at 2000 r / min for 10 min; this washing process is repeated 3 times, followed by drying and grinding.
[0026] Example 2 A method for preparing a nucleotide-containing slow-release fertilizer includes the following steps: by weight, 35 parts urea, 10 parts potassium sulfate, 8 parts superphosphate, 12 parts potassium nitrate, 15 parts diammonium phosphate, 6 parts fertilizer enhancer, 2 parts aspartic acid and 2-3 parts EDTA-Mn are mixed and stirred for 205 min; after stirring is completed, the resulting mixture is ground and passed through a 60-mesh sieve, then 5 parts polyvinyl alcohol are added, stirred for 25 min and granulated to obtain the nucleotide-containing slow-release fertilizer.
[0027] The preparation method of fertilizer efficiency enhancer includes the following steps: Step 1: Disperse β-cyclodextrin evenly in an 85wt% ethanol aqueous solution at a mass ratio of 1:10, then add 0.4 times the amount of 3-aminopropyltriethoxysilane to β-cyclodextrin, mix well, adjust the pH of the reaction system to 5.0, react at 55℃ for 4 hours, and then filter, wash and dry to obtain modified cyclodextrin.
[0028] Step 2: Disperse the functionalized zeolite powder evenly in N,N-dimethylformamide at a dosage ratio of 20-40 g / L. While stirring, add modified cyclodextrin, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine. After reacting at 40℃ for 20 h, filter, wash, and vacuum dry the reaction solution sequentially. Then, soak the obtained solid material in a 35 g / L aqueous solution of 5'-adenine nucleotide disodium salt for 15 h, filter it out, and dry it. The mass ratio of functionalized zeolite powder, modified cyclodextrin, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine is 3:1:8:1.
[0029] Functionalized zeolite powder is prepared by the following method: 3-aminopropyltrimethoxysilane is uniformly dispersed in N,N-dimethylformamide at a dosage ratio of 25 g / L. Then, succinic anhydride with a mass of 1.5 times that of 3-aminopropyltrimethoxysilane is added. After mixing and stirring for 3 hours, modified zeolite powder with a mass of 4 times that of succinic anhydride and deionized water with a volume of 20% of N,N-dimethylformamide are added. After stirring for another 5 hours, centrifugation is performed. The resulting solid material is washed twice with alternating ethanol and deionized water and then vacuum dried.
[0030] Modified zeolite powder is prepared by the following method: pretreated zeolite powder is uniformly dispersed in an ethanol aqueous solution with a mass of 25 times that of the pretreated zeolite powder and a concentration of 50 wt%. Then, a tetraethyl orthosilicate solution with a mass of 0.6 times that of the pretreated zeolite powder is added dropwise. The pH of the reaction system is adjusted to 10, and the mixture is magnetically stirred for 4 hours under a closed system at room temperature. The reaction solution is then subjected to centrifugation, washing, drying, and grinding to obtain the modified zeolite powder. The mass ratio of tetraethyl orthosilicate, ethanol, and water in the tetraethyl orthosilicate solution is 4:25:5, and its pH is 3.8.
[0031] The pretreated zeolite powder is prepared by the following method: 150-mesh clinoptilolite powder is washed with deionized water and then centrifuged at 3000 r / min for 15 min; this washing process is repeated 4 times, followed by drying and grinding.
[0032] Example 3 A method for preparing a nucleotide-containing slow-release fertilizer includes the following steps: by weight, 40 parts of urea, 12 parts of potassium sulfate, 10 parts of superphosphate, 15 parts of potassium nitrate, 20 parts of diammonium phosphate, 8 parts of fertilizer enhancer, 3 parts of threonine and 4 parts of EDTA-Zn are mixed and stirred for 30 minutes; after stirring is completed, the resulting mixture is ground and passed through an 80-mesh sieve, then 8 parts of polyvinyl alcohol are added, stirred for 30 minutes and granulated to obtain the nucleotide-containing slow-release fertilizer.
[0033] The preparation method of fertilizer efficiency enhancer includes the following steps: Step 1: Disperse β-cyclodextrin evenly in a 90wt% ethanol aqueous solution at a mass ratio of 1:15, then add 0.5 times the amount of 3-aminopropyltriethoxysilane to β-cyclodextrin, mix well, adjust the pH of the reaction system to 5.5, react at 60℃ for 3 hours, and then filter, wash and dry to obtain modified cyclodextrin. Step 2: Disperse the functionalized zeolite powder evenly in N,N-dimethylformamide at a dosage ratio of 40 g / L. While stirring, add modified cyclodextrin, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine. After reacting at 45°C for 15 h, filter, wash, and vacuum dry the reaction solution sequentially. Then, soak the obtained solid material in an aqueous solution of 5'-cytosine monophosphate disodium salt at a concentration of 40 g / L (6 times its mass) for 20 h. After filtration, dry the solid material. The mass ratio of functionalized zeolite powder, modified cyclodextrin, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine is 4:1:10:1.5.
