Special formula fertilizer for increasing yield of spring corn and application method thereof

Abstract

The invention relates to the technical field of agricultural fertilizers, and discloses a special formula fertilizer for increasing the yield of spring corn, which comprises the following components in percentage by weight: 15-25% of nitrogen fertilizer, 20-35% of phosphate fertilizer, 20-35% of potash fertilizer and 1-2% of molybdenum-based catalyst, and also discloses a preparation method of the special formula fertilizer for increasing the yield of spring corn. Comprising the following steps: S1, mixing a nitrogen fertilizer, a phosphate fertilizer, a potash fertilizer and trace elements, and granulating by using a fluidized bed granulator, and discloses an application method of the special formula fertilizer for spring corn yield increase, and the application method comprises the following steps: base fertilizer application: 7-10 days before sowing, the fertilizer is uniformly spread, and the application amount per mu is 40 kg. By reasonably configuring the proportion of nitrogen, phosphorus and potassium and combining a nitrogen trapping catalyst, nitrogen-fixing microorganisms and a controlled-release material, the nutrient utilization rate is increased, the nitrogen loss is reduced, the stress resistance of crops and the soil health are enhanced, and the corn yield and the environmental protection property and the use efficiency of the fertilizer are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural fertilizers, in particular to a special formula fertilizer for increasing spring corn yield and an application method thereof. Background Art

[0002] In agricultural production, corn, as a high-yield food crop, has a large demand for major nutrients such as nitrogen, phosphorus, and potassium, and the supply of these nutrients mainly depends on chemical fertilizers. However, the use of traditional fertilizers has exposed many problems in corn cultivation, resulting in low fertilizer utilization, serious environmental pollution, and insignificant crop yield increase effects. Nitrogen, as one of the most important nutrients, is seriously lost in the traditional fertilization process and enters the environment mainly through volatilization, leaching, etc., resulting in fertilizer waste and ecological pollution. In addition, conventional fertilizers are released quickly, with an oversupply in the early stage, while in the later stage of the crop, the nutrient supply is insufficient, which seriously affects the final yield of corn.

[0003] In the existing technology, in order to solve the problem of nitrogen loss, although biological nitrogen fixation technology and some controlled release technology have been proposed, the traditional biological nitrogen fixation efficiency is low and cannot meet the nitrogen demand of crops. The existing controlled release fertilizers mainly rely on physical coating materials. Although they can delay the release of nutrients, they are difficult to promote on a large scale due to their high cost and the fact that the controlled release effect is greatly affected by environmental factors. In addition, the long-term use of chemical fertilizers alone will also lead to a decrease in soil fertility, affecting the growth of crops and the ability to increase sustainable production.

[0004] In view of the above problems in the prior art, the present invention provides a special formula fertilizer for increasing spring corn yield and an application method thereof. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a special formula fertilizer for increasing spring corn yield and an application method thereof, which solves the problems of low nutrient utilization rate, serious nitrogen loss, decreased soil fertility and insignificant crop yield increase effect in traditional fertilizers.

[0006] To achieve the above objectives, the present invention is implemented through the following technical scheme: a special formula fertilizer for increasing spring corn yield, comprising the following components by weight percentage: 15%-25% nitrogen fertilizer, 20%-35% phosphorus fertilizer, 20%-35% potassium fertilizer, 1%-2% molybdenum-based catalyst, 0.4%-1% iron-based catalyst, 0.4%-1% graphene composite catalyst, 1%-2% nitrogen-fixing microorganism, 2%-4% thermosensitive polymer, 1%-3% moisture-sensitive polymer, 1%-2% sodium alginate, 2%-4% potassium humate, and 2%-4% water retaining agent.

[0007] Preferably, the nitrogen-fixing microorganism is a genetically engineered strain of the genus Azotobacter, which is fixed on a porous carrier by a chitosan and sodium alginate cross-linking material.

[0008] Preferably, the temperature-sensitive polymer is poly (N-isopropylacrylamide), and the moisture-sensitive polymer is sodium polyacrylate.

[0009] A method for preparing a special formula fertilizer for increasing spring corn yield is prepared by using the components of the special formula fertilizer for increasing spring corn yield described above, comprising the following steps:

[0010] S1. Mix nitrogen fertilizer, phosphate fertilizer, potash fertilizer and trace elements, and granulate them using a fluidized bed granulator, with the temperature controlled below 120°C;

[0011] S2. preparing a nitrogen capture and conversion catalyst, loading a molybdenum-based and an iron-based catalyst on a porous carrier by an impregnation method, calcining to form a bimetallic catalyst, and compounding with graphene;

[0012] S3, culturing engineered nitrogen-fixing microorganisms, and fixing the microorganisms on a carrier using chitosan-sodium alginate;

[0013] S4, mixing the nitrogen-fixing microorganism carrier and the nitrogen capture catalyst into the basic fertilizer particles according to a certain proportion;

[0014] S5, using temperature-sensitive and moisture-sensitive controlled-release materials to coat fertilizer particles to form intelligent controlled-release formula fertilizer. Preferably, the step S1 specifically includes the following steps:

[0015] S1.1, premixing: nitrogen fertilizer, phosphate fertilizer, potash fertilizer and trace elements are mixed in proportion, the mixing time is controlled at 5-15min, and the speed of the mixing equipment is controlled at 50-80rpm;

[0016] S1.2, Granulation preparation: The mixed material is evenly fed into the fluidized bed granulator through a conveying device, and the feeding speed is controlled at 5-10kg / min;

[0017] S1.3, Granulation process: The temperature of the granulator is controlled at 100-120℃, a binder is used, the amount of the binder added is 0.5%-1% of the total material, auxiliary granulation, the air flow speed is controlled at 0.5-1.5m / s, the residence time of the particles in the granulator is 10-20min, and the final particle diameter is controlled between 2-5mm;

[0018] S1.4, Drying and cooling: The temperature of the dried particles is controlled at 40-50°C, and the moisture content is reduced to 8%-10% by a dryer;

[0019] S1.5, Screening and packaging: The qualified particle size after screening is 2-5mm. Particles that are too small or too large can be returned for granulation.

