Compound microbial agent and application thereof in improving saline-alkali soil
By leveraging the synergistic effects of multiple strains and substances in compound microbial agents, saline-alkali land can be improved, solving the problem of insignificant improvement effects and achieving efficient and economical soil improvement and increased cotton yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INST OF COTTON RES CHINESE ACAD OF AGRI SCI
- Filing Date
- 2026-04-01
- Publication Date
- 2026-06-26
AI Technical Summary
Existing saline-alkali land improvement technologies suffer from high costs, insignificant effects, poor technological synergy, and repeated salinization, making it difficult to effectively improve soil quality and cotton yield in saline-alkali land.
A composite microbial agent, including Chaetomium globosum, Bacillus subtilis, Bacillus licheniformis, Bacillus belye, humic acid, biochar, and diatomaceous earth, is used to promote the proliferation of the agent through a porous composite carrier, adsorb salt ions, and improve soil structure and cotton growth.
It significantly improves soil desalination rate, reduces soil pH, enhances cotton root vitality and yield, improves fiber quality, and reduces salt content and soil alkalinity in saline-alkali land.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of saline-alkali land improvement technology, specifically relating to a compound microbial agent and its application in improving saline-alkali land. Background Technology
[0002] Saline-alkali land is a general term for saline-alkali soils, characterized by high salt and high alkali content. This leads to soil compaction, increased osmotic pressure, plant dehydration and death, and reduced soil microbial activity and organic matter conversion efficiency. Current improvement technologies mainly include three methods: First, water conservancy engineering measures, such as large-scale irrigation to leach salt, which can reduce topsoil salinity in the short term but easily leads to the loss of nutrients such as calcium and phosphorus and exacerbates water consumption, resulting in limited long-term effects; second, chemical improvement, such as applying desulfurized gypsum and phosphogypsum to reduce sodium ion content through ion exchange, but this involves large dosages, high costs, and the risk of cumulative side effects; third, biological agronomic measures, such as planting salt-tolerant crops, which, while having ecological benefits, are insufficient for improving severely saline-alkali land and have a long cycle. In recent years, comprehensive improvement models, such as the "engineering + agronomy + biology" three-in-one approach, have been gradually promoted, but problems such as poor technical synergy and repeated salinization still need to be addressed.
[0003] Compound microbial agents, through the synergistic effect of multiple functional strains, have become an innovative direction for the improvement of saline-alkali land. Their core advantages lie in low cost, ecological safety, and compatibility with existing agronomic practices. For example, a compound microbial community constructed using Rs-198, *Pseudomonas aeruginosa* R5, and *Bacillus subtilis* GB03 can secrete organic acids to neutralize alkaline substances, while simultaneously producing extracellular polysaccharides to promote soil aggregate formation, significantly improving soil permeability and organic matter content. Compared to physicochemical methods, these agents require no large-scale engineering investment and can be directly applied through drip irrigation systems, achieving "improvement while production." In cotton cultivation, the benefits of these agents are particularly prominent: cotton, as a pioneer crop in salt tolerance, can grow in soils with a salt content of 0.3%, and compound microbial agents further enhance its resistance. For example, after applying salt-alkali resistant microbial agents to severely saline-alkali cotton fields in Korla, Xinjiang, the cotton emergence rate increased by 11.1%, the number of bolls per plant increased by 1.75, and the soil electrical conductivity in the root zone significantly decreased. A Trichoderma-containing remediation agent developed in Shandong can also inhibit Verticillium wilt pathogens, simultaneously addressing the dual stresses of saline-alkali land and soil-borne diseases. Furthermore, the preparation of these microbial agents can be combined with the resource utilization of agricultural waste (such as extracting cellulose from cotton stalks as a microcapsule framework), further reducing application costs and promoting circular agriculture. In summary, these microbial agents provide an integrated solution for "soil improvement-disease resistance-yield increase" in saline-alkali cotton cultivation, which is of great significance for ensuring the sustainable development of agriculture in saline-alkali areas.
