Soil fertilizer containing fish enzyme and preparation method thereof

Abstract

The present application relates to the field of fertilizers, and in particular to a soil fertilizer containing fish enzymes and a preparation method thereof. A soil fertilizer containing fish enzymes, the raw materials of which include, by mass, 10 to 20 parts of fish enzymes, 30 to 50 parts of urea, 5 to 10 parts of polyglutamic acid complex, 5 to 10 parts of modified chitosan, 1 to 3 parts of humic acid, 1 to 3 parts of aminobutyric acid, 10 to 20 parts of inorganic metal compounds, 4 to 6 parts of phosphate fertilizers, 1 to 5 parts of binders, 4 to 10 parts of surfactants, and 50 to 80 parts of deionized water. The fish enzyme fertilizer prepared in the present application can not only significantly improve soil fertility, increase crop product quality, promote crop growth, and improve soil, but it is also different from existing enzyme / protein fertilizers and has excellent self-stability, thereby avoiding the technical problems of difficult storage, difficult transportation, and easy deterioration and inactivation of existing organic fertilizers of this type, and has excellent market prospects.

Description

Technical Field

[0001] The present application relates to the field of fertilizers, and in particular to a soil fertilizer containing fish enzymes and a preparation method thereof. Background Art

[0002] Currently, the majority of fertilizers used in agriculture are chemical fertilizers. The long-term use of chemical fertilizers not only pollutes the environment but, more seriously, significantly degrades soil quality, ultimately impacting the quality of plants and crops. In recent years, the pursuit of "organic green products" has, in turn, raised the bar for the agricultural sector, particularly for the use of chemical fertilizers. To better meet this demand, the use of organic fertilizers has increased year by year, significantly increasing the organic matter content and fertility of agricultural soils. Furthermore, the use of organic fertilizers can improve crop quality and protect the ecological environment.

[0003] Enzyme fertilizers, due to their excellent soil-safety properties and rich content of essential organic matter and trace elements, have become a key focus of non-toxic organic fertilizer research and development in recent years. Enzyme fertilizers containing proteins and polypeptides, in particular, have become a hot topic among researchers in this field due to their more comprehensive nutritional balance and soil-improving effects. However, these fertilizers still face challenges in storage, transportation, and potential deterioration and inactivation.

[0004] Therefore, in order to solve the above problems, the present application provides a soil fertilizer containing fish enzymes and a preparation method thereof. The prepared fish enzyme-containing fertilizer can not only greatly improve soil fertility, increase the quality of crop products, promote crop growth and improve soil, but it is also different from existing enzyme / protein fertilizers and has excellent self-stability, thereby avoiding the technical problems of existing organic fertilizers of this type, such as difficult storage, difficult transportation and easy deterioration and inactivation, and has excellent market prospects. Summary of the Invention

[0005] In order to solve the above problems, the first aspect of the present application provides a soil fertilizer containing fish enzyme. The raw materials include, by mass: 10 to 20 parts of fish enzyme, 30 to 50 parts of urea, 5 to 10 parts of polyglutamic acid complex, 5 to 10 parts of modified chitosan, 1 to 3 parts of humic acid, 1 to 3 parts of aminobutyric acid, 10 to 20 parts of inorganic metal compound, 4 to 6 parts of phosphate fertilizer, 1 to 5 parts of binder, 4 to 10 parts of surfactant, and 50 to 80 parts of deionized water.

[0006] As a preferred solution, the mass ratio of the fish enzyme, urea and polyglutamic acid complex is (1.5~2): (4~5): (0.6~1).

[0007] As a preferred solution, the mass ratio of the fish enzyme, urea and polyglutamic acid complex is 1.5:4.5:0.8.

[0008] As a preferred solution, the preparation method of the fish enzyme includes the following steps: S1: adding sugar and sterile water to a mixing container, stirring evenly, then adding chopped fish skin and stirring continuously to disperse evenly; S2: heating to 40-50°C and fermenting at a constant temperature for 10-15 days, during which time regularly checking and replenishing the missing water every day; S3: after S2 is completed, filtering the product to obtain a filtrate, keeping the filtrate warm and shaking at 30-40°C for 4-6 hours to obtain a shaken liquid, and then storing the shaken liquid in a cool and ventilated place at room temperature for 5-8 days.

[0009] As a preferred solution, the average size of the chopped fish skin is (1-3) × (1-3) cm.

