Special full-nutrient compound fertilizer for corn and preparation method of special full-nutrient compound fertilizer

Abstract

The invention discloses a special full-nutrient compound fertilizer for corn and a preparation method thereof, relates to the technical field of compound fertilizers, and particularly belongs to the patent classification number C05G3 / 00. The preparation method comprises the following steps: weighing the slow-release urea composite particles, the diammonium phosphate, the potassium chloride, the zinc sulfate, the borax, the monosodium glutamate leftovers, the composite bacillus, the octanoic acid diethylaminoethanol ester and the sodium tetramethyl glutarate, pouring into a stirrer, and uniformly stirring and mixing to obtain the full-nutrient compound fertilizer special for the corn. The compound fertilizer can regulate and control the release speed of nitrogen elements, so that nitrogen elements are supplied for corn production for a long time, and waste of nitrogen fertilizers is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of compound fertilizers, specifically belonging to the patent classification number C05G3 / 00, and particularly to a corn-specific all-nutrient compound fertilizer and its preparation method. Background Art

[0002] With the rapid advancement of agricultural modernization, corn, as an important food and feed crop widely planted globally, its yield and quality have received increasing attention. The growth of corn goes through multiple critical stages, and the nutrient requirements at each stage vary significantly. From the initial demand for nitrogen in the seedling stage to promote the growth of stems and leaves, to the large intake of various nutrients such as nitrogen, phosphorus, and potassium in the ear stage to ensure ear development, and then to the dependence on various medium and trace elements in the flowering and grain-filling stage to improve the plumpness of grains. Only by meeting these complex and detailed nutritional requirements can high and excellent yields of corn be achieved.

[0003] In this context, corn all-nutrient compound fertilizers have emerged. Such fertilizers integrate large elements such as nitrogen, phosphorus, and potassium, medium elements, and trace elements. Through scientific proportioning, they strive to provide comprehensive nutritional support for corn growth, make up for the deficiencies of single fertilizers in nutrients, simplify the fertilization process, improve fertilization efficiency, and reduce planting costs.

[0004] However, there are still prominent problems in the actual application of current corn all-nutrient compound fertilizers. Among them, the too-fast release of nitrogen element has become a key factor restricting the fertilizer effect and corn growth. Nitrogen element plays a core role in the growth process of corn. It is a component of important substances such as proteins and chlorophyll, and is of great significance to the photosynthesis and plant morphology construction of corn. But in most existing products, nitrogen is rapidly released in the soil. In the early stage of corn growth, the roots of seedlings are tender and their absorption capacity is limited. Facing the high concentration of nitrogen in the soil in a short time, the root cells will experience reverse water loss due to osmotic pressure imbalance. This not only causes the growth of corn plants to stagnate, become short and yellow, and even wither and die severely in serious cases, greatly affecting corn growth. Moreover, the too-fast released nitrogen cannot be continuously and stably supplied throughout the growth period of corn. A large amount of unabsorbed nitrogen is leached away with water or volatilized into the atmosphere, resulting in waste of resources and causing a series of environmental pollution problems such as water eutrophication, soil compaction, and increased greenhouse gas emissions, seriously violating the concept of sustainable agricultural development. Summary of the Invention

[0005] The purpose of the present invention is to provide a corn-specific all-nutrient compound fertilizer and its preparation method to solve the technical problem of the too-fast release of nitrogen element in the fertilizer proposed in the above background art. The compound fertilizer of the present invention can regulate the release rate of nitrogen element, thereby continuously supplying nitrogen element for corn production in the long term and avoiding waste of nitrogen fertilizer.

[0006] To achieve the above object, the present invention provides the following technical solutions: A corn-specific all-nutrient compound fertilizer, comprising the following components by weight: 40 - 50 parts of slow-release urea composite granules, 20 - 25 parts of diammonium phosphate, 15 - 20 parts of potassium chloride, 1.5 - 2.5 parts of zinc sulfate, 1 - 1.5 parts of borax, 5 - 10 parts of monosodium glutamate waste, 0.5 - 1 part of compound Bacillus, 0.1 - 0.3 part of diethylaminoethyl caprylate, and 0.1 - 0.3 part of sodium tetramethylglutarate.

