Special slow-release compound fertilizer for corn and preparation method of special slow-release compound fertilizer

Abstract

The invention discloses a special slow-release compound fertilizer for corn and a preparation method thereof, the special slow-release compound fertilizer comprises the following raw materials by weight: 30-40 parts of urea, 15-20 parts of ammonium sulfate, 20-25 parts of potassium sulfate, 15-25 parts of monoammonium phosphate, 2-3 parts of a seaweed extract, 0.5-1.5 parts of polyaspartic acid, 0.5-1.5 parts of trace elements, and 0.5-1 part of a slow-release agent, the slow-release agent comprises DMPP, the trace elements comprise zinc-boron-titanium citrate, and the slow-release agent comprises potassium sulfate, potassium sulfate, potassium sulfate, monoammonium phosphate, polyaspartic acid, zinc-boron-titanium citrate. The seaweed extract comprises chitosan. DMMP is added into the formula, so that stable supply of nitrogen and synergistic yield increase benefits are achieved; the chitosan, the titanium zinc borate citrate and the polyaspartic acid are added, so that the absorption efficiency of the root system is further improved, the robust growth of corn plants is promoted together, and the acre yield and the grain quality of the corn are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of compound fertilizers, in particular to a slow-release compound fertilizer special for corn and a preparation method thereof. Background Art

[0002] In 2024, corn planting area reached 671 million mu (approximately 1.6 million hectares), accounting for 37.5% of the total grain planting area; corn production reached 294.92 million tons, approximately 42.0% of total grain production. Corn is my country's leading grain crop in terms of both planting area and overall yield. Corn can be grown in a variety of ecological zones, adapting to different planting seasons and soil conditions. During corn cultivation, scientific and rational fertilization is one of the most important measures for high-quality, high-yield, and efficient corn production.

[0003] For example, the Chinese invention disclosure with announcement number CN117263743A, published on December 22, 2023, discloses a special compound fertilizer for corn and its preparation method. A special compound fertilizer for corn, comprising the following raw materials in parts by weight: 15-20 parts of urea, 8-10 parts of ammonium sulfate, 20-30 parts of potassium sulfate, 5-10 parts of diammonium phosphate, 5-10 parts of negative potential powder, and 1-3 parts of a composite zinc additive; the composite zinc additive is a mixture of citric acid chelated zinc and amino acids; the mass ratio of the citric acid chelated zinc and amino acids is 1: (1-2). The plant height of corn obtained by applying this application is 235-236cm, and the maximum single ear amount, ear length, ear grain number and per mu yield are 0.256 kg, 22.49 cm, 510 grains and 608.4 kg respectively, which improves the growth and yield of corn plants, thereby improving the fertilizer utilization rate of the compound fertilizer.

[0004] The corn-specific fertilizers described above utilize additives to improve compound fertilizer utilization. However, while this can increase fertilizer utilization during use, the release rate of the fertilizer cannot be controlled, resulting in the fertilizer not being effective for a long time. Furthermore, the absorption of trace elements remains to be improved. The present invention provides a corn-specific slow-release compound fertilizer and a preparation method thereof to address these issues. Summary of the Invention

[0005] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a slow-release compound fertilizer specifically for corn and a preparation method thereof.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A slow-release compound fertilizer specifically for corn comprises the following raw materials in parts by weight: 30-40 parts of urea, 15-20 parts of ammonium sulfate, 20-25 parts of potassium sulfate, 15-25 parts of monoammonium phosphate, 2-3 parts of seaweed extract, 0.5-1.5 parts of polyaspartic acid, 0.5-1.5 parts of trace elements, and 0.5-1 part of a slow-release agent, wherein the slow-release agent comprises DMPP (3,4-dimethylpyrazole phosphate).

