CN101190856A - A kind of nitrification inhibitor and its application - Google Patents

Abstract

The invention relates to a stable fertilizer, specifically a nitrification inhibitor and its application in a stable fertilizer, which is 4-chloro-3-methylpyrazole; the stable fertilizer is composed of ammonium nitrogen fertilizer or ammonium-producing nitrogen fertilizer added with pure The nitrification inhibitor 4-chloro-3-methylpyrazole (CLMP) with an N content of 0.1-5.0% is prepared. As a nitrification inhibitor, CLMP has the advantages of high inhibitory efficiency, low dosage, not easy to leaching with water, low toxicity and less environmental pollution. After the nitrogen fertilizer containing this compound is applied to the soil, the oxidation process of nitrogen fertilizer in the soil can be regulated, thereby maintaining a high NH ₄ ⁺ -N content in the soil for a long time, reducing the accumulation of NO ₃ ^- -N in the soil, Then reduce the leaching and denitrification loss of soil N, prolong the efficiency of N fertilizer, improve the utilization efficiency of N fertilizer, and increase the absorption of phosphorus fertilizer by crops at the same time. The fertilizer can be used as a base fertilizer for one-time application, and can meet the nutrient requirements of crops during the entire growth period without topdressing, so as to achieve the purpose of saving labor and fertilizer.

Description

A kind of nitrification inhibitor and its application

technical field

The invention relates to a stable fertilizer, in particular to a nitrification inhibitor 4-chloro-3-methylpyrazole and its application in the stable fertilizer.

Background technique

N fertilizer is an important means of production in agricultural production and plays an important role in promoting the development of agricultural production. In recent years, with the continuous deterioration of the global ecological environment, the application of N fertilizer has become a farmland management technique with dual meanings in agronomy and ecology. The particularity of the transformation of N in the soil determines that its utilization rate is low, generally only about 30%. In agricultural production areas or vegetable production areas where fertilization is concentrated, the utilization rate of N fertilizer is even below 10%. The loss of N element due to volatilization, leaching and other ways is often as high as 70 or more. This not only causes a great waste of economy and resources, but also causes serious environmental problems such as air pollution, soil non-point source pollution, groundwater pollution and water eutrophication, and poses a threat to the environment and food safety on which human beings depend. .

Produce coated fertilizers and stabilized fertilizers through industrial means to achieve slow-release and long-acting N fertilizers, which can not only increase the utilization rate of N fertilizers, but also reduce the frequency of fertilization, reduce labor intensity, reduce environmental pollution, and improve the quality of agricultural products. The development of pollution-free agriculture and green agriculture in our country has important practical significance to take the road of sustainable development. Adding urease inhibitors and nitrification inhibitors to regulate the transformation of N in the soil to achieve high-efficiency fertilizer utilization is a potential nitrogen fertilizer management technology. Especially among the N fertilizer varieties used in the world today, the amount of ammonium N fertilizer and ammonium-producing N fertilizer accounts for more than 90%. Nitrification inhibitors are used to delay the oxidation process of ammonium N in the soil, especially in urea Adding urease and nitrification inhibitors at the same time or adding inhibitors to various solid fertilizer coatings is one of the trends in fertilizer production in the future.

After research, compounds containing pyrazole rings are a class of nitrification inhibitors with great potential for development. They have the advantages of high inhibition efficiency, low dosage, difficult leaching with water, low toxicity and low environmental pollution. The object of the company's research and development. According to literature reports, the newly developed nitrification inhibitor DMPP by German BASF company in recent years has a relatively significant effect, but there are few studies in my country. If it is introduced into my country, cost may become a major limiting factor. There are reports of pyrazole nitrification inhibitors including 3-methylpyrazole, but because it is in a liquid state at room temperature, it is difficult to add it in the fertilizer production granulation process, which greatly limits its use in stable fertilizer production. in the application. As a large agricultural country, it is imperative to research and develop environmentally friendly nitrification inhibitors and corresponding stable fertilizers that are highly efficient, low-toxic, widely adaptable, and low-cost, which are suitable for my country's national conditions.