[0007] In the technical solution of the present invention, slow-release urea composite granules are used to provide long-acting nitrogen, diammonium phosphate is used to supplement phosphorus and adjust soil pH, and potassium chloride is used to enhance stress resistance; zinc sulfate and borax are supplemented to accurately supply zinc and boron elements to solve the problems of nutrient deficiency such as "white seedling disease" and "empty ears" in corn. Adding monosodium glutamate waste can improve soil organic matter, and compound Bacillus can significantly improve fertilizer efficiency and soil health through synergistic effects. Diethylaminoethyl caprylate is used as a growth regulator to promote the transport of photosynthetic products, and sodium tetramethylglutarate activates enzyme activity and buffers the pH of the fertilizer. The overall formula takes into account the nutrient requirements of the whole growth period of corn and soil health, reduces nitrogen volatilization through slow-release technology, and reduces the amount of chemical fertilizer through microbial synergistic effects, thereby improving fertilizer utilization rate and enhancing stress resistance.

[0008] Preferably, the compound Bacillus consists of Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus.

[0009] Preferably, the viable count CFU ratio of Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus is 4:3:3.

[0010] Preferably, the preparation method of the slow-release urea composite granules comprises the following steps: S1. Add polyvinyl alcohol and humic acid to deionized water, heat and stir to dissolve to obtain an inner coating solution; S2. Spray the inner coating solution on the surface of large granular urea to obtain large granular urea coated granules; S3. Add the large granular urea coated granules and polypeptide urea to a drum equipment for coating treatment, so that the polypeptide urea is wrapped on the surface of the large granular urea coated granules to obtain composite granules; S4. Add humic acid and nano-silica to deionized water, heat and stir evenly to obtain an outer coating solution; S5. Spray the outer coating solution on the surface of the composite granules, and after drying, obtain slow-release urea composite granules.

[0011] In the technical solution of the present invention, according to the urgent need for nitrogen in the early stage of corn, the good water solubility of polypeptide urea enables it to quickly release nitrogen, meet the urgent demand for nitrogen during the rapid growth of corn seedlings, and promote the development of corn roots and leaves. Although corn urgently needs nitrogen in the early stage, the too-fast release of polypeptide urea is likely to cause nutrient loss. The outer coating can appropriately buffer the release rate of polypeptide urea, so that it can meet the urgent demand for nitrogen by corn in the early stage and avoid waste caused by excessive release. With the action of factors such as moisture and microorganisms in the soil, the outer coating gradually degrades, ensuring that the release rate of polypeptide urea precisely matches the growth rhythm of corn in the early stage and continuously and stably supplies nitrogen. The outer coating is composed of humic acid and nano-silica. Nano-silica has a large specific surface area and abundant silanol groups, which can undergo a condensation reaction with carboxyl groups and phenolic hydroxyl groups in humic acid. The two are closely connected and jointly build a complex network structure. Nano-silica is like a fine filter, effectively refining the pore size of the humic acid coating. When the composite particles are applied to the soil, the smaller pore size forms a strong hindrance to the penetration of water. The release of nitrogen depends on the dissolution of urea by water. The rate of water entry is slowed down, and the release rate of nitrogen from the inside of the particles to the outside is greatly reduced, achieving a slow-release effect.

[0012] In the middle and late stages of corn growth, the nitrogen released in the early stage is gradually consumed. At this time, the large-particle urea-coated particles begin to play a role. Due to the barrier of the inner coating and its relatively slow release rate, the release rate of large-particle urea is relatively slow and stable. Under the combined action of factors such as soil microorganisms, moisture, and temperature, the inner coating gradually degrades, and the large-particle urea slowly dissolves and releases nitrogen, continuously providing nutrients for corn growth. The inner coating is composed of polyvinyl alcohol and humic acid. The polyvinyl alcohol molecule is rich in hydroxyl groups. These hydroxyl groups can not only interact with each other through hydrogen bonds but also form hydrogen bonds with active groups such as carboxyl groups and phenolic hydroxyl groups in humic acid. Based on these intermolecular forces, polyvinyl alcohol and humic acid are tightly combined to build a continuous and dense film on the surface of the large-particle urea, significantly slowing down the hydrolysis process of urea and achieving a slow-release effect.

[0013] The present invention realizes the coordinated cooperation of the inner and outer two-layer coating films, releases nitrogen in stages and differentially, precisely fits the fertilizer demand law of different growth stages of corn, greatly improves the fertilizer utilization rate, reduces the loss and waste of nitrogen, avoids the burning of corn seedlings and nitrogen loss caused by the large amount of nitrogen released by traditional urea in a short period, greatly improves the utilization rate of nitrogen elements in the fertilizer, reduces the amount and frequency of fertilization, and lowers the production cost.

