Double-source fermentation and decomposition element and application thereof

Abstract

The invention discloses a double-source fermentation and decomposition element and application thereof. Respectively crushing vinasse and straw, mixing to obtain a mixture, adjusting the water content of the mixture, sterilizing to obtain a solid-state fermentation culture medium, spraying acid-resistant compound bacteria liquid into the solid-state fermentation culture medium, and performing sealed fermentation to obtain a fermentation product after fermentation is finished; and mixing the fermentation product with alkali liquor, stirring at constant temperature under a water bath condition for extraction, collecting supernate after extraction is finished, dropwise adding a hydrochloric acid solution into the supernate, standing for 2 hours, centrifuging and collecting precipitates, thereby obtaining the double-source fermentation and decomposition element rich in functional groups such as phenolic hydroxyl groups and carboxyl groups. The prepared double-source fermentation and decomposition element and polyurethane coated fertilizer are mixed and then applied together, degradation of a film shell can be achieved under the illumination or dark condition, in-situ degradation of controlled-release fertilizer micro-plastics is achieved, meanwhile, the crop yield can be increased, and a new thought is provided for in-situ treatment of farmland micro-plastics.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fertilizers, in particular to a double-source ferrocorrin and application thereof. BACKGROUND

[0002] Coated fertilizers are slow-release fertilizers formed by physical coating technology. The core principle is to form a semi-permeable membrane layer using inorganic or organic materials to achieve synchronization with crop fertilizer requirements through diffusion or rupture mechanisms. Main coating materials include sulfur, high molecular polymers, resins, and mineral-organic composite materials. Different materials optimize slow-release performance through thickness control, osmotic pressure adjustment, and composite modification. Among high molecular polymer coating materials, polypropylene and polyurethane are most commonly used.

[0003] After coated fertilizers absorb water, the fertilizer inside the coating material dissolves and is released into the soil through the pores on the coating material. Although the coating material may partially rupture during nutrient release, it will remain in the soil and degrade into microplastics over several years. Coating materials change the physical properties of the soil, such as affecting soil aggregate structure, porosity, and water permeability; the pores on the coating material can adsorb heavy metals and persistent organic pollutants (POPs) in the soil, becoming their carriers and exacerbating pollution; they can be mistakenly eaten by soil animals (such as earthworms), accumulate in their bodies, cause physical damage and physiological toxicity, and be transmitted through the food chain; they change the diversity and activity of soil microorganisms, affecting nutrient cycling processes. In areas where coated fertilizers are used extensively and for a long time, polymer film shells accumulate in the soil year after year, not only forming a large amount of pollutants but also affecting crop yields, etc.

[0004] Currently, the degradation of polymers mainly includes biological degradation, chemical degradation and physical degradation. Biological degradation mainly uses microorganisms to decompose polymers, chemical degradation mainly uses reactions such as hydrolysis and photolysis to break the main chain chemical bonds of polymers, and physical degradation mainly includes thermal degradation, mechanical degradation and solvent-induced degradation. However, the environment of the coating material is in the soil, and chemical degradation and physical degradation need to be screened out from the soil before they can be carried out. The biological degradation speed is slow, and the microorganisms may affect the growth of crops or affect the types and contents of soil bacteria, so the coating material in the soil is more difficult to degrade than other polymers. The patent with application number 202110842452.4 discloses a degradable polyurethane foam material and its preparation method, which mentions using humic acid to degrade polyurethane. However, the degradation principle of the scheme is that water and humic acid in the soil enter the inside of the polyurethane foam material at the same time. The water activates the persulfate, and the humic acid reduces the ferric ion to ferrous ion. The ferrous ion and the activated persulfate jointly decompose the polyurethane foam material, so that the polyurethane foam material releases degradable segments. The necessary condition for degrading polyurethane is to have persulfate and ferric ion. For the coated fertilizer without persulfate and ferric ion, the degradation of the coating material cannot be realized. Therefore, a double-source ferrohumus is needed to be designed, which can be used together with the polymer coated fertilizer. It can not only increase the yield of the product as a fertilizer, but also degrade the polymer coating of the polymer coated fertilizer, achieving multiple purposes at once. SUMMARY

