Microbial composition and method for improving saline-alkali land

Abstract

The present invention relates to the technical field of soil improvement, and in particular to a microbial composition and a comprehensive method for improving saline-alkali land. The microbial composition for improving saline-alkali land comprises a salt-clearing and alkali-regulating bacterial agent, a bacterial supplement and a biological liquid fertilizer, wherein the salt-clearing and alkali-regulating bacterial agent and the bacterial supplement contain a salt-tolerant and alkali-reducing bacterial group, and the salt-tolerant and alkali-reducing bacterial group includes one or more of Daban halobacillus NBL-BS214 and Bacillus subtilis 21c, wherein the deposit number of Daban halobacillus NBL-BS214 is CCTCC NO: 20221370, and the deposit number of Bacillus subtilis 21c is CCTCC M 2018565. According to the formation characteristics of saline-alkali land, the present invention proposes a "clearing, regulating and supplementing + planting" improvement method specifically for saline-alkali land, and the improvement materials containing salt-tolerant and alkali-reducing bacterial groups can effectively improve the pH and salt content of saline-alkali land, increase the emergence rate and yield of crops, and are simple and easy to operate, with low investment, long-term effect, ecological and environmental protection, no secondary pollution, and high output in the year of improvement.

Description

Technical Field

[0001] The present invention relates to the technical field of soil improvement, and in particular to a microbial composition and method for improving saline-alkali land. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Saline-alkali land is a precious land resource, and land salinization is a global problem facing mankind. By repairing and improving saline-alkali land, the amount of saline-alkali land can be reduced and the amount of arable land can be increased. This "one reduction" and "one increase" have a significant impact and significance on the national economic sustainable development strategy, local economic development, and solving the "three rural" problems.

[0004] In order to reduce salt and restore the productivity of saline-alkali land, irrigation and drainage measures are often used, but traditional leaching methods increase the consumption of freshwater resources, and the investment in salt drainage systems is large. Frequent water washing will also take away soil nutrients and organic matter, causing the soil environment to be barren and unfavorable for plant growth. Chemical measures only treat the symptoms and not the root cause. They are difficult to promote on a large scale and there is a risk of secondary pollution. Planting salt-alkali tolerant plants mostly contributes little to reducing the total amount of salt.

[0005] The invention patent with publication number: CN104115586B discloses a method for treating moderate to severe saline-alkali land, which uses a method of bulldozing-burying pipes to lay gravel layers-covering fertilizer-leveling-washing alkali to treat saline-alkali land; the invention patent with publication number: CN 114026984 B discloses a saline-alkali land improvement covering and leaching device and a saline-alkali land improvement engineering operation method, which uses a drip tank + covering and leaching + in-situ blasting deep loosening and compacted saline-alkali land operation method. In the prior art, saline-alkali land improvement is mainly carried out by engineering measures, water conservancy measures, and physical measures. The amount of work is large during the implementation process, and it will also cause problems such as decreased soil fertility and groundwater salinization.

[0006] Therefore, how to achieve an economically feasible method for improving saline-alkali land with good salt removal, blocking salt return, saving water resources, improving soil health and protecting water bodies remains a problem that urgently needs to be solved in this field. Summary of the invention

[0007] In order to solve the deficiencies of the prior art, the purpose of the present invention is to provide a microbial composition and method for improving saline-alkali land. Based on the formation characteristics of saline-alkali land, the present invention targets the key technical requirements for saline-alkali land improvement, and proposes a "cleaning, regulating and supplementing + planting" improvement method specifically for saline-alkali land, focusing on the three dimensions of "adapting superior varieties to soil, testing soil and matching bacteria, and improving soil and benefiting varieties". The microbial composition containing salt-tolerant and alkali-reducing bacteria can effectively improve the pH and salt content of saline-alkali land, increase crop emergence rate and yield, and is simple and easy to operate, with low investment, long-term effect, ecological and environmental protection, no secondary pollution, and high output in the year of improvement.

