An improved soil ecological base material for ecological slope protection

Abstract

The present invention relates to an improved soil ecological substrate for ecological slope protection, comprising: humic acid and biochar with a mass ratio of 20-30%; modified clay with a mass ratio of 25-30%; microbial nutrient agent with a mass ratio of 10-20%; nutrient slow-release agent with a mass ratio of 5-10%; curing agent with a mass ratio of 5-10%; humic acid, biochar, modified clay, microbial nutrient agent, nutrient slow-release agent and curing agent are fully mixed according to the above ratio, and water is added to form a plastic mixture, and then the plastic mixture is placed in a mold to form a substrate block or particle of a desired shape and size, and naturally air-dried or low-temperature dried to obtain an improved soil ecological substrate. The present invention not only has the ability to adsorb and fix soil, reduce the risk of soil erosion, but also utilizes microbial nutrient agent immobilization technology to slowly release nutrients, absorb water, and maintain the stable growth of plants. It is suitable for various ecological restoration projects of various ecological slope protections, and has significant environmental benefits and social and economic benefits.

Description

Technical Field

[0001] The invention relates to the technical field of soil environmental restoration, and in particular to an improved soil ecological base material for ecological slope protection. Background Art

[0002] As a technical means to balance environmental protection and economic development, ecological slope protection is widely used in various fields. For example, under the influence of natural and human factors, many slopes are facing the risk of erosion, especially in areas with frequent rainfall and floods. Through the anchoring and covering effects of vegetation roots, the direct erosion of rainwater on the soil is reduced, soil loss is prevented, and natural disasters caused by soil erosion, such as mudslides and landslides, are reduced, and farmland, houses and infrastructure in downstream areas are protected from damage caused by erosion. In places such as highways, railways, river banks, and reservoirs, it is necessary to enhance the stability of slopes through ecological measures, such as the use of ecological materials such as ecological bags and geogrids, combined with plant growth, to prevent slope collapse and landslide accidents, ensure the safety of transportation facilities and buildings, reduce maintenance costs, and extend the service life of slope facilities. In urban green spaces, on both sides of rivers and other areas, the construction of ecological corridors can provide migration channels for wild animals and plants, maintain the health of the ecosystem, promote the protection of biodiversity, and enhance the self-regulation and resilience of the ecosystem. Through reasonable planning and implementation, ecological slope protection can not only effectively prevent soil erosion and improve soil quality, but also enhance slope stability, promote biodiversity, beautify the environment, reduce environmental pollution, and has a high economic cost-effectiveness.

[0003] In ecological slope protection, improved soil ecological substrate is used more and more widely as an important ecological restoration material. The materials used to improve the physical, chemical and biological properties of the soil are aimed at enhancing soil fertility, optimizing soil structure and promoting plant growth. Summary of the invention

[0004] The purpose of the present invention is to propose an improved soil ecological substrate for ecological slope protection, which improves soil remediation efficiency and promotes ecological restoration by optimizing material composition and structure, especially improves soil nutrient composition, improves plant survival rate and growth conditions, so as to obtain multiple benefits such as beautifying the environment, protecting ecology, and reducing maintenance costs.

[0005] To achieve the above object, the present invention provides an improved soil ecological substrate for ecological slope protection, comprising:

[0006] A humic acid and biochar with a mass ratio of 20-30%, wherein the humic acid is a humic acid finished product with a soluble humic acid content of more than 60% and a pass rate of more than 90% through an 80-mesh sieve; the biochar is made of rice straw husks, crushed into particles less than 1 cm, and dried at 60° C. to a moisture content of less than 10%, heated to 500° C. in an oxygen-deficient environment for 30 minutes in a high-temperature pyrolysis furnace, and the screened humic acid and biochar are mixed in proportion according to the properties of the soil at the site of use;

[0007] A modified clay with a mass ratio of 25 to 30%, wherein the modified clay is made from natural kaolin and montmorillonite and surface-modified with aluminum salt or iron salt;

[0008] A microbial nutrient with a mass ratio of 10 to 20%, wherein the microbial nutrient is prepared by mixing bacterial species, sesbania gum and sodium polyacrylate solution, dripping the mixture into a calcium chloride solution to form an immobilized carrier, and then allowing the bacterial species to adhere to a fibrous permeable plate by soaking or spraying the immobilized carrier, wherein the bacterial species and the required nutrients are selected to match the local soil;