[0005] In view of the above prior art, the purpose of the present application is to provide a double-source ferrohumus and its application. The double-source ferrohumus rich in functional groups such as phenolic hydroxyl and carboxyl is obtained by fermentation and alkali solution putrefaction of distiller's grains and straw; after mixing with polyurethane coated fertilizer, the double-source ferrohumus is applied together. Under light, the phenolic hydroxyl of the double-source ferrohumus reacts with the quinone group to generate reactive oxygen species (ROS) through light excitation, which initiates the oxidative cleavage of the carbon skeleton of PU-MPs (polyurethane microplastics); in a dark environment, the double-source ferrohumus generates free radical sites by initiating the cleavage or isomerization of C-H bonds in PU-MPs molecules, which provides a new idea for in-situ management of farmland microplastics.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: In a first aspect of the present application, a double-source ferrohumus is provided, which is prepared by the following method: (1) The distiller's grains and straw are crushed separately, and a mixture is obtained by mixing. The moisture content of the mixture is adjusted, and a solid-state fermentation medium is obtained after sterilization. Acid-tolerant composite bacteria solution is sprayed to the solid-state fermentation medium for sealed fermentation, and a fermentation product is obtained after fermentation. (2) The fermentation product is mixed with an alkali solution, and extraction is carried out under constant temperature stirring in a water bath. After the extraction is completed, the supernatant is collected. Hydrochloric acid solution is added dropwise to the supernatant, and the mixture is allowed to stand for 2 hours. The precipitate is collected by centrifugation to obtain the double-source ferrohumus.

[0007] Preferably, in step (1), the moisture content of the distiller's grains is < 15wt%; the straw is corn straw or wheat straw.

[0008] Preferably, in step (1), the mass ratio of the distiller's grains and the straw is 3:1; the moisture content of the mixture is 65-70wt%.

[0009] Preferably, in step (1), the acid-resistant composite bacteria are obtained by culturing Aspergillus niger and Lactobacillus acidophilus at a mass ratio of 3:1; the strain number of the Aspergillus niger is CICC 2460; the strain number of the Lactobacillus acidophilus is CICC 20248; the spraying amount of the acid-resistant composite bacteria liquid is 5% of the mass of the solid-state fermentation medium.

[0010] The Aspergillus niger and the Lactobacillus acidophilus are both purchased from the China Industrial Microbial Culture Collection Center.

[0011] Preferably, in step (1), the culturing is: the acid-resistant composite bacteria are diluted with sterile water to a concentration of 10 8 CFU / mL to obtain a bacterial suspension, and the bacterial suspension is activated in a constant-temperature shaker at 30℃ for 2 hours.

[0012] Preferably, in step (1), the fermentation is solid-state fermentation at 30-35℃, the heap is turned over once a day for the first 5 days, and the heap is turned over once every 2 days starting from the 6th day, and the total fermentation period is 12-15 days.

[0013] Preferably, in step (2), the alkali solution is a 10wt% sodium hydroxide solution; the mass ratio of the fermentation product to the sodium hydroxide solution is 1:10.

[0014] Preferably, in step (2), the temperature of the water bath is 60-65℃; the extraction time is 2h; the concentration of the hydrochloric acid solution is 6M; and the dropping amount of the hydrochloric acid solution is the same as the volume of the alkali solution.

[0015] Preferably, the phenolic hydroxyl content of the double-source humic substance is 3.91meq g -1 , the carboxyl content is 3.26meq g -1 , and the total content of acidic functional groups is more than 7.0meq g -1 .

[0016] In the second aspect of the present application, the double-source humic substance is provided for use in degrading the membrane shell of a coated fertilizer.

[0017] Preferably, the material of the membrane shell is polyurethane.

[0018] In a second aspect of the present application, a method for degrading the coating film of a double-source fermentin coated fertilizer is provided, comprising: mixing the double-source fermentin and the polyurethane coated fertilizer according to a mass ratio of 3:7, adding the double-source fermentin into the soil according to a dosage of 120 kg hm -2 , and degrading the coating film to 90% of the initial coating film mass after 221 days.

