A soil conditioner for saline-alkali land and its manufacturing method

Abstract

This invention discloses a soil conditioner for saline-alkali land and its manufacturing method, belonging to the field of soil management and regulation technology. The conditioner comprises organic regulating components, microorganisms and their fermentation products, and active regulating ingredients. In this invention, the organic components (physical salt control), microorganisms (biological salt reduction), and active regulating ingredients (physiological salt tolerance) form a complete saline-alkali regulation chain. Humic acid complexes with Na+. + Subsequently, it is degraded by microorganisms and transformed into a leaching-compatible state; the sodium alginate hydrogel slows down the upward movement of salt and creates a microenvironment for microbial colonization; the root expansion promoted by spermine further enhances the microbial-plant interaction, forming a virtuous cycle, synergistically improving the soil desalination effect, optimizing the crop growth environment, and realizing the efficient utilization of saline-alkali land.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of soil treatment and regulation, and particularly relates to a saline-alkali soil conditioner and a manufacturing method thereof. BACKGROUND

[0002] The saline-alkali soil is a general term for various types of soils affected by salt and alkali components in the soil body, including saline soil and alkaline soil. Due to the influence of the formation reason, the saline soil and the alkaline soil often coexist. The salt components in the saline-alkali soil are harmful salts such as sodium chloride, sodium sulfate, sodium bicarbonate and sodium carbonate, or the exchangeable sodium in the soil accounts for a certain proportion of the cation exchange capacity. The saline-alkali soil has the following characteristics: high pH value, containing harmful salts, poor air permeability, easy to be cemented, and low fertility. Soil salinization is a serious problem affecting agricultural production and ecological environment, and is also one of the two soil factors restricting agricultural yield increase. As a land resource, the saline-alkali soil has great development potential. Saline-alkali soil treatment can not only improve the ecological environment of the saline-alkali area, enrich the local greening landscape pattern, and provide new habitats for biodiversity, but also better solve the problems encountered in regional environmental development and forestry economic development, and provide a broad space for realizing ecological benign circulation and sustainable development.

[0003] Soil improvement is a process of taking corresponding physical, biological or chemical measures to improve soil properties, increase soil fertility, increase crop yield, and improve the human living soil environment, aiming at the poor soil texture and structure. Any material mainly used to improve the physical, chemical and biological properties of soil to make it more suitable for plant growth, rather than mainly providing plant nutrients, is called soil conditioner.

[0004] Soil conditioner is a preparation that can improve soil structure and physical and chemical indicators. After being applied to the soil, it can improve soil structure, increase soil nutrient components, and maintain soil moisture, etc. It is more and more widely used in the aspects of curbing soil degradation, improving low-yield fields, increasing capacity and storage, etc. At the same time, soil conditioner has been widely used in crop production, protective forest planting, grassland production, urban greening, highway greening and flower production, etc.

[0005] For example, Chinese patent application CN201810692279.2 discloses a saline-alkali soil conditioner, which is prepared from the following raw materials by weight: plant leaf litter compost 18-20 parts, plant straw compost 15-20 parts, pond mud 5-10 parts, powdered illite 20-40 parts, granular illite 30-60 parts, and humic acid 5-10 parts. The raw materials are treated respectively, and then mixed uniformly to prepare the soil conditioner of the application.

[0006] For example, Chinese patent application CN201510859400.2 discloses a saline-alkali soil improvement method, mainly including the following processing steps: improvement of land site investigation; water sampling; soil sample analysis; water sample analysis; design of improvement scheme; indoor leaching test: soil bulking agent and chemical modifier are fully mixed with raw soil, loaded into soil column, watered for leaching test, wherein the soil bulking agent addition amount is 5%-20% by volume ratio of saline-alkali soil; the chemical modifier addition amount is 0.5kg / m 2 -5kg / m 2 ; the soil bulking agent and the chemical modifier are uniformly mixed with the saline-alkali soil in proportion; the salt discharge groove is set; the salt discharge device is buried; water is irrigated and salt is discharged; the leaching water and the soil physical and chemical indexes are measured; the present application provides a saline-alkali soil improvement method, which can completely improve the saline-alkali soil without replacing the soil, so that it can be used for agricultural production or urban greening.

[0007] Most of the current soil conditioners focus on adding various acid adjusting substances or chemical reagents, which have very limited control effect on the soil, weak control ability, single function and poor persistence. Therefore, it is urgent to develop a new type of efficient and environmentally friendly soil conditioner to realize efficient improvement of saline-alkali soil. SUMMARY

[0008] The present application screens a high-efficiency salt-tolerant and alkali-tolerant functional microorganism, and combines with the active adjusting components composed of sodium alginate, spermine and brassinosteroid to realize efficient adjustment of saline-alkali soil, improve soil biological activity, improve soil structure, promote salt leaching, improve kinetic parameters, reduce soil water evaporation, and thus change the salt composition, which is conducive to reducing the salt-alkali barrier of saline-alkali soil.

