Organic water-soluble fertilizer based on honey fermentation concentrate and preparation method thereof

Abstract

This invention belongs to the field of agricultural fertilizer technology, specifically relating to an organic water-soluble fertilizer based on molasses fermentation concentrate and its preparation method. The organic water-soluble fertilizer comprises molasses fermentation concentrate, a compound enzyme preparation, polyaspartic acid, EDTA-2Na, and water-soluble nitrogen, phosphorus, and potassium fertilizer. It employs a staged temperature-varying enzymatic hydrolysis process. Laccase first oxidizes and degrades polyphenols at 30–35°C, opening the polyphenol-polysaccharide complex structure. Then, the temperature is raised to 42–48°C, where β-glucanase, xylanase, and mannanase directionally degrade colloidal polysaccharides. Simultaneously, EDTA-2Na is introduced to chelate metal ions, and polyaspartic acid inhibits scale dispersion. These three components synergistically form an "enzymatic hydrolysis-chelation-scale inhibition" anti-clogging system. This invention addresses the technical problems of existing molasses fermentation concentrate fertilizers being prone to clogging in drip irrigation systems, having low efficiency in constant-temperature synchronous enzymatic hydrolysis, and having an imperfect single anti-clogging mechanism. It provides an organic water-soluble fertilizer composed of molasses fermentation concentrate, a compound enzyme preparation, polyaspartic acid, EDTA-2Na, and water-soluble nitrogen, phosphorus, and potassium fertilizer. This invention effectively solves the problem of clogging of honey fermentation concentrate in drip irrigation systems, improves enzymatic hydrolysis efficiency, and is suitable for drip irrigation fertilization of various crops such as bananas and vegetables.

Description

Technical Field

[0001] This invention relates to the field of agricultural fertilizer technology, specifically to an organic water-soluble fertilizer based on honey fermentation concentrate and its preparation method, and more particularly to an organic water-soluble fertilizer suitable for drip irrigation systems and its preparation method. Background Technology

[0002] Molasses fermentation waste liquid is the waste liquid produced in the sugar industry after molasses is fermented with yeast to produce alcohol, yeast, and other products. It contains rich organic matter, amino acids, humic acid, and nutrients such as nitrogen, phosphorus, and potassium, which are essential for plants. Evaporating and concentrating this molasses fermentation waste liquid to prepare organic water-soluble fertilizer not only realizes the resource utilization of industrial waste but also provides high-quality organic fertilizer for agricultural production.

[0003] Molasses fermentation waste liquid is rich in organic matter, amino acids, humic acid, and essential nutrients for plants such as nitrogen, phosphorus, and potassium. Concentrating this waste liquid through evaporation to produce water-soluble organic fertilizer not only enables the resource utilization of industrial waste but also provides high-quality organic fertilizer for agricultural production. Molasses fermentation concentrate can be used as an auxiliary material for foliar fertilizers, liquid fertigation fertilizers, and solid organic granular fertilizers, or directly diluted for use.

[0004] However, the composition of molasses fermentation wastewater is extremely complex. Molasses fermentation industrial wastewater contains high levels of organic pollutants, strong acidity, high salinity, and various heavy metals. In addition to five heavy metals—As, Hg, Cd, Pb, and Cr—it also contains Mn, Cu, Zn, Ni, and Se. During the sugar-making process, molasses itself contains colloids and ash, with colloids significantly increasing its viscosity. Molasses fermentation alcoholic wastewater also contains oligosaccharides that alcohol yeast cannot ferment, pectin, alcohols (ethanol, glycerol, etc.), organic acids, caramel coloring, and other substances. In addition to the aforementioned beneficial components, the concentrated molasses fermentation liquid also contains a large amount of colloidal substances (such as β-glucan, xylan, mannan, etc.), polyphenols, and various metal ions such as calcium, magnesium, iron, and manganese.

[0005] The coexistence of these substances leads to serious compatibility issues with drip irrigation systems. Studies have shown that the fouling produced during the concentration process of molasses fermentation wastewater mainly consists of inorganic, insoluble salts, primarily calcium and sulfate salts, along with organic matter and colloidal particles. High temperatures disrupt the stable state of organic matter and large colloidal particles in the wastewater, causing the organic matter and large colloidal molecules to aggregate. Once the organic matter is destroyed, its dispersing and suspending effect on calcium sulfate crystals disappears, leading to the precipitation of calcium sulfate crystals. With temperature changes, various metal salts in the wastewater crystallize and precipitate mixed crystals, forming fouling. Therefore, the aggregation of colloidal substances, the crystallization of metal ions, and the complex precipitation of organic and inorganic matter mutually reinforce each other, collectively constituting a complex clogging mechanism in drip irrigation systems.

[0006] Colloidal substances are the primary cause of drip irrigation clogging. Colloidal substances in molasses (such as β-glucan, xylan, and mannan) have high molecular weights and viscosity. Large molecular weight viscous substances like pectin, starch, glucan, and hemicellulose from the raw materials in sugarcane juice are themselves major sources of clogging risk. When the molasses fermentation concentrate enters the drip irrigation system, these soluble colloidal substances cannot be retained by conventional filters. They gradually accumulate and adsorb within the dripper channels due to sudden changes in flow rate and temperature, eventually forming organic blockages. In severe cases, this can cause complete dripper blockage within hours.

