Reinforced fertilizer for forage grass planting and preparation method thereof
By utilizing humic acid and potassium dihydrogen phosphate to form a stable complex in forage planting, and chelating it with trace elements, combined with modified bentonite, a slow-release fortified fertilizer was prepared. This solved the problems of excessively rapid release and low utilization rate of traditional fertilizers, improved nutrient utilization and soil health, and promoted forage growth.
Patent Information
- Application Number
- CN202511663815.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-13
- Publication Date
- 2026-01-23
AI Technical Summary
Traditional fertilizers release nutrients too quickly in forage planting, are easily washed away or volatilized by rainwater, have low utilization rates, and lead to resource waste and environmental pollution. In addition, existing slow-release fertilizers are expensive, complicated to prepare, and affect the activity of soil microorganisms.
By forming a stable complex with the carboxyl group on the humic acid molecule and the phosphate ion dissociated from potassium dihydrogen phosphate, and combining with trace element ions to form a ternary chelate, fortified fertilizers can be prepared. Modified bentonite can be used to improve soil structure and promote the slow release and absorption of nutrients.
It significantly reduced the soil fixation rate of phosphorus, improved the utilization rate of trace elements, improved soil structure, promoted forage growth, and increased yield and quality.
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Figure CN121377883A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of forage grass planting, and particularly relates to a reinforced fertilizer for forage grass planting and a preparation method thereof. BACKGROUND
[0002] Forage grass planting is the basis for the development of animal husbandry, and the use of fertilizer directly affects the yield and quality of forage grass. Traditional fertilizers such as urea, superphosphate and potassium chloride can provide essential nutrients, but they have problems such as rapid nutrient release, easy washing or volatilization loss, and low utilization rate, which not only leads to resource waste, but also may cause environmental problems such as water eutrophication and soil compaction; although slow-release fertilizers can partially solve these problems, most slow-release fertilizers have high cost and complex preparation, and may affect soil microbial activity. In the prior art, physical coating or simple mixing is commonly used to achieve slow release, but the effect is unstable, and there is a lack of specificity for the specific needs of forage grass.
[0003] Therefore, there is an urgent need to develop a reinforced fertilizer for forage grass planting, which can not only achieve slow release of nutrients, but also improve soil structure and promote forage grass growth. SUMMARY
[0004] In view of the deficiencies of the prior art, the present application provides a reinforced fertilizer for forage grass planting and a preparation method thereof. The present application utilizes the hydrogen bond and coordination bond between the carboxyl group on the humic acid molecule and the phosphate ion dissociated from potassium dihydrogen phosphate, to form a stable complex. The complex acts as a mixed ligand and undergoes chelation reaction with the ions of trace elements to form a ternary chelate, which can effectively prevent the conversion of trace elements into ineffective state in the soil, solving the technical problems of easy fixation of phosphorus elements in the existing forage grass fertilizer, low availability of trace elements, and low utilization rate caused by different release of nutrients.
[0005] To achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows:
[0006] The present application provides a reinforced fertilizer for forage grass planting, which comprises the following components by weight: humic acid 15-25 parts, potassium dihydrogen phosphate 20-30 parts, urea 10-20 parts, potassium sulfate 15-25 parts, zinc sulfate 2-4 parts, ammonium molybdate 0.5-1.5 parts, and modified bentonite 8-12 parts.
[0007] Further, the preparation method of the modified bentonite is: (1) sodium-based bentonite is mixed with 1 mol / L hydrochloric acid solution at a mass-volume ratio of 1 g:5 mL, and is acidified at 60 DEG C for 2 hours; (2) after acidification treatment, the filter cake is obtained by filtration, and then the filter cake is washed with deionized water until the filtrate is neutral, 3% of the weight of the sodium-based bentonite is added to cetyltrimethylammonium bromide, and is reacted at 70 DEG C for 3 hours; (3) after the reaction is completed, it is filtered, dried, and crushed to pass through a 200 mesh sieve to obtain the modified bentonite.
[0008] Further, the humic acid is a lignite extract; the ammonium molybdate is agricultural ammonium molybdate; and the urea is agricultural urea.
[0009] The application further provides a preparation method of the reinforced fertilizer for forage grass planting.
