Water-soluble fertilizer containing humic acid as well as preparation method and application of water-soluble fertilizer

Abstract

The invention relates to the field of fertilizers, in particular to a water-soluble fertilizer containing humic acid and a preparation method and application thereof.The water-soluble fertilizer containing humic acid is prepared from, by weight, 30-40 parts of pyroligneous liquor, 20-30 parts of humic acid, 14-26 parts of basic fertilizer, 2-4 parts of microelement fertilizer, 0.15-0.45 part of modified xanthine gum and 20-30 parts of water. The humic acid-containing water-soluble fertilizer prepared by the invention is simple in preparation method, good in fertilizer efficiency and high in fertilizer utilization rate, can promote the growth of crops and improve the yield, and the effective components are not easy to settle and excellent in stability.

Description

Technical Field

[0001] The present invention relates to the field of fertilizers, and specifically relates to a water-soluble fertilizer containing humic acid, a preparation method thereof, and an application thereof. Background Art

[0002] Water-soluble fertilizers usually contain a large number of elements such as nitrogen, phosphorus, and potassium, as well as compound components such as medium and trace elements, amino acids, humic acid, and alginic acid. Compared with traditional fertilizers, water-soluble fertilizers have the advantages of good water solubility, no residue, and high fertilizer efficiency. The water-soluble fertilizer containing humic acid is a new type of fertilizer formed by combining humic acid with a large number of elements or trace elements such as nitrogen, phosphorus, and potassium, and has the functions of improving soil, increasing fertilizer utilization rate, promoting crop growth, improving crop quality, and preventing chlorosis, and is gradually favored by people.

[0003] Patent CN116606179B discloses a humic acid water-soluble fertilizer and a preparation method thereof. The humic acid water-soluble fertilizer comprises the following raw materials in parts by weight: 15-20 parts of highly active humic acid loaded with magnetite, 30-45 parts of macronutrients, and 2-4 parts of micronutrients; the highly active humic acid loaded with magnetite is obtained by subjecting poplar leaf powder and urea to high-temperature treatment under a nitrogen atmosphere and then performing hydrothermal compounding with ferrous sulfate heptahydrate. The preparation method of the humic acid water-soluble fertilizer described in the invention is simple and can promote the growth and development of plants. However, after this highly active humic acid is complexed with heavy metals, it is more easily leached out of the soil, resulting in a reduction in fertilizer efficiency.

[0004] Patent CN104119117B discloses a preparation method of a humic acid water-soluble fertilizer, which comprises the following steps: 1) preparation of organic selenium; 2) acidification of humic acid; 3) stirring; 4) chelation; 5) concentration. The preparation method provided by the invention is simple to operate and easy to implement. The product prepared by the method provided by the invention can not only reduce the heavy metal and pesticide residues in agricultural products, but also increase the yield of crops while ensuring the quality and safety of agricultural products, meeting the national standards for selenium-rich agricultural products and having broad market prospects. However, the complex formed by the acidified humic acid and heavy metals is less stable and more easily leached out of the soil, also resulting in a reduction in fertilizer efficiency.

[0005] Therefore, there is an urgent need in the market for a water-soluble fertilizer containing humic acid with high fertilizer utilization rate and good fertilizer efficiency. Summary of the Invention

[0006] Aiming at the problems existing in the prior art, the purpose of the present invention is to obtain a water-soluble fertilizer containing humic acid with high fertilizer utilization rate, good fertilizer efficiency, and high stability.

[0007] In order to achieve the above purpose, the technical solutions adopted by the present invention are as follows:

[0008] In the first aspect of the present invention, a water-soluble fertilizer containing humic acid is provided. In parts by weight, it includes the following raw materials: 30 - 40 parts of wood vinegar liquid, 20 - 30 parts of humic acid, 14 - 26 parts of basic fertilizer, 2 - 4 parts of trace element fertilizer, 0.15 - 0.45 parts of modified xanthine gum, and 20 - 30 parts of water.

