Three-in-one slow-release ecological compound fertilizer and preparation method thereof

Abstract

The invention relates to the technical field of agricultural slow-release fertilizers, and discloses a three-in-one slow-release ecological compound fertilizer which comprises the following raw materials in parts by weight: 30-50 parts of an organic fertilizer, 20-40 parts of an inorganic fertilizer, 10-20 parts of a slow-release material, 5-10 parts of a coating material and 1-3 parts of a microbial agent, the organic fertilizer comprises decomposed livestock and poultry manure, straw compost and humic acid; the inorganic fertilizer comprises nitrogen, phosphorus and potassium compounds; the sustained-release material comprises a high-molecular polymer, zeolite and montmorillonite; the coating material comprises vegetable oil and isocyanate; the microbial agent comprises bacillus, trichoderma and rhizobium. The slow-release material and the coating material are added, so that the nutrient release rate is subjected to dual regulation and control. Therefore, fertilizer nutrients can be continuously and stably supplied to crops in the whole growth cycle of the crops, the utilization efficiency of the fertilizer is greatly improved, and unnecessary waste is avoided.

Description

Technical Field

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

[0002] With the continuous improvement of human living standards, people have higher and higher requirements for the quality of crops and their agricultural and sideline products. Traditional planting methods and long-term application of chemical fertilizers alone can no longer meet the requirements of green organic food supply and production. In agricultural production, the soil that has been cultivated for a long time lacks organic matter on the surface and has a poor structure. Under the external factors of irrigation or rainfall, the aggregate structure is destroyed, the soil material is dispersed, and after drying, the soil surface becomes hard due to the cohesive force. In addition, the long-term application of a single fertilizer cannot replenish organic matter in time.

[0003] Traditional chemical fertilizers can indeed provide crops with the nutrients necessary for their growth in a relatively short period of time in agricultural production. The utilization rate of fertilizers is generally low, and a large amount of nutrients cannot be fully absorbed and utilized by crops, resulting in serious waste of resources. However, the release rate of nutrients from chemical fertilizers is often too fast, making it difficult to match the growth rhythm and needs of crops. Excessive or improper use of traditional chemical fertilizers can easily cause environmental pollution and have a significant negative impact on ecological balance and environmental quality. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a three-in-one slow-release ecological compound fertilizer and a preparation method thereof, which solves the problem that the nutrient release rate of chemical fertilizers is often too fast, the utilization rate of fertilizers is generally low, and the resulting serious waste of resources and environmental pollution.

[0005] To achieve the above purpose, the present invention is implemented by the following technical scheme: a three-in-one slow-release ecological compound fertilizer, comprising the following raw materials by weight: 30-50 parts of organic fertilizer, 20-40 parts of inorganic fertilizer, 10-20 parts of slow-release material, 5-10 parts of coating material, and 1-3 parts of microbial agent; The organic fertilizers include decomposed livestock and poultry manure, straw compost and humic acid; The inorganic fertilizers include nitrogen, phosphorus and potassium compounds; The sustained-release material includes high molecular polymer, zeolite and montmorillonite; The coating material includes vegetable oil and isocyanate; The microbial agents include Bacillus, Trichoderma and Rhizobium.

[0006] Preferably, the organic fertilizer comprises the following raw materials in parts by weight: 15 to 20 parts of decomposed livestock and poultry manure, 10 to 20 parts of straw compost and 5 to 10 parts of humic acid.

[0007] Preferably, the inorganic fertilizer comprises the following raw materials in parts by weight: 5 to 10 parts of the nitrogen compound, 5 to 10 parts of the phosphorus compound and 5 to 10 parts of the potassium compound; The nitrogen compound, phosphorus compound and potassium compound are urea, diammonium phosphate and potassium sulfate respectively, and the inorganic fertilizer also includes 5 to 10 parts of calcium magnesium phosphate fertilizer.

[0008] Preferably, the sustained-release material comprises the following raw materials in parts by weight: 3 to 7 parts of the high molecular polymer, 4 to 8 parts of zeolite and 3 to 5 parts of montmorillonite.

[0009] Preferably, the coating material comprises the following raw materials in parts by weight: 3 to 8 parts of vegetable oil and 2 to 8 parts of isocyanate.

[0010] Preferably, the microbial agent comprises the following raw materials in parts by weight: 0.3-1 parts of the Bacillus, 0.5-1.5 parts of Trichoderma and 0.2-0.5 parts of Rhizobium.

