Saline-alkali soil improvement microbial agent and application method thereof

Abstract

The invention discloses a microbial agent for improving saline-alkali soil and an application method. The invention relates to the technical field of saline-alkali soil improvement, in particular to a saline-alkali soil improvement microbial agent. The saline-alkali soil improvement microbial agent is prepared from, by mass, 5-7 parts of saline-alkali soil improvement microbial agent freeze-dried powder, 3-9 parts of trehalose buffer solution, 30-42 parts of biochar, 50-60 parts of fluffy soil and 20-25 parts of straw. The application method of the material comprises the following steps: B1, adding freeze-dried powder of the saline-alkali soil improvement microbial agent into a trehalose buffer solution; b2, mixing the biological carbon, the fluffy soil and the straw; b3, mixing the prepared substances of B1 and B2; b4, treating the saline-alkali soil and applying the final mixture; and B5, repeating the operation every two to three months. The problems of high cost, complex technology, environmental risk and the like of a soil conditioner for the saline-alkali soil can be effectively solved by treating the saline-alkali soil problem through the method.

Description

Technical Field

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

[0002] Soil salinization refers to the phenomenon that under the conditions of arid and little rainfall and lack of irrigation, the surface evaporation is strong, resulting in the upward movement of the water in the deep soil layer along the capillary action, and the salts dissolved in the water accumulate on the soil surface layer, forming salinization. The reasons for soil salinization include natural factors and human factors. Natural factors include small precipitation, large evaporation, high groundwater level, high salinity, and topography and landform, etc.; human factors are mainly manifested in unreasonable irrigation methods, such as long-term irrigation with slightly saline water or industrial wastewater with high salt content, as well as unreasonable fertilization, heavy irrigation and light drainage and other agricultural activities, which will all exacerbate the accumulation of salts in the soil and cause secondary salinization of cultivated land.

[0003] Salinization has a certain impact on our agricultural production and life. Among them, the high-concentration cations and anions in the soil will make it difficult for crops to absorb water, damage a series of physiological and biochemical functions of crops, and even cause death in severe cases. Moreover, salinization will also reduce the fertility of the land, etc., affect the release of nutrients in the soil itself and the absorption of nutrients by crops, and further reduce the yield and quality of crops.

[0004] In the Chinese invention patent application publication specification CN201610450240.0, a microbial soil conditioner for saline-alkali land is disclosed, which comprises the following raw materials: Acaulospora esau, Glomus macrocarpum, Trichoderma reesei FS10-C, Nocardia sp., Pseudomonas fluorescens, Rhodococcus coprophilus, Lactobacillus rhamnosus, catalase, phosphatase, peanut shell powder, soybean straw powder, cow dung pellets, Dicranopteris dichotoma powder, reed powder, Arundo donax powder, Zoige Plateau peat, potassium feldspar and tartaric acid.

[0005] After the microbial soil conditioner is applied to the soil of saline-alkali land, it improves its physical and chemical properties and creates a soil environment suitable for crop growth; at the same time, it improves the soil fertility and its above-ground biomass. However, the soil conditioner prepared by this method has a high cost, complex technology, and certain environmental risks. Summary of the Invention

[0006] (1) Technical Problems to be Solved

[0007] Aiming at the deficiencies of the prior art, the present invention provides a microbial agent for saline-alkali soil improvement, which solves the problems of high cost, complex technology and environmental risks of the soil conditioner for saline-alkali land.

[0008] (2) Technical Solutions

[0009] To achieve the above object, the present application provides a microbial agent for saline-alkali soil improvement, adopting the following technical solutions:

[0010] A microbial agent for saline-alkali soil improvement is prepared as follows:

[0011] A1: First, culture according to the following media respectively: Use TSA + 3% NaCl medium for Marinobacter, PDA + 0.1% streptomycin medium for Trichoderma harzianum, LB + 0.1% cycloheximide medium for Bacillus subtilis, and LB + 1% NaCl medium for Bacillus alkalophilus.

[0012] A2: When the colony count of Marinobacter ≥ 10 8 CFU / mL, the colony count of Trichoderma harzianum ≥ 10 6 CFU / mL, the colony count of Bacillus subtilis ≥ 10 9 CFU / mL, and the colony count of Bacillus alkalophilus ≥ 10 9 CFU / mL, set aside for later use.

[0013] A3: After preparing the medium with 3% glucose, 2% peptone, 2% NaCl, 0.5% K2HPO, 0.05% MgSO4·7H2O, 50 mM Tris-HCl, 0.001% FeSO4·7H2O, and 0.1% chitosan oligosaccharide, inoculate Trichoderma harzianum and pre-culture it on a shaker at 200 - 220 rpm for 24 h, then inoculate Marinobacter, Bacillus subtilis, and Bacillus alkalophilus on the medium.

[0014] A4: Centrifuge the cultured bacterial liquid, collect the bacterial cells, wash the bacterial cells with PBS, and after washing, add 10% - 50% of the mass of the bacterial cells of trehalose and place them in a freeze dryer, and pre-freeze at -40°C to -50°C for 1 - 2 h.