[0007] The slow-release agent DMPP in this application utilizes the principle of soil colloid adsorption of ammonium ions to control the conversion of ammonium nitrogen into nitrate nitrogen and achieve a stable supply of nitrogen. After application, it can reduce the leaching of nitrate nitrogen, the loss of denitrification and the emission of nitrogen oxides, and provide ammonium nitrogen and nitrate nitrogen at the same time according to crop needs, so as to improve the utilization rate of chemical fertilizers and promote the healthy growth of corn.

[0008] The special slow-release compound fertilizer for corn in the present application can be prepared by selecting 30-40 parts of urea, 15-20 parts of ammonium sulfate, 20-25 parts of potassium sulfate, 15-25 parts of monoammonium phosphate, 2-3 parts of seaweed extract, 0.5-1.5 parts of polyaspartic acid, 0.5-1.5 parts of trace elements, and 0.5-1 part of slow-release agent. Any value within the respective ranges can be selected, which can improve the fertilizer utilization rate of the special slow-release compound fertilizer for corn and control the release rate of the fertilizer.

[0009] Furthermore, a slow-release compound fertilizer specifically for corn comprises the following raw materials in parts by weight: 30-35 parts of urea, 15-20 parts of ammonium sulfate, 20-23 parts of potassium sulfate, 20-25 parts of monoammonium phosphate, 2-3 parts of seaweed extract, 0.5-1 part of polyaspartic acid, 0.5-1 part of trace elements, and 0.5-1 part of a slow-release agent.

[0010] Furthermore, a slow-release compound fertilizer specifically for corn comprises the following raw materials in parts by weight: 35 parts of urea, 18 parts of ammonium sulfate, 22 parts of potassium sulfate, 20 parts of monoammonium phosphate, 2.5 parts of seaweed extract, 1 part of polyaspartic acid, 1 part of trace elements, and 0.5 parts of slow-release agent.

[0011] Furthermore, the trace elements include zinc boron titanium citrate, wherein the zinc content is ≥8.5%, the boron content is ≥2.0%, and the titanium content is ≥4.0%; and the seaweed extract includes chitosan.

[0012] Furthermore, by weight, the nitrogen content of urea is 46%, the nitrogen content of ammonium sulfate is 21%, the potassium content of potassium sulfate is 52%, the nitrogen content of monoammonium phosphate is 12%, and the phosphorus content of monoammonium phosphate is 43.8%.

[0013] According to an embodiment of the present invention, the present invention also provides a method for preparing the above-mentioned slow-release compound fertilizer for corn, which comprises the following steps: S1: Initial mixing: 30-40 parts of urea, 15-20 parts of ammonium sulfate, 20-25 parts of potassium sulfate, and 15-25 parts of monoammonium phosphate are added into a stirring device and mixed at a stirring speed of 300 r / min for 60 minutes to obtain a primary mixed material; S2 Second Mixing: 2-3 parts of seaweed extract, 0.5-1.5 parts of polyaspartic acid, 0.5-1.5 parts of trace elements, and 0.5-1 part of sustained-release agent are put into a stirring device and mixed at a stirring speed of 200 r / min for 30 minutes to obtain a second mixed material; S3 final mixing: the primary mixed material of S1 and the secondary mixed material of S2 are put into the mixing equipment in proportion and mixed. The stirring speed is controlled at 300 r / min and stirred for 60 min to obtain the final mixed material; S4 granulation: The final mixed material of step S3 is fed into a rotary drum granulator. Under the action of the rotary drum, the raw materials interact with the added medium such as water or steam to form granules. The granulation temperature is controlled at 40-50°C, the rotary drum speed is generally 10r / min, and the granulation time is 15 minutes; S5 Drying: The compound fertilizer granules after S4 granulation are sent to the drying equipment for drying to remove moisture from the granules. The drying temperature is generally controlled at 90~110℃. The drying time is determined by the granule size and initial moisture content, and is generally 30~60 minutes. S6 screening: The compound fertilizer particles dried in S5 are sent to a vibrating screening machine for screening to select qualified fertilizer particles of 3-4 mm; S7 cooling: The qualified compound fertilizer granules screened in S6 are passed through a fluidized bed cooler or cooled naturally to 40-50°C to obtain corn-specific slow-release compound fertilizer granules.

