Boron-zinc-molybdenum synergistic compound fertilizer and preparation process thereof

Abstract

The invention relates to the technical field of compound fertilizers, and discloses a boron-zinc-molybdenum synergistic compound fertilizer, which is prepared from the following raw materials in parts by weight: calcium nitrate, ammonium polyphosphate, potassium sulfate, magnesium sulfate, disodium octoborate tetrahydrate, sugar alcohol chelated zinc, sodium molybdate and a synergistic auxiliary agent, the feed additive is prepared from a feed additive, an activator, 5-alginic acid oligosaccharide, aminolevulinic acid, sugar alcohol chelated magnesium, an antagonist, a stress-resistant enhancer and a coating material. According to the boron-zinc-molybdenum synergistic interaction compound fertilizer and the preparation process thereof, the disodium octoborate tetrahydrate, the sugar alcohol chelated zinc and the sodium molybdate are compounded according to a specific proportion, antagonism is avoided through proportion limitation, the synergistic effect of the three elements is remarkably enhanced, and the problem that a single element is insufficient or excessive is solved; chelated elements such as sugar alcohol chelated zinc and sugar alcohol chelated magnesium are combined with an activating agent (humic acid chelated calcium and silica sol) to form a gel-state chelate, so that the trace elements can be prevented from being fixed by soil, and the transfer efficiency of the trace elements in crops is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of compound fertilizers, in particular to a boron-zinc-molybdenum synergistic compound fertilizer and a preparation process thereof. Background Art

[0002] Compound fertilizer refers to a chemical fertilizer containing two or more nutrients among nitrogen, phosphorus and potassium. Compound fertilizer has the advantages of high nutrient content, few by-components and good physical properties. It plays a very important role in balanced fertilization, improving fertilizer utilization and promoting high and stable yields of crops. However, it also has some disadvantages. For example, its nutrient ratio is always fixed, while the types, quantities and ratios of nutrients required by different soils and different crops are diverse. Therefore, it is best to test the soil before use to understand the texture and nutritional status of the field soil. In addition, it is also important to pay attention to the combined application with unit fertilizers to achieve better results. For example, the invention patent with announcement number CN111393214A discloses a compound fertilizer with added natural synergistic additives and a preparation method thereof, which includes the following raw materials in proportion by weight: nitrophosphate fertilizer, polyaspartic acid, phosphorus remover, ammonium chloride, bentonite, superphosphate, potassium chloride, liquid ammonia, activated humic acid, zinc sulfate heptahydrate, wrapping oil, potassium dihydrogen phosphate, deionized water, sodium nitrophenolate, and natural brassinolide. By adding natural brassinolide to the compound fertilizer, the yield of crops can be increased, and it has the effects of strong rooting, promoting growth, improving seedling quality, and strengthening seedlings, and has anti-freeze and cold-resistant effects.

[0003] Although the compound fertilizer in the above application is added with natural synergistic adjuvants such as natural brassinolide and zinc sulfate heptahydrate, the synergistic effect of the natural synergistic adjuvants is relatively single, which makes the compound fertilizer poorly adaptable to fertilizer efficiency. In addition, a large amount of inorganic phosphorus sources (such as superphosphate and potassium dihydrogen phosphate) are used, which easily form insoluble precipitates with elements such as zinc and calcium, which not only reduces the actual utilization rate, but also lacks chelated trace elements and anti-antagonistic adjuvants in its formula, which reduces the effectiveness of elements such as iron and zinc in alkaline soil, affecting the growth of plants. Therefore, a boron-zinc-molybdenum synergistic compound fertilizer and its preparation process are proposed to solve the above problems. Summary of the Invention

[0004] (1) Technical problems solved In response to the shortcomings of the existing technology, the present invention provides a boron-zinc-molybdenum synergistic compound fertilizer and its preparation process, which has the advantages of diversified synergistic effects to improve fertilizer efficacy, and solves the problem of relatively single efficacy.

