Iridoid glycoside crop yield increasing and efficiency improving fertilizer, and preparation method and application thereof

Abstract

This invention provides a cyclohexene glycoside-based fertilizer for increasing crop yield and efficiency, its preparation method, and its application. The method first prepares an aqueous solution of the cyclohexene glycoside substrate, and then prepares a nutrient matrix consisting of at least two of nitrogen, phosphorus, and potassium components mixed with an organic carrier. Next, nutrient-converting functional bacteria and cyclohexene glycoside-activating functional bacteria are separately cultured and then compounded to form a synthetic bacterial agent with specific β-glucosidase activity and an effective viable count. The cyclohexene glycoside substrate is then loaded onto diatomaceous earth particles with high open porosity to obtain a stabilized carrier. Subsequently, the carrier, nutrient matrix, and synthetic bacterial agent are mixed, and granulated under the condition of adding a binder to obtain wet granules. Finally, the granules are dried at low temperature in two stages until the moisture content is ≤8 wt%, and then granulated to obtain the finished fertilizer. This fertilizer integrates the active components of cyclohexene glycosides, compound nutrients, and functional microorganisms, which can synergistically promote crop growth and nutrient utilization, and is suitable for a variety of crops, achieving increased yield and efficiency.

Description

Technical Field

[0001] This invention belongs to the field of fertilizer technology, specifically relating to a crop yield-enhancing and efficiency-enhancing fertilizer containing iridoid glycosides, its preparation method, and its application. Background Technology

[0002] In modern agriculture, the excessive use of chemical fertilizers leads to soil degradation and environmental pollution. To address this problem, fertilizers with added biostimulants or functional microorganisms have emerged on the market, aiming to improve utilization and soil structure. However, existing technologies have limitations: traditional biostimulants have unstable effects, while single microbial agents are difficult to colonize in the soil, and the synergistic growth-promoting mechanism of both on crops is insufficient.

[0003] In the prior art, such as the Chinese patent application document with publication number CN118978415A, a fertilizer and fertilization method for increasing rice yield and efficiency are disclosed. This technology uses resin-coated slow-release nitrogen fertilizer as base fertilizer, urea as booting fertilizer, and phosphorus and potassium fertilizer as base fertilizer in one application, forming a simplified fertilization mode of one base and one topdressing. This makes the nitrogen release process highly matched with the fertilizer requirements of rice, thereby significantly improving yield and nitrogen fertilizer utilization efficiency.

[0004] Currently, there are very few compound fertilizers that use iridoid glycosides as additives. Iridoid glycosides are a class of natural compounds that significantly promote plant growth and stress resistance, and have great potential as novel biostimulants. However, their properties are unstable, and they face key technical bottlenecks when compounded with fertilizers and living microorganisms: they are easily degraded and inactivated during processing, and may inhibit microbial activity; at the same time, there is a lack of effective solutions to enable functional microorganisms and microorganisms that can specifically activate these compounds to coexist stably and synergistically enhance their effects.

[0005] Therefore, there is an urgent need for existing technologies to prepare fertilizers that contain iridoid glycosides as one of the stable additives for increasing crop yield and efficiency, so as to achieve precise compatibility and synergy with compound microorganisms and nutrient substrates, thereby developing a truly efficient and green new generation of functional fertilizers. Summary of the Invention

[0006] To address the aforementioned deficiencies, this invention provides a cyclohexene ether glycoside-based fertilizer for increasing crop yield and efficiency, its preparation method, and its application. This application introduces organic carriers such as humic acid, fulvic acid and its salts, hydrolyzed protein, and seaweed extract into the nutrient matrix, supplemented with chelated micronutrients. This expands the nutrient system from a single macronutrient supply to a multi-level, multi-scale nutrient regulation system. The chelated metal elements reduce the risk of fixation and precipitation in the soil through stable complexation structures, improving the bioavailability of micronutrients such as iron, zinc, boron, manganese, copper, molybdenum, magnesium, and calcium. Synergistically working with synthetic microbial agents, it can significantly promote crop photosynthesis, chlorophyll synthesis, and cell wall development, thereby providing a more comprehensive and balanced nutritional guarantee for efficient crop growth.

[0007] This invention provides the following technical solution: a method for preparing a crop yield-enhancing and efficiency-enhancing fertilizer containing iridoid glycosides, comprising the following steps: S1: Select an iridoid glycoside substrate and prepare it into an aqueous solution. The amount of the iridoid glycoside substrate added, based on the final product, is 0.01 wt% to 2.0 wt%. S2: Select at least two nutrient sources from nitrogen, phosphorus and potassium sources and mix them with an organic carrier. The added organic carrier shall be 10 wt% to 45 wt% based on the final product to obtain a nutrient matrix. S3: Place the nutrient-converting bacteria and the iridoid glycoside-activating bacteria in a culture environment to prepare seed culture and expand the culture to the end-log phase or stationary phase; concentrate the fermentation broth by centrifugation, spray drying or freeze drying to obtain bacterial powder or high-viability bacterial suspension, add a protectant at 0.1-5 wt% of the synthetic bacterial agent as needed, and adjust the count to the target viable count; combine the nutrient-converting bacteria and the iridoid glycoside-activating bacteria at a mass ratio of (1-20):(1-20) to prepare a synthetic bacterial agent, wherein the β-glucosidase activity of the synthetic bacterial agent is 10 U / g-500 U / g and the effective viable count is 1×10⁻⁶ based on the synthetic bacterial agent. 7 CFU / g ~ 1×10 11 CFU / g; The nutrient conversion functional bacteria are used to achieve one or two of the following functions: nitrogen fixation, phosphorus solubilization, or potassium solubilization; S4: The iridoid glycoside substrate is loaded onto a diatomaceous earth particle support to obtain a stabilized iridoid glycoside support; the open porosity of the diatomaceous earth particle support is 70%–90%. S5: The stabilized iridoid glycoside carrier, the nutrient matrix and the synthetic bacterial agent are mixed and granulated to obtain wet particles with a particle size D50 of 1 mm to 6 mm. S6: The wet granules obtained in step S5 are dried at 30℃~55℃ until the moisture content is ≤8wt%, and then granulated to obtain the finished fertilizer; the effective viable bacteria count of the finished fertilizer is 1×10⁻⁶ in the final product. 6 CFU / g ~ 1×10 10 CFU / g.

[0008] Furthermore, the nutrient conversion functional bacteria include at least one of the following: Paenibacillus polymyxa, Bacillus megaterium, Bacillus mucilaginosus, Bacillus subtilis, and Bacillus amyloliquefaciens, and the compound ratio of the nutrient conversion functional bacteria satisfies the following: the mass ratio of nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, and potassium-solubilizing bacteria is (1-10):(1-10):(1-10).

