Slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer and preparation method thereof

Abstract

The invention discloses a slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer and a preparation method thereof, and relates to the technical field of compound fertilizer preparation. The compound fertilizer comprises 35-50 parts of nitrogen fertilizer, 30-45 parts of phosphate fertilizer, 20-35 parts of potash fertilizer, 8-18 parts of slow release agent and 5-9 parts of synergist. The slow-release fertilizer has the beneficial technical effects that through slow-release components such as the coated urea, nutrients can be slowly released in a relatively long time, so that crops can continuously obtain required nutrients in the whole growth cycle, and the problems of excessive nutrient supply in the early stage and insufficient nutrients in the later stage of a common compound fertilizer are avoided; the slow release of the nutrients can also reduce loss and waste caused by rapid release of the nutrients, and the utilization rate of the fertilizer is improved.

Description

Technical Field

[0001] The invention relates to the technical field of compound fertilizer preparation, in particular to a slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer and a preparation method thereof. Background Art

[0002] In modern agricultural production, fertilizer is one of the key factors to ensure high and stable yields of crops. With the continuous development and progress of agricultural technology, the requirements for fertilizers are getting higher and higher. Although traditional single fertilizers such as nitrogen fertilizers, phosphorus fertilizers, and potassium fertilizers can provide specific nutrients for crops, they have problems such as unbalanced nutrition, single fertilizer effect, and low utilization rate.

[0003] NPK compound fertilizer is a kind of fertilizer that mixes the three main nutrients of nitrogen, phosphorus and potassium in a certain proportion. Its appearance meets the needs of crops for multiple nutrients. Compared with single fertilizers, NPK compound fertilizer has a higher fertilizer utilization rate. Through scientific formula design and production process, different nutrients can work together to reduce nutrient loss and waste. For example, a reasonable ratio of NPK can promote the absorption and utilization of nutrients by plants, while reducing the pollution to the environment caused by excess nutrients.

[0004] In addition, with the increasing shortage of land resources and the requirement for sustainable agricultural development, the use of nitrogen, phosphorus and potassium compound fertilizers can also help improve soil structure and fertility. Long-term use of a single fertilizer can easily lead to problems such as soil compaction and nutrient imbalance, while the multiple nutrients in compound fertilizers can alleviate these problems to a certain extent and maintain the ecological balance of the soil.

[0005] However, the existing common compound fertilizers also have the following disadvantages: the nutrients in common compound fertilizers are released quickly, usually in large quantities in a short period of time. This can easily lead to excessive nutrient supply in the early stage, which may cause problems such as leggy growth and lodging of crops. In the later stage of growth, the nutrients in the fertilizer are exhausted and cannot continuously meet the needs of crops, so that the crops may be affected by insufficient nutrients in the later stage, affecting the yield and quality; due to the rapid release of nutrients in common compound fertilizers, when encountering rain or irrigation, nutrients such as nitrogen, phosphorus, and potassium that are not absorbed by crops in time are easily lost with water, especially ammonium nitrogen and nitrate nitrogen in nitrogen fertilizers, as well as water-soluble phosphate fertilizers and potash fertilizers. This not only causes a waste of fertilizers, but also pollutes the environment such as soil and water bodies; for soils with poor fertilizer retention capacity such as sandy soils, the problem of nutrient loss of common compound fertilizers is more prominent. The pores between these soil particles are large, and water and nutrients are easily lost through infiltration and leaching, making it difficult for common compound fertilizers to fully exert their fertilizer effect in such soils; because the fertilizer effect of common compound fertilizers lasts for a short time, in order to meet the nutrient needs of crops throughout the entire growth cycle, multiple fertilizations are often required. This not only increases labor and time costs, but may also cause certain damage to the crop roots due to multiple fertilizations; frequent fertilization may also cause soil compaction, affecting soil permeability and water retention, and further affecting crop growth and development. Summary of the invention

[0006] In order to solve the above problems, that is, to solve the problems raised by the above background technology, the present invention proposes a slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer and a preparation method thereof. The specific technical scheme is as follows:

[0007] A slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer comprises 35-50 parts of nitrogen fertilizer, 30-45 parts of phosphorus fertilizer, 20-35 parts of potassium fertilizer, 8-18 parts of slow-release agent and 5-9 parts of synergist.

[0008] Preferably, the compound fertilizer includes 43 parts of nitrogen fertilizer, 38 parts of phosphate fertilizer, 28 parts of potassium fertilizer, 12 parts of slow-release agent, and 7 parts of synergist.

