Microbial bacterial fertilizer, its preparation method and application

Abstract

The application discloses a microbial fertilizer and a preparation method and application thereof. The microbial fertilizer comprises the following raw material components in parts by weight: urea 30-50 parts, di-potassium hydrogen phosphate 20-40 parts, calcium ammonium nitrate 10-20 parts, bentonite 10-30 parts, oligosaccharide 3-10 parts, biochar 60-120 parts, microbial agent 20-40 parts, polyvinyl alcohol aqueous solution 3-10 parts, and microbial agent culture solution 120-300 parts. The microbial fertilizer is suitable for various grains and vegetables and can promote yield increase. The combination of pecticoligosaccharide and ulvan oligosaccharide in the microbial fertilizer component can promote lettuce growth and yield increase, the combination of peanut shell biochar and water caltrop shell biochar can promote cotton yield increase, and the combination of bacillus mycoides and bacillus atrophaeus can improve pepper yield.

Description

Technical Field

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

[0002] Microbial fertilizers, as an important component of green agriculture, are considered a key way to reduce reliance on chemical fertilizers, improve soil, and enhance sustainable crop productivity. However, their practical application faces many inherent defects that severely restrict the stable performance of their efficacy and their widespread market acceptance. From a biological perspective, the core defect of microbial fertilizers lies in the unreliability of the survival, colonization, and functional expression of functional strains in complex field environments. Even strains that perform well under controlled conditions often lose their activity or fail to colonize sustainably after being applied to the soil due to drastic fluctuations in temperature, humidity, pH, and intense competition from native microorganisms. This makes it difficult to realize their expected functions such as promoting growth, fixing nitrogen, or solubilizing phosphorus. This inconsistency in field effects is the most criticized common problem.

[0003] Closely related to biological deficiencies are shortcomings in technology and product formulation. Currently, the formulation technology for most commercial products is still immature. Commonly used carriers such as peat and vermiculite have poor compatibility and stability with bacterial strains, making it difficult to provide an effective protective barrier for live bacteria throughout storage, transportation, and application. This results in short product shelf life and rapid decline in live bacteria count, further exacerbating the unpredictability of effects in field applications. In addition, there is a scarcity of high-quality and efficient functional bacterial strains, and the screening mechanisms have systematic biases. Many studies focus too much on a single growth-promoting indicator of the strain under ideal conditions, while neglecting its compatibility and broad-spectrum adaptability with specific crop root systems and soil ecosystems. This leads to vastly different performance of the developed strains when promoted to different regions and crops. The soil environment created by the long-term excessive application of chemical fertilizers in agricultural production can inhibit or mask the effectiveness of microbial fertilizers, resulting in a negative impression of "poor results" and thus falling into a vicious cycle of "the less people believe in them, the less they use them." This reflects that there are still fundamental misconceptions in the current understanding and application strategies of microbial fertilizers. It is urgent to organically combine strain selection, intelligent formulation development, interdisciplinary system verification, and targeted agronomic extension to break through these interconnected bottlenecks and truly unleash their ecological and economic benefits. Summary of the Invention

[0004] The purpose of this invention is to provide a microbial fertilizer, its preparation method, and its application.

[0005] A microbial fertilizer comprises the following raw material components in parts by weight: 30-50 parts urea, 20-40 parts dipotassium hydrogen phosphate, 10-20 parts calcium ammonium nitrate, 10-30 parts bentonite, 3-10 parts oligosaccharide, 60-120 parts biochar, 20-40 parts microbial inoculant, 3-10 parts polyvinyl alcohol aqueous solution, and 120-300 parts inoculant culture medium.

[0006] The oligosaccharide is a mixture of pectin oligosaccharide and ulmoides oligosaccharide in a mass ratio of (1-3):1.

[0007] The pectin oligosaccharide has an average degree of polymerization of 4-8; the ulna oligosaccharide has an average degree of polymerization of 5-10.

[0008] The biochar is a mixture of peanut shell biochar and water chestnut shell biochar in a mass ratio of (2-4):1.

[0009] The preparation method of the biochar is as follows: peanut shells and water chestnut shells are dried and placed in a carbonization furnace, carbonized at 450-600℃ for 4-8 hours, cooled to room temperature (25℃), pulverized, and passed through a 60-100 mesh sieve to obtain biochar.