[0004] Therefore, developing a new type of efficient, economical, and environmentally friendly compound microbial agent is of great significance for solving the problem of low yield in cotton cultivation in saline-alkali land. Summary of the Invention
[0005] The purpose of this invention is to provide a compound microbial agent and its application in improving saline-alkali land, so as to solve the problems existing in the prior art.
[0006] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of the present invention is a compound microbial agent comprising the following components in parts by weight: 0.5-1 parts of Chaetomium globosum, 0.3-0.6 parts of Bacillus subtilis, 0.3-0.6 parts of Bacillus licheniformis, 0.3-0.6 parts of Bacillus belye, 10-15 parts of humic acid, 6-10 parts of biochar, and 10-15 parts of diatomaceous earth.
[0007] Preferably, the live spore content of the *Chaetomium globosa* is ≥100 million CFU / g.
[0008] Preferably, the live bacteria content of the Bacillus subtilis is ≥1 billion CFU / g.
[0009] Preferably, the viable bacterial content of the Bacillus licheniformis is ≥1 billion CFU / g.
[0010] Preferably, the viable bacterial content of the Bacillus belyssus is ≥1 billion CFU / g.
[0011] Preferably, the soluble humic acid content of the fulvic acid is ≥45%.
[0012] Preferably, the fulvic acid is bio-derived potassium fulvicate with a fulvic acid content ≥45%, a pH of 5-6, and a particle size greater than 80 mesh; the biochar is a product of straw pyrolysis with a specific surface area ≥300 m². 2 / g, pore volume ≥0.25cm³ 3 / g, ash content ≤20%; the diatomaceous earth has a SiO2 content ≥80% and a bulk density of 0.25~0.35g / cm³. 3 Moisture content ≤5%, particle size greater than 100 mesh.
[0013] Preferably, the preparation method of the composite microbial agent is as follows: humic acid, biochar and diatomaceous earth are mixed evenly to obtain a porous composite carrier; then, Chaetomium globosum, Bacillus subtilis, Bacillus licheniformis, Bacillus belyeis and the porous composite carrier are mixed evenly to obtain the composite microbial agent.
[0014] The second technical solution of the present invention: the application of a composite microbial agent as described above in the improvement of saline-alkali land.
[0015] Preferably, the improvement of saline-alkali land includes reducing soil pH, reducing electrical conductivity, reducing soluble salt concentration, reducing sodium ion content, increasing organic matter content, increasing cotton seedling emergence rate, increasing cotton root vigor, increasing cotton chlorophyll content, increasing single boll weight, increasing seed cotton yield, increasing fiber length, increasing specific strength, increasing micronaire value, and increasing uniformity of cotton.
[0016] It is understood that the *Chaetomium globulum* in this invention is a mycelial powder raw material of *Chaetomium globulum*, *Bacillus subtilis* is a mycelial powder raw material of *Bacillus subtilis*, *Bacillus licheniformis* is a mycelial powder raw material of *Bacillus licheniformis*, and *Bacillus belyss* is a mycelial powder raw material of *Bacillus belyss*.
[0017] Compared with the prior art, the present invention has the following technical effects: (1) In the composite microbial agent components of the present invention, humic acid serves as a microbial carbon source, promoting the proliferation of the composite agent and accelerating the release of salt ions (Na+). + Adsorption; diatomaceous earth and biochar form a porous composite, which prolongs the salt adsorption cycle.
[0018] (2) The compound microbial agent provided by the present invention can significantly improve the soil desalination rate, reduce and maintain soil pH stability, enhance cotton root vitality, increase cotton seedling rate, significantly increase cotton seed yield, and improve cotton fiber quality after being applied to saline-alkali land. Detailed Implementation
[0019] Various exemplary embodiments of the present invention will now be described in detail. It should be understood that this detailed description is not intended to limit the present invention, but rather to provide a more comprehensive description of certain aspects, features, and embodiments of the present invention.
[0020] It should be understood that the terminology used in this invention is for describing specific embodiments only and is not intended to limit the invention. Furthermore, regarding numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included within this invention. The upper and lower limits of these smaller ranges may be independently included in or excluded from the range.
