Saline-alkali resistant fertilizer containing Ectoin and Bacillus velezensis and preparation method thereof

Abstract

The invention relates to a saline-alkali resistant fertilizer containing Ectoine and Bacillus velezensis and a preparation method thereof, and belongs to the technical field of saline-alkali resistant fertilizers. The salt and alkali resistant fertilizer disclosed by the invention mainly comprises the following components in parts by weight: 0.1-0.5 part of ectoin, 5-10 parts of bacillus velezensis, 0.5-5 parts of a protective agent, 20-150 parts of nitrogen phosphorus and potassium nutrients, 10-30 parts of a modifier and 0.3-1.3 parts of an auxiliary material. The saline-alkali resistant fertilizer provided by the invention has obvious saline-alkali resistant effect and plant growth promoting effect, can effectively improve the soil environment of saline-alkali soil, and provides favorable conditions for crop growth.

Description

Technical Field

[0001] This invention belongs to the field of salt-alkali resistant fertilizer technology, and relates to a salt-alkali resistant fertilizer containing ectoine and Bacillus belye and its preparation method. Background Technology

[0002] Excessive salt and alkali content in soil can cause salt damage to plants. Sodium salts are the main cause of excessive salt content. Conventionally, soils primarily containing Na₂CO₃ and NaHCO₃ are called alkaline soils, while soils primarily containing NaCl and Na₂SO₄ are called saline soils. However, in reality, both types often coexist in soil, so they are collectively referred to as saline-alkali soils. The classification indicators for saline-alkali land are as follows: slightly saline soil, with a salt content of 0.1–0.2%; moderately saline soil, with a salt content of 0.2–0.4%; and severely saline soil, with a salt content of 0.4–0.6%. Generally, a soil salt content of 0.2%–0.5% is detrimental to plant growth, while saline-alkali soils have salt contents as high as 0.6%–10%.

[0003] The harm of saline-alkali land to plants is mainly manifested in the following four aspects: (a) Causing physiological drought in plants Saline soil contains excessive soluble salts, which can increase the osmotic pressure of the soil solution, thereby causing physiological drought in plants. This prevents plant roots and seeds from absorbing enough water from the soil during germination, and may even cause water to seep out of the root cells, leading to wilting or even death of the plant.

[0004] (ii) Damage to plant tissues Excessive soil salinity, especially during dry seasons, causes salts to accumulate in the topsoil and damage the hypocotyl, with sodium carbonate and potassium carbonate being the most damaging. High pH levels can also lead to direct damage from hydroxide ions to plants. In some plants, excessive salt accumulation can damage protoplasm, severely hindering protein synthesis and resulting in the accumulation of nitrogenous intermediate metabolites, causing cell poisoning.

[0005] (iii) Affecting normal plant nutrition Competition from sodium ions reduces the absorption of potassium, phosphorus, and other nutrients by plants, and inhibits phosphorus transfer, thus affecting the nutritional status of plants.

[0006] (iv) Affecting stomatal closure in plants Under the influence of high salt concentrations, starch formation in the stomatal guard cells is hindered, preventing the guard cells from closing, thus making the plant susceptible to drought, wilting, and death.

[0008] Existing salt-alkali resistant fertilizers have three major bottlenecks: First, chemical amendments (such as gypsum) can only reduce salt concentration in the short term, and the improvement effect lasts for less than 6 months; second, the survival rate of microbial agents in high-salt-alkali environments is less than 15%, making it difficult to colonize and play a role; third, there is a lack of a synergistic system of "soil improvement-crop protection-nutrient supply". For example, CN120398616A only uses Bacillus vesiculosus fermentation broth combined with calcium lignosulfonate, without combining fertilizer to enhance efficiency. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the first objective of this invention is to achieve a long-term reduction in pH value and sodium ion concentration in saline-alkali land, extending the improvement cycle to more than 6 months; the second objective is to improve the colonization rate of Bacillus belye in saline-alkali environments (survival rate ≥60%); and the third objective is to simultaneously enhance crop stress resistance and soil fertility through the synergistic effect of fertilizers, ectoine, and microbial agents.