Contents of the invention

The purpose of the present invention is to provide a nitrification inhibitor and its application in stable fertilizers. The present invention provides a novel nitrification inhibitor CLMP to promote the development of high-efficiency utilization technology of N fertilizer through biochemical pathways. The process of the invention is simple, and can be produced on the basis of the existing production process of N fertilizer (ammonium bicarbonate, urea, etc.) with a small amount of investment and transformation.

To achieve the above object, the technical solution adopted in the present invention is:

A nitrification inhibitor, which is 4-chloro-3-methylpyrazole, abbreviated as CLMP, white or yellowish crystal, easily soluble in alcohol, ether, ketone, benzene and other organic solvents, not easily soluble in water; its chemical The structural formula is:

In the application of the nitrification inhibitor in stable N fertilizer, the nitrification inhibitor CLMP of 0.1-5.0% of pure N weight is added in the N-containing fertilizer (ie ammonium nitrogen fertilizer or ammonium nitrogen fertilizer); Effect, the best addition amount is 0.1-2.0% of the pure N amount, which can have a significant nitrification inhibitory effect; if the fertilizer used is urea, add a small amount of urease inhibitor hydroquinone (HQ) or N-butylthiophosphoryl Triamine (NBPT), the effect is better, the mass ratio of nitrification inhibitor and urease inhibitor is 2-6:1. The present invention regulates the transformation of N in the soil by adding a novel nitrification inhibitor CLMP to the N-containing fertilizer, so as to realize the stable and long-acting N fertilizer; the N-containing fertilizer is ammonium bicarbonate, ammonium sulfate, ammonium chloride and / or urea.

The nitrification inhibitor CLMP is directly blended into the N-containing fertilizer or added to its production process, or the nitrification inhibitor CLMP is directly added to the coating material of the N fertilizer and then coated on the fertilizer.

Add the stable fertilizer preparation method of nitrification inhibitor CLMP as follows:

1. Preparation of stable urea: After the concentration and separation process of the original urea production process, add solid (microcrystalline or powder) CLMP into molten urine and mix well before entering the granulation process: or grind the very fine CLMP (>200 mesh), use a powder sprayer to spray on the high-temperature or semi-molten urea drops that have just been sprayed out of the prilling tower to complete the prilling process. Its production process is shown in Figure 1 or Figure 2.

2. Preparation of film-stabilized urea: using fluidized bed spray coating technology, the polymer material and CLMP are simultaneously dissolved in a volatile organic solvent, and additives such as film conditioner and plasticizer are added at the same time. The outer surface of the fluidized granular urea is sprayed and coated to form a smooth, uniform and continuous coating layer. Figure 3 is a schematic diagram of the fluidized bed coating process.

The principle of the present invention is: after ammonium N fertilizer or ammonium-producing N fertilizer is applied to the soil, the local NH ₄ ⁺ -N concentration of the soil will increase rapidly, resulting in a micro-domain environment with high pH in the soil. As a result, on the one hand, NH ₃ volatilization loss, on the one hand, high ammonium concentration and high pH will stimulate the proliferation of nitrifying bacteria in the soil, accelerate the oxidation of NH ₄ ⁺ in the soil, and cause a large accumulation of NO ₃ ^- -N in the soil. NO ₃ ^- -N is not easy to be adsorbed by soil colloids. In the case of large amount of irrigation water or heavy rainfall, it is easy to be leached to the lower layer of the soil with water or lost with surface runoff, and at the same time cause pollution to groundwater and surface water. In addition, NO ₃ ^- -N is the substrate of denitrification, and higher NO ₃ ^- -N content in the soil will enhance the intensity of denitrification, resulting in an increase of greenhouse gas N ₂ O emissions. This is the biochemical transformation process of N in soil. Therefore, reducing the accumulation of NO ₃ ^- -N in soil is the fundamental measure to reduce the leaching loss and denitrification loss of N, reduce environmental pollution and improve the utilization rate of N. After the nitrification inhibitor is applied to the soil, it can effectively inhibit the activity of nitrosifying bacteria and nitrifying bacteria involved in the NH ₄ ⁺ oxidation process in the soil, thereby inhibiting the oxidation process of NH ₄ ⁺ and keeping the soil at a higher NH level for a longer period of time. ₄ ⁺ -N content. While increasing the NH ₄ ⁺ nutrition of plants, when plants absorb NH ₄ ⁺ -N, they will release H ⁺ into the soil environment through the root system and reduce the soil pH, which is beneficial to increase phosphorus, iron, zinc, manganese, etc. around the rhizosphere Availability of other nutrients.