[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation for the purpose of disclosing and describing the methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the contents of this specification shall prevail.
[0022] Without departing from the scope or spirit of this invention, those skilled in the art will obviously be able to make various improvements and modifications to the specific embodiments described in this specification. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. The specification and embodiments of this invention are merely exemplary.
[0023] The terms “include,” “including,” “have,” and “contain” used in this article are all open-ended terms, meaning they include but are not limited to.
[0024] It should be noted that the contents not described in detail in this invention are all conventional practices in the field and are not the focus of this invention.
[0025] Unless otherwise specified, "room temperature" and "room temperature" mentioned in the specific embodiments of the present invention refer to 20~30℃; and all "parts" mentioned refer to "parts by weight".
[0026] This invention provides a compound microbial inoculant comprising the following components in parts by weight: 0.5-1 parts of Chaetomium globosum, 0.3-0.6 parts of Bacillus subtilis, 0.3-0.6 parts of Bacillus licheniformis, 0.3-0.6 parts of Bacillus belyssus, 10-15 parts of fulvic acid, 6-10 parts of biochar, and 10-15 parts of diatomaceous earth. This invention does not specifically limit the source of Bacillus subtilis, Bacillus licheniformis, and Bacillus belyssus; all can be commercially available products with an effective viable count ≥ 1 billion CFU / g.
[0027] The Chaetomium globulum in this invention is Chaetomium globulum spore powder, and the preparation method of Chaetomium globulum spore powder is as follows: (1) Preparation of fermentation substrate: Select dry, mold-free cotton stalks, pulverize them using a pulverizer, and then pass them through a 40-60 mesh sieve to obtain uniform cotton stalk powder. Mix the cotton stalk powder with auxiliary materials (such as wheat bran or rice bran) at a mass ratio of (7:3) to (8:2) to enhance the nutritional value and aeration of the substrate, thus obtaining a mixed substrate. Add 50% to 60% of the total mass of clean water to the mixed substrate and stir thoroughly to control the moisture content of the substrate at 50% to 55%, thus obtaining a wet mixed substrate. Distribute the wet mixed substrate into shallow, heat-resistant trays (such as enamel or stainless steel trays) with a thickness of 3 to 5 cm to ensure uniform heat and oxygen transfer during fermentation.
[0028] (2) Substrate sterilization: Place the shallow dish containing the substrate in a high-pressure steam sterilizer and sterilize it at 121℃ and 0.1MPa for 60-90 minutes to thoroughly kill any bacteria and insect eggs in the substrate. After sterilization, transfer the shallow dish to a sterile cooling room or a laminar flow hood and cool it to room temperature (25-28℃) to obtain the sterilized substrate.
[0029] (3) Inoculation: Under aseptic conditions, pre-activated Chaetomium globosum ( Chaetomium globosum Use a sterile sprayer to evenly spray the spore suspension or liquid culture of CGMCC No. 11313 onto the surface of the cooled sterilized substrate at an inoculation rate of 5% to 10% (v / w), and gently mix it evenly.
[0030] (4) Shallow tray fermentation culture: After inoculation, transfer the shallow trays to a temperature- and humidity-controlled sterile fermentation chamber. Maintain the chamber temperature at 25–28°C and the relative humidity (RH) at 70%–85% to prevent premature water loss from the substrate surface. During fermentation, gently agitate the substrate 1–2 times daily to dissipate metabolic heat, replenish oxygen, prevent excessive mycelial entanglement, and promote uniform spore formation. The fermentation cycle is 7–10 days. Fermentation is considered terminated when a large number of grayish-green to olive-green ascocarps and ascospores are observed in the substrate, and the spore maturity reaches 90% or higher.
[0031] (5) Post-processing and preparation of mycelium powder: The fermented solid culture was removed from the shallow dish and laid flat to air dry in a sterile, dry, and ventilated environment, or dried in a low-temperature airflow below 40°C until the moisture content was below 8%. The dried, blocky fermentation material was then pulverized using sterile mechanical grinding equipment. The pulverized material was processed using spore isolation and purification techniques (such as airflow classification, sieving, and other physical methods) to separate and enrich high-purity Chaetomium globosum ascospores, obtaining Chaetomium globosum spore powder. The viable spore content was greater than 6 billion CFU / g, as determined by the hemocytometer method.
