Microbial preparation for improving soil-borne diseases of soil and preparation method thereof

Abstract

The invention relates to the technical field of microorganisms, and particularly discloses a microbial preparation for improving soil-borne diseases of soil and a preparation method thereof.The microbial preparation is prepared from modified biochar, a compound microbial agent, plant essential oil, chitosan and konjaku flour; the preparation method comprises the following steps: soaking the modified charcoal in the compound microbial agent, adding the konjaku flour, the chitosan and the plant essential oil, uniformly stirring and mixing, and then freeze-drying to obtain the required microbial preparation for improving the soil-borne diseases of the soil. The microbial preparation prepared by the invention has the beneficial effects of promoting plant root growth and improving soil-borne diseases.

Description

Technical Field

[0001] The present application relates to the field of microbial technology, and more specifically, to a microbial preparation for improving soil-borne diseases and a preparation method thereof. Background Art

[0002] Soil-borne diseases refer to diseases caused by pathogens such as fungi, bacteria, nematodes and viruses that live in the soil with diseased remains and attack crops from the roots or stems when conditions are right.

[0003] The main causes of soil-borne diseases are: 1. Continuous cropping: Continuously planting a type of crop allows certain corresponding pathogens to multiply year after year, accumulate in large quantities in the soil, form diseased soil, and cause diseases every year; 2. Improper fertilization: Large amounts of chemical fertilizers, especially nitrogen fertilizers, can stimulate the growth of Fusarium, Verticillium and Rhizoctonia among soil-borne pathogens, thereby aggravating the occurrence of soil-borne diseases; 3. Nematode infestation: Soil nematodes cause wounds on the plant roots, which facilitate the infection of pathogens and aggravate the disease.

[0004] The following measures are taken for the prevention and control of soil-borne diseases: 1. Crop rotation has a certain degree of prevention and control of soil-borne diseases, but the effect is slow and cannot quickly reduce the number of soil-borne pathogens; 2. The use of traditional methods such as chemical pesticides and fumigation can quickly kill soil-borne pathogens in a short period of time, but at the same time it will also reduce the diversity of soil microbial communities and cannot effectively respond to the outbreak of soil-borne diseases in the long term, and excessive use of pesticides can easily cause soil environmental pollution; 3. Breeding resistant varieties is difficult, and cannot resist complex soil-borne pathogen communities at the same time.

[0005] In the prior art, microbial agents are given great attention in the prevention and control of soil-borne diseases. Generally, biological composite agents are used alone or in combination with chemical fungicides to prevent and control soil-borne diseases. However, the following problems are still faced: 1. Only specific soil-borne diseases can be solved, and multiple soil-borne diseases cannot be prevented and controlled at the same time; 2. The soil still needs to be rotated quarterly or annually to reduce the incidence of soil-borne diseases in the next quarter or year.

[0006] Therefore, based on the above statements, the present application provides a microbial preparation for improving soil-borne diseases and a preparation method thereof. Summary of the invention

[0007] In order to solve the technical problems raised in the background technology, the present application provides a microbial preparation for improving soil-borne diseases and a preparation method thereof.

[0008] In the first aspect, the present application provides a microbial preparation for improving soil-borne diseases, using the following technical solution:

[0009] A microbial preparation for improving soil-borne diseases, comprising the following raw materials in parts by weight:

[0010] 5-10 parts of modified biochar, 60-80 parts of composite microbial agents, 0.4-0.8 parts of plant essential oils, 1-2 parts of chitosan, and 3-5 parts of konjac flour.

[0011] Preferably, the preparation method of the modified biochar is as follows:

[0012] A1. Add the biochar raw material into a pulverizer and crush it, sieve it to obtain dry powder, put the dry powder, distilled water and complex enzyme into a reaction container for enzymolysis, filter, wash and dry after enzymolysis to obtain mixture 1;

[0013] A2, pyrolyzing the mixture 1 in step A1 at 200-400° C. under anaerobic conditions for 3-5 hours, cooling to room temperature, ultrasonically washing in distilled water after cooling, and drying to obtain a mixture 2;

[0014] A3. Place the mixture 2 in step A2 in a citric acid solution with a mass concentration of 20-30%, treat with acid for 1-3 hours, filter, and then place in a sophorolipid solution with a mass concentration of 10-20%, treat for 1-3 hours, filter, and dry to obtain the desired modified biochar.

[0015] Preferably, in step A1, the biochar raw material is at least one of straw, husk and sawdust; the complex enzyme is a mixture of lignin peroxidase and laccase in a mass ratio of 1:3-5; and the mass ratio of dry powder, distilled water and complex enzyme is 1:8-10:0.2-0.6.

[0016] Preferably, in step A3, the mass ratio of mixture 2, citric acid solution and sophorolipid solution is 1:10-12:10-12.

[0017] Preferably, the composite microbial agent is a mixture of Paecilomyces mosseae, Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus with a viable cell count ratio of 1:2-3:1-3:4-6.

[0018] Preferably, the effective viable bacteria count in the composite microbial agent is 3×10 12 -5×10 12 CFU / g.

