Evaluation and screening method for grass seeds suitable for vegetation concrete

Abstract

The invention discloses an evaluation and screening method for grass seeds suitable for vegetation concrete, and belongs to the technical field of ecological restoration and slope protection. The method comprises the following steps: constructing an evaluation index system of the vegetation concrete protection plant comprising a plurality of evaluation indexes, and setting grading standards of four grades A, B, C and D for each evaluation index; determining the weight of each evaluation index, and extracting a decisive index from the evaluation indexes; the screening process comprises two stages: first-stage theoretical screening is based on grass seed data contrast grading standards, and direct elimination is carried out when decisive indexes appear in a D stage; and second-stage practice verifies that the grass seeds screened out in the first stage are sown in plant-growing concrete with the pH value larger than or equal to 10, and according to the actual measurement performance of the germination rate and the growth speed, the grass seeds with the two indexes both reaching the preset qualified standard are screened out to serve as the final applicable grass seeds. Through systematic quantification and dual verification, the grass seed screening problem in the high-alkali environment is scientifically solved.

Description

Evaluation and screening method for grass species suitable for growing concrete Technical Field

[0001] This invention relates to the field of ecological restoration and slope protection technology, specifically to an evaluation and screening method for grass species suitable for planting concrete. Background Technology

[0002] In highway, railway, mining, and municipal engineering projects, numerous exposed slopes are often created. While traditional engineering protection methods such as grouted rubble masonry and shotcrete can stabilize slopes, they damage the original vegetation and ecosystem. Ecological concrete (vegetated concrete), as a new type of ecological slope protection material, combines plants with engineering materials to achieve the dual goals of slope stabilization and ecological restoration.

[0003] However, existing high-strength vegetation concrete releases a large amount of OH during the hardening process. ⁻ The presence of ions causes the pH value of the soil layer to remain above 10 for an extended period, creating a highly alkaline environment. Under these conditions, grass seeds commonly used for ecological restoration experience low germination rates, slow growth, and even death, making it difficult to realize the ecological functions of vegetated concrete. Furthermore, the formulation of vegetated concrete needs to be adjusted for different application scenarios (such as high altitudes, steep slopes, and rainy areas) (e.g., by adding water-retaining agents and toughening materials), which further alters the microenvironment for plant growth and places more complex demands on the stress resistance of grass seeds.

[0004] Currently, there is a lack of a systematic and quantitative method for evaluating and selecting grass species that can adapt to the unique and demanding environment of vegetated concrete. In engineering practice, grass species selection often relies on experience, resulting in a low success rate and failing to guarantee long-term slope protection effects and ecological stability. Therefore, there is an urgent need to develop a scientific and efficient method for evaluating and selecting grass species to guide the optimal selection and application of grass species in vegetated concrete projects. Summary of the Invention

[0005] This invention aims to overcome the shortcomings of existing technologies and provide a method for evaluating and screening grass species suitable for vegetated concrete, thereby addressing the technical problems of poor adaptability and unsatisfactory ecological restoration effects of conventional grass species due to the highly alkaline environment and complex additives in vegetated concrete. This invention establishes a comprehensive evaluation index system and employs a dual screening process combining theoretical screening with practical verification to scientifically and efficiently select grass species that can germinate normally, grow healthily, and stably perform slope protection and ecological restoration functions in vegetated concrete.

