CN110800760A

CN110800760A - Earthworm hydrolysate and preparation method and application thereof

Info

Publication number: CN110800760A
Application number: CN201811602485.6A
Authority: CN
Inventors: 李俊良; 张小梅; 崔文静; 张华杰; 梅傲雪
Original assignee: Qingdao Agricultural University
Current assignee: Qingdao Agricultural University
Priority date: 2018-12-26
Filing date: 2018-12-26
Publication date: 2020-02-18
Anticipated expiration: 2038-12-26
Also published as: CN110800760B

Abstract

The invention provides an earthworm hydrolysate and a preparation method and application thereof, belonging to the technical field of biological fertilizers. The earthworm hydrolysate comprises the following raw materials: earthworms and urea; the mass ratio of the earthworms to the urea is 3-7: 1. In the present invention, urea is used as a denaturing agent to denature and inactivate non-covalently bound proteins (e.g., outer membrane proteins) in the plasma membrane of cells and to increase the solubility of these proteins. After the urea is mixed with the earthworms, the plasma membrane structure of the earthworm cell is damaged, substances in the cell rapidly seep out, the earthworm body protein is effectively hydrolyzed by proteolytic enzyme, and hydrolysate with near neutral pH value and high bacteriostatic activity can be prepared without living earthworms and providing proper living conditions for the living earthworms. Meanwhile, the urea adopted by the invention is a common chemical fertilizer in agricultural production, is mixed with earthworms, forms an organic-inorganic compound fertilizer after hydrolysis, can be directly used for preparing water-soluble fertilizers, and provides richer nutrition for plants.

Description

Earthworm hydrolysate and preparation method and application thereof

Technical Field

The invention belongs to the technical field of biological fertilizers, and particularly relates to earthworm hydrolysate and a preparation method and application thereof.

Background

Chemical fertilizers and pesticides are important agricultural production materials. In recent years, with the increase of crop seeding area and the over-pursuit of agricultural product yield, the use amount of fertilizers and pesticides is on the whole in an increasing trend. The excessive use of chemical fertilizers and pesticides not only increases the production cost, but also affects the quality safety and ecological environment safety of agricultural products. Therefore, the method greatly promotes the reduction and the efficiency improvement of chemical fertilizers and the reduction and the harm control of pesticides, and goes the way of modern agriculture development with environmental friendliness. The method has the advantages that the method is popularized in fertilization modes such as water and fertilizer integration and foliage spraying, organic fertilizers are used for replacing partial fertilizers, organic and inorganic combination is realized, and the like, and the method is an effective way for reducing and increasing the amount of the fertilizers. And the development and popularization of new environment-friendly, efficient, low-toxicity and low-residue pesticides can improve the control efficiency, effect and benefit, and is an important measure for realizing zero increase of pesticide usage and promoting ecological civilization construction.

The earthworm is commonly called earthworm, also called song eel, is a representative animal of oligochaeta of Annelida, is called the most valuable animal in the world by Darwen, and has the characteristics of strong adaptability, wide distribution, wide eating quality, large eating quantity, difficult illness, high reproduction rate and the like. The earthworm is rich in protein, amino acid, vitamins, mineral elements, antioxidant enzyme, thrombolytic enzyme, hemolysin and antitumor components. Wherein the protein content is about 70% of the dry weight of the earthworms. Meanwhile, the earthworm digestive tract contains more than 10 active proteolytic enzymes, so that the earthworm body protein can be effectively hydrolyzed, the hydrolysate is rich in 18 essential amino acids, antibacterial peptides, vitamins, potassium, zinc, iron, manganese and other nutrient elements, and can be used for preparing amino acid-containing pesticides, amino acid water-soluble fertilizers and the like, so that rich nutrition can be provided for plant growth, the crop yield can be improved, the capability of resisting plant diseases and insect pests of crops can be obviously improved, the use of chemical fertilizers and pesticides can be reduced, and the pollution to the environment can be reduced.

