Method for preparing saline-alkali soil conditioner by using microbial agent to activate coal-based solid waste

Abstract

The invention discloses a method for preparing a saline-alkali soil conditioner by activating coal-based solid waste through a microbial agent, and is suitable for the fields of coal-based solid waste resource utilization and soil improvement. Coal gangue and weathered coal are crushed, screened and then mixed, a proper amount of salt and clay mineral are added into a culture medium, microorganisms with an activation effect on elements in the coal gangue and the weathered coal are subjected to directional domestication, and the cell quantity of the microorganisms under the high salt concentration and the expression quantity of extracellular active components are increased; compounding the directionally domesticated microbial strains to obtain a compound microbial agent, and performing solid-state fermentation on coal gangue and weathered coal components by using the compound microbial agent to obtain a soil conditioner product. The soil conditioner prepared by the method can effectively improve the soil property of the saline-alkali soil, and ecological utilization of the coal gangue and the weathered coal and soil improvement of the saline-alkali soil are realized.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste recycling and soil improvement, and in particular to a method for preparing a saline-alkali land soil improver by activating coal-based solid waste with a microbial agent. Background Art

[0002] Gangue is a byproduct of coal mining and beneficiation, and has good physical properties, such as good drainage and ventilation. Weathered coal is rich in organic matter and mineral elements, which helps to improve soil structure and nutrients. In recent years, environmental protection needs to take waste utilization as an important strategy to reduce the impact of the accumulation of gangue and weathered coal on the ecological environment. The nutrients contained in gangue and weathered coal can provide the necessary trace elements and organic matter for crop growth, improve soil fertility, and promote plant growth.

[0003] Saline-alkali land is caused by water evaporation, improper irrigation, poor drainage, or coastal beach transformation. The salinization of the land leads to the accumulation of salt on the soil surface, affecting plant growth and low land use efficiency. Globally, the area of ​​saline-alkali land is increasing year by year. The area of ​​saline-alkali land in my country is about 30 million hectares, of which coastal saline-alkali land is mainly concentrated in coastal areas, especially in eastern coastal provinces such as Jiangsu, Zhejiang, Shandong, Liaoning and other places. The saline-alkali land in these areas is usually located near the coastline. Affected by factors such as seawater erosion, surface water evaporation and groundwater rise, salt accumulation and alkalinity increase in the soil. Saline-alkali land is an important reserve arable land. Under the current situation of arable land protection and food security, ecological management of saline-alkali land can not only fully tap the comprehensive utilization potential of coastal saline-alkali land, but also greatly expand agricultural production space, which is of great significance to ensuring national food security.

[0004] At present, the methods for preparing soil conditioners from coal gangue and weathered coal include physical, chemical and biological methods, which are mainly prepared by crushing the raw materials of gangue and weathered coal, treating them with high temperature, acid and alkali or microbial agents, and then adding some organic or inorganic fertilizers. Among them, the preparation of conditioners by activating gangue or weathered coal with microbial agents has economic and environmentally friendly characteristics.

[0005] The use of microbial activation technology to activate the nutrients in gangue and weathered coal to prepare soil conditioners for saline-alkali soil can, on the one hand, achieve value-added utilization of waste, reduce dependence on traditional fertilizers, and reduce agricultural costs. On the other hand, gangue and weathered coal can improve the structure of the soil, change soil pH and conductivity and other indicators, help reduce the salt concentration in the soil, and improve soil fertility. However, due to the general low nutrients and high salinity in saline-alkali soil, the survival rate of most microorganisms is low, and there are rich types of inorganic and organic nutrients in gangue and weathered coal, which require the synergistic action of multiple microorganisms to achieve their common activation. The extracellular active components of microorganisms play an important role in the activation process of elements, but current technologies rarely involve increasing the activation rate of nutrients by increasing the expression of active components through domestication and cultivation. At present, the preparation of saline-alkali soil conditioners from gangue and weathered coal has relevant applications in inland saline-alkali lands such as the Northeast and Northwest, but is less used in coastal saline-alkali lands. Therefore, in order to expand the application of coal gangue and weathered coal in soil improvement in coastal saline-alkali land, it is necessary to develop a soil conditioner that can adapt to the activation of coal gangue and weathered coal and have a good improvement effect in saline-alkali land. Summary of the invention

[0006] In view of the shortcomings of the existing technology, a method for preparing a saline-alkali land soil conditioner using microbial agents to activate coal-based solid waste is provided, and a composite agent suitable for activating coal gangue and weathered coal is obtained, which expands the application of coal gangue and weathered coal in improving coastal saline-alkali land soil.