[0010] As a preferred solution, the weight ratio of the fish skin, sugar and sterile water is (3-5): (0.5-1): (20-40).

[0011] As a preferred solution, the weight ratio of the fish skin, sugar and sterile water is (3-4.5): (0.5-1): (20-30).

[0012] As a preferred solution, the sugar is brown sugar or dark brown sugar.

[0013] As a preferred solution, the preparation method of the polyglutamic acid complex comprises the following steps: S1: mixing magnesium sulfate and polyglutamic acid and adding them to a reaction vessel, adding a reaction solvent, and adjusting the pH to 4-7; S2: heating to 40-50°C, then keeping the temperature to react for 0.5-4 hours, and always controlling the pH to 4-7 during the reaction; S3: after the reaction is completed, filtering the product to remove impurities to obtain a filtrate, then adding alkyl polyglycoside to the filtrate, and mixing evenly to obtain the polyglutamic acid complex.

[0014] As a preferred solution, the mass ratio of magnesium sulfate to polyglutamic acid is (1-2): (3-5).

[0015] As a preferred solution, the mass ratio of magnesium sulfate to polyglutamic acid is (1-1.5): (4-4.5).

[0016] As a preferred solution, the mass ratio of the filtrate to the alkyl glycoside is (80-90): (10-20).

[0017] As a preferred solution, the mass ratio of the filtrate to the alkyl glycoside is 85:15.

[0018] As a preferred solution, the mass ratio of the polyglutamic acid complex to the surfactant is (0.6-1): (0.5-0.8).

[0019] As a preferred solution, the mass ratio of the polyglutamic acid complex to the surfactant is 0.8:0.6.

[0020] As a preferred solution, the mass ratio of the modified chitosan, aminobutyric acid and inorganic metal compound is (0.8-1): (0.1-0.2): (1-1.5).

[0021] As a preferred solution, the mass ratio of the modified chitosan, aminobutyric acid and inorganic metal compound is 0.8:0.1:1.2.

[0022] As a preferred solution, the preparation method of the modified chitosan comprises the following steps: S1: dissolving chitosan in an acetic acid solution, adding a glutaraldehyde aqueous solution, a succinic anhydride aqueous solution and a silane coupling agent, and reacting at 30-45°C under microwave heating for 0.5-1h to obtain pretreated chitosan; S2: soaking the pretreated chitosan in an alkaline solvent, adding chloroacetic acid and potassium chloride, and reacting at 40-45°C under microwave heating for 1-1.5h; S3: adding thiourea after the reaction is completed, stirring and reacting at 60-80°C and 200-300 r / min for 4-8h, and filtering and washing the product to obtain.

[0023] As a preferred solution, the mass concentration of the glutaraldehyde aqueous solution is 10-25%.

[0024] As a preferred solution, the mass concentration of the succinic anhydride aqueous solution is 10-25%.

[0025] As a preferred solution, the silane coupling agent is 3-aminopropyltriethoxysilane.

[0026] As a preferred solution, the mass ratio of the pretreated chitosan, chloroacetic acid and potassium chloride is (1-2): (0.5-1): (0.1-0.5).

[0027] As a preferred solution, the mass ratio of the pretreated chitosan, chloroacetic acid and potassium chloride is (1-1.5): (0.5-0.6): (0.3-0.4).

[0028] As a preferred solution, the molar ratio of chitosan to thiourea is (1-2):1.

[0029] In the present application, by adding the above-mentioned modified chitosan to the fertilizer, the thermal stability of the soil fertilizer containing fish enzyme, the soil improvement effect and the penetration of the fertilizer can be greatly improved. This is mainly because the modified chitosan in the present application forms a complex multi-microporous structure with a suitable pore structure size, which can strongly selectively adsorb fish enzyme active molecules and nitrogen-based molecules, and can serve as a carrier of enzyme live bacteria in the pore size and provide a good nutrient storage space, thereby allowing the enzyme to be stably adsorbed and present in the modified chitosan particles. When used, it can also be slowly released after the modified chitosan penetrates deeply; on the other hand, the surface of the modified chitosan in the present application contains more thiourea, which has a good affinity for the nitrogen substance in the present application, can form a strong adsorption system, and will not easily break away from the adsorption effect in high heat and transportation environments, thereby obtaining excellent stability and soil improvement effects.

[0030] As a preferred solution, the inorganic metal compound is at least one of potassium dihydrogen phosphate, potassium sulfate, sodium borate, sodium bicarbonate, sodium nitrate, sodium chloride, magnesium sulfate, calcium sulfate, potassium nitrate, zinc sulfate, and copper chloride.

