Saline-alkali soil conditioner as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of soil improvement, and particularly relates to a saline-alkali soil conditioner as well as a preparation method and application thereof. The saline-alkali soil conditioner is a compound microbial agent for saline-alkali soil improvement. The compound microbial agent is prepared by jointly mixing and fermenting a seed solution of lactobacillus acidophilus, a seed solution of lactobacillus casei and a seed solution of streptococcus thermophilus; the volume ratio of the seed solution of the lactobacillus acidophilus to the seed solution of the lactobacillus casei to the seed solution of the streptococcus thermophilus is 1: (0.8-1.2): (0.8-1.2). The saline-alkali soil conditioner provided by the invention has the characteristics of quickly reducing alkaline harm of saline-alkali soil, promoting crop growth, improving nutrient absorption and utilization, improving microbial diversity and functional activity of soil, and being easy to apply, low in cost, quick in effect and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil improvement, and particularly relates to a saline-alkali soil conditioner, a preparation method thereof and an application thereof. Background Art

[0002] Saline-alkali soil is usually damaged by both soil salt and alkali, and reducing the pH value of saline-alkali soil is the core task of saline-alkali soil improvement. A large amount of salt ions such as Ca 2+ , Mg 2+ , K + , Na + , Cl - , CO3 2- and HCO3 - are aggregated in saline-alkali soil. These salt ions are redistributed in the horizontal or vertical direction of the soil, causing salts to gradually accumulate on the soil surface, which affects the normal growth of plants. Under such conditions, the saline-alkali soil becomes compacted, the soil porosity decreases accordingly, and the air permeability and water permeability become worse and worse, affecting the growth, abundance, metabolism of functional microorganisms in the soil and the activity of soil enzymes, and reducing the conversion rate of soil organic matter. Soil salinization destroys the soil structure, reduces the soil fertility, changes the soil animal community structure, and affects the absorption and metabolism functions of plants. Soil salinization hinders the development of China's agricultural production. The continuous increase in the area of saline-alkali soil results in a reduction in the cultivated land area, and the ecological balance is seriously affected. Therefore, improving saline-alkali soil has become an urgent problem to be solved.

[0003] At present, the improvement and treatment models, experience and technologies for saline-alkali land are divided into the following four aspects: physical improvement, chemical improvement, water conservancy improvement, and biological improvement. Physical improvement refers to improving the soil structure to achieve a scientific and appropriate balance between the salt and water in the soil, ultimately enabling the salt to transfer downward and not accumulate on the surface. For example, loosening, leveling, and replacing the soil of the land. Chemical improvement refers to applying scientific modifiers and appropriate dosages to adjust alkaline soil, thereby reducing the alkalinity of the soil and improving soil fertility. Commonly used chemical modifiers include sulfur-containing materials and carbon-containing materials. Sulfur-containing materials include: desulfurized gypsum, sulfur, aluminum sulfate, and ferrous sulfate, etc. Carbon-containing materials include: biochar, straw, and weathered coal, etc. Water conservancy improvement mainly regulates drainage and irrigation to enable the timely discharge of salt in the planting soil layer. For example, digging drainage ditches, flushing the salt with water, etc. Biological improvement uses the metabolism and growth of plants and microorganisms to transfer salt ions in the soil, thereby improving the quality of the soil. For example, plants such as Suaeda glauca, Tamarix chinensis, and Atriplex patens, etc., and the application of microbial bacterial fertilizers. In summary, the current improvement of saline-alkali soil mainly adopts traditional saline-alkali land improvement measures such as physical improvement, water conservancy improvement, and chemical improvement. These traditional saline-alkali land improvement measures have problems such as high input, large project volume, long time cycle, and slow effect, and are more suitable for the improvement of severely saline-alkali land with rich funds, flat terrain, and good basic conditions for salt and alkali drainage. For moderately and slightly saline-alkali land distributed in inland areas, facing characteristics such as shortage of fresh water resources, scarce precipitation, and extremely fragile ecology, in the context of generally adopting water-saving irrigation and precise improvement of the root zone of saline-alkali land crops, it is difficult to meet the technical requirements for drip irrigation and precise reduction of alkaline hazards in the root zone during the improvement of saline-alkali land by using the above traditional saline-alkali land improvement measures. Therefore, it is necessary to develop a fully water-soluble saline-alkali land modifier for the soil improvement of moderately and slightly alkaline land.

[0004] Research on the use of functional lactic acid bacteria preparations for farmland soil improvement has been reported, mainly for passivating heavy metals, degrading pesticide residues, and inhibiting the proliferation of pathogenic and spoilage bacteria. The method of using functional lactic acid bacteria preparations for farmland soil improvement can solve the defect that the above traditional saline-alkali land improvement measures are difficult to meet the technical requirements for precise reduction of drip irrigation and alkaline hazards in the root zone during the improvement of saline-alkali land, and can be used for the soil improvement of moderately and slightly alkaline land located inland.

