Functional microorganism agent-containing compound fertilizer, preparation method and use thereof

Abstract

This invention discloses a compound fertilizer containing functional microbial agents, its preparation method, and its uses, relating to the field of microbial fertilizers. The compound fertilizer consists of core fertilizer granules and a microbial agent encapsulated thereon. The core fertilizer comprises urea, monoammonium phosphate, potassium chloride, and potassium humate; the microbial agent contains Bacillus cereus, sucrose, and a composite carrier composed of polyvinyl alcohol or sodium carboxymethyl cellulose, chitosan, and peat. This invention significantly improves the survival rate and colonization efficiency of the compound microorganisms after fertilizer storage and application by optimizing the carrier composition. Field trials show that this compound fertilizer containing functional microbial agents significantly promotes the growth and yield of corn and rice crops, with significantly better results than the control treatment.

Description

Technical Field

[0001] This invention relates to the field of agricultural microbial fertilizer technology, specifically to a compound fertilizer containing functional microbial agents, its preparation method, and its application in promoting crop growth and increasing crop yield. Background Technology

[0002] The long-term excessive use of traditional chemical fertilizers has led to a series of environmental problems, including soil compaction, eutrophication of water bodies, and greenhouse gas emissions, necessitating a shift towards green and sustainable agricultural practices. Against this backdrop, microbial fertilizers, due to their positive effects on soil health, eco-friendliness, and efficient resource utilization, are gradually becoming an important alternative to traditional chemical fertilizers. However, the current bio-fertilizer market is flooded with a wide variety of products of varying quality, hindering the healthy development of the industry. Therefore, leveraging the advantages of microbial fertilizers in soil remediation, nutrient enhancement, and environmental pollution reduction has become a key research topic in modern agricultural science and technology.

[0003] Microbial fertilizer carriers are a type of multifunctional material that can provide protection and nutrition to functional microorganisms and regulate their microenvironment through physical, chemical, or biological means. Today, the role of carriers is no longer limited to the original "microbial transport vehicle," but has evolved into a key unit capable of dynamically regulating the entire "soil-microorganism-plant" system.

[0004] Different microorganisms have different requirements for their carriers. Some microorganisms grow well on specific carriers, while they grow slowly or die on other carriers. This invention, by selecting suitable carrier types, prepares an environment that provides a suitable environment for the survival and function of functional microorganisms, thereby significantly improving the fertilizer efficiency of compound fertilizers. Summary of the Invention

[0005] Purpose

[0006] To address the technical bottlenecks of low survival rates and unstable effects of functional microbial strains in existing microbial fertilizers, this invention provides a compound fertilizer containing functional microbial agents. This fertilizer, used in combination with a carrier and microbial strains, can improve the survival rate and colonization efficiency of microorganisms during fertilizer storage and application, thereby promoting crop growth and increasing yield.

[0007] Another objective of this invention is to provide a method for preparing the above-mentioned fertilizer, which has a simple process flow and is suitable for industrial production.

[0008] Technical solution

[0009] This invention provides a compound fertilizer containing functional microbial agents, characterized in that it comprises core fertilizer particles and microbial agents coated on the surface of the core particles;

[0010] The core fertilizer is made from the following raw materials in parts by weight: 15-35 parts urea, 10-20 parts monoammonium phosphate, 5-15 parts potassium chloride, and 0.5-5 parts potassium humate.

[0011] The microbial agent is made from the following raw materials in parts by weight: 1-5 parts microorganisms, 5-20 parts sucrose, and 5-20 parts carrier.

[0012] The microorganism in question is Bacillus cereus, taxonomically named Bacillus cereus, which was deposited on July 10, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 35197.

[0013] The carrier consists of polyvinyl alcohol or sodium carboxymethyl cellulose, chitosan, and peat.

[0014] Preferably, in the carrier, the mass ratio of polyvinyl alcohol or sodium carboxymethyl cellulose, chitosan and peat is (1-5):(1-5):(1-5).

[0015] Preferably, the number of viable bacteria in the compound fertilizer is 1×10⁻⁶. 8 ~ 5×10 8 CFU / g.

[0016] As a preferred embodiment, the compound fertilizer containing functional microbial agents comprises the following components by weight: 25 parts urea, 15 parts monoammonium phosphate, 10 parts potassium chloride, and 2 parts potassium humate; the microorganisms in the microbial agents are Bacillus cereus; and the mass ratio of polyvinyl alcohol or sodium carboxymethyl cellulose, chitosan, and peat in the carrier is 1:1:1.