[0019] Advantages of the present application: The present application uses distiller's grains and straw as raw materials to obtain double-source fermentin rich in acidic functional groups such as phenolic hydroxyl and carboxyl groups through fermentation and alkali liquor corruption; after mixing with polyurethane coated fertilizer, the double-source fermentin is applied together, under light, the phenolic hydroxyl groups of the double-source fermentin and the quinone groups generate reactive oxygen species (ROS) through light excitation, which initiates the oxidative cleavage of the carbon skeleton of PU-MPs (polyurethane microplastics); in a dark environment, the double-source fermentin generates free radical sites by initiating the cleavage or isomerization of the C-H bond in the PU molecule, which provides a new idea for in-situ management of farmland microplastics. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 : (a) infrared spectrum curve and (b) key section peak fitting spectrum of Example 1 and Comparative Example 1; Figure 2 : (a) functional group content, (b) ash content, and (c) UV-Vis spectrum E 465 / E 665 value of Example 1 and Comparative Example 1; Figure 3 : (a) scanning electron microscope image and (b) atomic force microscope image of the residual film particles of the controlled-release fertilizer after cultivation in the light environment under different treatment conditions; Figure 4 : (a) weight loss rate of the residual film of the controlled-release fertilizer after cultivation for 15 days and 30 days under different treatment conditions; (b) particle size distribution after degradation for 15 days under different treatment conditions; (c) particle size distribution after degradation for 30 days under different treatment conditions; Figure 5 : degradation rate curve of the polyurethane residual film based on the first-order kinetic equation fitting; Figure 6 : corn yield in 2023 and 2024 under different treatment conditions; Figure 7 : (a) actual photo, (b) scanning electron microscope image, and (c) EDS surface scanning element content of the residual film of the controlled-release fertilizer in the control group after corn harvest; (e) actual photo, (f) scanning electron microscope image, and (g) EDS surface scanning element content of the residual film of the controlled-release fertilizer in the Comparative Example 1 group; (h) actual photo, (i) scanning electron microscope image, and (j) EDS surface scanning element content of the residual film of the controlled-release fertilizer in the Example 1 group. DETAILED DESCRIPTION

[0021] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0022] As introduced in the background section, current methods for polymer degradation mainly include biodegradation, chemical degradation, and physical degradation. Biodegradation primarily utilizes microorganisms to break down polymers, while chemical degradation mainly uses reactions such as hydrolysis and photolysis to disrupt the main chain chemical bonds of polymers. Physical degradation mainly includes thermal degradation, mechanical degradation, and solvent-induced degradation. However, coating materials exist in the soil environment. Chemical and physical degradation require the coating materials to be screened out of the soil before they can proceed. Biodegradation is slow, and microorganisms may affect crop growth. Therefore, coating materials in soil are more difficult to degrade compared to other polymers.

[0023] Therefore, the purpose of this invention is to provide a dual-source fermenting agent and its application. This invention uses distiller's grains and straw as raw materials. Distillers' grains are rich in protein, residual sugar, and small-molecule organic acids, while straw is rich in cellulose, hemicellulose, and lignin. Using both as raw materials, the complex structure of the raw materials is broken down through synergistic fermentation by acid-resistant microorganisms. The monosaccharides produced by the decomposition of straw and the residual sugar in the distillers' grains are used to synthesize metabolites such as yeast polysaccharides and amino acids. These products further undergo condensation and polymerization reactions with small-molecule peptides and organic acids to form humification precursors. Then, alkali extraction is used to dissolve humic acid-like salts, soluble proteins, sodium salts of small-molecule polysaccharides, and other substances. Finally, acidification is used to regenerate carboxyl and phenolic hydroxyl groups from humic acid-like molecules, achieving the precipitation and separation of insoluble humic substances to obtain highly active dual-source fermentation enzymes.

