Method for preparing organic fertilizer by utilizing brewing byproducts

Abstract

The invention belongs to the technical field of organic fertilizers. The invention provides an organic fertilizer prepared from brewing by-products and a preparation method of the organic fertilizer. The organic fertilizer is prepared from the following raw materials in parts by weight: 900 parts of brewing by-products, 15-30 parts of wood chips, 1-2 parts of complex microbial inoculants, 10-20 parts of Angel yeast, 20-50 parts of bentonite and 0.5-1 part of wine brewing bacterium liquid. According to the preparation method of the organic fertilizer, substances harmful to the environment in the brewing byproducts are degraded, and organic matters in the brewing byproducts are efficiently utilized; the preparation method is short in time consumption, and organic conversion of a brewing byproduct-organic fertilizer within 3h is realized; the prepared organic fertilizer can regulate the granular structure of soil, provide necessary nutrient elements for plant growth and improve the quality of agricultural products.

Description

Technical Field

[0001] The invention belongs to the technical field of organic fertilizers, and in particular relates to a method for preparing agricultural organic fertilizers by utilizing brewing byproducts. Background Art

[0002] As the main by-products of Chinese liquor production, the output of lees and sludge in 2020 is about 2.2×10 7 tons, the ratio of liquor output to vinasse is about 1:3, and there is a certain amount of sludge after the wastewater treatment in the production. Vinasse usually contains a large amount of nutrients, including starch, protein, lipids and water-soluble vitamins; sludge contains phosphorus, nitrogen and other organic matter. Direct landfill or disposal is a very common way to deal with hazardous materials, which leads to environmental pollution and waste of resources. Therefore, a lot of research has been carried out on vinasse and sludge to explore their potential utilization value, such as protein feed, bio-organic fertilizer, chemical products, bacterial cellulose and fuel. At present, the main treatment method for vinasse and sludge is aerobic stacking fermentation, but aerobic stacking fermentation has problems such as long fermentation cycle and large production site. Summary of the invention

[0003]

Technical issues

[0004] Currently, the main treatment method for wine grains and sludge is aerobic stacking fermentation. However, aerobic stacking fermentation has problems such as long fermentation cycle and large production site.

[0005]

Technical solution

[0006] The present invention utilizes bentonite as a carrier and multiple enzyme-controlling agents and microorganisms as catalysts to efficiently ripen and transform distiller's grains and sludge. The organic matter in the liquor distiller's grains and filtered sludge is degraded under the conditions of the enzyme-controlling agents and microorganisms, thereby becoming humus and inorganic matter that are easily absorbed by plants. The application of organic fertilizer can increase soil fertility, which can be applied to increase the yield and improve the quality of crops such as sorghum, thereby increasing the recycling of resources and realizing green circular brewing.

[0007] The first object of the present invention is to provide an organic fertilizer prepared by using brewing by-products, wherein the raw materials are composed of the following parts by weight: 900 parts of brewing by-products, 15-30 parts of sawdust, 1-2 parts of composite bacterial agent, 10-20 parts of Angel Yeast, 20-50 parts of bentonite and 0.5-1 part of brewing bacteria liquid.

[0008] In one embodiment of the present invention, the organic fertilizer is a water-soluble fertilizer containing humic acid.

[0009] In one embodiment of the present invention, the method for preparing brewing by-products is: mixing brewing sludge with wine lees, controlling the moisture content to 40-50wt%, to obtain brewing by-products.

[0010] In one embodiment of the present invention, the mixing mass ratio of brewing sludge to wine lees is 8:1 to 5:4.

[0011] Brewing sludge is the wastewater generated in the brewing process that is treated with the A2O process to remove nitrogen and phosphorus. During this process, aerobic microorganisms continue to multiply and metabolize, and the microbial metabolites and dead microorganisms precipitate to form fresh brewing sludge, which is then obtained by filter pressing.

[0012] In one embodiment of the present invention, the pH of the wine lees is 2.5-4.5, the alcohol content is 2-5% vol, and the water content is 45-60wt%.

[0013] In one embodiment of the present invention, the moisture content of the brewing sludge is 50-70 wt %.

