A preparation method for enhancing the efficacy of phosphate compound fertilizers using polyglycoside technology

Abstract

This invention discloses a method for preparing phosphate compound fertilizer enhanced by polyglycoside technology, belonging to the field of special fertilizers. It constructs a synergistic enhancement system of "phospholipid-plant glycoside complex-bioactive peptide-phosphate-solubilizing microorganisms-medium-element slow-release agent" and employs a double-layer coating granulation process to achieve the spatially ordered distribution of functional components. Specifically, it includes: preparing a phospholipid-plant glycoside complex, a bioactive peptide solution, and a compound microbial agent; mixing and kneading a basic fertilizer source with a medium-element slow-release agent, a pore-forming agent, and the compound microbial agent, followed by extrusion, spheroidization, granulation, and drying to obtain a porous fertilizer core; then mixing the phospholipid-plant glycoside complex with the bioactive peptide solution to prepare a coating liquid, which is then sprayed onto the core surface via fluidized bed spraying; finally, it is melted and condensed in a high-tower cooling tower to obtain the polyglycoside-enhanced phosphate compound fertilizer, achieving a synergistic improvement in crop yield and efficient fertilizer utilization.

Description

Technical Field

[0001] This invention belongs to the field of special fertilizer technology, specifically relating to a preparation method for enhancing the efficiency of phosphate compound fertilizers using polyglycoside technology. Background Technology

[0002] Phosphorus is one of the key nutrients limiting crop yield. When traditional phosphate compound fertilizers (such as monoammonium phosphate and potassium dihydrogen phosphate) are applied to the soil, available phosphorus is easily fixed by ions such as iron, aluminum, and calcium, forming insoluble phosphates, resulting in a utilization rate of less than 25% for the current crop. This not only causes huge resource waste and economic losses but also leads to phosphorus migration into water bodies, causing environmental problems such as eutrophication. To improve the efficiency of phosphate fertilizers, existing technologies mainly develop along three paths: first, physicochemical modification, such as using sulfur coating and polymer coating to achieve slow nutrient release, but this is costly and the coating materials may pose environmental risks; second, adding chemical activators, such as polyaspartic acid and humic acid, to reduce phosphorus fixation through chelation, but their ability to regulate the rhizosphere microenvironment is limited; and third, introducing biotechnology, such as inoculating phosphorus-solubilizing microorganisms, but the survival and colonization ability of these microorganisms in fertilizer processing, storage, and soil is unstable, resulting in large fluctuations in effectiveness.

[0003] In recent years, plant-derived bioactive substances have become a research hotspot due to their green and multifunctional characteristics. For example, iridoid glycosides (plant glycosides) extracted from gardenia and eucommia have been proven to regulate plant hormones, enhance stress resistance, and promote nutrient absorption. Public data shows that foliar spraying of Bohai Bio-glycosides can increase cotton lint yield. However, current technologies mostly use these substances as foliar fertilizers or seed treatment agents, and research on their functional complementarity and spatiotemporal synergy with bulk solid phosphate compound fertilizers, especially through systematic process design, remains lacking. Furthermore, single enhancement pathways often cannot overcome the multiple obstacles of soil phosphorus fixation. Systematically integrating and spatially assembling multiple enhancement mechanisms, including physical, chemical, and biological methods, is key to breaking through the current bottleneck in phosphate fertilizer efficiency.

[0004] Therefore, this invention aims to develop a novel method for preparing synergistic phosphate compound fertilizers. The core innovation of this method lies in the construction of a quaternary synergistic system consisting of "phospholipid-plant glycoside complex—bioactive peptide—phosphate-solubilizing microorganisms—medium-element slow-release agent," enabling the components to achieve spatially ordered distribution and time-programmed release within the fertilizer granules. This design comprehensively matches the phosphorus requirements of crops from "rapid root activation" to "long-term conversion and supply," and is expected to significantly improve phosphate fertilizer utilization and crop yield while achieving a green, economical, and sustainable synergistic technology. Summary of the Invention

[0005] The purpose of this invention is to overcome the technical defects of existing phosphate compound fertilizers, such as low utilization rate, single function, and difficulty in survival of biological agents, and to provide a method for preparing phosphate compound fertilizers with enhanced efficiency through polyglycoside technology. This method creates a phospholipid-plant glycoside complex as a highly efficient penetration enhancer and activator, synergistically combining it with bioactive peptide signaling substances, phosphorus-solubilizing microorganisms, and medium-element slow-release agents. Utilizing a double-layer coating granulation process, it achieves precise positioning and spatiotemporal progressive release of each functional component in the "shell" and "core" layers of the fertilizer granules, thereby constructing a novel intelligent phosphate compound fertilizer that simultaneously promotes early root growth, continuously solubilizes phosphorus, provides long-term fertilization, and improves soil quality. Ultimately, it aims to significantly improve phosphorus utilization, enhance crop resistance, and increase yield and quality. The core of this method lies in constructing and realizing the synergistic effect of a four-component system: "phospholipid-plant glycoside complex (penetration enhancer and activator layer) – bioactive peptide (nutrient signaling layer) – phosphorus-solubilizing microorganisms (biotransformation layer) – medium-element slow-release agent (long-term regulatory layer)".

