CN114920610B

CN114920610B - Effervescent tablet containing nitrification inhibitor and preparation method thereof

Info

Publication number: CN114920610B
Application number: CN202210634431.8A
Authority: CN
Inventors: 刘蕊; 李冬佳; 黄致祥; 张卫峰; 刘家欢; 张福锁; 雷吉琳
Original assignee: China Agricultural University
Current assignee: China Agricultural University
Priority date: 2022-06-07
Filing date: 2022-06-07
Publication date: 2023-01-24
Anticipated expiration: 2042-06-07
Also published as: CN114920610A

Abstract

The invention discloses an effervescent tablet containing a nitrification inhibitor and a preparation method thereof. The effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 30-50 parts of 3, 4-dimethylpyrazole phosphate as a nitrification inhibitor, 15-30 parts of an acid source, 25-40 parts of an alkali source and 1-4 parts of a binder. Preferably, the effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 30-50 parts of nitrification inhibitor 3, 4-dimethylpyrazole phosphate, 25-30 parts of acid source, 25-30 parts of alkali source and 1-4 parts of binder. The nitrification inhibitor DMPP is prepared into the effervescent tablet, so that the technical defects of effervescent tablets without nitrification inhibitors in the market are overcome, the effervescent tablet has great application value, and the main component DMPP with nitrification inhibition activity is ensured not to degrade effective components and not to reduce the action effect after being prepared into the effervescent tablet.

Description

Effervescent tablet containing nitrification inhibitor and preparation method thereof

Technical Field

The invention belongs to the technical field of nitrification inhibitor preparations, and particularly relates to an effervescent tablet containing a nitrification inhibitor and a preparation method thereof.

Background

The mass production and application of chemical nitrogen fertilizers significantly increases crop yield, but excessive and unreasonable nitrogen fertilizer management leads to numerous environmental problems, further compromising the service functions of the ecosystem and posing a threat to human health. For example, application of nitrogen fertilizer to farmland systems can result in NO in the soil ₃ ^- Is not accumulated, and NO ₃ ^- The nitrogen fertilizer is easy to be leached to the lower layer of soil along with water in the soil, and enters underground water to cause the overhigh content of nitrate in the underground water, thus threatening the health of human beings, and at present, it is clear that the excessive application of the nitrogen fertilizer in the farmland is a main contribution source for causing the pollution of the underground water. Greenhouse gas N ₂ The main source of emission of O is also agricultural source nitrogen fertilizer application.

Reduce the number ofOne of these methods of nitrogen loss is to add nitrification inhibitors to the fertilizer to increase fertilizer utilization. Research shows that the nitrification inhibitor can inhibit the activity of nitrifying bacteria in soil, reduce the conversion of ammonium nitrogen into nitrate nitrogen and inhibit greenhouse gas N effectively ₂ O emissions and nitrate wash losses. Among them, 3, 4-dimethylpyrazole phosphate (DMPP) has been extensively tested in toxicology and field tests and is a highly effective, green nitrification inhibitor.

The main application forms of the nitrification inhibitor are as follows: firstly, the fertilizer is added as a production raw material in the fertilizer production process; secondly, before fertilization, the fertilizer is mixed with the fertilizer and applied in the field. Wherein, if the nitrification inhibitor is added in the fertilizer production, the dosage of the nitrification inhibitor is difficult to adjust by farmers according to the self condition; on the other hand, if the nitrification inhibitor is mixed and applied in the field, the recommended dosage of the nitrification inhibitor is 0.8% -1.6% of the total amount of the amide nitrogen and the ammonium nitrogen in the nitrogen fertilizer, and the application dosage is less, and the uniform mixing is difficult to ensure by applying the raw materials, so that a liquid preparation prepared by using the nitrification inhibitor is also proposed to be added, for example, a liquid preparation of the nitrification inhibitor for adding a drip irrigation system is proposed in WO2020109044 A1. However, the liquid preparation contains organic solvents, the environmental risk is unknown, and the production and transportation requirements are strict. The effervescent tablet is used as a solid tablet capable of accurately metering dosage, and is beneficial to metering and adding small-dosage medicine in the using process. Meanwhile, the effervescent tablet contains a disintegration component, so that the application procedure is more facilitated to be simplified, the efficacy is improved, and certain approval is obtained in agriculture, for example, the granted patent CN 11289676B develops an effervescent tablet for preventing and treating rice sheath blight disease.

