Multilayer composite nutrient turf

Abstract

The application relates to the technical field of turf, and discloses a multi-layer composite nutrient turf, which sequentially comprises a bottom substrate layer, a middle substrate layer, a top substrate layer and a seed layer, the top substrate layer comprises first fermentation products of sludge fermentation in the 10th-15th day, the middle substrate layer comprises second fermentation products of sludge fermentation in the 20th-30th day, and the bottom substrate layer comprises third fermentation products of sludge fermentation in the 45th-60th day. The fermentation products in different fermentation stages are layered and paved on the seedling layer, a gradient nutrient structure matched with the growth development stage and the spatial distribution of the turfgrass root system is constructed, the germination rate of the turfgrass on the turf is effectively improved, the nutrients of the turfgrass in each growth stage are met, and the turf coverage is improved.

Description

Technical Field

[0001] This application relates to the field of grass carpet technology, specifically to a multi-layer composite nutrient grass carpet. Background Technology

[0002] Turf mats are lawn products made by pre-cultivating turfgrass on a fiber or substrate carrier under factory conditions, and can be rolled up, transported, and laid. Compared with traditional sod rolls, turf mats are usually thinner and lighter, and are suitable for applications such as rooftop greening, slope protection, and temporary greening.

[0003] The substrate layer of a grass mat serves as both a nutrient carrier for plant growth and the structural framework of the mat. Currently, nutrient supply to the substrate layer typically employs a "uniform mixing" method, where all substrate components are evenly mixed before being laid out in one go, ensuring consistent nutrient content across all parts of the mat. Existing technologies utilize sludge, coconut fiber waste, and straw ash as raw materials to form the substrate, or optimize substrate particle size to improve mat quality. However, these methods significantly reduce grass tillering and leaf growth rates, decrease overall coverage, and easily lead to patchy bare soil or exposed soil. The industry commonly employs controlled-release fertilization technology or stratified fertilization to prolong fertilizer effectiveness; however, the following problems still exist: 1. Turfgrass has different nutrient requirements at different growth stages, and fertilizer supply cannot be precisely matched. For example, the germination period requires fast-acting nitrogen to promote leaf growth, the establishment period requires phosphorus and potassium to promote root development, and the maturity period requires long-acting slow-release nutrients. If a uniformly mixed substrate is used, the fast-acting nutrients will be released quickly in the early stage, which can easily burn the seedlings, and will be depleted in the later stage, leading to nutrient deficiency. If multiple top-dressings are applied, the maintenance cost will increase. 2. To compensate for the inadequacy of uniform fertilizer supply, some technologies use microcapsules or coated slow-release fertilizers. However, the coating materials are mostly high molecular polymers, which are costly and non-degradable, increasing the environmental burden. Summary of the Invention

[0004] This application provides a multi-layer composite nutrient turf mat that solves the problems of existing turf mats, such as mismatch between nutrient supply and growth rhythm, low germination rate, slow turf establishment, lack of fertilizer in the later stage, and environmentally unfriendly slow-release materials.

[0005] In a first aspect, this application provides a multi-layer composite nutrient mat, comprising a bottom substrate layer, a middle substrate layer, a top substrate layer, and a seed layer. The top substrate layer comprises a first fermentation product from sludge fermentation for 10-15 days, the middle substrate layer comprises a second fermentation product from sludge fermentation for 20-30 days, and the bottom substrate layer comprises a third fermentation product from sludge fermentation for 45-60 days.

[0006] In one alternative embodiment, the thickness of the top matrix layer is 1 cm - 2 cm.

[0007] In one alternative embodiment, the thickness of the central matrix layer is 2 cm to 3 cm.

[0008] In one alternative embodiment, the thickness of the bottom matrix layer is 2 cm to 4 cm.

[0009] In an optional embodiment, the top substrate layer further includes a loosening agent and a water-retaining agent. Preferably, in the top substrate layer, the first fermentation product comprises 70-85 parts by weight, the loosening agent comprises 10-20 parts by weight, and the water-retaining agent comprises 5-10 parts by weight. In one optional embodiment, the intermediate substrate layer further includes phosphate fertilizer and potassium fertilizer. Preferably, in the intermediate substrate layer, the second fermentation product comprises 80-90 parts by weight, phosphate fertilizer comprises 5-10 parts by weight, and potassium fertilizer comprises 3-5 parts by weight.

[0010] In one optional embodiment, the bottom substrate layer further includes a water-retaining agent and a modifier. Preferably, in the bottom substrate layer, the weight parts of the third fermentation product are 85-95 parts, the water-retaining agent is 5-10 parts, and the modifier is 3-5 parts.

[0011] In one alternative embodiment, the raw materials for the fermented sludge include sludge and biomass.

[0012] In one optional embodiment, the fermentation temperature of the first fermentation product is 50°C-65°C.

[0013] In one optional embodiment, the fermentation temperature of the second fermentation product is 48°C-52°C.

[0014] In one optional embodiment, the fermentation temperature of the third fermentation product is 30°C-45°C.