[0006] The "polyglycoside technology" described in this invention refers to a technology that uses plant-derived iridoid glycosides as the core functional unit, and combines them with phospholipids to form a "phospholipid-plant glycoside complex" with an amphiphilic structure. Furthermore, it is used in synergy with bioactive peptides, phosphate-solubilizing microorganisms, and medium-element slow-release agents to construct a functional synergistic system that integrates permeation promotion, signal regulation, biotransformation, and nutrient slow release.

[0007] The core of this technology lies in: "Poly" represents compounding and synergy, that is, combining plant glycosides and phospholipids through intermolecular forces to form a stable functional complex, and integrating with other synergistic components in terms of space and function. "Glycoside" represents plant glycoside active substances, mainly derived from plant extracts such as gardenia, eucommia, and rehmannia, which have biological activities such as regulating plant hormones, enhancing stress resistance, and promoting nutrient absorption.

[0008] In fertilizer preparation, "polyglycoside technology" not only refers to the preparation method of phospholipid-plant glycoside complex, but also covers the "quaternary synergistic system" jointly constructed with biopeptides, phosphorus-solubilizing microorganisms and medium-element slow-release agents, as well as the overall technical solution to achieve programmed release of functional components through "shell-core" spatial structure design.

[0009] A method for preparing glycoside-enhanced phosphate compound fertilizer using polyglycoside technology includes: 1) preparation of phospholipid-plant glycoside complex; 2) enzymatic hydrolysis of bioactive peptide solution; 3) compounding and protection of compound microbial agents; 4) mixing monoammonium phosphate, potassium dihydrogen phosphate, urea, potassium chloride, etc., as base fertilizer sources with the above-mentioned functional components, binders, pore-forming agents, etc., in a specific order; 5) obtaining granular polyglycoside-enhanced phosphate compound fertilizer using a fluidized bed-high tower coupled granulation process. This invention improves the activation efficiency, slow-release performance, and crop absorption and utilization rate of phosphorus. While achieving a 13.4% increase in cotton lint yield and a 25.7% increase in cucumber yield, it controls the cumulative release rate of phosphorus nutrients over 45 days to below 86%, and increases fertilizer utilization rate by more than 30%.

[0010] To achieve the above objectives, the present invention provides a method for preparing phosphate compound fertilizers enhanced with polyglycoside technology, comprising the following steps: S1. Preparation of functional synergistic components: including S1.1 preparation of phospholipid-plant glycoside complex, S1.2 preparation of bioactive peptide solution, and S1.3 preparation of compound microbial agent; S2. Preparation of base fertilizer slurry and core material: Weigh monoammonium phosphate, potassium dihydrogen phosphate, urea, potassium chloride, medium-element slow-release agent, and pore-forming agent and mix them in a mixer to obtain a core solid mixture; the total dry basis mass of the core solid mixture is the sum of the masses of monoammonium phosphate, potassium dihydrogen phosphate, urea, potassium chloride, medium-element slow-release agent, and pore-forming agent; then add 0.5%~2.0% of the total dry basis mass of the core solid mixture, mix evenly, add binder A, and knead into a plastic core wet material; S3. Core Granulation and Primary Drying: The plastic core wet material obtained in S2 is fed into an extrusion rounding granulator for granulation and drying to obtain a porous fertilizer core. S4. Active shell coating and final granulation: The phospholipid-plant glycoside complex is mixed with the bioactive peptide solution, and binder B solution is added to prepare the coating solution; the fertilizer core is placed in a fluidized bed coating machine, preheated, sprayed, and granulated, and then the particles are sent to a high tower granulation system for melting, condensation and shaping, and sieving to obtain the final product; Further, the specific steps for preparing the S1.1 phospholipid-plant glycoside complex are as follows: soybean lecithin and plant glycoside extract powder are dispersed in an ethanol-water solution at a mass ratio of 1:(0.5~2) at 60~70℃, so that the soybean lecithin concentration is 50~100g / L; the reaction is carried out under nitrogen protection and stirring at 300~500rpm for 2~4 hours, and then the ethanol is removed by rotary evaporation at -0.08~-0.1MPa and 45~55℃ to obtain a viscous phospholipid-plant glycoside complex.

[0011] Further, the preparation of the S1.2 biopeptide solution is as follows: soybean meal protein powder is dissolved in phosphate buffer at a solid-liquid ratio of 1g:(10-15)mL, and protease is added at a concentration of 1% to 3% of the soybean meal protein powder. The mixture is enzymatically hydrolyzed at 50 to 55℃ and pH 7.5 to 8.5 for 4 to 6 hours, followed by enzyme inactivation at 90±3℃ for 10±3 minutes. The mixture is then centrifuged at 8000-10000rpm for 15 to 20 minutes, and the supernatant is collected. The supernatant is then concentrated through an ultrafiltration membrane with a molecular weight cutoff of 900-1100Da to obtain a biopeptide solution with a solid content of 15% to 25%.

[0012] Further, the preparation of the S1.3 composite microbial agent specifically involves mixing the fermentation broths of Bacillus spp. and Bacillus megaterium at a volume ratio of 1:(1-3) to obtain a total viable count ≥5.0 × 10⁻⁶. 9 A mixed bacterial solution with CFU / mL was prepared. The mixed bacterial solution was then mixed with trehalose and skim milk powder at a volume-to-mass ratio of 1mL:0.1g:0.05g, and then freeze-dried to obtain a compound microbial agent.

