Composite bacterial fertilizer with microorganisms loaded by carbon material and preparation method of composite bacterial fertilizer

Abstract

The invention discloses a compound bacterial fertilizer with microorganisms loaded by a carbon material and a preparation method of the compound bacterial fertilizer, and belongs to the technical field of fertilizer preparation. The preparation method comprises the following steps: mixing and stirring an activated carbon material and a mixed bacterial liquid according to a weight part ratio of (2-3): (6-10), and filtering to obtain a carbon immobilized bacterial agent; mixing the carbon immobilized microbial inoculum, distiller's grains and agricultural by-products according to the weight part ratio of 2: (5-6): (1-3), adding water, wetting to form a fermentation substrate, and composting and fermenting the fermentation substrate to obtain a fermented bacterial fertilizer mixture; the fermented bacterial fertilizer mixture and the fertilizer synergist are mixed according to the weight part ratio of 1: (0.01-0.02) to obtain the compound bacterial fertilizer. The activated carbon material and the mixed bacterial liquid are mixed, stirred and adsorbed to obtain the immobilized bacterial agent, the immobilized bacterial agent, the distiller's grains and the agricultural by-products are mixed and fermented to obtain the fermented bacterial fertilizer mixture, and finally the fermented bacterial fertilizer mixture is mixed with the fertilizer efficiency synergist, so that the prepared composite bacterial agent has good fertilizer efficiency.

Description

Technical Field

[0001] This invention belongs to the field of fertilizer preparation technology, specifically relating to a compound microbial fertilizer loaded with carbon materials and its preparation method. Background Technology

[0002] Agriculture is the foundation of the national economy, and fertilizer is a fundamental production material widely used in agricultural production to supply crops with the nutrients needed for growth and development and to improve soil structure. Chemical fertilizers dominate fertilizer use, primarily due to their rapid dissolution and nutrient release, which can significantly increase yields in a short period. While chemical fertilizers offer the advantage of quick-acting action, the rapid development of modern agriculture has led to an increasing demand for fertilizers in farmland, resulting in significant harms such as soil nutrient imbalances, soil depletion, and eutrophication. In today's world, where environmental protection, sustainable agriculture, and pollution-free agriculture are increasingly emphasized, chemical fertilizers clearly cannot meet the requirements of environmentally friendly and sustainable development. Therefore, technological innovation and product development to produce environmentally friendly and efficient modern fertilizers are of great importance. Microbial fertilizers are biological fertilizers made from one or more beneficial microorganisms, culture media, and additives. Their fertilizer effect is mainly achieved by providing a "microbial community" beneficial to crop growth. Only when these beneficial microorganisms have normal growth and reproduction functions can they convert some substances in the soil that crops cannot directly utilize into nutrients that can be absorbed and utilized. Furthermore, the secondary metabolites produced by these microorganisms have a stimulating effect on plants, promoting the absorption of nutrients, and at the same time, they have an antagonistic effect on certain pathogenic microorganisms.

[0003] Patent CN117700273A discloses a compound microbial fertilizer and its preparation method. This invention uses *Serratia marcescens* and *Bacillus belye* as inoculants in the compound microbial fertilizer. The combined use of these two microorganisms results in a better control effect against bacterial wilt in tomatoes than biofertilizers containing a single inoculant. Furthermore, both have a synergistic effect on promoting tomato plant growth. Patent CN118955208A discloses a compound microbial fertilizer, its preparation method, and its application. This invention uses *Bacillus subtilis*, *Bacillus belye*, rhizobia, EM inoculants, and *Trichoderma* as microbial raw materials to prepare a compound microbial fertilizer. Applying this fertilizer to peanut cultivation significantly improves peanut germination rate and yield, reduces peanut disease incidence, and enhances the control effect against peanut root rot.