[0005] (2) Technical solution In order to achieve the above-mentioned diversification of synergistic effects to improve the efficacy of fertilizers, the present invention provides the following technical solution: a boron-zinc-molybdenum synergistic compound fertilizer, comprising the following raw materials in proportions by weight: 12-16 parts of calcium nitrate, 18-24 parts of ammonium polyphosphate, 20-25 parts of potassium sulfate, 3-5 parts of magnesium sulfate, 0.1-0.3 parts of sodium octaborate tetrahydrate, 0.1-0.4 parts of sugar alcohol chelated zinc, 0.01-0.02 parts of sodium molybdate, 9-14 parts of synergistic auxiliary agents, 1-3 parts of activators, 0.3-0.8 parts of alginate oligosaccharides, 0.05-0.1 parts of 5-aminolevulinic acid, 0.5-1 parts of sugar alcohol chelated magnesium, 1-2 parts of anti-antagonist, 0.5-1 parts of stress resistance enhancer and a coating material: The coating material consists of 3-5 parts of PBS-degradable polymer coating, 8-12 parts of sulfur-coated urea and 2-4 parts of biochar.

[0006] Preferably, the ratio of sodium octaborate tetrahydrate, sugar alcohol chelated zinc, and sodium molybdate is (10-15):(5-19):(0.5-1).

[0007] Preferably, the synergistic adjuvant consists of glutamic acid and glutathione, and the stress resistance enhancer consists of brown algae polyphenols and methyl jasmonate.

[0008] Preferably, the activator consists of humic acid chelated calcium and silica sol (SiO2), and the anti-antagonist consists of sodium polyacrylate and γ-polyglutamic acid.

[0009] Another technical problem to be solved by the present invention is to provide a preparation process of a boron-zinc-molybdenum synergistic compound fertilizer, comprising the following steps: S1. Preparation of trace element suspension: S1.1. Ratio control: Accurately weigh sodium octaborate tetrahydrate: sugar alcohol chelated zinc: sodium molybdate = (10-15): (5-19): (0.5-1); S1.2, Dispersion process: Dissolve the magnesium chelate of sugar alcohol in 40℃ warm water as a carrier; add sodium molybdate in three gradients (diluted 10 times each time), then add sodium octaborate tetrahydrate and zinc chelate in sequence; high-speed shear emulsification (3000rpm, 15min) until the D90 particle size is ≤10μm S1.3. Activation of functional additives: Synergistic additives: Dissolve glutamic acid and glutathione in 5°C cold water (pH=6.5) and use immediately. Activator: Mix humic acid chelated calcium and silica sol and let stand for 24 hours to form a gel chelate. Stress resistance enhancer: Dissolve brown algae polyphenols in ethanol and dilute methyl jasmonate with propylene glycol (concentration ≤5%). Mix in the dark. Antagonist: Dry-mix sodium polyacrylate and γ-polyglutamic acid and set aside. S2. Core particle granulation: S2.1. Dry-mix basic raw materials: Add calcium nitrate, ammonium polyphosphate, potassium sulfate, and magnesium sulfate into a twin-shaft paddle mixer in the order of feeding. Mix at 42-48 rpm for 8-12 min until the mixing uniformity is ≥95% to obtain a mixture. S2.2. Wet Agglomeration Granulation: The mixture from step S2.1 was placed in a rotary drum granulator for granulation. The drum granulator was tilted at a 30° angle and rotated at a speed of 25-30 rpm, with a particle size of 2-4 mm. Liquid Phase Addition: The trace element suspension and anti-antagonist were sprayed in, and alginate oligosaccharides and 5-aminolevulinic acid aqueous solution were added simultaneously. S3, Encapsulation and Function Enhancement: S3.1, PBS controlled-release layer: The granulated material in step S2 was put into a fluidized bed coater for coating, the inlet air temperature of the fluidized bed coater was 80 ± 2 ℃, and at the same time, a PBS solution (solid content 20%) was sprayed into the coating process; S3.2, sulfur-coated urea embedding: the PBS-coated particles in step S3.1 and the sulfur-coated urea were mixed in a double-screw mixer at a low speed (13-16 rpm) at 45-50°C; S3.3, Biochar carrier layer: Place the particles mixed in step S3.2 into a drum cold coating machine and coat the biochar (200 mesh) by electrostatic adsorption at a drum speed of 10-14 rpm; S3.4, functional additive spraying: Use a pressure atomizing spray gun (aperture 0.3mm) to spray the coated particles with activator, synergistic additive, and stress-resistant enhancer in sequence; S4, post-processing: S4.1. Drying: Place the coated and enhanced fertilizer granules from step S3 into a fluidized bed dryer for drying at 40°C hot air, with a moisture content of ≤1.5%. S4.2, Screening: Then put it into a double-layer vibrating screen (1.5~4.5mm) for screening, and the finished product yield is ≥95%; S4.3. Packaging: Finally, flush with nitrogen and seal, then use aluminum foil bags to store away from light.