[0009] A nutrient sustained-release agent with a mass ratio of 5 to 10%, wherein the nutrient sustained-release agent is a microcapsule formed by encapsulating the nutrient substance with a degradable green and environmentally friendly packaging material;

[0010] A curing agent with a mass ratio of 5 to 10%, wherein the curing agent includes 60 to 70% of a vinyl acetate polymer, 10 to 15% of a polyethylene glycol, 5 to 10% of a silane coupling agent, 5 to 10% of an acrylate copolymer, 10 to 20% of pure water or deionized water, and a trace amount of a preservative;

[0011] Humic acid, biochar, modified clay, microbial nutrients, nutrient slow-release agents and curing agents are fully mixed according to the above proportions, and water is added to form a plastic mixture. The plastic mixture is then placed in a mold to form substrate blocks or particles of a desired shape and size, and naturally air-dried or low-temperature dried to obtain an improved soil ecological substrate.

[0012] Preferably, for the use scenario of sandy soil with low fertility and poor water retention, the mixing mass ratio of humic acid to biochar is 2:1; for the use scenario of clay with serious pollution and poor air permeability, the mixing mass ratio of humic acid to biochar is 1:1; for the use scenario of slope protection dominated by drought-resistant plants, the mixing mass ratio of humic acid to biochar is 1:1.5; for the use scenario of slope protection dominated by fertilizer-loving plants, the mixing mass ratio of humic acid to biochar is 1.5:1.

[0013] Preferably, after the humic acid and biochar are mixed, the step of adjusting the pH value of the mixture by adding an acid-base regulator according to the properties of the soil at the site of use is further included, and the pH value of the mixture is adjusted to 6-7.5.

[0014] Preferably, the step of surface modification using aluminum salt or iron salt comprises:

[0015] a) Raw material selection: natural kaolin or montmorillonite is selected as the raw material and crushed for later use;

[0016] b) Modifier preparation: Aluminum sulfate and ferric sulfate are selected as modifiers, and the aluminum sulfate and ferric sulfate are dissolved in deionized water or distilled water at a concentration of 0.2 mol / L to 0.8 mol / L, and stirred until the modifier is completely dissolved in the water;

[0017] c) Reaction preparation: 6 parts by weight of the modifier is prepared in a reaction kettle, and the stirrer is turned on at a stirring speed of 60 to 80 rpm. After the stirring speed is stabilized, 4 parts by weight of crushed kaolin or montmorillonite powder is slowly added for a period of not less than 30 minutes; after the solution is evenly mixed, the heating rod is turned on, the temperature is set to 50 to 80° C., and the time is 2 to 4 hours; after the reaction is completed, the mixture is filtered to separate the solid product; the solid product is washed with deionized water for multiple times;

[0018] d) drying: drying the washed solid product at 80-120° C. for 4-8 hours;

[0019] e) Crushing and sieving: The dried solid product is crushed and sieved to obtain modified clay with a particle size of 60 to 80 mesh.

[0020] Preferably, the preparation steps of the microbial nutrient include: mixing bacterial strains, sesbania gum and sodium polyacrylate solution, and dropping them into a calcium chloride solution to form a beaded immobilization carrier, wherein the mass ratio of sesbania gum is 3-5%, the mass ratio of sodium polyacrylate is 5-8%, and the mass concentration of calcium chloride solution is 0.2%-5%; the bacterial strains are attached to a fibrous permeable plate by soaking and spraying, and the fibrous permeable plate is made by soaking the permeable plate with nano-scale silica sol and then drying it.

[0021] Preferably, the preparation of the microcapsules comprises: dissolving chitosan in a dilute acetic acid solution with a mass concentration of 1 to 5% to prepare a chitosan solution, wherein the mass concentration of chitosan is 1 to 3%; stirring and heating at 60 to 80 rpm and 50 to 60° C. to fully dissolve and obtain a uniform chitosan acetic acid solution; dissolving sodium polyacrylate in deionized water to prepare a sodium polyacrylate solution with a concentration of 2 to 5%, and stirring to uniformly dissolve; mixing the chitosan acetic acid solution and the sodium polyacrylate solution in a mass ratio of (1 to 3):1, stirring, and adding nutrients, and after the addition is completed, slowly dripping a glutaraldehyde solution with a mass concentration of 0.1 to 1% of the chitosan, and continuously stirring the reaction for 1 to 6 hours; pouring the above mixed and cross-linked solution into a mold, removing moisture by evaporation drying, freeze drying or vacuum drying, and forming the packaging material to obtain microcapsules.

