Fulvic acid type compound microbial organic fertilizer and preparation method thereof

Abstract

The invention relates to the technical field of fertilizers, in particular to a fulvic acid type compound microbial organic fertilizer and a preparation method thereof. The method comprises the following steps: preparing compound microorganism bacterium powder from bacillus subtilis, bacillus megatherium, bacillus licheniformis, pseudomonas fluorescens and bacillus psychrosaccharolyticus; preparing a solid-phase substance from ferric chloride hexahydrate, terephthalic acid and dimethylformamide; generating hydrogel on the surface of the chemical fertilizer in situ, and adding a solid-phase substance to obtain a slow-release chemical fertilizer; and preparing an organic fertilizer, and mixing the organic fertilizer with the compound microbial powder, the slow-release chemical fertilizer and the organic fertilizer to obtain the compound microbial organic fertilizer. According to the compound microbial organic fertilizer provided by the invention, the chemical fertilizer, the organic fertilizer and the microbial fertilizer synergistically promote the growth of plants, and the use of the chemical fertilizer is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of fertilizers, and particularly relates to a fulvic acid-type compound microbial organic fertilizer and a preparation method thereof. Background Art

[0002] Compound microbial fertilizers combine inorganic nutrient elements, organic matter, and microbial bacteria into one, reflecting the comprehensive effects of inorganic chemical fertilizers, organic fertilizers, and microbial fertilizers. They are fertilizers that can resolve soil compaction, repair and condition the soil, improve the utilization rate of chemical fertilizers, reduce river pollution, reduce the occurrence of pests and diseases, enhance the stress resistance of crops, and improve the quality and yield of crop fruits. Long-term use of compound microbial fertilizers can improve the physical and chemical properties of the soil, increase the available fertility of the soil, inhibit the occurrence of soil-borne diseases, and promote the growth of crops, which is of great significance for increasing yields and the sustainable development of agriculture. However, some chemical fertilizers contain high concentrations of ammonium nitrogen and nitrate nitrogen, and their strong oxidizing properties, high osmotic pressure, or special chemical environment are not conducive to the survival of microorganisms. For example, if a high-concentration urea solution is mixed with a microbial inoculant, the ammonia produced by the hydrolysis of urea will increase the alkalinity of the local environment, making it difficult for some microorganisms to adapt and weakening the activity of the inoculant.

[0003] For example, CN116462558A discloses a compound microbial fertilizer for special use in tower base vegetation restoration and a preparation method thereof. This application uses Bacillus subtilis, Bacillus megaterium, Bacillus mucilaginosus, and Bacillus laterosporus as the main functional bacteria to prepare a bacterial powder with a specific viable count; an organic fertilizer fully decomposed from chicken manure and mushroom bran as raw materials, and a chemical fertilizer with urea, potassium dihydrogen phosphate, and potassium sulfate as raw materials are prepared, and the two are fully mixed in a specific ratio, and then the functional bacterial powder is added and stirred evenly; the prepared semi-finished compound microbial fertilizer is granulated by a disc granulator, and water is intermittently sprayed with a watering can during the granulation process, and then it is air-dried and sieved to obtain the compound microbial fertilizer; the compound microbial fertilizer prepared by the present invention can improve the physical structure, biological fertility structure, etc. of the soil through biological adsorption, biological passivation, etc., improve the stress resistance of tower base vegetation, and improve the environment around the tower base. However, the chemical fertilizer added in this application has a greater harm to the functional bacterial powder, weakening the activity of the microbial bacterial powder.

[0004] A microbial liquid, a liquid microbial fertilizer, a production method thereof and an application thereof as disclosed in CN103570434A. The fermentation medium in the fermentation production includes: 40%-60% of yeast waste liquid, 0.1-0.135% of starch, 0.35-0.45% of sucrose, 0.35-0.45% of peptone, 0.7-0.9% of soybean meal, 0.21-0.27% of KH2PO4 and water. At the same time, a liquid microbial fertilizer produced by using the microbial liquid is provided, which includes 1-3% of microbial liquid, 10-40% of yeast waste liquid, appropriate inorganic nutrients and water; the total nutrients N+P2O5+K2O brought by the inorganic nutrients ≥ 4%. The nitrogen content of this application is too high, and no protection measures are taken for the microbial inoculant, resulting in a lack of microbial activity in the fertilizer.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a fulvic acid type compound microbial organic fertilizer and a preparation method thereof. The present invention provides that chemical fertilizers, organic fertilizers and microbial fertilizers in the compound microbial organic fertilizer synergistically promote the growth of plants and reduce the use of chemical fertilizers.