[0004] While the aforementioned microbial fertilizers have achieved certain fertilization effects, their effectiveness is often reduced during direct application to the soil due to factors such as soil temperature, pH, and rainwater runoff. They are also sometimes rejected by native soil microorganisms. Therefore, minimizing the impact of the soil environment on microbial fertilizers is of great significance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention involves immobilizing a microbial agent obtained by mixing and adsorbing activated carbon materials and mixed bacterial solutions. This immobilized agent is then fermented with distiller's grains and agricultural byproducts to obtain a fermented microbial fertilizer mixture. Finally, this mixture is combined with a fertilizer synergist, resulting in a composite microbial agent with excellent fertilizer efficacy, thereby solving the technical problems mentioned in the background art. Specifically, the technical solution of this invention includes the following: One objective of this invention is to provide a method for preparing a compound microbial fertilizer loaded with carbon materials, the method comprising the following steps: The activated carbon material and the mixed bacterial solution were mixed and stirred in a weight ratio of 2~3:6~10, and then filtered to obtain the carbon-immobilized bacterial agent. Carbon-immobilized microbial agent, liquor lees and agricultural by-products are mixed in a weight ratio of 2:5~6:1~3, and water is added to wet the mixture to form a fermentation substrate. The fermentation substrate is then composted to obtain a fermented microbial fertilizer mixture. The compound microbial fertilizer is obtained by mixing the fermented microbial fertilizer mixture and the fertilizer synergist at a weight ratio of 1:0.01~0.02.

[0006] Furthermore, the preparation method of the activated carbon material includes the following steps: Straw pellets are calcined at 500℃~600℃ for 1h~2h to obtain charcoal pellets; Carbon particles and nitric acid solution are mixed at a weight ratio of 1:30~35 and then heated to 70℃~80℃ for 2h~3h to obtain carbon oxide particles; The activated carbon material is obtained by mixing carbon oxide particles, amino acid solution and p-toluenesulfonic acid in a weight ratio of 1:6~8:0.01~0.02 and heating to 110℃~120℃ for 2h~3h.

[0007] Furthermore, the straw pellets include corn straw pellets with a mesh size of 10.

[0008] Furthermore, the nitric acid solution has a mass fraction of 45%.

[0009] Furthermore, the amino acid solution comprises a 30% L-serine solution by mass.

[0010] Furthermore, the mixed bacterial solution is composed of Candida utilis seed solution, Bacillus amyloliquefaciens seed solution and Bacillus licheniformis seed solution in a weight ratio of 0.7:2~3:0.4.

[0011] Furthermore, the OD of the *Candida utilis* seed culture... 600 The OD value of the Bacillus amyloliquefaciens seed solution is 0.8. 600 The OD value of the Bacillus licheniformis seed solution is 0.6. 600 It is 0.8.

[0012] Furthermore, the mixing conditions include a stirring speed of 100 r / min to 150 r / min, a stirring temperature of 25°C, and a stirring time of 12 h to 15 h.

[0013] Furthermore, the agricultural by-products include wheat bran.

[0014] Furthermore, the water content of the fermentation substrate is 40% to 50%.

[0015] Furthermore, the conditions for composting fermentation include a stack size of 1m long × 1m wide × 0.4m high, a fermentation environment temperature of 30℃~35℃, a fermentation time of 4 to 6 days, and turning the material once every 24 hours.

[0016] Furthermore, the fertilizer synergist includes polyglutamic acid of type 1002.

[0017] The second objective of this invention is to provide a compound microbial fertilizer that uses carbon materials to support microorganisms.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses carbon material obtained from the high-temperature calcination and carbonization of straw as an immobilization carrier. The carbon material undergoes oxidation treatment to activate its surface, generating oxygen-containing groups such as hydroxyl and carboxyl groups. Then, it undergoes a chemical condensation reaction with amino acids to obtain activated carbon material. On the one hand, the introduced amino acids can serve as a carbon and nitrogen source for microbial metabolism; on the other hand, hydrogen bonding enhances the immobilization load on microorganisms, making them less prone to detachment. The framework protection of the carbon material helps improve the biological activity of microorganisms, thereby increasing fermentation activity. The immobilized microbial agent obtained after mixing and adsorbing the activated carbon material with a mixed bacterial solution is then fermented with distillery lees and agricultural byproducts. Distillery lees contain abundant nutrients such as protein and amino acids, while the loose and porous nature of wheat bran ensures good aeration during fermentation, thus promoting microbial fermentation. This not only improves the vitality of the microorganisms but also enriches the variety of nutrients. Finally, it is mixed with a fertilizer synergist, resulting in a compound microbial agent with excellent fertilizer effects. Detailed Implementation

[0019] 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.

