Silicon-containing water-soluble fertilizer and method for preparing the same

Abstract

The present application relates to the technical field of chemical fertilizer, in particular to a kind of silicon-containing water-soluble fertilizer and its preparation method.The silicon-containing water-soluble fertilizer includes the following raw materials by mass fraction: 80-100 parts of orthosilicic acid solution, 3-5 parts of organic acid dispersant or polycarboxylic acid high molecular dispersant, 5-10 parts of anti-settling chelating agent and 10-15 parts of acid-base buffer regulator.The silicon-containing water-soluble fertilizer of the present application uses active orthosilicic acid as silicon source, prevents the polymerization of orthosilicic acid to polysilicic acid by adding organic acid dispersant or polycarboxylic acid high molecular dispersant, and realizes the synergistic effect of silicon and carbon;It also introduces an anti-settling complexing agent to prevent the combination of silicate and other metal ions and prevent precipitation;In addition, an acid-base buffer regulator is added to stabilize the pH value of the fertilizer in the mixing and application to the soil in the appropriate range, to avoid the rapid rise of pH in a short period of time to cause root damage, with the characteristics of slow-release acid, anti-settling, high absorption, suitable for drip irrigation system, and can be mixed with conventional fertilizer.

Description

Technical Field

[0001] This invention relates to the field of fertilizer technology, and in particular to a silicon-containing water-soluble fertilizer and its preparation method. Background Technology

[0002] With the development of facility agriculture, soil acidification caused by continuous cropping obstacles is becoming increasingly serious. Acidified soil not only leads to the toxicity of metal ions such as aluminum and manganese, but also reduces the availability of nutrients such as phosphorus, potassium, calcium, and magnesium, inhibits crop root growth, reduces fertilizer utilization, and seriously affects crop yield and quality. Silicon fertilizer, known as the fourth major element fertilizer, not only enhances crops' drought resistance, disease resistance, and lodging resistance, but also contains silicate ions (SiO3). 2- It is alkaline and can effectively neutralize soil acidity. Southern red soil and greenhouse cultivation soils are generally acidic, so it is necessary to use special water-soluble fertilizers for improvement, and silicon fertilizer is a commonly used improver.

[0003] Currently, common silicon fertilizer products on the market mainly include water-soluble silicon fertilizer and silicon-containing compound fertilizer. Water-soluble silicon fertilizer is a strongly alkaline silicon fertilizer made from potassium silicate, sodium silicate, and other raw materials. This fertilizer has poor compatibility and easily forms precipitation in acidic soils, reducing its effectiveness. In addition, when strongly alkaline silicon fertilizer is applied to acidic soil, its high pH value causes a rapid increase in soil pH in a short period of time, which may damage seedling roots. Furthermore, due to its lack of buffering capacity, the soil pH value drops rapidly as it is leached by rainwater or irrigation water, resulting in a short-lived improvement effect. Silicon-containing compound fertilizer is prepared by physically mixing silicon fertilizer with nitrogen, phosphorus, potassium, or trace elements. The silicon in it is mostly in the form of polysilicic acid or insoluble silicate, which needs to be depolymerized into orthosilicic acid (H4SiO4) in the soil for a long time before it can be absorbed by crops. It has a slow onset of action and cannot meet the silicon requirements of crops during their critical growth stages.

[0004] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a silicon-containing water-soluble fertilizer and its preparation method, which aims to solve the technical problems of liquid silicon fertilizer in acidic soil, such as easy precipitation, drastic and short-lived acidity adjustment, and easy polymerization failure of effective silicon.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides a silicon-containing water-soluble fertilizer, which, by mass parts, comprises the following raw materials: 80-100 parts of orthosilicic acid solution, 3-5 parts of organic acid dispersant or polycarboxylic acid polymeric dispersant, 5-10 parts of anti-precipitation chelating agent, and 10-15 parts of acid-base buffer regulator.

[0007] The silicon-containing water-soluble fertilizer is wherein the orthosilicic acid solution is prepared by preparing ionic silicon stock solution from silica-rich minerals through a high-temperature and high-pressure alkali dissolution method, and then purifying it through a cation exchange resin; the silica-rich minerals include at least one of diatomaceous earth, fly ash, kaolin, and rice husk.