[0006] To achieve the above objectives, the technical solution adopted by this invention is as follows: A method for evaluating and screening grass species suitable for vegetated concrete, comprising: S1. Constructing an evaluation index system for vegetated concrete protective plants including multiple evaluation indicators, and setting four levels of grading standards (A, B, C, D) for each evaluation indicator, wherein each level corresponds to a preset quantitative value range or judgment condition; S2. Determining the weight of each evaluation indicator and extracting the decisive indicator from the evaluation indicators; S3. First-level theoretical screening: For each grass species to be screened, the following operations are performed: S31. Based on the inherent biological characteristics data of the grass species, publicly available cultivation data, or test data obtained through preset experiments, compare with the preset quantitative value range or judgment condition in S1. The judgment criteria are as follows: determine the grade of the grass species on each evaluation indicator and assign a score; if the grade on any decisive indicator is D, the subsequent screening process is terminated; S32. Calculate the weighted total score based on the assigned scores and weights of each evaluation indicator; S33. Divide the grass species into first-level, second-level, or third-level according to the weighted total score; S4. Second-level practical verification: the grass species classified into first-level and / or second-level in S3 are sown in the target formula vegetated concrete substrate with a pH value of not less than 10 for actual planting experiments. By observing and evaluating the germination rate and seedling growth rate of each grass species in the experimental environment, grass species that meet the preset qualified standards in terms of actual germination rate and seedling growth rate are selected as the final grass species suitable for vegetated concrete.

[0007] Furthermore, multiple evaluation indicators are divided into the following three categories based on three dimensions: plant stress resistance, plant physiological characteristics, and ecological function value: Plant stress resistance: salt and alkali tolerance, high pH tolerance, poor soil tolerance, heavy metal tolerance, drought tolerance, waterlogging tolerance, cold resistance, heat resistance, disease resistance, and insect resistance; Plant physiological characteristics: survival rate, germination rate, germination time, growth rate, life form, plant mass, plant reproductive regeneration, coverage, root depth, and root pull-out resistance; Ecological function value: soil and water conservation capacity, soil remediation capacity, biodiversity support capacity, plant ornamental value, and plant safety.

[0008] Furthermore, salt and alkali tolerance, high pH tolerance, biodiversity support capacity, and plant safety are the decisive indicators.

[0009] Furthermore, in S2, the weights of each evaluation indicator are determined using the analytic hierarchy process (AHP).

[0010] Furthermore, in S31, the scores are as follows: A grade is assigned 4 points, B grade is assigned 2 points, C grade is assigned 1 point, and D grade is assigned 0 points.

[0011] Furthermore, in S32, the formula for calculating the weighted total score is: Weighted total score = Σ (the score assigned to the evaluation indicator × the weight of the evaluation indicator).

[0012] Furthermore, in S33, the weighted total score is converted into a 10-point total score, and the grass species are divided into Level 1, Level 2 and Level 3 based on the 10-point total score.

[0013] Furthermore, the conversion formula for the 10-point total score is: 10-point total score = weighted total score × 10 / 4; where the 10-point total score corresponding to Level 1 is 8-10 points, the 10-point total score corresponding to Level 2 is 6-8 points (excluding 8 points), and the 10-point total score corresponding to Level 3 is 0-6 points (excluding 6 points).

[0014] Furthermore, in S4, the preset qualification standard is: the germination rate of grass seeds in the vegetated concrete is not less than 40%, and the seedling growth rate is not less than 0.2 cm / day.

[0015] Furthermore, in S4, the actual planting experiment adopted a mixed sowing method.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. Systematic and scientific: For the first time, a comprehensive evaluation system with multiple dimensions (resistance, physiological characteristics, and ecological functions) and multiple indicators for the special habitat of vegetated concrete has been established. By setting specific quantitative value ranges or judgment conditions and weights for each evaluation indicator, the transformation from qualitative experience to quantitative evaluation has been realized.

[0017] 2. Highly targeted: Decisive indicators including salt and alkali tolerance and high pH tolerance have been specifically established, and a corresponding D-level veto exclusion mechanism has been set up to ensure that the selected grass species must have the key ability to adapt to the high alkaline core environment stress of vegetated concrete, thus ensuring the targeted nature of the selection from the source.

