Microbial decomposing inoculant for straw and preparation method thereof

Abstract

The invention discloses a microbial decomposing inoculant for straws and a preparation method thereof, and belongs to the technical field of microorganisms. The microbial decomposing inoculant for straw is prepared from the following raw materials in parts by weight: 15-18 parts of functional microbial liquid, 3-5 parts of neutral protease, 1-3 parts of laccase, 20-25 parts of a nano-porous diatomite carrier, 5-7 parts of a humectant, 2-3 parts of humic acid chelated trace elements and 2-4 parts of an inducer. The preparation method comprises the following steps: screening talaromyces thermophilus, Guangxi thermoactinomycetes and arthrobacter habitualis to form a functional microbial liquid, adding a laccase-protease compounding system to cooperate with the physical adsorption effect of diatomite, and adding humic acid chelated trace elements to form an ion exchange network with polyglutamic acid; straw components are efficiently degraded through a triple mechanism of'enzymatic degradation-element supplementation-microenvironment regulation and control ', the decomposition process is accelerated, and the straw compost quality is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and in particular relates to a microbial decomposing agent for straw and a preparation method thereof. Background Art

[0002] Straw is a byproduct of agricultural products that is left idle after harvest. my country is a major grain producer, and there are many types of straw in large quantities. At present, most straw comes from corn, rice and wheat, and returning straw to the field is a problem we are concerned about. Crop straw contains nutrients such as nitrogen, phosphorus, potassium and trace elements, and is a sustainable biological resource. Returning straw to the field can increase the content of soil organic matter and is one of the important measures to promote the benign cycle of agricultural ecosystems. However, under natural conditions, the degradation rate of straw is relatively slow. However, adding straw composting agents during the straw composting process can significantly increase the soluble organic carbon, microbial biomass carbon, particulate organic carbon, and soil high, medium and low active organic carbon content in the modes of no-till straw mulching, deep loosening straw burying and rotary tillage straw burying. Straw composting agents are beneficial to the decomposition of difficult-to-decompose substances in straw and can accelerate the release of organic carbon, nitrogen and phosphorus in straw.

[0003] However, the chemical and physical structure of straw is complex, and it is extremely difficult to be degraded into monomers by microorganisms and enzymes; degrading straw requires a variety of enzymes with different specificities. Therefore, it is particularly important to prepare decomposing microbial agents that can effectively accelerate straw decomposition and promote the quality of straw composting. Summary of the invention

[0004] The purpose of the present invention is to provide a microbial composting agent for straw, which can efficiently degrade straw components, accelerate the composting process, and improve the quality of straw compost through the triple mechanism of "enzymatic degradation-element supplementation-microenvironment regulation".

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is: A straw decomposing microbial agent comprises the following raw materials in parts by weight: 15-18 parts of functional microbial liquid, 3-5 parts of neutral protease, 1-3 parts of laccase, 20-25 parts of nanoporous diatomaceous earth carrier, 5-7 parts of moisturizing agent, 2-3 parts of humic acid chelated trace elements and 2-4 parts of inducer.

[0006] Furthermore, the functional microbial culture liquid is thermophilic talaromyces, Guangxi thermophilic actinomyces, and soil-dwelling Arthrobacter; the thermophilic talaromyces (Talaromyces thermophilus) was purchased from the China General Microbiological Culture Collection Administration Center, address: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, preservation date: February 19, 2016, and preservation number is CGMCC No.3.15538; the Guangxi thermophilic actinomyces (Thermoactinomyces guangxiensis) was purchased from the China General Microbiological Culture Collection Administration Center, address: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, preservation date: January 22, 2014, and preservation number is CGMCC No. 4.7156; the soil-dwelling Arthrobacter (Arthrobacter humicola) was purchased from China General Microbiological Culture Collection Center, address: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, deposit date: March 5, 2016, deposit number: CGMCC No. 1.15654.

[0007] Furthermore, the preparation method of the functional microbial bacterial solution is: the thermophilic thallus, the Guangxi thermophilic actinomycetes, and the soil bacterium are activated and expanded separately to obtain a viable bacterial count of 1×10 9 CFU / ml of bacterial solution, and then mix the three bacterial solutions in a volume ratio of 1:1:1 to obtain a functional microbial bacterial solution.