[0024] In darkness, bi-source oxidases undergo non-photoinduced electron transfer with the CH bonds on the polyurethane molecular chain via their acidic groups. Due to the bond energies of the CH bonds in polyurethane, bi-source oxidases preferentially act on CH bond sites with lower bond energies and higher electron cloud density, directly cleaving or isomerizing the CH bonds by breaking σ bonds, generating free radical sites, and indirectly producing free radicals such as •OH and •O. 2 - and 1 O2 and ROS further promote the breaking or rearrangement of CO bonds, or alter the -CH2- structure through nucleophilic / electrophilic reactions; the intermediate product is converted to -OH / OOH through electron transfer. Under light irradiation, the phenolic hydroxyl and carboxyl functional groups in this product absorb light and induce electron transitions, accumulating large amounts of •OH and •O. 2- , 1 O2 and CO 2•- The •OH group acts as an electrophile, attacking the carbon backbone of the polyurethane molecule to generate CO.2•- It also breaks CH and CO bonds. This product significantly improves the degradation efficiency of the controlled-release fertilizer membrane shell by amplifying ROS generation; the abundance of acidic functional groups (hydroxyl and oxygen) in its structure is the most critical characteristic driving this process. To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0025] Note: The distillers' grains used in the examples are corn distillers' grains (DDGS), purchased from Jinan Shuangshi Biotechnology Co., Ltd.

[0026] The test materials used in the embodiments of this invention are all conventional test materials in the art and can be purchased through commercial channels.

[0027] Example 1: Preparation of dual-source fermenting agent (1) Select distiller's grains (without mold and a moisture content of <15%), rinse them 2-3 times with clean water to remove residual alcohol, sugar and surface impurities, and then dry them; remove withered leaves and insect-infested parts from the corn stalks. Put both into a high-speed pulverizer and pulverize them into powder with a particle size of 1-2 mm; mix them at a mass ratio of distiller's grains: straw = 3:1, and add deionized water to adjust the moisture content of the mixture to 65%. Put the mixture into an autoclave and sterilize it at 121℃ and 0.1MPa for 30 minutes to kill the miscellaneous bacteria in the raw materials and avoid contamination by miscellaneous bacteria during subsequent fermentation.

[0028] A compound bacterial strain was prepared by mixing *Aspergillus niger* (CICC 2460) and *Lactobacillus acidophilus* (CICC 20248) at a mass ratio of 3:1. The compound bacterial strain was diluted with sterile water to a concentration of 10. 8 The bacterial suspension at CFU / mL was activated in a constant temperature shaker at 30℃ for 2 hours to ensure the activity of the bacterial strain and obtain an acid-resistant compound bacterial solution.

[0029] Spray the sterilized mixture with 5wt% acid-resistant compound bacterial solution, stir to mix thoroughly, then transfer to a sealed fermentation bag and carry out solid-state fermentation at 33℃. Turn the pile once a day for the first 5 days, and turn it once every 2 days from the 6th day onwards, for a total of 15 days of fermentation. When the material turns dark brown, has no obvious straw fiber structure, and has no odor, the fermentation is complete and the fermentation product is obtained.

[0030] (2) Mix the fermentation product with 10wt% sodium hydroxide solution at a mass ratio of 1:10, transfer the mixture to an extraction tank, and extract at a constant temperature of 65℃ with stirring for 2 hours. After extraction, collect the supernatant, add an equal volume of 6M HCl solution to the supernatant, let stand for 2 hours, and then centrifuge at a rate of 8000rpm×15min to collect the insoluble matter. After washing with water several times, dry the mixture (to remove excess acid) to obtain the dual-source fermentation agent.

[0031] Comparative Example 1: Preparation of Humic Acid Prepared according to the method in Example 2 of the application No. 202211034685.2, which discloses a low molecular weight, high-functionality modified humic acid and its preparation and application: Weathered coal was mechanically crushed to micron-sized particles in a ball mill. 5g of the crushed coal was taken, and 50mL of 10% (v / v) H₂O₂ was added to form the first reaction system. 0.05g of a metal-doped sodium manganese oxide catalyst was then added to the first reaction system, and the mixture was stirred continuously for 45min. After the reaction, the mixture was filtered. Following filtration, a 1% (w / v) NaOH solution was added to the insoluble matter at a solid-liquid ratio of 1g:10ml to form the second reaction system. This system was reacted at 70℃ for 60min. After the reaction was complete, the mixture was cooled to room temperature and centrifuged at 3200rpm for 15min to obtain alkali-soluble humic acid.

