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 invention belongs to the technical field of fertilizers, and in particular relates to a fulvic acid type composite microbial organic fertilizer and a preparation method thereof. Background Art

[0002] Compound microbial fertilizers are inorganic nutrients, organic matter, and microorganisms that are organically combined 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 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 quick-acting 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 sustainable agricultural development. However, some chemical fertilizers contain high concentrations of ammonium nitrogen and nitrate nitrogen, which are highly oxidizing, have high osmotic pressure, or special chemical environments that are not conducive to the survival of microorganisms. For example, if a high-concentration urea solution is mixed with a microbial agent, 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 agent.

[0003] For example, CN116462558A discloses a special composite microbial fertilizer for tower base vegetation restoration and a preparation method thereof. The application uses Bacillus subtilis, Bacillus megaterium, Bacillus gelatinus, and Bacillus laterosporei as main functional bacteria to prepare bacterial powder with a specific number of live bacteria; fully decomposed organic fertilizers made from chicken manure and mushroom chaff, and chemical fertilizers made from urea, potassium dihydrogen phosphate, and potassium sulfate are prepared, the two are fully mixed in a specific proportion, and then the functional bacteria powder is added and stirred evenly; the prepared composite microbial fertilizer semi-finished product is granulated by a disc granulator, water is sprayed intermittently with a watering can during the granulation process, and then it is air-dried and sieved to obtain the composite microbial fertilizer; the composite microbial fertilizer prepared by the present invention can improve the soil physical structure, biological fertility structure, etc. 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 fertilizers added in this application are very harmful to the functional bacterial powder and weaken the activity of the microbial powder.

[0004] For example, CN103570434A discloses a microbial liquid, a liquid microbial fertilizer, a production method and an application thereof, wherein the fermentation medium in the fermentation production includes: 40%-60% yeast waste liquid, 0.1-0.135% starch, 0.35-0.45% sucrose, 0.35-0.45% peptone, 0.7-0.9% soybean meal, 0.21-0.27% KH2PO4 and water. At the same time, a liquid microbial fertilizer produced with the liquid is provided: including 1-3% microbial liquid, 10-40% yeast waste liquid, an appropriate amount of inorganic nutrients and water; the total nutrients N+P2O5+K2O brought by the inorganic nutrients are ≥4%. The nitrogen content of the application is too high, and the microbial agent does not take any protective measures, resulting in a lack of microbial activity in the fertilizer.

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

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

[0007] In order to achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for preparing a fulvic acid-type composite microbial organic fertilizer, comprising the following steps: 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 washed, 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.

[0008] In a preferred embodiment, in step S1, the number of viable bacteria in the microbial solution is 1 10 9-4 10 10 CFU / mL.

[0009] 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).

[0010] In a preferred embodiment, in step S1, the reaction time is 1-2 hours.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] Furthermore, Bacillus subtilis and Bacillus licheniformis can secrete a variety of antibiotics to 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 inhibition line of defense against pathogens of soil-borne diseases such as wilt and root rot, reducing the risk of plant disease infection; when Bacillus pyrolyticus and Pseudomonas fluorescens 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 disease resistance. If combined with Bacillus subtilis and Bacillus licheniformis that secrete antibacterial substances, it will improve both internal and external health, weakening the activity of pathogens and strengthening the defense of the plant itself, jointly protecting plant health.

[0015] It should also be noted that several types of Bacillus will secrete a large amount of extracellular polysaccharides and enzymes into the soil during their growth and reproduction. These substances interact with soil particles, promote the formation of soil granular structure, and make the soil loose and breathable. Some metabolites produced by Pseudomonas fluorescens can also enhance the water and fertilizer retention properties of the soil, and together create a high-quality environment for plant root growth and microbial reproduction. In addition, the acid and alkaline substances produced by their metabolic activities can buffer the pH value of the soil, prevent the soil from being too acidic or alkaline, maintain a relatively stable pH value, ensure that all types of microorganisms can survive and function stably, and continue to help soil fertility and plant growth.