[0019] Preferably, the preparation method of the plant essential oil is as follows:

[0020] B1, mixing cinnamon essential oil, Torreya grandis essential oil and thyme essential oil to obtain a plant essential oil mixture;

[0021] B2. Place the emulsifier in distilled water and stir at 60-80°C at 100-140 rpm for 0.3-0.6 h to obtain an emulsion;

[0022] B3, adding the emulsion in step B2 dropwise to the plant essential oil mixture in step B1, stirring at a rate of 300-400 rpm in a magnetic stirrer for 0.5-1 h to obtain the desired plant essential oil.

[0023] Preferably, the emulsifier is one of gum arabic, gum tragacanth and gelatin.

[0024] Preferably, in step B1, the mass ratio of cinnamon essential oil, Torreya grandis essential oil and thyme essential oil is 1:0.8-1.2:0.8-1.2; in step B2, the mass ratio of emulsifier to distilled water is 1:8-12; and in step B3, the mass ratio of emulsion to plant essential oil mixture is 0.1-0.3:1.

[0025] In a second aspect, the present application provides a method for preparing a microbial preparation for improving soil-borne diseases, using the following technical solution:

[0026] A method for preparing a microbial preparation for improving soil-borne diseases comprises the following steps:

[0027] The modified biochar is soaked in a composite microbial agent, konjac flour, chitosan and plant essential oil are added, stirred and mixed, and freeze-dried to obtain the desired microbial preparation for improving soil-borne diseases.

[0028] In summary, this application has the following beneficial effects:

[0029] 1. The present application crushes the biochar raw material, hydrolyzes it with lignin peroxidase and laccase, pyrolyzes it under high temperature and anaerobic conditions after hydrolysis, ultrasonically washes it after pyrolysis, first treats it in a citric acid solution, and then treats it in a sophorolipid solution to obtain the desired modified biochar. Lignin peroxidase and laccase hydrolysis can remove lignin in the biochar raw material to a greater extent, avoiding the reduction of biochar pores caused by coking of lignin in the biochar raw material during high temperature pyrolysis. Porous biochar provides a living environment for beneficial microorganisms, which competitively occupy the ecological niche of pathogens and inhibit the growth and reproduction of pathogens.

[0030] Citric acid treatment can remove impurities in biochar and improve its purity, change the surface charge and wettability of biochar, and make it easier for sophorolipids to penetrate into the interior of biochar. Sophorolipids have broad-spectrum antibacterial activity, can inhibit the growth and reproduction of a variety of pathogens, exert antibacterial effects, and reduce the number of pathogens; at the same time, the degradation products of sophorolipids can be used as carbon sources and energy sources for beneficial microorganisms, promoting the metabolic activities of beneficial microorganisms.

[0031] Biochar is also rich in plant-usable basic ions, such as potassium, calcium, magnesium, zinc, etc. These elements are necessary for plant growth. Adding biochar can provide rich nutrients for plant roots and promote root growth and development.

[0032] 2. The composite microbial agent of the present application is a mixture of Pipe Sphaerotheca mosseae, Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus. Pipe Sphaerotheca mosseae forms a symbiont by infecting plant roots, expanding the absorption surface area of ​​plant roots, increasing the absorption of mineral nutrients, and improving plant growth; Trichoderma harzianum can quickly establish a bacterial community, inhibit harmful bacteria in the soil, prevent the occurrence of soil-borne diseases, and colonize around plant roots, improve the microenvironment of plant roots, and stimulate plant root growth; Bacillus subtilis can secrete substances that promote root growth to stimulate crop root development, improve the root system's ability to absorb water and nutrients, and can secrete a variety of antibiotics to inhibit the growth and infection of harmful bacteria. It has broad-spectrum antibacterial activity and extremely strong stress resistance, and can effectively prevent the occurrence of a variety of soil-borne diseases such as root rot, sheath blight, wilt, Verticillium wilt, damping-off, and damping-off. Paecilomyces lilacinus is an important natural enemy of plant parasitic nematodes. It can significantly reduce the damage caused by plant nematode diseases such as root-knot nematodes in many crops. It can also secrete hormone-like substances to promote the germination of plant seeds, the development of root systems and the growth of plants.

[0033] The mixture of the four acts together on the plant roots, promoting the development and growth of the roots and improving the roots' ability to absorb nutrients and water. The mixture of the four improves the plant's disease resistance and reduces the occurrence of soil-borne diseases by producing active substances such as antibiotics and antibacterial proteins and inducing plants to produce defensive responses.