[0015] A5: Under vacuum conditions, set the temperature to -20°C to -30°C and continuously freeze-dry for 10 - 20 h, then raise the temperature to 20°C - 30°C and continuously maintain for 4 - 8 h to obtain the freeze-dried powder of the microbial agent for saline-alkali soil improvement.

[0016] A6: Put the freeze-dried powder of the microbial agent for saline-alkali soil improvement after drying into a sealed vial or aluminum foil bag, and store it in a low-temperature, dry, and light-proof environment.

[0017] Preferably, after inoculating Trichoderma harzianum and then inoculating Marinobacter, Bacillus subtilis, and Bacillus alkalophilus on the medium, the ratio is 1 - 3:2 - 4:1 - 3, and the total inoculation amount is 10 (v / v), where Trichoderma harzianum accounts for 20% - 35%;

[0018] Among them, it should be specifically noted that Halomonas has strong salt tolerance and can survive and reproduce in a high-salt environment, which helps to improve the microbial community structure of saline-alkali land and enhance the biological activity of the soil. The substances it secretes can improve the adaptability of plants to saline-alkali land, improve the soil structure and aeration, and enhance the water and fertilizer retention capacity of the soil; Trichoderma harzianum can inhibit the growth of pathogenic bacteria in the soil, reduce the occurrence of plant diseases, and improve the stress resistance of plants. The extracellular polysaccharides it secretes can bind to the cations that cause salinization in the soil, thereby alleviating land salinization; Bacillus subtilis can produce a variety of antibacterial substances, inhibit the growth of pathogenic bacteria in the soil, and reduce the occurrence of plant diseases. The various extracellular secretions it produces can promote the growth and development of plant roots and improve the adaptability of plants to saline-alkali land; Bacillus alkalophilus has strong alkali tolerance and can survive and reproduce in a high-alkali environment, which helps to improve the microbial community structure of saline-alkali land and enhance the biological activity of the soil. It promotes the growth and development of plant roots, thereby improving the adaptability of plants to saline-alkali land.

[0019] Preferably, the lyophilized powder of the microbial agent for saline-alkali land improvement is added to a 5%-10% trehalose buffer solution according to a volume ratio of (2-6):(3-9).

[0020] Among them, it should be specifically noted that the lyophilized powder is added to a 5%-10% trehalose buffer solution according to a volume ratio of (2-6):(3-9). This ratio range is the best effect value range preset and implemented during the experiment, and it also ensures the balance and complementarity among various microorganisms, thereby improving the overall effect.

[0021] Among them, it should be specifically noted that after being prepared into lyophilized powder, it can ensure that the microbial agent is more convenient to store and transport. At the same time, the operation method is simple, and it can be directly, quickly and evenly applied to the improvement of saline-alkali land. The lyophilized mass obtained by using the above-mentioned strains to prepare a mixed strain can be efficiently and quickly applied to the actual process to improve the soil structure, increase soil fertility, reduce soil salinity and alkalinity, etc., to improve saline-alkali land.

[0022] An application method of a microbial agent for saline-alkali land improvement requires the following materials: 5-7 parts by mass of the lyophilized powder of the microbial agent for saline-alkali land improvement, 3-9 parts by mass of trehalose buffer solution, 30-42 parts by mass of biochar, 50-60 parts by mass of fluffy soil, and 20-25 parts by mass of straw, and includes the following steps:

[0023] B1: Add the lyophilized powder of the microbial agent for saline-alkali land improvement to the trehalose buffer solution according to the volume ratio, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the lyophilized powder, and set aside;

[0024] B2: Wet and mix the biochar screened to 80 - 100 mesh, the loosened soil after being broken up, and the straw sheared to 2 - 5 cm to make a premix.

[0025] B3: Add the completely dissolved microbial agent for saline - alkali land improvement to the mixture obtained in B2, mix it in a stirring tank for 20 - 30 min, and keep it in a moist state to obtain a microbial mixture for saline - alkali land improvement.

[0026] B4: After deep plowing 20 - 30 cm on the saline - alkali land to be improved and then rolling it, spray irrigation water, apply the microbial mixture for saline - alkali land improvement obtained in step B3 at 2 - 3 kg per mu of land, and use a rotary tiller to mix the modifier with the 10 - cm plow layer soil evenly.

[0027] B5: Repeat the above operations on the saline - alkali land every two to three months.

[0028] Preferably, for the application method of the microbial agent for saline - alkali land improvement, the materials required include: 5 - 7 parts by mass of freeze - dried powder of the microbial agent for saline - alkali land improvement, 3 - 9 parts by mass of trehalose buffer solution, 30 - 42 parts by mass of biochar, 50 - 60 parts by mass of loosened soil, and 20 - 25 parts by mass of straw.

[0029] Among them, it should be specifically noted that by applying the mixture containing the microbial agent, the salinity of the soil can be effectively reduced. The active substances in the microbial agent can react chemically with the salts in the soil to form insoluble salts, thereby reducing the salinity of the soil, improving the physical structure of the soil, enhancing the soil's water - holding and nutrient - holding capacities, and providing more favorable soil conditions for plant growth.

[0030] Preferably, the straw is any one or more of the remaining parts of wheat, rice, corn, potatoes, rape, cotton, sugarcane or other crops after harvesting the seeds.