However, no report on the research on the nitrification inhibitor effervescent tablet exists at present, and the research is blank to some extent. Meanwhile, in the research on the nitrification inhibitor DMPP, the most probable reason for causing the instability of the DMPP agricultural application is that the DMPP has an unstable structure, so that the DMPP is easy to degrade in a complex environment to further reduce the effect, for example, the research shows that the DMPP degradation is possibly influenced by the pH value of the environment, the type and the concentration of metal ions and the like. Because the raw materials of the effervescent tablet may relate to a wetting agent, a dispersing agent, a disintegrating agent, a binder and other multiple components, whether the preparation of the nitrification inhibitor DMPP into the effervescent tablet can cause the degradation of the DMPP or not is unknown.

Disclosure of Invention

In view of the above, the invention aims to provide a stable effervescent tablet containing a nitrification inhibitor and a preparation method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides an effervescent tablet containing a nitrification inhibitor, which is prepared from the following raw materials in parts by weight: 30-50 parts of 3, 4-dimethylpyrazole phosphate as a nitrification inhibitor, 15-30 parts of an acid source, 25-40 parts of an alkali source and 1-4 parts of a binder.

Preferably, the feed additive is prepared from the following raw materials in parts by weight: 30-50 parts of 3, 4-dimethylpyrazole phosphate as a nitrification inhibitor, 15-30 parts of an acid source, 25-40 parts of an alkali source and 1-4 parts of a binder. For example, the feed additive is prepared from the following raw materials in parts by weight: 39 parts of nitrification inhibitor 3, 4-dimethylpyrazole phosphate, 15-30 parts of acid source, 25-40 parts of alkali source and 1-4 parts of binder.

More preferably, the feed additive is prepared from the following raw materials in parts by weight: 30-50 parts of 3, 4-dimethylpyrazole phosphate as a nitrification inhibitor, 25-30 parts of an acid source, 25-30 parts of an alkali source and 1-4 parts of a binder. For example, the feed additive is prepared from the following raw materials in parts by weight: 39 parts of nitrification inhibitor, 25-30 parts of acid source, 25-30 parts of alkali source and 1-4 parts of binder.

Further preferably, the feed additive is prepared from the following raw materials in parts by weight: 30-50 parts of 3, 4-dimethylpyrazole phosphate serving as a nitrification inhibitor, 30 parts of an acid source, 25 parts of an alkali source and 1-4 parts of a binder. For example, the traditional Chinese medicine is prepared from the following raw materials in parts by weight: 39 parts of nitrification inhibitor 3, 4-dimethylpyrazole phosphate, 30 parts of acid source, 25 parts of alkali source and 1-4 parts of binder.

By way of example, the effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 39 parts of nitrification inhibitor 3, 4-dimethylpyrazole phosphate, 30 parts of acid source, 25 parts of alkali source and 2 parts of binder.

In the effervescent tablet containing nitrification inhibitor, the acid source may be any inorganic acid or organic acid capable of providing acidic conditions, such as citric acid, fumaric acid, malic acid, adipic acid, etc., and citric acid monohydrate is preferred.

In the above effervescent tablet containing nitrification inhibitor, the alkali source can be any inorganic or organic alkali capable of providing alkaline conditions, such as sodium bicarbonate, sodium carbonate, calcium carbonate, etc., preferably sodium bicarbonate.

In the effervescent tablet containing the nitrification inhibitor, any lubricant commonly used in the effervescent tablet can be used as the lubricant, such as polyethylene glycol 400, polyethylene glycol 6000, sodium lauryl sulfate, magnesium stearate and the like, and preferably PEG6000 (polyethylene glycol 6000).

In the effervescent tablet containing the nitrification inhibitor, the binder can be any binder commonly used in effervescent tablets, such as polyvinylpyrrolidone, starch, dextrin and the like;

as an example, the polyvinylpyrrolidone is K30, and is added in the form of an ethanol solution of polyvinylpyrrolidone with a mass percentage of 30%.