[0013] Furthermore, the preparation of the S2. base fertilizer slurry and core material specifically involves: S2.1 Weigh the following basic fertilizer sources in parts by weight: 25-40 parts monoammonium phosphate, 10-20 parts potassium dihydrogen phosphate, 20-35 parts urea, and 10-18 parts potassium chloride; S2.2 The above-mentioned basic fertilizer source is premixed with 5-15 parts of medium-element slow-release agent, 0.5-2 parts of pore-forming agent, and 0.5%-2.0% of compound microbial agent (based on the total dry weight of the core solid mixture) in a mixer at 50-60°C for 15-30 minutes to obtain the core solid mixture; the total dry weight of the core solid mixture is calculated as the sum of the masses of monoammonium phosphate, potassium dihydrogen phosphate, urea, potassium chloride, medium-element slow-release agent, and pore-forming agent. S2.3 Add binder A solution to the core solid mixture from step S2.2. The binder A is a polyvinyl alcohol aqueous solution with a mass fraction of 5% to 10% or a hydroxypropyl methylcellulose aqueous solution with a mass fraction of 3% to 8%. The amount used is 3% to 8% of the total dry basis mass of the core solid mixture. Knead the mixture in a kneader to form a plastic core wet material.

[0014] Further, S3. Core granulation and primary drying specifically involves: feeding the plastic core wet material obtained in step S2.3 into an extrusion spheroidizing granulator to produce spherical wet granules with a particle size of 1.0~1.8mm, and then drying them in a fluidized bed at 60~75℃ until the moisture content is less than 3% to obtain a porous fertilizer core; the spheroidizing speed is 800~1200rpm. Further, S4. Active shell coating and final granulation specifically involves: Preparation of coating solution S4.1: The phospholipid-plant glycoside complex prepared in S1.1 and the bioactive peptide solution prepared in S1.2 are mixed and stirred at a dry basis mass ratio of 1:(1~3) to obtain an active ingredient mixture. A binder B solution is then added to prepare the coating solution. The binder B is sodium alginate or chitosan. When the binder B is sodium alginate, sodium alginate is dissolved in deionized water to prepare a 1%~3% sodium alginate aqueous solution. The active ingredient mixture is then mixed with the sodium alginate aqueous solution and stirred until homogeneous to obtain the coating solution. When the binder B is chitosan, chitosan is dissolved in a 1%~2% acetic acid aqueous solution to prepare a 1%~2% chitosan acetic acid solution. The active ingredient mixture is then mixed with the chitosan acetic acid solution and stirred until homogeneous to obtain the coating solution. The amount of binder B used is 2%~5% of the total dry basis mass of the outer shell. S4.2 The fertilizer core obtained in S3 is placed in a fluidized bed coating machine and preheated to 40~50℃. Using a bottom spraying process, the coating liquid prepared in S4.1 is sprayed onto the surface of the core at a rate of 3~10mL / min. The air inlet temperature is controlled at 60~80℃ and the material temperature at 40~55℃. The coating weight gain is 5%~15% of the core mass, forming particles with an active outer shell. S4.3 The coated granules are fed into the high-tower granulation system and subjected to surface finishing and densification treatment in the melting section at 125~135℃ for 1~3 seconds. Then, they are dropped and condensed in cold air at 5~15℃ to solidify and are sieved to obtain the final polyglycoside-enhanced phosphate compound fertilizer granules with a particle size of 2.0~4.0mm.

[0015] Further, the preparation method of the plant glycoside extract powder is as follows: the dried tissues of Gardenia, Eucommia, or Rehmannia are pulverized and passed through a 40-80 mesh sieve, and extracted twice by reflux at 75-85°C with a volume fraction of 70%-85% ethanol aqueous solution at a solid-liquid ratio of 1:(10-15), each time for 2 hours; the extracts are combined, filtered through a 0.4-0.5μm microporous membrane, and then passed through an AB-8 type macroporous adsorption resin column. First, impurities are eluted with 3-5 BV of deionized water, and then the target component is eluted with a volume fraction of 55-65% ethanol aqueous solution at a flow rate of 1-3 BV / h; the eluent is collected, concentrated under reduced pressure, and spray-dried to obtain the plant glycoside extract powder, wherein the content of iridoid glycosides is not less than 60 mg / g; Furthermore, the medium-element slow-release agent is calcium citrate or magnesium citrate coated particles with bentonite or diatomaceous earth as carrier, with a particle size of 0.1~0.5mm and a calcium or magnesium content of 5%~15%. Its nutrient release period in static water is no less than 30 days, during which 80% of the nutrients are released. Furthermore, the protease is a complex enzyme of alkaline protease and flavor protease, with a mass ratio of 1 to 2:1, and the enzymatic hydrolysis pH is maintained by automatically adding 1 to 2 mol / L NaOH solution; the pore-forming agent is ammonium bicarbonate or azodicarbonamide; when the pore-forming agent is ammonium bicarbonate, its particle size is 150 to 200 mesh, and it is used to decompose in the kernel drying step at 60 to 70°C to generate pores.