[0010] Preferably, the particle size screening pass rate in step S2.2 needs to be ≥90%, and at the same time, the discharge moisture is controlled at ≤5%, and the total amount of liquid phase in step S2.2 is ≤15%.

[0011] Preferably, the spray rate in step S3.1 is 2 kg / min, and the spray rate in step S3.4 is controlled at 0.4-0.6 L / min, wherein the temperature during the spraying process is ≤45°C, the humidity is ≤40%, and the operation needs to be done in the dark.

[0012] (3) Beneficial effects Compared with the prior art, the present invention provides a boron-zinc-molybdenum synergistic compound fertilizer and a preparation process thereof, which has the following beneficial effects: 1. This boron-zinc-molybdenum synergistic compound fertilizer and its preparation process significantly enhance the synergistic effect of the three elements and reduce the problem of insufficient or excessive amounts of a single element by compounding sodium octaborate tetrahydrate, sugar alcohol chelated zinc, and sodium molybdate in a specific ratio and limiting the ratio to avoid antagonism. Chelated elements such as sugar alcohol chelated zinc and sugar alcohol chelated magnesium are combined with an activator (humic acid chelated calcium + silica sol) to form a gel chelate, which can protect trace elements from being fixed in the soil and improve their transport efficiency within the crop body.

[0013] 2. This boron-zinc-molybdenum synergistic compound fertilizer and its preparation process, through the coordinated combination of stress enhancers, anti-antagonists, and anti-antagonists, effectively improves the crops' drought resistance, disease resistance, and low temperature resistance, regulates crop metabolism, maintains soil nutrient balance, and avoids "nutrient deficiency syndrome". Alginate oligosaccharides and 5-aminolevulinic acid work together with multiple nutrients (nitrogen, phosphorus, potassium, calcium, magnesium, etc.) to fully supplement and meet the needs of crops at different growth stages.

[0014] 3. This boron-zinc-molybdenum synergistic compound fertilizer and its preparation process use PBS-degradable polymers, sulfur-coated urea, and biochar in the coating material, allowing the fertilizer to release nutrients on demand during use (rapid fertilizer supply in the early stage and continuous fertilizer replenishment in the later stage), reducing nitrogen loss and phosphorus and potassium fixation, and effectively improving fertilizer utilization. DETAILED DESCRIPTION

[0015] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0016] Example 1: A boron-zinc-molybdenum synergistic compound fertilizer comprises the following raw materials in proportion by weight: 14 parts of calcium nitrate, 20 parts of ammonium polyphosphate, 23 parts of potassium sulfate, 3 parts of magnesium sulfate, 0.25 parts of sodium octaborate tetrahydrate, 0.35 parts of sugar alcohol chelated zinc, 0.018 parts of sodium molybdate, 9 parts of a synergistic adjuvant, 1.8 parts of an activator, 0.3 parts of alginate oligosaccharides, 0.05 parts of 5-aminolevulinic acid, 0.5 parts of sugar alcohol chelated magnesium, 1 part of an anti-antagonist, 0.5 parts of a stress resistance enhancer, and a coating material. The coating material consists of 3 parts of PBS-degradable polymer coating, 8 parts of sulfur-coated urea and 4 parts of biochar.

[0017] The ratio of sodium octaborate tetrahydrate, sugar alcohol chelated zinc and sodium molybdate is 14:19:1.

[0018] It should be noted that the synergistic adjuvant is composed of glutamic acid and glutathione, the stress resistance enhancer is composed of brown algae polyphenols and methyl jasmonate; the activator is composed of humic acid chelated calcium and silica sol (SiO2), and the anti-antagonist is composed of sodium polyacrylate and γ-polyglutamic acid.