[0020] Preferably, the step S2 specifically includes the following steps:

[0021] S2.1, carrier pretreatment: select porous zeolite or silica gel as the carrier material, the pore size is 3-10nm, the carrier is pretreated at a high temperature of 200℃-300℃ for 1-2h, and then cooled for use;

[0022] S2.2, preparation of molybdenum-based catalyst: prepare 0.05-0.1M ammonium molybdate solution, immerse the pretreated porous support in the ammonium molybdate solution for 2-4 hours;

[0023] S2.3, preparation of iron-based catalyst: prepare 0.05-0.1M iron nitrate solution, immerse the carrier in the iron nitrate solution according to the ratio of Mo=3:1, and immerse for 2-4h;

[0024] S2.4, calcining to form a bimetallic catalyst: placing the impregnated carrier under nitrogen protection, calcining at 600°C for 2-3 hours. During the calcination process, ammonium molybdate and iron nitrate decompose into molybdenum oxide and iron oxide, which are attached to the surface of the carrier respectively, forming a molybdenum-iron bimetallic catalyst;

[0025] S2.5, graphene composite: the prepared bimetallic catalyst and nitrogen-doped graphene are mixed in a mass ratio of 1:1, the catalyst and graphene are uniformly dispersed by a solvent method, ultrasonically treated for 15-30 minutes, and the mixture is placed at a high temperature of 400-500°C for reduction treatment for 1-2 hours to form a molybdenum-iron bimetallic and graphene composite catalyst;

[0026] S2.6. Nitrogen capture performance test: The nitrogen capture efficiency is tested within 1-24 hours by a nitrogen adsorption instrument, and the capture amount is measured in mg ammonia / g catalyst.

[0027] Preferably, the step S3 specifically includes the following steps:

[0028] S3.1. Cultivation of nitrogen-fixing strains: Cultivate engineered Azotobacter strains in LB medium containing limited nitrogen at 28-32°C, aeration rate of 0.5-1.5 vvm, stirring rate of 200-300 rpm, and cultivation time of 48-72 h.

[0029] S3.2, bacterial cell collection and freeze drying: after the culture is completed, the bacterial cells are collected by centrifugation at 6000-8000 rpm for 10-15 min, and the bacterial cells are suspended in 0.5%-1% sodium alginate solution, mixed evenly, and then dried by freeze drying;

[0030] S3.3, preparing a chitosan-sodium alginate mixed solution: mixing a 1%-2% chitosan solution with a sodium alginate solution in a volume ratio of 1:1 to 2:1 to form a cross-linking fixative solution;

[0031] S3.4, Carrier-loaded microorganisms: Immerse the porous zeolite or silica gel carrier in the nitrogen-fixing microorganism suspension for 1-2 hours;

[0032] S3.5. Cross-linking and fixation: transfer the microbial carrier to a 0.5%-1% calcium chloride solution for cross-linking reaction for 15-30 minutes, so that chitosan and sodium alginate form a stable cross-linking film, and finally fix it.

[0033] Preferably, the step S4 specifically includes the following steps:

[0034] S4.1, proportion weighing:

[0035] Nitrogen-fixing microbial carrier: weighed at 0.5%-1.0% of the total weight of the fertilizer;

[0036] Nitrogen capture catalyst: weighed at 0.5%-2% of the total weight of the fertilizer;

[0037] S4.2, Mixing process: Pour the granulated basic fertilizer granules into the mixer, add the nitrogen-fixing microbial carrier and the nitrogen capture catalyst, mix for 10-15 minutes, and control the stirring speed at 50-100 rpm.

[0038] Preferably, the step S5 specifically includes the following steps:

[0039] S5.1. Prepare controlled release materials:

[0040] Temperature-sensitive material: prepare a poly (N-isopropylacrylamide) solution with a concentration of 1%-2%;

[0041] Moisture-sensitive materials: prepare a sodium polyacrylate solution with a concentration of 1%-2%;

[0042] S5.2, coating process: the fertilizer particles are evenly spread in the spraying equipment, the temperature-sensitive material is first sprayed, the spraying rate is controlled at 1-2mL / min, and then dried at 40-50℃ for 15-30min to form the first layer of controlled-release film, and then the second layer of moisture-sensitive material is sprayed, the spraying rate is also 1-2mL / min, and the drying time is 15-30min;

[0043] S5.3. Multilayer film curing: After the coating is completed, the fertilizer particles are cured at 40-50°C for 20-40 minutes;

[0044] S5.4, Controlled release performance test: Conduct soil simulation tests under different temperature and humidity conditions, and record the release rates of nitrogen, phosphorus and potassium of the fertilizer;

[0045] S5.5. Packaging and storage: The dried fertilizer granules are screened, bagged and stored in a dry environment at room temperature.

[0046] A method for applying a special formula fertilizer for increasing spring corn yield, used in conjunction with the above-mentioned special formula fertilizer for increasing spring corn yield, comprises the following steps:

[0047] Application of base fertilizer: 7-10 days before sowing, spread the fertilizer evenly at a rate of 40 kg per mu and turn it into the soil 15-20 cm deep;

[0048] Topdressing: During the jointing stage of corn, apply 20-30 kg of fertilizer per mu, using furrow or hole application, and combine irrigation after fertilization to activate nutrients;

[0049] Supplementary fertilizer during the ear stage: During the grain filling period of corn, apply 5-10 kg of fertilizer per mu, using drip irrigation, root application or foliar spraying for fixed-point supplementation.

[0050] The present invention provides a special formula fertilizer for increasing spring corn yield and an application method thereof. It has the following beneficial effects:

[0051] 1. The special formula fertilizer for increasing spring corn yield of the present invention ensures that corn obtains continuous nutrient supply at different growth stages by reasonably allocating the ratio of nitrogen, phosphorus and potassium, and combining functional components such as nitrogen capture catalysts and nitrogen-fixing microorganisms. In particular, the fertilizer can provide sufficient nitrogen, phosphorus and potassium for crops during the jointing and filling stages, significantly improving the ear length, ear weight and number of grains of corn, and greatly increasing the yield per mu.

[0052] 2. The present invention can effectively capture nitrogen in the air and convert it into ammonium ions and nitrates that can be absorbed by crops by introducing molybdenum-based, iron-based catalysts and graphene composite catalysts, thereby reducing nitrogen loss. At the same time, nitrogen-fixing microorganisms further enhance nitrogen fixation, reduce dependence on chemical nitrogen fertilizers, and significantly improve the utilization efficiency of nitrogen, phosphorus and potassium. In addition, temperature-sensitive and humidity-sensitive controlled-release materials adjust the nutrient release rate according to changes in the soil environment, thereby achieving long-term nutrient supply, avoiding rapid nutrient loss, extending the effective nutrient supply period, and reducing the frequency of fertilization.

[0053] 3. The functional components such as sodium alginate and potassium humate added to the fertilizer of the present invention can promote the growth of corn roots, enhance the resistance of crops to adversity, and improve drought resistance and lodging resistance. Potassium humate also improves soil structure, enhances soil water retention and fertility, and further improves the stable growth and adaptability of crops.

