Self-repairing polysaccharide-based soil-fixing and soil-moisture preserving biological agent and preparation method thereof

Abstract

The application provides a self-repairing polysaccharide-based soil-fixing and soil-moisture preserving biological agent and a preparation method thereof, and relates to the technical field of soil improvement.The humic acid-cellulose mixed solution and the emulsified plant oil are prepared respectively; then the humic acid-cellulose mixed solution and the emulsified plant oil are mixed to obtain a mother liquor; finally, the natural mineral, the microalgae and the microbial agent are added into the mother liquor, and after being fully mixed, the self-repairing polysaccharide-based soil-fixing and soil-moisture preserving biological agent is obtained.The biological agent can realize four core functions of soil fixation, erosion prevention, heat preservation, soil moisture preservation, microbial activation and organic carbon accumulation, and solves the complicated process of separately applying soil-fixing agents, soil-moisture preserving agents and microbial agents in the traditional technology.The biological agent is in a liquid state, is suitable for mechanized operation, is convenient to operate, has a wide source of raw materials and controllable cost, and meets the application requirements of large-scale agriculture.

Description

Technical Field

[0001] This invention provides a self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent and its preparation method, belonging to the field of soil improvement technology. Background Technology

[0002] Black soil is characterized by high organic matter content and abundant fertility. However, due to long-term cultivation and utilization, it faces prominent problems such as soil structure damage, increased erosion and loss, decreased moisture retention capacity, and degradation of the organic carbon pool. Currently, black soil regions generally exhibit reduced soil aggregate stability (content of water-stable aggregates greater than 0.25 mm ≤ 40%) and increased topsoil bulk density (≥ 1.3 g / cm³). 3 During the dry season, the soil moisture content is less than 15%, and the water evaporation loss rate is as high as 30%-40%. At the same time, the organic carbon content of black soil decreases at a rate of 0.1-0.3 g / kg per year, the activity of soil microorganisms decreases, the structure of the native beneficial microbial community is unbalanced, which leads to the obstruction of soil nutrient cycling and the limitation of crop yield improvement.

[0003] Currently, numerous improvement products and technologies exist for soil stabilization and moisture retention in black soil, but they have significant limitations. Traditional chemical soil stabilizing agents, such as polyacrylamide, can quickly form a crust, but they are environmentally unfriendly, easily causing secondary soil pollution, and lack fertilizer retention and microbial activation functions. Single organic moisture-retaining materials, such as decomposed straw and simple polysaccharides, have weak soil stabilization effects, and the crust layer is easily eroded by rainfall or damaged by cultivation, resulting in insufficient long-term effectiveness. Existing microbial preparations lack effective protection mechanisms; the survival rate of exogenous beneficial microorganisms in the black soil environment is less than 25% (20 days after application), making it difficult to form a dominant community and sustain their effects.

[0004] Current black soil improvement products cannot achieve multiple functions such as soil stabilization, moisture retention, microbial activation, and carbon accumulation, and lack self-healing properties. Therefore, developing an environmentally friendly, self-healing, and multifunctional synergistic microbial preparation specifically for black soil stabilization and moisture retention is crucial to solving the problem of black soil degradation. Summary of the Invention

[0005] Based on this, the present invention provides a self-healing polysaccharide-based soil stabilization and moisture retention biological agent and its preparation method. The present invention, through the synergistic effect of organic-inorganic cementing materials, microorganisms, and self-healing components, solves the problems of poor soil stabilization and erosion prevention, insufficient moisture retention, difficulty in maintaining microbial activity, and lack of self-healing function in degraded soils such as black soil, achieving integrated comprehensive management of black soil structure improvement, heat preservation and moisture retention, microbial activation, and organic carbon accumulation.

