Microbial complex microbial inoculant for promoting crop yield and preparation method thereof

Abstract

The application discloses a kind of microbial compound microbial inoculum for promoting crop yield and preparation method thereof, belong to agricultural microbial preparation technical field.The preparation method includes the following steps: activated biochar and mixed bacteria liquid are mixed according to the ratio of weight parts 2~3:10~21 and are adsorbed in 25 DEG C for 15h~19h to obtain carbon-based compound microbial inoculum;Carbon-based compound microbial inoculum, straw and wheat bran are mixed according to the ratio of weight parts 1:4~6:2~4, then add water to wet and form to be fermented raw material, and the microbial compound microbial inoculum is obtained after compost fermentation of to be fermented raw material.The application is mixed to form mixed bacteria liquid by bacillus subtilis, trichoderma koningii and monascus after salt-tolerant domestication, then adsorbed on activated biochar, and then mixed with straw and wheat bran to ferment to obtain microbial compound microbial inoculum with good fertilizer efficiency.

Description

Technical Field

[0001] This invention belongs to the field of agricultural microbial preparation technology, specifically relating to a microbial compound agent for promoting crop yield and its preparation method. Background Technology

[0002] Fertilizers and pesticides are essential agricultural inputs, playing a crucial role in ensuring high and stable grain yields in my country. However, for a long time, my country has experienced significant overuse of chemical fertilizers and pesticides, leading not only to increased production costs but also to major problems such as environmental pollution and agricultural product quality and safety. Data shows that my country's current average fertilizer usage per mu (a Chinese unit of area, approximately 0.067 hectares) is 21.9 kg, far exceeding the world average (8 kg per mu). Furthermore, in 2022, my country's total pesticide usage reached 1.83 million tons, 2.3 times that of the United States and twice that of the European Union. Gansu Province, as a major commodity grain base in China, holds a pivotal position in the national food security strategy. According to data from the Third National Land Change Survey, Gansu Province has 5.2141 million hectares of arable land, accounting for 12.62% of the province's total land area. However, the arable land area is relatively small, and much of it is of medium to low quality. Large areas of saline-alkali land and desertified arable land exist, soil organic matter content is low, overall arable land quality is not high, and arable land pollution is a prominent issue, seriously affecting crop yield and quality. Meanwhile, continuous cropping is prevalent and severe in most parts of Gansu Province, leading to significant obstacles to crop rotation, exacerbating soil-borne diseases, and directly impacting crop yield and marketability. These factors have become major constraints on the green, organic, and sustainable development of Gansu agriculture.

[0003] Plant health is crucial to plant yield, quality, and the ecological environment, and ensuring plant health is of particular importance for promoting the green and high-quality development of the planting industry. Traditional agriculture, characterized by a "dual structure" of animals and plants, is transforming into a new type of agriculture with a "ternary structure" of animals, plants, and microorganisms, leading to a greater recognition of the importance of microorganisms in agriculture. Microorganisms play an irreplaceable role in the ecosystem; they are the driving force behind material cycling, propelling the biogeochemical cycling of nutrients in nature. Soil microorganisms, in particular, possess a high capacity for nutrient transformation during soil quality evolution. Microorganisms can both fix nutrients, serving as temporary "sinks," and release nutrients, acting as "sources," thus actively influencing the energy and material flow within the ecosystem, thereby affecting soil structure, soil fertility, plant growth, and health. With the development of "ecological agriculture" and "organic agriculture" and the increasing awareness of environmental protection, the research and development of microbial inoculants has attracted worldwide attention. However, in production practice, it has been found that single-strain microbial inoculants, due to their limited functionality, often have a narrow application range, low soil conditioning capacity, and insignificant effects. To achieve optimal results, the synergistic effect of various microbial strains with different functions is necessary. However, complex relationships exist between different microorganisms, including symbiosis, antagonism, and competition. Furthermore, high demands are placed on production processes and technologies. Improper handling can easily lead to vicious competition and mutual exclusion among active bacteria, resulting in reduced survival rates. Therefore, researching and developing microbial compound agents that synergistically enhance crop yield through different microorganisms is of great significance for reducing the use of chemical fertilizers and pesticides, producing green products, improving the quality of agricultural products, maintaining sustainable agricultural development, and enhancing the market competitiveness of agricultural products. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention uses Bacillus subtilis, Trichoderma cornuta, and Monascus purpureus, which are acclimated to salt and alkali tolerance to form a mixed bacterial solution. This solution is then adsorbed onto activated biochar and fermented with straw and wheat bran to obtain a microbial compound agent with good fertilizer efficacy, thereby solving the technical problems mentioned in the background art. Specifically, the technical solution of this invention includes the following:

[0005] One objective of this invention is to provide a method for preparing a microbial compound inoculant that promotes crop yield increase, the method comprising the following steps:

[0006] Activated biochar and mixed bacterial solution were mixed at a weight ratio of 2~3:10~21 and adsorbed at 25℃ for 15h~19h to obtain a carbon-based composite bacterial agent;

[0007] Carbon-based compound microbial agent, straw and wheat bran are mixed in a weight ratio of 1:4~6:2~4, and then water is added to wet the mixture to form a fermentation base material. The fermentation base material is then composted to obtain the microbial compound microbial agent.

[0008] Furthermore, the method for preparing the activated biochar includes the following steps:

[0009] Peanut shell particles are pyrolyzed at 400℃~500℃ for 2h~3h to obtain biochar;

[0010] The activated biochar was obtained by mixing biochar and hydrogen peroxide solution at a solid-liquid ratio of 1g:20mL~30mL and then oxidizing at 25℃ for 1h~2h.