[0007] The synergistic effect of polyphenols and metal ions is another important factor exacerbating clogging. Polyphenols in molasses fermentation concentrate have strong complexing abilities, readily forming insoluble metal-organic complex precipitates with metal ions such as calcium, magnesium, iron, and manganese in the solution. Studies have shown that molasses fermentation industrial wastewater contains various metal ions such as Mn, Cu, Zn, Ni, and Se. These metal ions can not only crystallize and precipitate at the dripper due to changes in concentration and pH, but also form complex precipitates with polyphenols and humic acids. These complex precipitates have a denser structure and are more difficult to remove, making them one of the most stubborn types of clogging in drip irrigation systems.

[0008] To address the aforementioned problems, existing technologies typically employ simple physical filtration methods to treat molasses fermentation concentrate, such as centrifugal filters and screen filters. However, physical filtration has fundamental limitations: it can only retain solid suspended matter with a particle size larger than the filtration precision. Conventional drip irrigation system filters (120-200 mesh disc filters, with a filtration precision of approximately 75-150 μm) can retain particles much larger than soluble colloidal substances, polyphenols, and dissolved metal ions. The main substances in molasses fermentation concentrate that truly cause drip irrigation blockages are soluble colloids, polyphenols, and dissolved metal ions, with particle sizes ranging from nanometer to submicron, which can freely pass through physical filter layers. Therefore, physical filtration cannot solve the blockage problem at its root, which remains a technological bottleneck that existing technologies have yet to overcome.

[0009] Furthermore, while existing research has explored the use of biodegradable agents such as pectinase and glucanase in the sugar refining industry to treat molasses and reduce its viscosity—for example, a patent discloses a biodegradable agent for reducing viscosity and starch content in the sugar refining industry, composed of 12-20% glucanase, 8-12% pectinase, 10-15% xylanase, 15-25% amylase, and 5-10% protease—it can effectively degrade large molecular sticky substances such as pectin, starch, glucan, and hemicellulose from the raw materials in sugarcane juice, reducing the risk of clogging—other patents have also disclosed a scheme using laccase in combination with pectinase and xylanase in the sugar refining industry.

[0010] However, it must be pointed out that the aforementioned enzymatic hydrolysis technologies are mainly applied to the clarification and viscosity reduction of molasses during the sugar refining process, aiming to improve sugar recovery and product quality. These technologies do not involve the application of enzymatically hydrolyzed molasses in fertilizer production, nor do they optimize the enzymatic hydrolysis process for the anti-clogging needs of drip irrigation systems. The two differ fundamentally in their technical objectives, treatment targets, and desired effects: the sugar industry focuses on sugar recovery and finished sugar quality, while fertilizer production focuses on nutrient retention and application safety; sugar refining processes fresh sugarcane juice or molasses, while fertilizer production processes concentrated fermentation waste liquid, resulting in significant differences in composition. Therefore, those skilled in the art cannot directly apply enzymatic hydrolysis technologies from the sugar refining industry to drip irrigation anti-clogging in fertilizer production.

[0011] Furthermore, existing molasses fermentation liquid-based water-soluble fertilizers lack standardized application plans for drip irrigation systems. Some products on the market recommend dilution ratios of 400-700 times, with a maximum dilution ratio of 1000 times; others recommend a 50-fold dilution for direct application via fertigation or irrigation; still others simply state that "it can be diluted and applied with water, or used for drip irrigation." Recommended dilution ratios vary widely and inconsistently among different manufacturers, ranging from 50 to 1000 times. When the dilution ratio is too low, the concentration of residual colloids and polyphenols in the fertilizer remains high, and the risk of dripper clogging is not effectively controlled. When the dilution ratio is too high, the nutrient concentration is too low to meet the crop's growth needs, and it increases irrigation water consumption and fertilization frequency, reducing the operational efficiency of the fertigation system. This lack of application plans leads to frequent dripper clogging even after purchasing commercially available molasses fermentation liquid-based fertilizers, severely hindering the large-scale promotion and application of molasses fermentation liquid-based organic water-soluble fertilizers in fertigation technology. Summary of the Invention

[0012] This invention addresses the technical problems of existing organic water-soluble fertilizers based on molasses fermentation concentrate, such as easy clogging in drip irrigation systems, low enzymatic hydrolysis efficiency, easy loss of heat-sensitive nutrients, and a single anti-clogging mechanism. It provides an organic water-soluble fertilizer based on molasses fermentation concentrate and its preparation method.

[0013] To achieve the above objectives, in one aspect, the present invention provides an organic water-soluble fertilizer based on honey fermentation concentrate, comprising the following raw materials in parts by weight:

[0014] 50-78 parts of concentrated honey fermentation broth;

[0015] 0.5–2 parts of compound enzyme preparation;

[0016] 1-4 parts of polyaspartic acid;

[0017] EDTA-2Na 0.5–2 parts;

[0018] 5-14 parts of water-soluble nitrogen, phosphorus, and potassium fertilizer.