[0054] 4. The present invention can capture nitrogen from the air and convert it into a nitrogen source that can be absorbed by crops through the action of nitrogen capture catalysts, thereby reducing the amount of nitrogen fertilizer used and reducing nitrogen loss. In addition, the controlled-release material effectively controls the rapid loss of nutrients under rainfall or irrigation conditions, reduces nitrogen pollution to the environment, and significantly reduces the problem of soil nitrogen loss caused by excessive use of nitrogen fertilizers in traditional fertilizers, making the fertilizer more environmentally friendly and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 is a flow chart of the preparation method of the present invention;

[0056] Figure 2 The figure is a flow chart of the method for using the present invention. DETAILED DESCRIPTION

[0057] 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.

[0058] Please refer to the attached Figure 1 The embodiment of the present invention provides a special formula fertilizer for increasing spring corn yield, which includes the following components by weight percentage: 15%-25% nitrogen fertilizer, 20%-35% phosphorus fertilizer, 20%-35% potassium fertilizer, 1%-2% molybdenum-based catalyst, 0.4%-1% iron-based catalyst, 0.4%-1% graphene composite catalyst, 1%-2% nitrogen-fixing microorganism, 2%-4% thermosensitive polymer, 1%-3% moisture-sensitive polymer, 1%-2% sodium alginate, 2%-4% potassium humate, and 2%-4% water retaining agent.

[0059] The nitrogen-fixing microorganism is a strain of Azotobacter modified by genetic engineering and is fixed on a porous carrier through chitosan and sodium alginate cross-linking materials.

[0060] The temperature-sensitive polymer is poly-N-isopropylacrylamide, and the moisture-sensitive polymer is sodium polyacrylate.

[0061] A method for preparing a special formula fertilizer for increasing spring corn yield is prepared by using the components of the special formula fertilizer for increasing spring corn yield, comprising the following steps:

[0062] S1. Mix nitrogen fertilizer, phosphate fertilizer, potash fertilizer and trace elements, and granulate them using a fluidized bed granulator, with the temperature controlled below 120°C;

[0063] S2. preparing a nitrogen capture and conversion catalyst, loading a molybdenum-based and an iron-based catalyst on a porous carrier by an impregnation method, calcining to form a bimetallic catalyst, and compounding with graphene;

[0064] S3, culturing engineered nitrogen-fixing microorganisms, and fixing the microorganisms on a carrier using chitosan-sodium alginate;

[0065] S4, mixing the nitrogen-fixing microorganism carrier and the nitrogen capture catalyst into the basic fertilizer particles according to a certain proportion;

[0066] S5. Use temperature-sensitive and moisture-sensitive controlled-release materials to coat fertilizer particles to form intelligent controlled-release formula fertilizer.

[0067] Step S1 specifically includes the following steps:

[0068] S1.1, premixing: nitrogen fertilizer, phosphate fertilizer, potash fertilizer and trace elements are mixed in proportion, the mixing time is controlled at 5-15min, and the speed of the mixing equipment is controlled at 50-80rpm;

[0069] S1.2, Granulation preparation: The mixed material is evenly fed into the fluidized bed granulator through a conveying device, and the feeding speed is controlled at 5-10kg / min;

[0070] S1.3, Granulation process: The temperature of the granulator is controlled at 100-120℃, a binder is used, the amount of the binder added is 0.5%-1% of the total material, auxiliary granulation, the air flow speed is controlled at 0.5-1.5m / s, the residence time of the particles in the granulator is 10-20min, and the final particle diameter is controlled between 2-5mm;

[0071] S1.4, Drying and cooling: The temperature of the dried particles is controlled at 40-50°C, and the moisture content is reduced to 8%-10% by a dryer;

[0072] S1.5, Screening and packaging: The qualified particle size after screening is 2-5mm. Particles that are too small or too large can be returned for granulation.

[0073] The S2 step specifically includes the following steps:

[0074] S2.1, carrier pretreatment: select porous zeolite or silica gel as the carrier material, the pore size is 3-10nm, the carrier is pretreated at a high temperature of 200℃-300℃ for 1-2h, and then cooled for use;

[0075] S2.2, preparation of molybdenum-based catalyst: prepare 0.05-0.1M ammonium molybdate solution, immerse the pretreated porous support in the ammonium molybdate solution for 2-4 hours;

[0076] S2.3, preparation of iron-based catalyst: prepare 0.05-0.1M iron nitrate solution, immerse the carrier in the iron nitrate solution according to the ratio of Mo=3:1, and immerse for 2-4h;

[0077] S2.4, calcining to form a bimetallic catalyst: placing the impregnated carrier under nitrogen protection, calcining at 600°C for 2-3 hours. During the calcination process, ammonium molybdate and iron nitrate decompose into molybdenum oxide and iron oxide, which are attached to the surface of the carrier respectively, forming a molybdenum-iron bimetallic catalyst;

[0078] S2.5, graphene composite: the prepared bimetallic catalyst and nitrogen-doped graphene are mixed in a mass ratio of 1:1, the catalyst and graphene are uniformly dispersed by a solvent method, ultrasonically treated for 15-30 minutes, and the mixture is placed at a high temperature of 400-500°C for reduction treatment for 1-2 hours to form a molybdenum-iron bimetallic and graphene composite catalyst;

[0079] S2.6. Nitrogen capture performance test: The nitrogen capture efficiency is tested within 1-24 hours by a nitrogen adsorption instrument, and the capture amount is measured in mg ammonia / g catalyst.

[0080] The S3 step specifically includes the following steps:

[0081] S3.1. Cultivation of nitrogen-fixing strains: Cultivate engineered Azotobacter strains in LB medium containing limited nitrogen at 28-32°C, aeration rate of 0.5-1.5 vvm, stirring rate of 200-300 rpm, and cultivation time of 48-72 h.

[0082] S3.2, bacterial cell collection and freeze drying: after the culture is completed, the bacterial cells are collected by centrifugation at 6000-8000 rpm for 10-15 min, and the bacterial cells are suspended in 0.5%-1% sodium alginate solution, mixed evenly, and then dried by freeze drying;

[0083] S3.3, preparing a chitosan-sodium alginate mixed solution: mixing a 1%-2% chitosan solution with a sodium alginate solution in a volume ratio of 1:1 to 2:1 to form a cross-linking fixative solution;

[0084] S3.4, Carrier-loaded microorganisms: Immerse the porous zeolite or silica gel carrier in the nitrogen-fixing microorganism suspension for 1-2 hours;

[0085] S3.5. Cross-linking and fixation: transfer the microbial carrier to a 0.5%-1% calcium chloride solution for cross-linking reaction for 15-30 minutes, so that chitosan and sodium alginate form a stable cross-linking film, and finally fix it.

