Water-soluble fertilizer containing rare earth and preparation method thereof

Abstract

The invention provides a water-soluble fertilizer containing rare earth and a preparation method thereof. The water-soluble fertilizer is prepared from the following raw materials in parts by weight: 30 to 40 parts of nitrogen phosphorus and potassium components, 10 to 15 parts of calcium magnesium components, 3 to 5 parts of mineral element components, 0.5 to 1.0 part of nickel cobalt selenium components, 10 to 15 parts of humic acid, 5 to 10 parts of sodium alginate, 5 to 10 parts of fish protein, 3 to 5 parts of pyroligneous liquor, 2 to 4 parts of chelating agents and 0.5 to 1.0 part of rare earth. Wherein the nitrogen-phosphorus-potassium component is prepared by mixing urea, monoammonium phosphate, diammonium phosphate and potassium nitrate according to the mass ratio of (2-3): (1-2): (1-2): (2-3), the anti-caking agent is prepared from starch phosphate, microcrystalline cellulose and nano clay according to the mass ratio of (2.0-4.0): (1.5-3.5): (1.0-2.0), and the chelating agent is prepared from ethylenediamine tetraacetic acid, erythritol, glycine, salicylic acid or derivatives thereof according to the mass ratio of (4-6): (2-3): (1-2): (0.1-0.6). The complex multi-element ligand system is formed by combined use of ethylenediamine tetraacetic acid, erythritol, glycine, salicylic acid or derivatives thereof. Through the synergistic effect of a multi-element ligand system, rare earth ions are more effectively stabilized, and more stable chelated rare earth is formed, so that the solubility of the chelated rare earth in water is improved.

Description

Technical Field

[0001] The invention relates to the technical field of water-soluble fertilizers, and in particular to a water-soluble fertilizer containing rare earth and a preparation method thereof. Background Art

[0002] Water-soluble fertilizer is a modern and efficient fertilizer that can be quickly dissolved in water, making it easy for crops to quickly absorb and utilize it. This fertilizer is rich in a variety of nutrients required for crop growth and can meet the nutrient needs of crops. Due to its strong water solubility, it is particularly suitable for modern agricultural irrigation systems such as drip irrigation and sprinkler irrigation to achieve efficient management of water and fertilizer integration. The use of water-soluble fertilizers can not only improve the yield and quality of crops, but also effectively reduce the waste of fertilizers and water, which meets the requirements of sustainable development of modern agriculture. At the same time, there are various types of water-soluble fertilizers, and customized formulas can be made according to the growth characteristics and nutritional needs of different crops, so as to maximize the healthy growth of crops. Rare earths play a significant role in plant growth. They can effectively increase the chlorophyll content of plants, thereby enhancing photosynthesis, helping root development, and further increasing the root system's ability to absorb nutrients. In addition, rare earths can also help promote seed germination, significantly improve the germination rate, and provide a good boost for seedling growth. Not only that, rare earths can also enhance the disease resistance, cold resistance and drought resistance of crops. Therefore, applying rare earths to water-soluble fertilizers can further enhance the fertilizer effect of water-soluble fertilizers. However, the solubility of rare earth in water is low. If rare earth is directly added to water-soluble fertilizer, only a small part of it will be absorbed and utilized by plants, resulting in great waste. Therefore, how to improve the solubility of rare earth in water-soluble fertilizer is an urgent problem to be solved. Summary of the invention

[0003] In view of this, the present invention provides a water-soluble fertilizer containing rare earth and a preparation method thereof to solve the above problems.

[0004] The technical solution of the present invention is achieved as follows: a water-soluble fertilizer containing rare earths, comprising the following raw materials in parts by weight: 30-40 parts of nitrogen, phosphorus and potassium components, 10-15 parts of calcium and magnesium components, 3-5 parts of mineral element components, 0.5-1.0 parts of nickel, cobalt and selenium components, 10-15 parts of humic acid, 10-15 parts of anti-caking agents, 5-10 parts of sodium alginate, 5-10 parts of fish protein, 3-5 parts of wood vinegar, 2-4 parts of chelating agents, and 0.5-1.0 parts of rare earths, wherein the nitrogen, phosphorus and potassium components are in a mass ratio of (2-3 The invention discloses a novel nanostructured carbonyl phosphate (N-C) ...