[0006] The present invention is specifically implemented using the following technical solutions: A method for preparing a self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent includes the following steps: Step 1: Prepare humic acid-cellulose mixture Humic acid is dispersed in water and stirred evenly. Then cellulose is added and stirred to obtain a humic acid-cellulose mixture. The mass ratio of humic acid to cellulose in the humic acid-cellulose mixture is 2~4:1~3. Step 2: Prepare emulsified vegetable oil Mix vegetable oil and emulsifier at a mass ratio of 40~60:1~3 and stir until milky white to obtain emulsified vegetable oil; Step 3: Prepare the mother liquor The humic acid-cellulose mixture and the emulsified vegetable oil are mixed to obtain a mother liquor; The mass percentage of emulsified vegetable oil in the mother liquor is 1-5%; The mass percentage of humic acid in the mother liquor is 5-10%. Step 4: Add natural minerals, microalgae, and microbial agents to the mother liquor and mix to prepare a polysaccharide-based soil-fixing and moisture-retaining microbial preparation; the mass concentration of microalgae in the polysaccharide-based soil-fixing and moisture-retaining microbial preparation is 0.5-2%; the mass concentration of microbial agents in the polysaccharide-based soil-fixing and moisture-retaining microbial preparation is 0.5-2%; and the mass concentration of natural minerals in the polysaccharide-based soil-fixing and moisture-retaining microbial preparation is 5-10%.

[0007] Preferably, the cellulose is one or more of methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, and cellulose acetate.

[0008] Preferably, the emulsifier is one or more of sucrose fatty acid esters, polyglycerol esters, and polyglycerol polyricinoleate.

[0009] Preferably, the vegetable oil is soybean oil.

[0010] Preferably, the microbial agent is at least one of Bacillus or Pseudomonas; wherein the viable microbial count is ≥2×10⁻⁶. 10 CFU / g.

[0011] Preferably, the natural mineral is selected from at least one of kaolin, montmorillonite, and attapulgite. More preferably, the montmorillonite has a particle size ≤ 5 μm and a cation exchange capacity ≥ 100 meq / 100g.

[0012] Preferably, the microalgae is at least one of Chlorella proteoglycans, Anabaena nitrogen-fixing algae, or Pseudobranchia.

[0013] This invention also protects the self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent obtained by the above preparation method, as well as the method of using the biological agent.

[0014] The method of using the self-healing polysaccharide-based soil-stabilizing and moisture-retaining biological agent of this invention is to dilute the biological agent with water at a volume ratio of 1:10-1:50, filter it, and then spray it evenly onto the black soil using a backpack electric sprayer, manual sprayer, large mobile sprayer, or drone, at a spraying rate of 0.3~1.0 L / m³. 2 .

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention prepares a humic acid-cellulose mixture and an emulsified vegetable oil separately; then, the humic acid-cellulose mixture and the emulsified vegetable oil are mixed to obtain a mother liquor; finally, natural minerals, microalgae, and microbial agents are added to the mother liquor, and after thorough mixing, a self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent is obtained. The self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent prepared by this invention has a pH of 5.5-7.0 and a viscosity of 800-1500 mPa·s (25℃). Under sealed conditions at room temperature, the stability of the biological agent of this invention is ≥6 months. Spraying the biological agent of this invention onto black soil for 1-3 hours can form a dense crust layer on the surface of the black soil, with a crust layer thickness of 0.5-1.5 mm, increasing soil moisture content by 20-30%, increasing the organic carbon accumulation rate by 0.2-0.4 g / (kg·quarter), and increasing soil urease activity to ≥2.5 mg / (g·d).

[0016] The biological agent of this invention achieves a synergistic effect of organic-inorganic remediation, realizing long-term self-repair and soil moisture retention. This invention utilizes a cementing matrix formed by carboxymethyl cellulose and natural minerals, which can rapidly resist erosion and retain water and heat. It fully leverages the self-repairing properties of microalgae, enabling them to autonomously proliferate and repair themselves after the crust layer is damaged.

[0017] The biological agent of the present invention can secrete polysaccharides during use, which not only act as an activator but also play a role in carbon fixation and can significantly accelerate the accumulation of soil organic carbon.

[0018] The biological agent of this invention can achieve four core functions: soil stabilization and erosion prevention, heat preservation and moisture retention, microbial activation, and organic carbon accumulation, solving the cumbersome process of traditional technologies that require the separate application of soil stabilizing agents, moisture-retaining agents, and microbial agents. The biological agent of this invention is in liquid form, suitable for mechanized operations, convenient to use, and has widely available and cost-controllable raw materials, meeting the needs of large-scale agricultural applications. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0020] Figure 1 This is a flowchart illustrating the preparation process of the self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent of the present invention. Detailed Implementation

[0021] The present invention will be further illustrated below with specific implementation examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0022] Unless otherwise specified, the instruments, reagents, and materials used in the following embodiments are all conventional instruments, reagents, and materials already available in the prior art and can be obtained through legitimate commercial channels. Unless otherwise specified, the experimental methods and detection methods used in the following embodiments are all conventional experimental methods and detection methods already available in the prior art.