[0014] Preferably, in the step S1, the mass ratio of polyvinyl alcohol to humic acid is 3:1 - 2.

[0015] Preferably, the mass ratio of the large-particle urea-coated particles to the polypeptide urea is 1:2 - 3.

[0016] Preferably, the mass ratio of humic acid to nano-silica is 1:0.2 - 0.5.

[0017] In the technical solution of the present invention, as described above, silica can refine the pore size of the humic acid coating, thereby achieving an excellent slow-release effect on nitrogen. Through experiments, the present invention found that to achieve a good slow-release effect on nitrogen for the outer coating, a sufficient amount of nano-silica must be proportioned. Therefore, the present invention controls the mass ratio of humic acid to nano-silica to be less than 1:0.2. However, the research team of the present invention unexpectedly found that when the nano-silica is added to a certain amount, that is, when the mass ratio of humic acid to nano-silica is less than 1:0.5, the slow-release effect of the outer coating on nitrogen suddenly drops significantly, which was not expected by the research team of the present invention. After research, it was found that this is because excessive addition of nano-silica will cause a decrease in the mechanical strength of the outer coating, and during the subsequent drying process, a large number of cracks and peeling occur on the outer coating, thereby causing the outer coating to lose its slow-release effect on nitrogen and resulting in a large release of nitrogen.

[0018] A preparation method of a special all-nutrient compound fertilizer for corn, comprising the following steps: Weigh slow-release urea composite granules, diammonium phosphate, potassium chloride, zinc sulfate, borax, monosodium glutamate waste, compound bacillus spores, diethylaminoethanol octanoate, and sodium tetramethylglutarate, pour them into a blender, and stir and mix evenly to obtain a special all-nutrient compound fertilizer for corn.

[0019] Compared with the prior art, the beneficial effects of the present invention are: 1. According to the fertilizer requirements of different growth stages of corn, in the early stage, the nitrogen release of polypeptide urea is rapid and buffered by the outer coating, meeting the urgent demand for nitrogen during the seedling stage; in the middle and late stages, through the barrier of the inner coating, the large-grained urea slowly and steadily releases nitrogen. The inner and outer coatings cooperate synergistically to supply nitrogen in stages and differentially, precisely fitting the fertilizer requirement law of corn, greatly improving the fertilizer utilization rate, reducing nitrogen loss and waste, and avoiding the phenomenon of seedling burning; 2. Control the mass ratio range of humic acid to nano-silica, reasonably control the addition amount of nano-silica, avoid the decrease in the mechanical strength of the outer coating and cracking and peeling caused by excessive amount, ensure a good slow-release effect of the outer coating on nitrogen, and guarantee the overall performance of the fertilizer. Specific Embodiments

[0020] The technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Example 1 A special all - nutrient compound fertilizer for corn, comprising the following components by weight: 48 parts of slow - release urea composite granules, 24 parts of diammonium phosphate, 19 parts of potassium chloride, 2.3 parts of zinc sulfate, 1.4 parts of borax, 9 parts of monosodium glutamate waste, 0.9 part of compound Bacillus (Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus are proportioned according to the viable bacteria count of 4:3:3), 0.25 part of diethylaminoethanol octanoate, 0.25 part of sodium tetramethylglutamate.

[0022] Preparation of slow - release urea composite granules: S1. Pour 150 g of polyvinyl alcohol and 90 g of humic acid into a glass beaker containing 500 mL of deionized water, place it in a constant - temperature water bath at 80 °C, stir at a speed of 200 r / min for 1 h until completely dissolved to obtain an inner - layer coating solution; S2. Connect the spray gun to the compressed air source, adjust the spraying pressure to 0.3 MPa, fix the spray gun on the bracket, adjust the distance between the spray gun and the container for large - granule urea below to 20 cm, turn on the spray gun, and evenly spray the inner - layer coating solution on the surface of 80 g of large - granule urea. Continuously turn the large - granule urea during the spraying process to ensure uniform coating, and obtain large - granule urea coated granules; S3. Pour 80 g of large - granule urea coated granules and 220 g of polypeptide urea into a drum equipment, set the drum rotation speed to 50 r / min, and perform a coating treatment for 20 min. Through the observation window of the drum equipment, check the mixing situation of the materials to make the polypeptide urea evenly wrap on the surface of the large - granule urea coated granules to obtain composite granules; S4. Pour 200 g of humic acid and 80 g of nano - silica into a glass beaker containing 500 mL of deionized water, place it in a constant - temperature water bath at 80 °C, and stir at a speed of 200 r / min for 1 h to obtain an outer - layer coating solution; S5. Connect the spray gun to the compressed air source again, adjust the spraying pressure to 0.3 MPa, adjust the distance between the spray gun and the container for composite granules below to 20 cm, turn on the spray gun, and evenly spray the outer - layer coating solution on the surface of the composite granules. Continuously turn the composite granules during the spraying process to ensure uniform coating. After spraying, transfer the granules to a drying oven and dry at 60 °C for 2 h to obtain slow - release urea composite granules.