[0031] Among them, it should be specifically noted that the straw can be added according to the local available straw plants according to local conditions, which is of great significance and role for the local ecological cycle.

[0032] (III) Beneficial Effects

[0033] The present invention provides a microbial agent for saline - alkali land improvement, which has the following beneficial effects:

[0034] The saline-alkali soil improvement microbial inoculant, through the mixed use of the freeze-dried powder of the saline-alkali soil improvement microbial inoculant, trehalose buffer solution, biochar, fluff and straw, reduces the soil salinity while improving the soil structure, thereby enhancing the soil fertility, better restoring its production capacity, and because this method is easy to operate and the materials are also easier to obtain compared with other saline-alkali soil improvement methods, it has a certain environmental friendliness and conforms to the concept of contemporary sustainable development. Detailed implementation manners

[0035] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0036] Preparation Example 1

[0037] A saline-alkali soil improvement microbial inoculant, and its preparation method is as follows:

[0038] A1: First, culture according to the following media respectively: for Marinobacter, use TSA + 3% NaCl medium; for Trichoderma harzianum, use PDA + 0.1% streptomycin medium; for Bacillus subtilis, use LB + 0.1% cycloheximide medium; for Bacillus alkaliphilus: LB + 1% NaCl medium;

[0039] A2: When the colony number of Marinobacter ≥ 10 8 CFU / mL, the colony number of Trichoderma harzianum ≥ 10 6 CFU / mL, the colony number of Bacillus subtilis ≥ 10 9 CFU / mL, the colony number of Bacillus alkaliphilus ≥ 10 9 CFU / mL, set aside;

[0040] A3: Prepare the medium with 3% glucose, 2% peptone, 2% NaCl, 0.5% K2HPO, 0.05% MgSO4·7H2O, 50 mM Tris-HCl, 0.001% FeSO4·7H2O, 0.1% chitosan oligosaccharide, then inoculate Trichoderma harzianum and pre-culture it on a shaker at 200 rpm for 24 h, and then inoculate Marinobacter, Bacillus subtilis and Bacillus alkaliphilus on the medium according to 1:2:1, with the total inoculation amount of 10 (v / v), and Trichoderma harzianum accounts for 20%;

[0041] A4: Centrifuge the cultured bacterial liquid, collect the bacterial cells, wash the bacterial cells with PBS, and after washing, add 10% - 50% of the mass of the bacterial cells of trehalose and place them in a freeze dryer, and pre-freeze at -50 °C for 1 h;

[0042] A5: Under vacuum conditions, set the temperature to -30 °C and continue freeze-drying for 10 h, then raise the temperature to -30 °C and continue for 4 h to obtain the freeze-dried powder of the saline-alkali soil improvement microbial inoculant;

[0043] A6: Place the freeze-dried powder of the microbial agent for saline-alkali land improvement after drying into a sealed vial or aluminum foil bag, and store it in a low-temperature, dry, and light-proof environment.

[0044] Preparation Example 2

[0045] A microbial agent for saline-alkali land improvement, and its preparation method is as follows:

[0046] A1: First, culture according to the following media respectively: For Marinobacter, use TSA + 3% NaCl medium; for Trichoderma harzianum, use PDA + 0.1% streptomycin medium; for Bacillus subtilis, use LB + 0.1% cycloheximide medium; for Bacillus alkalophilus: LB + 1% NaCl medium;

[0047] A2: When the colony count of Marinobacter ≥ 10 8 CFU / mL, the colony count of Trichoderma harzianum ≥ 10 6 CFU / mL, the colony count of Bacillus subtilis ≥ 10 9 CFU / mL, the colony count of Bacillus alkalophilus ≥ 10 9 CFU / mL, then set aside;

[0048] A3: After preparing the medium with 3% glucose, 2% peptone, 2% NaCl, 0.5% K2HPO, 0.05% MgSO4·7H2O, 50 mM Tris-HCl, 0.001% FeSO4·7H2O, 0.1% chitosan oligosaccharide, inoculate Trichoderma harzianum and pre-culture it on a shaker at 200 - 220 rpm for 24 h, then inoculate Marinobacter, Bacillus subtilis and Bacillus alkalophilus on the medium, with a ratio of 2:3:2 and a total inoculation amount of 10 (v / v), and Trichoderma harzianum accounts for 25%;

[0049] A4: Centrifuge the cultured bacterial liquid, collect the bacterial cells, wash the bacterial cells with PBS, and after washing, add 30% of the mass of the bacterial cells of trehalose and place them in a freeze dryer, and pre-freeze at -40 °C for 1 h;

[0050] A5: Under vacuum conditions, set the temperature to -20 °C and continue freeze-drying for 10 h, then raise the temperature to 20 °C and continue for 6 h to obtain the freeze-dried powder of the microbial agent for saline-alkali land improvement;

[0051] A6: Place the freeze-dried powder of the microbial agent for saline-alkali land improvement after drying into a sealed vial or aluminum foil bag, and store it in a low-temperature, dry, and light-proof environment.

