A composite microbial soil conditioner, its preparation method and application

Abstract

This invention discloses a composite microbial soil conditioner, its preparation method, and its application. The soil conditioner, by weight, comprises 400-500 parts of substrate, 40-60 parts of microbial inoculant, and 500-600 parts of excipients. Through the synergistic effect of multiple microbial strains, this invention can alleviate soil compaction, improve the pH conditions of acidified soil, and increase the content of ammonia nitrogen in the soil, thereby enhancing soil fertility and significantly improving the diversity of soil microorganisms in acidified soil, making the acidified soil suitable for crop growth. The addition of organic components provides sufficient nutrients for crops, promoting crop growth and increasing yield and quality. It shortens the soil improvement time while enhancing the improvement effect, and the mixing of multiple substances allows for better improvement results with a smaller dosage, comprehensively saving on soil improvement costs.

Description

Technical Field

[0001] This invention belongs to the field of soil improvement technology, and in particular relates to a compound microbial soil conditioner, its preparation method and application. Background Technology

[0002] Currently, the effective remediation of heavy metal-contaminated soil has become a research hotspot of widespread international concern. Soil conditioners are an important means of remediating heavy metals in farmland soils, and they have been widely used in the improvement of degraded soils. Their specific effects are reflected in the following aspects: First, they improve the physical properties of the soil, enhance its water and soil retention capacity, and increase the availability of nutrients, thereby improving soil fertility. Second, they promote the activity of beneficial microorganisms and enzymes, inhibit pathogenic microorganisms, and enhance plant resistance. Finally, they reduce the migration capacity of heavy metals (such as Cd, Pb, and As) in contaminated soils, thereby inhibiting the absorption of heavy metals by crops.

[0003] While natural soil conditioners contribute to soil remediation, they suffer from short-lasting effects and limited reserves. Synthetic polymers, on the other hand, are limited in application due to high cost and potential environmental pollution risks. Furthermore, single soil conditioners (such as zeolite, fly ash, sludge, green manure, and polyacrylamide) often have incomplete remediation effects and may cause varying degrees of negative impacts. Biochar holds great potential for soil acidification improvement and heavy metal pollution remediation; however, its direct application in these areas remains limited. Biochar's alkalinity is insufficient, requiring large quantities to achieve similar acidity neutralization, resulting in high costs and hindering practical production. Summary of the Invention

[0004] The first objective of this invention is to provide a compound microbial soil conditioner, the second objective is to provide a method for preparing the compound microbial soil conditioner, and the third objective is to provide an application of the compound microbial soil conditioner in the improvement of acidified soil.

[0005] The first objective of this invention is achieved through the following technical solution: the soil conditioner, by weight, comprises 400-500 parts of substrate, 40-60 parts of microbial agent, and 500-600 parts of auxiliary materials, wherein the total bacterial count of the soil conditioner is ≥ 1 billion / g.

[0006] Furthermore, the microbial agents include Bacillus amyloliquefaciens YWF-17-0001 and Bacillus vesicle YWF-17-0003 fermentation broth, with a ratio of 1:1. The total bacterial activity of Bacillus amyloliquefaciens YWF-17-0001 (YWF-17-0001) is ≥20 billion / g, and the total bacterial activity of Bacillus vesicle YWF-17-0003 (YWF-17-0003) fermentation broth is ≥5 billion / ml.

[0007] The second objective of this invention is achieved through the following technical solution: S1. First, prepare Bacillus amyloliquefaciens YWF-17-0001 bacterial inoculum and Bacillus vesicle YWF-17-0003 fermentation broth in a 1:1 ratio for later use; then dilute Bacillus amyloliquefaciens YWF-17-0001 bacterial inoculum with water at a 1:1 ratio, and then mix it with Bacillus vesicle YWF-17-0003 fermentation broth in a 2:1 ratio, and then add the modifier and mix evenly to obtain a mixed bacterial solution; S2. Add the substrate to the mixer and mix thoroughly. During the mixing process, use a spraying device to evenly spray the mixed bacterial solution prepared in step S1 onto the surface of the substrate to obtain the mixture. S3. Add auxiliary materials to the mixture that has been mixed evenly in step S2 in batches and mix evenly to obtain a semi-finished product; S4. The semi-finished product prepared in step S3 is dried by a vacuum dryer to obtain the finished soil conditioner. The total bacterial count of the soil conditioner is ≥ 1.3 billion / g.

[0008] The third objective of this invention is achieved through the following technical solution: adding the soil conditioner to acidified soil at a ratio of 40 kg / acre.

