Application of succinic acid, long-acting nitrification inhibitor and preparation method

Abstract

The invention discloses application of succinic acid as a protective agent of a nitrification inhibitor 3, 4-dimethyl pyrazole phosphate, a long-acting nitrification inhibitor prepared from succinic acid and 3, 4-dimethyl pyrazole phosphate and a preparation method of the long-acting nitrification inhibitor. According to the invention, succinic acid has inhibition and protection effects on decomposition of DMPP, and combination of succinic acid and DMPP can effectively prolong nitration inhibition performance of DMPP.

Description

Technical Field

[0001] The invention relates to the field of nitrogen fertilizer nitrification inhibitors, and in particular to use of succinic acid as a protective agent for nitrification inhibitors, a long-acting nitrification inhibitor and a preparation method thereof. Background Art

[0002] The utilization rate of nitrogen fertilizer in the current season for my country's three major grain crops, rice, corn, and wheat, is only 40.2% (Ministry of Agriculture and Rural Affairs, 2021), which is nearly 20 percentage points lower than that in developed agricultural countries. The low utilization rate of nitrogen fertilizer has caused serious economic losses, resource depletion, and environmental pollution. Improving the utilization rate of nitrogen fertilizer is an important problem facing my country's agricultural sector. Stable fertilizers are produced by adding urease inhibitors and (or) nitrification inhibitors to regulate the activity of microorganisms and enzymes in the soil that affect the conversion of fertilizer nitrogen, thereby achieving high efficiency and long-term nitrogen. The application of stable fertilizers can effectively increase the retention of ammonium nitrogen in the soil and increase the utilization rate of nitrogen by 20%-38%, while reducing the emission of different forms of nitrogen such as ammonia and nitrate into the atmosphere and water environment by 25%-71%. Nitrification inhibitors are the core of stable fertilizers, which can greatly improve the utilization rate of nitrogen fertilizers, reduce nitrate leaching, and gas emissions such as nitrous oxide. DMPP (3,4-dimethylpyrazole phosphate) is a nitrification inhibitor that is currently used more frequently. However, DMPP is easily affected by the soil environment, especially pH. It is easy to decompose in an alkaline environment, resulting in inactivation and failure to play its role. my country has a vast territory and diverse soil types, among which alkaline soil exists in a large area, mainly concentrated in the coastal areas in the eastern part of the north, saline-alkali land in the Songnen Plain in the northeast, and semi-desert inland saline soil. The land with agricultural production value and affected by saline-alkali obstacles exceeds 500 million mu. Therefore, it is of great application value to develop a protective agent for DMPP to improve its effect in alkaline soil. Summary of the invention

[0003] One of the purposes of the present invention is to provide the use of succinic acid as a protective agent for nitrification inhibitor DMPP. Succinic acid, also known as succinic acid, is a colorless crystal, tastes sour, is soluble in water and ethanol, and has the advantages of being non-toxic, safe, and stable. Molecular formula C4H6O4, molecular weight 118.088, CAS registration number: 110-15-6, density: 1.409g / cm 3 , melting point 185°C, boiling point 236.15°C, pH value of 1% solution is about 2.7. The present invention finds that succinic acid can effectively protect DMPP in alkaline soil, slow down the decomposition of DMPP and make it fully exert its function as a nitrification inhibitor.

[0004] Another object of the present invention is to provide a long-acting nitrification inhibitor, which is made of the following components by weight: 8-9 parts of succinic acid and 1-2 parts of 3,4-dimethylpyrazole phosphate.

[0005] The present invention also provides a method for preparing the above-mentioned long-acting nitrification inhibitor, comprising the following steps:

[0006] Step 1: dissolve 8-9 parts of succinic acid and 1-2 parts of 3,4-dimethylpyrazole phosphate in hot water to obtain a mixed solution;

[0007] Step 2: heating and drying the mixed solution while stirring until the water content of the material is 3.0% w / w to obtain a dried material;

[0008] Step 3: The dried material is crushed by a mechanical crusher to obtain a long-acting nitrification inhibitor.