[0052] Preparation Example 3

[0053] A microbial agent for saline-alkali land improvement, and its preparation method is as follows:

[0054] A1: First, culture them respectively according to the following media: Use TSA + 3% NaCl medium for Marinobacter sp., PDA + 0.1% streptomycin medium for Trichoderma harzianum, LB + 0.1% cycloheximide medium for Bacillus subtilis, and LB + 1% NaCl medium for Bacillus alkalophilus;

[0055] A2: When the colony count of Marinobacter sp. ≥ 10 8 CFU / mL, the colony count of Trichoderma harzianum ≥ 10 6 CFU / mL, the colony count of Bacillus subtilis ≥ 10 9 CFU / mL, and the colony count of Bacillus alkalophilus ≥ 10 9 CFU / mL, set aside for later use;

[0056] A3: Prepare the medium with 3% glucose, 2% peptone, 2% NaCl, 0.5% K2HPO, 0.05% MgSO4·7H2O, 50 mM Tris-HCl, 0.001% FeSO4·7H2O, and 0.1% chitosan oligosaccharide. Then inoculate Trichoderma harzianum and pre-culture it on a shaker at 200 - 220 rpm for 24 h. Then inoculate Marinobacter sp., Bacillus subtilis and Bacillus alkalophilus onto the medium according to a ratio of 3:4:3, with a total inoculation amount of 10 (v / v), and Trichoderma harzianum accounts for 25%;

[0057] A4: Centrifuge the cultured bacterial liquid, collect the bacterial cells, wash the bacterial cells with PBS, and after washing, add 30% of the mass of the bacterial cells of trehalose and place them in a freeze dryer, and pre-freeze at -40 °C for 2 h;

[0058] A5: Under vacuum conditions, set the temperature to -20 °C and continue freeze-drying for 15 h. Then raise the temperature to 30 °C and continue for 6 h to obtain the freeze-dried powder of the microbial inoculant for saline-alkali land improvement;

[0059] A6: Put the freeze-dried powder of the microbial inoculant for saline-alkali land improvement after drying into a sealed vial or aluminum foil bag, and store it in a low-temperature, dry and light-proof environment.

[0060] Example 1

[0061] Specifically, it is a microbial inoculant for saline-alkali land improvement, which is composed of the following raw materials: 5 parts by mass of the freeze-dried powder of the microbial inoculant for saline-alkali land improvement, 3 parts by mass of trehalose buffer solution, 30 parts by mass of biochar, 50 parts by mass of fluffy soil, and 20 parts by mass of straw. The application method of the above microbial inoculant for saline-alkali land improvement is as follows:

[0062] B1: Add the freeze-dried powder of the microbial inoculant for saline-alkali land improvement to the trehalose buffer solution, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder, and set aside for later use.

[0063] B2: Wet and mix the biochar sieved through 80 mesh, the loosened soil after being broken up, and the straw cut to 5 cm to make a premix.

[0064] B3: Add the completely dissolved microbial agent for saline-alkali land improvement into the mixture obtained in B2, mix and stir in a stirring tank for 20 min, and keep it in a moist state to obtain a microbial mixture for saline-alkali land improvement.

[0065] B4: After deep plowing the saline-alkali land to be improved to a depth of 30 cm and then compacting it, spray irrigation water, apply the microbial mixture for saline-alkali land improvement obtained in step B3 at a rate of 2 kg per mu of land, and use a rotary tiller to mix the improver evenly with the 10-cm plough layer soil.

[0066] B5: Repeat the above operations on the saline-alkali land every two to three months.

[0067] Note: Use the freeze-dried powder of the microbial agent for saline-alkali land improvement prepared in Preparation Example 1.

[0068] Example 2

[0069] Specifically, it is a microbial agent for saline-alkali land improvement, which is composed of the following raw materials: 5 parts by mass of freeze-dried powder of the microbial agent for saline-alkali land improvement, 3 parts by mass of trehalose buffer solution, 30 parts by mass of biochar, 50 parts by mass of loosened soil, and 20 parts by mass of straw. The application method of the above microbial agent for saline-alkali land improvement is as follows:

[0070] B1: Add the freeze-dried powder of the microbial agent for saline-alkali land improvement into the trehalose buffer solution, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder, and set aside.

[0071] B2: Wet and mix the biochar sieved through 80 mesh, the loosened soil after being broken up, and the straw cut to 5 cm to make a premix.

[0072] B3: Add the completely dissolved microbial agent for saline-alkali land improvement into the mixture obtained in B2, mix and stir in a stirring tank for 20 min, and keep it in a moist state to obtain a microbial mixture for saline-alkali land improvement.

[0073] B4: After deep plowing the saline-alkali land to be improved to a depth of 30 cm and then compacting it, spray irrigation water, apply the microbial mixture for saline-alkali land improvement obtained in step B3 at a rate of 2 kg per mu of land, and use a rotary tiller to mix the improver evenly with the 10-cm plough layer soil.

[0074] B5: Repeat the above operations on the saline-alkali land every two to three months.

[0075] Note: Use the freeze-dried powder of the microbial agent for saline-alkali land improvement prepared in Preparation Example 2.

[0076] Example 3

[0077] Specifically, it is a microbial agent for saline-alkali land improvement, which is composed of the following raw materials: 5 parts by mass of freeze-dried powder of the microbial agent for saline-alkali land improvement, 3 parts by mass of trehalose buffer solution, 30 parts by mass of biochar, 50 parts by mass of fluffy soil, and 20 parts by mass of straw. The application method of the above-mentioned microbial agent for saline-alkali land improvement is as follows:

[0078] B1: Add the freeze-dried powder of the microbial agent for saline-alkali land improvement into the trehalose buffer solution, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder, and set aside.