[0005] Furthermore, a water-soluble fertilizer containing rare earths includes the following raw materials in parts by weight: 35 parts of nitrogen, phosphorus and potassium components, 12.5 parts of calcium and magnesium components, 4 parts of mineral element components, 0.7 parts of nickel, cobalt and selenium components, 12.5 parts of humic acid, 7.5 parts of sodium alginate, 7.5 parts of fish protein, 4 parts of wood vinegar, 3 parts of chelating agents, and 0.8 parts of rare earths, wherein the nitrogen, phosphorus and potassium components are prepared by mixing urea, monoammonium phosphate, diammonium phosphate and potassium nitrate in a mass ratio of 2.5:1.5:1.5:2.5, the anti-caking agent is composed of starch phosphate, microcrystalline cellulose and nanoclay in a mass ratio of 3.0:2.5:1.5, and the chelating agent is composed of ethylenediaminetetraacetic acid, erythritol and glycine in a mass ratio of 5:2.5:1.5.

[0006] Furthermore, the calcium-magnesium component is prepared by mixing calcium nitrate and magnesium sulfate, and the mass ratio of calcium nitrate to magnesium sulfate is (1.5-2.0):(1.0-1.5).

[0007] Furthermore, the mineral element component is prepared by mixing ferrous sulfate, manganese sulfate, copper sulfate, zinc sulfate, boric acid and sodium molybdate, and the mass ratio of ferrous sulfate, manganese sulfate, copper sulfate, zinc sulfate, boric acid and sodium molybdate is (3.0-5.0):(1.0-3.0):(1.0-2.0):(2.0-3.0):(1.0-2.0):(0.5-1.0).

[0008] Furthermore, the nickel-cobalt-selenium component is prepared by mixing nickel sulfate, cobalt chloride and sodium selenite, and the mass ratio of nickel sulfate, cobalt chloride and sodium selenite is (1.0-3.0):(1.0-3.0):(0.5-1.0).

[0009] Furthermore, the rare earth is selected from one of lanthanum nitrate, cerium nitrate, praseodymium nitrate, neodymium nitrate, samarium nitrate, europium nitrate and terbium nitrate.

[0010] Furthermore, salicylic acid or its derivative is one of salicylic acid, methyl salicylate, ethyl salicylate, propyl salicylate, acetylsalicylic acid, and β-hydroxy acid.

[0011] Furthermore, a method for preparing a water-soluble fertilizer containing rare earth comprises the following steps:

[0012] S1, weighing the chelating agent and rare earth by weight, adding the chelating agent to a reactor, adding deionized water 4-5 times its volume, and then adding the rare earth, ultrasonic treatment, and then concentrating and drying to obtain the chelated rare earth for standby use;

[0013] S2, weighing nitrogen, phosphorus and potassium components, calcium and magnesium components, mineral element components, nickel, cobalt and selenium components, humic acid, sodium alginate and fish protein according to weight, and stirring evenly to obtain a mixture I;

[0014] S3, weighing the anti-caking agent according to weight, adding it to the mixture I, stirring evenly, to obtain the mixture II;

[0015] S4, weighing the wood vinegar by weight and spraying it evenly into the mixed material II, stirring and spraying, to obtain a mixed material III;

[0016] S5. Add the chelated rare earth prepared in step S1 to the mixed material III, stir evenly, and obtain a water-soluble fertilizer containing rare earth.

[0017] Furthermore, in S1, the ultrasonic treatment power is 800-1000 W, the ultrasonic treatment time is 30-40 min, and then concentrated at a pressure of 0.05-0.10 MPa for 2-3 h, and dried at 60-80° C. for 1-2 h.

[0018] Furthermore, in S2, the stirring speed is 500-1000 r / min and the stirring time is 20-30 min, in S3, the stirring speed is 500-1000 r / min and the stirring time is 15-20 min, in S4, the stirring speed is 500-1000 r / min and the stirring time is 15-20 min, in S5, the stirring speed is 600-800 r / min and the stirring time is 8-12 min, and the drying is carried out at 40-60°C for 40-60 min.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: the erythritol in the chelating agent of the present invention improves the solubility of rare earth ions by adjusting the polarity and dielectric constant of the solution, which is conducive to the chelation of rare earth ions with glycine, ethylenediaminetetraacetic acid, salicylic acid or its derivatives. Glycine coordinates with rare earth ions to form a stable five-membered or six-membered chelate ring, which helps to enhance the solubility of rare earth ions. Ethylenediaminetetraacetic acid combines with rare earth ions through multiple coordination bonds to form a stable ring structure, thereby improving the solubility of rare earth in water. The oxygen atoms in the hydroxyl group and carboxyl group on the molecules of salicylic acid or its derivatives act as ligands to coordinate with rare earth ions to form coordination bonds, so that the rare earth ions are stably fixed in the molecular structure of salicylic acid or its derivatives to form a chelate. When diaminetetraacetic acid, erythritol, glycine, salicylic acid or its derivatives are used in combination, a more complex multi-ligand system is formed. This multi-ligand system can more effectively stabilize rare earth ions through synergistic action, form more stable chelated rare earths, and thus improve their solubility in water.