[0023] A preparation method of a special all - nutrient compound fertilizer for corn, comprising the following steps: Weigh the slow - release urea composite granules, diammonium phosphate, potassium chloride, zinc sulfate, borax, monosodium glutamate waste, compound Bacillus, diethylaminoethanol octanoate, and sodium tetramethylglutamate, pour them into a mixer, set the stirring speed to 100 r / min, and stir for 30 min to obtain a special all - nutrient compound fertilizer for corn.

[0024] Example 2 A special all - nutrient compound fertilizer for corn, comprising the following components by weight: 42 parts of slow - release urea composite granules, 21 parts of diammonium phosphate, 16 parts of potassium chloride, 1.8 parts of zinc sulfate, 1.2 parts of borax, 6 parts of monosodium glutamate waste, 0.6 part of compound Bacillus (Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus are proportioned according to the viable count of 4:3:3), 0.15 part of diethylaminoethanol octanoate, 0.15 part of sodium tetramethylglutamate.

[0025] Preparation of slow - release urea composite granules: S1. Pour 150 g of polyvinyl alcohol and 60 g of humic acid into a glass beaker containing 500 mL of deionized water, place it in a constant - temperature water bath at 80 °C, stir at a speed of 200 r / min for 1 h until completely dissolved to obtain an inner - layer coating solution; S2. Connect the spray gun to a compressed air source, adjust the spraying pressure to 0.3 MPa, fix the spray gun on a bracket, adjust the distance between the spray gun and the container for large - granule urea below to 20 cm, turn on the spray gun, and evenly spray the inner - layer coating solution on the surface of 80 g of large - granule urea. Continuously turn the large - granule urea during the spraying process to ensure uniform coating, and obtain large - granule urea coated granules; S3. Pour 80 g of large - granule urea coated granules and 180 g of polypeptide urea into a drum equipment, set the drum rotation speed to 50 r / min, and perform a coating treatment for 20 min. Through the observation window of the drum equipment, check the mixing situation of the materials to make the polypeptide urea evenly wrap on the surface of the large - granule urea coated granules to obtain composite granules; S4. Pour 200 g of humic acid and 50 g of nano - silicon dioxide weighed into a glass beaker containing 500 mL of deionized water, place it in a constant - temperature water bath at 80 °C, and stir at a speed of 200 r / min for 1 h to obtain an outer - layer coating solution; S5. Connect the spray gun to the compressed air source again, adjust the spraying pressure to 0.3 MPa, adjust the distance between the spray gun and the container for composite granules below to 20 cm, turn on the spray gun, and evenly spray the outer - layer coating solution on the surface of the composite granules. Continuously turn the composite granules during the spraying process to ensure uniform coating. After spraying, transfer the granules to a drying oven and dry at 60 °C for 2 h to obtain slow - release urea composite granules.

[0026] A preparation method of a special all - nutrient compound fertilizer for corn, comprising the following steps: Weigh the slow - release urea composite granules, diammonium phosphate, potassium chloride, zinc sulfate, borax, monosodium glutamate waste, compound Bacillus, diethylaminoethanol octanoate, and sodium tetramethylglutamate, pour them into a blender, set the stirring speed to 100 r / min, and stir for 30 min to obtain a special all - nutrient compound fertilizer for corn.

[0027] Example 3 A special all - nutrient compound fertilizer for corn, comprising the following components by weight: 45 parts of slow - release urea composite granules, 23 parts of diammonium phosphate, 17 parts of potassium chloride, 2 parts of zinc sulfate, 1.3 parts of borax, 8 parts of monosodium glutamate waste, 0.7 part of compound Bacillus (Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus are proportioned according to the viable bacteria count of 4:3:3), 0.2 part of diethylaminoethanol octanoate, 0.2 part of sodium tetramethylglutamate.

