A functional water-soluble fertilizer containing humic acid and its preparation method

Abstract

This invention relates to the field of fertilizer technology and proposes a functional water-soluble fertilizer containing humic acid, comprising the following raw materials in parts by weight: 35-40 parts urea, 40-50 parts modified humic acid, 10-15 parts modified chitosan, 25-30 parts monoammonium phosphate, 30-40 parts diammonium hydrogen phosphate, 20-25 parts dipotassium hydrogen phosphate, 20-25 parts potassium carbonate, 25-30 parts potassium nitrate, and 25-30 parts magnesium sulfate; wherein the modified humic acid is obtained by modifying humic acid with sodium sulfite and formaldehyde; and the modified chitosan is obtained by modifying chitosan with 1-methyl-1H-imidazolium-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid. Through the above technical solution, the problem of low utilization rate of humic acid-containing water-soluble fertilizers in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of fertilizer technology, specifically to a functional water-soluble fertilizer containing humic acid and its preparation method. Background Technology

[0002] Humic acid is a complex network polymer containing numerous functional groups and elements such as carbon, hydrogen, oxygen, nitrogen, sulfur, and other metals. It not only alters the composition of soil nutrients but also enhances soil biological activity, making it an excellent fertilizer with ecological functions. However, humic acid itself is insoluble in water, so it typically exists in fertilizers as humate salts. During application, these humate salts react with calcium and magnesium ions in water to form less soluble calcium and magnesium humates, thus reducing the actual utilization rate of the fertilizer and causing resource waste. Summary of the Invention

[0003] This invention proposes a functional water-soluble fertilizer containing humic acid and its preparation method, which solves the problem of low utilization rate of water-soluble fertilizers containing humic acid in related technologies.

[0004] The technical solution of the present invention is as follows: This invention proposes a functional water-soluble fertilizer containing humic acid, comprising the following raw materials in parts by weight: 35-40 parts urea, 40-50 parts modified humic acid, 10-15 parts modified chitosan, 25-30 parts monoammonium phosphate, 30-40 parts diammonium hydrogen phosphate, 20-25 parts dipotassium hydrogen phosphate, 20-25 parts potassium carbonate, 25-30 parts potassium nitrate, and 25-30 parts magnesium sulfate; The modified humic acid is obtained by modifying humic acid with sodium sulfite and formaldehyde; The modified chitosan is obtained by modifying chitosan with 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid.

[0005] As a further technical solution, the method for preparing the modified humic acid includes the following steps: S1. Add humic acid to water, adjust the pH to alkaline, mix well, and obtain mixture I; S2. Add anhydrous sodium sulfite to water, then add formaldehyde solution to react and obtain mixture II; S3. Add mixture II to mixture I to obtain modified humic acid.

[0006] As a further technical solution, S1 involves adding humic acid to water, adjusting the pH to 10-11, mixing thoroughly, and obtaining mixture I.

[0007] As a further technical solution, the mixing temperature in S1 is 80~85℃.

[0008] As a further technical solution, the reaction temperature in S2 is 50~60℃, and the reaction time is 45~50min.

[0009] As a further technical solution, the formaldehyde solution in S2 is composed of a 37% formaldehyde solution and water in a mass ratio of 4:1.

[0010] As a further technical solution, the mass ratio of 1-methyl-1H-imidazolium-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid is 1~3:1.

[0011] As a further technical solution, the mass ratio of 1-methyl-1H-imidazolium-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid is 2:1.

[0012] As a further technical solution, the total mass of the 1-methyl-1H-imidazolium-4,5-dicarboxylic acid and the 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid is 2% to 4% of the mass of chitosan.

[0013] As a further technical solution, the total mass of the 1-methyl-1H-imidazolium-4,5-dicarboxylic acid and the 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid is 3% of the mass of chitosan.

[0014] As a further technical solution, the preparation method of the modified chitosan includes the following steps: A1. Add chitosan and sodium hydroxide to water and mix well to obtain pretreated chitosan; A2. Add the pretreated chitosan to an ethanol solution, adjust the pH to alkaline, add 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid to modify it, and obtain modified chitosan.

[0015] As a further technical solution, the modification temperature is 55~65℃ and the modification time is 5~6h.

[0016] As a further technical solution, the ethanol solution is composed of anhydrous ethanol and water in a volume ratio of 1:9.

[0017] The present invention also includes a method for preparing a functional water-soluble fertilizer containing humic acid, comprising the following steps: crushing the raw materials and mixing them evenly to obtain a functional water-soluble fertilizer containing humic acid.