[0020] In the process of preparing water-soluble fertilizer, the present invention adopts ionomics technology to add nitrogen, phosphorus and potassium components, calcium and magnesium components, mineral element components, and nickel, cobalt and selenium components into the water-soluble fertilizer, which not only meets the different needs of crop growth stages, but also solves the problem of exhaustion of trace elements and trace elements in the soil.

[0021] The present invention adds an anti-caking agent composed of starch phosphate, microcrystalline cellulose and nanoclay in a specific ratio, wherein the starch phosphate can absorb and retain a certain amount of water, forming a thin moist film covering the surface of the water-soluble fertilizer, thereby reducing direct contact and friction between particles, preventing agglomeration caused by electrostatic attraction or water evaporation, and effectively preventing water bridging between fertilizer particles. Microcrystalline cellulose can absorb excess grease and water, reducing the agglomeration phenomenon promoted by the presence of grease and water. At the same time, microcrystalline cellulose can form a stable network structure. Thereby increasing the spatial distance between fertilizer particles, reducing the contact opportunity between particles, and then preventing the crystals from agglomerating together to form a large crystal, thereby playing an anti-caking role. Nanoclay has excellent adsorption capacity and dispersibility due to its extremely small particle size and high specific surface area. It can fill the tiny gaps between fertilizer particles, forming a physical barrier to prevent close contact between particles. Therefore, nanoclay, starch phosphate and microcrystalline cellulose cooperate with each other, and through physical barriers and adsorption, jointly maintain the dispersed state of fertilizer particles, thereby enhancing the uniformity and effectiveness of the entire anti-caking agent system.

[0022] The present invention DETAILED DESCRIPTION

[0023] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0024] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0025] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0026] Example 1

[0027] A water-soluble fertilizer containing rare earths comprises the following raw materials in parts by weight: 30 parts of nitrogen, phosphorus and potassium components, 15 parts of calcium and magnesium components, 5 parts of mineral element components, 1.0 part of nickel, cobalt and selenium components, 10 parts of humic acid, 10 parts of anti-caking agents, 5 parts of sodium alginate, 5 parts of fish protein, 3 parts of wood vinegar, 2 parts of chelating agents and 0.5 parts of rare earths. Among them, the nitrogen, phosphorus and potassium components are prepared by mixing urea, monoammonium phosphate, diammonium phosphate and potassium nitrate in a mass ratio of 2:1:1:2, the calcium and magnesium components are prepared by mixing calcium nitrate and magnesium sulfate in a mass ratio of 1.5:1.0, the mineral element component is prepared by mixing ferrous sulfate, manganese sulfate, copper sulfate, zinc sulfate, boric acid and sodium molybdate in a mass ratio of 3.0:1.0:1.0:2.0:1.0:0.5, the nickel, cobalt and selenium components are prepared by mixing nickel sulfate, cobalt chloride and sodium selenite in a mass ratio of 1.0:1.0:0.5, the anti-caking agent is composed of starch phosphate, microcrystalline cellulose and nanoclay in a mass ratio of 2.0:1.5:1.0, the chelating agent is composed of ethylenediaminetetraacetic acid, erythritol, glycine and salicylic acid in a mass ratio of 4:2:1:0.1, and the rare earth is selected from lanthanum nitrate.

[0028] Example 2

[0029] A water-soluble fertilizer containing rare earths comprises the following raw materials in parts by weight: 40 parts of nitrogen, phosphorus and potassium components, 10 parts of calcium and magnesium components, 3 parts of mineral element components, 0.5 parts of nickel, cobalt and selenium components, 15 parts of humic acid, 15 parts of anti-caking agents, 10 parts of sodium alginate, 10 parts of fish protein, 5 parts of wood vinegar, 4 parts of chelating agents and 1.0 part of rare earth. Among them, the nitrogen, phosphorus and potassium components are prepared by mixing urea, monoammonium phosphate, diammonium phosphate and potassium nitrate in a mass ratio of 3:2:2:3, the calcium and magnesium components are prepared by mixing calcium nitrate and magnesium sulfate in a mass ratio of 2.0:1.5, the mineral element component is prepared by mixing ferrous sulfate, manganese sulfate, copper sulfate, zinc sulfate, boric acid and sodium molybdate in a mass ratio of 5.0:3.0:2.0:3.0:2.0:1.0, the nickel, cobalt and selenium components are prepared by mixing nickel sulfate, cobalt chloride and sodium selenite in a mass ratio of 3.0:3.0:1.0, the anti-caking agent is composed of starch phosphate, microcrystalline cellulose and nanoclay in a mass ratio of 4.0:3.5:2.0, the chelating agent is composed of ethylenediaminetetraacetic acid, erythritol, glycine and methyl salicylate in a mass ratio of 6:3:2:0.6, and the rare earth is selected from europium nitrate.

