Nitrogen fertilizer composite inhibiting oil suspending agent, preparation method and application thereof

Abstract

This invention relates to the field of fertilizer technology, specifically to a nitrogen fertilizer compound oil suspension inhibitor, its preparation method, and its application. This invention provides a nitrogen fertilizer compound oil suspension inhibitor, comprising, by weight, the following raw materials: 15-25 parts urease inhibitor, 5-15 parts nitrification inhibitor, 20-60 parts solvent, 1-5 parts stabilizer, and 5-20 parts co-solvent. This invention combines the use of urease inhibitor and nitrification inhibitor to achieve dual-stage control of the nitrogen conversion process. The urease inhibitor inhibits rapid urea hydrolysis and reduces ammonia volatilization, while the nitrification inhibitor delays the conversion of ammonium nitrogen to nitrate nitrogen, reducing nitrate nitrogen leaching and denitrification losses. The synergistic effect of both extends fertilizer efficiency by more than 30%, significantly improving nitrogen fertilizer utilization. Furthermore, this invention uses solvent and stabilizer, improving the stability and hydrophilicity of the oil suspension, and is environmentally friendly.

Description

Technical Field

[0001] This invention relates to the field of fertilizer technology, specifically to a nitrogen fertilizer compound oil suspension inhibitor, its preparation method, and its application. Background Technology

[0002] In agricultural production, nitrogen fertilizer is a crucial nutrient element for ensuring crop growth and development, playing a key role in improving crop yield and quality. However, current nitrogen fertilizer applications suffer from low utilization rates. Large amounts of nitrogen are lost through ammonia volatilization, leaching, and denitrification, leading not only to resource waste but also to ecological and environmental problems such as soil acidification and eutrophication. Urease inhibitors and nitrification inhibitors are commonly used to enhance the effectiveness of nitrogen fertilizers. Urease inhibitors suppress the activity of urease in the soil, slowing down the hydrolysis of urea and reducing ammonia volatilization losses. Nitrification inhibitors, on the other hand, inhibit the activity of nitrifying bacteria, slowing the conversion of ammonium nitrogen to nitrate nitrogen and reducing nitrate nitrogen leaching and denitrification losses. However, in current technologies, urease inhibitors and nitrification inhibitors are mostly used alone, making it difficult to achieve complete control over the nitrogen conversion process. Furthermore, some inhibitors suffer from poor stability, poor compatibility with fertilizers, and easy degradation during application. Additionally, traditional inhibitor formulations are mostly powders, which disperse unevenly in fertilizers, affecting the longevity of the fertilizer effect.

[0003] Therefore, developing a compound nitrogen fertilizer inhibitor that can achieve dual control of urease inhibition and nitrification inhibition, has good stability and strong compatibility, can quickly penetrate during fertilizer application, and can replace some of the anti-caking agents in granular fertilizers, is of great significance for improving nitrogen fertilizer utilization, reducing nitrogen loss, and promoting sustainable agricultural development. Summary of the Invention

[0004] This invention provides a nitrogen fertilizer compound oil suspension inhibitor, its preparation method, and its application, to solve the problems of limited effect, poor stability, poor compatibility, and low fertilizer effect persistence of existing nitrogen fertilizer compound oil suspension inhibitors when used alone.

[0005] In a first aspect, the present invention provides a nitrogen fertilizer compound inhibitory oil suspension agent, comprising the following raw materials in parts by weight: 15-25 parts of urease inhibitor, 5-15 parts of nitrification inhibitor, 20-60 parts of solvent, 1-5 parts of stabilizer, and 5-20 parts of cosolvent.

[0006] In an optional embodiment, the urease inhibitor comprises N-(butyl)thiophosphoryltriamide (CAS No.: 94317-64-3), hydroquinone (CAS No.: 123-31-9), n-propylthiophosphoryltriamide (CAS No.: 916809-14-8), thiophosphoryltriamide (CAS No.: 13455-05-5), phosphoryltriamide (CAS No.: 13597-72-3), O-phenyl-N,N'- At least one of the following: dimethylphosphoric acid diamine ester (CAS No.: 1754-58-1), catechol (CAS No.: 120-80-9), N-(2-nitrophenyl)phosphoryltriamide (CAS No.: 874819-71-3), phloroglucinol (CAS No.: 6099-90-7), 2-thiouracil (CAS No.: 141-90-2), 1H-benzotriazole (CAS No.: 95-14-7), and humic acid derivatives.