[0010] S1: preparing a humic acid-phosphate complex: humic acid is mixed with deionized water, and potassium dihydrogen phosphate is slowly added under stirring at 50 DEG C and 300 rpm, and the pH is adjusted to 4.5-5.5 by using 5% dilute hydrochloric acid, and the reaction is carried out for 2 hours, which promotes the hydrogen bond combination of the carboxyl group of humic acid and the phosphate group under acidic conditions, and a humic acid-phosphate complex is formed;
[0011] S2: preparing a trace element chelating solution: zinc sulfate and ammonium molybdate are dissolved in deionized water, and the humic acid-phosphate complex is added, and the reaction is carried out at 60 DEG C for 1 hour, and in the reaction process, the humic acid-phosphate complex acts as a mixed ligand to form a ternary chelate with zinc ions and molybdate ions, and a stable trace element chelating solution is obtained;
[0012] S3: compounding and granulating: urea, potassium sulfate and the modified bentonite are uniformly mixed, and the trace element chelating solution prepared in S2 is added, and the granulation is carried out by using an extrusion granulator, and the particle size is 3-4 mm;
[0013] S4: solidification treatment: the granules are dried in a fluidized bed at 80 DEG C for 1 hour, and then are solidified at 40 DEG C for 24 hours to obtain the reinforced fertilizer for forage grass planting.
[0014] Compared with the prior art, the application has the following beneficial effects:
[0015] (1) under specific acidic conditions, the abundant carboxyl and phenolic hydroxyl groups on the humic acid molecules are combined with the phosphate ions dissociated from potassium dihydrogen phosphate through hydrogen bonds and coordination bonds to form a stable "humic acid-phosphate complex", which changes the existing form of phosphorus elements, and converts the inorganic orthophosphate which is easily fixed in the soil into an organic-inorganic complex form with larger molecular weight and more stable structure, thereby significantly reducing the soil fixation rate of phosphorus and imparting the slow-release property.
[0016] (2) After the humic acid-phosphoric acid complex is prepared, the zinc ion and molybdate ion are further reacted to form a ternary chelate, and the ternary chelate ensures that zinc and molybdenum are absorbed by forage grass in a stable and effective form. Compared with traditional fertilizers, water-soluble potassium dihydrogen phosphate is applied to the soil, and phosphorus is easily combined with calcium, iron, aluminum and other ions to form insoluble phosphate; zinc and molybdenum are also easily adsorbed by soil colloids or precipitated. The prepared fortified fertilizer can be absorbed by forage grass, and the utilization rate of phosphorus and trace elements is significantly improved.
[0017] (3) Humic acid is a natural soil adhesive and water-retaining agent; modified bentonite has excellent ion exchange performance and swelling property, and the synergistic effect of humic acid and modified bentonite can improve the soil aggregate structure, enhance the water and fertilizer retention capacity and cation exchange capacity of the soil, and create a healthier growth environment for the root system of forage grass, further promote the absorption of nutrients, and thus improve the yield and quality of forage grass. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 The chemical process occurring in the preparation of the humic acid-phosphoric acid complex of the present application is shown, wherein R represents a variable side chain group connected to the aromatic skeleton in the humic acid molecule;
[0019] Figure 2 The nitrogen release rate of the fortified fertilizer prepared by the present application on the 1st day, the 7th day and the 14th day, respectively;
[0020] Figure 3 The phosphorus release rate of the fortified fertilizer prepared by the present application on the 1st day, the 7th day and the 14th day, respectively;
[0021] Figure 4 The potassium release rate of the fortified fertilizer prepared by the present application on the 1st day, the 7th day and the 14th day, respectively;
[0022] Figure 5 The fresh weight and dry weight of rye grass planted using the fortified fertilizer prepared by the present application. DETAILED DESCRIPTION
[0023] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Methods and materials similar or equivalent to those described herein can be used in the practice of the present application. The preferred materials and methods are described herein, although any method and material similar or equivalent to those described herein can be used. The materials, methods, and examples are illustrative only and not intended to be limiting.
[0025] Example 1: The present embodiment provides a fortified fertilizer for forage planting, and the raw materials for preparing the fertilizer include the following components by weight: humic acid 15 parts, potassium dihydrogen phosphate 20 parts, urea 10 parts, potassium sulfate 15 parts, zinc sulfate 2 parts, ammonium molybdate 0.5 parts, and modified bentonite 8 parts.
