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

Abstract

The invention discloses application of gallic acid as a protective agent of a nitrification inhibitor 3, 4-dimethyl pyrazole phosphate, a long-acting nitrification inhibitor prepared from the gallic acid and the 3, 4-dimethyl pyrazole phosphate and a preparation method of the long-acting nitrification inhibitor. According to the invention, gallic acid has inhibition and protection effects on decomposition of DMPP, and combination of gallic 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 gallic 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 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 efficient 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 nitrates 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 gallic acid as a protective agent for nitrification inhibitor DMPP. Gallic acid (Gallic acid), chemical name 3,4,5-trihydroxybenzoic acid, molecular formula C7H6O5, is a polyphenol organic compound, widely found in plants such as palm leaf rheum, large leaf eucalyptus, cornus officinalis, etc., soluble in hot water, difficult to dissolve in cold water. CAS number: 149-91-7, density: 1.694g / cm 3 , melting point: 252° C., boiling point: 501.1° C., flash point: 270.1° C. The present invention finds that gallic acid can effectively protect DMPP in alkaline soil, slow down the decomposition of DMPP and enable it to 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 prepared from the following components by weight percentage: 18-20 parts of gallic 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: dissolving 18-20 parts of gallic 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 moisture content of the material is 3-6% 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, 18-20 parts of gallic acid and 1-2 parts of 3,4-dimethylpyrazole phosphate are dissolved in a solution prepared by 30-40 parts of water and 40-50 parts of alcohol at 60-70° C. to obtain a mixed solution;

[0010] In the step 2, the mixed solution is stirred and heat-dried under normal pressure until the moisture content of the material is 3-6% w / w to obtain 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. Finally, through continuous plot and field tests, it is verified that gallic acid is one of the relatively ideal nitrification inhibitor protective materials. The present invention finds that gallic acid has an inhibitory and protective effect on the decomposition of DMPP, and the combination of gallic acid and DMPP can effectively prolong the nitrification inhibition performance of DMPP. DETAILED DESCRIPTION

[0013] The present invention is further described below by specific implementation methods, and the following percentages are by weight:

[0014] 1. Sample Preparation

[0015] At 65°C, 19 parts of gallic acid and 1 part of DMPP were dissolved in a solution of 30 parts of water and 50 parts of alcohol, stirred evenly, and dried under normal pressure while stirring until the moisture content of the material was 5.0%. The material was crushed with a mechanical crusher to a particle size of ≤1 mm, and then crushed with an air vortex micronizer to 0.05-0.075 mm to obtain a material A of gallic acid and DMPP; at room temperature, 1 part of DMPP was dissolved in a solution of 30 parts of water and 50 parts of alcohol, stirred evenly, and dried evenly under normal pressure while stirring until the moisture content of the material was 5.0%. The mixture was mixed and stirred evenly, and then heated and dried under normal pressure while stirring until the moisture content of the material was 5.0%; the material was crushed with a mechanical crusher to a particle size of ≤1 mm, and then crushed with an air flow vortex micronizer to 0.05-0.075 mm to obtain material B; 22.3 parts of 85% phosphoric acid and 1 part of DMPP were dissolved in 26.7 parts of water and 50 parts of alcohol solution, stirred evenly, and heated and dried under normal pressure while stirring until the moisture content of the material was 5.0% to obtain a viscous mixture C.

[0016] 2. Indoor simulation test

[0017] Soil from the tillage layer of 0-20cm was collected from the farmland in Ping'an Village, Jianping Township, Zhenlai County, Baicheng City, Jilin Province, brought back to the laboratory, mixed evenly, and measured its pH to be 8.9 using a "Lemagnetic" acidometer pH meter S-25. The soil sample was air-dried to a moisture content of about 3.0%, and 18 portions of soil were taken, each of which was 500.0 grams. Among them, 9 portions: 9 portions of material B 0.050 grams were weighed, first mixed evenly with 5 grams of soil, then mixed evenly with the remaining 495 grams of soil, put into a culture pot, and water was added to the content of 15.0%; the other 9 portions: 9 portions of material A 1.00 grams were weighed, first mixed evenly with 5 grams of soil, then mixed evenly with the remaining 495 grams of soil, put into a culture pot, and water was added to the content of 15.0%. All 18 treated samples were placed in a constant temperature incubator, maintained at a temperature of 30.0°C, and water was regularly added according to weight loss every day. The content of DMPP in the soil was measured on the 3rd, 5th, and 10th days respectively. The soil sample in the culture pot was poured out and mixed, 5.0 g of the soil sample was taken into a shaking bottle, 50.0 ml of deionized water was added, and the mixture was shaken at 200 r / min for 2 h, and centrifuged at 1000 r / min. The clarified liquid was taken and the DMPP content was determined using a liquid chromatograph at a detection wavelength of 224 nm. At the same time, the DMPP aqueous solution was used for detection and analysis, and a standard curve was drawn. For each test, destructive sampling was used for the treatment of DMPP and DMPP+gallic acid, and three soil samples from each culture pot were taken for testing, and the average was taken. The results are shown in Table 1.