[0011] A method for preparing a three-in-one slow-release ecological compound fertilizer, the method comprising the following steps: Step 1: Pretreatment of raw materials First, prepare organic fertilizer, inorganic fertilizer, slow-release material, coating material and microbial agent, and then use a pulverizer to pulverize the raw materials to make the particle size of organic fertilizer less than 5 mm and the particle size of inorganic fertilizer less than 2 mm; Step 2: Organic fertilizer pretreatment Put the processed decomposed livestock and poultry manure, straw compost and humic acid into a stirring device for mixing, and then place them in a well-ventilated environment and dry them for 1 to 2 days to reduce their moisture content to 20% to 30%; Step 3: Pretreatment of inorganic fertilizers The urea, diammonium phosphate, potassium sulfate and calcium magnesium phosphate fertilizer are crushed respectively to a particle size of less than 2 mm, passed through an 80-100 mesh sieve, and then the crushed inorganic fertilizers are placed in a stirring device for mixing; Step 4: Slow-release material processing The high molecular polymer is heated to a molten state, and the temperature is maintained at 150°C to 200°C, and the zeolite and montmorillonite are ground, and the particle size of the zeolite and montmorillonite is less than 1 mm, and the particles are passed through a 100-120 mesh sieve, and then the ground zeolite and montmorillonite are added to the molten high molecular polymer, and the mixture is placed in a stirring device for mixing to form a sustained-release material mixture; Step 5: Initial mixing Put the pretreated organic fertilizer and inorganic fertilizer into a mixer, and stir at a speed of 50 to 80 rpm for 15 to 20 minutes to fully mix the organic fertilizer and inorganic fertilizer; Step 6: Add slow-release materials and microbial agents After the initial mixing, first add the slow-release material mixture prepared in step 4, continue stirring for 10 to 15 minutes, then add the prepared microbial agent, stir for 5 to 10 minutes to fully blend the materials, and convey the mixed materials to a disc granulator for granulation to form particles with a particle size of 2.0 mm to 3.0 mm; Step 7: Encapsulation The granules obtained by the above granulation are sprayed into a fluidized bed coating machine by in-situ polymerization reaction of vegetable oil and isocyanate, and the coating solution is evenly sprayed on the surface of the granules by a spray gun to form a coating layer; Step 8: Drying and Cooling The coated particles are placed in a drying oven and dried at 50-60°C for 3-5 hours to reduce the moisture content of the coated particles to below 2.5%. After drying, the coated particles are taken out and naturally cooled to room temperature to obtain a three-in-one slow-release ecological compound fertilizer. Step 9: Quality Inspection and Packaging The prepared three-in-one slow-release ecological compound fertilizer is quality tested to check whether its nutrient content, microbial activity, and slow-release performance indicators meet the requirements. Qualified products are packaged, and moisture-proof, humidity-proof, and corrosion-resistant packaging materials are selected to ensure product quality and stability.

[0012] Preferably, in step 2, the stirring device stirs at a low speed of 30 rpm for 5 minutes, gradually increases the stirring speed to 50 rpm, continues stirring for 8 minutes, adjusts the stirring speed back to 30 rpm, and continues stirring for 2 minutes; In the step 3, the mixture is first stirred at a speed of 40 rpm for 3 minutes, then the speed is steadily increased to 60 rpm, and stirring is continued for 5 minutes. During the 5-minute stirring period.

[0013] Preferably, in step 4, the mixture is first stirred at a low speed of 20 rpm for 3 minutes, and the zeolite and montmorillonite are added to the stirring device in small amounts and multiple times. After each addition, the stirring speed is increased to 40 rpm and stirred for 5 minutes until all the zeolite and montmorillonite are added, and then stirred at 20 rpm for 2 minutes.

[0014] Preferably, in step seven, the formation of the envelope layer comprises the following specific steps: Add vegetable oil and isocyanate into preheated containers respectively, heat to 50℃~80℃ for later use; Then, the preheated materials are sprayed into the fluidized bed coating machine at a uniform speed, the fluidized bed is started to make the materials in a fluidized state, and the mixed materials are sprayed evenly on the surface of the materials to be coated in the form of mist through a spray gun, the pressure of the spray gun is controlled to be 0.3-0.5MPa, and the spraying time is 3-5 minutes; During the entire coating process, the temperature of the fluidized bed is controlled at 60-70°C and the wind speed is 2-3m / s to ensure that the coating material can be evenly attached to the surface of the material to be coated to form a complete and uniform coating layer.