[0007] In an optional embodiment, the nitration inhibitor comprises at least one selected from 3,4-dimethylpyrazole (CAS No.: 2820-37-3), 3,4-dimethylpyrazole phosphate (CAS No.: 202842-98-6), dicyandiamide (CAS No.: 461-58-5), 2-chloro-6-trichloromethylpyridine (CAS No.: 1929-82-4), amidothiourea (CAS No.: 2114-02-5), 4-amino-1,2,4-triazole (CAS No.: 584-13-14), and ammonium thiosulfate (CAS No.: 7783-18-8).

[0008] In one optional embodiment, the solvent includes at least one of polar aprotic solvents, saturated fatty acid methyl esters, unsaturated fatty acid methyl esters, mineral oil solvents, and complex alcohol ether solvents.

[0009] Optionally, the polar aprotic solvent includes at least one of dimethyl sulfoxide, N,N-dimethylformamide, and cyclohexanone.

[0010] In one optional embodiment, the stabilizer comprises at least one of the following: an organic salt modified eutectic solution, an alcohol-polyol modified eutectic solution, a malic acid modified urea-based eutectic solvent, and a betaine-xylitol eutectic solution.

[0011] Optionally, the mass ratio of urea to choline chloride in the organic salt-modified eutectic solution is (1.5-2.5):(0.5-1.5). Optionally, the mass ratio of glycerol to choline chloride in the alcohol-polyol modified eutectic solution is (1.5-2.5):(0.5-1.5). Optionally, the mass ratio of urea to malic acid in the malic acid-modified urea-based eutectic solvent is (0.5-1.5):(0.5-1.5). Optionally, the mass ratio of betaine to xylitol in the betaine-xylitol eutectic solution is (0.5-1.5):(0.5-1.5).

[0012] It should be noted that the core effects of the stabilizer can be summarized in two points: 1) It significantly slows down the oxidation / hydrolysis rate of urease inhibitors (such as NBPT and DMPP), extending their effective action period in the soil; 2) It enhances the compatibility of urease inhibitors with fertilizers, reduces activity loss during storage, and does not reduce their inhibitory activity against urease / nitrifying bacteria. It should be noted that the working principle of the stabilizer is as follows: 1. To construct a "low water activity" microenvironment to inhibit the hydrolysis of urease inhibitors; 2. To enhance the solubility and dispersibility of the inhibitors and avoid "local inactivation".

[0013] In one optional embodiment, the co-solvent includes at least one of polar aprotic solvents, alcohol solvents, glycol ether solvents, and alkoxy alcohol solvents.

[0014] Optionally, the polar aprotic solvent includes at least one of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, and N-pyrrolidone; Optionally, the alcohol solvent includes at least one of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, glycerol, polyethylene glycol 400, and polyethylene glycol 600. Optionally, the glycol ether solvent includes at least one of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-propoxy-2-propanol, high-boiling-point complex alcohol ether solvent D190, and high-boiling-point complex alcohol ether solvent F150; Optionally, the alkoxy alcohol solvent includes at least one of 1-methoxy-3-propanol, 1-ethoxy-3-propanol, 1-propoxy-3-propanol, 1-methoxy-4-butanol, 1-ethoxy-4-butanol, and 1-propoxy-4-butanol. It should be noted that the core effects of the solubilizer can be summarized in three points: 1) Improving the solubility of inhibitors: Urease inhibitors and nitrification inhibitors such as NBPT and DMPP may have poor solubility. The solubilizer can help the inhibitor disperse better in the solvent through interaction with the inhibitor molecules, thereby improving its solubility and allowing it to be more evenly distributed in the fertilizer system to fully exert its inhibitory effect; 2) Enhancing system stability: The solubilizer can reduce the aggregation and reaction between inhibitor molecules through intermolecular interactions, thereby improving the chemical stability of the inhibitor in the system and preventing decomposition and deterioration during storage and use; 3) Improving the application performance of the formulation: The solubilizer can affect the dispersion and penetration performance of fertilizer formulations in the soil.