[0016] The following is the inventive design concept of this invention: 1. Constructing a Quadruple Synergistic Enhancement System: This invention abandons the single-effect enhancement approach and systematically integrates four enhancement pathways with different mechanisms: "chemical activation (phospholipid-plant glycoside complex)," "nutrient signaling (bioactive peptides)," "biotransformation (phosphate-solubilizing microorganisms)," and "physical slow release (medium-element slow-release agent)." The components are not simply blended but designed based on the principle of functional complementarity: the phospholipid-plant glycoside complex reduces root surface tension, promoting the translocation of plant glycosides and phosphorus into the roots; phosphate-solubilizing microorganisms activate and dissociate fixed phosphorus; and the medium-element slow-release agent stabilizes soil pH and provides long-term support for microbial activity. These four components form a closed-loop enhancement cycle of "activation-signaling-transformation-supply."

[0017] 2. Optimized Design Based on a "Shell-Core" Structure: This invention achieves the spatial synergistic combination of functional components through a coupled process of "extrusion spheroidization to form a porous core" and "fluidized bed spray coating to form an active outer shell." The rapidly acting phospholipid-plant glycoside complex and some bioactive peptides are positioned in the outer shell, dissolving quickly after fertilization and playing a crucial role in promoting root growth and activating the rhizosphere during the early stages of crop growth. Meanwhile, environmentally sensitive phosphorus-solubilizing microorganisms and long-release medium-element slow-release agents are protected within the porous network of the core, continuously releasing phosphorus as the core slowly disintegrates, thus providing long-lasting phosphorus solubilization and fertilization functions.

[0018] 3. Preparation of Phospholipid-Plant Glycoside Complex and its Permeation-Enhancing Mechanism: Soybean lecithin and plant glycosides are combined through intermolecular forces (such as hydrogen bonds and hydrophobic interactions) to form a complex. This complex is amphiphilic, and its critical micelle concentration (CMC) is significantly lower than that of single phospholipids. It can form micelles more effectively at the root-soil interface, thereby simultaneously enhancing the solubility and transmembrane transport efficiency of plant glycosides (regulatory hormones) and phosphorus nutrients (complex activation) in the rhizosphere microdomain, achieving the dual functions of "carrier" and "medicinal efficacy".

[0019] 4. Embedded protection of phosphate-solubilizing microorganisms: By preparing a porous core together with composite microbial agents, pore-forming agents, and binders, the microorganisms are fixed and protected within the pores.

[0020] Beneficial technical effects of the present invention: 1. Revolutionary Improvement in Phosphorus Utilization and Fertilizer Efficiency: This invention's fertilizer achieves "on-demand supply" of phosphorus nutrients through quaternary synergy and spatially ordered release. Tests show that its cumulative phosphorus release rate gradually increases to around 85% over 45 days, lower than the rapid release of most ordinary phosphate compound fertilizers, effectively reducing fixation and loss. In field trials, it has shown significant yield-increasing effects on crops such as cotton and cucumber (16.0% increase in lint yield and 25.7% increase in cucumber yield), with overall fertilizer utilization efficiency improved compared to traditional products.

[0021] 2. Simultaneous improvement of crop stress resistance and soil health: The synergistic effect of plant glycosides and bioactive peptides significantly enhances the crop's resistance to abiotic stresses such as drought and salinity. The long-term colonization of phosphorus-solubilizing microorganisms and the supply of mesonutrients promote the formation of soil aggregates, increase soil organic matter and available phosphorus pool capacity, achieve a combination of nutrient utilization and improve soil microecology.

[0022] 3. Excellent physical properties and convenient application: Through high-tower melting and smoothing, the final product has round particles, high strength, and good flowability, making it fully suitable for mechanized fertilization and modern integrated water and fertilizer systems. The shell-core structure also avoids the loss and deactivation of functional components during storage and transportation.

[0023] 4. Environmentally friendly and with outstanding economic benefits: Under the same yield target, the amount of phosphate fertilizer applied can be reduced, thereby mitigating the risk of agricultural non-point source pollution at the source. Although functional components have been added, the overall cost per unit area of ​​planting is reduced due to the significantly improved fertilizer efficiency and the reduced number of fertilizations, resulting in significant economic benefits. Attached Figure Description

[0024] Figure 1 This is a flowchart of the preparation process of polyglycoside-enhanced phosphate compound fertilizer in Example 1 of the present invention. Detailed Implementation

[0025] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0026] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by those skilled in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of those skilled in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or identical to those described in the embodiments of this invention may be used to implement this invention.

[0027] Unless otherwise stated, the test methods, detection methods and preparation methods disclosed in this invention all adopt conventional techniques in this technical field.

[0028] I. Source of Main Raw Materials, Reagents and Equipment: Plant materials: Gardenia (purchased from Zhangshu Medicinal Herb Market in Jiangxi Province, moisture content ≤10%), Eucommia ulmoides leaves (purchased from Cili County, Hunan Province, moisture content ≤12%), pulverized and passed through a 60-mesh sieve for later use.

[0029] Soy lecithin (product number: B28313-5mg): purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0030] Soybean meal protein powder (also known as soybean protein powder, food grade, CAS number: 9010-10-0): purchased from Hebei Zhongzhisheng Biotechnology Co., Ltd.

[0031] Protease (alkaline protease, 200,000 U / g%): purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0032] Protease (flavor protease, 150,000 U / g%): purchased from Shanghai Myriel Biochemical Technology Co., Ltd.

