Application and use method of catechin, fertilizer preparation method and fertilizer

Abstract

The invention discloses application of catechin as a nitrification inhibitor, a use method of catechin as a nitrification inhibitor, a preparation method of a fertilizer formed by the catechin and the fertilizer. According to indoor simulation and field plot and field experiments, the catechin shows a good inhibition effect on soil ammonia oxidizing bacteria when the dosage per mu is 40.0-100.0 g, conversion from ammonium nitrogen to nitrate nitrogen can be effectively delayed, and compared with a traditional nitrification inhibitor, the catechin has the advantage in the later stage of nitrification inhibition.

Description

Technical Field

[0001] The invention relates to the field of fertilizers, and in particular to the use of catechins as nitrification inhibitors, a use method, a fertilizer preparation method and the fertilizer. Background Art

[0002] Fertilizer is the "food" of food, and it plays a vital role in ensuring national food security and ecological security. Due to the defects of traditional chemical fertilizers themselves and their unscientific and unreasonable application, a series of problems have been caused, such as low nutrient utilization rate, serious waste of fertilizer resources, and increased non-point source pollution. Stable fertilizers containing nitrification inhibitors can delay the conversion of ammonium nitrogen (including ammonium nitrogen directly contained in nitrogen fertilizers or compound fertilizers or ammonium nitrogen converted from amide nitrogen) to nitrate nitrogen, so that nitrogen exists in the soil in the form of ammonium nitrogen that is easily adsorbed by soil colloids. At the same time, it has the characteristics of nutrient release mode being synchronized with crop absorption law, which can significantly improve fertilizer utilization rate and provide an effective way to solve problems such as fertilizer resource waste and agricultural non-point source pollution. Existing chemically synthesized nitrification inhibitors have the disadvantages of single inhibitor source, short effective period in soil, and easy decomposition. In recent years, Germany's BASF has launched new inhibitors LIMUS and DMPSA, but their core is still the derivatives of the original urease inhibitor NBPT and nitrification inhibitor DMPP, and there are still a series of problems. The source of inhibitors is still relatively single, mainly chemical synthesis, and there are still problems such as being affected by environmental factors, easy to decompose by heat, and fast degradation in the soil, which reduces the efficiency of inhibitor use and increases the application cost. Therefore, the development of a new generation of plant-based and microbial-based inhibitors has broad prospects.

[0003] Catechins are a class of phenolic active substances extracted from natural plants such as tea leaves. 15 H 14 O6, relative molecular mass is 290.28. It is white needle-shaped crystal (water-acetic acid), melting point 93-96℃ (containing water), 175-177℃ (excluding water), boiling point 630.38℃, soluble in hot water, ethanol, glacial acetic acid, acetone, slightly soluble in cold water and ether. The use of catechins in fertilizers has been disclosed in patents, such as invention patent application CN 106518294 A discloses a high-efficiency slow-release fertilizer capable of increasing the soluble sugar content of carambola fruit and its preparation method, including catechins, oyster shells, polylactic acid, viscous starch paste and other ingredients, where catechins are used as nutrients. Invention patent application CN 106892742 A discloses a built-in trace element-containing slow-release urea and its preparation method, which combines urea with polyphenols such as tea polyphenols and epicatechin and metal ions, forms a three-dimensional network structure through polyphenol compounds and metal ions, and places urea microparticles between the three-dimensional network structure to form tiny coated particles to form a stable slow-release system. It can be seen that none of the above patents involve the use of catechins as nitrification inhibitors. Summary of the invention

[0004] One of the purposes of the present invention is to provide the use of catechins as nitrification inhibitors, that is, catechins can inhibit the conversion of ammonium nitrogen contained in nitrogen fertilizers or compound fertilizers or ammonium nitrogen produced from amide nitrogen contained therein into nitrate nitrogen. This new property of catechins has not been known and utilized before.

[0005] The present invention also provides a method for preparing fertilizer, wherein urea or compound fertilizer is mixed with catechin, wherein the weight of catechin is 0.1-0.5% of the weight of urea or compound fertilizer. The fertilizer prepared by the method has a nitrification inhibition function.