[0008] The silicon-containing water-soluble fertilizer, wherein the organic acid dispersant includes at least one of: sodium ethylenediaminetetramethylene phosphate (EDTMPS), diethylenetriaminepentamethylenephosphonic acid (DTPMPA), aminotrimethylenephosphonic acid (ATMP), diethylenetriaminepentamethylenephosphonate (DETPMPS), hydroxyethylidene diphosphonic acid (HEDP), and aminetrimethylene phosphate.

[0009] The silicon-containing water-soluble fertilizer, wherein the polycarboxylic acid polymeric dispersant includes at least one of citric acid and tartaric acid.

[0010] The silicon-containing water-soluble fertilizer, wherein the anti-precipitation chelating agent includes at least one of the following: polyacrylate, polystyrene sulfonate, polyethylene glycol, polyether, and sodium lignosulfonate.

[0011] The silicon-containing water-soluble fertilizer, wherein the acid-base buffer regulator includes at least one of the following: ammonia-ammonium chloride buffer solution, borax-boric acid buffer solution, potassium dihydrogen phosphate-dipoxat phosphate, and sodium dihydrogen phosphate-disodium hydrogen phosphate.

[0012] The silicon-containing water-soluble fertilizer, wherein the orthosilicic acid is prepared by preparing an ionic silicon stock solution from silica-rich minerals through a high-temperature, high-pressure alkali dissolution method, followed by purification using a cation exchange resin. Specifically, the process includes the following steps: adding silica-rich minerals and sodium hydroxide or potassium hydroxide in a ratio of (1-2):1 to a reaction vessel; adding hot water, with a mass ratio of silica-rich minerals to hot water of 1:(10-20); stirring for 3-5 hours at 50-90℃ and 0.5-1.0 MPa; filtering to remove residue to obtain the ionic silicon stock solution; and purifying the ionic silicon stock solution using a cation exchange resin to remove cations to obtain an orthosilicic acid solution.

[0013] The silicon-containing water-soluble fertilizer also includes 2 to 5 parts of a thickener.

[0014] The second aspect of this invention provides a method for preparing a silicon-containing water-soluble fertilizer, which includes the following steps: adding an organic acid dispersant, an anti-precipitation chelating agent, and a thickener sequentially to an orthosilicic acid solution while dispersing, controlling the temperature not to exceed 50°C, and dissolving completely to obtain a mixed solution; slowly adding an acid-base buffer to the mixed solution, stirring evenly, and adjusting the pH of the solution to between 8.5 and 10.5; allowing it to stand to defoam, and detecting the effective silicon content and pH value to obtain the finished product.

[0015] Beneficial effects: This invention provides a silicon-containing water-soluble fertilizer, which adopts a quaternary compound system of orthosilicic acid, organic acid dispersant or polycarboxylic acid polymeric dispersant, anti-precipitation chelating agent and acid-base buffer regulator. In the system, the dispersant combines with orthosilicic acid to effectively prevent the dehydration and polymerization between orthosilicic acid molecules and improve its stability; while the anti-precipitation chelating agent in the system combines with metal ions to reduce the formation of insoluble silicate precipitates by the combination of metal ions and silicate ions; and the addition of acid-base buffer regulator achieves slow-release acidification, realizing long-term and gradual improvement of soil acidification. Detailed Implementation

[0016] This invention provides a silicon-containing water-soluble fertilizer and its preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following embodiments are provided to further illustrate the invention in detail. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0017] The first aspect of the present invention provides a silicon-containing water-soluble fertilizer, which, by mass parts, comprises the following raw materials: 80-100 parts of orthosilicic acid solution, 3-5 parts of organic acid dispersant or polycarboxylic acid polymeric dispersant, 5-10 parts of anti-precipitation chelating agent, and 10-15 parts of acid-base buffer regulator.

