An organic nitrogen fertilizer synergist and a method for preparing the same

Abstract

The application relates to the technical field of fertilizer synergists, and discloses an organic nitrogen fertilizer synergist and a preparation method thereof, which comprises the following components in mass fractions: 15-20 parts of potassium humate, 8-12 parts of a plant source compound, 5-8 parts of polyglutamic acid, 3-5 parts of a compound microbial agent, 5-8 parts of sodium alginate oligosaccharide, 12-18 parts of dicyanamide and 25-35 parts of diatomite. In the application, the compound microbial agent can be used to promote the degradation of complex organic molecules such as proteins and starches in the organic nitrogen fertilizer, and the slow mineralization problem of the organic nitrogen is solved; the dicyanamide and ginkgo leaf powder in the plant source compound form a double nitration inhibition system, the conversion of ammonium nitrogen into nitrate nitrogen is blocked from different target points, and nitrogen leaching and ammonia volatilization loss are greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of fertilizer synergists, and more specifically, to an organic nitrogen fertilizer synergist and its preparation method. Background Technology

[0002] Organic nitrogen fertilizers (such as livestock and poultry manure, oilseed cake, and biogas slurry) are highly favored due to their comprehensive nutrient content and ability to improve soil. However, their nitrogen is mainly found in complex organic molecules (such as proteins and uric acid), and needs to be mineralized by soil microorganisms into ammonium nitrogen (NH4). + ) and nitrate nitrogen (NO3) - Only when the ammonium nitrogen produced can it be absorbed by crops. This process has two major problems: First, the mineralization rate is greatly affected by environmental factors and is often out of sync with the crop's nutrient requirements, leading to insufficient supply in the early stage and possible excessive release in the later stage; Second, the ammonium nitrogen produced is easily converted into easily leached nitrate nitrogen in the soil through nitrification, or is directly lost through ammonia volatilization.

[0003] Currently, common nitrogen fertilizer enhancement technologies mainly target chemically synthesized nitrogen fertilizers, such as using nitrification inhibitors (e.g., DMPP, DCD) or urease inhibitors (e.g., NBPT). However, these inhibitors have limited control over the initial mineralization process of organic nitrogen fertilizers and exhibit poor compatibility and stability with organic carriers. Furthermore, nutrient release from organic nitrogen fertilizers is more dependent on microbial activity, and simply inhibiting a single step may disrupt its virtuous cycle.

[0004] Based on this, a special synergist is provided that can synergistically regulate the rate of organic nitrogen mineralization, inhibit nitrification loss, and promote crop absorption, which is of great significance for the development of efficient ecological agriculture. Summary of the Invention

[0005] In view of this, the present invention proposes an organic nitrogen fertilizer synergist and its preparation method, aiming to solve at least one of the problems in the current background art.

[0006] This invention proposes an organic nitrogen fertilizer synergist, comprising the following components in parts by weight: Potassium humate 15-20 parts, plant-derived complex 8-12 parts, polyglutamic acid 5-8 parts, compound microbial agent 3-5 parts, sodium alginate oligosaccharide 5-8 parts, dicyandiamide 12-18 parts, diatomaceous earth 25-35 parts.

[0007] Preferably, the plant-derived complex includes moringa seed powder, ginkgo leaf powder, and pine needle powder, wherein the mass ratio of moringa seed powder, ginkgo leaf powder, and pine needle powder is 1-2:1-2:1-2.

[0008] Preferably, the compound microbial agent comprises Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens in a mass ratio of 1:1:1, and the effective viable count of each of the Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens is ≥2.0 × 10⁻⁶. 9 CFU / g.

[0009] Preferably, the sodium alginate oligosaccharide has a molecular weight of 3000-5000 Da and a purity of ≥90%; the potassium humate has a particle size of 80-100 μm; and the dicyandiamide has a particle size of 50-80 μm.