[0031] As a preferred solution, the inorganic metal compound is magnesium sulfate, zinc sulfate, potassium sulfate and copper chloride.

[0032] As a preferred solution, the mass ratio of magnesium sulfate, zinc sulfate, potassium sulfate and copper chloride is (5-6): (1-3): (3-4): (0.5-1).

[0033] As a preferred solution, the mass ratio of magnesium sulfate, zinc sulfate, potassium sulfate and copper chloride is (5-6): (1-3): (3-4): (0.5-1).

[0034] As a preferred solution, the binder is at least one of gum arabic, polyethylene glycol, polyvinyl pyrrolidone, carrageenan, and peach gum.

[0035] As a preferred solution, the binder is gum arabic and polyethylene glycol.

[0036] As a preferred solution, the mass ratio of gum arabic to polyethylene glycol is (3-4): (1-1.5).

[0037] As a preferred solution, the polyethylene glycol is polyethylene glycol 200-2000.

[0038] As a preferred solution, the surfactant is cetearyl alcohol polyoxyethylene ether or isomeric C13 fatty alcohol polyoxyethylene ether.

[0039] As a preferred solution, the surfactant is cetearyl alcohol polyoxyethylene ether.

[0040] As a preferred solution, the hydroxyl value of the cetearyl alcohol polyoxyethylene ether is 80-160 mgKOH / g.

[0041] As a preferred solution, the hydroxyl value of the cetearyl alcohol polyoxyethylene ether is 100-150 mgKOH / g.

[0042] In the present application, by adopting the above-mentioned specific hydroxyl value range of cetearyl alcohol polyoxyethylene ether and fish enzymes and other raw materials, the permeability dispersion of soil fertilizer and its own stability can be greatly improved. This is mainly because the cetearyl alcohol polyoxyethylene ether added in this application and the alkyl glycoside in the complex can form a good surface double-layer package structure in the mixed phase of the complex and fish enzyme. The presence of this structure can greatly increase the steric hindrance of the active molecules between the layers, and greatly reduce the frequency of interactive collisions between active molecules, and then in an environment such as high heat, suppress the reaction between active molecules, thereby ensuring the stable presence of active molecules in the fertilizer system, thereby greatly improving the self-stability of the fertilizer.

[0043] The second aspect of the present application provides a method for preparing the above-mentioned soil fertilizer containing fish enzymes, and the preparation method comprises the following steps: S1: mixing urea, an inorganic metal compound, a phosphate fertilizer, and a binder, mechanically crushing the mixture through a 100-200 mesh sieve, and adding the mixture to deionized water to obtain a mixture; S2: adding the remaining raw materials to the mixture in sequence, adjusting the pH value to 7-8 and the temperature to 30-40°C, keeping it still and keeping it warm for 4-6 days, then heating it to 50-55°C and stirring it for 3-6 hours. Beneficial effects

[0044] 1. The soil fertilizer containing fish enzymes provided in this application can not only significantly improve soil fertility, increase crop product quality, promote crop growth and improve soil, but also is different from existing enzyme / protein fertilizers and has excellent self-stability, thus avoiding the technical problems of existing organic fertilizers of this type, such as difficult storage, difficult transportation and easy deterioration and inactivation, and has excellent market prospects.

[0045] 2. The soil fertilizer containing fish enzyme provided in the present application can greatly improve the thermal stability, soil improvement effect and penetration of the soil fertilizer containing fish enzyme by adding modified chitosan; the modified chitosan forms a complex multi-microporous structure with an appropriate pore size, which can strongly selectively adsorb fish enzyme active molecules and nitrogen-based molecules, and can serve as a carrier of enzyme live bacteria in the pore diameter and provide good nutrient storage space, thereby allowing the enzyme to be stably adsorbed and present in the modified chitosan particles, and when used, it can also be slowly released after the modified chitosan penetrates deeply.

[0046] 3. A soil fertilizer containing fish enzyme provided in the present application, in which cetearyl alcohol polyoxyethylene ether within a specific hydroxyl value range is compounded with raw materials such as fish enzyme, can greatly improve the permeability, dispersibility and self-stability of the soil fertilizer; cetearyl alcohol polyoxyethylene ether and the alkyl glycoside in the complex can form a good surface double-layer wrapping structure in the mixed phase of the complex and fish enzyme. The existence of this structure can greatly increase the steric hindrance of the active molecules between the layers and greatly reduce the frequency of interactive collisions between the active molecules, thereby inhibiting the reaction between the active molecules under high heat and other environments, thereby ensuring the stable existence of the active molecules in the fertilizer system, thereby greatly improving the stability of the fertilizer itself.