[0014] Furthermore, in the screening step S6, sieves with apertures of 1-3 mm and 4-8 mm are used for screening to screen out qualified fertilizer particles of 3-4 mm, particles <2.8 mm are transported as return material to the granulator for re-granulation, and particles >4 mm are transported as return material to the mixing equipment for mixing.

[0015] Compared with the prior art, the present invention provides a slow-release compound fertilizer specifically for corn and a preparation method thereof, which has the following beneficial effects: 1. The present invention discloses a slow-release compound fertilizer specifically for corn and a method for preparing the same. Utilizing the principle of ammonium ion adsorption by soil colloids, the nitrification inhibitor DMPP is added to the compound fertilizer to control the conversion of ammonium nitrogen to nitrate nitrogen, providing both ammonium nitrogen and nitrate nitrogen according to corn demand. This achieves a stable nitrogen supply and utilizes the enhanced absorption of ammonium nitrogen and nitrate nitrogen by corn to achieve a synergistic yield-increasing benefit, promoting healthy corn growth and increasing corn yield while reducing nitrogen usage. Furthermore, the invention reduces nitrate nitrogen leaching, denitrification losses, and nitrogen oxide emissions, thereby improving fertilizer utilization, conserving resources, protecting the environment, and promoting agricultural development.

[0016] 2. The present invention discloses a slow-release compound fertilizer specifically for corn and its preparation method. By adding seaweed extract to the compound fertilizer, the fertilizer stimulates corn root growth, promotes root branching, increases root surface area, and significantly improves root absorption efficiency. By adding trace elements such as zinc citrate, boron, and titanium to the compound fertilizer, the fertilizer facilitates zinc absorption by corn, making it easier for the corn roots to absorb zinc and providing long-term zinc nutrition for corn. This can further improve corn's absorption and utilization of zinc in the compound fertilizer, allowing it to participate in various enzymatic reactions in corn and promote overall corn growth. By adding polyaspartic acid to the compound fertilizer, the fertilizer can stimulate root cell division and elongation, further increasing the number and length of roots and enhancing corn's resistance to adverse conditions such as drought and cold. These effects collectively promote the robust growth of corn plants and effectively increase corn yield per mu and grain quality. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below with reference to the embodiments.

[0018] The following raw materials in this application are all commercially available products. They are provided for the purpose of ensuring full disclosure of the raw materials in this application and should not be construed as limiting the sources of the raw materials. Specifically, they are: urea, total nitrogen content ≥46%; ammonium sulfate, 100 mesh particle size, active substance content 80%; potassium sulfate, 80 mesh particle size; monoammonium phosphate, active phosphorus content ≥44%; chitosan, active substance content ≥90%; potassium polyaspartate, active substance content ≥20%; zinc boron titanium citrate, zinc content ≥8.5%, boron content ≥2.0%, titanium content ≥4.0%; DMMP (3,4-dimethylpyrazole phosphate), 300 mesh particle size.

[0019] Example 1: The slow-release compound fertilizer for corn in Example 1 is prepared by the following preparation method: According to the dosage in Table 1, the raw materials are sequentially subjected to primary mixing, secondary mixing, final mixing, granulation, drying, screening, cooling, and packaging to obtain the slow-release compound fertilizer for corn.

[0020] Example 2-17: The preparation methods of the slow-release compound fertilizers for corn in Examples 2-17 are the same as those in Example 1, except that the dosages of the raw materials are different. See Table 1 for details.