[0018] This invention uses active orthosilicic acid as the silicon source and adds organic acid-based anti-polymerization dispersants to prevent orthosilicic acid from polymerizing into polysilicic acid, thereby achieving synergistic effects between silicon and carbon. At the same time, an anti-precipitation complexing agent is introduced to fix other heavy metals through complexation, preventing silicate ions from combining with other metal ions and preventing precipitation. In addition, an acid-base buffering regulator is added to keep the pH value of the fertilizer stable within a suitable range after mixing and application to the soil, avoiding a rapid increase in pH in a short period of time that could damage the roots.

[0019] Preferably, the original silica solution is prepared by preparing ionic silicon raw solution from silica-rich minerals through a high-temperature and high-pressure alkaline dissolution method, followed by purification through a cation exchange resin; the silica-rich minerals include at least one of diatomaceous earth, fly ash, kaolin, and rice husk.

[0020] Preferably, the organic acid dispersant comprises at least one of: ethylenediaminetetramethylenebisphosphate sodium (EDTMPS), diethylenetriaminepentamethylenephosphonic acid (DTPMPA), aminotrimethylenephosphonic acid (ATMP), diethylenetriaminepentamethylenephosphonate (DETPMPS), hydroxyethylidene diphosphonic acid (HEDP), and aminetrimethylene phosphate. The polycarboxylic acid polymeric dispersant comprises at least one of: citric acid and tartaric acid. By utilizing the complexing effect of organic acid dispersants or carboxylic acid polymeric dispersants to combine with orthosilicic acid, polymerization reactions can be prevented, achieving the effect of dispersing the solution. Simultaneously, the organic acid dispersant can also form stable complexes with iron and aluminum ions in the soil, reducing the toxicity of aluminum ions to the roots and preventing Al2O3 formation. 3+ It disrupts the structure of silicate ions.

[0021] Preferably, the anti-precipitation chelating agent comprises at least one of: polyacrylate, polystyrene sulfonate, polyethylene glycol, polyether, and sodium lignosulfonate. These anti-precipitation chelating agents can chelate Ca in water. 2+ Mg 2+ Plasma prevents silicate precipitation.

[0022] Preferably, the acid-base buffering agent comprises at least one of the following: ammonia-ammonium chloride buffer solution, borax-boric acid buffer solution, potassium dihydrogen phosphate-dapoxetine hydrogen phosphate, and sodium dihydrogen phosphate-disodium hydrogen phosphate. This endows the fertilizer with a unique pH buffering capacity. When the fertilizer is applied to acidic soil, it does not instantly neutralize the acidity like a strong alkali, causing a sharp spike in pH. Instead, it slowly releases alkalinity as the soil acidity is depleted, maintaining the pH value within a suitable range. This achieves long-term, gradual improvement of soil acidification and avoids over-flushing.

[0023] Preferably, the orthosilicic acid is prepared by preparing an ionic silicon stock solution from silica-rich minerals through a high-temperature, high-pressure alkaline dissolution method, followed by purification using a cation exchange resin. Specifically, the process includes the following steps: adding silica-rich minerals and sodium hydroxide or potassium hydroxide to a reaction vessel at a ratio of (1-2):1, adding hot water (the mass ratio of silica-rich minerals to hot water is 1:(10-20), stirring for 3-5 hours at 50-90℃ and 0.5-1.0 MPa, filtering to remove residue, and obtaining the ionic silicon stock solution; purifying the ionic silicon stock solution using a cation exchange resin to remove cations, thus obtaining an orthosilicic acid solution.

[0024] Preferably, the silicon-containing water-soluble fertilizer further includes 2-5 parts of a thickener. The thickener may be selected from xanthan gum, sodium alginate, methylcellulose, etc.

[0025] A second aspect of this invention provides a method for preparing a silicon-containing water-soluble fertilizer, comprising the following steps: Organic acid dispersant and anti-precipitation chelating agent are added sequentially to the original silicic acid solution while dispersing. During dispersion, a shear disperser or an ultrasonic-assisted dispersion process can be used instead of mechanical shearing. If a shear disperser is used, the speed of shear dispersion can be adjusted to 3000-10000 rpm. During dispersion, the temperature is controlled not to exceed 50℃ to ensure complete dissolution and obtain a mixed solution. Slowly add the acid-base buffer to the mixture, stir well, and adjust the pH of the solution to between 8.5 and 10.5; After standing to defoam, the effective silicon content and pH value are tested to obtain the finished product.