[0007] The present invention is to provide a method for preparing a saline-alkali soil conditioner by activating coal-based solid waste with a microbial agent, comprising the following steps:

[0008] a) Using the method of directional domestication to domesticate microorganisms to salt tolerance, the survival rate of microorganisms in sodium chloride is improved through domestication, and microorganisms that are not salt-tolerant are eliminated. Clay is used to increase the amount of extracellular cell components of microorganisms to make microorganisms more salt-tolerant. Microorganisms include bacteria and fungi. The activation efficiency of elements is improved through the synergistic effect of multiple microorganisms and the content of extracellular substances in which microorganisms participate in element activation;

[0009] The bacteria that have an activation effect on inorganic elements in gangue are cultured in beef extract peptone medium to the logarithmic stage, and the fungi that have an activation effect on weathered coal are cultured in potato glucose medium to the logarithmic stage, and the bacteria and fungal spores in the logarithmic growth stage are separated by centrifugation;

[0010] The obtained bacteria are acclimated and cultured in a beef extract peptone medium supplemented with 1%-10% sodium chloride and 0.1%-0.5% clay by mass, and the obtained fungal spores are transferred to a potato glucose medium supplemented with 1%-10% sodium chloride and 0.1%-0.5% clay by mass for acclimation and culture to a logarithmic phase, and the bacteria and fungal spores are separated by centrifugation as the first directional acclimation components;

[0011] The bacteria obtained by the first domestication are transferred to a new beef extract peptone medium for domestication culture again, the mass percentage of sodium chloride in the new beef extract peptone medium is increased by 2% on the original basis, and the amount of clay added remains unchanged; the fungal spores obtained by the first domestication are transferred to a new potato glucose medium for domestication culture, the mass percentage of sodium chloride in the new potato glucose medium is increased by 2% on the original basis, and the amount of clay added remains unchanged, and a second domestication culture is carried out to the logarithmic phase, and the bacteria and fungal spores are centrifuged to obtain a second domestication culture; repeat the steps of this paragraph, transfer the bacteria obtained by the second domestication to a new beef extract peptone medium for domestication culture again, and transfer the fungal spores obtained by the second domestication to a new potato glucose medium for domestication culture, the mass percentage of sodium chloride in the new medium is increased by 2% each time, and the clay content remains unchanged for directional domestication, and the cell mass and the expression amount of the extracellular active components under high salt concentration are increased until the preset domestication times are reached, or the sodium chloride concentration in the new medium rises to the point that the bacteria and fungi no longer grow, and then the domestication is stopped;

[0012] b) compounding the microbial strains that have completed the targeted domestication to obtain a composite microbial agent;

[0013] c) crushing and screening the gangue and weathered coal and mixing them in a mass ratio of 1:1 to 1:3;

[0014] d) Using composite microbial agents to activate the nutrient components in coal gangue and weathered coal, thereby improving the activation efficiency of nutrient elements and obtaining a soil conditioner.

[0015] Furthermore, in step a), the gangue and weathered coal are crushed and then passed through a 100-mesh standard sieve.

[0016] Furthermore, the preset number of acclimation for bacteria and fungi is no less than 3 times, and the number of cells of the acclimated bacteria and fungi strains reaches 10 when they are cultured in the improved medium to the logarithmic growth phase. 8 Pieces / mL.

[0017] Furthermore, during the centrifugal separation process, the centrifugal parameters are as follows: the inoculation amount of bacteria and fungal spores in the culture process is 10%, the culture system is 100 mL, the temperature is 30°C, and the centrifugation is carried out at 10,000 rpm and 4°C for 15 minutes in a high-speed centrifuge; and the separation is a heating extraction method.