[0022] Preferably, the preparation of the microcapsules further comprises: treating with alkaline solution to neutralize the residual acetic acid, then washing the packaging material to remove unreacted raw materials and impurities and then drying.

[0023] Based on the above technical solution, the advantages of the present invention are:

[0024] The improved soil ecological substrate of the present invention can not only effectively absorb and fix the ability of soil, reduce the risk of soil erosion, but also use microbial nutrient immobilization technology to slowly release nutrients, absorb water, and maintain the stable growth of plants. At the same time, the curing agent and nutrient regulator in the substrate further optimize the soil microenvironment, providing favorable conditions for continuous absorption of water and slow release of nutrients. In addition, the substrate has a stable structure, is easy to construct and deploy, is suitable for various ecological restoration projects of various ecological slope protection, and has significant environmental benefits and social and economic benefits. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described in detail below through embodiments.

[0026] The present invention provides an improved soil ecological substrate for ecological slope protection, including: biochar + humic acid: 20% to 30%, which has a high specific surface area and rich pore structure, contains nutrients required by plants, and can achieve the purpose of soil consolidation and water conservation by planting suitable vegetation; modified clay: 25% to 30%, an effective reinforcement material, adding chemical reagents (such as organic quaternary ammonium salts, silane coupling agents, etc.) for surface modification, changing the surface charge state of clay, improving adsorption capacity, and mixing the modified clay with soil in a certain proportion to enhance the cohesive force and shear strength of the soil, effectively preventing soil and water loss. Microbial nutrient agent 10% to 20%, select microbial carrier, through chemical modification or composite use with other materials, has a high porosity and a large surface area, forms a stable network structure, is convenient for microorganisms to attach to its structure, and is suitable for fixing microorganisms and providing a growth environment. Nutrient slow-release agent: 5% to 10%, provides necessary nutrients for microbial growth, accelerates the repair process; curing agent: 5% to 10%, improves soil moisture retention capacity, and maintains a suitable microbial living environment.

[0027] The improved soil ecological substrate includes humic acid and biochar in a mass ratio of 20-30%, wherein the humic acid is a humic acid finished product with a soluble humic acid content greater than 60% and a pass rate of more than 90% through an 80-mesh sieve; the biochar is made of rice straw husks, crushed into particles less than 1 cm, and dried at 60°C until the moisture content is less than 10%, and heated to 500°C in an oxygen-deficient environment for 30 minutes using a high-temperature pyrolysis furnace, and the sieved humic acid and biochar are mixed in proportion according to the properties of the soil in the use area. The mixture can improve soil fertility and promote crop growth, and at the same time, has good stability and high adsorption capacity.

[0028] Preferably, for the use scenario of sandy soil with low fertility and poor water retention, the mixing mass ratio of humic acid to biochar is 2:1; for the use scenario of clay with serious pollution and poor air permeability, the mixing mass ratio of humic acid to biochar is 1:1; for the use scenario of slope protection dominated by drought-resistant plants, the mixing mass ratio of humic acid to biochar is 1:1.5; for the use scenario of slope protection dominated by fertilizer-loving plants, the mixing mass ratio of humic acid to biochar is 1.5:1.

[0029] Humic acid is selected from products with excellent quality, soluble humic acid content greater than 60, and the passing rate of humic acid through 80-mesh sieve is more than 90%, and is set aside.

[0030] Preparation of biochar: ① Select rice straw husk as raw material and crush it into particles less than 1 cm; ② Dry the crushed rice straw husk at 60°C until the moisture content is less than 10%; ③ Put the dried rice straw husk into a high-temperature pyrolysis furnace and heat it to 500°C in an oxygen-deficient environment for 30 minutes to activate its adsorption properties. ④ Crush the dried biochar and select products that pass through 80-100 mesh sieves to improve the compatibility of the two materials.

[0031] According to the nature of the soil at the place of use, humic acid and biochar are mixed in different proportions and can be mixed by mechanical stirring, manual stirring, etc. to ensure that the two are fully and evenly mixed, give full play to the synergistic effect of the two materials, and improve the fertility and water retention of the soil. Preferably, after the humic acid and biochar are mixed, the step of adjusting the pH value of the mixture by adding an acid-base regulator according to the nature of the soil at the place of use is also included. The pH value of the mixture is adjusted to 6-7.5, which can create a suitable growth environment for specific plants and improve the survival rate of plants.