[0009] Furthermore, the mass ratio of the nutrient conversion functional bacteria to the iridoid glycoside activating functional bacteria is (1-20):(1-20), and the β-glucosidase activity of the synthetic bacterial agent is 10 U / g to 500 U / g, calculated based on the synthetic bacterial agent; where U is the enzyme activity unit that catalyzes the production of 1 μmol of product per minute under specified conditions.

[0010] Furthermore, the activating bacteria of the iridoid glycosides are one or more of Trichoderma harzianum, Trichoderma viride, Bacillus licheniformis, or Bacillus subtilis, and the substrate of the iridoid glycosides includes at least one or more of genipin, catalpol, harbacoside, and geniposide.

[0011] Further, the nitrogen source is selected from one or more of urea, ammonium sulfate, ammonium nitrate, and polymer-coated urea; the phosphorus source is selected from one or more of monoammonium phosphate (MAP), diammonium phosphate (DAP), potassium dihydrogen phosphate (MKP), and superphosphate; the potassium source is selected from one or more of potassium sulfate, potassium chloride, and potassium nitrate; the organic carrier is selected from one or more of humic acid, fulvic acid, humate, fulvic acid, hydrolyzed soybean protein, casein hydrolysate, seaweed extract, and peat; and 0.1–3 wt% of trace elements are added, wherein the trace elements are chelated metal elements, and the chelated metal elements are one or more of chelated iron, chelated zinc, chelated boron, chelated manganese, chelated copper, chelated molybdenum, chelated magnesium, and chelated calcium; the amount of trace elements added is calculated based on chelated Fe, Zn, B, Mn, Cu, Mo, Mg, and Ca; ethylenediaminetetraacetic acid salts of the corresponding metal elements can be used.

[0012] 6. The method according to claim 1, wherein the culture environment of the nutrient conversion functional bacteria and the iridoid glycoside activation functional bacteria in step S3 is: culture temperature of 25℃~37℃, culture pH of 5.5~8.0, and culture time of 12h~72h; the added protective agent is one or more of trehalose, glycerol, or skim milk powder.

[0013] Furthermore, in step S5, granulation is performed using a rotary drum granulation method, with a drum rotation speed of 8 r / min to 25 r / min, a drum tilt angle of 2° to 6°, a granulation time of 5 min to 25 min, and a material moisture content of 18 wt% to 30 wt% during granulation. During the granulation process, a granulation binder is added at a mass percentage of 0.2 wt% to 5 wt% based on the final product. The granulation binder is one or more of lignin sulfonate, starch, and polyglutamic acid.

[0014] Furthermore, in step S6, the drying process is divided into a pre-heating drying stage and a post-heating drying stage. The temperature of the pre-heating stage is 30℃~45℃, and the temperature of the post-heating stage is 45℃~55℃. The total drying time for the pre-heating drying stage and the post-heating drying stage is 0.5~6 h. When the synthetic microbial agent is a heat-sensitive bacteria or contains Trichoderma, the synthetic microbial agent is added by spraying during the post-heating drying stage, and then cured for a short time at a temperature not exceeding 45℃ for 0.2~2 h.

[0015] According to a second aspect of the present invention, a crop yield-enhancing and efficiency-enhancing fertilizer of iridoid glycosides prepared by the preparation method described above is also provided.

[0016] According to a third aspect of the present invention, an application of the iridoid glycoside crop yield-enhancing and efficiency-enhancing fertilizer as described above is provided.

[0017] The beneficial effects of this invention are as follows: 1. In the overall system construction, this application synergistically designs iridoid glycoside active substrates, nutrient matrix, and synthetic microbial agents, transforming the fertilizer from a simple nutrient supply carrier into a composite system with both nutrient supply and biotransformation functions. By introducing nitrogen-fixing, phosphorus-solubilizing, and potassium-solubilizing bacteria into the nutrient matrix, nitrogen, phosphorus, and potassium resources that are difficult to directly absorb and utilize in the soil can be continuously converted into forms that crops can absorb. At the same time, combined with organic matter carriers, it improves soil aggregate structure and rhizosphere microecological environment, providing crops with a more stable, long-lasting, and slow-release nutrient supply foundation, thereby avoiding the problems of low nutrient utilization, rapid loss, and easy deterioration of soil physicochemical properties in traditional chemical fertilizers.

[0018] 2. This application further introduces cycloalkenyl glycoside-activating bacteria with β-glucosidase activity to enable the directed biotransformation of cycloalkenyl glycoside substrates in the rhizosphere environment. This gradually transforms the originally stable but physiologically limited glycoside compounds into active forms that are more easily absorbed by plants or have a greater biostimulatory effect. This process does not rely on high temperature, high pressure, or strong acid-base chemical treatment, but rather completes the transformation in situ in the rhizosphere through microbial enzyme systems. This synchronizes the release of active substances with the crop growth rhythm, thereby significantly improving the utilization efficiency and biological effectiveness of cycloalkenyl glycoside functional components in agricultural settings.

[0019] 3. This application employs a combination of nutrient-converting functional bacteria and iridoid glycoside-activating functional bacteria to construct a synthetic microbial agent, creating a continuous biological reaction chain in the system: "nutrient conversion—active molecule generation—root absorption response." The nutrient-converting functional bacteria provide basic nutritional support for crops, while the iridoid glycoside-activating functional bacteria enhance the crop's physiological metabolic regulation and stress resistance. The two types of microbial communities form a synergistic symbiotic relationship in the rhizosphere, upgrading the fertilizer system from a traditional compound fertilizer of chemical fertilizers and functional additives to a compound fertilizer system model centered on microbial metabolic regulation and featuring the continuous generation and release of functional molecules. This fundamentally improves the biological intelligence and ecological adaptability of the fertilizer system.

[0020] 4. This application stabilizes and controls the slow release of active ingredients by loading iridoid glycoside substrates onto diatomaceous earth particles with high open porosity. The porous structure of diatomaceous earth not only effectively adsorbs and protects iridoid glycoside substrates, reducing their degradation risk during storage and application, but also gradually releases the active substances into the soil, forming a stable and continuous effective concentration range in the rhizosphere. This avoids waste or biotoxicity risks caused by one-time application, thereby significantly improving the utilization rate and safety of the active ingredients. Attached Figure Description