[0008] Furthermore, the preparation method of the nanoporous diatomaceous earth carrier is: (1) Diatomite pretreatment: diatomite was soaked in 10% HCl solution, stirred at 60°C for 2 h, rinsed with deionized water until neutral, dried, sieved with 200 mesh, and calcined at 600°C for 2 h; (2) Construction of nanoscale microporous structure: Grind the diatomaceous earth in step (1) with a ball mill until the particle size is less than 100 nm, mix the diatomaceous earth, PEG, and deionized water in a ratio of 1 kg: 0.2 kg: 3 L to form a slurry, dry it, and calcine it in a high-temperature furnace at 400 °C for 2 h; (3) Surface functionalization modification: The diatomaceous earth prepared in step (2) was immersed in a 3% NaOH solution and subjected to ultrasonic treatment for 30 minutes. Then, a 3% KH-550 solution was mixed with the diatomaceous earth and reacted at 60° C. for 4 hours. The diatomaceous earth was then washed three times with anhydrous ethanol and vacuum dried to constant weight to obtain a nanoporous diatomaceous earth carrier.

[0009] Furthermore, in step (3), the 3% KH-550 solution is prepared by dissolving KH-550 in ethanol; the 3% KH-550 solution and diatomaceous earth are mixed in a mass ratio of 2:1.

[0010] Furthermore, the preparation method of the humic acid chelated trace elements is: (1) Humic acid alkaline solution: Mix humic acid powder and deionized water in a mass ratio of 1:20, slowly add 1 mol / L NaOH solution, adjust the pH to 8, and stir until the humic acid is completely dissolved; (2) Preparation of metal salt solution: prepare 0.3 mol / L ferric nitrate solution, zinc chloride solution and sodium molybdate solution, and mix the three solutions to obtain a metal salt solution; (3) Chelating reaction: Add the metal salt solution to the humic acid solution, adjust the pH to 7, react at 70°C for 2 h, filter to remove unreacted particles, and spray dry the solution to obtain humic acid chelated metal elements.

[0011] Furthermore, the volume ratio of the metal salt solution to the humic acid solution is 3:1.

[0012] Furthermore, the moisturizing agent is polyglutamic acid; and the inducing agent is trehalose and proline in a mass ratio of 1:1.

[0013] A method for preparing a straw-use microbial decomposing agent is prepared by the following steps: (1) Preparation of nanoporous diatomaceous earth carrier, functional microbial culture liquid, and humic acid chelated trace elements; (2) mixing the nanoporous diatomaceous earth carrier, neutral protease, laccase, moisturizer, humic acid chelated trace elements, and inducer uniformly, placing the mixture in a granulator for granulation, and obtaining solid carrier particles with a particle size of 3-5 mm; (3) Preparation of functional microbial culture liquid; (4) The solid carrier particles prepared in step (2) are added to the functional microbial solution prepared in step (3) for sufficient adsorption, followed by air drying to obtain the final product microbial agent.

[0014] When the bacterial agent of the present invention is used for straw fermentation, the added amount is 1-3‰ of the mass of the straw raw material.

[0015] All raw materials of the present invention are commercially available.

[0016] The present invention selects three strains of thermophilic tularensis, Guangxi thermophilic actinomycetes, and soil-dwelling bacillus to prepare functional bacterial liquid to accelerate the decomposition of straw. Among them, thermophilic tularensis can secrete cellulase and xylanase, accelerate the decomposition of cellulose, hemicellulose and lignin in straw, convert them into small molecular organic matter that can be used by plants, and at the same time help the straw pile to heat up and maintain a high temperature environment, accelerating the decomposition process of straw; Guangxi thermophilic actinomycetes can secrete cellulase, hemicellulose and lignin peroxidase, break the hard structure of straw, accelerate decomposition, and still maintain activity during the high temperature period of composting, can quickly increase the temperature of the pile, can continuously decompose difficult-to-degrade organic matter, shorten the straw decomposition cycle, and at the same time can effectively kill pathogenic microorganisms and weed seeds during the high temperature stage of composting, and improve the safety of composting. Arthrobacter solani can convert straw decomposition products into humic acid precursors, accelerate the synthesis of humus, regulate the microecological environment, produce microorganisms, amino acids and other growth-promoting substances, stimulate the growth of other bacteria, form a synergistic effect, and have the ability to degrade organophosphorus pesticides, reducing the negative impact of pollutants in straw on the soil. The three bacteria have a synergistic effect when mixed in equal proportions, which can achieve efficient decomposition and rapid composting of straw, while promoting the formation of humus and nutrient release. After the composted straw is returned to the soil, the organic matter content is increased and the soil ecology is improved.