Compared with the existing slow-release, controlled-release and stable fertilizers, the present invention has the following advantages:

1. Lower cost. The present invention uses 4-chloro-3-methylpyrazole as a nitrification inhibitor for regulating soil N conversion, and is used in the preparation of stable fertilizer; the stable fertilizer produced by it has less investment in production, is easy to carry out technical grafting and transformation, and has high product quality. Stable and easy to manage.

2. The production process is simple: the synthesis process of the nitrification inhibitor CLMP added in the stabilized fertilizer is simple, the recovery rate is high, and the production cost is low.

3. The application effect is good. After the present invention is applied to the soil in the stabilized fertilizer, the transformation of N can be effectively regulated, and compared with the control without the application of inhibitors, it can maintain a higher concentration of NH ₄ ⁺ -N and a lower concentration of NO for a longer period of time ₃ ^-- N. And because of its low water solubility, the degree of movement with water in the soil profile is small, which reduces the possibility of its separation from NH ₄ ⁺ -N and the risk of pollution caused by leaching into groundwater.

4. Save resources and labor. The stable fertilizer prepared by the invention can be used as a base fertilizer and applied to the soil at one time without topdressing, which can meet the nutrient requirements of crops in the whole growth period and achieve the purpose of labor and fertilizer saving.

5. Compared with the existing nitrification inhibitor DMPP, the present invention has the advantages of simple synthesis method, wide source of raw materials and low cost.

6. Compared with 3-methylpyrazole, the present invention has the advantages of solid state, low vapor pressure, low volatility, can be directly added to the fertilizer production process, and has good storage stability.

In conclusion, the CLMP of the present invention is a nitrification inhibitor with stabilizing effect. As a nitrification inhibitor, CLMP has the advantages of high inhibitory efficiency, low dosage, not easy to leaching with water, low toxicity and less environmental pollution. After the nitrogen fertilizer containing this compound is applied to the soil, the oxidation process of nitrogen fertilizer in the soil can be regulated, thereby maintaining a high NH ₄ ⁺ -N content in the soil for a long time, reducing the accumulation of NO ₃ ^- -N in the soil, Then reduce the leaching and denitrification loss of soil N, prolong the efficiency of N fertilizer, improve the utilization efficiency of N fertilizer, and increase the absorption of phosphorus fertilizer by crops at the same time. The fertilizer can be used as a base fertilizer for one-time application, and can meet the nutrient requirements of crops during the entire growth period without topdressing, so as to achieve the purpose of saving labor and fertilizer.

Description of drawings

Fig. 1 is the production process flowchart that solid CLMP is added in the urine of molten state;

Fig. 2 is the process flow diagram of spraying the ultrafine CLMP (>200 order) of grinding on the urea drops in high temperature or semi-molten state just sprayed out from the prilling tower with a duster;

Figure 3 shows the use of fluidized bed spray coating technology, the high molecular polymer material and CLMP are dissolved in the volatile organic solvent at the same time, and additives such as membrane conditioner and plasticizer are added at the same time. The process flow chart of spray coating on the surface to form a smooth, uniform and continuous coating layer; where: 1. Spray tower 2. Fertilizer feed port 3. Exhaust gas discharge port 4. Atomizing nozzle 5. Flow controller 6. Air inlet channel 7. Heat exchanger 8. Orifice plate flowmeter 9. Blower 10. Liquid tank T1. Inlet air thermometer T ₂ . Material thermometer T ₃ . Exhaust air thermometer SL. Heat exchange direction.