[0009] To achieve the above technical purposes, the technical scheme adopted by the present application is as follows:

[0010] A saline-alkali soil conditioner, comprising the following raw material components: an organic adjusting component, a microorganism and its fermentation product, and an active adjusting component.

[0011] Further, the organic adjusting component comprises earthworm manure, coconut fur compost and humic acid, and the mass ratio of the three is (10-20):(15-23):(7-10).

[0012] Further, the microorganism and its fermentation product are mixed fermentation of the salt-tolerant and alkali-tolerant Bacillus halodurans and the strain number CGMCC No.1.16084 of Halomonas salinum.

[0013] Further, the salt-tolerant and alkali-tolerant Bacillus halodurans (Alkalibacillus haloalkaliphilus The accession number of the sample is CGMCC No.70240, the accession date is June 16, 2023, and it is deposited at the China General Microbiological Culture Collection Center, located at No.3, No.1 Beichen West Road, Chaoyang District, Beijing.

[0014] The *Bacillus halophilus* was isolated from the rhizosphere soil of rice in Sijiqing Town, Lindian District, Daqing City, Heilongjiang Province. The screening method was as follows: 10g of rice rhizosphere soil was added to an Erlenmeyer flask containing 90mL of sterile water, and shaken on a shaker at 30℃ and 160r / min for 30min. -1 Dilute sequentially to 10 -7 Take 10 -5 10 -6 10 -7 100 μL of soil suspensions of each gradient were spread on LB agar plates, with three replicates for each gradient. After incubation at 30°C for 2-4 days, strains with different colony morphologies were selected for isolation and purification. Single colonies were then stored at 4°C for later use.

[0015] The salt and alkali tolerance of the obtained strains were determined. The strains were inoculated at 1% in LB liquid medium containing 0.1-1.7 mol / L NaCl, 100, 150, 200, 250, and 300 mmol / L sodium bicarbonate, and pH 3.0-11.0, respectively. After incubation at 25-35℃ and 160 r / min for 24 h with shaking, the absorbance (OD) was measured. 600 This was repeated three times. Finally, a strain exhibiting the highest tolerance under different salt concentrations and pH values ​​was selected, namely *Bacillus halophilus*. When this strain was streaked onto LB agar, the colonies were found to be round, white, and transparent with relatively neat edges, easily picked up, and exhibiting the following morphology: Figure 1 As shown.

[0016] Furthermore, the yellow-flowered Campylobacter cirrhosa ( Flaviflexus salsibiostraticola The strain has the accession number CGMCC No. 1.16084, the original accession date was January 15, 2017, and it is deposited at the China General Microbiological Culture Collection Center. This strain can be purchased through the collection center without the need for secondary preservation.

[0017] Furthermore, the active regulatory component is composed of sodium alginate, spermine, and brassinosteroids in a mass ratio of 1:1:1.

[0018] A method for manufacturing a soil conditioner for saline-alkali land includes the following preparation steps:

[0019] (1) Preparation of organic regulating components:

[0020] Mix raw coconut coir with microbial inoculant at a mass ratio of 1:0.05, adjust the moisture content to 60%-65%, compost for 24-26 days at a temperature of 55-65℃, turn the compost every 3 days, and after composting, the pH drops to 7.2-7.5 and the C / N ratio stabilizes at 22-24 to obtain mature coconut coir. Crush earthworm castings and mature coconut coir into particles ≤2mm, mix them evenly at a mass ratio of earthworm castings, mature coconut coir, and humic acid of (10-20):(15-23):(7-10), adjust the moisture content of the mixture to 30%-35%, and let it stand for 5 days to enhance the binding force to obtain organic conditioning components.

[0021] (2) Preparation of microorganisms and their fermentation products:

[0022] *Bacillus halophilus* was inoculated into activation medium A and cultured on a shaker at 28-30℃ and 150-200 rpm for 48 hours to obtain an activated bacterial solution of *Bacillus halophilus*. *Campylobacter hygroscopicus* was inoculated into activation medium B and cultured on a shaker at 28-30℃ and 120-150 rpm for 48 hours to obtain an activated bacterial solution of *Campylobacter hygroscopicus*. The two bacterial solutions were mixed at a volume ratio of 2:1 and inoculated into the fermentation carrier at 8% of the carrier's mass. The moisture content was adjusted to 50%-55%, and the pH to 8.5-9.0. Fermentation was carried out for 70-90 hours, with the carrier turned over every 8 hours to ensure uniform cell distribution. After fermentation, the cells were freeze-dried under vacuum to retain their activity and metabolites. Finally, the cells were ultra-finely pulverized to a particle size ≤0.1 mm and passed through a 200-mesh sieve to obtain a grayish-white powder mixture, which is the microorganism and its fermentation product.

[0023] (3) Preparation of improver: The organic regulating components, microorganisms and their fermentation products and active regulating ingredients are mixed evenly in a mass ratio of 20:3:1, and granulated by twin-screw extruder with a die diameter of 3-5 mm. The granules are dried to a moisture content of ≤8% to obtain the final product.

