Synergistic fertilizer for high yield and emission reduction of rice and preparation method thereof
By encapsulating nitrogen sources with chitosan microcapsules and combining them with attached nitrification inhibitors, the problem of unstable nitrification inhibitor effects was solved, achieving high yield and emission reduction in rice.
Patent Information
- Application Number
- CN202511681035.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-17
- Publication Date
- 2026-01-13
AI Technical Summary
In existing technologies, the inhibitory effect of nitrification inhibitors cannot be maintained within a suitable range for a long period of time during the rice growth cycle, resulting in low nitrogen fertilizer utilization, serious nitrogen loss, and impacting rice yield and the environment.
A nitrogen source is encapsulated in chitosan microcapsules and combined with an attached nitration inhibitor. The inhibitor is attached to the microcapsule wall material through an esterification reaction, which slows down the release of nitrogen source and maintains the nitration inhibition effect for a long time.
This achieves a match between nitrogen source release and rice growth needs, improves nitrogen utilization, reduces nitrogen loss, lowers greenhouse gas emissions, and maintains soil microbial balance.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of organic fertilizer and microbial fertilizer manufacturing technology, specifically, it relates to an efficiency-enhancing fertilizer for high-yield and emission-reduction rice cultivation and its preparation method. Background Technology
[0002] In rice production, the scientific application of nitrogen fertilizer is key to achieving high yields. Simply increasing the amount of nitrogen fertilizer applied will not effectively increase rice yield if the utilization rate of nitrogen fertilizer is not improved. Under the action of nitrifying and denitrifying bacteria in the soil, ammonium nitrogen in the soil will first be converted into nitrate nitrogen by nitrifying bacteria and then into nitrous oxide by denitrifying bacteria, which is then lost into the atmosphere. This not only enhances the greenhouse effect but also severely reduces the utilization rate of nitrogen fertilizer in the soil. Therefore, to improve the utilization rate of nitrogen fertilizer in the soil and thus increase rice yield, inhibiting nitrification is particularly important. Although there are already many nitrification inhibitors in existing technologies, the nitrification inhibition process does not last throughout the entire growth cycle of rice. After the main peak period of nitrogen absorption in rice, if the soil... Nitrogen remains in the ammonium state and will be lost in large quantities due to ammonia volatilization. At this time, nitrifying bacteria are needed to convert some of the ammonium nitrogen into nitrate nitrogen so that nitrogen can be absorbed by the soil roots. Nitrification is a natural and important link in the soil nitrogen cycle. Long-term inhibition of nitrification will disrupt the balance of the soil microbial community. Therefore, most nitrification inhibitors are designed with an effective period of 4 to 8 weeks. During this period, the nitrification inhibition effect is constantly weakened due to the continuous dissolution of the nitrification inhibitor. Since the inhibition effect gradually decays, it often leads to an excessively strong inhibition effect in the early stage and an insufficient inhibition effect in the later stage, making it impossible to maintain within the appropriate range for a long time. To solve the above technical defects, this invention provides an efficiency-enhancing base fertilizer for high-yield and emission-reduction rice and its preparation method. Summary of the Invention
[0003] The purpose of this invention is to provide an efficient fertilizer for high-yield and emission-reducing rice cultivation and its preparation method, in order to solve the problems mentioned in the background art.
[0004] The objective of this invention can be achieved through the following technical solutions: A method for preparing an efficiency-enhancing fertilizer for high-yield and emission-reduction rice cultivation includes the following steps: Step 1: Formulate sustained-release microcapsules with a nitrogen source as the core material and chitosan as the wall material; Step 2: Mix the slow-release microcapsules and the attached nitrification inhibitor to obtain the enhanced fertilizer.
[0005] Furthermore, the nitrogen source is at least one of urea, ammonium bicarbonate, and ammonium sulfate.
[0006] Furthermore, the mass ratio of slow-release microcapsules to attached nitrification inhibitors used in the preparation of the synergistic fertilizer is 30–40:0.2–0.3.