[0047] 4. The soil fertilizer containing fish enzymes provided in this application has a simple preparation method, does not involve complex chemical reactions, is non-toxic and pollution-free, and will not corrode or pollute the preparation equipment and the environment, greatly reducing the labor and maintenance costs during mass production, and has good market prospects. DETAILED DESCRIPTION

[0048] The following text further illustrates and demonstrates the technical solutions described in the above-mentioned summary of the invention in the form of specific implementation plans. The following examples are merely practical examples used to illustrate and explain the technical solutions in the specification and should not limit the scope of the claims to be protected by this application. All technical products based on the technical solutions described in the summary of the invention in this application should be included in the scope of protection to be protected by this application.

[0049] In the following examples, unless otherwise specified, the raw materials are all commercially available products or can be prepared by methods well known to those skilled in the art.

[0050] Example 1: The first aspect provides a soil fertilizer containing fish enzyme. The raw materials include, by mass: 15 parts of fish enzyme, 45 parts of urea, 8 parts of polyglutamic acid complex, 8 parts of modified chitosan, 2 parts of humic acid, 1 part of aminobutyric acid, 12 parts of inorganic metal compound, 5 parts of phosphate fertilizer, 3 parts of binder, 6 parts of surfactant, and 75 parts of deionized water.

[0051] The preparation method of fish enzyme includes the following steps, calculated by mass: S1: adding 1 part of brown sugar and 25 parts of sterile water into a mixing container, stirring evenly, then adding 4 parts of chopped fish skin and stirring continuously to disperse evenly; S2: heating to 45°C and fermenting at a constant temperature for 12 days, during which time regular inspections are carried out every day and missing water is replenished; S3: after S2 is completed, filtering the product to obtain a filtrate, keeping the filtrate warm and shaking at 40°C for 5 hours to activate it, and then storing the shaking liquid in a cool and ventilated place at room temperature for 7 days.

[0052] The average size of the chopped fish skin was 2 × 2 cm.

[0053] The preparation method of the polyglutamic acid complex comprises the following steps, calculated in parts by mass: S1: mixing 1.5 parts of magnesium sulfate and 4 parts of polyglutamic acid and adding the mixture into a reaction container, adding 50 parts of deionized water, and adjusting the pH to 6; S2: heating to 50°C, then keeping the temperature to react for 2.5 hours, and always controlling the pH to be 6-6.5 during the reaction; S3: after the reaction is completed, filtering the product to remove impurities to obtain a filtrate, then adding alkyl polyglycoside to the filtrate, and mixing uniformly to obtain the polyglutamic acid complex.

[0054] The mass ratio of the filtrate to the alkyl glycoside is 85:15.

[0055] The preparation method of modified chitosan includes the following steps, calculated by mass: S1: dissolving 0.5 parts of chitosan in 20 parts of 2% acetic acid solution, adding 2 parts of glutaraldehyde (25wt%) aqueous solution, 1.5 parts of succinic anhydride (20wt%) aqueous solution and 0.2 parts of 3-aminopropyltriethoxysilane, and reacting under 200W microwave heating at 35°C for 1 hour to obtain pretreated chitosan; S2: soaking 1 part of pretreated chitosan in 10 parts of sodium hydroxide aqueous solution (10wt%), adding 0.5 parts of chloroacetic acid and 0.3 parts of potassium chloride, and reacting under 300W microwave heating at 45°C for 1 hour; S3: adding thiourea after the reaction is completed, stirring and reacting at 75°C and 300 r / min for 6 hours, and filtering and washing the product to obtain.

[0056] The molar ratio of chitosan and thiourea is 1:1.

[0057] The inorganic metal compound is magnesium sulfate, zinc sulfate, potassium sulfate and copper chloride, and the mass ratio thereof is 5:2:3:0.8.

[0058] The binder is gum arabic and polyethylene glycol 800; the gum arabic was purchased from Hebei Tuohai Biotechnology Co., Ltd., a food-grade gum arabic product with a molecular weight of 280,000 Da.

[0059] The surfactant was cetearyl alcohol polyoxyethylene ether O-3, with a hydroxyl value of 145 mgKOH / g, purchased from Hai'an Guoyun Chemical Co., Ltd.