Currently, the preparation of earthworm hydrolysate mostly adopts an endogenous enzymolysis method, namely, earthworm protease is used for autolysis hydrolysis of the body protein. For example, Chinese patent documents CN 103771925A discloses a preparation method of a rice foliar fertilizer, CN 107417401A discloses a Chinese herbal medicine foliar fertilizer for preventing and treating vegetable powdery mildew, CN 108424205A discloses a Chinese earthworm foliar fertilizer and a manufacturing method thereof, CN 107311707A discloses a preparation method of a selenium-rich earthworm organic foliar fertilizer, and CN 107353122A discloses a Chinese herbal medicine foliar fertilizer for inducing melon vegetable powdery mildew resistance and a manufacturing method thereof. These methods all obtain earthworm slurry by shaking or beating fresh live earthworms. However, earthworms are temperature-variable animals, and the temperature is an important factor influencing the metabolism, growth and development of the earthworms. Generally, the metabolism is most vigorous when the ambient temperature is 20 to 27 ℃ and the humidity is 60 to 80%. When the outdoor conditions are not suitable, the temperature and humidity are required to be artificially controlled for cultivation under indoor environmental conditions such as a simple greenhouse, which undoubtedly increases the earthworm cultivation cost and increases the cost of organic fertilizers or pesticides using earthworms as raw materials.

Disclosure of Invention

In view of the above, the invention provides an earthworm hydrolysate and a preparation method and application thereof, so that the preparation cost of the earthworm hydrolysate is greatly reduced, the earthworm hydrolysis rate is accelerated, and the bacteriostatic activity of the hydrolysate is improved.

In order to solve the above problems, the present invention provides the following technical solutions:

the invention provides earthworm hydrolysate which comprises the following raw materials: earthworms and urea;

the mass ratio of the earthworms to the urea is 3-7: 1.

Preferably, the preservative is sorbic acid, potassium sorbate, sodium benzoate or potassium benzoate.

Preferably, the mass ratio of the preservative to the earthworms is 0.004-0.015: 4-6.

Preferably, the earthworms are frozen earthworms.

The invention provides a preparation method of earthworm hydrolysate, which comprises the following steps:

1) mixing the raw materials according to the scheme, and hydrolyzing for 24-28 h at 40-50 ℃ and 60-150 rpm to obtain a hydrolysate;

2) filtering the hydrolysate obtained in the step 1), and adjusting the pH value of the obtained filtrate to 6-8 to obtain the earthworm hydrolysate.

Preferably, the pH value adjusting solution in step 2) is an acid solution.

Preferably, the acid solution is a phosphoric acid solution or a nitric acid solution.

Preferably, the molar concentration of the acid solution is 0.15-0.25 mol/L.

The invention provides application of the earthworm hydrolysate prepared by the scheme or the earthworm hydrolysate prepared by the method in preparation of fertilizers and/or pesticides.

The invention provides earthworm hydrolysate which comprises the following raw materials: earthworms and urea; the mass ratio of the earthworms to the urea is 3-7: 1. In the present invention, urea is used as a denaturing agent to denature and inactivate non-covalently bound proteins (e.g., outer membrane proteins) in the plasma membrane of cells and to increase the solubility of these proteins. After the urea is mixed with the earthworms, the plasma membrane structure of the earthworm cell is damaged, substances in the cell rapidly seep out, and proteolytic enzyme is used for effectively hydrolyzing the earthworm body protein to obtain hydrolysate with a pH value close to neutral, wherein the hydrolysate mainly contains 18 amino acids, antibacterial peptide, potassium, zinc, ferrum, manganese and other nutrient elements, vitamin A, vitamin B1, vitamin B2, vitamin E, vitamin C and other nutrient substances.

Meanwhile, the urea adopted by the invention is a common chemical fertilizer in agricultural production, is mixed with earthworms, forms an organic-inorganic compound fertilizer after hydrolysis, can be directly used for preparing water-soluble fertilizers, and provides richer nutrition for plants.