[0021] The invention will now be described in more detail with reference to embodiments and the accompanying drawings. Figure 1 The illustration shows a comparison of leaf gloss status after applying fertilizers from different embodiments or comparative proportions to maize leaves at the four-leaf to six-leaf stages. Figure 2 A comparative bar chart showing the relative chlorophyll values ​​of maize leaves after applying fertilizers from Examples 1-4 and Comparative Examples 1-2 at the four-leaf to six-leaf stage; Figure 3 A comparative bar chart showing the leaf thickness of maize after applying the fertilizers of Examples 1-4 and Comparative Examples 1-2 at the four-leaf to six-leaf stage; Figure 4 The bar charts show the comparison of leaf gloss after applying the fertilizers of Examples 1-4 and Comparative Examples 1-2 to maize leaves from the four-leaf to six-leaf stage, reflecting the changes in the development level of the epidermal wax layer and leaf surface reflectivity under different treatment conditions. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the following embodiments of the present invention, the materials and reagents used in the embodiments are all commercially available unless otherwise specified. For example, sodium lignosulfonate, polyglutamic acid, soluble starch, diatomaceous earth, and skim milk powder were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with product numbers S140863, P774285, S111914, K131669, and N752146, respectively; urea, ammonium sulfate, diammonium phosphate, potassium nitrate, potassium chloride, potassium sulfate, sodium humate, glycerol, trehalose, and iridoid glycoside substrates (genipin, catalpol, harbazoside, and geniposide) were also purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. The catalog numbers for the following products are listed: Geniposide (G101668); Catalpol (C110216); Harpagide (H115697); Geniposidic acid (G129326). Urea (U111898); Ammonium sulfate (A774581); Diammonium phosphate (A112553); Glycerin (G358402); Trehalose (T100012); Potassium nitrate (A434068); Potassium chloride (P112504); Potassium sulfate (P112463); Sodium humate (H102874). Superphosphate and humic acid were purchased from Wuhan Jiyesheng Chemical Co., Ltd., with product codes W00254 and W00271, respectively. Commercially available acidic peat moss was used as the peat source. The following examples and comparative examples used acidic peat moss purchased from Stanley Horticulture online, product code 100033062554. The nutrient conversion functional bacteria and iridoid glycoside activating functional bacteria used in the following examples of this invention were all obtained from the China General Microbiological Culture Collection Center (CGMCC).

[0024] Example 1 This embodiment provides a method for preparing a crop yield-enhancing and efficiency-enhancing fertilizer containing iridoid glycosides, comprising the following steps S1-S6: S1: Harpaginoside was selected as the iridoid glycoside compound and prepared into a 5 wt% aqueous solution for later use. The amount of harpaginoside added was 1.20 wt% based on the final fertilizer product.

[0025] S2: Select phosphorus and potassium sources as the nutrient source combination, specifically: The phosphorus source is superphosphate, and its addition amount is 16.0 wt% based on the final product. The potassium source is potassium nitrate, and its addition amount is 9.0 wt% based on the final product. The organic carrier is peat, which is added at a rate of 35 wt% based on the final product. The amount of trace elements added is 2.00 wt% based on the final product. Chelated manganese and chelated copper are selected. The chelated manganese is disodium ethylenediaminetetraacetate manganese, and the chelated copper is disodium ethylenediaminetetraacetate copper; the mass ratio of disodium ethylenediaminetetraacetate manganese to disodium ethylenediaminetetraacetate copper is 1:1.

[0026] The phosphorus source, potassium source, organic carrier, and trace elements are mixed evenly at room temperature to obtain a nutrient matrix.

[0027] S3: The preparation of synthetic microbial agents specifically includes the following steps (1)-(4): (1) Bacillus mucilaginosus (CGMCC No. 7549) was selected as the nutrient conversion functional bacterium, which has the functions of phosphorus solubilization and potassium solubilization. The Bacillus mucilaginosus strain was inoculated into liquid culture medium and cultured at a temperature of 34 ℃, a pH of 7.2 and a culture time of 48 h to obtain the fermentation broth.

[0028] (2) Bacillus subtilis (CGMCC No.3222) was selected as the functional bacterium for activating iridoid glycosides, which has β-glucosidase activity.

[0029] Bacillus subtilis strain was inoculated into liquid culture medium and cultured at a temperature of 34 ℃, a pH of 7.2, and a culture time of 48 h to obtain fermentation broth.

[0030] This step completes the cultivation of bacteria with cyclohexene glycoside activation function.

[0031] (3) The fermentation broths of the two bacteria were concentrated by centrifugation to obtain high-viability bacterial suspensions. Glycerol was added to the high-viability bacterial suspensions as a protective agent, and the amount added was 3.00 wt% based on the mass of the synthetic bacterial agent. The mixture was stirred evenly and then set aside.

[0032] (4) Compound preparation of microbial agents Nutrient-converting bacteria and iridoid glycoside-activating bacteria were compounded at a mass ratio of 12:8 to obtain a synthetic bacterial agent. The synthetic bacterial agent had a β-glucosidase activity of 300 U / g and an effective viable count of 2 × 10⁻⁶ bacteria based on the synthetic bacterial agent. 10 CFU / g.

[0033] S4: Diatomaceous earth particles were selected as the porous carrier material, with an open porosity of 85%. The harbazoside solution prepared in step S1 was mixed with diatomaceous earth particles at a liquid-to-solid ratio of 5.0 mL / g, and impregnated at 30 ℃ for 150 min to allow harbazoside to fully penetrate the diatomaceous earth's pore structure. After loading, the material was pre-dried at 45 ℃ for 1.5 h to obtain a stabilized iridoid glycoside carrier.

[0034] S5: The stabilized iridoid glycoside carrier obtained in step S4, the nutrient matrix prepared in step S2, and the synthetic bacterial agent prepared in step S3 are mixed. Granulation is performed using a rotary drum granulation method, with a drum speed of 18 r / min, a drum inclination angle of 4°, and a granulation time of 18 min. Polyglutamic acid is added as a granulation binder during the granulation process, with an addition amount of 2.50 wt% based on the final product, maintaining the total material moisture content at 26 wt%. After granulation, wet granules with a particle size D50 of 4.0 mm are obtained.

[0035] S6: The wet granules obtained in step S5 are subjected to segmented heating and drying: the initial heating temperature is 40 ℃, and the initial heating time is 2.0 h. The subsequent heating temperature is 52 ℃, and the subsequent heating time is 2.0 h. The total drying time is 4.0 h. In this embodiment, the synthetic microbial agent is not added by the subsequent spraying method, but is already mixed into the fertilizer before granulation. During the drying process, the drying temperature of the wet granules is controlled at 50 ℃, and the moisture content at the drying endpoint is 6.0 wt%. After granulation, the finished fertilizer is obtained, and its effective viable bacteria count, based on the final product, is 2 × 10⁻⁶. 9 CFU / g.

[0036] Example 2 This embodiment provides a method for preparing a crop yield-enhancing and efficiency-enhancing fertilizer containing iridoid glycosides, comprising the following steps S1-S6: S1: Genipin was selected as the iridoid glycoside compound and prepared into a 3 wt% aqueous solution for later use. The amount of genipin added was 0.01 wt% based on the final fertilizer product.