Preferably, the effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 30-50 parts of nitrification inhibitor 3, 4-dimethylpyrazole phosphate, 15-30 parts of acid source, 25-40 parts of alkali source, 3-8 parts of lubricant and 1-4 parts of binder. For example, the effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 39 parts of nitrification inhibitor, 15-30 parts of acid source, 25-40 parts of alkali source, 3-8 parts of lubricant and 1-4 parts of binder.

More preferably, the effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 30-50 parts of 3, 4-dimethylpyrazole phosphate as a nitrification inhibitor, 25-30 parts of an acid source, 25-30 parts of an alkali source, 3-8 parts of a lubricant and 1-4 parts of a binder. For example, the effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 39 parts of nitrification inhibitor, 25-30 parts of acid source, 25-30 parts of alkali source, 3-8 parts of lubricant and 1-4 parts of binder.

Further preferably, the effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 30-50 parts of nitrification inhibitor 3, 4-dimethylpyrazole phosphate, 30 parts of acid source, 25 parts of alkali source, 3-8 parts of lubricant and 1-4 parts of binder. For example, the effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 39 parts of nitrification inhibitor, 30 parts of acid source, 25 parts of alkali source, 3-8 parts of lubricant and 1-4 parts of binder.

By way of example, the effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 39 parts of nitrification inhibitor 3, 4-dimethylpyrazole phosphate, 30 parts of acid source, 25 parts of alkali source, 4 parts of lubricant and 2 parts of binder.

In a second aspect, the present invention provides a method for preparing an effervescent tablet containing a nitrification inhibitor, which comprises the following steps:

1) Stirring and grinding the acid source and the nitrification inhibitor until the acid source and the nitrification inhibitor are uniformly mixed;

2) Adding the binder into the mixture obtained in the step 1) for granulation, and then carrying out drying treatment and screening;

3) Mixing the particles obtained in step 2) with the dried alkali source;

4) Tabletting the mixture obtained in the step 3) to obtain the effervescent tablet containing the nitrification inhibitor.

In the preparation method, in the step 1), the stirring and grinding are performed in an environment with air humidity lower than 20%;

in the step 2), the drying treatment is drying until the water content is less than or equal to 3%; the sieve is sieved by a sieve of 20 meshes to 40 meshes, such as a sieve of 20 meshes;

in the step 3), the drying treatment is drying until the water content is less than or equal to 3%;

in the step 3), the lubricant is dried and then mixed with the particles obtained in the step 2) together with the alkali source; the drying treatment of the lubricant is drying until the water content is less than or equal to 3 percent.

In a fourth aspect, the present invention provides a method for applying a nitrogen fertilizer, comprising the steps of: dissolving the effervescent tablet containing the nitrification inhibitor in water, adding a nitrogen fertilizer to prepare a mixed solution, and carrying out drip irrigation on the mixed solution to soil.

In the treatment method, the application amount of the effervescent tablet containing the nitrification inhibitor can be folded to be 2-4% of the pure nitrogen content, and specifically can be 2.5%;

the application amount of the nitrogen fertilizer can be 0.05-0.15 g of N/kg of soil, and specifically can be 0.1g of N/kg of soil.

In the above method, the nitrogen fertilizer can be added directly by adding solid fertilizer, or by adding fertilizer solution in any form (for example, injecting fertilizer solution through a fertilizer injection tube).

The invention has the following beneficial effects:

(1) The effervescent tablet is prepared from the nitrification inhibitor DMPP, so that the technical defects of effervescent tablets without nitrification inhibitors in the market are overcome, the effervescent tablet has great application value, and the main component DMPP with nitrification inhibition activity is ensured not to degrade effective components and not to reduce the action effect after being prepared into the effervescent tablet.

(2) In the DMPP effervescent tablet raw material system, the content of the nitrification inhibitor is related to the fluidity and the hygroscopicity, and when the content of the nitrification inhibitor is within the range of the invention, the raw material system can be ensured to have the optimal fluidity and the hygroscopicity, thereby ensuring the subsequent industrial production.