[0010] The present invention employs the following technical solutions to achieve the above objectives: A salt-alkali resistant fertilizer containing ectoine and Bacillus belye contains the following main components: Ectoin 0.1~0.5 parts by weight, Bacillus vesiculosus 5~10 parts by weight, Protectant 0.5~5 parts by weight, Nitrogen, Phosphorus and Potassium Nutrients 20~150 parts by weight, Improver 10~30 parts by weight, Excipients 0.3~1.3 parts by weight.

[0011] Specifically, The improver contains yeast cell wall polysaccharides and sulfonated graphene; Preferably, the mass ratio of yeast cell wall polysaccharide to sulfonated graphene is 1:(1-3).

[0012] The protective agent is one or a mixture of two of polyethylene glycol and sorbitol; More preferably, the protective agent is a mixture of polyethylene glycol and sorbitol in a mass ratio of (2~4):(6~8).

[0013] The nitrogen, phosphorus, and potassium nutrients contain 5-50 parts by weight of urea, 5-30 parts by weight of monoammonium phosphate, 2-10 parts by weight of ammonium polyphosphate, and 8-60 parts by weight of potassium sulfate.

[0014] The excipients contain 0.1 to 0.3 parts by weight of polyhydroxy fatty acid ester and 0.2 to 1.0 parts by weight of polyglutamic acid.

[0015] Furthermore, the preparation method of the salt-alkali resistant fertilizer includes the following steps: Step 1, Preparation of the modifier: Mix yeast cell wall polysaccharide, sulfonated graphene and water, stir in a mixer at a speed of 50-150 rpm for 2-4 hours, and then dry at 60-70℃ to obtain the modifier; Step 2, Preparation of bacterial agent coating solution: Dissolve polyhydroxy fatty acid ester and polyglutamic acid in deionized water to obtain a bacterial agent coating solution with a concentration of 10-15%; Step 3, bacterial fixation: Mix Bacillus belye with the protectant, add the modifier, and continue stirring in a mixer at a speed of 50-100 rpm, controlling the temperature at 25±5℃ for 2-4 hours to form a bacterial-modifier complex; spray the bacterial coating solution evenly onto the surface of the bacterial-modifier complex through a centrifugal spray drying tower to form microcapsule particles; Step 4, fertilizer granulation: Mix nitrogen, phosphorus and potassium nutrients with microcapsule particles of bacteria-amendant complex to make 2-4 mm bacteria-containing fertilizer granules; Step 5, spraying and drying: Spray ectoine evenly onto the surface of the bacterial fertilizer granules and dry at 40-50℃ until the moisture content is ≤5%; As a preferred embodiment, in step 1 of the salt-alkali resistant fertilizer preparation method, the thickness of the sulfonated graphene sheets is 2-10 nm, and the specific surface area is >1000 m². 2 / g.

[0016] As a preferred embodiment, the concentration of *Bacillus belye* in step 3 of the salt-alkali resistant fertilizer preparation method is 1 × 10⁻⁶. 8 ~1×10 9 CFU / mL.

[0017] As a preferred embodiment, the live bacteria encapsulation rate in step 3 of the salt-alkali resistant fertilizer preparation method is ≥85%.

[0018] The present invention has the following beneficial effects: 1. The modifier prepared by yeast cell wall polysaccharide and sulfonated graphene in this invention has a large specific surface area and improves the adsorption capacity of microbial agents, thereby improving the adsorption and fixation capacity of microbial agents and solving the problem of easy inactivation of existing microbial agents and chemical fertilizers during storage. 2. This invention uses a specific adsorption process to immobilize Bacillus belye, combined with the use of a protective agent, which significantly improves the survival rate and stability of the microorganisms and overcomes the shortcomings of insufficient microbial activity in the prior art; 3. This invention uses a composite granulation of nutrient carrier and microbial-amendant microcapsule particles, which makes the release of microorganisms and chemical fertilizers in the soil more uniform and lasting. Sulfonated graphene can also fix nitrogen and activate phosphorus through ion activation chelation, thereby improving the utilization rate and effect of fertilizer. 4. The present invention uses an ectoine ethanol solution spraying process, which can precisely control the moisture content, ensuring the uniformity and stability of the fertilizer, and solving the problem of difficult control of moisture content in the integrated granulation of chemical fertilizers and organic matter in the prior art. 5. The fertilizer prepared by this invention has significant anti-salt-alkali effect and plant growth-promoting effect, which can effectively improve the soil environment of saline-alkali land, provide favorable conditions for the rapid growth of crops, and overcome the problems of slow effect and long cycle of existing saline-alkali land improvement.

