A slow-release boron fertilizer and preparation method thereof

Abstract

The invention provides a slow-release boron fertilizer and a preparation method thereof. The slow-release boron fertilizer comprises a core material and a coating material, wherein the core material is made of calcium fertilizer, borax, sodium 4-nitrophenolate, zeatin, potassium dihydrogen phosphate, and water, and the coating material is made of small molecule peptides, hydroxyethyl cellulose, castor oil, xanthan gum, magnesium stearate, and water. The small molecule peptides contained in the coating material can promote plant elongation, and after the coating material is released, an organic layer is formed in the soil, which helps the released effective boron to be retained for a longer time.

Description

Technical Field

[0001] The invention relates to the field of fertilizers, and in particular to a slow-release boron fertilizer and a preparation method thereof. Background Art

[0002] my country is a major agricultural producer, and it is very important for farmers to increase the yield of crops. For farmers engaged in planting in rural areas, fertilizers with large usage, such as urea, compound fertilizer, phosphate fertilizer, and organic fertilizer, are very familiar. However, there is a kind of trace fertilizer, boron fertilizer, which is different. Because of its small usage, it is often ignored by everyone, and even fewer people know about it.

[0003] Boron is a trace element. Although crops require very little of it, its role is no less than that of nitrogen, phosphorus and potassium fertilizers used in large quantities. Lack of boron can cause a series of symptoms in crops. For example, radishes will become hollow if they lack boron, rice will have more barren grains if it lacks boron, cotton will have "buds but no flowers" if it lacks boron, rapeseed will have "flowers but no fruits" if it lacks boron, apples will have "shrinkage", peanuts will have "fruits without kernels", wheat will have "shriveled seeds", citrus will have severe flower drop and deformed young fruits if it lacks boron, and pear trees will have "dry tip disease" if they lack boron. Currently, boron fertilizer is mainly obtained by adding boric acid or borate to urea and compound fertilizers. However, this mixed fertilizer is very easy to leach and lose in the soil. Not only does it not get absorbed by plants, but it also causes water eutrophication and pollutes the environment. Therefore, it is very important to study a fertilizer that is not easy to lose and can decompose slowly.

[0004] Small molecule peptides play an important role in the root development process. Studies have shown that the external application of small molecule peptides can promote the division of cells in the meristem of the plant root tip, further elongate the main root of the plant, and also promote the occurrence and elongation of adventitious roots of the plant. Excessive concentrations of small molecule peptides will inhibit the occurrence and elongation of adventitious roots of plants, and have the same mechanism of action as auxin and cell division to induce callus rooting. Therefore, the application prospects of small molecule peptides in fertilizers are very broad.

[0005] The existing slow-release fertilizer application in China with the publication number CN112624865A discloses a water-retaining slow-release fertilizer, including a fertilizer core, a slow-release layer and a water-retaining layer, wherein the innermost layer is the fertilizer core, the inner layer is the slow-release layer, and the outer layer is the water-retaining layer; the fertilizer core is fertilizer particles, the slow-release layer is polycaprolactone-polyurethane block copolymer; and the water-retaining layer is cyclodextrin-halloysite-polyacrylonitrile resin. The fertilizer can have a slow-release and water-retaining effect, but the controllability of the slow-release of the fertilizer and the durability of the fertilizer are ignored.

[0006] In view of the problems existing in the prior art, the present application aims to solve the problems of the lack of trace element boron in the soil, the excessively fast release rate of ordinary boron fertilizers, easy loss, and excessive boron fertilizers leading to boron poisoning in plants. Summary of the invention

[0007] Purpose of the invention: The purpose of the present invention is to provide a slow-release boron fertilizer and a preparation method thereof, so as to overcome the problems of boron deficiency in the soil, too fast boron fertilizer release rate, easy loss, and excessive boron fertilizer leading to boron poisoning in plants.

[0008] The technical solution of the present invention:

[0009] A slow-release boron fertilizer comprises a core material and a coating material; the core material is made of calcium fertilizer, borax, sodium 4-nitrophenolate, zeatin, potassium dihydrogen phosphate and water, and the coating material is made of small molecule peptide, hydroxyethyl cellulose, castor oil, xanthan gum, magnesium stearate and water.

[0010] Preferably, the raw materials of the core material, calculated as 100% by mass, include: 15-28% calcium fertilizer, 25-40% borax, 5-8% sodium 4-nitrophenolate, 10-20% zein, 10-15% potassium dihydrogen phosphate, and 15-25% water.

[0011] Preferably, the raw materials of the coating material, calculated as 100% by mass, include: 15-20% small molecule peptides, 30-45% hydroxyethyl cellulose, 10-15% castor oil, 10-20% xanthan gum, 5-8% magnesium stearate, and 15-25% water.