[0030] Example 3

[0031] A water-soluble fertilizer containing rare earths comprises the following raw materials in parts by weight: 35 parts of nitrogen, phosphorus and potassium components, 12.5 parts of calcium and magnesium components, 4 parts of mineral element components, 0.7 parts of nickel, cobalt and selenium components, 12.5 parts of humic acid, 12.5 parts of anti-caking agent, 7.5 parts of sodium alginate, 7.5 parts of fish protein, 4 parts of wood vinegar, 3 parts of chelating agent, and 0.8 parts of rare earths, wherein the nitrogen, phosphorus and potassium components are prepared by mixing urea, monoammonium phosphate, diammonium phosphate and potassium nitrate in a mass ratio of 2.5:1.5:1.5:2.5, the calcium and magnesium components are prepared by mixing calcium nitrate and magnesium sulfate in a mass ratio of 1.8:1.3, and the mineral elements are prepared by mixing 1.5:1.5:2.5. The element components are prepared by mixing ferrous sulfate, manganese sulfate, copper sulfate, zinc sulfate, boric acid and sodium molybdate in a mass ratio of 4.0:2.0:1.5:2.5:1.5:0.8; the nickel, cobalt and selenium components are prepared by mixing nickel sulfate, cobalt chloride and sodium selenite in a mass ratio of 2.0:2.0:0.7; the anti-caking agent is composed of starch phosphate, microcrystalline cellulose and nanoclay in a mass ratio of 3.0:2.5:1.5; the chelating agent is composed of ethylenediaminetetraacetic acid, erythritol, glycine and β-hydroxy acid in a mass ratio of 5:2.5:1.5:0.4; and the rare earth is selected from terbium nitrate.

[0032] A water-soluble fertilizer containing rare earth in Examples 1-3 is prepared according to the following steps:

[0033] S1. Weigh the chelating agent and rare earth by weight, add the chelating agent to a reactor, add 4.5 times the volume of deionized water, then add the rare earth, perform ultrasonic treatment for 35 min at an ultrasonic treatment power of 1000 W, then concentrate at a pressure of 0.08 MPa for 2.5 h, and then dry at 70 ° C for 1.5 h to obtain chelated rare earth for standby use;

[0034] S2, weighing nitrogen, phosphorus and potassium components, calcium and magnesium components, mineral element components, nickel, cobalt and selenium components, humic acid, sodium alginate and fish protein according to weight, stirring at 750 r / min for 25 min to obtain a mixture I;

[0035] S3, weigh the anti-caking agent according to weight, add it to the mixture I, stir at 750r / min for 17.5min, and obtain the mixture II;

[0036] S4, weigh the wood vinegar by weight and spray it evenly into the mixture II, stirring while spraying, stirring at 750r / min for 17.5min, to obtain a mixture III;

[0037] S5. Add the chelated rare earth prepared in step S1 to the mixed material III, stir at 700 r / min for 10 min, and dry at 50° C. for 50 min to obtain a water-soluble fertilizer containing rare earth.

[0038] Example 4

[0039] The difference between this embodiment and embodiment 3 is that the water-soluble fertilizer containing rare earth is prepared according to the following steps:

[0040] S1. Weigh the chelating agent and rare earth by weight, add the chelating agent to a reactor, add deionized water 4 times its volume, then add the rare earth, perform ultrasonic treatment for 40 min at an ultrasonic treatment power of 800 W, then concentrate for 3 h at a pressure of 0.05 MPa, and then dry for 2 h at 60 ° C to obtain chelated rare earth for standby use;

[0041] S2, weighing nitrogen, phosphorus and potassium components, calcium and magnesium components, mineral element components, nickel, cobalt and selenium components, humic acid, sodium alginate and fish protein according to weight, stirring at 500 r / min for 30 min to obtain a mixture I;

[0042] S3, weighing the anti-caking agent according to weight, adding it to the mixture I, stirring at 500 r / min for 20 min, to obtain the mixture II;

[0043] S4, weighing wood vinegar by weight and spraying it evenly into mixed material II, stirring while spraying, stirring at 500 r / min for 20 min, to obtain mixed material III;

[0044] S5. Add the chelated rare earth prepared in step S1 to the above mixed material III, stir at 600 r / min for 12 min, and dry at 40° C. for 60 min to obtain a water-soluble fertilizer containing rare earth.