[0005] At present, the relevant patents that have been applied for mainly use lactic acid bacteria as the active strain, and compound other materials to prepare improved preparations for saline-alkali soil improvement. For example, the Chinese patent with the application number CN202510039803 discloses a multifunctional soil conditioner for improving saline-alkali soil, its preparation method and application; the Chinese patent with the application number CN202411603210 discloses a composite saline-alkali soil improvement composition based on biochar and its preparation method; the Chinese patent with the application number CN202410884392 discloses a saline-alkali soil conditioner. These improved preparations for saline-alkali soil improvement have the problems of not being completely soluble in water, not meeting the requirements of drip irrigation or being prone to clogging drip irrigation pipes. Summary of the Invention

[0006] To solve the problems that the improved preparations for saline-alkali soil improvement in the prior art cannot be completely dissolved in water, cannot meet the requirements of drip irrigation or are prone to clogging drip irrigation pipes, and to achieve the above object, the present invention adopts the following technical solutions.

[0007] The present invention provides a saline-alkali soil conditioner, and the saline-alkali soil conditioner is a composite microbial inoculant for saline-alkali soil improvement.

[0008] The composite microbial inoculant is formed by co-mixing and fermenting the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus.

[0009] The volume ratio of the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus is 1:0.8 - 1.2:0.8 - 1.2.

[0010] The saline-alkali soil conditioner provided by the present invention utilizes three strains, Lactobacillus acidophilus, Lactobacillus casei, and Streptococcus thermophilus, to carry out mixed fermentation in a sealed and light-proof environment. The fermented liquid obtained by fermentation contains organic acids, antibacterial peptides, polypeptides, microbial proteins, small molecule carbon and other substances, and finally forms a composite microbial inoculant that is completely water-soluble and strongly acidic. This composite microbial inoculant can be completely dissolved in water, can be watered by drip irrigation, and directly send the composite microbial inoculant to the roots of crops along with water, without causing clogging of drip irrigation pipes.

[0011] First of all, the organic acid substances in the composite microbial inoculant can neutralize the OH− ions in the root zone of crops, thereby quickly reducing the alkaline harm in the root zone of crops, promoting the release of nutrients such as nitrogen, phosphorus, and potassium that are difficult to dissolve in the soil, and then improving the effectiveness of nutrients in the soil in the root zone of crops. In addition, the composite microbial inoculant is rich in nutrients such as polypeptides, antibacterial peptides, and small molecule carbon, which can enhance the diversity and functional activity of rhizosphere microorganisms of crops, improve the ability of crop roots to absorb nitrogen, phosphorus, and potassium nutrients in the soil, and then increase crop yields.

[0012] The present invention also provides a preparation method of the saline-alkali soil conditioner, comprising the following steps: The seed liquid of the Lactobacillus acidophilus, the seed liquid of the Lactobacillus casei and the seed liquid of the Streptococcus thermophilus are jointly added to the same lactic acid bacteria culture medium to obtain a mixed liquid.

[0013] The mixed liquid is subjected to mixed fermentation under dark conditions.

[0014] When the pH of the bacterial liquid after mixed fermentation is below 4.5, the bacterial liquid after mixed fermentation is collected to obtain the saline-alkali soil conditioner.

[0015] Preferably, the volume ratio of the seed liquid of the Lactobacillus acidophilus, the seed liquid of the Lactobacillus casei and the seed liquid of the Streptococcus thermophilus is 1:1:1.

[0016] Preferably, the viable bacteria count in the seed liquid of the Lactobacillus acidophilus, the seed liquid of the Lactobacillus casei and the seed liquid of the Streptococcus thermophilus all reaches more than 80 million / mL.

[0017] Preferably, the percentage of the seed liquid of the Lactobacillus acidophilus, the seed liquid of the Lactobacillus casei and the seed liquid of the Streptococcus thermophilus in the volume of the lactic acid bacteria culture medium is all 3% - 7%.

[0018] Preferably, the lactic acid bacteria culture medium is composed of the following materials at the final concentrations: active nitrogen source 9.8 g / L - 10.2 g / L, beef extract 4.8 g / L - 5.2 g / L, yeast extract 3.8 g / L - 4.2 g / L, active carbon source 19.8 g / L - 20.2 g / L, dipotassium hydrogen phosphate 1.8 g / L - 2.2 g / L, ammonium citrate 1.8 g / L - 2.2 g / L, sodium acetate 4.8 g / L - 5.2 g / L, magnesium sulfate 0.18 g / L - 0.22 g / L, manganese sulfate 0.048 g / L - 0.052 g / L, Tween 80 0.8 g / L - 1.2 g / L, and the solvent is water.

[0019] The active nitrogen source includes any one of peptone, soy peptone and tryptone.

[0020] The active carbon source includes any one of glucose, molasses and edible brown sugar.