[0015] Optionally, the saturated fatty acid methyl ester includes at least one of methyl laurate, methyl hexanoate, methyl octanoate, and methyl decanoate; Optionally, the unsaturated fatty acid methyl ester includes at least one of methyl oleate, methyl linoleate, methyl linolenate, and methyl palmitate; Optionally, the mineral oil solvent includes at least one of aromatic oil series solvents, paraffin oil, and white oil; Optionally, the composite alcohol ether solvent includes D190.

[0016] In one alternative embodiment, the optimal combination of the urease inhibitor and the nitration inhibitor is as follows: N-(Butyl)thiophosphoric triamide + 3,4-dimethylpyrazole phosphate (NBPT+DMPP): Suitable for field crops (wheat, corn), highly tolerant of acidic soil, stable in pH 5.5-8.0 environments, and can improve nitrogen use efficiency by 15%-20%; N-(Butyl)thiophosphoric triamide + 2-chloro-6-trichloromethylpyridine (NBPT+CP): Suitable for economic crops (fruits and vegetables), it inhibits nitrification quickly and can reduce the accumulation of nitrate nitrogen in fruits and improve quality; N-(Butyl)thiophosphoric triamide + dicyandiamide (NBPT+DCD): Suitable for low-temperature environments (such as spring sowing in the north). DCD can still maintain its activity at low temperatures, preventing nitrogen loss in early spring. Avoid using amidothiourea alone as a nitrification inhibitor: amidothiourea needs to be converted into sulfite to be effective, and it is easily deactivated in alkaline soils. It is recommended to use it in combination with DMPP (ratio 1:2).

[0017] Secondly, the present invention also provides a method for preparing the above-mentioned nitrogen fertilizer compound inhibitor of oil suspension, comprising the following steps: S1, Mix the solvent and co-solvent to obtain a mixed solvent; S2, the pretreated urease inhibitor and nitrification inhibitor are dispersed in a mixed solvent to obtain a mixture; S3, the stabilizer is added to the mixture and heat-treated to obtain the nitrogen fertilizer composite oil suspension inhibitor.

[0018] In one optional embodiment, the pretreatment includes pulverizing and mixing the urease inhibitor and the nitrification inhibitor, followed by drying. In one optional implementation, in S1, the mixing includes stirring at room temperature; In an alternative implementation, in S2, the dispersion includes stirring and ultrasonication; Optionally, the stirring speed is 300-500 r / min and the stirring time is 10-15 min; Optionally, the ultrasound includes intermittent ultrasound.

[0019] Further optionally, the intermittent ultrasound includes ultrasound for 4-6 minutes, pause for 1-3 minutes, and repeat 3-4 times; Optionally, the power of the ultrasound is 300-500W, and the total time is 15-25min.

[0020] In one optional embodiment, in S3, the heat treatment temperature is 35-45°C, the time is 25-35 min, and the rotation speed is 400-600 r / min.

[0021] In one optional embodiment, the preparation method of the nitrogen fertilizer compound inhibitory oil suspension agent includes the following steps: (1) Raw material pretreatment The selected urease inhibitor and nitration inhibitor are pulverized and mixed in a pulverizer; the pulverized material is then subjected to vacuum drying in a double cone vacuum dryer to control the moisture content to below 0.5% in order to avoid moisture affecting the stability of the oil.

[0022] (2) Initial mixing Add the solvent and co-solvent to the mixing vessel equipped with a stirring device and an ultrasonic dispersion device according to the specified ratio. Turn on the stirring and mix at room temperature for 300-500 r / min for 10-15 minutes to form a uniform mixture.

