Lawn with self-repairing function and construction method thereof

Abstract

The invention relates to the technical field of greening, in particular to a lawn with a self-repairing function and a construction method thereof.The construction method includes the steps that rotary tillage equipment is used for conducting scarification pretreatment on surface soil of a construction area, mixed grass seeds of zoysia japonica and cynodon dactylon are selected, and composite coating treatment is conducted to obtain composite coating type grass seeds; sodium carboxymethyl cellulose and nano layered silicate with the mass being 2%-5% of the mass of the sodium carboxymethyl cellulose are compounded to form thixotropic hydrogel, a hydrogel matrix is obtained, the composite coated grass seeds and the hydrogel matrix are mixed according to the mass ratio to prepare slurry, the slurry is evenly sprayed to a target area through a spray head, first irrigation is conducted through a mist sprayer within 5 minutes after spray-seeding is completed, and the thixotropic hydrogel is obtained. According to the method, the grass seeds are subjected to composite coating treatment, particularly, the first layer of nutrient gel coating film provides initial nutrients needed by germination of the grass seeds, the water retention layer effectively maintains the microenvironment humidity around the grass seeds, and rapid germination of the grass seeds and robust growth of seedlings are jointly promoted.

Description

Technical Field

[0001] This invention relates to the field of greening technology, specifically to a self-healing lawn and its construction method. Background Technology

[0002] Lawns, as an important component of urban greening and landscape construction, are widely used in parks, sports fields, golf courses, and residential areas. However, over long-term use, lawns are prone to partial bareness or degradation due to factors such as mechanical trampling, pests and diseases, drought, and soil erosion, significantly affecting their aesthetics and functionality. Traditional lawn restoration methods usually rely on manual replanting or replacement of turf, but these methods have problems such as complex construction, high costs, and long restoration cycles, and the restored lawns have limited resilience and sustainability.

[0003] In existing technologies, some lawn restoration solutions achieve a certain degree of self-repair by selecting grass species with creeping growth or high reproductive capacity (such as creeping ryegrass or bermudagrass). For example, CN110754162 A discloses a lawn restoration and maintenance technology that involves mixing grass seeds with peat moss, soaking them, and then sowing them in degraded or bald areas of the lawn, combined with regular irrigation and maintenance, to promote seed germination and improve emergence and survival rates. However, such methods mainly rely on the natural dispersal ability of grass seeds, and the restoration efficiency is limited by soil conditions, climate, and maintenance levels, making it difficult to achieve efficient restoration under high-intensity use or extreme environments. In addition, existing grass seed coating technologies mostly use a single nutrient coating or water-retaining material to improve germination rates, but the coating structure is simple and has limited function, making it difficult to meet the needs of rapid germination and long-term restoration.

[0004] In recent years, the integration of microorganisms with lawn ecosystems has attracted attention. For example, *Pseudomonas fluorescens* and arbuscular mycorrhizal fungi can enhance lawn root development and stress resistance through growth-promoting effects. However, the application of microorganisms in current technologies is usually carried out through direct spraying or soil mixing, which has problems such as difficulty in maintaining activity and uncontrollable release, limiting their application effectiveness in lawn restoration.

[0005] Therefore, there is an urgent need for a lawn construction technology that integrates multi-layer seed coating, precise low-temperature processing, and functional substrate optimization to achieve efficient and long-lasting self-repair capabilities and adapt to diverse environments and usage scenarios. Summary of the Invention

[0006] Therefore, the purpose of this invention is to provide a self-healing lawn and its construction method, which can provide an efficient and sustainable lawn restoration solution for urban greening and high-intensity use scenarios, improve lawn quality, reduce maintenance costs, and enhance environmental adaptability.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for constructing a self-healing lawn includes the following steps:

[0009] S1. Use rotary tillage equipment to loosen and pretreat the surface soil in the construction area.

[0010] S2. Select mixed seeds of Zoysia japonica and Bermuda grass and perform compound coating treatment:

[0011] S21. After soaking the grass seeds in an aqueous nutrient gel, they are dried, and a first nutrient gel coating is formed on the grass seeds.

[0012] S22. Spray a chitosan-sodium alginate mixed solution onto the outside of the first nutrient gel membrane, and spray in calcium chloride aqueous solution to form a cross-linked structure. Then freeze for 2 hours and then sublimate and dry to form the second porous skeleton membrane.

[0013] S23. Using a piezoelectric nozzle, a sodium polyacrylate solution is sprayed to form an irregular patchy water-retaining layer, which is then dried at 30-35°C for 30-40 minutes to obtain composite coated grass seeds.