[0032] In this invention, the preparation of Chaetomium globosum powder adopts the shallow pan solid-state fermentation method, which has the advantages of simple equipment, low investment, easy to scale up production, and can obtain extremely high spore yield.
[0033] In this invention, the fulvic acid is bio-derived potassium fulvicate with a fulvic acid content ≥45%, a pH of 5-6, and a particle size greater than 80 mesh.
[0034] In this invention, the biochar is a product of straw pyrolysis with a specific surface area ≥300 m². 2 / g, pore volume ≥0.25cm³ 3 / g, ash content ≤20%.
[0035] In this invention, the diatomaceous earth has a SiO2 content ≥80% and a bulk density of 0.25~0.35 g / cm³. 3 Moisture content ≤5%, particle size greater than 100 mesh.
[0036] The Bacillus subtilis, Bacillus licheniformis, and Bacillus belesia lappa used in Examples 1-3 and Comparative Examples 1-9 were all commercially available products with an effective viable count of 30 billion CFU / g. The fulvic acid used in Examples 1-3 and Comparative Examples 1-9 was commercially available, specifically bio-derived potassium fulvicate, a byproduct of molasses fermentation yeast, with a fulvic acid content ≥45%, pH 5-6, and particle size greater than 80 mesh. The biochar was commercially available, a product of straw pyrolysis, with a specific surface area ≥300 m². 2 / g, pore volume ≥0.25cm³ 3 / g, ash content ≤20%; diatomaceous earth sourced commercially, SiO2 content ≥80%, bulk density 0.25~0.35g / cm³ 3 Moisture content ≤5%, particle size greater than 100 mesh.
[0037] The Chaetomium globosum used in Examples 1-3 and Comparative Examples 1-9 below is Chaetomium globosum spore powder. The preparation method of Chaetomium globosum spore powder is as follows: (1) Preparation of fermentation substrate: Dry, mold-free cotton stalks are selected, pulverized using a pulverizer, and then passed through a 40-mesh sieve to obtain uniform cotton stalk powder. The cotton stalk powder is mixed with an auxiliary material (wheat bran) at a mass ratio of 7:3 to enhance the nutritional value and aeration of the substrate, resulting in a mixed substrate. Clean water is added to the mixed substrate and thoroughly stirred until the moisture content is controlled at 50%, resulting in a wet mixed substrate. The wet mixed substrate is then divided into shallow, heat-resistant trays (such as enamel or stainless steel trays), with a thickness controlled at 3 cm to ensure uniform heat and oxygen transfer during fermentation.
[0038] (2) Substrate sterilization: The shallow dish containing the substrate was placed in an autoclave and sterilized at 121°C and 0.1 MPa for 60 minutes to thoroughly kill any bacteria and insect eggs in the substrate. After sterilization, the shallow dish was transferred to a sterile cooling room or a laminar flow hood and cooled to room temperature to obtain the sterilized substrate.
[0039] (3) Inoculation: Under aseptic conditions, pre-activated Chaetomium globosum ( Chaetomium globosum The spore suspension or liquid culture of CGMCC No. 11313 is inoculated at a rate of 5% (v / w) and evenly sprayed onto the surface of the cooled sterilized substrate using a sterile sprayer, and then gently mixed.
[0040] (4) Shallow tray fermentation culture: After inoculation, transfer the shallow trays to a temperature- and humidity-controlled sterile fermentation chamber. Maintain the chamber temperature at 25°C and the relative humidity (RH) at 70% to prevent premature water loss from the substrate surface. During fermentation, gently agitate the substrate once daily to dissipate metabolic heat, replenish oxygen, prevent excessive mycelial entanglement, and promote uniform spore formation. The fermentation cycle is 7 days. Fermentation is considered terminated when a large number of grayish-green to olive-green ascocarps and ascospores are observed in the substrate, and the spore maturity reaches 90% or higher, through periodic microscopic examination.