[0015] In one optional embodiment, the first fermentation product has an organic matter content of 35 wt%-45 wt%, a carbon-to-nitrogen ratio of 25-35, an ammonium nitrogen content of 800 mg / kg-1500 mg / kg, a nitrate nitrogen content of 20 mg / kg-100 mg / kg, and a humic acid content of 8 wt%-12 wt%; the first fermentation product has a total phosphorus content of 0.8 wt%-1.2 wt% and a total potassium content of 0.3 wt%-0.6 wt%.

[0016] In one optional embodiment, the second fermentation product has an organic matter content of 30 wt%-40 wt%, a carbon-to-nitrogen ratio of 15-25, a total phosphorus content of 1.5 wt%-2.5 wt%, a total potassium content of 1.0 wt%-2.0 wt%, an ammonium nitrogen content of 300 mg / kg-500 mg / kg, a nitrate nitrogen content of 150 mg / kg-300 mg / kg, and a humic acid content of 15 wt%-20 wt%.

[0017] In one optional embodiment, the third fermentation product has an organic matter content of 25 wt%-35 wt%, a carbon-to-nitrogen ratio of 10-15, an ammonium nitrogen content of 50 mg / kg-200 mg / kg, a nitrate nitrogen content of 200 mg / kg-400 mg / kg, and a humic acid content of 25 wt%-35 wt%. The total phosphorus content of the third fermentation product is 1.0 wt%-1.5 wt%, and the total potassium content is 0.8 wt%-1.2 wt%.

[0018] In one alternative embodiment, at least one separator layer is provided between each matrix layer.

[0019] In one alternative embodiment, the grass mat further includes a fully decomposed sludge layer covering the seed layer, the fully decomposed sludge layer comprising fully decomposed sludge, the thickness of the fully decomposed sludge layer being 2mm-5mm.

[0020] In one alternative implementation, the seeding rate is 25 g / m². 2 -40g / m 2 .

[0021] In one optional embodiment, each of the separating layers comprises either hemp fiber or coconut fiber; the length of the hemp fiber or coconut fiber in the separating layer is 1-3 cm; the thickness of each separating layer is 2 mm-5 mm; and the porosity of the separating layer is greater than or equal to 80%.

[0022] In one alternative embodiment, the grass mat further includes a protective layer covering the seed layer or the fully decomposed sludge layer.

[0023] In one alternative embodiment, the loosening agent includes at least one of vermiculite or perlite.

[0024] In one alternative embodiment, the water-retaining agent of the top matrix layer and / or the bottom matrix layer includes at least one of attapulgite, bentonite, and sodium polyacrylate.

[0025] In one alternative embodiment, the modifier comprises biochar.

[0026] In one alternative embodiment, the protective layer comprises at least one of a nonwoven fabric or a plant fiber web.

[0027] In one optional embodiment, the sludge is dewatered sludge from an urban wastewater treatment plant. This application utilizes the natural succession of organic matter forms during the aerobic fermentation of sludge: the initial fermentation product is rich in readily available nitrogen and easily decomposable organic matter (rapid release); the mid-fermentation product is relatively rich in phosphorus and potassium (moderate release); and the late-fermentation product is mainly stable humus (slow release). By spatially stratifying the products of these three stages, a natural nutrient release gradient of "fast at the top - medium in the middle - slow at the bottom" is formed. Nutrients in the top substrate layer are released 0-30 days after sowing, nutrients in the middle substrate layer are released intensively from 30-60 days, and nutrients in the bottom substrate layer are continuously released from 60-180 days, requiring no artificial fertilization throughout the entire process.

[0028] The nutrient gradient of the turfgrass mat provided in this application is precisely matched with the spatial distribution of turfgrass roots and the growth rhythm of turfgrass. The distribution of turfgrass roots in the mat exhibits a "dense at the top and sparse at the bottom" characteristic: the surface root density is high, with many fine roots, and a high demand for readily available nitrogen; the deep root density is low, with coarse roots as the main component, and a high demand for phosphorus, potassium, and slow-release nutrients. This application places the top substrate layer at the uppermost layer (the area with the densest root system), the middle substrate layer in the middle layer (where lateral roots and tillering nodes are located), and the bottom substrate layer at the lowermost layer (the area where the taproot extends and anchors), achieving a spatial match between nutrient supply and root demand. At the same time, the release sequence of nutrients in each layer coincides with the growth rhythm of the turfgrass: readily available nitrogen is needed during the germination period to promote leaf growth (corresponding to the upper layer), phosphorus and potassium are needed during the establishment period to promote root growth and tillering (corresponding to the middle layer), and slow-release nutrients are needed during the maturity period to maintain turf quality (corresponding to the bottom layer).

[0029] The turf carpet provided by this application requires no additional fertilization after installation, significantly reducing maintenance costs. Traditional turf carpets require users to apply fertilizer multiple times during germination, establishment, and before summer / winter, increasing labor and fertilizer costs. The multi-layered composite nutrient turf carpet provided by this application has a built-in complete nutrient supply system at the factory. After installation, the turfgrass automatically obtains nutrients as needed, simplifying maintenance to just watering. This makes it particularly suitable for greening projects in remote areas such as slopes and mines where professional maintenance personnel are lacking.