[0023] (3) Inhibitor dispersion The pretreated urease inhibitor and nitrification inhibitor are slowly added to the mixture, and stirring is continued for 20-30 minutes to allow the inhibitors to initially disperse. Then, the ultrasonic dispersion equipment is started, using intermittent ultrasonication (5 minutes of ultrasonication, 2 minutes of pause, repeated 3-4 times), with an ultrasonic power of 300-500W and a total ultrasonic time of 15-25 minutes, so that the inhibitors form nanoscale dispersed particles, improving their dispersion uniformity and stability in the system.

[0024] (4) Stabilizer addition Slowly add the urea-choline chloride eutectic solution stabilizer to the ultrasonically treated system, adjust the reactor temperature to 35-45℃, increase the stirring speed to 400-600 r / min, and stir for 25-35 minutes to ensure that the stabilizer is fully dissolved and evenly dispersed in the system to form a stable system.

[0025] Thirdly, the present invention provides the application of the above-mentioned nitrogen fertilizer compound oil suspension inhibitor or the nitrogen fertilizer compound oil suspension inhibitor prepared by the above-mentioned preparation method in agricultural production and fertilizer production.

[0026] The technical solution of this invention has the following advantages: 1. The present invention provides a nitrogen fertilizer compound inhibitor of oil suspension, which, by weight, comprises the following raw materials: 15-25 parts of urease inhibitor, 5-15 parts of nitrification inhibitor, 20-50 parts of solvent, 1-5 parts of stabilizer, and 5-20 parts of cosolvent. This invention combines urease inhibitors and nitrification inhibitors to achieve dual-stage control of the nitrogen conversion process. The urease inhibitors suppress rapid urea hydrolysis and reduce ammonia volatilization, while the nitrification inhibitors delay the conversion of ammonium nitrogen to nitrate nitrogen, reducing nitrate nitrogen leaching and denitrification losses. The synergistic effect of these two inhibitors extends fertilizer efficiency by more than 30%, significantly improving nitrogen fertilizer utilization. Furthermore, the invention uses solvents and stabilizers to improve the stability and hydrophilicity of the oil suspension, while being environmentally friendly. The oil suspension provided by this invention is compatible with mainstream nitrogen fertilizers such as urea, compound fertilizers, and water-soluble fertilizers, and supports various processing methods such as spraying and mixing. The addition amount is 0.2%-0.4% of the total ammonium and amide nitrogen in the fertilizer, making it suitable for different types of fertilizer production and agricultural production scenarios. It is simple to operate and easy to promote and apply.

[0027] 2. The preparation method of the nitrogen fertilizer compound inhibitor oil suspension provided by the present invention includes the following steps: the pretreatment can control the moisture content of urease inhibitor and nitrification inhibitor to be less than 0.5%, avoiding the influence of moisture on the stability of the oil suspension; the dispersion enables the components to form a nanoscale dispersion system, further enhancing the stability and dispersibility of the product; the heat treatment ensures that the stabilizer is fully dissolved and uniformly dispersed in the system, forming a stable system. Detailed Implementation

[0028] The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having” and any variations thereof in the text of this application are intended to cover non-exclusive inclusion.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers from a to b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed herein, and "0-5" is merely a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥ 2, it is equivalent to disclosing that the parameter can be, for example, integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0032] In the description of the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0033] In the description of the embodiments of this application, the term "at least one" refers to one or more (including two).

[0034] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0035] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0036] Example 1 This embodiment provides a nitrogen fertilizer compound oil suspension inhibitor, and the specific steps and parameter settings are as follows, based on parts by weight: S1. Add 50 parts of solvent (dimethyl sulfoxide and methyl laurate in a mass ratio of 20:30) and 19 parts of co-solvent (ethylene glycol monoethyl ether and high-boiling-point composite alcohol ether solvent D190 in a mass ratio of 7:12) to a mixing vessel equipped with a stirring device and an ultrasonic dispersion device. Stir at 400 r / min for 15 min at room temperature to obtain a mixed solvent. S2, 20 parts of pretreated urease inhibitor (N-(butyl)thiophosphoryltriamide) and 15 parts of nitration inhibitor (2-chloro-6-trichloromethylpyridine) were slowly added to the mixed solvent while stirring. Then, the ultrasonic dispersion device was started and intermittent ultrasonication was used (ultrasonication for 5 min, pause for 2 min, repeated 3 times). The ultrasonic power was 400W and the total ultrasonic time was 20 min to obtain the mixture. S3, add 2 parts of stabilizer (polyol modified eutectic solution, in which the mass ratio of glycerol and choline chloride is 2:1) to the mixture, adjust the reactor temperature to 40°C, increase the stirring speed to 500 r / min, and stir for 30 min to obtain the nitrogen fertilizer composite oil suspension inhibitor.