[0014] S3. Sodium carboxymethyl cellulose is compounded with 2%-5% of its mass of nano-layered silicate to form a thixotropic hydrogel. After stirring and shear thinning to a stable state, 1%-2% of bilayer microgel is added to obtain the hydrogel matrix.

[0015] S4. Mix the composite coated grass seeds with the hydrogel matrix at a mass ratio of 1:20 to make a slurry. Use a fan-shaped nozzle with a nozzle diameter of 4mm and a pressure of 0.5±0.1 MPa to spray it evenly on the target area. The grass seed spraying rate is 80-100 grams / square meter.

[0016] S5. Within 5 minutes after the spraying is completed, use a mist sprayer to irrigate for the first time, with a water volume of 5-10 mm. After that, keep the surface soil moist for no less than 7 days a day.

[0017] The present invention is further configured such that the loosening pretreatment specifically involves: removing surface weeds and gravel, using a grooving roller to form a shallow trench structure with a depth of 5-10 cm and a spacing of 20-30 cm on the surface, and pre-wetting the surface before spraying to make the soil moisture content reach 10%-15%.

[0018] The present invention is further configured such that: the aqueous nutrient gel is composed of sodium alginate, humic acid, and EDTA-chelated trace elements, and the weight ratio of its components is: 1-2 parts sodium alginate, 0.5-1 part humic acid, 0.1-0.2 parts EDTA-chelated iron, zinc, and manganese mixed trace elements, and 100 parts water.

[0019] In step S21, the grass seeds are immersed in an aqueous nutrient gel for 10-15 seconds, and then dried in an environment of 35-38°C for 30-40 minutes to form the first nutrient gel coating.

[0020] The present invention is further configured such that: in step S22, a cross-linked structure is formed by spraying in a 2% calcium chloride aqueous solution, followed by freezing at -40°C for 2 hours, and then sublimation drying at 0-10°C for 8 hours and desorption drying at 20-25°C for 4 hours to form a second porous skeleton membrane.

[0021] The present invention is further configured such that: the core of the double-layered microcapsule is a mixed inoculant of *Pseudomonas fluorescens* and *Arbuscular mycorrhizal fungi*, wherein the concentration of *Pseudomonas fluorescens* is [missing information]. CFU / g, concentration of arbuscular mycorrhizal fungi: CFU / g;

[0022] The inner shell is made of pH-sensitive acrylic resin with a pH response range of 5.5 to 6.8;

[0023] The outer shell is made of carboxymethyl cellulose.

[0024] The present invention is further configured such that: the mass ratio of chitosan to sodium alginate in the chitosan-sodium alginate mixed solution is 1:1, the crosslinking time is 60 seconds, the thickness of the resulting second porous framework membrane is 3-5 micrometers, and the porosity after drying is 70%±5%.

[0025] The present invention is further configured such that: the spraying density of the water-retaining layer is 20-30 water-retaining particles / mm², the particle size is 100±20 micrometers, and the moisture content of the dried grass seeds is less than 8%.

[0026] A self-healing lawn is constructed using the aforementioned construction method.

[0027] The present invention is further configured such that the lawn structure includes:

[0028] Soil base layer;

[0029] An active remediation layer is fixed to the surface of the soil base layer. The active remediation layer is composed of a mixture of composite-coated grass seeds and functional hydrogel matrix. The surface of the composite grass seeds has a nutrient layer, a porous skeleton layer and a discrete water-retaining layer arranged in sequence. The hydrogel matrix contains microbial bilayer microcapsules.

[0030] Compared with the shortcomings of the prior art, the beneficial effects of the present invention are as follows:

[0031] By applying a composite coating to the grass seeds, the first layer of nutrient gel coating provides the initial nutrients needed for seed germination, while the water-retaining layer effectively maintains the humidity of the microenvironment around the seeds, thus promoting rapid germination and robust seedling growth.

[0032] By introducing bilayered microcapsules encapsulating microorganisms into a hydrogel matrix and designing a pH-sensitive release mechanism, beneficial microorganisms (Pseudomonas fluorescens and arbuscular mycorrhizal fungi) can be precisely released when the lawn is damaged or the local pH is altered by exudates from newly formed roots. These microorganisms form a symbiotic relationship with the newly formed roots, promoting rapid repair and regeneration of the lawn. Attached Figure Description

[0033] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0034] Reference Figure 1 This invention provides a method for constructing a self-healing lawn and the constructed lawn. Further, this invention involves treating grass seeds with a composite coating process and then mixing and spraying them with a functional hydrogel matrix containing microbial double-layer microcapsules. This activates the activity of microorganisms after the lawn is damaged, synergistically promoting the self-repair of the lawn.

