Compound microbial agent, soil modifier, preparation method and application

Abstract

This application belongs to the field of mine ecological restoration and soil improvement technology, and particularly relates to compound microbial agents, soil conditioners, preparation methods, and applications. This application provides a compound microbial agent comprising: Bacillus subtilis, Trichoderma reesei, Trichoderma harzianum, Bacillus megaterium, and Bacillus mucilaginosus. This application also provides a soil conditioner comprising lignite and the compound microbial agent as raw materials, and its preparation method. This application further provides the application of the above-mentioned compound microbial agent or the above-mentioned soil conditioner or the above-mentioned soil conditioner preparation method in in-situ improvement of topsoil in black soil mining areas. In this application, the compound microbial agent decomposes the organic matter of lignite, promoting its conversion to humic acid, forming a synergistic effect with the indigenous microbial community of the soil. Utilizing the suitable environmental conditions of autumn soil temperature and humidity for microbial proliferation, the activation process is completed simultaneously with autumn land preparation, improving the efficiency of soil improvement. Tests have shown that applying the soil conditioner to the topsoil of the mining area to be improved can effectively improve soil conditions.

Description

Technical Field

[0001] This application belongs to the field of mine ecological restoration and soil improvement technology, and particularly relates to compound microbial agents, soil conditioners, preparation methods and applications. Background Technology

[0002] The black soil region is one of the world's three major black soil belts and is a core resource for maintaining regional ecological balance and agricultural production. Open-pit coal mining has caused significant damage to the topsoil of the black soil region, resulting in reduced topsoil thickness, sandification, and decreased soil aeration, water retention, and fertilizer retention capacity. At the same time, mining activities have destroyed the original topography and landforms, exacerbated wind and water erosion, and triggered the risk of desertification.

[0003] In existing technologies, common methods for improving topsoil in open-pit coal mines in black soil regions include two approaches: the first is the traditional reclamation model of topsoil stripping, storage, and backfilling; the second is the use of compound humic acid soil conditioners. The traditional reclamation model involves piling up mature topsoil and backfilling it after mining. This results in low soil microbial activity, slow vegetation growth, and limited ecological restoration efficiency after reclamation. The compound humic acid soil conditioner process requires significant storage and fermentation plant space and is greatly affected by climate. The humic acid conversion rate is constrained by factors such as raw material ratios and microbial activity, leading to insufficient stability. All existing methods for improving topsoil in open-pit coal mines in black soil regions involve a disconnect between human intervention and natural ecological processes, resulting in low restoration efficiency. Furthermore, the use of microbial fermentation for improvement can easily lead to microbial ecological disorder.

[0004] Therefore, the development of compound microbial agents, soil conditioners, preparation methods, and applications to address the technical shortcomings of existing methods for improving topsoil in open-pit coal mines in black soil areas, such as low restoration efficiency and susceptibility to microbial disorder, has become a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] Therefore, it is necessary to address the technical shortcomings of existing methods for improving topsoil in open-pit coal mines in black soil areas, such as low restoration efficiency and susceptibility to microbial disturbances, and to provide methods for preparing and applying compound microbial agents and soil conditioners.

[0006] This application provides a compound microbial agent, which includes: Bacillus subtilis, Trichoderma reesei, Trichoderma harzianum, Bacillus megaterium, and Bacillus mucilaginosus.

[0007] In one embodiment, the compound microbial agent comprises, by weight percentage: 10-25% Bacillus subtilis, 20-40% Trichoderma reesei, 15-30% Trichoderma harzianum, 15-20% Bacillus megaterium, and 15-20% Bacillus mucilaginosus.

[0008] This application also provides a soil conditioner, the raw materials of which include: lignite and a compound microbial agent, the compound microbial agent including: Bacillus subtilis, Trichoderma reesei, Trichoderma harzianum, Bacillus megaterium, and Bacillus mucilaginosus.

[0009] This application also provides a method for preparing a soil conditioner, the method comprising: mixing a logarithmic phase compound microbial culture solution with lignite, reacting at 30°C for 10-15 days, mixing thoroughly and drying to obtain the soil conditioner.