[0011] Furthermore, the peanut shell particles are obtained by passing them through a 50-100 mesh sieve.

[0012] Furthermore, the hydrogen peroxide solution has a mass fraction of 25% to 30%.

[0013] Furthermore, the mixed bacterial solution is composed of salt- and alkali-tolerant Bacillus subtilis solution, salt- and alkali-tolerant Trichoderma koreana solution, and salt- and alkali-tolerant Monascus purpureus solution in a weight ratio of 2:1~1.5:0.5~1.

[0014] Furthermore, the preparation method of the salt- and alkali-tolerant Bacillus subtilis bacterial solution includes the following steps:

[0015] The first domesticated Bacillus subtilis was obtained by inoculating Bacillus subtilis in nutrient broth agar medium with sodium chloride content of 0.5% and culturing it at 30°C for 18-20 h.

[0016] The first domesticated Bacillus subtilis was inoculated into nutrient broth agar medium with a sodium chloride content of 0.7% and cultured at 30°C for 18-20 h to obtain the second domesticated Bacillus subtilis.

[0017] The second domesticated Bacillus subtilis was inoculated into nutrient broth agar medium with a sodium chloride content of 1% and cultured at 30°C for 18-20 h to obtain the third domesticated Bacillus subtilis.

[0018] The third domesticated Bacillus subtilis was inoculated into a nutrient broth liquid medium and cultured at 35°C until the OD600 was 0.6~0.7 to obtain the salt-tolerant domesticated Bacillus subtilis bacterial solution.

[0019] Furthermore, the strain number of the Bacillus subtilis is CICC 24713.

[0020] Furthermore, the preparation method of the salt- and alkali-tolerant Trichoderma koreanum solution includes the following steps:

[0021] The first domesticated Trichoderma koningii was obtained by inoculating Trichoderma koningii into PDA agar medium with sodium chloride content of 0.3% and culturing it at 28°C for 20-24 hours.

[0022] The first domesticated Trichoderma koningii was inoculated into PDA agar medium with a sodium chloride mass fraction of 0.6% and cultured at 28°C for 20-24 h to obtain the second domesticated Trichoderma koningii.

[0023] The second domesticated Trichoderma Corningensis was inoculated into PDA agar medium with a sodium chloride mass fraction of 1% and cultured at 28℃ for 20-24 h to obtain the third domesticated Trichoderma Corningensis;

[0024] The third acclimatized Trichoderma koningii was inoculated into PDA liquid medium and cultured at 30°C until the OD600 was 0.7~0.8 to obtain the salt- and alkali-tolerant acclimatized Trichoderma koningii liquid solution.

[0025] Furthermore, the strain number of the Corning Trichoderma is CICC 13031.

[0026] Furthermore, the preparation method of the salt- and alkali-tolerant Monascus purpureus solution includes the following steps:

[0027] Monascus purpureus was inoculated into malt extract agar medium with sodium chloride content of 0.5% and cultured at 30°C for 28-30 h to obtain the first domesticated Monascus purpureus.

[0028] The first domesticated Monascus purpureus was inoculated into malt extract agar medium with sodium chloride content of 0.7% and cultured at 30°C for 28-30 h to obtain the second domesticated Monascus purpureus;

[0029] The second domesticated Monascus was inoculated into malt extract agar medium with 1% sodium chloride and cultured at 30°C for 28-30 h to obtain the third domesticated Monascus.

[0030] The third domesticated Monascus purpureus was inoculated into malt extract liquid medium and cultured at 35°C until the OD600 was 0.7~0.8 to obtain the salt- and alkali-tolerant domesticated Monascus purpureus liquid.

[0031] Furthermore, the strain of Monascus purpureus is designated CICC 40712.

[0032] Furthermore, the straw includes corn straw that has passed through a 50-mesh sieve or rice straw that has passed through a 50-mesh sieve.

[0033] Furthermore, the moisture content of the substrate to be fermented is 40%~50%.

[0034] Furthermore, the conditions for composting fermentation include a stack size of 1m long × 1m wide × 0.2m~0.3m high, a fermentation environment temperature of 28℃~30℃, a fermentation time of 5~7 days, and turning the material once every 24 hours.

[0035] The second objective of this invention is to provide a microbial compound inoculant that promotes crop yield.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] (1) In this invention, Bacillus subtilis, Trichoderma koningii, and Monascus purpureus are mixed and acclimatized to salt and alkali to form a mixed bacterial solution, which is then adsorbed onto activated biochar and fermented with straw and wheat bran. Bacillus subtilis can dissolve insoluble phosphorus and potassium in the soil by secreting organic acids, phytase, etc., converting ineffective nutrients into available forms that can be absorbed by crops; at the same time, it can synthesize plant growth regulators to promote crop root development and plant vigor, and can also inhibit the growth and reproduction of pathogens in the soil by secreting lipopeptide antibiotics and other substances, reducing the occurrence of soil-borne diseases and reducing the disease resistance pressure on crops; Trichoderma koningii, Trichoderma koningii, and Monascus purpureus are mixed and acclimatized to salt and alkali to form a mixed bacterial solution, which is then adsorbed onto activated biochar and then mixed with straw and wheat bran for fermentation. Trichoderma ningpoensis can rapidly decompose lignocellulose by secreting cellulase, hemicellulase, and lignin peroxidase, converting them into small-molecule organic acids, polysaccharides, and amino acids. On the one hand, it provides carbon and nitrogen sources for itself and other strains, promoting the fermentation and proliferation of compound inoculants; on the other hand, it provides organic nutrients for crops and improves the soil carbon-nitrogen ratio. At the same time, it attaches to the hyphae of pathogens through hyperparasitism, secretes cell wall degrading enzymes to destroy the structure of pathogens, and produces antibiotics such as trichomycin and mycotoxins, which synergize with the antibacterial substances of Bacillus subtilis to enhance the control effect against soil-borne diseases. Monascus purpureus produces various organic acids such as citric acid, succinic acid, and lactic acid through metabolism. These acids can neutralize the alkalinity of saline-alkali soils, lower the soil pH, and alleviate the corrosion and toxicity of salt and alkali on crop roots. At the same time, the organic acids can chelate sodium and calcium ions in the soil, reducing the stress of salt ions on crops. They can also produce amylase, protease, and saccharifying enzymes to decompose starch and protein, releasing readily available nutrients such as glucose and amino acids, providing energy for the proliferation of the complex strains and providing easily absorbed nutrients for crop seedling growth. In addition, the coenzymes and vitamins produced by Monascus purpureus metabolism can act as growth factors for Bacillus subtilis and Trichoderma cornuta, promoting the metabolism and functional expression of both strains.