[0015] The present invention provides a three-in-one slow-release ecological compound fertilizer and a preparation method thereof. It has the following beneficial effects: 1. The present invention adds slow-release materials and coating materials to double-regulate the nutrient release rate, which enables fertilizer nutrients to continuously and stably supply nutrients to crops throughout the entire growth cycle of the crops, greatly improving the utilization efficiency of fertilizers and avoiding unnecessary waste.

[0016] 2. The slow-release material used in the present invention has significant advantages. It can regulate the release rate of fertilizer nutrients, which not only meets the nutrient demand of crops during growth, but also effectively avoids the imbalance of nutrient supply, thereby greatly increasing crop yields. At the same time, it significantly improves the quality of crops, and helps to achieve high-quality and high-yield agricultural production.

[0017] 3. The present invention introduces organic materials, which greatly increases the organic matter content of the soil, which helps to improve the soil structure, making it more loose and breathable, which is conducive to root growth. At the same time, it improves soil fertility and creates a good soil environment for crop growth. This is not only beneficial to the growth of current crops, but also can provide sustainable soil conditions for subsequent planting, and promote the long-term and stable development of agriculture.

[0018] 4. The present invention effectively reduces environmental pollution problems caused by nutrient loss. By precisely controlling nutrient release, it avoids excess nutrients from entering water bodies and soil, reduces the risk of water eutrophication and soil compaction and acidification, protects the ecological balance, and promotes the development of agriculture in a green and sustainable direction, which has important ecological significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a flow chart of a method for preparing a three-in-one slow-release ecological compound fertilizer. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example: Please see attached Figure 1 The embodiment of the present invention provides a three-in-one slow-release ecological compound fertilizer, comprising the following raw materials in parts by weight: 30 to 50 parts of organic fertilizer, 20 to 40 parts of inorganic fertilizer, 10 to 20 parts of slow-release material, 5 to 10 parts of coating material, and 1 to 3 parts of microbial agent; Organic fertilizers include decomposed livestock and poultry manure, straw compost and humic acid; Inorganic fertilizers include nitrogen, phosphorus, and potassium compounds; Sustained-release materials include high molecular weight polymers, zeolites, and montmorillonites; Coating materials include vegetable oils and isocyanates; Microbial agents include Bacillus, Trichoderma and Rhizobium.

[0022] The organic fertilizer comprises the following raw materials in parts by weight: 15 to 20 parts of decomposed livestock and poultry manure, 10 to 20 parts of straw compost and 5 to 10 parts of humic acid.

[0023] The inorganic fertilizer includes the following raw materials in parts by weight: 5 to 10 parts of nitrogen compound, 5 to 10 parts of phosphorus compound and 5 to 10 parts of potassium compound; The nitrogen compound, phosphorus compound and potassium compound are urea, diammonium phosphate and potassium sulfate respectively, and the inorganic fertilizer also includes 5 to 10 parts of calcium magnesium phosphate fertilizer.

[0024] The sustained-release material comprises the following raw materials in parts by weight: 3-7 parts of high molecular polymer, 4-8 parts of zeolite and 3-5 parts of montmorillonite.

[0025] The coating material comprises the following raw materials in parts by weight: 3 to 8 parts of vegetable oil and 2 to 8 parts of isocyanate.

[0026] The microbial agent comprises the following raw materials in parts by weight: 0.3-1 part of bacillus, 0.5-1.5 parts of trichoderma and 0.2-0.5 parts of rhizobium.