[0007] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0008] In the first aspect, the present invention provides a preparation method of a fulvic acid type compound microbial organic fertilizer, including the following steps:

[0009] S1, mixing Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis, Pseudomonas fluorescens, and Bacillus glycolysis frigoritolerans to form a microbial liquid, mixing the microbial liquid with sodium alginate, glycerol, trehalose, and gelatin, then adding calcium lactate, and freeze-drying after reaction to obtain a compound microbial powder;

[0010] S2, mixing ferric chloride hexahydrate, terephthalic acid, and dimethylformamide, stirring evenly, reacting, filtering, washing, and drying after cooling to obtain a solid phase;

[0011] S3, mixing gelatin, carboxymethyl cellulose, and water evenly, then adding urea, ammonium dihydrogen phosphate, and potassium dihydrogen phosphate, then adding ammonium persulfate for a primary reaction, then adding acrylamide, acrylic acid, and N,N'-methylenebisacrylamide for a secondary reaction, then adding the solid phase in step S2, ultrasonically treating and then maintaining the reaction temperature, and finally drying, grinding, and sieving to obtain a slow-release chemical fertilizer;

[0012] S4, using animal feces as raw materials, composting and ripening, mixing with biochar and fulvic acid to obtain an organic fertilizer, mixing the compound microbial powder and the organic fertilizer, and then mixing with the slow-release chemical fertilizer to obtain a compound microbial organic fertilizer.

[0013] In a preferred embodiment, in step S1, the number of viable bacteria in the microbial solution is 5 x 10 9 -3 x 10 10 CFU / ml.

[0014] In a preferred embodiment, in step S1, the mass ratio of the microbial liquid, sodium alginate, glycerol, trehalose and gelatin is 10: (5-10): (5-15 g): (3-8 g): (1-5 g): (8-20 g).

[0015] In a preferred embodiment, in step S1, the reaction time is 1-2 hours.

[0016] Various strains are compounded in the present invention, and the compounded strains of the present invention promote the growth and development of plants, reduce the use of chemical fertilizers, and prevent the damage of chemical fertilizers and other substances to the microbial powder by forming capsules on the surface of the microbial powder.

[0017] Specifically, Bacillus megaterium has a significant ability to solubilize phosphorus, and can convert insoluble phosphorus in the soil into a state that can be absorbed by plants; Bacillus saccharolyticus has both nitrogen fixation and a certain degree of potassium solubilization. They work together to release a large amount of phosphorus and potassium elements that were originally fixed in the soil, thereby improving soil fertility. Bacillus subtilis and Bacillus licheniformis produce a variety of organic acids during their growth and metabolism. On the one hand, these organic acids can further activate mineral nutrients in the soil and assist Bacillus megaterium, Bacillus saccharolyticus, etc. in the process of solubilizing phosphorus and potassium. On the other hand, they can chelate metal ions to make nutrients easier for plants to absorb. Bacillus saccharolyticus is responsible for nitrogen fixation, converting nitrogen in the air into nitrogen-containing compounds; Bacillus subtilis decomposes soil organic matter to produce ammonium nitrogen; Pseudomonas fluorescens participates in the nitrification process, converting ammonium nitrogen into nitrate nitrogen, which is more conducive to plant root absorption. Several bacteria form a relay in the nitrogen fixation, conversion, and absorption process to ensure that plants have an adequate supply of nitrogen.

[0018] Furthermore, in the complex soil environment, these types of bacteria have different reproduction rates and adaptability to the environment. Bacillus licheniformis has outstanding biological oxygen-snatching ability and can quickly consume local oxygen to create living space for anaerobic or facultative anaerobic beneficial microorganisms; aerobic bacteria such as Pseudomonas fluorescens and Bacillus subtilis use the remaining oxygen to fill the ecological niches of the aerobic environment. They work together to exclude pathogens in the soil and prevent the growth and colonization of harmful bacteria. Bacillus licheniformis and Bacillus subtilis can produce sticky substances such as extracellular polysaccharides to help the bacterial community attach to the surface of plant roots and form a biofilm. Once some bacteria colonize first, other bacteria can use the existing biofilm structure to more easily colonize the root system, thereby enhancing the overall competitiveness of the bacterial community in the rhizosphere of plants and providing fertilizer and disease prevention for plants at close range.