[0017] The present invention introduces a laccase-protease compound system, and cooperates with the physical adsorption effect of diatomaceous earth to significantly improve the lignin degradation efficiency. The humic acid added in the present invention chelates trace elements and forms an ion exchange network with polyglutamic acid, extending the effective period of the microbial agent to 120 days.

[0018] Beneficial Effects The present invention realizes a "mesophilic bacteria-thermophilic bacteria" gradient activation system, and realizes continuous degradation in the 40-60°C normal temperature period and the high temperature period through the nanocarrier sustained release technology. The microbial composting agent of the present invention can efficiently degrade straw components, accelerate the composting process, and improve the quality of composting through the triple mechanism of "enzymatic degradation-element supplementation-microenvironment regulation". The microbial composting agent of the present invention is suitable for the fermentation of corn, wheat and other straws, with a small amount of addition and high composting efficiency. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below in conjunction with specific embodiments, but is not limited thereto.

[0020] Example 1 A straw decomposing microbial agent comprises the following raw materials in parts by weight: 15 parts of functional microbial liquid, 3 parts of neutral protease, 1 part of laccase, 20 parts of nanoporous diatomaceous earth carrier, 5 parts of moisturizer, 2 parts of humic acid chelated trace elements and 2 parts of inducer.

[0021] The functional microbial culture liquid includes thermophilic Talaromyces, Guangxi thermoactinomyces, and Arthrobacter humicola; the strain number of the thermophilic Talaromyces (Talaromyces thermophilus) is CGMCC No.3.15538; the strain number of the Guangxi thermoactinomyces (Thermoactinomyces guangxiensis) is CGMCC No. 4.7156; the strain number of the Arthrobacter humicola (Arthrobacter humicola) is CGMCC No. 1.15654.

[0022] The preparation method of the functional microbial bacterial liquid is as follows: the thermophilic thallus, the Guangxi thermophilic actinomycetes, and the soil bacterium are activated and expanded separately to obtain a viable bacterial count of 1×10 9 CFU / ml of bacterial solution, and then mix the three bacterial solutions in a volume ratio of 1:1:1 to obtain a functional microbial bacterial solution.

[0023] The preparation method of the nanoporous diatomaceous earth carrier is: (1) Diatomite pretreatment: diatomite was soaked in 10% HCl solution, stirred at 60°C for 2 h, rinsed with deionized water until neutral, dried, sieved with 200 mesh, and calcined at 600°C for 2 h; (2) Construction of nanoscale microporous structure: Grind the diatomaceous earth in step (1) with a ball mill until the particle size is less than 100 nm, mix the diatomaceous earth, PEG, and deionized water in a ratio of 1 kg: 0.2 kg: 3 L to form a slurry, dry it, and calcine it in a high-temperature furnace at 400 °C for 2 h; (3) Surface functionalization modification: The diatomaceous earth prepared in step (2) was immersed in a 3% NaOH solution and subjected to ultrasonic treatment for 30 minutes. Then, a 3% KH-550 solution was mixed with the diatomaceous earth and reacted at 60° C. for 4 hours. The diatomaceous earth was then washed three times with anhydrous ethanol and vacuum dried to constant weight to obtain a nanoporous diatomaceous earth carrier.

[0024] The 3% KH-550 solution in step (3) is prepared by dissolving KH-550 in ethanol; the 3% KH-550 solution and diatomaceous earth are mixed in a mass ratio of 2:1.

[0025] The preparation method of the humic acid chelated trace elements is: (1) Humic acid alkaline solution: Mix humic acid powder and deionized water in a mass ratio of 1:20, slowly add 1 mol / L NaOH solution, adjust the pH to 8, and stir until the humic acid is completely dissolved; (2) Preparation of metal salt solution: prepare 0.3 mol / L ferric nitrate solution, zinc chloride solution and sodium molybdate solution, and mix the three solutions to obtain a metal salt solution; (3) Chelating reaction: Add the metal salt solution to the humic acid solution, adjust the pH to 7, react at 70°C for 2 h, filter to remove unreacted particles, and spray dry the solution to obtain humic acid chelated metal elements.

[0026] The volume ratio of the metal salt solution to the humic acid solution is 3:1.