[0009] Preferably, the nitrogen fertilizer specifically includes: 15-20 parts of urea, 10-15 parts of ammonium sulfate, and 10-15 parts of slow-release urea; the phosphate fertilizer specifically includes: 15-20 parts of superphosphate, 10-15 parts of diammonium phosphate, and 5-10 parts of ammonium polyphosphate; the potash fertilizer specifically includes: 10-15 parts of potassium chloride, 5-10 parts of potassium sulfate, and 5-10 parts of slow-release potash fertilizer; the slow-release agent specifically includes: 2-5 parts of sulfur, 1-3 parts of resin coating material, and 5-10 parts of zeolite; the synergist specifically includes: 3-5 parts of humic acid, 1-2 parts of microbial agent, and 1-2 parts of amino acid.

[0010] Preferably, the nitrogen fertilizer specifically includes: 18 parts of urea, 12 parts of ammonium sulfate, and 13 parts of slow-release urea; the phosphate fertilizer specifically includes: 16 parts of superphosphate, 13 parts of diammonium phosphate, and 9 parts of ammonium polyphosphate; the potash fertilizer specifically includes: 13 parts of potassium chloride, 6 parts of potassium sulfate, and 9 parts of slow-release potash fertilizer; the slow-release agent specifically includes 3 parts of sulfur, 2 parts of resin coating material, and 7 parts of zeolite; the synergist specifically includes 4 parts of humic acid, 1 part of microbial agent, and 2 parts of amino acid.

[0011] Preferably, the resin coating material is polyolefin resin, paper resin or epoxy resin; the humic acid is specifically weathered coal humic acid or lignite humic acid; the microbial agent is one or a mixture of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and potassium-solubilizing bacteria; the amino acid is specifically a mixture of glutamic acid, aspartic acid, lysine and methionine.

[0012] A method for preparing the above-mentioned slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer is characterized in that the method comprises the following steps: crushing each raw material of nitrogen fertilizer, phosphate fertilizer and potash fertilizer to 40-60 mesh, mixing them evenly according to the nitrogen fertilizer, phosphate fertilizer and potash fertilizer groups, and setting aside; heating and melting sulfur, and coating nitrogen fertilizer particles in sulfur by spraying and active impregnation to form slow-release nitrogen fertilizer particles; heating the resin coating material to a molten state, coating the phosphate fertilizer by fluidized bed coating technology, and preparing slow-release phosphate fertilizer; activating zeolite to improve adsorption performance, mixing the above-treated raw materials according to the formula, stirring them evenly, adding humic acid, microbial agents and amino acids, stirring them evenly again, and granulating, drying, screening and other treatments on the mixed fertilizer to prepare the slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer.

[0013] Preferably, the above-mentioned step of activating the zeolite is specifically an acid treatment activation method, comprising the following steps: placing the zeolite in an acid-resistant container, adding dilute hydrochloric acid at a solid-liquid ratio of 1:10, stirring and reacting at 50-80°C for 2-4 hours, after the reaction is completed, filtering out the acid solution, repeatedly rinsing the zeolite with clean water until the pH value of the rinsing solution is close to neutral, and drying the rinsed zeolite at 100-120°C for 2 hours to obtain activated zeolite.

[0014] The beneficial technical effects of the present invention are:

[0015] Through slow-release ingredients such as coated urea, nutrients can be slowly released over a long period of time, ensuring that crops can continue to obtain the nutrients they need throughout the entire growth cycle, avoiding the problem of excessive nutrient supply in the early stage and insufficient nutrients in the later stage of ordinary compound fertilizers; the slow release of nutrients can also reduce the loss and waste caused by rapid nutrient release, and improve the utilization rate of fertilizers;

[0016] The formula contains zeolite, humic acid and other substances with adsorption and slow-release effects. Zeolite can absorb some nutrients and slowly release them in the soil, thereby extending the supply time of nutrients. Humic acid can form complexes with nutrients to improve the stability and effectiveness of nutrients and reduce the fixation and loss of nutrients. The addition of microbial agents also helps to improve nutrient utilization. At the same time, microorganisms can also improve soil structure, increase soil permeability and water retention, create a good growth environment for crop roots, and further improve nutrient absorption efficiency.

[0017] Due to its long-lasting fertilizer effect, slow-release compound fertilizer does not need to be applied as frequently as ordinary compound fertilizer. It not only saves labor and time costs, but also reduces the damage to crop roots caused by multiple fertilizations. The funny use of this compound fertilizer can also reduce the amount of fertilizer applied and reduce production costs. At the same time, it is beneficial to environmental protection and reduces fertilizer pollution to soil and water. DETAILED DESCRIPTION

[0018] The preferred embodiments of the present invention are described below. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0019] Example 1