[0010] This invention also provides a method for preparing an organic nitrogen fertilizer synergist, comprising the following steps: Diatomaceous earth is activated at high temperature, then cooled and crushed, and passed through a 100-120 mesh sieve to obtain activated diatomaceous earth. Moringa seeds, ginkgo leaves and pine needles were washed, dried and crushed separately to obtain moringa seed powder, ginkgo leaf powder and pine needle powder. They were then mixed to obtain a plant-derived complex. The activated diatomaceous earth is mixed with potassium humate and dicyandiamide, and stirred for the first time to obtain a first mixture. Polyglutamic acid and sodium alginate oligosaccharide were added to the first mixture for a second mixing to obtain a second mixture; The second mixture is cooled down, then mixed with a compound microbial agent, and the resulting mixture is spray-dried to obtain the organic nitrogen fertilizer enhancer.

[0011] Preferably, the high-temperature activation treatment is performed at a temperature of 550-650°C for 2-3 hours.

[0012] Preferably, the first stirring speed is 320-360 r / min and the time is 20-30 min; the second stirring speed is 280-300 r / min, the temperature is 40-50 and the time is 20-30 min.

[0013] Preferably, the temperature after cooling is 25-30℃, and the mixing with the compound microbial agent specifically involves stirring for 12-15 minutes at a rotation speed of 150-200 r / min.

[0014] Preferably, the inlet air temperature of the spray dryer is 170-175°C, and the outlet air temperature is 70-75°C.

[0015] This invention also provides an application of an organic nitrogen fertilizer synergist in soil improvement, wherein the organic nitrogen fertilizer synergist is the organic nitrogen fertilizer synergist described in the above technical solution.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention achieves precise regulation of the organic nitrogen mineralization rate through the synergistic design of microbial mineralization promotion and dual nitrification inhibition. The compound microbial agent can specifically promote the degradation of complex organic molecules such as proteins and starches in organic nitrogen fertilizers, solving the problem of slow organic nitrogen mineralization; dicyandiamide and ginkgo leaf powder in the plant-derived compound form a dual nitrification inhibition system, blocking the conversion of ammonium nitrogen to nitrate nitrogen from different target sites, significantly reducing nitrogen leaching and ammonia volatilization loss, and significantly improving nitrogen utilization rate compared with traditional organic nitrogen fertilizers, changing the current situation where the regulation effect of traditional inhibitors on organic nitrogen fertilizers is limited. At the same time, each component has excellent compatibility with the organic carrier, will not disrupt the benign cycle of the soil microbial community, and ensure the ecological advantages of organic nitrogen fertilizers.

[0017] (2) The different components of this invention work synergistically to construct a synergistic system for nitrogen regulation, nutrient absorption and soil improvement. Potassium humate, diatomaceous earth and polyglutamic acid work synergistically to improve the soil’s ability to retain fertilizer and water, reduce nutrient loss and improve soil structure; plant-derived complex, compound microbial agent and sodium alginate oligosaccharide work synergistically to promote crop root growth and photosynthesis, enhance nutrient absorption capacity, optimize soil microbial community structure and improve soil enzyme activity, so as to achieve simultaneous improvement of fertilizer efficiency and soil fertility, increase soil organic matter content and significantly improve soil aggregate structure, and solve the problem of traditional fertilization that only focuses on yield and ignores soil sustainability. Detailed Implementation

[0018] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0019] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0020] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0021] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0022] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0023] This invention provides an organic nitrogen fertilizer synergist, comprising the following components in parts by weight: Potassium humate 15-20 parts, plant-derived complex 8-12 parts, polyglutamic acid 5-8 parts, compound microbial agent 3-5 parts, sodium alginate oligosaccharide 5-8 parts, dicyandiamide 12-18 parts, diatomaceous earth 25-35 parts.

[0024] The preferred composition by mass percentage is: 15-18 parts potassium humate, 8-10 parts plant-derived complex, 5-6 parts polyglutamic acid, 3-4 parts compound microbial agent, 5-6 parts sodium alginate oligosaccharide, 12-14 parts dicyandiamide, and 25-28 parts diatomaceous earth.

[0025] Specifically, in the organic nitrogen fertilizer enhancer of the present invention, the potassium humate molecule contains a large number of active groups such as carboxyl and hydroxyl groups, which can form a stable organic-inorganic complex with soil particles, improve soil aggregate structure, reduce soil bulk density, and enhance soil aeration and permeability; its strong adsorption properties can adsorb free ammonium nitrogen and nitrate nitrogen in the soil, reduce nitrogen leaching, and at the same time slowly release the adsorbed nitrogen, prolonging the nitrogen supply cycle; in addition, potassium humate can also regulate soil pH, creating a suitable acid-base environment for microbial growth and crop root development, especially suitable for soils with strong acidity or alkalinity.