[0021] In the present invention, specifically aiming at the problem of soil alkalinity hazard faced in the process of inland saline-alkali land treatment, by establishing a low-cost and high-efficiency culture medium to directionally regulate functional lactic acid bacteria to continuously produce active metabolites, rapid and precise reduction of the alkalinity hazard in the root zone of saline-alkali land crops is achieved, which is a fully water-soluble measure for saline-alkali land soil improvement. Therefore, for inland moderately and slightly saline-alkali lands with water shortage, a low-cost, easy-to-use, quick-acting and drip-irrigation-useable microbial improver is invented to achieve cost reduction and efficiency improvement in the improvement of moderately and slightly saline-alkali lands, so as to rapidly improve moderately and slightly saline-alkali lands and increase crop production capacity.

[0022] Preferably, the time for the mixed fermentation is 3 days to 5 days; the temperature for the mixed fermentation is 20°C to 35°C.

[0023] The present invention also provides an application of a saline-alkali land soil improver in the improvement of saline-alkali land soil.

[0024] Preferably, the saline-alkali land soil improver is directly applied.

[0025] Preferably, the application rate of the saline-alkali land soil improver is 80 L / mu to 120 L / mu.

[0026] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention provides a saline-alkali land soil improver, which uses Lactobacillus acidophilus (from China General Microbiological Culture Collection Center, strain number: CGMCC No. 26888), Lactobacillus casei (from China General Microbiological Culture Collection Center, strain number: CGMCC No. 26585), and Streptococcus thermophilus (from China General Microbiological Culture Collection Center, strain number: CGMCC No. 25311) strains as functional strains. Using Lactobacillus acidophilus to generate and release fully water-soluble organic acids such as lactic acid and acetic acid, using Lactobacillus casei to transform and generate fully water-soluble lactic acid and polypeptides, and inhibiting other harmful bacteria in the culture solution, using Streptococcus thermophilus to transform and generate fully water-soluble small molecule carbons such as galactose, glucose, and fructose, making full use of the proliferation, fission and metabolic characteristics of the three kinds of bacteria, with complementary advantages and synergistic cooperation, to generate a fully water-soluble saline-alkali land soil improver rich in lactic acid, lactate, antibacterial peptides, organic acids, etc. The components in this fully water-soluble saline-alkali land soil improver can all dissolve in water, and can be sent directly to the roots of crops along with water through drip irrigation, without causing blockage of the drip irrigation belt, solving the problems in the prior art that the improvement preparations for saline-alkali land soil improvement cannot all dissolve in water, cannot meet drip irrigation requirements or are prone to causing blockage of the drip irrigation belt.

[0027] 2. The present invention provides a liquid and low-cost saline-alkali soil conditioner rich in various functional species, which can reduce the soil pH of saline-alkali soil and supplement active small-molecule carbon sources to mitigate the alkaline hazard of saline-alkali soil and improve crop production capacity. The saline-alkali soil conditioner is based on a lactic acid bacteria culture medium (its components are: peptone 10.0 g / L (or replaced with soy peptone, tryptone), beef extract 5.0 g / L, yeast extract 4.0 g / L, glucose 20.0 g / L (or replaced with molasses, edible brown sugar), dipotassium hydrogen phosphate 2.0 g / L, ammonium citrate 2.0 g / L, sodium acetate 5.0 g / L, magnesium sulfate 0.2 g / L, manganese sulfate 0.05 g / L, Tween (80) 1.0 g / L, and tap water or clean groundwater is added according to the required amount in proportion). The saline-alkali soil conditioner prepared from the functional lactic acid bacteria liquid prepared by using the above strains and lactic acid bacteria culture medium not only has a good effect on mitigating the alkaline hazard of saline-alkali soil, but also can improve the composition and diversity of soil microbial communities, and has good economic and ecological benefits.

[0028] 3. A saline-alkali soil conditioner provided by the present invention uses 9 materials including active nitrogen source, active carbon source, dipotassium hydrogen phosphate, ammonium citrate, sodium acetate, magnesium sulfate, manganese sulfate and Tween 80. After adding water and dissolving them, a basic culture solution is prepared. Then, three strains of Lactobacillus acidophilus, Lactobacillus casei and Streptococcus thermophilus are inoculated into the basic culture solution. In a sealed and light-proof environment, the three strains grow and reproduce in the basic culture solution, decomposing, synthesizing and transforming the 9 materials into organic acids, antibacterial peptides, polypeptides, cell body proteins, small-molecule carbon and other substances, and finally forming a completely water-soluble and strongly acidic compound microbial agent. By drip irrigation, the compound microbial agent is directly sent to the roots of crops along with water. On the one hand, the organic acid substances in the compound microbial agent can neutralize the OH − ions, thus quickly mitigating the alkaline hazard in the root zone of crops, promoting the release of nutrients such as nitrogen, phosphorus and potassium that are difficult to dissolve in the soil, and further improving the effectiveness of nutrients in the soil in the root zone of crops; in addition, the compound microbial agent is rich in nutrients such as polypeptides, antibacterial peptides and small-molecule carbon, which can enhance the diversity and functional activity of rhizosphere microorganisms of crops, improve the ability of crop roots to absorb nitrogen, phosphorus and potassium nutrients in the soil, and further increase crop yields.