[0035] Example 1 includes the following steps:

[0036] S1. Soil loosening pretreatment:

[0037] This step aims to provide a good soil environment for the growth of grass seeds, and the specific operation is as follows:

[0038] Remove surface weeds and gravel: Use manual or mechanical methods to thoroughly remove weeds and gravel from the surface of the construction area to reduce competition and obstacles to lawn growth.

[0039] Grooving rollers create shallow trench structures: Grooving rollers with a grooving structure are used to create shallow trenches 5 cm deep and 20 cm apart on the ground surface. These trenches help guide the even distribution of grass seeds and provide some fixation for subsequent hydroseeding, reducing runoff loss.

[0040] Pre-wetting the soil surface before hydroseeding: Before hydroseeding, the soil surface is pre-wetted using spraying equipment to bring the soil moisture content to 10%. Pre-wetting improves soil wettability, which is beneficial for the penetration and diffusion of the hydroseeding slurry and promotes good contact between the grass seeds and the soil.

[0041] S2. Composite coating treatment: Through multi-layer coating, the grass seeds are provided with nutrition, structural support, water retention and protection against microorganisms, creating favorable conditions for the germination and early growth of the grass seeds, and endowing them with self-repair function.

[0042] S21, First layer of nutrient gel coating:

[0043] Preparation of the aqueous nutrient gel: The aqueous nutrient gel is composed of sodium alginate, humic acid, and EDTA-chelated trace elements. In this embodiment, the weight ratio of its components is: 1 part sodium alginate, 0.5 parts humic acid, 0.1 parts EDTA-chelated iron, zinc, and manganese mixed trace elements, and 100 parts water. These components are thoroughly mixed and dissolved to form a viscous nutrient gel.

[0044] Sodium alginate: As a natural high-molecular-weight polysaccharide, it has good biocompatibility and gelling properties, and can be used as a matrix material for coating.

[0045] Humic acid is a natural organic substance rich in various nutrients that can promote the germination of grass seeds and root growth.

[0046] EDTA chelates trace elements (iron, zinc, manganese): EDTA chelation can improve the solubility and absorption rate of trace elements, providing essential mineral nutrition for grass seeds.

[0047] Impregnation and Drying: The selected mixed seeds of Zoysia japonica and Bermuda grass were impregnated in the above-mentioned aqueous nutrient gel for 10 seconds to ensure a uniform coating of nutrient gel on the seed surface. They were then dried at 35°C for 30 minutes to form the first nutrient gel coating. The impregnation time affects the amount of nutrient gel adhering, while the drying temperature and time affect the degree of coating curing.

[0048] S22, Second porous framework membrane:

[0049] This step aims to form a skeleton layer with a certain structural strength and porosity on the outside of the grass seeds, providing physical support for the seedlings to break through the coating, while the porous structure is conducive to gas exchange.

[0050] Spraying a chitosan-sodium alginate mixed solution: A mixed solution of chitosan and sodium alginate in a 1:1 mass ratio was prepared. This mixed solution was then uniformly sprayed onto the outer surface of grass seeds coated with a first layer of nutrient gel using a spraying device. Both chitosan and sodium alginate are natural polymer materials with good biocompatibility and film-forming properties.

[0051] A cross-linking structure is formed by spraying in a calcium chloride aqueous solution: A 2% calcium chloride aqueous solution is immediately sprayed in before the chitosan-sodium alginate mixture has completely solidified. Calcium chloride, as a divalent cation, can undergo an ionic cross-linking reaction with sodium alginate to form a stable gel structure. Simultaneously, electrostatic interactions exist between chitosan and sodium alginate, enhancing the stability of the structure. The cross-linking time is controlled at 60 seconds.

[0052] Sodium alginate molecules contain a large number of carboxyl groups (-COOH), which dissociate into carboxylate ions in aqueous solution. ), calcium ions in calcium chloride aqueous solution ( It interacts with alginate ions via electrostatic attraction, forming an "egg-box" structure, thereby crosslinking the sodium alginate molecular chains to form a gel.

[0053] The kinetics of the cross-linking reaction can be described using a bimolecular reaction model, with the reaction rate being directly proportional to the product of the concentrations of sodium alginate carboxylate ions and calcium ions. in, This is the reaction rate constant. In practice, the degree and rate of the crosslinking reaction are controlled by adjusting the concentration and injection speed of the calcium chloride solution. A crosslinking time of 60 seconds is an optimal time determined based on preliminary experiments, which can obtain suitable crosslinking strength and pore structure.