[0038] (2) Salt and alkali tolerance acclimatization can reduce the stress of soil saline-alkali environment on strains, thereby enhancing the metabolic capacity of strains and ensuring stable nutrient activation function in saline-alkali land.

[0039] (3) The porous structure of biochar provides a solid protective structure for the strain, reducing the damage to the strain from salt ions and soil pathogens, and prolonging the activity of the strain. In addition, biochar can adsorb activated nitrogen and phosphorus nutrients, realizing the slow release of nutrients and avoiding seedling burn and nutrient deficiency in the later stage of crop growth.

[0040] (4) The microbial compound inoculant prepared by the present invention has good fertilizer effect and promotes crop growth. Detailed Implementation

[0041] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0043] Preparation Example 1

[0044] The preparation process of activated biochar is as follows:

[0045] Peanut shells were rinsed with clean water and then dried in an oven at 80℃ for 12 hours. They were then removed, pulverized using a grinder, and passed through a 50-mesh sieve to obtain peanut shell granules. These granules were placed in a muffle furnace, and the furnace was heated to 400℃ at a rate of 10℃ / min, where they were pyrolyzed and carbonized for 2 hours. After carbonization, the mixture was cooled to room temperature to obtain biochar. 100g of biochar and 2L of a 25% hydrogen peroxide solution were weighed, mixed, and dispersed using an ultrasonic power of 400W for 20 minutes. Then, the mixture was stirred and oxidized at 25℃ and 200r / min for 1 hour. After treatment, the solid particles were centrifuged, rinsed repeatedly with deionized water, and finally dried in a vacuum drying oven at 55℃ for 12 hours to obtain activated biochar.

[0046] Preparation Example 2

[0047] The preparation process of activated biochar is as follows:

[0048] Peanut shells were rinsed with clean water and then dried in an oven at 80℃ for 12 hours. They were then removed, pulverized using a grinder, and passed through an 80-mesh sieve to obtain peanut shell granules. These granules were placed in a muffle furnace, and the furnace was heated to 400℃ at a rate of 10℃ / min, where they were pyrolyzed and carbonized for 2.5 hours. After carbonization, the mixture was cooled to room temperature to obtain biochar. 100g of biochar and 2L of a 25% hydrogen peroxide solution were weighed, mixed, and dispersed using an ultrasonic power of 400W for 20 minutes. Then, the mixture was oxidized by stirring at 200r / min at 25℃ for 1.5 hours. After treatment, the solid particles were centrifuged, rinsed repeatedly with deionized water, and finally dried in a vacuum drying oven at 55℃ for 12 hours to obtain activated biochar.

[0049] Preparation Example 3

[0050] The preparation process of activated biochar is as follows:

[0051] Peanut shells were rinsed with clean water and then dried in an oven at 80℃ for 12 hours. They were then removed, pulverized using a grinder, and passed through a 100-mesh sieve to obtain peanut shell granules. These granules were placed in a muffle furnace, and the furnace was heated to 450℃ at a rate of 10℃ / min, where they were pyrolyzed and carbonized for 2.5 hours. After carbonization, the mixture was cooled to room temperature to obtain biochar. 100g of biochar and 2.5L of a 30% hydrogen peroxide solution were weighed, mixed, and dispersed using an ultrasonic power of 400W for 20 minutes. Then, the mixture was oxidized by stirring at 200r / min at 25℃ for 1.5 hours. After treatment, the solid particles were centrifuged, rinsed repeatedly with deionized water, and finally dried in a vacuum drying oven at 55℃ for 12 hours to obtain activated biochar.

[0052] Preparation Example 4

[0053] The preparation process of activated biochar is as follows:

[0054] Peanut shells were rinsed with clean water and then dried in an oven at 80℃ for 12 hours. They were then removed, pulverized using a grinder, and passed through a 100-mesh sieve to obtain peanut shell granules. These granules were placed in a muffle furnace, which was then heated to 500℃ at a rate of 10℃ / min, and subjected to pyrolysis carbonization for 3 hours. After carbonization, the mixture was cooled to room temperature to obtain biochar. 100g of biochar and 3L of a 30% hydrogen peroxide solution were weighed and mixed together, then dispersed using an ultrasonic power of 400W for 20 minutes. The mixture was then stirred and oxidized at 25℃ and 200r / min for 2 hours. After treatment, the solid particles were centrifuged, rinsed repeatedly with deionized water, and finally dried in a vacuum drying oven at 55℃ for 12 hours to obtain activated biochar.