[0086] The S4 step specifically includes the following steps:

[0087] S4.1, proportion weighing:

[0088] Nitrogen-fixing microbial carrier: weighed at 0.5%-1.0% of the total weight of the fertilizer;

[0089] Nitrogen capture catalyst: weighed at 0.5%-2% of the total weight of the fertilizer;

[0090] S4.2, Mixing process: Pour the granulated basic fertilizer granules into the mixer, add nitrogen-fixing microbial carrier and nitrogen capture catalyst, mix for 10-15 minutes, and control the stirring speed at 50-100rpm.

[0091] Step S5 specifically includes the following steps:

[0092] S5.1. Prepare controlled release materials:

[0093] Temperature-sensitive material: prepare a poly (N-isopropylacrylamide) solution with a concentration of 1%-2%;

[0094] Moisture-sensitive materials: prepare a sodium polyacrylate solution with a concentration of 1%-2%;

[0095] S5.2, coating process: the fertilizer particles are evenly spread in the spraying equipment, the temperature-sensitive material is first sprayed, the spraying rate is controlled at 1-2mL / min, and then dried at 40-50℃ for 15-30min to form the first layer of controlled-release film, and then the second layer of moisture-sensitive material is sprayed, the spraying rate is also 1-2mL / min, and the drying time is 15-30min;

[0096] S5.3. Multilayer film curing: After the coating is completed, the fertilizer particles are cured at 40-50°C for 20-40 minutes;

[0097] S5.4, Controlled release performance test: Conduct soil simulation tests under different temperature and humidity conditions, and record the release rates of nitrogen, phosphorus and potassium of the fertilizer;

[0098] S5.5. Packaging and storage: The dried fertilizer granules are screened, bagged and stored in a dry environment at room temperature.

[0099] Please refer to the attached Figure 2 A method for applying a special formula fertilizer for increasing spring corn yield, used in conjunction with the above-mentioned special formula fertilizer for increasing spring corn yield, comprises the following steps:

[0100] Application of base fertilizer: 7-10 days before sowing, spread the fertilizer evenly at a rate of 40 kg per mu and turn it into the soil 15-20 cm deep;

[0101] Topdressing: During the jointing stage of corn, apply 20-30 kg of fertilizer per mu, using furrow or hole application, and combine irrigation after fertilization to activate nutrients;

[0102] Supplementary fertilizer during the ear stage: During the grain filling period of corn, apply 5-10 kg of fertilizer per mu, using drip irrigation, root application or foliar spraying for fixed-point supplementation.

[0103] Embodiment 1:

[0104] Formula of Example 1: nitrogen fertilizer: 15%; phosphorus fertilizer: 20%; potash fertilizer: 20%; molybdenum-based catalyst: 1%; iron-based catalyst: 0.4%; graphene composite catalyst: 0.4%; nitrogen-fixing microorganism: 1%; thermosensitive polymer: 2%; moisture-sensitive polymer: 1%; sodium alginate: 1%; potassium humate: 2%; water retaining agent: 2%.

[0105] Implementation steps:

[0106] S1. Batching and granulation:

[0107] Nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer and trace elements are mixed in proportion, the mixing time is 10 minutes, the rotation speed is controlled at 60rpm; then they are sent to the fluidized bed granulator through a conveying device, the feed rate is 7kg / min, the granulation temperature is controlled at 110°C, the air flow velocity is 1m / s, and the final particle diameter is 3mm.

[0108] S2. Preparation of catalyst:

[0109] The porous zeolite carrier was pretreated at 250°C for 1.5 hours, impregnated with ammonium molybdate and iron nitrate solution according to Mo=3:1, calcined and mixed with graphene in a ratio of 1:1, and reduced at 400°C for 1.5 hours.

[0110] S3. Cultivation of nitrogen-fixing microorganisms:

[0111] The culture temperature of the engineered Azotobacter strain was set at 30°C, the aeration rate was 1 vvm, the culture time was 48 hours, and the bacteria were suspended using 0.8% sodium alginate and then freeze-dried.

[0112] S4, Mixing and granulation:

[0113] The nitrogen-fixing microorganism carrier and the catalyst were mixed with the basic fertilizer granules at a ratio of 0.8% and 1.5%, and the mixing time was 12 minutes.

[0114] S5, Intelligent Wrapping:

[0115] A 1.5% temperature-sensitive polymer and a 1.5% humidity-sensitive polymer solution were prepared with a spraying speed of 1.5 mL / min. After coating, the solution was cured at 45° C. for 30 minutes.

[0116] Summarize:

[0117] This embodiment is designed based on the basic ratio, which can meet the basic needs of nitrogen, phosphorus and potassium, and utilizes the intelligent controlled release and nitrogen fixation functions to meet the nutritional needs of crops at different growth stages.

[0118] Embodiment 2:

[0119] Formula of Example 2: nitrogen fertilizer: 20%; phosphorus fertilizer: 25%; potash fertilizer: 25%; molybdenum-based catalyst: 1.5%; iron-based catalyst: 0.6%; graphene composite catalyst: 0.6%; nitrogen-fixing microorganisms: 1.5%; thermosensitive polymer: 3%; humidity-sensitive polymer: 1.5%; sodium alginate: 1.5%; potassium humate: 3%; water retaining agent: 3%.

[0120] Implementation steps:

[0121] S1. Batching and granulation:

[0122] The batching and mixing time was 12 minutes, the rotation speed was controlled at 70 rpm, the granulation temperature was controlled at 115°C, the air flow velocity was 1.2 m / s, and the final granule diameter was 3.5 mm.

[0123] S2. Preparation of catalyst:

[0124] The porous zeolite carrier was pretreated for 2 hours, the ratio of molybdenum-based to iron-based catalysts in the impregnation solution was adjusted to 1.5%, the calcination temperature was maintained at 600°C, and the graphene was mixed and reduced at 450°C for 2 hours.

[0125] S3. Cultivation of nitrogen-fixing microorganisms:

[0126] The culture time of the engineered Azotobacter strain was extended to 72 h, 1% sodium alginate was used for fixation, and the centrifugation speed was increased to 8000 rpm.

[0127] S4, Mixing and granulation:

[0128] The nitrogen-fixing microorganism carrier and the catalyst were mixed in a ratio of 1.2% and 1.8%, and the mixing time was extended to 15 minutes.