[0021] Table 1 The dosage of each raw material of the slow-release compound fertilizer for corn in the examples and comparative examples (kg)

[0022] The preparation method of the slow-release compound fertilizer in the above-mentioned Examples 1-17 and Comparative Examples 1-4 comprises the following steps: S1: Primary mixing: urea, ammonium sulfate, potassium sulfate, and monoammonium phosphate are added into a stirring device according to a weight ratio and mixed at a stirring speed of 300 r / min for 60 min to obtain a primary mixed material; S2 Second Mixing: Add seaweed extract, polyaspartic acid, trace elements, and sustained-release agent into a stirring device according to weight proportion and mix at a stirring speed of 200 r / min for 30 min to obtain a second mixed material; S3 final mixing: the primary mixed material of S1 and the secondary mixed material of S2 are put into the mixing equipment in proportion and mixed. The stirring speed is controlled at 300 r / min and stirred for 60 min to obtain the final mixed material; S4 granulation: The final mixed material of step S3 is fed into a rotary drum granulator. Under the action of the rotary drum, the raw materials interact with the added medium such as water or steam to form granules. The granulation temperature is controlled at 40-50°C, the rotary drum speed is generally 10r / min, and the granulation time is 15 minutes; S5 Drying: The compound fertilizer granules after S4 granulation are sent to the drying equipment for drying to remove moisture from the granules. The drying temperature is generally controlled at 90~110℃. The drying time is determined by the granule size and initial moisture content, and is generally 30~60 minutes. S6 screening: The compound fertilizer granules dried in S5 are sent to a vibrating screening machine for screening. Screens with apertures of 1-3 mm and 4-8 mm are used to screen out qualified fertilizer granules of 3-4 mm. S7 cooling: The qualified compound fertilizer granules screened in S6 are passed through a fluidized bed cooler or cooled naturally to 40-50°C to obtain corn-specific slow-release compound fertilizer granules.

[0023] The slow-release compound fertilizer for corn prepared in the above Examples 1-17 and Comparative Examples 1-4 was used for fertilization experiments and comparisons on corn. A flat and uniformly fertilized plot was selected. The experimental method was a comparison of equal-area field fertilization. The experiment adopted a randomized block design. A total of 21 treatments were set up in the experiment (i.e., Examples 1-17 and Comparative Examples 1-4), 3 replicates for each treatment, and a total of 63 plots. The fertilizer application rate was 50 kg / mu. The plot was 15 cm long and 5 cm wide. Protective rows were set around the plot. To prevent water and fertilizer from flowing between plots, ridges were made between the experimental plots and the plots, and between the plots and the protective rows, and film was covered. Each plot was fertilized separately and managed normally.

[0024] Table 2 Fertilization test results of slow-release compound fertilizer for corn in various embodiments and comparative examples

[0025] Table 2 shows the fertilization test results of the slow-release compound fertilizer for corn in Examples 1-17 and Comparative Examples 1-4. As can be seen from Table 2, by comparing the experimental results of Examples 1-3, the ear length, ear thickness, single ear weight, number of grains per ear, bald tip length and per mu yield of Example 2 are all better than those of Examples 1 and 3, indicating that the urea content in the slow-release compound fertilizer is more suitable at 35 components; by comparing the experimental results of Example 2 and Examples 4-5, the ear length, ear thickness, single ear weight, number of grains per ear, bald tip length and per mu yield of Example 2 are all better than those of Examples 4 and 5, indicating that the ammonium sulfate content in the slow-release compound fertilizer is more suitable at 18 components. Suitable; Comparing the experimental results of Example 2 with those of Example 6-7, the ear length, ear thickness, single ear weight, number of grains per ear, bald tip length and per mu yield of Example 2 are all better than those of Examples 6 and 7, indicating that the dosage of potassium sulfate in the slow-release compound fertilizer is 22 components, which is more suitable; Comparing the experimental results of Example 2 with those of Example 8-9, the ear length, ear thickness, single ear weight, number of grains per ear, bald tip length and per mu yield of Example 2 are all better than those of Examples 8 and 9, indicating that the dosage of 20 components in the slow-release compound fertilizer is more suitable. Since the ear length, ear thickness, single ear weight, number of grains per ear, bald tip length and per mu yield of Example 2 are all better than those of Example 1 and Examples 3-9, it is indicated that the dosage of urea, ammonium sulfate, potassium sulfate and monoammonium phosphate in the slow-release compound fertilizer is 35, 18, 22 and 22 components, respectively, which is more suitable.