[0034] Functionalized zeolite powder is prepared by the following method: N-(β-aminoethyl)-γ-aminopropyltriethoxysilane is uniformly dispersed in N,N-dimethylformamide at a dosage ratio of 30 g / L. Then, succinic anhydride with a mass of 2 times that of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane is added and mixed and stirred for 4 h. Then, modified zeolite powder with a mass of 5 times that of succinic anhydride and deionized water with a volume of 25% of N,N-dimethylformamide are added. After stirring for another 6 h, centrifugation is performed. The resulting solid material is washed three times alternately with ethanol and deionized water and then vacuum dried.
[0035] Modified zeolite powder is prepared by the following method: pretreated zeolite powder is uniformly dispersed in an ethanol aqueous solution with a concentration of 60 wt% and a mass of 30 times that of the pretreated zeolite powder, and then tetraethyl orthosilicate solution with a mass of 0.8 times that of the pretreated zeolite powder is added dropwise. The pH of the reaction system is adjusted to 11, and the mixture is magnetically stirred for 5 hours under a closed system at room temperature. The reaction solution is then subjected to centrifugation, washing, drying, and grinding to obtain the modified zeolite powder. The mass ratio of tetraethyl orthosilicate, ethanol, and water in the tetraethyl orthosilicate solution is 5:30:10, and its pH is 4.
[0036] The pretreated zeolite powder is prepared by the following method: 200-mesh clinoptilolite powder is washed with deionized water and then centrifuged at 4000 r / min for 20 min; this washing process is repeated 5 times, followed by drying and grinding.
[0037] Comparative Example 1: The difference from Example 1 is that an equal amount of modified zeolite powder is used instead of fertilizer enhancer in this comparative example.
[0038] Comparative Example 2: The difference from Example 1 is that the fertilizer enhancer prepared in this comparative example does not contain 5'-guanine nucleoside monophosphate disodium salt, that is, the solid material obtained in step two of preparing the fertilizer enhancer was not soaked in an aqueous solution of 5'-adenine nucleotide disodium salt.
[0039] Comparative Example 3: The difference from Example 1 is that an equal amount of pretreated zeolite powder was used instead of fertilizer enhancer in this comparative example.
[0040] Performance testing
[0041] Experiment 1: Slow-release effect and water retention performance test: The slow-release fertilizer samples containing nucleotides prepared in Examples 1-3 and Comparative Examples 1-3 were tested for performance. The 24-hour release rate, 7-day cumulative release rate, 28-day cumulative release rate, and time required for 80% release of fertilizer were tested in accordance with GB / T23348-2009 "Slow-release Fertilizers". The water retention in the soil was measured using the soil column method. The effect of fertilizer on the infiltration amount was determined at the same infiltration distance. The infiltration amount was based on the drop in water level (cm) in the Marshall bottle.
[0042] Experiment 2, Nucleotide slow-release cycle: High performance liquid chromatography (HPLC) was used to determine the time (in days) required for the cumulative release rate of nucleotides in the slow-release fertilizer samples containing nucleotides prepared in Examples 1-3 and Comparative Examples 1-3 to reach 80% in a soil leaching simulation device. The longer the time, the better the slow-release and protective effect on nucleotides.
[0043] The experimental data obtained above are recorded in Table 1. Table 1: Test results of slow-release and water-retention properties of slow-release fertilizers containing nucleotides.
[0044]
[0045] Note: "None" in the table indicates that the slow-release fertilizer prepared does not contain nucleotides.
[0046] Experiment 3: The nucleotide-containing slow-release fertilizer samples prepared in Examples 1-3 and Comparative Examples 1-3 were used in a small-plot rice experiment. Each plot was 10m long and 4m wide, with protective rows around the perimeter. The fertilizer application rate was 40kg / mu as basal application. The rice growth and yield are shown in Table 2. Table 2. Effects of slow-release fertilizers containing nucleotides on rice growth and yield.
[0047]
[0048] By comparing and analyzing the relevant data in Tables 1 and 2, it can be seen that the slow-release fertilizer prepared by this invention not only provides crops with abundant nutrients and promotes their growth, but also improves their drought tolerance and meets the comprehensive nutritional needs of crops at different growth stages. Furthermore, the fertilizer efficiency enhancer effectively prevents the rapid loss and degradation of nucleotides, achieving long-term synergy between chemical nutrition and biostimulation. This indicates that the nucleotide-containing slow-release fertilizer and its preparation method provided by this invention have a broader market prospect and are more suitable for widespread application.