[0007] Furthermore, the microcapsules can be prepared by the following steps: A chitosan aqueous solution was prepared, and a nitrogen source was added to the chitosan aqueous solution as an aqueous phase solution for later use. A liquid paraffin solution of emulsifier was prepared as an oil phase solution for later use. Then, the aqueous phase solution was added dropwise to the oil phase, and after emulsification by high-speed stirring, glutaraldehyde aqueous solution was added dropwise to the system. The stirring was maintained at a constant speed for 4-6 hours, and then the stirring was stopped and the solid was separated by centrifugation. The obtained solid was washed with petroleum ether and anhydrous ethanol in sequence and dried to obtain sustained-release microcapsules.
[0008] Furthermore, the glutaraldehyde aqueous solution has a mass fraction of 50%.
[0009] Furthermore, the emulsifier is at least one of span80 and span60.
[0010] Furthermore, the conditions for high-speed stirring emulsification are stirring at a speed of 1000–1500 rpm for 2–3 hours.
[0011] Furthermore, the attached nitrification inhibitor can be prepared by the following steps: S1. The product of 4-acetylphenylboronic acid pinacol ester and diethyl oxalate undergoes a Claisen condensation reaction, and the product is then reacted with hydrazine hydrate to undergo a kronol pyrazole synthesis reaction to obtain a nitration inhibitor precursor. The reaction process is as follows: 4-acetylphenylboronic acid pinacol ester, diethyl oxalate, sodium di(trimethylsilyl)aminodimethyl ...
[0012] S2. The nitration inhibitor is obtained by nucleophilic substitution reaction between the nitration inhibitor precursor and an acetonitrile derivative containing a halogen atom in its structure. The reaction process is as follows: The nitration inhibitor precursor, acetonitrile derivative with halogen atoms in its structure, potassium carbonate, and toluene are mixed in a reaction vessel. After magnetic stirring is turned on, the reaction is carried out at a temperature of 45-75℃ for 2-3 hours. After the reaction is completed, deionized water is added to the reaction solution for washing. After separating the organic phase, the solvent is removed by rotary evaporation of the organic phase to obtain the nitration inhibitor.
[0013] S3. Hydrolyze the nitrification inhibitor under acidic conditions to obtain an attached nitrification inhibitor.
[0014] The reaction process is as follows: Nitrification inhibitor, hydrochloric acid, and tetrahydrofuran are mixed in a reaction vessel, and after magnetic stirring is turned on, the reaction is carried out at a temperature of 40-70℃ for 0.5-1.5h. After the reaction is completed, the reaction solution is poured into deionized water, the solid is separated by filtration, the obtained solid is washed with deionized water and dried, and then recrystallized with anhydrous ethanol to obtain the attached nitration inhibitor.
[0015] Furthermore, the acetonitrile derivative containing halogen atoms in the structure is one of chloroacetonitrile or bromoacetonitrile.
[0016] Furthermore, the concentration of the hydrochloric acid used is 1–2 M.
[0017] Furthermore, the hydrazine hydrate aqueous solution has a mass fraction of 80%.
[0018] An efficient fertilizer for high-yield and emission-reduction rice production is prepared by any of the above steps.
[0019] The beneficial effects of this invention are: 1) This invention prepares a nitrogen source encapsulated in microcapsules to achieve slow release of nitrogen source, so that the release of nitrogen source can better match the growth needs of rice and effectively improve the nitrogen utilization rate in fertilizer. In addition, since the nitrogen source encapsulated inside the microcapsule is not affected by the microbial community and environment in the soil, it can be applied in large quantities at one time in the basal fertilizer stage, which greatly saves labor costs and reduces the emission of greenhouse gas nitrous oxide generated by denitrification.