[0012] Preferably, the calcium fertilizer is a mixture of one or more of quicklime, calcium chloride, calcium lignin sulfonate, and EDTA chelated calcium.

[0013] Preferably, the borax is a mixture of one or more of anhydrous borax, borax pentahydrate and borax decahydrate.

[0014] Preferably, the small molecule peptide is a mixture of one or more of polyglutamic acid, polyaspartic acid, and poly-D-leucine.

[0015] The method for preparing the coating material comprises the following steps:

[0016] (1) Stir small molecule peptide, hydroxyethyl cellulose and water evenly;

[0017] (2) In step (1), castor oil, xanthan gum, and magnesium stearate are slowly added in sequence and stirred evenly to obtain a coating material.

[0018] Preferably, the weight of the coating material is 10-15% of the weight of the core material; and the mass ratio of the small molecule peptide to hydroxyethyl cellulose is 1:2-3.

[0019] The present application also provides a method for preparing a slow-release boron fertilizer, which is characterized by comprising the following steps:

[0020] (1) Weighing sodium 4-nitrophenolate, zeatin, potassium dihydrogen phosphate and water, adding them into a reactor equipped with a stirrer, stirring them evenly, and heating them to react to obtain a mixture A;

[0021] (2) mixing calcium fertilizer and borax uniformly to obtain a mixture B;

[0022] (3) slowly pouring the mixture prepared in step (1) into the mixture B prepared in step (2), setting the reaction temperature, and stirring for a period of time to obtain a mixture C;

[0023] (4) filtering and drying the mixture C prepared in step (3), and then granulating the mixture using a granulator to obtain a core material;

[0024] (5) Spraying the coating material on the surface of the core material obtained in step (4) and drying it to obtain a slow-release boron fertilizer.

[0025] Preferably, the reaction temperature of step (1) is 60-90°C, and the reaction time is 1-2h; the reaction temperature of the temperature-raising reaction of step (3) is 80-90°C, and the stirring is 60-90min; the drying temperature of step (4) is 100-150°C, and the granulation particle size in the granulator is 2-5mm; the spraying speed of step (5) is 2-5g / min, and the drying temperature is 80-100°C.

[0026] The slow-release boron fertilizer consists of two parts: a core material and a coating material. The addition of zeatin to the core material can promote cell growth and differentiation, and sodium 4-nitrophenolate can improve plant cell vitality. Mixing with borax allows the effective use of the boron element. The small molecule peptides contained in the coating material can promote plant elongation. The coating material decomposes slowly, and the release time of the core material can be predicted. After the coating material is released, an organic matter layer is formed in the soil, which helps the released effective boron to be retained for a longer time.

[0027] Beneficial effects:

[0028] The invention provides a slow-release boron fertilizer, which can control the release rate, keep the boron element at a certain level for a long time, and ensure that the boron content in plants is appropriate, thereby improving the supply of organic matter in various organs of crops, ensuring normal crop growth, and increasing the fruit setting rate and fruit setting rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Boron content in soil. DETAILED DESCRIPTION

[0030] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0031] γ-Polyglutamic acid was purchased from Hubei Mingtuo Biotechnology Co., Ltd., polyaspartic acid was purchased from Zhengzhou Longchen Chemical Co., Ltd., poly-D-leucine was purchased from Hubei Guangao Biotechnology Co., Ltd., CAS No.: 63038-44-8; sodium 4-nitrophenolate was purchased from Shanghai Yihe Biotechnology Co., Ltd., CAS No.: 824-78-2, zeatin was purchased from Shandong Xinjiang Chemical Co., Ltd.; castor oil was purchased from Shandong Feiyu Chemical Technology Co., Ltd.; xanthan gum was purchased from Shandong Kuoyi Biotechnology Co., Ltd., EDTA chelated calcium was purchased from Shandong Junning Biotechnology Co., Ltd., and calcium lignin sulfonate was purchased from Jinan Hongtai Chemical Co., Ltd.

[0032] Preparation of coating material A:

[0033] (1) 1.5 kg of weighed small molecule peptide (γ-polyglutamic acid, polyaspartic acid, poly-D-leucine in a mass ratio of 1:1:1), 3 kg of hydroxyethyl cellulose and 15 kg of water were stirred evenly at a speed of 200 rpm / min for 1 h;

[0034] (2) In step (1), 1.5 kg of castor oil, 2 kg of xanthan gum, and 0.5 kg of magnesium stearate were slowly added in sequence, and stirred at 200 rpm / min for 1 h to obtain coating material A.

[0035] Preparation of coating material B:

[0036] (1) 1.5 kg of weighed small molecule peptide (γ-polyglutamic acid, polyaspartic acid, poly-D-leucine in a mass ratio of 1:1:1), 5 kg of hydroxyethyl cellulose and 1.5 kg of water were stirred evenly at a speed of 200 rpm / min for 1 h;

[0037] (2) In step (1), 1.5 kg of castor oil, 2 kg of xanthan gum, and 0.5 kg of magnesium stearate were slowly added in sequence, and stirred at 200 rpm / min for 1 h to obtain coating material B.