[0020] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0021] Preparation Example 1 The preparation method of Candida utilis seed culture is as follows: A loopful of *Candida utilis* strain CICC 31430 was streaked gently back and forth on the surface of sterilized malt extract agar medium using a sterilized inoculation loop. The medium was then incubated at 25°C for 24 hours to obtain activated *Candida utilis*. Subsequently, another loopful of the activated *Candida utilis* was inoculated into sterilized malt extract agar medium and incubated at 25°C with shaking at 100 rpm until the OD of the culture was reached. 600 The concentration reached 0.8, thus completing the preparation of the Candida utilis seed culture.

[0022] Preparation Example 2 The preparation method of Bacillus amyloliquefaciens seed culture is as follows: A loopful of *Bacillus amyloliquefaciens* strain CICC 10158 was streaked gently back and forth on sterilized potato dextrose agar medium using a sterilized inoculation loop. The medium was then incubated at 25°C for 24 hours to obtain activated *Bacillus amyloliquefaciens*. Subsequently, a loopful of the activated *Bacillus amyloliquefaciens* was inoculated into sterilized malt extract medium using a sterilized inoculation loop and incubated at 30°C with shaking at 100 rpm until the OD of the bacterial culture reached a certain level. 600 The concentration reached 0.6, thus completing the preparation of Bacillus amyloliquefaciens seed culture.

[0023] Preparation Example 3 The preparation method of Bacillus licheniformis seed liquid is as follows: A loopful of Bacillus licheniformis strain CICC 10100 was streaked gently back and forth on the surface of sterilized broth agar medium using a sterilized inoculation loop. The medium was then incubated at 25°C for 24 hours to obtain activated Bacillus licheniformis. Subsequently, another loopful of the activated Bacillus licheniformis was inoculated into sterilized broth medium using a sterilized inoculation loop and incubated at 30°C with shaking at 100 rpm until the OD of the bacterial culture reached its maximum. 600The concentration reached 0.8, thus completing the preparation of Bacillus licheniformis seed solution.

[0024] Preparation Example 4 The preparation method of Bacillus licheniformis seed liquid is as follows: A loopful of Bacillus licheniformis strain CICC 10100 was streaked gently back and forth on the surface of sterilized broth agar medium using a sterilized inoculation loop. The medium was then incubated at 25°C for 24 hours to obtain activated Bacillus licheniformis. Subsequently, another loopful of the activated Bacillus licheniformis was inoculated into sterilized broth medium using a sterilized inoculation loop and incubated at 30°C with shaking at 100 rpm until the OD of the bacterial culture reached its maximum. 600 The seed culture of Bacillus licheniformis was prepared by reaching version 1.0.

[0025] Preparation Example 5 The preparation method of the mixed bacterial solution is as follows: Weigh 0.7 parts by weight of the Candida utilis seed culture obtained in Preparation Example 1, 2 parts by weight of the Bacillus amyloliquefaciens seed culture obtained in Preparation Example 2, and 0.4 parts by weight of the Bacillus licheniformis seed culture obtained in Preparation Example 3, mix them together, and store them at 5°C for later use.

[0026] Preparation Example 6 The preparation method of the mixed bacterial solution is as follows: Weigh 0.7 parts by weight of the Candida utilis seed culture obtained in Preparation Example 1, 2.4 parts by weight of the Bacillus amyloliquefaciens seed culture obtained in Preparation Example 2, and 0.4 parts by weight of the Bacillus licheniformis seed culture obtained in Preparation Example 3, mix them together, and store them at 5°C for later use.

[0027] Preparation Example 7 The preparation method of the mixed bacterial solution is as follows: Weigh 0.7 parts by weight of the Candida utilis seed culture obtained in Preparation Example 1, 2.8 parts by weight of the Bacillus amyloliquefaciens seed culture obtained in Preparation Example 2, and 0.4 parts by weight of the Bacillus licheniformis seed culture obtained in Preparation Example 3, mix them together, and store them at 5°C for later use.

[0028] Preparation Example 8 The preparation method of the mixed bacterial solution is as follows: Weigh 0.7 parts by weight of the Candida utilis seed culture obtained in Preparation Example 1, 3 parts by weight of the Bacillus amyloliquefaciens seed culture obtained in Preparation Example 2, and 0.4 parts by weight of the Bacillus licheniformis seed culture obtained in Preparation Example 3, mix them together, and store them at 5°C for later use.