[0079] B2: Wet and mix the biochar sieved through 80 meshes, the fluffy soil after being dispersed, and the straw cut to 5 cm to make a premix.

[0080] B3: Add the completely dissolved microbial agent for saline-alkali land improvement into the mixture obtained in B2, mix it in a stirring tank for 20 min, and keep it in a moist state to obtain a microbial mixture for saline-alkali land improvement.

[0081] B4: After deep plowing the saline-alkali land to be improved by 30 cm and then rolling it, spray irrigation water, apply the microbial mixture for saline-alkali land improvement obtained in step B3 at 2 kg per mu of land, and use a rotary tiller to mix the improver with the 10-cm plough layer soil evenly.

[0082] B5: Repeat the above operations on the saline-alkali land every two to three months.

[0083] Note: Use the freeze-dried powder of the microbial agent for saline-alkali land improvement prepared in Preparation Example 3.

[0084] Example 4

[0085] Specifically, it is a microbial agent for saline-alkali land improvement, which is composed of the following raw materials: 6 parts by mass of freeze-dried powder of the microbial agent for saline-alkali land improvement, 6 parts by mass of trehalose buffer solution, 35 parts by mass of biochar, 50 parts by mass of fluffy soil, and 20 parts by mass of straw. The application method of the above-mentioned microbial agent for saline-alkali land improvement is as follows:

[0086] B1: Add the freeze-dried powder of the microbial agent for saline-alkali land improvement into 5%-10% trehalose buffer solution, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder, and set aside.

[0087] B2: Wet and mix the biochar sieved through 80 meshes, the fluffy soil after being dispersed, and the straw cut to 5 cm to make a premix.

[0088] B3: Add the completely dissolved microbial agent for saline-alkali land improvement to the mixture obtained in B2, mix it in a stirring tank for 30 min, and keep it in a moist state to obtain the microbial mixture for saline-alkali land improvement.

[0089] B4: After deep plowing the saline-alkali land to be improved by 30 cm and then compacting it, spray irrigation water, apply the microbial mixture for saline-alkali land improvement obtained in step B3 at a rate of 2 kg per mu of land, and use a rotary tiller to mix the improver with the 10-cm plow layer soil.

[0090] B5: Repeat the above operations on the saline-alkali land every two to three months.

[0091] Note: Use the freeze-dried powder of the microbial agent for saline-alkali land improvement prepared in Preparation Example 1.

[0092] Example 5

[0093] Specifically, it is a microbial agent for saline-alkali land improvement, which is composed of the following raw materials: 6 parts by mass of freeze-dried powder of microbial agent for saline-alkali land improvement, 6 parts by mass of trehalose buffer solution, 35 parts by mass of biochar, 50 parts by mass of fluffy soil, and 20 parts by mass of straw. The application method of the above microbial agent for saline-alkali land improvement is as follows:

[0094] B1: Add the freeze-dried powder of the microbial agent for saline-alkali land improvement to 5%-10% trehalose buffer solution, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder, and set aside.

[0095] B2: Wet and mix the biochar sieved through 80 meshes, the fluffy soil after being loosened, and the straw cut to 5 cm to make a premix.

[0096] B3: Add the completely dissolved microbial agent for saline-alkali land improvement to the mixture obtained in B2, mix it in a stirring tank for 30 min, and keep it in a moist state to obtain the microbial mixture for saline-alkali land improvement.

[0097] B4: After deep plowing the saline-alkali land to be improved by 30 cm and then compacting it, spray irrigation water, apply the microbial mixture for saline-alkali land improvement obtained in step B3 at a rate of 2 kg per mu of land, and use a rotary tiller to mix the improver with the 10-cm plow layer soil.

[0098] B5: Repeat the above operations on the saline-alkali land every two to three months.

[0099] Note: Use the freeze-dried powder of the microbial agent for saline-alkali land improvement prepared in Preparation Example 2.

[0100] Example 6

[0101] Specifically, it is a microbial agent for saline-alkali land improvement, which is composed of the following raw materials: 6 parts by mass of freeze-dried powder of microbial agent for saline-alkali land improvement, 6 parts by mass of trehalose buffer solution, 35 parts by mass of biochar, 50 parts by mass of fluffy soil, and 20 parts by mass of straw. The application method of the above-mentioned microbial agent for saline-alkali land improvement is as follows:

[0102] B1: Add the freeze-dried powder of the microbial agent for saline-alkali land improvement into 5%-10% trehalose buffer solution, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder, and set aside.

[0103] B2: Wet and mix the biochar sieved through 80 meshes, the fluffy soil after being dispersed, and the straw cut to 5 cm, and make a premix.

[0104] B3: Add the completely dissolved microbial agent for saline-alkali land improvement into the mixture obtained in B2, mix it in a stirring tank for 30 min, and keep it in a moist state to obtain a microbial mixture for saline-alkali land improvement.