[0055] Preparation Example 5

[0056] The preparation process of activated biochar is as follows:

[0057] Peanut shells were rinsed with clean water and then dried in an oven at 80℃ for 12 hours. They were then removed, pulverized, and passed through a 10-mesh sieve to obtain peanut shell granules. These granules were placed in a muffle furnace, which was then heated to 500℃ at a rate of 10℃ / min, and subjected to pyrolysis carbonization for 3 hours. After carbonization, the mixture was cooled to room temperature to obtain biochar. 100g of biochar and 3L of a 30% hydrogen peroxide solution were weighed, mixed, and dispersed using an ultrasonic power of 400W for 20 minutes. The mixture was then stirred and oxidized at 25℃ and 200r / min for 2 hours. After treatment, the solid particles were centrifuged, rinsed repeatedly with deionized water, and finally dried in a vacuum drying oven at 55℃ for 12 hours to obtain activated biochar.

[0058] Preparation Example 6

[0059] The preparation process of activated biochar is as follows:

[0060] Peanut shells were rinsed with clean water and then dried in an oven at 80℃ for 12 hours. They were then removed, pulverized, and passed through a 100-mesh sieve to obtain peanut shell granules. These granules were placed in a muffle furnace, which was then heated to 600℃ at a rate of 10℃ / min, and subjected to pyrolysis carbonization for 4 hours. After carbonization, the mixture was cooled to room temperature to obtain biochar. 100g of biochar and 3L of a 30% hydrogen peroxide solution were weighed, mixed, and dispersed using an ultrasonic power of 400W for 20 minutes. The mixture was then stirred and oxidized at 25℃ and 200r / min for 2 hours. After treatment, the solid particles were centrifuged, rinsed repeatedly with deionized water, and finally dried in a vacuum drying oven at 55℃ for 12 hours to obtain activated biochar.

[0061] Preparation Example 7

[0062] The preparation process of activated biochar is as follows:

[0063] Peanut shells were rinsed with clean water and then dried in an oven at 80℃ for 12 hours. They were then removed, pulverized using a grinder, and passed through a 100-mesh sieve to obtain peanut shell granules. These granules were placed in a muffle furnace, which was then heated to 500℃ at a rate of 10℃ / min, and subjected to pyrolysis carbonization for 3 hours. After carbonization, the mixture was cooled to room temperature to obtain biochar. 100g of biochar and 3L of a 40% hydrogen peroxide solution were weighed, mixed, and dispersed using an ultrasonic power of 400W for 20 minutes. The mixture was then stirred and oxidized at 25℃ and 200r / min for 3 hours. After treatment, the solid particles were centrifuged, rinsed repeatedly with deionized water, and finally dried in a vacuum drying oven at 55℃ for 12 hours to obtain activated biochar.

[0064] Preparation Example 8

[0065] The preparation method of salt- and alkali-tolerant Bacillus subtilis bacterial suspension includes the following steps:

[0066] On a clean bench, a loopful of Bacillus subtilis strain CICC 24713 was inoculated onto 0.5% sodium chloride nutrient broth agar (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. The agar was then incubated upside down in a 30°C incubator for 18 h to obtain the first domesticated Bacillus subtilis strain. Next, a loopful of the first domesticated Bacillus subtilis strain was inoculated onto 0.7% sodium chloride nutrient broth agar (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. This was then incubated upside down in a 30°C incubator for 18 h to obtain the second domesticated Bacillus subtilis strain. Next, using a sterilized inoculation loop, a loopful of the second domesticated Bacillus subtilis was inoculated into nutrient broth agar medium (sterilized at 121℃ for 20 min before use), and then incubated upside down in a 30℃ incubator for 18 h to obtain the third domesticated Bacillus subtilis. Finally, using a sterilized inoculation loop, a loopful of the third domesticated Bacillus subtilis was inoculated into nutrient broth liquid medium (sterilized at 121℃ for 20 min before use), and then placed in a shaker at 35℃ and shaken at 200 rpm until the OD of the bacterial culture reached a certain level. 600 The concentration reached 0.6, completing the preparation of salt- and alkali-tolerant Bacillus subtilis culture.

[0067] Preparation Example 9

[0068] The preparation method of salt- and alkali-tolerant Bacillus subtilis bacterial suspension includes the following steps:

[0069] On a clean bench, a loopful of Bacillus subtilis strain CICC 24713 was inoculated onto 0.5% sodium chloride nutrient broth agar (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. The agar was then incubated upside down at 30°C for 20 h to obtain the first domesticated Bacillus subtilis strain. Next, a loopful of the first domesticated Bacillus subtilis strain was inoculated onto 0.7% sodium chloride nutrient broth agar (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. This was then incubated upside down at 30°C for 20 h to obtain the second domesticated Bacillus subtilis strain. Next, using a sterilized inoculation loop, a loopful of the second domesticated Bacillus subtilis was inoculated into nutrient broth agar medium (sterilized at 121℃ for 20 min before use), and then incubated upside down in a 30℃ incubator for 20 h to obtain the third domesticated Bacillus subtilis. Finally, using a sterilized inoculation loop, a loopful of the third domesticated Bacillus subtilis was inoculated into nutrient broth liquid medium (sterilized at 121℃ for 20 min before use), and then placed in a shaker at 35℃ and shaken at 200 rpm until the OD of the bacterial culture reached a certain level. 600 The concentration reached 0.7, completing the preparation of salt-tolerant Bacillus subtilis culture.