[0009] The beneficial effects of this invention are as follows: through the synergistic effect of multiple microbial strains, it can alleviate soil compaction, improve the pH conditions of acidified soil, and increase the content of trace elements in the soil, thereby improving soil fertility. It can significantly improve the diversity of soil microorganisms in acidified soil, enabling acidified soil to reach a slightly acidic to neutral soil environment conducive to crop growth. The addition of organic components can provide sufficient nutrition for crops, promote crop growth, and increase yield and quality. It can shorten the soil improvement time while improving the improvement effect. Moreover, through the mixing of multiple substances, better improvement effect can be achieved with less usage, thus comprehensively saving the cost of soil improvement. Detailed Implementation

[0010] To enable those skilled in the art to better understand the technical solution of the present invention, its specific embodiments are described in detail below.

[0011] The microbial agents include Bacillus amyloliquefaciens YWF-17-0001 and Bacillus vesicle YWF-17-0003 fermentation broth, with a ratio of 1:1. The total bacterial activity of Bacillus amyloliquefaciens YWF-17-0001 (YWF-17-0001) is ≥20 billion / g, and the total bacterial activity of Bacillus vesicle YWF-17-0003 (YWF-17-0003) fermentation broth is ≥5 billion / ml.

[0012] The substrate is organic fertilizer.

[0013] The auxiliary material is a mineral powder, which includes silicon dioxide, calcium, magnesium, manganese and zinc, and the ratio of the five is 1~2:1~2:1:1:1.

[0014] The microbial agent further includes 2-5 parts of a modifier, which includes any one or at least two of lanthanum chloride, cerium nitrate, praseodymium acetate, and neodymium sulfate, in a ratio of 1:1:1:1; the concentrations of lanthanum chloride, cerium nitrate, praseodymium acetate, and neodymium sulfate are all 40-170 mg / L; when preparing the modifier, if more than two components are selected, the modifier is also prepared in an equal ratio of 1:1 or 1:1:1.

[0015] The *Bacillus amyloliquefaciens* YWF-17-0001, with accession number CGMCC NO.23617, was deposited on October 18, 2021, at the China General Microbiological Culture Collection Center, located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing; the *Bacillus belyssae*... Bacillus velezensis YWF-17-0003, with accession number CCTCC NO: M 2022752, was deposited at the China Center for Type Culture Collection on May 30, 2022, at Wuhan University, Wuhan, China.

[0016] Example 1 A method for preparing a compound microbial soil conditioner includes the following steps: S1. First, prepare Bacillus amyloliquefaciens YWF-17-0001 bacterial agent and Bacillus vesicle YWF-17-0003 fermentation broth in a 1:1 ratio for later use; then dilute 20-30 parts of Bacillus amyloliquefaciens YWF-17-0001 bacterial agent with water at a 1:1 ratio, and then mix it with 20-30 parts of Bacillus vesicle YWF-17-0003 fermentation broth in a 2:1 ratio, and then add 2-5 parts of modifier and mix evenly to obtain a mixed bacterial solution; S2. Add 400-500 parts of substrate to the mixer and mix thoroughly. During the mixing process, use a spraying device to evenly spray the mixed bacterial solution prepared in step S1 onto the surface of the substrate to obtain the mixture. S3. In the mixture that has been mixed evenly in step S2, add the auxiliary materials in three batches. Add 250-300 parts of the first batch and mix well, then add 150-200 parts of the second batch and mix well, and finally add 100 parts of the third batch and mix well to obtain a semi-finished product. S4. The semi-finished product prepared in step S3 is dried in a vacuum dryer at a temperature of 50°C for 30 minutes to obtain a slightly alkaline soil conditioner product with a total bacterial count ≥ 1.3 billion / g.

[0017] The application of the compound microbial soil conditioner in the improvement of acidified soil is specifically as follows: the soil conditioner is added to the acidified soil at a ratio of 40 kg / mu.

[0018] Example 2 A compound microbial soil conditioner, by weight, comprises 400 parts of substrate, 40 parts of microbial agent, 500 parts of excipients, and 2 parts of modifier, wherein the total bacterial count of the soil conditioner is ≥ 1 billion / g. Example

[0019] A compound microbial soil conditioner, by weight, comprises 450 parts of substrate, 50 parts of microbial agent, 550 parts of excipients, and 3 parts of modifier, wherein the total bacterial count of the soil conditioner is ≥ 1 billion / g. Example

[0020] A compound microbial soil conditioner, by weight, comprises 500 parts of substrate, 60 parts of microbial agent, 600 parts of auxiliary material, and 5 parts of modifier, wherein the total bacterial count of the soil conditioner is ≥ 1 billion / g.

[0021] Example 5 To verify the effects of organic fertilizer, compound fertilizer, and compound microbial soil conditioner on potted maize, experiments were conducted in a greenhouse.