[0037] Example 2 This embodiment provides a nitrogen fertilizer compound oil suspension inhibitor, and the specific steps and parameter settings are as follows, based on parts by weight: S1. Add 53 parts of solvent (N,N-dimethylformamide, methyl lauryl ester, ethylene glycol monomethyl ether in a mass ratio of 30:3:20) and 15 parts of co-solvent (ethylene glycol, tetrahydrofurfuryl alcohol in a mass ratio of 5:10) to a mixing vessel equipped with a stirring device and an ultrasonic dispersion device. Stir at 400 r / min for 15 min at room temperature to obtain a mixed solvent. S2, 15 parts of pretreated urease inhibitor (n-propylthiophosphoryltriamide) and 15 parts of nitration inhibitor (3,4-dimethylpyrazole) were slowly added to the mixed solvent while stirring. Then, the ultrasonic dispersion device was started and intermittent ultrasonication was used (ultrasound for 5 min, pause for 2 min, repeat 3 times). The ultrasonic power was 400W and the total ultrasonic time was 20 min to obtain the mixture. S3, add 2 parts of stabilizer (polyol modified eutectic solution, in which the mass ratio of glycerol and choline chloride is 2:1) to the mixture, adjust the reactor temperature to 40°C, increase the stirring speed to 500 r / min, and stir for 30 min to obtain the nitrogen fertilizer composite oil suspension inhibitor.

[0038] Example 3 This embodiment provides a nitrogen fertilizer compound oil suspension inhibitor, and the specific steps and parameter settings are as follows, based on parts by weight: S1. Add 55 parts of solvent (mass ratio of 200# aromatic oil, high-boiling-point complex alcohol ether solvent D190, and cyclohexanone = 40:9:6) and 9 parts of co-solvent (mass ratio of 2-pyrrolidone and high-boiling-point complex alcohol ether solvent F150 = 3:6) to a mixing vessel equipped with a stirring device and an ultrasonic dispersion device, and stir at 400 r / min for 15 min at room temperature to obtain a mixed solvent. S2, 25 parts of pretreated urease inhibitor (N-(butyl)thiophosphoric triamide) and 8 parts of nitration inhibitor (dicyandiamide) were slowly added to the mixed solvent while stirring. Then, the ultrasonic dispersion device was started and intermittent ultrasonication was used (ultrasonication for 5 min, pause for 2 min, repeated 3 times). The ultrasonic power was 400W and the total ultrasonic time was 20 min to obtain the mixture. S3, add 2 parts of stabilizer (polyol modified eutectic solution, in which the mass ratio of glycerol and choline chloride is 2:1) to the mixture, adjust the reactor temperature to 40°C, increase the stirring speed to 500 r / min, and stir for 30 min to obtain the nitrogen fertilizer composite oil suspension inhibitor.