[0045] Example 5

[0046] The difference between this embodiment and embodiment 3 is that the water-soluble fertilizer containing rare earth is prepared according to the following steps:

[0047] S1. Weigh the chelating agent and rare earth by weight, add the chelating agent to a reactor, add deionized water 5 times its volume, then add the rare earth, perform ultrasonic treatment for 30 min at an ultrasonic treatment power of 1200 W, then concentrate at a pressure of 0.10 MPa for 2 h, and then dry at 80 ° C for 1 h to obtain chelated rare earth for standby use;

[0048] S2, weighing nitrogen, phosphorus and potassium components, calcium and magnesium components, mineral element components, nickel, cobalt and selenium components, humic acid, sodium alginate and fish protein according to weight, stirring at 1000 r / min for 20 min to obtain a mixture I;

[0049] S3, weigh the anti-caking agent according to weight, add it to the mixture I, stir at 1000r / min for 15min, and obtain the mixture II;

[0050] S4, weighing wood vinegar by weight and spraying it evenly into mixed material II, stirring while spraying, stirring at 1000 r / min for 15 min, to obtain mixed material III;

[0051] S5. Add the chelated rare earth prepared in step S1 to the above mixed material III, stir at 800 r / min for 12 min, and dry at 60° C. for 40 min to obtain a water-soluble fertilizer containing rare earth.

[0052] Comparative Example 1

[0053] This comparative example is compared with Example 3, the difference is that the chelating agent is ethylenediaminetetraacetic acid.

[0054] Comparative Example 2

[0055] Compared with Example 3, the difference between this comparative example and Example 3 is that the chelating agent consists of ethylenediaminetetraacetic acid, erythritol, glycine, salicylic acid or its derivatives in a mass ratio of 7.0:1.0:0.5:0.8.

[0056] Comparative Example 3

[0057] The difference between this comparative example and Example 3 is that ultrasonic treatment is not performed when preparing the chelated rare earth, and stirring at 750 r / min for 35 min is used instead of ultrasonic treatment.

[0058] Comparative Example 4

[0059] The difference between this comparative example and Example 3 is that the water-soluble fertilizer raw material containing rare earth does not contain wood vinegar.

[0060] Comparative Example 5

[0061] Compared with Example 3, this comparative example includes the following raw materials in parts by weight: 45 parts of nitrogen, phosphorus and potassium components, 18 parts of calcium and magnesium components, 7 parts of mineral element components, 1.5 parts of nickel, cobalt and selenium components, 20 parts of humic acid, 13 parts of sodium alginate, 13 parts of fish protein, 8 parts of wood vinegar, 6 parts of chelating agents, and 2 parts of rare earth.

[0062] 1. Surface tension measurement

[0063] The surface tension of the water-soluble fertilizer containing rare earth obtained in Examples 1-5 and Comparative Examples 1-5 was measured. 100 g of the water-soluble fertilizer obtained in Examples 1-5 and Comparative Examples 1-5 were taken respectively, and 10 times of water was added to dissolve them respectively. The surface tension was measured respectively. The measured results are shown in Table 1:

[0064] Table 1

[0065]

[0066]

[0067] It can be seen from Table 1 that the surface tension of the rare earth-containing water-soluble fertilizers prepared in Examples 1-5 is much higher than that in Comparative Examples 1-5. It can be seen that the rare earth-containing water-soluble fertilizers prepared in Examples 1-5 have better solubility performance, especially Example 3 has a better effect.

[0068] Example 3 Compared with Comparative Example 1, in Example 3, erythritol improves the solubility of rare earth ions by adjusting the polarity and dielectric constant of the solution, which is conducive to the chelation of rare earth ions with glycine, ethylenediaminetetraacetic acid, salicylic acid or its derivatives. The carboxyl group in glycine is coordinated to the rare earth ions in a bidentate form, that is, the two oxygen atoms in the carboxyl group form a coordination bond with the rare earth ions. The ring structure formed by the coordination helps to enhance the solubility of the rare earth ions and improve the stability of the complex. The middle N atom and the four carboxyl groups in the molecular structure of ethylenediaminetetraacetic acid can each provide a lone pair of electrons on an O atom for coordination, and a total of six coordinated atoms can chelate rare earth ions to form coordinated ions. There are two C atoms between the coordinated atoms N and O, which makes the ethylenediaminetetraacetic acid molecule have good flexibility and can form a stable five-membered ring chelate structure with rare earth ions. When combined with rare earth ions, ethylenediaminetetraacetic acid has a high complexing ability and can effectively improve the stability of rare earth ions in solution. The oxygen atoms in the hydroxyl and carboxyl groups on the molecules of salicylic acid or its derivatives act as ligands to coordinate with rare earth ions to form coordination bonds, so that the rare earth ions are stably fixed in the molecular structure of salicylic acid or its derivatives to form chelates. When salicylic acid or its derivatives coordinate with rare earth ions, a stable six-membered chelate ring can be formed. The formation of this chelate ring further enhances the binding force between the rare earth ions and the ligands, making the chelate more stable. Therefore, ethylenediaminetetraacetic acid, erythritol, glycine, salicylic acid or its derivatives increase the surface tension of water-soluble fertilizers through coordination synergy. And when ethylenediaminetetraacetic acid, erythritol, glycine and salicylic acid or its derivatives coexist, the interaction between them enhances the intermolecular attraction on the surface of the solution, thereby increasing the surface tension of the water-soluble fertilizer and enhancing its stability.