[0010] The microbial agent is Bacillus mycoides (B. mycoides). Bacillus mycoides TA-203 inoculant and Bacillus atrophus ( Bacillus atrophaeus A126 microbial agent is a mixture of ingredients at a mass ratio of (1-3):1.

[0011] The Bacillus mycoides, with accession number CGMCC No. 19224, was purchased from the China General Microbiological Culture Collection Center, and the viable count in the inoculum was 1-4 × 10⁻⁶. 8 CFU / g, the Bacillus atrophus ( Bacillus atrophaeus A126, with accession number CGMCC No. 32444, was purchased from the China General Microbiological Culture Collection Center (CGMCC). The viable count in the inoculum is 2-5 × 10⁻⁵. 8 CFU / g.

[0012] The bacterial culture medium is 3-5 wt% brown sugar water.

[0013] The preparation method of the microbial fertilizer is carried out according to the following steps: (1) Add biochar and microbial agent to the microbial agent culture medium, then place it in a constant temperature shaker at 28-32℃ for 18-36h, and then dry it by vacuum spray to prepare a biochar-based composite microbial agent with a water content of 6-10%. (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 20-40 minutes at a speed of 60-100 rpm. Spray polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated.

[0014] The mass percentage concentration of the polyvinyl alcohol aqueous solution is 3-6%.

[0015] The beneficial effects of this invention: The microbial fertilizer of this invention is suitable for various grains and vegetables, promoting their yield increase. The combined use of pectin oligosaccharide and ulmoides oligosaccharide in the fertilizer components promotes lettuce growth and increases yield; the combined use of peanut shell biochar and water chestnut shell biochar promotes cotton yield increase; and Bacillus mycoides (…) Bacillus mycoides TA-203 inoculant and Bacillus atrophus ( Bacillus atrophaeus The combined use of A126 microbial agent can increase chili pepper yield. Detailed Implementation

[0016] To facilitate understanding of the present invention, a more comprehensive description will be given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0017] Example 1 A microbial fertilizer comprises the following raw material components in parts by weight: 40 parts urea, 32 parts dipotassium hydrogen phosphate, 15 parts calcium ammonium nitrate, 16 parts bentonite, 8 parts oligosaccharide, 95 parts biochar, 30 parts microbial agent, 8 parts polyvinyl alcohol aqueous solution, and 220 parts 4 wt% brown sugar water.

[0018] The oligosaccharide is a mixture of pectin oligosaccharide and Ulva oligosaccharide in a mass ratio of 2:1. The average degree of polymerization of the pectin oligosaccharide is 6; the average degree of polymerization of the Ulva oligosaccharide is 8.

[0019] The biochar is a mixture of peanut shell biochar and water chestnut shell biochar at a mass ratio of 3:1. The preparation method of the biochar is as follows: the peanut shells and water chestnut shells are dried and placed in a carbonization furnace, carbonized at 520℃ for 6 hours, cooled to room temperature (25℃), pulverized, and passed through an 80-mesh sieve to obtain biochar.

[0020] The microbial agent is Bacillus mycoides (B. mycoides). Bacillus mycoides TA-203 inoculant and Bacillus atrophus ( Bacillus atrophaeus The A126 bacterial agent is a mixture prepared by mixing bacteria at a mass ratio of 2:1. The Bacillus mycoides has the preservation number CGMCC No. 19224, and the viable count in the bacterial agent is 3 × 10⁻⁶. 8CFU / g, the Bacillus atrophus ( Bacillus atrophaeus The A126 culture has the CGMCC No. 32444 preservation number and contains 3 × 10⁻⁶ viable bacteria. 8 CFU / g.

[0021] The preparation method of the microbial fertilizer is carried out according to the following steps: (1) Add biochar and microbial agent to the microbial agent culture medium, then place it in a constant temperature shaker at 30℃ for 24h, and then dry it by vacuum spray to prepare a biochar-based composite microbial agent with a water content of 8%. (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 30 minutes at a speed of 80 rpm. Spray 4.5 wt% polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated.