[0020] 2) This invention prepares an attached nitrification inhibitor with a boric acid structure in its structure. This attached nitrification inhibitor can attach to the wall material structure of the slow-release microcapsule by esterification reaction between the boric acid structure and the 1,2-diol structure, which greatly reduces dissolution loss. Therefore, during the presence of the microcapsule, the nitrification inhibition level in the soil can be maintained within a suitable range for a long time. When the chitosan in the microcapsule wall material is consumed by microorganisms in the soil, the attached nitrification inhibitor also loses its attachment target and can be quickly dissolved by water, thus restoring the nitrification reaction in the soil.
[0021] 3) The attached nitrification inhibitor prepared in this invention has sterically hindered substituents at the 3-substitution and 5-substitution positions of the pyrazole ring structure. These substituents can enhance the binding ability of the attached nitrification inhibitor to AMO enzymes in nitrifying bacteria, improve the nitrification inhibition effect of the attached nitrification inhibitor, effectively protect the core pyrazole ring, and reduce the decomposition loss of the attached nitrification inhibitor in the soil. Detailed Implementation
[0022] The technical solution 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.
[0023] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.
[0024] It should be understood that the use of “including,” “having,” or “containing,” including its grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.
[0025] It should be understood that the order of the steps or the order in which certain actions are performed is not important as long as the invention remains operational. Furthermore, two or more steps or actions can be performed simultaneously.
[0026] Furthermore, the numerical ranges and parameters used to define the present invention are approximate values, and the relevant values in the specific embodiments have been presented as precisely as possible. However, any value inevitably contains standard deviations due to individual test methods. Therefore, unless explicitly stated otherwise, it should be understood that all ranges, quantities, values, and percentages used in this disclosure are modified with the word "approximately". Here, "approximately" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specific value or range.
[0027] Example 1 A method for preparing an efficiency-enhancing fertilizer for high-yield and emission-reduction rice cultivation includes the following steps: Step 1: Add 12 parts of chitosan to 600 parts of 2% (v / v) aqueous acetic acid solution, then add 48 parts of urea to the system as an aqueous phase solution for later use, and dissolve 72 parts of Span80 in 2328 parts of liquid paraffin solution as an oil phase solution for later use; then add the aqueous phase solution dropwise to the oil phase, and after the addition is complete, stir at 1000 rpm for 3 hours, then add 15 parts of 50% (w / w) glutaraldehyde aqueous solution to the system dropwise, and continue stirring at the same speed for 6 hours, then stop stirring and centrifuge to separate the solid. The obtained solid is washed with petroleum ether and anhydrous ethanol in sequence and dried to obtain sustained-release microcapsules; Step 2: Mix 30 parts slow-release microcapsules with 0.3 parts attached nitrification inhibitor by weight to obtain the synergistic fertilizer.
[0028] The attached nitrification inhibitor used in this embodiment is prepared by the following steps: S1. By mass fraction, 1 part of 4-acetylphenylboronic acid pinacol ester, 0.6 parts of diethyl oxalate, 0.75 parts of sodium di(trimethylsilyl)amino)acetate, and 6 parts of toluene were mixed in a reaction vessel under ice-water bath conditions. After turning on the magnetic stirrer, the ice-water bath was removed, and the reaction was carried out at room temperature for 2 hours. Then, 0.25 parts of glacial acetic acid and 0.64 parts of 80% hydrazine hydrate aqueous solution were added to the system, and the reaction was carried out at 90°C for 2.5 hours. After the reaction was completed, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water, dried, and then recrystallized with ethanol to obtain the nitration inhibitor precursor.
[0029] S2. By mass, 0.93 parts of nitration inhibitor precursor, 0.24 parts of chloroacetonitrile, 0.8 parts of potassium carbonate, and 10 parts of toluene are mixed in a reaction vessel. After turning on the magnetic stirrer, the mixture is reacted at 45°C for 3 hours. After the reaction is completed, deionized water is added to the reaction solution for washing. After separating the organic phase, the solvent is removed by rotary evaporation of the organic phase to obtain the nitration inhibitor.