[0069] Compared with Comparative Example 2, Example 3 shows that the four components of ethylenediaminetetraacetic acid, erythritol, glycine, salicylic acid or its derivatives can only be used to prepare a water-soluble fertilizer with high surface tension in a specific ratio. The specific ratio can ensure that the synergistic effect between the components is maximized, thereby increasing the surface tension of the water-soluble fertilizer.

[0070] Compared with Comparative Example 3, the mechanical vibration and cavitation effect of ultrasound in Example 3 can strengthen the contact and collision between EDTA, erythritol, glycine and salicylic acid or its derivatives and rare earth, thereby increasing the chelation reaction, helping to form a more stable chelate, and further increasing the surface tension of the water-soluble fertilizer.

[0071] Compared with Comparative Example 4, in Example 3, wood vinegar contains abundant organic acids, which can change the charge distribution and intermolecular interaction force on the solution surface, thereby increasing the surface tension. And the organic acid molecules form a layer of close arrangement on the solution surface, which enhances the interaction between molecules and increases the surface tension. At the same time, the organic components in wood vinegar help to improve the solubility of water-soluble fertilizers, making it easier to dissolve in water, forming a smoother solution surface, thereby increasing the surface tension. In addition, wood vinegar and the chelated rare earth in the water-soluble fertilizer work synergistically to jointly increase the surface tension of the water-soluble fertilizer.

[0072] Compared with Comparative Example 5, Example 3 shows that the components in the water-soluble fertilizer are mixed in a specific ratio, which can ensure the balance between the various nutrients and can better dissolve in each other to form a uniform solution, thereby improving the solubility and surface tension of the fertilizer.

[0073] 2. Planting performance determination

[0074] The test field was divided into 4 test groups, each test group was provided with 10 test fields of 4 m×5 m in size, and the 10 test fields in each test group were sprayed with the water-soluble fertilizers in Examples 1-5 and Comparative Examples 1-5, respectively. The crops planted in each test group were peppers, cherry tomatoes, beans and rice, respectively, and the yields of the test fields in different experimental groups were recorded, and the recorded data are shown in Table 2:

[0075] Table 2

[0076]

[0077] It can be seen from Table 2 that the water-soluble fertilizers prepared by using Examples 1-5 can harvest higher crop yields than the water-soluble fertilizers prepared by using Comparative Examples 1-5. Further, by comparing Example 3 with Example 1-2, it can be seen that by further optimizing the ratio of raw materials, the fertilizer efficiency of the water-soluble fertilizer can be effectively improved, thereby increasing the yield of the crop. Further, by comparing Example 3 with Example 4-5, it can be seen that by further controlling each parameter in the preparation process, the water-soluble fertilizer obtained has better performance, is more conducive to crop absorption and utilization after application, and thus harvests a higher yield.

[0078] By comparing Example 3 with Comparative Example 1, when ethylenediaminetetraacetic acid, erythritol, glycine, salicylic acid or its derivatives are used in combination in Example 3, a more complex multi-ligand system can be formed. This multi-ligand system can more effectively stabilize rare earth ions through synergistic effects, forming more stable chelated rare earths, thereby increasing their solubility in water. By increasing the solubility of chelated rare earths, the demand of crops for rare earth elements can be more effectively met, thereby promoting the growth and development of crops and ultimately increasing crop yields.

[0079] By comparing Example 3 with Comparative Example 2, based on coordination chemistry and biocompatibility, ethylenediaminetetraacetic acid, erythritol, glycine, salicylic acid or its derivatives need to be mixed in a specific ratio to best chelate the rare earth, thereby increasing the solubility of the rare earth and making it easier for crops to absorb and utilize it, thereby achieving high crop yields.