[0010] In one embodiment, the ratio of lignite to the compound microbial culture medium solution is 1:(10-50)Kg / L.

[0011] In one embodiment, the compound microbial culture medium solution comprises: a bacterial culture medium solution and a fungal culture medium solution, wherein the bacterial culture medium solution comprises: Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus, and the fungal culture medium solution comprises: Trichoderma reesei and Trichoderma harzianum; the volume ratio of the bacterial culture medium solution to the fungal culture medium solution is 1:(1-2).

[0012] In one embodiment, the bacterial culture medium solution is LB medium, and the fungal culture medium solution is PDA medium.

[0013] In one embodiment, the drying method includes drying in an oven at 30-45°C for 6-8 hours.

[0014] This application also provides the application of the above-mentioned compound microbial agent or the above-mentioned soil conditioner or the preparation method of the above-mentioned soil conditioner in the in-situ improvement of topsoil in black soil mining areas.

[0015] In one embodiment, the soil conditioner is used at a dosage of 0.1-0.4 kg / m³. 2 topsoil.

[0016] In summary, this application provides a compound microbial agent comprising: Bacillus subtilis, Trichoderma reesei, Trichoderma harzianum, Bacillus megaterium, and Bacillus mucilaginosus. This application also provides a soil conditioner comprising lignite and the compound microbial agent, and its preparation method. This application further provides the application of the aforementioned compound microbial agent, soil conditioner, or preparation method in in-situ improvement of topsoil in black soil mining areas. In the technical solution provided by this application, the compound microbial agent decomposes the organic matter of lignite, promoting its conversion to humic acid, forming a synergistic effect with the indigenous microbial community of the soil. Utilizing the suitable environmental conditions of autumn soil temperature and humidity for microbial proliferation, the activation process is completed simultaneously with autumn land preparation, improving the efficiency of soil improvement. Tests have shown that applying the soil conditioner to the topsoil of the mining area to be improved can effectively improve soil conditions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 A schematic diagram showing the soybean yield results of the experimental plot in the technical solution provided in the embodiments of this application; Figure 2 This is a schematic diagram showing the results of soil property analysis at the test site in the technical solution provided in the embodiments of this application. Detailed Implementation

[0019] This application provides a compound microbial agent, a soil conditioner, a preparation method, and its application, in order to solve the technical defects of existing methods for improving topsoil in open-pit coal mines in black soil areas, which suffer from low restoration efficiency and are prone to microbial disorder.

[0020] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0021] This application provides a compound microbial agent, including Bacillus subtilis, Trichoderma reesei, Trichoderma harzianum, Bacillus megaterium, and Bacillus mucilaginosus. The logarithmic phase compound microbial agent solution can be used to improve the soil in situ with the lignite contained in the topsoil of the mining area.

[0022] Alternatively, the logarithmic compound microbial agent can be mixed with lignite and fermented. After the fermentation, the mixture is dried and then applied to the topsoil of the mining area to be improved for in-situ soil improvement.

[0023] Furthermore, during autumn land preparation in the mining area, the compound microbial agent and lignite can be directly applied to the topsoil of the mining area to be improved. Taking advantage of the suitable temperature and humidity of autumn for microbial metabolic activities, the fermentation can be moved directly from the laboratory or factory to the original site of the topsoil in the mining area. This not only saves the factory space required for fermentation, but also further reduces the cost of improvement, achieving time-saving, land-saving and high-efficiency improvement of topsoil in the mining area.

[0024] The following will describe the compound microbial agent, soil conditioner, preparation method and application provided in this application with reference to specific embodiments.

[0025] Example 1 This embodiment is a specific example of preparing a compound microbial agent.

[0026] The compound microbial agent 1 contains, by mass percentage: 10% Bacillus subtilis, 40% Trichoderma reesei, 15% Trichoderma harzianum, 15% Bacillus megaterium, and 20% Bacillus mucilaginosus.