(3) In the raw material system of the DMPP effervescent tablet, the acid source and the alkali source play an important role in the stability of the nitrification inhibitor, the DMPP in the prepared DMPP effervescent tablet can be quickly decomposed due to improper proportioning of the acid source and the alkali source, and the optimal stability of the nitrification inhibitor can be obtained only within the range.

(4) When the DMPP effervescent tablet is applied by mixing with a fertilizer containing multiple nutrient elements, improper selection of an acid source and an alkali source can cause precipitation with trace elements in a medium fertilizer, for example, when a calcium-magnesium fertilizer is mixed, a small amount of flocculent precipitate is generated to block a drip irrigation nozzle. Research shows that when the acid source is citric acid monohydrate and the alkali source is sodium bicarbonate, the acid source and alkali source is combined with DMPP to produce no precipitate and no flocculent precipitate with medium trace element fertilizer containing calcium chloride and magnesium sulfate.

(5) In the DMPP effervescent tablet raw material system, PEG6000 is selected as a lubricant, so that the effervescent tablet can be guaranteed to have the optimal stability, and the problem of equipment abrasion caused by difficult demoulding in the process of preparing the effervescent tablet can be solved.

Detailed Description

The present invention is described in further detail below with reference to specific embodiments, which are given for the purpose of illustration only and are not intended to limit the scope of the invention. The examples provided below serve as a guide for further modifications by a person skilled in the art and do not constitute a limitation of the invention in any way.

The experimental methods used in the following examples are all conventional methods unless otherwise specified; the materials, reagents and the like used are commercially available unless otherwise specified. The percentages are mass percentages unless otherwise specified.

EXAMPLE 1 preparation of effervescent tablets containing Nitrification inhibitor

1. Composition of raw materials

39 parts of 3, 4-dimethylpyrazole phosphate (nitrification inhibitor), 30 parts of citric acid monohydrate (acid source), 25 parts of sodium bicarbonate (alkali source), 4 parts of PEG6000 (lubricant) and 2 parts of 30% polyvinylpyrrolidone K30 ethanol solution (binder).

2. Preparation process

An effervescent tablet containing a nitrification inhibitor is prepared according to the following steps:

1) Taking the acid source and the nitrification inhibitor according to the proportion, stirring and grinding the mixture to be uniformly mixed in the environment with the air humidity lower than 20 percent;

2) Adding all binder components into the mixture obtained in the step 1) for granulation, then drying until the water content is less than 3%, and sieving by a 20-mesh sieve;

3) Mixing the particles obtained in the step 2) and an alkali source and a lubricant which are uniformly dried until the water content is less than 3% according to a proportion;

4) Tabletting the mixture obtained in the step 3) according to the specification to obtain the effervescent tablet containing the nitrification inhibitor, and recording as treatment 1.

Comparative example 1

Effervescent tablets containing nitrification inhibitor were prepared according to the raw material composition in example 1, with the preparation process being adjusted only to the following steps:

1) Taking an acid source, an alkali source and a nitrification inhibitor according to a certain proportion, stirring and grinding the mixture until the mixture is uniformly mixed in an environment with air humidity lower than 20%;

2) Adding all binder components into the mixture obtained in the step 1) for granulation, and then drying until the water content is less than 3%;

3) Mixing the dried mixture obtained in the step 2) with all lubricants, and tabletting according to the specification to obtain the effervescent tablet treated as the control, which is marked as control 1.

Comparative example 2

Effervescent tablets containing nitrification inhibitor were prepared according to the raw material composition of example 1 without adding a binder, with the preparation process being adjusted only to the following steps:

1) Taking an acid source, an alkali source and a nitrification inhibitor according to a proportion, stirring and grinding the mixture under the environment that the air humidity is lower than 20 percent until the mixture is uniformly mixed;

2) Mixing the mixture obtained in the step 1) with all lubricants, and directly tabletting to obtain the effervescent tablet treated by the comparison, which is marked as comparison 2.