[0019] Furthermore, Bacillus subtilis and Bacillus licheniformis secrete a variety of antibiotics that inhibit fungal and bacterial plant pathogens; Pseudomonas fluorescens can also produce antibacterial substances. These antibiotics and antibacterial substances have different compositions and complementary antibacterial spectra. When multiple bacteria coexist, they can form a more comprehensive and powerful inhibitory defense line against the pathogenic bacteria of soil-borne diseases such as fusarium wilt and root rot, reducing the risk of plant infection; when Psychrobacillus cryoglucosus, Pseudomonas fluorescens, etc. are active in the rhizosphere of plants, they will induce a series of defense responses in plants, activate the plant's own immune system, and enhance the disease resistance ability. If combined with Bacillus subtilis and Bacillus licheniformis that secrete antibacterial substances, it will be both internal and external cultivation, weakening the activity of pathogenic bacteria and strengthening the defense of the plant itself, and jointly protecting the health of plants.

[0020] It should also be noted that during the growth and reproduction process of several Bacillus species, a large amount of extracellular polysaccharides and enzymes are secreted into the soil. These substances interact with soil particles to promote the formation of soil aggregate structures, making the soil loose and breathable. Some metabolites produced by Pseudomonas fluorescens can also enhance the water and fertilizer retention properties of the soil, jointly creating a high-quality environment for the growth of plant roots and the reproduction of microorganisms. And the acidic and alkaline substances produced by their metabolic activities can buffer the soil pH value, prevent the soil from being too acidic or too alkaline, maintain a relatively stable pH value, ensure the stable survival and function of various microorganisms, and continuously contribute to soil fertilization and plant growth.

[0021] In a preferred embodiment, in step S2, the mass ratio of ferric chloride hexahydrate, terephthalic acid, and dimethylformamide is 1:(1 - 3):(100 - 200).

[0022] In a preferred embodiment, in step S2, the reaction conditions are: temperature 120 - 150 °C, time 36 - 72 h.

[0023] In a preferred embodiment, in step S3, the mass ratio of gelatin, carboxymethyl cellulose, water, ammonium persulfate, acrylamide, acrylic acid, and N,N'-methylenebisacrylamide is 1:1:(50 - 100):(0.5 - 1):(2 - 4):(1 - 2):(0.1 - 0.5).

[0024] In a preferred embodiment, in step S3, based on the mass of 100 parts of carboxymethyl cellulose, the addition amount of urea is 50 - 100 parts.

[0025] In a preferred embodiment, in step S3, based on the mass of 100 parts of carboxymethyl cellulose, the addition amount of ammonium dihydrogen phosphate is 25 - 50 parts.

[0026] In a preferred embodiment, in step S3, based on 100 parts by mass of the carboxymethyl cellulose, the amount of potassium dihydrogen phosphate added is 25-50 parts.

[0027] In a preferred embodiment, in step S3, based on 100 parts by mass of the carboxymethyl cellulose, the amount of the solid phase added is 10-20 parts.

[0028] In a preferred embodiment, in step S3, the conditions of the primary reaction are: temperature 30-50°C, time 30-60 min.

[0029] In a preferred embodiment, in step S3, the conditions of the secondary reaction are: temperature 50-70° C., time 60-120 min.

[0030] In a preferred embodiment, in step S3, the power of the ultrasound is 50-100W.

[0031] In a preferred embodiment, in step S3, the conditions for the insulation reaction are: temperature 50-70° C., time 1-3 h.

[0032] The present invention first uses iron as a central node, coordinates with organic ligands such as terephthalic acid, and interconnects to form a three-dimensional porous network structure (solid phase), that is, to form a metal organic skeleton structure, and then generates hydrogel in situ on urea, ammonium dihydrogen phosphate and potassium dihydrogen phosphate, and fixes nitrogen, phosphorus and potassium fertilizer components in the hydrogel through the ordered pores of the solid phase, forming a stable slow-release structure, preventing nitrogen, phosphorus and potassium fertilizers from directly contacting the composite microbial powder, effectively avoiding the damage of nitrogen, phosphorus and potassium fertilizers to the composite microbial powder, and can release for a long time, effectively reducing the usage of nitrogen, phosphorus and potassium fertilizers. Adjusting the content of urea, ammonium dihydrogen phosphate and potassium dihydrogen phosphate can fine-tune the nitrogen, phosphorus and potassium content according to the needs of different crops to achieve the best adaptation ratio.