[0019] In another invention, the present invention also provides a method for preparing the above-mentioned organic water-soluble fertilizer based on honey fermentation concentrate, comprising the following steps:

[0020] S1. Preparation of a compound enzyme preparation: Specifically, β-glucanase, xylanase, mannanase and laccase are mixed evenly in a weight ratio of (1-3):(2-4):(1-2):(0.5-1.5) to obtain a compound enzyme preparation.

[0021] S2, enzymatically pretreated honey fermentation concentrate, specifically:

[0022] First, the laccase activation and enzymatic hydrolysis stage is carried out. The pH of the honey fermentation concentrate is adjusted to 4.8-5.2, the temperature is controlled at 30-35℃, and part of the compound enzyme preparation is added so that the amount of laccase added reaches 0.5-2.0U per gram of dry matter in the concentrate. Enzymatic hydrolysis is carried out for 1.5-2.5 hours under stirring conditions.

[0023] Then, the polysaccharide degradation enzymatic hydrolysis stage is carried out. The pH of the product obtained from the laccase activation enzymatic hydrolysis stage is adjusted to 5.5-6.0, the temperature is raised to 42-48℃, and the remaining compound enzyme preparation is added so that the amount of β-glucanase, xylanase and mannanase added reaches 1-3U, 2-4U and 1-2U per gram of concentrated dry matter, respectively. Enzymatic hydrolysis is continued for 3-5 hours under stirring conditions.

[0024] Finally, enzyme inactivation is performed. After enzymatic hydrolysis, the temperature is raised to 80-85℃ and the enzyme is inactivated for 10-15 minutes. The solution is then cooled to room temperature to obtain the enzymatic hydrolysis pretreatment solution.

[0025] S3, Fertilizer preparation: Add polyaspartic acid, EDTA-2Na and water-soluble nitrogen, phosphorus and potassium fertilizer to the enzymatic hydrolysis pretreatment solution obtained in step S2, stir and dissolve evenly to obtain organic water-soluble fertilizer based on honey fermentation concentrate.

[0026] The present invention has the following significant advantages over the prior art:

[0027] 1. In view of the problem of low efficiency in the existing isothermal synchronous enzymatic hydrolysis process, the present invention adopts a staged temperature change and step-by-step addition enzymatic hydrolysis process, so that each enzyme can play its role at its own optimal temperature, which significantly improves the enzymatic hydrolysis efficiency.

[0028] In current technologies, molasses enzymatic hydrolysis is mostly carried out under isothermal conditions, with all enzymes added at the same temperature all at once. Laccase exhibits better activity at lower temperatures, while β-glucanase, xylanase, and mannanase require higher temperatures to fully exert their effects, resulting in a significant mismatch in their optimal temperature ranges. If the temperature is fixed at a certain intermediate value as is the conventional approach, the activity of at least one enzyme will be inhibited, inevitably compromising the hydrolysis effect. This invention breaks down the enzymatic hydrolysis process into two temperature stages. Laccase first completes the oxidative degradation of polyphenols at a low temperature, releasing the colloidal polysaccharides in the polyphenol-polysaccharide complex. Then, the temperature is increased to add three other polysaccharide enzymes for targeted degradation. It can be understood that laccase acts as a catalyst, first breaking down the encapsulation layer of the complex structure, and then the polysaccharide enzymes follow to complete the cleanup. This sequential, coordinated approach, compared to adding all enzymes simultaneously, demonstrates its advantages in comparative experiments. The viscosity and colloidal residue after the staged temperature treatment are significantly lower than those after the one-step treatment, indicating that this process route of opening the structure first and then degrading is indeed more efficient.

[0029] 2. In response to the problem that a single anti-clogging mechanism cannot solve the problem of complex clogging in drip irrigation, this invention constructs a triple synergistic anti-clogging system of enzymatic hydrolysis, chelation and scale inhibition, which comprehensively solves the problem of drip irrigation clogging from three dimensions: organic colloidal clogging, inorganic salt crystallization clogging and metal-organic complex precipitation clogging.

[0030] Drip irrigation blockage is never caused by a single factor; organic colloidal substances in molasses fermentation concentrate can gradually accumulate in the flow channel to form a viscous deposit layer; polyphenols easily combine with metal ions to form insoluble complexes; and metal ions themselves can also concentrate and crystallize at the dripper due to water evaporation. The formation mechanisms of these three types of blockage are different; if only one type is addressed, the other types of blockage will still exist. This invention utilizes three polysaccharide enzymes to remove colloids while also introducing EDTA-2Na and polyaspartic acid. In this application, EDTA-2Na refers to disodium ethylenediaminetetraacetate, with the chemical formula C. 10 H 14 N2Na2O8 and EDTA-2Na can complex metal ions such as calcium, magnesium, iron, and manganese into soluble forms, making them difficult to bind with organic ligands; polyaspartic acid can disperse and inhibit the formation of inorganic salt microcrystals, preventing them from depositing at the dripper. The three substances target different types of blockages and complement each other in drip irrigation operation. This difference can be seen in simulation tests. The concentrated solution treated by this invention has a significantly smaller flow rate decline within the same operating time, and the water output uniformity of the dripper is also better. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the steps in the preparation method of the organic water-soluble fertilizer based on honey fermentation concentrate of the present invention. Detailed Implementation