[0028] Preparation of slow - release urea composite granules: S1. Pour 150 g of polyvinyl alcohol and 80 g of humic acid into a glass beaker containing 500 mL of deionized water, place it in a constant temperature water bath at 80 °C, stir at a speed of 200 r / min for 1 h until completely dissolved to obtain an inner coating solution; S2. Connect the spray gun to a compressed air source, adjust the spraying pressure to 0.3 MPa, fix the spray gun on a bracket, adjust the distance between the spray gun and the container for large - particle urea below to 20 cm, turn on the spray gun, and evenly spray the inner coating solution on the surface of 80 g of large - particle urea. Continuously stir the large - particle urea during the spraying process to ensure uniform coating, and obtain large - particle urea coated granules; S3. Pour 80 g of large - particle urea coated granules and 190 g of polypeptide urea into a drum equipment, set the drum rotation speed to 50 r / min, and perform a coating treatment for 20 min. Through the observation window of the drum equipment, check the mixing situation of the materials to make the polypeptide urea evenly wrap on the surface of the large - particle urea coated granules to obtain composite granules; S4. Pour 200 g of humic acid and 60 g of nano - silica into a glass beaker containing 500 mL of deionized water, place it in a constant temperature water bath at 80 °C, and stir at a speed of 200 r / min for 1 h to obtain an outer coating solution; S5. Connect the spray gun to the compressed air source again, adjust the spraying pressure to 0.3 MPa, adjust the distance between the spray gun and the container for composite granules below to 20 cm, turn on the spray gun, and evenly spray the outer coating solution on the surface of the composite granules. Continuously stir the composite granules during the spraying process to ensure uniform coating. After spraying, transfer the granules to a drying oven and dry at 60 °C for 2 h to obtain slow - release urea composite granules.

[0029] A preparation method of a special all - nutrient compound fertilizer for corn, comprising the following steps: Weigh the slow-release urea composite granules, diammonium phosphate, potassium chloride, zinc sulfate, borax, monosodium glutamate waste, compound Bacillus, diethylaminoethanol octanoate, and sodium tetramethylglutaconate, pour them into a blender, set the stirring speed to 100 r / min, and stir for 30 min to obtain a complete-nutrition compound fertilizer for corn.

[0030] Example 4 A complete-nutrition compound fertilizer for corn, comprising the following components by weight: 50 parts of slow-release urea composite granules, 25 parts of diammonium phosphate, 20 parts of potassium chloride, 2.5 parts of zinc sulfate, 1.5 parts of borax, 10 parts of monosodium glutamate waste, 1 part of compound Bacillus (Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus are proportioned according to the viable count of 4:3:3), 0.3 part of diethylaminoethanol octanoate, and 0.3 part of sodium tetramethylglutaconate.

[0031] Preparation of slow-release urea composite granules: S1. Pour 150 g of polyvinyl alcohol and 100 g of humic acid into a glass beaker containing 500 mL of deionized water, place it in a constant temperature water bath at 80 °C, and stir at a speed of 200 r / min for 1 h until completely dissolved to obtain an inner coating solution. S2. Connect the spray gun to the compressed air source, adjust the spraying pressure to 0.3 MPa, fix the spray gun on the bracket, adjust the distance between the spray gun and the container for large granular urea below to 20 cm, turn on the spray gun, and evenly spray the inner coating solution on the surface of 80 g of large granular urea. Continuously turn the large granular urea during the spraying process to ensure uniform coating and obtain large granular urea coated particles. S3. Pour 80 g of large granular urea coated particles and 240 g of polypeptide urea into a drum equipment, set the drum speed to 50 r / min, and perform a coating treatment for 20 min. Through the observation window of the drum equipment, check the mixing situation of the materials to make the polypeptide urea evenly wrap on the surface of the large granular urea coated particles and obtain composite granules. S4. Pour the weighed 200 g of humic acid and 100 g of nano-silica into a glass beaker containing 500 mL of deionized water, place it in a constant temperature water bath at 80 °C, and stir at a speed of 200 r / min for 1 h to obtain an outer coating solution. S5. Connect the spray gun to the compressed air source again, adjust the spraying pressure to 0.3 MPa, adjust the distance between the spray gun and the container for composite granules below to 20 cm, turn on the spray gun, and evenly spray the outer coating solution on the surface of the composite granules. Continuously turn the composite granules during the spraying process to ensure uniform coating. After spraying, transfer the granules to a drying oven and dry at 60 °C for 2 h to obtain slow-release urea composite granules.