[0019] 6. The fertilizer prepared by this invention can significantly reduce the pH and Ec values ​​of saline-alkali land through the continuous adsorption and replacement of sodium ions by macromolecular and porous materials, and the improvement effect can last for more than 6 months. Detailed Implementation

[0020] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope of protection of the claims of this application.

[0021] Example 1 Formula ingredients: Ectoin 0.1kg, Bacillus vesiculosus 5kg, polyethylene glycol 0.1kg, sorbitol 0.4kg, urea 5kg, monoammonium phosphate 5kg, ammonium polyphosphate 2kg, potassium sulfate 8kg, yeast cell wall polysaccharide 5kg, sulfonated graphene 5kg, polyhydroxy fatty acid ester 0.1kg, polyglutamic acid 0.2kg.

[0022] Preparation steps: Step 1, Preparation of the modifier: Mix yeast cell wall polysaccharide, sulfonated graphene and water, stir at 50 rpm for 4 hours in a mixer, and then dry at 60°C to obtain the modifier; Step 2, prepare the bacterial agent coating solution: dissolve polyhydroxy fatty acid ester and polyglutamic acid in deionized water to prepare a bacterial agent coating solution with a total concentration of 10%. Step 3, bacterial fixation: Bacillus belye (cell concentration 1×10⁻⁶) was added to the bacterial solution. 8 CFU / mL) was mixed with polyethylene glycol and sorbitol, and a modifier was added. The mixture was adsorbed at 30°C for 2 hours to form a bacterial-modifier complex (encapsulation rate of viable bacteria ≥85%). The bacterial agent coating solution was then uniformly sprayed onto the surface of the bacterial-modifier complex through a centrifugal spray drying tower to form bacterial-modifier microcapsule particles. Step 4, fertilizer granulation: Mix urea, monoammonium phosphate, ammonium polyphosphate, potassium sulfate and microcapsule particles of bacterial-modifier complex to make 2-4 mm bacterial fertilizer granules; Step 5, spraying and drying: Spray ectoine (dissolved in ethanol, with a mass concentration of 1%) evenly onto the surface of the granules and dry at 45°C until the moisture content is ≤5% to obtain salt-alkali resistant fertilizer.

[0023] Example 2 Formula ingredients: Ectoin 0.3kg, Bacillus vesiculosus 8kg, polyethylene glycol 0.8kg, sorbitol 1.2kg, urea 20kg, monoammonium phosphate 15kg, ammonium polyphosphate 5kg, potassium sulfate 30kg, yeast cell wall polysaccharide 5kg, sulfonated graphene 15kg, polyhydroxy fatty acid ester 0.2kg, polyglutamic acid 0.5kg.

[0024] Preparation steps: Step 1, Preparation of the modifier: Mix yeast cell wall polysaccharide, sulfonated graphene and water, stir at 50 rpm for 4 hours in a mixer, and then dry at 60°C to obtain the modifier; Step 2, prepare the bacterial agent coating solution: dissolve polyhydroxy fatty acid ester and polyglutamic acid in deionized water to prepare a bacterial agent coating solution with a total concentration of 10%. Step 3, bacterial fixation: Bacillus belye (cell concentration 1×10⁻⁶) was added to the bacterial solution. 8 CFU / mL) was mixed with polyethylene glycol and sorbitol, and a modifier was added. The mixture was adsorbed at 30°C for 2 hours to form a bacterial-modifier complex (encapsulation rate of viable bacteria ≥85%). The bacterial agent coating solution was then uniformly sprayed onto the surface of the bacterial-modifier complex through a centrifugal spray drying tower to form bacterial-modifier microcapsule particles. Step 4, fertilizer granulation: Mix urea, monoammonium phosphate, ammonium polyphosphate, potassium sulfate and microcapsule particles of bacterial-modifier complex to make 2-4 mm bacterial fertilizer granules; Step 5, spraying and drying: Spray ectoine (dissolved in ethanol, with a mass concentration of 1%) evenly onto the surface of the granules and dry at 45°C until the moisture content is ≤5% to obtain salt-alkali resistant fertilizer.