[0024] Furthermore, in step (1), the microbial agent is EM bacteria and Bacillus subtilis, with a mass ratio of 5:3.

[0025] Furthermore, according to the mass percentage: the composition of the activation culture medium A in step (2) is: 1% peptone, 0.5% yeast extract, 8% NaCl, with the remainder being water, pH 8.5-9.0; the composition of the culture medium B is: 2% glucose, 1% peptone, 5% NaCl, 0.1% MgSO4, with the remainder being water, pH 8.5; the composition of the fermentation carrier is: 60% corn cob powder, 30% soybean meal powder, 10% diatomaceous earth, with the water content adjusted to 50%-55%, pH 8.5-9.0.

[0026] All raw materials used in this invention are commercially available.

[0027] Usage and dosage:

[0028] Slightly saline-alkali land (EC < 4 mS / cm, pH < 8.5): 100-150 kg / mu.

[0029] Moderately saline-alkali land (EC 4-8 mS / cm, pH 8.5-9.0): 150-200 kg / mu.

[0030] Severely saline-alkali land (EC > 8 mS / cm, pH > 9.0): 200-250 kg / mu. Apply the soil conditioner evenly to the field surface, then till it to a depth of 20-30 cm using a rotary tiller, ensuring thorough mixing with the soil. After application, irrigate the field for 5-7 days to promote salt leaching and microbial colonization.

[0031] Applying the fertilizer continuously for two years, once or twice a year, can gradually transform saline-alkali land into high-yield fields.

[0032] Beneficial effects:

[0033] (1) The *Bacillus halophilus* strain obtained by screening in this invention can firstly tolerate high salinity and alkalinity environments, and secondly, the bioactive substances secreted by the strain, such as extracellular polysaccharides (EPS), can form a biofilm in the soil to encapsulate salt crystals and inhibit salt leaching; at the same time, it produces enzymes such as alkaline phosphatase and urease to promote the activation of insoluble phosphorus and potassium. The metabolites of *Campylobacter halophilus*, such as γ-aminobutyric acid (GABA) and proline, reduce the osmotic potential of plant cells, activate the expression of plant salt tolerance genes, enhance the regional isolation ability of cells against Na⁺, and improve the crop's salt and alkali resistance.

[0034] (2) Earthworm castings and decomposed coconut coir are rich in humus and colloidal substances, which can significantly increase the organic matter content of the soil. Through the physical adsorption and bridging effect of colloidal particles, they can promote the formation of soil aggregates, reduce soil bulk density, increase porosity, and enhance water permeability and aeration. The active groups such as carboxyl and phenolic hydroxyl groups of humic acid can react with Na+ in saline-alkali soil. + Ion exchange or complexation reactions occur, forming stable humic acid-sodium complexes, which effectively reduce the toxicity of sodium ions to plant roots and promote the leaching of salt ions with water. At the same time, the lignocellulose degradation products (such as reducing sugars) of the decomposed coconut coir provide long-lasting nutrition for microorganisms and maintain the activity of the microbial community.

[0035] (3) Active regulatory components can enhance crop resistance on the one hand and regulate microbial activity on the other. The β-1,4-mannuronic acid chain of sodium alginate can form a three-dimensional network hydrogel in the soil, lock in water, and reduce salt accumulation caused by evaporation; its oligosaccharide fragments can act as signaling molecules to induce the increase of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD) in plants, enhance the plant's resistance to oxidative stress, and further alleviate the stress of saline-alkali environment on crops. Spermine, as a polyamine, can promote the synthesis of cytokinins (such as Zr), stimulate the proliferation of root meristems, and inhibit the activity of ACC oxidase in the ethylene production pathway, thus delaying salt stress-induced senescence. Brassinosteroids are not only a good plant hormone, but they can also bind to regulatory proteins such as TypA and Lrp in microorganisms, inducing the synthesis of salt-alkali tolerance-related enzymes (such as urease and glutamine synthase) and secondary metabolites (such as antibiotics), enhancing the advantage of strains in competitive environments and ensuring their continuous and effective regulatory role.

[0036] (4) In summary, organic components (physical salt control), microorganisms (biological salt reduction), and active ingredients (physiological salt tolerance) form a complete salt-alkali regulation chain. For example, humic acid complexes with Na+. + Subsequently, it is degraded by microorganisms and transformed into a leaching-compatible state; the sodium alginate hydrogel slows down the upward movement of salt and creates a microenvironment for microbial colonization; the root expansion promoted by spermine further enhances the microbial-plant interaction, forming a virtuous cycle, synergistically improving the soil desalination effect, optimizing the crop growth environment, and realizing the efficient utilization of saline-alkali land. Attached Figure Description

[0037] Figure 1 This is a colony morphology diagram of Bacillus halophilus of the present invention;

[0038] Figure 2 The figures show experimental results of rice yield in both the example and comparative scenarios. Detailed Implementation

[0039] The technical solution of the present invention will be further described below with reference to specific embodiments, but it is not limited thereto.

[0040] Example 1

[0041] A soil conditioner for saline-alkali land comprises the following raw material components: organic conditioning components, microorganisms and their fermentation products, and active conditioning components.