[0034] 3. The present application mixes cinnamon essential oil, Torreya grandis essential oil and thyme essential oil to obtain a plant essential oil mixture, and an emulsifier is added dropwise to the plant essential oil mixture for emulsification reaction to obtain the desired plant essential oil. Cinnamon essential oil is rich in cinnamaldehyde, which can prevent the synthesis of chitin and glucan in the cell wall of pathogens, so that pathogens cannot form a complete cell wall of protective tissue, and eventually cause decline. Torreya grandis essential oil is rich in terpenes, which destroy the mitochondrial structure of pathogens, inhibit the expression of mitochondrial electron transfer proteins and aerobic respiration, affect its energy metabolism and eventually cause the death of pathogens. Thyme essential oil is rich in thymol, which easily passes through the fungal cell wall and plasma membrane, causing the cell membrane permeability to increase, the cell wall polysaccharide structure to be incomplete, breaking the orderly metabolism of pathogen cells, and inhibiting the growth of pathogens. The combination of the three essential oils can produce a synergistic effect and enhance the antibacterial effect against pathogens. The combined action of the three can destroy multiple physiological links of pathogens, making it more difficult for pathogens to adapt and resist.

[0035] The desired plant essential oil is obtained by adding an emulsifier to the plant essential oil mixture for emulsification reaction. The emulsified plant essential oil mixture is more stable and not easy to stratify or deteriorate; the emulsified essential oil molecules are smaller and can more easily penetrate into the soil and plant roots to play a better role.

[0036] 4. The microbial preparation for improving soil-borne diseases prepared in the present application has the beneficial effects of promoting plant root growth and improving soil-borne diseases. DETAILED DESCRIPTION

[0037] The present application is further described in detail below with reference to the embodiments.

[0038] The raw materials used in the examples and comparative examples of the present application are as follows:

[0039] Lignin peroxidase was purchased from Yuanye Biotechnology Co., Ltd., catalog number S27534;

[0040] Laccase was purchased from MacLean Reagent Company, catalog number L2157;

[0041] Pipeline cysts of mosseae were purchased from the College of Landscape Architecture and Horticulture of Yangtze University and named Pipeline cysts of mosseae (strain 1);

[0042] Trichoderma harzianum was purchased from Shanghai Xuanke Biotechnology Co., Ltd., with the catalog number XK-SH-6212;

[0043] Bacillus subtilis was purchased from Zhengzhou Fangjue Biotechnology Co., Ltd., strain number: HZB199346;

[0044] Paecilomyces lilacinus was purchased from Guangzhou Kefan Biotechnology Co., Ltd., with the catalog number BNCC185842;

[0045] Cinnamon essential oil was purchased from Shanghai Jingchun Biotechnology Co., Ltd.;

[0046] Torreya grandis essential oil was purchased from Zhejiang Tianzhiyuan Biotechnology Co., Ltd.;

[0047] Thyme essential oil was purchased from Lvyuan Natural Spice Oil Refinery, Qingyuan District, Ji'an City.

[0048] Embodiments 1-3 provide a microbial preparation for improving soil-borne diseases and a preparation method thereof.

[0049] Example 1

[0050] A microbial preparation for improving soil-borne diseases, comprising the following raw materials in parts by weight:

[0051] 5 parts of modified biochar, 60 parts of composite microbial agents, 0.4 parts of plant essential oils, 1 part of chitosan, and 3 parts of konjac flour.

[0052] Preparation of modified biochar:

[0053] A1. Add straw into a grinder and crush it, pass it through a 140-mesh sieve to obtain dry powder, place the dry powder, distilled water and complex enzyme in a mass ratio of 1:8:0.2 in a reaction vessel, adjust the reaction temperature to 30°C, the reaction pH to 5, react for 1 hour, filter after the reaction, take the filter cake, wash it with distilled water 3 times, and dry it in a 50°C oven for 6 hours to obtain mixture 1; wherein the complex enzyme is a mixture of lignin peroxidase and laccase in a mass ratio of 1:3;

[0054] A2, pyrolyzing the mixture 1 in step A1 at 200° C. under anaerobic conditions for 3 hours, cooling to room temperature, and then placing in distilled water for ultrasonic treatment at a frequency of 60 kHz for 10 hours. After the ultrasonic treatment, washing with distilled water for 3 times, and then placing in a 50° C. oven for drying for 6 hours to obtain a mixture 2;

[0055] A3. Place the mixture 2 in step A2 in a 20% mass concentration citric acid solution, treat with acid for 1 hour, filter, and then place in a 10% mass concentration sophorolipid solution for treatment for 1 hour, filter, and place in a 50° C. oven to dry for 6 hours to obtain the desired modified biochar; wherein the mass ratio of the mixture 2, the citric acid solution and the sophorolipid solution is 1:10:10.

[0056] Preparation of composite microbial agent: Dissolve freeze-dried powder of Pseudomonas mosesiensis, Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus in distilled water to prepare composite microbial agent. The number of functional live bacteria in the composite microbial agent is 3×10 12 CFU / g, the ratio of live bacteria counts of Pseudomonas mosseae, Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus was 1:2:1:4.

[0057] The preparation method of plant essential oil is as follows:

[0058] B1, mixing cinnamon essential oil, Torreya grandis essential oil and thyme essential oil in a mass ratio of 1:0.8:0.8 to obtain a plant essential oil mixture;

[0059] B2. Place gum arabic in distilled water and stir at 60°C at 100 rpm for 0.3 h to obtain an emulsion, wherein the mass ratio of gum arabic to distilled water is 1:8;

[0060] B3, the emulsion in step B2 is added dropwise to the plant essential oil mixture in step B1, and stirred at a rate of 300 rpm for 0.5 h in a magnetic stirrer to obtain required plant essential oil, wherein the mass ratio of the emulsion to the plant essential oil mixture is 0.1:1.