[0070] Preparation Example 10

[0071] The preparation method of salt- and alkali-tolerant Trichoderma koreanum solution includes the following steps:

[0072] On a clean bench, a loopful of Trichoderma Corning strain CICC 13031 was inoculated onto 0.3% sodium chloride PDA agar (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. The medium was then incubated upside down in a 28°C incubator for 20 h to obtain the first acclimatized Trichoderma Corning. Next, a loopful of the first acclimatized Trichoderma Corning was inoculated onto 0.6% sodium chloride PDA agar (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. The medium was then incubated upside down in a 28°C incubator for 20 h to obtain the second acclimatized Trichoderma Corning. Using a sterilized inoculation loop, one loopful of the second-acclimated *Trichoderma corniglita* was inoculated into 1% sodium chloride PDA agar medium (sterilized at 121°C for 20 min before use). The medium was then inverted and incubated at 28°C for 20 h to obtain the third-acclimated *Trichoderma corniglita*. Finally, using a sterilized inoculation loop, one loopful of the third-acclimated *Trichoderma corniglita* was inoculated into PDA liquid medium (sterilized at 121°C for 20 min before use). The medium was then placed in a shaker at 30°C and incubated at 180 rpm until the OD of the bacterial culture reached [missing value]. 600 The concentration reached 0.7, thus completing the preparation of the salt- and alkali-tolerant Trichoderma koreanum solution.

[0073] Preparation Example 11

[0074] The preparation method of salt- and alkali-tolerant Trichoderma koreanum solution includes the following steps:

[0075] On a clean bench, a loopful of Trichoderma Corning strain CICC 13031 was inoculated onto 0.3% sodium chloride PDA agar (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. The agar was then incubated upside down in a 28°C incubator for 24 h to obtain the first acclimatized Trichoderma Corning. Next, a loopful of the first acclimatized Trichoderma Corning was inoculated onto 0.6% sodium chloride PDA agar (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. The agar was then incubated upside down in a 28°C incubator for 24 h to obtain the second acclimatized Trichoderma Corning. Using a sterilized inoculation loop, one loopful of the second-acclimated *Trichoderma corniglita* was inoculated into 1% sodium chloride PDA agar medium (sterilized at 121°C for 20 min before use). The medium was then inverted and incubated at 28°C for 24 h to obtain the third-acclimated *Trichoderma corniglita*. Finally, using a sterilized inoculation loop, one loopful of the third-acclimated *Trichoderma corniglita* was inoculated into PDA liquid medium (sterilized at 121°C for 20 min before use). The medium was then placed in a shaker at 30°C and incubated at 180 rpm until the OD of the bacterial culture reached [missing value]. 600 The concentration reached 0.8, thus completing the preparation of the salt- and alkali-tolerant Trichoderma koreanum solution.

[0076] Preparation Example 12

[0077] The preparation method of salt- and alkali-tolerant Monascus purpureus solution includes the following steps:

[0078] On a clean bench, a loopful of Monascus purpureus strain CICC 40712 was spread onto 0.5% sodium chloride malt extract agar medium (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. The medium was then incubated upside down in a 30°C incubator for 28 h to obtain the first acclimatized Monascus purpureus. Next, a loopful of the first acclimatized Monascus purpureus was inoculated onto 0.7% sodium chloride malt extract agar medium (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. The medium was then incubated upside down in a 30°C incubator for 28 h to obtain the second acclimatized Monascus purpureus. Using a sterilized inoculation loop, one loopful of the second domesticated Monascus purpureus was inoculated into malt extract agar medium (sterilized at 121°C for 20 min before use) containing 1% sodium chloride. The medium was then inverted and cultured in a 30°C incubator for 28 h to obtain the third domesticated Monascus purpureus. Finally, using a sterilized inoculation loop, one loopful of the third domesticated Monascus purpureus was inoculated into malt extract liquid medium (sterilized at 121°C for 20 min before use). The medium was then placed in a shaker at 35°C and cultured at 150 rpm until the OD of the bacterial culture reached a certain level. 600 The concentration reached 0.7, thus completing the preparation of salt- and alkali-tolerant Monascus purpureus solution.

[0079] Preparation Example 13

[0080] The preparation method of salt- and alkali-tolerant Monascus purpureus solution includes the following steps:

[0081] On a clean bench, a loopful of Monascus purpureus strain CICC 40712 was spread onto 0.5% sodium chloride malt extract agar medium (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. The medium was then incubated upside down in a 30°C incubator for 30 h to obtain the first acclimatized Monascus purpureus. Next, a loopful of the first acclimatized Monascus purpureus was inoculated onto 0.7% sodium chloride malt extract agar medium (sterilized at 121°C for 20 min before use) using a sterilized inoculation loop. The medium was then incubated upside down in a 30°C incubator for 30 h to obtain the second acclimatized Monascus purpureus. Using a sterilized inoculation loop, one loopful of the second domesticated Monascus purpureus was inoculated into malt extract agar medium (sterilized at 121°C for 20 min before use) containing 1% sodium chloride. The medium was then inverted and cultured in a 30°C incubator for 30 h to obtain the third domesticated Monascus purpureus. Finally, using a sterilized inoculation loop, one loopful of the third domesticated Monascus purpureus was inoculated into malt extract liquid medium (sterilized at 121°C for 20 min before use). The medium was then placed in a shaker at 35°C and cultured at 150 rpm until the OD of the bacterial culture reached [missing value]. 600 The concentration reached 0.8, thus completing the preparation of salt- and alkali-tolerant Monascus purpureus solution.

[0082] Preparation Example 14

[0083] The preparation process of the mixed bacterial solution is as follows:

[0084] Two parts by weight of the salt-tolerant and alkali-tolerant Bacillus subtilis culture obtained in Preparation Example 8, one part by weight of the salt-tolerant and alkali-tolerant Trichoderma koningii culture obtained in Preparation Example 10, and 0.5 parts by weight of the salt-tolerant and alkali-tolerant Monascus purpureus culture obtained in Preparation Example 12 were weighed and mixed to form a mixed culture.