[0027] The compound microbial agent 2 contains, by mass percentage: 10% Bacillus subtilis, 35% Trichoderma reesei, 20% Trichoderma harzianum, 25% Bacillus megaterium, and 15% Bacillus mucilaginosus.

[0028] The compound microbial agent 3 contains, by mass percentage: 25% Bacillus subtilis, 20% Trichoderma reesei, 30% Trichoderma harzianum, 15% Bacillus megaterium, and 15% Bacillus mucilaginosus.

[0029] Example 2 This embodiment is a specific example of preparing a soil conditioner.

[0030] Soil conditioner 1 comprises the following raw materials: lignite and a logarithmic-phase compound microbial agent 1 culture solution. The ratio of lignite to compound microbial agent 1 solution is 1:30 kg / L. The compound microbial agent 1 culture solution includes equal volumes of bacterial culture solution 1 and fungal culture solution 1. Bacterial culture solution 1 includes Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus, and is cultured on LB medium. Fungal culture solution 1 includes Trichoderma reesei and Trichoderma harzianum, and is cultured on PDA medium. The logarithmic-phase compound microbial agent 1 culture solution is mixed with lignite and reacted at 30℃ for 10-15 days. After thorough mixing, it is dried to obtain soil conditioner 1.

[0031] Soil conditioner 2 contains lignite and a logarithmic-phase compound microbial agent 2 culture medium solution. The ratio of lignite to compound microbial agent 2 solution is 1:10 kg / L. The compound microbial agent 2 culture medium solution includes equal volumes of bacterial culture medium solution 2 and fungal culture medium solution 2. The bacterial culture medium solution 2 includes Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus, and is grown on LB medium. The fungal culture medium solution 2 includes Trichoderma reesei and Trichoderma harzianum, and is grown on PDA medium. The logarithmic-phase compound microbial agent 2 culture medium solution is mixed with lignite and reacted at 30℃ for 10-15 days. After thorough mixing, it is dried to obtain soil conditioner 2.

[0032] Soil conditioner 3 contains lignite and a logarithmic-phase compound microbial agent 3 culture medium solution. The ratio of lignite to compound microbial agent 3 solution is 1:50 kg / L. The compound microbial agent 3 culture medium solution includes equal volumes of bacterial culture medium solution 3 and fungal culture medium solution 3. The bacterial culture medium solution 3 includes Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus, and is prepared using LB medium. The fungal culture medium solution 3 includes Trichoderma reesei and Trichoderma harzianum, and is prepared using PDA medium. The logarithmic-phase compound microbial agent 3 culture medium solution is mixed with lignite and reacted at 30℃ for 10-15 days. After thorough mixing, it is dried to obtain soil conditioner 3.

[0033] Example 3 This embodiment is a specific example for determining the effect of soil conditioner 1 prepared in Example 2 on crop growth.

[0034] A field trial was conducted on newly reclaimed land (total area of ​​18 mu). The trial adopted a plot design, with each plot measuring 800 m² (50 m × 16 m). A 0.5 m wide isolation strip was set between plots to avoid cross-interference. The trial included three treatment groups with compound humic acid soil conditioner (high addition group H, medium addition group Z, and low addition group L) and one control group (CK, no conditioner added). Each treatment was replicated three times. Specifically, a rotary tiller was used to treat the top 20 cm of soil, and soil conditioners 1-3 were evenly spread onto the topsoil via broadcasting, followed by rotary tillage and leveling. Detailed plot setup and field layout are shown in Table 1.

[0035] Table 1. Treatment groups for soil improvement experiment using compound humic acid

[0036] The experimental crop was soybean variety No. 3, with a planting period of 100 days, during which conventional farmland management was implemented. The yield results after soybean maturity are as follows: Figure 1 As shown. From Figure 1 It can be concluded that the H treatment group had the highest average yield (close to 250 kg / mu), while the CK control group had the lowest yield (slightly higher than 200 kg / mu). The yields of the L and Z treatment groups were in between, but the difference was small. Compared with the CK, the theoretical yield of each treatment group (especially the H group) was increased, indicating that the soil conditioner prepared using the technical solution provided in the embodiments of this application has a promoting effect on soybean yield.