[0129] S5, Intelligent Wrapping:

[0130] The concentrations of the temperature-sensitive polymer and the moisture-sensitive polymer were increased to 3% and 1.5%, respectively, the spraying speed was adjusted to 1.8 mL / min, and the curing time was 35 min.

[0131] Summarize:

[0132] Compared with Example 1, Example 2 is optimized in terms of formulation ratio and processing conditions, thereby improving the activity and controlled release effect of the catalyst, and is suitable for larger-scale nutritional needs during the growth period of corn.

[0133] Embodiment 3:

[0134] Formula of Example 3: nitrogen fertilizer: 22%; phosphorus fertilizer: 28%; potash fertilizer: 28%; molybdenum-based catalyst: 1.8%; iron-based catalyst: 0.8%; graphene composite catalyst: 0.8%; nitrogen-fixing microorganisms: 1.8%; thermosensitive polymer: 3.5%; moisture-sensitive polymer: 2%; sodium alginate: 1.8%; potassium humate: 3.5%; water retaining agent: 3.5%.

[0135] Implementation steps:

[0136] S1. Batching and granulation:

[0137] The mixing time of the ingredients was 15 minutes, the rotation speed was 80 rpm, the granulation temperature was controlled at 118°C, the air flow velocity was 1.3 m / s, and the particle diameter was controlled at 4 mm.

[0138] S2. Preparation of catalyst:

[0139] The carrier pretreatment time was extended to 2.5 hours, the calcination temperature was maintained at 600°C, and the graphene reduction treatment temperature was increased to 480°C for 1.8 hours.

[0140] S3. Cultivation of nitrogen-fixing microorganisms:

[0141] The culture temperature of the engineered strain was maintained at 30°C, the sodium alginate concentration was increased to 1.2%, the culture time was 72 hours, and the final freeze-drying temperature was -20°C.

[0142] S4, Mixing and granulation:

[0143] The nitrogen-fixing microbial carrier and the catalyst are mixed with the basic fertilizer in a ratio of 1.5% and 2%, and the mixing time is controlled to be 16 minutes.

[0144] S5, Intelligent Wrapping:

[0145] The concentration of the temperature-sensitive polymer was increased to 3.5%, the concentration of the moisture-sensitive polymer was 2%, the spraying speed was 2 mL / min, the curing temperature was increased to 50°C, and the curing time was 40 minutes.

[0146] Summarize:

[0147] Example 3 further increases the ratio of catalyst to nitrogen-fixing microorganisms, enhances the performance of the controlled-release material, and improves the continuous fertilizer supply effect of the fertilizer in the later stage.

[0148] Embodiment 4:

[0149] Formula of Example 4: nitrogen fertilizer: 24%; phosphorus fertilizer: 30%; potash fertilizer: 30%; molybdenum-based catalyst: 1.9%; iron-based catalyst: 0.9%; graphene composite catalyst: 0.9%; nitrogen-fixing microorganisms: 1.9%; thermosensitive polymer: 3.8%; moisture-sensitive polymer: 2.5%; sodium alginate: 1.9%; potassium humate: 3.8%; water retaining agent: 3.8%.

[0150] Implementation steps:

[0151] S1. Batching and granulation:

[0152] The mixing time of ingredients was extended to 17 minutes, the granulation temperature was controlled at 119°C, the particle diameter was 4.5 mm, and the air flow velocity was 1.4 m / s.

[0153] S2. Preparation of catalyst:

[0154] The carrier pretreatment time was extended to 2.5 hours, the ratio of molybdenum-based and iron-based catalysts was 1.9%, the graphene reduction temperature was 490 °C, and the treatment time was 1.9 hours.

[0155] S3. Cultivation of nitrogen-fixing microorganisms:

[0156] The sodium alginate concentration was increased to 1.3%, the culture conditions remained unchanged, and the final drying temperature was -25°C.

[0157] S4, Mixing and granulation:

[0158] The ratio of nitrogen-fixing microorganism carrier to catalyst was 1.7% and 2.2% respectively, and the mixing time was 18 minutes.

[0159] S5, Intelligent Wrapping:

[0160] The concentration of the temperature-sensitive polymer is 3.8%, the concentration of the moisture-sensitive polymer is 2.5%, the spraying speed is 2.2 mL / min, and the curing time is 45 minutes.

[0161] Summarize:

[0162] Example 4 further increases the proportion of controlled-release materials and functional components, and is suitable for the long-term fertilizer supply needs of high-yield corn fields, especially for exerting a controlled-release effect under high temperature and high humidity conditions.

[0163] Embodiment 5:

[0164] Formula of Example 5: nitrogen fertilizer: 25%; phosphorus fertilizer: 35%; potash fertilizer: 35%; molybdenum-based catalyst: 2%; iron-based catalyst: 1%; graphene composite catalyst: 1%; nitrogen-fixing microorganisms: 2%; thermosensitive polymer: 4%; moisture-sensitive polymer: 3%; sodium alginate: 2%; potassium humate: 4%; water-retaining agent: 4%.

[0165] Implementation steps:

[0166] S1. Batching and granulation:

[0167] The mixing time was 18 minutes, the rotation speed was 80 rpm, the granulation temperature was controlled at 120°C, the particle diameter was 5 mm, and the air flow velocity was 1.5 m / s.

[0168] S2. Preparation of catalyst:

[0169] The carrier pretreatment time was 2.5 hours, the ratio of molybdenum-based and iron-based catalysts was 2%, the graphene composite reduction temperature was 500°C, and the treatment time was 2 hours.

[0170] S3. Cultivation of nitrogen-fixing microorganisms:

[0171] The culture conditions of the engineered strains remained unchanged, with a sodium alginate concentration of 1.5% and a freeze-drying temperature of -30 °C.

[0172] S4, Mixing and granulation:

[0173] The nitrogen-fixing microorganism carrier and the catalyst are mixed in a ratio of 2% and the mixing time is 20 minutes.

[0174] S5, Intelligent Wrapping:

[0175] Thermosensitive polymer 4%, moisture-sensitive polymer 3%, spraying speed 2.5mL / min, curing time 50 minutes.

[0176] Summarize:

[0177] Example 5 maximizes the ratio of nitrogen, phosphorus, potassium and catalyst, and is suitable for the ultra-high yield requirements of high-yield corn fields. The controlled-release material and the functional components achieve the best ratio, ensuring the best fertilizer supply effect under different environmental conditions.