[0041] (5) Post-processing and preparation of mycelium powder: The fermented solid culture was removed from the shallow dish and laid out to air dry in a sterile, dry, and ventilated environment. The dried, blocky fermentation material was then pulverized using sterile mechanical grinding equipment. The pulverized material was processed using spore isolation and purification technology (air classifier method) to separate and enrich high-purity Chaetomium globosum ascospores, obtaining Chaetomium globosum spore powder. The viable spore content was determined to be 8 billion CFU / g by hemocytometer analysis.
[0042] Example 1 The compound microbial agent of this embodiment is composed of the following components in parts by weight: 0.8 parts of Chaetomium globosum, 0.5 parts of Bacillus subtilis, 0.5 parts of Bacillus licheniformis, 0.5 parts of Bacillus belye, 12 parts of humic acid, 8 parts of biochar, and 12 parts of diatomaceous earth.
[0043] Example 2 The compound microbial agent of this embodiment is composed of the following components in parts by weight: 0.5 parts of Chaetomium globosum, 0.3 parts of Bacillus subtilis, 0.3 parts of Bacillus licheniformis, 0.3 parts of Bacillus belye, 10 parts of humic acid, 6 parts of biochar, and 10 parts of diatomaceous earth.
[0044] Example 3 The compound microbial agent of this embodiment is composed of the following components in parts by weight: 1.0 part of Chaetomium globosum, 0.6 parts of Bacillus subtilis, 0.6 parts of Bacillus licheniformis, 0.6 parts of Bacillus belye, 15 parts of humic acid, 10 parts of biochar, and 15 parts of diatomaceous earth.
[0045] Comparative Example 1 The only difference between the composite microbial agent of this comparative example and the composite microbial agent of Example 1 is that the amount of Chaetomium globosum in the composite microbial agent of this comparative example is 0, and the sum of the mass fractions of Bacillus subtilis, Bacillus licheniformis and Bacillus vesalis in the composite microbial agent is equal to the sum of the mass fractions of Chaetomium globosum, Bacillus subtilis, Bacillus licheniformis and Bacillus vesalis in the composite microbial agent of Example 1, and the mass ratio of Bacillus subtilis, Bacillus licheniformis and Bacillus vesalis in the composite microbial agent of Example 1 is equal to the mass ratio of Bacillus subtilis, Bacillus licheniformis and Bacillus vesalis in the composite microbial agent of Example 1.
[0046] Comparative Example 2 The only difference between the composite microbial agent of this comparative example and the composite microbial agent of Example 1 is that the amount of Bacillus subtilis in the composite microbial agent of this comparative example is 0, and the sum of the mass fractions of Chaetomium globosum, Bacillus licheniformis and Bacillus vesalis in the composite microbial agent is equal to the sum of the mass fractions of Chaetomium globosum, Bacillus subtilis, Bacillus licheniformis and Bacillus vesalis in the composite microbial agent of Example 1, and the mass ratio of Chaetomium globosum, Bacillus licheniformis and Bacillus vesalis in the composite microbial agent of Example 1 is equal to the mass ratio of Chaetomium globosum, Bacillus licheniformis and Bacillus vesalis in the composite microbial agent of Example 1.
[0047] Comparative Example 3 The only difference between the composite microbial agent of this comparative example and the composite microbial agent of Example 1 is that the amount of Bacillus licheniformis in the composite microbial agent of this comparative example is 0, and the sum of the mass fractions of Chaetomium globosum, Bacillus subtilis, and Bacillus vesalis in the composite microbial agent is equal to the sum of the mass fractions of Chaetomium globosum, Bacillus subtilis, Bacillus licheniformis, and Bacillus vesalis in the composite microbial agent of Example 1, and the mass ratio of Chaetomium globosum, Bacillus subtilis, and Bacillus vesalis is equal to the mass ratio of Chaetomium globosum, Bacillus subtilis, and Bacillus vesalis in the composite microbial agent of Example 1.