[0033] Specifically, the solid phase has a porous structure and a large specific surface area. It can efficiently adsorb nitrogen, phosphorus and potassium nutrients through physical adsorption, electrostatic action and other methods. Its pores can capture urea molecules, and the interlayer structure can chelate phosphate ions, gathering a large amount of fertilizer components inside the material to prevent rapid nutrient loss. The hydrogel contains abundant hydrophilic groups and has strong water absorption. It can absorb and lock a large amount of water, provide a solvent environment for fertilizer dissolution, and prevent the fertilizer from becoming ineffective due to drying. Moreover, the hydrogel itself can also retain some nutrients through physical encapsulation and hydrogen bonding, and together with the solid phase, it builds a nutrient storage depot, greatly expanding the load capacity of the fertilizer.

[0034] In addition, the crystal structure of the solid phase forms a natural barrier to nutrient release. Nutrients need to overcome pore resistance and coordination bond binding to diffuse out, which slows down the release rate. At the same time, it can dynamically adjust the opening and closing of pores according to changes in soil environmental humidity, temperature, and ion concentration, precisely regulating the release rhythm. When the hydrogel comes into contact with water, it swells, increasing the pores, and the encapsulated nutrients seep out accordingly. When the soil is short of water, the hydrogel shrinks, reducing the pores and restricting the outflow of nutrients. Its slow-release rhythm cooperates with that of the solid phase. During the period when the crop has a strong demand for fertilizers, both of them accelerate the release together. During the non-critical period, they cooperate to slow down the release, conforming to the growth law of plants.

[0035] Furthermore, the solid phase can firmly fix easily leached potassium ions, ammonium ions, etc. within its structure, reducing the risk of nutrient loss caused by rainwashing and irrigation. Even in the face of heavy rainfall, MOF can retain nutrients to the greatest extent due to its stable structure. The hydrogel has viscosity and can adhere to the surface of soil particles, reducing the movement of fertilizers with water flow. Moreover, it wraps MOF and fertilizers, further strengthening the overall structural stability, resisting external damage and microbial decomposition, and keeping the fertilizers staying near the rhizosphere persistently and stably.

[0036] Even further, the solid phase can buffer the soil pH, creating a suitable living condition for soil microorganisms. Moreover, it can slowly release trace metal ions (iron ions), activate the activity of soil enzymes, promote microbial metabolism, and indirectly assist in nutrient transformation. The soft and moist environment of the hydrogel is conducive to the penetration and extension of plant roots, inducing root development. And the hydrogel can adsorb microorganisms, providing a habitat for beneficial bacteria. These microorganisms, in turn, assist in fertilizer decomposition and nutrient absorption, and jointly activate the soil fertility cycle with the solid phase.

[0037] In a preferred embodiment, in step S4, the animal manure is one or more of chicken manure, sheep manure, and pig manure.

[0038] In a preferred embodiment, in step S4, the mass ratio of the biochar, animal manure, and fulvic acid is 1:(2 - 5):(2 - 4).

[0039] In a preferred embodiment, in step S4, the mass ratio of the compound microbial inoculum powder, slow-release chemical fertilizer, and organic fertilizer is (20 - 30):(20 - 40):(50 - 60).

[0040] The present invention promotes the growth of plants in various aspects by compounding organic fertilizers, microbial fertilizers, and chemical fertilizers, enriches the soil, reduces the use of chemical fertilizers, maximizes the role of microbial strains, and each component synergizes with each other to form an effective material cycle.

[0041] Specifically, the present invention particularly adds biochar as an organic fertilizer, providing a favorable site for the growth and reproduction of microorganisms, avoiding the adverse effects of contact between the microbial strains and chemical fertilizers during the release of the microbial strains, and on the other hand, fulvic acid provides the necessary nutrients for the growth of microorganisms. Moreover, the active functional groups carried by fulvic acid, such as carboxyl groups and phenolic hydroxyl groups, can regulate the enzyme activity within microbial cells and promote plant growth.

