Method for preparing humic acid water-soluble fertilizer from caragana microphylla slurry and melaleuca alternifolia essential oil

Abstract

The invention discloses a method for preparing a humic acid water-soluble fertilizer from caragana microphylla slurry and melaleuca alternifolia essential oil, and relates to the technical field of fertilizers. The problems that raw material resources for preparing the humic acid water-soluble fertilizer are limited, and the preparation cost is high are solved. The method specifically comprises the following steps: preparing raw materials: caragana microphylla, melaleuca alternifolia essential oil and an auxiliary reagent; preparation and biotransformation of caragana microphylla pulp; emulsifying the melaleuca alternifolia essential oil; performing fertilizer compounding and quality regulation and control; and processing and storing finished products. The method has the characteristics of efficient utilization of resources, function synergy and environmental friendliness, the caragana microphylla in the preparation raw materials is a waste branch in a desert area and can turn waste into wealth, the essential oil is a natural extract and replaces a chemical synthesis synergist in an existing preparation method, soil is improved through humic acid, soil-borne diseases are inhibited through the essential oil, root absorption is promoted through the essential oil, and the soil-borne diseases are prevented from being damaged. Meanwhile, the humic acid water-soluble fertilizer is free of harmful residues and suitable for green agriculture.

Description

Technical Field

[0001] This invention relates to the field of fertilizer technology, and in particular to a method for preparing humic acid water-soluble fertilizer using Caragana korshinskii sap and Melaleuca alternifolia essential oil. Background Technology

[0002] Humic acid-containing water-soluble fertilizers are water-soluble fertilizers containing humic acid and a large number of elements. They can improve soil fertility, promote crop growth, and enhance crop resistance to adverse conditions. Humic acid-containing water-soluble fertilizers can improve soil fertility, promote crop growth and resistance to adverse conditions, improve soil pH, reduce the effects of salinization and acidification, improve crop quality and taste, and protect the ecological environment. Rational use can increase crop yield and quality, increase farmers' income, and promote sustainable agricultural development.

[0003] However, traditional methods for preparing humic acid water-soluble fertilizers mostly rely on extracting humic acid from lignite / weathered coal. Since lignite / weathered coal are both non-renewable coal resources, there are problems such as limited raw material resources and high preparation costs for humic acid water-soluble fertilizers.

[0004] Caragana (a plant of the genus Caragana in the legume family) is a dominant shrub in arid regions. Its branches are rich in cellulose, hemicellulose, and protein, which can be biotransformed into humic acid-like active substances. Melaleuca alternifolia essential oil (the main component of which is 1,8-cineole) has antibacterial and growth-promoting functions. It has a strong inhibitory and bactericidal effect on various types of rot caused by fungi, bacteria, and viruses in crops and can be used as a natural synergist. The combination of the two can be used to develop a low-cost, multifunctional water-soluble fertilizer with a real effect on crops. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a method for preparing humic acid water-soluble fertilizer using Caragana korshinskii sap and Melaleuca alternifolia essential oil.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing humic acid water-soluble fertilizer using Caragana korshinskii sap and Melaleuca alternifolia essential oil includes the following steps: S1: Raw material preparation: Caragana korshinskii, Melaleuca alternifolia essential oil, auxiliary reagents; S2: Preparation and biotransformation of Caragana korshinskii slurry; S3: Emulsification treatment of Melaleuca alternifolia essential oil; S4: Fertilizer compounding and quality control; S5: Finished product handling and storage.

[0007] Preferably, in step S1, branches of Caragana korshinskii that have grown for more than 2 years are selected, with a thickness of 0.5-1cm. The leaves are removed, and the branches are washed and air-dried until the moisture content is ≤15%.

[0008] Furthermore: In S1, the essential oil of Melaleuca alternifolia is selected from oils with a 1,8-cineole content ≥70%, obtained by distillation extraction; In S1, the auxiliary reagents include compound enzymes, probiotics, emulsifiers, nitrogen, phosphorus and potassium sources, and trace elements.