[0023] Example 1 A method for preparing a self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent, such as... Figure 1 As shown, the specific steps are as follows: (1) Preparation of humic acid-cellulose mixture: Take 60g of humic acid (95% purity, 60% organic matter content), add it to 800mL of deionized water and stir to disperse it. Use a precision high-speed mixer with a speed of 400r / min and an ambient temperature of 22℃, and stir for 8min until the humic acid is completely dissolved and there are no visible particles. Then, while maintaining high-speed stirring, add 60g of carboxymethyl cellulose powder (viscosity of 5000mPa·s) and continue stirring for 15min to obtain a uniformly dispersed mixture for later use. (2) Preparation of emulsified vegetable oil: Add 1.5g of sucrose fatty acid ester emulsifier (HLB value 12, purity 98%) to 60g soybean oil (acid value 0.4mg KOH / g, iodine value 130g I2 / 100g), place it in a high-speed dispersion homogenizer, set the speed to 600r / min and the temperature to 28℃, stir for 10min until the system presents a uniform milky white emulsion state without layering, and collect the emulsified vegetable oil for later use; (3) Preparation of mother liquor: The humic acid-cellulose mixture was transferred to a high-speed dispersion homogenizer and stirred for 5 minutes at a speed of 600 r / min. The emulsified vegetable oil was then slowly added along the container wall. The speed was adjusted to 1000 r / min and stirred for 50 minutes. After stirring, the mixture was allowed to stand for 10 minutes to naturally remove the tiny bubbles generated in the system, resulting in a homogeneous and stable mother liquor. (4) Slowly add 2.5g of montmorillonite (particle size ≤ 5μm, cation exchange capacity 110meq / 100g) to the mother liquor, and stir for 30min at a speed of 800r / min to ensure uniform dispersion of the cementing material without agglomerates. Then add 25g of Chlorella proteoglycans, followed by 25g of Bacillus subtilis inoculum (2×10⁻⁶ viable cells). 10 The mixture (CFU / g) was thoroughly stirred to obtain a self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent.

[0024] Comparative Example 1 A biological agent was prepared according to the method of Example 1, except that no Chlorella proteoglycans were added.

[0025] The method of using the self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent prepared in Example 1 above is as follows: First, take out the prepared finished mother liquor and shake it well to ensure that the system is homogeneous and free of sediment; Secondly, dilute according to the degree of land degradation. For lightly degraded land, the volume ratio of the biological agent to water in Example 1 of this invention is 1:50-1:80; for moderately degraded land, the volume ratio is 1:30-1:50; and for severely degraded land, the volume ratio is 1:10-1:30. Add water first, then add the biological agent, stir and mix, and then filter with an 80-mesh filter to avoid clogging the nozzles. Then, choose a time when there is no wind or a light breeze and the weather is fine, such as early morning or evening, to spray. Use backpack sprayers, drones or other equipment to spray in a Z-shape, spraying 100-250ml per square meter to ensure that the ground surface is evenly covered without any missed areas. Secondly, depending on the degree of land degradation, decide whether to spray again. Regularly degraded land should be sprayed twice (10-15 days apart), and severely degraded land can be sprayed once more. Irrigation, deep plowing and other agricultural activities are prohibited within 24 hours after spraying. Finally, proper follow-up management is essential. If damage occurs due to heavy rain or strong winds, re-spray at 50-70% of the initial dosage within 48 hours. Diluted formulations can be stored for a maximum of 48 hours; after this period, they should be disposed of according to agricultural waste regulations.

[0026] The control group (denoted as CK1) was implemented. A field experiment was conducted in Gongzhuling City, Changchun City, Jilin Province. First, the experimental treatment plots were determined, with a concentration of 0.5 L / m². 2 The application rate was achieved by uniformly spraying in a zigzag pattern using a backpack electric sprayer. In this group, water was sprayed into the control (CK) area, followed by normal management. Plant and soil samples were collected for analysis after the corn matured. The corn planting and management practices in the following examples and comparative cases were the same as those in the control group (CK).