[0042] The organic regulating component comprises earthworm castings, decomposed coconut coir, and humic acid in a mass ratio of 20:15:7.

[0043] The microorganism and its fermentation product were obtained by mixed fermentation of Bacillus halophilus and Campylobacter salina strain numbered CGMCCNo.1.16084.

[0044] Furthermore, the Bacillus halophilus has the accession number CGMCC No.70240, the accession date is June 16, 2023, and it is deposited at the China General Microbiological Culture Collection Center, located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0045] The *Bacillus halophilus* was isolated from the rhizosphere soil of rice in Sijiqing Town, Lindian District, Daqing City, Heilongjiang Province. The screening method was as follows: 10g of rice rhizosphere soil was added to an Erlenmeyer flask containing 90mL of sterile water, and shaken on a shaker at 30℃ and 160r / min for 30min. -1 Dilute sequentially to 10 -7 Take 10 -5 10 -6 10 -7 100 μL of soil suspensions of each gradient were spread on LB agar plates, with three replicates for each gradient. After incubation at 30°C for 2-4 days, strains with different colony morphologies were selected for isolation and purification. Single colonies were then stored at 4°C for later use.

[0046] The salt and alkali tolerance of the obtained strains were determined. The strains were inoculated at 1% in LB liquid medium containing 0.1-1.7 mol / L NaCl, 100, 150, 200, 250, and 300 mmol / L sodium bicarbonate, and pH 3.0-11.0, respectively. After incubation at 25-35℃ and 160 r / min for 24 h with shaking, the absorbance (OD) was measured. 600 This was repeated three times. Finally, a strain exhibiting the highest tolerance under different salt concentrations and pH values ​​was selected, namely *Bacillus halophilus*. When this strain was streaked onto LB agar, the colonies were found to be round, white, and transparent with relatively neat edges, easily picked up, and exhibiting the following morphology: Figure 1 As shown.

[0047] The *Campylobacter oryzae* strain has the accession number CGMCC No. 1.16084, with an original accession date of January 15, 2017, and is deposited at the China General Microbiological Culture Collection Center. This strain can be purchased through the collection center without the need for secondary accession.

[0048] The active regulatory component is composed of sodium alginate, spermine, and brassinosteroids in a mass ratio of 1:1:1.

[0049] A method for manufacturing a soil conditioner for saline-alkali land includes the following preparation steps:

[0050] (1) Preparation of organic regulating components:

[0051] Raw material coconut coir is mixed with microbial inoculant at a mass ratio of 1:0.05, and the moisture content is adjusted to 60%-65%. Composting is carried out for 24-26 days at a temperature of 55-65℃, with turning every 3 days. After composting, the pH drops to 7.2-7.5 and the C / N ratio stabilizes at 22-24 to obtain mature coconut coir. Earthworm castings and mature coconut coir are crushed to a particle size ≤2mm and mixed evenly at a mass ratio of earthworm castings, mature coconut coir, and humic acid of 20:15:7. The moisture content of the mixture is adjusted to 30%-35%, and the mixture is left to stand for 5 days to enhance the binding force to obtain the organic conditioning component.

[0052] (2) Preparation of microorganisms and their fermentation products:

[0053] *Bacillus halophilus* was inoculated into activation medium A and cultured on a shaker at 28-30℃ and 150-200 rpm for 48 hours to obtain an activated bacterial solution of *Bacillus halophilus*. *Campylobacter oryzae* was inoculated into activation medium B and cultured on a shaker at 28-30℃ and 120-150 rpm for 48 hours to obtain an activated bacterial solution of *Campylobacter oryzae*. The two bacterial solutions were mixed at a volume ratio of 2:1 and inoculated into the fermentation carrier at 8% of the carrier's mass. The moisture content was adjusted to 50%-55%, and the pH to 8.5-9.0. Fermentation was carried out for 70 hours, with the mixture turned every 8 hours to ensure uniform cell distribution. After fermentation, the mixture was freeze-dried under vacuum to retain cell activity and metabolites. Finally, the mixture was ultra-finely pulverized to a particle size ≤0.1 mm and passed through a 200-mesh sieve to obtain a grayish-white powder mixture, which is the microorganism and its fermentation product.

[0054] (3) Preparation of improver: The organic regulating components, microorganisms and their fermentation products and active regulating ingredients are mixed evenly in a mass ratio of 20:3:1, and granulated by twin-screw extruder with a die diameter of 3-5 mm. The granules are dried to a moisture content of ≤8% to obtain the final product.

[0055] In step (1), the microbial agents are EM bacteria and Bacillus subtilis, with a mass ratio of 5:3.

[0056] According to the mass percentage: the composition of the activation culture medium A in step (2) is: 1% peptone, 0.5% yeast extract, 8% NaCl, with the remainder being water, pH 8.5-9.0; the composition of the culture medium B is: 2% glucose, 1% peptone, 5% NaCl, 0.1% MgSO4, with the remainder being water, pH 8.5; the composition of the fermentation carrier is: 60% corn cob powder, 30% soybean meal powder, 10% diatomaceous earth, with the water content adjusted to 50%-55%, pH 8.5-9.0.