[0030] S3. By mass, 0.8 parts of nitration inhibitor, 5 parts of 1M hydrochloric acid, and 15 parts of tetrahydrofuran are mixed in a reaction vessel. After turning on the magnetic stirrer, the mixture is reacted at 40°C for 1.5 hours. After the reaction is completed, the reaction solution is poured into deionized water. After filtering to separate the solid, the obtained solid is washed with deionized water and dried. Then, it is recrystallized with anhydrous ethanol to obtain the attached nitration inhibitor.
[0031] An enhanced fertilizer for high-yield and emission-reduction rice production, prepared by the above steps.
[0032] Example 2 A method for preparing an efficiency-enhancing fertilizer for high-yield and emission-reduction rice cultivation includes the following steps: Step 1: Add 14 parts of chitosan to 700 parts of 2% (v / v) aqueous acetic acid solution, then add 56 parts of ammonium sulfate to the system as an aqueous phase solution for later use, and dissolve 84 parts of Span60 in 2716 parts of liquid paraffin solution as an oil phase solution for later use; then add the aqueous phase solution dropwise to the oil phase, and after the addition is complete, stir at 1250 rpm for 2.5 h, then add 17.5 parts of 50% (w / w) aqueous glutaraldehyde solution to the system, and continue stirring at the same speed for 5 h, then stop stirring and centrifuge to separate the solid. The obtained solid is washed with petroleum ether and anhydrous ethanol in sequence and dried to obtain sustained-release microcapsules; Step 2: Mix 35 parts slow-release microcapsules with 0.25 parts attached nitrification inhibitor by weight to obtain the enhanced fertilizer.
[0033] The attached nitrification inhibitor used in this embodiment is prepared by the following steps: S1. By mass fraction, 1 part of 4-acetylphenylboronic acid pinacol ester, 0.6 parts of diethyl oxalate, 0.75 parts of sodium di(trimethylsilyl)amino)acetate, and 6 parts of toluene were mixed in a reaction vessel under ice-water bath conditions. After turning on the magnetic stirrer, the ice-water bath was removed, and the reaction was carried out at room temperature for 2.5 h. Then, 0.25 parts of glacial acetic acid and 0.64 parts of 80% hydrazine hydrate aqueous solution were added to the system, and the reaction was carried out at 100℃ for 2 h. After the reaction was completed, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water, dried, and then recrystallized with ethanol to obtain the nitration inhibitor precursor.
[0034] S2. By mass, 0.93 parts of nitration inhibitor precursor, 0.24 parts of chloroacetonitrile, 0.8 parts of potassium carbonate, and 10 parts of toluene are mixed in a reaction vessel. After turning on the magnetic stirrer, the mixture is reacted at 60°C for 2.5 hours. After the reaction is completed, deionized water is added to the reaction solution for washing. After separating the organic phase, the solvent is removed by rotary evaporation of the organic phase to obtain the nitration inhibitor.
[0035] S3. By mass, 0.8 parts of nitration inhibitor, 5 parts of 1.5M hydrochloric acid, and 15 parts of tetrahydrofuran are mixed in a reaction vessel. After turning on the magnetic stirrer, the mixture is reacted at 55°C for 1 hour. After the reaction is completed, the reaction solution is poured into deionized water. After filtering to separate the solid, the obtained solid is washed with deionized water and dried. Then, it is recrystallized with anhydrous ethanol to obtain the attached nitration inhibitor.
[0036] An enhanced fertilizer for high-yield and emission-reduction rice production, prepared by the above steps.