[0029] 4. The main component of the saline-alkali soil conditioner provided by the present invention is the fermentation metabolite of completely water-soluble microorganisms. The saline-alkali soil conditioner can be drip-irrigated or flushed, and the application method can be adjusted according to actual needs.

[0030] 5. The saline-alkali soil conditioner provided by the present invention is rich in various lactic acids and organic acids, etc., which can quickly reduce the soil pH value of saline-alkali soil, and thus quickly reduce the harm of strong alkali in saline-alkali soil to crops.

[0031] 6. The saline-alkali soil conditioner provided by the present invention is rich in highly active lactic acid bacteria strains. After being applied to the soil, it can continuously regulate the pH of the saline-alkali soil, enhance the release of nutrients such as nitrogen, phosphorus, and potassium in the soil, and promote the absorption and utilization of nitrogen, phosphorus, potassium, and trace elements by crop roots.

[0032] 7. The saline-alkali soil conditioner provided by the present invention is rich in various active substances such as antibacterial peptides, polypeptides, bioenzymes, and small molecule carbon. On the one hand, it can inhibit the growth of some harmful soil microorganisms, thereby reducing the occurrence of plant diseases. On the other hand, it can cultivate and enhance the microbial diversity and functional activity in the rhizosphere of saline-alkali land crops, and further improve the growth and yield of crop roots.

[0033] 8. The saline-alkali soil conditioner provided by the present invention has the characteristics of quickly reducing the alkaline harm of saline-alkali land, promoting crop growth, improving nutrient absorption and utilization, enhancing soil microbial diversity and functional activity, being easy to apply, having low cost, and quick effect. Description of the Drawings

[0034] Figure 1 Shows the reduction effect of different embodiments of the present invention on soil pH; among them, Figure 1 in (a) is the change of soil pH after the first application of the saline-alkali land conditioner; Figure 1 in (b) is the change of soil pH after the second application of the saline-alkali land conditioner; among them, Example 1 refers to Embodiment 1, Example 2 refers to Embodiment 2, Example 3 refers to Embodiment 2, and Example 4 refers to Embodiment 4.

[0035] Figure 2 Shows the influence of different embodiments of the present invention on the yield of potatoes in saline-alkali land; among them, Example 1 refers to Embodiment 1, Example 2 refers to Embodiment 2, Example 3 refers to Embodiment 2, and Example 4 refers to Embodiment 4. Detailed Embodiments

[0036] The present invention will be described in detail below with reference to the drawings and specific embodiments, but it should not be construed as a limitation of the present invention. Unless otherwise specified, the technical means used in the following embodiments are conventional means well-known to those skilled in the art, and the materials, reagents, etc. used in the following embodiments can be obtained from commercial channels unless otherwise specified.

[0037] Embodiment 1 A saline-alkali soil conditioner is prepared by mixing and fermenting the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus together.

[0038] The volume ratio of the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus is 1:1:1.

[0039] The above saline-alkali soil conditioner is prepared according to the following method: 1) Prepare 2 L of the first-stage seed culture solution of Lactobacillus acidophilus, 2 L of the first-stage seed culture solution of Lactobacillus casei, and 2 L of the first-stage seed culture solution of Streptococcus thermophilus respectively.

[0040] The number of bacteria in the prepared first-stage seed culture solutions of Lactobacillus acidophilus, Lactobacillus casei, and Streptococcus thermophilus all reached 80 million / mL. The first-stage seed culture solution of Lactobacillus acidophilus is the seed solution of Lactobacillus acidophilus; the first-stage seed culture solution of Lactobacillus casei is the seed solution of Lactobacillus casei; the first-stage seed culture solution of Streptococcus thermophilus is the seed solution of Streptococcus thermophilus.

[0041] Among them, the preparation methods of the first-stage seed culture solutions of Lactobacillus acidophilus, Lactobacillus casei, and Streptococcus thermophilus are the same, and the method is as follows: (1) Weigh 3 portions of the culture medium raw materials. Each portion of the culture medium is composed of 20.0 g of peptone, 10.0 g of beef extract, 8.0 g of yeast extract, 40.0 g of glucose, 4.0 g of dipotassium hydrogen phosphate, 4.0 g of trisodium citrate, 10.0 g of sodium acetate, 0.4 g of magnesium sulfate, 0.10 g of manganese sulfate, and 2.0 g of Tween 80.