Detailed ways

Example

86.1g (1.0mol) of formyl acetone, add 200ml of distilled water as a solvent, add 58.8g (1.0mol) of 85% hydrazine hydrate while stirring, add 2 drops of hydrochloric acid as a catalyst, control the temperature at 60-70°C for 1 hour, Cool and separate the aqueous layer, the organic layer is 3-methylpyrazole. The aqueous layer was extracted twice with 100 ml of carbon tetrachloride, and the extract was mixed with the original organic layer solution to obtain a carbon tetrachloride solution of 3-methylpyrazole. Pass chlorine flow for 30min at 80°C, keep the original temperature for 2h, filter, neutralize the obtained solid with dilute NaOH solution to a pH slightly greater than 10, and then filter to obtain the target product, dry to obtain 108.9g of CLMP, the recovery rate is 93.5 %. Recrystallize with ethanol to obtain white or slightly yellow needle-like crystals with a melting point of 64-65°C.

Because the production process of pyrolysis to produce acetylene often contains a small amount of impurity diacetylene, 3-methylpyrazole can also be obtained by absorbing diacetylene with hydrazine hydrate (the target product is obtained after chlorination), and the price is low.

Application example 1

4-chloro-3-methylpyrazole is crushed through a 60-mesh sieve, and the ratio of 100 parts by weight of urea plus 0.46 part of CLMP is measured and directly added to the molten urea of the former urea production process (Fig. 1) with a feeder, Mix evenly in the system and granulate to prepare stable urea containing nitrification inhibitor CLMP, the content of CLMP in the product is 1.0% of pure N.

Application example 2

Grind 4-chloro-3-methylpyrazole through a 200-mesh sieve, add 0.23 parts of CLMP to 100 parts of urea by weight, and then spray CLMP on the high-temperature or The urea in the semi-molten state is dropped, so that CLMP is attached to the surface of the urea granules, and the granulation process is completed (Figure 2). The content of CLMP in the product is 0.5% of the pure N amount.

Application example 3

Fully mix 1 part of hydroquinone crushed through a 60 mesh sieve with 4 parts of CLMP to form an additive to form an additive, and then add 0.3-0.5 parts of additive to 100 parts of urea by weight into the original urea production process through a feeder (Fig. 1) in the molten urea, mixed uniformly in the system, and granulated to obtain a stable fertilizer containing urease inhibitor hydroquinone and nitrification inhibitor CLMP. The hydroquinone content in the product is 0.13-0.22% of the pure N amount, and the CLMP content is 0.52-0.87% of the pure N amount.

Application example 4

Using fluidized bed technology (Figure 3) to spray coating, 50 parts by weight of acrylic resin RS100 and 50 parts of ethyl cellulose for coating are dissolved in 1000 parts of ethanol solvent; then add 6 parts of nitrification inhibitor to this solution Agent CLMP, 5 parts of inorganic membrane conditioner zeolite powder, and then add 4 parts of plasticizer polyethylene glycol, mix and pour into fluidized bed liquid tank, spray on the surface of 1000 parts of large particle urea. The operating parameters of the fluidized bed coating machine are: air inlet temperature 75°C, compressed air pressure 0.3Pa, nozzle atomization pressure 0.15Pa, after about 1 hour, the surface of the fertilizer core forms a milky white, smooth, continuous and uniform coating, Wherein the nitrification inhibitor CLMP content accounts for 0.6% of the total weight of the fertilizer and the membrane material.