[0037] Example 3 A method for preparing an efficiency-enhancing fertilizer for high-yield and emission-reduction rice cultivation includes the following steps: Step 1: 16 parts of chitosan were added to 800 parts of 2% (v / v) aqueous acetic acid solution. Then, 64 parts of ammonium bicarbonate were added to the system as an aqueous phase solution. 96 parts of emulsifier were dissolved in 3104 parts of liquid paraffin solution as an oil phase solution. The aqueous phase solution was then added dropwise to the oil phase. After the addition was complete, the mixture was stirred at 1500 rpm for 2 hours. Then, 20 parts of 50% (w / w) glutaraldehyde aqueous solution were added dropwise to the system. The mixture was stirred continuously at a constant speed for 4 hours. After stirring was stopped, the solid was separated by centrifugation. The obtained solid was washed with petroleum ether and anhydrous ethanol and dried to obtain sustained-release microcapsules. Step 2: Mix 40 parts of slow-release microcapsules with 0.2 parts of attached nitrification inhibitor by weight to obtain the enhanced fertilizer.
[0038] The attached nitrification inhibitor used in this embodiment is prepared by the following steps: S1. By mass fraction, 1 part of 4-acetylphenylboronic acid pinacol ester, 0.6 parts of diethyl oxalate, 0.75 parts of sodium di(trimethylsilyl)amino)acetate, and 6 parts of toluene were mixed in a reaction vessel under ice-water bath conditions. After turning on the magnetic stirrer, the ice-water bath was removed, and the reaction was carried out at room temperature for 3 hours. Then, 0.25 parts of glacial acetic acid and 0.64 parts of 80% hydrazine hydrate aqueous solution were added to the system, and the reaction was carried out at 110℃ for 1.5 hours. After the reaction was completed, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water, dried, and then recrystallized with ethanol to obtain the nitration inhibitor precursor.
[0039] S2. By mass, 0.93 parts of nitration inhibitor precursor, 0.38 parts of bromoacetonitrile, 0.8 parts of potassium carbonate, and 10 parts of toluene are mixed in a reaction vessel. After turning on the magnetic stirrer, the mixture is reacted at 75°C for 2 hours. After the reaction is completed, deionized water is added to the reaction solution for washing. After separating the organic phase, the solvent is removed by rotary evaporation of the organic phase to obtain the nitration inhibitor.
[0040] S3. By mass, 0.8 parts of nitration inhibitor, 5 parts of 2M hydrochloric acid, and 15 parts of tetrahydrofuran are mixed in a reaction vessel. After turning on the magnetic stirrer, the mixture is reacted at 70℃ for 0.5h. After the reaction is completed, the reaction solution is poured into deionized water. After filtering to separate the solid, the obtained solid is washed with deionized water and dried. Then it is recrystallized with anhydrous ethanol to obtain the attached nitration inhibitor.
[0041] An enhanced fertilizer for high-yield and emission-reduction rice production, prepared by the above steps.
[0042] Comparative Example 1 The difference between this comparative example and Example 1 is that microcapsules are not prepared; instead, the nitrogen source is directly mixed with the attached nitrification inhibitor to obtain the synergistic fertilizer.
[0043] A method for preparing an efficiency-enhancing fertilizer for high-yield and emission-reduction rice cultivation includes the following steps: By weight, 30 parts of urea and 0.3 parts of attached nitrification inhibitor are mixed to obtain an enhanced fertilizer.
[0044] The attached nitrification inhibitor used in this embodiment is prepared by the following steps: S1. By mass fraction, 1 part of 4-acetylphenylboronic acid pinacol ester, 0.6 parts of diethyl oxalate, 0.75 parts of sodium di(trimethylsilyl)amino)acetate, and 6 parts of toluene were mixed in a reaction vessel under ice-water bath conditions. After turning on the magnetic stirrer, the ice-water bath was removed, and the reaction was carried out at room temperature for 2 hours. Then, 0.25 parts of glacial acetic acid and 0.64 parts of 80% hydrazine hydrate aqueous solution were added to the system, and the reaction was carried out at 90°C for 2.5 hours. After the reaction was completed, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water, dried, and then recrystallized with ethanol to obtain the nitration inhibitor precursor.