Comparative example 3

1) Taking an acid source, an alkali source and a nitrification inhibitor according to a proportion, stirring and grinding the mixture under the environment that the air humidity is lower than 20 percent until the mixture is uniformly mixed, and drying the mixture until the water content is less than 3 percent;

2) Mixing the dried mixture obtained in the step 1) with all lubricants, and directly tabletting to obtain the effervescent tablet treated by the comparison, and marking as a comparison 3.

The effervescent tablets prepared in example 1 and comparative examples 1 to 3 by different processes were stored in a constant temperature incubator at 20 ℃ and the content of DMPP was measured periodically using liquid chromatography. The results are shown in Table 1. The initial DMPP content of all treated DMPP effervescent tablets was 39%.

The content of DMPP in the effervescent tablet is slightly modified according to the determination method of agricultural industry standard NY/T3423-2019. Preparing an effervescent tablet sample with the weight of 1g-4g according to the formula dosage of the patent, disintegrating the sample in 200ml of water, shaking for 30min at the room temperature of 180r/min, fixing the volume to 500ml, and filtering with a 0.45 mu m filter membrane to be detected. The sample solution or the dilution solution and the DMPP series standard solution are measured under the same conditions, and the corresponding mass concentration (mg/L) is found on the standard curve. The standard series of solutions have the mass concentration: 0mg/L, 20mg/L, 50mg/L, 100mg/L, 200mg/L, 300mg/L.

A chromatographic column: c ₁₈ ，5μm，150mm×4.6mm

Mobile phase: 1.38g of sodium dihydrogen phosphate monohydrate was dissolved in 1L of water, 175ml of acetonitrile was added, and degassing was conducted;

flow rate: 1.5ml/min

Column temperature: at room temperature

Sample injection amount: 10 μ L

Detection wavelength: 224nm

The content of DMPP in the effervescent tablet is calculated by mass fraction omega:

ρ: sample DMPP mass concentration (mg/L) found by standard curve

V: total volume of sample solution (ml)

D: dilution factor in measurement

m: effervescent tablet Total weight (g)

TABLE 1 DMPP effervescent tablets prepared by different processes with the change of DMPP content with storage time

As shown in table 1, DMPP effervescent tablets prepared by different processes seriously affect the DMPP content in the DMPP effervescent tablets during long-term storage, wherein, after the process preparation scheme 70d of example 1 is stored, the DMPP loss rate is only 2.92%, but the DMPP loss rate of other treatments is 6.91% -15.8%, and in comparison 3, the content measurement of the storage 70d is not performed because the loss rate reaches 15.6% when the DMPP effervescent tablets are stored at the storage 46 d.

Example 2

DMPP effervescent tablets were prepared according to the procedure in example 1, adjusting only the raw material composition as follows:

39 parts of 3, 4-dimethylpyrazole phosphate (nitrification inhibitor), 25 parts of citric acid monohydrate (acid source), 30 parts of sodium bicarbonate (alkali source), 4 parts of PEG6000 (lubricant) and 2 parts of 30% ethanol solution (binder) of polyvinylpyrrolidone K30.

The resulting effervescent tablet was prepared and is identified as treatment 2.

Example 3

39 parts of 3, 4-dimethylpyrazole phosphate (nitrification inhibitor), 15 parts of citric acid monohydrate (acid source), 40 parts of sodium bicarbonate (alkali source), 4 parts of PEG6000 (lubricant) and 2 parts of 30% ethanol solution (binder) of polyvinylpyrrolidone K30.

The resulting effervescent tablet was prepared and is identified as treatment 3.

Similarly, effervescent tablets prepared from different raw material compositions of example 2 and example 3 were stored in an incubator at 20 ℃ and periodically measured for DMPP content using liquid chromatography. The experimental results are shown in table 2 (DMPP loss rate = ω) ₀ -ω _i ，ω ₀ Is the initial content of DMPP in the effervescent tablet, omega _i The DMPP content of the effervescent tablets was determined for the ith sample. The initial DMPP content of all treated DMPP effervescent tablets was 39%.

TABLE 2 influence of different acid and alkali source ratios on DMPP loss rate in effervescent tablets

Research shows that the acid source and alkali source ratio has obvious influence on the content of the DMPP effervescent tablet. And with the increase of the alkali source component, the loss rate of the DMPP in the DMPP effervescent tablet is further increased.