[0009] Further preferred: the compound enzyme is composed of cellulase, hemicellulase and pectinase mixed in a ratio of 2:1:1, with a total enzyme activity ≥500U / g; The probiotics are Bacillus subtilis and lactic acid bacteria, with a live bacteria count ≥10. 8 CFU / g.

[0010] As a preferred embodiment of the present invention, the emulsifier is Tween 80; The nitrogen, phosphorus and potassium sources are urea, monoammonium phosphate and potassium sulfate; The trace element is one or both of borax and zinc sulfate.

[0011] As a further preferred embodiment of the present invention, in step S2, the preparation and biotransformation of the Caragana korshinskii sap includes the following steps: A1: Crushing and pulping: Crush the dried Caragana twigs into 20-40 mesh particles, add deionized water at a material-to-water ratio of 1:8-1:10 (w / v), and use a pulping machine to make a homogeneous pulp. The pulping machine speed is 3000-5000 rpm and the time is 10 minutes. A2: Enzymatic hydrolysis pretreatment: Adjust the pH of the slurry to 5.0-6.0 with dilute hydrochloric acid or lime water, add compound enzyme at 0.5-1% of dry weight, and hydrolyze at a constant temperature of 45-55℃ for 24 hours to destroy the cell wall structure. A3: Anaerobic fermentation: Inoculate probiotics into the enzymatic hydrolysate at an inoculation rate of 5-10% (v / v), seal, and then anaerobic ferment at 30-35℃ for 20-30 days. Stir and aerate for 10 minutes every 5 days to promote the production of humic acid. A4: Fermentation endpoint: The humic acid content was determined by ultraviolet spectrophotometry. When the humic acid content was ≥8%, the preparation and biotransformation of the Caragana korshinskii pulp were completed. A5: Filtration and impurity removal: After fermentation, filter with a 100-mesh sieve to collect the supernatant containing humic acid, amino acids, and small molecule organic carbon. The residue can be reused or composted.

[0012] As a further aspect of the present invention: in step S3, the emulsification treatment of Melaleuca alternifolia essential oil includes the following steps: B1: Premix: Mix Melaleuca alternifolia essential oil with soap bark extract preheated to 60°C and stir magnetically for 10 minutes to form a pre-emulsion; B2: High-pressure homogenization: A microfluidic nano-homogenizer was used at a pressure of 15000psi for 3 cycles to obtain a nanoemulsion with a particle size of <100nm.

[0013] Based on the aforementioned scheme: In step S4, fertilizer compounding and quality control include the following steps: C1: Basic nutrient addition: Add nitrogen, phosphorus and potassium sources to the supernatant. The ratio of nitrogen, phosphorus and potassium is: N-P2O5-K2O=10-15:5-8:5-10, w / w. After adjustment, the total nutrients are N+P2O5+K2O≥20%. C2: Add essential oil emulsion: Add emulsified essential oil at 2-5% of the volume of the supernatant. The essential oil accounts for 0.1-0.3% of the total mass of the fertilizer. Stir at a low speed of 200-300 rpm for 10 minutes to ensure uniform dispersion. C3: pH and EC adjustment: Adjust the pH to 5.5-6.5 with citric acid or potassium hydroxide, and use a conductivity meter to detect the EC value. Control the EC value between 1.5-3.0 mS / cm to avoid burning the seedlings; C4: Micronutrient addition: Add boron at 0.1-0.2% of the total fertilizer mass and zinc at 0.05-0.1% of the total fertilizer mass as needed to enhance fertilizer functionality.

[0014] Based on the aforementioned scheme, the preferred embodiment of step S5, which involves finished product processing and storage, includes the following steps: D1: Filtration sterilization: Filter with a 0.22μm microporous membrane to remove bacteria, or sterilize at 65℃ for 30 minutes using pasteurization. D2: Packaging: Sealed in dark plastic bottles or aluminum foil bags to prevent light and volatilization, labeled "Humic Acid Water-Soluble Fertilizer (Containing Natural Essential Oils)" and nutrient content; D3: Storage conditions: Store in a cool, dry place (below 25℃), shelf life ≥ 12 months.