[0008] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0009] In the first aspect, the present invention provides a microbial composition for improving saline-alkali land, comprising a salt-clearing and alkali-adjusting bacterial agent, a bacterial supplement and a biological liquid fertilizer, wherein the salt-clearing and alkali-adjusting bacterial agent and the bacterial supplement contain a salt-tolerant and alkali-reducing bacterial group, and the salt-tolerant and alkali-reducing bacterial group includes one or more of Daban halobacillus NBL-BS214 and Bacillus subtilis 21c, wherein the deposit number of Daban halobacillus NBL-BS214 is CCTCC NO: 20221370, and the deposit number of Bacillus subtilis 21c is CCTCCM 2018565. In the second aspect, the present invention provides a method for improving saline-alkali land, characterized in that the microbial composition as described in the first aspect is used, and the method comprises the following steps:

[0010] S1. Soil analysis to detect soil pH, salt content and type, and soil aggregation structure;

[0011] S2. Deeply plow the soil, keeping the depth within the range from the tillage layer to the plow bottom layer, breaking up the compacted soil as much as possible to improve the soil structure;

[0012] S3, clear salt and adjust alkali, spread salt clearing and alkali adjusting bacteria agent, till the soil and mix it evenly, harrow the land and then irrigate it;

[0013] S4, supplement high-quality bacteria, dilute the supplement and irrigate the soil;

[0014] S5, sowing crops;

[0015] S6. Adjust the soil and add bacteria, and apply bacterial supplements and biological liquid fertilizers during the crop growth period.

[0016] The beneficial effects achieved by one or more technical solutions of the present invention are as follows:

[0017] The microbial composition for improving saline-alkali land of the present invention comprises a salt-clearing and alkali-adjusting bacterial agent, a bacterial supplement, and a biological liquid fertilizer, wherein the salt-clearing and alkali-adjusting bacterial agent and the bacterial supplement contain salt-tolerant and alkali-reducing bacterial groups that are halophilic, salt-tolerant, can absorb salt, adjust alkali, improve soil and produce high amounts of organic acids, and the biological liquid fertilizer contains a composite effective microbial group that can improve soil structure, block salt return, fertilize soil, increase soil microbial abundance, activate soil microbial status and prevent and control diseases.

[0018] The use of the improved composition and method of the present invention can effectively reduce soil pH and salt content, significantly improve soil physical and chemical properties, and significantly increase crop emergence rate and yield.

[0019] Compared with traditional saline-alkali land improvement methods, the method provided by the present invention is simple and easy to operate, requires little investment, is long-lasting, environmentally friendly, and has no secondary pollution. The output in the year of improvement is high, and the method is suitable for application in agricultural production in moderately to severely saline-alkali areas around the Bohai Sea and areas with water shortages.

[0020] The present invention first utilizes salt-tolerant and halophilic microorganisms to absorb and clean the salt in the soil, utilizes metabolites such as organic acids secreted by microorganisms to adjust the acidity and alkalinity of saline-alkali land, and performs salt removal and alkali adjustment according to the degree of salinity, balances the pH and reduces the salt content. On this basis, a supplementary bacterial agent is added to block the return of saline-alkali components on the one hand, and on the other hand, soil fertility is improved, plant resistance to stress is improved, and soil microecology is improved by promoting growth and breeding of biocontrol strains. Sowing crops after the above-mentioned step-by-step implementation can achieve better results, reduce salt stress, increase crop emergence rate, promote crop growth, and increase crop yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] Figure 1 The photos are of corn seedling emergence in the control group, experimental group 1 and experimental group 2 in Example 1;

[0023] Figure 2 These are photos of wheat growth in the control group and experimental group in Example 2. DETAILED DESCRIPTION

[0024] A first typical embodiment of the present invention is a microbial composition for improving saline-alkali land, comprising a salt-clearing and alkali-adjusting bacterial agent, a bacterial supplement and a biological liquid fertilizer, wherein the salt-clearing and alkali-adjusting bacterial agent and the bacterial supplement contain a salt-tolerant and alkali-reducing bacterial group, and the salt-tolerant and alkali-reducing bacterial group includes one or more of Daban halobacillus NBL-BS214 and Bacillus subtilis 21c. The deposit number of Daban halobacillus NBL-BS214 is CCTCC NO: 20221370, and the deposit number of Bacillus subtilis 21c is CCTCC M 2018565.

[0025] In one or more embodiments of this implementation mode, the salt-removing and alkali-regulating bacterial agent is a granule or powder, and is composed of the following ingredients: in parts by mass, salt-tolerant and alkali-reducing bacterial group ≥ 2 billion / g, 50-80 parts of zeolite powder, 5-30 parts of humic acid, 1-5 parts of polyacrylamide, 1-5 parts of citric acid, and 10-30 parts of adhesive.