Application example 5

Adopt indoor culture method, be N source (CLMP content is 1.0% of pure N amount) with the ammonium sulfate stabilized fertilizer that adds nitrification inhibitor 4-chloro-3-methylpyrazole, with the equivalent amount that does not add nitrification inhibitor Ammonium sulfate was used as the control, and the amount of fertilizer was ±0.25g per kg. During the cultivation period, the soil water content was kept at 60% of the field water holding capacity, and it was placed in a 25°C incubator for constant temperature cultivation. After the cultivation began, regular samples were taken to determine the NH in the soil. ₄ ⁺ -N and NO ₃ ^- -N content.

Table 1 Effect of 4-chloro-3-methylpyrazole on N transformation in soil

The inhibitory effect of nitrification inhibitors should first be manifested as the increase of soil NH ₄ ⁺ -N content or the decrease of NO ₃ ^- -N content. The results in Table 1 show that the NH ₄ ⁺ -N concentrations in the soils of all treatments decreased with the prolongation of the culture time, and the NH ₄ ⁺ -N concentrations of the soils treated with the addition of inhibitors were significantly higher than those of the soils only applied with N fertilizers during the whole culture period. The reason is that the presence of nitrification inhibitor CLMP inhibits the oxidation process of NH ₄ ⁺ to NO ₃ ^- in the soil, thus keeping the NH ₄ ⁺ -N content at a high level. The data in the table showed that after the culture time reached 1 week, the NH ₄ ⁺ -N content of the CLMP treatment began to be significantly higher than that of the control, while the NO ₃ ^- -N content in the soil was significantly lower than that of the control. This trend was maintained throughout the 5-week culture trial.

comparative example

Adopt indoor culture method, with the ammonium sulfate stable fertilizer that adds nitrification inhibitor 4-chloro-3-methylpyrazole or DMPP as N source (inhibitor content is 1.0% of pure N amount), fertilizer consumption is every kg ± 0.25g. During the cultivation period, the soil water content was kept at 60% of the field water holding capacity, and placed in a 25°C incubator for constant temperature cultivation. After the cultivation began, regular samples were taken to measure the contents of NH ₄ ⁺ -N and NO ₃ ^-N in the soil.

Table 2 Comparison of the inhibitory effects of CLMP and DMPP on soil nitrification

Table 2 shows that the nitrification inhibitor CLMP involved in this patent has the same nitrification inhibitory effect as the nitrification inhibitor DMPP produced by BASF in Germany, and there is no significant difference in each period of cultivation.

Claims (6)

1. nitrification inhibitor is characterized in that: it is 4-chloro-3-methylpyrazole, is abbreviated as CLMP,

Its chemical structural formula is:

2. the application of the described nitrification inhibitor of claim 1 in stabile fertilizer is characterized in that: the nitrification inhibitor CLMP that is added with pure N weight 0.1-5.0% in containing N fertilizer.

3. according to the application of the described nitrification inhibitor of claim 2 in stabile fertilizer, it is characterized in that: the described N of containing fertilizer is bicarbonate of ammonia, ammonium sulfate, ammonium chloride and/or urea.

4. according to the application of the described nitrification inhibitor of claim 2 in stabile fertilizer, it is characterized in that: the nitrification inhibitor CLMP that in containing N fertilizer, is added with pure N weight 0.1-2.0%.

5. according to the application of the described nitrification inhibitor of claim 2 in stabile fertilizer, it is characterized in that: also add urease inhibitor hydroquinone or N-NBPT in the described N of the containing fertilizer, the mass ratio of nitrification inhibitor CLMP and urease inhibitor is 2-6: 1.

6. according to the application of the described nitrification inhibitor of claim 2 in stabile fertilizer, it is characterized in that: described nitrification inhibitor CLMP directly is blended into and contains in the N fertilizer or add in its production technique, and perhaps nitrification inhibitor CLMP directly adds in the coated fertilizer of N fertilizer and then fertilizer carried out coating.

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