Furthermore, preservatives (sorbic acid, potassium sorbate, sodium benzoate or potassium benzoate) are added into the raw materials, so that active substances in the raw materials can be kept alive to a greater extent, and the prepared hydrolysate has higher bacteriostatic activity.

The invention also provides a preparation method of the earthworm hydrolysate, which is characterized in that earthworms are fully mixed with urea by treatment at 60-150 rpm, so that the contact area is increased, the earthworm hydrolysis rate is accelerated, and hydrolysis is carried out within the optimum action temperature range of the earthworm proteolytic enzyme at 40-50 ℃, so that the higher activity of the hydrolytic enzyme is ensured, and the earthworm body protein is rapidly degraded.

Meanwhile, when the urea provided by the invention is used for preparing the earthworm hydrolysate, the preparation of the hydrolysate can be completed without live earthworms and providing proper living conditions for the live earthworms. Solves the problems that fresh earthworms are easily limited by factors such as seasonal climate, regions and the like, are not easy to store, have high raw material cost and the like. The method has high hydrolysis efficiency, and the hydrolysate has high antibacterial activity.

Detailed Description

The invention provides earthworm hydrolysate which comprises the following raw materials: earthworms and urea; the mass ratio of the earthworms to the urea is 3-7: 1.

The raw materials of the earthworm hydrolysate provided by the invention comprise earthworms. The physiological condition of the earthworms is not particularly limited, and fresh or frozen earthworms can be used. Frozen earthworms are preferred in the present invention. The variety and source of the earthworms are not particularly limited, the earthworms are obtained by adopting conventional commercial products, and Eisenia fetida Daping No. two earthworms are adopted in the embodiment of the invention.

The raw materials of the earthworm hydrolysate provided by the invention comprise urea. In the invention, the mass ratio of the earthworms to the urea is 3-7: 1, preferably 5: 1.

In the prior art, fresh live earthworms are used for preparing the bio-organic fertilizer by using the earthworms. The living conditions of the earthworms are harsh, and proper temperature (5-30 ℃), humidity (60-80%) and quiet environment are required. In winter when the north is cold and when the south is extremely hot, artificial culture under natural conditions cannot be realized, and transportation is difficult, so that the cost for preparing the bio-organic fertilizer by using the earthworms is increased. In the present invention, urea acts as a denaturing agent to denature non-covalently bound proteins (e.g., outer membrane proteins) in the plasma membrane of cells and to increase the solubility of these proteins. After the urea is mixed with the earthworms, the plasma membrane structure of the earthworm cell is damaged, substances in the cell rapidly seep out, and the protein hydrolase effectively hydrolyzes the earthworm body protein to obtain hydrolysate with a pH value close to neutral and higher bacteriostatic activity. Further, when live earthworms are adopted, urea is mixed with the earthworms, the urea can denature and inactivate peripheral proteins on earthworm cell membranes, and the earthworms generate stress reaction under external stimulation to secrete proteolytic enzyme; meanwhile, the structure of the cytoplasmic membrane is broken down, and the earthworms are hydrolyzed; intracellular proteins, etc. leak to the outside of the cell and are degraded by hydrolytic enzymes. When the frozen earthworms are adopted, the earthworms can secrete a large amount of proteolytic enzymes after receiving freezing stimulation, and the plasma membrane structure of cells can be damaged; after the urea is mixed with the frozen earthworms, the frozen and damaged cytoplasmic membrane structure is further damaged, and substances (such as protein and the like) in cells are quickly leaked out, so that the hydrolysis speed of the earthworms is further accelerated; the optimum action temperature range of the proteolytic enzyme is 40-50 ℃, which ensures the rapid hydrolysis of the earthworm body protein and shortens the hydrolysis time. And hydrolysis can be completed without live earthworms and suitable living conditions for live earthworms, and hydrolysate with a nearly neutral pH value is obtained. Moreover, the frozen earthworms are easy to store, are not limited by seasonal climate and regions, and greatly reduce the cost of raw materials (14 yuan/kg, 30 yuan/kg of live earthworms).