[0057] Example 2

[0058] A soil conditioner for saline-alkali land comprises the following raw material components: organic conditioning components, microorganisms and their fermentation products, and active conditioning components.

[0059] The organic regulating component comprises earthworm castings, decomposed coconut coir, and humic acid in a mass ratio of 20:23:10.

[0060] The microorganism and its fermentation product were obtained by mixed fermentation of Bacillus halophilus and Campylobacter salina strain numbered CGMCCNo.1.16084.

[0061] The Bacillus halophilus has the accession number CGMCC No.70240, the accession date is June 16, 2023, and it is deposited at the China General Microbiological Culture Collection Center, located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0062] The isolation and screening method for Bacillus halophilus is the same as in Example 1.

[0063] The yellow curved bacteria described in the salt membrane are the same as in Example 1.

[0064] The active regulatory component is composed of sodium alginate, spermine, and brassinosteroids in a mass ratio of 1:1:1.

[0065] A method for manufacturing a soil conditioner for saline-alkali land includes the following preparation steps:

[0066] (1) Preparation of organic regulating components:

[0067] Raw material coconut coir is mixed with microbial inoculant at a mass ratio of 1:0.05, and the moisture content is adjusted to 60%-65%. Composting is carried out for 24-26 days at a temperature of 55-65℃, with turning every 3 days. After composting, the pH drops to 7.2-7.5 and the C / N ratio stabilizes at 22-24 to obtain mature coconut coir. Earthworm castings and mature coconut coir are crushed to a particle size ≤2mm and mixed evenly at a mass ratio of earthworm castings, mature coconut coir, and humic acid of 20:23:10. The moisture content of the mixture is adjusted to 30%-35%, and the mixture is left to stand for 5 days to enhance the binding force to obtain organic conditioning components.

[0068] (2) Preparation of microorganisms and their fermentation products:

[0069] *Bacillus halophilus* was inoculated into activation medium A and cultured on a shaker at 28-30℃ and 150-200 rpm for 48 hours to obtain an activated bacterial solution of *Bacillus halophilus*. *Campylobacter hygroscopicus* was inoculated into activation medium B and cultured on a shaker at 28-30℃ and 120-150 rpm for 48 hours to obtain an activated bacterial solution of *Campylobacter hygroscopicus*. The two bacterial solutions were mixed at a volume ratio of 2:1 and inoculated into the fermentation carrier at 8% of the carrier's mass. The moisture content was adjusted to 50%-55%, and the pH to 8.5-9.0. Fermentation was carried out for 90 hours, with the mixture turned every 8 hours to ensure uniform bacterial distribution. After fermentation, the mixture was freeze-dried under vacuum to retain bacterial activity and metabolites. Finally, the mixture was ultra-finely pulverized to a particle size ≤0.1 mm and passed through a 200-mesh sieve to obtain a grayish-white powdery mixture, which is the microorganism and its fermentation product.

[0070] (3) Preparation of improver: The organic regulating components, microorganisms and their fermentation products and active regulating ingredients are mixed evenly in a mass ratio of 20:3:1, and granulated by twin-screw extruder with a die diameter of 3-5 mm. The granules are dried to a moisture content of ≤8% to obtain the final product.

[0071] In step (1), the microbial agents are EM bacteria and Bacillus subtilis, with a mass ratio of 5:3.

[0072] According to the mass percentage: the composition of the activation culture medium A in step (2) is: 1% peptone, 0.5% yeast extract, 8% NaCl, with the remainder being water, pH 8.5-9.0; the composition of the culture medium B is: 2% glucose, 1% peptone, 5% NaCl, 0.1% MgSO4, with the remainder being water, pH 8.5; the composition of the fermentation carrier is: 60% corn cob powder, 30% soybean meal powder, 10% diatomaceous earth, with the water content adjusted to 50%-55%, pH 8.5-9.0.

[0073] Comparative Example 1

[0074] In this comparative example, except that only Campylobacter cirrhosa was used in the microorganisms and their fermentation products, the other raw materials and process steps were the same as in Example 1.

[0075] A soil conditioner for saline-alkali land comprises the following raw material components: organic conditioning components, microorganisms and their fermentation products, and active conditioning components.

[0076] The organic regulating component comprises earthworm castings, decomposed coconut coir, and humic acid in a mass ratio of 20:15:7.

[0077] The microorganism and its fermentation product were obtained by fermentation of Campylobacter cirrhosa, strain number CGMCC No.1.16084.

[0078] The *Campylobacter oryzae* strain has the accession number CGMCC No. 1.16084, with an original accession date of January 15, 2017, and is deposited at the China General Microbiological Culture Collection Center. This strain can be purchased through the collection center without the need for secondary accession.

[0079] The active regulatory component is composed of sodium alginate, spermine, and brassinosteroids in a mass ratio of 1:1:1.