[0026] This invention uses dicyandiamide as a dedicated nitrification inhibitor, which can selectively inhibit the activity of nitrifying bacteria in the soil, block the conversion pathway of ammonium nitrogen to nitrate nitrogen, and reduce nitrogen loss caused by leaching (especially in soils with frequent irrigation during the rainy season) and denitrification. At the same time, it slows down the nitrogen conversion rate, making the nitrogen release pattern more consistent with the crop's nutrient requirements, avoiding the problems of insufficient nitrogen supply in the early stage and excessive nitrogen in the later stage. Its specific particle size design (50-80μm) can ensure uniform distribution in the soil, improve the stability and durability of the inhibition effect, and has good compatibility with organic carriers, without disrupting the benign cycle of the soil microbial community.

[0027] In this invention, the plant-derived complex comprises moringa seed powder, ginkgo leaf powder, and pine needle powder, wherein the preferred mass ratio of moringa seed powder, ginkgo leaf powder, and pine needle powder is 1-2:1-2:1-2. Specifically, moringa seed powder contains moringin, which provides natural active substances, promotes crop root growth, and enhances crop resistance. Specifically, it has antibacterial and bactericidal effects, which can inhibit the reproduction of harmful pathogens in the soil and reduce the occurrence of soil-borne diseases in crops. Flavonoids can stimulate the division and elongation of crop root cells, increase the root surface area, and improve the crop's absorption efficiency of nutrients such as nitrogen, phosphorus, and potassium. At the same time, the various amino acids and minerals it contains can supplement the trace elements needed for crop growth and enhance the crop's drought and cold resistance.

[0028] Ginkgo flavonoids in ginkgo leaf powder can competitively inhibit the activity of nitrifying bacteria in the soil, slow down the conversion rate of ammonium nitrogen to nitrate nitrogen, and reduce nitrate nitrogen leaching and ammonia volatilization loss; lactones can promote chlorophyll synthesis in crops, improve photosynthetic efficiency, enhance the crop's ability to assimilate and utilize nitrogen, and improve crop yield and quality.

[0029] Pine needle powder provides pine needle flavonoids, organic acids, and other components, which can improve the soil microbial community structure and enhance soil enzyme activity. Specifically, the organic acids in pine needles can regulate the pH of the soil microenvironment, providing conditions for the growth of beneficial microorganisms; flavonoids can stimulate the activity of soil hydrolytic enzymes such as urease and protease, promoting the degradation of complex organic molecules such as proteins and uric acid in organic nitrogen fertilizers, accelerating nitrogen mineralization and transformation, while its fiber structure can increase the soil organic matter content, further improving soil fertility.

[0030] In addition, polyglutamic acid is a water-soluble polymer. The large number of carboxyl groups on its molecular chain can form hydrogen bonds with water molecules. Each gram of polyglutamic acid can absorb hundreds of times its own weight in water, significantly improving the soil's water retention capacity, making it particularly suitable for arid regions or areas with insufficient irrigation. Its carboxyl groups can form stable chelates with ammonium nitrogen, reducing nitrogen volatilization and leaching, while promoting the absorption and transport of nitrogen by crop roots. Furthermore, polyglutamic acid can form a protective film on the surface of crop roots, reducing the damage to roots caused by soil salinity and heavy metals, enhancing the crop's resistance to salinity and heavy metal stress, and increasing soil organic matter content, further improving soil fertility.

[0031] In this invention, the composite microbial agent preferably comprises Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens, with a preferred mass ratio of 1:1:1. The effective viable count of each of the Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens is preferably ≥2.0 × 10⁻⁶. 9 CFU / g.