[0026] The experimental results of Example 2 were compared with those of Example 10-11 and Comparative Example 4. The ear length, ear thickness, single ear weight, number of grains per ear, bald tip length and yield per mu of Example 2 were all better than those of Examples 10 and 11, and better than those of Comparative Example 4. On the one hand, it was shown that the addition of seaweed extract in the slow-release compound fertilizer improved the root absorption efficiency and promoted the growth of corn. On the other hand, it was shown that the dosage of seaweed extract in the slow-release compound fertilizer was 2.5 components, which was more appropriate. The experimental results of Example 2 were compared with those of Example 12-13 and Comparative Example 3. The ear length, ear thickness, single ear weight, number of grains per ear, bald tip length and yield per mu of Example 2 were all better than those of Examples 12 and 13, and better than those of Comparative Example 3. On the one hand, it was shown that the addition of polyaspartic acid in the slow-release compound fertilizer was beneficial to improving the root absorption efficiency and promoting the growth of corn. On the other hand, it was shown that the dosage of polyaspartic acid in the slow-release compound fertilizer was 2.5 components, which was more appropriate. The experimental results of Example 2 are compared. The ear length, ear thickness, single ear weight, number of grains per ear, bald tip length and yield per mu of Example 2 are better than those of Examples 14 and 15, and are all better than those of Comparative Example 2. On the one hand, it is explained that the addition of zinc boron titanium citrate in the slow-release compound fertilizer is more conducive to the absorption of zinc by corn, is easily absorbed by the corn root system, and improves the long-term zinc nutrition for corn, thereby promoting the overall growth of corn; on the other hand, it is explained that the dosage of zinc boron titanium citrate in the slow-release compound fertilizer is 1 component, which is more appropriate; the experimental results of Example 2 are compared with those of Examples 16-17 and Comparative Example 1. The ear length, ear thickness, single ear weight, number of grains per ear, bald tip length and yield per mu of Example 2 are all better than those of Examples 16 and 17, and are all better than those of Comparative Example 1. On the one hand, it is explained that the addition of DMPP in the slow-release compound fertilizer promotes the enhanced effect of corn absorbing ammonium nitrogen and nitrate nitrogen, obtains the synergistic yield-increasing benefit, and promotes the healthy growth of corn; on the other hand, it is explained that the dosage of DMPP in the slow-release compound fertilizer is 0.5 components, which is more appropriate.

[0027] As can be seen from Table 2, the ear length, ear diameter, single ear weight, number of grains per ear, bald tip length and yield per mu of Example 2 are all better than those of Example 1, Examples 3-17 and Comparative Examples 1-4. On the one hand, it shows that the dosages of urea, ammonium sulfate, potassium sulfate, monoammonium phosphate, seaweed extract, polyaspartic acid, zinc boron titanium citrate, and DMPP in the slow-release compound fertilizer are 35, 18, 22, 22, 2.5, 1, 1, and 0.5, respectively, which are more suitable. On the other hand, it shows that the slow-release agent and other additives in Example 2 achieve the yield-increasing benefit of slow release and synergistic effect on corn.

[0028] In summary, the slow-release fertilizer for corn provided by the embodiments of the present invention has a reasonable nutrient distribution ratio and is rich in various nutrients. It can not only meet the absorption amount of various elements by corn, but also achieve a stable supply of nitrogen through the slow-release agent. By adding seaweed extract, trace elements and polyaspartic acid, it promotes the absorption of nutrients by corn and improves the utilization rate of fertilizer.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A slow-release compound fertilizer for corn, characterized by: The invention comprises the following raw materials in parts by weight: 30-40 parts of urea, 15-20 parts of ammonium sulfate, 20-25 parts of potassium sulfate, 15-25 parts of monoammonium phosphate, 2-3 parts of seaweed extract, 0.5-1.5 parts of polyaspartic acid, 0.5-1.5 parts of trace elements, and 0.5-1 part of a sustained-release agent, wherein the sustained-release agent comprises DMPP (3,4-dimethylpyrazole phosphate).