[0048] Comparative Example 4 The only difference between the composite microbial agent of this comparative example and the composite microbial agent of Example 1 is that the amount of Bacillus belye in the composite microbial agent of this comparative example is 0, and the sum of the mass fractions of Chaetomium globosum, Bacillus subtilis, and Bacillus licheniformis in the composite microbial agent is equal to the sum of the mass fractions of Chaetomium globosum, Bacillus subtilis, Bacillus licheniformis, and Bacillus belye in the composite microbial agent of Example 1, and the mass ratio of Chaetomium globosum, Bacillus subtilis, and Bacillus licheniformis is equal to the mass ratio of Chaetomium globosum, Bacillus subtilis, and Bacillus licheniformis in the composite microbial agent of Example 1.
[0049] Comparative Example 5 The only difference between the composite microbial agent in this comparative example and the composite microbial agent in Example 1 is that diatomaceous earth is replaced with bentonite (the SiO2 content in bentonite is <10%).
[0050] Comparative Example 6 The composite microbial agent of this comparative example is composed of the following components in parts by weight: 1.0 part of Bacillus subtilis, 12 parts of humic acid, 8 parts of biochar, and 12 parts of diatomaceous earth.
[0051] Comparative Example 7 The only difference between the composite microbial agent in this comparative example and the composite microbial agent in Example 1 is that biochar is replaced with rice husk charcoal (the specific surface area of rice husk charcoal is <50m²). 2 / g).
[0052] Comparative Example 8 The composite microbial agent of this comparative example is composed of the following components in parts by weight: 35 parts gypsum, 15 parts fulvic acid, and 10 parts sodium humate.
[0053] Comparative Example 9 The compound microbial agent used in this comparative example is a commercially available microbial agent containing Bacillus subtilis agent (live count ≥ 10 billion / g).
[0054] Application examples Location: Saline-alkali land in Aksu, Xinjiang Soil background values: pH 8.9, EC 4.8 mS / cm, Na + 1.35%, organic matter 0.6% Cotton variety: Lumianyan 37 (salt-tolerant variety) Experimental groups: Examples 1-3, Comparative Examples 1-6, and Blank Control Group (CK). Cell design: randomized block design, 3 replicates, cell area 30m² 2 Application method: Apply via drip irrigation with water when seedlings emerge, 3 kg / mu.
[0055] Detection indicators and methods: When determining the organic matter content, soil samples were collected from the rhizosphere soil within 5 cm of the cotton plant roots, and the test was conducted in accordance with the provisions of HJ 615-2011 "Determination of Soil Organic Carbon by Potassium Dichromate Oxidation-Spectrophotometric Method".
[0056] The uniformity test method is as follows: During the flowering period, the protective row of 1m around the plot is removed to eliminate the edge effect. Five sampling points (four corners and center) are selected along the diagonal of the plot. Ten representative plants are continuously investigated at each point. The effective sample size of the whole plot is n≥50 plants. The measured indicators include plant height and stem diameter. After the measurement, the average values of plant height and stem diameter are calculated. Finally, the minimum value of the proportion of individuals with plant height within the range of average plant height × (1±10%) and the proportion of individuals with stem diameter within the range of average stem diameter × (1±10%) is calculated to obtain the uniformity.
[0057] Experimental results data: Table 1. Comparison of soil improvement effects (harvest period data) Note: * indicates that no external organic matter was replenished, and that the organic matter content decreased slightly due to the crop's absorption and consumption of the soil's original nutrients caused by the increased crop yield.
[0058] Table 2 Cotton growth indicators and yield performance Table 3. Results of cotton fiber quality testing (HVI) Due to the colonization characteristics of microbial agents, their improving effect is mainly concentrated in the rhizosphere microenvironment. Data shows that this invention can significantly enrich rhizosphere organic matter, improve the rhizosphere microecology, and thus promote root growth.