[0178] Summary:

[0179] From Example 1 to Example 5, the formula ratio, catalyst preparation, nitrogen-fixing microorganism culture and controlled-release material design have been gradually optimized, especially in terms of high-yield and high-efficiency fertilizer supply, and the adaptability of fertilizers under different environmental conditions has been gradually improved. Innovation and deepening have been carried out between each example, and finally the long-term effect of the fertilizer, continuous fertilizer supply capacity and intelligent controlled release function have been fully optimized.

[0180] 1. Experimental Design Overview

[0181] 1. Purpose of the experiment

[0182] The following comparative experiment was designed to verify the remarkable effects of the present invention - a special formula fertilizer for increasing spring corn yield - in increasing corn yield, improving nutrient utilization and environmental friendliness, especially its advantages compared with existing conventional fertilizers. The experiment will compare the field performance of the formula fertilizers of the five embodiments with conventional fertilizers, and evaluate their effects on corn growth, yield, stress resistance and soil fertility, so as to verify the innovation and technical effectiveness of the present invention. At the same time, independent tests were conducted on the nitrogen capture efficiency and controlled release performance of the formula fertilizer to further prove its unique functions in efficient nitrogen utilization and long-term nutrient supply.

[0183] 2. Experimental Design

[0184] The experiment is divided into three main parts:

[0185] Field comparison experiment: compare the different field performances of the formula fertilizers of the five embodiments with conventional fertilizers, covering multiple growth cycles, and testing yield, nutrient utilization, stress resistance, soil health, etc.

[0186] Laboratory testing experiments: Detailed testing is carried out under laboratory controlled conditions on key functions of formula fertilizers, such as nitrogen capture and conversion efficiency, nutrient controlled release performance, soil nitrogen cycle, etc.

[0187] Long-term soil health monitoring experiment: Through multi-year field experiments, the soil nutrient changes, organic matter accumulation and microbial activity are monitored to verify the soil friendliness of the present invention.

[0188] 2. Field comparative experiment

[0189] 1. Experimental Design

[0190] 1.1 Experimental group settings

[0191] The experiment was set up with 7 experimental groups as follows:

[0192] Control group (Group C): conventional fertilizer was used with an NPK ratio of 15-15-15, without special components such as nitrogen capture catalysts, nitrogen-fixing microorganisms, and intelligent controlled-release materials.

[0193] Example 1 Group (T1 Group): The formula fertilizer of Example 1 was used.

[0194] Example 2 Group (T2 Group): The formula fertilizer of Example 2 was used.

[0195] Example 3 Group (T3 Group): The formula fertilizer of Example 3 was used.

[0196] Example 4 Group (T4 Group): The formula fertilizer of Example 4 was used.

[0197] Example 5 Group (T5 Group): The formula fertilizer of Example 5 was used.

[0198] High-dose chemical nitrogen fertilizer group (CN group): This group used a high-dose chemical nitrogen fertilizer (the amount of nitrogen in conventional fertilizers was increased by 30%).

[0199] 1.2 Experimental parameter settings

[0200] Experimental plots: Each group was set up with 10 replicate fields, each field had an area of ​​20 mu, and there were 70 experimental plots in total. The experimental plots were randomly arranged.

[0201] Crop varieties: Use high-yield spring corn varieties uniformly to ensure that the crop varieties of all experimental groups are consistent.

[0202] Experimental period: The experimental period was set to three growing seasons to monitor cross-seasonal nutrient utilization and soil changes.

[0203] Fertilization plan: Base fertilizer is applied before corn sowing each season, and topdressing and supplementary fertilizer during the ear stage are carried out at different stages of crop growth.

[0204] Monitoring cycle: Field data for each season, including plant growth, stress resistance, yield and soil health indicators, will be collected regularly at different points in the growing season.

[0205] 1.3 Experimental data collection

[0206] Growth indicator collection:

[0207] Plant height and stem diameter: Measure plant height and stem diameter every 10 days to record the growth rate and robustness of the corn.

[0208] Chlorophyll content: Chlorophyll content is measured at the seedling stage, jointing stage, heading stage and grain filling stage in each growth period to evaluate the nitrogen absorption of crops.

[0209] Stress resistance test: Under stress conditions such as drought and high temperature, the survival rate and stress resistance response (such as drought resistance, lodging resistance, etc.) of crops are measured.

[0210] Yield and nutrient uptake indicators:

[0211] Ear length, ear weight, and number of kernels: Thirty corn ears were randomly collected from each group at the corn maturity stage, and their length, weight, and number of kernels were measured.

[0212] Yield per mu: After harvest, record the yield per mu of each group and calculate the total yield increase rate of corn.

[0213] Nutrient absorption: Determine the content of nitrogen, phosphorus and potassium in corn kernels and plants to evaluate the nutrient utilization efficiency of each group of fertilizers.

[0214] Nitrogen utilization and loss monitoring:

[0215] Nitrogen use efficiency (NUE): The nitrogen use efficiency of corn is measured by nitrogen content measurement and isotope tracking technology.

[0216] Nitrogen residue and loss monitoring: After each growing season, the nitrogen residue in the field soil and the nitrogen loss in the deep soil are tested.

[0217] Soil Health Monitoring:

[0218] Organic matter content: Determine the organic matter content of the soil after harvest to assess the impact of fertilizers on the long-term health of the soil.

[0219] Soil microbial activity: Monitor the activity and diversity of soil microbial communities through soil microbial DNA sequencing technology.

[0220] Changes in soil fertility: Through soil nutrient dynamic testing, evaluate changes in N, P, and K content in the soil and observe the long-term effects of fertilizers on soil fertility.

[0221] 2. Experimental Procedure

[0222] Field preparation: Select the field experimental plots and allocate 7 experimental groups to the experimental plots according to the random block design. Apply basal fertilizer one week before sowing, and the fertilizer amount is set according to each experimental group.

[0223] Management and topdressing during the growth period: According to the different growth stages of corn, topdressing and supplementary fertilizers are applied in the jointing stage and the grain filling stage. After fertilization, irrigation is combined to activate nutrients.

[0224] Field data collection: Regularly collect crop growth data, stress resistance response, and nutrient absorption data, and collect soil samples for analysis after each season.

[0225] 3. Data Results

[0226] Table 1: Growth and stress resistance comparison test results

[0227]

[0228] Table 2: Yield and nutrient absorption comparison test results

[0229]

[0230]

[0231] Table 3: Soil health monitoring experiment results

[0232]

[0233]

[0234] 3. Laboratory Test Experiment

[0235] Experiment 1: Nitrogen capture and conversion efficiency test

[0236] 1. Purpose of the experiment

[0237] Laboratory tests were conducted to verify the efficiency of the nitrogen capture catalyst in the fertilizer formula of the present invention in capturing atmospheric nitrogen and converting it into ammonium ions or nitrates that can be absorbed by crops.