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

[0019] DMPP content (mg / kg) Day 3 Day 5 Day 10 DMPP group 52.9 35.5 19.7 DMPP+gallic acid group 74.4 66.3 46.2

[0020] It can be seen from Table 1 that gallic acid has shown a good inhibitory effect on the degradation of DMPP in alkaline soil since the third day. This helps to reduce the dosage of DMPP and prolong the regulatory effect of DMPP on nitrogen transformation in the middle and late stages.

[0021] 3. Comparative test

[0022] Soil from the tillage layer of 0-20 cm was collected from the farmland in Ping'an Village, Jianping Township, Zhenlai County, Baicheng City, Jilin Province, brought back to the laboratory, mixed evenly, and the pH value was measured to be 8.9 using a "Leci" acidometer pH meter S-25. 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, 0.050 g each, 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, 1.00 g each, 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, 1.00 g each, 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. The soil sample in the culture pot was poured out and mixed, 5.0 g of the soil sample was taken into a shaking bottle, 50.0 ml of deionized water was added, and the mixture was shaken at 180 r / min for 2 h, centrifuged at 1000 r / min, and the clarified liquid was taken. The DMPP content was determined using a liquid chromatograph at a detection wavelength of 224 nm. At the same time, the DMPP aqueous solution was used for detection and analysis, and a standard curve was drawn. For each test, all treatments were destructively sampled, and three soil samples from each culture pot were taken for testing, and the average was taken. The results are shown in Table 2.

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

[0024] DMPP content (mg / kg) Day 2 Day 3 DMPP group 44.3 33.8 DMPP+gallic acid group 75.2 62.3 DMPP+Phosphate Group 51.7 37.4

[0025] It can be seen from Table 2 that at a culture temperature of 40°C, gallic acid showed a good protective effect, and the same amount of phosphoric acid showed a certain effect, but the difference was still not significant and could not be applied in practice. The reason may be that liquid phosphoric acid is easier to separate from DMPP in the soil solution and lose its effect, while solid gallic acid and DMPP are prepared into one particle, which wraps DMPP in it and plays a better role.

[0026] 3. Application in large-scale equipment production

[0027] A tower melt granulation process is used to produce compound fertilizers with a nitrogen, phosphorus and potassium ratio of 26-10-12, and three kinds of fertilizers are produced respectively: (1) conventional compound fertilizer: the raw materials used per ton are 511.1 kg of urea (46%), 227.2 kg of monoammonium phosphate (11-44-0), 200.0 kg of potassium chloride (60%) and 61.7 kg of filler. All the materials are crushed through a 20-mesh sieve, mixed evenly, melted, sprayed, cooled, sieved and packaged to obtain conventional compound fertilizer C; (2) conventional compound fertilizer + DMPP: the raw materials used per ton are 511.1 kg of urea (46%), 227.2 kg of monoammonium phosphate (11-44-0), 200.0 kg of potassium chloride (60%), 1.0 kg of material B and 60.7 kg of filler. All materials were crushed and passed through a 20-mesh sieve, and then material B was first mixed with ten times the weight of urea powder, and then put into the urea feeding port, mixed and then mixed with monoammonium phosphate, potassium chloride, and filler, and then melted, sprayed, cooled, sieved, and packaged to obtain compound fertilizer D containing DMPP; (3) Conventional compound fertilizer + DMPP + gallic acid: The raw materials used per ton are urea (46%) 511.1kg, monoammonium phosphate (11-44-0) 227.2kg, potassium chloride (60%) 200.0kg, material A 20.0kg and filler 41.7kg. All materials were crushed and passed through a 20-mesh sieve, and then material A was put into the urea feeding port, mixed and then mixed with monoammonium phosphate, potassium chloride, and filler, and then melted, sprayed, cooled, sieved, and packaged to obtain fertilizer E containing DMPP and gallic acid.