[0032] Example 1

[0033] This embodiment provides an organic water-soluble fertilizer based on honey fermentation concentrate, comprising the following raw materials in parts by weight:

[0034] 70 portions of concentrated honey fermentation liquid;

[0035] 1.2 portions of compound enzyme preparation;

[0036] 2.5 parts of polyaspartic acid;

[0037] EDTA-2Na 1.3 parts;

[0038] 15 parts of water-soluble nitrogen, phosphorus, and potassium fertilizer;

[0039] The water-soluble nitrogen, phosphorus, and potassium fertilizer is a mixture of urea, potassium dihydrogen phosphate, and potassium nitrate in a weight ratio of 2:1:1.

[0040] The weight ratio of β-glucanase, xylanase, mannanase and laccase in the compound enzyme preparation is 2:3:1.5:1;

[0041] The total solids content of the honey fermentation concentrate is 72.5%, the total sugar content is 38.6%, the crude protein content is 8.5%, the pH value is 4.8, and the Brix value is 65°Bx.

[0042] The laccase is derived from Trametes versicolor and has an enzyme activity of 12000 U / g.

[0043] Reference Figure 1 As shown, the preparation method of this embodiment is as follows:

[0044] S1. Preparation of a compound enzyme preparation: Specifically, β-glucanase, xylanase, mannanase and laccase are mixed evenly in a weight ratio of 2:3:1.5:1 to obtain a compound enzyme preparation.

[0045] S2, enzymatically pretreated honey fermentation concentrate, specifically:

[0046] First, the laccase activation and enzymatic hydrolysis stage was carried out. 700g of honey fermentation concentrate was taken, and the pH was adjusted to 4.8 using a citric acid-sodium citrate buffer system. The temperature was controlled at 32℃, and 40% of the total amount of compound enzyme preparation was added so that the amount of laccase added reached 1.0U per gram of dry matter in the concentrate. Enzymatic hydrolysis was carried out for 2.0h under the condition of stirring speed of 80rpm.

[0047] Then, the polysaccharide degradation enzymatic hydrolysis stage was carried out. The product obtained from the laccase activation enzymatic hydrolysis stage was adjusted to pH 5.8 using a potassium dihydrogen phosphate-sodium hydroxide buffer system, heated to 45℃, and the remaining compound enzyme preparation was added so that the addition amount of β-glucanase, xylanase and mannanase reached 2.0U, 3.0U and 1.5U per gram of concentrated dry matter, respectively. Enzymatic hydrolysis was continued for 4.0h under stirring speed of 50rpm.

[0048] Finally, enzyme inactivation was performed. After the enzymatic hydrolysis was completed, the temperature was raised to 82°C and the enzyme was inactivated for 12 minutes. The solution was then cooled to room temperature to obtain the enzymatic hydrolysis pretreatment solution.

[0049] S3. Prepare fertilizer by adding 25g of polyaspartic acid, 13g of EDTA-2Na and 150g of water-soluble nitrogen, phosphorus and potassium fertilizer to the enzymatic hydrolysis pretreatment solution obtained in step S2, stirring and dissolving evenly to obtain an organic water-soluble fertilizer based on honey fermentation concentrate.

[0050] This embodiment targets crop-producing areas in South China, where drip irrigation systems are commonly used for fertilization and irrigation. However, the region experiences high temperatures and humidity, leading to frequent operation of drip irrigation systems. In high-temperature environments, colloidal substances and metal ions within the pipes and drippers are more prone to aggregation and reaction, significantly increasing the risk of clogging. Previous studies have shown that applying molasses-based alcohol fermentation broth to drip irrigation has a positive impact on banana yield and quality; however, directly introducing untreated fermentation broth into the drip irrigation system still poses a clogging risk. This embodiment utilizes staged, temperature-controlled enzymatic hydrolysis pretreatment to fully degrade colloidal polysaccharides in the molasses fermentation concentrate. Simultaneously, EDTA-2Na is used to chelate metal ions, and polyaspartic acid is used for scale inhibition and dispersion, ensuring stable operation of the fertilizer under high-frequency drip irrigation conditions in banana orchards without clogging the drippers.

[0051] Experimental group 1

[0052] An organic water-soluble fertilizer was prepared using the formula and preparation method described in Example 1. Specifically, it consisted of: 70 parts honey fermentation concentrate, 1.2 parts compound enzyme preparation, 2.5 parts polyaspartic acid, 1.3 parts EDTA-2Na, and 15 parts water-soluble nitrogen, phosphorus, and potassium fertilizer; the weight ratio of β-glucanase, xylanase, mannanase, and laccase in the compound enzyme preparation was 2:3:1.5:1; prepared according to steps S1 to S3 of Example 1. The obtained fertilizer was diluted 500 times and connected to a drip irrigation system in a banana plantation in South China (using inlaid patch drip irrigation tape, dripper spacing of 30 cm, and working pressure of 0.1 MPa), running continuously for 48 hours, observing changes in dripper flow rate and clogging.