[0025] Example 3 Formula ingredients: Ectoin 0.5kg, Bacillus vesiculosus 10kg, polyethylene glycol 2kg, sorbitol 3kg, urea 50kg, monoammonium phosphate 30kg, ammonium polyphosphate 10kg, potassium sulfate 60kg, yeast cell wall polysaccharide 10kg, sulfonated graphene 20kg, polyhydroxy fatty acid ester 0.3kg, polyglutamic acid 1.0kg.

[0026] Preparation steps: Step 1, Modifier Pretreatment: Mix yeast cell wall polysaccharide, sulfonated graphene and water, stir at 150 rpm for 2 hours in a mixer, and then dry at 70°C to obtain the modifier; Step 2, prepare the bacterial agent coating solution: dissolve polyhydroxy fatty acid ester and polyglutamic acid in deionized water to obtain a bacterial agent coating solution with a concentration of 15%; Step 3, bacterial fixation: Bacillus belye (cell concentration 1×10⁻⁶) was added to the bacterial solution. 9The bacterial agent (CFU / mL) was mixed with polyethylene glycol and sorbitol, and a modifier was added. The mixture was then adsorbed at 20°C for 4 hours to form a bacterial-modifier complex. The bacterial agent coating solution was then uniformly sprayed onto the surface of the bacterial-modifier complex through a centrifugal spray drying tower to form bacterial-modifier microcapsule particles.

[0027] Step 4, fertilizer granulation: Mix urea, monoammonium phosphate, ammonium polyphosphate, potassium sulfate and microcapsule particles of bacterial-modifier complex to make 2-4 mm bacterial fertilizer granules; Step 5, spraying and drying: Spray ectoine (dissolved in ethanol, with a mass concentration of 0.4%) evenly onto the surface of the granules and dry at 48°C until the moisture content is ≤5% to obtain salt-alkali resistant fertilizer.

[0028] Example 4 Formula ingredients: Ectoin 0.5kg, Bacillus vesiculosus 6kg, polyethylene glycol 1.6kg, sorbitol 2.4kg, urea 40kg, monoammonium phosphate 25kg, ammonium polyphosphate 8kg, potassium sulfate 40kg, yeast cell wall polysaccharide 9kg, sulfonated graphene 9kg, polyhydroxyalkanoate 0.2kg, polyglutamic acid 0.8kg.

[0029] Preparation steps: Step 1, Modifier Pretreatment: Mix yeast cell wall polysaccharide, sulfonated graphene and water, stir at 150 rpm for 2 hours in a mixer, and then dry at 70°C to obtain the modifier; Step 2, prepare the bacterial agent coating solution: dissolve polyhydroxy fatty acid ester and polyglutamic acid in deionized water to obtain a bacterial agent coating solution with a concentration of 15%; Step 3, bacterial fixation: Bacillus belye (cell concentration 1×10⁻⁶) was added to the bacterial solution. 9 The bacterial agent (CFU / mL) was mixed with polyethylene glycol and sorbitol, and a modifier was added. The mixture was then adsorbed at 20°C for 4 hours to form a bacterial-modifier complex. The bacterial agent coating solution was then uniformly sprayed onto the surface of the bacterial-modifier complex through a centrifugal spray drying tower to form bacterial-modifier microcapsule particles.

[0030] Step 4, fertilizer granulation: Mix urea, monoammonium phosphate, ammonium polyphosphate, potassium sulfate and microcapsule particles of bacterial-modifier complex to make 2-4 mm bacterial fertilizer granules; Step 5, spraying and drying: Spray ectoine (dissolved in ethanol, with a mass concentration of 0.4%) evenly onto the surface of the granules and dry at 48°C until the moisture content is ≤5% to obtain salt-alkali resistant fertilizer.

[0031] Performance testing Experiment 1 A tomato planting experiment was conducted in saline-alkali land in Changji, Xinjiang, with four treatment zones, each 100m² in size.2 Repeat the treatment 3 times.