[0018] 3. Dual Validation for Reliable Results: A dual screening model combining "primary theoretical screening" and "secondary practical verification" is employed. The primary theoretical screening stage rapidly and efficiently identifies potential varieties from a vast pool of candidate grass species. The secondary practical verification stage places the candidate grass species selected in the primary screening in a highly alkaline (pH≥10) vegetated concrete environment simulating real engineering conditions for actual cultivation and observation. This stage, as a necessary supplement to theoretical evaluation, can verify and screen grass species that truly possess adaptability and growth capacity in complex real-world environments, thereby significantly improving the engineering practicality and ecological reliability of the final recommended results. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0020] It should be noted that in this invention, the "growth rate" index has different specific meanings and units of measurement at different screening stages. This is to optimize the objectives of each stage: in the first-level theoretical screening (S1, S3), it is the rate of dry matter accumulation per unit area (g DM / m² / day), used to scientifically assess the growth potential of plants; in the second-level practical verification (S4), it is the linear growth rate of seedling height (cm / day), used to quickly and conveniently evaluate the early adaptability of grass species in actual engineering environments. Both are encompassed under the A, B, C, and D grade evaluation framework constructed in this invention.

[0021] Example 1. This example details the construction and weight determination process of the evaluation index system of the present invention.

[0022] An evaluation index system was constructed: Based on the characteristics of the vegetated concrete environment and the ecological restoration goals, 25 evaluation indicators were selected from three dimensions: plant stress resistance, plant physiological characteristics, and ecological function value, as shown in Table 1.

[0023] Table 1

[0024] Set grading standards: Set four levels, A, B, C and D, for each evaluation indicator and their corresponding specific quantitative value ranges or judgment conditions, as shown in Table 2.

[0025] Table 2

[0026] Determining Indicator Weights: The Analytic Hierarchy Process (AHP) was used to determine the weights of each indicator. Specifically, the 25 indicators were numbered sequentially from C1 to C25. The importance value of each indicator was determined based on subjective assignment, and a judgment matrix was established. By calculating the eigenvectors of the matrix and performing a consistency check, the weight coefficients of each evaluation indicator were finally obtained, as shown in Table 3.

[0027] Table 3

[0028] Among them, salt and alkali tolerance, high pH tolerance, biodiversity support capacity, and plant safety were designated as decisive indicators.

[0029] Example 2. In this example, the method of the present invention was applied to evaluate and screen 11 plants, including pigeon pea, purple locust, ryegrass, tall fescue, donkey bean, alfalfa, bahiagrass, orchardgrass, oriental goat bean, Mexican corn grass, and Sudan grass.

[0030] First-level theoretical screening: Based on the known biological characteristics and cultivation test data of each grass species, and in accordance with the evaluation index system established in Example 1, their level on each evaluation index was determined and scored. The results are shown in Table 4.

[0031] Table 4

[0032] None of the grass species achieved a grade D in terms of salt and alkali tolerance, high pH tolerance, biodiversity support capacity, or plant safety, and all proceeded to the next stage of evaluation.

[0033] Based on the assigned scores of each evaluation indicator and the weights of Example 1, the weighted total score is calculated, and the results are shown in Table 5.

[0034] Table 5

[0035] The weighted total score was converted into a 10-point total score, and each grass species was divided into Level 1, Level 2 and Level 3 according to the 10-point total score. The results are shown in Table 6.

[0036] Table 6

[0037] The first level includes seven plant species: Amorpha fruticosa, ryegrass, tall fescue, sedge, alfalfa, orchardgrass, and goat's bean, which are recommended for planting as protective vegetation on concrete structures. The second level includes pigeon pea, bahia grass, and Mexican corn grass, which should be planted with caution based on the actual situation. The third level, Sudan grass, is not recommended for planting.

[0038] Secondary practical verification: Ten primary and secondary grass species (a total of 10 species) were selected as candidates for secondary practical verification. To simplify the verification scale, this embodiment selected eight species for verification: pigeon pea, purple locust, ryegrass, tall fescue, donkey bean, alfalfa, bahiagrass, and orchardgrass.