[0037] S2: Select nitrogen, phosphorus, and potassium sources as the nutrient source combination, specifically: Urea was selected as the nitrogen source, with an addition amount of 12.0 wt% based on the final product; monoammonium phosphate was selected as the phosphorus source, with an addition amount of 10.0 wt% based on the final product; potassium sulfate was selected as the potassium source, with an addition amount of 8.0 wt% based on the final product; sodium humate was selected as the organic matter carrier, with an addition amount of 10 wt% based on the final product; and trace elements were added at an amount of 0.10 wt% based on the final product, with ethylenediaminetetraacetic acid sodium iron salt selected as the chelated iron supply source. The above nitrogen, phosphorus, potassium, organic matter, and trace elements were mixed evenly at room temperature to obtain the nutrient matrix.

[0038] S3: This step involves the preparation of synthetic microbial agents, specifically including the following steps (1)-(4): (1) Polymyxin Bacillus (CGMCC No. 7250) was selected as the nutrient conversion functional bacterium, which has nitrogen fixation and phosphorus solubilization functions. The polymyxin Bacillus strain was inoculated into liquid culture medium and cultured at a temperature of 25 ℃, a pH of 5.5 and a culture time of 12 h to obtain fermentation broth.

[0039] (2) Bacillus licheniformis (CGMCC No. M206082) was selected as the functional bacterium for activating iridoid glycosides, as it has β-glucosidase activity. The Bacillus licheniformis strain was inoculated into liquid culture medium and cultured at a temperature of 25 ℃, a pH of 5.5, and a culture time of 12 h to obtain the fermentation broth.

[0040] (3) The fermentation broths of the two bacteria were spray-dried to obtain bacterial powder. Skim milk powder was added to the bacterial powder as a protectant, and the amount added was 0.10 wt% based on the mass of the synthetic bacterial agent. The mixture was then mixed evenly and set aside.

[0041] (4) The nutrient-converting bacteria and the iridoid glycoside-activating bacteria were compounded at a mass ratio of 10:5 to obtain a synthetic bacterial agent. The β-glucosidase activity of the synthetic bacterial agent was 10 U / g, and the effective viable count based on the synthetic bacterial agent was 1×10⁻⁶. 7 CFU / g. The carrier and trace elements are mixed evenly at room temperature to obtain the nutrient matrix.

[0042] S4: Diatomaceous earth particles with an open porosity of 90% were selected as the porous support material. The genipin solution prepared in step S1 was mixed with diatomaceous earth particles at a liquid-to-solid ratio of 2.0 mL / g, and impregnated at 20 °C for 30 min to allow genipin to fully penetrate the pore structure of the diatomaceous earth. After loading, the material was pre-dried at 25 °C for 0.5 h to obtain a stabilized iridoid glycoside support.

[0043] S5: The stabilized iridoid glycoside carrier obtained in step S4, the nutrient matrix prepared in step S2, and the synthetic bacterial agent prepared in step S3 are mixed. Granulation is performed using a rotary drum granulation method. During granulation, the drum speed is controlled at 8 r / min, the drum inclination angle at 2°, and the granulation time at 5 min. The moisture content of the material during granulation is 18 wt%. Sodium lignosulfonate is added as a granulation binder during granulation, with an addition amount of 0.20 wt% based on the final product. After granulation, wet granules with a D50 of 1.0 mm are obtained.

[0044] S6: The wet granules obtained in step S5 are subjected to segmented heating and drying treatment: the heating temperature of the first stage is 45 ℃ and the heating time is 0.15 h; the heating temperature of the second stage is 45 ℃ and the heating time is 0.35 h; the total drying time is 0.5 h.

[0045] In this embodiment, the synthetic microbial agent is not added via post-treatment spraying, but rather added entirely and uniformly mixed with the material before granulation. During the drying process, the drying temperature of the wet granules is controlled at 30 ℃, and the moisture content at the drying endpoint is 8.0 wt%. After granulation, the finished fertilizer is obtained, with an effective viable bacteria count of 1 × 10⁻⁶ based on the final product. 6 CFU / g.

[0046] Example 3 This embodiment provides a method for preparing a crop yield-enhancing and efficiency-enhancing fertilizer containing iridoid glycosides, specifically including the following steps S1-S6: S1: Gardeninoic acid was selected as the iridoid glycoside compound and prepared into an 8 wt% aqueous solution for later use. The amount of gardeninoic acid added was 2.00 wt% based on the final fertilizer product.

[0047] S2: A nitrogen and potassium source combination was selected, specifically: ammonium sulfate was used as the nitrogen source, with an addition amount of 18.0 wt% based on the final product; potassium chloride was used as the potassium source, with an addition amount of 12.0 wt% based on the final product; seaweed extract was used as the organic carrier in this embodiment, with an addition amount of 22 wt% based on the final product; and trace elements were added at an addition amount of 1.00 wt% based on the final product. The trace elements included chelated zinc and chelated boron. Disodium ethylenediaminetetraacetate (EDTA) was used as the source of chelated zinc, and ethanolamine borate was used as the source of chelated boron. The mass ratio of EDTA to ethanolamine borate was 1:1. The above nitrogen source, potassium source, organic carrier, and trace elements were mixed evenly at room temperature to obtain the nutrient matrix.

[0048] S3: Specifically includes the following steps (1)-(4) (1) Cultivation of nutrient-converting bacteria Bacillus amyloliquefaciens (CGMCC No. 8720) was selected as the nutrient conversion functional bacterium, possessing nitrogen-fixing capabilities. The Bacillus amyloliquefaciens strain was inoculated into liquid culture medium and cultured at 37 ℃, pH 8.0, and for 72 h to obtain the fermentation broth.

[0049] (2) Cultivation of bacteria with cyclohexene glycoside activation function *Trichoderma viride* (CGMCC No. 1498) was selected as the functional bacterium for activating iridoid glycosides, as it possesses β-glucosidase activity. The *Trichoderma viride* strain was inoculated into liquid culture medium and cultured at 37 ℃, pH 8.0, and for 72 h to obtain the fermentation broth.

[0050] (3) Preparation of bacterial preparations The fermentation broths of the two bacteria were spray-dried separately to obtain bacterial powder. Trehalose and glycerol were added to the bacterial powder as protective agents, wherein the mass ratio of trehalose to glycerol was 1:1, and the total amount of protective agents added was 5.00 wt% based on the mass of the synthesized bacterial agent. The mixture was then thoroughly mixed and set aside.

[0051] (4) Compound preparation of microbial agents Nutrient-converting bacteria and iridoid glycoside-activating bacteria were compounded at a mass ratio of 20:1 to obtain a synthetic bacterial agent. The synthetic bacterial agent had a β-glucosidase activity of 500 U / g and an effective viable count of 1 × 10⁻⁶ bacteria based on the synthetic bacterial agent. 11 CFU / g.

[0052] S4: Diatomaceous earth particles with an open porosity of 78% were selected as the porous support material. The geniposide solution prepared in step S1 was mixed with diatomaceous earth particles at a liquid-to-solid ratio of 6.0 mL / g, and impregnated at 25 °C for 90 min to allow geniposide to fully penetrate the pore structure of the diatomaceous earth. After loading, the material was pre-dried at 55 °C for 1.0 h to obtain a stabilized iridoid glycoside support.