[0080] A method for manufacturing a soil conditioner for saline-alkali land includes the following preparation steps:

[0081] (1) Preparation of organic regulating components:

[0082] Raw material coconut coir is mixed with microbial inoculant at a mass ratio of 1:0.05, and the moisture content is adjusted to 60%-65%. Composting is carried out for 24-26 days at a temperature of 55-65℃, with turning every 3 days. After composting, the pH drops to 7.2-7.5 and the C / N ratio stabilizes at 22-24 to obtain mature coconut coir. Earthworm castings and mature coconut coir are crushed to a particle size ≤2mm and mixed evenly at a mass ratio of earthworm castings, mature coconut coir, and humic acid of 20:15:7. The moisture content of the mixture is adjusted to 30%-35%, and the mixture is left to stand for 5 days to enhance the binding force to obtain the organic conditioning component.

[0083] (2) Preparation of microorganisms and their fermentation products:

[0084] Campylobacter chrysogenum was inoculated into activation medium B and cultured on a shaker at 28-30℃ and 120-150 rpm for 48 hours to obtain activated Campylobacter chrysogenum solution. The activated solution was then inoculated into the fermentation carrier at 8% of the carrier mass, and the water content was adjusted to 50%-55%, pH 8.5-9.0. Fermentation was carried out for 70 hours, with the carrier being turned over every 8 hours to ensure uniform distribution of the bacteria. After fermentation, the bacteria were freeze-dried under vacuum to retain their activity and metabolites. Finally, the mixture was ultra-finely pulverized to a particle size ≤0.1 mm and passed through a 200-mesh sieve to obtain a grayish-white powdery mixture, which is the microorganism and its fermentation product.

[0085] (3) Preparation of improver: The organic regulating components, microorganisms and their fermentation products and active regulating ingredients are mixed evenly in a mass ratio of 20:3:1, and granulated by twin-screw extruder with a die diameter of 3-5 mm. The granules are dried to a moisture content of ≤8% to obtain the final product.

[0086] Comparative Example 2

[0087] In this comparative example, except that only Bacillus halophilus was used in the microorganisms and their fermentation products, the other raw materials and process steps were the same as in Example 1.

[0088] A soil conditioner for saline-alkali land comprises the following raw material components: organic conditioning components, microorganisms and their fermentation products, and active conditioning components.

[0089] The organic regulating component comprises earthworm castings, decomposed coconut coir, and humic acid in a mass ratio of 20:15:7.

[0090] The microorganism and its fermentation product are obtained by fermentation of selected alkali-loving Bacillus.

[0091] The Bacillus halophilus has the accession number CGMCC No.70240, the accession date is June 16, 2023, and it is deposited at the China General Microbiological Culture Collection Center, located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0092] The isolation and screening method for Bacillus halophilus is the same as in Example 1.

[0093] A method for manufacturing a soil conditioner for saline-alkali land includes the following preparation steps:

[0094] (1) Preparation of organic regulating components:

[0095] Raw material coconut coir is mixed with microbial inoculant at a mass ratio of 1:0.05, and the moisture content is adjusted to 60%-65%. Composting is carried out for 24-26 days at a temperature of 55-65℃, with turning every 3 days. After composting, the pH drops to 7.2-7.5 and the C / N ratio stabilizes at 22-24 to obtain mature coconut coir. Earthworm castings and mature coconut coir are crushed to a particle size ≤2mm and mixed evenly at a mass ratio of earthworm castings, mature coconut coir, and humic acid of 20:15:7. The moisture content of the mixture is adjusted to 30%-35%, and the mixture is left to stand for 5 days to enhance the binding force to obtain the organic conditioning component.

[0096] (2) Preparation of microorganisms and their fermentation products:

[0097] Bacillus halophilus was inoculated into activation medium A and cultured on a shaker at 28-30℃ and 150-200 rpm for 48 hours to obtain an activated bacterial solution. The bacterial solution was then inoculated into the fermentation carrier at 8% of the carrier's mass, and the water content was adjusted to 50%-55%, pH 8.5-9.0. Fermentation was carried out for 70 hours, with the carrier being turned over every 8 hours to ensure uniform distribution of the bacteria. After fermentation, the bacteria were freeze-dried under vacuum to retain their activity and metabolites. Finally, the mixture was ultra-finely pulverized to a particle size ≤0.1 mm and passed through a 200-mesh sieve to obtain a grayish-white powdery mixture, which is the microorganism and its fermentation product.

[0098] (3) Preparation of improver: The organic regulating components, microorganisms and their fermentation products and active regulating ingredients are mixed evenly in a mass ratio of 20:3:1, and granulated by twin-screw extruder with a die diameter of 3-5 mm. The granules are dried to a moisture content of ≤8% to obtain the final product.

[0099] Comparative Example 3

[0100] In this comparative example, except that spermine is not used in the active ingredient, all other raw materials and process steps are the same as in Example 1.

[0101] The active regulatory component is composed of sodium alginate and brassinosteroids in a mass ratio of 1:1.