[0018] Furthermore, the formula of the composite microbial agent in step b) is as follows: the volume ratio of the microbial strain composite ratio of bacteria in the logarithmic growth phase to fungal culture solution is 1:1 to 4:1.

[0019] Furthermore, the bacteria are Bacillus megaterium and Bacillus colloids, and the fungi are Trichoderma harzianum and Penicillium purpurogenum, and the composition comprises the following components in parts by weight: 25-40 parts of Bacillus megaterium, 25-40 parts of Bacillus colloids, 10-25 parts of Trichoderma harzianum and 10-25 parts of Penicillium purpurogenum.

[0020] Furthermore, the preparation method of the soil conditioner is as follows: a composite microbial agent and a mixture of coal gangue and weathered coal are mixed in a mass ratio of 1:5 to 1:20, and the mixture is fermented and cultured for 20-30 days, during which the humidity is maintained at 40-60%, the mixture is fermented and the temperature is controlled at 30-40° C., to obtain a soil conditioner characterized by a moisture content of ≤20%, a pH of ≤7.00, an organic matter content of ≥560 mg / Kg, an alkaline nitrogen content of ≥200 mg / Kg, an available phosphorus content of ≥300 mg / Kg, and an available potassium content of ≥200 mg / kg;

[0021] A soil conditioner prepared by a method of preparing a saline-alkali soil conditioner by activating coal-based solid waste with a microbial agent has good ecological utilization performance and can effectively enhance the survival rate of microorganisms in saline-alkali soil. The properties of the saline-alkali soil, including organic matter content, total nitrogen, phosphorus, potassium, and pH, are significantly improved.

[0022] Furthermore, the soil conditioner is mixed with the saline-alkali soil in a mass ratio of 1:1 to 1:4.

[0023] Beneficial effects: The present invention improves the extracellular active substance content of the strains by special directional domestication of existing commercial strains, improves the activation efficiency of the nutrients in gangue and weathered coal and the survival ability in saline-alkali environment, and then compound the strains to obtain a composite bacterial agent that simultaneously activates the inorganic and organic nutrients in gangue and weathered coal, prepares the soil conditioner by solid-state fermentation, and finally improves the saline-alkali soil to improve the soil properties. The soil conditioner prepared by this method has the characteristics of simultaneously activating the organic and inorganic nutrients in gangue and weathered coal, improves the stock rate of functional microorganisms in saline-alkali soil, and can effectively improve the soil properties of saline-alkali soil, and has a good application prospect.

[0024] Appendix Description

[0025] Figure 1 Schematic diagram for comparing the states of four microorganisms after different times of domestication in the embodiment of the present invention; a. Cell concentration in the logarithmic growth phase, b. Content of extracellular active components of the cells, D1 represents the first domestication, D2 represents the second domestication, and D3 represents the third domestication. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are further described below in conjunction with the attached table:

[0027] A method for preparing a saline-alkali land soil conditioner by activating coal-based solid waste with a microbial agent comprises the following steps:

[0028] Step 1: crush the gangue and weathered coal, pass them through a 100-mesh standard sieve, and mix them in a certain ratio after screening, with the mixing ratio being 1:1 to 3:1 (mass ratio), and fully mixing;

[0029] The strains selected in step 2 include bacteria that have an activation effect on inorganic elements in gangue: Bacillus megaterium and Bacillus mucilaginosus, and fungi that have an activation effect on organic matter in weathered coal: Trichoderma harzianum and Penicillium purpurogenum, wherein the bacteria are cultured in a beef extract peptone liquid medium, and the fungi are cultured in a potato glucose liquid medium;

[0030] Step 3: After the bacteria and fungi are activated to the logarithmic growth phase with beef extract peptone and potato glucose liquid medium respectively, the bacterial and fungal spore inoculation amount during the culture process is 10%, the culture system is 100 mL, the temperature is 30°C, and the bacteria in the culture solution are collected by high-speed centrifuge at 10,000 rpm and 4°C for 15 min. The fungi are first filtered with quantitative filter paper and then centrifuged at 10,000 rpm and 4°C for 15 min to harvest the spores in the filtrate, and the corresponding bacteria and fungal spores are suspended with 10 mL of sterile culture medium;