[0085] Preparation Example 15

[0086] The preparation process of the mixed bacterial solution is as follows:

[0087] Weigh 2 parts by weight of the salt-tolerant and alkali-tolerant Bacillus subtilis culture obtained in Preparation Example 8, 1.2 parts by weight of the salt-tolerant and alkali-tolerant Trichoderma koningii culture obtained in Preparation Example 10, and 0.6 parts by weight of the salt-tolerant and alkali-tolerant Monascus purpureus culture obtained in Preparation Example 12 and mix them to form a mixed culture.

[0088] Preparation Example 16

[0089] The preparation process of the mixed bacterial solution is as follows:

[0090] Weigh 2 parts by weight of the salt-tolerant and alkali-tolerant Bacillus subtilis culture obtained in Preparation Example 9, 1.4 parts by weight of the salt-tolerant and alkali-tolerant Trichoderma koningii culture obtained in Preparation Example 11, and 0.8 parts by weight of the salt-tolerant and alkali-tolerant Monascus purpureus culture obtained in Preparation Example 13 and mix them to form a mixed culture.

[0091] Preparation Example 17

[0092] The preparation process of the mixed bacterial solution is as follows:

[0093] Two parts by weight of the salt-tolerant Bacillus subtilis culture obtained in Preparation Example 9, 1.5 parts by weight of the salt-tolerant Trichoderma koningii culture obtained in Preparation Example 11, and 1 part by weight of the salt-tolerant Monascus purpureus culture obtained in Preparation Example 13 were weighed and mixed to form a mixed culture.

[0094] Example 1

[0095] A method for preparing a microbial compound inoculant to promote crop yield, the specific process of which is as follows:

[0096] Two parts by weight of the activated biochar obtained in Preparation Example 1 and ten parts by weight of the mixed bacterial solution obtained in Preparation Example 14 were weighed and mixed. The mixture was then transferred to a temperature environment of 25°C and stirred at a speed of 120 r / min for 15 h to obtain a carbon-based composite bacterial agent. One part by weight of the carbon-based composite bacterial agent, four parts by weight of 50-mesh corn stalks and two parts by weight of wheat bran were weighed and mixed evenly. The mixture was then sprayed with deionized water to wet it, so that the moisture content reached 40% to form a substrate for fermentation. The fermentation substrate was piled into a stack with a length of 1 m × width of 1 m × height of 0.2 m. The fermentation environment temperature was controlled at 28°C. The substrate was turned over once every 24 h. After a total of 5 days of fermentation, a microbial composite bacterial agent was obtained.

[0097] Example 2

[0098] A method for preparing a microbial compound inoculant to promote crop yield, the specific process of which is as follows:

[0099] 2.4 parts by weight of the activated biochar obtained in Example 2 and 14 parts by weight of the mixed bacterial solution obtained in Example 15 were weighed and mixed. The mixture was then transferred to a temperature environment of 25°C and stirred at 120 r / min for 16 h to obtain a carbon-based composite bacterial agent. 1 part by weight of the carbon-based composite bacterial agent, 4 parts by weight of 50-mesh corn stalks and 3 parts by weight of wheat bran were weighed, mixed and stirred evenly. Then, deionized water was sprayed on to wet the mixture, so that the moisture content reached 45% to form the fermentation substrate. The fermentation substrate was piled into a stack 1m long × 1m wide × 0.2m high. The fermentation temperature was controlled at 28°C. The substrate was turned over every 24 h. After a total of 6 days of fermentation, the microbial composite bacterial agent was obtained.

[0100] Example 3

[0101] A method for preparing a microbial compound inoculant to promote crop yield, the specific process of which is as follows:

[0102] 2.8 parts by weight of the activated biochar obtained in Preparation Example 3 and 18 parts by weight of the mixed bacterial solution obtained in Preparation Example 16 were weighed and mixed. The mixture was then transferred to a temperature environment of 25°C and stirred at a speed of 120 r / min for 18 h to obtain a carbon-based composite bacterial agent. 1 part by weight of the carbon-based composite bacterial agent, 5 parts by weight of 50-mesh rice straw and 3 parts by weight of wheat bran were weighed, mixed and stirred evenly. Then, deionized water was sprayed on to wet the mixture, so that the moisture content reached 45% to form the fermentation substrate. The fermentation substrate was piled into a stack 1m long × 1m wide × 0.3m high. The fermentation temperature was controlled at 30°C. The substrate was turned over every 24 h. After a total of 6 days of fermentation, the microbial composite bacterial agent was obtained.

[0103] Example 4

[0104] A method for preparing a microbial compound inoculant to promote crop yield, the specific process of which is as follows:

[0105] Three parts by weight of the activated biochar obtained in Preparation Example 4 and 21 parts by weight of the mixed bacterial solution obtained in Preparation Example 17 were weighed and mixed. The mixture was then transferred to a temperature environment of 25°C and stirred at a speed of 120 r / min for 19 h to obtain a carbon-based composite bacterial agent. One part by weight of the carbon-based composite bacterial agent, six parts by weight of 50-mesh rice straw and four parts by weight of wheat bran were weighed and mixed evenly. The mixture was then sprayed with deionized water to wet it, so that the moisture content reached 50% to form a substrate for fermentation. The fermentation substrate was piled into a stack with a length of 1 m × width of 1 m × height of 0.3 m. The fermentation temperature was controlled at 30°C. The substrate was turned over once every 24 h. After a total of 7 days of fermentation, a microbial composite bacterial agent was obtained.