[0027] A method for preparing a three-in-one slow-release ecological compound fertilizer, the method comprising the following steps: Step 1: Pretreatment of raw materials First, prepare organic fertilizer, inorganic fertilizer, slow-release material, coating material and microbial agent, and then use a pulverizer to pulverize the raw materials to make the particle size of organic fertilizer less than 5 mm and the particle size of inorganic fertilizer less than 2 mm; Step 2: Organic fertilizer pretreatment Put the processed decomposed livestock and poultry manure, straw compost and humic acid into a stirring device for mixing, and then place them in a well-ventilated environment and dry them for 1 to 2 days to reduce their moisture content to 20% to 30%; Step 3: Pretreatment of inorganic fertilizers The urea, diammonium phosphate, potassium sulfate and calcium magnesium phosphate fertilizer are crushed respectively to a particle size of less than 2 mm, passed through an 80-100 mesh sieve, and then the crushed inorganic fertilizers are placed in a stirring device for mixing; Step 4: Slow-release material processing The high molecular polymer is heated to a molten state, and the temperature is maintained at 150°C to 200°C, and the zeolite and montmorillonite are ground, and the particle size of the zeolite and montmorillonite is less than 1 mm, and the particles are passed through a 100-120 mesh sieve, and then the ground zeolite and montmorillonite are added to the molten high molecular polymer, and the mixture is placed in a stirring device for mixing to form a sustained-release material mixture; Step 5: Initial mixing Put the pretreated organic fertilizer and inorganic fertilizer into a mixer, and stir at a speed of 50 to 80 rpm for 15 to 20 minutes to fully mix the organic fertilizer and inorganic fertilizer; Step 6: Add slow-release materials and microbial agents After the initial mixing, first add the slow-release material mixture prepared in step 4, continue stirring for 10 to 15 minutes, then add the prepared microbial agent, stir for 5 to 10 minutes to fully blend the materials, and convey the mixed materials to a disc granulator for granulation to form particles with a particle size of 2.0 mm to 3.0 mm; Step 7: Encapsulation The granules obtained by the above granulation are sprayed into a fluidized bed coating machine by in-situ polymerization reaction of vegetable oil and isocyanate, and the coating solution is evenly sprayed on the surface of the granules by a spray gun to form a coating layer; Step 8: Drying and Cooling The coated particles are placed in a drying oven and dried at 50-60°C for 3-5 hours to reduce the moisture content of the coated particles to below 2.5%. After drying, the coated particles are taken out and naturally cooled to room temperature to obtain a three-in-one slow-release ecological compound fertilizer. Step 9: Quality Inspection and Packaging The prepared three-in-one slow-release ecological compound fertilizer is quality tested to check whether its nutrient content, microbial activity, and slow-release performance indicators meet the requirements. Qualified products are packaged, and moisture-proof, humidity-proof, and corrosion-resistant packaging materials are selected to ensure product quality and stability.

[0028] In step 2, the stirring device is stirred at a low speed of 30 rpm for 5 minutes, the stirring speed is gradually increased to 50 rpm, stirring is continued for 8 minutes, and the stirring speed is adjusted back to 30 rpm again, and stirring is continued for 2 minutes; In step three, first stir at a speed of 40 rpm for 3 minutes, then steadily increase the speed to 60 rpm and continue stirring for 5 minutes. During this 5-minute stirring period.

[0029] In step 4, first stir at a low speed of 20 rpm for 3 minutes, add zeolite and montmorillonite to the stirring device in small amounts and multiple times, and after each addition, increase the stirring speed to 40 rpm and stir for 5 minutes until all the zeolite and montmorillonite are added, and finally stir at 20 rpm for 2 minutes.

[0030] In step seven, the formation of the envelope layer includes the following specific steps: Add vegetable oil and isocyanate into preheated containers respectively, heat to 50℃~80℃ for later use; Then, the preheated materials are sprayed into the fluidized bed coating machine at a uniform speed, the fluidized bed is started to make the materials in a fluidized state, and the mixed materials are sprayed evenly on the surface of the materials to be coated in the form of mist through a spray gun, the pressure of the spray gun is controlled to be 0.3-0.5MPa, and the spraying time is 3-5 minutes; During the entire coating process, the temperature of the fluidized bed is controlled at 60-70°C and the wind speed is 2-3m / s to ensure that the coating material can be evenly attached to the surface of the material to be coated to form a complete and uniform coating layer.

[0031] The following is an introduction in conjunction with specific embodiments: Embodiment 1: 30 parts of organic fertilizer, 15 parts of decomposed livestock and poultry manure, 10 parts of straw compost, and 5 parts of humic acid; 20 parts of inorganic fertilizers, 5 parts of urea, 5 parts of diammonium phosphate, 5 parts of potassium sulfate, and 5 parts of calcium magnesium phosphate; 10 parts of sustained-release material, 3 parts of high molecular polymer, 4 parts of zeolite, and 3 parts of montmorillonite; 5 parts of coating material, 3 parts of vegetable oil and 2 parts of isocyanate; 1 part of microbial agent, 0.3 parts of Bacillus, 0.5 parts of Trichoderma, and 0.2 parts of Rhizobium.