[0015] The beneficial effects of this invention are as follows: 1. The humic acid water-soluble fertilizer provided by this invention has the characteristics of efficient resource utilization, synergistic function and environmental friendliness. The raw material is Caragana korshinskii, which is a waste branch in sandy areas, which can turn waste into treasure. The essential oil is a natural extract, which replaces the chemically synthesized synergists in the existing preparation method. The humic acid improves the soil, and the essential oil inhibits soil-borne diseases and promotes root absorption, thereby improving the fertilizer utilization rate. At the same time, this humic acid water-soluble fertilizer has no harmful residues and is suitable for green agriculture. Attached Figure Description

[0016] Figure 1 This is a schematic flowchart of the method for preparing humic acid water-soluble fertilizer from Caragana korshinskii sap and Melaleuca alternifolia essential oil proposed in this invention. Figure 2This is a schematic diagram of the preparation and biotransformation process of the *Caragana korshinskii* slurry in the method for preparing humic acid water-soluble fertilizer using *Caragana korshinskii* slurry and *Melaleuca alternifolia* essential oil proposed in this invention. Figure 3 This is a schematic diagram of the emulsification process of Melaleuca alternifolia essential oil in the method for preparing humic acid water-soluble fertilizer using Caragana korshinskii sap and Melaleuca alternifolia essential oil proposed in this invention. Figure 4 This is a schematic diagram of the fertilizer compounding and quality control process of the method for preparing humic acid water-soluble fertilizer using Caragana korshinskii sap and Melaleuca alternifolia essential oil proposed in this invention. Figure 5 This is a schematic diagram of the finished product processing and storage flow of the method for preparing humic acid water-soluble fertilizer from Caragana korshinskii sap and Melaleuca alternifolia essential oil proposed in this invention. Detailed Implementation

[0017] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0018] Example 1: A method for preparing humic acid water-soluble fertilizer using Caragana korshinskii sap and Melaleuca alternifolia essential oil, such as... Figure 1-5 As shown, it includes the following steps: S1: Raw material preparation: Caragana korshinskii, Melaleuca alternifolia essential oil, auxiliary reagents; S2: Preparation and biotransformation of Caragana korshinskii slurry; S3: Emulsification treatment of Melaleuca alternifolia essential oil; S4: Fertilizer compounding and quality control; S5: Finished product handling and storage.

[0019] In step S1, select branches of Caragana korshinskii that have grown for more than 2 years, with a thickness of 0.5-1cm. Remove the leaves, wash and air dry until the moisture content is ≤15%. In S1, the essential oil of Melaleuca alternifolia is selected from oil with a 1,8-cineole content ≥70% and is obtained by distillation extraction. In S1, the auxiliary reagents include compound enzymes, probiotics, emulsifiers, nitrogen, phosphorus and potassium sources, and trace elements; The complex enzyme is composed of cellulase, hemicellulase and pectinase in a 2:1:1 ratio, with a total enzyme activity ≥500U / g. The probiotics are Bacillus subtilis and lactic acid bacteria, with a live bacteria count ≥10. 8 CFU / g; The emulsifier is Tween 80; The nitrogen, phosphorus and potassium sources are urea, monoammonium phosphate and potassium sulfate; The trace element is one or both of borax and zinc sulfate; In step S2, the preparation and biotransformation of Caragana korshinskii slurry includes the following steps: A1: Crushing and pulping: Crush the dried Caragana twigs into 20-40 mesh particles, add deionized water at a material-to-water ratio of 1:8-1:10 (w / v), and use a pulping machine to make a homogeneous pulp. The pulping machine speed is 3000-5000 rpm and the time is 10 minutes. A2: Enzymatic hydrolysis pretreatment: Adjust the pH of the slurry to 5.0-6.0 with dilute hydrochloric acid or lime water, add compound enzyme at 0.5-1% of dry weight, and hydrolyze at a constant temperature of 45-55℃ for 24 hours to destroy the cell wall structure. A3: Anaerobic fermentation: Inoculate probiotics into the enzymatic hydrolysate at an inoculation rate of 5-10% (v / v), seal, and then anaerobic ferment at 30-35℃ for 20-30 days. Stir and aerate for 10 minutes every 5 days to promote the production of humic acid. A4: Fermentation endpoint: The humic acid content was determined by ultraviolet spectrophotometry. When the humic acid content was ≥8%, the preparation and biotransformation of the Caragana korshinskii pulp were completed. A5: Filtration and impurity removal: After fermentation, filter with a 100-mesh sieve to collect the supernatant containing humic acid, amino acids, and small molecule organic carbon. The residue can be reused or composted.