[0032] The alkali-soluble humic acid was adjusted to pH=1 with HCl, and allowed to stand for 1 hour to allow the precipitate to precipitate completely. Finally, the precipitate was dried in a vacuum drying oven at 60℃ to obtain solid humic acid.

[0033] Example 2: Characterization The products prepared in Example 1 and Comparative Example 1 have a broad infrared spectrum as shown below. Figure 1 As shown, both Example 1 and Comparative Example 1 exhibit the typical functional group vibrational absorption patterns of organic compounds, but there are significant differences in the infrared absorption characteristics of O-H, C=O, and C-O functional groups. (1000-1800 cm⁻¹) -1 The region represents the region where the absorption peaks of oxygen-containing functional groups belong, with the highest relative content of phenolic hydroxyl groups, at 32.13% and 38.41% in Example 1 and Comparative Example 1, respectively. Compared with Comparative Example 1, the alkyl ether content in the structure of Example 1 decreased by 39.86%, while the aryl ether bond content increased by 210.68%. The increase in aryl ethers will make the organic matter more selective in aromatic nucleophilic substitution reactions, which also reflects that Example 1 exhibits stronger chemical polarity and reactivity.

[0034] Figure 2 As shown, compared to Comparative Example 1, the phenolic hydroxyl content in the product of Example 1 increased from 2.78 meq g. -1 Increased to 3.91 meq g -1 It increased by 40.6%, and the carboxyl content increased from 2.97 meq g. -1 Increased to 3.26 meq g -1 It increased by 9.8%, and the total content of acidic functional groups exceeded 7.0 meq g. -1Furthermore, the ash content of Example 1 was reduced by 29.6% compared to Comparative Example 1, and the E4 / E6 value was reduced by 36.7%, which fully demonstrates that the product of Example 1 has higher chemical activity.

[0035] Example 3: Degradation Fitting Controlled-release urea granules (3-5 mm in diameter, 46.4% nitrogen content) were prepared at the Engineering Research Center for High-Efficiency Soil and Fertilizer Utilization, Shandong Agricultural University, according to the method described in "Soybean oil modified petrochemical source polyester polyure-thane improves the nutrient release performance of coated urea" (Jingjing Dong et al., Agronomy, 2023, 13, 3008). First, the surface of the controlled-release urea granules was scored with a knife to disrupt the outer membrane structure and promote urea dissolution. The fertilizer granules were then immersed in 40℃ warm water to accelerate urea dissolution until the residual membrane floated to the surface. The residual membrane was collected, washed several times with clean water, and dried in a 45℃ oven to obtain a polyurethane residual membrane (3-5 mm).

[0036] At a 1:1 mass ratio, 0.5 g of polyurethane residual film (accurate to 0.0001 g) was mixed thoroughly with an equal amount of 0.5 g of the product powder prepared in Example 1 or Comparative Example 1 in a transparent glass bottle. A blank treatment was performed by adding only the polyurethane residual film. Then, 30 mL of deionized water was added, the bottle was sealed, and shaken to ensure uniform distribution of the mixture. This mixture was placed in a constant temperature and light incubation system and cultured at 25°C under continuous light from a 500W mercury lamp and a shaker at 150 rpm for 720 hours. The height of the mercury lamp was adjusted to ensure that the light intensity received by each glass bottle was controlled at 100 mW / cm². 2 Membrane shells and solutions were collected at 360 and 720 hours post-reaction for detailed analysis. Each treatment was repeated three times. The results are shown in [Figure number missing]. Figures 3~5 .

[0037] according to Figure 3As can be seen, the surface of the residual film in the clear water environment is smooth and flat, with only minor strip-like protrusions. After adding Comparative Example 1, obvious black patches are visible at the cracks and wrinkles of the residual film, and these black patches lead to a significant increase in the root mean square roughness. In contrast, Example 1 has a larger adhesion area on the surface of the residual film, and the root mean square roughness (Rq) is increased by 4.2 times and 1.0 times compared with the blank treatment and Comparative Example 1, respectively. The arithmetic mean roughness (Ra) is increased by 5.0 times and 1.0 times compared with the blank treatment and Comparative Example 1, respectively. This indicates that Example 1 can accelerate the wrinkling and deformation of the controlled-release fertilizer residual film and increase the specific surface area of ​​the residual film in contact with the medium.