[0042] Transfer the weighed above-mentioned culture medium raw materials to 3 flasks with a capacity of 3 L respectively, add 2 L of pure water to dissolve the culture medium raw materials fully, and place them in an autoclave. Set the temperature to 120 °C and sterilize for 30 minutes. After cooling, reserve.

[0043] (2) In a sterile operating table, use a pipette gun to transfer the Lactobacillus acidophilus strain, Lactobacillus casei strain, and Streptococcus thermophilus strain to 3 flasks respectively, seal them immediately, and then transfer the 3 flasks to an incubator. Cultivate them in the dark at 26 °C for 72 hours to obtain the first-stage seed solutions of Lactobacillus acidophilus, Lactobacillus casei, and Streptococcus thermophilus respectively.

[0044] Among them, the number of bacteria in the first-stage seed culture solution of Lactobacillus acidophilus is 80 million / mL; the number of bacteria in the first-stage seed culture solution of Lactobacillus casei is 80 million / mL; the number of bacteria in the first-stage seed culture solution of Streptococcus thermophilus is 80 million / mL.

[0045] The Lactobacillus acidophilus strain is purchased from / sourced from the China General Microbiological Culture Collection Center, strain number: CGMCC No. 26888. The Lactobacillus casei strain is purchased from / sourced from the China General Microbiological Culture Collection Center, strain number: CGMCC No. 26585. The Streptococcus thermophilus strain is purchased from / sourced from the China General Microbiological Culture Collection Center, strain number: CGMCC No. 25311.

[0046] 2) Weigh 1000.0 g of tryptone, 500.0 g of beef extract, 400.0 g of yeast extract, 2000.0 g of edible brown sugar, 200.0 g of dipotassium hydrogen phosphate, 200.0 g of ammonium citrate, 500.0 g of sodium acetate, 20.0 g of magnesium sulfate, 5 g of manganese sulfate and 100.0 g of Tween 80 respectively, and mix them evenly to obtain the raw materials for the lactic acid bacteria culture medium.

[0047] 3) Add the obtained raw materials for the lactic acid bacteria culture medium into an opaque water storage bucket with a volume of 100 L, add 90 L of water, stir to fully dissolve the raw materials for the lactic acid bacteria culture medium, and then simultaneously introduce the first-stage seed bacterium solution of Lactobacillus acidophilus, the first-stage seed bacterium solution of Lactobacillus casei and the first-stage seed bacterium solution of Streptococcus thermophilus into the water storage bucket to obtain a mixed solution.

[0048] 4) When the temperature of the mixed solution is 26 °C, under sealed conditions, carry out mixed fermentation for 5 days.

[0049] 5) When the pH of the mixed solution reaches 4.5, collect the bacterium solution after mixed fermentation to obtain the saline-alkali soil conditioner.

[0050] Example 2 A saline-alkali soil conditioner is formed by co-mixed fermentation of the seed solution of Lactobacillus acidophilus, the seed solution of Lactobacillus casei and the seed solution of Streptococcus thermophilus.

[0051] The volume ratio of the seed solution of Lactobacillus acidophilus, the seed solution of Lactobacillus casei and the seed solution of Streptococcus thermophilus is 1:1:1.

[0052] The above-mentioned saline-alkali soil conditioner is prepared according to the following method: 1) Prepare 2 L of the first-stage seed bacterium solution of Lactobacillus acidophilus, 2 L of the first-stage seed bacterium solution of Lactobacillus casei and 2 L of the first-stage seed bacterium solution of Streptococcus thermophilus respectively.

[0053] The number of bacteria in the prepared first-stage seed bacterium solution of Lactobacillus acidophilus, the first-stage seed bacterium solution of Lactobacillus casei and the first-stage seed bacterium solution of Streptococcus thermophilus all reaches 800 million / mL The first-stage seed bacterium solution of Lactobacillus acidophilus is the seed solution of Lactobacillus acidophilus; the first-stage seed bacterium solution of Lactobacillus casei is the seed solution of Lactobacillus casei; the first-stage seed bacterium solution of Streptococcus thermophilus is the seed solution of Streptococcus thermophilus.

[0054] 2) Weigh 1000 g of soy peptone, 250.0 g of beef extract, 200.0 g of yeast extract, 2000 g of molasses, 100.0 g of dipotassium hydrogen phosphate, 100.0 g of ammonium citrate, 250.0 g of sodium acetate, 10 g of magnesium sulfate, 2.5 g of manganese sulfate and 50.0 g of Tween 80 respectively, and mix them evenly to obtain the raw materials for the lactic acid bacteria culture medium.

[0055] 3) Add the raw materials of the lactic acid bacteria culture medium obtained above into an opaque water storage bucket with a volume of 100 L. After adding 90 L of water, stir to fully dissolve the raw materials of the lactic acid bacteria culture medium. Then, simultaneously introduce the primary seed bacterium solution of Lactobacillus acidophilus, the primary seed bacterium solution of Lactobacillus casei, and the primary seed bacterium solution of Streptococcus thermophilus into the water storage bucket to obtain a mixed solution.