[0016] In a preferred embodiment, in step S2, the mass ratio of ferric chloride hexahydrate, terephthalic acid and dimethylformamide is 1:(1-3):(100-200).

[0017] In a preferred embodiment, in step S2, the reaction conditions are: temperature 120-150° C., time 36-72 h.

[0018] 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).

[0019] In a preferred embodiment, in step S3, the amount of urea added is 50-100 parts by mass based on 100 parts by mass of the carboxymethyl cellulose.

[0020] In a preferred embodiment, in step S3, based on 100 parts by mass of the carboxymethyl cellulose, the amount of ammonium dihydrogen phosphate added is 25-50 parts.

[0021] 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.

[0022] 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.

[0023] In a preferred embodiment, in step S3, the conditions of the primary reaction are: temperature 30-50°C, time 30-60 min.

[0024] In a preferred embodiment, in step S3, the conditions of the secondary reaction are: temperature 50-70° C., time 60-120 min.

[0025] In a preferred embodiment, in step S3, the power of the ultrasound is 50-100W.

[0026] In a preferred embodiment, in step S3, the conditions for the insulation reaction are: temperature 50-70° C., time 1-3 h.

[0027] The present invention firstly uses iron as a central node to coordinate with organic ligands such as terephthalic acid, and connects with each other to form a three-dimensional porous network structure (solid phase), that is, to form a metal organic skeleton structure, and then in situ generates a hydrogel on urea, ammonium dihydrogen phosphate and potassium dihydrogen phosphate, and fixes the nitrogen, phosphorus and potassium fertilizer components in the hydrogel through the ordered pores of the solid phase, forming a stable slow-release structure, preventing the nitrogen, phosphorus and potassium fertilizers from directly contacting the composite microbial powder, effectively avoiding the damage of the nitrogen, phosphorus and potassium fertilizers to the composite microbial powder, and being able to release for a long time, effectively reducing the usage of the nitrogen, phosphorus and potassium fertilizers.

[0028] 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.

[0029] In addition, the crystal structure of the solid phase forms a natural obstacle to the release of nutrients. Nutrients need to overcome pore resistance and coordination bond constraints to diffuse out, which slows down the release rate. At the same time, it will dynamically adjust the opening and closing of the pores according to changes in soil environmental humidity, temperature, and ion concentration, and accurately control the release rhythm. When the hydrogel comes into contact with water, it swells, the pores increase, and the encapsulated nutrients seep out; when the soil is short of water, the hydrogel shrinks, the pores become smaller, and the outflow of nutrients is restricted. It cooperates with the slow-release rhythm of the solid phase. During the period when crops need fertilizer, the two jointly accelerate the release; during the non-critical period, they synergistically slow down the release, which is in line with the law of plant growth.

[0030] It is further explained that the solid phase can firmly fix potassium ions and ammonium ions that are easily leached in its structure, reducing the risk of nutrient loss caused by rain erosion and irrigation. Even in the event of heavy rainfall, MOF can retain nutrients to the greatest extent by virtue of its stable structure. The hydrogel is sticky and can adhere to the surface of soil particles, reducing the movement of fertilizer with water flow. Moreover, it wraps MOF and fertilizer, further enhancing the stability of the overall structure, resisting external damage and microbial decomposition, and allowing the fertilizer to stay near the rhizosphere for a long time and stably.

[0031] Furthermore, solid phases can buffer soil pH and create suitable living conditions for soil microorganisms; they can also slowly release trace metal ions (iron ions), activate soil enzyme activity, promote microbial metabolism, and indirectly assist nutrient conversion. The soft and moist environment of hydrogels is conducive to the interlacing and extension of plant roots, inducing root development. In addition, hydrogels can absorb microorganisms and provide a habitat for beneficial bacteria. These microorganisms in turn assist in the decomposition of fertilizers and nutrient absorption, and together with solid phases, activate the soil fertility cycle.

[0032] In a preferred embodiment, in step S4, the animal manure is one or more of chicken manure, duck manure, and pig manure.