[0032] Before transplanting, 40 kg / mu of salt-alkali resistant fertilizer (Example 1) was applied as base fertilizer to tomato patch 1, 40 kg / mu of salt-alkali resistant fertilizer (Example 2) was applied as base fertilizer to tomato patch 2, 40 kg / mu of commercially purchased fertilizer containing Bacillus belysin was applied as base fertilizer to tomato patch 3, and no base fertilizer was applied to tomato patch 4. Subsequent drip irrigation was used for unified fertilizer and water management.

[0033] Seven days after tomato transplanting, the survival rate of microbial strains in the soil and the survival rate of tomato seedlings were measured; 15 days after transplanting, the incidence of damping-off disease in tomatoes was recorded; 30 days after transplanting, the plant height of tomatoes was investigated; after the tomatoes matured and were harvested, the yield, soil Ec value, and soil pH of each treatment were recorded. The results are shown in Table 1 below.

[0034] Table 1 Comparison of bacterial survival rate and tomato seedling growth in different treatment plots As shown in Table 1, the survival rate of the strains treated with the products of Examples 1-2 was 13% higher than that of the control fertilizer, indicating that the bacterial agent modified with yeast cell wall polysaccharides and sulfonated graphene can effectively ensure the activity of Bacillus belyssus and avoid the death and reduced activity of the strains caused by the saline-alkali environment. The transplant survival rate was also significantly higher than that of the control fertilizer and the blank control, and the incidence of damping-off disease was lower than that of the control fertilizer and the blank control, indicating that the product of the present invention can effectively inhibit the occurrence of soil-borne diseases. At the same time, the ectoine in the fertilizer can enhance the salt tolerance of plant cells and improve the survival rate of seedlings. 30 days after transplanting, the plant height of tomato plants treated with the products of Examples 1-2 increased by 6.9% and 5.2% compared with the control fertilizer, indicating that the product of the present invention can promote crop growth.

[0035] Table 2 Comparison of Tomato Yield and Soil Indicators As can be seen from Table 2, the tomato yield was significantly increased after harvesting when the products of Examples 1-2 were applied, indicating that the products of this invention can effectively fix nitrogen and activate phosphorus, chelate trace elements that are not easily absorbed in the soil, promote crop growth, and increase crop yield. At the same time, the soil Ec value and soil pH after treatment with the products of Examples 1-2 were lower than those of the control fertilizer and the blank control, indicating that the products of this invention have the effect of regulating soil physicochemical properties and improving saline-alkali soil.

[0036] Experiment 2 Saline-alkali land in Aksu Prefecture, Xinjiang, was selected and divided into four plots, each 1 mu (approximately 0.16 acres). Cotton was planted. Plot 1 was fertilized with fertilizer from Example 3 via drip irrigation (5 kg); Plot 2 with fertilizer from Example 4 via drip irrigation (5 kg); Plot 3 with commercially purchased fertilizer containing Bacillus berberis via drip irrigation (5 kg); and Plot 4 with water-based drip irrigation (5 kg). Fertilizer was applied 8-10 times throughout the growing season. Twenty days after emergence, emergence rate, plant height, and root length were investigated. During the budding and boll-forming stage, SOD enzyme activity, CAT enzyme activity, POD enzyme activity, and malondialdehyde content were investigated. At harvest, seed cotton yield, soil EC value, and soil pH value were investigated.

[0037] Table 3. Effects of different fertilizers on cotton growth and soil. As shown in Table 3, the cotton treated with the products in Examples 3 and 4 was superior to the control fertilizer and the blank control in terms of emergence rate, plant height, and root length. This indicates that the synergistic substances in the product of this invention and Bacillus vesiculosus work together to create a more suitable soil microenvironment for crop growth.

[0038] SOD, CAT, and POD enzymes can scavenge cellular oxygen free radicals and play a significant role in maintaining cell stability. In Examples 3 and 4, the SOD, CAT, and POD enzyme activities in cotton cells treated with the product were significantly higher than those of the control fertilizer and the blank control. Malondialdehyde (MDA) content is an important indicator of the degree of damage to crop cells. The MDA content of cotton treated with the fertilizer of this invention was lower, indicating that it was less damaged by saline-alkali soil. This shows that the fertilizer of this invention can enhance the crop's resistance to adverse conditions such as salinity, drought, and cold damage, and can promote the robust growth of crops.