[0056] 4) When the temperature of the mixed solution is 26 °C, under sealed conditions, perform mixed fermentation for 5 days.

[0057] 5) When the pH of the mixed solution reaches 4.5, collect the bacterium solution after mixed fermentation to obtain the saline-alkali soil conditioner.

[0058] Example 3 A saline-alkali soil conditioner is formed by co-mixed fermentation of the seed solution of Lactobacillus acidophilus, the seed solution of Lactobacillus casei, and the seed solution of Streptococcus thermophilus; The volume ratio of the seed solution of Lactobacillus acidophilus, the seed solution of Lactobacillus casei, and the seed solution of Streptococcus thermophilus is 1:1:1.

[0059] The above saline-alkali soil conditioner is prepared according to the following method: 1) Respectively prepare 2 L of the primary seed bacterium solution of Lactobacillus acidophilus, 2 L of the primary seed bacterium solution of Lactobacillus casei, and 2 L of the primary seed bacterium solution of Streptococcus thermophilus.

[0060] The number of bacteria in the prepared primary seed bacterium solution of Lactobacillus acidophilus, the primary seed bacterium solution of Lactobacillus casei, and the primary seed bacterium solution of Streptococcus thermophilus all reaches 800 million / mL The primary seed bacterium solution of Lactobacillus acidophilus is the seed solution of Lactobacillus acidophilus; the primary seed bacterium solution of Lactobacillus casei is the seed solution of Lactobacillus casei; the primary seed bacterium solution of Streptococcus thermophilus is the seed solution of Streptococcus thermophilus.

[0061] 2) Respectively weigh 1000 g of soy peptone, 250.0 g of beef extract, 200.0 g of yeast extract, 2000 g of edible brown sugar, 100.0 g of dipotassium hydrogen phosphate, 100.0 g of ammonium citrate, 250.0 g of sodium acetate, 10 g of magnesium sulfate, 2.5 g of manganese sulfate, and 50.0 g of Tween 80, and mix them evenly to obtain the raw materials of the lactic acid bacteria culture medium.

[0062] 3) Add the raw materials of the lactic acid bacteria culture medium obtained above into an opaque water storage bucket with a volume of 100 L. After adding 90 L of water, stir to fully dissolve the raw materials of the lactic acid bacteria culture medium. Then, simultaneously introduce the primary seed bacterium solution of Lactobacillus acidophilus, the primary seed bacterium solution of Lactobacillus casei, and the primary seed bacterium solution of Streptococcus thermophilus into the water storage bucket to obtain a mixed solution.

[0063] 4) The mixed solution is fermented for 5 days under sealed conditions at an air temperature of 26°C.

[0064] 5) When the pH of the mixed solution reaches 4.5, collect the bacterial liquid after mixed fermentation to obtain the saline-alkali soil conditioner.

[0065] Example 4 A saline-alkali soil conditioner is prepared by co-fermenting the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus; The volume ratio of the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus is 1:1:1.

[0066] The above-mentioned saline-alkali soil conditioner is prepared by the following method: 1) Prepare 2 L of the first-stage seed bacterial liquid of Lactobacillus acidophilus, 2 L of the first-stage seed bacterial liquid of Lactobacillus casei, and 2 L of the first-stage seed bacterial liquid of Streptococcus thermophilus respectively.

[0067] The number of bacteria in the prepared first-stage seed bacterial liquid of Lactobacillus acidophilus, the first-stage seed bacterial liquid of Lactobacillus casei, and the first-stage seed bacterial liquid of Streptococcus thermophilus all reaches 800 million / mL.

[0068] The first-stage seed bacterial liquid of Lactobacillus acidophilus is the seed liquid of Lactobacillus acidophilus; the first-stage seed bacterial liquid of Lactobacillus casei is the seed liquid of Lactobacillus casei; the first-stage seed bacterial liquid of Streptococcus thermophilus is the seed liquid of Streptococcus thermophilus.

[0069] 2) Weigh 1000 g of tryptone, 250.0 g of beef extract, 200.0 g of yeast extract, 2000 g of glucose, 100.0 g of dipotassium hydrogen phosphate, 100.0 g of ammonium citrate, 250.0 g of sodium acetate, 10 g of magnesium sulfate, 2.5 g of manganese sulfate, and 50.0 g of Tween 80 respectively, and mix them evenly to obtain the raw materials of the lactic acid bacteria culture medium.

[0070] 3) Add the above-obtained raw materials of the lactic acid bacteria culture medium to an opaque water storage bucket with a volume of 100 L, add 90 L of water, stir to fully dissolve the raw materials of the lactic acid bacteria culture medium, and then simultaneously introduce the prepared first-stage seed bacterial liquid of Lactobacillus acidophilus, the first-stage seed bacterial liquid of Lactobacillus casei, and the first-stage seed bacterial liquid of Streptococcus thermophilus into the water storage bucket to obtain a mixed solution.