Example 4

An effervescent tablet containing a nitrification inhibitor was prepared according to the raw material composition of example 1 except for the lubricant, designated as treatment 4, in the same manner as in example 1 (treatment 1), except that no lubricant was added:

TABLE 3 Effect of Lubricant addition on DMPP content in DMPP effervescent tablets

As can be seen from table 3, the absence of lubricant does not affect the DMPP content as a function of storage time.

Example 4 application of DMPP effervescent tablets to inhibition of soil nitrogen transformation and nitrification

The test protocol was as follows:

(1) Air-drying the soil with pH of 7.2 and sieving with 2mm sieve, weighing 50g of air-dried soil, adjusting water content to 60% WFPS, and performing soil culture test at 25 deg.C;

(2) DMPP, DMPP effervescent tablets and effervescent tablet auxiliaries are prepared into solution for treating soil, and the addition amount of the DMPP effervescent tablets is converted into 2.5 percent of the pure nitrogen content. The fertilizer was added as an ammonium chloride (AR) solution in an amount of 0.1g N/kg soil. There were 4 treatments: blank (CK), DMPP effervescent tablet and effervescent tablet auxiliary agent. Wherein:

and (3) CK processing: adding only ammonium chloride (AR);

DMPP treatment: dissolving DMPP raw medicine and ammonium chloride (AR) in water to prepare a mixed solution;

and (3) DMPP effervescent tablet treatment: the application method of the DMPP effervescent tablet simulation effervescent tablet prepared in the embodiment 1 in a drip irrigation system comprises the steps of completely disintegrating 0.5g of effervescent tablet in 100ml of water, and adding ammonium chloride (AR) to prepare a mixed solution;

processing an effervescent tablet auxiliary agent: preparing effervescent tablet according to the composition and process in example 1 except for DMPP, i.e. using other components except DMPP, compressing into effervescent tablet, disintegrating completely in 100ml water, adding ammonium chloride (AR) to make mixed solution;

(3) Destructive sampling on days 1, 3, 5 and 10 after culture, and measuring NH in soil ₄ ⁺ 、NO ₃ ^- Content, soil pH. The results are shown in tables 3 to 5. Calculating the nitrification inhibition rates of different treatments according to the following calculation formula:

NI(％)＝(N ₀ -N ₁ )/N ₀ ×100％

in the formula: NI (%) is nitrification inhibition (%) and N ₀ Soil NO treated by single fertilizer ₃ ^- Content of-N, N ₁ Adding DMPP effervescent tablets or DMPP raw pesticide to treat soil NO at the same time ₃ ^- -N content.

TABLE 4DMPP effervescent tablets for soil ammonium nitrogen content (mg kg) ^-1 ) Influence of (2)

As shown in Table 4, the DMPP effervescent tablet can obviously improve the retention rate of ammonium nitrogen in soil, has no difference with the effect of a DMPP raw pesticide, and the retention rate of the ammonium nitrogen in the soil treated by adding the DMPP effervescent tablet is 54.94mg kg after the soil is cultured for 10 days ^-1 While the blank treatment without DMPP addition was only 2.35mg kg ^-1 。

TABLE 5 influence of DMPP effervescent tablets on nitrate nitrogen content of soil

As shown in Table 5, the DMPP effervescent tablets inhibit the conversion of ammonium nitrogen into nitrate nitrogen, so that the content of the nitrate nitrogen in the soil is remarkably reduced, the effect is not remarkably different from that of a DMPP raw pesticide, the DMPP effervescent tablets are cultured until the 10 th day, and the soil treated by adding the DMPP effervescent tabletsThe nitrate nitrogen content is 35.57mg kg ^-1 While the blank treatment without DMPP addition was only 117.6mg kg ^-1 。

TABLE 6 influence of DMPP effervescent tablets on nitrification inhibition (%)

The DMPP effervescent tablet can be dissolved in water into a relatively uniform solution without manual stirring because of its own foamability during use, and table 6 shows that the inhibition effect of DMPP crude drug on soil nitrification can not be reduced after DMPP is made into effervescent tablet, and the nitrification inhibitor activity of both can reach 70% after the culture is finished. Meanwhile, due to the addition of the auxiliary agent and the small amount of nitrification inhibition activity of the auxiliary agent, the DMPP effervescent tablet tends to have higher/lasting nitrification inhibition activity than DMPP raw pesticide along with the extension of the culture time.