[0020] A slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer, including 35 parts of nitrogen fertilizer, 30 parts of phosphate fertilizer, 20 parts of potash fertilizer, 8 parts of slow-release agent, and 5 parts of synergist. The nitrogen fertilizer includes 15 parts of urea, 10 parts of ammonium sulfate, and 10 parts of slow-release urea; the phosphate fertilizer includes 15 parts of potassium superphosphate, 10 parts of diammonium phosphate, and 5 parts of ammonium polyphosphate; the potash fertilizer includes 10 parts of potassium chloride, 5 parts of potassium sulfate, and 5 parts of slow-release potash fertilizer; the slow-release agent includes 2 parts of sulfur, 1 part of resin coating material, and 5 parts of zeolite; the synergist includes 3 parts of humic acid, 1 part of microbial agent, and 1 part of amino acid. Specifically, the resin coating material is polyolefin resin, the humic acid is weathered coal humic acid, the microbial agent is a mixture of nitrogen-fixing bacteria and potassium-dissolving bacteria, and the amino acid is a mixture of glutamic acid, aspartic acid, lysine, and methionine.

[0021] Example 2

[0022] A slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer, including 43 parts of nitrogen fertilizer, 38 parts of phosphate fertilizer, 28 parts of potash fertilizer, 12 parts of slow-release agent, and 7 parts of synergist. The nitrogen fertilizer includes 18 parts of urea, 12 parts of ammonium sulfate, and 13 parts of slow-release urea; the phosphate fertilizer includes 16 parts of superphosphate, 13 parts of diammonium phosphate, and 9 parts of ammonium polyphosphate; the potash fertilizer includes 13 parts of potassium chloride, 6 parts of potassium sulfate, and 9 parts of slow-release potash fertilizer; the slow-release agent includes 3 parts of sulfur, 2 parts of resin coating material, and 7 parts of zeolite; the synergist includes 4 parts of humic acid, 1 part of microbial agent, and 2 parts of amino acid. Specifically, the resin coating material is polyurethane resin, the humic acid is lignite humic acid, the microbial agent is a mixture of nitrogen-fixing bacteria and phosphate-solubilizing bacteria, and the amino acid is a mixture of glutamic acid, aspartic acid, lysine, and methionine.

[0023] Example 3

[0024] A slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer, comprising 50 parts of nitrogen fertilizer, 45 parts of phosphate fertilizer, 35 parts of potash fertilizer, 18 parts of slow-release agent, and 9 parts of synergist. The nitrogen fertilizer comprises 20 parts of urea, 15 parts of ammonium sulfate, and 15 parts of slow-release urea; the phosphate fertilizer comprises 20 parts of superphosphate, 15 parts of diammonium phosphate, and 10 parts of ammonium polyphosphate; the potash fertilizer comprises 10 parts of potassium chloride, 10 parts of potassium sulfate, and 10 parts of slow-release potash fertilizer; the slow-release agent comprises 5 parts of sulfur, 3 parts of resin coating material, and 10 parts of zeolite; the synergist comprises 5 parts of humic acid, 2 parts of microbial agent, and 2 parts of amino acid. Specifically, the resin coating material is epoxy resin, the humic acid is weathered coal humic acid, the microbial agent is nitrogen-fixing bacteria, and the amino acid is a mixture of glutamic acid, aspartic acid, lysine, and methionine.

[0025] The composite fertilizer raw materials described in the above-mentioned Examples 1-3 are processed according to the following preparation method: the raw materials of nitrogen fertilizer, phosphate fertilizer and potash fertilizer are crushed into 40-60 meshes, and the nitrogen fertilizer, phosphate fertilizer and potash fertilizer are grouped and mixed evenly for use; sulfur is heated and melted, and the nitrogen fertilizer particles are coated in sulfur by spraying and impregnation to form slow-release nitrogen fertilizer particles; the resin coating material is heated to a molten state, and the phosphate fertilizer is coated by fluidized bed coating technology to prepare a slow-release phosphate fertilizer; the zeolite is subjected to acid treatment activation method: the zeolite is placed in an acid-resistant container, and the solid-liquid ratio is 1:1. ∶10, add dilute hydrochloric acid, stir and react at 50-80℃ for 2-4h, after the reaction is completed, filter out the acid, repeatedly rinse the zeolite with clean water until the pH value of the rinse liquid is close to neutral, and dry the rinsed zeolite at 100-120℃ for 2h to obtain activated zeolite; mix the above-treated raw materials according to the formula, stir well, add humic acid, microbial agent and amino acid, stir well again, granulate, dry, screen and other treatments on the mixed fertilizer, and finally obtain the compound fertilizer described in Examples 1-3.