[0037] Soil conditioners 2 and 3 use the same raw materials and are prepared using similar methods as soil conditioner, and both can achieve the same experimental results as soil conditioner shown in the figure.

[0038] Example 4 This embodiment is a specific example for analyzing the effect of soil conditioner 1 prepared in Example 2 on soil fertility indicators.

[0039] Soil samples from the plot in Example 3 were tested to determine soil fertility indicators before and after the addition of the soil conditioner. The results can be found in [reference needed]. Figure 2 .

[0040] from Figure 2 ( Figure 2 a- Figure 2 From f), it can be concluded that compared with the control group (CK) without soil amendment, the organic matter content in groups L, Z, and H with soil amendment was significantly higher. Figure 2 a) Total nitrogen ( Figure 2 b) and soil bulk density ( Figure 2 f) all showed a slow upward trend with the increase of soil conditioner dosage; available phosphorus ( Figure 2 e) The effect was lower than that of the CK group after the addition of the modifier; fast-acting potassium ( Figure 2 c) The changes show a phased characteristic—as the amount of modifier added increases, its content gradually rises, but in the experimental group with the highest addition amount, the content of readily available potassium decreases significantly.

[0041] To comprehensively assess soil fertility, a quantitative analysis was conducted by calculating the Soil Fertility Index (IFI, ranging from 0 to 1, with higher values ​​indicating better soil fertility). The results showed that the average IFI of the soil treated with the soil amendment (mean value of 0.42 for groups L, Z, and H) was significantly higher than that of the untreated control soil (0.31 for the CK group), fully verifying that the soil amendment prepared using the technical solution provided in this application has a significant effect on improving soil fertility.

[0042] To facilitate rapid determination of the specific effects of soil conditioners, in Examples 3 and 4, the soil conditioners required for testing were prepared in an experimental environment. It should be noted that, in actual large-scale soil improvement, the fermentation process of the compound microbial agent and lignite can be carried out in situ on the soil to be improved.

[0043] From the above embodiments, it can be concluded that the compound microbial agent, soil conditioner, preparation method, and application provided in this application have the following advantages: First, by utilizing the fermentation effect of compound microbial agents and using lignite as the core humic acid raw material, lignite is widely distributed and easily obtained in black soil areas, combining resource availability and economic benefits. Transforming lignite into raw material for soil conditioners realizes the resource utilization of energy products, reduces the overall cost of topsoil improvement projects, and provides an economically feasible technical path for the ecological restoration of mining areas.

[0044] Secondly, the compound microbial agent ferments with lignite to form humic acid, which, according to tests, can effectively improve the structure and fertility of the damaged topsoil in open-pit coal mines after application.

[0045] Third, this application further proposes the idea of ​​in-situ soil improvement. In response to the pain points of traditional composting activation processes, such as long cycle, large space occupation, and climate constraints, it innovatively proposes the "autumn tillage in-situ activation" technology. By utilizing the traditional farming season of "autumn tillage" in Northeast China, lignite and microbial agents are applied to the topsoil simultaneously. The activation process is completed at the same time as the autumn tillage operation, without the need for additional factory or storage space.

[0046] Fourth, and further, unlike traditional composting processes which are completed in an artificially controlled environment, traditional techniques lack a co-evolutionary process between the microorganisms and the indigenous microbial communities of the black soil region when applied after composting. After being applied to the soil, exogenous microorganisms are easily deactivated due to competitive disadvantages or environmental maladaptation, failing to sustain their role in decomposing organic matter and promoting humic acid conversion, resulting in insufficient aftereffects of the soil conditioner. In contrast, this application involves in-situ soil amendment, effectively avoiding the problem of inactivation after application. The soil conditioner works synergistically with the indigenous microbial communities in the soil environment, further enhancing the biological activity of humic acid, improving the conversion rate, and ensuring the stable effect of the conditioner.