[0032] Step 1: Prepare the raw materials and crush the organic fertilizer with a crusher until the particle size is less than 5 mm; Step 2: Put the decomposed livestock and poultry manure, straw compost and humic acid into a stirring device, stir at 30 rpm for 5 minutes, increase the speed to 50 rpm for 8 minutes, then reduce the speed to 30 rpm for 2 minutes, place in a ventilated place to dry for 1 day, so that the moisture content reaches 20%; Step 3: Grind urea, diammonium phosphate, potassium sulfate and calcium magnesium phosphate fertilizer to a particle size of less than 2 mm, pass through an 80-mesh sieve, stir at 40 rpm for 3 minutes, and then increase the speed to 60 rpm for 5 minutes; Step 4: Heat the polymer to 150°C to melt, stir at 20 rpm for 3 minutes, grind the zeolite and montmorillonite to a particle size of less than 1 mm, pass through a 100-mesh sieve, and add a small amount to the molten polymer several times. After each addition, increase the speed to 40 rpm and stir for 5 minutes. After all additions are completed, stir at 20 rpm for 2 minutes to form a sustained-release material mixture; Step 5: Put the pretreated organic fertilizer and inorganic fertilizer into a blender and blend at 50 rpm for 15 minutes; Step 6: first add the slow-release material mixture to the initially mixed material, stir at 60 rpm for 10 minutes, then add the microbial agent, stir at 40 rpm for 5 minutes, and convey the mixed material to a disc granulator for granulation to obtain granules with a particle size of 2.0 mm; Step 7: Add vegetable oil and isocyanate to a preheated container respectively, and heat to 50°C for later use. Then, spray the granules obtained by the above granulation into the fluidized bed coating machine at a uniform speed, start the fluidized bed, make the material in a fluidized state, and spray the mixed material evenly on the surface of the particles to be coated in the form of mist through a spray gun. Control the pressure of the spray gun to be 0.3MPa, and the spraying time to be 3 minutes. During the entire coating process, control the temperature of the fluidized bed at 60°C and the wind speed to be 2m / s to ensure that the coating material can be evenly attached to the surface of the material to be coated to form a complete and uniform coating layer; Step 8: Place the coated material in a drying oven and dry it at 50°C for 5 hours to reduce the moisture content to below 2.5%, then take it out and cool it naturally to room temperature; Step 9: Carry out quality inspection and pack the qualified products with moisture-proof, humidity-proof and corrosion-resistant packaging materials.

[0033] Embodiment 2: 40 parts of organic fertilizer, 18 parts of decomposed livestock and poultry manure, 15 parts of straw compost, and 7 parts of humic acid; 30 parts of inorganic fertilizers, 8 parts of urea, 8 parts of diammonium phosphate, 7 parts of potassium sulfate, and 7 parts of calcium magnesium phosphate; 15 parts of sustained-release material, 5 parts of high molecular polymer, 6 parts of zeolite, 4 parts of montmorillonite; 8 parts of coating material, 4 parts of vegetable oil and 4 parts of isocyanate; 2 parts of microbial agents, 0.6 parts of Bacillus, 1 part of Trichoderma, 0.4 parts of Rhizobium, Step 1: Prepare the raw materials and crush the organic fertilizer with a crusher until the particle size is less than 5 mm; Step 2: Put the decomposed livestock and poultry manure, straw compost and humic acid into a stirring device, stir at 30 rpm for 5 minutes, increase the speed to 50 rpm for 8 minutes, then reduce the speed to 30 rpm for 2 minutes, and place in a ventilated place to dry for 1.5 days to make the moisture content reach 25%; Step 3: Grind urea, diammonium phosphate, potassium sulfate and calcium magnesium phosphate fertilizer to a particle size of less than 2 mm, pass through a 90-mesh sieve, stir at 40 rpm for 3 minutes, and then increase the speed to 60 rpm for 5 minutes; Step 4: Heat the polymer to 180°C to melt, stir at 20 rpm for 3 minutes, grind the zeolite and montmorillonite to a particle size of less than 1 mm, pass through a 110-mesh sieve, and add a small amount to the molten polymer several times. After each addition, increase the speed to 40 rpm and stir for 5 minutes. After all additions are completed, stir at 20 rpm for 2 minutes to form a sustained-release material mixture; Step 5: Put the pretreated organic fertilizer and inorganic fertilizer into a blender and blend at 65 rpm for 18 minutes; Step 6: first add the slow-release material mixture to the initially mixed material, stir at 70 rpm for 13 minutes, then add the microbial agent, stir at 50 rpm for 8 minutes, and convey the mixed material to a disc granulator for granulation to obtain granules with a particle size of 2.5 mm; Step 7: Add vegetable oil and isocyanate to a preheated container respectively, and heat to 65°C for use. Then, spray the granules obtained by the above granulation into the fluidized bed coating machine at a uniform speed, start the fluidized bed, make the material in a fluidized state, and spray the mixed material evenly on the surface of the particles to be coated in the form of mist through a spray gun. The pressure of the spray gun is controlled to be 0.4MPa, and the spraying time is 5 minutes. During the entire coating process, the temperature of the fluidized bed is controlled at 65°C and the wind speed is 2.5m / s to ensure that the coating material can be evenly attached to the surface of the material to be coated to form a complete and uniform coating layer; Step 8: Place the coated material in a drying oven and dry it at 55°C for 4 hours to reduce the moisture content to below 2.5%, then take it out and cool it naturally to room temperature; Step 9: Carry out quality inspection and pack the qualified products with moisture-proof, humidity-proof and corrosion-resistant packaging materials.