[0014] In one embodiment of the present invention, the composite bacterial agent is obtained by mixing a Cellulomonas bacterial solution with a Cellvibrio bacterial solution; the mixing mass ratio of the Cellulomonas bacterial solution to the Cellvibrio bacterial solution is 2 to 4:1; the concentration of the Cellulomonas bacterial cell in the Cellulomonas bacterial solution is ≥10 8 / mL, Vibrio spp. bacterial solution Vibrio spp. bacterial cell concentration ≥10 8 Pieces / mL.

[0015] In one embodiment of the present invention, the Cellulomonas bacteria in the Cellulomonas bacterial liquid are screened from humus soil, are 0.5-0.6 μm in length, 0.08-0.012 μm in width, are arranged in a V-shape, and occasionally have branches but no filaments.

[0016] In one embodiment of the present invention, the preparation method of the bacterial liquid of the genus Cellulomonas is as follows: 0.8 to 1.2 parts of humus soil by mass are suspended in 10 parts of sterile water and mixed, diluted 900 to 1000 times with sterile water, applied to a beef extract peptone medium plate for 42 to 54 hours, added with 0.8 to 1.2 mg / mL Congo red solution for staining for 0.5 to 1.5 hours, discarded the Congo red dye solution, added with 0.8 to 1.2 mol / L NaCl solution for washing for 0.5 to 1.5 hours, and took the colonies with clear transparent circles around them and transferred them to the culture medium for culture. When the colony diameter reaches 2 mm or more, the strains with a length of 0.5 to 0.6 μm, a width of 0.08 to 0.012 μm, a V-shaped arrangement, occasional branches but no filaments are selected, and activated and expanded to a bacterial liquid cell concentration of ≥10 8 Pieces / mL.

[0017] Humus soil is formed by the dead branches and leaves of trees in the topsoil layer after a long period of decay and fermentation.

[0018] Brewing bacteria refer to microorganisms that participate in the production of starch and sugars during the fermentation process of liquor.

[0019] In one embodiment of the present invention, the brewing bacteria is selected from one or more of Bacillus subtilis (with a preservation number of CCTCCNO: M2023090) and Wickerhamomyces anomalus (with a preservation number of CCTCCNO: M2023089).

[0020] In one embodiment of the present invention, the concentration of brewing bacteria in the brewing bacteria liquid is ≥10 8 Pieces / mL.

[0021] In one embodiment of the present invention, the particle size of the wood chips is 1 to 2 mm.

[0022] In one embodiment of the present invention, the particle size of the bentonite is 20 to 70 mm.

[0023] A second object of the present invention is to provide a method for preparing the above-mentioned organic fertilizer, comprising the steps of:

[0024] S1. Mix 900 parts of brewing byproducts and 15-30 parts of sawdust evenly;

[0025] S2, crushing the product of step S1;

[0026] S3, uniformly mixing the product of step S2, 10-20 parts of Angel Yeast and 1-2 parts of composite bacterial agent, and reacting;

[0027] S4, adding 20 to 50 parts of bentonite to the product of step S3 and mixing thoroughly;

[0028] S5, heating the product of step S4 for the first time and reacting it for the first time under stirring, and then heating it for the second time and reacting it for the second time;

[0029] S6. Add 0.5 to 1 part of brewing bacteria liquid to the product of step S5 and stir evenly, granulate and dry to obtain organic fertilizer.

[0030] In one embodiment of the present invention, the moisture content of the product in step S1 is 30-40 wt%.

[0031] In one embodiment of the present invention, in step S1, a mixing mixer is used for stirring.

[0032] In one embodiment of the present invention, the product of step S2 is particles with a diameter of 8 to 12 mm.

[0033] In one embodiment of the present invention, in step S3, the reaction temperature is 30-35° C., and the reaction time is 0.5-1.5 h.

[0034] In one embodiment of the present invention, in step S3, the reaction is carried out in a reactor.

[0035] In one embodiment of the present invention, in step S5, the first heating is to 40-50°C, and the first reaction time is 0.5-2h; the second heating is to 60-70°C, and the second reaction time is 2-3h.

[0036] In one embodiment of the present invention, in step S5, the reaction is carried out in a reactor.

[0037] In one embodiment of the present invention, in step S6, when the brewing bacteria liquid is added, the temperature of the product of step S5 is lower than 40°C.

[0038] In one embodiment of the present invention, in step S6, a disc granulating device is used for granulation.