[0105] B4: After deep plowing the saline-alkali land to be improved by 30 cm and then compacting it, spray irrigation water, apply the microbial mixture for saline-alkali land improvement obtained in step B3 at 2 kg per mu of land, and use a rotary tiller to mix the improver with the 10-cm plough layer soil evenly.

[0106] B5: Repeat the above operations on the saline-alkali land every two to three months.

[0107] Note: Use the freeze-dried powder of the microbial agent for saline-alkali land improvement prepared in Preparation Example 3.

[0108] Example 7

[0109] Specifically, it is a microbial agent for saline-alkali land improvement, which is composed of the following raw materials: 5 parts by mass of freeze-dried powder of microbial agent for saline-alkali land improvement, 7 parts by mass of trehalose buffer solution, 35 parts by mass of biochar, 60 parts by mass of fluffy soil, and 25 parts by mass of straw. The application method of the above-mentioned microbial agent for saline-alkali land improvement is as follows:

[0110] B1: Add the freeze-dried powder of the microbial agent for saline-alkali land improvement into 5%-10% trehalose buffer solution, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder, and set aside.

[0111] B2: Wet and mix the biochar sieved through 00 meshes, the fluffy soil after being dispersed, and the straw cut to 2 cm, and make a premix.

[0112] B3: Add the completely dissolved microbial agent for saline-alkali land improvement into the mixture obtained in B2, mix it in a stirring tank for 20 min, and keep it in a moist state to obtain a microbial mixture for saline-alkali land improvement.

[0113] B4: After deep plowing the saline-alkali land to be improved to a depth of 30 cm and then compacting it, spray irrigation water, apply the saline-alkali land improvement microbial mixture obtained in step B3 at a rate of 3 kg per mu of land, and use a rotary tiller to mix the improver evenly with the 10-cm plow layer soil.

[0114] B5: Repeat the above operations on the saline-alkali land every two to three months.

[0115] Note: Use the freeze-dried powder of the saline-alkali land improvement microbial agent prepared in Preparation Example 1.

[0116] Example 8

[0117] Specifically, a saline-alkali land improvement microbial agent is composed of the following raw materials: 5 parts by mass of freeze-dried powder of saline-alkali land improvement microbial agent, 7 parts by mass of trehalose buffer solution, 35 parts by mass of biochar, 60 parts by mass of fluffy soil, and 25 parts by mass of straw. The application method of the above saline-alkali land improvement microbial agent is as follows:

[0118] B1: Add the freeze-dried powder of the saline-alkali land improvement microbial agent to a 5%-10% trehalose buffer solution, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder, and set aside.

[0119] B2: Wet and mix the biochar sieved through 00 mesh, the fluffy soil after being loosened, and the straw cut to 2 cm to form a pre-mixture.

[0120] B3: Add the completely dissolved saline-alkali land improvement microbial agent to the mixture obtained in B2, mix it in a stirring tank for 20 min, and keep it in a moist state to obtain a saline-alkali land improvement microbial mixture.

[0121] B4: After deep plowing the saline-alkali land to be improved to a depth of 30 cm and then compacting it, spray irrigation water, apply the saline-alkali land improvement microbial mixture obtained in step B3 at a rate of 3 kg per mu of land, and use a rotary tiller to mix the improver evenly with the 10-cm plow layer soil.

[0122] B5: Repeat the above operations on the saline-alkali land every two to three months.

[0123] Note: Use the freeze-dried powder of the saline-alkali land improvement microbial agent prepared in Preparation Example 2.

[0124] Example 9

[0125] Specifically, a saline-alkali land improvement microbial agent is composed of the following raw materials: 5 parts by mass of freeze-dried powder of saline-alkali land improvement microbial agent, 7 parts by mass of trehalose buffer solution, 35 parts by mass of biochar, 60 parts by mass of fluffy soil, and 25 parts by mass of straw. The application method of the above saline-alkali land improvement microbial agent is as follows:

[0126] B1: Add the freeze-dried powder of the microbial agent for saline-alkali land improvement into 5%-10% trehalose buffer solution. After standing at room temperature for 5 min, vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder for standby.

[0127] B2: Wet and mix the biochar sieved through 00 mesh, the loosened soil after being broken up, and the straw cut to 2 cm to make a premix.

[0128] B3: Add the completely dissolved microbial agent for saline-alkali land improvement into the mixture obtained in B2, and mix in a stirring tank for 20 min while keeping it in a moist state to obtain a microbial mixture for saline-alkali land improvement.

[0129] B4: After deep plowing the saline-alkali land to be improved by 30 cm and then compacting it, spray irrigation water. Apply the microbial mixture for saline-alkali land improvement obtained in step B3 at 3 kg per mu of land, and use a rotary tiller to mix the improver evenly with the 10-cm plough layer soil.

[0130] B5: Repeat the above operations on the saline-alkali land every two to three months.

[0131] Note: Use the freeze-dried powder of the microbial agent for saline-alkali land improvement prepared in Preparation Example 3.

[0132] Example 10

[0133] Specifically, it is a microbial agent for saline-alkali land improvement, which is composed of the following raw materials: 3 parts by mass of the freeze-dried powder of the microbial agent for saline-alkali land improvement, 3-9 parts by mass of trehalose buffer solution, 42 parts by mass of biochar, 50 parts by mass of loosened soil, and 25 parts by mass of straw. The application method of the above microbial agent for saline-alkali land improvement is as follows:

[0134] B1: Add the freeze-dried powder of the microbial agent for saline-alkali land improvement into 5%-10% trehalose buffer solution. After standing at room temperature for 5 min, vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder for standby.