[0029] Preparation Example 9 The preparation method of the mixed bacterial solution is as follows: Weigh 0.7 parts by weight of the Candida utilis seed culture obtained in Preparation Example 1, 3 parts by weight of the Bacillus amyloliquefaciens seed culture obtained in Preparation Example 2, and 0.4 parts by weight of the Bacillus licheniformis seed culture obtained in Preparation Example 4, mix them together, and store them at 5°C for later use.

[0030] Preparation Example 10 The preparation method of activated carbon materials is as follows: After rinsing the corn stalks with water, they were dried in an oven at 105℃ for 15 hours. The stalks were then removed from the 10-mesh sieve to obtain corn stalk pellets. These pellets were placed in a muffle furnace, which was then heated to 500℃ at a rate of 10℃ / min for 1 hour of high-temperature carbonization. After carbonization, the pellets were cooled to room temperature to obtain charcoal particles. One part by weight of the charcoal particles and 30 parts by weight of a 45% nitric acid solution were placed together in a reactor and ultrasonically mixed and dispersed at 400W for 10 minutes. Subsequently, the mixture was heated to 70℃ for oxidative treatment for 2 hours. After treatment, the solid particles were removed by centrifugation and repeatedly rinsed with deionized water until the pH of the rinse water was neutral. Then, they were dried in a vacuum drying oven at 70°C for 12 hours to obtain carbon oxide particles. One part by weight of carbon oxide particles, six parts by weight of a 30% L-serine solution, and 0.01 parts by weight of p-toluenesulfonic acid were weighed and mixed, and then ultrasonically dispersed at 400W for 10 minutes to ensure uniform dispersion. The mixture was then stirred at 200 rpm and heated to 110°C for 2 hours. After the reaction, the solid obtained by centrifugation was repeatedly rinsed with deionized water until the pH of the rinse water was neutral. Then, it was dried in a vacuum drying oven at 70°C for 12 hours to obtain activated carbon material.

[0031] Preparation Example 11 The preparation method of activated carbon materials is as follows: After rinsing the corn stalks with water, they were dried in an oven at 105℃ for 15 hours. The stalks were then removed and passed through a 10-mesh sieve to obtain corn stalk pellets. These pellets were placed in a muffle furnace, which was then heated to 550℃ at a rate of 10℃ / min for 1 hour of high-temperature carbonization. After carbonization, the pellets were cooled to room temperature to obtain charcoal particles. One part by weight of the charcoal particles and 32 parts by weight of a 45% nitric acid solution were placed together in a reactor and ultrasonically mixed and dispersed at 400W for 10 minutes. Subsequently, the mixture was heated to 75℃ for oxidative treatment for 2 hours. After treatment, the solid particles were removed by centrifugation and repeatedly rinsed with deionized water until the pH of the rinse water was neutral. Then, they were dried in a vacuum drying oven at 70°C for 12 hours to obtain carbon oxide particles. One part by weight of carbon oxide particles, seven parts by weight of a 30% L-serine solution, and 0.015 parts by weight of p-toluenesulfonic acid were weighed and mixed, then ultrasonically dispersed at 400W for 10 minutes to ensure uniform dispersion. The mixture was then stirred at 200 rpm and heated to 110°C for 2.5 hours. After the reaction, the solid obtained by centrifugation was repeatedly rinsed with deionized water until the pH of the rinse water was neutral. Then, it was dried in a vacuum drying oven at 70°C for 12 hours to obtain activated carbon material.

[0032] Preparation Example 12 The preparation method of activated carbon materials is as follows: After rinsing the corn stalks with water, they were dried in an oven at 105℃ for 15 hours. The stalks were then removed and passed through a 10-mesh sieve to obtain corn stalk pellets. These pellets were placed in a muffle furnace, which was then heated to 550℃ at a rate of 10℃ / min for 2 hours of high-temperature carbonization. After carbonization, the pellets were cooled to room temperature to obtain charcoal particles. One part by weight of the charcoal particles and 34 parts by weight of a 45% nitric acid solution were placed together in a reactor and ultrasonically mixed and dispersed at 400W for 10 minutes. Subsequently, the mixture was heated to 80℃ for oxidative treatment for 2 hours. After treatment, the solid particles were removed by centrifugation and repeatedly rinsed with deionized water until the pH of the rinse water was neutral. Then, they were dried in a vacuum drying oven at 70°C for 12 hours to obtain carbon oxide particles. One part by weight of carbon oxide particles, seven parts by weight of a 30% L-serine solution, and 0.02 parts by weight of p-toluenesulfonic acid were weighed and mixed, then ultrasonically dispersed at 400W for 10 minutes to ensure uniform dispersion. The mixture was then stirred at 200 rpm and heated to 120°C for 2.5 hours. After the reaction, the solid obtained by centrifugation was repeatedly rinsed with deionized water until the pH of the rinse water was neutral. Then, it was dried in a vacuum drying oven at 70°C for 12 hours to obtain activated carbon material.