[0033] Microbial strains: Bacillus jellyoides (product number: SHMCCD53180), purchased from Shanghai Preservation Microbiology Co., Ltd.; Bacillus megaterium, purchased from Weifang Lvlong Biotechnology Co., Ltd.

[0034] Medium-element slow-release agent (calcium citrate coated granules, Ca content 10%, release period ≥35 days): Customized by Hubei Jusheng Technology Co., Ltd.

[0035] Adhesives: Polyvinyl alcohol (PVA-1788, Hubei Jusheng Technology Co., Ltd.), sodium alginate (CAS No.: 9005-38-3, Hubei Weishi Chemical Reagent Co., Ltd.).

[0036] Pore-forming agent: Food-grade ammonium bicarbonate (200 mesh, customized by Hubei Jusheng Technology Co., Ltd.).

[0037] The main equipment, such as the high-efficiency reflux extraction device, spray dryer, extrusion spheronizing granulator, fluidized bed coating machine, and high-tower granulation system, are all conventional equipment in this technical field and have no substantial impact on the core innovation and beneficial technical effects of this invention.

[0038] Example The following embodiments will demonstrate in detail the specific implementation process of the method of the present invention. Each embodiment is within the scope of the claims of the present invention, and the adjustability and efficiency of the technology are reflected by adjusting key parameters.

[0039] Example 1 Preparation of S1.1 Phospholipid-Plant Glycoside Complex: Weigh 50g of geniposide extract powder (glycoside content 65mg / g) and 50g of soybean lecithin, and disperse them together in 1L of ethanol aqueous solution at 65℃. Stir the mixture at 400rpm for 3 hours under nitrogen protection. The reaction solution is then rotary evaporated at 50℃ and -0.09MPa until it becomes viscous. S1.2 Preparation of bioactive peptide solution: 100g of soybean meal protein powder was dissolved in 1.2L of pH 7.5 phosphate buffer, 2g of alkaline protease and 1g of flavor protease (3g protease) were added, and the mixture was enzymatically hydrolyzed at 52℃ for 5 hours under conditions of continuously adjusting the pH to 8.0; after enzyme inactivation at 90℃, the mixture was centrifuged (centrifugation speed of 9000rpm for 15min), and the supernatant was concentrated to a solid content of 20% through an ultrafiltration membrane (MWCO 1000Da) to obtain the bioactive peptide solution; S1.3 Preparation of compound microbial inoculant: The fermentation broth of the two strains (both with a viable cell count of 2×10⁻⁶) was used to prepare the inoculant. 9 Mix CFU / mL) at a volume ratio of 1:2; take 100mL of the mixed bacterial solution, add 10g of trehalose and 5g of skim milk powder, mix well and freeze dry to obtain the compound microbial agent; S2. Core Preparation: Weigh 35 parts of monoammonium phosphate, 15 parts of potassium dihydrogen phosphate, 25 parts of urea, 15 parts of potassium chloride, 10 parts of medium-element slow-release agent (calcium citrate), 1 part of ammonium bicarbonate (200 mesh), and 1.5 parts of the composite microbial agent prepared in S1.3 into a high-speed mixer and mix at 55°C for 20 minutes; add 8% PVA aqueous solution (PVA amount is 5% of the total dry mass of the core), and knead in a kneader for 20 minutes to obtain a plastic core wet material; S3. Core granulation and primary drying: The plastic core wet material is fed into an extrusion spheroidizer and extruded through a 1.0 mm aperture. The material is spheroidized at 1000 rpm. The wet particles are placed in a fluidized bed and dried at 65°C for 20 minutes. The temperature is then raised to 75°C and dried to a moisture content of 2.5%, resulting in a porous fertilizer core with a particle size of 1.5 mm. S4. Shell Coating and Shaping: S1.1 phospholipid-plant glycoside complex (dry weight) and S1.2 bioactive peptide solution (dry weight) are mixed at a mass ratio of 1:2. Sodium alginate (3% of the dry weight of the shell) is added to prepare the coating solution. In a fluidized bed coating machine, the core is preheated to 45℃ and sprayed at a rate of 5 mL / min using a bottom spray method. The inlet air temperature is controlled at 70℃ and the material temperature at 48℃. Coating is continued until a 10% weight gain is achieved. After coating, the particles are sent to a high-pressure tower and treated in the 130℃ melting section for 2 seconds. Subsequently, they are condensed and dropped in 10℃ cold air, and 3.0 mm particles are sieved as the finished product.

[0040] Example 2 The difference from Example 1 is as follows: In S1.1, the mass ratio of lecithin to geniposide extract is changed to 1:1.5; In S4, the weight gain from coating is increased to 15%, making the outer shell thicker in order to enhance the early root-promoting effect; The amount of compound microbial agent added to the core was increased to 2.0 parts (1.3% of dry basis). The remaining steps and parameters are the same as in Example 1.

[0041] Example 3 The difference from Example 1 is as follows: In S1.1, the plant glycoside raw material was changed to Eucommia ulmoides leaf extract (glycoside content 58mg / g). In S2, the amount of ammonium bicarbonate as a pore-forming agent is increased to 1.5 parts, which aims to improve the core porosity to facilitate the release of microorganisms; In S3, the drying process is adjusted to dry directly at 70℃ to the endpoint in order to obtain different pore structures; The remaining steps and parameters are the same as in Example 1.