[0006] Preferably, the urea or compound fertilizer is mixed with catechins in one of the following two ways: (a) urea or compound fertilizer is directly and evenly mixed with catechins mechanically, and then directly applied or granulated before application; (b) catechins are dissolved in ethanol to prepare a solution, and then the solution is evenly sprayed on the surface of urea granules or compound fertilizer granules and dried.

[0007] More preferably, when catechin is dissolved in ethanol to prepare a solution, the mass ratio of catechin to volume of ethanol is 40.0-100.0 g:400.0-700.0 mL.

[0008] Furthermore, the mass ratio of catechins to the volume of ethanol is 40.0-100.0 g:500.0-600.0 mL.

[0009] Another object of the present invention is to provide a fertilizer composed of urea and catechins, or composed of compound fertilizer and catechins, wherein the weight of catechins is 0.1-0.5% of the weight of urea or compound fertilizer. The fertilizer has a nitrification inhibition function due to the mixing of catechins, and can delay the conversion of ammonium nitrogen into nitrate nitrogen.

[0010] Another object of the present invention is to provide a method for using catechins, which comprises mixing catechins at a dosage of 40.0-100.0 g per mu with fertilizers and applying the mixture to crop fields.

[0011] Preferably, the fertilizer is urea or compound fertilizer, the weight of catechin is 0.1-0.5% of the weight of urea or compound fertilizer, and the crop is corn or rice.

[0012] The present invention has the following beneficial effects: first, the nitrification inhibition effect of catechins in the field of fertilizers is discovered, and the effect is discovered in multiple rounds of screening for the nitrification inhibition performance of multiple materials. According to the screening results, it is judged that catechins have an inhibitory function on ammonia oxidizing bacteria, and have good chemical stability and environmental protection, and low toxicity. The present invention, through indoor simulation, field plot and field tests, concludes that catechins can inhibit soil ammonia oxidizing bacteria when the per mu dosage is 40.0-100.0g to effectively delay the conversion of ammonium nitrogen to nitrate nitrogen, can increase the content of ammonium nitrogen in the soil, reduce the content of nitrate nitrogen, and improve the utilization rate of nitrogen fertilizer. DETAILED DESCRIPTION

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

[0014] 1. Indoor simulation test

[0015] Soil samples of 0-20cm of the tillage layer were taken from the test site of Xijie Village, Zhouzhuang, Linshu County, Linyi City, Shandong Province, air-dried, and ground through a 2mm sieve for later use. Catechin and urea were crushed through a 1mm sieve. In the test group, catechin was 0.4% (weight percentage, the same below) of urea and 0.5% of air-dried soil. Catechin and urea were first mixed evenly, then mixed evenly with soil, and placed in a culture pot, with 200.0g of soil in each culture pot; in the control group, urea was 0.5% of air-dried soil and the two were mixed evenly, placed in a culture pot, with 200.0g of soil in each culture pot. Water was added to soak the soil in both the test group and the control group, so that the soil water content was maintained at 25%. Placed in the same constant temperature (30°C) environment, water was added every day according to weight loss. The content of nitrate nitrogen in the soil was measured on the 10th, 30th, 50th, and 70th days, respectively, and the results are shown in Table 1. Each time the sample was taken for determination, the soil in the culture pot was poured out and mixed evenly. 5.0 g of the soil was placed in a conical flask and 2.00 mol·L -1 100.0 mL of potassium chloride solution was placed in an oscillator, extracted for 1 hour, filtered, and measured with a 3-AA3 flow analyzer. The low nitrate nitrogen content indicates that catechins, as nitrification inhibitors, delay the conversion of ammonium nitrogen from urea decomposition in the soil to nitrate nitrogen. The test results show that catechins showed a good nitrification inhibition effect from the 10th day to the 70th day, effectively reducing the nitrate nitrogen content, making nitrogen fertilizer exist in the soil in the form of ammonium nitrogen, reducing the loss of nitrate nitrogen, and improving the utilization rate.