[0026] Preferably, the adhesive includes one or two or more of maltodextrin, glucose and bentonite.

[0027] In one or more embodiments of this embodiment, the bacterial supplement is a powder composed of the following components: by mass, salt-tolerant and alkali-reducing bacterial group ≥ 10 billion / g, 30-60 parts of potassium humate, 1-10 parts of biopolymer materials, 1-10 parts of trace elements, and the total amount is supplemented by glucose to 100 parts.

[0028] Preferably, the biopolymer material includes one or two of γ-polyglutamic acid, polyaspartic acid, and amino oligosaccharides.

[0029] Preferably, the trace elements include one or more of methionine zinc, methionine manganese, EDTA iron, EDTA manganese, and EDTA zinc.

[0030] In one or more examples of this implementation mode, the biological liquid fertilizer is prepared by mixed fermentation of a composite effective microbial community and biological source organic matter, the total number of effective live bacteria in the biological liquid fertilizer is ≥ 200 million / mL, and the organic matter is ≥ 20%.

[0031] The composite effective microbial community includes one or more of Bacillus subtilis 4(2), Bacillus dasaka halobacterium NBL-BS214, Bacillus amyloliquefaciens 44, yeast, and lactic acid bacteria. The preservation number of Bacillus subtilis 4(2) is CCTCC M 2018563, the preservation number of Bacillus dasaka halobacterium NBL-BS214 is CCTCC NO: 20221370, and the preservation number of Bacillus amyloliquefaciens 44 is CCTCC M 2018564.

[0032] Preferably, the added amount of the biogenic organic matter is 1%-10% of the mass of the biological liquid fertilizer, and the biogenic organic matter includes one or more of biochemical fulvic acid dry powder, liquid molasses, and molasses powder.

[0033] A second typical embodiment of the present invention is a method for improving saline-alkali land, using the microbial composition as described in the first typical embodiment, comprising the following steps:

[0034] S1. Soil analysis to detect soil pH, salt content and type, and soil aggregation structure;

[0035] S2. Deeply plow the soil, keeping the depth within the range from the tillage layer to the plow bottom layer, breaking up the compacted soil as much as possible to improve the soil structure;

[0036] S3, salt removal and alkali reduction, spread salt removal and alkali adjustment bacteria, till the soil and mix it evenly, harrow the land and then irrigate it;

[0037] S4, supplement high-quality bacteria, dilute the supplement and irrigate the soil;

[0038] S5, sowing crops;

[0039] S6. Adjust the soil and add bacteria, and apply bacterial supplements and biological liquid fertilizers during the crop growth period.

[0040] In one or more examples of this implementation mode, in step S3, the dosage of the salt-clearing and alkali-adjusting bacterial agent is 10-100 kg / mu.

[0041] In one or more examples of this implementation mode, in step S4, the dilution multiple of the bacterial supplement is 500-1000 times.

[0042] In one or more examples of this implementation mode, in step S4, the dosage of the microbial supplement is 1-5 kg / mu.

[0043] In one or more examples of this implementation mode, in step S6, the dosage of the bacterial supplement agent is 1-5 kg / mu, and the dosage of the biological liquid fertilizer is 1-100 L / mu.

[0044] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in combination with specific embodiments and comparative examples.

[0045] Example 1

[0046] The microbial composition for improving saline-alkali land used in this embodiment is as follows:

[0047] The salt-removing and alkali-adjusting bacterial agent is a granule composed of the following ingredients: by mass, 2 parts of salt-tolerant and alkali-reducing bacteria (Daban Halophilic Bacillus NBL-BS214: Bacillus subtilis 21c=1:1, with a total live bacteria count of 2 billion / g), 62 parts of zeolite powder, 15 parts of humic acid, 2 parts of anionic polyacrylamide (PAM), 4 parts of citric acid, and 15 parts of maltodextrin.

[0048] The microbial supplement is a powder composed of the following components: by mass, 10 parts of salt-tolerant and alkali-reducing bacteria (Daban Halophilic Bacillus NBL-BS214: Bacillus subtilis 21c=1:1, with a total viable count of 10 billion / g), 50 parts of potassium humate, 2 parts of γ-polyglutamic acid, 2 parts of amino oligosaccharides, 1 part of methionine zinc, 1 part of methionine manganese, and the rest is made up to 100 parts by glucose.