[0071] 4) The mixed solution is fermented for 5 days under sealed conditions at an air temperature of 26°C.

[0072] 5) When the pH of the mixed solution reaches 4.5, collect the bacterial liquid after mixed fermentation to obtain the saline-alkali soil conditioner.

[0073] In order to illustrate the effects of the saline-alkali soil conditioner provided by the present invention, the following research was conducted: Four saline-alkali soil conditioners prepared in Example 1, Example 2, Example 3, and Example 4 were used to carry out saline-alkali land improvement tests.

[0074] Among them, the saline-alkali land selected for the improvement test is located in Bainijing Town, Dingbian County, Yulin City, Shaanxi Province. The type of saline-alkali land is moderately saline-alkali land. On April 12, 2024, potatoes were planted, with the variety being Wotu No. 5. The seeding rate per mu was 4,200 plants. The ridging planting method was adopted, with a ridge width of 80 cm. After sowing, drip irrigation tapes were laid in the middle of the ridge top. There was a fertilization device in the field, including 4 water storage tanks (with a capacity of 1,000 L), 1 set of water pumps, and water delivery pipes and drip irrigation tapes distributed in the field. 40 L of the conditioner prepared according to different examples was poured into 4 water storage tanks respectively. After adding 760 L of water for dilution, drip irrigation and topdressing were carried out respectively. 4 test areas were selected in the same plot, with each test area having an area of 1 mu. In addition, a control area with an area of 1 mu was selected nearby in the plot.

[0075] At the beginning of May 2024, 40 L of each of the four saline-alkali soil conditioners prepared in Example 1, Example 2, Example 3, and Example 4 was respectively applied to 4 test areas through the farmland drip irrigation system. And at the beginning of June 2024, soil samples of each test area were collected for the first time. After the soil sample collection was completed, 40 L of the four saline-alkali soil conditioners was applied to the corresponding test areas for the second time. At the beginning of August 2024, soil samples of each test area were collected for the second time, and the potato tubers of each test area were harvested.

[0076] At the same time, in the control area, referring to the method of applying the bacterial agent, only 800 L of water was applied. The test in the control area was used as the control group.

[0077] The soil pH value is a benchmark index for quantitatively evaluating the acidity and alkalinity of the soil, that is, the higher the soil pH value, the stronger the alkalinity. Therefore, the soil pH values of the soil samples in each test area and the test areas of the control group collected above twice were respectively detected. At the same time, the potato tubers harvested from each test area and the test areas of the control group were harvested and the yields were measured, and the potato yields planted in each test area and the test areas of the control group were counted.

[0078] Among them, the detection method of the soil pH value is as follows: The soil samples collected from the test areas and the control group in each test area were passed through a 2-mm sieve and air-dried naturally. Then, according to the ratio of the mass of the soil sample to the volume of water at 1 g:2.5 mL, that is, 10 g of the air-dried soil sample was weighed and poured into a 50-mL beaker, and 25 mL of pure water was added to the beaker. After stirring evenly, it was left standing for 30 minutes to obtain the soil solution of the soil samples collected from the test areas of each test area and the control group for standby. Then, the glass electrode method was used for determination, that is, the glass probe of the pH meter was inserted into the soil solution of the soil samples collected from the test areas of each test area and the control group to read the values.

[0079] The calculation method of potato yield is as follows: The crops planted in the test areas of each test area and the control group were potatoes, and the planting method was ridge planting with a ridge width of about 80 cm. In the four test areas, potato plots with a ridge length of 10 m were selected respectively, and the total number of potato plants and the tuber weight in the statistical plots were counted to obtain the average yield per potato plant.

[0080] The results are as follows: 1. The reduction effect of different cases on the alkaline hazard of saline-alkali soil The reduction results of the saline-alkali soil improvers prepared by the four examples on the soil pH are as Figure 1 shown.

[0081] It can be seen from Figure 1 that the saline-alkali soil improvers prepared in Example 1, Example 2, Example 3 and Example 4 all have a certain effect on reducing the alkaline hazard of the soil. Among them, the saline-alkali soil improver prepared in Example 3 has the strongest reduction effect on the alkaline hazard of the soil. 30 days after the first application of the saline-alkali soil improver prepared in Example 3, the soil pH value decreased from 8.99 to 8.14; 30 days after the second application of the saline-alkali soil improver prepared in Example 3, the soil pH value decreased from 8.71 to 7.94. After two applications of the saline-alkali soil improver prepared in Example 3, the saline-alkali soil changed from strong alkalinity to weak alkalinity.

[0082] 2. The influence of different cases on the potato yield in saline-alkali soil The results of the saline-alkali soil improvers prepared by the four examples on improving the potato yield are as Figure 2 shown.