In the present invention, the raw material of the earthworm hydrolysate preferably further comprises a preservative. The preservative is preferably sorbic acid, potassium sorbate, sodium benzoate or potassium benzoate, more preferably sorbic acid. In the invention, the mass ratio of the preservative to the earthworms is preferably 0.004-0.015: 4-6, and more preferably 0.01: 5. The source of the preservative is not particularly limited in the present invention, and any conventional commercially available product in the art may be used. In the invention, the preservative can keep active substances in the hydrolysate to a greater extent, so that the prepared hydrolysate has higher bacteriostatic activity.

The raw materials are mixed, and hydrolyzed for 24-48 hours at 40-50 ℃ and 60-150 rpm to obtain a hydrolysate. In the present invention, when frozen earthworms are used, the earthworms are preferably cut into small pieces before hydrolysis. The size of the small block is preferably 3-5 cm multiplied by 3-5 cm. Before cutting, the earthworms are preferably cleaned. The cleaning mode is not particularly limited, the conventional cleaning mode in the field is adopted, and the embodiment of the invention adopts running water cleaning. In the invention, the hydrolysis temperature is 40-50 ℃, preferably 45 ℃; the stirring speed of the hydrolysis is 60-150 rpm, preferably 100 rpm; the hydrolysis time is 24-28 h, preferably 26 h. In the invention, the frozen earthworms are cut into small blocks, and the small blocks are fully mixed with urea under the stirring or rotating condition, so that the contact area is increased, and the hydrolysis speed of the earthworms is accelerated. In the invention, the temperature is 40-50 ℃ which is the optimum action temperature range of the earthworm proteolytic enzyme, the proteolytic enzyme has higher activity, and the rapid hydrolysis of the earthworm body protein by the proteolytic enzyme can be ensured under the condition. In the present invention, the hydrolysis is preferably carried out in a reaction tank.

After obtaining the hydrolysate, filtering the hydrolysate, and adjusting the pH value of the obtained filtrate to 6-8 to obtain the earthworm hydrolysate. In the present invention, the filtration is preferably performed by gauze filtration. In the present invention, the pH adjusting solution is preferably an acid solution. The acid solution is preferably phosphoric acid solution or nitric acid solution; the molar concentration of the acid solution is preferably 0.15-0.25 mol/L, and more preferably 0.2 mol/L.

The invention provides application of the earthworm hydrolysate prepared by the scheme or the earthworm hydrolysate prepared by the method in preparation of fertilizers and/or pesticides. In the present invention, the pesticide is preferably a pesticide for inhibiting phytopathogenic fungi.

In order to further illustrate the present invention, the following embodiments are described in detail, but they should not be construed as limiting the scope of the present invention.

Example 1

Weighing 1000g of frozen Eisenia foetida Danhei on the surface of which the frozen Eisenia foetida is cleaned by running water; cutting into small blocks of 5cm × 5cm × 5cm, placing in a reaction kettle, simultaneously adding 200g of urea and 1g of potassium sorbate, and mixing uniformly; placing on a vertical mixer, adjusting the running speed to 60rpm, and reacting at 45 ℃ for 26 h; and after the hydrolysis is finished, filtering the obtained product by using medical gauze, and adjusting the pH of the filtrate to 6-8 by using 0.15mol/L phosphoric acid to obtain earthworm hydrolysate.

Example 2

Weighing 1000g of frozen Eisenia foetida Danhei on the surface of which the frozen Eisenia foetida is cleaned by running water; cutting into small blocks of 3cm × 5cm × 5cm, placing in a reaction kettle, adding 333g of urea and 3.75g of potassium benzoate, and mixing; placing on a vertical mixer, adjusting the running speed to 150rpm, and reacting at 40 ℃ for 28 h; and after the hydrolysis is finished, filtering the obtained product by using medical gauze, and adjusting the pH of the filtrate to 6-8 by using 0.25mol/L nitric acid to obtain earthworm hydrolysate.