[0030] Secondly, this application provides a method for laying a multi-layer composite nutrient grass mat, including the following steps: S1, preparation of fermentation products for each substrate layer: according to the mass ratio of sludge to biomass of 80-90:10-20, sludge and straw are mixed evenly, piled up, and fermented using a forced intermittent ventilation aerobic composting process. The fermentation product on the 10th to 15th day of fermentation is taken as the first fermentation product, the fermentation product on the 20th to 30th day of fermentation is taken as the second fermentation product, and the fermentation product on the 45th to 60th day of fermentation is taken as the third fermentation product. S2. Preparation of each matrix layer: S11. Mix the first fermentation product, loosening agent and water-retaining agent evenly to obtain the top substrate layer; S12. Mix the second fermentation product, phosphate fertilizer and potassium fertilizer evenly to obtain the middle substrate layer; S13. Mix the third fermentation product, water-retaining agent and improver evenly to obtain the bottom substrate layer; S3. The bottom substrate layer, the first dividing layer, the middle substrate layer, the second dividing layer, and the top substrate layer are laid on the seedling layer in sequence. After each substrate layer is laid, it is leveled. Grass seeds are sown on the top substrate layer. Dividing layers are laid between each substrate layer. S4. Cover the grass seeds with fully decomposed sludge; S5. Cover the grass seed layer in step S3 or the fully decomposed sludge layer in step S4 with a protective layer.

[0031] In one alternative implementation, after each substrate layer is laid, water is sprayed onto each substrate layer to bring the moisture content of each substrate layer to 60-70 wt%.

[0032] In one optional embodiment, the grass mat is cultivated by placing it in a greenhouse or under natural light conditions, with the temperature controlled between 15-30℃. During cultivation, the substrate is kept moist but waterlogging is avoided. The cultivation period is 30-45 days. Once the turfgrass coverage reaches more than 85% and the roots have penetrated all layers of substrate and partially reached the bottom layer, it can be rolled up and shipped.

[0033] The application steps for grass mats are as follows: use a mat rolling machine to roll the grass mat along with each layer of substrate into a mat roll, transport it to the construction site, and during installation, unfold the grass mat and lay it on the target ground so that the bottom substrate layer is in direct contact with the ground. Watering is all that is needed for maintenance. After installation, the grass roots extend downward from the slow-release nutrient bottom layer into the lower soil layer. At the same time, the nutrients in each substrate layer are released in the designed sequence to meet the nutritional needs of the grass at different growth stages, without the need for additional fertilizer.

[0034] This application uses sludge as a fermentation raw material, opening up a new direction for high-value-added applications of sludge products. It upgrades the positioning of urban sewage sludge from "waste treatment" to "functional matrix material," and through fermentation-stage classification processing, enables the same batch of sludge to produce three different functional matrix components, maximizing the value of sludge resource products and providing a new technological path for the resource utilization of urban sludge.

[0035] The technical solution of this application has the following advantages: 1. This application provides a multi-layered composite nutrient turf mat, comprising a bottom substrate layer, a middle substrate layer, a top substrate layer, and a seed layer. The top substrate layer includes the first fermentation product from sludge fermentation for 10-15 days; the middle substrate layer includes the second fermentation product from sludge fermentation for 20-30 days; and the bottom substrate layer includes the third fermentation product from sludge fermentation for 45-60 days. This application layers fermentation products from different fermentation stages onto a seedling layer, constructing a gradient nutrient structure that matches the growth and development stages of turfgrass and the spatial distribution of its root system. This effectively improves the germination rate of turfgrass on the turf mat, meets the nutrient requirements of turfgrass at each growth stage, and increases the turf mat coverage. The top substrate layer consists of the first fermentation products from sludge fermentation for 10-15 days. These products are high in easily decomposable organic matter and rich in readily available nitrogen and soluble organic matter, providing rapid nutrient supply during the germination period of the turfgrass mat and promoting seed germination. The middle substrate layer consists of the second fermentation products from sludge fermentation for 20-30 days. These products contain a certain amount of easily decomposable organic matter, are rich in phosphorus and potassium, have a stable nitrogen content, and exhibit vigorous microbial activity, promoting root development and tillering. The bottom substrate layer consists of the third fermentation products from sludge fermentation for 45-60 days. These products are rich in stable humus, have a slow nutrient release rate, and strong water and fertilizer retention capacity. On the one hand, they provide long-lasting slow-release nutrients for the mat's mat mat maturation period; on the other hand, they serve as a transition layer between the mat and the ground, effectively buffering nutrient loss from the mat. This application uses fermentation products from different fermentation stages as nutrient layers for turfgrass mats, precisely regulating the organic matter and nutrient forms of the products. This results in a gradient change in the nutrient release rate of each substrate layer, from "fast" to "medium" to "slow," achieving a technological leap from "passive fertilization" to "active regulation." The three-layer structure is spatially superimposed and temporally relayed, enabling a one-time nutrient supply for the entire life cycle of turfgrass, eliminating the need for additional fertilization throughout the entire process.

[0036] 2. The multi-layer composite nutrient turf provided in this application has a separator layer between each substrate layer. By setting a separator layer between each substrate layer, this application allows root penetration while delaying the lateral diffusion of nutrients between layers through capillary blocking, thus maintaining the nutrient gradient between layers.