[0106] Comparative Example 1

[0107] A method for preparing a microbial compound inoculant to promote crop yield, the specific process of which is as follows:

[0108] Three parts by weight of the activated biochar obtained in Preparation Example 5 and 21 parts by weight of the mixed bacterial solution obtained in Preparation Example 17 were weighed and mixed. The mixture was then transferred to a temperature environment of 25°C and stirred at a speed of 120 r / min for 19 h to obtain a carbon-based composite bacterial agent. One part by weight of the carbon-based composite bacterial agent, six parts by weight of 50-mesh rice straw and four parts by weight of wheat bran were weighed, mixed and stirred evenly. The mixture was then sprayed with deionized water to wet it so that the moisture content reached 50% to form a substrate for fermentation. The fermentation substrate was piled into a stack with a length of 1 m × width of 1 m × height of 0.3 m. The fermentation environment temperature was controlled at 30°C. The substrate was turned over once every 24 h. After a total of 7 days of fermentation, a microbial composite bacterial agent was obtained.

[0109] Comparative Example 2

[0110] A method for preparing a microbial compound inoculant to promote crop yield, the specific process of which is as follows:

[0111] Three parts by weight of the activated biochar obtained in Preparation Example 6 and 21 parts by weight of the mixed bacterial solution obtained in Preparation Example 17 were weighed and mixed. The mixture was then transferred to a temperature environment of 25°C and stirred at a speed of 120 r / min for 19 h to obtain a carbon-based composite bacterial agent. One part by weight of the carbon-based composite bacterial agent, six parts by weight of 50-mesh rice straw and four parts by weight of wheat bran were weighed and mixed evenly. The mixture was then sprayed with deionized water to wet it so that the moisture content reached 50% to form a substrate for fermentation. The fermentation substrate was piled into a stack with a length of 1 m × width of 1 m × height of 0.3 m. The fermentation environment temperature was controlled at 30°C. The substrate was turned over once every 24 h. After a total of 7 days of fermentation, a microbial composite bacterial agent was obtained.

[0112] Comparative Example 3

[0113] A method for preparing a microbial compound inoculant to promote crop yield, the specific process of which is as follows:

[0114] Three parts by weight of the activated biochar obtained in Preparation Example 7 and 21 parts by weight of the mixed bacterial solution obtained in Preparation Example 17 were weighed and mixed. The mixture was then transferred to a temperature environment of 25°C and stirred at a speed of 120 r / min for 19 h to obtain a carbon-based composite bacterial agent. One part by weight of the carbon-based composite bacterial agent, six parts by weight of 50-mesh rice straw and four parts by weight of wheat bran were weighed and mixed evenly. The mixture was then sprayed with deionized water to wet it, so that the moisture content reached 50% to form a substrate for fermentation. The fermentation substrate was piled into a stack with a length of 1 m × width of 1 m × height of 0.3 m. The fermentation environment temperature was controlled at 30°C. The substrate was turned over once every 24 h. After a total of 7 days of fermentation, a microbial composite bacterial agent was obtained.

[0115] Comparative Example 4

[0116] A method for preparing a microbial compound inoculant to promote crop yield, the specific process of which is as follows:

[0117] Three parts by weight of the activated biochar obtained in Preparation Example 4 and 21 parts by weight of the salt-tolerant and alkali-tolerant Bacillus subtilis culture obtained in Preparation Example 8 were weighed and mixed. The mixture was then transferred to a temperature environment of 25°C and stirred at a speed of 120 r / min for 19 h to obtain a carbon-based composite microbial agent. One part by weight of the carbon-based composite microbial agent, six parts by weight of 50-mesh rice straw and four parts by weight of wheat bran were weighed and mixed evenly. The mixture was then sprayed with deionized water to wet it, so that the moisture content reached 50% to form a substrate for fermentation. The fermentation substrate was piled into a stack with a length of 1 m × width of 1 m × height of 0.3 m. The fermentation temperature was controlled at 30°C, and the substrate was turned over every 24 h. After a total of 7 days of fermentation, a microbial composite microbial agent was obtained.

[0118] Comparative Example 5

[0119] A method for preparing a microbial compound inoculant to promote crop yield, the specific process of which is as follows:

[0120] Three parts by weight of the activated biochar obtained in Preparation Example 4 and 21 parts by weight of the salt-tolerant and alkali-tolerant Trichoderma kolynense liquid obtained in Preparation Example 10 were weighed and mixed. The mixture was then transferred to a temperature environment of 25°C and stirred at a speed of 120 r / min for 19 h to obtain a carbon-based composite microbial agent. One part by weight of the carbon-based composite microbial agent, six parts by weight of 50-mesh rice straw and four parts by weight of wheat bran were weighed and mixed evenly. The mixture was then sprayed with deionized water to wet it, so that the moisture content reached 50% to form a substrate for fermentation. The fermentation substrate was piled into a stack with a length of 1 m × width of 1 m × height of 0.3 m. The fermentation environment temperature was controlled at 30°C. The substrate was turned over once every 24 h. After a total of 7 days of fermentation, a microbial composite microbial agent was obtained.

[0121] 10 kg of soil (taken from Yitiaoshan Town, Jingtai County, Baiyin City, Gansu Province; soil pH 7.63; available phosphorus 30.24 mg / kg; available potassium 156.21 mg / kg; organic matter 1.57 g / kg) was mixed with 200 g of the microbial compound inoculant obtained in Examples 1-4 and Comparative Examples 1-5. The mixture was then placed in flowerpots with a diameter of 50 cm and a height of 40 cm, and the water holding capacity was controlled at 70 ± 2%. Corn seeds were sown to a depth of 6 cm. The plants were then cultured in an environment with a humidity of 60 ± 5% and a temperature of 28 ± 2℃ for 50 days. Fresh weight and plant height were measured, and the results are shown in Table 1 below.