Example 3

Weighing 1000g of frozen Eisenia foetida Danhei on the surface of which the frozen Eisenia foetida is cleaned by running water; cutting into small pieces of 3cm × 3cm × 3cm, placing in a reaction kettle, adding 143g of urea and 0.7g of benzoic acid, and mixing; placing on a vertical mixer, adjusting the running speed to 100rpm, and reacting at 45 ℃ for 24 h; and after the hydrolysis is finished, filtering the obtained product by using medical gauze, and adjusting the pH of the filtrate to 6-8 by using 0.2mol/L nitric acid to obtain earthworm hydrolysate.

Comparative example 1

According to the preparation method of the rice foliar fertilizer disclosed in Chinese patent document CN 103771925A, fresh living Eisenia fetida Daping No. two are vibrated, earthworm is leached out, earthworm liquid is stirred and filtered, and earthworm hydrolysate is obtained.

Wherein the oscillation frequency of the earthworms is 280rpm, the amplitude is 20mm, and the oscillation time is 3 min; then adding water with the volume 10 times that of the earthworms to soak for 60 hours at 25 ℃; placing the mixed solution in a stirrer at 2900rpm, and stirring for 10 min; then filtering with medical gauze, standing the filtrate for 2h, and taking the supernatant.

Comparative example 2

Selecting 1000g of frozen Eisenia fetida Dalin II which is cleaned by running water; cutting the mixture into small blocks of 5cm multiplied by 5cm, putting the small blocks into a reaction kettle, simultaneously adding 200mL of distilled water and 1g of potassium sorbate, and uniformly mixing; placing on a vertical mixer, adjusting the running speed to 60rpm, and reacting at 45 ℃ for 26 h; and after the hydrolysis is finished, filtering the obtained product by using medical gauze, and adjusting the pH of the filtrate to 6-8 by using 0.2mol/L phosphoric acid to obtain earthworm hydrolysate.

Example 4

The invention has the efficiency of hydrolyzing earthworms.

Test samples: earthworm samples of inventive examples 1,2,3 and comparative examples 1, 2.

The test method comprises the following steps: the mass (m0) of the earthworms used in the experiments of examples 1,2 and 3 of the present invention and comparative examples 1 and 2, respectively, and the mass (m) of the solid remaining on the gauze after filtration were recorded. The earthworm hydrolysis rate is calculated according to the following formula:

the earthworm hydrolysis ratio (%) (1-m/m0) × 100. Each treatment was repeated three times.

The test results are shown in table 1 below.

TABLE 1 earthworm hydrolysis Rate

Test sample	Earthworm hydrolysis ratio (%)
		Comparative example 1	96.7±2.1
Comparative example 2	45.3±1.0
		Example 1	96.2±1.6
Example 2	95.6±0.3
		Example 3	92.1±0.7

As can be seen from Table 1, the earthworm hydrolysis efficiencies of examples 1,2 and 3 and comparative example 1 are all higher and reach more than 92%, while comparative example 2 has an earthworm hydrolysis efficiency of less than 50% and a poor hydrolysis effect. Compared with the example 1, the urea added in the example 2 has more amount, partial urea crystals are arranged around the reaction kettle mouth after the reaction is finished, the urea is wasted, and the hydrolysis rate is not as high as that in the example 1; in example 3, the hydrolysis rate was not higher than in examples 1 and 2 and comparative example 1 because the amount of urea added was small. Compared with the comparative example 1, the method provided by the invention has the characteristics of short earthworm hydrolysis time and high efficiency, and compared with the comparative example 2, the method provided by the invention has high earthworm hydrolysis efficiency.