[0037] 3. The multi-layer composite nutrient mat provided in this application further includes a protective layer that covers the seed layer or fully decomposed sludge layer. By covering the seed layer with this protective layer, this application can retain water and prevent the seeds from being pecked by birds. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the multi-layer composite nutrient grass mat structure provided in Embodiment 1 of this application.

[0040] Explanation of reference numerals in the attached figures: 1. Bottom substrate layer; 2. First separator layer; 3. Middle substrate layer; 4. Second separator layer; 5. Top substrate layer; 6. Seed layer; 7. Fully decomposed sludge layer; 8. Protective layer. Detailed Implementation

[0041] The following embodiments are provided to better understand this application. However, the following embodiments do not constitute a limitation on the content and scope of protection of this application. Any product that is the same as or similar to this application, derived by anyone under the guidance of this application or by combining the features of this application with other prior art, falls within the scope of protection of this application.

[0042] Unless otherwise specified, the experimental steps or conditions in the examples were performed in accordance with conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0043] Example 1 This embodiment provides a method for laying a multi-layer composite nutrient turf mat. The specific steps and parameters are as follows, and the structure of the turf mat to be laid is as follows: Figure 1 As shown: This embodiment was carried out in Leiyang, Hunan Province, with a production scale of 500m² gradient nutrient turf. (1) Preparation of fermentation product: Take dewatered sludge (78% moisture content) from an urban wastewater treatment plant. Add corn stalks crushed to 2-5cm in size to the dewatered sludge at 15% of the sludge weight. Mix well and pile into windrows (bottom width 1.5-2.0 m, height 1.0-1.5 m). Use a forced intermittent ventilation aerobic composting process to ferment the material. In this embodiment, the fermentation method is as follows: a ventilation pipe is laid at the bottom of the pile, and intermittent forced ventilation is used. The ventilation volume is 0.1-0.2 m³ / (m³·min), and the ventilation sequence is 10-20 minutes on and 40-50 minutes off. The oxygen concentration in the pile is controlled at 8%-15%. The turning frequency is: once every 2-3 days from day 1 to 7, once every 3-4 days from day 8 to 30, and once every 5-7 days after day 30. During fermentation, the temperature of the compost pile should be controlled between 55-70℃ for at least 7 days. If the temperature exceeds 75℃, the pile should be turned over immediately or ventilation should be increased to lower the temperature. The ambient temperature during fermentation should be 25℃.

[0044] The fermentation product was collected on the 12th day of fermentation. The temperature of the fermentation pile was 62℃. Sampling and testing showed that the organic matter content of the fermentation product was 42%, the carbon-nitrogen ratio (C / N) was 30, the ammonium nitrogen was 1050 mg / kg, the nitrate nitrogen was 78 mg / kg, the humic acid content was 10 wt%, the total phosphorus was 0.9 wt%, and the total potassium was 0.4 wt%. 400 kg of the fermentation product was collected and dried until the moisture content was 30 wt%, which yielded the first fermentation product. The remaining fermentation product continued to ferment.

[0045] The fermentation product was collected on day 25 of fermentation. The temperature of the fermentation pile was 48℃. Sampling and testing showed that the fermentation product had an organic matter content of 36%, a C / N ratio of 20, a total phosphorus content of 1.6%, a total potassium content of 1.2%, an ammonium nitrogen content of 420 mg / kg, a nitrate nitrogen content of 210 mg / kg, and a humic acid content of 18 wt%. 600 kg of the fermentation product was collected and dried until the moisture content was 30% to obtain the second fermentation product. The remaining fermentation product continued to ferment.

[0046] The fermentation product was collected on day 55 of fermentation. The temperature of the fermentation pile was 32℃. Sampling and testing showed that the organic matter content of the fermentation product was 28%, the C / N ratio was 12, the ammonium nitrogen was 150 mg / kg, the nitrate nitrogen was 320 mg / kg, the humic acid content was 28 wt%, the total phosphorus was 1.2 wt%, and the total potassium was 0.9 wt%. 800 kg of the fermentation product was collected and dried until the moisture content was 30%, which yielded the third fermentation product.

[0047] The fermentation product collected on day 75 was fully decomposed sludge. The fermentation product had an organic matter content of 22 wt%, a C / N ratio of 12, ammonium nitrogen of 150 mg / kg, nitrate nitrogen of 350 mg / kg, humic acid content of 28 wt%, total phosphorus of 1.1 wt%, total potassium of 0.9 wt%, pH of 7.0, and a seed germination index of 92%.

[0048] The organic matter content was determined according to Appendix C of NY / T 525-2021 by potassium dichromate titration method; ammonium nitrogen and nitrate nitrogen were determined according to HJ 634-2012 by potassium chloride solution extraction-spectrophotometry method; total nitrogen was determined according to GB / T 17767.1-2008; the carbon-nitrogen ratio was calculated from the ratio of total organic carbon to total nitrogen, where total organic carbon was converted from organic matter content (organic carbon = organic matter / 1.724); humic acid content was determined according to GB / T 35107-2017 by sodium pyrophosphate alkaline extraction-potassium dichromate oxidation method; and water content was determined according to CJ / T 221-2023 by gravimetric method.