[0054] Freeze-drying and sublimation drying: After forming the cross-linked structure, the grass seeds are frozen at -40°C for 2 hours to freeze the internal moisture. This is followed by sublimation drying at 0-10°C for 8 hours and desorption drying at 20-25°C for 4 hours. The freezing step rapidly freezes the moisture, forming ice crystals, which are then directly converted into vapor and removed during sublimation drying, resulting in a porous structure. Desorption drying further removes bound water, ensuring the stability of the skeletal structure.

[0055] The process by which matter transforms directly from a solid state to a gaseous state under vacuum and low temperature conditions. By controlling temperature and pressure, moisture can be effectively removed while preserving the original structure of the matter to the greatest extent possible.

[0056] The second porous framework membrane obtained after drying has a thickness of 3 micrometers and a porosity of 70% ± 5%. The pore structure can be observed and analyzed using methods such as scanning electron microscopy. The high porosity is conducive to the exchange of gas and moisture, promoting the germination of grass seeds.

[0057] S23, Water-retaining layer:

[0058] Piezoelectric nozzles spray sodium polyacrylate solution: Sodium polyacrylate solution is sprayed onto the surface of the second porous framework membrane using a piezoelectric nozzle, forming an irregularly patchy water-retaining layer. Sodium polyacrylate is a superabsorbent polymer with extremely strong water absorption capacity, capable of absorbing and storing moisture to provide a continuous water supply for grass seed germination. The piezoelectric nozzles can precisely control the size and distribution density of the water-retaining particles by controlling the droplet size and spray frequency.

[0059] The seeds were then dried at 30°C for 30 minutes to solidify the sodium polyacrylate solution and form a stable water-retaining layer. The dried grass seeds had a moisture content of less than 8%, which is beneficial for storage and transportation.

[0060] The spraying density of the water-retaining layer is 20 water-retaining particles / mm², with a particle size of 100 micrometers. The density and particle size of the water-retaining layer affect its water retention effect and distribution uniformity. The irregular patchy distribution can avoid completely sealing the grass seed surface and retain gas exchange channels.

[0061] The resulting composite coated grass seeds have a surface with a nutrient layer, a porous framework layer, and a discrete water-retaining layer arranged sequentially.

[0062] S3. Preparation of hydrogel matrix:

[0063] The functional hydrogel matrix prepared in this step is an important carrier for the self-repair function of lawns.

[0064] Preparation of thixotropic hydrogel: Sodium carboxymethyl cellulose was compounded with 2% (by weight) of nano-layered silicate to form a thixotropic hydrogel. Thixotropy refers to the property of viscosity decreasing under shear force and recovering after standing. This property is beneficial for the spraying of the slurry and its stability in soil.

[0065] Sodium carboxymethyl cellulose, as a water-soluble cellulose ether, has good thickening properties, stability, and biocompatibility, and is a major component of hydrogels.

[0066] Nanolayered silicates, acting as thixotropic agents, can form a network structure with sodium carboxymethyl cellulose, imparting thixotropic properties to hydrogels. The nanoscale size and layered structure increase their surface area and adsorption capacity.

[0067] Adding bilayer microcapsules: After stirring and shear-thinning to a stable state, 1% bilayer microcapsules were added to obtain the hydrogel matrix. The bilayer microcapsules encapsulate microorganisms, which are key to the self-repair function of lawns.

[0068] The bilayer microcapsule includes:

[0069] A mixed inoculum of Pseudomonas fluorescens and arbuscular mycorrhizal fungi.

[0070] *Pseudomonas fluorescens* is a common rhizosphere growth-promoting bacterium that can promote plant growth by secreting plant growth hormones, dissolving phosphorus, and fixing nitrogen, and also has certain biocontrol functions. The concentration was... CFU / g.

[0071] Arbuscular mycorrhizal fungi are fungi that form a symbiotic relationship with plant roots, expanding the absorption range of the root system, improving the efficiency of water and nutrient absorption, and enhancing the plant's resistance to adverse conditions. The concentration is... CFU / g. The synergistic effect of mixed microbial agents can more effectively promote lawn growth and repair.

[0072] The inner shell is made of pH-sensitive acrylic resin. This material swells or dissolves within a specific pH range, releasing the internal microorganisms. The pH response range is 5.5 to 6.8, which is typically the pH range where plant root exudates are present. Therefore, when the lawn is damaged, changes in the local pH due to new root exudates can trigger the dissolution of the microcapsules.

[0073] pH-sensitive acrylic resins contain acidic or basic functional groups. Under specific pH conditions, the degree of ionization of these functional groups changes, leading to a conformational change in the polymer chain, which in turn affects its solubility or swelling degree.