[0061] A method for preparing a microbial preparation for improving soil-borne diseases comprises the following steps:

[0062] The modified biochar was soaked in the composite microbial agent for 10 hours, konjac flour, chitosan and plant essential oil were added, stirred at 100 rpm for 2 hours, and then freeze-dried at minus 65°C for 1 hour to obtain the desired microbial preparation for improving soil-borne diseases.

[0063] Example 2

[0064] A microbial preparation for improving soil-borne diseases, comprising the following raw materials in parts by weight:

[0065] 7.5 parts of modified biochar, 70 parts of composite microbial agents, 0.6 parts of plant essential oils, 1.5 parts of chitosan, and 4 parts of konjac flour.

[0066] Preparation of modified biochar:

[0067] A1. Add husks into a grinder and crush them, pass them through a 160-mesh sieve to obtain dry powder, place the dry powder, distilled water and complex enzyme in a mass ratio of 1:9:0.4 in a reaction vessel, adjust the reaction temperature to 30°C, the reaction pH to 5, react for 1 hour, filter after the reaction, take the filter cake, wash it with distilled water 4 times, and dry it in a 50°C oven for 6 hours to obtain mixture 1; wherein the complex enzyme is a mixture of lignin peroxidase and laccase in a mass ratio of 1:4;

[0068] A2, pyrolyzing the mixture 1 in step A1 at 300° C. in the absence of oxygen for 4 hours, cooling to room temperature, and then placing in distilled water and ultrasonically treating at a frequency of 70 kHz for 10 hours. After the ultrasonic treatment, washing with distilled water for 4 times, and then placing in a 50° C. oven and drying for 6 hours to obtain a mixture 2;

[0069] A3. Place the mixture 2 in step A2 in a 25% mass concentration citric acid solution, treat with acid for 2 hours, filter, and then place in a 15% mass concentration sophorolipid solution for treatment for 2 hours, filter, and place in a 50° C. oven to dry for 6 hours to obtain the desired modified biochar; wherein the mass ratio of the mixture 2, the citric acid solution and the sophorolipid solution is 1:11:11.

[0070] Preparation of composite microbial agent: Dissolve freeze-dried powder of Pseudomonas mosesiensis, Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus in distilled water to prepare composite microbial agent. The effective viable bacteria count in the composite microbial agent is 4×10 12 CFU / g, the ratio of live bacteria counts of Pseudomonas mosseae, Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus was 1:1.5:2:5.

[0071] The preparation method of plant essential oil is as follows:

[0072] B1, mixing cinnamon essential oil, Torreya grandis essential oil and thyme essential oil in a mass ratio of 1:1:1 to obtain a plant essential oil mixture;

[0073] B2, placing tragacanth gum in distilled water, stirring at 70°C and 120 rpm for 0.45 h to obtain an emulsion, wherein the mass ratio of tragacanth gum to distilled water is 1:10;

[0074] B3, the emulsion in step B2 is added dropwise to the plant essential oil mixture in step B1, and stirred at a rate of 350 rpm for 0.75 h in a magnetic stirrer to obtain required plant essential oil, wherein the mass ratio of the emulsion to the plant essential oil mixture is 0.2:1.

[0075] A method for preparing a microbial preparation for improving soil-borne diseases comprises the following steps:

[0076] The modified biochar was soaked in the composite microbial agent for 13 hours, konjac flour, chitosan and plant essential oil were added, stirred at 120 rpm for 3 hours, and then freeze-dried at minus 55°C for 2 hours to obtain the desired microbial preparation for improving soil-borne diseases.

[0077] Example 3

[0078] A microbial preparation for improving soil-borne diseases, comprising the following raw materials in parts by weight:

[0079] 10 parts of modified biochar, 80 parts of composite microbial agents, 0.8 parts of plant essential oils, 2 parts of chitosan, and 5 parts of konjac flour.

[0080] Preparation of modified biochar:

[0081] A1. Sawdust was added into a grinder and crushed, and passed through a 180-mesh sieve to obtain dry powder. The dry powder, distilled water and complex enzyme in a mass ratio of 1:10:0.6 were placed in a reaction vessel, the reaction temperature was adjusted to 30° C., the reaction pH was 5, the reaction was carried out for 1 hour, and the filter cake was taken after the reaction. It was washed with distilled water for 5 times and then dried in an oven at 50° C. for 6 hours to obtain a mixture 1; wherein the complex enzyme was a mixture of lignin peroxidase and laccase in a mass ratio of 1:5;

[0082] A2, pyrolyzing the mixture 1 in step A1 at 400° C. in the absence of oxygen for 5 hours, cooling to room temperature, and then placing in distilled water and ultrasonically treating at a frequency of 80 kHz for 10 hours. After the ultrasonic treatment, washing with distilled water for 5 times, and then placing in a 50° C. oven and drying for 6 hours to obtain a mixture 2;

[0083] A3. Place the mixture 2 in step A2 in a 30% mass concentration citric acid solution, treat with acid for 3 hours, filter, and then place in a 20% mass concentration sophorolipid solution for treatment for 3 hours, filter, and place in a 50° C. oven dry for 6 hours to obtain the desired modified biochar; wherein the mass ratio of the mixture 2, the citric acid solution and the sophorolipid solution is 1:12:12.