[0031] Step 4: Add an appropriate amount of sodium chloride and a small amount of clay minerals to fresh 100 mL beef extract peptone liquid medium and potato dextrose liquid medium, the sodium chloride addition range is 1% to 10% (mass percentage), and the clay mineral addition range is 0.1% to 0.5%. The collected culture is inoculated with 10% of the fresh culture medium for directional acclimation and culture to the logarithmic phase, and the bacteria in the culture medium are collected by high-speed centrifuge at 10,000 rpm and 4°C for 15 minutes. The fungi are first filtered with quantitative filter paper and then centrifuged with high-speed centrifuge at 10,000 rpm and 4°C. After 15 minutes, the spores in the filtrate are harvested, and the obtained product is the first directed domestication component; the bacteria and fungal spores obtained by the first domestication are transferred to a new beef extract peptone and potato glucose medium, and the amount of salt added in the medium is increased, and the amount of clay added remains unchanged, and the second domestication culture is carried out to the logarithmic phase, and the bacteria and fungal spores are centrifuged according to the method in step 3 to obtain the second domestication culture; the salt content in the new medium is increased successively, and the amount of clay added is kept unchanged, and the second domestication is inoculated and cultured to the logarithmic phase, and the bacteria and fungal spores are centrifuged according to the method in step 3;

[0032] Step 5: The separation method of extracellular active substances of bacteria and fungal spores adopts the classic heating extraction method, and the specific scheme is as follows: the cultured microorganisms are centrifuged at 10000rpm for 10min at 4℃, the microbial cell sediment is suspended in phosphate buffer and placed in a constant temperature water bath for 80℃ for 1h to extract extracellular active substances, and then centrifuged at 10000rpm for 30min. The obtained supernatant is filtered and used for component characterization. The components and content characterization methods of active substances are as follows: using bovine serum albumin as a standard sample, the protein content in the extracted biofilm is determined by the Coomassie brilliant blue method; using glucose as a standard sample, the polysaccharide content in the extracted biofilm is determined by the phenol-sulfuric acid colorimetric method.

[0033] Step 6: Compounding the bacteria and fungi that have been acclimated and cultured to the logarithmic growth phase according to a culture solution volume ratio of 1:1 to 4:1 to obtain a composite bacterial agent;

[0034] Step 7: Inoculate the composite bacterial agent into a mixture of coal gangue and weathered coal at a ratio of 1:5 to 1:20 (mass ratio) for ventilation cultivation, control the humidity at 40-60%, provide sufficient oxygen, maintain the temperature at 30-40°C, and ferment for 20-30 days under ventilation. Control the humidity at 40-60%, and ferment for 20-30 days under ventilation to obtain a soil conditioner.

[0035] Step 6: Physically crush and sieve the prepared soil conditioner, mix it with saline-alkali soil in a ratio of 1:1 to 1:4, and treat it for 30 to 60 days. Analyze the organic matter content, total nitrogen, phosphorus, potassium, pH, conductivity and effective live bacteria count of the treated soil.

[0036] Embodiment 1

[0037] The raw materials for preparing a saline-alkali soil conditioner using a microbial agent to activate coal gangue and weathered coal include the following components: bacteria and fungi are obtained by taming culture media with different salinity ranges (1%-10%) for at least 3 times, wherein the bacteria include Bacillus megaterium (25-40 parts) and Bacillus colloids (25-40 parts), the fungi include Trichoderma harzianum (10-25 parts) and Penicillium purpurogenum (10-25 parts), and the cell amount of the bacteria and fungi when mixed is 10 8 / mL; the gangue and weathered coal are physically crushed and then passed through a 100-mesh sieve and then mixed, wherein the mixing ratio of the gangue to the weathered coal is 1:1 to 3:1 (mass ratio), and the composite bacterial agent is inoculated into the mixture of the gangue and the weathered coal at a ratio of 1:5 to 1:20 (mass ratio) for ventilation cultivation to obtain a soil conditioner.

[0038] Bacillus megaterium and Bacillus mucilaginosus were cultured with beef extract peptone medium, and Trichoderma harzianum and Penicillium purpurogenum were cultured with potato glucose medium. The composition of beef extract peptone medium was: 10g tryptone, 3.0g beef extract, 5g sodium chloride, 20g agar, and 1000mL deionized water; the composition of potato glucose medium was: 200g potato, 20g glucose, 18g agar, and 1000mL distilled water.