[0053] S5: Step S5 mainly completes the compound granulation. The stabilized iridoid glycoside carrier obtained in step S4, the nutrient matrix prepared in step S2, and the synthetic bacterial agent prepared in step S3 were mixed. Granulation was performed using a rotary drum granulation method. During granulation, the drum was rotated at 12 r / min and tilted at 3° for 10 min. Starch (1.00 wt% of the final product) was added as a granulation binder during the granulation process, and the moisture content of the material was maintained at 22 wt%. The final result was wet granules with a particle size D50 of 6.0 mm.

[0054] S6: The wet granules obtained in step S5 are subjected to segmented heating and drying, which consists of a pre-stage heating and drying process and a post-stage heating and drying process. The initial heating temperature is 35 ℃, and the initial heating and drying time is 1.8 h; The subsequent heating temperature is 55 ℃, and the subsequent heating and drying time is 1.2 h; The total drying time is 3.0 h.

[0055] In this embodiment, since the synthetic microbial agent contains Trichoderma, it is added via a post-treatment spraying method. Specifically, during the post-drying stage, the synthetic microbial agent is uniformly sprayed onto the surface of the wet granules. After spraying, a short-term curing treatment is performed at 35 °C for 2.0 h. During the drying process, the drying temperature of the wet granules is controlled at 55 °C, and the moisture content at the drying endpoint is 5.0 wt%. After granulation, the finished fertilizer is obtained, with an effective viable bacteria count of 1 × 10⁻⁶ based on the final product. 10 CFU / g.

[0056] Example 4 This embodiment provides a method for preparing a crop yield-enhancing and efficiency-enhancing fertilizer containing iridoid glycosides, specifically using the following steps S1-S6: S1: Catalpol was selected as the iridoid glycoside compound and prepared into a 4 wt% aqueous solution for later use. The amount of catalpol added was 0.60 wt% based on the final fertilizer product.

[0057] S2: This step mainly involves the preparation of the nutrient substrate, selecting nitrogen and phosphorus sources as the nutrient source combination, specifically: The nitrogen source is ammonium nitrate, and its addition amount is 10.0 wt% based on the final product. The phosphorus source is diammonium phosphate, and its addition amount is 14.0 wt% based on the final product. The organic carrier used is fulvic acid, which is added at a rate of 45 wt% based on the final product. The amount of trace elements added is 3.00 wt% based on the final product. The trace elements selected are chelated magnesium and chelated calcium. Magnesium disodium ethylenediaminetetraacetate is selected as the source of chelated magnesium, and calcium disodium ethylenediaminetetraacetate is selected as the source of chelated calcium. The mass ratio of magnesium disodium ethylenediaminetetraacetate to calcium disodium ethylenediaminetetraacetate is 1:1.

[0058] The nitrogen source, phosphorus source, organic carrier, and trace elements are mixed evenly at room temperature to obtain a nutrient matrix.

[0059] S3: The S3 step includes the following steps (1)-(4): (1) Bacillus megaterium (CGMCC No.10803) was selected as the nutrient conversion functional bacteria, which has the function of potassium solubilization. The Bacillus megaterium strain was inoculated into liquid culture medium and cultured at a temperature of 30 ℃, a pH of 6.2 and a culture time of 24 h to obtain fermentation broth.

[0060] (2) Trichoderma harzianum (CGMCC No. 21471) with β-glucosidase activity was selected as the functional strain for activating iridoid glycosides. The Trichoderma harzianum strain with β-glucosidase activity was inoculated into liquid culture medium and cultured at a temperature of 30 ℃, a pH of 6.2 and a culture time of 24 h to obtain fermentation broth.

[0061] (3) The fermentation broths of the two bacteria obtained in steps (1) and (2) above are freeze-dried to obtain bacterial powder. Trehalose is added to the bacterial powder as a protective agent, and the amount added is 1.00 wt% based on the mass of the synthetic bacterial agent. The mixture is then mixed evenly and set aside.

[0062] (4) The nutrient conversion functional bacteria and the iridoid glycoside activating functional bacteria were compounded at a mass ratio of 1:20 to obtain a synthetic bacterial agent. The β-glucosidase activity of the synthetic bacterial agent was 120 U / g, and the effective viable count based on the synthetic bacterial agent was 5 × 10⁻⁶. 8 CFU / g.

[0063] S4: Diatomaceous earth particles are selected as the porous carrier material, with an open porosity of 70%.

[0064] The catalpol solution prepared in step S1 was mixed with diatomaceous earth particles with an open porosity of 70% at a liquid-to-solid ratio of 3.5 mL / g, and impregnated at 35 °C for 240 min to allow the catalpol to fully penetrate the diatomaceous earth's pore structure. After loading, the material was pre-dried at 35 °C for 2.0 h to obtain a stabilized iridoid glycoside carrier.

[0065] S5: The stabilized iridoid glycoside carrier obtained in step S4, the nutrient matrix prepared in step S2, and the synthetic bacterial agent prepared in step S3 are mixed. Granulation is performed using a rotary drum granulation method with the following parameters: drum speed of 25 r / min, drum tilt angle of 6°, granulation time of 25 min, and material moisture content of 30 wt% during granulation.

[0066] A mixture of starch and polyglutamic acid is added as a granulation binder during the granulation process, wherein the mass ratio of starch to polyglutamic acid is 1:1, and the amount of the granulation binder added is 5.00 wt% based on the final product. After granulation, wet granules are obtained with a particle size D50 of 2.5 mm.

[0067] S6: The wet granules obtained in step S5 are subjected to segmented heating and drying treatment: the initial heating temperature is 30 ℃ and the initial heating time is 1.25 h; the subsequent heating temperature is 48 ℃ and the subsequent heating time is 1.75 h; the total drying time is 2.0 h.

[0068] In this embodiment, since the synthetic microbial agent contains Trichoderma, it is added via a post-treatment spraying method. Specifically, during the post-drying stage, the synthetic microbial agent is uniformly sprayed onto the surface of the wet granules. After spraying, a short-term curing treatment is performed at 40 °C for 0.6 h. During the drying process, the drying temperature of the wet granules is controlled at 45 °C, and the moisture content at the drying endpoint is 7.0 wt%. After granulation, the finished fertilizer is obtained, with an effective viable bacteria count of 3 × 10⁻⁶ based on the final product. 7 CFU / g.

[0069] Comparative Example 1 This comparative example provides a method for preparing a crop yield-enhancing and efficiency-enhancing fertilizer containing iridoid glycosides. The overall process flow is the same as in Example 1, except that: no synthetic microbial agents are prepared, i.e., no nutrient conversion functional bacteria or iridoid glycoside activating functional bacteria are introduced, and no microbial agent compounding and subsequent loading synergistic process is included. Except for the following differences, the steps, raw material composition ratios, process parameters, and operating conditions of this comparative example are exactly the same as those of Example 1.