[0032] The composite microbial agent of this invention utilizes the synergistic effect of different bacteria. Specifically, Bacillus subtilis can secrete various hydrolytic enzymes such as protease and urease to convert organic nitrogen such as protein and urea in organic nitrogen fertilizer into ammonium nitrogen that can be absorbed by crops, while simultaneously regulating the rate of nitrogen mineralization. Its proliferation in the soil can form a dominant bacterial community, inhibiting the growth and reproduction of pathogens and reducing the incidence of soil-borne diseases in crops. Simultaneously, it can also produce plant growth regulators such as gibberellin and auxin, promoting root growth and plant development. Bacillus licheniformis can secrete amylase and cellulase, synergistically degrading complex organic matter in organic nitrogen fertilizer with Bacillus subtilis, accelerating nutrient release. It is also tolerant of soil conditions. Extreme temperatures and pH levels in the soil can stabilize the soil microbial community structure and improve the stability of the soil ecosystem after the plant has established itself in the soil. Its metabolic products can enhance the thickness of crop cell walls, thereby improving the crop's resistance to lodging and pests. Bacillus amyloliquefaciens can efficiently degrade starchy substances in organic nitrogen fertilizers, converting them into small molecule sugars, providing energy for the growth of other microorganisms and crops. The antimicrobial peptides and antimicrobial proteins produced can inhibit a variety of plant pathogens, further enhancing the soil's disease resistance. At the same time, the inorganic ions released during its metabolism can promote the recycling of nutrients such as nitrogen, phosphorus, and potassium in the soil, improving the overall fertilizer utilization rate.

[0033] In this invention, the molecular weight of the sodium alginate oligosaccharide is preferably 3000-5000 Da and the purity is ≥90%; the particle size of the potassium humate is preferably 80-100 μm and the particle size of the dicyandiamide is preferably 50-80 μm.

[0034] Specifically, low molecular weight sodium alginate oligosaccharides are easily utilized by microorganisms, serving as a carbon and energy source for them. They promote the reproduction of beneficial bacteria in compound microbial agents, enhancing the activity of the microbial community. They can stimulate crop roots to secrete protons and organic acids, enhancing the roots' ability to absorb nitrogen, while also promoting photosynthesis and nutrient accumulation in crop leaves. Furthermore, sodium alginate oligosaccharides can bind with ammonium nitrogen in the soil through hydrogen bonds to form stable complexes, reducing nitrogen volatilization losses. At the same time, they can be degraded by microorganisms, releasing nitrogen for crop absorption, thus achieving a slow release of nitrogen.

[0035] This invention also provides a method for preparing an organic nitrogen fertilizer synergist, comprising the following steps: Diatomaceous earth is activated at high temperature, then cooled and crushed, and passed through a 100-120 mesh sieve to obtain activated diatomaceous earth. Moringa seeds, ginkgo leaves and pine needles were washed, dried and crushed separately to obtain moringa seed powder, ginkgo leaf powder and pine needle powder. They were then mixed to obtain a plant-derived complex. The activated diatomaceous earth is mixed with potassium humate and dicyandiamide, and stirred for the first time to obtain a first mixture. Polyglutamic acid and sodium alginate oligosaccharide were added to the first mixture for a second mixing to obtain a second mixture; The second mixture is cooled down, then mixed with a compound microbial agent, and the resulting mixture is spray-dried to obtain the organic nitrogen fertilizer enhancer.

[0036] In this invention, the temperature of the high-temperature activation treatment is preferably 550-650℃, more preferably 550-600℃, and the time is preferably 2-3h, more preferably 2-2.5h.

[0037] This invention specifies the high-temperature activation treatment of diatomaceous earth. Specifically, after activation at 550-650℃, diatomaceous earth forms a large number of microporous structures, significantly increasing its specific surface area. This allows it to serve as a carrier for other components (such as potassium humate, dicyandiamide, and microbial agents), achieving uniform dispersion of each component in the soil and avoiding excessively high or low local concentrations. Its microporous structure has strong adsorption properties, adsorbing free nitrogen and water in the soil, reducing nutrient loss and water evaporation, and improving the soil's ability to retain fertilizer and water. At the same time, its porous structure increases soil porosity, improves soil aeration, provides sufficient oxygen for crop root respiration and microbial metabolism, and promotes root growth and enhanced microbial activity.

[0038] In this invention, the speed of the first stirring is preferably 320-360 r / min, more preferably 320-340 r / min, and the time is preferably 20-30 min, more preferably 20-25 min; the speed of the second stirring is preferably 280-300 r / min, the temperature is preferably 40-50°C, and the time is preferably 20-30 min.