[0026] The preparation method of the modified bentonite is as follows: (1) 80 g of sodium-based bentonite is mixed with 1 mol / L hydrochloric acid solution at a mass-volume ratio of 1 g:5 mL, and acidification treatment is performed at 60°C for 2 hours; (2) after acidification treatment, the filter cake is obtained by filtration, and then the filter cake is washed with deionized water until the filtrate is neutral, 2.4 g of cetyltrimethylammonium bromide is added, and reaction is performed at 70°C for 3 hours; (3) after the reaction is completed, filtration, drying, and crushing through a 200-mesh sieve are performed to obtain the modified bentonite.
[0027] The present embodiment also provides a preparation method of a fortified fertilizer for forage planting, which includes the following steps:
[0028] S1: Preparation of humic acid-phosphate complex: humic acid is mixed with 300 mL of deionized water, and potassium dihydrogen phosphate is slowly added under stirring at 50°C and 300 rpm, and the pH is adjusted to 4.5 with 5% dilute hydrochloric acid, and reaction is performed for 2 hours. This step promotes the hydrogen bonding between the carboxyl groups of humic acid and phosphate ions under acidic conditions, and a humic acid-phosphate complex is formed, as shown in Figure 1 .
[0029] S2: Preparation of trace element chelate solution: zinc sulfate and ammonium molybdate are dissolved in 200 mL of deionized water, and the humic acid-phosphate complex prepared in S1 is added, and reaction is performed at 60°C for 1 hour. During the reaction, the humic acid-phosphate complex acts as a mixed ligand, and ternary chelates are formed with zinc ions and molybdate ions, and a stable trace element chelate solution is obtained.
[0030] S3: Compound granulation: urea, potassium sulfate, and modified bentonite are uniformly mixed, and the trace element chelate solution prepared in S2 is added as a binder, and granulation is performed by an extrusion granulator, and the particle size is 3-4 mm.
[0031] S4: Solidification treatment: the granules are dried in a fluidized bed at 80°C for 1 hour, and then solidified at 40°C for 24 hours to obtain the fortified fertilizer for forage planting.
[0032] The embodiment 2 provides a reinforced fertilizer for forage planting, and raw materials for preparing the reinforced fertilizer include the following components in parts by weight: humic acid 20 parts, potassium dihydrogen phosphate 25 parts, urea 15 parts, potassium sulfate 20 parts, zinc sulfate 3 parts, ammonium molybdate 1.0 part, and modified bentonite 10 parts.
[0033] The preparation method of the modified bentonite is as follows: (1) 100 g of sodium-based bentonite is mixed with 1 mol / L hydrochloric acid solution at a mass-volume ratio of 1 g:5 mL, and acidification treatment is performed at 60°C for 2 hours; (2) after the acidification treatment, a filter cake is obtained through filtration, and then the filter cake is washed with deionized water until the filtrate is neutral, 3 g of cetyltrimethylammonium bromide is added, and reaction is performed at 70°C for 3 hours; (3) after the reaction is completed, filtration is performed, drying is performed at 105°C until the weight is constant, and the modified bentonite is obtained by crushing through a 200-mesh sieve.
[0034] The embodiment also provides a preparation method of the reinforced fertilizer for forage planting, and the preparation method includes the following steps.
[0035] S1: preparing a humic acid-phosphoric acid compound: humic acid is mixed with 500 mL of deionized water, potassium dihydrogen phosphate is slowly added under stirring at 50°C and 300 rpm, a 5% dilute hydrochloric acid is used to adjust the pH to 5.0, reaction is performed for 2 hours, and a humic acid-phosphoric acid compound is formed;
[0036] S2: preparing a trace element chelate solution: zinc sulfate and ammonium molybdate are dissolved in 250 mL of deionized water, the humic acid-phosphoric acid compound prepared in S1 is added, reaction is performed at 60°C for 1 hour, a ternary chelate is formed, and a stable trace element chelate solution is obtained;
[0037] S3: compound granulation: urea, potassium sulfate and modified bentonite are uniformly mixed, the trace element chelate solution prepared in S2 is added as a binder, and granulation is performed through an extrusion granulator, and the particle size is 3-4 mm;
[0038] S4: solidification treatment: the granules are dried in a fluidized bed at 80°C for 1 hour, and then solidification is performed at 40°C for 24 hours, and the reinforced fertilizer for forage planting is obtained.