2. The slow-release compound fertilizer for corn according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 30-35 parts of urea, 15-20 parts of ammonium sulfate, 20-23 parts of potassium sulfate, 20-25 parts of monoammonium phosphate, 2-3 parts of seaweed extract, 0.5-1 part of polyaspartic acid, 0.5-1 part of trace elements and 0.5-1 part of sustained-release agent.

3. The slow-release compound fertilizer for corn according to claim 1, characterized in that: The preparation comprises the following raw materials in parts by weight: 35 parts of urea, 18 parts of ammonium sulfate, 22 parts of potassium sulfate, 20 parts of monoammonium phosphate, 2.5 parts of seaweed extract, 1 part of polyaspartic acid, 1 part of trace elements and 0.5 part of a sustained-release agent.

4. The slow-release compound fertilizer for corn according to claim 1, characterized in that: Trace elements include zinc boron titanium citrate, wherein the zinc content is ≥8.5%, the boron content is ≥2.0%, and the titanium content is ≥4.0%; the seaweed extract includes chitosan.

5. The slow-release compound fertilizer for corn according to claim 1, characterized in that: By weight, urea contains 46% nitrogen, ammonium sulfate contains 21% nitrogen, potassium sulfate contains 52% potassium, monoammonium phosphate contains 12% nitrogen, and monoammonium phosphate contains 43.8% phosphorus.

6. The method for preparing a slow-release compound fertilizer for corn according to any one of claims 1 to 5, characterized in that: It includes the following steps: S1: Initial mixing: 30-40 parts of urea, 15-20 parts of ammonium sulfate, 20-25 parts of potassium sulfate, and 15-25 parts of monoammonium phosphate are added into a stirring device and mixed at a stirring speed of 300 r / min for 60 minutes to obtain a primary mixed material; S2 Second Mixing: 2-3 parts of seaweed extract, 0.5-1.5 parts of polyaspartic acid, 0.5-1.5 parts of trace elements, and 0.5-1 part of sustained-release agent are put into a stirring device and mixed at a stirring speed of 200 r / min for 30 minutes to obtain a second mixed material; S3 final mixing: the primary mixed material of S1 and the secondary mixed material of S2 are put into the mixing equipment in proportion and mixed. The stirring speed is controlled at 300 r / min and stirred for 60 min to obtain the final mixed material; S4 granulation: The final mixed material of step S3 is fed into a drum granulator. Under the action of the rotation of the drum, the raw materials interact with the added medium such as water or steam to form granules. The granulation temperature is controlled at 40-50°C, the drum speed is generally 10 r / min, and the granulation time is 15 minutes; S5 Drying: The compound fertilizer granules after S4 granulation are sent to the drying equipment for drying to remove moisture from the granules. The drying temperature is generally controlled at 90~110℃. The drying time depends on the granule size and initial moisture content, and is generally 30~60 minutes. S6 screening: The compound fertilizer particles dried in S5 are sent to a vibrating screening machine for screening to select qualified fertilizer particles of 3-4 mm; S7 cooling: The qualified compound fertilizer granules screened in S6 are passed through a fluidized bed cooler or cooled naturally to 40-50°C to obtain corn-specific slow-release compound fertilizer granules.

7. The method for preparing a slow-release compound fertilizer specifically for corn according to claim 6, characterized in that: In the screening step S6, sieves with apertures of 1-3 mm and 4-8 mm are used for screening to screen out qualified fertilizer particles of 3-4 mm. Particles <2.8 mm are transported as return material to the granulator for re-granulation, and particles >4 mm are transported as return material to the mixing equipment for mixing.

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