[0009] Preferably, in step 1, 8-9 parts of succinic acid and 1-2 parts of 3,4-dimethylpyrazole phosphate are dissolved in 15-20 parts of 80°C water, and stirred for 5-8 minutes until uniform to obtain a mixed solution;

[0010] In the step 2, the mixed solution is heated to 95° C.-97° C., and is dried under normal pressure while being stirred until the moisture content of the material reaches 3.0% w / w, thereby obtaining a dried material;

[0011] In the step 3, the dried material is crushed by a mechanical crusher to a particle size of ≤1 mm, and then crushed by an air flow vortex micronizer to 0.05-0.075 mm to obtain a long-acting nitrification inhibitor.

[0012] The present invention has the following beneficial effects: according to the characteristics of alkaline soil and the mechanism of DMPP decomposition under alkaline conditions, multiple materials that may have the ability to control the decomposition of DMPP are theoretically screened out, and then the effect and strength of these materials on the control of DMPP decomposition are studied through indoor simulation tests, and the toxicity, stability and current economic cost of each material are analyzed, and finally, it is verified through continuous plot and field tests that succinic acid is one of the relatively ideal nitrification inhibitor protective materials. The present invention finds that succinic acid has an inhibitory and protective effect on the decomposition of DMPP, and the combination of succinic acid and DMPP can effectively prolong the nitrification inhibition performance of DMPP. DETAILED DESCRIPTION

[0013] The present invention is further described below through specific implementation modes:

[0014] 1. Sample Preparation

[0015] Dissolve 90 g of succinic acid and 10 g of DMPP in 150 g of 80°C water, stir for 5-8 minutes, heat and dry under normal pressure while stirring, keep the temperature at 95°C-97°C, and dry until the moisture content of the material is 3.0% w / w; crush the material with a mechanical crusher to a particle size of ≤1 mm, and then crush it with an air vortex micronizer to 0.05-0.075 mm to obtain material A of succinic acid and DMPP; at room temperature, dissolve 100 g of DMPP in 150 g of 80°C water, stir evenly, stir for 5-8 minutes, heat and dry under normal pressure while stirring, maintain the temperature at 95°C-97°C, and dry until the moisture content of the material is 3.0% w / w; crush the material with a mechanical crusher to a particle size of ≤1 mm, and then crush it with an air vortex micronizer to a particle size of 0.05-0.075 mm to obtain material A of succinic acid and DMPP; at room temperature, dissolve 100 g of DMPP in 150 g of 80°C water, stir evenly, stir for 5-8 minutes, heat and dry under normal pressure while stirring Stirring and hot drying, maintaining the temperature at 95°C-97°C, drying to a moisture content of 3.0% w / w; using a mechanical pulverizer to grind the material to a particle size of ≤1 mm, and then using an airflow vortex micronizer to grind to 0.05-0.075 mm, to obtain material B; dissolving 106 g of 85% phosphoric acid and 10 g of DMPP in 150 g of 80°C water, stirring evenly, stirring for 5-8 minutes, raising the temperature to 95°C, stirring and hot drying under normal pressure, maintaining the temperature at 95°C-97°C, drying to a moisture content of 3.0% w / w, to obtain a viscous material C.

[0016] 2. Indoor simulation test:

[0017] Soil from the tillage layer of 0-20cm was collected from the farmland in Qianzi Village, Qian'an Town, Qian'an County, Jilin Province, brought back to the laboratory, mixed evenly, and measured its pH to be 9.1 using a "Leci" acidometer pH meter S-25. The soil sample was air-dried to a moisture content of about 3.0% w / w, and 18 portions of soil were taken, each 500.0 grams, of which 9 portions: 9 portions of material B 0.060 grams were weighed, first mixed evenly with 5 grams of soil, then mixed evenly with the remaining 495 grams of soil, placed in a culture pot, and water was added to the content of 15.0% w / w; the other 9 portions: 9 portions of material A 0.60 grams were weighed, first mixed evenly with 5 grams of soil, then mixed evenly with the remaining 495 grams of soil, placed in a culture pot, and water was added to the content of 15.0% w / w. All 18 treated samples were placed in a constant temperature incubator, maintained at a temperature of 35.0℃, and water was regularly replenished according to weight loss every day. The content of DMPP in the soil was measured on the 3rd, 5th and 10th days. During the measurement, the soil sample in the culture pot was poured out and mixed, 5.0g of soil sample was taken into a shaking bottle, 50.0ml of deionized water was added, and the mixture was shaken at 180r / min for 2h, centrifuged at 1000r / min, and the clarified liquid was taken. The DMPP content was measured at a detection wavelength of 224nm using a liquid chromatograph, and the aqueous solution of DMPP was used for detection and analysis to draw a standard curve. For each test, destructive sampling was used for the treatment of DMPP and DMPP+succinic acid, and three soil samples from each culture pot were taken for detection, and the average was taken.

[0018] Table 1 Effect of succinic acid on DMPP decomposition at different time points

[0019] Content (mg / kg) Day 3 Day 5 Day 10 DMPP 49.5 26.4 10.1 DMPP+Succinic Acid 67.3 54.8 35.2

[0020] It can be seen from Table 1 that at a culture temperature of 35°C, DMPP decomposes very quickly, and is basically decomposed by half on the third day. Since the third day, succinic acid has shown a good inhibitory effect on the decomposition of DMPP, allowing DMPP to maintain a stable effect at a higher concentration.

[0021] 3. Comparative test

[0022] Soil from the tillage layer of 0-20 cm was collected from a farmland in Qianzi Village, Qian'an Town, Qian'an County, Jilin Province, brought back to the laboratory, mixed evenly, and the pH value was measured using a "Lei-Magnetic" acidometer pH meter S-25 to find that it was 9.1. The soil sample was air-dried to a moisture content of about 3.0%. 18 portions of 500.0 g soil were taken, of which 6 portions: 6 portions of material B were weighed, each portion of 0.050 g, first mixed with 5 g soil, then mixed with the remaining 495 g soil, put into a culture pot, and water was added to the content of 20.0%; 6 portions: 6 portions of material A were weighed, each portion of 0.50 g, first mixed with 5 g soil, then mixed with the remaining 495 g soil, put into a culture pot, and water was added to the content of 20.0%; 6 portions: 6 portions of material C were weighed, each portion of 0.50 g, first mixed with 5 g soil, then mixed with the remaining 495 g soil, put into a culture pot, and water was added to the content of 20.0%. All 18 treated samples were placed in a constant temperature incubator, maintained at a temperature of 40.0 ° C, and water was regularly added according to weight loss every day. The content of DMPP in the soil was measured on the 2nd and 3rd days respectively. Pour out the soil sample in the culture pot and mix it evenly. Take 5.0g of soil sample in a shaking bottle, add 50.0ml of deionized water, shake at 180r / min for 2h, centrifuge at 1000r / min, take the clarified liquid, use liquid chromatography to determine the DMPP content at a detection wavelength of 224nm, and at the same time use DMPP aqueous solution for detection and analysis to draw a standard curve. For each test, all treatments use destructive sampling, take three soil samples from each culture pot for testing, and take the average.

[0023] Table 2 Effects of succinic acid and phosphoric acid on the decomposition of DMPP at different time points

[0024] Content (mg / kg) Day 2 Day 3 DMPP 34.7 25.5 DMPP+Succinic Acid 44.5 36.2 DMPP+phosphoric acid 36.2 29.4

[0025] It can be seen from Table 2 that at the culture temperature of 40°C, succinic acid showed a good protective effect, while phosphoric acid, which is more acidic than succinic acid, did not show any effect. The reason may be that the dissolution rate of phosphoric acid in the soil solution is much faster than that of succinic acid, causing the separation of phosphoric acid and DMPP, and failing to provide a protective effect.