[0039] In this invention, the temperature after cooling is preferably 25-30℃, more preferably 25-28℃; the mixing with the compound microbial agent is preferably carried out by stirring for 12-15 minutes at a speed of 150-200 r / min.

[0040] In this invention, the inlet air temperature of the spray drying is preferably 170-175°C, more preferably 170-172°C, and the outlet air temperature is preferably 70-75°C, more preferably 70-72°C.

[0041] This invention also provides an application of an organic nitrogen fertilizer synergist in soil improvement, wherein the organic nitrogen fertilizer synergist is the organic nitrogen fertilizer synergist described in the above technical solution.

[0042] Example 1 (1) Accurately weigh each component according to the following mass proportions: 15 parts potassium humate (particle size 80μm), 8 parts plant-derived compound raw materials (moringa seeds, ginkgo leaves, and pine needles, prepared in a mass ratio of 1:1:1), 5 parts polyglutamic acid, and 3 parts compound microbial inoculant (Bacillus subtilis: Bacillus licheniformis: Bacillus amyloliquefaciens = 1:1:1, with an effective viable count ≥2.0×10⁻⁶). 9 CFU / g), 5 parts sodium alginate oligosaccharide (molecular weight 3000 Da, purity ≥90%), 12 parts dicyandiamide (particle size 50 μm), and 25 parts diatomaceous earth.

[0043] (2) Diatomaceous earth activation treatment: 25 portions of weighed diatomaceous earth were placed in a high-temperature muffle furnace and the temperature was set to 550℃ for 2 hours for high-temperature activation treatment. During the activation process, the furnace was observed every 30 minutes to ensure that the diatomaceous earth was heated evenly. After activation, the muffle furnace was turned off and allowed to cool naturally to room temperature. The cooled diatomaceous earth was then placed in a universal pulverizer for crushing. After crushing, the diatomaceous earth was passed through a 100-mesh sieve using an airflow sieve (airflow velocity 8m / s) and the sieve material was collected to obtain the activated diatomaceous earth, which was then sealed for later use.

[0044] (3) Preparation of plant-derived complex: Moringa seeds, ginkgo leaves, and pine needles prepared in proportion were placed in a clean water tank and rinsed 3-5 times with running water to remove surface mud, dust, and impurities. The cleaned raw materials were then spread out on a drying rack and dried in a naturally ventilated environment without direct sunlight for 48 hours, turning them regularly to ensure uniform drying. The moisture content of the dried raw materials was ≤8%. The dried moringa seeds, ginkgo leaves, and pine needles were placed in a high-speed pulverizer, and the pulverizer speed was adjusted to 4000 r / min. The pulverizer was crushed for 15 minutes. After crushing, the powders were passed through an 80-mesh sieve, and the sieve residue was collected to obtain moringa seed powder, ginkgo leaf powder, and pine needle powder. The three powders were placed in a double-helix conical mixer at a mass ratio of 1:1:1 and mixed for 10 minutes to obtain the plant-derived complex, which was then sealed and stored.

[0045] (4) Preparation of the first mixture: The activated diatomaceous earth, weighed 15 parts of potassium humate and 12 parts of dicyandiamide are added to the plow-type mixer. The stirring speed is set to 320 r / min and the stirring time is 20 min. During the stirring process, it is ensured that there are no dead corners in the mixer and that the mixture is fully and evenly mixed to obtain the first mixture.

[0046] (5) Preparation of the second mixture: 5 parts of polyglutamic acid and 5 parts of sodium alginate oligosaccharide are slowly added to the first mixture above. The speed of the mixer is adjusted to 280 r / min. At the same time, the heating device of the mixer is turned on to control the mixing temperature at 40℃. The mixture is stirred continuously for 20 min. During this period, the machine is stopped every 5 min to observe the material state to avoid material clumping. After the stirring is completed, the second mixture is obtained.

[0047] (6) Microbial agent mixing: Take out the second mixture and put it into a cooling tank. Cool it down to 25°C using natural cooling. Stir the material continuously during the process to accelerate the cooling rate. After the temperature reaches the set value, slowly add 3 parts of compound microbial agent to the cooled second mixture and transfer it to a low-speed mixer. Set the speed to 150 r / min and stir for 12 min to ensure that the microbial agent and the material are mixed evenly and to avoid damage to the live bacteria caused by high-speed stirring.