[0060] The second aspect of this embodiment provides a method for preparing the above-mentioned soil fertilizer with fish enzyme, and the preparation method comprises the following steps: S1: mixing urea, an inorganic metal compound, a phosphate fertilizer, and a binder, mechanically crushing the mixture through a 100-mesh sieve, and adding the mixture to deionized water to obtain a mixture; S2: adding the remaining raw materials to the mixture in sequence, adjusting the pH value to 7.5 and the temperature to 35°C, keeping it still and warm for 5 days, then heating it to 55°C and stirring for 4 hours to obtain the mixture.

[0061] Example 2: The first aspect provides a soil fertilizer containing fish enzyme. The raw materials include, by mass: 18 parts of fish enzyme, 40 parts of urea, 10 parts of polyglutamic acid complex, 10 parts of modified chitosan, 2 parts of humic acid, 1.5 parts of aminobutyric acid, 15 parts of inorganic metal compound, 5 parts of phosphate fertilizer, 3 parts of binder, 6 parts of surfactant, and 75 parts of deionized water.

[0062] The preparation method of fish enzyme includes the following steps, calculated by mass: S1: adding 1 part of brown sugar and 25 parts of sterile water into a mixing container, stirring evenly, then adding 4 parts of chopped fish skin and stirring continuously to disperse evenly; S2: heating to 45°C and fermenting at a constant temperature for 12 days, during which time regular inspections are carried out every day and missing water is replenished; S3: after S2 is completed, filtering the product to obtain a filtrate, keeping the filtrate warm and shaking at 40°C for 5 hours to activate it, and then storing the shaking liquid in a cool and ventilated place at room temperature for 7 days.

[0063] The average size of the chopped fish skin was 2 × 2 cm.

[0064] The preparation method of the polyglutamic acid complex comprises the following steps, calculated in parts by mass: S1: mixing 1.5 parts of magnesium sulfate and 4 parts of polyglutamic acid and adding the mixture into a reaction container, adding 50 parts of deionized water, and adjusting the pH to 6; S2: heating to 50°C, then keeping the temperature to react for 2.5 hours, and always controlling the pH to be 6-6.5 during the reaction; S3: after the reaction is completed, filtering the product to remove impurities to obtain a filtrate, then adding alkyl polyglycoside to the filtrate, and mixing uniformly to obtain the polyglutamic acid complex.

[0065] The mass ratio of the filtrate to the alkyl glycoside is 85:15.

[0066] The preparation method of modified chitosan includes the following steps, calculated by mass: S1: dissolving 0.5 parts of chitosan in 20 parts of 2% acetic acid solution, adding 2 parts of glutaraldehyde (25wt%) aqueous solution, 1.5 parts of succinic anhydride (20wt%) aqueous solution and 0.2 parts of 3-aminopropyltriethoxysilane, and reacting under 200W microwave heating at 35°C for 1 hour to obtain pretreated chitosan; S2: soaking 1 part of pretreated chitosan in 10 parts of sodium hydroxide aqueous solution (10wt%), adding 0.5 parts of chloroacetic acid and 0.3 parts of potassium chloride, and reacting under 300W microwave heating at 45°C for 1 hour; S3: adding thiourea after the reaction is completed, stirring and reacting at 75°C and 300 r / min for 6 hours, and filtering and washing the product to obtain.

[0067] The molar ratio of chitosan and thiourea is 1:1.

[0068] The inorganic metal compound is magnesium sulfate, zinc sulfate, potassium sulfate and copper chloride, and the mass ratio thereof is 5:2:3:0.8.

[0069] The binder is gum arabic and polyethylene glycol 800; the gum arabic was purchased from Hebei Tuohai Biotechnology Co., Ltd., a food-grade gum arabic product with a molecular weight of 280,000 Da.

[0070] The surfactant was cetearyl alcohol polyoxyethylene ether O-3, with a hydroxyl value of 145 mgKOH / g, purchased from Hai'an Guoyun Chemical Co., Ltd.

[0071] The second aspect of this embodiment provides a method for preparing the above-mentioned soil fertilizer with fish enzyme, and the preparation method comprises the following steps: S1: mixing urea, an inorganic metal compound, a phosphate fertilizer, and a binder, mechanically crushing the mixture through a 100-mesh sieve, and adding the mixture to deionized water to obtain a mixture; S2: adding the remaining raw materials to the mixture in sequence, adjusting the pH value to 7.5 and the temperature to 35°C, keeping it still and warm for 5 days, then heating it to 55°C and stirring for 4 hours to obtain the mixture.