[0049] The biological liquid fertilizer is prepared by mixed fermentation of Bacillus subtilis 4(2) (B. subtilis, with a preservation number of CCTCC M 2018563), Halobacillus dabanensis strain NBL-BS214 (Halobacillus dabanensis strain, with a preservation number of CCTCC NO: 20221370), Bacillus amyloliquefaciens 44 (B. amyloliquefaciens, with a preservation number of CCTCC M 2018564), yeast, and lactic acid bacteria, with molasses powder accounting for 5% of the total weight of the biological liquid fertilizer, the total number of viable bacteria being ≥200 million / mL, and organic matter being 20%.

[0050] The experimental site was Wudi County, Binzhou. The experimental land was severely saline-alkali land with severe soil compaction. After improvement, corn Nongda 372 was planted. Three treatments were set up in the experiment, marked as control group, experimental group 1, and experimental group 2.

[0051] The control group was modified according to the following steps:

[0052] 1) Soil analysis: Detect soil pH, salt content and type, and soil aggregation structure.

[0053] 2) Deep plowing. Keep the depth within the range from the tillage layer to the plow bottom layer, break up the compacted soil as much as possible and improve the soil structure.

[0054] 3) Plough the soil, harrow the land and then water it.

[0055] 4) Plant corn and carry out normal fertilization management in the field.

[0056] Experimental group 1 was modified according to the following steps:

[0057] 1) Soil analysis: Detect soil pH, salt content and type, and soil aggregation structure.

[0058] 2) Deep plowing. Keep the depth within the range from the tillage layer to the plow bottom layer, break up the compacted soil as much as possible and improve the soil structure.

[0059] 3) Salt removal and alkali adjustment. 35 days before sowing, spread 25 kg of salt removal and alkali adjustment bacteria, till the soil and mix evenly, reduce the salt content of the soil, and adjust the pH. After raking the land, water and irrigate to fully integrate the soil conditioner in the soil, improve the soil structure, block the return of salt, fertilize the soil, and provide sufficient nutrients for the growth of crops.

[0060] 4) Supplement high-quality bacteria. Dilute 1kg of the supplement 500 times and water the soil 3 days before sowing to increase the abundance of soil microorganisms and activate the soil microecology.

[0061] 5) Planting corn.

[0062] 6) Soil adjustment and bacteria matching. Apply 25L of biological liquid fertilizer during the jointing period of corn to achieve a balanced soil-microorganism-plant synergistic interaction system and improve crop resistance. It improves soil structure, loosens the soil, increases nutrient utilization, prevents salt return, and also has the effect of preventing and controlling diseases.

[0063] Experimental group 2 was modified according to the following steps:

[0064] 1) Soil analysis: Detect soil pH, salt content and type, and soil aggregation structure.

[0065] 2) Deep plowing. Keep the depth within the range from the tillage layer to the plow bottom layer, break up the compacted soil as much as possible and improve the soil structure.

[0066] 3) Salt removal and alkali adjustment. 35 days before sowing, spread 50 kg of salt removal and alkali adjustment bacteria agent, till the soil and mix evenly, reduce the salt content of the soil, and adjust the pH. After raking the land, irrigate it to fully integrate the soil conditioner and bacterial fertilizer in the soil, improve the soil structure, block the return of salt, fertilize the soil, and provide sufficient nutrients for the growth of crops.

[0067] 4) Supplement high-quality bacteria. Dilute 2kg of the supplement 500 times and water the soil 3 days before sowing to increase the abundance of soil microorganisms and activate the soil microecology.

[0068] 5) Planting corn.

[0069] 6) Soil adjustment and bacteria matching. Apply 50L of biological liquid fertilizer and 2kg of bacterial supplement during the jointing period of corn to achieve a balanced soil-microorganism-plant synergistic interaction system and improve crop resistance. Improve soil structure, loosen the soil, increase nutrient utilization, prevent salt return, and also have the effect of preventing and controlling diseases.

[0070] The field fertilization management was consistent for all treatments.

[0071] The survey results of corn under different experimental treatments are shown in Table 1.

[0072] Table 1 Corn survey results

[0073]

[0074] After the above steps, soil pH and total salt content decreased to varying degrees, with soil pH decreasing by 0.39 and 0.71 units, and total salt content decreasing by 39.7% and 61.9%, respectively. The physical and chemical properties of the soil improved significantly. The emergence rate of the improved soil was 27.9% and 41.6% higher than that of the control group, and the yield per mu increased by 63.7% and 102%. Figure 1 As shown, the growth of corn in experimental groups 1 and 2 was significantly improved compared with the control group.