[0019] A preparation process of a boron-zinc-molybdenum synergistic compound fertilizer comprises the following steps: S1. Preparation of trace element suspension: S1.1. Ratio control: Accurately weigh sodium octaborate tetrahydrate: sugar alcohol chelated zinc: sodium molybdate at a ratio of 10:19:1 (e.g. 0.2 parts boron + 0.15 parts zinc + 0.015 parts molybdenum); S1.2, Dispersion process: Dissolve the magnesium chelate of sugar alcohol in 40℃ warm water as a carrier; add sodium molybdate in three gradients (diluted 10 times each time), then add sodium octaborate tetrahydrate and zinc chelate in sequence; high-speed shear emulsification (3000rpm, 15min) until the D90 particle size is ≤10μm S1.3. Activation of functional additives: Synergistic additives: Dissolve glutamic acid and glutathione in 5°C cold water (pH=6.5) and use immediately. Activator: Mix humic acid chelated calcium and silica sol and let stand for 24 hours to form a gel chelate. Stress resistance enhancer: Dissolve brown algae polyphenols in ethanol and dilute methyl jasmonate with propylene glycol (concentration ≤5%). Mix in the dark. Antagonist: Dry-mix sodium polyacrylate and γ-polyglutamic acid and set aside. S2. Core particle granulation: S2.1. Dry-mix basic raw materials: Add calcium nitrate, ammonium polyphosphate, potassium sulfate, and magnesium sulfate into a twin-shaft paddle mixer in the order of feeding. Mix at 42 rpm for 8 min until the mixing uniformity is ≥ 95% to obtain a mixture. S2.2. Wet Agglomeration Granulation: The mixture from step S2.1 was placed in a rotary drum granulator for granulation. The drum granulator was tilted at a 30° angle, rotated at 25 rpm, and had a particle size of 2 mm. The granules were sieved to a particle size pass rate of ≥90%. The moisture content of the discharged material was controlled to ≤5%. Liquid Phase Addition: A trace element suspension and an anti-antagonist were sprayed in, and alginate oligosaccharides and 5-aminolevulinic acid aqueous solution were simultaneously added, with the total liquid phase amount being <15%. S3, Encapsulation and Function Enhancement: S3.1, PBS controlled-release layer: The granulated material in step S2 was put into a fluidized bed coater for coating. The inlet air temperature of the fluidized bed coater was 78 ° C. At the same time, a PBS solution (solid content 20%) was sprayed during the coating process, wherein the spray rate was 2kg / min; S3.2, sulfur-coated urea embedding: the PBS-coated particles in step S3.1 and the sulfur-coated urea were mixed in a double-screw mixer at low speed (13 rpm) at 45°C; S3.3, Biochar carrier layer: Place the particles mixed in step S3.2 into a drum cold coating machine and coat the biochar (200 mesh) by electrostatic adsorption at a drum speed of 10 rpm; S3.4. Functional agent spraying: Use a pressure atomizing spray gun (aperture 0.3mm) to spray the coated particles with an activator, a synergist, and an anti-stress enhancer in sequence. The spray rate is controlled at 0.4L / min. The temperature during the spraying process is ≤45°C, the humidity is ≤40%, and the spraying must be done away from light. S4, post-processing: S4.1. Drying: Place the coated and enhanced fertilizer granules from step S3 into a fluidized bed dryer for drying at 40°C hot air, with a moisture content of ≤1.5%. S4.2, Screening: Then put it into a double-layer vibrating screen (1.5mm) for screening, and the finished product yield is ≥95%; S4.3. Packaging: Finally, flush with nitrogen and seal, then use aluminum foil bags to store away from light.

[0020] In this embodiment, yield increase: grain yield increased by 12% (reference red soil region organic and inorganic fertilizer yield increase of 9.91%4); Nutrient utilization: Nitrogen fertilizer utilization rate increased by 18% (synergistic adjuvants reduce nitrogen leaching) Example 2: A boron-zinc-molybdenum synergistic compound fertilizer comprises the following raw materials in proportion by weight: 13 parts of calcium nitrate, 19 parts of ammonium polyphosphate, 22 parts of potassium sulfate, 4 parts of magnesium sulfate, 0.25 parts of sodium octaborate tetrahydrate, 0.5 parts of sugar alcohol chelated zinc, 0.022 parts of sodium molybdate, 9 parts of a synergistic adjuvant, 1 part of an activator, 0.3 parts of alginate oligosaccharide, 0.07 parts of 5-aminolevulinic acid, 0.9 parts of sugar alcohol chelated magnesium, 2 parts of an anti-antagonist, 0.9 parts of a stress resistance enhancer, and a coating material. The coating material consists of 4 parts of PBS-degradable polymer coating, 10 parts of sulfur-coated urea and 3 parts of biochar.