[0047] In summary, the technical solution provided in this application, through systematic optimization of raw materials, processes, and effects, not only solves the core problem of topsoil improvement in open-pit coal mines in black soil areas, but also provides a new, resource-recycling, and economically feasible model for ecological restoration of mining areas through a low-cost, high-efficiency technical approach, possessing significant value for widespread application. Breaking through the inefficient traditional reclamation model that relies on topsoil stripping, storage, and backfilling, this solution converts lignite into humic acid raw materials and simultaneously completes microbial activation and topsoil improvement during autumn land preparation, achieving multiple goals such as solid waste resource utilization, time-saving and land-saving processes, and improved improvement effects, thus providing a new technical path for ecological restoration of mining areas.

[0048] In summary, this application provides a compound microbial agent comprising: Bacillus subtilis, Trichoderma reesei, Trichoderma harzianum, Bacillus megaterium, and Bacillus mucilaginosus. This application also provides a soil conditioner comprising lignite and the compound microbial agent, and its preparation method. This application further provides the application of the aforementioned compound microbial agent, soil conditioner, or preparation method in in-situ improvement of topsoil in black soil mining areas. In the technical solution provided by this application, the compound microbial agent decomposes the organic matter of lignite, promoting its conversion to humic acid, forming a synergistic effect with the indigenous microbial community of the soil. Utilizing the suitable environmental conditions of autumn soil temperature and humidity for microbial proliferation, the activation process is completed simultaneously with autumn land preparation, improving the efficiency of soil improvement. Tests have shown that applying the soil conditioner to the topsoil of the mining area to be improved can effectively improve soil conditions.

[0049] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. Furthermore, other implementation methods can be derived from the above embodiments, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure.

[0050] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A compound microbial agent, characterized in that, The compound microbial agent includes: Bacillus subtilis, Trichoderma reesei, Trichoderma harzianum, Bacillus megaterium, and Bacillus mucilaginosus.

2. The compound microbial agent according to claim 1, characterized in that, The compound microbial agent comprises, by weight percentage: 10-25% Bacillus subtilis, 20-40% Trichoderma reesei, 15-30% Trichoderma harzianum, 15-20% Bacillus megaterium, and 15-20% Bacillus mucilaginosus.

3. A soil conditioner, characterized in that, The raw materials for the soil conditioner include: lignite and compound microbial agents, wherein the compound microbial agents include: Bacillus subtilis, Trichoderma reesei, Trichoderma harzianum, Bacillus megaterium, and Bacillus mucilaginosus.

4. A method for preparing a soil conditioner, characterized in that, The preparation method includes: mixing a logarithmic phase compound microbial culture solution with lignite, reacting at 20-35℃ for 10-15 days, mixing thoroughly, and then drying to obtain a soil conditioner.

5. The preparation method according to claim 4, characterized in that, The ratio of lignite to the compound microbial culture solution is 1:(10-50)Kg / L.

6. The preparation method according to claim 4 or 5, characterized in that, The compound microbial culture solution includes a bacterial culture solution and a fungal culture solution. The bacterial culture solution includes Bacillus subtilis, Bacillus megaterium, and Bacillus mucilaginosus. The fungal culture solution includes Trichoderma reesei and Trichoderma harzianum. The volume ratio of the bacterial culture solution to the fungal culture solution is 1:(1-2).

7. The preparation method according to claim 6, characterized in that, The culture medium for the bacterial culture solution is LB medium, and the culture medium for the fungal culture solution is PDA medium.

8. The preparation method according to claim 4, characterized in that, The drying method includes drying in an oven at 30-45 ℃ for 6-8 hours.

9. The application of a method for preparing a compound microbial agent according to any one of claims 1 to 2, a soil conditioner according to claim 3, or a soil conditioner according to any one of claims 4 to 8 in the in-situ improvement of topsoil in black soil mining areas.

10. The application according to claim 9, characterized in that, The soil conditioner is used in an amount of 0.1-0.4 Kg / m 2 Table soil.

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