[0102] Comparative Example 4

[0103] In this comparative example, except that brassinosteroids are not used in the active regulatory components, the raw materials and process steps are the same as in Example 1.

[0104] The active regulatory ingredient is composed of sodium alginate and spermine in a mass ratio of 1:1.

[0105] Comparative Example 5

[0106] In this comparative example, except that spermine and brassinosteroids are not used in the active regulatory components, the raw materials and process steps are the same as in Example 1.

[0107] The active regulatory ingredient is sodium alginate.

[0108] Experimental Test

[0109] Salt tolerance determination of the strains: *Bacillus halophilus* and *Campylobacter halophilus* were inoculated into LB liquid medium and cultured at 30℃ and 180 r / min until the OD600 value reached 0.6-0.8. The bacterial suspensions were streaked onto LB solid medium with pH 9.0 and NaCl concentrations of 0, 20, 40, 60, 80, 100, 120, 140, 160, 180, and 200 g / L, as well as with no pH adjustment and a salt concentration of 0 g / L [referred to as 0(-)]. The media were incubated upside down at 30℃. Colony diameter was measured every 24 hours, with each time point measured three times, and the average value was taken.

[0110] Table 1 Salt tolerance of *Bacillus halophilus* and *Campylobacter salina*

[0111]

[0112] Note: -: No growth; +: Growth and colony diameter <0.3 mm; ++: Colony diameter 0.3-0.5 mm; +++: Colony diameter 0.5-0.8 mm; ++++: Colony diameter >0.8 mm.

[0113] At pH 9.0, the strains can grow on LB plates with NaCl concentrations ranging from 0 to 180 g / L, with the best growth observed at NaCl concentrations of 60 to 140 g / L. Both strains exhibit good salt tolerance.

[0114] Determination of the alkali-lowering ability of the strain:

[0115] OD were inoculated into LB liquid medium at pH 80–10.0. 600 Alkali-loving Bacillus and Campylobacter salina were cultured at 30℃ and 180 r / min for 4 days with a pH of 0.6-0.8. Every 12 hours, 0.5 mL of the culture was centrifuged at 4000 r / min for 5 min, and the supernatant was used to determine the pH of the culture. The alkali reduction rate was calculated according to formula (1):

[0116] ηbase (%) = (before pH - after pH) / before pH × 100 (1)

[0117] In formula (1): ηbase represents the alkali-reducing ability of the strain; pH before is the pH value of the culture medium before fermentation; pH after is the pH value of the bacterial solution after fermentation.

[0118] Table 2. Alkali-lowering ability of *Bacillus halophilus* and *Campylobacter cirrhosa*.

[0119]

[0120] It can be seen that both strains possess excellent alkalinity-lowering capabilities. At pH 9.0, *Bacillus halophilus* exhibited a higher alkalinity-lowering rate than *Campylobacter halophilus*, demonstrating stronger adaptability to alkaline environments. With increasing pH, the alkalinity-lowering capabilities of both strains improved, indicating that they can maintain a certain level of growth activity in highly alkaline environments. The superior performance of these two strains in high-salt, high-alkaline environments provides strong evidence for their application in extreme environments.

[0121] Actual planting experiment

[0122] The experimental field is a newly developed saline-alkali land soil improvement and fertilization field test area. The crop grown in this area is rice, a single-crop crop per year with a growing period of approximately 130 days. The soil type in the experimental area is typical soda saline-alkali soil, with a shallow groundwater level of approximately 1.0-2.5 m. The soil texture is silty loam, with a pH of 10.2 and an EC of 2.23 (mS·cm). -1 ).

[0123] The experiment was set up with the following experimental groups:

[0124] The control group (T1) was not treated with any soil conditioner, the soil conditioners of Examples 1-2 of this invention were applied (T2-T3), the soil conditioners of Comparative Examples 1-5 were applied (T4-T8), and the aluminum sulfate control group (T9) was applied.

[0125] In the examples and comparative studies, the soil conditioner was evenly spread on the field surface at a rate of 100 kg / mu, and then tilled to a soil layer of 20-30 cm using a rotary tiller to ensure thorough mixing with the soil. The field was then irrigated for 5-7 days after application. The aluminum sulfate used in this experiment was industrial-grade iron-containing aluminum sulfate, light gray granular or flake-like; the application rate was 2 t·hm². -2 Each test area is 700m² 2 Each experimental area was equipped with independent water inlet and drainage systems. The base fertilizer was a 12-18-15% compound fertilizer, applied at a rate of 400 kg·hm². -2 Later, apply a uniform top dressing of 100 kg·hm². -2 .

[0126] The rice variety planted is Longjing 31, with a growth cycle of about 130 days.

[0127] Soil sample collection and analysis:

[0128] Soil samples were collected before the start of the experiment and after the rice harvest. For each treatment, a five-point sampling method was used, and a 1×1.5 m rectangular soil profile was excavated to collect soil samples from the 20-40 cm soil layer.

[0129] Plant roots, gravel, and other obvious debris were removed from the collected soil samples. After the soil samples were naturally air-dried indoors, they were sieved through 2mm and 0.25mm sieves to determine soil salinity and soil enzyme activity.