[0070] The difference is: 1) This comparative example does not prepare synthetic bacterial agents compared to Comparative Example 1. In this comparative example, the preparation process of the synthetic bacterial agent described in step S3 of Example 1 is omitted, and the cultivation, expansion, centrifugation concentration, drying, addition of protective agent, and compounding of bacterial agents are not performed on the nutrient conversion functional bacteria and the iridoid glycoside activated functional bacteria.

[0071] 2) This comparative example does not introduce any functional microorganisms compared to Example 1. The finished fertilizer does not contain any nutrient conversion bacteria or iridoid glycoside activating bacteria, and does not have nitrogen-fixing, phosphorus-solubilizing, or potassium-solubilizing functions, nor does it have β-glucosidase activity. Based on the final product: the effective viable bacteria count is 0 CFU / g, and the β-glucosidase activity is 0 U / g.

[0072] 3) Compared to Example 1, this comparative example does not include synthetic microbial agents in the granulation step. In this comparative example, the synthetic bacterial agent that was mixed with the nutrient substrate and the stabilized iridoid glycoside carrier in step S5 of Example 1 was omitted. Instead, the nutrient substrate and the stabilized iridoid glycoside carrier were mixed and then directly granulated.

[0073] Comparative Example 2 This comparative example provides a method for preparing a crop yield-enhancing and efficiency-enhancing fertilizer containing iridoid glycosides. The overall process flow is the same as in Example 1, except that only iridoid glycoside-activating bacteria are introduced, without introducing nutrient conversion bacteria. This ensures the fertilizer only possesses iridoid glycoside activation capabilities but lacks nitrogen fixation, phosphorus solubilization, or potassium solubilization functions, thus preventing the formation of a synergistic synthetic microbial agent structure. Except for the following differences, the remaining steps, raw material composition ratios, process parameters, and operating conditions are completely identical to those in Example 1.

[0074] The difference is: 1) No nutrient conversion bacteria were set up. In this comparative example, only cycloalkenyl glycoside activating bacteria were prepared and added; no nutrient conversion bacteria were prepared or added. The synthetic bacterial agent used was Bacillus licheniformis, a single-function bacterial agent. This strain has a stable β-glucosidase secretion ability but does not have any nutrient conversion function such as nitrogen fixation, phosphorus solubilization, or potassium solubilization. It is only used to catalyze the hydrolysis and activation of cycloalkenyl glycosides.

[0075] 2) Changes in the microbial composition of synthetic microbial agents The synthetic bacterial agent formed by the combination of nutrient conversion functional bacteria and iridoid glycoside activated functional bacteria described in the original Example 1 is changed in this comparative example to consist only of iridoid glycoside activated functional bacteria, and the combination between different functional bacteria is no longer carried out.

[0076] 3) Changes in the functional structure of microbial agents The bacterial agent prepared in this comparative example only possesses the ability to hydrolyze and activate iridoid glycosides, and only affects the conversion of iridoid glycosides into their active forms, but does not participate in the biotransformation and release regulation of nitrogen, phosphorus, and potassium nutrients in the soil.

[0077] 4) Changes in biological indicators of synthetic microbial agents Based on synthetic microbial agents: the effective viable count is 5 × 10⁻⁶. 8 The CFU / g effective viable count remains within the same order of magnitude as in Example 1; the β-glucosidase activity, calculated as a bacterial agent, is 120 U / g, where U represents the enzyme activity unit that catalyzes the production of 1 μmol of product per minute under specified conditions. The β-glucosidase activity remains comparable to that in Example 1; however, it no longer contains any nitrogen-fixing, phosphorus-solubilizing, or potassium-solubilizing bacterial populations.

[0078] Starting with basal application after corn emergence, fertilizers for each treatment group were continuously applied until the corn seedling stage, specifically the four- to six-leaf stage before jointing. Uniform sampling and measurement were conducted during this period. To ensure comparability of results across treatment groups, all groups were cultivated and managed within the same experimental plot under identical soil fertility conditions, following the same irrigation and fertilization regimes. Soil moisture content was kept consistent before sampling, and the effects of rainfall or artificial washing on leaf condition were avoided. Sampling and measurement were conducted uniformly at a fixed time on the same day, selecting the same functional leaf position from plants with consistent growth. Sampling areas were located in the middle of the leaf, avoiding the main vein and areas of mechanical damage, thus achieving uniform sampling and measurement under the same growth stage and environmental conditions.

[0079] Examples 1-4 and Comparative Examples 1-2 of this application were used, with each example and / or comparative example divided into three treatment groups (i.e., n=3). Chlorophyll relative content, leaf thickness, and leaf gloss were measured. Chlorophyll relative content was measured non-destructively using a handheld chlorophyll meter. The instrument used was a TYS-B plant chlorophyll meter from Zhejiang Top Cloud-Agri Technology Co., Ltd. This instrument is used to determine the relative chlorophyll content or greenness of leaves. The measurement procedure was performed according to the instrument's instruction manual. Multiple measurements were taken in the central area of ​​the leaf, and the average value was taken as the result for a single plant. The mean and standard deviation of the treatment groups were then calculated. Here, n=3 indicates that each indicator was obtained based on three independent biological replicate samples. Leaf gloss, expressed as GU, was measured using a portable gloss meter. The instrument used was a YG60S single-angle 60° gloss meter from Shenzhen Sanenshi Technology Co., Ltd. Multiple measurements were taken in the flat area in the central part of the leaf, and the average value was taken as the result for a single plant. The mean and standard deviation of the treatment groups were then calculated. Leaf thickness was measured using a digital outside micrometer. The instrument used was a digital outside micrometer from Guilin Guanglu Digital Measurement & Control Co., Ltd., model number 211-101F, with a measuring range of 0 mm to 25 mm and a resolution of 0.001 mm. Multiple measurements were taken at various points along the middle of the leaf, avoiding the main vein, and the average value was used as the result for each plant. Three independent biological replicates were set for each treatment group. Results are expressed as mean and standard deviation. The statistical results are shown in Table 1. Figure 1 The images show a comparison of leaf surface gloss after applying fertilizers from different embodiments or comparative examples.

[0080] Table 1. Effects of foliar fertilization on maize Table 1 contains a bar chart comparing the relative values ​​of chlorophyll, such as... Figure 2 As shown, this reflects the changes in the relative chlorophyll content of maize leaves under different fertilizer applications; there are also bar charts comparing leaf thickness, such as... Figure 3As shown, this reflects the differences in the degree of leaf tissue formation and mesophyll development under different fertilizer applications in maize; a bar chart comparing leaf gloss is also included. Figure 4 As shown, this reflects the changes in the development level of the epidermal wax layer and the leaf surface reflectivity under different treatment conditions.