[0039] like Figure 1 As shown, the activated bacteria and fungi are respectively cultured in liquid culture media with different salinity ranges (1%-10%), 1% for the first domestication, 3% for the second, and 5% for the third, with an increase of 2% each time. Clay mineral with a mass fraction of 0.3% is added to the culture medium for directional domestication culture (the above-mentioned beef extract peptone culture medium and potato glucose culture medium are not added with agar), 10-100g of sodium chloride is added to the beef extract peptone culture medium and potato glucose culture medium, and the addition ratio of sodium chloride in this embodiment is the optimal value of 50g, and 1.0-5.0g of clay mineral is added. After being cultured to the logarithmic growth phase, the cell concentration is calculated by the blood cell counting plate method. After multiple domestication, the number of live cells in the logarithmic growth phase reaches 10 8 / mL, cell counting results are as follows Figure 1 As shown in a. As can be seen from the figure, after the first acclimation D1, the concentrations of giant spores, colloid spores, Trichoderma harzianum and Penicillium purpurogenum were 0.44*10 8 / mL, 0.83*10 8 / mL, 0.27*10 8 / mL and 0.12*10 8 / mL, and after the third domestication, the concentrations of the four microorganisms reached 4.82*10 8 / mL, 6.43*10 8 / mL, 2.66*10 8 / mL and 2.84*10 8 Pieces / mL.

[0040] After three acclimation cycles, the cell concentrations of the four microorganisms in the 5% salinity medium increased significantly, reaching 10 8 Pieces / mL.

[0041] The content of extracellular active components Figure 1As shown in b, the extracellular sugar and protein concentrations of the control group were: giant spore (sugar 0.012 mg / mL, protein 0.187 mg / mL), gelatinous spore (sugar 0.014 mg / mL, protein 0.196 mg / mL), Trichoderma harzianum (sugar 0.048 mg / mL, protein 0.431 mg / mL) and Penicillium micropurpurogenum (sugar 0.039 mg / mL, protein 0.531 mg / mL). After three acclimation, the extracellular sugar and protein concentrations of the experimental group and the control group reached The extracellular sugar content of bacteria such as giant spore (sugar 0.084 mg / mL, protein 0.864 mg / mL), gelatinous spore (sugar 0.093 mg / mL, protein 0.795 mg / mL), Trichoderma harzianum (sugar 0.134 mg / mL, protein 1.123 mg / mL) and Penicillium micropurpurogenum (sugar 0.102 mg / mL, protein 1.092 mg / mL) increased by 6.6-7 times, the extracellular protein content increased by 4.5 times, and the protein content of the extracellular polysaccharides of fungi increased by 2.5 times.

[0042] The bacteria and fungi that have been domesticated for multiple times are cultured to the logarithmic growth phase, and then mixed according to a certain ratio, wherein the bacteria include Bacillus megaterium (25-40 parts) and Bacillus colloids (25-40 parts), and the fungi are Trichoderma harzianum (10-25 parts) and Penicillium purpurogenum (10-25 parts), to prepare a composite bacterial agent;

[0043] In a specific implementation process, the heavy metal elements in the gangue and weathered coal are lower than the risk standard. The gangue and weathered coal are finely crushed and screened, and are powdered after passing through a 100-mesh sieve. The industrial analysis and elemental analysis of the gangue and weathered coal are shown in Table 1;

[0044] Table 1 Work points and element points of coal gangue and weathered coal

[0045]

[0046] In a specific implementation process, the mixing ratio of coal gangue and weathered coal is 1:1 to 3:1 (mass ratio), and they are fully mixed. In this implementation process, the optimal ratio is 2:1;

[0047] In a specific implementation process, the composite bacterial agent is inoculated into a mixture of coal gangue and weathered coal at a mass ratio of 1:5 to 1:20 for ventilation cultivation. In this implementation process, the optimal ratio is 1:10, the humidity is maintained at 40-60%, the temperature is controlled at 30-40°C, and the ventilation fermentation culture is carried out for 20-30 days to obtain a soil conditioner, and its physicochemical properties are shown in Table 2.