[0039] In one embodiment of the present invention, in step S6, the granules obtained by granulation are cylindrical granules with a length of 0.5 to 1 cm.

[0040] In one embodiment of the present invention, in step S6, drying is performed to a moisture content of less than 30 wt%.

[0041] In one embodiment of the present invention, in step S6, the drying temperature is 50-70° C., and the drying time is 10-14 hours.

[0042] The third object of the present invention is the application of the above organic fertilizer in agriculture.

[0043] Beneficial effects:

[0044] 1. The method for preparing organic fertilizer of the present invention degrades harmful substances to the environment in brewing by-products, and efficiently utilizes organic matter in brewing by-products. The sludge filtered and precipitated in brewing by-products is usually difficult to handle, and it contains mineral oil that is difficult to degrade. Direct application to farmland brings environmental risks. The sludge contains nitrogen, phosphorus and more organic matter, which has a higher utilization value. When a certain amount of composite bacterial agent, Angel yeast, bentonite, Cellulomonas bacteria, Cellvibrio bacteria and brewing bacteria are added, the harmful substances to the environment in the sludge are effectively degraded after sufficient reaction. In the reaction, it is compounded with lees at the same time, and the dry matter, crude protein, crude protein and starch remaining in the lees after multi-grain brewing are efficiently utilized.

[0045] 2. The organic fertilizer preparation method of the present invention is time-saving and realizes the organic conversion of brewing byproducts to organic fertilizers within 5 hours. The present invention can quickly and effectively carry out organic conversion of sludge and lees, which are brewing byproducts. The conventional stacking fermentation time is as long as one week. The present method uses a new conversion mode with bentonite as a carrier and multiple composite bacterial agents as catalysts to realize the organic conversion of brewing byproducts to organic fertilizers within 5 hours, while further degrading harmful substances.

[0046] 3. The organic fertilizer of the present invention can adjust the soil aggregate structure, provide essential nutrients for plant growth, and improve the quality of agricultural products. The present invention uses natural bentonite as a carrier. Attapulgite has strong adsorption and catalytic properties, can adjust the soil aggregate structure, and improve the water retention and air permeability of the soil. Bentonite also contains a variety of trace elements, which provide essential nutrients for plant growth and improve the quality of agricultural products. DETAILED DESCRIPTION

[0047] Preparation of brewing bacteria liquid:

[0048] Prepare beef extract peptone slant culture medium: peptone 10g, beef extract 3g, sodium chloride: 5g, agar powder 15g, distilled water 1L, adjust the pH value to 7.0-7.2, heat and stir evenly, then divide into test tubes, place on a slant, and sterilize at 121℃ for 45min.

[0049] The brewing bacteria are inoculated into a beef extract peptone test tube slant medium for culturing at a temperature of 35 to 37° C. for 2 to 3 days, and then inoculated into a beef extract peptone test tube slant medium at a 20% inoculum volume for liquid culture at a temperature of 35 to 37° C., pH 7.0, for 2 to 3 days, and then transferred into a fermentation container for 1 to 2 days of expansion culture using the same liquid culture medium and conditions to obtain the desired brewing bacteria liquid, wherein the brewing bacteria cell concentration is ≥10 8 Pieces / mL.

[0050] Preparation of Cellulomonas bacterial solution:

[0051] Samples were collected from humus soil environments. Humus soil samples are generally formed by the decay and fermentation of dead branches and leaves of trees in the topsoil layer over a long period of time.

[0052] Cellulomonas has the ability to decompose cellulose and a transparent circle centered on Cellulomonas will appear in beef extract peptone medium stained with Congo red. Therefore, 1 mg / mL Congo red solution was used for preliminary screening. 10 g of humus soil was weighed and suspended in 100 mL of sterile water. The mixture was placed in a magnetic stirrer and thoroughly mixed. The suspension was diluted 1000 times with sterile water. 100 μL was spread on a beef extract peptone medium plate and cultured at 37 °C for 48 h. An appropriate amount of 1 mg / mL Congo red solution was added to the medium and stained for 1 h. The staining solution was discarded and an appropriate amount of 1 mol / L NaCl solution was added and washed for 1 h. A clear transparent circle will appear around the colony. The strain is selected according to the diameter of the transparent circle. The bacteria were transferred to beef extract peptone medium and cultured at 30-40 °C for 18 h. When the colony diameter reaches more than 2 mm, further screening is carried out. Through morphological observation, the cells of the genus Cellulomonas are slender irregular rods. Under micron-level microscope observation, the genus Cellulomonas is generally 0.5-0.6 μm long and about 0.01 μm wide, arranged in a V shape, with occasional branches but no filaments.