[0032] Steps for adjusting the pH value: 1. Determine the pH value of the soil at the place of use; 2. Determine and select solid pH adjusters, alkaline adjusters (such as calcium oxide, calcium carbonate, calcium hydroxide, wood ash, etc.) to neutralize acidic components; acidic adjusters (such as sulfur powder, ferrous sulfate, phosphoric acid, etc.) to lower the pH value of the mixture; 3. Determine the amount of the adjuster and fully mix the adjuster with the humic acid and biochar mixture by dry stirring.

[0033] The improved soil ecological substrate comprises 25-30% by mass of modified clay, wherein the modified clay is made of natural kaolin and montmorillonite and is surface-modified by aluminum salt or iron salt.

[0034] Preferably, the step of surface modification using aluminum salt or iron salt comprises:

[0035] a) Raw material selection: natural kaolin or montmorillonite is selected as the raw material and crushed for later use;

[0036] b) Modifier preparation: Aluminum sulfate and ferric sulfate are selected as modifiers, and the aluminum sulfate and ferric sulfate are dissolved in deionized water or distilled water at a concentration of 0.2 mol / L to 0.8 mol / L, and stirred until the modifier is completely dissolved in the water;

[0037] c) Reaction preparation: 6 parts by weight of the modifier is prepared in a reaction kettle, and the stirrer is turned on at a stirring speed of 60 to 80 rpm. After the stirring speed is stabilized, 4 parts by weight of crushed kaolin or montmorillonite powder is slowly added for a period of not less than 30 minutes; after the solution is evenly mixed, the heating rod is turned on, the temperature is set to 50 to 80° C., and the time is 2 to 4 hours; after the reaction is completed, the mixture is filtered to separate the solid product; the solid product is washed with deionized water for multiple times;

[0038] d) drying: drying the washed solid product at 80-120° C. for 4-8 hours;

[0039] e) Crushing and sieving: The dried solid product is crushed and sieved to obtain modified clay with a particle size of 60 to 80 mesh.

[0040] Furthermore, the improved soil ecological substrate includes a microbial nutrient agent with a mass ratio of 10 to 20%, wherein the microbial nutrient agent is prepared by mixing bacterial strains, sesbania gum and sodium polyacrylate solution, dropping the mixture into a calcium chloride solution to form an immobilized carrier, and then allowing the bacterial strains to adhere to a fibrous permeable plate by soaking or spraying the immobilized carrier. The bacterial strains are selected from microbial species and required nutrients that match the local soil.

[0041] Select microbial species and required nutrients that match the local soil. For example, Pseudomonas, actinomycetes (Streptomyces, Nocardia, Micromonas, Mycobacterium, Propionibacterium, Bifidobacterium), Frankia, fungi (growing in acidic soil, Penicillium, Aspergillus, Fusarium, Trichoderma, etc.). According to the characteristics of the local soil and the needs of the ecological environment, selecting appropriate microbial species can improve soil fertility, improve soil structure, and promote plant growth.

[0042] Preferably, the preparation steps of the microbial nutrient include: mixing bacterial strains, sesbania gum and sodium polyacrylate solution, and dropping them into a calcium chloride solution to form a beaded immobilization carrier, wherein the mass ratio of sesbania gum is 3-5%, the mass ratio of sodium polyacrylate is 5-8%, and the mass concentration of calcium chloride solution is 0.2%-5%; the bacterial strains are attached to a fibrous permeable plate by soaking and spraying, and the fibrous permeable plate is made by soaking the permeable plate with nano-scale silica sol and then drying it.

[0043] Furthermore, the improved soil ecological substrate comprises a nutrient slow-release agent in a mass ratio of 5 to 10%, wherein the nutrient slow-release agent is a microcapsule formed by encapsulating nutrients in a degradable green and environmentally friendly packaging material.

[0044] Material selection: Select green and environmentally friendly packaging materials and nutrients that can be slowly degraded. Chitosan and sodium polyacrylate are used as the main raw materials, and some cross-linking agents such as glutaraldehyde are added to make the packaging materials.

