Application of compound microbial agent in saline-alkali soil improvement

Abstract

The invention relates to an application of a compound microbial agent in improvement of saline-alkali soil. A bacterial strain in the compound microbial agent is composed of a bacillus coagulans BC66 bacterial strain with the preservation number of CGMCC (China General Microbiological Culture Collection Center) 21879 and a lactobacillus plantarum LP194 bacterial strain with the preservation number of CGMCC 21766. The invention develops a brand-new microbial preparation capable of solving the problem of soil salinization, researches find that the two strains are mutually matched and have synergistic interaction on the effects of reducing the content of soluble salt in soil, improving the soil salinization and increasing the emergence rate and yield of crops planted in saline-alkali soil, and under the condition that the using bacterium amount is consistent, the application range is wide, and the application range is wide. Compared with a single strain, the compounding of the two bacteria has the advantage that the effects are obviously improved. Therefore, the compound microbial agent provides a new strategy for improving the saline-alkali soil, protecting root systems of planted crops from being influenced by salinization and improving the emergence rate and the yield of the crops planted in the saline-alkali soil.

Description

Technical Field

[0001] The invention belongs to the technical field of saline-alkali land improvement and relates to application of a composite microbial agent in saline-alkali land improvement. Background Art

[0002] Salt-alkali land is a major challenge facing global agriculture. Its unique soil conditions limit the normal growth of crops, resulting in low yields and poor quality of agricultural products. Solving the problem of salt-alkali land and improving its agricultural production capacity are of great significance to ensuring food safety and promoting sustainable agricultural development. Traditional physical and chemical methods have problems such as high cost, limited effect, and easy to cause secondary environmental pollution in the improvement of salt-alkali land. Therefore, it is imperative to explore green, efficient and sustainable improvement methods. Microbial technology, as an environmentally friendly bioengineering technology, has gradually become the focus of salt-alkali land improvement research due to its unique advantages in promoting soil ecological balance and enhancing plant salt tolerance.

[0003] The application of microorganisms in saline-alkali land improvement is mainly based on their unique physiological and ecological functions and metabolic mechanisms. On the one hand, microorganisms can reduce the salt content in the soil and improve the physical and chemical properties of the soil by decomposing organic matter and converting inorganic salts; on the other hand, microorganisms can also produce a variety of plant growth regulators, such as plant hormones and vitamins, to promote crop growth and development. In addition, microorganisms can also form a symbiotic relationship through interaction with plant roots to improve plant resistance and adaptability. These microorganisms are particularly important in saline-alkali environments because high salinity conditions hinder the absorption and transportation of water and nutrients by plants. Through interaction with plant roots, these beneficial microorganisms can help plants overcome salt-alkali stress and enhance nutrient uptake and transportation, thus playing a vital role in improving soil conditions and helping plants adapt to saline-alkali environments.

[0004] In summary, the role of microbial agents in improving saline-alkali soil cannot be ignored. Microbial agents not only participate in regulating the salt content in the soil, but also provide more favorable soil conditions for plant growth by promoting the increase of organic matter and improving nutrient supply. These microbial-driven processes play a key role in improving soil quality and sustainable agricultural development. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide an application of a composite microbial agent in the improvement of saline-alkali land.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides an application of a composite microbial agent in saline-alkali land improvement, wherein the strains in the composite microbial agent are composed of Bacillus coagulans BC66 strain with a preservation number of CGMCC 21879 and Lactobacillus plantarum LP194 strain with a preservation number of CGMCC 21766.

[0008] The present invention has developed a new microbial preparation that can solve the problem of soil salinization. Its active microorganisms are composed of Bacillus coagulans BC66 strain and Lactobacillus plantarum LP194 strain. Studies have found that these two strains cooperate with each other in reducing the soluble salt content of soil and improving soil salinization, and synergize. When the amount of bacteria used is the same, compared with a single BC66 strain or a single LP194 strain, the compound of the two bacteria significantly improves the above-mentioned effects. Therefore, the composite microbial agent provides a new strategy for improving saline-alkali land and protecting the roots of planted crops from salinization.

[0009] Preferably, the ratio of the number of viable cells of the BC66 strain to that of the LP194 strain is (1-3):(1-3), for example 1:3, 1:2, 1:1, 2:1, 3:1, etc. Other specific point values ​​within the above numerical range can be selected and will not be described here one by one.

[0010] Based on the potential interaction between the BC66 strain and the LP194 strain, the present invention also found that when the two strains are compounded in the above-mentioned specific ratio of viable bacteria count, their effects in reducing the soluble salt content in the soil and improving soil salinization are more significant.