[0048] (7) Spray drying: The uniformly mixed material is fed into a centrifugal spray dryer. The inlet air temperature is set to 170℃, the outlet air temperature to 70℃, the feed rate to 5L / h, and the atomization pressure to 0.3MPa. During the drying process, the inlet air temperature, outlet air temperature, and material atomization state are monitored in real time to ensure stable drying effect. After drying, the powdery product at the bottom of the drying tower is collected, which is the organic nitrogen fertilizer synergist. After passing inspection, it is sealed and packaged.

[0049] Example 2 (1) Accurately weigh each component according to the mass fractions: 18 parts potassium humate (particle size 90μm), plant-derived compound raw materials (moringa seeds, ginkgo leaves, pine needles, prepared in a mass ratio of 1.5:1.5:1.5, total mass 10 parts), 6 parts polyglutamic acid, and 4 parts compound microbial inoculant (Bacillus subtilis: Bacillus licheniformis: Bacillus amyloliquefaciens = 1:1:1, effective viable count ≥ 2.0 × 10⁻⁶). 9 CFU / g), 6 parts sodium alginate oligosaccharide (molecular weight 4000 Da, purity ≥90%), 15 parts dicyandiamide (particle size 65 μm), and 30 parts diatomaceous earth.

[0050] (2) Diatomaceous earth activation treatment: 30 parts of diatomaceous earth were placed in a high-temperature muffle furnace, the temperature was set to 600℃, and the activation time was 2.5h. The activation process was observed at regular intervals. After activation, the diatomaceous earth was cooled to room temperature, crushed in a universal pulverizer, and passed through a 110-mesh sieve using an airflow sieve (airflow speed 10m / s). The sieve material was collected as activated diatomaceous earth and sealed for later use.

[0051] (3) Preparation of plant-derived complex: Moringa seeds, ginkgo leaves, and pine needles prepared in proportion were rinsed four times with running water to remove impurities. They were then laid flat on a drying rack and air-dried naturally for 60 hours, turning them several times during the process to ensure that the moisture content was ≤8%. The dried raw materials were then placed into a high-speed pulverizer and crushed at 4500 r / min for 12 min. The powders were then passed through a 90-mesh sieve and collected. The powders were then placed into a double-helix conical mixer at a mass ratio of 1.5:1.5:1.5 and mixed for 12 min to obtain the plant-derived complex, which was then sealed and stored.

[0052] (4) Preparation of the first mixture: Activated diatomaceous earth, 18 parts of potassium humate, and 15 parts of dicyandiamide are added to a plow-type mixer. The speed is set to 340 r / min and the mixture is stirred for 25 min to ensure that the materials are fully mixed and the first mixture is obtained.

[0053] (5) Preparation of the second mixture: Add 6 parts of polyglutamic acid and 6 parts of sodium alginate oligosaccharide to the first mixture, adjust the speed of the mixer to 290 r / min, heat to 45℃, stir for 25 min, observe the state of the material regularly during the process to avoid clumping, and obtain the second mixture.

[0054] (6) Microbial agent mixing: Place the second mixture into a cooling tank, stir and cool to 28°C, add 4 parts of compound microbial agent, transfer to a low-speed mixer, stir at 180r / min for 13min to ensure uniform dispersion of the agent and without damaging the live bacteria.

[0055] (7) Spray drying: The mixture is fed into a centrifugal spray dryer, with the inlet air temperature set to 172℃, the outlet air temperature to 72℃, the feed rate to 6L / h, and the atomization pressure to 0.35MPa. All parameters are monitored in real time. After drying, the powdered product is collected, and after passing inspection, it is sealed and packaged to obtain the organic nitrogen fertilizer enhancer.

[0056] Example 3 (1) Accurately weigh each component according to the following mass proportions: 20 parts potassium humate (particle size 100μm), 12 parts plant-derived compound raw materials (moringa seeds, ginkgo leaves, and pine needles, prepared in a mass ratio of 2:2:2, total mass), 8 parts polyglutamic acid, and 5 parts compound microbial inoculant (Bacillus subtilis: Bacillus licheniformis: Bacillus amyloliquefaciens = 1:1:1, with an effective viable count ≥ 2.0 × 10⁻⁶). 9 CFU / g), 8 parts sodium alginate oligosaccharide (molecular weight 5000 Da, purity ≥90%), 18 parts dicyandiamide (particle size 80 μm), and 35 parts diatomaceous earth.