[0020] In step S3, the emulsification treatment of Melaleuca alternifolia essential oil includes the following steps: B1: Premix: Mix Melaleuca alternifolia essential oil with soap bark extract preheated to 60°C and stir magnetically for 10 minutes to form a pre-emulsion; B2: High-pressure homogenization: A microfluidic nano-homogenizer was used at a pressure of 15000psi for 3 cycles to obtain a nanoemulsion with a particle size of <100nm.

[0021] In step S4, fertilizer compounding and quality control include the following steps: C1: Basic nutrient addition: Add nitrogen, phosphorus and potassium sources to the supernatant. The ratio of nitrogen, phosphorus and potassium is: N-P2O5-K2O=10-15:5-8:5-10, w / w. After adjustment, the total nutrients are N+P2O5+K2O≥20%. C2: Add essential oil emulsion: Add emulsified essential oil at 2-5% of the volume of the supernatant. The essential oil accounts for 0.1-0.3% of the total mass of the fertilizer. Stir at a low speed of 200-300 rpm for 10 minutes to ensure uniform dispersion. C3: pH and EC adjustment: Adjust the pH to 5.5-6.5 with citric acid or potassium hydroxide, and use a conductivity meter to detect the EC value. Control the EC value between 1.5-3.0 mS / cm to avoid burning the seedlings; C4: Micronutrient addition: Add boron at 0.1-0.2% of the total fertilizer mass and zinc at 0.05-0.1% of the total fertilizer mass as needed to enhance fertilizer functionality.

[0022] In step S5, the finished product processing and storage includes the following steps: D1: Filtration sterilization: Filter with a 0.22μm microporous membrane to remove bacteria, or sterilize at 65℃ for 30 minutes using pasteurization. D2: Packaging: Sealed in dark plastic bottles or aluminum foil bags to prevent light and volatilization, labeled "Humic Acid Water-Soluble Fertilizer (Containing Natural Essential Oils)" and nutrient content; D3: Storage conditions: Store in a cool, dry place (below 25℃), shelf life ≥ 12 months; In this embodiment, the product specifications for humic acid water-soluble fertilizer are as follows: Humic acid (calculated as fulvic acid) ≥8%; Total nutrients (N+P2O5+K2O) ≥ 20%; 1,8-Cineole content ≥0.1%; pH 5.5-6.5; EC 1.5-3.0 mS / cm; Heavy metals (Pb, Cd, As) comply with GB / T23349-2020 standard.

[0023] In this embodiment, the emulsification treatment of Melaleuca alternifolia essential oil is the same as the emulsification treatment step of Melaleuca alternifolia essential oil described in the preparation process of a pure plant essential oil disinfectant with patent number CN202511263698.0.

[0024] The humic acid water-soluble fertilizer prepared through the above steps has the characteristics of efficient resource utilization, synergistic function and environmental friendliness. The raw material, Caragana korshinskii, is a waste branch from sandy areas, which can turn waste into treasure. The essential oil is a natural extract that replaces the chemically synthesized synergists in the existing preparation methods. Humic acid improves the soil, and the essential oil inhibits soil-borne diseases and promotes root absorption, thereby improving fertilizer utilization. At the same time, this humic acid water-soluble fertilizer has no harmful residues and is suitable for green agriculture.

[0025] Application Example 1: A soybean field in a plain loess area was selected as the experimental site, and the following three experimental control groups were set up: Experimental group: The humic acid water-soluble fertilizer prepared according to this invention was applied to one acre of soybean field; Control group 1: In a one-acre soybean field, commercially available humic acid water-soluble fertilizer was applied; Control group 2: No fertilizer was applied to a one-acre soybean field.