[0016] Table 1 Monitoring results of nitrate nitrogen content in soil

[0017] Nitrate nitrogen (mg / kg) Day 10 Day 30 Day 50 Day 70 Experimental Group 121.7 185.0 412.9 598.3 Control group 157.8 405.2 693.1 834.6

[0018] 2. Comparative test

[0019] Soil samples of 0-20cm of the tillage layer were taken from the test site of Xijie Village, Zhouzhuang, Linshu County, Linyi City, Shandong Province, air-dried, and ground through a 2mm sieve for standby use. In the test group, catechin was 0.4% of urea and 0.5% of air-dried soil. Catechin and urea were crushed through a 1mm sieve, catechin and urea were first mixed, then mixed with soil, and put into culture pots, each culture pot was filled with 200.0g of soil; the control group used DCD (dicyandiamide) synthesized from chemical synthesis as a control, DCD was 0.6% of urea, urea and DCD were crushed through a 1mm sieve respectively, urea was 0.5% of air-dried soil, urea and DCD were mixed, then mixed with soil, and put into culture pots, each culture pot was filled with 200.0g of soil. Water was added to soak the soil in both the test group and the control group to keep the soil moisture content at 25% w / w. Placed in the same constant temperature (30°C) environment, water was added every day according to the weight loss. The nitrate nitrogen content in the soil was measured on the 10th, 30th, 50th and 70th days, and the results are shown in Table 2. Each time the soil in the culture pot was sampled and measured, the soil was poured out and mixed evenly, 5.0g of it was taken and placed in a conical flask, and 2.00mol·L -1 100.0 mL of potassium chloride solution was placed in an oscillator, extracted for 1 hour, filtered, and measured using a 3-AA3 flow analyzer.

[0020] Table 2 Comparison results between catechins and DCD

[0021] Nitrate nitrogen (mg / kg) Day 10 Day 30 Day 50 Day 70 Test group-catechins 121.7 185.0 412.9 598.3 Control group-DCD 125.0 207.3 406.2 619.2

[0022] From the above comparison, it can be seen that when the dosage is only 2 / 3 of the commonly used chemical synthesis inhibitor DCD, catechins show an inhibitory effect close to that of DCD; at the same time, compared with DCD, catechins are safer, greener and more harmless.

[0023] 3. Cell experiment

[0024] The experiment was conducted in Yongle Village, Yongsheng Town, Shuangcheng District, Harbin City, Heilongjiang Province. Each plot was 25m 2 (5m×5m). The experimental treatments were as follows: conventional fertilization (N), conventional fertilization + catechins, where the amount of catechins was 80.0g per mu.

[0025] Conventional fertilization: 977.7g of urea, 488.8g of heavy superphosphate, and 449.7g of potassium sulfate were applied to each plot. The three were crushed and passed through a 1mm sieve respectively, and then mixed evenly. Conventional fertilization + catechins: Fertilizers and catechins were crushed and passed through a 1mm sieve respectively. The amount and type of nitrogen, phosphorus and potassium used were the same as conventional fertilization. On this basis, 80.0g of catechins were applied per mu, and 2.99g was applied to each plot (the weight of catechins was 0.30% of the weight of urea). The seeds, pesticides, and farming and management methods of the plots where catechins were applied were consistent with those of the control plots where catechins were not applied. When applying fertilizer, the conventional fertilization plot uses 10 times the weight of dry farmland soil and fertilizer to mix evenly, evenly spread on the surface, and plow and sow corn. Each plot has 8 ridges, and 20 plants per ridge; after catechins are evenly mixed with fertilizer, 10 times the weight of dry farmland soil and fertilizer are evenly mixed, spread on the surface, plowed and harrowed, and sown. The amount of nitrate nitrogen and ammonium nitrogen in the soil was measured on the 20th, 40th, 60th, 80th, and 120th days, respectively. The results are shown in Tables 3 and 4. Test method for nitrate nitrogen and ammonium nitrogen in soil: Use a soil drill to take soil samples from the 0-20cm tillage layer, use the five-point cross sampling method, take 5 drills in each plot, and take about 300.0g of soil. Bring the soil sample back to the laboratory, sieve it, mix it, take 5.0g of it, and use 2.00mol·L -1 The solution was extracted with potassium chloride and measured with a 3-AA3 flow analyzer.