[0049] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0050] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A method for preparing a slow-release fertilizer containing nucleotides, characterized in that, The process includes the following steps: By weight, mix 30-40 parts urea, 10-12 parts potassium sulfate, 5-10 parts superphosphate, 10-15 parts potassium nitrate, 10-20 parts diammonium phosphate, 5-8 parts fertilizer enhancer, 1-3 parts amino acids, and 2-4 parts trace elements and stir for 20-30 minutes; after stirring, grind the resulting mixture and pass it through a 50-80 mesh sieve, then add 3-8 parts polyvinyl alcohol, stir for 20-30 minutes, and then granulate to obtain a slow-release fertilizer containing nucleotides.
2. The method for preparing a nucleotide-containing slow-release fertilizer according to claim 1, characterized in that, The preparation method of the fertilizer efficiency enhancer includes the following steps: Step 1: Disperse β-cyclodextrin evenly in an 85-90wt% ethanol aqueous solution at a mass ratio of 1:10-15. Then add 0.3-0.5 times the amount of 3-aminopropyltriethoxysilane to the β-cyclodextrin, mix well, adjust the pH of the reaction system to 4.5-5.5, react at 50-60℃ for 3-4 hours, and then filter, wash and dry to obtain modified cyclodextrin. Step 2: Disperse the functionalized zeolite powder evenly in N,N-dimethylformamide at a dosage ratio of 20-40 g / L. While stirring, add modified cyclodextrin, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine. React at 35-45℃ for 15-25 h. Then, filter, wash, and vacuum dry the reaction solution sequentially. Next, soak the obtained solid material in a nucleotide aqueous solution with a concentration of 30-40 g / L and a mass of 4-6 times its weight for 10-20 h. After filtration, dry the solid material. The mass ratio of functionalized zeolite powder, modified cyclodextrin, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine is 2-4:1:5-10:0.5-1.
5.
3. The method for preparing a nucleotide-containing slow-release fertilizer according to claim 2, characterized in that, Functionalized zeolite powder is prepared by the following method: Silane coupling agent is uniformly dispersed in N,N-dimethylformamide at a dosage ratio of 20-30 g / L. Then, succinic anhydride with a mass of 1.5-2 times that of the silane coupling agent is added. After mixing and stirring for 3-4 hours, modified zeolite powder with a mass of 3-5 times that of the succinic anhydride and deionized water with a volume of 15-25% of N,N-dimethylformamide are added. After stirring for 4-6 hours, centrifugation is performed. The resulting solid material is washed alternately with ethanol and deionized water 2-3 times and then vacuum dried.
4. The method for preparing a nucleotide-containing slow-release fertilizer according to claim 3, characterized in that: The silane coupling agent is selected from any one of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.
5. The method for preparing a nucleotide-containing slow-release fertilizer according to claim 3, characterized in that, Modified zeolite powder is prepared by the following method: pretreated zeolite powder is uniformly dispersed in an ethanol aqueous solution with a mass of 20-30 times that of the pretreated zeolite powder and a concentration of 40-60 wt%. Then, a tetraethyl orthosilicate solution with a mass of 0.5-0.8 times that of the pretreated zeolite powder is added dropwise. The pH of the reaction system is adjusted to 9-11, and the mixture is magnetically stirred for 3-5 hours under a closed system at room temperature. The reaction solution is then subjected to centrifugation, washing, drying, and grinding to obtain the modified zeolite powder. The mass ratio of tetraethyl orthosilicate, ethanol, and water in the tetraethyl orthosilicate solution is 3-5:20-30:5-10, and its pH is 3.5-4.
6. The method for preparing a nucleotide-containing slow-release fertilizer according to claim 5, characterized in that, The pretreated zeolite powder is prepared by the following method: zeolite powder with a particle size of 100-200 mesh is washed with deionized water, and then centrifuged at a speed of 2000-4000 r / min for 10-20 min; after repeating the washing process 3-5 times, it is dried and ground to obtain the final product.
7. The method for preparing a nucleotide-containing slow-release fertilizer according to claim 1, characterized in that: The amino acid is any one of glutamic acid, aspartic acid, threonine, and arginine.
8. The method for preparing a nucleotide-containing slow-release fertilizer according to claim 1, characterized in that: The trace element is any one of EDTA-Fe, EDTA-Mn, EDTA-Zn, and EDTA-Cu.
9. The method for preparing a nucleotide-containing slow-release fertilizer according to claim 2, characterized in that: The nucleotide is any one of 5'-guanine monophosphate disodium salt, 5'-adenine nucleotide disodium salt, and 5'-cytosine monophosphate disodium salt.
10. A slow-release fertilizer containing nucleotides, characterized in that, It is prepared by any one of the preparation methods described in claims 1-9.