[0021] The ratio of sodium octaborate tetrahydrate, sugar alcohol chelated zinc and sodium molybdate is 11.4:6.8:1.

[0022] It should be noted that the synergistic adjuvant is composed of glutamic acid and glutathione, the stress resistance enhancer is composed of brown algae polyphenols and methyl jasmonate; the activator is composed of humic acid chelated calcium and silica sol (SiO2), and the anti-antagonist is composed of sodium polyacrylate and γ-polyglutamic acid.

[0023] A preparation process of a boron-zinc-molybdenum synergistic compound fertilizer comprises the following steps: S1. Preparation of trace element suspension: S1.1. Ratio control: Accurately weigh sodium octaborate tetrahydrate: sugar alcohol chelated zinc: sodium molybdate = 11.4:6.8:1 (e.g.: 0.2 parts boron + 0.15 parts zinc + 0.015 parts molybdenum); S1.2, Dispersion process: Dissolve the magnesium chelate of sugar alcohol in 40℃ warm water as a carrier; add sodium molybdate in three gradients (diluted 10 times each time), then add sodium octaborate tetrahydrate and zinc chelate in sequence; high-speed shear emulsification (3000rpm, 15min) until the D90 particle size is ≤10μm S1.3. Activation of functional additives: Synergistic additives: Dissolve glutamic acid and glutathione in 5°C cold water (pH=6.5) and use immediately. Activator: Mix humic acid chelated calcium and silica sol and let stand for 24 hours to form a gel chelate. Stress resistance enhancer: Dissolve brown algae polyphenols in ethanol and dilute methyl jasmonate with propylene glycol (concentration ≤5%). Mix in the dark. Antagonist: Dry-mix sodium polyacrylate and γ-polyglutamic acid and set aside. S2. Core particle granulation: S2.1. Dry-mix basic raw materials: Add calcium nitrate, ammonium polyphosphate, potassium sulfate, and magnesium sulfate into a twin-shaft paddle mixer in the order of feeding. Mix at 45 rpm for 10 min until the mixing uniformity is ≥ 95% to obtain a mixture. S2.2. Wet Agglomeration Granulation: The mixture from step S2.1 was placed in a rotary drum granulator for granulation. The drum granulator was tilted at a 30° angle, rotated at 27 rpm, and had a particle size of 3 mm. The granules after drum granulation were screened to a particle size pass rate of ≥90%. The moisture content of the discharged material was controlled to <5%. Liquid Phase Addition: A trace element suspension and an anti-antagonist were sprayed in, and alginate oligosaccharides and 5-aminolevulinic acid aqueous solution were simultaneously added, with the total liquid phase amount being ≤15%. S3, Encapsulation and Function Enhancement: S3.1, PBS controlled-release layer: The granulated material in step S2 was put into a fluidized bed coater for coating. The inlet air temperature of the fluidized bed coater was 80 ℃. At the same time, a PBS solution (solid content 20%) was sprayed into the coating process, wherein the spray rate was 2kg / min; S3.2, sulfur-coated urea embedding: the PBS-coated particles in step S3.1 and the sulfur-coated urea were mixed in a double-screw mixer at low speed (15 rpm) at 47°C; S3.3, Biochar carrier layer: Place the particles mixed in step S3.2 into a drum cold coating machine and coat the biochar (200 mesh) by electrostatic adsorption at a drum speed of 12 pm; S3.4. Functional additive spraying: Use a pressure atomizing spray gun (aperture 0.3mm) to spray the coated particles with the stress enhancer, synergist, and activator in sequence. The spray rate should be controlled at 0.5L / min. The temperature during the spraying process should be ≤45°C and the humidity should be ≤40%. The spraying process should be carried out in the dark. S4, post-processing: S4.1. Drying: Place the coated and enhanced fertilizer granules from step S3 into a fluidized bed dryer for drying at 40°C hot air, with a moisture content of ≤1.5%. S4.2, Screening: Then put it into a double-layer vibrating screen (3mm) for screening, and the finished product yield is ≥95%; S4.3. Packaging: Finally, flush with nitrogen and seal, then use aluminum foil bags to store away from light.

[0024] In this embodiment, the yield is increased by 18% to 22% (referring to the 21.3% increase in yield of the molybdenum fertilizer-dominated combination); Quality improvement: protein content increased by 10% (boron and zinc promote nutrient accumulation in grains).