[0026] The present invention will be further illustrated by specific embodiments and comparative examples below. Unless otherwise specified, the experimental methods used in the embodiments are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0027] Example 1 A silicon-containing water-soluble fertilizer is prepared by the following steps: S01. Preparation of orthosilicic acid: Weigh 10 kg of diatomaceous earth and 10 kg of potassium hydroxide and place them in a reaction vessel. Add 100 kg of hot water at 60℃. Control the temperature of the reaction vessel at 60℃±5℃ and the pressure at 0.6 MPa. Stir thoroughly for 5 hours, filter to remove residue, and remove the main cations through a cation exchange resin to obtain an orthosilicic acid solution. S02. Add organic acid dispersant and anti-precipitation chelating agent: Place 100 kg of orthosilicic acid solution in a shear disperser, add 5 kg of aminotrimethylenephosphonic acid (ATMP) at 7000 rpm, shear for 30 min, then add 10 kg of polyethylene glycol, shear for 30 min, stir evenly to obtain a mixture; S03. Preparation of acid-base buffer regulator: To prepare a 0.05 M borax solution: Weigh 19.07 g of sodium tetraborate decahydrate (Na2B4O7·10H2O), dissolve it in distilled water and bring the volume to 1 L. A total of 8 L of 0.05 M borax solution needs to be prepared. To prepare a 0.2 M boric acid solution: Weigh 12.37 g of boric acid (H3BO3), dissolve it in distilled water and bring the volume to 1 L. A total of 2 L of 0.2 M boric acid solution needs to be prepared. Mix 8 L of borax solution and 2 L of boric acid solution thoroughly to obtain a borax-boric acid buffer solution. S04. Add acid-base buffer regulator: Add 10L of well-mixed borax-boric acid buffer solution to the original silicic acid solution, stir evenly, and let stand to defoam to obtain the silicon-containing water-soluble fertilizer.

[0028] Example 2 A silicon-containing water-soluble fertilizer is prepared in a way that differs from that in Example 1 in that the method for preparing orthosilicic acid is different. In this embodiment, the preparation method of orthosilicic acid is as follows: 10 kg of fly ash and 5 kg of potassium hydroxide are weighed and placed in a reaction vessel, 200 kg of hot water at 60°C is added, the temperature of the reaction vessel is controlled at 80°C±5°C, the pressure is 0.6 MPa, and the mixture is stirred thoroughly for 4 hours. The residue is removed by filtration, and the main cations are removed by cation exchange resin to obtain an orthosilicic acid solution.

[0029] Example 3 A silicon-containing water-soluble fertilizer, the preparation method of which differs from that of Example 1, is different in the method of preparing orthosilicic acid; In this embodiment, the preparation method of orthosilicic acid is as follows: 10 kg of kaolin and 6.66 kg of potassium hydroxide are weighed and placed in a reaction vessel, 150 kg of hot water at 60°C is added, the temperature of the reaction vessel is controlled at 80°C±5°C, the pressure is 0.8 MPa, and the mixture is stirred thoroughly for 3 hours. The residue is removed by filtration, and the main cations are removed by cation exchange resin to obtain an orthosilicic acid solution.

[0030] Example 4 A silicon-containing water-soluble fertilizer is prepared in a way that differs from that in Example 1 in that the method for preparing orthosilicic acid is different. In this embodiment, the preparation method of orthosilicic acid is as follows: 10 kg of diatomaceous earth and 10 kg of sodium hydroxide are weighed and placed in a reaction vessel, 100 kg of hot water at 60°C is added, the temperature of the reaction vessel is controlled at 80°C±5°C, the pressure is 0.8 MPa, and the mixture is stirred thoroughly for 3 hours. The residue is removed by filtration, and the main cations are removed by cation exchange resin to obtain an orthosilicic acid solution.