[0045] S2. By mass, 0.93 parts of nitration inhibitor precursor, 0.24 parts of chloroacetonitrile, 0.8 parts of potassium carbonate, and 10 parts of toluene are mixed in a reaction vessel. After turning on the magnetic stirrer, the mixture is reacted at 45°C for 3 hours. After the reaction is completed, deionized water is added to the reaction solution for washing. After separating the organic phase, the solvent is removed by rotary evaporation of the organic phase to obtain the nitration inhibitor.
[0046] S3. By mass, 0.8 parts of nitration inhibitor, 5 parts of 1M hydrochloric acid, and 15 parts of tetrahydrofuran are mixed in a reaction vessel. After turning on the magnetic stirrer, the mixture is reacted at 40°C for 1.5 hours. After the reaction is completed, the reaction solution is poured into deionized water. After filtering to separate the solid, the obtained solid is washed with deionized water and dried. Then, it is recrystallized with anhydrous ethanol to obtain the attached nitration inhibitor.
[0047] An enhanced fertilizer for high-yield and emission-reduction rice production, prepared by the above steps.
[0048] Example 2 The difference between this embodiment and Comparative Example 1 is that, instead of preparing an attached nitration inhibitor, an equal amount of the commercially available nitration inhibitor 3,4-dimethylpyrazole phosphate was used.
[0049] A method for preparing an efficiency-enhancing fertilizer for high-yield and emission-reduction rice cultivation includes the following steps: Step 1: Add 12 parts of chitosan to 600 parts of 2% (v / v) aqueous acetic acid solution, then add 48 parts of urea to the system as an aqueous phase solution for later use, and dissolve 72 parts of Span80 in 2328 parts of liquid paraffin solution as an oil phase solution for later use; then add the aqueous phase solution dropwise to the oil phase, and after the addition is complete, stir at 1000 rpm for 3 hours, then add 15 parts of 50% (w / w) glutaraldehyde aqueous solution to the system dropwise, and continue stirring at the same speed for 6 hours, then stop stirring and centrifuge to separate the solid. The obtained solid is washed with petroleum ether and anhydrous ethanol in sequence and dried to obtain sustained-release microcapsules; Step 2: Mix 30 parts of slow-release microcapsules with 0.3 parts of 3,4-dimethylpyrazole phosphate by weight to obtain the enhanced fertilizer.
[0050] An enhanced fertilizer for high-yield and emission-reduction rice production, prepared by the above steps.
[0051] Experimental Example Field experiments were conducted to test the synergistic fertilizers in Examples 1-3 and Comparative Examples 1-2. Five replicate plots of equal area were set up, with each plot having an area of 20m². 2 Each block was treated with 1.25 kg of superphosphate, 0.24 kg of potassium chloride, and 0.045 kg of zinc sulfate. Specifically, in the blocks of Example 1 and Comparative Examples 1-2, 0.26 kg of the synergistic fertilizer of this invention was applied; in the area of Example 2, 0.7 kg of the synergistic fertilizer of this invention was applied; and in the block of Example 3, 0.6 kg of the synergistic fertilizer of this invention was applied. (The nitrogen content varies depending on the nitrogen source, therefore the actual application amount differs.) No further fertilizers were applied. Ammonia and nitrous oxide were collected using a static chamber method at 1 day, 3 days, 7 days, 14 days, 28 days, and 42 days after fertilization. The nitrous oxide content in each block was tested (unit: μg·m³). －2 ·day －1 The final yield of rice in each block was recorded, and the results are shown in Tables 1-2.
[0052] Table 1 Table 2 As can be seen from Tables 1 and 2, the attached nitrification inhibitors of the present invention in Examples 1-3 all exhibited good nitrification inhibition effects within 28 days, and were able to begin to restore the soil's nitrification inhibition effect after day 42. However, although Comparative Example 2 used the same microcapsule encapsulation strategy, the nitrification inhibition effect in the soil began to weaken significantly on day 7 due to the continuous consumption of the added nitrification inhibitor 3,4-dimethylpyrazole phosphate, which could not match the growth cycle of rice.