[0033] In a preferred embodiment, in step S4, the mass ratio of the biochar, animal manure and fulvic acid is 1:(2-5):(2-4).

[0034] In a preferred embodiment, 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).

[0035] The present invention promotes plant growth from all 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 cooperates with each other to form an effective material cycle.

[0036] In particular, the present invention specifically adds biochar as an organic fertilizer, which provides a favorable place for the growth and reproduction of microorganisms, avoids the adverse effects of contact with chemical fertilizers when the microbial strains are released, and fulvic acid provides necessary nutrients for the growth of microorganisms. On the other hand, the active functional groups carried by fulvic acid, such as carboxyl and phenolic hydroxyl, can regulate the enzyme activity in microbial cells and promote plant growth.

[0037] 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 inside or surface of the pores, free from interference from physical scouring, mechanical extrusion and other factors in the external environment, ensuring the integrity of their own structure and facilitating colonization. In addition, the surface of biochar carries an electric charge and can absorb nutrients in the soil, such as ammonium ions, phosphate ions and small organic molecules, providing rich nutrition for newly colonized microbial strains, helping them to quickly adapt to the new environment, shorten the growth delay period, and accelerate the proliferation of the bacterial community. Microbial strains have a variety of enzyme systems that can decompose complex organic substances, such as Bacillus subtilis secreting extracellular enzymes to decompose plant residues; after biochar adsorbs these organic substrates, it can enrich the substrates around the microorganisms, prompting the microorganisms to mineralize organic matter more efficiently and accelerate 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. In addition, biochar itself has a certain buffering capacity, which regulates the pH of the soil and prevents the adverse effects of fulvic acid on microorganisms. Therefore, since the composite microbial powder and organic fertilizer were mixed first, a large amount of composite microbial powder entered into the pores of biochar, which increased the survival rate released from the capsules.

[0038] The second invention provides a Compared with the prior art, the advantages and beneficial effects of the present invention are: 1. Various strains are compounded in the present invention. The compounded strains of the present invention promote the growth and development of plants and reduce the use of chemical fertilizers. In addition, the present invention prevents the damage of chemical fertilizers and other substances to the microbial powder by forming capsules on the surface of the microbial powder.

[0039] 2. The present invention first uses iron as the central node to coordinate with organic ligands such as terephthalic acid, and connects them to form a three-dimensional porous network structure (solid phase), that is, a metal organic skeleton structure, and then in situ generates hydrogel on urea, ammonium dihydrogen phosphate and potassium dihydrogen phosphate, and fixes the nitrogen, phosphorus and potassium fertilizer components in the hydrogel through the ordered pores of the solid phase to form a stable slow-release structure, which prevents the nitrogen, phosphorus and potassium fertilizers from directly contacting the composite microbial powder, effectively avoiding the damage of the nitrogen, phosphorus and potassium fertilizers to the composite microbial powder, and can release them for a long time, effectively reducing the usage of the nitrogen, phosphorus and potassium fertilizers.

[0040] 3. The present invention promotes plant growth from all 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 cooperates with each other to form an effective material cycle.

[0041] In particular, the present invention specifically adds biochar as an organic fertilizer, which provides a favorable place for the growth and reproduction of microorganisms, avoids the adverse effects of contact with chemical fertilizers when the microbial strains are released, and fulvic acid provides necessary nutrients for the growth of microorganisms. On the other hand, the active functional groups carried by fulvic acid, such as carboxyl and phenolic hydroxyl, can regulate the enzyme activity in microbial cells and promote plant growth. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Unless otherwise specified, the raw materials and reagents used in the present invention are commercially available.