[0031] Example 5 A silicon-containing water-soluble fertilizer, the preparation method of which differs from that of Example 1, is different in that the organic acid dispersant is different; In this embodiment, the amount of organic acid dispersant added is 3 kg, which is composed of sodium ethylenediaminetetramethylene phosphate (EDTMPS) and hydroxyethylidene diphosphonic acid (HEDP) in a mass ratio of 1:1. During dispersion, it is sheared at 5000 rpm for 30 min.

[0032] Example 6 A silicon-containing water-soluble fertilizer, the preparation method of which differs from that of Example 1, is different in that the anti-precipitation chelating agent is different; In this embodiment, the amount of the anti-precipitation chelating agent added is 6 kg, and the anti-precipitation chelating agent is sodium lignosulfonate. When dispersed, it is sheared at 5000 rpm for 30 min.

[0033] Example 7 A silicon-containing water-soluble fertilizer, the preparation method of which differs from that of Example 1, is different in that the acid-base buffer regulator is different; In this embodiment, the acid-base buffer is an ammonia-ammonium chloride buffer solution, which is prepared as follows: Preparation of stock solution A (ammonium chloride solution): Weigh 5.4 g of solid ammonium chloride, dissolve it in 1000 mL of distilled water, and prepare a solution of about 0.1 M; Preparation of stock solution B (ammonia solution): Measure 35 mL of concentrated ammonia solution, dilute to 1000 mL, and prepare a solution of about 0.1 M; Mixing: Take 500 mL of stock solution A, add 350 mL of stock solution B, and dilute with distilled water to a total volume of 1 L; In this embodiment, the amount of ammonia-ammonium chloride buffer solution added is 12L, and the pH of the solution is adjusted to 9.2.

[0034] Comparative Example 1 A silicon-containing water-soluble fertilizer, the preparation method of which differs from that of Example 1, is that no organic acid dispersant is added.

[0035] Comparative Example 2 A silicon-containing water-soluble fertilizer, the preparation method of which differs from that of Example 1, is that no anti-precipitation chelating agent is added.

[0036] Comparative Example 3 A silicon-containing water-soluble fertilizer is prepared in a way that differs from that in Example 1 in that no acid-base buffer is added.

[0037] Comparative Example 4 A silicon-containing water-soluble fertilizer is prepared in a way that differs from that in Example 1 in that it does not contain organic acid dispersants, anti-precipitation chelating agents, or acid-base buffers.

[0038] Comparative Example 5 Potassium silicate (Si≥100g / L), a traditional strongly alkaline silicon fertilizer, is used.

[0039] Comparative Example 6 This comparative example uses traditional granular silicon-containing compound fertilizer (Si≥10%).

[0040] Test 1: Stability Experiment of Silicon Fertilizer Experimental design: The fertilizers prepared in the examples and comparative examples were placed at room temperature (25°C) for observation, and the water and fertilizer integration environment was simulated to test their compatibility with calcium and magnesium fertilizers.

[0041] Table 1 shows the stability test results. Table 1

[0042] As shown in Table 1, the silicon-containing water-soluble fertilizers prepared in Examples 1-7 exhibited excellent and consistent performance: Regarding appearance stability, all seven products maintained their initial liquid state after 14 days of storage, without any precipitation or flocculent material formation, demonstrating that the formulation system effectively inhibited silica polymerization and precipitation. In terms of mixing safety, the solutions of the seven products, when mixed with calcium and magnesium fertilizers, remained clear and free of turbidity. This is crucial for improving acidic red soil and in fertigation applications, avoiding the risk of dripper clogging. Furthermore, the pH values ​​of the seven products remained stable between 9.0 and 9.6, representing a slightly alkaline environment, which neutralizes soil acidity without burning crop roots like strong alkalis.

[0043] When the products of Comparative Examples 1 and 4 were mixed with calcium and magnesium fertilizer, the orthosilicic acid rapidly underwent a polymerization reaction, and the solution solidified directly. This proves that the organic acid dispersant is the key to maintaining the monomolecular state of orthosilicic acid and preventing gelation.

[0044] When the products in Comparative Examples 2 and 4 were mixed with calcium and magnesium fertilizer, obvious white precipitates appeared, and a large amount of precipitates were generated in the compatibility test. This indicates that the anti-precipitation chelating agent is essential for blocking calcium and magnesium ions in water and preventing the formation of silicate precipitates.