Example 5

Inhibition of common plant pathogenic bacteria by earthworm hydrolysate

Subject: botrytis cinerea (Botrytis cinerea), Sterculia fusca (Ceratococcus branchoides), Fusarium oxysporum (Fusarium oxysporum), and Verticillium dahliae (Verticillium dahliae) are all purchased from China general microbiological culture Collection center (CGMCC), and the serial numbers are CGMCC No.4584, CGMCC No.18340, CGMCC No.12196 and CGMCC No.15299 respectively.

Test samples: experimental samples-earthworm hydrolysate prepared in examples 1,2 and 3 of the present invention and comparative examples 1 and 2; reference control group: ketoconazole (prepared with 100% dimethyl sulfoxide to a final concentration of 1600 μ g/mL) test method: adding 0.25, 0.5 and 1mL of test sample into sterilized PDA culture medium cooled to about 50 deg.C, shaking, and making into plate containing Lumbricus hydrolysis solution or medicine, and repeating for 3 times. Wherein, 0.25, 0.5 and 1mL of sterilized urea aqueous solution with the mass concentration of 16.7 percent are respectively added into the blank culture medium; 0.25, 0.5 and 1mL of sterilized distilled water was added to the blank medium of the comparative example and the reference group, respectively. Punching holes on a microorganism plate with good growth at equal distance by using a puncher with the diameter of 5mm, inoculating fungus cake hyphae downwards to the centers of a medicine-containing plate and a control plate by using a pair of sterilization tweezers, culturing at a constant temperature of 28 ℃, observing the growth condition of the hyphae every day, measuring the diameter of a bacterial colony after a blank control grows over the plate, and calculating the bacteriostasis rate according to the following formula. Specific detection results are shown in table 2.

The inhibitory rate (%) × 100 [ (blank colony diameter-treated colony diameter)/(blank colony diameter-5) ].

TABLE 2 inhibition of common phytopathogens by earthworm hydrolysates

As can be seen from table 2: when 1mL of the earthworm hydrolysate prepared in the embodiment 1 of the invention is added into 100mL of the culture medium, the bacteriostasis rate of the earthworm hydrolysate on botrytis cinerea, sweet potato coracoid shell bacteria and dahlia verticillium all reaches more than 95%, and the bacteriostasis rate on fusarium oxysporum is 70.1 +/-2.2%; the bacteriostatic rate of examples 2 and 3 against pathogenic bacteria was slightly lower than that of example 1. The bacteriostasis rates of the examples 1,2 and 3 on pathogenic bacteria are all higher than the bacteriostasis rates of the ketoconazole and the comparative examples 1 and 2 on the pathogenic bacteria. The experimental results show that: the earthworm hydrolysate prepared by the invention has stronger in-vitro inhibition effect on common plant pathogenic bacteria, is safe and free from environmental pollution, and has wide application prospect.

Example 6

The prevention and treatment effect of the earthworm hydrolysate on the gray mold of tomato plants.

The test varieties are as follows: scarlet-zidary

Test samples: experimental samples-earthworm hydrolysate prepared in examples 1,2 and 3 of the present invention and comparative examples 1 and 2; control group: and (4) clear water.

The test method comprises the following steps: preparing spore suspension from 4-7 days old cultured Botrytis cinerea to make spore concentration in per ml liquid about 10⁵More than one. Diluting the earthworm hydrolysate prepared in the examples 1,2 and 3 and the comparative examples 1 and 2 respectively by 10 times and 100 times with distilled water, uniformly spraying the diluted solution and clear water on tomato plants with a growth cycle of one month by adopting a spraying method, sucking 25 mu L of botrytis cinerea spore suspension by using a sterilized suction head after 12h, and dripping the botrytis cinerea spore suspension on the tomato plantsThe leaves with the size and the growth vigor of the eggplant plants are similar and are evenly brushed by a sterilizing brush. And (4) carrying out moisture-preserving culture for 48h at 25 ℃. Each group had 10 plants, which were replicated three times. Afterwards, the morbidity and disease index of the plants treated differently were counted every 24 h. Specific detection results are shown in table 3.