[0059] Mechanism verification experiment: Microbial colonization dynamics (qPCR detection) Sampling method: Five-point sampling of rhizosphere soil (0~20cm depth) Target genes: Chaetoceros globosum: β-tubulin gene Bacillus group: gyrB conserved sequence Results: The 10% level was maintained in the Example 1 group 60 days after application. 6 CFU / g soil was significantly higher than that in the control group (10). 4 ~10 5 CFU / g).
[0060] Micro area Na + Adsorption experiment Method: Construct an undisturbed soil column (30cm in diameter, 50cm in height). Treatment: Inject 0.3% NaCl solution to simulate salt transport. Conclusion: Na in the bacterial agent treatment group + The adsorption capacity was 217% higher than the control, and the diatomaceous earth-biochar composite still maintained 85% of its adsorption capacity after 30 days.
[0061] Root exudate analysis (GC-MS) revealed that the content of organic acids (oxalic acid / citric acid) in the root exudates of the inoculant-treated group increased by 2.3 times, and the organic acids and Na+ content increased significantly. + It forms a complex, which promotes the elution of salt ions.
[0062] Application effect in cotton fields in Xinjiang (2024 data): The location was a severely saline-alkali land in Aksu, Xinjiang (initial EC 5.3 mS / cm). The compound microbial agent was applied twice (1.5 kg / time) at a rate of 3.0 kg / mu. The results showed that the application of compound microbial agent could significantly improve the emergence rate of cotton in saline-alkali land, which was 20% higher than the control. At the same time, it significantly improved the stunted seedling situation of cotton, with stunted seedlings reduced by 70% compared with the control, and the seed cotton yield increased by 60.2% compared with the control.
Claims
1. A complex microbial inoculant, characterized in that, The product comprises the following components in parts by weight: 0.5-1 part of Chaetomium globosum, 0.3-0.6 parts of Bacillus subtilis, 0.3-0.6 parts of Bacillus licheniformis, 0.3-0.6 parts of Bacillus belye, 10-15 parts of humic acid, 6-10 parts of biochar, and 10-15 parts of diatomaceous earth.
2. The complex microbial agent according to claim 1, wherein The viable spore content of the *Chaetoceros globosum* is ≥100 million CFU / g.
3. The complex microbial agent according to claim 1, wherein The viable bacterial count of the Bacillus subtilis is ≥1 billion CFU / g.
4. The compound microbial agent as described in claim 1, characterized in that, The viable bacterial count of the Bacillus licheniformis is ≥1 billion CFU / g.
5. The compound microbial agent as described in claim 1, characterized in that, The viable count of the *Bacillus belyssus* is ≥1 billion CFU / g.
6. The complex microbial agent according to claim 1, wherein The soluble humic acid content of the fulvic acid is ≥45%.
7. The composite microbial agent as described in claim 1, characterized in that, The fulvic acid is bio-derived potassium fulvicate, with a fulvic acid content ≥45%, pH 5-6, and particle size greater than 80 mesh; the biochar is a product of straw pyrolysis, with a specific surface area ≥300 m². 2 / g, pore volume ≥0.25cm³ 3 / g, ash content ≤20%; the diatomaceous earth has a SiO2 content ≥80% and a bulk density of 0.25~0.35g / cm³. 3 Moisture content ≤5%, particle size greater than 100 mesh.
8. The complex microbial agent according to claim 1, wherein The preparation method of the composite microbial agent is as follows: humic acid, biochar and diatomaceous earth are mixed evenly to obtain a porous composite carrier; then Chaetomium globosum, Bacillus subtilis, Bacillus licheniformis, Bacillus belyeis and the porous composite carrier are mixed evenly to obtain the composite microbial agent.
9. The application of a compound microbial agent as described in any one of claims 1-8 in the improvement of saline-alkali land.
10. Use according to claim 9, wherein The improvement of saline-alkali land includes reducing soil pH, reducing electrical conductivity, reducing soluble salt concentration, reducing sodium ion content, increasing organic matter content, increasing cotton seedling emergence rate, increasing cotton root vigor, increasing cotton chlorophyll content, increasing single boll weight, increasing seed cotton yield, increasing fiber length, increasing specific strength, increasing micronaire value, and increasing uniformity of cotton.