[0032] A preparation method of a complete-nutrition compound fertilizer for corn, comprising the following steps: Weigh the slow-release urea composite granules, diammonium phosphate, potassium chloride, zinc sulfate, borax, monosodium glutamate waste, compound Bacillus spores, diethylaminoethanol octanoate, and sodium tetramethylglutarate, pour them into a blender, set the stirring speed to 100 r / min, and stir for 30 min to obtain a full-nutrient compound fertilizer for corn.

[0033] Example 5 A full-nutrient compound fertilizer for corn, comprising the following components by weight: 40 parts of slow-release urea composite granules, 20 parts of diammonium phosphate, 15 parts of potassium chloride, 1.5 parts of zinc sulfate, 1 part of borax, 5 parts of monosodium glutamate waste, 0.5 part of compound Bacillus spores (Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus are proportioned according to the viable count of 4:3:3), 0.1 part of diethylaminoethanol octanoate, and 0.1 part of sodium tetramethylglutarate.

[0034] Preparation of slow-release urea composite granules: S1. Pour 150 g of polyvinyl alcohol and 50 g of humic acid into a glass beaker containing 500 mL of deionized water, place it in a constant temperature water bath at 80 °C, and stir at a speed of 200 r / min for 1 h until completely dissolved to obtain an inner coating solution. S2. Connect the spray gun to the compressed air source, adjust the spraying pressure to 0.3 MPa, fix the spray gun on the bracket, adjust the distance between the spray gun and the container for large granular urea below to 20 cm, turn on the spray gun, and evenly spray the inner coating solution on the surface of 80 g of large granular urea. Continuously turn the large granular urea during the spraying process to ensure uniform coating and obtain large granular urea coated particles. S3. Pour 80 g of large granular urea coated particles and 160 g of polypeptide urea into a drum equipment, set the drum speed to 50 r / min, and perform a coating treatment for 20 min. Through the observation window of the drum equipment, check the mixing situation of the materials to make the polypeptide urea evenly wrap on the surface of the large granular urea coated particles and obtain composite particles. S4. Pour 200 g of humic acid and 40 g of nano-silica into a glass beaker containing 500 mL of deionized water, place it in a constant temperature water bath at 80 °C, and stir at a speed of 200 r / min for 1 h to obtain an outer coating solution. S5. Connect the spray gun to the compressed air source again, adjust the spraying pressure to 0.3 MPa, adjust the distance between the spray gun and the container for composite particles below to 20 cm, turn on the spray gun, and evenly spray the outer coating solution on the surface of the composite particles. Continuously turn the composite particles during the spraying process to ensure uniform coating. After spraying, transfer the particles to a drying oven and dry at 60 °C for 2 h to obtain slow-release urea composite granules.

[0035] A preparation method of a special all-nutrient compound fertilizer for corn, comprising the following steps: Weigh slow-release urea compound granules, diammonium phosphate, potassium chloride, zinc sulfate, borax, monosodium glutamate waste, compound bacillus, diethylaminoethanol octanoate, and sodium tetramethylglutamate, pour them into a blender, set the stirring speed to 100 r / min, and stir for 30 min to obtain a special all-nutrient compound fertilizer for corn.

[0036] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the slow-release urea compound granules are replaced with a mixture of large granular urea and polypeptide urea, and the mass ratio of large granular urea to polypeptide urea is 80:220, and the rest of the operation steps are the same.

[0037] Comparative Example 2 The difference between Comparative Example 2 and Example 5 is that in the preparation process of the slow-release urea compound granules, the mass ratio of humic acid to nano-silica is 1:0.1, and the rest of the operation steps are the same.

[0038] Comparative Example 3 The difference between Comparative Example 3 and Example 4 is that in the preparation process of the slow-release urea compound granules, the mass ratio of humic acid to nano-silica is 1:0.6, and the rest of the operation steps are the same.

[0039] Comparative Example 4 The difference between Comparative Example 4 and Example 4 is that in the preparation process of the slow-release urea compound granules, the mass ratio of humic acid to nano-silica is 1:0.7, and the rest of the operation steps are the same.