[0022] Example 2 A microbial fertilizer comprises the following raw material components in parts by weight: 30-50 parts urea, 22 parts dipotassium hydrogen phosphate, 12 parts calcium ammonium nitrate, 13 parts bentonite, 4 parts oligosaccharide, 70 parts biochar, 22 parts microbial inoculant, 4 parts polyvinyl alcohol aqueous solution, and 160 parts 3wt% brown sugar water.

[0023] The oligosaccharide is a mixture of pectin oligosaccharide and Ulva oligosaccharide in a mass ratio of 1:1. The average degree of polymerization of the pectin oligosaccharide is 5; the average degree of polymerization of the Ulva oligosaccharide is 6.

[0024] The biochar is a mixture of peanut shell biochar and water chestnut shell biochar at a mass ratio of 2:1. The preparation method of the biochar is as follows: after drying the peanut shells and water chestnut shells, they are placed in a carbonization furnace and carbonized at 450℃ for 8 hours. After cooling to room temperature (25℃), they are pulverized and passed through a 60-mesh sieve to obtain biochar.

[0025] The microbial agent is Bacillus mycoides (B. mycoides). Bacillus mycoides TA-203 inoculant and Bacillus atrophus ( Bacillus atrophaeus The A126 bacterial agent is a mixture of bacteria at a mass ratio of 1:1. The Bacillus mycoides has the preservation number CGMCC No. 19224, and the viable count in the bacterial agent is 1 × 10⁻⁶. 8 CFU / g, the Bacillus atrophus ( Bacillus atrophaeus The A126 culture has the CGMCC No. 32444 preservation number and contains 2 × 10⁻⁶ viable bacteria. 8 CFU / g.

[0026] The preparation method of the microbial fertilizer is carried out according to the following steps: (1) Add biochar and microbial agent to the microbial agent culture medium, then place it in a constant temperature shaker at 28℃ for 36h, and then dry it by vacuum spray to prepare a biochar-based composite microbial agent with a water content of 6%; (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 20-40 minutes at a speed of 60-100 rpm. Spray polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated. The mass percentage concentration of the polyvinyl alcohol aqueous solution is 3-6%.

[0027] Example 3 A microbial fertilizer comprises the following raw material components in parts by weight: 48 parts urea, 38 parts dipotassium hydrogen phosphate, 20 parts calcium ammonium nitrate, 30 parts bentonite, 10 parts oligosaccharide, 120 parts biochar, 40 parts microbial agent, 10 parts polyvinyl alcohol aqueous solution, and 280 parts 5 wt% brown sugar water.

[0028] The oligosaccharide is a mixture of pectin oligosaccharide and Ulva oligosaccharide in a mass ratio of 3:1. The average degree of polymerization of the pectin oligosaccharide is 7; the average degree of polymerization of the Ulva oligosaccharide is 9.

[0029] The biochar is a mixture of peanut shell biochar and water chestnut shell biochar at a mass ratio of 4:1. The preparation method of the biochar is as follows: after drying the peanut shells and water chestnut shells, they are placed in a carbonization furnace and carbonized at 580℃ for 4 hours. After cooling to room temperature (25℃), they are pulverized and passed through a 100-mesh sieve to obtain biochar.

[0030] The microbial agent is Bacillus mycoides (B. mycoides). Bacillus mycoides TA-203 inoculant and Bacillus atrophus ( Bacillus atrophaeus The A126 bacterial agent is a mixture prepared by mixing bacteria at a mass ratio of 3:1. The Bacillus mycoides has the preservation number CGMCC No. 19224, and the viable count in the bacterial agent is 3 × 10⁻⁶. 8 CFU / g, the Bacillus atrophus ( Bacillus atrophaeus The A126 culture has the CGMCC No. 32444 preservation number and contains 4 × 10⁻⁶ viable bacteria. 8 CFU / g.

[0031] The preparation method of the microbial fertilizer is carried out according to the following steps: (1) Add biochar and microbial agent to the microbial agent culture medium, then place it in a constant temperature shaker at 32℃ for 20h, and then dry it by vacuum spray to prepare a biochar-based composite microbial agent with a water content of 9%; (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 25 minutes at a speed of 100 rpm. Spray 5% polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated.