[0081] Combination Figure 1 Table 1 and Figures 2-4 As shown, the corn leaves treated with the fertilizer of Example 1 exhibited a stable and uniform dark green color, with a significant increase in leaf thickness and a clearer waxy luster. Correspondingly, the relative chlorophyll content of Example 1 was 47.8, with a standard deviation of 1.5, a further increase of 6.3 compared to Comparative Example 2; the leaf thickness was 0.31 mm, with a standard deviation of 0.010 mm, an increase of 0.04 mm compared to Comparative Example 2; and the leaf gloss was 16.8 GU, with a standard deviation of 0.8 GU, an increase of 4.3 GU compared to Comparative Example 2. These data demonstrate that Example 1 can more effectively promote the accumulation of relative chlorophyll content and leaf tissue densification, while simultaneously enhancing the formation of the waxy layer and gloss performance, resulting in simultaneous improvement in leaf color, thickness, and gloss, exhibiting a more significant growth-promoting effect.

[0082] The corn leaves treated with the fertilizer of Example 2 showed a further deepening of color, enhanced leaf uprightness, and higher leaf gloss. The corresponding quantitative results showed that the relative chlorophyll value of Example 2 reached 52.2 (standard deviation 1.4); leaf thickness was 0.34 mm (standard deviation 0.010 mm); and leaf gloss was 19.6 GU (standard deviation 0.7 GU). Compared to Example 1, the relative chlorophyll value increased by 4.4, leaf thickness increased by 0.03 mm, and gloss increased by 2.8 GU, indicating that this treatment further improved the relative chlorophyll content, promoted leaf tissue formation, and enhanced the development of the leaf surface wax layer, resulting in a richer, darker green color, greater thickness, and more pronounced gloss characteristics in the leaves.

[0083] The corn leaves treated with the fertilizer of Example 3 showed more significant advantages, with the deepest leaf color, the thickest leaves, and a more pronounced glossy texture. Consistent with this, the relative chlorophyll value of Example 3 was 56.5 (standard deviation 1.3); the leaf thickness was 0.37 mm (standard deviation 0.009 mm); and the leaf gloss was 23.0 GU (standard deviation 0.7 GU). Compared to Comparative Example 1, Example 3 showed a 20.5 increase in relative chlorophyll value, a 0.13 mm increase in leaf thickness, and a 14.0 GU increase in gloss. Furthermore, the standard deviations for all indicators were relatively low, indicating that this treatment not only significantly improved photosynthetic pigment accumulation, tissue formation, and the development of the leaf wax layer, but also demonstrated good repeatability and stability, exhibiting a stronger comprehensive growth-promoting effect in both macroscopic morphology and microscopic quantitative data.

[0084] The corn leaves treated with the fertilizer in Comparative Example 1 were generally light green, with slight yellowing at the leaf tips in some areas. The leaves were thin and lacked luster. Consistent with this morphological characteristic, the relative chlorophyll value in Comparative Example 1 (shown in the blue bar chart) was 36.0, with a standard deviation of 1.8, indicating a low and fluctuating relative chlorophyll content. Regarding leaf thickness (shown in the orange bar chart), the leaves in Comparative Example 1 were 0.24 mm thick with a standard deviation of 0.012 mm, indicating weak leaf tissue formation. As for leaf gloss (shown in the green bar chart), Comparative Example 1 had a gloss level of 9.0 GU with a standard deviation of 0.9 GU, indicating insufficient development of the leaf wax layer and weak leaf reflectivity. All these data point to limited photosynthetic pigment accumulation in plants treated with Comparative Example 1, relatively loose leaf tissue structure, and low water retention and epidermal wax layer formation capabilities, resulting in a lighter color, thinner thickness, and insufficient gloss.

[0085] The corn leaves treated with fertilizer in Comparative Example 2 showed a significantly deeper color than those in Comparative Example 1, with improvements in leaf thickness and gloss. Quantitative results showed that the relative chlorophyll content in Comparative Example 2 increased to 41.5 (standard deviation 1.6), an increase of 5.5 compared to Comparative Example 1; leaf thickness was 0.27 mm (standard deviation 0.011 mm), an increase of 0.03 mm compared to Comparative Example 1; and leaf gloss was 12.5 GU (standard deviation 0.8 GU), an increase of 3.5 GU compared to Comparative Example 1. These results indicate that Comparative Example 2 can promote relative chlorophyll content and leaf tissue formation to some extent, and improve leaf surface reflectivity, transitioning the leaf appearance from a lighter green to a medium green. However, the improvement is limited, suggesting that while this treatment brings some physiological improvements, it is difficult to achieve a stronger overall synergistic effect.

[0086] This demonstrates that the fertilizer obtained in Comparative Example 1 consists of nutrient elements, organic matter carriers, and iridoid glycoside substrates. No functional microorganisms with nitrogen-fixing, phosphorus-solubilizing, potassium-solubilizing, or substrate-activating effects are introduced into the fertilizer. Therefore, its mechanism of action is mainly manifested in the supply of mineral nutrients and the external supplementation of functional molecules. It is difficult to form continuous biotransformation and synergistic amplification effects in the rhizosphere, thus forming a traditional fertilizer that mainly relies on the release of chemical nutrients and the role of added functional components.

[0087] Comparative Example 2 introduced only a single strain with β-glucosidase activity, resulting in a fertilizer that only had the ability to bioactivate iridoid glycoside substrates, but lacked the function of biotransformation and regulation of nitrogen, phosphorus, and potassium nutrients. This formed a single-pathway microbial fertilizer that mainly focused on functional molecule transformation but lacked nutrient regulation capabilities. Its overall synergistic efficiency was significantly lower than that of a compound microbial fertilizer that simultaneously possessed nutrient transformation and functional molecule activation capabilities.

[0088] The iridoid glycoside-based crop yield-enhancing and efficiency-enhancing fertilizer of this application can be obtained by the aforementioned preparation method. The finished product is a granular solid preparation with a particle D50 of 1 mm to 6 mm, a moisture content of no more than 8% by mass, and maintains an effective viable bacteria count of 1 x 10⁶ to 1 x 10¹⁰ per gram. The iridoid glycoside-based crop yield-enhancing and efficiency-enhancing fertilizer provided in this application is suitable for the cultivation and management of grain crops, cash crops, vegetable crops, fruit trees, and landscaping plants. It can be used as a basal or top dressing, and can be applied by trenching, hole application, strip application, broadcasting, or application with irrigation water. Taking corn seedlings as an example, after emergence, under the same cultivation and management conditions, leaf indicators were measured from the four-leaf stage to the six-leaf stage. The treatment group showed better results than the control in terms of relative chlorophyll value, leaf thickness, and leaf gloss, reflecting an improved trend in crop photosynthetic pigment accumulation, leaf tissue formation, and leaf surface structure development. In addition to increasing yield and efficiency, this fertilizer can also be used for applications such as promoting root growth and seedling development, helping seedlings recover from slow growth, enhancing stress resistance, and improving nutrient utilization. It is suitable for different cultivation conditions, such as open field and facility agriculture.