[0084] Preparation of composite microbial agent: Dissolve freeze-dried powder of Pseudomonas mosesiensis, Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus in distilled water to prepare composite microbial agent. The effective viable bacteria count in the composite microbial agent is 5×10 12 CFU / g, the ratio of live bacteria counts of Pseudomonas mosseae, Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus was 1:3:3:6.

[0085] The preparation method of plant essential oil is as follows:

[0086] B1, mixing cinnamon essential oil, Torreya grandis essential oil and thyme essential oil in a mass ratio of 1:1.2:1.2 to obtain a plant essential oil mixture;

[0087] B2. Place gelatin in distilled water and stir at 80°C at 140 rpm for 0.6 h to obtain an emulsion in which the mass ratio of gelatin to distilled water is 1:12;

[0088] B3, the emulsion in step B2 is added dropwise to the plant essential oil mixture in step B1, and stirred at a rate of 400 rpm for 1 h in a magnetic stirrer to obtain required plant essential oil, wherein the mass ratio of the emulsion to the plant essential oil mixture is 0.3:1.

[0089] A method for preparing a microbial preparation for improving soil-borne diseases comprises the following steps:

[0090] The modified biochar was soaked in the composite microbial agent for 16 hours, konjac flour, chitosan and plant essential oil were added, stirred at 140 rpm for 4 hours, and then freeze-dried at minus 45°C for 3 hours to obtain the desired microbial preparation for improving soil-borne diseases.

[0091] In order to verify the comprehensive performance of the microbial preparations for improving soil-borne diseases prepared in Examples 1-3 of the present application, the present application sets up comparative examples 1-11, which are as follows:

[0092] Comparative Example 1

[0093] Comparative Example 1 is the same as Example 1, except that, in the preparation of modified biochar, the composite enzyme is replaced by laccase, as follows:

[0094] Preparation of modified biochar:

[0095] A1. Add straw into a grinder and crush it, pass it through a 140-mesh sieve to obtain dry powder, place the dry powder, distilled water and laccase in a mass ratio of 1:8:0.2 in a reaction container, adjust the reaction temperature to 30°C, the reaction pH to 5, react for 1 hour, filter after the reaction, take the filter cake, wash it with distilled water 3 times, and dry it in a 50°C oven for 6 hours to obtain a mixture 1;

[0096] A2, pyrolyzing the mixture 1 in step A1 at 200° C. under anaerobic conditions for 3 hours, cooling to room temperature, and then placing in distilled water for ultrasonic treatment at a frequency of 60 kHz for 10 hours. After the ultrasonic treatment, washing with distilled water for 3 times, and then placing in a 50° C. oven for drying for 6 hours to obtain a mixture 2;

[0097] A3. Place the mixture 2 in step A2 in a 20% mass concentration citric acid solution, treat with acid for 1 hour, filter, and then place in a 10% mass concentration sophorolipid solution for treatment for 1 hour, filter, and place in a 50° C. oven to dry for 6 hours to obtain the desired modified biochar; wherein the mass ratio of the mixture 2, the citric acid solution and the sophorolipid solution is 1:10:10.

[0098] Comparative Example 2

[0099] Comparative Example 2 is the same as Example 1, except that no sophorolipid solution is added to the preparation of the modified biochar, as follows:

[0100] Preparation of modified biochar:

[0101] A1. Add straw into a grinder and crush it, pass it through a 140-mesh sieve to obtain dry powder, place the dry powder, distilled water and complex enzyme in a mass ratio of 1:8:0.2 in a reaction vessel, adjust the reaction temperature to 30°C, the reaction pH to 5, react for 1 hour, filter after the reaction, take the filter cake, wash it with distilled water 3 times, and dry it in a 50°C oven for 6 hours to obtain mixture 1; wherein the complex enzyme is a mixture of lignin peroxidase and laccase in a mass ratio of 1:3;

[0102] A2, pyrolyzing the mixture 1 in step A1 at 200° C. under anaerobic conditions for 3 hours, cooling to room temperature, and then placing in distilled water for ultrasonic treatment at a frequency of 60 kHz for 10 hours. After the ultrasonic treatment, washing with distilled water for 3 times, and then placing in a 50° C. oven for drying for 6 hours to obtain a mixture 2;

[0103] A3. Place the mixture 2 in step A2 in a citric acid solution with a mass concentration of 20%, treat with acid for 1 hour, filter, and dry in a 50° C. oven for 6 hours to obtain the desired modified biochar; wherein the mass ratio of the mixture 2 to the citric acid solution is 1:10.