[0075] Example 2

[0076] The microbial composition for improving saline-alkali land used in this embodiment is as follows:

[0077] The salt-removing and alkali-adjusting bacterial agent is a powder composed of the following ingredients: by mass, 3 parts of salt-tolerant and alkali-reducing bacteria (Daban Halophilic Bacillus NBL-BS214: Bacillus subtilis 21c=1:1, total viable count ≥2 billion / g), 60 parts of zeolite powder, 20 parts of humic acid, 5 parts of anionic polyacrylamide (PAM), 2 parts of citric acid, and 10 parts of glucose.

[0078] The microbial supplement is a powder composed of the following components: by mass, 12 parts of salt-tolerant and alkali-reducing bacteria (Daban Halophilic Bacillus NBL-BS214: Bacillus subtilis 21c=1:1, total viable count ≥10 billion / g), 50 parts of potassium humate, 5 parts of amino oligosaccharides, 1 part of methionine zinc, 2 parts of methionine manganese, and 100 parts of glucose are supplemented.

[0079] The biological liquid fertilizer is prepared by mixed fermentation of Bacillus subtilis 4(2) (B.subtilis, CCTCCM 2018563), Halobacillus dabanensis strain NBL-BS214 (Halobacillus dabanensis strain, with a preservation number of CCTCC NO: 20221370), Bacillus amyloliquefaciens 44 (B.amyloliquefaciens, with a preservation number of CCTCC M 2018564), yeast, and lactic acid bacteria, with molasses powder accounting for 5% of the total weight of the biological liquid fertilizer, and the total number of viable bacteria is ≥200 million / mL, and the organic matter is 20%.

[0080] The experimental site was Gaoqing County, Zibo City. The experimental land was severely saline-alkali land, which was improved and planted with Jimai 22. There were two treatments in the experiment, namely the control group and the experimental group.

[0081] The control group was modified according to the following steps:

[0082] 1) Soil analysis: Detect soil pH, salt content and type, and soil aggregation structure.

[0083] 2) Deep plowing. Keep the depth within the range from the tillage layer to the plow bottom layer, break up the compacted soil as much as possible and improve the soil structure.

[0084] 3) Plough the soil, harrow the land and then water it.

[0085] 4) Sowing wheat.

[0086] The experimental group was improved according to the following steps:

[0087] 1) Soil analysis: Detect soil pH, salt content and type, and soil aggregation structure.

[0088] 2) Deep plowing. Keep the depth within the range from the tillage layer to the plow bottom layer, break up the compacted soil as much as possible and improve the soil structure.

[0089] 3) Salt removal and alkali adjustment. Apply 25 kg of salt removal and alkali adjustment bacteria 30 days before sowing, till the soil and mix evenly, reduce the salt content of the soil, and adjust the pH. After raking the land, irrigate the soil to fully integrate the soil conditioner and bacterial fertilizer in the soil, improve the soil structure, block the return of salt, fertilize the soil, and provide sufficient nutrients for the growth of crops.

[0090] 4) Supplement high-quality bacteria. Dilute 2kg of the supplementary bacteria agent 500 times and water it 2 days before sowing to increase the abundance of soil microorganisms and activate the soil microbial state.

[0091] 5) Sowing wheat.

[0092] 6) Soil adjustment and bacteria matching. Apply 25L of biological liquid fertilizer and 2kg of bacterial supplement during the wheat greening period to achieve a balanced soil-microorganism-plant synergistic interaction system and improve crop resistance. Improve soil structure, loosen the soil, increase nutrient utilization, prevent salt return, and also have the effect of preventing and controlling diseases.

[0093] The field fertilization management was consistent for all treatments.

[0094] The survey results of wheat under different experimental treatments are shown in Table 2.