[0048] Table 2 Composition analysis of gangue and weathered coal after microbial activation

[0049]

[0050]

[0051] After the original gangue and weathered coal were mixed and activated by microorganisms, their organic matter content, alkaline nitrogen, available phosphorus and available potassium contents increased, while the pH value decreased.

[0052] In a specific embodiment, in order to verify the efficacy of the composite bacterial agent of the present invention in activating coal gangue and weathered coal to prepare a soil conditioner for saline-alkali soil, multiple groups of bare soil experiments were designed for in-depth exploration. The ratio of added materials to saline-alkali soil was 1:1 to 1:4 (mass ratio). In this implementation, the optimal ratio of 1:2 was selected, and the treatment time was 30-60 days.

[0053] In order to verify the effects of different soil conditioners on the properties of saline-alkali soil, eight groups of experiments were designed. The eight groups of experiments used the following soil conditioners and saline-alkali soil ratios: original saline-alkali soil (CK) as the control group; group with coal gangue (MGS) added alone; group with weathered coal (FHM) added alone; group with coal gangue added alone and compounded bacteria after three acclimations (MGS+D3); group with weathered coal added alone and compounded bacteria after three acclimations (FHM+D3); group with coal gangue and weathered coal added and compounded bacteria after one acclimation (Mix+D1); group with coal gangue and weathered coal added and compounded bacteria after two acclimations (Mix+D2); group with coal gangue and weathered coal added and compounded bacteria after three acclimations (Mix+D3). After 30-60 days of treatment, the soil organic matter content, total nitrogen, phosphorus, potassium, pH, conductivity and effective viable bacteria were analyzed.

[0054] Table 3 shows the changes in soil properties under different implementation conditions

[0055]

[0056] By comparing the properties of soils with different application conditions and the number of effective live microorganisms, it can be found that the bacterial agent formed after multiple domestication can more effectively activate coal gangue and weathered coal, and the formed soil conditioner can increase the content of organic matter and effective nitrogen, phosphorus and potassium in saline-alkali soil, and the number of live bacteria is significantly improved. It can be seen that the soil conditioner prepared by this method can improve the soil properties of saline-alkali soil, realize the ecological and environmental protection utilization of coal gangue and weathered coal, and has good applicability.

Claims

1. A method for preparing a saline-alkali land soil conditioner by activating coal-based solid waste with a microbial agent, characterized in that: The following steps are involved: a) Using the method of directional domestication to domesticate microorganisms to salt tolerance, the survival rate of microorganisms in sodium chloride is improved through domestication, and microorganisms that are not salt-tolerant are eliminated. Clay is used to increase the amount of extracellular cell components of microorganisms to make microorganisms more salt-tolerant. Microorganisms include bacteria and fungi. The activation efficiency of elements is improved through the synergistic effect of multiple microorganisms and the content of extracellular substances in which microorganisms participate in element activation; The bacteria that have an activation effect on inorganic elements in gangue are cultured in beef extract peptone medium to the logarithmic stage, and the fungi that have an activation effect on weathered coal are cultured in potato glucose medium to the logarithmic stage, and the bacteria and fungal spores in the logarithmic growth stage are separated by centrifugation; The obtained bacteria are acclimated and cultured in a beef extract peptone medium supplemented with 1%-10% sodium chloride and 0.1%-0.5% clay by mass, and the obtained fungal spores are transferred to a potato glucose medium supplemented with 1%-10% sodium chloride and 0.1%-0.5% clay by mass for acclimation and culture to a logarithmic phase, and the bacteria and fungal spores are separated by centrifugation as the first directional acclimation components; The bacteria obtained by the first domestication are transferred to a new beef extract peptone medium for domestication culture again, the mass percentage of sodium chloride in the new beef extract peptone medium is increased by 2% on the original basis, and the amount of clay added remains unchanged; the fungal spores obtained by the first domestication are transferred to a new potato glucose medium for domestication culture, the mass percentage of sodium chloride in the new potato glucose medium is increased by 2% on the original basis, and the amount of clay added remains unchanged, and a second domestication culture is carried out to the logarithmic phase, and the bacteria and fungal spores are centrifuged to obtain a second domestication culture; repeat the steps of this paragraph, transfer the bacteria obtained by the second domestication to a new beef extract peptone medium for domestication culture again, and transfer the fungal spores obtained by the second domestication to a new potato glucose medium for domestication culture, the mass percentage of sodium chloride in the new medium is increased by 2% each time, and the clay content remains unchanged for directional domestication, and the cell mass and the expression amount of the extracellular active components under high salt concentration are increased until the preset domestication times are reached, or the sodium chloride concentration in the new medium rises to the point that the bacteria and fungi no longer grow, and then the domestication is stopped; b) compounding the microbial strains that have completed the targeted domestication to obtain a composite microbial agent; c) crushing and screening the gangue and weathered coal and mixing them in a mass ratio of 1:1 to 1:3; d) Using composite microbial agents to activate the nutrient components in coal gangue and weathered coal, thereby improving the activation efficiency of nutrient elements and obtaining a soil conditioner.