[0053] Control group 1

[0054] A control fertilizer was prepared using an existing molasses fermentation liquid-based water-soluble fertilizer formula. Specifically, 70 portions of the same batch of concentrated molasses fermentation liquid as experimental group 1 were taken and directly mixed with 2.5 portions of polyaspartic acid and 15 portions of water-soluble nitrogen, phosphorus, and potassium fertilizer without any enzymatic pretreatment (referring to existing technical schemes for adding polyaspartic acid to molasses fermentation liquid fertilizers in the background section) to obtain the control fertilizer. The control fertilizer was diluted 500 times and connected to the same drip irrigation system as experimental group 1. It was run continuously for 48 hours under the same operating conditions, and the changes in dripper flow rate and clogging were observed.

[0055] After 48 hours of operation, the drippers in experimental group 1 operated normally, with both flow rate attenuation and clogging rates remaining at low levels. Control group 1, however, showed significant flow rate attenuation and partial dripper clogging. Disassembly and analysis of the clogged drippers revealed that organic colloidal substances dominated the clogging in control group 1, indicating that the large amount of colloidal substances in the untreated honey fermentation concentrate was the main cause of dripper clogging. In contrast, only trace amounts of deposits were observed on the inner walls of the drippers in experimental group 1, demonstrating that the S2 enzymatic pretreatment step of this invention, compared to the simple addition of polyaspartic acid in the prior art, can degrade colloidal polysaccharides in the honey fermentation concentrate at its source, significantly reducing the viscosity and clogging tendency of the concentrate.

[0056] As shown in the table below:

[0057] Honey fermentation concentrate 70 copies 70 copies Compound enzyme preparations It contains (β-glucanase + xylanase + mannanase + laccase) none EDTA-2Na have none Polyaspartic acid have have Water-soluble nitrogen, phosphorus and potassium fertilizer have have S2 enzymatic hydrolysis pretreatment step have none Laccase activation and enzymatic hydrolysis stage 32℃, pH 4.8, 2.0h none Polysaccharide degradation enzymatic hydrolysis stage 45℃, pH 5.8, 4.0h none Drip head flow rate attenuation rate after 48 hours of operation 8%～11% 40%～50% dripper clogging rate after 48 hours of operation 0%～2% 12%～18% Deposits on the inner wall of the dripper Only trace deposits were observed. Obvious sedimentary layers The proportion of organic colloidal substances in the blockage 5%～7% 62.3%

[0058] Table 1 shows the comparison of results between control group 1 and experimental group 1.

[0059] This invention, in Example 1, addresses drip irrigation applications in South China. It employs a staged, temperature-controlled, step-by-step enzymatic pretreatment process, combined with the synergistic effect of EDTA-2Na and polyaspartic acid, to fundamentally solve the drip clogging problem caused by colloidal substances. As described in the background section, molasses fermentation concentrate contains a large amount of soluble colloidal substances such as β-glucan, xylan, and mannan. These substances cannot be retained by physical filters and are the main cause of dripper clogging. In step S2 of this embodiment, a staged, temperature-controlled, step-by-step enzymatic hydrolysis process is used. Laccase first oxidizes and degrades polyphenols at a low temperature of 32°C, opening the polyphenol-polysaccharide complex structure and releasing bound colloidal polysaccharides. Subsequently, the temperature is raised to 45°C, where β-glucanase, xylanase, and mannanase directionally degrade the three types of colloidal polysaccharides, breaking them down from large molecules into small, soluble molecules. This process effectively removes the source of the blockage. Experimental data show that after the fertilizer treated in this embodiment runs in the drip irrigation system for 48 hours, the dripper flow rate attenuation rate is only 10% to 15% and the blockage rate is only 0% to 2%; while the control group used, under the same conditions, has a flow rate attenuation rate as high as 40% to 50%, a blockage rate as high as 12% to 18%, and organic colloidal substances account for 55% to 70% of the blockage.

[0060] The technical solution in this embodiment is primarily applicable to the operational characteristics of high-frequency drip irrigation in South China. South China experiences high temperatures and humidity, leading to frequent operation of drip irrigation systems. Colloidal substances within the pipes and drippers are more prone to aggregation and reaction under high-temperature conditions, significantly increasing the risk of blockage. This embodiment utilizes thorough enzymatic pretreatment to degrade colloidal substances into small, soluble molecules. Combined with EDTA-2Na chelating metal ions and polyaspartic acid scale inhibition and dispersion, this triple synergistic effect ensures stable fluid performance of the fertilizer under high-frequency, long-term drip irrigation conditions.

[0061] Example 2

[0062] This embodiment provides an organic water-soluble fertilizer based on honey fermentation concentrate, comprising the following raw materials in parts by weight:

[0063] 60 portions of concentrated honey fermentation liquid;

[0064] 1.5 portions of compound enzyme preparation;

[0065] 3.0 parts of polyaspartic acid;

[0066] EDTA-2Na 1.5 parts;

[0067] 14 parts of water-soluble nitrogen, phosphorus, and potassium fertilizer;

[0068] The water-soluble nitrogen, phosphorus, and potassium fertilizer is a mixture of potassium dihydrogen phosphate and potassium nitrate in a weight ratio of 1:1.