[0095] Table 2 Wheat survey results

[0096]

[0097]

[0098] The control group suffered from salt damage, seedling shortage, seedling burn, and yellowing. Wheat was missing seedlings and ears, grew weakly, matured late and unevenly. After the above steps were followed, the salinity of the soil was reduced in the year of improvement, the pH was reduced by 0.76, and the salt content was reduced by 51.6%, alleviating the salt stress of wheat. The wheat seeds in the experimental group had a high and uniform germination rate, no salinization damage during the entire growth period, grew vigorously, the wheat ears were neat and full, and the yield increased by 78.2% compared with the control group. Figure 2 As shown, the wheat growth in the experimental group was significantly improved compared with the control group.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A microbial composition for improving saline-alkali land, characterized in that: The invention comprises a salt-clearing and alkali-adjusting bacteria agent, a bacterial supplement agent and a biological liquid fertilizer, wherein the salt-clearing and alkali-adjusting bacteria agent and the bacterial supplement agent contain a salt-tolerant and alkali-reducing bacteria group, wherein the salt-tolerant and alkali-reducing bacteria group is Daban halobacillus NBL-BS214 and Bacillus subtilis 21c, wherein the deposit number of Daban halobacillus NBL-BS214 is CCTCCNO: 20221370, and the deposit number of Bacillus subtilis 21c is CCTCC M 2018565; The salt-removing and alkali-adjusting bacterial agent is a granule or powder, and is composed of the following components: by weight, the total viable count of salt-tolerant and alkali-reducing bacterial group is ≥ 2 billion / g, 50-80 parts of zeolite powder, 5-30 parts of humic acid, 1-5 parts of polyacrylamide, 1-5 parts of citric acid, and 10-30 parts of a binder; The bacterial supplement is a powder, which is composed of the following components: by weight, the total viable bacteria count of salt-tolerant and alkali-reducing bacteria group is ≥ 10 billion / g, 30-60 parts of potassium humate, 1-10 parts of biopolymer materials, 1-10 parts of trace elements, and the total amount is supplemented by glucose to 100 parts; The biological liquid fertilizer is prepared by adding a composite effective microbial community to biological source organic matter and mixing and fermenting, the total number of effective live bacteria in the biological liquid fertilizer is ≥ 200 million / mL, and the organic matter is ≥ 20%; The composite effective microbial community includes one or more of Bacillus subtilis 4(2), Bacillus dasaka halobacterium NBL-BS214, Bacillus amyloliquefaciens 44, yeast, and lactic acid bacteria. The deposit number of Bacillus subtilis 4(2) is CCTCCM 2018563, the deposit number of Bacillus dasaka halobacterium NBL-BS214 is CCTCC NO: 20221370, and the deposit number of Bacillus amyloliquefaciens 44 is CCTCC M 2018564.

2. The microbial composition according to claim 1, characterized in that The binder includes one or more of maltodextrin, glucose and bentonite.

3. The microbial composition according to claim 1, characterized in that The biopolymer material includes one or two of gamma-polyglutamic acid, polyaspartic acid and amino oligosaccharides.

4. The microbial composition according to claim 1, characterized in that The trace elements include one or more of methionine zinc, methionine manganese, EDTA iron, EDTA manganese, and EDTA zinc.

5. The microbial composition according to claim 1, characterized in that The added amount of the biological source organic matter is 1%-10% of the mass of the biological liquid fertilizer, including one or more of biochemical fulvic acid dry powder, liquid molasses, and molasses powder.

6. A method for improving saline-alkali land, characterized in that: Using the microbial composition according to any one of claims 1 to 5 comprises the following steps: S1. Soil analysis to detect soil pH, salt content and type, and soil aggregation structure; S2. Deeply plow the soil, keeping the depth within the range from the tillage layer to the plow bottom layer, breaking up the compacted soil as much as possible to improve the soil structure; S3, clear salt and adjust alkali, spread salt clearing and alkali adjusting bacteria agent, till the soil and mix it evenly, harrow the land and then irrigate it; S4, supplement high-quality bacteria, dilute the supplement and irrigate the soil; S5, sowing crops; S6. Adjust the soil and add bacteria, and apply bacterial supplements and biological liquid fertilizers during the crop growth period.

7. The method according to claim 6, characterized in that In step S3, the dosage of the salt-removing and alkali-adjusting bacterial agent is 10-100 kg / mu.

8. The method according to claim 6, characterized in that In step S4, the dilution multiple of the bacterial supplement is 500-1000 times.

9. The method according to claim 6, characterized in that In step S4, the dosage of the bacterial supplement is 1-5 kg / mu.

10. The method according to claim 6, characterized in that In step S6, the dosage of the bacterial supplement agent is 1-5 kg / mu, and the dosage of the biological liquid fertilizer is 1-100 L / mu.

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