[0039] First, the grass seed mixing ratio was designed. Eight grass seeds to be tested were mixed according to the following mass parts: 5-15 parts of ryegrass, 15-30 parts of tall fescue, 15-30 parts of orchardgrass, 10-20 parts of bahiagrass, 10-20 parts of foetida, 10-20 parts of alfalfa, 5-15 parts of purple acacia, and 5-15 parts of pigeon pea.

[0040] In this embodiment, grass seeds are mixed in the following mass ratio: ryegrass: tall fescue: orchardgrass: bahiagrass: lepidophyllum: alfalfa: purple locust: pigeon pea = 10:20:20:10:10:10:10:10. Wire mesh is laid on a simulated rock slope. A vegetation concrete substrate with pH > 10 is mixed with the mixed grass seeds (seed rate 50g / m²), and then dry-sprayed to form a vegetation base layer approximately 10cm thick, which is then cured in a natural environment.

[0041] In the secondary practical verification, to facilitate a rapid and non-destructive evaluation of the early adaptability of grass species in real engineering environments, the focus of observation was set on directly measurable morphological indicators. The actual germination rate (%) of each grass species in the planted concrete, as well as the daily growth rate of seedling height (i.e., linear growth rate, unit: cm / day) during the seedling stage were observed and recorded regularly.

[0042] The specific data of "germination rate" and "linear growth rate (cm / day)" obtained from the observation were compared with the secondary verification grading standard specifically preset for this stage in this invention to determine the performance level of each grass species in this experiment.

[0043] It is important to note that the grading standard for "growth rate" at this stage differs from the "growth rate" standard based on dry matter accumulation (g DM / m² / day) pre-set for the first-stage screening in S1 (system construction). This is to accommodate the objectives of different screening stages: the first-stage screening evaluates potential growth potential, requiring a more precise biomass indicator; the second-stage validation evaluates actual early survival and adaptability, employing a more convenient morphological indicator.

[0044] The following is an example of the secondary verification grading standard: Germination rate: Grade A (≥80%), Grade B (60%~80%), Grade C (40%~60%), Grade D (<40%).

[0045] Linear growth rate during the seedling stage (cm / day): Grade A (≥0.8), Grade B (0.5~0.8), Grade C (0.2~0.5), Grade D (<0.2).

[0046] Based on this, the specific evaluation results of each grass species are shown in Table 7.

[0047] Table 7

[0048] Based on the preset qualification standards (i.e., germination rate and growth rate are both not lower than grade C, corresponding to germination rate ≥ 40% and growth rate ≥ 0.2 cm / day), the results in Table 7 were evaluated. All eight grass species met these standards in both indicators (germination rate: AC; growth rate: AC), therefore all passed the verification and can be considered as candidate grass species suitable for vegetated concrete. Among them, ryegrass and tall fescue performed exceptionally well (germination rate A / B, growth rate A), making them suitable as pioneer grass species; pigeon pea and purple acacia also met the basic requirements and can be selected based on long-term soil stabilization goals.

[0049] The method provided by this invention has successfully screened out several grass species that can grow well in highly alkaline vegetated concrete environments from 11 candidate plants, and clarified their different uses, providing a reliable grass species selection scheme and technical support for vegetated concrete slope restoration projects.

[0050] Finally, it should be noted that the above embodiments are merely preferred embodiments of the present invention used to illustrate the technical solutions of the present invention, and are not intended to limit the invention, nor are they intended to limit the patent scope of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. That is to say, any changes or refinements made to the main design concept and spirit of the present invention that are not of substantial significance, but whose technical problems are still consistent with the present invention, should be included within the protection scope of the present invention. In addition, the direct or indirect application of the technical solutions of the present invention to other related technical fields are similarly included within the patent protection scope of the present invention.