[0104] Comparative Example 3

[0105] Comparative Example 3 is the same as Example 1, except that, in the preparation of the modified biochar, the citric acid solution and the sophorolipid solution are first mixed, and then the biochar is placed in the mixed solution for reaction, as follows:

[0106] Preparation of modified biochar:

[0107] A1. Add straw into a grinder and crush it, pass it through a 140-mesh sieve to obtain dry powder, place the dry powder, distilled water and complex enzyme in a mass ratio of 1:8:0.2 in a reaction vessel, adjust the reaction temperature to 30°C, the reaction pH to 5, react for 1 hour, filter after the reaction, take the filter cake, wash it with distilled water 3 times, and dry it in a 50°C oven for 6 hours to obtain mixture 1; wherein the complex enzyme is a mixture of lignin peroxidase and laccase in a mass ratio of 1:3;

[0108] A2, pyrolyzing the mixture 1 in step A1 at 200° C. under anaerobic conditions for 3 hours, cooling to room temperature, and then placing in distilled water for ultrasonic treatment at a frequency of 60 kHz for 10 hours. After the ultrasonic treatment, washing with distilled water for 3 times, and then placing in a 50° C. oven for drying for 6 hours to obtain a mixture 2;

[0109] A3. Mix a citric acid solution with a mass concentration of 20% and a sophorolipid solution with a mass concentration of 10% to obtain a mixed solution; place the mixture 2 in step A2 in the mixed solution for 2 hours, filter, and dry in an oven at 50°C for 6 hours to obtain the desired modified biochar; wherein the mass ratio of the citric acid solution to the sophorolipid solution is 1:1; the mass ratio of the mixture 2 to the mixed solution is 1:20.

[0110] Comparative Example 4

[0111] Comparative Example 4 is the same as Example 1, except that the composite microbial agent is prepared only from Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus, as follows:

[0112] Preparation of composite microbial agent: The freeze-dried powder of Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus was dissolved in distilled water to prepare the composite microbial agent. The number of functional live bacteria in the composite microbial agent was 3×10 12 CFU / g, the ratio of live bacteria counts of Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus was 2:1:4.

[0113] Comparative Example 5

[0114] Comparative Example 5 is the same as Example 1, except that the composite microbial agent is prepared from only Pseudomonas mosesiensis, Bacillus subtilis and Paecilomyces lilacinus, as follows:

[0115] Preparation of composite microbial agent: Dissolve freeze-dried powder of Pseudomonas mosesiensis, Bacillus subtilis and Paecilomyces lilacinus in distilled water to prepare composite microbial agent. The number of functional live bacteria in the composite microbial agent is 3×10 12 CFU / g, the ratio of live bacteria counts of Pseudomonas mosseae, Bacillus subtilis and Paecilomyces lilacinus was 1:1:4.

[0116] Comparative Example 6

[0117] Comparative Example 6 is the same as Example 1, except that, in the preparation of the composite microbial agent, only Pseudomonas mosesiensis, Trichoderma harzianum and Paecilomyces lilacinus are used, as follows:

[0118] Preparation of composite microbial agent: Dissolve freeze-dried powder of Pseudomonas mosesiensis, Trichoderma harzianum and Paecilomyces lilacinus in distilled water to prepare composite microbial agent. The number of functional live bacteria in the composite microbial agent is 3×10 12 CFU / g, the ratio of live bacteria counts of Acanthopanax mosseae, Trichoderma harzianum and Paecilomyces lilacinus was 1:2:4.

[0119] Comparative Example 7

[0120] Comparative Example 7 is the same as Example 1, except that the composite microbial agent is prepared only from Pseudomonas mosesiensis, Trichoderma harzianum and Bacillus subtilis, as follows:

[0121] Preparation of composite microbial agent: Dissolve freeze-dried powder of Piperacium mosesii, Trichoderma harzianum and Bacillus subtilis in distilled water to prepare composite microbial agent. The number of functional live bacteria in the composite microbial agent is 3×10 12 CFU / g, the ratio of live bacteria count of Pseudomonas mosseae, Trichoderma harzianum and Bacillus subtilis was 1:2:1.

[0122] Comparative Example 8

[0123] Comparative Example 8 is the same as Example 1, except that, in the preparation of plant essential oil, only Torreya grandis essential oil and thyme essential oil are used, as follows:

[0124] The preparation method of plant essential oil is as follows:

[0125] B1, mixing Torreya grandis essential oil and thyme essential oil in a mass ratio of 0.8:0.8 to obtain a plant essential oil mixture;

[0126] B2. Place gum arabic in distilled water and stir at 60°C at 100 rpm for 0.3 h to obtain an emulsion, wherein the mass ratio of gum arabic to distilled water is 1:8;

[0127] B3, the emulsion in step B2 is added dropwise to the plant essential oil mixture in step B1, and stirred at a rate of 300 rpm for 0.5 h in a magnetic stirrer to obtain required plant essential oil, wherein the mass ratio of the emulsion to the plant essential oil mixture is 0.1:1.