[0017] This invention provides a method for preparing the compound fertilizer containing functional microbial agents, characterized by comprising the following steps:

[0018] S1. Preparation of bacterial culture: The microorganisms, sucrose and carrier are mixed, deionized water is added, the mixture is stirred evenly and the concentration of the bacterial culture is adjusted to 5 billion to 30 billion CFU / g to obtain the microbial culture;

[0019] S2. Coating and granulation: The core fertilizer granules, preheated to 30-40℃, are added to a coating machine. The microbial liquid obtained in S1 is sprayed in while the machine is in a rolling state, and an anti-caking agent is added at the same time until the microbial agent is evenly coated on the surface of the core fertilizer granules. After drying, the compound fertilizer is obtained.

[0020] This invention provides a compound fertilizer containing functional microbial agents for increasing crop yields. Specifically, the crops mentioned are corn and rice.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] Synergistic effect of the carrier: This invention uses sodium carboxymethyl cellulose, chitosan, and peat to form a composite carrier. This composite carrier is not simply superimposed, but produces a synergistic effect: sodium carboxymethyl cellulose, as an excellent binder and film-forming agent, ensures that the microbial agent is firmly and uniformly coated on the surface of fertilizer granules; chitosan, with its natural antibacterial and film-forming properties, constructs a biological protective barrier for functional strains, effectively resisting the invasion of miscellaneous bacteria; peat, with its unique physical structure and rich organic matter, is conducive to the dormancy, survival, and slow release of microorganisms.

[0023] Highly functional strain: The *Bacillus cereus* strain selected in this invention is a type of beneficial rhizosphere bacterium with environmental adaptability and biocontrol potential. This strain has an extremely strong ability to colonize roots, rapidly forming biofilms, effectively occupying ecological niches, and crowding out and inhibiting the infection of soil-borne pathogens (such as Fusarium and Rhizoctonia). Its core advantage lies in its ability to efficiently secrete a variety of antibacterial active substances and to comprehensively enhance the crop's immunity level by inducing systemic resistance.

[0024] Different microorganisms have different requirements for carriers. In the compound fertilizers A and B of this invention, the microorganisms grow well on specific carriers. At the same time, the microorganisms are evenly dispersed on the fertilizer surface and firmly attached. After use, the microbial agent has an excellent propagation speed, and the synergistic effect of the microbial agent on the compound fertilizer is more easily exerted. Attached Figure Description

[0025] Figure 1 This is the growth curve of Bacillus cereus in this invention;

[0026] Figure 2 This is an image of the colony appearance of Bacillus cereus, a patent of this invention.

[0027] Figure 3 This is a microscopic morphological image of Bacillus cereus, a patented invention. Detailed Implementation

[0028] The present invention can be better understood from the following embodiments. However, those skilled in the art will readily understand that the descriptions in the embodiments are for illustrative purposes only and should not, and will not, limit the invention as detailed in the claims.

[0029] Example 1: Formulation of compound fertilizer containing functional microbial agents

[0030] Experimental materials: Microorganisms: Bacillus cereus (100 billion spores / gram); Auxiliary materials: polyvinyl alcohol, chitosan, sodium carboxymethyl cellulose, peat, sucrose; Fertilizer components: urea, monoammonium phosphate, potassium chloride, potassium humate.

[0031] Compound fertilizer A containing functional microbial agents,

[0032] It contains a main fertilizer component and a microbial agent component, with the microbial agent component wrapped around the main fertilizer component. The main fertilizer component contains the following components by weight: 25 parts urea, 15 parts monoammonium phosphate, 10 parts potassium chloride, and 1 part potassium humate. The microbial agent component contains the following components by weight: 1 part microorganism (Bacillus cereus), 4 parts carrier (polyvinyl alcohol: chitosan: peat in a mass ratio of 1:1:1), and 4 parts sucrose.

[0033] The specific preparation method is as follows:

[0034] Mix the core fertilizer raw materials, granulate them, and preheat them to 40°C for later use.

[0035] According to the different carrier combinations shown in Table 1, microorganisms, sucrose, carriers and deionized water were mixed to prepare a bacterial solution with a viable count of 10 billion CFU / g.