[0032] Comparative Example 1 A microbial fertilizer comprises the following raw material components in parts by weight: 40 parts urea, 32 parts dipotassium hydrogen phosphate, 15 parts calcium ammonium nitrate, 16 parts bentonite, 8 parts pectin oligosaccharide, 95 parts biochar, 30 parts microbial inoculant, 8 parts polyvinyl alcohol aqueous solution, and 220 parts 4 wt% brown sugar water. The average degree of polymerization of the pectin oligosaccharide is 6.

[0033] The biochar is a mixture of peanut shell biochar and water chestnut shell biochar at a mass ratio of 3:1. The preparation method of the biochar is as follows: the peanut shells and water chestnut shells are dried and placed in a carbonization furnace, carbonized at 520℃ for 6 hours, cooled to room temperature (25℃), pulverized, and passed through an 80-mesh sieve to obtain biochar.

[0034] The microbial agent is Bacillus mycoides (B. mycoides). Bacillus mycoides TA-203 inoculant and Bacillus atrophus ( Bacillus atrophaeus The A126 bacterial agent is a mixture prepared by mixing bacteria at a mass ratio of 2:1. The Bacillus mycoides has the preservation number CGMCC No. 19224, and the viable count in the bacterial agent is 3 × 10⁻⁶. 8 CFU / g, the Bacillus atrophus ( Bacillus atrophaeus The A126 culture has the CGMCC No. 32444 preservation number and contains 3 × 10⁻⁶ viable bacteria. 8 CFU / g.

[0035] The preparation method of the microbial fertilizer is carried out according to the following steps: (1) Add biochar and microbial agent to the microbial agent culture medium, then place it in a constant temperature shaker at 30℃ for 24h, and then dry it by vacuum spray to prepare a biochar-based composite microbial agent with a water content of 8%. (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, pectin oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 30 minutes at a speed of 80 rpm, and spray 4.5 wt% polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated.

[0036] Comparative Example 2 A microbial fertilizer comprises the following raw material components in parts by weight: 40 parts urea, 32 parts dipotassium hydrogen phosphate, 15 parts calcium ammonium nitrate, 16 parts bentonite, 8 parts ulva oligosaccharide, 95 parts biochar, 30 parts microbial inoculant, 8 parts polyvinyl alcohol aqueous solution, and 220 parts 4 wt% brown sugar water. The average degree of polymerization of the ulva oligosaccharide is 8.

[0037] The biochar is a mixture of peanut shell biochar and water chestnut shell biochar at a mass ratio of 3:1. The preparation method of the biochar is as follows: the peanut shells and water chestnut shells are dried and placed in a carbonization furnace, carbonized at 520℃ for 6 hours, cooled to room temperature (25℃), pulverized, and passed through an 80-mesh sieve to obtain biochar.

[0038] The microbial agent is Bacillus mycoides (B. mycoides). Bacillus mycoides TA-203 inoculant and Bacillus atrophus ( Bacillus atrophaeus The A126 bacterial agent is a mixture prepared by mixing bacteria at a mass ratio of 2:1. The Bacillus mycoides has the preservation number CGMCC No. 19224, and the viable count in the bacterial agent is 3 × 10⁻⁶. 8 CFU / g, the Bacillus atrophus ( Bacillus atrophaeus The A126 culture has the CGMCC No. 32444 preservation number and contains 3 × 10⁻⁶ viable bacteria. 8 CFU / g.

[0039] The preparation method of the microbial fertilizer is carried out according to the following steps: (1) Add biochar and microbial agent to the microbial agent culture medium, then place it in a constant temperature shaker at 30℃ for 24h, and then dry it by vacuum spray to prepare a biochar-based composite microbial agent with a water content of 8%. (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, ulcerative oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 30 minutes at a speed of 80 rpm. Spray 4.5 wt% polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated.

[0040] Comparative Example 3 A microbial fertilizer comprises the following raw material components in parts by weight: 40 parts urea, 32 parts dipotassium hydrogen phosphate, 15 parts calcium ammonium nitrate, 16 parts bentonite, 8 parts oligosaccharide, 95 parts peanut shell biochar, 30 parts microbial agent, 8 parts polyvinyl alcohol aqueous solution, and 220 parts 4 wt% brown sugar water.