[0128] Comparative Example 9

[0129] Comparative Example 9 is the same as Example 1, except that, in the preparation of plant essential oil, only cinnamon essential oil and thyme essential oil are used, as follows:

[0130] The preparation method of plant essential oil is as follows:

[0131] B1, cinnamon essential oil and thyme essential oil in a mass ratio of 1:0.8 were mixed to obtain a plant essential oil mixture;

[0132] B2. Place gum arabic in distilled water and stir at 60°C at 100 rpm for 0.3 h to obtain an emulsion, wherein the mass ratio of gum arabic to distilled water is 1:8;

[0133] B3, the emulsion in step B2 is added dropwise to the plant essential oil mixture in step B1, and stirred at a rate of 300 rpm for 0.5 h in a magnetic stirrer to obtain required plant essential oil, wherein the mass ratio of the emulsion to the plant essential oil mixture is 0.1:1.

[0134] Comparative Example 10

[0135] Comparative Example 10 is the same as Example 1, except that, in the preparation of plant essential oil, only cinnamon essential oil and Torreya grandis essential oil are used, as follows:

[0136] The preparation method of plant essential oil is as follows:

[0137] B1, mixing cinnamon essential oil and Torreya grandis essential oil in a mass ratio of 1:0.8 to obtain a plant essential oil mixture;

[0138] B2. Place gum arabic in distilled water and stir at 60°C at 100 rpm for 0.3 h to obtain an emulsion, wherein the mass ratio of gum arabic to distilled water is 1:8;

[0139] B3, the emulsion in step B2 is added dropwise to the plant essential oil mixture in step B1, and stirred at a rate of 300 rpm for 0.5 h in a magnetic stirrer to obtain required plant essential oil, wherein the mass ratio of the emulsion to the plant essential oil mixture is 0.1:1.

[0140] Comparative Example 11

[0141] Comparative Example 11 is the same as Example 1, except that, in the preparation of the plant essential oil, no emulsifier is used to emulsify the plant essential oil mixture, as follows:

[0142] The preparation method of plant essential oil is as follows:

[0143] The plant essential oil is obtained by mixing cinnamon essential oil, torreya grandis essential oil and thyme essential oil in a mass ratio of 1:0.8:0.8.

[0144] Performance Testing

[0145] The comprehensive performance of the microbial preparations for improving soil-borne diseases prepared in Examples 1-3 of the present application and Comparative Examples 1-11 were tested respectively.

[0146] 1. Determination of root growth indicators

[0147] The test material was tomato; tomato seedlings of the same growth state were transplanted into seedling pots filled with field soil, one seedling pot contained 2.5 kg of field soil, one tomato seedling was transplanted in one seedling pot, a total of 420 pots were transplanted, divided into 14 groups (Examples 1-3 and Comparative Examples 1-11), each group of 30 pots, the microbial preparations prepared in Examples 1-3 and Comparative Examples 1-11 were diluted with 10 times the volume of sterile water to obtain a dilute solution of the microbial preparation, and each group of seedling pots was applied with 30 mL of the dilute solution of the microbial preparations of Examples 1-3 and Comparative Examples 1-11 daily.

[0148] After 20 days of application of the above-mentioned diluted solution of microbial preparation, 6 plants were randomly selected from each group, the soil on the roots was washed off, and the root fresh weight and above-ground fresh weight were measured. Another 3 plants were selected from each group, the roots were washed in an ice water bath, and 0.5 g of fresh root tip samples were taken. The root activity of different treatment groups was measured by TTC staining. The results are shown in Table 1.

[0149] Table 1

[0150] Root fresh weight (g) Fresh weight above ground (g) <![CDATA[Root activity (mg·g -1 ·h -1 )]]> Example 1 260.8 340.9 13.1 Example 2 271.8 354.2 14.5 Example 3 267.3 347.1 13.9 Comparative Example 1 232.1 311.2 10.9 Comparative Example 2 223.4 309.4 11.4 Comparative Example 3 229.7 310.6 11.8 Comparative Example 4 168.4 254.1 4.3 Comparative Example 5 172.3 267.3 5.8 Comparative Example 6 182.1 254.3 4.9 Comparative Example 7 179.2 265.9 5.3 Comparative Example 8 243.1 321.1 12.1 Comparative Example 9 239.9 319.9 11.9 Comparative Example 10 235.1 321.9 11.5 Comparative Example 11 241.1 333.7 12.4

[0151] It can be seen from the data shown in Table 1 that the comprehensive performance of the microbial preparations prepared in Examples 1-3 is far superior to that of Comparative Examples 1-11. When the microbial preparations prepared in Examples 1-3 are applied during the growth of plants, the root system is highly active, the roots are fresh and large, and the plant growth state is good.