[0069] The weight ratio of β-glucanase, xylanase, mannanase and laccase in the compound enzyme preparation is 1.5:2.5:1.5:1;

[0070] The total solids content of the honey fermentation concentrate is 70.0%, the total sugar content is 35.0%, the crude protein content is 8.0%, the pH value is 5.0, and the Brix value is 60°Bx.

[0071] The laccase is derived from white-rot fungi and has an enzyme activity of 15000 U / g.

[0072] The preparation method in this embodiment is the same as in Example 1, except that:

[0073] In S2, the pH of the laccase activation and enzymatic hydrolysis stage is 5.0, the temperature is controlled at 35℃, and 35% of the total amount of compound enzyme preparation is added to make the laccase addition amount reach 1.5U per gram of concentrated dry matter. Enzymatic hydrolysis is carried out for 1.5 hours under the condition of stirring speed of 70 rpm.

[0074] During the enzymatic hydrolysis stage of polysaccharide degradation, the pH was 6.0 and the temperature was controlled at 48℃. The remaining compound enzyme preparation was added so that the addition amount of β-glucanase, xylanase and mannanase reached 2.5U, 3.5U and 1.8U per gram of dry matter of concentrated liquid, respectively. Enzymatic hydrolysis was continued for 3.5h under the condition of stirring speed of 45rpm.

[0075] The enzyme inactivation temperature was 85℃, and the inactivation time was 10 min.

[0076] This embodiment targets vegetable production areas in northern regions, where drip irrigation under mulch is the mainstream fertigation technology for greenhouse vegetable production. However, greenhouse vegetable soils in the north generally suffer from secondary salinization and low organic matter content. Compared to field crops, greenhouse vegetable drip irrigation systems have finer pipes and smaller dripper spacing, placing higher demands on fertilizer water solubility and fluid stability. Simultaneously, the low temperatures inside greenhouses in northern winters affect fertilizer solubility and flowability. This embodiment addresses this scenario by appropriately increasing the proportion of compound enzyme preparations and polyaspartic acid to ensure good fertilizer water solubility and drip irrigation compatibility even at lower ambient temperatures, while simultaneously protecting the fine drip irrigation system by enhancing scale inhibition and dispersion.

[0077] An organic water-soluble fertilizer was prepared using the formula and preparation method described in Example 2. Specifically, it consisted of: 60 parts honey fermentation concentrate, 1.5 parts compound enzyme preparation, 3.0 parts polyaspartic acid, 1.5 parts EDTA-2Na, and 14 parts water-soluble nitrogen, phosphorus, and potassium fertilizer; the weight ratio of β-glucanase, xylanase, mannanase, and laccase in the compound enzyme preparation was 1.5:2.5:1.5:1; and it was prepared according to the method described in Example 2 (laccase activation enzymatic hydrolysis stage: pH 5.0, temperature 35℃, time 1.5h; polysaccharide degradation enzymatic hydrolysis stage: pH 6.0, temperature 48℃, time 3.5h). The obtained fertilizer was diluted 400 times and connected to a drip irrigation system under film for northern greenhouse vegetables (using labyrinth drip irrigation tape, dripper spacing 20cm, working pressure 0.08MPa), and ran continuously for 48h, observing changes in dripper flow rate and clogging.

[0078] Control group 2

[0079] A control fertilizer was prepared using an existing enzymatic hydrolysis method for reducing molasses viscosity in the sugar refining industry. Specifically, 60 portions of the same batch of molasses fermentation concentrate as in Experimental Group 2 were taken. Following the isothermal synchronous enzymatic hydrolysis method used in the sugar refining industry (this technology has been used to reduce molasses viscosity in the sugar refining industry), the pH was adjusted to 5.8, and the temperature was controlled at 45℃. β-glucanase, xylanase, mannanase, and laccase (the total amount and proportion of the four enzymes were the same as in Experimental Group 2) were added simultaneously. Enzymatic hydrolysis was carried out at a constant temperature with stirring for 5.0 h, followed by enzyme inactivation at 80℃ for 10 min. After cooling, 3.0 portions of polyaspartic acid, 1.5 portions of EDTA-2Na, and 14 portions of water-soluble nitrogen, phosphorus, and potassium fertilizer were added and stirred until dissolved to obtain the control fertilizer. The control fertilizer was diluted 400 times and connected to the same drip irrigation system as Experimental Group 2. It was run continuously for 48 h under the same operating conditions, and the changes in dripper flow rate and clogging were observed.

[0080] After 48 hours of operation, the drippers in experimental group 2 performed well, with both flow rate attenuation and clogging rates remaining at low levels. While control group 2 showed some improvement compared to the completely non-enzymatic hydrolysis approach, its flow rate attenuation was still significantly higher than that of experimental group 2. Analysis of the enzymatic hydrolysis effects of the two groups of fertilizers showed that experimental group 2 had significantly higher colloid degradation and viscosity reduction rates than control group 2. These results indicate that although the constant-temperature synchronous enzymatic hydrolysis method used in the sugar refining industry in the background technology can reduce molasses viscosity to some extent, the activity of some enzymes is inhibited under constant-temperature conditions due to the difference in the optimal temperatures of laccase and polysaccharide enzymes, resulting in limited enzymatic hydrolysis effects. In contrast, the staged temperature-varying, step-by-step enzymatic hydrolysis process of this invention allows each enzyme to exert its catalytic activity at its optimal temperature, resulting in more complete enzymatic hydrolysis. Therefore, its anti-clogging effect in drip irrigation systems is significantly superior to the constant-temperature synchronous enzymatic hydrolysis scheme of the background technology.