[0039] Example 4 This embodiment provides a nitrogen fertilizer compound oil suspension inhibitor, and the specific steps and parameter settings are as follows, based on parts by weight: S1. Add 20 parts of solvent (dimethyl sulfoxide and methyl laurate in a mass ratio of 20:30) and 20 parts of co-solvent (ethylene glycol monoethyl ether and high-boiling-point composite alcohol ether solvent D190 in a mass ratio of 7:12) to a mixing vessel equipped with a stirring device and an ultrasonic dispersion device. Stir at 400 r / min for 15 min at room temperature to obtain a mixed solvent. S2, 15 parts of pretreated urease inhibitor (N-(butyl)thiophosphoryltriamide) and 15 parts of nitration inhibitor (2-chloro-6-trichloromethylpyridine) were slowly added to the mixed solvent while stirring. Then, the ultrasonic dispersion device was started and intermittent ultrasonication was used (ultrasonication for 5 min, pause for 2 min, repeated 3 times). The ultrasonic power was 400W and the total ultrasonic time was 20 min to obtain the mixture. S3, add 1 part of stabilizer (polyol modified eutectic solution, in which the mass ratio of glycerol and choline chloride is 2:1) to the mixture, adjust the reactor temperature to 45°C, increase the stirring speed to 400 r / min, stir for 35 min, and obtain the nitrogen fertilizer composite oil suspension inhibitor.

[0040] Example 5 This embodiment provides a nitrogen fertilizer compound oil suspension inhibitor, and the specific steps and parameter settings are as follows, based on parts by weight: S1. Add 60 parts of solvent (dimethyl sulfoxide and methyl laurate in a mass ratio of 20:30) and 5 parts of co-solvent (ethylene glycol monoethyl ether and high-boiling-point composite alcohol ether solvent D190 in a mass ratio of 7:12) to a mixing vessel equipped with a stirring device and an ultrasonic dispersion device. Stir at 400 r / min for 15 min at room temperature to obtain a mixed solvent. S2, 25 parts of pretreated urease inhibitor (N-(butyl)thiophosphoryltriamide) and 5 parts of nitration inhibitor (2-chloro-6-trichloromethylpyridine) were slowly added to the mixed solvent while stirring. Then, the ultrasonic dispersion device was started and intermittent ultrasonication was used (ultrasonication for 5 min, pause for 2 min, repeated 3 times). The ultrasonic power was 400W and the total ultrasonic time was 20 min to obtain the mixture. S3, add 5 parts of stabilizer (polyol modified eutectic solution, in which the mass ratio of glycerol and choline chloride is 2:1) to the mixture, adjust the reactor temperature to 35°C, increase the stirring speed to 600 r / min, and stir for 25 min to obtain the nitrogen fertilizer composite oil suspension inhibitor.

[0041] Comparative Example 1 This comparative example provides a nitrogen fertilizer compound inhibitor of oil suspension, which differs from Example 1 only in that the urease inhibitor is replaced with an equal mass of nitrification inhibitor. The rest is the same as in Example 1.

[0042] Comparative Example 2 This comparative example provides a nitrogen fertilizer compound inhibitor of oil suspension, which differs from Example 1 only in that the nitrification inhibitor is replaced with an equal mass of urease inhibitor. The rest is the same as in Example 1.

[0043] Comparative Example 3 This comparative example provides a nitrogen fertilizer compound oil suspension inhibitor, which differs from Example 1 only in that the solvent and co-solvent are replaced with equal masses of water; The rest is the same as in Example 1.

[0044] Comparative Example 4 This comparative example provides a nitrogen fertilizer compound oil suspension inhibitor, which differs from Example 1 only in that the co-solvent (mass ratio of ethylene glycol monoethyl ether and high-boiling-point compound alcohol ether solvent D190 = 7:12) is replaced with an equal mass of solvent (mass ratio of dimethyl sulfoxide and methyl laurate = 20:30). The rest is the same as in Example 1.

[0045] Comparative Example 5 This comparative example provides a nitrogen fertilizer compound oil suspension inhibitor, which differs from Example 1 only in that the stabilizer is replaced with an equal mass of solvent; The rest is the same as in Example 1.

[0046] Experimental Example 1 The performance of the nitrogen fertilizer compound inhibitory oil suspensions obtained in each embodiment and comparative example was tested. The test indicators included: urease inhibition rate, nitrification inhibition rate, nitrogen utilization rate, and thermal stability.