[0072] Example 3: The first aspect provides a soil fertilizer containing fish enzyme, in which the raw materials include, by mass: 15 parts of fish enzyme, 45 parts of urea, 8 parts of polyglutamic acid complex, 8 parts of modified chitosan, 2 parts of humic acid, 1 part of aminobutyric acid, 12 parts of inorganic metal compound, 5 parts of phosphate fertilizer, 3 parts of binder, 6 parts of surfactant, and 75 parts of deionized water.

[0073] The preparation method of fish enzyme includes the following steps, calculated by mass: S1: adding 1 part of brown sugar and 25 parts of sterile water into a mixing container, stirring evenly, then adding 4 parts of chopped fish skin and stirring continuously to disperse evenly; S2: heating to 45°C and fermenting at a constant temperature for 12 days, during which time regular inspections are carried out every day and missing water is replenished; S3: after S2 is completed, filtering the product to obtain a filtrate, keeping the filtrate warm and shaking at 40°C for 5 hours to activate it, and then storing the shaking liquid in a cool and ventilated place at room temperature for 7 days.

[0074] The average size of the chopped fish skin was 2 × 2 cm.

[0075] The preparation method of the polyglutamic acid complex comprises the following steps, calculated in parts by mass: S1: mixing 1.5 parts of magnesium sulfate and 4 parts of polyglutamic acid and adding the mixture into a reaction container, adding 50 parts of deionized water, and adjusting the pH to 6; S2: heating to 50°C, then keeping the temperature to react for 2.5 hours, and always controlling the pH to be 6-6.5 during the reaction; S3: after the reaction is completed, filtering the product to remove impurities to obtain a filtrate, then adding alkyl polyglycoside to the filtrate, and mixing uniformly to obtain the polyglutamic acid complex.

[0076] The mass ratio of the filtrate to the alkyl glycoside is 90:10.

[0077] The preparation method of modified chitosan includes the following steps, calculated by mass: S1: dissolving 0.5 parts of chitosan in 20 parts of 2% acetic acid solution, adding 2 parts of glutaraldehyde (25wt%) aqueous solution, 1.5 parts of succinic anhydride (20wt%) aqueous solution and 0.2 parts of 3-aminopropyltriethoxysilane, and reacting under 200W microwave heating at 35°C for 1 hour to obtain pretreated chitosan; S2: soaking 1 part of pretreated chitosan in 10 parts of sodium hydroxide aqueous solution (10wt%), adding 0.5 parts of chloroacetic acid and 0.3 parts of potassium chloride, and reacting under 300W microwave heating at 45°C for 1 hour; S3: adding thiourea after the reaction is completed, stirring and reacting at 75°C and 300 r / min for 6 hours, and filtering and washing the product to obtain.

[0078] The molar ratio of chitosan to thiourea is 1.5:1.

[0079] The inorganic metal compound is magnesium sulfate, zinc sulfate, potassium sulfate and copper chloride, and the mass ratio thereof is 6:1:4:1.

[0080] The binders are gum arabic and polyethylene glycol 600; the gum arabic was purchased from Hebei Tuohai Biotechnology Co., Ltd., a food-grade gum arabic product with a molecular weight of 250,000 Da.

[0081] The surfactant was cetearyl alcohol polyoxyethylene ether O-5, with a hydroxyl value of 115 mgKOH / g, purchased from Hai'an Guoyun Chemical Co., Ltd.

[0082] The second aspect of this embodiment provides a method for preparing the above-mentioned soil fertilizer with fish enzyme, and the preparation method comprises the following steps: S1: mixing urea, an inorganic metal compound, a phosphate fertilizer, and a binder, mechanically crushing the mixture through a 100-mesh sieve, and adding the mixture to deionized water to obtain a mixture; S2: adding the remaining raw materials to the mixture in sequence, adjusting the pH value to 7.5 and the temperature to 35°C, keeping it still and warm for 5 days, then heating it to 55°C and stirring for 4 hours to obtain the mixture.

[0083] Comparative Example 1

[0084] The specific implementation of this comparative example is basically the same as that of Example 1, except that ordinary chitosan is used instead of modified chitosan.