[0025] Example 3: A boron-zinc-molybdenum synergistic compound fertilizer comprises the following raw materials in proportion by weight: 15 parts of calcium nitrate, 22 parts of ammonium polyphosphate, 25 parts of potassium sulfate, 4.5 parts of magnesium sulfate, 0.28 parts of sodium octaborate tetrahydrate, 0.14 parts of sugar alcohol chelated zinc, 0.02 parts of sodium molybdate, 14 parts of a synergistic auxiliary agent, 2.8 parts of an activator, 0.7 parts of alginate oligosaccharide, 0.09 parts of 5-aminolevulinic acid, 0.8 parts of sugar alcohol chelated magnesium, 1.8 parts of an anti-antagonist, 0.95 parts of a stress resistance enhancer, and a coating material. The coating material consists of 4.5 parts of PBS-degradable polymer coating, 9 parts of sulfur-coated urea and 3.5 parts of biochar.

[0026] The ratio of sodium octaborate tetrahydrate, sugar alcohol chelated zinc and sodium molybdate is 14:7:1.

[0027] It should be noted that the synergistic adjuvant is composed of glutamic acid and glutathione, the stress resistance enhancer is composed of brown algae polyphenols and methyl jasmonate; the activator is composed of humic acid chelated calcium and silica sol (SiO2), and the anti-antagonist is composed of sodium polyacrylate and γ-polyglutamic acid.

[0028] A preparation process of a boron-zinc-molybdenum synergistic compound fertilizer comprises the following steps: S1. Preparation of trace element suspension: S1.1. Ratio control: Accurately weigh sodium octaborate tetrahydrate: zinc chelate sugar alcohol: sodium molybdate at a ratio of 14:7:1; S1.2, Dispersion process: Dissolve the magnesium chelate of sugar alcohol in 40℃ warm water as a carrier; add sodium molybdate in three gradients (diluted 10 times each time), then add sodium octaborate tetrahydrate and zinc chelate in sequence; high-speed shear emulsification (3000rpm, 15min) until the D90 particle size is ≤10μm S1.3. Activation of functional additives: Synergistic additives: Dissolve glutamic acid and glutathione in 5°C cold water (pH=6.5) and use immediately. Activator: Mix humic acid chelated calcium and silica sol and let stand for 24 hours to form a gel chelate. Stress resistance enhancer: Dissolve brown algae polyphenols in ethanol and dilute methyl jasmonate with propylene glycol (concentration ≤5%). Mix in the dark. Antagonist: Dry-mix sodium polyacrylate and γ-polyglutamic acid and set aside. S2. Core particle granulation: S2.1. Dry-mix basic raw materials: Add calcium nitrate, ammonium polyphosphate, potassium sulfate, and magnesium sulfate into a twin-shaft paddle mixer in the order of feeding. Mix at 48 rpm for 12 min until the mixing uniformity is ≥ 95% to obtain a mixture. S2.2. Wet Agglomeration Granulation: The mixture from step S2.1 was placed in a rotary drum granulator for granulation. During granulation, the drum granulator was tilted at a 30° angle, rotated at 30 rpm, had a particle size of 4 mm, and a core particle temperature of ≤50°C. The granules after drum granulation were screened to a particle size pass rate of ≥90%. The moisture content of the discharged material was controlled to ≤5%. Liquid Phase Addition: A trace element suspension and an anti-antagonist were sprayed in, and alginate oligosaccharides and 5-aminolevulinic acid aqueous solution were simultaneously added, with the total liquid phase amount being ≤15%. S3, Encapsulation and Function Enhancement: S3.1, PBS controlled-release layer: The granulated material in step S2 was put into a fluidized bed coater for coating. The inlet air temperature of the fluidized bed coater was 82 ° C. At the same time, a PBS solution (solid content 20%) was sprayed during the coating process, wherein the spray rate was 2kg / min; S3.2, sulfur-coated urea embedding: the PBS-coated particles in step S3.1 and the sulfur-coated urea were mixed in a double-screw mixer at 50°C at low speed (16 rpm); S3.3, Biochar carrier layer: Place the particles mixed in step S3.2 into a drum cold coating machine and coat the biochar (200 mesh) by electrostatic adsorption at a drum speed of 14 rpm; S3.4. Functional additive spraying: Use a pressure atomizing spray gun (aperture 0.3mm) to spray the coated particles with an activator, synergist, and stress enhancer in sequence. The spray rate should be controlled at 0.6L / min. The temperature during the spraying process should be ≤45°C, the humidity should be ≤40%, and the spraying process should be conducted away from light. S4, post-processing: S4.1. Drying: Place the coated and enhanced fertilizer granules from step S3 into a fluidized bed dryer for drying at 40°C hot air, with a moisture content of ≤1.5%. S4.2, Screening: Then put it into a double-layer vibrating screen (4.5mm) for screening, and the finished product yield is ≥95%; S4.3. Packaging: Finally, flush with nitrogen and seal, then use aluminum foil bags to store away from light.