[0036] The preheated core fertilizer granules are placed in a coating machine. The core fertilizer is sprayed with the above-mentioned bacterial solution while it is rolling. Then, an appropriate amount of anti-caking agent (liquid paraffin: talc = 1:1) is added until the bacterial agent is evenly coated. After low-temperature drying, the finished compound fertilizer is obtained. The number of live bacteria in the finished product is controlled at about 200 million CFU / g.

[0037] Compound fertilizer B containing functional microbial agents,

[0038] It comprises a main fertilizer component and a microbial inoculant component, with the microbial inoculant coating the main fertilizer component. The main fertilizer component contains the following parts by weight: 25 parts urea, 15 parts monoammonium phosphate, 10 parts potassium chloride, and 1 part potassium humate. The microbial inoculant component contains the following parts by weight: 1 part microorganism (Bacillus cereus), 4 parts carrier (sodium carboxymethyl cellulose: chitosan: peat in a mass ratio of 1:1:1), and 4 parts sucrose. The preparation method is the same as above.

[0039] Compound fertilizer C containing functional microbial agents,

[0040] It comprises a main fertilizer component and a microbial inoculant component, with the microbial inoculant coating the main fertilizer component. The main fertilizer component contains the following parts by weight: 25 parts urea, 15 parts monoammonium phosphate, 10 parts potassium chloride, and 1 part potassium humate. The microbial inoculant component contains the following parts by weight: 1 part microorganism (Bacillus cereus), 4 parts carrier (polyvinyl alcohol: chitosan: biochar in a mass ratio of 1:1:1), and 4 parts sucrose. The preparation method is the same as above.

[0041] Compound fertilizer D containing functional microbial agents,

[0042] It comprises a main fertilizer component and a microbial inoculant component, with the microbial inoculant coating the main fertilizer component. The main fertilizer component contains the following parts by weight: 25 parts urea, 15 parts monoammonium phosphate, 10 parts potassium chloride, and 1 part potassium humate. The microbial inoculant component contains the following parts by weight: 1 part microorganism (Bacillus cereus), 4 parts carrier (polyvinyl alcohol: chitosan in a 1:1 mass ratio), and 4 parts sucrose. The preparation method is the same as above.

[0043] Compound fertilizer E containing functional microbial agents,

[0044] It comprises a main fertilizer component and a microbial inoculant component, with the microbial inoculant coating the main fertilizer component. The main fertilizer component contains the following parts by weight: 25 parts urea, 15 parts monoammonium phosphate, 10 parts potassium chloride, and 1 part potassium humate. The microbial inoculant component contains the following parts by weight: 1 part microorganism (Bacillus cereus), 4 parts carrier (chitosan: peat in a 1:1 mass ratio), and 4 parts sucrose. The preparation method is the same as above.

[0045] Compound fertilizer F containing functional microbial agents,

[0046] It comprises a main fertilizer component and a microbial inoculant component, with the microbial inoculant component coated on the outside of the main fertilizer component. The main fertilizer component contains the following parts by weight: 25 parts urea, 15 parts monoammonium phosphate, 10 parts potassium chloride, and 1 part potassium humate. The microbial inoculant component contains the following parts by weight: 1 part microorganism (Bacillus cereus), 4 parts carrier (polyvinyl alcohol: peat in a 1:1 mass ratio), and 4 parts sucrose. The preparation method is the same as above.

[0047] Application Example 1: Field Fertilizer Effect of Compound Fertilizer Containing Functional Microbial Agents on Summer Corn

[0048] Experimental site overview: The soil type is light loam, and the previous crop was wheat. The soil organic matter content is 1.15%, and the pH is 7.0.

[0049] Experimental method: The experiment adopted a randomized block design, with a plot area of ​​50 m². 2 Repeated 3 times. Each 667 m 2 Apply 40 kg of compound fertilizer as a base fertilizer, sowing the seed and fertilizer simultaneously. No further topdressing is required later. Yield is measured separately for each plot.

[0050] Experimental results:

[0051] Table 1: Results of fertilizer effect experiment on summer maize under different treatments

[0052] Note: CK represents fertilizers using only the main fertilizer components; A~F represent different compound fertilizers containing functional microbial agents in the "Specific Implementation Methods" above.