[0041] The oligosaccharide is a mixture of pectin oligosaccharide and Ulva oligosaccharide in a mass ratio of 2:1. The average degree of polymerization of the pectin oligosaccharide is 6; the average degree of polymerization of the Ulva oligosaccharide is 8.

[0042] The preparation method of the peanut shell biochar is as follows: after drying the peanut shells, place them in a carbonization furnace and carbonize them at 520℃ for 6 hours. After cooling to room temperature (25℃), crush them and pass them through an 80-mesh sieve to obtain peanut shell biochar.

[0043] The microbial agent is Bacillus mycoides (B. mycoides). Bacillus mycoides TA-203 inoculant and Bacillus atrophus ( Bacillus atrophaeus The A126 bacterial agent is a mixture prepared by mixing bacteria at a mass ratio of 2:1. The Bacillus mycoides has the preservation number CGMCC No. 19224, and the viable count in the bacterial agent is 3 × 10⁻⁶. 8 CFU / g, the Bacillus atrophus ( Bacillus atrophaeus The A126 culture has the CGMCC No. 32444 preservation number and contains 3 × 10⁻⁶ viable bacteria. 8 CFU / g.

[0044] The preparation method of the microbial fertilizer is carried out according to the following steps: (1) Add peanut shell biochar and microbial agent to the microbial agent culture solution, then place it in a constant temperature shaker at 30℃ for 24h, and then dry it by vacuum spray to prepare a biochar-based composite microbial agent with a water content of 8%. (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 30 minutes at a speed of 80 rpm. Spray 4.5 wt% polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated.

[0045] Comparative Example 4 A microbial fertilizer comprises the following raw material components in parts by weight: 40 parts urea, 32 parts dipotassium hydrogen phosphate, 15 parts calcium ammonium nitrate, 16 parts bentonite, 8 parts oligosaccharide, 95 parts water chestnut shell biochar, 30 parts microbial agent, 8 parts polyvinyl alcohol aqueous solution, and 220 parts 4 wt% brown sugar water.

[0046] The oligosaccharide is a mixture of pectin oligosaccharide and Ulva oligosaccharide in a mass ratio of 2:1. The average degree of polymerization of the pectin oligosaccharide is 6; the average degree of polymerization of the Ulva oligosaccharide is 8.

[0047] The method for preparing the water chestnut shell biochar is as follows: after drying the water chestnut shells, place them in a carbonization furnace and carbonize them at 520℃ for 6 hours. After cooling to room temperature (25℃), pulverize them and pass them through an 80-mesh sieve to obtain biochar.

[0048] The microbial agent is Bacillus mycoides (B. mycoides). Bacillus mycoides TA-203 inoculant and Bacillus atrophus ( Bacillus atrophaeus The A126 bacterial agent is a mixture prepared by mixing bacteria at a mass ratio of 2:1. The Bacillus mycoides has the preservation number CGMCC No. 19224, and the viable count in the bacterial agent is 3 × 10⁻⁶. 8 CFU / g, the Bacillus atrophus ( Bacillus atrophaeus The A126 culture has the CGMCC No. 32444 preservation number and contains 3 × 10⁻⁶ viable bacteria. 8 CFU / g.

[0049] The preparation method of the microbial fertilizer is carried out according to the following steps: (1) Add water chestnut shell biochar and microbial agent to the microbial agent culture solution, then place it in a constant temperature shaker at 30℃ for 24h, and then dry it by vacuum spray to prepare biochar-based composite microbial agent with a water content of 8%; (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 30 minutes at a speed of 80 rpm. Spray 4.5 wt% polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated.

[0050] Comparative Example 5 A microbial fertilizer comprises the following raw material components in parts by weight: 40 parts urea, 32 parts dipotassium hydrogen phosphate, 15 parts calcium ammonium nitrate, 16 parts bentonite, 8 parts oligosaccharides, 95 parts biochar, and Bacillus mycoides (…). Bacillus mycoides 30 parts of TA-203 bacterial agent, 8 parts of polyvinyl alcohol aqueous solution, and 220 parts of 4wt% brown sugar water.