[0026] A test field was selected and divided into 4 equal parts, marked as No. 1, 2, 3, and 4, and the same corn seeds were planted. All planting conditions were the same. The slow-release synergistic compound fertilizers No. 1, 2, and 3 of the examples were applied to the test field, and the conventional compound fertilizer on the market was applied to the test field No. 4 as a comparative example. After one harvest cycle, the harvested corn data were as follows:

[0027] Experimental Field Plant height Number of ear rows Hundred Grain Weight Disease rate Yield 1 295.37 17 40.59 3.67 1642 2 295.72 18 41.03 3.42 1694 3 295.24 17 40.96 3.51 1657 4 294.10 17 39.8 4.15 1549

[0028] According to the above data, it can be known that the corn yield after applying the slow-release synergistic compound fertilizer described in Examples 1-3 is generally higher than the corn yield after using ordinary compound fertilizers, and the 100-grain weight is higher and the diseased plant rate is lower. At the same time, it can be seen that the various data of corn after applying the slow-release synergistic compound fertilizer described in Example 2 are better. Therefore, it can be concluded that the fertilizer effect of the slow-release synergistic nitrogen, phosphorus and potassium compound fertilizer described in the examples is superior to ordinary compound fertilizers on the market in all aspects.

[0029] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0030] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments, but it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer, characterized in that: The compound fertilizer comprises 35-50 parts of nitrogen fertilizer, 30-45 parts of phosphorus fertilizer, 20-35 parts of potassium fertilizer, 8-18 parts of slow-release agent and 5-9 parts of synergist.

2. A slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer according to claim 1, characterized in that: The compound fertilizer comprises 43 parts of nitrogen fertilizer, 38 parts of phosphorus fertilizer, 28 parts of potassium fertilizer, 12 parts of slow-release agent and 7 parts of synergist.

3. A slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer according to claim 1, characterized in that: The nitrogen fertilizer specifically includes: 15-20 parts of urea, 10-15 parts of ammonium sulfate, and 10-15 parts of slow-release urea; the phosphate fertilizer specifically includes: 15-20 parts of superphosphate, 10-15 parts of diammonium phosphate, and 5-10 parts of ammonium polyphosphate; the potash fertilizer specifically includes: 10-15 parts of potassium chloride, 5-10 parts of potassium sulfate, and 5-10 parts of slow-release potash fertilizer; the slow-release agent specifically includes: 2-5 parts of sulfur, 1-3 parts of resin coating material, and 5-10 parts of zeolite; the synergist specifically includes: 3-5 parts of humic acid, 1-2 parts of microbial agent, and 1-2 parts of amino acid.

4. A slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer according to claim 3, characterized in that: The nitrogen fertilizer specifically includes: 18 parts of urea, 12 parts of ammonium sulfate, and 13 parts of slow-release urea; the phosphate fertilizer specifically includes: 16 parts of superphosphate, 13 parts of diammonium phosphate, and 9 parts of ammonium polyphosphate; the potash fertilizer specifically includes: 13 parts of potassium chloride, 6 parts of potassium sulfate, and 9 parts of slow-release potash fertilizer; the slow-release agent specifically includes 3 parts of sulfur, 2 parts of resin coating material, and 7 parts of zeolite; the synergist specifically includes 4 parts of humic acid, 1 part of microbial agent, and 2 parts of amino acid.

5. A slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer according to claim 3, characterized in that: The resin coating material is polyolefin resin, polyurethane resin or epoxy resin; the humic acid is specifically weathered coal humic acid or lignite humic acid; the microbial agent is one or a mixture of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and potassium-solubilizing bacteria; the amino acid is specifically a mixture of glutamic acid, aspartic acid, lysine and methionine.

6. A method for preparing the slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: crushing each raw material of nitrogen fertilizer, phosphate fertilizer and potash fertilizer into 40-60 meshes, and mixing them evenly according to the nitrogen fertilizer, phosphate fertilizer and potash fertilizer groups for standby use; heating and melting sulfur, and coating nitrogen fertilizer particles in sulfur by spraying and active impregnation to form slow-release nitrogen fertilizer particles; heating the resin coating material to a molten state, and coating the phosphate fertilizer by fluidized bed coating technology to prepare slow-release phosphate fertilizer; activating zeolite to improve adsorption performance, mixing the above-treated raw materials according to a formula, fully stirring, adding humic acid, microbial agents and amino acids, stirring again, and granulating, drying, screening and other treatments on the mixed fertilizer to prepare a slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer.

7. The method for preparing a slow-release synergistic nitrogen-phosphorus-potassium compound fertilizer according to claim 6, characterized in that: The above-mentioned step of activating the zeolite is specifically an acid treatment activation method, which includes the following steps: placing the zeolite in an acid-resistant container, adding dilute hydrochloric acid at a solid-liquid ratio of 1:10, stirring and reacting at 50-80°C for 2-4 hours, after the reaction is completed, filtering out the acid solution, repeatedly rinsing the zeolite with clean water until the pH value of the rinsing solution is close to neutral, and drying the rinsed zeolite at 100-120°C for 2 hours to obtain the activated zeolite.