[0053] Activate the strains. Prepare a test tube with 10 mL of liquid beef extract peptone medium. Use a sterilized inoculation loop to inoculate the selected strains into the liquid medium. Then place the incubator. The activation temperature is 37°C and the activation time is 24 h. Then draw 2 mL of bacterial solution into 200 mL of beef extract peptone medium and culture under the same conditions. The bacterial concentration is ≥10 8 Pieces / mL.

[0054] Preparation of Vibrio fimbriae bacterial solution:

[0055] The strain was purchased from Wuhan Huizao Biotechnology Co., Ltd. The purchased strain was evenly spread on beef extract peptone medium and cultured at 25℃-30℃ for 24h. When the colony diameter reaches 2mm or more, the Vibrio genus was activated. To activate the strain, prepare a test tube of liquid beef extract peptone medium with a volume of 10mL. The screened strain was inoculated into the liquid medium with a sterilized inoculation loop and then placed in an incubator. The activation temperature was 30℃ and the activation time was 24h. Then 2mL of bacterial solution was aspirated into 200mL beef extract peptone medium and cultured under the same conditions. The bacterial concentration was ≥10 8 Pieces / mL.

[0056] Preparation of compound bacterial agent:

[0057] Mix 3 parts of the Cellulomonas bacterial solution with 1 part of the Cellulovibrio bacterial solution by mass.

[0058] Example 1

[0059] An agricultural organic fertilizer comprises the following raw materials in parts by weight: 900 parts of brewing by-products, 20 parts of sawdust, 2 parts of compound bacterial agents, 15 parts of Angel Yeast, 30 parts of bentonite and 1 part of brewing fungus liquid.

[0060] Among them, the brewing bacteria of the brewing bacteria liquid is Bacillus subtilis, which was screened, isolated, purified and screened by Jiangsu Yanghe Brewery Co., Ltd. The strain was deposited in the China Center for Type Culture Collection (CCTCC for short, address: No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province, Postal Code: 430000) on February 3, 2023, and the deposit number is CCTCCNO: M2023090.

[0061] The method for preparing the agricultural organic fertilizer comprises the following steps:

[0062] S1. Dry fresh liquor lees and brewing sludge to 50% moisture, mix them evenly in a mass ratio of 2:7 to obtain brewing by-products, and then mix them with sawdust and stir them evenly;

[0063] The pH value of the fresh liquor lees used was 3.58, the alcohol content was 4% vol, the water content was 60%, and the water content of the liquor brewing sludge was 68%;

[0064] S2, conveying the product of step S1 to a crusher by a conveyor belt, and crushing it into particles with a diameter of 8 to 12 mm;

[0065] S3, adding the product of step S2, Angel Yeast and composite bacterial agent into the reactor, stirring evenly, and reacting at 30°C for 1h;

[0066] S4, adding bentonite into the reactor and mixing thoroughly;

[0067] S5, heating the reactor to 45°C for the first time under stirring, reacting for 1 hour, and then heating the reactor to 65°C for the second time, reacting for 2 hours;

[0068] S6. After the product of step S5 is cooled to below 40° C., add brewing bacteria solution and stir evenly, granulate into cylindrical particles with a length of 0.5 to 1 cm, and dry to a moisture content of less than 30 wt % to obtain an organic fertilizer.

[0069] Example 2

[0070] An agricultural organic fertilizer comprises the following raw materials in parts by weight: 900 parts of brewing by-products, 15 parts of sawdust, 2 parts of compound bacterial agents, 15 parts of Angel Yeast, 30 parts of bentonite and 1 part of brewing fungus liquid.

[0071] Among them, the brewing bacteria of the brewing bacteria liquid is Wickerhamomyces anomalus, which was screened, isolated, purified and screened by Jiangsu Yanghe Brewery. The strain was deposited in the China Center for Type Culture Collection (CCTCC for short, address: No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province, Postal Code: 430000) on February 10, 2023, with the deposit number CCTCCNO: M2023089.