[0039] The embodiment 3 provides a reinforced fertilizer for forage planting, and raw materials for preparing the reinforced fertilizer include the following components in parts by weight: humic acid 25 parts, potassium dihydrogen phosphate 30 parts, urea 20 parts, potassium sulfate 25 parts, zinc sulfate 4 parts, ammonium molybdate 1.5 parts, and modified bentonite 12 parts.
[0040] The preparation method of the modified bentonite is as follows: (1) 120 g of sodium-based bentonite is mixed with 1 mol / L hydrochloric acid solution at a mass-volume ratio of 1 g:5 mL, and acidification treatment is carried out at 60°C for 2 hours; (2) after acidification treatment, filtration is carried out to obtain a filter cake, and then the filter cake is washed with deionized water until the filtrate is neutral, 3.6 g of cetyltrimethylammonium bromide is added, and reaction is carried out at 70°C for 3 hours; (3) after the reaction is completed, filtration is carried out, drying is carried out at 105°C until the weight is constant, and crushing is carried out through a 200-mesh sieve, to obtain the modified bentonite.
[0041] The embodiment also provides a preparation method of the fortified fertilizer for forage grass planting, including the following steps:
[0042] S1: preparation of humic acid-phosphoric acid complex: humic acid is mixed with 750 mL of deionized water, and potassium dihydrogen phosphate is slowly added under stirring at 50°C and 300 rpm, and the pH is adjusted to 5.5 by using dilute hydrochloric acid with a concentration of 5%, and reaction is carried out for 2 hours to form the humic acid-phosphoric acid complex;
[0043] S2: preparation of trace element chelating solution: zinc sulfate and ammonium molybdate are dissolved in 300 mL of deionized water, and the humic acid-phosphoric acid complex prepared in S1 is added, and reaction is carried out at 60°C for 1 hour to form a ternary chelate, to obtain a stable trace element chelating solution;
[0044] S3: compound granulation: urea, potassium sulfate and the modified bentonite are uniformly mixed, the trace element chelating solution prepared in S2 is added as a binder, and granulation is carried out through an extrusion granulator, and the particle size is 3-4 mm;
[0045] S4: solidification treatment: the granules are dried in a fluidized bed at 80°C for 1 hour, and then solidification is carried out at 40°C for 24 hours, to obtain the fortified fertilizer for forage grass planting.
[0046] Comparative Example 1: The difference between the comparative example and Example 2 is that the modified bentonite is not used, but an equal weight part of unmodified sodium-based bentonite is used, that is, the preparation raw materials are: humic acid 20 parts, potassium dihydrogen phosphate 25 parts, urea 15 parts, potassium sulfate 20 parts, zinc sulfate 3 parts, ammonium molybdate 1.0 part, and unmodified sodium-based bentonite 10 parts; in the preparation method, the unmodified sodium-based bentonite is directly used in S3 step to mix with urea and potassium sulfate, and the remaining steps are the same as those in Example 2.
[0047] Comparative Example 2: The difference between the comparative example and Example 2 is that S1 step is changed, and the humic acid-phosphoric acid complex is not formed, that is, in S1 step, the humic acid is directly mixed with the potassium dihydrogen phosphate, but the pH is not adjusted, and no reaction is carried out, but the mixture is simply mixed; in S2 step, after the zinc sulfate and the ammonium molybdate are dissolved in water, the mixture of the humic acid and the potassium dihydrogen phosphate is directly added, and no chelation reaction is carried out; the remaining steps are the same as those in Example 2.