[0026] 4. Application in large-scale equipment production

[0027] The rotary drum granulation process is used to produce compound fertilizers with a nitrogen, phosphorus and potassium ratio of 26-12-10, and three kinds of fertilizers are produced respectively: (1) conventional compound fertilizer: the raw materials used per ton are 500.0 kg of urea (46%), 272.7 kg of monoammonium phosphate (11-44-0), 166.7 kg of potassium chloride (60%) and 60.6 kg of filler. All the materials are crushed through a 20-mesh sieve, and then all the materials are mixed evenly, and then put into the rotary drum for granulation, drying, cooling, screening and packaging to obtain conventional compound fertilizer C; (2) conventional compound fertilizer + DMPP: the raw materials used per ton are 500.0 kg of urea (46%), 272.7 kg of monoammonium phosphate (11-44-0), 166.7 kg of potassium chloride (60%), 1.5 kg of material B and 59.2 kg of filler. All materials were crushed and passed through a 20-mesh sieve. Material B was then mixed evenly with 15 times the weight of urea powder and then fed into the urea feeding port. After mixing, the material was mixed evenly with monoammonium phosphate, potassium chloride and filler. The material was then fed into a rotary drum for granulation, drying, cooling, sieving and packaging to obtain compound fertilizer D containing DMPP. (3) Conventional compound fertilizer + DMPP + succinic acid: the raw materials used per ton were 500.0 kg of urea (46%), 272.7 kg of monoammonium phosphate (11-44-0), 166.7 kg of potassium chloride (60%), 15.0 kg of material A and 45.7 kg of filler. All materials were crushed and passed through a 20-mesh sieve, and then material A was first mixed evenly with 15 times the weight of urea powder, and then fed into the urea feeding port, mixed evenly, and then mixed evenly with monoammonium phosphate, potassium chloride, and filler, and then fed into a rotary drum for granulation, drying, cooling, sieving, and packaging to obtain a compound fertilizer E containing DMPP and succinic acid.

[0028] 5. Cell experiment

[0029] The test site is located in Qianzi Village, Qian'an Town, Qian'an County, Jilin Province. The plot with uniform soil fertility was selected to plant corn. The soil pH was 9.1. The setting area was 25m 2There were 9 plots (5m*5m), and each treatment was repeated 3 times. (1) Conventional fertilizer: 0.75 kg urea, 0.51 kg monoammonium phosphate, and 0.31 kg potassium chloride were applied to each plot. The three materials were crushed to a particle size of less than 0.1 mm, then mixed evenly, and then mixed with 10 times the weight of dry soil, and evenly spread on the surface, plowed, and sown; (2) Conventional fertilizer + DMPP: 0.75 kg urea, 0.51 kg monoammonium phosphate, 0.31 kg potassium chloride, and 2.81 g material B were applied to each plot. Urea, monoammonium phosphate, and potassium chloride were crushed to a particle size of less than 0.1 mm, material B was first mixed with urea, then mixed with the other two materials, and then mixed with 10 times the weight of dry soil, and evenly spread on the surface, plowed, and sown; (3) Conventional fertilizer + DMPP + succinic acid: 0.75 kg urea, 0.51 kg monoammonium phosphate, 0.31 kg potassium chloride, material A were applied to each plot. 28.1g, crush urea, monoammonium phosphate and potassium chloride to a particle size of less than 0.1mm, first mix material A with the three materials evenly, then mix them evenly with 10 times the weight of dry soil, evenly spread them on the surface, plow and sow. No topdressing will be required in the later stage of all treatments, and seeds, pesticides and other management will remain consistent. The amount of nitrate nitrogen and ammonium nitrogen in the soil was determined on the 20th, 80th and 100th days. During the measurement, a soil drill was used to take soil samples from the 0-20cm tillage layer, and a five-point cross sampling method was used. Five drills were taken from each plot, and about 300g of soil was taken. After taking the soil sample back to the laboratory, it was sieved and mixed, and 5.0g of it was taken and 2.00mol·L -1 The corn was extracted with potassium chloride solution and measured with a 3-AA3 flow analyzer. The results are shown in Tables 3 and 4. The yield was measured at harvest time. From the fifth plant in each of the four ridges in the middle of each plot, five plants were taken in succession, for a total of 20 plants. The corn was broken off and brought back to the laboratory for threshing, air drying, and weighing. The yield per mu was calculated. The results are shown in Table 5.