[0080] By comparing Example 3 with Comparative Example 3, the cavitation effect of ultrasound in Example 3 can generate local high temperature and high pressure, which helps to break the chemical bonds of rare earths, making it easier to combine with ethylenediaminetetraacetic acid, erythritol, and glycine. Ultrasound can also increase the rate of chemical reactions, thereby improving the efficiency of chelation reactions, so that more rare earths are effectively chelated. The chelated rare earths after ultrasound treatment have a smaller molecular size and good water solubility, and are more likely to pass through the cell membrane of crops and enter the interior of cells, which helps crops absorb rare earth elements and thus increase crop yields.

[0081] By comparing Example 3 with Comparative Example 4, the acetic acid and other organic acids contained in the wood vinegar in Example 3 can promote soil acidification, help improve the effectiveness of nutrients in the soil, make it easier for crops to absorb and utilize these nutrients, thereby promoting the growth and development of crops. Acetic acid can also improve the microbial environment of the soil, maintain the ecological balance of the soil, improve the fertility of the soil, and provide more favorable conditions for crop growth. And wood vinegar can also enhance the disease resistance of crops, reduce the impact of diseases on crops, ensure the healthy growth of crops, and thus help to increase yields.

[0082] By comparing Example 3 with Comparative Example 5, each component can effectively meet the needs of crops at different growth stages only when it is in a specific ratio, thereby promoting the healthy growth and development of crops and ultimately increasing the yield of crops.

[0083] The existing water-soluble fertilizer is easy to clump due to the pressure of material stacking during storage, and the agglomerated product has a great impact on the quality and effect of the water-soluble fertilizer. Therefore, comparative example 6 is added to test the anti-caking effect.

[0084] Comparative Example 6

[0085] The difference between this comparative example and Example 3 is that the raw materials do not contain an anti-caking agent.

[0086] 3. Anti-caking effect detection

[0087] Weigh 100g of the water-soluble fertilizer obtained in Example 3 and Comparative Example 6 respectively and put them into ziplock bags, seal 3 bags respectively, stack the 3 bags and place them on a horizontal flat plate, and place a 10kg flat plate on the top. After 10 days, remove the flat plate and drop the ziplock bags 2 times from a height of 1m above the ground. Pass the dropped water-soluble fertilizer through a sieve with a pore size of 2.8mm, weigh the mass of the sample on the sieve, calculate the caking rate, and take the average value and record it in Table 3. The caking rate is calculated according to the following formula:

[0088]

[0089] Table 3

[0090] Example 3 Comparative Example 6 Agglomeration rate % 5.8 27.3

[0091] It can be seen from Table 3 that the caking rate of the water-soluble fertilizer with the anti-caking agent is greatly reduced, from 27.3% to 5.8%. It can be seen that the anti-caking agent of the present invention has a significant anti-caking effect. The starch phosphate can absorb and retain a certain amount of water, forming a thin layer of moist film covering the surface of the water-soluble fertilizer, thereby reducing the direct contact and friction between the particles, preventing caking caused by electrostatic attraction or water evaporation, and effectively preventing moisture bridging between fertilizer particles. Microcrystalline cellulose can absorb excess oil and water, reducing the caking phenomenon promoted by the presence of oil and water. At the same time, microcrystalline cellulose can form a stable network structure. Thereby increasing the spatial distance between fertilizer particles, reducing the contact opportunity between particles, and then preventing the grains from aggregating together to form large crystals, thereby playing an anti-caking role. At the same time, it provides a better attachment point for nanoclay, enhancing the overall anti-caking effect. Nanoclay has excellent adsorption capacity and dispersibility due to its extremely small particle size and high specific surface area. It can fill the tiny gaps between fertilizer particles, forming a physical barrier to prevent close contact between particles. At the same time, nanoclay can also absorb and fix certain active ingredients in fertilizers, reducing agglomeration caused by component migration. Therefore, nanoclay, starch phosphate and microcrystalline cellulose work together to maintain the dispersion of fertilizer particles through physical barrier and adsorption, thus enhancing the uniformity and effectiveness of the entire anti-caking agent system.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A water-soluble fertilizer containing rare earth, characterized in that: The invention comprises the following raw materials in parts by weight: 30-40 parts of nitrogen, phosphorus and potassium components, 10-15 parts of calcium and magnesium components, 3-5 parts of mineral element components, 0.5-1.0 parts of nickel, cobalt and selenium components, 10-15 parts of humic acid, 10-15 parts of anti-caking agent, 5-10 parts of sodium alginate, 5-10 parts of fish protein, 3-5 parts of wood vinegar, 2-4 parts of chelating agent and 0.5-1.0 parts of rare earth, wherein the nitrogen, phosphorus and potassium components are prepared in a mass ratio of (2-3):(1-2):(1-2 The invention discloses a novel nanostructured carbonyl phosphate (N-C) nanocarbon ...