[0083] It can be seen from Figure 2It can be seen that the saline-alkali soil conditioners prepared in Example 1, Example 2, Example 3 and Example 4 all increase the yield of potatoes in saline-alkali land. By comparison, it is found that the saline-alkali soil conditioners prepared in Example 1, Example 2, Example 3 and Example 4 can all increase the yield of potatoes in saline-alkali land. Among them, the saline-alkali soil conditioner prepared in Example 3 has the most significant effect on improving the potato production capacity in saline-alkali land. After applying the saline-alkali soil conditioner prepared in Example 3 twice by flushing, the yield per potato plant increased from 1.04 kg to 1.60 kg.

[0084] From the above results, it can be known that after the saline-alkali soil conditioner provided by the present invention is applied, it can reduce the alkaline harm of saline-alkali soil and increase the potato yield. The saline-alkali soil conditioner provided by the present invention can directly reach the root zone of potato crops in saline-alkali farmland by means of small-flow drip irrigation (drip water volume 2 L / hour). It is rich in active substances such as organic acids, polypeptide galactose, glucose, and fructose, and can accurately and quickly reduce the alkaline harm of the soil in the root zone. Other saline-alkali soil conditioners that are not water-soluble are usually used as base fertilizers and are applied to saline-alkali farmland by means of extensive spreading during the tillage of saline-alkali land. They cannot be applied to farmland by means of small-flow drip irrigation, and the reduction effect on the alkaline harm of the root zone of saline-alkali crops is not accurate and efficient enough.

[0085] Therefore, the components in the fully water-soluble saline-alkali soil conditioner provided by the present invention can all dissolve in water, and the compound microbial inoculum can be directly sent to the roots of crops along with the water through drip irrigation without causing blockage of the drip irrigation belt, solving the problems in the prior art that the improvement preparations for saline-alkali soil improvement cannot all dissolve in water, cannot meet drip irrigation requirements or are prone to cause blockage of the drip irrigation belt.

[0086] It should be noted that when the present invention involves numerical ranges, it should be understood that any value between the two endpoints of each numerical range and the two endpoints can be selected. To prevent repetition, preferred embodiments of the present invention are described.

[0087] Although the preferred embodiments of the present invention have been described, once those skilled in the art learn the basic creative concept, additional changes and modifications can be made to these embodiments, and all such changes and modifications fall within the scope of the present invention.

Claims

1. A saline-alkali soil conditioner, characterized in that, The saline-alkali soil conditioner is a compound microbial inoculant for improving saline-alkali soil; The compound microbial inoculant is prepared by co-mixing and fermenting the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus; The volume ratio of the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus is 1: 0.8-1.2: 0.8-1.

2.

2. The preparation method of the saline-alkali soil conditioner according to claim 1, characterized in that, It includes the following steps: The seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus are added together to the same lactic acid bacteria culture medium to obtain a mixed solution; The mixed solution is subjected to mixed fermentation under dark conditions; When the pH of the fermented bacterial liquid after mixed fermentation is below 4.5, the fermented bacterial liquid after mixed fermentation is collected to obtain the saline-alkali soil conditioner.

3. The preparation method according to claim 2, characterized in that, The volume ratio of the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus is 1: 1:

1.

4. The preparation method according to claim 3, characterized in that, The viable count in the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus all reaches more than 80 million / mL.

5. The preparation method according to claim 2, wherein The percentage of the seed liquid of Lactobacillus acidophilus, the seed liquid of Lactobacillus casei, and the seed liquid of Streptococcus thermophilus in the volume of the lactic acid bacteria culture medium is 3%-7%.

6. The preparation method according to claim 5, wherein The lactic acid bacteria culture medium is composed of the following materials at the final concentrations: active nitrogen source 9.8 g / L-10.2 g / L, beef extract 4.8 g / L-5.2 g / L, yeast extract 3.8 g / L-4.2 g / L, active carbon source 19.8 g / L-20.2 g / L, dipotassium hydrogen phosphate 1.8 g / L-2.2 g / L, ammonium citrate 1.8 g / L-2.2 g / L, sodium acetate 4.8 g / L-5.2 g / L, magnesium sulfate 0.18 g / L-0.22 g / L, manganese sulfate 0.048 g / L-0.052 g / L, Tween 80 0.8 g / L-1.2 g / L, and the solvent is water; The active nitrogen source includes any one of peptone, soy peptone, and tryptone; The active carbon source includes any one of glucose, molasses, and edible brown sugar.

7. The preparation method according to claim 2, characterized in that, The time of the mixed fermentation is 3 days-5 days; the temperature of the mixed fermentation is 20°C-35°C.

8. Application of the saline-alkali soil conditioner described in claim 1 in improving saline-alkali soil.

9. The application according to claim 8, wherein The saline-alkali soil conditioner is directly applied.

10. The application according to claim 9, characterized in that, The application amount of the saline-alkali soil conditioner is 80 L / mu-120 L / mu.

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