[0045] When products in Comparative Examples 3 and 5 are mixed with calcium and magnesium fertilizer, although they remain in liquid form, the pH value is as high as 12.5-12.6. Although this strong alkalinity can temporarily dissolve the product, when applied to acidic soil, it will cause acid-base neutralization heat and root burn. Furthermore, it lacks buffering capacity and cannot effectively regulate acidity in the long term.

[0046] The product of Comparative Example 6 is granular, but it precipitates during the dissolution process and has a low effective silicon content of only 1.2%, which is far lower than the 77 g / L of Example Group, demonstrating the inadequacy of traditional solid fertilizers in improving acidic soils.

[0047] Test 2: The pH-regulating effect of different silicon fertilizer formulations on acidic soils Experimental Design: A pot experiment was conducted using typical acidic red soil with an initial pH of 4.8. Examples 1-7, comparative examples 1-6, and a blank control group (CK) were set up, and all soils were treated with the same amount of silicon fertilizer and managed with conventional water management. Soil samples were collected at 1, 2, 3, 5, 10, 30, 60, and 90 days after application, and the pH values ​​were measured. Table 2 shows the test results.

[0048] Table 2

[0049] As shown in Table 2, Examples 1-7 all exhibited excellent slow-release stability. In the initial application period (1-10 days), the pH gradually increased from 4.8 to approximately 6.2, reaching a pH of 6.5 around day 30, which provides a suitable slightly acidic environment for crop growth, and remained highly stable over the following 90 days. This demonstrates that the acid-base buffer played a crucial role in preventing drastic pH fluctuations.

[0050] Comparative Example 3: The pH value spiked sharply to 6.8 on day 1, then quickly dropped back, reaching 4.9 by day 90. This indicates that the lack of a buffer system led to an over-flushing of soil acidity regulation, which not only posed a risk of root damage but also failed to maintain the pH regulation effect in the long term.

[0051] Comparative Example 5: It exhibited a typical rapid rise and fall. On the first day, the pH soared to 7.5, and then due to rain leaching and lack of buffer, the pH quickly rebounded back to acidic, and the improvement effect was short-lived.

[0052] Comparative Examples 1, 2, and 4: Due to the lack of key dispersing or chelating agents, silicon fertilizers were ineffective or precipitated, resulting in a weak ability to regulate soil acidity, with the pH value consistently maintained at a low level.

[0053] This invention successfully solves the technical problem of the drastic and short-lived acidity regulation of traditional liquid silicon fertilizer by introducing an acid-base buffer pair, and achieves long-term and stable regulation of soil pH.

[0054] The above results demonstrate that this invention successfully solves the technical challenges of easy polymerization and precipitation of orthosilicic acid through a triple synergistic mechanism of organic acid dispersion, anti-precipitation chelation, and acid-base buffering. While maintaining a high concentration of available silicon, the product also possesses excellent physical stability and chemical compatibility, and has a mild pH value, making it highly suitable for drip irrigation and fertigation in acidic soils.

[0055] Test 3: The effect of different silicon fertilizer formulations on rice yield increase Experimental Design: A field experiment was conducted in a typical acidic red soil region of Guangdong Province, with rice as the test crop. Examples 1-7, comparative examples 1-6, and a blank control group (CK) were set up. Under the condition of applying the same amount of silicon fertilizer with different formulations, all treatment groups underwent uniform field management. After rice harvest, the effective tiller number, effective panicle number, thousand-grain weight, seed setting rate, and yield were determined by artificial seed testing method, and the yield increase rate was calculated. The results are shown in Table 3.

[0056] Table 3

[0057] As shown in Table 3, the silicon fertilizer products in the embodiments significantly improved rice yield. The rice yields of all embodiments were significantly higher than those of the control group and the CK group, with Embodiment 4 exhibiting the highest yield at 698.3 kg / mu. The number of effective tillers and effective panicles in all seven embodiments were significantly higher than those in the CK group. This demonstrates that the orthosilicic acid in the fertilizer of this invention, combined with the organic acid dispersant, can effectively alleviate aluminum ion toxicity in acidic soils, protect the root system, and promote tillering. Furthermore, the thousand-grain weight and grain filling rate of the embodiments were superior to those of the control group. This is attributed to the fact that silicon element enhances stem strength, improves field ventilation and light penetration, thereby increasing photosynthetic efficiency and grain filling fullness.