[0074] The outer shell is made of carboxymethyl cellulose. As a biocompatible polymer material, it can provide additional protection for the pH-sensitive inner shell and control the release rate of microorganisms.

[0075] The double-layered design better protects microorganisms from external environmental disturbances and allows for precise control of their release when needed. When the lawn is damaged, the secretions from new roots alter the soil microenvironment pH to 5.5–6.8, causing the pH-sensitive inner shell to dissolve and release the microorganisms.

[0076] S4. Slurry preparation and spraying:

[0077] This step involves mixing the composite-coated grass seeds with a functional hydrogel matrix to form a sprayable slurry, which is then evenly applied to the target area.

[0078] The composite-coated grass seeds and hydrogel matrix were mixed at a mass ratio of 1:20 and thoroughly stirred to form a homogeneous slurry. The ratio of grass seeds to matrix affects the uniformity of spraying and the density of the grass seeds.

[0079] A fan-shaped nozzle with a 4mm diameter and a pressure of 0.5MPa is used to evenly spray the slurry onto the target area. The fan-shaped nozzle helps achieve uniform coverage over a large area. Spraying pressure affects the spraying range and atomization effect. The grass seeding rate is controlled at 80 grams per square meter. This rate ensures sufficient grass seed density, guaranteeing rapid establishment and restoration of the lawn.

[0080] S5. Initial watering and subsequent maintenance:

[0081] This step aims to provide the necessary moisture for the germination of grass seeds and to sustain the initial growth of the lawn.

[0082] Within 5 minutes of hydroseeding, apply the first irrigation using a mist sprayer with a water volume of 5 mm. Mist spraying avoids eroding the freshly sprayed slurry, and the 5 mm of water fully moistens the soil surface, promoting seed water absorption and expansion.

[0083] Afterward, keep the topsoil moist for at least 7 days each day. A continuous supply of water is essential for seed germination and seedling growth. Keeping the topsoil moist prevents dryness from damaging the seeds and seedlings.

[0084] The lawn constructed using the above construction method has the following structural characteristics:

[0085] Soil base layer: The original pre-treated soil layer provides the physical support and basic nutrients needed for lawn growth.

[0086] Active remediation layer fixed to the surface of soil base layer: composed of a mixture of composite-coated grass seeds and functional hydrogel matrix.

[0087] Compound grass seeds: The surface has a nutrient layer (providing nutrients), a porous skeleton layer (providing structural support and gas exchange channels), and a discrete water-retaining layer (providing moisture) arranged in sequence.

[0088] Functional hydrogel matrix: dispersed with microbial bilayer microcapsules.

[0089] The constructed lawn possesses a unique self-repairing ability, the mechanism of which is as follows:

[0090] When a lawn is damaged, the plant initiates a repair mechanism, and new roots begin to grow. These new roots secrete root exudates containing organic acids and other substances that can alter the pH of the local microenvironment. When the pH of the local microenvironment reaches 5.5–6.8, it triggers the dissolution of the pH-sensitive inner shell of the microbial bilayer microcapsules within the hydrogel matrix.

[0091] Upon dissolution, the microcapsules release *Pseudomonas fluorescens* and arbuscular mycorrhizal fungi. These microorganisms can colonize the soil and establish a symbiotic relationship with the root system of seedlings formed from germinating grass seeds. *Pseudomonas fluorescens* promotes seedling growth, while arbuscular mycorrhizal fungi improve the efficiency of seedlings in absorbing water and nutrients, enhancing their resistance to adverse conditions.

[0092] Grass seeds swell after absorbing water, and the physical expansion force generated during seed germination can cause structural damage to the brittle middle layer (second porous skeleton membrane) in the coating.

[0093] Providing a channel for seedling emergence: The disruption of the skeleton layer provides a channel for grass seedlings to break through the seed coat and emerge smoothly from the soil. The brittle skeleton design ensures that the seedlings can break through when needed, while the porous structure provides gas exchange before the seedlings emerge from the soil.

[0094] Example 2: This example is based on Example 1, but some parameters are adjusted to demonstrate the operability of the present invention.

[0095] S1. Soil loosening pretreatment: Same as Example 1.

[0096] S2, Composite Coating Treatment:

[0097] S21. First layer of nutrient gel coating: The weight ratio of the aqueous nutrient gel components is as follows: sodium alginate 1.5 parts, humic acid 0.75 parts, EDTA-chelated iron, zinc, and manganese mixed trace elements 0.15 parts, and water 100 parts. Grass seeds are immersed in the aqueous nutrient gel for 12 seconds, followed by drying at 36°C for 35 minutes.