[0011] Preferably, the content of live bacteria in the composite microbial agent is not less than 2×10 9 CFU / g or 2×10 9 CFU / mL, for example 2×10 9 CFU / mL (CFU / g), 5×10 9 CFU / mL (CFU / g), 1×10 10 CFU / mL (CFU / g), 1×10 11 CFU / mL (CFU / g), 1×10 12 CFU / mL (CFU / g), etc.; other specific point values ​​within this numerical range can be selected and will not be described here one by one.

[0012] Preferably, the composite microbial agent is in the form of a solution or a powder.

[0013] The dosage form of the composite microbial agent of the present invention is not limited, including the most commonly used solutions, powders, or further prepared capsules, tablets or granules.

[0014] Preferably, the composite microbial agent is in the form of a powder, which is prepared by a method comprising the following steps:

[0015] The BC66 strain and the LP194 strain are inoculated into a culture medium respectively for activation and fermentation culture in sequence to obtain a fermentation broth; the fermentation broth is centrifuged respectively, mixed with a protective agent and then dried to obtain BC66 bacterial powder and LP194 bacterial powder; the BC66 bacterial powder and the LP194 bacterial powder are mixed according to the ratio of the number of live bacteria to obtain the composite microbial agent.

[0016] Alternatively, the BC66 strain and the LP194 strain are inoculated into a culture medium together for activation and fermentation culture in sequence to obtain a fermentation broth; the fermentation broth is centrifuged, mixed with a protective agent, and then dried to obtain the composite microbial agent.

[0017] The protective agent includes any one of skim milk, gelatin, dextrin, gum arabic, dextran, sodium alginate, polyvinyl pyrrolidone, sucrose, lactose, trehalose, sorbitol or xylitol, or a combination of at least two thereof.

[0018] Preferably, the composite microbial agent is in the form of a solution, which is prepared by a method comprising the following steps:

[0019] The BC66 strain and the LP194 strain are inoculated into a culture medium respectively for activation and fermentation culture in sequence to obtain a fermentation broth; the fermentation broth is centrifuged respectively, and the bacterial sludge is resuspended to obtain a BC66 bacterial suspension and a LP194 bacterial suspension; the BC66 bacterial suspension and the LP194 bacterial suspension are mixed according to the ratio of the number of live bacteria to obtain the composite microbial agent.

[0020] Alternatively, the BC66 strain and the LP194 strain are co-inoculated into a culture medium for activation and fermentation culture in sequence to obtain a fermentation broth; the fermentation broth is centrifuged, and the bacterial sludge is resuspended to obtain the composite microbial agent.

[0021] Preferably, the composite microbial agent also contains a bacterial protective agent and / or a nutritional component.

[0022] In a second aspect, the present invention also provides a method for improving the emergence rate and yield of crops planted in saline-alkali land, the method comprising: mixing a composite microbial agent with water and applying the mixture to the saline-alkali land planted with crops using a drip irrigation facility;

[0023] The strains in the composite microbial agent are composed of Bacillus coagulans BC66 strain with a preservation number of CGMCC 21879 and Lactobacillus plantarum LP194 strain with a preservation number of CGMCC 21766.

[0024] The present invention develops a new microbial preparation capable of improving the emergence rate and yield of crops planted in saline-alkali land, wherein the strains are composed of Bacillus coagulans BC66 strain and Lactobacillus plantarum LP194 strain. Studies have found that the two strains cooperate with each other in improving the emergence rate and yield of crops planted in saline-alkali land, and synergize to enhance the effect. When the amount of bacteria used is the same, compared with a single BC66 strain or a single LP194 strain, the compound of the two bacteria significantly improves the above-mentioned effect. Therefore, the composite microbial agent provides a new strategy for protecting the root system of crops planted in saline-alkali land from salinization and improving the emergence rate and yield of crops.

[0025] Preferably, the ratio of the number of viable cells of the BC66 strain to that of the LP194 strain is (1-3):(1-3), for example 1:3, 1:2, 1:1, 2:1, 3:1, etc. Other specific point values ​​within the above numerical range can be selected and will not be described here one by one.

[0026] Based on the potential interaction between the BC66 strain and the LP194 strain, the present invention also found that when the two strains are compounded with the above-mentioned specific ratio of viable bacteria count, their efficacy in protecting the roots of crops planted in saline-alkali land from salinization and increasing the emergence rate and yield of crops is more significant.

[0027] Preferably, the composite microbial agent is in the form of a solution or a powder; the content of live bacteria in the composite microbial agent is not less than 2×10 9 CFU / g or 2×10 9 CFU / mL, for example 2×10 9 CFU / mL (CFU / g), 5×10 9 CFU / mL (CFU / g), 1×10 10 CFU / mL (CFU / g), 1×10 11 CFU / mL (CFU / g), 1×10 12 CFU / mL (CFU / g), etc.; other specific point values ​​within this numerical range can be selected and will not be described here one by one.