[0018] The working principle and beneficial effects of this invention are as follows: 1. In this invention, adding humic acid modified with sodium sulfite and formaldehyde to the water-soluble fertilizer can improve the solubility of humic acid in water, thereby increasing the utilization rate of the humic acid-containing water-soluble fertilizer. Adding chitosan modified with 1-methyl-1H-imidazolium-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid can not only improve the water solubility of chitosan, but also prevent the modified humic acid and chitosan from being precipitated by calcium and magnesium ions in the water, thus improving the hard water resistance of the humic acid-containing water-soluble fertilizer and further improving the utilization rate of the humic acid-containing water-soluble fertilizer. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] In the following examples and comparative examples, The humic acid is grade 75 and the manufacturer is Shandong New Power Ecological Agriculture Technology Co., Ltd. The chitosan is designated as KGT001 and manufactured by Qingdao Haijingling Algae Biotechnology Group. The urea is grade 01 and manufactured by Jinan Tianjiang Chemical Technology Co., Ltd. Magnesium sulfate, manufactured by Shandong Chengyao Fertilizer Processing Co., Ltd. The anhydrous sodium sulfite has the product number 123 and is manufactured by Tianjin Dingshengxin Chemical Co., Ltd. The formaldehyde solution consists of a 37% formaldehyde solution and water in a mass ratio of 4:1. The ethanol solution consists of anhydrous ethanol and water in a volume ratio of 1:9.

[0021] Example 1 A method for preparing a functional water-soluble fertilizer containing humic acid includes the following steps: 35 parts urea, 40 parts modified humic acid, 10 parts modified chitosan, 25 parts monoammonium phosphate, 30 parts diammonium hydrogen phosphate, 20 parts dipotassium hydrogen phosphate, 20 parts potassium carbonate, 25 parts potassium nitrate, and 25 parts magnesium sulfate are pulverized to 100 mesh and mixed evenly to obtain a functional water-soluble fertilizer containing humic acid.

[0022] The preparation method of modified humic acid includes the following steps: S1. Add 60g of humic acid to 500mL of water, adjust the pH of the solution to 10 with 1mol / L sodium hydroxide solution, and stir continuously at 80℃ until dissolved to obtain mixture I; S2. Add 49.92g of anhydrous sodium sulfite to 200mL of water, then add 30.84g of formaldehyde solution, and react at 50℃ for 50min to obtain mixture II; S3. Add mixture II to mixture I to obtain modified humic acid.

[0023] The preparation method of modified chitosan includes the following steps: A1. Add 20g chitosan and 35g sodium hydroxide to 800mL of water, mix well, refrigerate in a -10℃ refrigerator for 24h, take out, wash and dry to obtain pretreated chitosan; A2. Add the pretreated chitosan to 600 mL of ethanol solution, adjust the pH of the solution to 12 with 1 mol / L sodium hydroxide solution, add 0.3 g of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 0.3 g of 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid, and modify it in a hydrothermal reactor at 55 °C for 6 h to obtain modified chitosan.

[0024] Example 2 38 parts urea, 45 parts modified humic acid, 13 parts modified chitosan, 28 parts monoammonium phosphate, 35 parts diammonium hydrogen phosphate, 23 parts dipotassium hydrogen phosphate, 23 parts potassium carbonate, 28 parts potassium nitrate, and 28 parts magnesium sulfate were pulverized to 100 mesh and mixed evenly to obtain a functional water-soluble fertilizer containing humic acid.

[0025] The preparation method of modified humic acid includes the following steps: S1. Add 60g of humic acid to 500mL of water, adjust the pH of the solution to 10 with 1mol / L sodium hydroxide solution, and stir continuously at 83℃ until dissolved to obtain mixture I; S2. Add 49.92g of anhydrous sodium sulfite to 200mL of water, then add 30.84g of formaldehyde solution, and react at 55℃ for 48min to obtain mixture II; S3. Add mixture II to mixture I to obtain modified humic acid.

[0026] The preparation method of modified chitosan includes the following steps: A1. Add 20g chitosan and 35g sodium hydroxide to 800mL of water, mix well, refrigerate in a -10℃ refrigerator for 24h, take out, wash and dry to obtain pretreated chitosan; A2. Add the pretreated chitosan to 600 mL of ethanol solution, adjust the pH of the solution to 12 with 1 mol / L sodium hydroxide solution, add 0.3 g of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 0.3 g of 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid, and modify it in a hydrothermal reactor at 60 °C for 5.5 h to obtain modified chitosan.