[0044] Bacillus subtilis was purchased from Huachuang Microbial Technology (Yantai) Co., Ltd.; Bacillus megaterium was purchased from Shandong Yihao Biotechnology Co., Ltd.; Bacillus licheniformis was purchased from Zhejiang Jingxin Pharmaceutical Co., Ltd.; Pseudomonas fluorescens was purchased from Huachuang Microbial Technology (Yantai) Co., Ltd.; Bacillus saccharolyticus was purchased from Huachuang Microbial Technology (Yantai) Co., Ltd.; Biochar, with an average particle size of 200 nm, was purchased from Shandong Tairan Bioengineering Co., Ltd.

[0045] Example 1 This embodiment provides a method for preparing a humic acid type composite microbial organic fertilizer, comprising the following steps: S1, Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis, Pseudomonas fluorescens, and Bacillus saccharolyticus are mixed to form a microbial culture liquid, and 10 parts of the microbial culture liquid are mixed with 8 parts of sodium alginate, 10 parts of glycerol, 5 parts of trehalose, and 3 parts of gelatin by mass, and then 15 parts of calcium lactate are added, wherein the number of viable bacteria in the microbial culture liquid is 2 10 10 CFU / mL, and freeze-dried after 1.5 h of reaction to obtain composite microbial powder; 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 hours, filtered, washed, dried, and ground through a 200-mesh sieve after cooling to obtain a solid phase; S3, by mass, 1 part of gelatin, 1 part of carboxymethyl cellulose, and 100 parts of water are mixed uniformly, then 1 part of urea, 0.5 parts of ammonium dihydrogen phosphate and 0.5 parts of potassium dihydrogen phosphate are added, then 0.6 parts of ammonium persulfate are added, and the mixture is reacted at 40°C for 45 minutes, then 3 parts of acrylamide, 1.5 parts of acrylic acid and 0.4 parts of N,N'-methylenebisacrylamide are added, and the mixture is reacted at 60°C for 100 minutes, then 0.2 parts of the solid phase in step S2 are added, and the mixture is ultrasonicated at a power of 75 W for 5 minutes, then the mixture is kept warm at 60°C for 2 hours, and finally the mixture is washed, dried, ground, and sieved to obtain a slow-release chemical fertilizer; S4, by mass, 1 part of chicken manure and 1 part of duck manure are composted until the moisture content is less than 20%, and then mixed with 1 part of biochar and 4 parts of fulvic acid to obtain organic fertilizer, and 20 parts of composite microbial powder and 60 parts of organic fertilizer are mixed, and then mixed with 20 parts of slow-release chemical fertilizer to obtain composite microbial organic fertilizer.

[0046] Example 2 This embodiment provides a method for preparing a humic acid type composite microbial organic fertilizer, comprising the following steps: S1, Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis, Pseudomonas fluorescens, and Bacillus saccharolyticus are mixed to form a microbial culture liquid, and 10 parts of the microbial culture liquid are mixed with 8 parts of sodium alginate, 10 parts of glycerol, 5 parts of trehalose, and 3 parts of gelatin by mass, and then 15 parts of calcium lactate are added, wherein the number of viable bacteria in the microbial culture liquid is 3 10 10 CFU / mL, and freeze-dried after 2 h of reaction to obtain composite microbial powder; 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 hours, filtered, washed, dried, and ground through a 200-mesh sieve after cooling to obtain a solid phase; S3, by mass, 1 part of gelatin, 1 part of carboxymethyl cellulose, and 100 parts of water are mixed uniformly, then 1 part of urea, 0.5 parts of ammonium dihydrogen phosphate and 0.5 parts of potassium dihydrogen phosphate are added, then 0.6 parts of ammonium persulfate are added, and the mixture is reacted at 40°C for 45 minutes, then 3 parts of acrylamide, 1.5 parts of acrylic acid and 0.4 parts of N,N'-methylenebisacrylamide are added, and the mixture is reacted at 60°C for 100 minutes, then 0.2 parts of the solid phase in step S2 are added, and the mixture is ultrasonicated at a power of 75 W for 5 minutes, then the mixture is kept warm at 60°C for 2 hours, and finally the mixture is washed, dried, ground, and sieved to obtain a slow-release chemical fertilizer; S4, by mass, 1 part of pig manure and 1 part of duck manure are composted until the moisture content is less than 20%, and then mixed with 1 part of biochar and 4 parts of fulvic acid to obtain organic fertilizer. 28 parts of composite microbial powder and 55 parts of organic fertilizer are mixed, and then mixed with 35 parts of slow-release chemical fertilizer to obtain composite microbial organic fertilizer.