[0042] Example 4 The difference from Example 1 is as follows: In S4.1, the ratio of phospholipid-plant glycoside complex to bioactive peptide dry basis in the coating solution is adjusted to 1:1, and binder B is replaced with chitosan acetate solution (concentration 1.5%). In S4.3, the temperature of the high tower melting section is 125℃, and the temperature of the condensing air is 5℃, in order to obtain a denser and brighter outer shell; The remaining steps and parameters are the same as in Example 1.

[0043] Comparative Example 1: Simple physical mixture (no spatial distribution design) Weigh out the same types and weights of the basic fertilizer source, medium-element slow-release agent, plant glycoside powder (non-complex), soybean meal protein powder (non-enzymatic peptide), compound microbial agent, and PVA binder as in Example 1. Add all solid powders and liquids to a mixer at once and mix and knead under the same conditions. Then, directly granulate using a high-tower granulation method, without extrusion spheroidization or fluidized bed coating steps. That is, all functional components are randomly distributed in the particles, without a "shell-core" structure.

[0044] Comparative Example 2: Lacking the components of "phospholipid-plant glycoside complex" and "bioactive peptide". Phospholipid-plant glycoside complexes and bioactive peptide solutions were not prepared. The S2 core preparation was the same as in Example 1. The S4 coating solution was only a 3% sodium alginate aqueous solution. This means the fertilizer lacks the rapidly released root-promoting and signaling components from the outer shell, relying solely on the microorganisms and slow-release agent in the core.

[0045] Comparative Example 3: Lacks "phosphate-solubilizing microorganisms" and "medium-element slow-release agents" No compound microbial agents or medium-element slow-release agents are added in S1.3 and S2. The core is made only of basic fertilizer source, pore-forming agent, and binder. The outer shell coating liquid is the same as in Example 1. That is, the fertilizer lacks long-lasting biotransformation and supply components.

[0046] Comparative Example 4: Spatial Distribution Order Reversed The spatial distribution order of Example 1 was reversed. Specifically, during the preparation of the core (S2), a phospholipid-plant glycoside complex and bioactive peptide powder were added; while the outer shell coating solution (S4) contained a suspension of composite microbial agents protected with trehalose and fine powder of medium-element slow-release agents. This was an attempt to create a reverse structure of "long-term slow release from the outer shell and rapid release from the core."

[0047] Comparative Example 5: Commercially available ammonium polyphosphate compound fertilizer control Commercially available ordinary ammonium polyphosphate compound fertilizer (purchased from Hubei Shiteng Chemical Technology Co., Ltd.) has a total nutrient content of ≥62% (N-P2O5-K2O is 18-46-0), with phosphorus mainly in the forms of ammonium pyrophosphate and ammonium tripolyphosphate. Testing showed that its phosphorus release rate in still water at 25℃ was greater than 50% within one day, indicating it does not possess slow-release properties.

[0048] Test case I. Testing Methods Determination of static nutrient release rate: Refer to the static water extraction method in "Slow-Release Fertilizers" (GB / T23348-2009). Accurately weigh 5.00g of each sample and place it in a nylon mesh bag, immerse it in 250mL of deionized water, and let it stand at a constant temperature of 25℃. Samples were taken at regular intervals of 1, 3, 5, 7, 14, 28, and 45 days to determine the concentrations of phosphorus (vanadium molybdenum yellow colorimetric method), nitrogen (distillation method), potassium (flame photometry method), and calcium (EDTA titration method) in the extract, and the cumulative release rate was calculated.

[0049] Field fertilizer effectiveness trial: Cotton Experiment: Conducted in the Alar Reclamation Area, Xinjiang. Nine treatments were set up (Examples 1-4, Comparative Examples 1-5), with three replicates per treatment, using a randomized block design. Basal application of the same phosphorus content (P2O5 120 kg / ha) of experimental fertilizer was used. At the initial flowering stage, except for Comparative Example 5 which received conventional topdressing, no topdressing was applied to the other treatments. Lint yield was measured in each plot at harvest.

[0050] Cucumber experiment: Conducted in a greenhouse in Shouguang, Shandong. Nine treatments were set up (as above). During seedling raising, seeds were treated with fertilizer powder equivalent to 0.3% of their weight (comparative treatment 5 used water as a control). At transplanting, fertilizer was applied in furrows at a rate equivalent to 90 kg / ha of P2O5. The cumulative marketable cucumber yield of each plot was recorded.

[0051] Test Results Table 1 Comparison of cumulative phosphorus nutrient release rate (%) between the examples and comparative examples Table 2. Yield Increase Effects of Field Experiments in Examples and Comparative Examples Based on Tables 1 and 2 above, the possible reasons for the discrepancies in the test results are as follows: Slow-release performance analysis: Examples 1-4 all exhibited ideal, gradual release curves (74-77.1% at 28 days, 84-85.2% at 45 days), meeting the standards for slow-release fertilizers. Comparative Example 1 (simple mixture) showed relatively rapid release, indicating that without the control of the "shell-core" structure, all nutrients quickly came into contact with water, resulting in a poor slow-release effect. Comparative Example 2 (lacking shell active substances) showed extremely slow initial release, but accelerated later. This is because the lack of early root-promoting substances may have delayed crop root development, and the shell only served as a physical barrier. Comparative Example 4 (inverted distribution) showed the slowest initial release because its shell is a long-release component, severely affecting the rapid acquisition of phosphorus by crop seedlings, leading to insufficient nutrient supply in the early stages.