[0027] The moisturizing agent is polyglutamic acid; the inducing agent is trehalose and proline in a mass ratio of 1:1.

[0028] A method for preparing a straw-use microbial decomposing agent is prepared by the following steps: (1) Preparation of nanoporous diatomaceous earth carrier, functional microbial culture liquid, and humic acid chelated trace elements; (2) mixing the nanoporous diatomaceous earth carrier, neutral protease, laccase, moisturizer, humic acid chelated trace elements, and inducer uniformly, placing the mixture in a granulator for granulation, and obtaining solid carrier particles with a particle size of 3-5 mm; (3) Preparation of functional microbial culture liquid; (4) The solid carrier particles prepared in step (2) are added to the functional microbial solution prepared in step (3) for sufficient adsorption, followed by air drying to obtain the final product microbial agent.

[0029] Example 2 A straw decomposing microbial agent comprises the following raw materials in parts by weight: 16 parts of functional microbial bacterial liquid, 4 parts of neutral protease, 2 parts of laccase, 23 parts of nanoporous diatomaceous earth carrier, 6 parts of moisturizing agent, 3 parts of humic acid chelated trace elements and 3 parts of inducer.

[0030] The functional microbial culture liquid includes thermophilic Talaromyces, Guangxi thermoactinomyces, and Arthrobacter humicola; the strain number of the thermophilic Talaromyces (Talaromyces thermophilus) is CGMCC No.3.15538; the strain number of the Guangxi thermoactinomyces (Thermoactinomyces guangxiensis) is CGMCC No. 4.7156; the strain number of the Arthrobacter humicola (Arthrobacter humicola) is CGMCC No. 1.15654.

[0031] The preparation method of the functional microbial bacterial liquid is as follows: the thermophilic thallus, the Guangxi thermophilic actinomycetes, and the soil bacterium are activated and expanded separately to obtain a viable bacterial count of 1×10 9 CFU / ml of bacterial solution, and then mix the three bacterial solutions in a volume ratio of 1:1:1 to obtain a functional microbial bacterial solution.

[0032] The preparation method of the nanoporous diatomaceous earth carrier is: (1) Diatomite pretreatment: diatomite was soaked in 10% HCl solution, stirred at 60°C for 2 h, rinsed with deionized water until neutral, dried, sieved with 200 mesh, and calcined at 600°C for 2 h; (2) Construction of nanoscale microporous structure: Grind the diatomaceous earth in step (1) with a ball mill until the particle size is less than 100 nm, mix the diatomaceous earth, PEG, and deionized water in a ratio of 1 kg: 0.2 kg: 3 L to form a slurry, dry it, and calcine it in a high-temperature furnace at 400 °C for 2 h; (3) Surface functionalization modification: The diatomaceous earth prepared in step (2) was immersed in a 3% NaOH solution and subjected to ultrasonic treatment for 30 minutes. Then, a 3% KH-550 solution was mixed with the diatomaceous earth and reacted at 60° C. for 4 hours. The diatomaceous earth was then washed three times with anhydrous ethanol and vacuum dried to constant weight to obtain a nanoporous diatomaceous earth carrier.

[0033] The 3% KH-550 solution in step (3) is prepared by dissolving KH-550 in ethanol; the 3% KH-550 solution and diatomaceous earth are mixed in a mass ratio of 2:1.

[0034] The preparation method of the humic acid chelated trace elements is: (1) Humic acid alkaline solution: Mix humic acid powder and deionized water in a mass ratio of 1:20, slowly add 1 mol / L NaOH solution, adjust the pH to 8, and stir until the humic acid is completely dissolved; (2) Preparation of metal salt solution: prepare 0.3 mol / L ferric nitrate solution, zinc chloride solution and sodium molybdate solution, and mix the three solutions to obtain a metal salt solution; (3) Chelating reaction: Add the metal salt solution to the humic acid solution, adjust the pH to 7, react at 70°C for 2 h, filter to remove unreacted particles, and spray dry the solution to obtain humic acid chelated metal elements.

[0035] The volume ratio of the metal salt solution to the humic acid solution is 3:1.

[0036] The moisturizing agent is polyglutamic acid; the inducing agent is trehalose and proline in a mass ratio of 1:1.