[0034] Embodiment three: 50 parts of organic fertilizer, 20 parts of decomposed livestock and poultry manure, 20 parts of straw compost, and 10 parts of humic acid; 40 parts of inorganic fertilizers, 10 parts of urea, 10 parts of diammonium phosphate, 10 parts of potassium sulfate, and 10 parts of calcium magnesium phosphate; 20 parts of sustained-release material, 7 parts of high molecular polymer, 8 parts of zeolite, and 5 parts of montmorillonite; 10 parts of coating material, 5 parts of vegetable oil and 3 parts of isocyanate; 3 parts of microbial agents, 1 part of Bacillus, 1.5 parts of Trichoderma, and 0.5 part of Rhizobium.

[0035] Step 1: Prepare the raw materials and crush the organic fertilizer with a crusher until the particle size is less than 5 mm; Step 2: Put the decomposed livestock and poultry manure, straw compost and humic acid into a stirring device, stir at 30 rpm for 5 minutes, increase the speed to 50 rpm for 8 minutes, then reduce the speed to 30 rpm for 2 minutes, and place in a ventilated place to dry for 2 days to make the moisture content reach 30%; Step 3: Grind urea, diammonium phosphate, potassium sulfate and calcium magnesium phosphate fertilizer to a particle size of less than 2 mm, pass through a 100-mesh sieve, stir at 40 rpm for 3 minutes, and then increase the speed to 60 rpm for 5 minutes; Step 4: Heat the polymer to 200°C to melt, stir at 20 rpm for 3 minutes, grind the zeolite and montmorillonite to a particle size of less than 1 mm, pass through a 120-mesh sieve, and add a small amount to the molten polymer several times. After each addition, increase the speed to 40 rpm and stir for 5 minutes. After all additions are completed, stir at 20 rpm for 2 minutes to form a sustained-release material mixture; Step 5: Put the pretreated organic fertilizer and inorganic fertilizer into a blender and blend at 80 rpm for 20 minutes; Step 6: first add the slow-release material mixture to the initially mixed material, stir at 80 rpm for 15 minutes, then add the microbial agent, stir at 60 rpm for 10 minutes, and convey the mixed material to a disc granulator for granulation to obtain granules with a particle size of 3.0 mm; Step 7: Add vegetable oil and isocyanate to a preheated container respectively, and heat to 80°C for later use. Then, spray the granules obtained by the above granulation into the fluidized bed coating machine at a uniform speed, start the fluidized bed, make the material in a fluidized state, and spray the mixed material evenly on the surface of the particles to be coated in the form of mist through a spray gun. The pressure of the spray gun is controlled to be 0.5MPa, and the spraying time is 4 minutes. During the entire coating process, the temperature of the fluidized bed is controlled at 70°C and the wind speed is 3m / s to ensure that the coating material can be evenly attached to the surface of the material to be coated to form a complete and uniform coating layer; Step 8: Place the coated material in a drying oven and dry it at 60°C for 3 hours to reduce the moisture content to below 2.5%, then take it out and cool it naturally to room temperature; Step 9: Carry out quality inspection and pack the qualified products with moisture-proof, humidity-proof and corrosion-resistant packaging materials.