[0049] (2) Preparation of each matrix layer: Top substrate: 80kg of first fermentation product, 15kg of vermiculite, and 5kg of attapulgite, mixed evenly; The middle substrate consists of 87 kg of the second fermentation product, 8 kg of bone meal, and 5 kg of wood ash, mixed evenly.

[0050] Bottom substrate: 90 kg of third fermentation product, 7 kg of attapulgite soil, and 3 kg of biochar, mixed evenly.

[0051] (3) Laying of grass carpets: On a 1.2m wide seedling conveyor belt, the following layers are laid in sequence: bottom substrate (3cm thick), hemp fiber (actually hemp fiber nonwoven fabric, 3mm thick, porosity ≥80%, fiber length 2cm), middle substrate (2.5cm thick), coconut fiber (3mm thick, porosity ≥85%, fiber length 2cm), and top substrate (1.5cm thick). Each layer of substrate must be leveled after laying, forming bottom substrate layer 1, first dividing layer 2, middle substrate layer 3, second dividing layer 4, and top substrate layer 5. Then, grass seeds (tall fescue, 35g / m²) are sown on the surface of the top substrate layer to form seed layer 6. 2 Then, a fully decomposed sludge layer 7 (2mm thick) is formed by covering the grass seed surface with a layer of fully decomposed sludge, and then a biodegradable non-woven fabric is covered to form a protective layer 8.

[0052] Example 2 This embodiment provides a method for laying a multi-layer composite nutrient turf mat, with specific steps and parameters as follows: This embodiment was carried out in Leiyang, Hunan Province, with a production scale of 500m² gradient nutrient turf.

[0053] (1) Preparation of fermentation product: Take dewatered sludge (78% moisture content) from a municipal wastewater treatment plant, add corn stalks crushed to 2-5cm at 15% of the sludge weight, mix evenly and pile into windrows, and ferment the fermented material using a forced intermittent ventilation aerobic composting process (the fermentation method is the same as in Example 1), with an ambient temperature of 25℃, and regularly turn and monitor the compost during the fermentation process.

[0054] The fermentation product was collected on the 10th day of fermentation. The temperature of the fermentation pile was 65℃. The sample was tested and found that the organic matter content of the fermentation product was 45%, the C / N ratio was 32, the ammonium nitrogen was 1180 mg / kg, the nitrate nitrogen was 45 mg / kg, and the humic acid content was 8 wt%. 400 kg of the fermentation product was collected and dried until the moisture content was 30% to obtain the first fermentation product. The remaining fermentation product continued to ferment. The fermentation product was collected on day 30 of fermentation. The temperature of the fermentation pile was 46℃. Sampling and testing showed that the organic matter content of the fermentation product was 33%, the C / N ratio was 17, the total phosphorus was 1.5%, the total potassium was 1.1%, the ammonium nitrogen was 360 mg / kg, the nitrate nitrogen was 270 mg / kg, and the humic acid content was 21 wt%. 600 kg of the fermentation product was collected and dried until the moisture content was 30% to obtain the second fermentation product. The remaining fermentation product continued to ferment. The fermentation product was collected on day 60 of fermentation. The temperature of the fermentation pile was 31℃. The sample was tested and found that the organic matter content of the fermentation product was 25%, the C / N ratio was 10, the ammonium nitrogen was 110mg / kg, the nitrate nitrogen was 410mg / kg, and the humic acid content was 31wt%. 800kg of the fermentation product was collected and dried until the moisture content was 30%, and the third fermentation product was obtained.

[0055] The fermentation product was collected on the 80th day of fermentation. The temperature of the fermentation pile was 28-30℃. Sampling and testing showed that the fermentation product had an organic matter content of 20wt%, a C / N ratio of 10, ammonium nitrogen of 120mg / kg, nitrate nitrogen of 420mg / kg, humic acid content of 30wt%, pH value of 7.2, and seed germination index of 95%. After drying until the moisture content was ≤30%, fully decomposed sludge was obtained.

[0056] (2) Preparation of each matrix layer: Top substrate: 70kg of first fermentation product, 20kg of vermiculite, and 10kg of water-retaining agent, mixed evenly; The middle substrate consists of 91 kg of the second fermentation product, 5 kg of bone meal, and 4 kg of wood ash, mixed evenly.

[0057] Bottom substrate: 85 kg of third fermentation product, 10 kg of attapulgite soil, and 5 kg of biochar, mixed evenly.

[0058] (3) Laying of grass carpets: On a 1.2m wide seedling conveyor belt, the following layers are laid in sequence: bottom substrate (2cm thick), hemp fiber (5mm thick, 2cm long), middle substrate (3cm thick), coconut fiber (2mm thick, 1.5cm long), and top substrate (1cm thick). Each layer is leveled after laying, forming the bottom substrate layer, first fiber separator layer, middle substrate layer, second fiber separator layer, and top substrate layer. Then, grass seeds (tall fescue, 35g / m²) are sown on the surface of the top substrate layer to form a seed layer. 2 Then, a layer of fully decomposed sludge (2mm thick) is placed on the surface of the grass seeds to form a fully decomposed sludge layer, and then covered with biodegradable non-woven fabric to form a protective layer.