[0135] B2: Wet and mix the biochar sieved through 100 mesh, the loosened soil after being broken up, and the straw cut to 2 cm to make a premix.

[0136] B3: Add the completely dissolved microbial agent for saline-alkali land improvement into the mixture obtained in B2, and mix in a stirring tank for 30 min while keeping it in a moist state to obtain a microbial mixture for saline-alkali land improvement.

[0137] B4: After deep plowing the saline-alkali land to be improved by 20 cm and then compacting it, spray irrigation water. Apply the microbial mixture for saline-alkali land improvement obtained in step B3 at 2 kg per mu of land, and use a rotary tiller to mix the improver evenly with the 10-cm plough layer soil.

[0138] B5: Repeat the above operations on saline-alkali land every two to three months.

[0139] Note: Use the freeze-dried powder of the microbial agent for saline-alkali land improvement prepared in Preparation Example 1.

[0140] Example 11

[0141] Specifically, it is a microbial agent for saline-alkali land improvement, which is composed of the following raw materials: 3 parts by mass of the freeze-dried powder of the microbial agent for saline-alkali land improvement, 3 - 9 parts by mass of trehalose buffer solution, 42 parts by mass of biochar, 50 parts by mass of fluffy soil, and 25 parts by mass of straw. The application method of the above microbial agent for saline-alkali land improvement is as follows:

[0142] B1: Add the freeze-dried powder of the microbial agent for saline-alkali land improvement into 5% - 10% trehalose buffer solution, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder, and set aside.

[0143] B2: Wet and mix the biochar sieved through 100 meshes, the fluffy soil after being dispersed, and the straw cut to 2 cm to make a premix.

[0144] B3: Add the completely dissolved microbial agent for saline-alkali land improvement into the mixture obtained in B2, mix it in a stirring tank for 30 min, and keep it in a moist state to obtain a microbial mixture for saline-alkali land improvement.

[0145] B4: After deep plowing the saline-alkali land to be improved by 20 cm and then rolling it, spray irrigation water, apply the microbial mixture for saline-alkali land improvement obtained in step B3 at 2 kg per mu of land, and use a rotary tiller to mix the modifier with the 10 cm plow layer soil evenly.

[0146] B5: Repeat the above operations on saline-alkali land every two to three months.

[0147] Note: Use the freeze-dried powder of the microbial agent for saline-alkali land improvement prepared in Preparation Example 2.

[0148] Example 12

[0149] Specifically, it is a microbial agent for saline-alkali land improvement, which is composed of the following raw materials: 3 parts by mass of the freeze-dried powder of the microbial agent for saline-alkali land improvement, 3 - 9 parts by mass of trehalose buffer solution, 42 parts by mass of biochar, 50 parts by mass of fluffy soil, and 25 parts by mass of straw. The application method of the above microbial agent for saline-alkali land improvement is as follows:

[0150] B1: Add the freeze-dried powder of the microbial agent for saline-alkali land improvement into 5% - 10% trehalose buffer solution, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder, and set aside.

[0151] B2: Wet and mix the biochar sieved to 100 mesh, the fluffy soil after being broken up, and the straw cut to 2 cm to prepare a premix.

[0152] B3: Add the completely dissolved microbial agent for saline-alkali land improvement to the mixture obtained in B2, mix it in a stirring tank for 30 min, and keep it in a moist state to obtain a microbial mixture for saline-alkali land improvement.

[0153] B4: After deep plowing the saline-alkali land to be improved to a depth of 20 cm and then compacting it, spray irrigation water, apply the microbial mixture for saline-alkali land improvement obtained in step B3 at 2 kg per mu of land, and use a rotary tiller to mix the improver with the 10-cm plow layer soil.

[0154] B5: Repeat the above operations on the saline-alkali land every two to three months.

[0155] Note: Use the freeze-dried powder of the microbial agent for saline-alkali land improvement prepared in Preparation Example 3.

[0156] Comparative Example 1

[0157] Compared with Example 1, the difference is: a blank test is conducted without applying the microbial agent for saline-alkali land improvement described in the present invention.

[0158] Comparative Example 2

[0159] Compared with Example 1, the same as Example 1, the difference is: the microbial mixed agent is replaced with a single marine-derived bacterial agent.

[0160] Comparative Example 3

[0161] Compared with Example 1, the same as Example 1, the difference is: the microbial mixed agent is replaced with a single Trichoderma harzianum agent.

[0162] Comparative Example 4

[0163] Compared with Example 1, the same as Example 1, the difference is: the microbial mixed agent is replaced with a single Bacillus subtilis agent.

[0164] Comparative Example 5

[0165] Compared with Example 1, the same as Example 1, the difference is: the microbial mixed agent is replaced with a single Bacillus halophilus.