[0052] Analysis of Yield Increase: Examples 1-4 showed significant yield increases (cotton 12-16.0%, cucumber 23-26%), attributed to the perfect synergistic match between the quaternary system and the crop's nutrient requirements. Comparative Example 1 showed a slight yield increase, demonstrating that although the simple mixture contained all the necessary substances, the disordered release prevented the synergistic effect from being realized, and plant glycosides and other substances may have degraded prematurely in the soil. Comparative Example 2 showed even a reduction in cotton lint yield, indicating a lack of early root promotion and signal initiation; even with later microbial phosphorus solubilization, the crop's weak root system prevented efficient absorption. Comparative Example 3 showed a limited but certain yield increase, indicating that only early root promotion was provided without long-term biological phosphorus solubilization and medium-level element support, resulting in insufficient sustained fertilizer effect. Comparative Example 4 showed a yield reduction, with the inverted distribution disrupting the crop's nutrient absorption rhythm, leading to insufficient phosphorus supply in the early stages and delayed release in the later stages.

[0053] Example 2 yielded the best experimental results, primarily due to its relatively thick outer shell coating and the high amount of compound microbial inoculant added to the core. This process design creates a good synergistic match between the early root-promoting function and the later long-lasting fertilization function. Comparison of the results from the various comparative examples shows that whether a functional component is missing or its spatial distribution is altered (e.g., placing a component that should be distributed in the outer shell into the core), the overall performance of the fertilizer significantly decreases, even exhibiting negative effects. These results fully demonstrate that the quaternary synergistic system and spatially ordered distribution design constructed in this invention are not simply the superposition of components, but rather an organic whole with a rigorous logical and functional coupling relationship, capable of achieving substantial synergistic effects.

[0054] In summary, this invention has produced a novel polyglycoside-fortified phosphate compound fertilizer with excellent slow-release properties, highly synchronized with crop nutrient requirements, and significantly improved phosphate fertilizer utilization and crop yield. This invention demonstrates clear inventiveness, outstanding practicality, and significant progress.

[0055] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing phosphate compound fertilizers enhanced with polyglycoside technology, characterized in that, Includes the following steps: S1. Preparation of functional synergistic components: including S1.1 preparation of phospholipid-plant glycoside complex, S1.2 preparation of bioactive peptide solution, and S1.3 preparation of compound microbial agent; S2. Preparation of base fertilizer slurry and core material: Weigh monoammonium phosphate, potassium dihydrogen phosphate, urea, potassium chloride, medium-element slow-release agent, and pore-forming agent and mix them in a mixer to obtain a core solid mixture; the total dry basis mass of the core solid mixture is the sum of the masses of monoammonium phosphate, potassium dihydrogen phosphate, urea, potassium chloride, medium-element slow-release agent, and pore-forming agent; then add 0.5%~2.0% of the total dry basis mass of the core solid mixture, mix evenly, add binder A, and knead into a plastic core wet material; S3. Core Granulation and Primary Drying: The plastic core wet material obtained in S2 is fed into an extrusion rounding granulator for granulation and drying to obtain a porous fertilizer core. S4. Active shell coating and final granulation: The phospholipid-plant glycoside complex is mixed with the bioactive peptide solution, and binder B solution is added to prepare the coating solution; the fertilizer core is placed in a fluidized bed coating machine, preheated, sprayed, and granulated, and then the particles are sent to a high tower granulation system for melting, condensation and shaping, and sieving to obtain the final product.

2. The method according to claim 1, characterized in that: The specific steps for preparing the S1.1 phospholipid-plant glycoside complex are as follows: soybean lecithin and plant glycoside extract powder are dispersed in an ethanol-water solution at a mass ratio of 1:(0.5~2) at 60~70℃, so that the soybean lecithin concentration is 50~100g / L; the reaction is carried out under nitrogen protection and stirring at 300~500rpm for 2~4 hours, and then the ethanol is removed by rotary evaporation at -0.08~-0.1MPa and 45~55℃ to obtain a viscous phospholipid-plant glycoside complex.

3. The method according to claim 1, characterized in that: The preparation of the S1.2 biopeptide solution is as follows: Soybean meal protein powder is dissolved in phosphate buffer at a solid-liquid ratio of 1g:(10-15)mL in pH 7.0-8.

0. Protease is added at a concentration of 1%-3% of the soybean meal protein powder. The solution is enzymatically hydrolyzed at 50-55℃ and pH 7.5-8.5 for 4-6 hours. Then, the enzyme is inactivated at 90±3℃ for 10±3 minutes. The solution is centrifuged at 8000-10000rpm for 15-20 minutes, and the supernatant is collected. The supernatant is then concentrated through an ultrafiltration membrane with a molecular weight cutoff of 900-1100Da to obtain a biopeptide solution with a solid content of 15%-25%.

4. The method according to claim 1, characterized in that: The preparation of the S1.3 composite microbial agent specifically involves mixing the fermentation broths of Bacillus subtilis and Bacillus megaterium at a volume ratio of 1:(1-3) to obtain a total viable count ≥5.0×10⁻⁶. 9 A mixed bacterial solution with CFU / mL was prepared. The mixed bacterial solution was then mixed with trehalose and skim milk powder at a volume-to-mass ratio of 1mL:0.1g:0.05g, and then freeze-dried to obtain a compound microbial agent.