[0027] Example 2 (denoted as PA) Before spraying, the biological agent of Example 1 was diluted with water at a volume ratio of 1:30 to prepare a soil-fixing and moisture-retaining biological agent spray solution. The spraying amount was the same as that of the control. The spray solution was evenly sprayed in the experimental plot labeled PA. Subsequently, field operations were carried out in accordance with the same management procedures as the control plot, and samples were collected at the preset time nodes.

[0028] Example 3 (denoted as PB) Before spraying, the biological agent was diluted with water at a volume ratio of 1:40 to prepare a soil-fixing and moisture-retaining biological agent spray solution, and the spraying amount was the same as that of the control. The spray solution was evenly sprayed in the experimental plot labeled PB. Subsequently, field operations were carried out in accordance with the same management procedures as the control plot, and samples were collected at the preset time nodes.

[0029] Example 4 (denoted as PC) Before spraying, the biological agent of Example 1 was diluted with water at a volume ratio of 1:50 to prepare a soil-fixing and moisture-retaining biological agent spray solution. The spraying amount was the same as that of the control. The spray solution was evenly sprayed in the experimental plot labeled PC. Subsequently, field operations were carried out in accordance with the same management procedures as the control plot, and samples were collected at the preset time nodes.

[0030] Example 5 (denoted as PD) Before spraying, the biological agent of Example 1 was diluted with water at a volume ratio of 1:60 to prepare a soil-fixing and moisture-retaining biological agent spray solution. The spraying amount was the same as that of the control. The spray solution was evenly sprayed in the experimental plot labeled PD. Subsequently, field operations were carried out in accordance with the same management procedures as the control plot, and samples were collected at the preset time nodes.

[0031] Example 6 (denoted as CK2) Before spraying, the biological agent of Comparative Example 1 was diluted with water at a volume ratio of 1:50 to prepare a soil-fixing and moisture-retaining biological agent spray solution. The spraying amount was the same as that of the control. The spray solution was evenly sprayed in the experimental plot labeled CK2. Subsequently, field operations were carried out in accordance with the same management procedures as the control plot, and samples were collected at the preset time nodes.

[0032] The following data were measured from the collected samples: Table 1 Soil physical properties

[0033] Table 2 Soil Chemical Properties

[0034] Table 3. Maize Growth and Yield Indicators

[0035] Table 4 Microbial activity and microalgae survival

[0036] Table 5. Cerebral layer properties and self-healing effect

[0037] As shown in Table 1, the soil physical properties of all treatment groups (PA-PD) were significantly higher than those of the water control group (CK1) in terms of saturated water content and total porosity, while the soil bulk density was lower in all treatment groups. Among them, the PB group (1:40 dilution) performed best, with a saturated water content of 46.21%, a total porosity of 55.44%, and a bulk density of 1.2080 g / cm³. 3 Compared with CK1, the values ​​increased by 28.9%, 14.6%, and decreased by 11.1%, respectively.

[0038] Compared with the CK2 group without microalgae, the PA-PD group had better physical properties.

[0039] This study demonstrates that the organic-inorganic cementing matrix formed by carboxymethyl cellulose and montmorillonite effectively promotes soil aggregate formation and increases water retention and aeration space. The addition of microalgae further enhances the cementing stability, meeting the improvement requirements of black soil for "loose structure + water retention and locking". Meanwhile, the control group also confirmed the significant effect of the cementing mechanism.

[0040] Table 2 shows that the organic matter, available phosphorus, and available potassium contents of the treatment groups were all higher than those of CK1 and CK2. Among them, the PA group (1:30 dilution) had an organic matter content of 17.71 g / kg, available phosphorus of 49.05 g / kg, and available potassium of 143.79 mg / kg, which were 3.4%, 33.6%, and 15.3% higher than those of CK1, respectively. The PA (1:30 concentration) was more effective than PB-PD, indicating that the 1:30 dilution concentration was more effective in improving soil moisture retention and heat preservation.

[0041] The humic acid and polysaccharides secreted by microorganisms in the biological agent of this invention can act as carbon source activators, accelerating the accumulation of soil organic carbon, and also promoting the accumulation of nitrogen, phosphorus and other trace elements in the soil; while the synergistic effect of microalgae and exogenous microorganisms further optimizes the soil nutrient cycle, making the nutrient supply rhythm more in line with the growth needs of organisms, and solving the pain point of traditional soil conditioners that only change the structure but do not increase fertility.