[0238] 2. Experimental Design

[0239] Experimental groups:

[0240] Control group (conventional fertilizer without nitrogen capture catalyst).

[0241] Example 1 group to Example 5 group.

[0242] Test method: A nitrogen adsorption instrument and a gas chromatograph were used to measure the nitrogen capture efficiency of the catalyst and record the ammonia (NH 3 ) and nitrate (NO 3 ) was generated, and the experiment lasted for 24 hours.

[0243] Test conditions: The experiment simulates the field atmospheric environment, with nitrogen accounting for 78% of the air, relative humidity maintained at 60%, and temperature controlled at 25°C.

[0244] 3. Data Results

[0245]

[0246]

[0247] Experiment 2: Intelligent controlled release performance test

[0248] 1. Purpose of the experiment

[0249] Through laboratory environment simulation, the ability of temperature-sensitive and humidity-sensitive controlled-release materials to regulate the release rate of fertilizer nutrients under different temperature and humidity conditions is verified.

[0250] 2. Experimental Design

[0251] Experimental conditions: The experiment set up three temperature (20℃, 25℃, 35℃) and three humidity (40%, 60%, 80%) conditions to measure the release amount and release rate of nitrogen, phosphorus and potassium respectively.

[0252] Experimental groups: control group (conventional fertilizer, without controlled-release material) and Example 1 to Example 5 groups.

[0253] 3. Data Results

[0254]

[0255]

[0256] 4. Long-term soil health monitoring experiment

[0257] 1. Purpose of the experiment

[0258] Through a three-year soil monitoring cycle, the effectiveness of the formula fertilizer of the present invention in maintaining and improving soil health was verified, especially its long-term advantages in organic matter accumulation, microbial activity, etc.

[0259] 2. Experimental Design

[0260] Experimental period: 3 years, fertilization 3 times a year, and soil analysis at the end of the year.

[0261] Experimental groups: consistent with the 7 experimental groups in the field comparative experiment.

[0262] 3. Data Results

[0263]

[0264]

[0265] V. Experimental Summary

[0266] According to the data of the field comparison experiment, the groups using the special formula fertilizer for increasing spring corn yield of the present invention significantly increased the yield and nutrient utilization rate of corn. Compared with conventional fertilizers, crops using the fertilizer of the present invention showed higher plant height, ear length and ear weight, especially in terms of stress resistance indicators such as drought resistance and lodging resistance, the performance of the formula fertilizer group at different growth stages was more superior, indicating that the application of the fertilizer of the present invention under adverse environmental conditions has obvious advantages.

[0267] From the yield and nutrient absorption data, the per-acre yield of the fertilizer group of the present invention is significantly higher than that of conventional fertilizers, and the utilization rates of nitrogen, phosphorus and potassium are also greatly improved. The highest yield group (T5 group) showed the highest nitrogen utilization rate and the lowest nitrogen loss rate, indicating that the synergistic effect of nitrogen capture catalyst and nitrogen-fixing microorganisms effectively reduced nitrogen loss and significantly improved nutrient utilization efficiency.

[0268] Laboratory test results have verified the high efficiency of the nitrogen capture catalyst in the present invention, which can effectively capture nitrogen in the air and convert it into a nitrogen source that can be absorbed by crops, reducing dependence on chemical nitrogen fertilizers. At the same time, the function of temperature-sensitive and humidity-sensitive controlled-release materials to adjust the nutrient release rate has been verified. Under different temperature and humidity conditions, the nutrient release is more uniform, avoiding excessive nutrient loss.

[0269] Data from long-term soil health monitoring experiments show that the application of the fertilizer of the present invention can significantly increase the organic matter content and microbial activity in the soil. In particular, after continuous use for multiple seasons, the soil fertility is significantly improved, proving that the fertilizer of the present invention can not only increase corn yields, but also improve soil quality, laying the foundation for sustainable crop yield increases.

[0270] In summary, the special formula fertilizer for increasing spring corn yield of the present invention significantly improves corn yield, nutrient utilization rate and stress resistance through efficient nitrogen capture, controlled release technology and soil health improvement, and provides a guarantee for long-term soil health, with significant economic and environmental benefits.

[0271] 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 special formula fertilizer for increasing spring corn yield, characterized in that: The invention comprises the following components by weight percentage: 15%-25% nitrogen fertilizer, 20%-35% phosphorus fertilizer, 20%-35% potassium fertilizer, 1%-2% molybdenum-based catalyst, 0.4%-1% iron-based catalyst, 0.4%-1% graphene composite catalyst, 1%-2% nitrogen-fixing microorganism, 2%-4% thermosensitive polymer, 1%-3% moisture-sensitive polymer, 1%-2% sodium alginate, 2%-4% potassium humate and 2%-4% water-retaining agent.

2. The special formula fertilizer for increasing spring corn yield according to claim 1, characterized in that: The nitrogen-fixing microorganism is a strain of Azotobacter transformed by genetic engineering and is fixed on a porous carrier by means of chitosan and sodium alginate cross-linking materials.

3. The special formula fertilizer for increasing spring corn yield according to claim 1, characterized in that: The temperature-sensitive polymer is poly-N-isopropylacrylamide, and the moisture-sensitive polymer is sodium polyacrylate.

4. A method for preparing a special formula fertilizer for increasing spring corn yield, characterized in that: The preparation method of the special formula fertilizer for increasing spring corn yield according to any one of claims 1 to 3 comprises the following steps: S1. Mix nitrogen fertilizer, phosphate fertilizer, potash fertilizer and trace elements, and granulate them using a fluidized bed granulator, with the temperature controlled below 120°C; S2. preparing a nitrogen capture and conversion catalyst, loading a molybdenum-based and an iron-based catalyst on a porous carrier by an impregnation method, calcining to form a bimetallic catalyst, and compounding with graphene; S3, culturing engineered nitrogen-fixing microorganisms, and fixing the microorganisms on a carrier using chitosan-sodium alginate; S4, mixing the nitrogen-fixing microorganism carrier and the nitrogen capture catalyst into the basic fertilizer particles according to a certain proportion; S5. Use temperature-sensitive and moisture-sensitive controlled-release materials to coat fertilizer particles to form intelligent controlled-release formula fertilizer.