[0036] Table 1 shows that by using raw materials in different weight proportions, the corresponding proportion can be selected according to different land conditions, which effectively improves the nutrient utilization rate in the fertilizer and continuously and stably supplies nutrients to crops.

[0037] Comparative Table 1 of Nitrogen Utilization Rates in Fertilizers in Examples 1 to 3: Example Embodiment 1 Embodiment 2 Embodiment 3 Composted livestock and poultry manure (portions) 15 18 20 Straw compost (shares) 10 15 20 Humic acid (parts) 5 7 10 Urea (parts) 5 8 10 Diammonium phosphate (parts) 5 8 10 Potassium sulfate (parts) 5 7 10 Calcium magnesium phosphate fertilizer (parts) 5 7 10 High molecular weight polymer (parts) 3 5 7 Zeolite (parts) 4 6 8 Montmorillonite (parts) 3 4 5 Vegetable oil (part) 3 4 5 Isocyanate (parts) 2 4 3 Bacillus (part) 0.3 0.6 1 Trichoderma (part) 0.5 1 1.5 Rhizobium (parts) 0.2 0.4 0.5 Sustained release period (days) 60 80 90 Initial nutrient release rate 3.5% 2.0% 1.5% Cumulative nutrient release rate over 28 days 48% 42% 38% Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A three-in-one slow-release ecological compound fertilizer, characterized in that: The invention comprises the following raw materials in parts by weight: 30 to 50 parts of organic fertilizer, 20 to 40 parts of inorganic fertilizer, 10 to 20 parts of slow-release material, 5 to 10 parts of coating material, and 1 to 3 parts of microbial agent; The organic fertilizers include decomposed livestock and poultry manure, straw compost and humic acid; The inorganic fertilizers include nitrogen, phosphorus and potassium compounds; The sustained-release material includes high molecular polymer, zeolite and montmorillonite; The coating material includes vegetable oil and isocyanate; The microbial agents include Bacillus, Trichoderma and Rhizobium.

2. A three-in-one slow-release ecological compound fertilizer according to claim 1, characterized in that: The organic fertilizer comprises the following raw materials in parts by weight: 15 to 20 parts of decomposed livestock and poultry manure, 10 to 20 parts of straw compost and 5 to 10 parts of humic acid.

3. A three-in-one slow-release ecological compound fertilizer according to claim 1, characterized in that: The inorganic fertilizer comprises the following raw materials in parts by weight: 5 to 10 parts of the nitrogen compound, 5 to 10 parts of the phosphorus compound and 5 to 10 parts of the potassium compound; The nitrogen compound, phosphorus compound and potassium compound are urea, diammonium phosphate and potassium sulfate respectively, and the inorganic fertilizer also includes 5 to 10 parts of calcium magnesium phosphate fertilizer.

4. The three-in-one slow-release ecological compound fertilizer according to claim 1, characterized in that: The sustained-release material comprises the following raw materials in parts by weight: 3 to 7 parts of the high molecular polymer, 4 to 8 parts of zeolite and 3 to 5 parts of montmorillonite.

5. The three-in-one slow-release ecological compound fertilizer according to claim 1, characterized in that: The coating material comprises the following raw materials in parts by weight: 3 to 8 parts of vegetable oil and 2 to 8 parts of isocyanate.

6. The three-in-one slow-release ecological compound fertilizer according to claim 1, characterized in that: The microbial agent comprises the following raw materials in parts by weight: 0.3 to 1 part of the bacillus, 0.5 to 1.5 parts of trichoderma and 0.2 to 0.5 parts of rhizobium.