[0038] according to Figure 4 It can be seen that the particle size distribution of the residual film particles changed significantly after 15 days of reaction in a light environment. After adding Comparative Example 1 and Example 1, the D50 particle size decreased from 0.87 mm to 0.67 mm and 0.45 mm, respectively. With the extension of time, after 30 days of reaction, the D50 particle size distribution of the blank treatment and Comparative Example 1 tended to be consistent, approximately 0.71-0.74 mm, while the D50 particle size of Example 1 was 0.36 mm. After 15 days of cultivation, the weight loss rate of Comparative Example 1 and Example 1 increased by 35.6% and 93.3% respectively compared with the blank treatment; after 30 days of cultivation, the weight loss rate of Comparative Example 1 and Example 1 increased by 53.1% and 61.9% respectively compared with the blank treatment, with the weight loss rate of Example 1 reaching as high as 8.99%. This indicates that Example 1 has a significant effect on the degradation of controlled-release fertilizer residual film.

[0039] like Figure 5 As shown, the dynamic process of controlled-release fertilizer residue degradation was analyzed based on first-order kinetic equations. In the blank treatment, the half-life of the residue was 201.8 days, and it took 663.4 days to degrade to 90% of the initial input. The addition of organic materials significantly accelerated the degradation process of the residue. Comparative Example 1 and Example 1 reduced the half-life of the residue from 201.8 days to 74.3 days and 65.1 days, respectively; the time required for Comparative Example 1 and Example 1 to degrade to 90% of the initial input (initial mass of the residue) was 345.1 days and 196.8 days, respectively. Compared with the control treatment and Comparative Example 1, the degradation cycle of Example 1 was shortened by 70.3% and 43.0%, respectively.

[0040] Experimental Example: Field Degradation Efficacy Verification The tested variety was Denghai 605 (growing period 128 days, thousand-grain weight 367g). Six rows of maize were planted with a row spacing of 60cm and a plant spacing of 20cm, equivalent to 5555 plants / mu. Fertilizer was applied and then deeply tilled to a depth of 10cm, with maize seeds buried 5cm deep. The nitrogen, phosphorus, and potassium fertilizer application rates for each treatment were N-P₂O₅-K₂O (kg / 667m²). 2 )=14-3-9(N 210kg / hm 2P2O5 45 kg / hm 2 K2O 135kg / hm 2 The fertilizers used in the experiment were commercially available controlled-release urea (purchased from Henan Xinlianxin Chemical Industry Group Co., Ltd., polyurethane coating weight 3%; N 44.5%), superphosphate granules (P2O5 16.0%), and potassium chloride granules (K2O 60%). The experiment was divided into three groups: a control group, a comparative example 1 group, and an example 1 group. The control group only received controlled-release urea, while the comparative example 1 group and the example 1 group received 120 kg / hm² of dual-source humic acid or humic acid. 2 The fertilizer was applied at a mass ratio of 3:7 with controlled-release urea. The planting method was mechanical deep tillage and ridging – fertilizer application followed by tilling – mechanical sowing. All plots (3.6m × 4.2m = 15.12 m) were treated. 2 The plot (approximately 0.0227 mu / plot) was irrigated uniformly, and weeding and pest control were carried out according to local practices. This plot had not previously been treated with coated controlled-release urea. The experiment was conducted for two consecutive years in the same plot under the same fertilization treatment. Soil samples were collected between plants during the corn jointing and grain-filling stages to determine soil nutrient content. After harvest, corn yields for each treatment were tallied, and controlled-release fertilizer residues in the soil were collected and analyzed for their physicochemical properties. The results are shown in [Table / Reference]. Figures 6~7 .