[0047] Comparative Example 1 The difference between this comparative example and Example 1 is that Bacillus subtilis is not added.

[0048] Comparative Example 2 The difference between this comparative example and Example 1 is that Bacillus megaterium is not added.

[0049] Comparative Example 3 The difference between this comparative example and Example 1 is that Bacillus licheniformis is not added.

[0050] Comparative Example 4 The difference between this comparative example and Example 1 is that Pseudomonas fluorescens is not added.

[0051] Comparative Example 5 The difference between this comparative example and Example 1 is that no cold saccharolytic Bacillus was added.

[0052] Comparative Example 6 The difference between this comparative example and Example 1 is that instead of mixing 20 parts of composite microbial powder and 60 parts of organic fertilizer and then mixing with 20 parts of slow-release chemical fertilizer, 70 parts of organic fertilizer and then mixing with 30 parts of slow-release chemical fertilizer are used.

[0053] Comparative Example 7 The difference between this comparative example and Example 1 is that step S2 is not performed, and the solid phase in step S2 is not added to the original step S3.

[0054] Comparative Example 8 The difference between this comparative example and Example 1 is that step S2 and step S3 are not performed, and 20 parts of slow-release chemical fertilizers are replaced by 10 parts of urea, 5 parts of ammonium dihydrogen phosphate and 5 parts of potassium dihydrogen phosphate.

[0055] Comparative Example 9 The difference between this comparative example and Example 1 is that no biochar is added in step S4.

[0056] Performance Testing Example 1: The test crop is pepper, variety "Sharp Pepper 22"; the planting density is 3000 plants / mu; there are four treatments, 4 replications, and each plot is 20m 2 The fertilizers obtained in the embodiment and the comparative example were respectively used for fertilization at 50 kg / mu to test the effects on the agronomic traits and yield of peppers. The average values ​​were taken and the results are shown in Table 1.

[0057] Table 1 Effects of the fertilizers of the examples and comparative examples on agronomic traits and yield of peppers In case 2, the test crop was corn, variety "Zhengdan 958"; the planting density was 4000 plants / mu; there were four treatments, 4 replicates, and each plot was 30m2. 2 The fertilizers obtained in the embodiment and the comparative example were respectively used for fertilization at 50 kg / mu to test the effects on the agronomic traits and yield of corn, and the average values ​​were taken. The results are shown in Table 2.

[0058] Table 2 Effects of the fertilizers of the examples and comparative examples on agronomic traits and yield of corn Case 3: The test crop is wheat, variety "Jimai 38"; the planting density is 12kg / mu; there are four treatments, 4 replicates, and each plot is 24m 2 The fertilizers obtained in the embodiment and the comparative example were respectively used for fertilization at 200 kg / mu to test the effects on the agronomic traits and yield of wheat, and the average values ​​were taken. The results are shown in Table 3.

[0059] Table 3 Effects of the fertilizers of the examples and comparative examples on agronomic traits and yield of wheat From the above performance test results, it can be seen that Examples 1-2 have the strongest growth and reproduction ability, especially Example 2 has the most outstanding comprehensive performance, which is mainly because the chemical fertilizer, organic fertilizer, and microbial fertilizer in the composite microbial organic fertilizer synergistically promote the growth of plants and reduce the use of chemical fertilizers. The comparative example is significantly worse than the example in the corresponding performance test because it does not adopt the necessary technical solution, which better proves the irreplaceable nature of the specific technical solution of this application in achieving technical effects and solving technical problems.

[0060] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection 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 washed, 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 1 10 9 -4 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, duck 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 method for preparing the fulvic acid type composite microbial organic fertilizer according to any one of claims 1 to 9.

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