[0089] This application utilizes systematic parameter control in the process pathway, encompassing microbial culture, inoculant protection, granulation, and low-temperature drying, to maintain a high survival rate and stable enzyme activity levels of the active microbial community during industrial preparation. By employing low-temperature drying and spray-on inoculant application, the destruction of live bacteria and enzyme activity during high-temperature granulation is effectively avoided, ensuring the finished fertilizer maintains high biological activity during transportation and storage, providing a reliable foundation for subsequent field application.

[0090] Based on the above comparative analysis, this application constructs a multi-level fertilizer system with microbial transformation as the core driving force, iridoid glycoside functional molecules as physiological regulatory factors, and porous carriers and organic nutrient substrates as the structural and energy basis. This transforms fertilizer from a traditional passive nutrient supply product into a complex biological functional system with the ability to continuously transform nutrients, generate active substances in situ, and synergistically regulate the rhizosphere microecology. As a result, it achieves significant comprehensive effects in terms of increasing crop yield, improving quality, enhancing nutrient utilization, and restoring soil ecology.

[0091] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for preparing a crop yield-enhancing and efficiency-enhancing fertilizer containing iridoid glycosides, characterized in that, Includes the following steps: S1: Select an iridoid glycoside substrate and prepare it into an aqueous solution. The amount of the iridoid glycoside substrate added, based on the final product, is 0.01 wt% to 2.0 wt%. S2: Select at least two nutrient sources from nitrogen, phosphorus and potassium sources and mix them with an organic carrier. The added organic carrier shall be 10 wt% to 45 wt% based on the final product to obtain a nutrient matrix. S3: Place the nutrient-converting bacteria and the iridoid glycoside-activating bacteria in a culture environment to prepare seed culture and expand the culture to the end-log phase or stationary phase; concentrate the fermentation broth by centrifugation, spray drying or freeze drying to obtain bacterial powder or high-viability bacterial suspension, add a protectant at 0.1-5 wt% of the synthetic bacterial agent as needed, and adjust the count to the target viable count; combine the nutrient-converting bacteria and the iridoid glycoside-activating bacteria at a mass ratio of (1-20):(1-20) to prepare a synthetic bacterial agent, wherein the β-glucosidase activity of the synthetic bacterial agent is 10 U / g-500 U / g and the effective viable count is 1×10⁻⁶ based on the synthetic bacterial agent. 7 CFU / g ~ 1×10 11 CFU / g; The nutrient conversion functional bacteria are used to achieve one or two of the following functions: nitrogen fixation, phosphorus solubilization, or potassium solubilization; S4: The iridoid glycoside substrate is loaded onto a diatomaceous earth particle support to obtain a stabilized iridoid glycoside support; the open porosity of the diatomaceous earth particle support is 70%–90%. S5: The stabilized iridoid glycoside carrier, the nutrient matrix and the synthetic bacterial agent are mixed and granulated to obtain wet particles with a particle size D50 of 1 mm to 6 mm. S6: The wet granules obtained in step S5 are dried at 30℃~55℃ until the moisture content is ≤8wt%, and then granulated to obtain the finished fertilizer; the effective viable bacteria count of the finished fertilizer is 1×10⁻⁶ in the final product. 6 CFU / g ~ 1×10 10 CFU / g.

2. The method according to claim 1, characterized in that, The nutrient conversion functional bacteria include at least one of the following: Bacillus polymyxa, Bacillus megaterium, Bacillus colloidis, Bacillus subtilis, and Bacillus amyloliquefaciens, and the compound ratio of the nutrient conversion functional bacteria satisfies the following: the mass ratio of nitrogen-fixing bacteria, phosphorus-solubilizing bacteria and potassium-solubilizing bacteria is (1-10):(1-10):(1-10).

3. The method according to claim 2, characterized in that, The mass ratio of the nutrient conversion functional bacteria to the iridoid glycoside activating functional bacteria is (1-20):(1-20), and the β-glucosidase activity of the synthetic bacterial agent is 10 U / g to 500 U / g based on the synthetic bacterial agent.

4. The method according to claim 1, characterized in that, The activating bacteria of the iridoid glycosides are one or more of Trichoderma harzianum, Trichoderma viride, Bacillus licheniformis, or Bacillus subtilis, and the substrates of the iridoid glycosides include at least one or more of genipin, catalpol, harbazone, and geniposide.

5. The method according to claim 1, characterized in that, The nitrogen source is selected from one or more of urea, ammonium sulfate, ammonium nitrate, and polymer-coated urea; the phosphorus source is selected from one or more of monoammonium phosphate, diammonium phosphate, potassium dihydrogen phosphate, and superphosphate; the potassium source is selected from one or more of potassium sulfate, potassium chloride, and potassium nitrate; the organic carrier is selected from one or more of humic acid, fulvic acid, humate, fulvic acid, hydrolyzed soybean protein, casein hydrolysate, seaweed extract, and peat; and 0.1–3 wt% of trace elements are added, wherein the trace elements are chelated metal elements, and the chelated metal elements are one or more of chelated iron, chelated zinc, chelated boron, chelated manganese, chelated copper, chelated molybdenum, chelated magnesium, and chelated calcium.

6. The method according to claim 1, characterized in that, The culture environment for the nutrient conversion functional bacteria and the iridoid glycoside activation functional bacteria in step S3 is as follows: culture temperature is 25℃~37℃, culture pH is 5.5~8.0, and culture time is 12h~72h; the added protective agent is one or more of trehalose, glycerol, or skim milk powder.

7. The method according to claim 1, characterized in that, In step S5, granulation is performed using a rotary drum granulation method. The drum speed is 8 r / min to 25 r / min, the drum tilt angle is 2° to 6°, the granulation time is 5 min to 25 min, and the moisture content of the material during granulation is 18 wt% to 30 wt%. During the granulation process, a granulation binder is added at a mass percentage of 0.2 wt% to 5 wt% based on the final product. The granulation binder is one or more of lignin sulfonate, starch, and polyglutamic acid.

8. The method according to claim 1, characterized in that, In step S6, the drying process is divided into a pre-heating drying stage and a post-heating drying stage. The temperature of the pre-heating stage is 30℃~45℃, and the temperature of the post-heating stage is 45℃~55℃. The total drying time for the pre-heating drying stage and the post-heating drying stage is 0.5~6 h. When the synthetic microbial agent is a heat-sensitive bacteria or contains Trichoderma, the synthetic microbial agent is added by spraying during the post-heating drying stage. After spraying, a short-term curing at a temperature not exceeding 45℃ is performed for 0.2~2 h.

9. A crop yield-enhancing and efficiency-enhancing fertilizer of iridoid glycosides prepared by the preparation method according to any one of claims 1-8.

10. The application of a crop yield-enhancing and efficiency-enhancing fertilizer of iridoid glycosides as described in claim 9.

Images