5. The method according to claim 1, characterized in that: The preparation of the S2. basic fertilizer slurry and core material is specifically as follows: S2.1 Weigh the following basic fertilizer sources in parts by weight: 25-40 parts monoammonium phosphate, 10-20 parts potassium dihydrogen phosphate, 20-35 parts urea, and 10-18 parts potassium chloride; S2.2 The above-mentioned basic fertilizer source is premixed with 5-15 parts of medium-element slow-release agent, 0.5-2 parts of pore-forming agent, and 0.5%-2.0% of compound microbial agent (based on the total dry weight of the core solid mixture) in a mixer at 50-60°C for 15-30 minutes to obtain the core solid mixture; the total dry weight of the core solid mixture is calculated as the sum of the masses of monoammonium phosphate, potassium dihydrogen phosphate, urea, potassium chloride, medium-element slow-release agent, and pore-forming agent. S2.3 Add binder A solution to the core solid mixture from step S2.

2. The binder A is a polyvinyl alcohol aqueous solution with a mass fraction of 5% to 10% or a hydroxypropyl methylcellulose aqueous solution with a mass fraction of 3% to 8%. The amount used is 3% to 8% of the total dry basis mass of the core solid mixture. Knead the mixture in a kneader to form a plastic core wet material.

6. The method according to claim 1, characterized in that: S3. Core granulation and primary drying specifically involves feeding the plastic core wet material obtained in step S2.3 into an extrusion spheroidizing granulator to produce spherical wet granules with a particle size of 1.0~1.8mm. Subsequently, the granules are dried in a fluidized bed at 60~75℃ until the moisture content is less than 3%, resulting in a porous fertilizer core. The spheroidizing speed is 800~1200rpm.

7. The method according to claim 1, characterized in that: S4. Active shell coating and final granulation specifically involves: Preparation of coating solution S4.1: The phospholipid-plant glycoside complex prepared in S1.1 and the bioactive peptide solution prepared in S1.2 are mixed and stirred at a dry basis mass ratio of 1:(1~3) to obtain an active ingredient mixture. A binder B solution is then added to prepare the coating solution. The binder B is sodium alginate or chitosan. When the binder B is sodium alginate, sodium alginate is dissolved in deionized water to prepare a 1%~3% sodium alginate aqueous solution. The active ingredient mixture is then mixed with the sodium alginate aqueous solution and stirred until homogeneous to obtain the coating solution. When the binder B is chitosan, chitosan is dissolved in a 1%~2% acetic acid aqueous solution to prepare a 1%~2% chitosan acetic acid solution. The active ingredient mixture is then mixed with the chitosan acetic acid solution and stirred until homogeneous to obtain the coating solution. The amount of binder B used is 2%~5% of the total dry basis mass of the outer shell. S4.2 The fertilizer core obtained in S3 is placed in a fluidized bed coating machine and preheated to 40~50℃. Using a bottom spraying process, the coating liquid prepared in S4.1 is sprayed onto the surface of the core at a rate of 3~10mL / min. The air inlet temperature is controlled at 60~80℃ and the material temperature at 40~55℃. The coating weight gain is 5%~15% of the core mass, forming particles with an active outer shell. S4.3 The coated granules are fed into the high-tower granulation system and subjected to surface finishing and densification treatment in the melting section at 125~135℃ for 1~3 seconds. Then, they are dropped and condensed in cold air at 5~15℃ to solidify and are sieved to obtain the final polyglycoside-enhanced phosphate compound fertilizer granules with a particle size of 2.0~4.0mm.

8. The method according to claim 1, characterized in that: The preparation method of the plant glycoside extract powder is as follows: the dried tissues of Gardenia, Eucommia, or Rehmannia are pulverized and passed through a 40-80 mesh sieve, and extracted twice by reflux at 75-85°C with a volume fraction of 70%-85% ethanol aqueous solution at a solid-liquid ratio of 1:(10-15), each time for 2 hours; the extracts are combined, filtered through a 0.4-0.5μm microporous membrane, and then passed through an AB-8 type macroporous adsorption resin column. First, impurities are eluted with 3-5 BV of deionized water, and then the target component is eluted with a volume fraction of 55-65% ethanol aqueous solution at a flow rate of 1-3 BV / h; the eluent is collected, concentrated under reduced pressure, and spray-dried to obtain the plant glycoside extract powder, wherein the content of iridoid glycosides is not less than 60 mg / g.

9. The method according to claim 1, characterized in that: The medium-element slow-release agent is calcium citrate or magnesium citrate coated particles with bentonite or diatomaceous earth as carriers, with a particle size of 0.1~0.5mm and a calcium or magnesium content of 5%~15%. Its nutrient release period in static water requires no less than 30 days to release 80% of the nutrients.

10. The method according to claim 3, characterized in that: The protease is a complex enzyme of alkaline protease and flavor protease, with a mass ratio of 1 to 2:

1. The enzymatic hydrolysis pH is maintained by automatically adding 1 to 2 mol / L NaOH solution. The pore-forming agent is ammonium bicarbonate or azodicarbonamide. When the pore-forming agent is ammonium bicarbonate, its particle size is 150 to 200 mesh, and it is used to decompose in the kernel drying step at 60 to 70°C to generate pores.

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