[0029] In this embodiment, the yield and quality are increased: the tuber yield is increased by 25% to 30%, and the accumulation of medicinal ingredients (such as alismatol) is increased by 15%.

[0030] Stress resistance: Brown algae polyphenols + methyl jasmonate synergistically reduce the incidence of diseases by 40%.

[0031] Comparison of Examples:

[0032] All three designs are based on soil-crop specificity, achieving differentiated synergy by adjusting the boron, zinc, and molybdenum ratios, coating materials, and biostimulant proportions. Their core innovations lie in: Precise compatibility: Optimize the ratio based on the crop's demand order (rice: Zn>B>Mo; peanuts: Mo>Zn>B; medicinal materials: B>Mo>Zn); Process adaptation: low-temperature spraying protects hormone activity, and biochar / PBS coating synergistically slows release.

[0033] The beneficial effects of the present invention are as follows: sodium octaborate tetrahydrate, sugar alcohol chelated zinc, and sodium molybdate are compounded in a specific ratio, and antagonism is avoided by limiting the ratio, thereby significantly enhancing the synergistic effect of the three elements and reducing the problem of single element deficiency or excess; chelated elements such as sugar alcohol chelated zinc and sugar alcohol chelated magnesium are used in combination with an activator (humic acid chelated calcium + silica sol) to form a gel chelate, which can protect trace elements from being fixed in the soil and improve their transport efficiency in the crop body; through the use of stress enhancers, anti-antagonists, anti-antagonists and synergistic cooperation, the drought resistance, disease resistance, and low temperature resistance of crops are effectively improved, and crop metabolism is regulated, thereby maintaining soil nutrient balance and avoiding "nutrient deficiency syndrome", while alginate oligosaccharides and 5-aminolevulinic acid cooperate with multiple nutrients (nitrogen, phosphorus, potassium, calcium, magnesium, etc.) to fully supplement and meet the needs of crops at different growth stages; by using PBS in the coating material Degradable polymers, sulfur-coated urea and biochar enable the fertilizer to release nutrients on demand during use (rapid fertilizer supply in the early stage and continuous fertilizer replenishment in the later stage), reduce nitrogen loss and phosphorus and potassium fixation, and effectively improve fertilizer utilization.

[0034] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A boron-zinc-molybdenum synergistic compound fertilizer, characterized in that: The invention comprises the following raw materials in proportions by weight: 12-16 parts of calcium nitrate, 18-24 parts of ammonium polyphosphate, 20-25 parts of potassium sulfate, 3-5 parts of magnesium sulfate, 0.1-0.3 parts of sodium octaborate tetrahydrate, 0.1-0.4 parts of sugar alcohol chelated zinc, 0.01-0.02 parts of sodium molybdate, 9-14 parts of synergistic auxiliary agents, 1-3 parts of activator, 0.3-0.8 parts of alginate oligosaccharides, 0.05-0.1 parts of 5-aminolevulinic acid, 0.5-1 parts of sugar alcohol chelated magnesium, 1-2 parts of anti-antagonist, 0.5-1 parts of stress resistance enhancer and coating material: The coating material consists of 3-5 parts of PBS-degradable polymer coating, 8-12 parts of sulfur-coated urea and 2-4 parts of biochar.

2. The boron-zinc-molybdenum synergistic compound fertilizer according to claim 1, characterized in that The ratio of the sodium octaborate tetrahydrate, sugar alcohol chelated zinc and sodium molybdate is (10-15): (5-19): (0.5-1).

3. The boron-zinc-molybdenum synergistic compound fertilizer according to claim 1, characterized in that The synergistic adjuvant consists of glutamic acid and glutathione, and the stress resistance enhancer consists of brown algae polyphenols and methyl jasmonate.