[0166] Select the soil at a depth of 15 cm from the ground for detection, record various parameters of the microbial agents for saline-alkali land improvement in Examples 1-18 and Comparative Examples 1-3 respectively, and obtain the following results, as shown in Table 1 specifically:

[0167] Table 1: Comparison of test parameters of Examples 1-12 and Comparative Examples 1-5

[0168]

[0169]

[0170] It can be seen from the comparison of the test data of Examples 1-12 and Comparative Example 1 in Table 1 that the saline-alkali land improvement microbial inoculum and application method obtained by the technical solution of the present application play an important role in the improvement of saline-alkali land. The intuitive data comparison can clearly show that the use of this microbial inoculum has an intuitive and obvious effect on the improvement of alkaline land.

[0171] It can be seen from the comparison of the test data of Examples 1-12 and Comparative Examples 1-5 in Table 1 that in the freeze-drying of the saline-alkali land improvement microbial inoculum, trehalose buffer solution, biochar, fluffy soil and straw, it can effectively reduce the salinity of the soil, improve the physical structure of the soil, thereby enhancing the water and nutrient retention capacity of the soil and providing more favorable soil conditions for plant growth.

[0172] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A microbial inoculant for saline-alkali soil improvement, characterized in that: The preparation process of the microbial inoculant for saline-alkali land improvement is as follows: A1: First, culture according to the following media respectively: Use TSA + 3% NaCl medium for Marinobacter sp., PDA + 0.1% streptomycin medium for Trichoderma harzianum, LB + 0.1% cycloheximide medium for Bacillus subtilis, and LB + 1% NaCl medium for Bacillus alkalophilus; A2: When the number of colonies of Marinobacter ≥ 10 8 CFU / mL, the number of colonies of Trichoderma harzianum ≥ 10 6 CFU / mL, the number of colonies of Bacillus subtilis ≥ 10 9 CFU / mL, the number of colonies of Bacillus alkalophilus ≥ 10 9 CFU / mL, set aside for later use; A3: After preparing the medium with 3% glucose, 2% peptone, 2% NaCl, 0.5% K2HPO, 0.05% MgSO4·7H2O, 50 mM Tris-HCl, 0.001% FeSO4·7H2O, and 0.1% chitosan oligosaccharide, inoculate Trichoderma harzianum and pre-culture it on a shaker at 200 - 220 rpm for 24 h, then inoculate Marinobacter sp., Bacillus subtilis, and Bacillus alkalophilus on the medium; A4: Centrifuge the cultured bacterial liquid, collect the bacterial cells, wash the bacterial cells with PBS, and add 10% - 50% of the mass of the bacterial cells of trehalose after washing, then place them in a freeze dryer and pre-freeze at -40°C to -50°C for 1 - 2 h; A5: Under vacuum conditions, set the temperature at -20°C to -30°C and continue freeze-drying for 10 - 20 h, then raise the temperature to 20°C - 30°C and continue for 4 - 8 h to obtain the freeze-dried powder of the microbial inoculant for saline-alkali land improvement; A6: Put the freeze-dried powder of the microbial inoculant for saline-alkali land improvement into a sealed vial or aluminum foil bag and store it in a low-temperature, dry, and light-proof environment; After inoculating Trichoderma harzianum and then inoculating Marinobacter sp., Bacillus subtilis, and Bacillus alkalophilus on the medium, the ratio is 1 - 3:2 - 4:1 - 3, and the total inoculation amount is 10 (v / v), among which Trichoderma harzianum accounts for 20% - 35%; The freeze-dried powder of the microbial inoculant for saline-alkali land improvement is added to a 5% - 10% trehalose buffer solution according to a volume ratio of (2 - 6):(3 - 9).

2. The application method of a microbial agent for saline-alkali soil improvement according to claim 1, characterized in that: It includes the following steps: B1: Add the freeze-dried powder of the microbial inoculant for saline-alkali land improvement to the trehalose buffer solution according to the volume ratio, let it stand at room temperature for 5 min, then vortex and centrifuge for 5 seconds to completely dissolve the freeze-dried powder for standby; B2: Wet and mix the biochar sieved through 80 - 100 meshes, the fluffy soil after being loosened, and the straw cut to 2 - 5 cm to make a pre-mixture; B3: Add the completely dissolved microbial inoculant for saline-alkali land improvement to the mixture obtained in B2, mix it in a stirring tank for 20 - 30 min, and keep it in a moist state to obtain the microbial mixture for saline-alkali land improvement; B4: After deep plowing the saline-alkali land to be improved by 20 - 30 cm and then rolling it, spray irrigation water, apply the microbial mixture for saline-alkali land improvement obtained in step B3 at 2 - 3 kg per mu of land, and use a rotary tiller to mix the modifier with the 10-cm plow layer soil evenly; B5: Repeat the above operation on the saline-alkali land every two to three months; For the application method of the microbial inoculant for saline-alkali land improvement, the required materials include: 5 - 7 parts by mass of the freeze-dried powder of the microbial inoculant for saline-alkali land improvement, 3 - 9 parts by mass of the trehalose buffer solution, 30 - 42 parts by mass of biochar, 50 - 60 parts by mass of fluffy soil, and 20 - 25 parts by mass of straw; The straw is any one or more of the remaining parts of wheat, rice, corn, potatoes, rapeseed, cotton, sugarcane or other crops after harvesting the seeds.

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