2. A water-soluble fertilizer containing rare earth as claimed in claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 35 parts of nitrogen, phosphorus and potassium components, 12.5 parts of calcium and magnesium components, 4 parts of mineral element components, 0.7 parts of nickel, cobalt and selenium components, 12.5 parts of humic acid, 7.5 parts of sodium alginate, 7.5 parts of fish protein, 4 parts of wood vinegar, 3 parts of chelating agent and 0.8 parts of rare earth. The nitrogen, phosphorus and potassium components are prepared by mixing urea, monoammonium phosphate, diammonium phosphate and potassium nitrate in a mass ratio of 2.5:1.5:1.5:2.5; the anti-caking agent is composed of starch phosphate, microcrystalline cellulose and nano clay in a mass ratio of 3.0:2.5:1.5; and the chelating agent is composed of ethylenediaminetetraacetic acid, erythritol, glycine, salicylic acid or its derivatives in a mass ratio of 5:2.5:1.5:0.

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3. A water-soluble fertilizer containing rare earth as claimed in claim 1 or 2, characterized in that: The calcium-magnesium component is prepared by mixing calcium nitrate and magnesium sulfate, and the mass ratio of calcium nitrate to magnesium sulfate is (1.5-2.0):(1.0-1.5).

4. A water-soluble fertilizer containing rare earth as claimed in claim 1 or 2, characterized in that: The mineral element component is prepared by mixing ferrous sulfate, manganese sulfate, copper sulfate, zinc sulfate, boric acid and sodium molybdate, and the mass ratio of ferrous sulfate, manganese sulfate, copper sulfate, zinc sulfate, boric acid and sodium molybdate is (3.0-5.0):(1.0-3.0):(1.0-2.0):(2.0-3.0):(1.0-2.0):(0.5-1.0).

5. A water-soluble fertilizer containing rare earth as claimed in claim 1 or 2, characterized in that: The nickel-cobalt-selenium component is prepared by mixing nickel sulfate, cobalt chloride and sodium selenite, and the mass ratio of the nickel sulfate, cobalt chloride and sodium selenite is (1.0-3.0):(1.0-3.0):(0.5-1.0).

6. A water-soluble fertilizer containing rare earth as claimed in claim 1 or 2, characterized in that: The rare earth is selected from one of lanthanum nitrate, cerium nitrate, praseodymium nitrate, neodymium nitrate, samarium nitrate, europium nitrate and terbium nitrate.

7. A water-soluble fertilizer containing rare earth as claimed in claim 1 or 2, characterized in that: The salicylic acid or its derivative is one of salicylic acid, methyl salicylate, ethyl salicylate, propyl salicylate, acetylsalicylic acid, and β-hydroxy acid.

8. A method for preparing a water-soluble fertilizer containing rare earth as claimed in claim 1 or 2, characterized in that: The following steps are involved: S1, weighing the chelating agent and rare earth by weight, adding the chelating agent to a reactor, adding deionized water 4-5 times its volume, and then adding the rare earth, ultrasonic treatment, and then concentrating and drying to obtain the chelated rare earth for standby use; S2, weighing nitrogen, phosphorus and potassium components, calcium and magnesium components, mineral element components, nickel, cobalt and selenium components, humic acid, sodium alginate and fish protein according to weight, and stirring evenly to obtain a mixture I; S3, weighing the anti-caking agent according to weight, adding it to the mixture I, stirring evenly, to obtain the mixture II; S4, weighing the wood vinegar by weight and spraying it evenly into the mixture II, stirring and spraying, to obtain a mixture III; S5. Add the chelated rare earth obtained in step S1 to the mixed material III, stir evenly, and dry to obtain a water-soluble fertilizer containing rare earth.

9. The method for preparing a water-soluble fertilizer containing rare earth as claimed in claim 8, characterized in that: In the S1, the ultrasonic treatment power is 800-1000 W, the ultrasonic treatment time is 30-40 min, and then concentrated at a pressure of 0.05-0.10 MPa for 2-3 h, and dried at 60-80° C. for 1-2 h.

10. The method for preparing a water-soluble fertilizer containing rare earth as claimed in claim 9, characterized in that: In the S2, the stirring speed is 500-1000r / min and the stirring time is 20-30min, in the S3, the stirring speed is 500-1000r / min and the stirring time is 15-20min, in the S4, the stirring speed is 500-1000r / min and the stirring time is 15-20min, in the S5, the stirring speed is 600-800r / min and the stirring time is 8-12min, and the drying is carried out at 40-60°C for 40-60min.

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