[0048] Experimental method:
[0049] Nutrient release rate test: According to the standard GB / T 23348-2009 "Determination of nutrient release rate of slow-release fertilizer", the fertilizer samples prepared in Examples 1-3 and Comparative Examples 1-2 were placed in water and soaked at 25℃, and the nitrogen, phosphorus and potassium contents in the water were determined on the 1st day, 7th day and 14th day, respectively, and the nutrient release rate was calculated, as shown in Table 1. Figures 2-4
[0050] Soil incubation experiment: The same mass of soil was placed in pots, and an equal amount of fertilizer of Examples 1-3 and Comparative Examples 1-2 was added, and ryegrass was planted, and incubated under the same conditions for 30 days, and the fresh weight and dry weight of the ryegrass were determined, and the results are shown in Table 2. Figure 5
[0051] Fertilizer stability test: The fertilizer samples prepared in Examples 1-3 and Comparative Examples 1-2 were stored at 40℃ and 75% relative humidity for 30 days, and the caking was observed, and the nutrient retention rate was determined, and the results are shown in Table 1.
[0052] Table 1 Fertilizer stability test results
[0053]
[0054] From the experimental results, it can be seen that the fertilizer of Example 1-3 shows a more gentle release in terms of nutrient release rate, and the nitrogen, phosphorus and potassium release rates on the 14th day are lower than those of the comparative examples, indicating that the enhanced fertilizer prepared by the present application has better slow-release performance; in the soil incubation experiment, the fresh weight and dry weight of the ryegrass of Example 1-3 are significantly higher than those of Comparative Examples 1 and 2, indicating that the enhanced fertilizer prepared by the present application can effectively promote the growth of forage grass and improve nutrient absorption; in the stability test, Example 1-3 has no caking and high nutrient retention rate, while Comparative Examples 1 and 2 have caking and low nutrient retention rate. This shows that the use of modified bentonite and humic acid-phosphoric acid complex in the present application significantly improves the slow-release performance, nutrient utilization rate and stability of the fertilizer.
[0055] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.
[0056] The above describes the present application and its embodiments, which are not limited, and the drawings only show one of the embodiments of the present application, and the actual application is not limited thereto. In general, if a person skilled in the art is inspired by it, without departing from the purpose of the present application, without creative design, similar ways and embodiments of the technical solution should belong to the protection scope of the present application.
Claims
1. A fortified fertilizer for forage crop cultivation, characterized in that, The raw materials include the following parts by weight: 15-25 parts humic acid, 20-30 parts potassium dihydrogen phosphate, 10-20 parts urea, 15-25 parts potassium sulfate, 2-4 parts zinc sulfate, 0.5-1.5 parts ammonium molybdate, and 8-12 parts modified bentonite. The modified bentonite is prepared by: (1) mixing sodium bentonite with 1 mol / L hydrochloric acid solution for acidification; (2) obtaining a filter cake after acidification, then washing the filter cake with deionized water until the filtrate is neutral, and adding hexadecyltrimethylammonium bromide for reaction; (3) after the reaction is completed, filtering, drying, crushing and sieving to obtain modified bentonite.
2. The fortified fertilizer for forage planting according to claim 1, characterized in that, The humic acid is an extract from lignite.
3. The fortified fertilizer for forage planting according to claim 1, characterized in that, The ammonium molybdate is agricultural ammonium molybdate; the urea is agricultural urea.
4. The fortified fertilizer for forage planting according to claim 1, characterized in that, The mass-volume ratio of sodium-based bentonite to hydrochloric acid in the preparation method (1) of modified bentonite is 1g:5mL.
5. A method for preparing a fortified fertilizer for forage planting according to any one of claims 1-4, characterized in that, Includes the following steps: S1: Preparation of humic acid-phosphate complex: Humic acid and deionized water are mixed and stirred, then potassium dihydrogen phosphate is slowly added, and the pH is adjusted with dilute hydrochloric acid to obtain humic acid-phosphate complex. S2: Preparation of trace element chelate: Zinc sulfate and ammonium molybdate are dissolved in deionized water, and then humic acid-phosphate complex is added to react and a stable trace element chelate is obtained. S3: Composite granulation: Urea, potassium sulfate and modified bentonite are mixed evenly, and then the trace element chelate solution prepared by S2 is added to granulate the mixture. S4: Solidification treatment: The granules are dried and solidified to obtain the fortified fertilizer used for forage planting.
6. A method for preparing a fortified fertilizer for forage planting according to claim 5, characterized in that, The pH range for adjusting with dilute hydrochloric acid in step S1 is 4.5-5.5.