[0042] Specifically, biochar has porosity and a large specific surface area. These pore structures provide an ideal habitat for microbial strains. Microorganisms can attach to the interior or surface of the pores, protected from interference by factors such as physical scouring and mechanical extrusion in the external environment, ensuring the integrity of their own structures and facilitating colonization. And the surface of biochar is charged and can adsorb nutrients in the soil, such as ammonium ions, phosphate ions, and organic small molecules, supplying rich nutrients to the newly colonized microbial strains, helping them quickly adapt to the new environment, shortening the growth lag phase, and accelerating the proliferation of the microbial community. Microbial strains have diverse enzyme systems and can decompose complex organic substances. For example, Bacillus subtilis secretes extracellular enzymes to decompose plant residues. After biochar adsorbs these organic substrates, it can concentrate the substrates around the microorganisms, promoting more efficient mineralization of organic matter by the microorganisms and accelerating nutrient release. The insoluble phosphorus adsorbed by biochar will also be converted into a form that can be absorbed by plants under the action of organic acids produced by microbial metabolism. Moreover, biochar itself has a certain buffering capacity, regulating the soil pH and preventing the adverse effects of the acidity of fulvic acid on microorganisms. Therefore, due to the prior mixing of the compound microbial powder and the organic fertilizer, a large amount of the compound microbial powder enters the pores of the biochar, increasing the survival rate released from the capsule.

[0043] Second invention, the present invention provides one as described above

[0044] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0045] 1. In the present invention, various strains are compounded. The strains compounded by the present invention promote the growth and development of plants, reduce the usage amount of chemical fertilizers, and the present invention forms a capsule on the surface of the microbial powder, preventing the harm brought by substances such as chemical fertilizers to the microbial powder.

[0046] 2. First, in the present invention, iron is used as the central node, which undergoes a coordination reaction with organic ligands such as terephthalic acid and is interconnected to form a three-dimensional porous network structure (solid phase), that is, a metal-organic framework structure is formed. Then, a hydrogel is in-situ generated on urea, ammonium dihydrogen phosphate, and potassium dihydrogen phosphate, and the nitrogen, phosphorus, and potassium fertilizer components are fixed in the hydrogel through the ordered pores of the solid phase, forming a stable slow-release structure, preventing the direct contact between the nitrogen, phosphorus, and potassium fertilizers and the compound microbial bacteria powder, effectively avoiding the damage of the nitrogen, phosphorus, and potassium fertilizers to the compound microbial bacteria powder, and enabling sustained release, effectively reducing the usage amount of the nitrogen, phosphorus, and potassium fertilizers.

[0047] 3. The present invention promotes the growth of plants in various aspects by compounding organic fertilizers, microbial fertilizers, and chemical fertilizers, promotes soil fertility, reduces the use of chemical fertilizers, maximizes the role of microbial strains, and each component synergizes with each other to form an effective material cycle.

[0048] In particular, biochar is specifically added as an organic fertilizer in the present invention, providing a favorable place for the growth and reproduction of microorganisms, avoiding the adverse effects of contact between the released microbial strains and chemical fertilizers. On the other hand, fulvic acid provides the necessary nutrients for the growth of microorganisms. Moreover, the active functional groups carried by fulvic acid, such as carboxyl groups and phenolic hydroxyl groups, can regulate the enzyme activity in microbial cells and promote plant growth. Detailed implementation manners

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without any creative work belong to the scope of protection of the present invention.

[0050] Unless otherwise specified, the raw materials and reagents used in the present invention are all obtained commercially.

[0051] Bacillus subtilis was purchased from Huachuang Microbial Technology (Yantai) Co., Ltd.

[0052] Bacillus megaterium was purchased from Shandong Yihao Biotechnology Co., Ltd.

[0053] Bacillus licheniformis was purchased from Zhejiang Jingxin Pharmaceutical Co., Ltd.

[0054] Pseudomonas fluorescens was purchased from Huachuang Microbial Technology (Yantai) Co., Ltd.

[0055] Bacillus glycolicus was purchased from Huachuang Microbial Technology (Yantai) Co., Ltd.

[0056] Biochar, with an average particle size of 200 nm, was purchased from Shandong Tairan Bioengineering Co., Ltd.