[0026] Table 3 Monitoring results of nitrate nitrogen in soil

[0027]

[0028] Table 4 Monitoring results of ammonium nitrogen in soil

[0029]

[0030] The yield was measured at the harvest time. In the 4th and 5th ridges in the middle of each plot, 5 plants were taken from the 7th plant in each ridge, for a total of 10 plants. The corn was taken back to the laboratory, threshed, air-dried, and weighed. The weight measurement results were: the average yield of the experimental group was 997.4 kg / mu; the average yield of the control group was 924.1 kg / mu. The average yield increase rate was 7.9%. It can be seen that catechins showed a good nitrification inhibition effect in the corn plot test, effectively increased the ammonium nitrogen content in the soil, reduced the nitrate nitrogen content, and effectively increased the corn yield.

[0031] 4. Field trials

[0032] Field trials were conducted to further test the effects of catechins combined with urea.

[0033] (1) Anhui corn experiment: The experimental site is located in the seed breeding farm of Guzhen County, Bengbu City, Anhui Province. Setup: conventional fertilization and conventional fertilization + catechins, three replicates for each treatment, 1 mu for each treatment, and the initial fertility level of each plot is consistent. The dosage of catechins is 40.0 g per mu. First, catechins are dissolved in 500 mL of ethanol to prepare a solution. Then, 24.5 kg of urea (catechins are 0.16% w / w of urea), 6.5 kg of potassium chloride (potassium oxide ≥ 62%), and 7.5 kg of diammonium phosphate (18-46-0) are applied per mu. The ethanol solution of catechins is evenly sprayed on the surface of urea particles, dried, and evenly mixed with potassium chloride and diammonium phosphate. Seed fertilizer is applied with a seeder, and sowing and fertilization are completed simultaneously. For conventionally fertilized plots, 24.5 kg of urea, 6.5 kg of potassium chloride (potassium oxide ≥ 62%), and 7.5 kg of diammonium phosphate (18-46-0) are applied per mu. Urea, potassium chloride, and diammonium phosphate are directly mixed evenly, and the seed fertilizer is applied with the seeder, so that sowing and fertilization are completed simultaneously. No more topdressing is done in the later stage, and weeding, spraying and other measures are kept consistent. At the harvesting period, a harvester is used, and each plot is harvested separately. After drying and dehydration, the harvest is weighed to obtain the actual yield. The average yield of the three plots is the final data.

[0034] (2) Hubei rice experiment: The experimental site was located in Zhaoyao Village, Zhifang Street, Jiangxia District, Wuhan City. Two treatments were set up: conventional fertilization and conventional fertilization + catechins. Each treatment had 3 replicates and each treatment area was 1 mu. The initial fertility level of each plot was kept consistent. The dosage of catechins was 100.0 g per mu. First, catechins were dissolved in 600.0 mL of ethanol to prepare a solution. Conventional compound fertilizer with a nitrogen, phosphorus and potassium nutrient ratio of 23-10-12 was used as base fertilizer. It was applied at a dosage of 40.0 kg per mu (catechins were 0.25% w / w of compound fertilizer). The ethanol solution of catechins was evenly sprayed on the surface of fertilizer particles and dried. The control plot was applied at a dosage of 40.0 kg per mu, and only conventional compound fertilizer with a nitrogen, phosphorus and potassium nutrient ratio of 23-10-12 was applied. The fields were plowed, soaked, and raked. The machine-transplanted synchronous side deep fertilization technology was used, and transplanting and fertilization were carried out simultaneously. All treatments in the jointing stage were smeared with 10 kg / mu of urea, and other weeding and spraying measures were kept the same. At the harvesting stage, a harvester was used to harvest each plot separately, and the actual yield was obtained by weighing after drying and dehydration. The average yield of the three plots was the final data.