The grading standard of the leaf disease is judged according to the pesticide detection standard of Ministry of agriculture.

The formula for calculating the incidence of disease is as follows: i (%) × 100 (number of diseased leaves/total number of inoculated leaves);

calculation formula of average severity: s (%) ═ Σ (si × xi)/∑ xi × 100, where s is the average severity; si is each level of severity; xi is the number of survey values at each level.

The disease index calculation formula is as follows: DI is I × s/100, where DI is the disease index, I is the incidence, and s is the mean severity.

The prevention and treatment effect calculation formula is as follows: the preventing and treating effect (%) is (contrast disease index-treatment disease index)/contrast disease index x 100.

TABLE 3 control of Botrytis cinerea of tomato plants

As can be seen from Table 3, sporadic disease spots can be observed on leaves of the clear water control group 48h after the tomato botrytis cinerea is inoculated, more serious disease spots appear on all inoculated leaves 120h later, the plants almost die, the disease incidence is 100%, and the disease index is 74.6 +/-1.2. After the plant is sprayed with the hydrolysate which is diluted by 100 times in comparative examples 1 and 2 and examples 1,2 and 3 and the hydrolysate which is diluted by 10 times in comparative example 2, the occurrence of the tomato gray mold is obviously delayed, sporadic disease spots appear at about 72 hours, and the number of the disease spots and the disease progression and the prevention and treatment effect are different at 120 hours, and the disease incidence is respectively 66.7 +/-1.2, 100 +/-0.5, 33.3 +/-1.3, 38.7 +/-1.5, 46.7 +/-2.4 and 60 +/-0.8 percent; the corresponding disease indexes are 25 +/-1.1, 61.9 +/-1.1, 18.3 +/-0.9, 20.5 +/-0.5, 24.2 +/-0.8 and 38 +/-0.7 respectively; the control effect is 66.5, 17.0, 75.5, 72.5, 67.6 and 49.1 percent respectively. After the hydrolysate diluted by 10 times in comparative example 1 and examples 1,2 and 3 is sprayed, the disease attack time of the plants is further delayed until the plants are cultured for 96 hours, disease spots can be seen on a plurality of leaves at random, and the control effect is 82.2, 91.0, 85.3 and 83.0 percent respectively. The control effects of examples 1,2 and 3 are better than those of comparative example 1, and the control effects of examples 1,2 and 3 are the best as that of example 1.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The earthworm hydrolysate is characterized by comprising the following raw materials: earthworms and urea;

the mass ratio of the earthworms to the urea is 3-7: 1.

2. The earthworm hydrolysate of claim 1, further comprising a preservative, wherein the preservative is sorbic acid, potassium sorbate, sodium benzoate, or potassium benzoate.

3. The earthworm hydrolysate of claim 2, wherein the mass ratio of the preservative to the earthworms is 0.004-0.015: 4-6.

4. The earthworm hydrolysate according to any one of claims 1 to 3, wherein the earthworms are frozen earthworms.

5. The method for preparing the earthworm hydrolysate according to any one of claims 1 to 4, comprising the steps of:

1) mixing the raw materials according to any one of claims 1 to 4, and hydrolyzing at 40 to 50 ℃ and 60 to 150rpm for 24 to 28 hours to obtain a hydrolysate;

6. The method according to claim 5, wherein the pH-adjusted solution in step 2) is an acid solution.

7. The method according to claim 6, wherein the acid solution is a phosphoric acid solution or a nitric acid solution.

8. The method according to claim 6 or 7, wherein the molar concentration of the acid solution is 0.15 to 0.25 mol/L.

9. Use of the earthworm hydrolysate according to any one of claims 1 to 4 or the earthworm hydrolysate prepared by the method according to any one of claims 5 to 8 in the preparation of fertilizers and/or pesticides.