[0085] Comparative Example 2

[0086] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of modified chitosan comprises the following steps, in parts by mass: S1: dissolving 0.5 parts of chitosan in 20 parts of 2% acetic acid solution, adding 2 parts of glutaraldehyde (25wt%) aqueous solution, 1.5 parts of succinic anhydride (20wt%) aqueous solution and 0.2 parts of 3-aminopropyltriethoxysilane, and reacting under 200W microwave heating at 35°C for 1 hour to obtain pretreated chitosan; S2: soaking 1 part of pretreated chitosan in 10 parts of sodium hydroxide aqueous solution (10wt%), adding 0.5 parts of chloroacetic acid and 0.3 parts of potassium chloride, and reacting under 300W microwave heating at 45°C for 1 hour; S3: after the reaction is completed, adding thiourea, stirring and reacting at 75°C and 300 r / min for 6 hours, and filtering and washing the product to obtain.

[0087] The molar ratio of chitosan to thiourea is 5:1.

[0088] Comparative Example 3

[0089] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of modified chitosan comprises the following steps, in parts by mass: S1: dissolving 0.5 parts of chitosan in 20 parts of 2% acetic acid solution, adding 2 parts of glutaraldehyde (25wt%) aqueous solution, and reacting under 200W microwave heating at 35°C for 1 hour to obtain pretreated chitosan; S2: soaking 1 part of pretreated chitosan in 10 parts of sodium hydroxide aqueous solution (10wt%), adding 0.5 parts of chloroacetic acid, and reacting under 300W microwave heating at 45°C for 1 hour; S3: after the reaction is completed, adding thiourea, stirring and reacting at 75°C and 300r / min for 6 hours, and filtering and washing the product to obtain.

[0090] The molar ratio of chitosan and thiourea is 1:1.

[0091] Comparative Example 4

[0092] The specific implementation of this comparative example is basically the same as that of Example 1, except that the surfactant is polyvinyl pyrrolidone K60.

[0093] Comparative Example 5

[0094] The specific implementation of this comparative example is basically the same as that of Example 1, except that the surfactant is cetearyl alcohol polyoxyethylene ether O-30, which has a hydroxyl value of 36 mgKOH / g and is purchased from Hai'an Guoyun Chemical Co., Ltd.

[0095] Performance evaluation

[0096] Thermal stability: The fish enzyme fertilizers prepared in the examples and comparative examples were stored in a constant temperature box at 55±4°C and 75% humidity for 14 days. The mass decomposition rate (mass decrease percentage %) of the fertilizer as a whole after 14 days of storage was calculated, and the average value of 10 measured values ​​was recorded in Table 1.

[0097] Fertilizer efficiency: A 9-mu experimental field was opened for testing, which was divided into a 3-mu embodiment group, a 5-mu comparative group and a 1-mu control group. The enzyme fertilizer prepared from the embodiment and the comparative group was fertilized on transplanted longevity vegetables at a fertilizer rate of 3 kg / mu. The longevity vegetables were transplanted at an equal distance of 8×8 cm per mu. The diseased plant rate 30 days after fertilization was recorded and calculated, and a control group with pure urea fertilizer was set for comparison. The average value of the measured values ​​​​was taken from 5 tests and recorded in Table 1.

[0098]

[0099] From the examples and comparative examples of the present application and the data results in Table 1, it can be seen that Examples 1 to 3, which adopt the necessary technical solutions given in this application, have achieved excellent results in terms of thermal stability and fertilizer efficiency of fertilizers, which enables them to effectively replace existing enzyme fertilizers, thereby achieving excellent fertilizer efficiency while avoiding the technical problems of difficult storage, difficult transportation, and large environmental impacts existing in enzyme fertilizers in the prior art. However, since Comparative Examples 1 to 5 do not fully adopt the necessary technical solutions described by the applicant, they are significantly worse than Examples 1 to 3 in the corresponding test results, which better demonstrates the irreplaceable nature of the specific technical solutions of this application in achieving technical effects and solving technical problems.