[0038] Preparation of coating material C:

[0039] (1) 2.25 kg of weighed small molecule peptide (γ-polyglutamic acid, polyaspartic acid, poly-D-leucine in a mass ratio of 1:1:1), 2.25 kg of hydroxyethyl cellulose and 1.5 kg of water were stirred evenly at a speed of 200 rpm / min for 1 h;

[0040] (2) In step (1), 1.5 kg of castor oil, 2 kg of xanthan gum, and 0.5 kg of magnesium stearate were slowly added in sequence, and stirred at 200 rpm / min for 1 h to obtain coating material C.

[0041] Preparation of coating material D:

[0042] (1) Stir 3 kg of hydroxyethyl cellulose and 1.5 kg of water at a speed of 200 rpm / min for 1 h;

[0043] (2) In step (1), 1.5 kg of castor oil, 2 kg of xanthan gum, and 0.5 kg of magnesium stearate were slowly added in sequence, and stirred at 200 rpm / min for 1 h to obtain coating material D.

[0044] Preparation method of slow-release boron fertilizer:

[0045] (1) Weighing sodium 4-nitrophenolate, zeatin, potassium dihydrogen phosphate and water, adding them into a reactor equipped with a stirrer, stirring evenly, the reaction temperature is 80° C., the reaction time is 1 h, and a mixture A is prepared;

[0046] (2) mixing calcium fertilizer and borax uniformly to obtain a mixture B;

[0047] (3) slowly pouring the mixture prepared in step (1) into the mixture B prepared in step (2), the reaction temperature is 85° C., and stirring is performed for 80 min to obtain a mixture C;

[0048] (4) filtering the mixture C obtained in step (3), drying at 120° C., and granulating the mixture using a granulator to obtain a core material with a particle size of 3 mm;

[0049] (5) Spraying the coating material on the surface of the core material obtained in step (4) at a spraying rate of 3 g / min and a drying temperature of 85° C. to obtain a slow-release boron fertilizer.

[0050] Examples 1 to 7

[0051] The slow-release boron fertilizers were prepared according to the above-mentioned preparation method. Table 1 is the ingredient list of the slow-release boron fertilizers of Examples 1 to 7.

[0052] Table 1 Ingredients of high elastic and precipitation resistant materials of Examples 1 to 7

[0053]

[0054]

[0055] Note: The weight of the covering material is calculated as a percentage of the core material weight.

[0056] The high-elastic and precipitation-resistant materials were prepared according to the above-mentioned preparation method. Table 2 is the ingredient list of the high-elastic and precipitation-resistant materials of Comparative Examples 1 to 6.

[0057] Table 2 Ingredients of high elastic and precipitation resistant materials for comparative examples 1 to 6

[0058]

[0059] Performance test experiment:

[0060] 1. Release rate: According to standard HG / T4216-2011, the cumulative release of slow-release nutrients in a period of time is measured as the mass fraction of the total amount of the nutrients, expressed as the mass fraction of the sum of the nutrient releases in each continuous period of a certain period in still water at 25°C.

[0061] 2. Boron content: Soil from the granite region in southern my country was tested for its initial boron content; the laboratory environment was 20°C, the air humidity was 80%, and the light was irradiated for 11 hours a day. 500g of slow-release boron fertilizer was buried in the soil at a depth of 10cm. The boron content in the soil was tested for 15 days, 30 days, 3 months, 6 months, and 12 months. At the same time, soil with 500g of borax added and blank control were set to test the boron content in the soil for 15 days, 30 days, 3 months, 6 months, and 12 months, respectively. The effective boron content in the soil was determined by a spectrophotometer. The test results are as follows: Figure 1 shown.

[0062] 3. Pea planting experiment: Soil was taken from the granite area in southern my country, and peas were planted in the soil with or without 25 mg / kg of slow-release boron fertilizer, and the flowering and fruiting rates of peas were observed.