[0053] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.
Claims
1. A method for preparing an efficient fertilizer for high-yield and emission-reduction rice cultivation, characterized in that, Includes the following steps: Step 1: Formulate sustained-release microcapsules with a nitrogen source as the core material and chitosan as the wall material; Step 2: Mix the slow-release microcapsules and the attached nitrification inhibitor to obtain a synergistic fertilizer; The attached nitration inhibitor is prepared by the following steps: S1. The product of 4-acetylphenylboronic acid pinacol ester and diethyl oxalate undergoes a Claisen condensation reaction, and the product is then reacted with hydrazine hydrate to undergo a kronol pyrazole synthesis reaction to obtain a nitration inhibitor precursor. S2. The nitration inhibitor is obtained by nucleophilic substitution reaction between the nitration inhibitor precursor and an acetonitrile derivative containing a halogen atom in its structure. S3. Hydrolyze the nitrification inhibitor under acidic conditions to obtain an attached nitrification inhibitor.
2. The method for preparing an efficient fertilizer for high-yield and emission-reduction rice cultivation according to claim 1, characterized in that, The nitrogen source is at least one of urea, ammonium bicarbonate, and ammonium sulfate.
3. The method for preparing an efficient fertilizer for high-yield and emission-reduction rice cultivation according to claim 1, characterized in that, The acetonitrile derivative containing halogen atoms in the structure is one of chloroacetonitrile or bromoacetonitrile.
4. The method for preparing an efficient fertilizer for high-yield and emission-reduction rice cultivation according to claim 1, characterized in that, The mass ratio of sustained-release microcapsules to attached nitration inhibitors used was 30–40:0.2–0.
3.
5. The method for preparing an efficient fertilizer for high-yield and emission-reduction rice cultivation according to claim 1, characterized in that, The preparation method of the attached nitration inhibitor is as follows: S1. Under ice-water bath conditions, 4-acetylphenylboronic acid pinacol ester, diethyl oxalate, sodium di(trimethylsilyl)amino)toluene and toluene were mixed and reacted at room temperature. Then, glacial acetic acid and hydrazine hydrate were added to the product system and the reaction was continued at a temperature of 90-110℃ to obtain the nitration inhibitor precursor. S2. The nitration inhibitor is obtained by mixing the nitration inhibitor precursor, the acetonitrile derivative containing halogen atoms in its structure, potassium carbonate, and toluene and reacting them at a temperature of 45-75℃. S3. The nitration inhibitor, hydrochloric acid, and tetrahydrofuran are mixed and reacted at a temperature of 40-70℃ to obtain the attached nitration inhibitor.
6. The method for preparing an efficient fertilizer for high-yield and emission-reduction rice cultivation according to claim 1, characterized in that, The microcapsules were prepared by the following steps: A chitosan aqueous solution was prepared, and then a nitrogen source was added to the chitosan aqueous solution as an aqueous phase solution for later use. A liquid paraffin solution of emulsifier was prepared as an oil phase solution for later use. Then, the aqueous phase solution was added dropwise to the oil phase, and after emulsification by high-speed stirring, glutaraldehyde aqueous solution was added dropwise to the system. The reaction was continued by stirring at a constant speed to obtain sustained-release microcapsules.
7. A method for preparing an efficient fertilizer for high-yield and emission-reduction rice cultivation according to claim 6, characterized in that, The mass fraction of the glutaraldehyde aqueous solution is 50%.
8. A method for preparing an efficient fertilizer for high-yield and emission-reduction rice cultivation according to claim 6, characterized in that, The emulsifier is at least one of span80 and span60.
9. A method for preparing an efficient fertilizer for high-yield and emission-reduction rice cultivation according to claim 6, characterized in that, The conditions for high-speed stirring emulsification are stirring at a speed of 1000-1500 rpm for 2-3 hours.
10. The enhanced fertilizer for high-yield and emission-reduction rice prepared by the method of claim 1.