[0037] A method for preparing a straw-use microbial decomposing agent is prepared by the following steps: (1) Preparation of nanoporous diatomaceous earth carrier, functional microbial culture liquid, and humic acid chelated trace elements; (2) mixing the nanoporous diatomaceous earth carrier, neutral protease, laccase, moisturizer, humic acid chelated trace elements, and inducer uniformly, placing the mixture in a granulator for granulation, and obtaining solid carrier particles with a particle size of 3-5 mm; (3) Preparation of functional microbial culture liquid; (4) The solid carrier particles prepared in step (2) are added to the functional microbial solution prepared in step (3) for sufficient adsorption, followed by air drying to obtain the final product microbial agent.

[0038] Example 3 A straw decomposing microbial agent comprises the following raw materials in parts by weight: 18 parts of functional microbial bacterial liquid, 5 parts of neutral protease, 3 parts of laccase, 25 parts of nanoporous diatomaceous earth carrier, 7 parts of moisturizing agent, 3 parts of humic acid chelated trace elements and 4 parts of inducer.

[0039] The functional microbial culture liquid includes thermophilic Talaromyces, Guangxi thermoactinomyces, and Arthrobacter humicola; the strain number of the thermophilic Talaromyces (Talaromyces thermophilus) is CGMCC No.3.15538; the strain number of the Guangxi thermoactinomyces (Thermoactinomyces guangxiensis) is CGMCC No. 4.7156; the strain number of the Arthrobacter humicola (Arthrobacter humicola) is CGMCC No. 1.15654.

[0040] The preparation method of the functional microbial bacterial liquid is as follows: the thermophilic thallus, the Guangxi thermophilic actinomycetes, and the soil bacterium are activated and expanded separately to obtain a viable bacterial count of 1×10 9 CFU / ml of bacterial solution, and then mix the three bacterial solutions in a volume ratio of 1:1:1 to obtain a functional microbial bacterial solution.

[0041] The preparation method of the nanoporous diatomaceous earth carrier is: (1) Diatomite pretreatment: diatomite was soaked in 10% HCl solution, stirred at 60°C for 2 h, rinsed with deionized water until neutral, dried, sieved with 200 mesh, and calcined at 600°C for 2 h; (2) Construction of nanoscale microporous structure: Grind the diatomaceous earth in step (1) with a ball mill until the particle size is less than 100 nm, mix the diatomaceous earth, PEG, and deionized water in a ratio of 1 kg: 0.2 kg: 3 L to form a slurry, dry it, and calcine it in a high-temperature furnace at 400 °C for 2 h; (3) Surface functionalization modification: The diatomaceous earth prepared in step (2) was immersed in a 3% NaOH solution and subjected to ultrasonic treatment for 30 minutes. Then, a 3% KH-550 solution was mixed with the diatomaceous earth and reacted at 60° C. for 4 hours. The diatomaceous earth was then washed three times with anhydrous ethanol and vacuum dried to constant weight to obtain a nanoporous diatomaceous earth carrier.

[0042] The 3% KH-550 solution in step (3) is prepared by dissolving KH-550 in ethanol; the 3% KH-550 solution and diatomaceous earth are mixed in a mass ratio of 2:1.

[0043] The preparation method of the humic acid chelated trace elements is: (1) Humic acid alkaline solution: Mix humic acid powder and deionized water in a mass ratio of 1:20, slowly add 1 mol / L NaOH solution, adjust the pH to 8, and stir until the humic acid is completely dissolved; (2) Preparation of metal salt solution: prepare 0.3 mol / L ferric nitrate solution, zinc chloride solution and sodium molybdate solution, and mix the three solutions to obtain a metal salt solution; (3) Chelating reaction: Add the metal salt solution to the humic acid solution, adjust the pH to 7, react at 70°C for 2 h, filter to remove unreacted particles, and spray dry the solution to obtain humic acid chelated metal elements.

[0044] The volume ratio of the metal salt solution to the humic acid solution is 3:1.

[0045] The moisturizing agent is polyglutamic acid; the inducing agent is trehalose and proline in a mass ratio of 1:1.

[0046] A method for preparing a straw-use microbial decomposing agent is prepared by the following steps: (1) Preparation of nanoporous diatomaceous earth carrier, functional microbial culture liquid, and humic acid chelated trace elements; (2) mixing the nanoporous diatomaceous earth carrier, neutral protease, laccase, moisturizer, humic acid chelated trace elements, and inducer uniformly, placing the mixture in a granulator for granulation, and obtaining solid carrier particles with a particle size of 3-5 mm; (3) Preparation of functional microbial culture liquid; (4) The solid carrier particles prepared in step (2) are added to the functional microbial solution prepared in step (3) for sufficient adsorption, followed by air drying to obtain the final product microbial agent.