[0035] (3) Corn experiment in Liaoning: The experimental site was located in Renyi Village, Zhenxing Town, Xifeng County, Tieling City, Liaoning Province (the experiment was conducted in a different location from the corn experiment in Anhui). Settings: two treatments: conventional fertilization and conventional fertilization + catechins, with 3 replicates for each treatment and an area of ​​1 mu for each treatment. The initial fertility level of each plot was kept consistent. The dosage of catechins was 60.0 g per mu. The catechins were dissolved in 500.0 mL of ethanol to prepare a solution. A compound fertilizer with a nitrogen, phosphorus and potassium ratio of 26-10-12 was used as the base fertilizer. It was applied at a dosage of 50.0 kg per mu (catechins were 0.12% w / w of the compound fertilizer). The catechin ethanol solution was evenly sprayed on the surface of the compound fertilizer particles and dried. For the control treatment, only a compound fertilizer with a nitrogen, phosphorus and potassium ratio of 26-10-12 was used. It was applied at a dosage of 50.0 kg per mu. All treatments were applied with a seed drill, and sowing and fertilization were completed simultaneously. In the later period, no topdressing was applied, and weeding and spraying were kept the same. At the harvesting period, a harvester was used to harvest each plot separately, and the crops were weighed after drying and dewatering to obtain the actual yield. The average yield of the three plots was the final data, and the results are shown in Table 5.

[0036] Table 5 Yield measurement results at harvest time

[0037] Yield (kg / mu) Anhui Corn Hubei Rice Liaoning Corn Experimental Group 687 598 874 Control group 625 546 802 Yield increase rate (%) 9.9 9.5 8.9

[0038] In summary, catechins can be used as nitrification inhibitors to effectively inhibit the conversion of ammonium nitrogen in fertilizers to nitrate nitrogen. Mixing catechins with urea or compound fertilizers can effectively increase grain yields.

[0039] 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 catechins as nitrification inhibitors.

2. The use according to claim 1, characterized in that Catechins are used to inhibit the conversion of ammonium nitrogen contained in or produced by nitrogen fertilizers or compound fertilizers into nitrate nitrogen.

3. A method for making a fertilizer, characterized in that Urea or compound fertilizer is mixed with catechins, and the weight of catechins is 0.1-0.5% of the weight of urea or compound fertilizer.

4. The method for making the fertilizer according to claim 3, characterized in that The urea or compound fertilizer is mixed with catechins in one of the following two ways: (a) the urea or compound fertilizer is directly and evenly mixed with catechins mechanically, and then directly applied or granulated and then applied; (b) the catechins are dissolved in ethanol to prepare a solution, and then the solution is evenly sprayed on the surface of urea granules or compound fertilizer granules and dried.

5. The method for making the fertilizer according to claim 4, characterized in that When catechin is dissolved in ethanol to prepare a solution, the mass ratio of catechin to volume of ethanol is 40.0-100.0 g:400.0-700.0 mL.

6. The method for making the fertilizer according to claim 5, characterized in that The mass ratio of catechin to volume of ethanol is 40.0-100.0 g:500.0-600.0 mL.

7. A fertilizer, characterized in that The invention consists of urea and catechin, or compound fertilizer and catechin, wherein the weight of catechin is 0.1-0.5% of the weight of urea or compound fertilizer.

8. The fertilizer according to claim 7, characterized in that It is manufactured by the manufacturing method according to any one of claims 3 to 6.

9. A method for using catechins, characterized in that The dosage of catechins is 40.0-100.0 g per mu, mixed with fertilizer and applied to crop fields.

10. The method for using catechins according to claim 9, characterized in that The fertilizer is urea or compound fertilizer, the weight of catechin is 0.1-0.5% of the weight of urea or compound fertilizer, and the crop is corn or rice.

Images