[0057] Example 1

[0058] This example provides a preparation method of a fulvic acid type compound microbial organic fertilizer, which includes the following steps:

[0059] S1, Powders of Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis, Pseudomonas fluorescens, and Sporolactobacillus glycolicus were mixed in a ratio of 1:1:1:1:1 by mass, and then sterile water was added to form a microbial bacterial liquid. Among them, the viable bacteria count in the microbial bacterial liquid was 2×10 10 CFU / ml. By mass, 10 parts of the microbial bacterial liquid were mixed with 8 parts of sodium alginate, 10 parts of glycerol, 5 parts of trehalose, and 3 parts of gelatin. Then, 15 parts of calcium lactate were added, and after reacting for 1.5 h, it was freeze-dried to obtain a compound microbial bacterial powder;

[0060] S2, By mass, 1 part of ferric chloride hexahydrate, 2 parts of terephthalic acid, and 150 parts of dimethylformamide were mixed and stirred evenly, reacted at 140 °C for 72 h, cooled, filtered, washed, dried, and then ground through a 200-mesh sieve to obtain a solid phase;

[0061] S3, By mass, 1 part of gelatin, 1 part of carboxymethyl cellulose, and 100 parts of water were mixed evenly. Then, 1 part of urea, 0.5 part of ammonium dihydrogen phosphate, and 0.5 part of potassium dihydrogen phosphate were added. Then, 0.6 part of ammonium persulfate was added, and it was reacted at 40 °C for 45 min. Then, 3 parts of acrylamide, 1.5 parts of acrylic acid, and 0.4 part of N,N'-methylenebisacrylamide were added, and it was reacted at 60 °C for 100 min. Then, 0.2 part of the solid phase obtained in step S2 was added, ultrasonically treated at a power of 75 W for 5 min, then kept warm at 60 °C for 2 h, and finally dried, ground, and sieved to obtain a slow-release chemical fertilizer;

[0062] S4, By mass, 1 part of chicken manure and 1 part of sheep manure compost were matured until the moisture content was less than 20%. Then, they were mixed with 1 part of biochar and 4 parts of fulvic acid to obtain an organic fertilizer. 20 parts of the compound microbial bacterial powder and 60 parts of the organic fertilizer were mixed, and then mixed with 20 parts of the slow-release chemical fertilizer to obtain a fulvic acid type compound microbial organic fertilizer.

[0063] Example 2

[0064] This example provides a preparation method of a fulvic acid type compound microbial organic fertilizer, which includes the following steps:

[0065] S1. Mix the powders of Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis, Pseudomonas fluorescens, and Sporolactobacillus cryophilus in a ratio of 1:1:1:1:1 by mass, and then add sterile water to form a microbial bacterial liquid. Among them, the viable bacteria count in the microbial bacterial liquid is 3×10 10 CFU / ml. By mass, mix 10 parts of the microbial bacterial liquid with 8 parts of sodium alginate, 10 parts of glycerol, 5 parts of trehalose, and 3 parts of gelatin. Then add 15 parts of calcium lactate, react for 2 h, and then freeze-dry to obtain a composite microbial bacterial powder;

[0066] S2. By mass, mix 1 part of ferric chloride hexahydrate, 2 parts of terephthalic acid, and 150 parts of dimethylformamide, stir evenly, react at 140 °C for 72 h, cool, filter, wash, dry, and then grind through a 200-mesh sieve to obtain a solid phase;

[0067] S3. By mass, mix 1 part of gelatin, 1 part of carboxymethyl cellulose, and 100 parts of water evenly. Then add 1 part of urea, 0.5 part of ammonium dihydrogen phosphate, and 0.5 part of potassium dihydrogen phosphate. Then add 0.6 part of ammonium persulfate, react at 40 °C for 45 min, add 3 parts of acrylamide, 1.5 parts of acrylic acid, and 0.4 part of N,N'-methylenebisacrylamide, react at 60 °C for 100 min, add 0.2 part of the solid phase in step S2, ultrasonicate at a power of 75 W for 5 min, then keep warm at 60 °C for 2 h, and finally dry, grind, and sieve to obtain a slow-release chemical fertilizer;

[0068] S4. By mass, compost 1 part of pig manure and 1 part of sheep manure until the moisture content is less than 20%, then mix with 1 part of biochar and 4 parts of fulvic acid to obtain an organic fertilizer. Mix 28 parts of the composite microbial bacterial powder and 55 parts of the organic fertilizer, and then mix with 35 parts of the slow-release chemical fertilizer to obtain a composite microbial organic fertilizer.

[0069] Comparative Example 1

[0070] The difference between this comparative example and Example 1 is that Bacillus subtilis is not added.