[0041] like Figure 6 As shown, under controlled conditions with identical nitrogen, phosphorus, and potassium application rates, Example 1 significantly improved maize yield compared to the control and Comparative Example 1. Data from the 2023 trial showed that, compared to the control group receiving controlled-release urea alone, the maize yield with the addition of Example 1 increased by 20.7%, and compared to Comparative Example 1, the yield increased by 9.0%. In the 2024 follow-up trial, the yield-increasing advantage of this treatment was further highlighted: compared to the control group, the yield increase expanded to 25.4%, an increase of 4.7 percentage points compared to 2023; compared to Comparative Example 1, the yield increase reached 9.9%, an increase of 0.9 percentage points compared to 2023.

[0042] like Figure 7As shown, in the controlled-release fertilizer residue collected in 2023, it was found that the control group's controlled-release fertilizer residue maintained an intact hollow capsule structure with uniformly distributed pores and shallow wrinkles on the surface. In contrast, the capsule walls of the controlled-release fertilizer residue with added organic materials ruptured, and deeper cracks and sharp-angled fractures appeared in the example, with large areas of brownish-red patches visible inside. Compared with the control group and Comparative Example 1, the carbon content on the surface of the controlled-release fertilizer residue treated in Example 1 decreased from 68.7% and 61.4% to 41.3%, the oxygen content increased from 26.5% and 34.9% to 39.4%, and the silicon content increased from 0.6% and 0.8% to 10.1%, respectively. This indicates that Example 1 has superior performance in accelerating the degradation of controlled-release fertilizer residue and reducing the risk of residue residue.

[0043] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A dual-source fermenting agent, characterized in that, Prepared by the following method: (1) The lees and straw are crushed separately, mixed to obtain a mixture, the water content of the mixture is adjusted, and after sterilization, a solid fermentation culture medium is obtained. Acid-resistant compound bacterial liquid is sprayed into it for sealed fermentation, and the fermentation product is obtained after the fermentation is completed. (2) Mix the fermentation product with alkaline solution and extract it by stirring under constant temperature in a water bath. After extraction, collect the supernatant, add hydrochloric acid solution to the supernatant, let it stand for 2 hours, and then centrifuge to collect the precipitate to obtain the dual-source fermentation agent.

2. The dual-source fermenting agent according to claim 1, characterized in that, In step (1), the moisture content of the lees is <15wt%; the straw is corn straw or wheat straw.

3. The dual-source fermenting agent according to claim 1, characterized in that, In step (1), the mass ratio of the distiller's grains to the straw is 3:1; the water content of the mixture is 65~70wt%.

4. The dual-source fermenting agent according to claim 1, characterized in that, In step (1), the acid-resistant compound bacteria are obtained by culturing Aspergillus niger and Lactobacillus acidophilus at a mass ratio of 3:1; the strain preservation number of Aspergillus niger is CICC 2460; the strain preservation number of Lactobacillus acidophilus is CICC 20248; and the spraying amount of the acid-resistant compound bacteria solution is 5% of the mass of the solid fermentation culture medium.

5. The dual-source fermenting agent according to claim 4, characterized in that, In step (1), the cultivation involves diluting the acid-resistant compound bacteria with sterile water to a concentration of 10. 8 A bacterial suspension was obtained at CFU / mL and activated in a constant temperature shaker at 30°C for 2 hours.

6. The dual-source fermenting agent according to claim 1, characterized in that, In step (1), the fermentation is carried out in solid state at 30-35℃. The pile is turned over once a day for the first 5 days, and then turned over once every 2 days from the 6th day onwards. The total fermentation cycle is 12-15 days.

7. The dual-source fermenting agent according to claim 1, characterized in that, In step (2), the alkaline solution is a 10 wt% sodium hydroxide solution; the mass ratio of the fermentation product to the sodium hydroxide solution is 1:

10.

8. The dual-source fermenting agent according to claim 1, characterized in that, In step (2), the temperature of the water bath is 60-65℃; the extraction time is 2h; the concentration of the hydrochloric acid solution is 6M; and the amount of hydrochloric acid solution added is the same as the volume of the alkali solution.

9. The application of the dual-source humicin according to any one of claims 1 to 8 in degrading the coating of coated fertilizer and increasing crop yield.

10. The application according to claim 9, characterized in that, The membrane shell is made of polyurethane.

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