[0081] Honey fermentation concentrate 60 copies 60 copies Compound enzyme preparations It contains (β-glucanase + xylanase + mannanase + laccase) Yes (the total amount and proportion added are the same as in experimental group 2). EDTA-2Na have have Polyaspartic acid have have Water-soluble nitrogen, phosphorus and potassium fertilizer have have Enzymatic hydrolysis Graded temperature variation Constant temperature (45℃) Enzyme addition method Add in stages (first add 35% of the total amount of the compound enzyme preparation containing laccase, then add the remaining 65%). Add at once Laccase activation and enzymatic hydrolysis stage 35℃, pH 5.0, 1.5h No independent phase (laccase and polysaccharide enzyme react simultaneously at 45℃). Polysaccharide degradation enzymatic hydrolysis stage 48℃, pH 6.0, 3.5h No independent phase (laccase and polysaccharide enzyme react simultaneously at 45℃). Total enzymatic hydrolysis time 5.0h (1.5h + 3.5h) 5.0h Colloidal degradation rate 60%～70% 40%～50% Concentrate viscosity reduction rate 60%～70% 40%～50% Drip head flow rate attenuation rate after 48 hours of operation 8%～12% 24%～30% dripper clogging rate after 48 hours of operation 0%～2% 4%～8%

[0082] Table 2 shows the comparison of results between control group 2 and experimental group 2.

[0083] Embodiment 2 of the present invention is designed for drip irrigation under film in northern facility vegetables. By improving the enzymatic hydrolysis process through graded temperature variation and step-by-step addition, it achieves significantly better technical results compared with the constant temperature synchronous enzymatic hydrolysis scheme in the sugar refining industry in the background technology.

[0084] The staged temperature-controlled process ensures that each enzyme exerts its catalytic activity at its optimal temperature, significantly improving enzymatic hydrolysis efficiency. As described in the background section, existing molasses enzymatic hydrolysis technologies all employ a constant-temperature synchronous enzymatic hydrolysis mode. However, there is a significant mismatch between the optimal temperature ranges of laccase and β-glucanase, xylanase, and mannanase. Laccase exhibits optimal activity at 35°C, while the three polysaccharide enzymes reach their highest activity between 45 and 48°C. If the constant-temperature method of the background technique (e.g., 45°C) is used, laccase activity is significantly inhibited; if the temperature is lowered to 35°C, polysaccharide enzyme activity is insufficient. This embodiment divides the enzymatic hydrolysis process into two temperature stages: laccase first completes the oxidative degradation of polyphenols at 35°C, releasing colloidal polysaccharides in the polyphenol-polysaccharide complex, and then the temperature is raised to 48°C to add the other three polysaccharide enzymes for targeted degradation. Experimental data show that the colloid degradation rate in this embodiment reaches 60%–70%, and the viscosity reduction rate of the concentrate reaches 60%–70%, while the control group using constant temperature synchronous enzymatic hydrolysis in the background technology only has a colloid degradation rate of 40%–50% and a viscosity reduction rate of only 40%–50% under the same conditions. The difference between the two is significant, proving that the staged temperature variation process is superior to the constant temperature compromise solution.

[0085] In this embodiment, laccase-containing fraction (35% of the total compound enzyme preparation) is added first. After the laccase completes the "disassembly" of the polyphenol-polysaccharide complex, the remaining 65% polysaccharide-containing enzyme fraction is added for degradation. This sequential coordination is equivalent to laccase "opening the way" first, followed by polysaccharide enzyme "cleaning up," forming a relay effect. In contrast, the synchronous addition method in the background technology adds all enzymes simultaneously, causing laccase and polysaccharide enzyme to compete for substrates and reaction conditions in the same system, making sequential coordination impossible. Experimental data shows that after 48 hours of operation in a simulated drip irrigation system, the dripper flow rate attenuation rate in this embodiment is only 8%–12%, and the clogging rate is only 0%–2%, while the control group has rates of 24%–30% and 4%–8%, respectively. These data demonstrate that the staged temperature-varying, step-by-step addition process of this embodiment has unexpected technical advantages compared to the isothermal synchronous enzymatic hydrolysis process of the background technology.

[0086] The same or similar labels correspond to the same or similar parts;

[0087] The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0088] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. An organic water-soluble fertilizer based on honey fermentation concentrate, characterized in that, Including the following parts by weight of raw materials: 50-78 parts of concentrated honey fermentation broth; 0.5–2 parts of compound enzyme preparation; 1-4 parts of polyaspartic acid; EDTA-2Na 0.5–2 parts; 5-14 parts of water-soluble nitrogen, phosphorus, and potassium fertilizer; The molasses fermentation concentrate is a concentrate obtained by evaporating and concentrating molasses fermentation waste liquid to a Brix value of 45-75°Bx, with a total solids content of 65-78%, a total sugar content of 30-45%, a crude protein content of 5-12%, and a pH value of 4.5-5.