[0028] Preferably, the usage of the composite microbial agent is 2-20kg / mu, for example, 3kg / mu, 4kg / mu, 5kg / mu, 6kg / mu, 7kg / mu, 8kg / mu, 9kg / mu, 10kg / mu, 12kg / mu, 15kg / mu, 17kg / mu, 19kg / mu, etc.; other specific point values ​​within this numerical range can be selected, and they will not be described one by one here.

[0029] Preferably, the crop comprises cotton.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention has developed a new microbial preparation that can solve the problem of soil salinization. Its active microorganisms are composed of Bacillus coagulans BC66 strain and Lactobacillus plantarum LP194 strain. Studies have found that these two strains cooperate with each other in reducing the soluble salt content of soil, improving soil salinization, and increasing the emergence rate and yield of crops planted in saline-alkali land. When the amount of bacteria used is the same, compared with a single BC66 strain or a single LP194 strain, the combination of the two bacteria significantly improves the above-mentioned effects. Therefore, the composite microbial agent provides a new strategy for improving saline-alkali land, protecting the roots of planted crops from salinization, and increasing the emergence rate and yield of crops planted in saline-alkali land.

[0032] The BC66 strain involved in the present invention is classified and named Bacillus coagulans. The preservation unit is the General Microbiology Center of China Microorganism Culture Collection Administration. The preservation time is March 8, 2021. The preservation number is CGMCC 21879. The address is: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0033] The LP194 strain involved in the present invention is classified and named Lactobacillus plantarum, and the preservation unit is the General Microbiology Center of China Microorganism Culture Collection Administration. The preservation time is January 29, 2021, the preservation number is CGMCC 21766, and the address is: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing. DETAILED DESCRIPTION

[0034] In order to further explain the technical means and effects adopted by the present invention, the technical solution of the present invention is further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0035] The BC66 strain involved in the following experiment is classified and named Bacillus coagulans, deposited on March 8, 2021, and has a deposit number of CGMCC 21879.

[0036] The LP194 strain involved in the following experiment is classified and named Lactobacillus plantarum, the preservation date is January 29, 2021, and the preservation number is CGMCC 21766.

[0037] The preparation method of the bacterial powder involved in the following test is as follows: the desired strain is inoculated into PCA liquid culture medium, cultured at 37°C for 24 hours for activation, and activated twice continuously to obtain an activated solution; the activated solution is inoculated into PCA liquid culture medium at an inoculum amount of 5% (v / v), and cultured at 37°C to obtain a bacterial solution; the bacterial solution is centrifuged at 5000 rpm for 10 minutes at 4°C, filtered to obtain bacterial bodies, and then mixed and emulsified with a protective agent (15% skim milk, 5% glycerol, 80% water) in a mass ratio of 1:1, and freeze-dried to obtain BC66 bacterial powder, LP194 bacterial powder and other commercially available bacterial powders, and the number of viable bacteria is 1×10 10 CFU / g.

[0038] Example

[0039] Verification of the effect of composite microbial agents on saline-alkali land improvement:

[0040] (1) Grouping: The experiment was conducted in a cotton production base in Xinjiang and was divided into 9 groups: blank control group;

[0041] Medium-dose intervention groups: BC66 group (intervention with BC66 powder), LP194 group (intervention with LP194 powder), BC66+LP194 group 1 (intervention with BC66 powder and LP194 powder, with a live bacteria count ratio of 3:1), BC66+LP194 group 2 (intervention with BC66 powder and LP194 powder, with a live bacteria count ratio of 1:1), BC66+LP194 group 3 (intervention with BC66 powder and LP194 powder, with a live bacteria count ratio of 1:3), ATCC7050+ATCC8014 group (intervention with commercially available Bacillus coagulans ATCC7050 powder and commercially available Lactobacillus plantarum ATCC8014 powder, with a live bacteria count ratio of 3:1);

[0042] Low-dose intervention group: BC66+LP194 group 1 (combined intervention with BC66 powder and LP194 powder, with a live bacteria count ratio of 3:1);

[0043] High-dose intervention group: BC66+LP194 group 1 (combined intervention with BC66 powder and LP194 powder, with a ratio of live bacteria count of 3:1).

[0044] (2) Planting method: The base fertilizer is commercially available compound fertilizer (30-12-4) with an application of 50 kg per mu. Soil type: chestnut soil, saline-alkali land. The test temperature range is 10℃-32℃. The soil moisture is controlled between 50%-70%. The watering method is drip irrigation with a water volume of 20 tons / mu. The test plot is divided into nine plots on average. There is an aisle of about 20 cm between the plots. The shape of each plot is 5×10m. The planting density is 0.8m in row spacing and 25cm in plant spacing per row. The cultivation and management measures of each group are consistent.