[0039] After cotton harvest, the Ec and pH values ​​of the topsoil were measured. The Ec and pH values ​​of the soil treated with the products in Examples 3 and 4 were significantly lower than those of the blank control, indicating that the fertilizer of the present invention has a stable and long-term effect in controlling soil salinity and alkalinity.

[0040] The cotton yield measurement results showed that the cotton yield after treatment with the products in Examples 3 and 4 was significantly higher than that after treatment with the control fertilizer, indicating that the fertilizer of the present invention can comprehensively improve the crop growth health and increase the crop yield by inhibiting and regulating soil salinity and alkalinity and enhancing the crop's resistance to stress in saline-alkali soil environment.

Claims

1. A salt-alkali resistant fertilizer containing ectoine and Bacillus belye, characterized in that, It contains the following ingredients: Ectoin 0.1~0.5 parts by weight, Bacillus vesiculosus 5~10 parts by weight, Protectant 0.5~5 parts by weight, Nitrogen, Phosphorus and Potassium Nutrients 20~150 parts by weight, Improver 10~30 parts by weight, Excipients 0.3~1.3 parts by weight.

2. The salt-alkali resistant fertilizer as described in claim 1, characterized in that, The improver contains yeast cell wall polysaccharide and sulfonated graphene in a mass ratio of 1:(1-3).

3. The salt-alkali resistant fertilizer as described in claim 1, characterized in that, The protective agent is one or a mixture of two of polyethylene glycol and sorbitol.

4. The salt-alkali resistant fertilizer as described in claim 3, characterized in that, The protective agent is a mixture of polyethylene glycol and sorbitol in a mass ratio of (2~4):(6~8).

5. The salt-alkali resistant fertilizer as described in claim 1, characterized in that, The excipients contain 0.1 to 0.3 parts by weight of polyhydroxy fatty acid ester and 0.2 to 1.0 parts by weight of polyglutamic acid.

6. The salt-alkali resistant fertilizer as described in claim 1, characterized in that, The nitrogen, phosphorus, and potassium nutrients contain 5-50 parts by weight of urea, 5-30 parts by weight of monoammonium phosphate, 2-10 parts by weight of ammonium polyphosphate, and 8-60 parts by weight of potassium sulfate.

7. The salt-alkali resistant fertilizer according to any one of claims 1-6, characterized in that, The method for preparing the salt-alkali resistant fertilizer includes the following steps: Step 1, Preparation of the modifier: Mix yeast cell wall polysaccharide, sulfonated graphene and water, stir in a mixer at a speed of 50-150 rpm for 2-4 hours, and then dry at 60-70℃ to obtain the modifier; Step 2, Preparation of bacterial agent coating solution: Dissolve polyhydroxy fatty acid ester and polyglutamic acid in deionized water to obtain a bacterial agent coating solution with a concentration of 10-15%; Step 3, bacterial fixation: Mix Bacillus belye with a protectant, add a modifier, and stir at 50-100 rpm for 2-4 hours at 25±5℃ to form a bacterial-modifier complex; spray the bacterial coating solution onto the surface of the bacterial-modifier complex to form microcapsule particles; Step 4, fertilizer granulation: Mix nitrogen, phosphorus and potassium nutrients with microcapsule particles of bacteria-amendant complex to make 2-4 mm bacteria-containing fertilizer granules; Step 5, spraying and drying: Spray ectoine onto the surface of the bacterial fertilizer granules and dry at 40-50℃ until the moisture content is ≤5%.

8. The salt-alkali resistant fertilizer as described in claim 7, characterized in that, In step 1 of the method for preparing the salt-alkali resistant fertilizer, the thickness of the sulfonated graphene sheets is 2-10 nm, and the specific surface area is >1000 m². 2 / g.

9. The salt-alkali resistant fertilizer as described in claim 7, characterized in that, The concentration of Bacillus belyceae in step 3 of the salt-alkali resistant fertilizer preparation method is 1×10⁻⁶. 8 ~1×10 9 CFU / mL.

10. The salt-alkali resistant fertilizer as described in claim 7, characterized in that, In step 3 of the method for preparing salt-alkali resistant fertilizer, the encapsulation rate of live bacteria is ≥85%.

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