[0071] Comparative Example 2

[0072] The difference between this comparative example and Example 1 is that Bacillus megaterium is not added.

[0073] Comparative Example 3

[0074] The difference between this comparative example and Example 1 is that Bacillus licheniformis is not added.

[0075] Comparative Example 4

[0076] The difference between this comparative example and Example 1 is that Pseudomonas fluorescens is not added.

[0077] Comparative Example 5

[0078] The difference between this comparative example and Example 1 is that Bacillus psychrosaccharolyticus is not added.

[0079] Comparative Example 6

[0080] The difference between this comparative example and Example 1 is that "mixing 20 parts of the compound microbial powder and 60 parts of the organic fertilizer and then mixing with 20 parts of the slow-release chemical fertilizer" is changed to "mixing 20 parts of the compound microbial powder and 70 parts of the organic fertilizer and then mixing with 30 parts of the slow-release chemical fertilizer".

[0081] Comparative Example 7

[0082] The difference between this comparative example and Example 1 is that step S2 is not carried out, and the solid phase substance in step S2 is not added in the original step S3.

[0083] Comparative Example 8

[0084] The difference between this comparative example and Example 1 is that steps S2 and S3 are not carried out, and 20 parts of the slow-release chemical fertilizer are changed to 10 parts of urea, 5 parts of ammonium dihydrogen phosphate, and 5 parts of potassium dihydrogen phosphate.

[0085] Comparative Example 9

[0086] The difference between this comparative example and Example 1 is that biochar is not added in step S4.

[0087] Performance Test

[0088] Test Example 1, the test crop is pepper, variety "Jianjiao 22"; the planting density is 3000 plants / mu; a total of four treatments are set, with 4 replicates, and the area of each plot is 20m 2 , arranged in a randomized block design. The fertilizers obtained from the examples and comparative examples are used for fertilization at 50 kg / mu respectively, and the agronomic traits and yield of the peppers are tested, and their averages are taken. The results are shown in Table 1.

[0089]

[0090]

[0091] Test Example 2, the test crop is corn, variety "Zhengdan 958"; the planting density is 4000 plants / mu; a total of four treatments are set, with 4 replicates, and the area of each plot is 30m 2 , arranged in a randomized block design. The fertilizers obtained from the examples and comparative examples are used for fertilization at 50 kg / mu respectively, and the agronomic traits and yield of the corn are tested, and their averages are taken. The results are shown in Table 2.

[0092] Table 2 Effects of the fertilizers of the examples and comparative examples on the agronomic traits and yield of corn

[0093]

[0094]

[0095] Test Example 3. The test crop is wheat, variety "Jimai 38"; the planting density is 12 kg / mu; a total of four treatments are set, with 4 replicates, and the area of each plot is 24 m 2 , arranged in a randomized block design. The fertilizers obtained from the examples and comparative examples were applied at 200 kg / mu respectively, and the agronomic traits and yield of wheat were tested, and the average values were taken. The results are shown in Table 2.

[0096] Table 3 Effects of the fertilizers of the examples and comparative examples on the agronomic traits and yield of wheat

[0097] Plant height / cm Yield / kg / mu Example 1 78.6 712.4 Example 2 81.2 723.8 Comparative Example 1 66.5 655.8 Comparative Example 2 64.8 645.2 Comparative Example 3 65.9 648.9 Comparative Example 4 67.2 661.2 Comparative Example 5 65.1 650.4 Comparative Example 6 70.7 685.6 Comparative Example 7 68.4 671.2 Comparative Example 8 60.3 627.9 Comparative Example 9 64.1 639.5

[0098] From the above performance test results, it can be seen that the growth promotion and reproduction ability of Examples 1-2 is the strongest, especially the comprehensive performance of Example 2 is the most prominent. This is mainly because the chemical fertilizer, organic fertilizer, and microbial fertilizer in the compound microbial organic fertilizer synergistically promote the growth of plants and reduce the use of chemical fertilizers. In this application, the ratio of Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis, Pseudomonas fluorescens, and Psychrobacillus glycolicus was not further studied. The test results of Comparative Examples 1-5 compared with Example 1 show that the combined effect of the five microorganisms used together is better. The comparative examples are significantly worse than the examples in the corresponding performance tests because they do not adopt the necessary technical solutions, which better proves the irreplaceability of the specific technical solution of this application for achieving the technical effect and solving the technical problem.