[0058] The rice yields corresponding to the silicon fertilizer products in Comparative Examples 1 and 4 were relatively low, at only 540 kg / mu. This was because the lack of dispersants or chelating agents caused the orthosilicic acid to polymerize and solidify or form precipitates, preventing the rice from absorbing silicon nutrients. In addition, the soil acidity was not improved, and aluminum toxicity inhibited growth.

[0059] The impact of silicon fertilizer products at ratios 3 and 5 on rice yield data is similar because neither of them has a buffering effect. Although they provide a silicon source, their strong alkalinity causes acid-base neutralization heat in the early stages of application to acidic soil, which can lead to root burn and offset some of the yield increase potential.

[0060] The silicon fertilizer product in Comparative Example 6 had a limited yield-increasing effect due to its low silicon content and poor solubility, and could not meet the high silicon requirements of rice.

[0061] The above results demonstrate that the orthosilicic acid-containing water-soluble fertilizer of this invention, through the synergistic effect of anti-precipitation dispersion and acid-base buffering, not only eliminates the aluminum toxicity hazard of acidic soils but also achieves efficient silicon absorption. This directly translates into superior agronomic traits in rice, such as more panicles, larger grains, and higher seed setting, achieving a more significant yield increase than existing technologies and possessing extremely high value for widespread application.

[0062] Test 4: Effects of different silicon fertilizer formulations on rice resistance Experimental Design: At the maturity stage of the rice plants in the above-mentioned experimental groups, rice plants with moderate and uniform growth were selected for physical and mechanical tests. The test indicators included the compressive strength of the second internode, the fresh weight of the single diameter of the rice plant, and the height of the center of gravity of the rice stem. The lodging index was then calculated, and the formula for calculating the lodging index is as follows: Lodging index = Fresh weight of single stem × Stem center of gravity height ÷ Bending resistance of second internode The results are shown in Table 4.

[0063] Table 4

[0064] The results above show that in all the rice varieties corresponding to the examples, the compressive strength of the second internode reached over 58.0 N, far exceeding the 40.1 N of the control group. Example 4 showed the best performance, with a compressive strength as high as 59.3 N. This demonstrates that the orthosilicic acid in this invention, after being efficiently absorbed by the rice, deposits in the stem epidermal cells to form silicified cells, significantly enhancing the mechanical hardness of the stem. Furthermore, the lodging index of the rice varieties corresponding to the examples was controlled between 13.1 and 14.5, far lower than other treatments. This is attributed to the optimization of plant type by silicon, which increases stem wall thickness, lowers the center of gravity, and strengthens bending resistance.

[0065] Comparative Examples 1, 2, and 4 showed compressive strengths of only 39.1-44.0 N and lodging indices as high as 18.6-25.5. This was because of the lack of dispersants or chelating agents, causing silicon fertilizer to polymerize or precipitate, preventing rice from absorbing effective silicon, resulting in thin and soft stems that were extremely prone to lodging.

[0066] Although Comparative Examples 3 and 5 provided a certain silicon source and their compressive strength and lodging index were better than CK, they were significantly worse than the embodiments of the present invention. This indicates that traditional strongly alkaline silicon fertilizers are easily affected by acid-base neutralization heat in acidic soils, resulting in limited silicon absorption rate. Furthermore, they may damage the root system in the early stages, affecting the later stem strengthening effect.

[0067] Comparative Example 6: The compressive strength was 53.7 N and the lodging index was 13.4. Although it had some effect, due to its low solubility and slow release, it could not provide enough silicon nutrition to build a strong stem structure during the critical growth period of rice.

[0068] The above results demonstrate that the silicon-containing water-soluble fertilizer of the present invention can significantly promote the silicification of rice stems, greatly improve the compressive strength and lodging resistance of stems, and effectively reduce the risk of crop lodging under the climatic background of multiple typhoons and rainstorms, ensuring stable and high crop yields.