[0027] Example 3 40 parts urea, 50 parts modified humic acid, 15 parts modified chitosan, 30 parts monoammonium phosphate, 40 parts diammonium hydrogen phosphate, 25 parts dipotassium hydrogen phosphate, 25 parts potassium carbonate, 30 parts potassium nitrate, and 30 parts magnesium sulfate are pulverized to 100 mesh and mixed evenly to obtain a functional water-soluble fertilizer containing humic acid.

[0028] The preparation method of modified humic acid includes the following steps: S1. Add 60g of humic acid to 500mL of water, adjust the pH of the solution to 11 with 1mol / L sodium hydroxide solution, and stir continuously at 85℃ until dissolved to obtain mixture I; S2. Add 49.92g of anhydrous sodium sulfite to 200mL of water, then add 30.84g of formaldehyde solution, and react at 60℃ for 45min to obtain mixture II; S3. Add mixture II to mixture I to obtain modified humic acid.

[0029] The preparation method of modified chitosan includes the following steps: A1. Add 20g chitosan and 35g sodium hydroxide to 800mL of water, mix well, refrigerate in a -10℃ refrigerator for 24h, take out, wash and dry to obtain pretreated chitosan; A2. Add the pretreated chitosan to 600 mL of ethanol solution, adjust the pH of the solution to 12 with 1 mol / L sodium hydroxide solution, add 0.3 g of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 0.3 g of 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid, and modify it in a hydrothermal reactor at 65 °C for 5 h to obtain modified chitosan.

[0030] Example 4 The only difference between this embodiment and Example 1 is the addition of 0.2g of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 0.2g of 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid.

[0031] Example 5 The only difference between this embodiment and Example 1 is the addition of 0.4g of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 0.4g of 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid.

[0032] Example 6 The only difference between this embodiment and Example 1 is the addition of 0.4g of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 0.2g of 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid.

[0033] Example 7 The only difference between this embodiment and Example 1 is the addition of 0.45g of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 0.15g of 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid.

[0034] Example 8 The only difference between this embodiment and Example 1 is the addition of 0.2g of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 0.4g of 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid.

[0035] Example 9 The only difference between this embodiment and Example 1 is the addition of 0.48g of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 0.12g of 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid.

[0036] Comparative Example 1 The only difference between this comparative example and Example 1 is that the modified chitosan was replaced with an equal amount of chitosan.

[0037] Comparative Example 2 The only difference between this comparative example and Example 1 is that 1-methyl-1H-imidazol-4,5-dicarboxylic acid is not added.

[0038] Comparative Example 3 The only difference between this comparative example and Example 1 is that 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid is not added.

[0039] Performance testing: (1) Hard water resistance test Take 10g of each of the functional water-soluble fertilizers containing humic acid obtained in Examples 1-9 and Comparative Examples 1-3, dilute them 300 times with standard hard water to obtain diluted solutions, let them stand at 25°C for 24 hours, filter them with filter paper, separate the filtrate, dry the sediment to constant weight, and determine the mass of the sediment.

[0040] (2) Detection of the effect of functional water-soluble fertilizer containing humic acid on the yield of Chinese cabbage Twelve test zones were set up, each with an area of ​​20m². 2 The functional water-soluble fertilizers containing humic acid obtained in Examples 1-9 and Comparative Examples 1-3 were used to fertilize the experimental crop, Chinese cabbage.

[0041] Fertilization treatment method: After conventional fertilization, spray the leaves of the bok choy seedlings (one leaf and one heart) with a 600-fold diluted solution of functional water-soluble fertilizer containing humic acid for the first time (125g per test area, 75kg of water per spray). Then spray the leaves a second and third time every 10 days, for a total of three sprays. Finally, the yield of the bok choy is counted.

[0042] 3. Detect the effect of humic acid-containing functional water-soluble fertilizers on the activity of soil microorganisms. Soil respiration intensity was selected as the main microbiological indicator reflecting soil quality. The soil respiration intensity was measured after 24 hours by indoor closed culture and absorption with 0.1 mol / L sodium hydroxide solution.

[0043] Table 1. Performance test results of humic acid-containing functional water-soluble fertilizers obtained in Examples 1-9 and Comparative Examples 1-3

[0044] In this invention, compared with Example 1, Comparative Example 1 replaced the modified chitosan with an equal amount of chitosan, Comparative Example 2 did not add 1-methyl-1H-imidazol-4,5-dicarboxylic acid, and Comparative Example 3 did not add 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid. The results showed that the sedimentation in Comparative Examples 1 to 3 was greater than that in Example 1, the yield of Chinese cabbage was lower than that in Example 1, and the soil respiration intensity was lower than that in Example 1. This indicates that adding chitosan modified with 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid to functional water-soluble fertilizer containing humic acid can improve the hard water resistance and utilization rate of functional water-soluble fertilizer containing humic acid, and reduce the impact on the activity of microorganisms in the soil.