[0028] 4. Cell experiment

[0029] The test site is located in Ping'an Village, Jianping Township, Zhenlai County, Baicheng City, Jilin Province. The plot with uniform soil fertility was selected to plant corn. The soil pH was 8.9. The setting area was 25m 2There are 9 (5m*5m) plots, and each treatment is repeated 3 times. (1) Conventional fertilizer: 0.96kg urea, 0.42kg monoammonium phosphate, and 0.37kg potassium chloride are applied to each plot. The three materials are crushed to a particle size of less than 0.1mm, and then the three materials are mixed evenly, and then mixed evenly with 10 times the weight of dry soil, and evenly spread on the surface, plowed, and sown. (2) Conventional fertilizer + DMPP: 0.96kg urea, 0.42kg monoammonium phosphate, 0.37kg potassium chloride, and 1.875g of material B prepared in the above embodiment are applied to each plot. Urea, monoammonium phosphate, and potassium chloride are crushed to a particle size of less than 0.1mm, material B is first mixed with urea, and 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 + gallic acid: 0.96 kg of urea, 0.42 kg of monoammonium phosphate, 0.37 kg of potassium chloride, and 37.5 g of material A prepared in the above example were applied to each plot. The three materials of urea, monoammonium phosphate, and potassium chloride were crushed to a particle size of less than 0.1 mm. Material A was first mixed evenly with the three materials, and then mixed evenly with 10 times the weight of dry soil, and evenly spread on the surface, plowed, and sown. No topdressing was applied in the later stage of all treatments, and seeds, pesticides and other management were kept consistent. The amount of nitrate nitrogen and ammonium nitrogen in the soil was measured on the 20th, 80th, and 100th days. The results are shown in Tables 3 and 4. During the operation, a soil drill was used to take soil samples from the 0-20 cm tillage layer. The five-point cross sampling method was adopted. Five drills were taken from each plot, and about 300 g of soil was taken. The soil samples were brought back to the laboratory, sieved, mixed, and 5.0 g was taken. 2.00 mol·L -1 The corn was extracted with potassium chloride solution and measured with a 3-AA3 flow analyzer. The yield was measured at harvest time. From the fifth plant in each ridge 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, threshed, air-dried, weighed, and the yield per mu was calculated. The results are shown in Table 5.

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

[0031]

[0032]

[0033] Table 4 Effect of gallic acid combined with DMPP on increasing soil ammonium nitrogen

[0034] Ammonium nitrogen (mg / kg) Day 20 Day 80 Day 120 Conventional fertilization 27.2 20.3 14.5 Conventional fertilization + DMPP 37.3 29.3 21.2 Conventional fertilization + DMPP + gallic acid 42.9 34.1 27.4

[0035] Table 5 Effect of gallic acid combined with DMPP on increasing corn yield

[0036]

[0037] In summary, compared with the use of DMPP alone, DMPP protected by gallic acid showed good effects in reducing soil nitrate nitrogen, increasing ammonium nitrogen and increasing corn yield.

[0038] 5. Field trials

[0039] The test site is located in Xinfu Village, Fengshou Town, Da'an City, Jilin Province. The soil fertility is uniform and the terrain is flat. The pH of the soil plough layer was measured to be 8.6 before planting. Three treatments were set: Treatment 1 conventional compound fertilizer (conventional compound fertilizer C prepared in the above embodiment), Treatment 2 conventional compound fertilizer + DMPP (compound fertilizer D prepared in the above embodiment), Treatment 3 conventional compound fertilizer + DMPP + gallic acid (compound fertilizer E prepared in the above embodiment), each treatment 3 replicates, each treatment area 1 mu. All three treatments applied the corresponding fertilizer products at 50 kg per mu of land, plowed, raked and then applied seed fertilizer with a sowing machine, sowing and fertilization were completed simultaneously. No more topdressing in the later period, weeding, spraying and other measures are kept consistent. At the harvest time, a harvester was used, each repetition was harvested separately, and the actual yield was obtained after drying and dehydration. The average yield of the three replicates is the final data. The results are shown in Table 6. The corn yield of the treatment with conventional compound fertilizer + DMPP + gallic acid was the highest, which reflects the delayed and protective effect of gallic acid on the decomposition of DMPP, and ultimately effectively increased grain yield.

[0040] Table 6 Effect of gallic acid combined with DMPP on increasing corn yield

[0041]

[0042] 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 gallic acid as a protective agent for nitrification inhibitor 3,4-dimethylpyrazole phosphate.

2. The use according to claim 1, characterized in that Gallic 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: 18-20 parts of gallic 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: dissolving 18-20 parts of gallic 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 moisture content of the material is 3-6% 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, 18-20 parts of gallic acid and 1-2 parts of 3,4-dimethylpyrazole phosphate are dissolved in a solution prepared by 30-40 parts of water and 40-50 parts of alcohol at 60-70° C. to obtain a mixed solution; In the step 2, the mixed solution is stirred and heat-dried under normal pressure until the moisture content of the material is 3-6% w / w to obtain 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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