[0122] Table 1. Fertilizer Efficacy of Microbial Compound Inoculants

[0123] Source of materials Fresh weight (g) Plant height (cm) Example 1 73.5 77.6 Example 2 75.2 78.3 Example 3 77.8 81.5 Example 4 79.1 81.8 Comparative Example 1 43.2 46.8 Comparative Example 2 40.7 44.5 Comparative Example 3 39.6 43.1 Comparative Example 4 48.4 50.7 Comparative Example 5 47.9 50.2

[0124] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for preparing a microbial compound inoculant to promote crop yield, characterized in that, The preparation method includes the following steps: Activated biochar and mixed bacterial solution were mixed at a weight ratio of 2~3:10~21 and adsorbed at 25℃ for 15h~19h to obtain a carbon-based composite bacterial agent; Carbon-based compound microbial agent, straw and wheat bran are mixed in a weight ratio of 1:4~6:2~4, and then water is added to wet the mixture to form a fermentation base material. The fermentation base material is then composted to obtain the microbial compound microbial agent.

2. The method for preparing a microbial compound inoculant for promoting crop yield according to claim 1, characterized in that, The method for preparing the activated biochar includes the following steps: Peanut shell particles are pyrolyzed at 400℃~500℃ for 2h~3h to obtain biochar; The activated biochar was obtained by mixing biochar and hydrogen peroxide solution at a solid-liquid ratio of 1g:20mL~30mL and then oxidizing at 25℃ for 1h~2h.

3. The method for preparing a microbial compound inoculant for promoting crop yield according to claim 2, characterized in that, The hydrogen peroxide solution has a mass fraction of 25% to 30%.

4. The method for preparing a microbial compound inoculant for promoting crop yield according to claim 1, characterized in that, The mixed bacterial solution is composed of salt-tolerant and alkali-acclimated Bacillus subtilis solution, salt-tolerant and alkali-acclimated Trichoderma koningii solution, and salt-tolerant and alkali-acclimated Monascus purpureus solution in a weight ratio of 2:1~1.5:0.5~1.

5. The method for preparing a microbial compound inoculant for promoting crop yield according to claim 4, characterized in that, The method for preparing the salt- and alkali-tolerant Bacillus subtilis bacterial suspension includes the following steps: The first domesticated Bacillus subtilis was obtained by inoculating Bacillus subtilis in nutrient broth agar medium with sodium chloride content of 0.5% and culturing it at 30°C for 18-20 h. The first domesticated Bacillus subtilis was inoculated into nutrient broth agar medium with a sodium chloride content of 0.7% and cultured at 30°C for 18-20 h to obtain the second domesticated Bacillus subtilis. The second domesticated Bacillus subtilis was inoculated into nutrient broth agar medium with a sodium chloride content of 1% and cultured at 30°C for 18-20 h to obtain the third domesticated Bacillus subtilis. The third domesticated Bacillus subtilis was inoculated into nutrient broth liquid medium and cultured at 35°C until OD. 600 The salt-tolerant and alkali-tolerant Bacillus subtilis culture solution was obtained with a concentration of 0.6~0.

7.

6. The method for preparing a microbial compound inoculant for promoting crop yield according to claim 4, characterized in that, The preparation method of the salt- and alkali-tolerant Trichoderma acclimatization solution includes the following steps: The first domesticated Trichoderma koningii was obtained by inoculating Trichoderma koningii into PDA agar medium with sodium chloride content of 0.3% and culturing it at 28°C for 20-24 hours. The first domesticated Trichoderma koningii was inoculated into PDA agar medium with a sodium chloride mass fraction of 0.6% and cultured at 28°C for 20-24 h to obtain the second domesticated Trichoderma koningii. The second domesticated Trichoderma Corningensis was inoculated into PDA agar medium with a sodium chloride mass fraction of 1% and cultured at 28℃ for 20-24 h to obtain the third domesticated Trichoderma Corningensis; The third domesticated Trichoderma cornuta was inoculated into PDA liquid medium and cultured at 30°C until OD. 600 The salt- and alkali-tolerant Trichoderma acclimatization solution was obtained with a concentration of 0.7 to 0.

8.

7. The method for preparing a microbial compound inoculant for promoting crop yield according to claim 4, characterized in that, The preparation method of the salt- and alkali-tolerant Monascus purpureus solution includes the following steps: Monascus purpureus was inoculated into malt extract agar medium with sodium chloride content of 0.5% and cultured at 30°C for 28-30 h to obtain the first domesticated Monascus purpureus. The first domesticated Monascus purpureus was inoculated into malt extract agar medium with sodium chloride content of 0.7% and cultured at 30°C for 28-30 h to obtain the second domesticated Monascus purpureus; The second domesticated Monascus was inoculated into malt extract agar medium with 1% sodium chloride and cultured at 30°C for 28-30 h to obtain the third domesticated Monascus. The third domesticated Monascus purpureus was inoculated into malt extract liquid medium and cultured at 35°C until OD. 600 The salt- and alkali-tolerant Monascus purpureus solution was obtained with a concentration of 0.7 to 0.

8.

8. The method for preparing a microbial compound inoculant for promoting crop yield according to claim 1, characterized in that, The moisture content of the substrate to be fermented is 40%~50%.

9. The method for preparing a microbial compound inoculant for promoting crop yield according to claim 1, characterized in that, The conditions for composting fermentation include a stack size of 1m long × 1m wide × 0.2m~0.3m high, a fermentation environment temperature of 28℃~30℃, a fermentation time of 5~7 days, and turning the material once every 24 hours.

10. A microbial compound inoculant for promoting crop yield, characterized in that, The microbial compound inoculant is prepared by the method for preparing a microbial compound inoculant for promoting crop yield as described in any one of claims 1 to 9.