[0059] Example 3 This embodiment provides a method for laying a multi-layer composite nutrient turf mat, with specific steps and parameters as follows: This embodiment was carried out in Leiyang, Hunan Province, with a production scale of 500m² gradient nutrient turf.

[0060] (1) Preparation of fermentation product: Take dewatered sludge (78% moisture content) from a municipal wastewater treatment plant, add corn stalks crushed to 2-5cm at 15% of the sludge weight, mix evenly and pile into windrows, and ferment the fermented material using a forced intermittent ventilation aerobic composting process (the fermentation method is the same as in Example 1), with an ambient temperature of 26℃, and regularly turn and monitor the compost during the fermentation process.

[0061] The fermentation product was collected on the 15th day of fermentation. The temperature of the fermentation pile was 60℃. The sample was tested and found that the organic matter content of the fermentation product was 40%, the C / N ratio was 27, the ammonium nitrogen was 950 mg / kg, the nitrate nitrogen was 95 mg / kg, and the humic acid content was 11 wt%. 400 kg of the fermentation product was collected and dried until the moisture content was 30% to obtain the first fermentation product. The remaining fermentation product continued to ferment. The fermentation product was collected on day 20 of fermentation. The temperature of the fermentation pile was 52℃. Sampling and testing showed that the organic matter content of the fermentation product was 38%, the C / N ratio was 22, the total phosphorus was 1.5%, the total potassium was 1.1%, the ammonium nitrogen was 500 mg / kg, the nitrate nitrogen was 150 mg / kg, and the humic acid content was 15 wt%. 600 kg of the fermentation product was collected and dried until the moisture content was 30% to obtain the second fermentation product. The remaining fermentation product continued to ferment. The fermentation product was collected on day 45 of fermentation. The temperature of the fermentation pile was 35℃. The sample was tested and found that the organic matter content of the fermentation product was 30%, the C / N ratio was 14, the ammonium nitrogen was 200 mg / kg, the nitrate nitrogen was 280 mg / kg, and the humic acid content was 24 wt%. 800 kg of the fermentation product was collected and dried until the moisture content was 30%, which yielded the third fermentation product.

[0062] The fermentation product was collected on the 70th day of fermentation. The temperature of the fermentation pile was 30℃. The sample was tested and found that the organic matter content was 23wt%, the C / N ratio was 11, the ammonium nitrogen was 130mg / kg, the nitrate nitrogen was 380mg / kg, the humic acid content was 29wt%, the pH value was 7.1, and the seed germination index was 93%. After drying until the moisture content was ≤30%, fully decomposed sludge was obtained.

[0063] (2) Preparation of each matrix layer: Top substrate: 85 kg of first fermentation product, 10 kg of vermiculite, and 5 kg of water-retaining agent, mixed evenly; The middle substrate consists of 86 kg of the second fermentation product, 10 kg of bone meal, and 4 kg of wood ash, mixed evenly.

[0064] Bottom substrate: 92 kg of third fermentation product, 5 kg of attapulgite soil, and 3 kg of biochar, mixed evenly.

[0065] (3) Laying of grass carpets: On a 1.2m wide seedling conveyor belt, the following layers are laid in sequence: bottom substrate (4cm thick), hemp fiber (5mm thick, 2cm long), middle substrate (2cm thick), coconut fiber (2mm thick, 1.5cm long), and top substrate (2cm thick). Each layer is leveled after laying, forming the bottom substrate layer, first fiber separator layer, middle substrate layer, second fiber separator layer, and top substrate layer. Finally, grass seeds (tall fescue, 35g / m²) are sown on the surface of the top substrate layer to form a seed layer. 2 Then, a layer of fully decomposed sludge (2mm thick) is placed on the surface of the grass seeds to form a fully decomposed sludge layer, and then covered with biodegradable non-woven fabric to form a protective layer.

[0066] Comparative Example 1 This comparative example provides a method for preparing a single-layer composite nutrient grass mat, the specific steps and methods are as follows: The fully decomposed sludge from Example 1 was mixed with coconut fiber waste and straw ash in a mass ratio of 6:3:1 to form a matrix; On a 1.2-meter-wide seedling conveyor belt, a 6-centimeter-thick substrate layer is laid to form a substrate layer. Then, tall fescue seeds (35 g / m²) are sown on the surface of the substrate layer. A 2-millimeter-thick layer of fully decomposed sludge (fully decomposed sludge provided in Example 1) is then placed on top of the grass seeds, and finally, biodegradable nonwoven fabric is covered.

[0067] Comparative Example 2 This comparative example provides a method for preparing a single-layer composite nutrient grass mat, the specific steps and methods are as follows: The top matrix prepared in step (2) of Example 1 was used as the matrix of this comparative example; On a 1.2-meter-wide seedling conveyor belt, a 6-centimeter-thick substrate layer is laid to form a substrate layer. Then, tall fescue seeds (35 g / m²) are sown on the surface of the substrate layer. A 2-millimeter-thick layer of fully decomposed sludge (fully decomposed sludge provided in Example 1) is then placed on top of the grass seeds, and finally, biodegradable nonwoven fabric is covered.