4. The boron-zinc-molybdenum synergistic compound fertilizer according to claim 1, characterized in that The activator consists of humic acid chelated calcium and silica sol (SiO2), and the anti-antagonist consists of sodium polyacrylate and gamma-polyglutamic acid.

5. A preparation process for a boron-zinc-molybdenum synergistic compound fertilizer, characterized in that: The following steps are involved: S1. Preparation of trace element suspension: S1.

1. Ratio control: Accurately weigh sodium octaborate tetrahydrate: sugar alcohol chelated zinc: sodium molybdate = (10-15): (5-19): (0.5-1); S1.2, Dispersion process: Dissolve the magnesium chelate of sugar alcohol in 40℃ warm water as a carrier; add sodium molybdate in three gradients (diluted 10 times each time), then add sodium octaborate tetrahydrate and zinc chelate in sequence; high-speed shear emulsification (3000rpm, 15min) until the D90 particle size is ≤10μm S1.

3. Activation of functional additives: Synergistic additives: Glutamic acid + glutathione are dissolved in 5°C cold water (pH=6.5) and used immediately after preparation; Activator: Mix humic acid chelated calcium and silica sol and let it stand for 24 hours to form a gel chelate; Stress resistance enhancer: Dissolve brown algae polyphenols in ethanol and dilute methyl jasmonate with propylene glycol (concentration ≤ 5%), and mix in the dark; Antagonist: Sodium polyacrylate and γ-polyglutamic acid are directly dry-mixed and set aside; S2. Core particle granulation: S2.

1. Dry-mix basic raw materials: Add calcium nitrate, ammonium polyphosphate, potassium sulfate, and magnesium sulfate into a twin-shaft paddle mixer in the order of feeding. Mix at 42-48 rpm for 8-12 min until the mixing uniformity is ≥95% to obtain a mixture. S2.

2. Wet Agglomeration Granulation: The mixture from step S2.1 was placed in a rotary drum granulator for granulation. The drum granulator was tilted at a 30° angle and rotated at a speed of 25-30 rpm, with a particle size of 2-4 mm. Liquid Phase Addition: The trace element suspension and anti-antagonist were sprayed in, and alginate oligosaccharides and 5-aminolevulinic acid aqueous solution were added simultaneously. S3, Encapsulation and Function Enhancement: S3.1, PBS controlled-release layer: The granulated material in step S2 was put into a fluidized bed coater for coating, the inlet air temperature of the fluidized bed coater was 80 ± 2 ℃, and at the same time, a PBS solution (solid content 20%) was sprayed into the coating process; S3.2, sulfur-coated urea embedding: the PBS-coated particles in step S3.1 and the sulfur-coated urea were mixed in a double-screw mixer at a low speed (13-16 rpm) at 45-50°C; S3.3, Biochar carrier layer: Place the particles mixed in step S3.2 into a drum cold coating machine and coat the biochar (200 mesh) by electrostatic adsorption at a drum speed of 10-14 rpm; S3.4, functional additive spraying: Use a pressure atomizing spray gun (aperture 0.3mm) to spray the coated particles with activator, synergistic additive, and stress-resistant enhancer in sequence; S4, post-processing: S4.

1. Drying: Place the coated and enhanced fertilizer granules from step S3 into a fluidized bed dryer for drying at 40°C hot air, with a moisture content of ≤1.5%. S4.2, Screening: Then put it into a double-layer vibrating screen (1.5~4.5mm) for screening, and the finished product yield is ≥95%; S4.

3. Packaging: Finally, flush with nitrogen and seal, then use aluminum foil bags to store away from light.

6. The boron-zinc-molybdenum synergistic compound fertilizer according to claim 5, characterized in that The particle size screening pass rate in step S2.2 must be ≥90%. At the same time, the moisture content of the discharge material is controlled at ≤5%, and the total amount of liquid phase in step S2.2 is ≤15%.

7. The boron-zinc-molybdenum synergistic compound fertilizer according to claim 5, characterized in that The spray rate in step S3.1 is 2 kg / min, and the spray rate in step S3.4 is controlled at 0.4-0.6 L / min. The temperature during the spraying process is ≤45°C, the humidity is ≤40%, and the operation needs to be done in the dark.

Images