[0045] Production process: ① Dissolve chitosan in a dilute acetic acid solution with a mass concentration of 1-5% to prepare a chitosan solution. The mass concentration of chitosan is between 1 and 3%, which can be adjusted according to the performance of the required packaging material. Turn on stirring (60-80 rpm) and heat to 50-60°C to fully dissolve it to obtain a uniform chitosan acetic acid solution. ② Dissolve sodium polyacrylate in deionized water to prepare a sodium polyacrylate solution with a mass concentration of 2-5%, stir evenly to ensure that it is completely dissolved. ③ Mix the chitosan acetic acid solution and the sodium polyacrylate solution in a ratio of 1:1 to 3:1, start stirring, add nutrients (add common bacterial nutrients such as glucose, urea, calcium phosphate, potassium formate, etc.), and slowly add glutaraldehyde solution after the addition is completed. The amount of glutaraldehyde is 0.1%-1% of the mass of chitosan. The reaction time is about 1 to 6 hours, and stirring is continued until the reaction is complete. ④ Pour the mixed cross-linked solution into a specific mold, remove moisture by evaporation, freeze drying or vacuum drying to form the packaging material.

[0046] Cleaning and impurity removal: Use alkaline solution to neutralize residual acetic acid, increase the pH value of the packaging material, wash the packaging material, remove unreacted raw materials and impurities, and then dry it for later use.

[0047] Furthermore, the improved soil ecological substrate includes a curing agent in a mass ratio of 5 to 10%, and the curing agent includes 60 to 70% of the total mass of the curing agent, polyethylene glycol accounting for 10 to 15% of the total mass of the curing agent, 5 to 10% of the total mass of the curing agent, 5 to 10% of the total mass of the curing agent, acrylate copolymer accounting for 5 to 10% of the total mass of the curing agent, 10 to 20% of the total mass of the curing agent, and pure water or deionized water accounting for 10 to 20% of the total mass of the curing agent, and a trace amount of preservatives.

[0048] A composite soil solidifier with vinyl acetate as raw material is selected. After mixed use, it can enhance the compactness and stability between soil particles, improve the mechanical strength of the solidified soil, and make it more resistant to wear and impact.

[0049] Humic acid, biochar, modified clay, microbial nutrients, nutrient slow-release agents and curing agents are fully mixed according to the above proportions, and water is added to form a plastic mixture. The plastic mixture is then placed in a mold to form substrate blocks or particles of a desired shape and size, and naturally air-dried or low-temperature dried to obtain an improved soil ecological substrate.

[0050] The improved soil ecological substrate of the present invention can not only effectively absorb and fix the ability of soil, reduce the risk of soil erosion, but also use microbial nutrient immobilization technology to slowly release nutrients, absorb water, and maintain the stable growth of plants. At the same time, the curing agent and nutrient regulator in the substrate further optimize the soil microenvironment, providing favorable conditions for continuous absorption of water and slow release of nutrients. In addition, the substrate has a stable structure, is easy to construct and deploy, is suitable for various ecological restoration projects of various ecological slope protection, and has significant environmental benefits and social and economic benefits.

[0051] The improved soil ecological substrate of the present invention can be used according to the following steps:

[0052] (1) Preliminary preparation and investigation

[0053] a) Geological exploration: Drilling, sampling and other methods are used to understand basic information such as the geological structure, soil type, and groundwater level of the slope.

[0054] b) Soil testing: Collect soil samples and test soil pH, organic matter content, nutritional status, permeability and other parameters.

[0055] c) Environmental assessment: Assess local climate conditions, rainfall patterns, vegetation types, etc. to provide a basis for the selection of ecological substrates.

[0056] Function: To clarify the geological conditions of the slope and provide data support for subsequent design and construction; to understand the soil properties and provide a basis for the proportion of ecological base materials.

[0057] (2) Design and planning

[0058] a) Design plan: Based on the results of the preliminary investigation, draw the design drawings of the ecological slope protection and clarify the geometric parameters such as the height, width, slope, etc. of the slope protection.

[0059] b) Material selection: Select appropriate ecological substrate components according to soil type and environmental conditions, ensuring their compatibility with local soil.

[0060] c) Vegetation selection: Select plant species suitable for local climate and soil conditions, giving priority to native species to facilitate ecosystem recovery.

[0061] Function: The design scheme conforms to the actual geological and environmental conditions, ensuring the feasibility of ecological slope protection; the material selection is reasonable and can effectively improve soil quality and vegetation growth conditions.