7. A method for preparing a three-in-one slow-release ecological compound fertilizer, characterized in that: A three-in-one slow-release ecological compound fertilizer applied to any one of claims 1 to 6, the method comprising the following steps: Step 1: Pretreatment of raw materials First, prepare organic fertilizer, inorganic fertilizer, slow-release material, coating material and microbial agent, and then use a pulverizer to pulverize the raw materials to make the particle size of organic fertilizer less than 5 mm and the particle size of inorganic fertilizer less than 2 mm; Step 2: Organic fertilizer pretreatment Put the processed decomposed livestock and poultry manure, straw compost and humic acid into a stirring device for mixing, and then place them in a well-ventilated environment and dry them for 1 to 2 days to reduce their moisture content to 20% to 30%; Step 3: Pretreatment of inorganic fertilizers The urea, diammonium phosphate, potassium sulfate and calcium magnesium phosphate fertilizer are crushed respectively to a particle size of less than 2 mm, passed through an 80-100 mesh sieve, and then the crushed inorganic fertilizers are placed in a stirring device for mixing; Step 4: Slow-release material processing The high molecular polymer is heated to a molten state, and the temperature is maintained at 150°C to 200°C, and the zeolite and montmorillonite are ground, and the particle size of the zeolite and montmorillonite is less than 1 mm, and the particles are passed through a 100-120 mesh sieve, and then the ground zeolite and montmorillonite are added to the molten high molecular polymer, and the mixture is placed in a stirring device for mixing to form a sustained-release material mixture; Step 5: Initial Mixing Put the pretreated organic fertilizer and inorganic fertilizer into a mixer, and stir at a speed of 50 to 80 rpm for 15 to 20 minutes to fully mix the organic fertilizer and inorganic fertilizer; Step 6: Add slow-release materials and microbial agents After the initial mixing, first add the slow-release material mixture prepared in step 4, continue stirring for 10 to 15 minutes, then add the prepared microbial agent, stir for 5 to 10 minutes to fully blend the materials, and convey the mixed materials to a disc granulator for granulation to form particles with a particle size of 2.0 mm to 3.0 mm; Step 7: Encapsulation The granules obtained by the above granulation are sprayed into a fluidized bed coating machine by in-situ polymerization reaction of vegetable oil and isocyanate, and the coating solution is evenly sprayed on the surface of the granules by a spray gun to form a coating layer; Step 8: Drying and Cooling The coated particles are placed in a drying oven and dried at 50-60°C for 3-5 hours to reduce the moisture content of the coated particles to below 2.5%. After drying, the coated particles are taken out and naturally cooled to room temperature to obtain a three-in-one slow-release ecological compound fertilizer. Step 9: Quality Inspection and Packaging The prepared three-in-one slow-release ecological compound fertilizer is quality tested to check whether its nutrient content, microbial activity, and slow-release performance indicators meet the requirements. Qualified products are packaged, and moisture-proof, humidity-proof, and corrosion-resistant packaging materials are selected to ensure product quality and stability.

8. A three-in-one slow-release ecological compound fertilizer and a preparation method thereof according to claim 7, characterized in that: In the step 2, the stirring device is stirred at a low speed of 30 rpm for 5 minutes, the stirring speed is gradually increased to 50 rpm, stirring is continued for 8 minutes, the stirring speed is adjusted back to 30 rpm again, and stirring is continued for 2 minutes; In the step 3, the mixture is first stirred at a speed of 40 rpm for 3 minutes, then the speed is steadily increased to 60 rpm, and stirring is continued for 5 minutes. During the 5-minute stirring period.

9. A three-in-one slow-release ecological compound fertilizer and a preparation method thereof according to claim 7, characterized in that: In the step 4, the mixture is first stirred at a low speed of 20 rpm for 3 minutes, and the zeolite and montmorillonite are added to the stirring device in small amounts and multiple times. After each addition, the stirring speed is increased to 40 rpm and stirred for 5 minutes until all the zeolite and montmorillonite are added, and finally stirred at a speed of 20 rpm for 2 minutes.

10. The three-in-one slow-release ecological compound fertilizer and its preparation method according to claim 7, characterized in that: In the step 7, the formation of the envelope layer includes the following specific steps: Add vegetable oil and isocyanate into preheated containers respectively, heat to 50℃~80℃ for later use; Then, the preheated materials are sprayed into the fluidized bed coating machine at a uniform speed, the fluidized bed is started to make the materials in a fluidized state, and the mixed materials are sprayed evenly on the surface of the materials to be coated in the form of mist through a spray gun, the pressure of the spray gun is controlled to be 0.3-0.5MPa, and the spraying time is 3-5 minutes; During the entire coating process, the temperature of the fluidized bed is controlled at 60-70°C and the wind speed is 2-3m / s to ensure that the coating material can be evenly attached to the surface of the material to be coated to form a complete and uniform coating layer.

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