[0026] In the experimental group and control group 1, 500L of diluted humic acid water-soluble fertilizer was applied as a foliar spray at the soybean seedling stage, flowering stage and pod-setting stage. The following indicators were measured before fertilization, 10 days after the last fertilization, and at the soybean harvest: soil physicochemical properties, soybean plant growth indicators, soybean disease incidence, and soybean quality.

[0027] Then, using the measurement data of control group 2 as a benchmark, the following control data was obtained: Data obtained from Application Example 1 shows that this humic acid water-soluble fertilizer, combined with the antibacterial and growth-promoting functions of Caragana korshinskii sap and Melaleuca alternifolia essential oil, can effectively improve the soil microecology, promote crop growth and development, and increase crop yield and nutritional quality. The antibacterial activity of Melaleuca alternifolia essential oil inhibits common crop diseases and is suitable for the efficient planting of green crops.

[0028] Application Example 2: A major wheat-producing area in a plain was selected as the experimental site, and the following three experimental control groups were set up: Experimental group: The humic acid water-soluble fertilizer prepared according to this invention was applied to one acre of wheat field; Control group 1: In one acre of wheat field, commercially available humic acid water-soluble fertilizer was applied; Control group 2: No fertilizer was applied to a one-acre wheat field.

[0029] In the experimental group and control group 1, 500L of diluted humic acid water-soluble fertilizer was applied as a foliar spray at a rate of 1 acre, once each during the wheat greening stage, jointing stage, and booting stage. The following indicators were measured before fertilization, 7 days after the last fertilization, and at the wheat harvest: soil physicochemical properties, wheat plant growth indicators, wheat disease incidence, and wheat quality.

[0030] Then, using the measurement data of control group 2 as a benchmark, the following control data was obtained: Data obtained from Application Example 2 shows that this humic acid water-soluble fertilizer, combined with the antibacterial and growth-promoting functions of Caragana korshinskii sap and Melaleuca alternifolia essential oil, can effectively improve the soil microecology, promote crop growth and development, and increase crop yield and nutritional quality. The antibacterial activity of Melaleuca alternifolia essential oil inhibits common crop diseases and is suitable for the efficient planting of green crops.

[0031] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing humic acid water-soluble fertilizer using Caragana korshinskii sap and Melaleuca alternifolia essential oil, characterized in that, Includes the following steps: S1: Raw material preparation: Caragana korshinskii, Melaleuca alternifolia essential oil, auxiliary reagents; S2: Preparation and biotransformation of Caragana korshinskii slurry; S3: Emulsification treatment of Melaleuca alternifolia essential oil; S4: Fertilizer compounding and quality control; S5: Finished product handling and storage.

2. The method for preparing humic acid water-soluble fertilizer from Caragana korshinskii sap and Melaleuca alternifolia essential oil according to claim 1, characterized in that, In step S1, select branches of Caragana korshinskii that have grown for more than 2 years, with a thickness of 0.5-1cm. Remove the leaves, wash and air dry until the moisture content is ≤15%.

3. The method for preparing humic acid water-soluble fertilizer from *Caragana korshinskii* sap and *Melaleuca alternifolia* essential oil according to claim 2, characterized in that, In S1, the essential oil of Melaleuca alternifolia is selected from oil with a 1,8-cineole content ≥70% and is obtained by distillation extraction. In S1, the auxiliary reagents include compound enzymes, probiotics, emulsifiers, nitrogen, phosphorus and potassium sources, and trace elements.

4. The method for preparing humic acid water-soluble fertilizer from *Caragana korshinskii* sap and *Melaleuca alternifolia* essential oil according to claim 3, characterized in that, The complex enzyme is composed of cellulase, hemicellulase and pectinase in a 2:1:1 ratio, with a total enzyme activity ≥500U / g. The probiotics are Bacillus subtilis and lactic acid bacteria, with a live bacteria count ≥10. 8 CFU / g.

5. The method for preparing humic acid water-soluble fertilizer from *Caragana korshinskii* sap and *Melaleuca alternifolia* essential oil according to claim 3, characterized in that, The emulsifier is Tween 80; The nitrogen, phosphorus and potassium sources are urea, monoammonium phosphate and potassium sulfate; The trace element is one or both of borax and zinc sulfate.