[0033] Preparation Example 13 The preparation method of activated carbon materials is as follows: After rinsing the corn stalks with water, they were dried in an oven at 105℃ for 15 hours. The stalks were then removed and passed through a 10-mesh sieve to obtain corn stalk pellets. These pellets were placed in a muffle furnace, which was then heated to 600℃ at a rate of 10℃ / min for 2 hours of high-temperature carbonization. After carbonization, the pellets were cooled to room temperature to obtain charcoal particles. One part by weight of the charcoal particles and 35 parts by weight of a 45% nitric acid solution were placed together in a reactor and ultrasonically mixed and dispersed at 400W for 10 minutes. Subsequently, the mixture was heated to 80℃ for oxidation treatment for 3 hours. After treatment, the solid particles were removed by centrifugation and repeatedly rinsed with deionized water until the pH of the rinse water was neutral. Then, they were dried in a vacuum drying oven at 70°C for 12 hours to obtain carbon oxide particles. One part by weight of carbon oxide particles, eight parts by weight of a 30% L-serine solution, and 0.02 parts by weight of p-toluenesulfonic acid were weighed and mixed, and then ultrasonically dispersed at 400W for 10 minutes to ensure uniform dispersion. The mixture was then stirred at 200 rpm and heated to 120°C for 3 hours. After the reaction, the solid obtained by centrifugation was repeatedly rinsed with deionized water until the pH of the rinse water was neutral. Then, it was dried in a vacuum drying oven at 70°C for 12 hours to obtain activated carbon material.

[0034] Preparation Example 14 The preparation method of activated carbon materials is as follows: After rinsing the corn stalks with water, they were dried in an oven at 105°C for 15 hours. The stalks were then removed from the 10-mesh sieve to obtain corn stalk pellets. These pellets were placed in a muffle furnace, which was then heated to 700°C at a rate of 10°C / min for high-temperature carbonization for 2 hours. The remaining preparation process was the same as in Preparation Example 13.

[0035] Example 1

[0036] A method for preparing a compound microbial fertilizer loaded with carbon materials specifically includes the following steps: Two parts by weight of the activated carbon material obtained in Preparation Example 10 and six parts by weight of the mixed bacterial solution obtained in Preparation Example 5 were weighed and mixed. The mixture was then stirred at 100 r / min for 12 h at a temperature of 25 °C. After stirring, the mixture was filtered to obtain the carbon-immobilized bacterial agent. Two parts by weight of the carbon-immobilized bacterial agent, five parts by weight of baijiu lees and one part by weight of wheat bran were weighed and mixed evenly. Deionized water was then sprayed on the mixture to make its moisture content reach 40% to obtain the fermentation substrate. The fermentation substrate was piled into a stack with a length of 1 m × width of 1 m × height of 0.4 m. The temperature was controlled at 30 °C and the mixture was turned over every 24 h. The fermentation was carried out for a total of 4 days to obtain the fermented bacterial fertilizer mixture. One part by weight of the fermented bacterial fertilizer mixture and 0.01 parts by weight of polyglutamic acid fertilizer synergist of type 1002 were weighed and mixed evenly to obtain the compound bacterial fertilizer.

[0037] Example 2

[0038] A method for preparing a compound microbial fertilizer loaded with carbon materials specifically includes the following steps: Two parts by weight of the activated carbon material obtained in Preparation Example 11 and eight parts by weight of the mixed bacterial solution obtained in Preparation Example 6 were weighed and mixed. The mixture was then stirred at 100 r / min for 13 h at a temperature of 25 °C. After stirring, the mixture was filtered to obtain the carbon-immobilized bacterial agent. Two parts by weight of the carbon-immobilized bacterial agent, five parts by weight of baijiu lees and two parts by weight of wheat bran were weighed and mixed evenly. Deionized water was then sprayed on the mixture to make its moisture content reach 40% to obtain the fermentation substrate. The fermentation substrate was piled into a stack with a length of 1 m × width of 1 m × height of 0.4 m. The temperature was controlled at 30 °C, and the mixture was turned over every 24 h. The fermentation was carried out for a total of 5 days to obtain the fermented bacterial fertilizer mixture. One part by weight of the fermented bacterial fertilizer mixture and 0.01 parts by weight of polyglutamic acid fertilizer synergist of type 1002 were weighed and mixed evenly to obtain the compound bacterial fertilizer.