[0130] Soil pH was determined using a glass electrode pH meter with a soil-to-water ratio of 5:1; soil salinity was determined using the drying method; urease was measured using the sodium phenoxide-sodium hypochlorite colorimetric method; sucrase was measured using the sodium thiosulfate titration method; catalase was measured using the potassium permanganate titration method; and alkaline phosphatase was measured using the disodium phenyl phosphate colorimetric method. Ten samples were taken for each soil indicator, and the results were averaged.

[0131] Determination of rice yield and quality:

[0132] Yield measurements were conducted on rice in each experimental area during the rice ripening period.

[0133] Method for calculating the sodium adsorption ratio in soil:

[0134] The soil sodium adsorption ratio (SAR) formula (1) is shown in the figure:

[0135] (1)

[0136] Table 3 Soil Conditioning Data

[0137]

[0138] As can be seen from the data in Table 3, the application of the soil conditioner of the present invention can effectively reduce the soil pH level and reduce the soil salinity, thereby improving the soil permeability and crop growth environment.

[0139] Table 4 Enzyme activity in rice root soil

[0140]

[0141] Tables 3-4 show that there are significant differences in enzyme activity between the soil treated with the soil amendment and the untreated soil. The soil enzyme activities in Examples 1 and 2 are generally higher, especially urease and sucrase activities, which are much higher than those in the comparative examples and the untreated soil in T1. This indicates that the application of the soil amendment can effectively enhance the biological activity of the soil, thus providing a more favorable environment for rice growth. Comparative examples 1-5, which altered the microbial composition and active ingredients, also showed varying degrees of increase in soil enzyme activity, but all were lower than those in the examples, further demonstrating the superiority of the soil amendment of this invention.

[0142] It should be noted that the above embodiments are merely some preferred embodiments of the present invention, and not all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

Claims

1. A saline soil conditioner, characterized in that, The preparation method comprises the following steps:

2. A method of manufacturing the saline soil conditioner according to claim 1, characterized by, (1) preparation of the organic adjustment component: The raw material coconut shell and the microbial inoculant are mixed in a mass ratio of 1:0.05, the water content is adjusted to 60%-65%, compost fermentation is carried out for 24-26 days, the temperature is 55-65 DEG C, the turning frequency is once every 3 days, the pH is reduced to 7.2-7.5 after maturation, the C / N ratio is stable at 22-24 to obtain the coconut shell compost; the earthworm manure, the coconut shell compost and the humic acid are crushed to a particle size of ≤2 mm, and then uniformly mixed in a mass ratio of (10-20):(15-23):(7-10), the water content of the mixture is adjusted to 30%-35%, and the mixture is aged for 5 days to enhance the binding force, thereby obtaining the organic adjustment component; in step (1), the microbial inoculant is EM bacteria and Bacillus subtilis, and the mass ratio of the two is 5:3; (2) preparation of the microorganism and its fermentation product: The halophilic alkaliphilic Bacillus is inoculated into the activated culture medium A, and cultured at 28-30 DEG C and a rotation speed of 150-200 rpm for 48 hours to obtain the activated bacterial solution of the halophilic alkaliphilic Bacillus; the Haliangium sp. is inoculated into the activated culture medium B, and cultured at 28-30 DEG C and a rotation speed of 120-150 rpm for 48 hours to obtain the activated bacterial solution of the Haliangium sp.; the two kinds of bacterial solutions are mixed in a volume ratio of 2:1, inoculated into the fermentation carrier at 8% of the mass of the fermentation carrier, the water content is adjusted to 50%-55%, the pH is 8.5-9.0, and fermentation culture is carried out, the fermentation time is 70-90 hours, the material is turned every 8 hours to ensure uniform distribution of the bacterial cells; after the fermentation is completed, vacuum freeze-drying is adopted to retain the bacterial activity and metabolic products; finally, the mixture is ultra-finely ground to a particle size of ≤0.1 mm and sieved through a 200-mesh sieve to obtain a gray-white powder, which is the microorganism and its fermentation product; (3) preparation of the modifier: the organic adjustment component, the microorganism and its fermentation product, and the active adjustment component are uniformly mixed in a mass ratio of 20:3:1, granulated by using a double-screw extrusion granulator, the die hole diameter is 3-5 mm, and the granules are dried to a water content of ≤8% to obtain the final product. ​ 3. The method for manufacturing the saline-alkali soil conditioner according to claim 2, characterized in that, According to the mass percentage: wherein the composition of the activated culture medium A in step (2) is: peptone 1%, yeast extract 0.5%, NaCl 8%, the rest is water, pH 8.5-9.0; the composition of the culture medium B is: glucose 2%, peptone 1%, NaCl 5%, MgSO4 0.1%, the rest is water, pH 8.5; the composition of the fermentation carrier is: corn cob powder 60%, soybean meal powder 30%, diatomite 10%, the moisture content is adjusted to 50%-55%, pH 8.5-9.0.

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