[0072] The method for preparing the agricultural organic fertilizer comprises the following steps:

[0073] S1. Dry fresh liquor lees and brewing sludge to 50% moisture, mix them evenly in a mass ratio of 4:5 to obtain brewing by-products, and then mix them with sawdust and stir them evenly;

[0074] The pH value of the fresh liquor lees used was 3.96, the alcohol content was 3.5% vol, the water content was 55%, and the water content of the liquor brewing sludge was 68%;

[0075] S2, conveying the product of step S1 to a crusher by a conveyor belt, and crushing it into particles with a diameter of 8 to 12 mm;

[0076] S3, adding the product of step S2, Angel Yeast and composite bacterial agent into the reactor, stirring evenly, and reacting at 35°C for 1h;

[0077] S4, adding bentonite into the reactor and mixing thoroughly;

[0078] S5, heating the reactor to 45°C for the first time under stirring, reacting for 1 hour, and then heating the reactor to 65°C for the second time, reacting for 2.5 hours;

[0079] S6. After the product of step S5 is cooled to below 40° C., add brewing bacteria solution and stir evenly, granulate into cylindrical particles with a length of 0.5 to 1 cm, and dry to a moisture content of less than 30 wt % to obtain an organic fertilizer.

[0080] According to the standard test methods "NY / T525-2021", "GB / T8576-2010", "GB / T19524.1-2004", "GB / T15063-2020" and "NY / T1978-2022", the indicators of the organic fertilizer prepared in Example 1 were tested, and the results are shown in Table 1.

[0081] Table 1 Test results of Example 1

[0082]

[0083]

[0084] The test results show that the test indicators of the organic fertilizer prepared by the present invention reach or exceed the quality standards of the Ministry of Agriculture for biological organic fertilizer in terms of technology and harmlessness, opening up a new path for directly and quickly utilizing the brewing by-products of liquor to prepare high-quality biological organic fertilizer, and having good advancement and practicality.

[0085] The organic fertilizer made from liquor brewing byproducts prepared in Examples 1 and 2 of the present invention also has the above-mentioned test effects, and there is no significant difference between the examples.

[0086] Example 3

[0087] Experiment on converting brewing by-product into organic fertilizer using sorghum.

[0088] Experimental materials: The sorghum variety used for the test was sorghum (Hongnuo 16).

[0089] Test fertilizer: organic fertilizer prepared in Example 1, and commercially available common fertilizer (special fertilizer for sorghum 26N-12P-12K) were used as control.

[0090] Experimental method: Four treatments were used, namely treatment A, treatment B, treatment C, and treatment D. Treatment A applied 50 kg (26N-12P-12K) conventional fertilizer per mu, treatment B applied 300 kg organic fertilizer per mu, treatment C applied 400 kg organic fertilizer per mu, and treatment D applied 500 kg organic fertilizer per mu. The row spacing was 60 cm*25 cm, and 4447 plants were planted per mu. The treatment was repeated 3 times and arranged in random blocks. The experiments were all applied once when applying the base fertilizer. Other cultivation methods and management methods were the same.

[0091] Results and analysis: The five-point sampling method was used to pick sorghum in groups and measure its yield. The results are shown in Table 2. The data were analyzed using Duncan's new multiple range test method of DPS software. The results are shown in Table 3.

[0092] Table 2 Sorghum yield with different fertilizers (kg / mu)

[0093]

[0094]

[0095] Note: Different letters indicate significant differences

[0096] Table 3 Sorghum yield results new multiple range method test table

[0097]

[0098] Note: Lowercase letters indicate significant differences at the 5% level, and uppercase letters in the fourth column indicate significant differences at the 1% level.

[0099] The above results show that the average yield of treatment A with simple application of chemical fertilizer (50kg / mu) is 501.09kg / mu, the average yield of treatment B with 300kg organic fertilizer per mu is 464.37kg / mu, the average yield of treatment C with 400kg organic fertilizer per mu is 506.03kg / mu, and the average yield of treatment D with 500kg organic fertilizer per mu is 552.67kg / mu. Compared with CK, treatment D has an increase of 10.29%.