[0068] Comparative Example 3 This comparative example provides a method for preparing a single-layer composite nutrient grass mat, the specific steps and methods are as follows: The middle matrix prepared in step (2) of Example 1 was used as the matrix of this comparative example; On a 1.2-meter-wide seedling conveyor belt, a 6-centimeter-thick substrate layer is laid to form a substrate layer. Then, tall fescue seeds (35 g / m²) are sown on the surface of the substrate layer. A 2-millimeter-thick layer of fully decomposed sludge (fully decomposed sludge provided in Example 1) is then placed on top of the grass seeds, and finally, biodegradable nonwoven fabric is covered.

[0069] Comparative Example 4 This comparative example provides a method for preparing a single-layer composite nutrient grass mat, the specific steps and methods are as follows: The bottom matrix prepared in step (2) of Example 1 was used as the matrix of this comparative example; On a 1.2-meter-wide seedling conveyor belt, a 6-centimeter-thick substrate layer is laid to form a substrate layer. Then, tall fescue seeds (35 g / m²) are sown on the surface of the substrate layer. A 2-millimeter-thick layer of fully decomposed sludge (fully decomposed sludge provided in Example 1) is then placed on top of the grass seeds, and finally, biodegradable nonwoven fabric is covered.

[0070] Experimental Example The grass mats laid in Examples 1-3 and Comparative Examples 1-4 were cultivated in a greenhouse at 25°C. The substrate was kept moist by spraying water daily. During the cultivation period, samples were taken on the 10th, 30th and 60th day after sowing to detect the grass mat coverage, lawn height, root development, number of seed tillers and nutrient content changes in each layer of substrate. The results are shown in Table 1.

[0071] Method for determining grass canopy coverage: At each detection time point, five 50cm × 50cm quadrats were randomly selected from each treatment group. A digital camera was used to photograph the lawn canopy from directly above at a vertical height of 1.2m, ensuring the quadrats were completely within the viewfinder and free from shadows. The photographs were imported into image processing software (such as ImageJ), and each pixel was segmented into green vegetation and soil / matrix using binarization. The percentage of pixels with vegetation coverage relative to the total number of pixels in the quadrats was used as the coverage of that quadrats. The average of the five quadrats for each treatment group was taken as the final coverage measurement result for that group, expressed as a percentage (%).

[0072] Table 1. Results of Grass Mat Testing

[0073] The detection methods for the organic matter content, phosphorus content, potassium content, ammonium nitrogen content, and humic acid content of each substrate layer in Table 1 are the same as those for the detection methods for the content of each substance in the fermentation product of Example 1.

[0074] According to the results in Table 1, compared with Comparative Examples 1-4, which used a single-layer substrate as the base layer for the grass mat, Comparative Example 1, which used fully decomposed sludge as the main substrate, Comparative Example 2, which used the first fermentation product from the early stage of fermentation, Comparative Example 3, which used the second fermentation product from the middle stage of fermentation, and Comparative Example 4, which used the third fermentation product from the later stage of fermentation, all showed unsatisfactory performance in the early stage after sowing, including germination rate, seedling height, and grass mat coverage. In the middle stage of sowing, the phosphorus content of Comparative Example 1 (single layer of fully decomposed sludge) was only 0.5%, and the initial value was low, indicating that nutrients had been depleted in the early stage. Although the initial values ​​of phosphorus and potassium in Comparative Example 3 (single layer of middle substrate only) were high, the consumption was less on day 30 (only decreasing from 1.6% to 1.15%) because there was no grass seed absorption channel in the top substrate layer, and nutrients could not be effectively utilized. The initial phosphorus and potassium content of Comparative Example 4 (bottom substrate only) was even lower. These comparisons demonstrate the necessity of the layered structure for nutrient release and absorption.

[0075] This application uses fermentation products from different fermentation stages as the nutrient layer of a straw mat. Specifically, the straw mat is formed by using the first fermentation product from the initial fermentation stage as the main raw material for the top substrate layer, the second fermentation product from the middle fermentation stage as the main raw material for the middle substrate layer, and the third fermentation product from the later fermentation stage as the main raw material for the bottom substrate layer. In the early sowing stage, a large amount of ammonium nitrogen in the top substrate layer is consumed, effectively improving the seed germination rate and resulting in good seedling height. Meanwhile, the nutrients in the middle substrate layer are not released and are retained. Furthermore, in the middle sowing stage, the nutrients in the middle substrate layer can be retained for 30-60 days after sowing. The concentrated release of phosphorus and potassium elements promotes root development and tillering of grass seeds. The grass mats provided in Examples 1-3 consume 40%-50% of phosphorus and potassium in the middle of the period after sowing, which indicates that phosphorus and potassium have been absorbed and utilized by the grass mats. This proves that the timing of nutrient release is in line with expectations, avoiding "nutrient waste" or "slow release". This application achieves "on-demand supply". In the later stage of sowing, the bottom substrate layer with high organic matter content and high humic acid content can provide nutrients for the turfgrass on the grass mat, so that the turfgrass maintains a good growth status. Moreover, in the later stage of sowing, the layered grass mats provided by this application have a stronger ability to retain long-lasting nutrients and less nutrient loss.