[0009] The water-soluble humic acid fertilizer prepared by the present application through the combined use of wood vinegar liquid, humic acid, basic fertilizer, trace element fertilizer, and modified xanthine gum can improve the nutrient absorption efficiency of plants, increase the chlorophyll content, and promote root growth. Using this fertilizer can improve the soil structure, increase microbial diversity, is environmentally friendly, and reduces the dependence on traditional chemical fertilizers. In addition, the water-soluble fertilizer containing humic acid also has the functions of resisting diseases and pests, enhancing the comprehensive disease resistance and stress resistance of plants. Furthermore, the amount of pesticide used can be reduced and labor costs can be saved. In addition, the humic acid water-soluble fertilizer provided by the present invention contains modified xanthine gum, and xanthine gum can increase the viscosity of the water-soluble fertilizer containing humic acid. Therefore, it can prevent the precipitation of the humic acid water-soluble fertilizer, improve the stability of the water-soluble fertilizer containing humic acid, and further improve the utilization rate of the water-soluble fertilizer containing humic acid.

[0010] In some embodiments, the basic fertilizer is a composition of urea, potassium nitrate, and potassium dihydrogen phosphate, and the mass ratio of the three is 1:(1 - 1.4):(0.5 - 1).

[0011] In some embodiments, the trace element fertilizer is a composition of calcium nitrate, boric acid, zinc sulfate, and manganese sulfate, and the mass ratio of the four is 1:(0.5 - 1):(0.5 - 1):(0.5 - 1).

[0012] In some embodiments, the preparation method of the modified xanthine gum includes the following steps:

[0013] A1. Add acrylic acid to deionized water, add sodium hydroxide until the neutralization degree is 77 - 82%, add 2-acrylamide-2-methylpropanesulfonic acid and stir for 30 - 60 min to obtain a monomer solution;

[0014] A2. Add xanthine gum to deionized water, heat to 30 - 50 °C and stir for 20 - 30 min, add the monomer solution obtained in step A1 and silicon dioxide, stir at 30 - 40 °C for 20 - 30 min, then ultrasonicate for 30 - 40 min, add an initiator, react at 65 - 75 °C for 3 - 4 h, dry, crush, and sieve to obtain the modified xanthine gum.

[0015] Preferably, the initiator is 2,2'-azobis(2-methylpropionamidine) dihydrochloride.

[0016] Preferably, the mass ratio of acrylic acid to deionized water in step A1 is 1:(1.2 - 1.5).

[0017] Preferably, the mass ratio of the xanthan gum to deionized water in step A2 is 1:(60 - 80).

[0018] The side chains of xanthan gum contain groups such as mannose, glucuronic acid, and pyruvic acid. These side chains endow the xanthan gum molecules with a high negative charge, enabling them to form a network structure in water and thus exhibit high suspension ability. Adding it to the water-soluble fertilizer system containing humic acid can improve its stability and thus is conducive to improving the fertilizer utilization rate. However, in the water-soluble fertilizer prepared in this application containing basic fertilizer and trace element fertilizer, xanthan gum will complex with the basic fertilizer and metal ions. Although it can further slow down the release rate of metal ions and is beneficial to enhancing the fertilizer effect, its own suspension performance is also affected. To address the above problems, in this application, by modifying xanthan gum, on the one hand, the influence of metal ions on the suspension of xanthan gum is reduced, making the active ingredients of the obtained water-soluble fertilizer containing humic acid uniform and having a high utilization rate. This may be because after the introduction of sulfonic acid groups, metal ions will preferentially complex with the sulfonic acid groups, thereby reducing the influence on the suspension of xanthan gum; on the other hand, after copolymerization of xanthan gum and sodium acrylate, it has a higher molecular weight and better water solubility, which can further improve the slow-release performance and stability of the fertilizer. In addition, the silica has a porous structure, and fixing humic acid, basic fertilizer, and trace element fertilizer in the pores can further improve the slow-release effect of the water-soluble fertilizer and thus increase the fertilizer utilization rate. In addition, xanthan gum can increase the liquid-phase viscosity, while silica particles can increase the gaps between various substances, prevent the aggregation of active ingredients, and thus produce a synergistic effect to further improve the stability of the water-soluble fertilizer.