[0045] (3) Intervention method: The bacterial powder or mixed bacterial powder in each group was first mixed with water and applied together with drip irrigation facilities. The blank control group used water without bacterial agent (20 tons / mu) for drip irrigation; the medium-dose intervention group used water (20 tons / mu) containing bacterial powder or mixed bacterial powder (total usage 5 kg / mu) for drip irrigation; the low-dose intervention group used water (20 tons / mu) containing bacterial powder or mixed bacterial powder (total usage 2 kg / mu) for drip irrigation; the high-dose intervention group used water (20 tons / mu) containing bacterial powder or mixed bacterial powder (total usage 10 kg / mu) for drip irrigation. The drip irrigation was carried out 10 times in total.

[0046] (4)Indicator analysis:

[0047] (4.1) The soluble salt content, pH and electrical conductivity of the soil at 0-20 cm were measured on the 1st, 30th, 90th and 180th day after planting. The soluble salt content of the soil includes HCO3 - 、CO3 2- 、SO4 2- , Cl - , Ca + Mg + 、Na + , K + The determination method refers to the method in "Soil Agrochemical Analysis" (Bao Shidan third edition) to determine the soluble salt ions, HCO3 - 、CO3 2- Using double indicator neutralization titration method, SO4 2- Using EDTA indirect complexometric titration, Cl - Using silver nitrate titration, Ca + and Mg + Using EDTA titration method, Na + and K + The flame photometry method was used. The results are shown in Table 1.

[0048] Table 1

[0049]

[0050]

[0051] (4.2) The cotton seed germination rate was measured on the 30th day after cotton sowing, the crop yield was measured at the cotton harvest period, and the cotton roots were taken to measure the root salt content; the root salt determination method was to kill the root sample at 105℃ for 30 minutes and then dry it at 70℃ to constant weight. The dry sample was ground and sieved, and then the Ca content in the plant root was determined by atomic absorption spectrophotometry. + Mg + 、Na + , K + The results are shown in Table 2.

[0052] Table 2

[0053]

[0054] It can be seen from the data results in Table 1 and Table 2 that, compared with the blank control group, a single bacterial agent or a commercially available bacterial agent, the composite microbial agent involved in the present invention can effectively reduce the soluble salt content, pH value and conductivity of saline-alkali soil, reduce the accumulation of soluble salt in the soil, and increase the emergence rate and yield of cotton, indicating that the microbial agent can protect the cotton root system from absorbing soil salt and reduce the accumulation of soil salt, thereby achieving the effect of improving saline-alkali land.

[0055] The applicant declares that the present invention illustrates the technical solution of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0056] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0057] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. Application of a composite microbial agent in saline-alkali land improvement, characterized in that: The strains in the composite microbial agent are composed of Bacillus coagulans BC66 strain with a preservation number of CGMCC 21879 and Lactobacillus plantarum LP194 strain with a preservation number of CGMCC 21766.

2. The use according to claim 1, characterized in that: The ratio of the number of viable bacteria of the BC66 strain to that of the LP194 strain is (1-3):(1-3).

3. The use according to claim 1, characterized in that: The content of live bacteria in the composite microbial agent is not less than 2×10 9 CFU / g or 2×10 9 CFU / mL.

4. The use according to claim 1, characterized in that: The dosage form of the composite microbial agent includes solution or powder.

5. The use according to claim 1, characterized in that: The composite microbial agent also contains a bacterial protective agent and / or a nutritional component.

6. A method for improving the emergence rate and yield of crops planted in saline-alkali land, characterized in that: The method comprises: mixing the composite microbial agent with water and applying the mixture to the saline-alkali land where crops are planted using a drip irrigation facility; The strains in the composite microbial agent are composed of Bacillus coagulans BC66 strain with a preservation number of CGMCC 21879 and Lactobacillus plantarum LP194 strain with a preservation number of CGMCC 21766.

7. The method according to claim 6, characterized in that The ratio of the number of viable bacteria of the BC66 strain to that of the LP194 strain is (1-3):(1-3).

8. The method according to claim 6, characterized in that The dosage form of the composite microbial agent is a solution or a powder; the content of live bacteria in the composite microbial agent is not less than 2×10 9 CFU / g or 2×10 9 CFU / mL.

9. The method according to claim 8, characterized in that The usage of the composite microbial agent is 2-20 kg / mu.

10. The method according to claim 6, characterized in that The crops include cotton.

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