[0076] This application achieves a technological leap from "passive fertilization" to "active regulation" by precisely controlling the organic matter and nutrient forms of the product, so that the nutrient release rate of each substrate layer presents a gradient change of "fast-medium-slow". The three-layer structure is superimposed in space and relayed in time, realizing a one-time nutrient supply for the entire life cycle of turfgrass, without the need for additional fertilization.

[0077] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A multi-layer composite nutrient grass mat, characterized in that, It consists of, in sequence, a bottom matrix layer, a middle matrix layer, a top matrix layer, and a seed layer. The top substrate layer comprises the first fermentation products from sludge fermentation days 10-15. The middle substrate layer includes the second fermentation product from the sludge fermentation process on days 20-30. The bottom substrate layer includes the third fermentation product from the 45th to 60th day of sludge fermentation.

2. The multi-layer composite nutrient turf blanket according to claim 1, characterized in that, The thickness of the top matrix layer is 1cm-2cm; And / or, the thickness of the central matrix layer is 2cm-3cm; And / or, the thickness of the bottom matrix layer is 2cm-4cm.

3. The multi-layer composite nutrient turf blanket according to claim 1, characterized in that, The top matrix layer also includes a loosening agent and a water-retaining agent; And / or, the middle matrix layer also includes phosphate fertilizer and potash fertilizer; And / or, the bottom matrix layer further includes a water-retaining agent and a modifier; And / or, the raw materials for the sludge fermentation include sludge and biomass.

4. The multi-layer composite nutrient turf mat according to claim 3, characterized in that, In the top substrate layer, the weight parts of the first fermentation product are 70-85 parts, the weight parts of the loosening agent are 10-20 parts, and the weight parts of the water-retaining agent are 5-10 parts. And / or, in the middle substrate layer, the weight parts of the second fermentation product are 80-90 parts, 5-10 parts of phosphate fertilizer, and 3-5 parts of potassium fertilizer; And / or, in the bottom substrate layer, the weight parts of the third fermentation product are 85-95 parts, the water-retaining agent is 5-10 parts, and the improver is 3-5 parts; And / or, the water-retaining agent of the top matrix layer and / or the bottom matrix layer includes at least one of attapulgite, bentonite, and sodium polyacrylate; And / or, the modifier includes biochar.

5. The multi-layer composite nutrient turf blanket according to claim 1, characterized in that, The fermentation temperature of the first fermentation product is 50℃-65℃; And / or, the fermentation temperature of the second fermentation product is 48℃-52℃; And / or, the fermentation temperature of the third fermentation product is 30℃-45℃.

6. The multi-layer composite nutrient turf blanket according to claim 5, characterized in that, The first fermentation product has an organic matter content of 35 wt%-45 wt%, a carbon-to-nitrogen ratio of 25-35, an ammonium nitrogen content of 800 mg / kg-1500 mg / kg, a nitrate nitrogen content of 20 mg / kg-100 mg / kg, and a humic acid content of 8 wt%-12 wt%; the first fermentation product has a total phosphorus content of 0.8 wt%-1.6 wt% and a total potassium content of 0.3 wt%-1.2 wt%. And / or, the second fermentation product has an organic matter content of 30 wt%-40 wt%, a carbon-to-nitrogen ratio of 15-25, a total phosphorus content of 1.5 wt%-2.0 wt%, a total potassium content of 1.0 wt%-2.0 wt%, an ammonium nitrogen content of 300 mg / kg-500 mg / kg, a nitrate nitrogen content of 150 mg / kg-300 mg / kg, and a humic acid content of 15 wt%-20 wt%. And / or, the third fermentation product has an organic matter content of 25 wt%-35 wt%, a carbon-to-nitrogen ratio of 10-15, an ammonium nitrogen content of 50 mg / kg-200 mg / kg, a nitrate nitrogen content of 200 mg / kg-400 mg / kg, a humic acid content of 25 wt%-35 wt%, a total phosphorus content of 1.0 wt%-1.7 wt%, and a total potassium content of 0.8 wt%-1.3 wt%.

7. The multi-layer composite nutrient turf blanket according to claim 1, characterized in that, At least one separator layer is provided between each matrix layer; And / or, the grass mat further includes a fully decomposed sludge layer covering the seed layer, the fully decomposed sludge layer comprising fully decomposed sludge, the thickness of the fully decomposed sludge layer being 2mm-5mm.

8. The multi-layer composite nutrient turf blanket according to claim 7, characterized in that, The seeding rate for grass is 25g / m². 2 -40g / m 2 ; And / or, each of the said separating layers comprises one of hemp fiber or coconut fiber; And / or, the thickness of each of the said separator layers is 2mm-5mm; And / or, the porosity of the separator layer is greater than or equal to 80%.

9. The multi-layer composite nutrient turf blanket according to claim 8, characterized in that, The grass mat also includes a protective layer that covers the seed layer or the fully decomposed sludge layer; And / or, the loosening agent includes at least one of vermiculite or perlite; And / or, the length of the hemp fiber or coconut fiber in the separating layer is 1-3 cm.

10. The multi-layer composite nutrient turf blanket according to claim 9, characterized in that, The protective layer includes at least one of nonwoven fabric or plant fiber web.

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