[0051] The oligosaccharide is a mixture of pectin oligosaccharide and Ulva oligosaccharide in a mass ratio of 2:1. The average degree of polymerization of the pectin oligosaccharide is 6; the average degree of polymerization of the Ulva oligosaccharide is 8.

[0052] The biochar is a mixture of peanut shell biochar and water chestnut shell biochar at a mass ratio of 3:1. The preparation method of the biochar is as follows: the peanut shells and water chestnut shells are dried and placed in a carbonization furnace, carbonized at 520℃ for 6 hours, cooled to room temperature (25℃), pulverized, and passed through an 80-mesh sieve to obtain biochar.

[0053] The Bacillus mycoides was deposited under CGMCC No. 19224, and the viable count in the inoculum was 6 × 10⁻⁶. 8 CFU / g.

[0054] The preparation method of the microbial fertilizer is carried out according to the following steps: (1) Biochar and Bacillus mycoides ( Bacillus mycoides TA-203 bacterial agent was added to the bacterial agent culture medium, and then placed in a constant temperature shaker at 30℃ for 24 hours. After that, it was dried by vacuum spray to prepare a biochar-based composite microbial agent with a water content of 8%. (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 30 minutes at a speed of 80 rpm. Spray 4.5 wt% polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated.

[0055] Comparative Example 6 A microbial fertilizer comprises the following raw material components in parts by weight: 40 parts urea, 32 parts dipotassium hydrogen phosphate, 15 parts calcium ammonium nitrate, 16 parts bentonite, 8 parts oligosaccharides, 95 parts biochar, and Bacillus atrophus (…). Bacillus atrophaeus 30 parts of A126 bacterial agent, 8 parts of polyvinyl alcohol aqueous solution, and 220 parts of 4wt% brown sugar water.

[0056] The oligosaccharide is a mixture of pectin oligosaccharide and Ulva oligosaccharide in a mass ratio of 2:1. The average degree of polymerization of the pectin oligosaccharide is 6; the average degree of polymerization of the Ulva oligosaccharide is 8.

[0057] The biochar is a mixture of peanut shell biochar and water chestnut shell biochar at a mass ratio of 3:1. The preparation method of the biochar is as follows: the peanut shells and water chestnut shells are dried and placed in a carbonization furnace, carbonized at 520℃ for 6 hours, cooled to room temperature (25℃), pulverized, and passed through an 80-mesh sieve to obtain biochar.

[0058] The Bacillus atrophus ( Bacillus atrophaeus The A126 culture has the CGMCC No. 32444 accession number and contains 6 × 10⁻⁶ viable bacteria. 8 CFU / g.

[0059] The preparation method of the microbial fertilizer is carried out according to the following steps: (1) Biochar and Bacillus atrophus ( Bacillus atrophaeus A126 bacterial agent was added to the bacterial agent culture medium, and then placed in a constant temperature shaker at 30°C for 24 hours. Then it was dried by vacuum spray to prepare a biochar-based composite microbial agent with a water content of 8%. (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 30 minutes at a speed of 80 rpm. Spray 4.5 wt% polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated.

[0060] Experimental example: In the vegetable garden, plots of 3m × 3m were randomly divided. Microbial fertilizers prepared in Examples 1-3 and Comparative Examples 1-2 were applied as base fertilizer at a rate of 400g per plot. Lettuce was planted using conventional methods. After maturity, lettuce yield (kg / mu) and vitamin C (mg·kg⁻¹) were recorded. -1 The content of vitamin C was determined by titration with 2,6-dichlorophenolindophenol. Statistical analysis was performed on the experimental results, and the measurement data were analyzed using... Mean ± standard deviation is expressed as mean ± standard deviation. The Kolmogorov-Smirnov test was used to test the normality of the data. For normally distributed data, the t-test was used to compare the differences in means between two groups, with P < 0.05 considered statistically significant. The results are shown in Table 1. Table 1

[0061] Note: * indicates P < 0.05 compared to Example 1 group. In a field, plots of 6m × 6m were randomly divided. Microbial fertilizers prepared in Examples 1-3 and Comparative Examples 3-4 were applied as base fertilizer at a rate of 3 kg / plot. Cotton was planted using conventional methods. After the cotton matured and was harvested, the lint yield (kg / mu) was recorded. Statistical analysis was performed on the experimental results, and the quantitative data were used as... Mean ± standard deviation is expressed as mean ± standard deviation. The Kolmogorov-Smirnov test was used to test the normality of the data. For normally distributed data, the t-test was used to compare the differences in means between two groups, with P < 0.05 considered statistically significant. The results are shown in Table 2. Table 2