[0098] S22. Second porous framework coating: A 2% calcium chloride aqueous solution was sprayed in to form a cross-linked structure for 60 seconds. Subsequently, it was frozen at -45°C for 2 hours, followed by sublimation drying at 5°C for 8 hours and desorption drying at 22°C for 4 hours to form the second porous framework coating. The resulting second porous framework coating has a thickness of 4 micrometers and a porosity of 70% ± 5%.

[0099] S23, Water-retaining layer: The spraying density of the water-retaining layer is 25 water-retaining particles / mm², and the particle size is 120 micrometers. It is then dried at 32°C for 35 minutes, resulting in a grass seed moisture content of less than 8%.

[0100] S3. Preparation of hydrogel matrix: Sodium carboxymethyl cellulose was compounded with 3.5% by weight of nanolayered silicate to form a thixotropic hydrogel. After stirring and shear thinning to a stable state, 1.5% of bilayer microcapsules were added to obtain the hydrogel matrix. The core, inner shell, and outer shell of the bilayer microcapsules are the same as in Example 1.

[0101] S4. Slurry Preparation and Spraying: The composite coated grass seeds and hydrogel matrix are mixed at a mass ratio of 1:20 to prepare the slurry. A fan-shaped nozzle with a nozzle diameter of 4 mm and a pressure of 0.6 MPa is used to spray the slurry evenly onto the target area. The grass seed spraying rate is 90 g / m².

[0102] S5. Initial Irrigation and Post-Irrigation Maintenance: The initial irrigation volume is 7 mm. Afterward, keep the topsoil moist for at least 7 days each day.

[0103] Example 3: This example is based on Example 1, with some parameters further adjusted to demonstrate the optimal range of the present invention.

[0104] S1. Soil loosening pretreatment: Same as Example 1.

[0105] S2, Composite Coating Treatment:

[0106] S21. First layer of nutrient gel coating: The weight ratio of the aqueous nutrient gel components is: 2 parts sodium alginate, 1 part humic acid, 0.2 parts EDTA-chelated iron, zinc, and manganese mixed trace elements, and 100 parts water. The grass seeds are immersed in the aqueous nutrient gel for 15 seconds, followed by drying at 38°C for 40 minutes.

[0107] S22. Second porous framework coating: A 2% calcium chloride aqueous solution is sprayed in to form a cross-linked structure for 60 seconds. Subsequently, it is frozen at -50°C for 2 hours, followed by sublimation drying at 10°C for 8 hours and desorption drying at 25°C for 4 hours to form the second porous framework coating. The resulting second porous framework coating has a thickness of 5 micrometers and a porosity of 70% ± 5%.

[0108] S23, Water-retaining layer: The spraying density of the water-retaining layer is 30 water-retaining particles / mm², and the particle size is 80 micrometers. It is then dried at 35°C for 40 minutes, resulting in a grass seed moisture content of less than 8%.

[0109] S3. Preparation of hydrogel matrix: Sodium carboxymethyl cellulose was compounded with 5% by weight of nanolayered silicate to form a thixotropic hydrogel. After stirring and shear thinning to a stable state, 2% of bilayer microcapsules were added to obtain the hydrogel matrix. The core, inner shell, and outer shell of the bilayer microcapsules are the same as in Example 1.

[0110] S4. Slurry Preparation and Spraying: The composite coated grass seeds and hydrogel matrix are mixed at a mass ratio of 1:20 to prepare the slurry. A fan-shaped nozzle with a nozzle diameter of 4 mm and a pressure of 0.4 MPa is used to spray the slurry evenly onto the target area. The grass seed spraying rate is 100 g / m².

[0111] S5. Initial Irrigation and Post-Irrigation Maintenance: The initial irrigation volume is 10 mm. Afterward, keep the topsoil moist for at least 7 days each day.

[0112] Comparative Example 1: No composite coating treatment performed:

[0113] This comparative example omits step S2, i.e., the composite coating treatment of grass seeds is not performed. Uncoated Zoysia japonica and Bermuda grass seeds are directly mixed with hydrogel matrix at a mass ratio of 1:20 to form a slurry, which is then sprayed. Other steps are the same as in Example 1.

[0114] Comparative Example 2: The hydrogel matrix does not contain bilayer microcapsules:

[0115] This comparative example omits the latter half of step S3, which involves adding bilayer microcapsules to the hydrogel matrix. That is, the hydrogel matrix is ​​composed only of sodium carboxymethyl cellulose and nanolayered silicate, and does not contain microbial bilayer microcapsules. The composite-coated grass seeds (prepared according to the method in Example 1) are mixed with the microcapsule-free hydrogel matrix at a mass ratio of 1:20 to form a slurry, which is then sprayed. Other steps are the same as in Example 1.