[0047] Comparative Example In each comparative example, the volume ratio of the bacterial solution of Thermophilic Bacillaceae, Guangxi Thermoactinomycetes, and Arthrobacter solani in the preparation of the functional microbial bacterial solution was changed, and the remaining raw materials and steps were the same as those in Example 3. The specific bacterial solution composition is shown in Table 1.

[0048] Table 1 Bacterial solution composition of each comparative example Performance Testing The test straw was corn straw.

[0049] A total of 12 treatment groups were set up in the experiment: microbial decomposition agents prepared in Examples 1-3 and Comparative Examples 1-9 were added.

[0050] The corn stalks were collected, dried, and sorted, and then crushed into small pieces of 3-5 cm. The moisture content was adjusted to about 60%. The material was squeezed by hand so that water could be found between the fingers but not flow out. The corresponding microbial decomposition agent was added to each treatment group. The amount added was evenly sprinkled according to 1‰ of the stalk mass. After mixing evenly, it was piled into a long strip pile of length × width × height = 2m × 1m × 1.5m. The piles were turned over on the 1st, 3rd, 7th, 10th, 17th, 30th, 45th, and 60th days.

[0051] Test methods for each indicator: (1) Pile temperature The pile temperature was tested every day initially, and then every 3 days after 17 days, with 3 replicates for each measurement.

[0052] (2) Determination of total nitrogen, total potassium and total phosphorus At the end of the composting period, samples were collected by 5-point mixed sampling method, with about 0.5 kg collected at each point. Total nitrogen was determined by SKALAR interval flow analyzer; total phosphorus was determined by molybdenum antimony colorimetry; total potassium was determined by flame spectrophotometer; 3 replicates were taken each time for measurement.

[0053] (3) Determination of C / N At the end of composting, samples were collected using the 5-point mixed sampling method. The air-dried samples were crushed using a grinder and passed through a 100-mesh sieve. 20 mg of the sample was weighed out and placed in tin foil. The total nitrogen and total carbon contents were detected using an elemental analyzer, and the C / N ratio was calculated. The measurement was repeated three times for each treatment group.

[0054] (4) Straw weight loss rate Crush the corn stalks into small segments of 3-5 cm, weigh 1000 g and put them into a nylon bag, dry them at 85°C for 4 h, accurately measure the initial weight W0, and then add the microbial composting agent of each treatment group into the nylon bag. The amount of composting agent added is 1 g, and the water holding capacity is controlled to be about 60%. Set up 3 replicates for each treatment group. After the stalks are decomposed, rinse them with tap water until the dripping water is colorless, then place the samples at 85°C and dry them for 12 h, and record the weight W1 of each bag of straw.

[0055] Straw weight loss rate (%) = (W0-W1) / W0×100%; W0 is the original straw weight (g), and W1 is the dry weight of the straw after decomposition (g).

[0056] Table 2 Test results of straw composting test From the data in Tables 1 and 2, it can be seen that the microbial composting agent of the present invention has high composting efficiency and good degradation effect, which is specifically reflected in that the maximum temperature can reach 67°C in about 7 days after adding the microbial composting agent of the present invention, and the duration of the temperature reaching above 50°C is significantly prolonged; in addition, the weight loss rate of the straw can reach 65% after adding the composting agent, and it has high organic matter, total nitrogen, total potassium and total phosphorus content. In the comparative example 1-9 treatment group with changed composition of the agent, the synergistic balance of the three bacteria, thermophilic cynamidae, Guangxi thermophilic actinomycetes and soil bacillus, was broken, causing the straw composting effect to decrease to varying degrees. Therefore, the three functional strains selected in the microbial composting agent of the present invention are indispensable.

[0057] It should be noted that the above embodiments are only partial embodiments of the preferred methods of implementing the present invention, rather than all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

Claims

1. A straw decomposing microorganism agent, characterized in that: The invention comprises the following raw materials in parts by weight: 15-18 parts of functional microbial liquid, 3-5 parts of neutral protease, 1-3 parts of laccase, 20-25 parts of nano porous diatomaceous earth carrier, 5-7 parts of moisturizing agent, 2-3 parts of humic acid chelated trace elements and 2-4 parts of inducer.