[0039] Example 3

[0040] A method for preparing a compound microbial fertilizer loaded with carbon materials specifically includes the following steps: Three parts by weight of the activated carbon material obtained in Preparation Example 12 and eight parts by weight of the mixed bacterial solution obtained in Preparation Example 7 were weighed and mixed. The mixture was then stirred at 150 r / min for 14 h at a temperature of 25 °C. After stirring, the mixture was filtered to obtain the carbon-immobilized bacterial agent. Two parts by weight of the carbon-immobilized bacterial agent, six parts by weight of baijiu lees and two parts by weight of wheat bran were weighed and mixed evenly. Deionized water was then sprayed on the mixture to make its moisture content reach 50% to obtain the fermentation substrate. The fermentation substrate was piled into a stack with a length of 1 m × width of 1 m × height of 0.4 m. The temperature was controlled at 35 °C, and the mixture was turned over every 24 h. The fermentation was carried out for a total of 6 days to obtain the fermented bacterial fertilizer mixture. One part by weight of the fermented bacterial fertilizer mixture and 0.01 parts by weight of polyglutamic acid fertilizer synergist of type 1002 were weighed and mixed evenly to obtain the compound bacterial fertilizer.

[0041] Example 4

[0042] A method for preparing a compound microbial fertilizer loaded with carbon materials specifically includes the following steps: Weigh 3 parts by weight of the activated carbon material obtained in Preparation Example 13 and 10 parts by weight of the mixed bacterial solution obtained in Preparation Example 8, mix them, and then stir them at a stirring speed of 150 r / min for 15 h at a temperature of 25 °C. After stirring, filter to obtain carbon immobilized bacterial agent. Weigh 2 parts by weight of carbon immobilized bacterial agent, 6 parts by weight of baijiu lees and 3 parts by weight of wheat bran, mix them evenly, and then spray deionized water to make its moisture content reach 50% to obtain fermentation substrate. Pile the fermentation substrate into a pile with a length of 1 m × width of 1 m × height of 0.4 m, and then control the temperature at 35 °C. Turn the material once every 24 h and ferment for a total of 6 days to obtain fermented bacterial fertilizer mixture. Weigh 1 part by weight of fermented bacterial fertilizer mixture and 0.02 parts by weight of polyglutamic acid fertilizer synergist of type 1002, mix them evenly to obtain compound bacterial fertilizer.

[0043] Comparative Example 1 A method for preparing a compound microbial fertilizer loaded with carbon materials specifically includes the following steps: The mixed bacterial solution in Example 4 was replaced with the mixed bacterial solution obtained in Preparation Example 9, and the rest of the preparation process was the same as in Example 4.

[0044] Comparative Example 2 A method for preparing a compound microbial fertilizer loaded with carbon materials specifically includes the following steps: The activated carbon material in Example 4 was replaced with the activated carbon material obtained in Preparation Example 14, and the rest of the preparation process was the same as in Example 4.

[0045] Comparative Example 3 A method for preparing a compound microbial fertilizer loaded with carbon materials specifically includes the following steps: In Example 4, the polyglutamic acid was replaced with polyglutamic acid of type 1001. The rest of the preparation process was the same as in Example 4. It was found that the polyglutamic acid and the fermented fertilizer mixture were difficult to mix evenly. This may be because the polyglutamic acid of type 1001 was too viscous and difficult to mix evenly with the fermented fertilizer mixture directly. The preparation failed.

[0046] Fertilizer efficacy verification: Take a plastic flowerpot with a diameter of 20cm and a height of 15cm. First, fill the plastic flowerpot with soil separately, controlling the filling height to 9cm. Then, mix the compound microbial fertilizer prepared in Examples 1-4 and Comparative Examples 1-2 evenly with the soil (the mixing ratio of compound microbial fertilizer to soil is 1:20 by weight). Then, spread it evenly on the top layer of soil in the plastic flowerpot to a height of 3cm. Then, plant the pre-cultivated cabbage seedlings into the plastic flowerpot and water them to keep the soil moisture content within the range of 70±2%. Finally, measure the fresh weight and root length on the 30th day. The results are shown in Table 1 below.