[0022] 1. Test materials Test crop: Maize; Soil conditioner: Any of the compound microbial soil conditioners prepared in Examples 1-4; Organic fertilizer: Oil cake organic fertilizer; Compound fertilizer (15-15-15).

[0023] 2. Test Methods The experiment consisted of four treatments: organic fertilizer, compound fertilizer, and compound microbial soil conditioner. 40 kg of fertilizer was applied per acre, spread around the base of the corn plants, followed by watering. Each potted corn plant represented one treatment, with three replicates per treatment. Except for the type and amount of fertilizer used, all other management practices were consistent with conventional field management, as detailed in Table 1.

[0024] Table 1 Processing Design

[0025] 2.1 Survey Methodology One month later, the corn plant height, stem diameter, chlorophyll content, and soil pH were measured. The results are shown in Tables 2-5.

[0026] Table 2. Survey data on maize plant height

[0027] Table 3. Maize chlorophyll survey data

[0028] Table 4. Survey data on corn stalk diameter

[0029] Table 5 Soil pH Survey Data

[0030] According to the statistical results in Tables 1-5, the compound microbial soil conditioner of this invention showed significant differences compared to the control treatment. The compound microbial soil conditioner treatment had a good growth-promoting effect on maize, significantly improving growth traits such as plant height, stem diameter, and chlorophyll content. Before application, the pH value of the maize root soil was 5.6. After 30 days of application, the pH value was 6.48; after 45 days, it decreased to 6.33; and after 60 days, it decreased to 6.28. Compared to existing organic fertilizers and compound fertilizers, the compound microbial soil conditioner of this invention can significantly improve acidic soil. In summary, the compound microbial soil conditioner of this invention can effectively improve acidic soil, transforming it into a slightly acidic to neutral soil environment conducive to crop growth. While possessing excellent soil improvement effects, it also has a good growth-promoting function for crops, and can be used as a new alternative to existing soil conditioners.

Claims

1. A compound microbial soil conditioner, characterized in that: The soil conditioner, by weight, comprises 400-500 parts of substrate, 40-60 parts of microbial agent, and 500-600 parts of auxiliary materials, wherein the total bacterial count of the soil conditioner is ≥ 1 billion / g.

2. The compound microbial soil conditioner according to claim 1, characterized in that: The microbial agents include Bacillus amyloliquefaciens YWF-17-0001 and Bacillus vesicle YWF-17-0003 fermentation broth, with a ratio of 1:

1. The total bacterial activity of Bacillus amyloliquefaciens YWF-17-0001 (YWF-17-0001) is ≥20 billion / g, and the total bacterial activity of Bacillus vesicle YWF-17-0003 (YWF-17-0003) fermentation broth is ≥5 billion / ml.

3. The compound microbial soil conditioner according to claim 1, characterized in that: The substrate is organic fertilizer.

4. The compound microbial soil conditioner according to claim 1, characterized in that: The excipients are mineral powders, including silicon dioxide, calcium, magnesium, manganese, and zinc.

5. The compound microbial soil conditioner according to claim 1, characterized in that: It also includes 2 to 5 parts of modifier, which includes any one or at least two of lanthanum chloride, cerium nitrate, praseodymium acetate, and neodymium sulfate, and the ratio of the four is 1:1:1:

1.

6. The method for preparing the composite microbial soil conditioner according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. First, prepare Bacillus amyloliquefaciens YWF-17-0001 bacterial inoculum and Bacillus vesicle YWF-17-0003 fermentation broth in a 1:1 ratio for later use; then dilute Bacillus amyloliquefaciens YWF-17-0001 bacterial inoculum with water at a 1:1 ratio, and then mix it with Bacillus vesicle YWF-17-0003 fermentation broth in a 2:1 ratio, and then add the modifier and mix evenly to obtain a mixed bacterial solution; S2. Add the substrate to the mixer and mix thoroughly. During the mixing process, use a spraying device to evenly spray the mixed bacterial solution prepared in step S1 onto the surface of the substrate to obtain the mixture. S3. Add auxiliary materials to the mixture that has been mixed evenly in step S2 in batches and mix evenly to obtain a semi-finished product; S4. The semi-finished product prepared in step S3 is dried by a vacuum dryer to obtain the finished soil conditioner. The total bacterial count of the soil conditioner is ≥ 1.3 billion / g.

7. The application of the compound microbial soil conditioner according to any one of claims 1 to 6 in the improvement of acidified soil.

8. The application of the composite microbial soil conditioner according to claim 7 in the improvement of acidified soil, characterized in that: Add the soil conditioner to the acidified soil at a ratio of 40 kg / acre.

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