5. The aforementioned compound enzyme preparation is composed of β-glucanase, xylanase, mannanase, and laccase in a weight ratio of (1-3):(2-4):(1-2):(0.5-1.5); The laccase is derived from *Trametes versicolor* or white-rot fungi. Its optimal reaction pH is 4.5–5.0, its optimal reaction temperature is 30–40℃, and its enzyme activity is ≥10000 U / g. The enzyme activity unit is defined as the amount of enzyme required to oxidize 1 μmol of guaiacol per minute under the conditions of 30℃ and pH 4.5, which is 1 enzyme activity unit (U).

2. The organic water-soluble fertilizer based on honey fermentation concentrate according to claim 1, characterized in that, The total solids content of the honey fermentation concentrate is 70-75%, the total sugar content is 35-42%, and the crude protein content is 8-10%.

3. The organic water-soluble fertilizer based on honey fermentation concentrate according to claim 1, characterized in that, The weight ratio of β-glucanase, xylanase, mannanase and laccase in the compound enzyme preparation is 2:3:1.5:

1.

4. The organic water-soluble fertilizer based on honey fermentation concentrate according to claim 1, characterized in that, The water-soluble nitrogen, phosphorus, and potassium fertilizer is any two or three of the following: urea, potassium dihydrogen phosphate, and potassium nitrate.

5. A method for preparing an organic water-soluble fertilizer based on honey fermentation concentrate as described in any one of claims 1-4, characterized in that, Includes the following steps: S1, to prepare a compound enzyme preparation, specifically, to mix β-glucanase, xylanase, mannanase and laccase in a weight ratio of (1-3):(2-4):(1-2):(0.5-1.5) evenly to obtain a compound enzyme preparation; S2, enzymatic hydrolysis pretreatment of honey fermentation concentrate, specifically: First, in the laccase activation and hydrolysis stage, the pH of the honey fermentation concentrate is adjusted to 4.8–5.2, the temperature is controlled at 30–35℃, and part of the aforementioned compound enzyme preparation is added, so that the laccase addition reaches 0.5–2.0 U per gram of dry matter in the concentrate. Enzymatic hydrolysis is carried out for 1.5–2.5 hours under stirring conditions. Then, in the polysaccharide degradation and hydrolysis stage, the pH of the product obtained from the laccase activation and hydrolysis stage is adjusted to 5.5–6.0, the temperature is raised to 42–48℃, and the remaining of the aforementioned compound enzyme preparation is added, so that the addition amounts of β-glucanase, xylanase, and mannanase reach 1–3 U, 2–4 U, and 1–2 U per gram of dry matter in the concentrate, respectively. Enzymatic hydrolysis is continued for 3–5 hours under stirring conditions. Finally, enzyme inactivation is performed. After the enzymatic hydrolysis is completed, the temperature is raised to 80–85℃, the enzyme is inactivated for 10–15 minutes, and then cooled to room temperature to obtain the enzymatic hydrolysis pretreatment solution. S3. Prepare fertilizer: Add polyaspartic acid, EDTA-2Na and water-soluble nitrogen, phosphorus and potassium fertilizer to the enzymatic hydrolysis pretreatment solution obtained in step S2, stir and dissolve evenly to obtain organic water-soluble fertilizer based on honey fermentation concentrate.

6. The preparation method according to claim 5, characterized in that, In step S2, the compound enzyme preparation added during the laccase activation and hydrolysis stage accounts for 30-50% of the total amount of the compound enzyme preparation; In step S2, the polysaccharide degradation enzymatic hydrolysis stage, the added compound enzyme preparation accounts for 50-70% of the total compound enzyme preparation.

7. The preparation method according to claim 6, characterized in that, The compound enzyme preparation added in step S2, the laccase activation and hydrolysis stage, accounts for 40% of the total compound enzyme preparation, and the compound enzyme preparation added in step S2, the polysaccharide degradation and hydrolysis stage, accounts for 60% of the total compound enzyme preparation.

8. The preparation method according to claim 5, characterized in that, In step S2, the pH is adjusted to 4.8–5.2 using a citrate-sodium citrate buffer system during the laccase activation and hydrolysis stage; and the pH is adjusted to 5.5–6.0 using a potassium dihydrogen phosphate-sodium hydroxide buffer system during the polysaccharide degradation and hydrolysis stage of step S2.

9. The preparation method according to claim 5, characterized in that, In step S2, during the laccase activation and hydrolysis stage, the stirring conditions are a stirring speed of 60-100 rpm; in step S2, during the polysaccharide degradation and hydrolysis stage, the stirring conditions are a stirring speed of 40-60 rpm.

10. The preparation method according to claim 5, characterized in that, In step S2, during the laccase activation and hydrolysis stage, the total time of the enzymatic hydrolysis pretreatment is controlled between 4.5 and 7.5 hours, and the maximum temperature during the entire enzymatic hydrolysis pretreatment process does not exceed 48°C.

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