[0116] Comparative Example 3: Only S21 and S23 are covered, S22 is omitted:

[0117] This comparative example only involves the first layer of nutrient gel coating and water-retaining layer coating, omitting the second porous framework coating. That is, the grass seeds are only treated in steps S21 and S23. The grass seeds with two coating layers are mixed with the hydrogel matrix (containing double-layer microcapsules, prepared according to the method of Example 1) at a mass ratio of 1:20 to form a slurry, which is then sprayed. Other steps are the same as in Example 1.

[0118] Based on the above experiments conducted in Examples 1-3 and Comparative Examples 1-3, the specific results are shown in Table 1:

[0119]

[0120] Examples 1, 2, and 3 all showed high grass seed germination rates, seedling growth rates, and lawn uniformity. In particular, Example 3 performed best in all indicators, which is related to the preferred range parameters used.

[0121] All indicators of Comparative Example 1 (without composite coating) were significantly lower than those of Example 1, indicating that composite coating treatment has an important promoting effect on the germination and early growth of grass seeds. The nutrient layer provides the nutrients required for initial growth, and the water-retaining layer maintains moisture, which helps to improve the germination rate and growth rate.

[0122] While Comparative Example 2 (hydrogel matrix without microcapsules) showed better turf establishment, its repair rate after damage was significantly lower than that of the Example 2. This demonstrates the crucial role of the microbial bilayer microcapsules in the turf's self-repair function. The microorganisms released after damage can promote the growth of new roots and accelerate turf recovery.

[0123] The germination and repair rates of Comparative Example 3 (without the porous skeletal membrane) were also lower than those of the Example, indicating that the porous skeletal membrane plays an important role in seedling emergence and the activation of subsequent repair mechanisms. The skeletal structure provides a breakthrough channel for seedlings and may also affect water and gas exchange, thereby affecting the activity of microorganisms.

[0124] In summary, the technical solution of this invention, through the synergistic effect of composite-coated grass seeds and a hydrogel matrix containing microbial bilayer microcapsules, can significantly improve the establishment efficiency of lawns and endow them with excellent self-repair capabilities. Example 3, using parameters within the preferred range, exhibits the best overall effect.

[0125] To verify the technical effect of the present invention, the control group was set up as follows:

[0126] Control group 1: The traditional lawn construction method was used, which involved directly sowing uncoated Zoysia japonica and Bermuda grass seeds on the soil after simple land preparation, without using hydrogel matrix or any coating treatment.

[0127] Control group 2: Using conventional hydroseeding methods, uncoated grass seeds were mixed with ordinary hydrogel (without nanolayered silicate and double-layer microcapsules) and sprayed.

[0128] Performance testing methods:

[0129] Grass seed germination rate: On the 7th day after hydroseeding, multiple 30cm x 30cm areas were randomly selected, the number of germinated grass seeds was counted, and the average germination rate was calculated.

[0130] Seedling growth rate: On the 14th day after hydroseeding, multiple areas were randomly selected to measure the average height of the grass seedlings.

[0131] Lawn uniformity: On the 30th day after spraying, the uniformity and density of the lawn cover are visually assessed and divided into four levels: excellent, good, fair, and poor.

[0132] Repair rate after damage: After the lawn has stabilized (approximately 60 days), sections of lawn are manually mowed in different areas, creating damaged areas approximately 30cm x 30cm in size. On day 21 after the damage, the area of ​​newly grown lawn within the damaged area is measured, and the proportion of the restored area to the original damaged area is calculated.

[0133] Lawn health: Observe the color and density of lawn leaves at different times, record the occurrence of diseases and pests, and comprehensively assess the health status of the lawn.

[0134] Experimental data:

[0135]

[0136] Experimental results show that, compared with traditional lawn construction methods (control groups 1 and 2), the construction methods of this invention (Examples 1, 2, and 3) can significantly improve the germination rate of grass seeds and the growth rate of seedlings, creating a more uniform and healthy lawn. In particular, the lawn constructed by this invention exhibits excellent self-repair capabilities after damage, with a repair rate far exceeding that of the control groups. This fully verifies the technical effectiveness of this invention, namely, that the composite coating treatment provides a favorable growth environment for the grass seeds, while the hydrogel matrix containing microbial double-layer microcapsules activates microbial activity after lawn damage, synergistically promoting the rapid recovery of the lawn.