5. The method for preparing a special formula fertilizer for increasing spring corn yield according to claim 4, characterized in that: The S1 step specifically includes the following steps: S1.1, premixing: nitrogen fertilizer, phosphate fertilizer, potash fertilizer and trace elements are mixed in proportion, the mixing time is controlled at 5-15min, and the speed of the mixing equipment is controlled at 50-80rpm; S1.2, Granulation preparation: The mixed material is evenly fed into the fluidized bed granulator through a conveying device, and the feeding speed is controlled at 5-10kg / min; S1.3, Granulation process: The temperature of the granulator is controlled at 100-120℃, a binder is used, the amount of the binder added is 0.5%-1% of the total material, auxiliary granulation, the air flow speed is controlled at 0.5-1.5m / s, the residence time of the particles in the granulator is 10-20min, and the final particle diameter is controlled between 2-5mm; S1.4, Drying and cooling: The temperature of the dried particles is controlled at 40-50°C, and the moisture content is reduced to 8%-10% by a dryer; S1.5, Screening and packaging: The qualified particle size after screening is 2-5mm. Particles that are too small or too large can be returned for granulation.

6. The method for preparing a special formula fertilizer for increasing spring corn yield according to claim 4, characterized in that: The S2 step specifically includes the following steps: S2.1, carrier pretreatment: select porous zeolite or silica gel as the carrier material, the pore size is 3-10nm, the carrier is pretreated at a high temperature of 200℃-300℃ for 1-2h, and then cooled for use; S2.2, preparation of molybdenum-based catalyst: prepare 0.05-0.1M ammonium molybdate solution, immerse the pretreated porous support in the ammonium molybdate solution for 2-4 hours; S2.3, preparation of iron-based catalyst: prepare 0.05-0.1M iron nitrate solution, immerse the carrier in the iron nitrate solution according to the ratio of Mo=3:1, and immerse for 2-4h; S2.4, calcining to form a bimetallic catalyst: placing the impregnated carrier under nitrogen protection, calcining at 600°C for 2-3 hours. During the calcination process, ammonium molybdate and iron nitrate decompose into molybdenum oxide and iron oxide, which are attached to the surface of the carrier respectively, forming a molybdenum-iron bimetallic catalyst; S2.5, graphene composite: the prepared bimetallic catalyst and nitrogen-doped graphene are mixed in a mass ratio of 1:1, the catalyst and graphene are uniformly dispersed by a solvent method, ultrasonically treated for 15-30 minutes, and the mixture is placed at a high temperature of 400-500°C for reduction treatment for 1-2 hours to form a molybdenum-iron bimetallic and graphene composite catalyst; S2.

6. Nitrogen capture performance test: The nitrogen capture efficiency is tested within 1-24 hours by a nitrogen adsorption instrument, and the capture amount is measured in mg ammonia / g catalyst.

7. The method for preparing a special formula fertilizer for increasing spring corn yield according to claim 4, characterized in that: The S3 step specifically includes the following steps: S3.

1. Cultivation of nitrogen-fixing strains: Cultivate engineered Azotobacter strains in LB medium containing limited nitrogen at 28-32°C, aeration rate of 0.5-1.5 vvm, stirring rate of 200-300 rpm, and cultivation time of 48-72 h. S3.2, bacterial cell collection and freeze drying: after the culture is completed, the bacterial cells are collected by centrifugation at 6000-8000 rpm for 10-15 min, and the bacterial cells are suspended in 0.5%-1% sodium alginate solution, mixed evenly, and then dried by freeze drying; S3.3, preparing a chitosan-sodium alginate mixed solution: mixing a 1%-2% chitosan solution with a sodium alginate solution in a volume ratio of 1:1 to 2:1 to form a cross-linking fixative solution; S3.4, Carrier-loaded microorganisms: Immerse the porous zeolite or silica gel carrier in the nitrogen-fixing microorganism suspension for 1-2 hours; S3.

5. Cross-linking and fixation: transfer the microbial carrier to a 0.5%-1% calcium chloride solution for cross-linking reaction for 15-30 minutes, so that chitosan and sodium alginate form a stable cross-linking film, and finally fix it.

8. The method for preparing a special formula fertilizer for increasing spring corn yield according to claim 4, characterized in that: The S4 step specifically includes the following steps: S4.1, proportion weighing: Nitrogen-fixing microbial carrier: weighed at 0.5%-1.0% of the total weight of the fertilizer; Nitrogen capture catalyst: weighed at 0.5%-2% of the total weight of the fertilizer; S4.2, Mixing process: Pour the granulated basic fertilizer granules into the mixer, add nitrogen-fixing microbial carrier and nitrogen capture catalyst, mix for 10-15 minutes, and control the stirring speed at 50-100rpm.

9. The method for preparing a special formula fertilizer for increasing spring corn yield according to claim 4, characterized in that: The step S5 specifically includes the following steps: S5.

1. Prepare controlled release materials: Temperature-sensitive material: prepare a poly (N-isopropylacrylamide) solution with a concentration of 1%-2%; Moisture-sensitive materials: prepare a sodium polyacrylate solution with a concentration of 1%-2%; S5.2, coating process: the fertilizer particles are evenly spread in the spraying equipment, the temperature-sensitive material is first sprayed, the spraying rate is controlled at 1-2mL / min, and then dried at 40-50℃ for 15-30min to form the first layer of controlled-release film, and then the second layer of moisture-sensitive material is sprayed, the spraying rate is also 1-2mL / min, and the drying time is 15-30min; S5.

3. Multilayer film curing: After the coating is completed, the fertilizer particles are cured at 40-50°C for 20-40 minutes; S5.4, Controlled release performance test: Conduct soil simulation tests under different temperature and humidity conditions, and record the release rates of nitrogen, phosphorus and potassium of the fertilizer; S5.

5. Packaging and storage: The dried fertilizer granules are screened, bagged and stored in a dry environment at room temperature.

10. A method for applying a special formula fertilizer for increasing spring corn yield, characterized in that: The method is used in conjunction with the spring corn yield-increasing special formula fertilizer according to any one of claims 1 to 3, comprising the following steps: Application of base fertilizer: 7-10 days before sowing, spread the fertilizer evenly at a rate of 40 kg per mu and turn it into the soil 15-20 cm deep; Topdressing: During the jointing stage of corn, apply 20-30 kg of fertilizer per mu, using furrow or hole application, and combine irrigation after fertilization to activate nutrients; Supplementary fertilizer during the ear stage: During the grain filling period of corn, apply 5-10 kg of fertilizer per mu, using drip irrigation, root application or foliar spraying for fixed-point supplementation.

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