[0069] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A silicon-containing water-soluble fertilizer, characterized in that, The preparation materials, by mass parts, include the following: 80-100 parts of orthosilicic acid solution, 3-5 parts of organic acid dispersant or polycarboxylic acid polymeric dispersant, 5-10 parts of anti-precipitation chelating agent, and 10-15 parts of acid-base buffer regulator.

2. The silicon-containing water-soluble fertilizer according to claim 1, characterized in that, The original silica solution is prepared by preparing ionic silicon raw solution from silica-rich minerals through high temperature and high pressure alkali dissolution method, and then purifying it through cation exchange resin; the silica-rich minerals include at least one of diatomaceous earth, fly ash, kaolin, and rice husk.

3. The silicon-containing water-soluble fertilizer according to claim 1, characterized in that, The organic acid dispersant includes at least one of the following: sodium ethylenediaminetetramethylene phosphate (EDTMPS), diethylenetriaminepentamethylenephosphonic acid (DTPMPA), aminotrimethylenephosphonic acid (ATMP), diethylenetriaminepentamethylenephosphonate (DETPMPS), hydroxyethylidene diphosphonic acid (HEDP), and aminetrimethylene phosphate.

4. The silicon-containing water-soluble fertilizer according to claim 1, characterized in that, The polycarboxylic acid polymeric dispersant includes at least one of citric acid and tartaric acid.

5. The silicon-containing water-soluble fertilizer according to claim 1, characterized in that, The anti-precipitation chelating agent includes at least one of the following: polyacrylate, polystyrene sulfonate, polyethylene glycol, polyether, and sodium lignosulfonate.

6. The silicon-containing water-soluble fertilizer according to claim 1, characterized in that, The acid-base buffer regulator includes at least one of the following: ammonia-ammonium chloride buffer solution, borax-boric acid buffer solution, potassium dihydrogen phosphate-dipoxat phosphate, and sodium dihydrogen phosphate-disodium hydrogen phosphate.

7. The silicon-containing water-soluble fertilizer according to claim 2, characterized in that, The orthosilicic acid is prepared by using a high-temperature, high-pressure alkaline dissolution method to prepare an ionic silicon stock solution from silica-rich minerals, followed by purification using a cation exchange resin. The specific steps include: Add silica-rich minerals and sodium hydroxide or potassium hydroxide to a reaction vessel in a ratio of (1-2):1, add hot water, and the mass ratio of silica-rich minerals to hot water is 1:(10-20). Stir for 3-5 hours at 50-90℃ and 0.5-1.0MPa, filter to remove residue, and obtain ion-silicon stock solution. The ionic silicon stock solution was purified by passing it through a cation exchange resin to remove cations, resulting in an orthosilicic acid solution.

8. The silicon-containing water-soluble fertilizer according to claim 1, characterized in that, The preparation materials, by mass parts, include the following: 100 parts of orthosilicic acid solution, 5 parts of aminotrimethylenephosphonic acid (ATMP), 10 parts of polyethylene glycol, and 10 parts of borax-boric acid buffer solution; The original silicic acid solution is prepared by diatomaceous earth through a high-temperature and high-pressure alkaline dissolution method to prepare ionic silicon raw solution, and then purified by cation exchange resin; in the high-temperature and high-pressure alkaline dissolution method, sodium hydroxide is used as the alkali.

9. The silicon-containing water-soluble fertilizer according to claim 1, characterized in that, It also includes 2 to 5 parts of thickener.

10. A method for preparing a silicon-containing water-soluble fertilizer, characterized in that, The preparation of the silicon-containing water-soluble fertilizer as described in any one of claims 1-8 comprises the following steps: Organic acid dispersant and anti-precipitation chelating agent are added sequentially to the original silicic acid solution while dispersing, and the temperature is controlled not to exceed 50°C. The solution is fully dissolved to obtain a mixed solution. Slowly add the acid-base buffer to the mixture, stir well, and adjust the pH of the solution to between 8.5 and 10.5; After standing to defoam, the effective silicon content and pH value are tested to obtain the finished product.

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