[0042] Table 3 shows that the 100-kernel weight and yield per mu (667 square meters) of all treatment groups were significantly higher than those of CK1 and CK2. The PA group (1:30 dilution) performed best, with an average 100-kernel weight of 37.20 g and a yield of 1035.81 kg per mu, representing increases of 9.8% and 26.3% respectively compared to CK1, and increases of 5.6% and 22.1% respectively compared to CK2. The yield ranking was PA > PB > PC > PD > CK2 > CK1. This indicates that diluting the biological agents with water at a volume ratio of 1:30-1:40 maximizes the synergistic effects of the agents in soil stabilization, moisture retention, microbial promotion, and fertilization, meeting the needs of moderately and severely degraded black soil improvement. The CK2 group (without microalgae) had a lower yield than the PA-PD group, further validating the indispensability of microalgae in long-term moisture retention and microbial synergy.

[0043] As shown in Tables 4 and 5 regarding microbial activity and crust self-repair function, the soil urease activity and Bacillus count in the biological agent treatment group were significantly higher than those in CK1 and CK2. The PA group showed a urease activity of 3.85 mg / (g·d) and a Bacillus count of 12.6 × 10⁻⁶. 6 The CFU / g dry soil concentrations were 171.1% and 293.8% higher than those in CK1, respectively, and Chlorella survival was detected only in the PA-PD group (up to 7.3 × 10⁻⁶). 7 (cells / g). Based on the crust performance data in Table 5, the PA group had a crust thickness of 4.56 mm, a hardness of 0.223 N, and a repair rate of 99.24% after damage, which were significantly better than the CK2 group (repair rate of 89.23%). Overall, the self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent of this invention has the best comprehensive improvement effect, and provides long-term ecological restoration of black soil. It achieves the synergistic development of improving soil structure and enhancing the crop growth environment, and verifies the feasibility of the preparation method and application technology of the biological agent of this invention.

[0044] This invention effectively solves the technical pain points of traditional black soil amendments, such as single function, insufficient long-term effect, and lack of self-repair. It provides a brand-new technical solution for the ecological restoration of degraded black soil and dryland farmland, with significant economic benefits and ecological value, and broad application prospects.

[0045] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for preparing a self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent, characterized in that, The specific steps are as follows: Step 1: Preparation of humic acid-cellulose mixture Humic acid is dispersed in water and stirred evenly. Then cellulose is added and stirred to obtain a humic acid-cellulose mixture. The mass ratio of humic acid to cellulose in the humic acid-cellulose mixture is 2~4:1~3. Step 2: Prepare emulsified vegetable oil Mix vegetable oil and emulsifier at a mass ratio of 40~60:1~3 and stir until milky white to obtain emulsified vegetable oil; Step 3: Prepare the mother liquor The humic acid-cellulose mixture and the emulsified vegetable oil are mixed to obtain a mother liquor; The mass percentage of emulsified vegetable oil in the mother liquor is 1-5%; The mass percentage of humic acid in the mother liquor is 5-10%. Step 4: Add natural minerals, microalgae, and microbial agents to the mother liquor and mix to prepare a polysaccharide-based soil-fixing and moisture-retaining microbial preparation; the mass concentration of microalgae in the polysaccharide-based soil-fixing and moisture-retaining microbial preparation is 0.5-2%; the mass concentration of microbial agents in the polysaccharide-based soil-fixing and moisture-retaining microbial preparation is 0.5-2%; the mass concentration of natural minerals in the polysaccharide-based soil-fixing and moisture-retaining microbial preparation is 0.1-0.25%. The emulsifier is one or more of sucrose fatty acid esters, polyglycerol esters, and polyglycerol polyricinoleate. The microbial agent is at least one of Bacillus and Pseudomonas; wherein the viable microbial count is ≥2×10⁻⁶. 10 CFU / g; The natural mineral is selected from at least one of kaolin, montmorillonite, and attapulgite. The microalgae are at least one of Chlorella proteoglycans, Anabaena nitrogen-fixing algae, or Pseudobranchia.

2. The preparation method of the self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent as described in claim 1, characterized in that, The cellulose is one or more of methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, and cellulose acetate.

3. A self-healing polysaccharide-based soil-fixing and moisture-retaining biological agent, characterized in that, It is prepared by the preparation method according to any one of claims 1-2.

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