[0057] (2) Diatomaceous earth activation treatment: 35 parts of diatomaceous earth were placed in a high-temperature muffle furnace, the temperature was set at 650℃, and the activation time was 3h. During the activation process, the diatomaceous earth was closely monitored. After activation, the diatomaceous earth was cooled to room temperature, crushed in a universal pulverizer, and passed through a 120-mesh sieve using an airflow sieve (airflow speed 12m / s). The sieve material was collected as activated diatomaceous earth and sealed for later use.

[0058] (3) Preparation of plant-derived complex: Moringa seeds, ginkgo leaves, and pine needles prepared in proportion were rinsed 5 times with running water to remove impurities. They were then laid flat on a drying rack and air-dried naturally for 72 hours, turning them frequently to ensure a moisture content of ≤8%. The dried raw materials were then placed into a high-speed pulverizer and crushed at 5000 r / min for 10 min. The powders were then passed through a 100-mesh sieve and collected. The powders were then placed into a double-helix conical mixer at a mass ratio of 2:2:2 and mixed for 15 min to obtain the plant-derived complex, which was then sealed and stored.

[0059] (4) Preparation of the first mixture: Add activated diatomaceous earth, 20 parts of potassium humate, and 18 parts of dicyandiamide to a plow-type mixer, set the speed to 360 r / min, and stir for 30 min to ensure that the materials are fully mixed to obtain the first mixture.

[0060] (5) Preparation of the second mixture: Add 8 parts of polyglutamic acid and 8 parts of sodium alginate oligosaccharide to the first mixture, adjust the speed of the mixer to 300 r / min, heat to 50℃, stir for 30 min, observe the state of the material regularly during the period to avoid clumping, and obtain the second mixture.

[0061] (6) Microbial agent mixing: Put the second mixture into the cooling tank, stir and cool down to 30°C, add 5 parts of compound microbial agent, transfer to a low speed mixer, stir at 200r / min for 15min to ensure uniform dispersion of the agent and without damaging the live bacteria.

[0062] (7) Spray drying: The mixture is fed into a centrifugal spray dryer, with the inlet air temperature set to 175℃, the outlet air temperature to 75℃, the feed rate to 7L / h, and the atomization pressure to 0.4MPa. All parameters are monitored in real time. After drying, the powdered product is collected, and after passing inspection, it is sealed and packaged to obtain the organic nitrogen fertilizer enhancer.

[0063] Performance testing Test samples: Organic nitrogen fertilizer synergists prepared in Examples 1-3, and blank control group (no synergists added, only organic nitrogen fertilizer was used).

[0064] Test crops: Tomato (variety: Zhongza 105), wheat (variety: Jimai 44).

[0065] Soil for testing: Three types of soil were selected: acidic soil (pH=5.5), neutral soil (pH=7.0), and alkaline soil (pH=8.5). The soil organic matter content was 1.2%-1.5%, and the initial nitrogen content was 0.08%-0.10%.

[0066] Test Design: A pot experiment (tomato) and a field plot experiment (wheat) were conducted, with three replicates for each group. The application rate of organic nitrogen fertilizer was 20 g / pot (potted plants) and 300 kg / mu (field), with the synergist added at 5% of the organic nitrogen fertilizer mass. The pot experiment lasted 90 days, and the field experiment lasted 120 days. After the experiments, nitrogen use efficiency, crop yield, and soil indicators (soil improvement effect) were measured. The test results are shown in Table 1. Table 1. Results of Nitrogen Utilization Rate Test

[0067] Table 2 Crop Yield Test Results

[0068] Table 3 Soil Improvement Effect Test Table

[0069] Table 4. Results of Nitrogen Loss Rate Test

[0070] Based on Table 1, the average nitrogen utilization rate of Examples 1-3 was 43.95%-49.95%, which was 94.0%-120.6% higher than that of the blank control group. This indicates that the synergist of the present invention can effectively promote organic nitrogen mineralization, inhibit nitrogen loss, and significantly improve nitrogen utilization efficiency. Based on Table 2, the yields of tomatoes and wheat increased by 15.2%-25.1% and 16.3%-24.8% respectively compared with the blank control group, demonstrating that the present invention has the effect of improving fertilizer efficiency.