[0053] Table 1 shows that after applying compound fertilizer, the physiological indicators of summer maize were significantly improved compared with the control (CK). Plant height increased by 1.68%–5.59%, stem diameter increased by 2.28%–11.87%, and yield increased by 8.97%–18.58%, demonstrating a significant yield increase. In particular, treatments A and B showed significant yield increases, showing a marked difference from the other treatments.

[0054] Application Example 2: Field Fertilizer Effect of Compound Fertilizer Containing Functional Microbial Agents on Rice

[0055] Experimental site overview: The soil is sandy loam with 2.65% organic matter and pH 6.0.

[0056] Experimental method: The experiment adopted a randomized block design, with a plot area of ​​45 m². 2 Repeated 3 times. 667 m 2 Apply 30 kg of compound fertilizer as base fertilizer, and later apply 667 m³ of fertilizer. 2 Apply 15 kg of urea as a top dressing. Yield test results for each plot were obtained separately.

[0057] Experimental results:

[0058] Table 2: Results of fertilizer effect experiment on rice under different treatments

[0059] Note: CK represents fertilizers using only the main fertilizer components; A~F represent different compound fertilizers containing functional microbial agents in the "Specific Implementation Methods" above.

[0060] As shown in Table 2, after applying compound fertilizer, compared with the control (CK), there were no significant changes in plant height and panicle length of rice, but the yield increased by 3.42%–8.82%, demonstrating a yield-increasing effect. In particular, treatments A and B showed significant yield-increasing effects, forming a significant difference from other treatments.

[0061] Based on the two test data above, it is inferred that different microorganisms have different requirements for the carrier. The microorganisms in treatment A and treatment B grew well on the specific carriers. At the same time, the microorganisms were evenly dispersed on the fertilizer surface and firmly attached. After use, the microbial agent had an excellent propagation speed, and the synergistic effect of the microbial agent on the compound fertilizer was more easily exerted.

[0062] The above description is only a preferred embodiment of the present invention. For those skilled in the art, appropriate improvements can be made without departing from the original material of the present invention, and these improvements are also within the protection scope of the present invention.

Claims

1. A compound fertilizer containing functional microbial agents, characterized in that, It includes core fertilizer granules and microbial agents wrapped around the fertilizer granules; The core fertilizer is made from the following raw materials in parts by weight: 15-35 parts urea, 10-20 parts monoammonium phosphate, 5-15 parts potassium chloride, and 0.5-5 parts potassium humate. The microbial inoculant is made from the following raw materials in parts by weight: 1-5 parts microorganisms, 5-20 parts carrier, and 5-20 parts sucrose. The microorganism is Bacillus cereus, taxonomically named, and was deposited on July 10, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 35197. The carrier consists of polyvinyl alcohol or sodium carboxymethyl cellulose, chitosan, and peat.

2. The compound fertilizer according to claim 1, characterized in that, In the carrier, the mass ratio of polyvinyl alcohol or sodium carboxymethyl cellulose, chitosan and peat is (1-5):(1-5):(1-5).

3. The compound fertilizer according to claim 2, characterized in that, The number of live bacteria in the compound fertilizer is 1×10⁻⁶. 8 ~ 5×10 8 CFU / g.

4. The compound fertilizer containing functional microbial agents according to claim 3, characterized in that, The main fertilizer components include the following parts by weight: 25 parts urea, 15 parts monoammonium phosphate, 10 parts potassium chloride, and 2 parts humic acid; the microbial agent is Bacillus cereus; the carrier contains polyvinyl alcohol or sodium carboxymethyl cellulose, chitosan, and peat in a mass ratio of 1:1:

1.

5. The method for preparing compound fertilizer containing functional microbial agents according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Preparation of bacterial culture: The microorganisms, sucrose and carrier are mixed, deionized water is added, the mixture is stirred evenly and the bacterial culture concentration is adjusted to 50 to 30 billion CFU / g to obtain the microbial culture; S2. Fertilizer granulation: After preheating the coating machine to 40°C, add the core fertilizer granules. Spray the microbial liquid obtained in S1 while the granules are rolling, and add an anti-caking agent until the core fertilizer granules are evenly coated. After drying, the compound fertilizer is obtained.

6. The use of the compound fertilizer containing functional microbial agents according to any one of claims 1-4 for increasing crop yield.

7. The use according to claim 6, characterized in that, The crops mentioned are corn and rice.

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