[0047] Table 1 Fertilizer Efficiency Test The following conclusions can be drawn from Table 1 above: (1) It can be seen from Examples 1 to 4 that the compound microbial fertilizer prepared by the present invention has good fertilizer effect.

[0048] (2) Comparative Example 1 shows that if the OD600 is too high, it may lead to over-cultivation, which will greatly reduce the vitality of the bacteria and result in poor fertilizer efficiency of the compound microbial fertilizer prepared by subsequent fermentation.

[0049] (3) Comparative Example 2 shows that the high temperature during the high-temperature calcination and carbonization of corn straw particles may have caused excessive damage to the pore structure of the carbon material, which weakened the adsorption and fixation of microorganisms, resulting in poor fertilizer performance of the final compound microbial fertilizer.

[0050] 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 compound microbial fertilizer loaded with carbon materials, characterized in that, The preparation method includes the following steps: The activated carbon material and the mixed bacterial solution were mixed and stirred in a weight ratio of 2~3:6~10, and then filtered to obtain the carbon-immobilized bacterial agent. Carbon-immobilized microbial agent, liquor lees and agricultural by-products are mixed in a weight ratio of 2:5~6:1~3, and water is added to wet the mixture to form a fermentation substrate. The fermentation substrate is then composted to obtain a fermented microbial fertilizer mixture. The compound microbial fertilizer is obtained by mixing the fermented microbial fertilizer mixture and the fertilizer synergist at a weight ratio of 1:0.01~0.

02.

2. The method for preparing a compound microbial fertilizer loaded with carbon materials according to claim 1, characterized in that, The preparation method of the activated carbon material includes the following steps: Straw pellets are calcined at 500℃~600℃ for 1h~2h to obtain charcoal pellets; Carbon particles and nitric acid solution are mixed at a weight ratio of 1:30~35 and then heated to 70℃~80℃ for 2h~3h to obtain carbon oxide particles; The activated carbon material is obtained by mixing carbon oxide particles, amino acid solution and p-toluenesulfonic acid in a weight ratio of 1:6~8:0.01~0.02 and heating to 110℃~120℃ for 2h~3h.

3. The method for preparing a compound microbial fertilizer loaded with carbon materials according to claim 2, characterized in that, The amino acid solution includes an L-serine solution with a mass fraction of 30%.

4. The method for preparing a compound microbial fertilizer loaded with carbon materials according to claim 1, characterized in that, The mixed bacterial solution is composed of Candida utilis seed solution, Bacillus amyloliquefaciens seed solution and Bacillus licheniformis seed solution in a weight ratio of 0.7:2~3:0.

4.

5. The method for preparing a compound microbial fertilizer loaded with carbon materials according to claim 1, characterized in that, The OD of the *Candida utilis* seed culture 600 The OD value of the Bacillus amyloliquefaciens seed solution is 0.

8. 600 The OD value of the Bacillus licheniformis seed solution is 0.

6. 600 It is 0.

8.

6. The method for preparing a compound microbial fertilizer loaded with carbon materials according to claim 1, characterized in that, The agricultural by-products include wheat bran.

7. The method for preparing a compound microbial fertilizer loaded with carbon materials according to claim 1, characterized in that, The moisture content of the fermentation substrate is 40% to 50%.

8. The method for preparing a compound microbial fertilizer loaded with carbon materials according to claim 1, characterized in that, The conditions for composting fermentation include a stack size of 1m long × 1m wide × 0.4m high, a fermentation environment temperature of 30℃~35℃, a fermentation time of 4 to 6 days, and turning the material once every 24 hours.

9. The method for preparing a compound microbial fertilizer loaded with carbon materials according to claim 1, characterized in that, The fertilizer synergist includes polyglutamic acid with model number 1002.

10. A compound microbial fertilizer loaded with carbon materials, characterized in that, The compound microbial fertilizer is prepared by any one of the methods described in claims 1 to 9 for preparing a compound microbial fertilizer by loading microorganisms onto carbon materials.

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