[0062] (3) Preparation before construction

[0063] a) Site cleaning: remove weeds, garbage and other obstacles on the slope to ensure the construction area is clean.

[0064] b) Leveling the ground: Level the slope to ensure a smooth surface for easy laying of the ecological base material.

[0065] c) Trench excavation: Dig necessary trenches according to design requirements to facilitate drainage or installation of fixed structures.

[0066] Function: The construction area is clean and tidy, which is convenient for subsequent construction operations; the slope surface is flat, which is conducive to the uniform laying of the ecological base material.

[0067] (4) Laying of ecological substrate

[0068] a) Mixed substrate: biochar, humic acid, modified clay, microbial nutrient, nutrient slow-release agent and curing agent are mixed according to the above proportions to finally obtain the ecological substrate.

[0069] b) Layered laying: Lay the mixed ecological base material evenly in layers on the slope. The thickness of each layer should be controlled within a reasonable range (generally 10-20cm).

[0070] c) Compaction: Use appropriate tools (such as rollers or portable compactors) to compact the laid base material to ensure that the base material is tightly combined with the soil.

[0071] Function: The ecological base material is evenly distributed and can effectively improve the soil structure; after compaction, the base material is tightly combined with the soil to improve the stability of the slope.

[0072] (5) Vegetation Planting

[0073] a) Seeding or transplanting: Sow grass seeds or transplant seedlings on the ecological substrate, and arrange the planting density reasonably according to the growth habits of the plants.

[0074] b) Watering and fertilizing: Water in time to keep the soil moist and apply appropriate amount of fertilizer when necessary.

[0075] c) Covering and protection: Eco bags, geogrids or other covering materials can be used to protect newly planted vegetation and prevent soil erosion.

[0076] Function: Rapid vegetation growth improves the aesthetics and ecological function of the slope; reduces water evaporation and soil erosion through covering and protection.

[0077] (6) Drainage system setting

[0078] a) Set up drainage ditches: Set up drainage ditches or pipes at appropriate locations on the slope to ensure that rainwater can be discharged smoothly.

[0079] b) Protective facilities: Necessary protective facilities such as retaining walls, foot guards, etc. should be set up at the top and bottom of the slope to prevent water erosion.

[0080] Function: The drainage system is smooth, preventing slope erosion caused by water accumulation; the protective facilities are stable, further improving the stability of the slope.

[0081] (7) Post-maintenance

[0082] a) Regular inspection: Regularly check the stability of the ecological slope protection and the growth of vegetation.

[0083] b) Timely replanting: If vegetation is found to be dead or sparse, it should be replanted in time.

[0084] c) Pest and disease control: Pay attention to whether there are any pests and diseases, and take necessary prevention and control measures.

[0085] d) Pruning management: Prune plants that are too long or too dense in a timely manner to maintain good ventilation and light conditions.

[0086] Function: Timely discover and solve potential problems to ensure the long-term stability of ecological slope protection; maintain good growth of vegetation through pruning management.

[0087] To further illustrate the effect of the improved soil ecological substrate for ecological slope protection of the present invention, a typical hilly area in southern China was selected as a test project for ecological slope protection. The average annual rainfall in the area is about 1200 mm, the slope height is 5 meters, the length is 20 meters, and the slope is about 30°.

[0088] The specific steps for implementing the pilot project are as follows:

[0089] Geological exploration: Through drilling and sampling, it was found that the slope is mainly composed of sandy soil and the groundwater level is low. Soil test: The test results show that the soil pH is 7.2, the organic matter content is 1.5%, and the permeability is 0.02cm / s. Environmental assessment: The assessment shows that the climate in the area is mild and suitable for the growth of a variety of plants.

[0090] Design and planning specific steps: Design plan: draw a design drawing with a slope height of 5 meters and a width of 20 meters, and determine the slope gradient to be 30°. Material selection: decide to use biochar + humic acid (30%), modified clay (30%), microbial nutrient (15%), nutrient slow-release agent (7%), and curing agent (8%). Vegetation selection: select herbaceous plants (such as alfalfa), shrubs (such as Amorpha fruticosa) and trees (such as willow) suitable for the local climate.

[0091] Specific steps for preparation before construction: Site cleaning: remove weeds and garbage on the slope. Level the ground: use a bulldozer to level the slope. Dig a trench: dig a drainage ditch 0.5 meters wide and 0.3 meters deep at the bottom of the slope. The construction area is clean and tidy for subsequent operations. The slope surface is flat, which is conducive to the laying of ecological substrate.