[0030] Table 3 Effect of succinic acid combined with DMPP on reducing nitrate nitrogen

[0031]

[0032] Table 4 Effect of succinic acid combined with DMPP on increasing soil ammonium nitrogen

[0033]

[0034] Table 5 Effect of succinic acid combined with DMPP on increasing corn yield

[0035]

[0036] In summary, compared with the use of DMPP alone, DMPP protected by succinic acid showed good effects in reducing soil nitrate nitrogen, increasing ammonium nitrogen and increasing corn yield.

[0037] 5. Field experiment. The experimental site is located in Qianzi Village, Qian'an Town, Qian'an County, Jilin Province. The soil fertility is uniform and the terrain is flat. The pH of the soil plough layer was measured to be 9.1 before planting. Three treatments were set up: Treatment 1 conventional fertilization (i.e. the conventional compound fertilizer C mentioned above), Treatment 2 conventional compound fertilizer + DMPP (i.e. the compound fertilizer D mentioned above), Treatment 3 conventional compound fertilizer + DMPP + succinic acid (i.e. the compound fertilizer E mentioned above), each treatment has 3 replicates, and each treatment area is 1 mu. The three treatments all applied the corresponding fertilizer products at 50 kg per mu of land, and the seed fertilizer was applied with the seeder after plowing and raking, and sowing and fertilization were completed simultaneously. No more topdressing was done in the later stage, and the weeding, spraying and other measures were kept consistent. At the harvest time, a harvester was used, and each replicate was harvested separately, and the weight was weighed after drying and dehydration to obtain the actual yield. The average yield of the three replicates was the final data.

[0038] Table 6 Effect of succinic acid combined with DMPP on increasing corn yield

[0039]

[0040] The above embodiments are intended to illustrate the present invention rather than to limit it. Under the concept of the present invention, technical solutions that have not been substantially changed are still protected by the present invention.

Claims

1. Use of succinic acid as a protective agent for nitrification inhibitor 3,4-dimethylpyrazole phosphate.

2. The use according to claim 1, characterized in that Succinic acid is used to slow down the decomposition of the nitrification inhibitor 3,4-dimethylpyrazole phosphate in alkaline soils.

3. A long-acting nitrification inhibitor, characterized in that The invention is prepared from the following components by weight: 8-9 parts of succinic acid and 1-2 parts of 3,4-dimethylpyrazole phosphate.

4. The method for preparing the long-acting nitrification inhibitor according to claim 3, characterized in that The steps include: Step 1: dissolve 8-9 parts of succinic acid and 1-2 parts of 3,4-dimethylpyrazole phosphate in hot water to obtain a mixed solution; Step 2: heating and drying the mixed solution while stirring until the water content of the material is 3.0% w / w to obtain a dried material; Step 3: The dried material is crushed by a mechanical crusher to obtain a long-acting nitrification inhibitor.

5. The preparation method according to claim 4, characterized in that: In the step 1, 8-9 parts of succinic acid and 1-2 parts of 3,4-dimethylpyrazole phosphate are dissolved in 15-20 parts of 80° C. water, and stirred for 5-8 minutes until uniform to obtain a mixed solution; In step 2, the mixed solution is heated to 95° C.-97° C., and is dried under normal pressure while being stirred until the moisture content of the material reaches 3.0% w / w, thereby obtaining a dried material; In the step 3, the dried material is crushed by a mechanical crusher to a particle size of ≤1 mm, and then crushed by an air flow vortex micronizer to 0.05-0.075 mm to obtain a long-acting nitrification inhibitor.

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