6. The method for preparing humic acid water-soluble fertilizer from *Caragana korshinskii* sap and *Melaleuca alternifolia* essential oil according to claim 1, characterized in that, In step S2, the preparation and biotransformation of Caragana korshinskii slurry includes the following steps: A1: Crushing and pulping: Crush the dried Caragana twigs into 20-40 mesh particles, add deionized water at a material-to-water ratio of 1:8-1:10 (w / v), and use a pulping machine to make a homogeneous pulp. The pulping machine speed is 3000-5000 rpm and the time is 10 minutes. A2: Enzymatic hydrolysis pretreatment: Adjust the pH of the slurry to 5.0-6.0 with dilute hydrochloric acid or lime water, add compound enzyme at 0.5-1% of dry weight, and hydrolyze at a constant temperature of 45-55℃ for 24 hours to destroy the cell wall structure. A3: Anaerobic fermentation: Inoculate probiotics into the enzymatic hydrolysate at an inoculation rate of 5-10% (v / v), seal, and then anaerobic ferment at 30-35℃ for 20-30 days. Stir and aerate for 10 minutes every 5 days to promote the production of humic acid. A4: Fermentation endpoint: The humic acid content was determined by ultraviolet spectrophotometry. When the humic acid content was ≥8%, the preparation and biotransformation of the Caragana korshinskii pulp were completed. A5: Filtration and impurity removal: After fermentation, filter with a 100-mesh sieve to collect the supernatant containing humic acid, amino acids, and small molecule organic carbon. The residue can be reused or composted.

7. The method for preparing humic acid water-soluble fertilizer from *Caragana korshinskii* sap and *Melaleuca alternifolia* essential oil according to claim 1, characterized in that, In step S3, the emulsification treatment of Melaleuca alternifolia essential oil includes the following steps: B1: Premix: Mix Melaleuca alternifolia essential oil with soap bark extract preheated to 60°C and stir magnetically for 10 minutes to form a pre-emulsion; B2: High-pressure homogenization: A microfluidic nano-homogenizer was used at a pressure of 15000psi for 3 cycles to obtain a nanoemulsion with a particle size of <100nm.

8. The method for preparing humic acid water-soluble fertilizer from *Caragana korshinskii* sap and *Melaleuca alternifolia* essential oil according to claim 1, characterized in that, In step S4, fertilizer compounding and quality control include the following steps: C1: Basic nutrient addition: Add nitrogen, phosphorus and potassium sources to the supernatant. The ratio of nitrogen, phosphorus and potassium is: N-P2O5-K2O=10-15:5-8:5-10, w / w. After adjustment, the total nutrients are N+P2O5+K2O≥20%. C2: Add essential oil emulsion: Add emulsified essential oil at 2-5% of the volume of the supernatant. The essential oil accounts for 0.1-0.3% of the total mass of the fertilizer. Stir at a low speed of 200-300 rpm for 10 minutes to ensure uniform dispersion. C3: pH and EC adjustment: Adjust the pH to 5.5-6.5 with citric acid or potassium hydroxide, and use a conductivity meter to detect the EC value. Control the EC value between 1.5-3.0 mS / cm to avoid burning the seedlings; C4: Micronutrient addition: Add boron at 0.1-0.2% of the total fertilizer mass and zinc at 0.05-0.1% of the total fertilizer mass as needed to enhance fertilizer functionality.

9. The method for preparing humic acid water-soluble fertilizer from *Caragana korshinskii* sap and *Melaleuca alternifolia* essential oil according to claim 1, characterized in that, In step S5, the finished product processing and storage includes the following steps: D1: Filtration sterilization: Filter with a 0.22μm microporous membrane to remove bacteria, or sterilize at 65℃ for 30 minutes using pasteurization. D2: Packaging: Sealed in dark plastic bottles or aluminum foil bags to prevent light and volatilization, labeled "Humic Acid Water-Soluble Fertilizer (Contains Natural Essential Oils)" and nutrient content; D3: Storage conditions: Store in a cool, dry place (below 25℃), shelf life ≥ 12 months.

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