[0071] Based on Table 3, it can be seen that in acidic soils, Examples 1-3 can adjust the soil pH to 6.2-6.5, which is more suitable for crop growth; the soil organic matter content increases by 19.7%-51.6%, the proportion of aggregate structure increases by 36.8%-50.9%, and the soil bulk density decreases by 9.7%-20.7%, effectively improving soil structure and fertility, and solving the problem that traditional synergists only focus on fertilizer effect and neglect soil improvement; based on Table 4, it can be seen that the total nitrogen loss rate of Examples 1-3 is only 14.4%-18.7%, which is 54.4%-64.9% lower than the blank control group (41.0%), indicating that the synergistic system of dual nitrification inhibition and adsorption fertilizer retention of the present invention can effectively block the nitrogen volatilization and leaching pathways.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An organic nitrogen fertilizer synergist, characterized in that, The components include the following parts by mass: Potassium humate 15-20 parts, plant-derived complex 8-12 parts, polyglutamic acid 5-8 parts, compound microbial agent 3-5 parts, sodium alginate oligosaccharide 5-8 parts, dicyandiamide 12-18 parts, diatomaceous earth 25-35 parts.

2. The organic nitrogen fertilizer synergist according to claim 1, characterized in that, The plant-derived complex includes moringa seed powder, ginkgo leaf powder, and pine needle powder, wherein the mass ratio of moringa seed powder, ginkgo leaf powder, and pine needle powder is 1-2:1-2:1-2.

3. The organic nitrogen fertilizer synergist according to claim 1, characterized in that, The compound microbial agent comprises Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens in a mass ratio of 1:1:1, and the effective viable count of each of the Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens is ≥2.0 × 10⁻⁶. 9 CFU / g.

4. The organic nitrogen fertilizer synergist according to claim 1, characterized in that, The sodium alginate oligosaccharide has a molecular weight of 3000-5000 Da and a purity of ≥90%; the potassium humate has a particle size of 80-100 μm; and the dicyandiamide has a particle size of 50-80 μm.

5. A method for preparing the organic nitrogen fertilizer synergist according to any one of claims 1-4, characterized in that, Includes the following steps: Diatomaceous earth is activated at high temperature, then cooled and crushed, and passed through a 100-120 mesh sieve to obtain activated diatomaceous earth. Moringa seeds, ginkgo leaves and pine needles were washed, dried and crushed separately to obtain moringa seed powder, ginkgo leaf powder and pine needle powder. They were then mixed to obtain a plant-derived complex. The activated diatomaceous earth is mixed with potassium humate and dicyandiamide, and stirred for the first time to obtain a first mixture. Polyglutamic acid and sodium alginate oligosaccharide were added to the first mixture for a second mixing to obtain a second mixture; The second mixture is cooled down, then mixed with a compound microbial agent, and the resulting mixture is spray-dried to obtain the organic nitrogen fertilizer enhancer.

6. The method for preparing the organic nitrogen fertilizer synergist according to claim 5, characterized in that, The high-temperature activation treatment is performed at a temperature of 550-650℃ for 2-3 hours.

7. The method for preparing the organic nitrogen fertilizer synergist according to claim 5, characterized in that, The first stirring speed is 320-360 r / min, and the time is 20-30 min; the second stirring speed is 280-300 r / min, the temperature is 40-50, and the time is 20-30 min.

8. The method for preparing the organic nitrogen fertilizer synergist according to claim 5, characterized in that, The temperature after cooling is 25-30℃, and the mixing with the compound microbial agent specifically involves stirring for 12-15 minutes at a speed of 150-200 r / min.

9. The method for preparing the organic nitrogen fertilizer synergist according to claim 5, characterized in that, The inlet air temperature of the spray dryer is 170-175℃, and the outlet air temperature is 70-75℃.

10. The application of an organic nitrogen fertilizer synergist in soil improvement, characterized in that, The organic nitrogen fertilizer enhancer is the organic nitrogen fertilizer enhancer according to any one of claims 1-3.

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