Claims

1. A soil fertilizer containing fish enzyme, characterized by: The soil fertilizer containing fish enzyme comprises, by weight, 10-20 parts of fish enzyme, 30-50 parts of urea, 5-10 parts of polyglutamic acid complex, 5-10 parts of modified chitosan, 1-3 parts of humic acid, 1-3 parts of aminobutyric acid, 10-20 parts of inorganic metal compound, 4-6 parts of phosphate fertilizer, 1-5 parts of binder, 4-10 parts of surfactant, and 50-80 parts of deionized water; The mass ratio of the fish enzyme, urea and polyglutamic acid complex is (1.5-2): (4-5): (0.6-1); The preparation method of the fish enzyme comprises the following steps: S1: adding sugar and sterile water to a mixing container, stirring evenly, then adding chopped fish skin and stirring continuously to disperse evenly; S2: heating to 40-50° C. and fermenting at a constant temperature for 10-15 days, during which period, regular inspections are performed every day and missing water is replenished; S3: after S2 is completed, filtering the product to obtain a filtrate, keeping the filtrate at 30-40° C. and shaking it for 4-6 hours to obtain a shaken liquid, and then storing the shaken liquid in a cool, ventilated place at room temperature for 5-8 days to obtain the product; The weight ratio of the fish skin, sugar and sterile water is (3-5): (0.5-1): (20-40); The preparation method of the polyglutamic acid complex comprises the following steps: S1: mixing magnesium sulfate and polyglutamic acid into a reaction vessel, adding a reaction solvent, and adjusting the pH to 4-7; S2: heating to 40-50° C., then maintaining the temperature for reaction for 0.5-4 hours, and controlling the pH to 4-7 throughout the reaction process; S3: after the reaction is completed, filtering the product to remove impurities to obtain a filtrate, then adding an alkyl polyglycoside to the filtrate, and mixing uniformly to obtain the polyglutamic acid complex; The mass ratio of magnesium sulfate to polyglutamic acid is (1-2): (3-5); The mass ratio of the filtrate to the alkyl glycoside is (80-90): (10-20); The mass ratio of the polyglutamic acid complex and the surfactant is (0.6-1): (0.5-0.8); The preparation method of the modified chitosan comprises the following steps: S1: dissolving chitosan in an acetic acid solution, adding a glutaraldehyde aqueous solution, a succinic anhydride aqueous solution and a silane coupling agent, and reacting the mixture at 30-45° C. under microwave heating for 0.5-1 hour to obtain pretreated chitosan; S2: soaking the pretreated chitosan in an alkaline solvent, adding chloroacetic acid and potassium chloride, and reacting the mixture at 40-45° C. under microwave heating for 1-1.5 hours; S3: adding thiourea after the reaction is completed, stirring the mixture at 60-80° C. and 200-300 r / min for 4-8 hours, and filtering and washing the product to obtain the product; The mass ratio of the pretreated chitosan, chloroacetic acid and potassium chloride is (1-2): (0.5-1): (0.1-0.5); The molar ratio of chitosan to thiourea is (1-1.5):1; The surfactant is cetearyl alcohol polyoxyethylene ether; the hydroxyl value of the cetearyl alcohol polyoxyethylene ether is 115-145 mgKOH / g.

2. The soil fertilizer containing fish enzyme according to claim 1, characterized in that: The mass ratio of the modified chitosan, aminobutyric acid and inorganic metal compound is (0.8-1): (0.1-0.2): (1-1.5).

3. The soil fertilizer containing fish enzyme according to claim 2, characterized in that: The inorganic metal compound is at least one of potassium dihydrogen phosphate, potassium sulfate, sodium borate, sodium bicarbonate, sodium nitrate, sodium chloride, magnesium sulfate, calcium sulfate, potassium nitrate, zinc sulfate, and copper chloride.

4. The soil fertilizer containing fish enzyme according to claim 3, characterized in that: The inorganic metal compounds are magnesium sulfate, zinc sulfate, potassium sulfate and copper chloride.

5. The soil fertilizer containing fish enzyme according to claim 4, characterized in that: The mass ratio of the magnesium sulfate, zinc sulfate, potassium sulfate and copper chloride is (5-6): (1-3): (3-4): (0.5-1).

6. The soil fertilizer containing fish enzyme according to claim 5, characterized in that: The binder is at least one of gum arabic, polyethylene glycol, polyvinyl pyrrolidone, carrageenan and peach gum.

7. A method for preparing a soil fertilizer containing fish enzyme according to any one of claims 1 to 6, characterized in that: Preparation method The following steps are involved: S1: urea, an inorganic metal compound, a phosphate fertilizer, and a binder are mixed, mechanically crushed, passed through a 100-200 mesh sieve, and added to deionized water to obtain a mixture; S2: the remaining raw materials are added to the mixture in sequence, the pH value is adjusted to 7-8, the temperature is 30-40°C, and the mixture is kept warm for 4-6 days, and then the temperature is raised to 50-55°C and mixed and stirred for 3-6 hours to obtain the mixture.

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