[0040] Performance Test 1. Pot experiment: The pot experiment simulates the actual growth environment of corn to verify the fertilizer effect. A total of 5 example groups (Examples 1-5), 4 comparative example groups (Comparative Examples 1-4) are set in the experiment, and an additional blank control group is established to provide a reference for comparative analysis. Each group is set with 5 replicates to reduce experimental errors and ensure data reliability. Select flowerpots with uniform specifications and good air permeability, and fill them with equal amounts of soil that has been sterilized at high temperature to remove impurities and germs. Select corn seeds with plump grains and no pests or diseases, and sow 5 seeds in each flowerpot. After the seeds emerge and the seedlings grow stably, keep 2 seedlings with good growth and the same height in each pot. During the experiment, strictly control the watering amount of each pot to ensure balanced soil humidity, and place the flowerpots in a site with uniform light conditions to maintain the same light duration and intensity. According to the preset fertilization amount, record the growth status of corn plants at three key stages of the seedling stage, ear stage, and flowering and grain filling stage of corn growth, and the experimental results are shown in Table 1.

[0041] Table 1: 2. Determination of Soil Nitrogen Content To monitor the dynamic changes in soil nitrogen content after fertilization, soil samples were collected on the 7th, 14th, 28th, and 56th days after fertilization. During collection, a professional soil sampler was used to collect soil from multiple points at different positions in each flower pot and then mixed evenly to ensure the representativeness of the samples. The total nitrogen content in the soil was determined using the classical Kjeldahl method. This method converts the nitrogen-containing organic matter in the soil into ammonium salts and then precisely calculates the total nitrogen content through steps such as distillation and titration. The nitrogen content in the soil was determined using a continuous flow analyzer, and the experimental results are shown in Table 2.

[0042] Table 2: Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A full-nutrient compound fertilizer for corn, characterized in that: It comprises the following components by weight: 40-50 parts of slow-release urea composite granules, 20-25 parts of diammonium phosphate, 15-20 parts of potassium chloride, 1.5-2.5 parts of zinc sulfate, 1-1.5 parts of borax, 5-10 parts of monosodium glutamate scraps, 0.5-1 part of complex bacillus, 0.1-0.3 parts of diethylaminoethanol octanoate, and 0.1-0.3 parts of sodium tetramethyl glutarate.

2. The full-nutrient compound fertilizer for corn according to claim 1, characterized in that: The composite bacillus consists of bacillus subtilis, bacillus megaterium and bacillus gelatinous.

3. The full-nutrient compound fertilizer for corn according to claim 2, characterized in that: The CFU ratio of the Bacillus subtilis, Bacillus megaterium and Bacillus gelatinosa is 4:3:

3.

4. The full-nutrient compound fertilizer for corn according to claim 1, characterized in that: The preparation method of the slow-release urea composite particles comprises the following steps: S1, adding polyvinyl alcohol and humic acid into deionized water, heating and stirring to dissolve, to obtain an inner coating solution; S2, spraying the inner coating solution on the surface of the large urea particles to obtain large urea coated particles; S3, adding the large urea coated particles and the polypeptide urea into a rotary drum device for coating treatment, so that the polypeptide urea is coated on the surface of the large urea coated particles to obtain composite particles; S4, adding humic acid and nano-silicon dioxide into deionized water, heating and stirring evenly to obtain an outer coating solution; S5. Spraying the outer coating solution on the surface of the composite particles, and drying them to obtain slow-release urea composite particles.

5. The full-nutrient compound fertilizer for corn according to claim 4, characterized in that: In the step S1, the mass ratio of polyvinyl alcohol to humic acid is 3:1-2.

6. The full-nutrient compound fertilizer for corn according to claim 4, characterized in that: In the step S3, the mass ratio of the large urea coated particles to the polypeptide urea is 1:2-3.

7. The full-nutrient compound fertilizer for corn according to claim 4, characterized in that: In step S4, the mass ratio of humic acid to nano-silicon dioxide is 1:0.2-0.

5.

8. A method for preparing a special full-nutrient compound fertilizer for corn, characterized in that: The following steps are involved: Weigh slow-release urea composite granules, diammonium phosphate, potassium chloride, zinc sulfate, borax, monosodium glutamate scraps, compound Bacillus, diethylaminoethanol octanoate, and sodium tetramethylglutarate, pour them into a blender, stir and mix them evenly to obtain a full-nutrient composite fertilizer for corn.

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