TABLE 7 influence of DMPP effervescent tablets on the pH value of the soil

Since nitrification inhibitors can alter the nitrogen circulation in soil, numerous studies have shown that the application of nitrification inhibitors can alter the soil pH over time. As shown in table 7, the ammonium nitrate ratio in the soil increased after the DMPP effervescent tablets were used, and therefore the pH of the soil increased in a short period of time.

The present invention has been described in detail above. It will be apparent to those skilled in the art that the invention can be practiced in a wide range of equivalent parameters, concentrations, and conditions without departing from the spirit and scope of the invention and without undue experimentation. While the invention has been described with reference to specific embodiments, it will be appreciated that the invention can be further modified. In general, this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. The use of some of the essential features is possible within the scope of the claims attached below.

Claims

1. An effervescent tablet containing a nitrification inhibitor is prepared from the following raw materials in parts by weight: 30-50 parts of 3, 4-dimethylpyrazole phosphate serving as a nitrification inhibitor, 15-30 parts of an acid source, 25-40 parts of an alkali source and 1-4 parts of a binder;

the preparation method of the effervescent tablet containing the nitrification inhibitor comprises the following steps:

3) Mixing the particles obtained in step 2) with the dried alkali source;

2. The effervescent tablet containing a nitrification inhibitor according to claim 1, wherein: the acid source is citric acid, fumaric acid, malic acid or adipic acid;

the alkali source is sodium bicarbonate, sodium carbonate or calcium carbonate.

3. The effervescent tablet containing a nitrification inhibitor according to claim 1 or 2, wherein: the binder is polyvinylpyrrolidone, starch or dextrin.

4. The effervescent tablet containing a nitrification inhibitor according to claim 3, wherein: the polyvinylpyrrolidone is K30 and is added in the form of 30% by mass of ethanol solution of the polyvinylpyrrolidone.

5. Effervescent tablet containing a nitrification inhibitor according to claim 1 or 2, characterized in that: the effervescent tablet containing the nitrification inhibitor is prepared from the following raw materials in parts by weight: 30-50 parts of nitrification inhibitor 3, 4-dimethylpyrazole phosphate, 15-30 parts of acid source, 25-40 parts of alkali source, 3-8 parts of lubricant and 1-4 parts of binder.

6. The effervescent tablet containing a nitrification inhibitor according to claim 5, wherein: the lubricant is polyethylene glycol 400, polyethylene glycol 6000, sodium dodecyl sulfate or magnesium stearate.

7. A process for the preparation of effervescent tablets containing a nitrification inhibitor according to any one of claims 1 to 5, comprising the steps of:

3) Mixing the particles obtained in step 2) with the dried alkali source;

8. The method of claim 7, wherein: in the step 1), the stirring and grinding are carried out in an environment with the air humidity lower than 20%;

in the step 2), the drying treatment is drying until the water content is less than or equal to 3%; the screening is to pass through a 20-40 mesh sieve;

in the step 3), the lubricant is dried and then mixed with the particles obtained in the step 2) together with the alkali source.

9. Use of an effervescent tablet comprising a nitrification inhibitor according to any one of claims 1 to 5 as an adjuvant for nitrogen fertilizers; the nitrogen fertilizer is an ammonium nitrogen fertilizer.

10. A nitrogen fertilizer application method comprises the following steps: dissolving the effervescent tablet containing the nitrification inhibitor of any one of claims 1 to 5 in water, adding a nitrogen fertilizer to prepare a mixed solution, and carrying out drip irrigation on the mixed solution to soil;

the nitrogen fertilizer is an ammonium nitrogen fertilizer.

11. The method of claim 10, wherein: the application amount of the effervescent tablet containing the nitrification inhibitor is converted into 2 to 4 percent of the content of pure nitrogen;

the application amount of the nitrogen fertilizer is 0.05-0.15 g N/kg soil.