2. The straw decomposing microbial agent according to claim 1, characterized in that: The functional microbial bacterial liquid is thermophilic tularensis, Guangxi thermoactinomycetes, and soil arthrobacter; the thermophilic tularensis ( Talaromyces thermophilus ) is numbered as CGMCC No.3.15538; the Guangxi thermophilic actinomycetes ( Thermoactinomyces guangxiensis ) is numbered as CGMCC No. 4.7156; the Arthrobacter terrestris ( Arthrobacter humicola ) is numbered CGMCC No. 1.15654.

3. The straw decomposing microbial agent according to claim 2, characterized in that: The preparation method of the functional microbial bacterial liquid is as follows: the thermophilic thallus, the Guangxi thermophilic actinomycetes, and the soil bacterium are activated and expanded separately to obtain a viable bacterial count of 1×10 9 CFU / ml of bacterial solution, and then mix the three bacterial solutions in a volume ratio of 1:1:1 to obtain a functional microbial bacterial solution.

4. The straw decomposing microbial agent according to claim 1, characterized in that: The preparation method of the nanoporous diatomaceous earth carrier is: (1) Diatomite pretreatment: diatomite was soaked in 10% HCl solution, stirred at 60°C for 2 h, rinsed with deionized water until neutral, dried, sieved with 200 mesh, and calcined at 600°C for 2 h; (2) Construction of nanoscale microporous structure: Grind the diatomaceous earth in step (1) with a ball mill until the particle size is less than 100 nm, mix the diatomaceous earth, PEG, and deionized water in a ratio of 1 kg: 0.2 kg: 3 L to form a slurry, dry it, and calcine it in a high-temperature furnace at 400 °C for 2 h; (3) Surface functionalization modification: The diatomaceous earth prepared in step (2) was immersed in a 3% NaOH solution and subjected to ultrasonic treatment for 30 minutes. Then, a 3% KH-550 solution was mixed with the diatomaceous earth and reacted at 60° C. for 4 hours. The diatomaceous earth was then washed three times with anhydrous ethanol and vacuum dried to constant weight to obtain a nanoporous diatomaceous earth carrier.

5. The microbial composting agent for straw according to claim 4, characterized in that: The 3% KH-550 solution in step (3) is prepared by dissolving KH-550 in ethanol; the 3% KH-550 solution and diatomaceous earth are mixed in a mass ratio of 2:

1.

6. The straw decomposing microbial agent according to claim 1, characterized in that: The preparation method of the humic acid chelated trace elements is: (1) Humic acid alkaline solution: Mix humic acid powder and deionized water in a mass ratio of 1:20, slowly add 1 mol / L NaOH solution, adjust the pH to 8, and stir until the humic acid is completely dissolved; (2) Preparation of metal salt solution: prepare 0.3 mol / L ferric nitrate solution, zinc chloride solution and sodium molybdate solution, and mix the three solutions to obtain a metal salt solution; (3) Chelating reaction: Add the metal salt solution to the humic acid solution, adjust the pH to 7, react at 70°C for 2 h, filter to remove unreacted particles, and spray dry the solution to obtain humic acid chelated metal elements.

7. The straw decomposing microbial agent according to claim 6, characterized in that: The volume ratio of the metal salt solution to the humic acid solution is 3:

1.

8. The straw decomposing microbial agent according to claim 1, characterized in that: The moisturizing agent is polyglutamic acid; the inducing agent is trehalose and proline in a mass ratio of 1:

1.

9. A method for preparing the straw-decomposing microbial agent according to any one of claims 1 to 8, characterized in that: Prepared by the following steps: (1) Preparation of nanoporous diatomaceous earth carrier, functional microbial culture liquid, and humic acid chelated trace elements; (2) mixing the nanoporous diatomaceous earth carrier, neutral protease, laccase, moisturizer, humic acid chelated trace elements, and inducer uniformly, placing the mixture in a granulator for granulation, and obtaining solid carrier particles with a particle size of 3-5 mm; (3) Preparation of functional microbial culture liquid; (4) The solid carrier particles prepared in step (2) are added to the functional microbial solution prepared in step (3) for sufficient adsorption, followed by air drying to obtain the final product, a microbial decomposition agent.

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