[0045] Compared with Example 1, Examples 4-5 changed the mass and proportion of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid to chitosan. The results showed that the sedimentation in Examples 4-5 was greater than that in Example 1, the yield of pakchoi was lower than that in Example 1, and the soil respiration intensity was lower than that in Example 1. This indicates that when the total mass of 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid is 3% of the mass of chitosan, the hard water resistance and utilization rate of the functional water-soluble fertilizer containing humic acid can be further improved, as well as the impact on the activity of microorganisms in the soil can be reduced.

[0046] Compared with Example 1, Examples 6-9 changed the mass ratio of 1-methyl-1H-imidazolium-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid. The results showed that in Examples 8-9, the sediment content was higher than in Examples 1 and 6-7, the yield of pakchoi was lower than in Examples 1 and 6-7, and the soil respiration intensity was lower than in Examples 1 and 6-7. This indicates that when the mass ratio of 1-methyl-1H-imidazolium-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid is 1-3:1, it is possible to achieve the desired effect. Further improvements were made to the hard water resistance and utilization rate of the humic acid-containing functional water-soluble fertilizer, as well as to reduce its impact on soil microbial activity. Furthermore, in Examples 1 and 7, the sedimentation was greater than in Example 6, the yield of Chinese cabbage was lower than in Example 6, and the soil respiration intensity was lower than in Example 6. This indicates that a mass ratio of 2:1 between 1-methyl-1H-imidazolium-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid can further improve the hard water resistance and utilization rate of the humic acid-containing functional water-soluble fertilizer, and reduce its impact on soil microbial activity.

[0047] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A functional water-soluble fertilizer containing humic acid, characterized in that, The raw materials include the following components by weight: 35-40 parts urea, 40-50 parts modified humic acid, 10-15 parts modified chitosan, 25-30 parts monoammonium phosphate, 30-40 parts diammonium hydrogen phosphate, 20-25 parts dipotassium hydrogen phosphate, 20-25 parts potassium carbonate, 25-30 parts potassium nitrate, and 25-30 parts magnesium sulfate. The modified humic acid is obtained by modifying humic acid with sodium sulfite and formaldehyde; The modified chitosan is obtained by modifying chitosan with 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid; The mass ratio of 1-methyl-1H-imidazol-4,5-dicarboxylic acid to 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid is 1~3:1; The total mass of the 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid is 3% of the mass of chitosan.

2. The functional water-soluble fertilizer containing humic acid according to claim 1, characterized in that, The method for preparing the modified humic acid includes the following steps: S1. Add humic acid to water, adjust the pH to alkaline, mix well, and obtain mixture I; S2. Add anhydrous sodium sulfite to water, then add formaldehyde solution to react and obtain mixture II; S3. Add mixture II to mixture I to obtain modified humic acid.

3. The functional water-soluble fertilizer containing humic acid according to claim 2, characterized in that, S1 involves adding humic acid to water, adjusting the pH to 10-11, and mixing thoroughly to obtain mixture I.

4. The functional water-soluble fertilizer containing humic acid according to claim 2, characterized in that, The mixing temperature in S1 is 80~85℃.

5. A functional water-soluble fertilizer containing humic acid according to claim 2, characterized in that, The reaction temperature in S2 is 50~60℃, and the reaction time is 45~50min.

6. The functional water-soluble fertilizer containing humic acid according to claim 1, characterized in that, The method for preparing the modified chitosan includes the following steps: A1. Add chitosan and sodium hydroxide to water and mix well to obtain pretreated chitosan; A2. Add the pretreated chitosan to an ethanol solution, adjust the pH to alkaline, add 1-methyl-1H-imidazol-4,5-dicarboxylic acid and 3-[(2-carboxyethyl-dimethyl-silyl)oxy-dimethyl-silyl]propionic acid to modify it, and obtain modified chitosan.

7. A functional water-soluble fertilizer containing humic acid according to claim 6, characterized in that, The modification temperature is 55~65℃, and the modification time is 5~6h.

8. A method for preparing a functional water-soluble fertilizer containing humic acid according to any one of claims 1 to 7, characterized in that, Includes the following steps: The raw materials are crushed and mixed evenly to obtain a functional water-soluble fertilizer containing humic acid.

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