[0099] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing fulvic acid type composite microbial organic fertilizer, characterized in that: The following steps are involved: S1, mixing Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis, Pseudomonas fluorescens, and Bacillus saccharolyticus to form a microbial liquid, mixing the microbial liquid with sodium alginate, glycerol, trehalose, and gelatin, then adding calcium lactate, reacting, and freeze-drying to obtain a composite microbial powder; S2, mixing ferric chloride hexahydrate, terephthalic acid and dimethylformamide, stirring and reacting, cooling, filtering, washing and drying to obtain a solid phase; S3, gelatin, carboxymethyl cellulose and water are mixed evenly, and then urea, ammonium dihydrogen phosphate and potassium dihydrogen phosphate are added, and then ammonium persulfate is added for a primary reaction, and then acrylamide, acrylic acid and N,N'-methylenebisacrylamide are added for a secondary reaction, and then the solid phase in step S2 is added, ultrasonically followed by heat preservation reaction, and finally dried, ground and sieved to obtain a slow-release chemical fertilizer; S4, composting animal manure as raw material and mixing it with biochar and fulvic acid to obtain organic fertilizer, mixing composite microbial powder and organic fertilizer and then mixing with slow-release chemical fertilizer to obtain composite microbial organic fertilizer.

2. The method for preparing the fulvic acid type composite microbial organic fertilizer according to claim 1, characterized in that: In step S1, the number of viable bacteria in the microbial solution is 5 x 10 9 -3 x 10 10 CFU / ml.

3. The method for preparing the fulvic acid type composite microbial organic fertilizer according to claim 1, characterized in that: In step S1, the mass ratio of the microbial liquid, sodium alginate, glycerol, trehalose and gelatin is 10: (5-10): (5-15 g): (3-8 g): (1-5 g): (8-20 g); And / or, in step S1, the reaction time is 1-2h.

4. The method for preparing the fulvic acid type composite microbial organic fertilizer according to claim 1, characterized in that: In step S2, the mass ratio of ferric chloride hexahydrate, terephthalic acid and dimethylformamide is 1:(1-3):(100-200).

5. The method for preparing the fulvic acid type composite microbial organic fertilizer according to claim 1, characterized in that: In step S2, the reaction conditions are: temperature 120-150° C., time 36-72 h.

6. The method for preparing the fulvic acid type composite microbial organic fertilizer according to claim 1, characterized in that: In step S3, the mass ratio of gelatin, carboxymethyl cellulose, water, ammonium persulfate, acrylamide, acrylic acid and N,N'-methylenebisacrylamide is 1:1:(50-100):(0.5-1):(2-4):(1-2):(0.1-0.5); And / or, in step S3, based on 100 parts by mass of the carboxymethyl cellulose, the amount of urea added is 50-100 parts; And / or, in step S3, based on 100 parts by mass of the carboxymethyl cellulose, the amount of the added ammonium dihydrogen phosphate is 25-50 parts; And / or, in step S3, based on 100 parts by mass of the carboxymethyl cellulose, the amount of potassium dihydrogen phosphate added is 25-50 parts; And / or, in step S3, based on 100 parts by mass of the carboxymethyl cellulose, the amount of the solid phase added is 10-20 parts; And / or, in step S3, the conditions of the primary reaction are: temperature 30-50° C., time 30-60 min.

7. The method for preparing the fulvic acid type composite microbial organic fertilizer according to claim 1, characterized in that: In step S3, the conditions of the secondary reaction are: temperature 50-70°C, time 60-120min; And / or, in step S3, the power of the ultrasound is 50-100W; And / or, in step S3, the conditions of the heat preservation reaction are: temperature 50-70° C., time 1-3 h.

8. The method for preparing the fulvic acid type composite microbial organic fertilizer according to claim 1, characterized in that: In step S4, the animal manure is one or more of chicken manure, sheep manure, and pig manure; And / or, in step S4, the mass ratio of the biochar, animal manure and fulvic acid is 1:(2-5):(2-4).

9. The method for preparing the fulvic acid type composite microbial organic fertilizer according to claim 1, characterized in that: In step S4, the mass ratio of the composite microbial powder, the slow-release chemical fertilizer and the organic fertilizer is (20-30): (20-40): (50-60).

10. A composite microbial organic fertilizer obtained by the preparation method of the fulvic acid type composite microbial organic fertilizer according to any one of claims 1 to 9.

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