[0019] In some embodiments, the particle size of the silica is 100 - 150 nm.

[0020] By limiting the particle size of the silica in this application, the slow-release effect and stability of the water-soluble fertilizer can be further improved. This may be because the silica particles with this particle size have a higher specific surface area and can thus adsorb more active ingredients, and the silica particles with this particle size have good dispersibility in the water-soluble fertilizer system of this application.

[0021] In some embodiments, the mass ratio of acrylic acid to 2-acrylamido-2-methylpropanesulfonic acid is 1:(0.1 - 0.4).

[0022] In some embodiments, the mass ratio of xanthan gum to acrylic acid is 1:(0.3 - 0.6).

[0023] In some embodiments, the mass ratio of xanthan gum to silica is 1:(0.1 - 0.5).

[0024] The contents of acrylamide groups, sodium acrylate segments, and silica affect the water solubility of modified xanthopuccine gum. In this application, by limiting the ratios of acrylic acid to 2-acrylamido-2-methylpropanesulfonic acid, xanthopuccine gum to acrylic acid, and xanthopuccine gum to silica, the modified xanthopuccine gum can endow the water-soluble fertilizer with excellent sustained-release performance and suspension property. Moreover, the introduction of more acrylamide groups can increase the nitrogen element content in the fertilizer, thereby enhancing the fertilizer efficiency of the water-soluble fertilizer.

[0025] The second aspect of the present invention provides a preparation method of a water-soluble fertilizer containing humic acid, comprising the following steps:

[0026] S1. Add the modified xanthopuccine gum into water, heat up to 40 - 50 °C, and stir for 1 - 2 h to obtain a mixed solution;

[0027] S2. Add wood vinegar liquid, humic acid, basic fertilizer, and trace element fertilizer into the mixed solution obtained in step S1, and stir at 40 - 50 °C for 1 - 2 h to obtain the water-soluble fertilizer containing humic acid.

[0028] The third aspect of the present invention provides an application of the water-soluble fertilizer containing humic acid. The water-soluble fertilizer containing humic acid is diluted with water before use, and the mass ratio of the two is 1:(800 - 1000).

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The humic acid water-soluble fertilizer prepared by the present invention through the combined use of wood vinegar liquid, humic acid, basic fertilizer, trace element fertilizer, and modified xanthopuccine gum can effectively improve fertilizer utilization rate, fertilizer efficiency, and stability.

[0031] (2) By modifying xanthopuccine gum, on the one hand, the present invention reduces the influence of metal ions on the suspension property of xanthopuccine gum, making the active ingredients of the obtained water-soluble fertilizer containing humic acid uniform and having a high utilization rate; on the other hand, after copolymerization with sodium acrylate, xanthopuccine gum has a higher molecular weight and better water solubility, which can further improve the sustained-release performance and stability of the fertilizer. In addition, silica has a porous structure, and humic acid, basic fertilizer, and trace element fertilizer are fixed in the pores, which can further enhance the sustained-release effect of the water-soluble fertilizer, thereby improving the fertilizer utilization rate. In addition, xanthopuccine gum can increase the liquid phase viscosity, while silica particles can increase the gap between various substances, preventing the aggregation of active ingredients, and thus producing a synergistic effect to further enhance the stability of the water-soluble fertilizer.

[0032] (3) By defining the ratios of acrylic acid to 2-acrylamido-2-methylpropanesulfonic acid, xanthan gum to acrylic acid, and xanthan gum to silicon dioxide, the modified xanthan gum can have good slow-release performance while the water-soluble fertilizer has excellent suspension. And the introduction of more acrylamide groups can increase the nitrogen element content in the fertilizer, thereby improving the fertilizer efficiency of the water-soluble fertilizer. Detailed implementation manners

[0033] The following will describe the present invention in conjunction with specific implementation manners. It should be noted that the following examples are examples of the present invention, only for illustrating the present invention, and not for limiting the present invention. Without departing from the gist or scope of the present invention, other combinations and various improvements within the concept of the present invention can be made.