[0047] (1) Urease inhibition rate and nitrification inhibition rate: The test methods for urease inhibition rate and nitrification inhibition rate are as follows: Soil (with water content maintained at 70% of field capacity), nitrogen fertilizer compound inhibitor oil suspension prepared in each example and comparative example, and nitrogen fertilizer (Xinlianxin urea, total nitrogen content > 46%) were mixed at a mass ratio of 100:0.000013:0.0227 and incubated in a constant temperature incubator at 25℃ for 8h, 1d, 7d, and 21d, respectively. After 21 days of incubation, samples were taken, and the urease inhibition rate and nitrification inhibition rate of the soil samples were determined according to NYT 2543-2014 "Requirements for Fertilizer Synergist Effect Test and Evaluation".

[0048] (2) Nitrogen utilization rate: The nitrogen use efficiency was determined using a field plot experiment method. Group according to the following settings: Control group: Nitrogen fertilizer (Xinlianxin urea, total nitrogen content > 46%). Experimental group: Nitrogen fertilizer (Xinlianxin urea, total nitrogen content > 46%) and nitrogen fertilizer compound inhibitor of oil suspension in each example and comparative example were mixed at a ratio of 1000:2; Each group was set to 3 replicates, using a randomized block arrangement (each block area was 20m²). 2 (Isolation rows were set up between small groups, and protective rows were set up around the perimeter to avoid cross-contamination). The fertilization was carried out according to local conventional methods (spot application, fertilizer amount of 20 kg / mu) and planting density (3-4 plants per square meter). In the experimental group, the nitrogen fertilizer compound inhibitor was applied simultaneously with nitrogen fertilizer in each example and comparative example.

[0049] The total nitrogen content of maize plants (Liangyu 99 variety), the nitrogen accumulation in grains, and the residual nitrogen in the soil were measured at the crop maturity stage (harvested in early to mid-October). The nitrogen use efficiency was calculated using the following formula: Nitrogen utilization rate calculation formula: .

[0050] In the formula: NUE—Nitrogen utilization rate, % U plant —Total nitrogen accumulation in crop plants (including grains), in kg / hm² 2 ; Total nitrogen accumulation of the crop plant (including grain) (kg / hm) 2 = Nitrogen accumulation in a single location (kg / plot) × 10000 (m²) 2 / hm 2 ) ÷ Area of ​​the community (m 2 ), The nitrogen accumulation in a single part (kg / plot) = dry weight of that part (kg / plot) × nitrogen content of that part (%), wherein the nitrogen content of that part is determined by the Kjeldahl method in GB / T 5009.5-2016 "Determination of Protein in Food"; S residual —Residual nitrogen in the soil after harvest, in kg / hm² 2 ; The post-harvest residual nitrogen content in the soil (kg / hm²) = soil nitrogen content (mg / kg) × soil bulk density (g / cm³) 3 ) × sampling depth (cm) × 10, The ammonium nitrogen and nitrate nitrogen content in the soil were determined using NY / T 142-1990 "Determination of Ammonium Nitrogen in Soil" and NY / T 1116-2014 "Determination of Nitrate Nitrogen in Soil", respectively. N applied —Total nitrogen input through fertilization, in kg / hm² 2 .

[0051] (3) Thermal stability (granulation compatibility): The high-temperature treatment-residue determination method was adopted: the fertilizer drying temperature was simulated (60-80℃), and the nitrogen fertilizer compound inhibitor oil suspension prepared in each example and comparative example was mixed with nitrogen fertilizer at a dosage ratio of 2:1000 for 30 minutes. The residual amount of inhibitor in the nitrogen fertilizer compound inhibitor oil suspension after high-temperature treatment was determined by HPLC, and the thermal stability residual rate was calculated.

[0052] Formula for calculating thermal stability residual rate: .

[0053] In the formula: RR—Residual thermal stability, % C t —The mass concentration of inhibitor in the nitrogen fertilizer compound inhibitory oil suspension after high-temperature treatment, in g / L; C0—Initial mass concentration of inhibitor in nitrogen fertilizer compound inhibitor oil suspension before high temperature treatment, in g / L.