[0152] 2. Determination of soil-borne disease incidence

[0153] The test material is tomato; tomato seedlings of the same growth state are transplanted into seedling pots filled with continuous cropping soil, one seedling pot contains 2.5 kg continuous cropping soil, one tomato seedling is transplanted in one seedling pot, a total of 420 pots are transplanted, divided into 14 groups (Examples 1-3 and Comparative Examples 1-11), each group has 30 pots, the microbial preparations prepared in Examples 1-3 and Comparative Examples 1-11 are diluted with 10 times the volume of sterile water to obtain a dilute solution of the microbial preparation, and each group of seedling pots is applied with 30 mL of the dilute solution of the microbial preparations of Examples 1-3 and Comparative Examples 1-11 daily. The growth cycle is 90 days, and the incidence of tomatoes is regularly observed and recorded, and the results are shown in Table 2.

[0154] Table 2

[0155] Number of cases (strains) Incidence (%) Example 1 2 6.6 Example 2 0 0 Example 3 1 3.3 Comparative Example 1 6 20 Comparative Example 2 6 20 Comparative Example 3 6 20 Comparative Example 4 8 26.6 Comparative Example 5 12 40 Comparative Example 6 14 46.6 Comparative Example 7 13 43.3 Comparative Example 8 13 43.3 Comparative Example 9 15 50 Comparative Example 10 14 46.6 Comparative Example 11 4 13.3

[0156] From the data shown in Table 2, it can be seen that the comprehensive performance of the microbial preparations prepared in Examples 1-3 is far superior to that of Comparative Examples 1-11. When the plants grown in the continuous cropping soil are applied with the microbial preparations prepared in Examples 1-3, fewer plants are diseased and the incidence rate is low.

[0157] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A microbial preparation for improving soil-borne diseases, characterized in that: The invention comprises the following raw materials in parts by weight: 5-10 parts of modified biochar, 60-80 parts of composite microbial agent, 0.4-0.8 parts of plant essential oil, 1-2 parts of chitosan and 3-5 parts of konjac flour.

2. The microbial preparation for improving soil-borne diseases according to claim 1, characterized in that: The preparation method of the modified biochar is as follows: A1. Add the biochar raw material into a pulverizer and crush it, sieve it to obtain dry powder, put the dry powder, distilled water and complex enzyme into a reaction container for enzymolysis, filter, wash and dry after enzymolysis to obtain mixture 1; A2, pyrolyzing the mixture 1 in step A1 at 200-400° C. under anaerobic conditions for 3-5 hours, cooling to room temperature, ultrasonically washing in distilled water after cooling, and drying to obtain a mixture 2; A3. Place the mixture 2 in step A2 in a citric acid solution with a mass concentration of 20-30%, treat with acid for 1-3 hours, filter, and then place in a sophorolipid solution with a mass concentration of 10-20%, treat for 1-3 hours, filter, and dry to obtain the desired modified biochar.

3. The microbial preparation for improving soil-borne diseases according to claim 2, characterized in that: In step A1, the biochar raw material is at least one of straw, husk and sawdust; the complex enzyme is a mixture of lignin peroxidase and laccase in a mass ratio of 1:3-5; the mass ratio of dry powder, distilled water and complex enzyme is 1:8-10:0.2-0.

6.

4. The microbial preparation for improving soil-borne diseases according to claim 2, characterized in that: The mass ratio of the mixture 2, the citric acid solution and the sophorolipid solution in step A3 is 1:10-12:10-12.

5. The microbial preparation for improving soil-borne diseases according to claim 1, characterized in that: The composite microbial agent is a mixture of Pseudomonas mosseae, Trichoderma harzianum, Bacillus subtilis and Paecilomyces lilacinus with a live bacteria count ratio of 1:2-3:1-3:4-6.

6. The microbial preparation for improving soil-borne diseases according to claim 5, characterized in that: The effective viable bacteria count in the composite microbial agent is 3×10 12 -5×10 12 CFU / g.

7. The microbial preparation for improving soil-borne diseases according to claim 1, characterized in that: The preparation method of the plant essential oil is as follows: B1, mixing cinnamon essential oil, Torreya grandis essential oil and thyme essential oil to obtain a plant essential oil mixture; B2. Place the emulsifier in distilled water and stir at 60-80°C at 100-140 rpm for 0.3-0.6 h to obtain an emulsion; B3, adding the emulsion in step B2 dropwise to the plant essential oil mixture in step B1, stirring at a rate of 300-400 rpm in a magnetic stirrer for 0.5-1 h to obtain the desired plant essential oil.

8. The microbial preparation for improving soil-borne diseases according to claim 7, characterized in that: The emulsifier is one of gum arabic, gum tragacanth and gelatin.

9. The microbial preparation for improving soil-borne diseases according to claim 7, characterized in that: In the step B1, the mass ratio of cinnamon essential oil, Torreya grandis essential oil and thyme essential oil is 1:0.8-1.2:0.8-1.2; in the step B2, the mass ratio of emulsifier to distilled water is 1:8-12; in the step B3, the mass ratio of emulsion to plant essential oil mixture is 0.1-0.3:

1.

10. A method for preparing the microbial preparation for improving soil-borne diseases according to any one of claims 1 to 9, characterized in that: The following steps are involved: The modified biochar is soaked in a composite microbial agent, konjac flour, chitosan and plant essential oil are added, stirred and mixed, and freeze-dried to obtain the desired microbial preparation for improving soil-borne diseases.