[0034] In the following examples and comparative examples, the compounds and related reagents used can be purchased from the market. Among them, the average particle size of xanthan gum is 200 mesh, purchased from Guangzhou Taili Chemical Industry Co., Ltd.; the average particle size of silicon dioxide-1 is 120 nm, and the average particle size of silicon dioxide-2 is 200 nm, both purchased from Nangong Rongbang New Material Technology Co., Ltd.

[0035] Preparation Example 1

[0036] A preparation method of modified xanthan gum-1, comprising the following steps:

[0037] A1. Add 4.5 g of acrylic acid to 6.1 g of deionized water, add sodium hydroxide until the neutralization degree is 80%, add 2 g of 2-acrylamido-2-methylpropanesulfonic acid and stir for 45 min to obtain a monomer solution;

[0038] A2. Add 10 g of xanthan gum to 70 g of deionized water, heat up to 45 °C and stir for 25 min, add the monomer solution obtained in step A1 and 3 g of silicon dioxide-1, stir at 35 °C for 25 min, then ultrasonicate for 35 min, add 0.1 g of 2,2'-azobis(2-methylpropionamidine) dihydrochloride, react at 70 °C for 3.5 h, dry, crush, and sieve to obtain modified xanthan gum-1.

[0039] Preparation Example 2

[0040] A preparation method of modified xanthan gum-2, the specific implementation manner is the same as that of Preparation Example 1, the difference is that silicon dioxide-1 is replaced with silicon dioxide-2 in equal amount.

[0041] Preparation Example 3

[0042] A preparation method of modified xanthan gum-3, the specific implementation manner is the same as that of Preparation Example 1, the difference is that the addition amount of 2-acrylamido-2-methylpropanesulfonic acid is 2.5 g.

[0043] Preparation Example 4

[0044] Preparation method of modified purine gum-4. The specific implementation is the same as that of Preparation Example 1, except that the addition amount of acrylic acid is 7 g.

[0045] Preparation Example 5

[0046] Preparation method of modified purine gum-5. The specific implementation is the same as that of Preparation Example 1, except that the addition amount of silicon dioxide is 6 g.

[0047] Example 1

[0048] A water-soluble fertilizer containing humic acid, by weight, includes the following raw materials: 35 parts of wood vinegar liquid, 25 parts of humic acid, 20 parts of basic fertilizer, 3 parts of trace element fertilizer, 0.3 part of modified purine gum-1, and 25 parts of deionized water; the basic fertilizer is a composition of urea, potassium nitrate, and potassium dihydrogen phosphate, and the mass ratio of the three is 1:1.2:0.7; the trace element fertilizer is a composition of calcium nitrate, boric acid, zinc sulfate, and manganese sulfate, and the mass ratio of the four is 1:0.7:0.7:0.7.

[0049] The preparation method of the water-soluble fertilizer containing humic acid in this example includes the following steps:

[0050] S1. Add modified purine gum-1 to deionized water, heat up to 45 °C and stir for 1.5 h to obtain a mixed solution;

[0051] S2. Add wood vinegar liquid, humic acid, basic fertilizer, and trace element fertilizer to the mixed solution obtained in step S1, stir at 45 °C for 1.5 h to obtain a water-soluble fertilizer containing humic acid.

[0052] Example 2

[0053] A water-soluble fertilizer containing humic acid, by weight, includes the following raw materials: 30 parts of wood vinegar liquid, 20 parts of humic acid, 14 parts of basic fertilizer, 2 parts of trace element fertilizer, 0.15 part of modified purine gum-1, and 20 parts of deionized water; the basic fertilizer is a composition of urea, potassium nitrate, and potassium dihydrogen phosphate, and the mass ratio of the three is 1:1:0.5; the trace element fertilizer is a composition of calcium nitrate, boric acid, zinc sulfate, and manganese sulfate, and the mass ratio of the four is 1:0.5:0.5:0.5.