[0063] Table 3: Test results

[0064]

[0065] It can be seen from the above data that the slow-release boron fertilizer prepared by the present invention has the effect of slowly releasing fertilizer and improves the fruit setting rate of plants. Specifically, from the comparison between Examples 4 and 7 and Example 2, it can be seen that the use of the small molecule peptide and hydroxyethyl cellulose mass ratio is unreasonable, resulting in the slow release rate of the slow-release boron fertilizer by the prepared coating material solution, and the release effect within the expected time cannot be achieved; from the comparison between Example 5 and Example 2, it can be seen that the reduction of the calcium fertilizer used causes the slow-release boron fertilizer to act on the plants, which will lead to a decrease in the fruit setting rate of the plants; from the comparison between Example 6 and Example 1, it can be seen that when the content of calcium fertilizer and borax in the core material is unreasonable, the calcium fertilizer and borax will have a nodular effect, which will cause the boron fertilizer to be lost too quickly and the release speed is faster; from the comparison between Comparative Example 1 and Example 1 It can be seen that the slow-release boron fertilizer without calcium fertilizer will lead to a lower flowering and fruiting rate of plants, and the function of the fertilizer is single; from the comparison between Comparative Example 2 and Example 2, it can be seen that not adding sodium 4-nitrophenol may affect the use effect of the slow-release boron fertilizer; from the comparison between Comparative Example 3 and Example 3, it can be seen that when there is too much coating material, the release rate will slow down; from the comparison between Comparative Example 4 and Example 2, it can be seen that when there is too little coating material, the release rate will increase; from the comparison between Comparative Example 5 and Example 2, it can be seen that the slow-release boron fertilizer prepared using a coating material solution that does not contain small molecule peptides has a too fast release rate and is not easy to retain; from the comparison between Comparative Example 6 and Example 2, it can be seen that when the slow-release boron fertilizer contains a slow-release material, the release rate of the fertilizer is too fast and the loss is also fast, which is very different from our target effect.

[0066] In the pea planting experiment, the fruit setting rate of peas planted in the soil without slow-release boron fertilizer was 46%. Compared with the results in Table 3, it can be seen that the fruit setting rate of peas planted in the soil with slow-release boron fertilizer was higher.

[0067] from Figure 1 By comparing ordinary borax with the blank control, it can be seen that the use of our slow-release boron fertilizer can retain the boron element in the soil longer and maintain a high level for a long time.

[0068] The present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A slow-release boron fertilizer, characterized in that: The slow-release boron fertilizer comprises a core material and a coating material; the core material is made of calcium fertilizer, borax, sodium 4-nitrophenolate, zeatin, potassium dihydrogen phosphate, and water, and the coating material is made of small molecule peptide, hydroxyethyl cellulose, castor oil, xanthan gum, magnesium stearate, and water; The raw materials of the core material, calculated by mass percentage as 100%, include: 15-28% calcium fertilizer, 25-40% borax, 5-8% sodium 4-nitrophenolate, 10-20% zein, 10-15% potassium dihydrogen phosphate, and 15-25% water; The raw materials of the coating material are calculated as 100% by mass, including: 15-20% small molecule peptide, 30-45% hydroxyethyl cellulose, 10-15% castor oil, 10-20% xanthan gum, 5-8% magnesium stearate, and 15-25% water; The weight of the coating material is 10-15% of the weight of the core material; The mass ratio of the small molecule peptide to hydroxyethyl cellulose is 1:2-3.

2. The slow-release boron fertilizer according to claim 1, characterized in that The calcium fertilizer is a mixture of one or more of quicklime, calcium chloride, calcium lignin sulfonate, and EDTA chelated calcium.

3. The slow-release boron fertilizer according to claim 1, characterized in that The borax is a mixture of one or more of anhydrous borax, borax pentahydrate and borax decahydrate.

4. The slow-release boron fertilizer according to claim 1, characterized in that The small molecule peptide is a mixture of one or more of γ-polyglutamic acid, polyaspartic acid and poly-D-leucine.

5. The slow-release boron fertilizer according to claim 1, characterized in that The method for preparing the coating material comprises the following steps: (1) Stir small molecule peptide, hydroxyethyl cellulose and water evenly; (2) In step (1), castor oil, xanthan gum, and magnesium stearate are slowly added in sequence and stirred evenly to obtain a coating material.

6. The method for preparing the slow-release boron fertilizer according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Weighing sodium 4-nitrophenolate, zeatin, potassium dihydrogen phosphate and water, adding them into a reactor equipped with a stirrer, stirring them evenly, and heating them to react to obtain a mixture A; (2) mixing calcium fertilizer and borax evenly to obtain a mixture B; (3) slowly pouring the mixture prepared in step (1) into the mixture B prepared in step (2), setting the reaction temperature, and stirring for a period of time to obtain a mixture C; (4) filtering and drying the mixture C obtained in step (3), and then granulating the mixture using a granulator to obtain a core material; (5) Spraying the coating material on the surface of the core material obtained in step (4) and drying it to obtain a slow-release boron fertilizer.

7. The method for preparing the slow-release boron fertilizer according to claim 6, characterized in that: The reaction temperature of the temperature-raising reaction in step (1) is 60-90°C, and the reaction time is 1-2h; the reaction temperature in step (3) is 80-90°C, and the stirring is 60-90min; the drying temperature in step (4) is 100-150°C, and the granulation particle size in the granulator is 2-5mm; the spraying speed in step (5) is 2-5g / min, and the drying temperature is 80-100°C.

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