Claims

1. A method for evaluating and screening grass species suitable for growing concrete, characterized in that, include: S1. Construct an evaluation index system for vegetation concrete protective plants that includes multiple evaluation indicators, and set four levels of grading standards (A, B, C, D) for each evaluation indicator, with each level corresponding to a preset quantitative value range or judgment condition. S2. Determine the weight of each evaluation indicator and extract the decisive indicator from the evaluation indicators; S3. First-level theoretical screening: For each grass species to be screened, perform the following operations: S31. Based on the inherent biological characteristics data of the grass species, publicly available cultivation data, or test data obtained through preset experiments, compare with the preset quantitative value range or judgment conditions in S1 to determine the grass species' level on each evaluation indicator and assign scores. If the grade on any decisive indicator is D, the subsequent screening process is terminated; S32. Calculate the weighted total score based on the assigned scores and weights of each evaluation indicator; S33. Divide the grass species into first-level, second-level, or third-level according to the weighted total score; S4. Secondary Practice Verification: The grass species classified as Level 1 and / or Level 2 in S3 are sown in the target formula vegetated concrete substrate with a pH value of not less than 10 for actual planting experiments. By observing and evaluating the germination rate and seedling growth rate of each grass species in the experimental environment, grass species that meet the preset qualified standards in terms of actual germination rate and seedling growth rate are selected as the final grass species suitable for vegetated concrete.

2. The evaluation and screening method for grass species suitable for growing concrete according to claim 1, characterized in that, Multiple evaluation indicators are categorized into three types based on three dimensions: plant stress resistance, plant physiological characteristics, and ecological function value. Plant stress resistance includes: tolerance to salinity and alkali, tolerance to high pH, ​​tolerance to poor soil, tolerance to heavy metals, drought resistance, waterlogging resistance, cold resistance, heat resistance, disease resistance, and insect resistance. Plant physiological characteristics include: survival rate, germination rate, germination time, growth rate, life form, plant mass, plant reproductive regeneration, coverage, root depth, and root pull-out resistance. Ecological function value includes: soil and water conservation capacity, soil remediation capacity, biodiversity support capacity, plant ornamental value, and plant safety.

3. The evaluation and screening method for grass species suitable for growing concrete according to claim 2, characterized in that, Salt and alkali tolerance, high pH tolerance, biodiversity support capacity, and plant safety are the decisive indicators.

4. The evaluation and screening method for grass species suitable for growing concrete according to claim 1, characterized in that, In S2, the weights of each evaluation indicator are determined using the analytic hierarchy process (AHP).

5. The evaluation and screening method for grass species suitable for growing concrete according to claim 1, characterized in that, In S31, the scores are as follows: A grade is assigned 4 points, B grade is assigned 2 points, C grade is assigned 1 point, and D grade is assigned 0 points.

6. The evaluation and screening method for grass species suitable for growing concrete according to claim 1, characterized in that, In S32, the formula for calculating the weighted total score is: Weighted total score = Σ (the score assigned to the evaluation indicator × the weight of the evaluation indicator).

7. The evaluation and screening method for grass species suitable for growing concrete according to claim 1, characterized in that, In S33, the weighted total score is converted into a 10-point total score, and grass species are divided into Level 1, Level 2 and Level 3 based on the 10-point total score.

8. The method for evaluating and screening grass species suitable for growing concrete according to claim 7, characterized in that, The conversion formula for the 10-point total score is: 10-point total score = weighted total score × 10 / 4; where the 10-point total score corresponding to Level 1 is 8-10 points, the 10-point total score corresponding to Level 2 is 6-8 points (excluding 8 points), and the 10-point total score corresponding to Level 3 is 0-6 points (excluding 6 points).

9. The evaluation and screening method for grass species suitable for growing concrete according to claim 7, characterized in that, In S4, the preset qualification standard is: the germination rate of grass seeds in the vegetated concrete is not less than 40%, and the seedling growth rate is not less than 0.2cm / day.

10. The method for evaluating and screening grass species suitable for growing concrete according to claim 7, characterized in that, In S4, the actual planting experiment adopted a mixed sowing method.

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