[0054] The preparation method of the water-soluble fertilizer containing humic acid in this example includes the following steps:

[0055] S1. Add modified purine gum-1 to deionized water, heat up to 40 °C and stir for 2 h to obtain a mixed solution;

[0056] S2. Add wood vinegar liquid, humic acid, basic fertilizer, and trace element fertilizer to the mixed solution obtained in step S1, stir at 40 °C for 2 h to obtain a water-soluble fertilizer containing humic acid.

[0057] Example 3

[0058] A water-soluble fertilizer containing humic acid, by weight, includes the following raw materials: 40 parts of wood vinegar liquid, 30 parts of humic acid, 26 parts of basic fertilizer, 4 parts of trace element fertilizer, 0.45 part of modified purine gum-1, and 30 parts of deionized water; the basic fertilizer is a composition of urea, potassium nitrate, and potassium dihydrogen phosphate, and the mass ratio of the three is 1:1.4:1; the trace element fertilizer is a composition of calcium nitrate, boric acid, zinc sulfate, and manganese sulfate, and the mass ratio of the four is 1:1:1:1.

[0059] The preparation method of the water-soluble fertilizer containing humic acid in this example includes the following steps:

[0060] S1. Add modified purine gum-1 to deionized water, heat up to 50 °C and stir for 1 h to obtain a mixed solution;

[0061] S2. Add the wood vinegar liquid, humic acid, basic fertilizer, and trace element fertilizer to the mixed solution obtained in step S1, and stir at 50 °C for 1 h to obtain the water-soluble fertilizer containing humic acid.

[0062] Example 4

[0063] A water-soluble fertilizer containing humic acid and its preparation method, the specific implementation method is the same as that of Example 1, the difference is that modified purine gum-1 is equally replaced by modified purine gum-2.

[0064] Example 5

[0065] A water-soluble fertilizer containing humic acid and its preparation method, the specific implementation method is the same as that of Example 1, the difference is that modified purine gum-1 is equally replaced by modified purine gum-3.

[0066] Example 6

[0067] A water-soluble fertilizer containing humic acid and its preparation method, the specific implementation method is the same as that of Example 1, the difference is that modified purine gum-1 is equally replaced by modified purine gum-4.

[0068] Example 7

[0069] A water-soluble fertilizer containing humic acid and its preparation method, the specific implementation method is the same as that of Example 1, the difference is that modified purine gum-1 is equally replaced by modified purine gum-5.

[0070] Comparative Example 1

[0071] A water-soluble fertilizer containing humic acid and its preparation method, the specific implementation method is the same as that of Example 1, the difference is that modified purine gum-1 is equally replaced by purine gum.

[0072] Performance Test

[0073] 1. Stability

[0074] Take 500 ml of the water-soluble fertilizer containing humic acid prepared in each example and comparative example, and let it stand at 25 °C for 3 months to observe whether it settles.

[0075] 2. Field Test

[0076] Test area: Aksu, Xinjiang; Variety: Jun jujube; Planting method: row spacing 5 meters, plant spacing 3 meters.

[0077] Dilute the water-soluble fertilizer containing humic acid prepared in each of the above examples and comparative examples with water to obtain a dilution. The mass ratio of the water-soluble fertilizer containing humic acid to water is 1:900. Fertilize the jujube trees during the early flowering stage, young fruit stage and nucleation stage, and apply 1000 g of the dilution per mu of land. When harvesting, randomly arrange 3 points, and randomly select 10 jujube trees at each point to measure the number of jujubes per plant, single fruit weight and yield, and take the average value.

[0078] The test results are shown in Table 1.

[0079] Table 1

[0080] Component Stability Number of single jujube trees (pcs) Single fruit weight (g) Yield (kg / mu) Example 1 No sedimentation 215.12 21.53 253.3 Example 2 No sedimentation 209.86 19.88 230.8 Example 3 No sedimentation 213.45 20.57 242.4 Example 4 Sedimentation 201.87 19.56 215.8 Example 5 Sedimentation 205.42 20.01 222.1 Example 6 Sedimentation 202.92 19.83 217.3 Example 7 Sedimentation 203.85 19.87 218.7 Comparative Example 1 Sedimentation 194.76 19.37 203.7