[0100] Table 4 Growth period of sorghum with different fertilizers (days)

[0101] 1st time 2nd 3rd average Process A 119 119 117 118.3 Treatment B 122 121 123 122 Process C 115 116 115 115.3 Processing D 112 110 113 111.7

[0102] Table 4 shows the growth period of sorghum with different fertilizers. The results show that the average growth period of sorghum in treatment A with simple application of chemical fertilizer (50 kg / mu) is 118.3 days, the average growth period of sorghum in treatment B with 300 kg of organic fertilizer per mu is 122 days, the average growth period of sorghum in treatment C with 400 kg of organic fertilizer per mu is 115.3 days, and the average growth period of sorghum in treatment D with 500 kg of organic fertilizer per mu is 111.7 days. Among them, treatments C and D are 3 days and 6.6 days earlier than CK, respectively. It further shows that the application of 500 kg / mu of organic fertilizer can not only increase sorghum yield, but also shorten the growth cycle of sorghum.

[0103] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. An organic fertilizer prepared using brewing by-products, characterized in that: The raw material composition is as follows, in parts by weight: 900 parts of brewing by-products, 15-30 parts of sawdust, 1-2 parts of composite bacterial agent, 10-20 parts of Angel Yeast, 20-50 parts of bentonite and 0.5-1 part of brewing bacteria liquid.

2. The organic fertilizer according to claim 1, characterized in that The preparation method of brewing by-products comprises the following steps: mixing brewing sludge with wine lees, controlling the water content to be 40-50wt%, and obtaining brewing by-products; the mixing mass ratio of brewing sludge to wine lees is 8:1-5:4; the pH value of wine lees is 2.5-4.5, the alcohol content is 2-5%vol, and the water content is 45-60wt%; the water content of brewing sludge is 50-70wt%; The composite bacterial agent is obtained by mixing a bacterial solution of the genus Cellulomonas and a bacterial solution of the genus Cellulomonas; the mixing mass ratio of the bacterial solution of the genus Cellulomonas and the bacterial solution of the genus Cellulomonas is 2 to 4:1; the bacterial cell concentration of the genus Cellulomonas in the bacterial solution of the genus Cellulomonas is ≥10 8 / mL, Vibrio spp. bacterial solution Vibrio spp. bacterial cell concentration ≥10 8 Pieces / mL; The brewing bacteria is selected from one or more of Bacillus subtilis and abnormal Wickham yeast; the brewing bacteria concentration of the brewing bacteria liquid is ≥10 8 Pieces / mL.

3. The organic fertilizer according to claim 2, characterized in that The Cellulomonas bacteria in the Cellulomonas bacterial liquid were screened from humus soil, with a length of 0.5-0.6 μm, a width of 0.08-0.012 μm, and a V-shaped arrangement, with occasional branches but no filaments; the Bacillus subtilis deposit number is CCTCCNO: M2023090; the abnormal Wickham yeast deposit number is CCTCCNO: M2023089.

4. The method for preparing the organic fertilizer according to claim 1, characterized in that: Includes steps: S1. Mix 900 parts of brewing byproducts and 15-30 parts of sawdust evenly; S2, crushing the product of step S1; S3, mixing the product of step S2, 10-20 parts of Angel Yeast and 1-2 parts of composite bacterial agent evenly, and reacting; S4, adding 20 to 50 parts of bentonite to the product of step S3 and mixing thoroughly; S5, heating the product of step S4 for the first time and reacting it for the first time under stirring, and then heating it for the second time and reacting it for the second time; S6. Add 0.5 to 1 part of brewing bacteria liquid to the product of step S5 and stir evenly, granulate and dry to obtain organic fertilizer.

5. The preparation method according to claim 4, characterized in that: The moisture content of the product of step S1 is 30-40 wt%.

6. The preparation method according to claim 4, characterized in that: The product of step S2 is particles with a diameter of 8 to 12 mm.

7. The preparation method according to claim 4, characterized in that: In step S3, the reaction temperature is 30-35° C., and the reaction time is 0.5-1.5 h.

8. The preparation method according to claim 4, characterized in that: In step S5, the first heating is to heat to 40-50°C, and the first reaction time is 0.5-2h; the second heating is to heat to 60-70°C, and the second reaction time is 2-3h.

9. The preparation method according to claim 4, characterized in that: In step S6, when the brewing bacteria liquid is added, the temperature of the product of step S5 is lower than 40°C.

10. Use of the organic fertilizer according to claim 1 in agriculture.

Images