[0137] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any ordinary changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included within the protection scope of the present invention.

Claims

1. A construction method for a lawn with self-healing function, characterized in that, Includes the following steps: S1. Use rotary tillage equipment to loosen and pretreat the surface soil in the construction area. S2. Select mixed seeds of Zoysia japonica and Bermuda grass and perform compound coating treatment: S21. After soaking the grass seeds in an aqueous nutrient gel, they are dried, and a first nutrient gel coating is formed on the grass seeds. S22. Spray a chitosan-sodium alginate mixed solution onto the outside of the first nutrient gel membrane, and spray in calcium chloride aqueous solution to form a cross-linked structure. Then freeze for 2 hours and then sublimate and dry to form the second porous skeleton membrane. S23. Using a piezoelectric nozzle, a sodium polyacrylate solution is sprayed to form an irregular patchy water-retaining layer, which is then dried at 30-35°C for 30-40 minutes to obtain composite coated grass seeds. S3. Sodium carboxymethyl cellulose is compounded with 2%-5% of its mass of nano-layered silicate to form a thixotropic hydrogel. After stirring and shear thinning to a stable state, 1%-2% of bilayer microgel is added to obtain the hydrogel matrix. S4. Mix the composite coated grass seeds with the hydrogel matrix at a mass ratio of 1:20 to make a slurry. Use a fan-shaped nozzle with a nozzle diameter of 4mm and a pressure of 0.5±0.1 MPa to spray it evenly on the target area. The grass seed spraying rate is 80-100 grams / square meter. S5. Within 5 minutes after the spraying is completed, use a mist sprayer to irrigate for the first time, with a water volume of 5-10 mm. After that, keep the surface soil moist for no less than 7 days a day.

2. The construction method for a self-healing lawn according to claim 1, characterized in that, The loosening pretreatment specifically involves: removing surface weeds and gravel, using a grooving roller to form shallow trenches 5-10 cm deep and 20-30 cm apart on the surface, and pre-wetting the surface before spraying to achieve a soil moisture content of 10%-15%.

3. The construction method for a self-healing lawn according to claim 2, characterized in that, The aqueous nutrient gel is composed of sodium alginate, humic acid, and EDTA-chelated trace elements. The weight ratio of its components is: sodium alginate 1-2 parts, humic acid 0.5-1 part, EDTA-chelated iron, zinc, and manganese mixed trace elements 0.1-0.2 parts, and water 100 parts. In step S21, the grass seeds are immersed in an aqueous nutrient gel for 10-15 seconds, and then dried in an environment of 35-38°C for 30-40 minutes to form the first nutrient gel coating.

4. The construction method for a self-healing lawn according to claim 3, characterized in that, In step S22, a cross-linked structure is formed by spraying in a 2% calcium chloride aqueous solution, followed by freezing at -40°C for 2 hours, then sublimation drying at 0-10°C for 8 hours and desorption drying at 20-25°C for 4 hours to form a second porous framework membrane.

5. The construction method for a self-healing lawn according to claim 4, characterized in that, The core of the double-layered microcapsule is a mixed inoculum of *Pseudomonas fluorescens* and *Arbuscular mycorrhizal fungi*, wherein the concentration of *Pseudomonas fluorescens* is [missing information]. CFU / g, concentration of arbuscular mycorrhizal fungi: CFU / g; The inner shell is made of pH-sensitive acrylic resin with a pH response range of 5.5 to 6.8; The outer shell is made of carboxymethyl cellulose.

6. The construction method for a self-healing lawn according to claim 2, characterized in that, In the chitosan-sodium alginate mixed solution, the mass ratio of chitosan to sodium alginate is 1:1, the cross-linking time is 60 seconds, the thickness of the resulting second porous framework membrane is 3-5 micrometers, and the porosity after drying is 70%±5%.

7. The construction method for a self-healing lawn according to claim 2, characterized in that, The spraying density of the water-retaining layer is 20-30 water-retaining particles / mm², the particle size is 100±20 micrometers, and the moisture content of the dried grass seeds is less than 8%.

8. A lawn with self-healing capabilities, characterized in that, Constructed by the construction method according to any one of claims 1-8.

9. A lawn with self-healing ability according to claim 8, characterized in that, The lawn structure includes: Soil base layer; An active remediation layer is fixed to the surface of the soil base layer. The active remediation layer is composed of a mixture of composite-coated grass seeds and functional hydrogel matrix. The surface of the composite grass seeds has a nutrient layer, a porous skeleton layer and a discrete water-retaining layer arranged in sequence. The hydrogel matrix contains microbial bilayer microcapsules.

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