[0092] Specific steps for laying ecological substrate: Mixed substrate: Mix various substrate components according to the predetermined ratio. Layered laying: Lay the mixed ecological substrate evenly on the slope in layers, with each layer being 15 cm thick. Compacting: Use a compactor to compact the laid substrate. The ecological substrate is evenly distributed to improve the soil structure. After compaction, the substrate is tightly combined with the soil to improve the stability of the slope.

[0093] Specific steps for planting vegetation: Seeding or transplanting: Sow grass seeds on the ecological substrate and transplant the seedlings. Watering and fertilizing: Water once in the morning and evening every day to keep the soil moist. Covering and protection: Use ecological bags to cover the newly planted vegetation to prevent soil erosion. Vegetation grows rapidly and the coverage rate reaches more than 90%. Through covering and protection, water evaporation and soil erosion are reduced.

[0094] Specific steps for setting up the drainage system: Set up drainage ditches: Set up drainage ditches at the bottom of the slope to ensure smooth drainage of rainwater. Protective facilities: Set up retaining walls at the top of the slope. The drainage system is smooth to prevent water accumulation on the slope. The retaining wall is stable to improve the stability of the slope.

[0095] Specific steps for later maintenance: Regular inspection: Check the stability of the slope and the growth of vegetation once a week. Timely replanting: Replant in time when sparse vegetation is found. Pest and disease control: Regularly check whether there are pests and diseases, and take preventive measures. Pruning management: Prune overgrown plants. Find problems in time to ensure the long-term stability of the ecological slope protection. Vegetation grows healthily and maintains good ventilation and light conditions.

[0096] Specific steps for effect evaluation: Environmental monitoring: Soil erosion: Install soil erosion monitoring devices to record soil erosion on the slopes before and after rainfall. Vegetation coverage: Use drones to take photos of the slopes and calculate the vegetation coverage. Soil quality: Regularly sample and test the soil's organic matter content, pH value and other indicators.

[0097] After sampling and testing, the implementation effect data is as follows:

[0098] 1. Soil and water loss is reduced. Before the rain: the amount of soil and water loss on the slope is 20 tons per hectare per year; after the rain: the amount of soil and water loss on the slope is reduced to 2 tons per hectare per year.

[0099] 2. Increased vegetation coverage. Before construction: the slope vegetation coverage was 10%; after construction: the slope vegetation coverage reached more than 90%.

[0100] 3. Improved soil quality. Before construction: soil organic matter content was 1.5%; after construction: soil organic matter content increased to 3.5%.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. An improved soil ecological substrate for ecological slope protection, characterized in that: include: A humic acid and biochar with a mass ratio of 20-30%, wherein the humic acid is a humic acid finished product with a soluble humic acid content of more than 60% and a pass rate of more than 90% through an 80-mesh sieve; the biochar is made of rice straw husks, crushed into particles less than 1 cm, and dried at 60° C. to a moisture content of less than 10%, heated to 500° C. in an oxygen-deficient environment for 30 minutes in a high-temperature pyrolysis furnace, and the screened humic acid and biochar are mixed in proportion according to the properties of the soil at the site of use; A modified clay with a mass ratio of 25 to 30%, wherein the modified clay is made from natural kaolin and montmorillonite and surface-modified with aluminum salt or iron salt; A microbial nutrient with a mass ratio of 10 to 20%, wherein the microbial nutrient is prepared by mixing bacterial species, sesbania gum and sodium polyacrylate solution, dripping the mixture into a calcium chloride solution to form an immobilized carrier, and then allowing the bacterial species to adhere to a fibrous permeable plate by soaking or spraying the immobilized carrier, wherein the bacterial species and the required nutrients are selected to match the local soil; A nutrient sustained-release agent with a mass ratio of 5 to 10%, wherein the nutrient sustained-release agent is a microcapsule formed by encapsulating the nutrient substance with a degradable green and environmentally friendly packaging material; A curing agent with a mass ratio of 5 to 10%, wherein the curing agent includes 60 to 70% of a vinyl acetate polymer, 10 to 15% of a polyethylene glycol, 5 to 10% of a silane coupling agent, 5 to 10% of an acrylate copolymer, 10 to 20% of pure water or deionized water, and a trace amount of a preservative; Humic acid, biochar, modified clay, microbial nutrients, nutrient slow-release agents and curing agents are fully mixed according to the above proportions, and water is added to form a plastic mixture. The plastic mixture is then placed in a mold to form substrate blocks or particles of a desired shape and size, and naturally air-dried or low-temperature dried to obtain an improved soil ecological substrate.