2. The method for preparing a saline-alkali land soil conditioner by activating coal-based solid waste with a microbial agent according to claim 1, characterized in that: In step a), the gangue and weathered coal are crushed and then passed through a 100-mesh standard sieve.

3. The method for preparing a saline-alkali land soil conditioner by activating coal-based solid waste with a microbial agent according to claim 1, characterized in that: The preset number of acclimation for bacteria and fungi is no less than 3 times, and the number of cells of the acclimated bacteria and fungi strains reaches 10 when they are cultured in the improved medium to the logarithmic growth phase. 8 Pieces / mL.

4. The method for preparing a saline-alkali land soil conditioner by activating coal-based solid waste with a microbial agent according to claim 1, characterized in that: During the centrifugal separation process, the centrifugal parameters are as follows: the inoculation amount of bacteria and fungal spores in the culture process is 10%, the culture system is 100 mL, the temperature is 30°C, and the centrifugation is carried out at 10,000 rpm and 4°C for 15 minutes in a high-speed centrifuge; the separation is a heating extraction method.

5. The method for preparing a saline-alkali land soil conditioner by activating coal-based solid waste with a microbial agent according to claim 1, characterized in that: The formula of the composite microbial agent in step b) is as follows: the volume ratio of the bacterial culture solution in the logarithmic growth period to the fungal culture solution of the microbial strains is 1:1 to 4:

1.

6. The method for preparing a saline-alkali land soil conditioner by activating coal-based solid waste with a microbial agent according to claim 1, characterized in that: The bacteria are Bacillus megaterium and Bacillus colloids, the fungi are Trichoderma harzianum and Penicillium purpurogenum, and the composition comprises the following components in parts by weight: 25-40 parts of Bacillus megaterium, 25-40 parts of Bacillus colloids, 10-25 parts of Trichoderma harzianum and 10-25 parts of Penicillium purpurogenum.

7. The method for preparing a saline-alkali land soil conditioner by activating coal-based solid waste with a microbial agent according to claim 1, characterized in that: The preparation method of the soil conditioner is as follows: a composite microbial agent, a mixture of coal gangue and weathered coal are mixed in a mass ratio of 1:5 to 1:20, and the mixture is ventilated and fermented for 20-30 days, during which the humidity is maintained at 40-60%, the mixture is ventilated and fermented, and the temperature is controlled at 30-40°C to obtain a soil conditioner characterized by moisture ≤20%, pH ≤7.00, organic matter content ≥560mg / Kg, alkaline nitrogen ≥200mg / Kg, available phosphorus ≥300mg / Kg, and available potassium ≥200mg / kg.

8. A soil conditioner prepared by the method for preparing a saline-alkali soil conditioner by activating coal-based solid waste with microbial agents as described in any one of claims 1 to 7, which has good ecological utilization performance and can effectively enhance the survival rate of microorganisms in saline-alkali soil, and the properties of saline-alkali soil including organic matter content, total nitrogen, phosphorus, potassium, and pH are significantly improved.

9. The use of the soil conditioner according to claim 1, characterized in that: Mix the soil conditioner with saline-alkali soil in a mass ratio of 1:1 to 1:4.

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