[0062] Note: * indicates P < 0.05 compared to Example 1 group. In a field, plots of 6m × 6m were randomly divided. Microbial fertilizers prepared in Examples 1-3 and Comparative Examples 5-6 were applied as base fertilizer at a rate of 2.5 kg / plot. Chili peppers were planted using conventional methods. Yields (kg / acre) were recorded after harvesting. Statistical analysis was performed on the experimental results, and the quantitative data were presented using... Mean ± standard deviation is expressed as mean ± standard deviation. The Kolmogorov-Smirnov test was used to test the normality of the data. For normally distributed data, the t-test was used to compare the differences in means between two groups, with P < 0.05 considered statistically significant. The results are shown in Table 3. Table 3

[0063] Note: * indicates P < 0.05 compared to Example 1 group. The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A microbial fertilizer, characterized in that, The raw material components include the following parts by weight: 30-50 parts urea, 20-40 parts dipotassium hydrogen phosphate, 10-20 parts calcium ammonium nitrate, 10-30 parts bentonite, 3-10 parts oligosaccharide, 60-120 parts biochar, 20-40 parts microbial inoculant, 3-10 parts polyvinyl alcohol aqueous solution, and 120-300 parts inoculant culture medium.

2. The microbial fertilizer according to claim 1, characterized in that, The oligosaccharide is a mixture of pectin oligosaccharide and ulmoides oligosaccharide in a mass ratio of (1-3):

1.

3. The microbial fertilizer according to claim 2, characterized in that, The pectin oligosaccharide has an average degree of polymerization of 4-8; the ulna oligosaccharide has an average degree of polymerization of 5-10.

4. The microbial fertilizer according to claim 1, characterized in that, The biochar is a mixture of peanut shell biochar and water chestnut shell biochar in a mass ratio of (2-4):

1.

5. The microbial fertilizer according to claim 4, characterized in that, The preparation method of the biochar is as follows: peanut shells and water chestnut shells are dried and placed in a carbonization furnace, carbonized at 450-600℃ for 4-8 hours, cooled to room temperature and then pulverized and passed through a 60-100 mesh sieve to obtain biochar.

6. The microbial fertilizer according to claim 1, characterized in that, The microbial agent is Bacillus mycoides (B. mycoides). Bacillus mycoides TA-203 inoculant and Bacillus atrophus ( Bacillus atrophaeus A126 microbial agent is a mixture of ingredients at a mass ratio of (1-3):

1.

7. The microbial fertilizer according to claim 6, characterized in that, The Bacillus mycoides has the preservation number CGMCC No. 19224, and the viable count in the inoculum is 1-4 × 10⁻⁶. 8 CFU / g, the Bacillus atrophus ( Bacillus atrophaeus The A126 accession number is CGMCC No. 32444, and the viable count in the inoculum is 2-5 × 10⁻⁵. 8 CFU / g.

8. The microbial fertilizer according to claim 1, characterized in that, The bacterial culture medium is 3-5 wt% brown sugar water.

9. The method for preparing the microbial fertilizer according to claim 1, characterized in that, Follow these steps: (1) Add biochar and microbial agent to the microbial agent culture medium, then place it in a constant temperature shaker at 28-32℃ for 18-36h, and then dry it by vacuum spray to prepare a biochar-based composite microbial agent with a water content of 6-10%. (2) Take urea, dipotassium hydrogen phosphate, calcium ammonium nitrate, bentonite, oligosaccharide and biochar-based composite microbial agent prepared in step (1) and put them into a coating machine. Stir for 20-40 minutes at a speed of 60-100 rpm. Spray polyvinyl alcohol aqueous solution while stirring to make the material fully mixed and granulated.

10. The method for preparing microbial fertilizer according to claim 1, characterized in that, The mass percentage concentration of the polyvinyl alcohol aqueous solution is 3-6%.

Images