[0081] It can be seen from the data in Table 1 that the water-soluble fertilizers containing humic acid prepared in Examples 1-3 of the present invention can effectively improve the fertilizer utilization rate, fertilizer efficiency and stability; by comparing Example 4 with Example 1, it can be seen that changing the particle size of silica may lead to a decrease in the stability of the water-soluble fertilizer and a decrease in the slow-release performance of the fertilizer, thereby reducing the yield; by comparing Examples 5, 6, 7 with Example 1, it can be seen that changing the ratio of acrylic acid to 2-acrylamido-2-methylpropanesulfonic acid, xanthan gum to acrylic acid, and xanthan gum and silica may lead to a decrease in the suspension performance of the modified xanthan gum, a decrease in the stability of the water-soluble fertilizer, and a deterioration of the fertilizer efficiency, thereby reducing the yield; by comparing Example 1 with Comparative Example 1, it can be seen that the stability of the fertilizer may decrease and the yield may decrease due to the poor suspension ability of xanthan gum after complexation with metal ions.

[0082] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A water-soluble fertilizer containing humic acid, characterized in that, Comprising the following raw materials by weight parts, Comprising the following raw materials: 30-40 parts of wood vinegar liquid, 20-30 parts of humic acid, 14-26 parts of basic fertilizer, 2-4 parts of trace element fertilizer, 0.15-0.45 parts of modified xanthopurine gum, and 20-30 parts of water.

2. The water-soluble fertilizer containing humic acid according to claim 1, characterized in that, The basic fertilizer is a composition of urea, potassium nitrate, and potassium dihydrogen phosphate, and the mass ratio of the three is 1:(1-1.4):(0.5-1).

3. The water-soluble fertilizer containing humic acid according to claim 1, characterized in that, The trace element fertilizer is a composition of calcium nitrate, boric acid, zinc sulfate, and manganese sulfate, and the mass ratio of the four is 1:(0.5-1):(0.5-1):(0.5-1).

4. The water-soluble fertilizer containing humic acid according to claim 1, characterized in that, The preparation method of the modified xanthopurine gum comprises the following steps: A1. Add acrylic acid into deionized water, add sodium hydroxide until the neutralization degree is 77-82%, add 2-acrylamido-2-methylpropanesulfonic acid and stir for 30-60 min to obtain a monomer solution; A2. Add xanthopurine gum into deionized water, heat up to 30-50 °C and stir for 20-30 min, add the monomer solution obtained in step A1 and silica, stir at 30-40 °C for 20-30 min, then ultrasonicate for 30-40 min, add an initiator, react at 65-75 °C for 3-4 h, dry, crush, and sieve to obtain the modified xanthopurine gum.

5. The water-soluble fertilizer containing humic acid according to claim 4, characterized in that The particle size of the silica is 100-150 nm.

6. The water-soluble fertilizer containing humic acid according to claim 4, characterized in that The mass ratio of the acrylic acid to 2-acrylamido-2-methylpropanesulfonic acid is 1:(0.1-0.4).

7. The water-soluble fertilizer containing humic acid according to claim 4, characterized in that, The mass ratio of the xanthopurine gum to acrylic acid is 1:(0.3-0.6).

8. The water-soluble fertilizer containing humic acid according to claim 4, characterized in that The mass ratio of the xanthopurine gum to silica is 1:(0.1-0.5).

9. A method for preparing a water-soluble fertilizer containing humic acid according to any one of claims 1-8, characterized in that, Comprising the following steps: S1. Add the modified xanthopurine gum into water, heat up to 40-50 °C and stir for 1-2 h to obtain a mixed solution; S2. Add the wood vinegar liquid, humic acid, basic fertilizer, and trace element fertilizer into the mixed solution obtained in step S1, stir at 40-50 °C for 1-2 h to obtain the water-soluble fertilizer containing humic acid.

10. Use of a water-soluble fertilizer containing humic acid according to any one of claims 1-8 or a water-soluble fertilizer containing humic acid obtained by the preparation method according to claim 9, characterized in that, The water-soluble fertilizer containing humic acid is diluted with water before use, and the mass ratio of the two is 1:(800-1000).