2. The improved soil ecological substrate according to claim 1, characterized in that: For the use scenario of sandy soil with low fertility and poor water retention, the mixing mass ratio of humic acid to biochar is 2:1; for the use scenario of clay with serious pollution and poor air permeability, the mixing mass ratio of humic acid to biochar is 1:1; for the use scenario of slope protection dominated by drought-resistant plants, the mixing mass ratio of humic acid to biochar is 1:1.5; for the use scenario of slope protection dominated by fertilizer-loving plants, the mixing mass ratio of humic acid to biochar is 1.5:

1.

3. The improved soil ecological substrate according to claim 1, characterized in that: After the humic acid and biochar are mixed, the step of adjusting the pH value of the mixture by adding an acid-base regulator according to the properties of the soil at the place of use is also included.

4. The improved soil ecological substrate according to claim 1, characterized in that: The steps of surface modification using aluminum salt or iron salt include: a) Raw material selection: natural kaolin or montmorillonite is selected as the raw material and crushed for later use; b) Modifier preparation: Aluminum sulfate and ferric sulfate are selected as modifiers, and the aluminum sulfate and ferric sulfate are dissolved in deionized water or distilled water at a concentration of 0.2 mol / L to 0.8 mol / L, and stirred until the modifier is completely dissolved in the water; c) Reaction preparation: 6 parts by weight of the modifier is prepared in a reaction kettle, and the stirrer is turned on at a stirring speed of 60 to 80 rpm. After the stirring speed is stabilized, 4 parts by weight of crushed kaolin or montmorillonite powder is slowly added for a period of not less than 30 minutes; after the solution is evenly mixed, the heating rod is turned on, the temperature is set to 50 to 80° C., and the time is 2 to 4 hours; after the reaction is completed, the mixture is filtered to separate the solid product; the solid product is washed with deionized water for multiple times; d) drying: drying the washed solid product at 80-120° C. for 4-8 hours; e) Crushing and sieving: The dried solid product is crushed and sieved to obtain modified clay with a particle size of 60 to 80 mesh.

5. The improved soil ecological substrate according to claim 1, characterized in that: The preparation steps of the microbial nutrient include: mixing bacterial strains, sesbania gum and sodium polyacrylate solution, and dripping them into a calcium chloride solution to form a beaded immobilization carrier, wherein the mass ratio of sesbania gum is 3-5%, the mass ratio of sodium polyacrylate is 5-8%, and the mass concentration of the calcium chloride solution is 0.2%-5%; and the bacterial strains are attached to a fibrous permeable plate by soaking and spraying, wherein the fibrous permeable plate is prepared by soaking the permeable plate with nano-scale silica sol and then drying it.

6. The improved soil ecological substrate according to claim 1, characterized in that: The preparation of the microcapsules comprises: dissolving chitosan in a dilute acetic acid solution with a mass concentration of 1 to 5% to prepare a chitosan solution, wherein the mass concentration of chitosan is 1 to 3%; stirring and heating at 60 to 80 rpm and 50 to 60° C. to fully dissolve and obtain a uniform chitosan acetic acid solution; dissolving sodium polyacrylate in deionized water to prepare a sodium polyacrylate solution with a concentration of 2 to 5%, and stirring to uniformly dissolve; mixing the chitosan acetic acid solution and the sodium polyacrylate solution in a mass ratio of (1 to 3):1, stirring, and adding nutrients, and after the addition is completed, slowly dripping a glutaraldehyde solution with a mass concentration of 0.1 to 1% of the mass of chitosan, and continuously stirring for a reaction of 1 to 6 hours; pouring the mixed and cross-linked solution into a mold, removing moisture by evaporation drying, freeze drying or vacuum drying, and forming a packaging material to obtain a microcapsule.

7. The improved soil ecological substrate according to claim 6, characterized in that: The preparation of the microcapsules also includes: treating with alkali solution to neutralize the residual acetic acid, then washing the packaging material, removing unreacted raw materials and impurities, and then drying.