[0054] The specific test results are shown in the table below: Table 1 Performance Test Data

[0055] The data above shows that the nitrogen fertilizer compound inhibitor provided by this invention achieves the technical goals of efficient nitrogen utilization and stable product compatibility. Its specific effects are as follows: the urease inhibitor and nitrification inhibitor work synergistically to jointly inhibit ammonia volatilization and nitrate nitrogen leaching. The nitrogen utilization rate is far higher than that of a single inhibitor group. Moreover, it is more compatible with the granulation process and can better withstand the high temperature of fertilizer granulation. At the same time, it further reduces the agglomeration rate and ensures the stability of the product.

[0056] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A nitrogen fertilizer compound oil suspension inhibitor, characterized in that, By weight, it includes the following raw materials: 15-25 parts of urease inhibitor, 5-15 parts of nitration inhibitor, 20-60 parts of solvent, 1-5 parts of stabilizer, and 5-20 parts of cosolvent.

2. The nitrogen fertilizer compound oil suspension inhibitor according to claim 1, characterized in that, The urease inhibitors include at least one of N-(butyl)thiophosphoryltriamide, hydroquinone, n-propylthiophosphoryltriamide, thiophosphoryltriamide, phosphoryltriamide, O-phenyl-N,N'-dimethylphosphoryldiamine ester, catechol, N-(2-nitrophenyl)phosphoryltriamide, phloroglucinol, 2-thiouracil, 1H-benzotriazole, and humic acid derivatives.

3. The nitrogen fertilizer compound oil suspension inhibitor according to claim 1 or 2, characterized in that, The nitration inhibitor includes at least one selected from 3,4-dimethylpyrazole, 3,4-dimethylpyrazole phosphate, dicyandiamide, 2-chloro-6-trichloromethylpyridine, amidothiourea, 4-amino-1,2,4-triazole, and ammonium thiosulfate.

4. The nitrogen fertilizer compound oil suspension inhibitor according to any one of claims 1-3, characterized in that, The solvent includes at least one of polar aprotic solvents, saturated fatty acid methyl esters, unsaturated fatty acid methyl esters, mineral oil solvents, and complex alcohol ether solvents.

5. The nitrogen fertilizer compound oil suspension inhibitor according to any one of claims 1-4, characterized in that, The stabilizer includes at least one of the following: organic salt modified eutectic solution, alcohol-polyol modified eutectic solution, malic acid modified urea-based eutectic solvent, and betaine-xylitol eutectic solution.

6. The nitrogen fertilizer compound oil suspension inhibitor according to any one of claims 1-5, characterized in that, The co-solvent includes at least one of polar aprotic solvents, alcohol solvents, glycol ether solvents, and alkoxy alcohol solvents.

7. A method for preparing the nitrogen fertilizer compound oil suspension inhibitor according to any one of claims 1-6, characterized in that, Includes the following steps: S1, Mix the solvent and co-solvent to obtain a mixed solvent; S2, the pretreated urease inhibitor and nitrification inhibitor are dispersed in a mixed solvent to obtain a mixture; S3, the stabilizer is added to the mixture and heat-treated to obtain the nitrogen fertilizer composite oil suspension inhibitor.

8. The preparation method according to claim 7, characterized in that, In S3, the heat treatment temperature is 35-45℃, the time is 25-35min, and the rotation speed is 400-600r / min.

9. The application of a nitrogen fertilizer compound oil suspension inhibitor as described in any one of claims 1-6 or a nitrogen fertilizer compound oil suspension inhibitor prepared by the preparation method described in any one of claims 7-8 in agricultural production and fertilizer production.

10. The application according to claim 9, characterized in that, The applications include mixing the nitrogen fertilizer compound oil suspension inhibitor with nitrogen fertilizer for spraying or mixing with fertilizer. Optionally, the amount of the nitrogen fertilizer compound oil suspension inhibitor added is 0.2%-0.4% of the total amount of ammonium nitrogen and amide nitrogen in the nitrogen fertilizer; Optionally, the nitrogen fertilizer includes at least one of urea, compound fertilizer, and water-soluble fertilizer.

Images