A grassland restoration method and restoration combination suitable for alpine short-lived habitat mountain meadow steppe of Xilingol

Abstract

The application discloses a grassland restoration method and a restoration combination suitable for Xilingol alpine short habitat mountain meadow grassland, belongs to the technical field of ecological restoration, and adopts no-tillage strip sowing integrated operation to synchronously complete weed inhibitor spraying, native grass reseeding, mineral fertilizer application and light tamping procedures before the rainy season in the middle and late June. The application adopts a 2:2:3:3 ratio of Agrostis stolonifera, Elymus dahuricus, Thinopyrum ponticum, and Medicago polymorpha var. varia Mengnuo No. 2 perennial cold-resistant native grass seed combination, is matched with Trichoderma harzianum (T. Trichoderma harzianum ) MCBC3 powder seed dressing treatment, is matched with bentazone weed control and mineral fertilizer to form a restoration combination. Field tests show that the application can improve the seedling emergence rate, overwintering rate and community stability of the forage grass, the grassland vegetation coverage is significantly improved after restoration, the proportion of weeds is greatly reduced, and the dry grass yield can reach 280-380 kg / mu, and stable yield can be obtained for many years.

Description

Technical Field

[0001] This invention belongs to the field of ecological restoration and grassland cultivation technology, specifically relating to a grassland restoration method and restoration combination suitable for alpine short-habitat mountain meadow grasslands in Huitengxile. Background Technology

[0002] Huitengxile Mountain Meadow Grassland is located in Chayouzhong Banner, Ulanqab City, Inner Mongolia Autonomous Region. Situated at 41°±1′N and an altitude of 2000±50m, it belongs to a high-altitude, cold-temperate, humid to semi-humid mountain climate type, with an average annual temperature of about 0℃, a frost-free period of less than 80 days, and an annual precipitation of 280-380mm. The soil type is mainly black calcareous soil or chestnut calcareous soil, and it is known as the "Little Qinghai-Tibet Plateau". The grassland in this area is dominated by perennial herbs, accounting for 81.82%, and is a typical high-altitude, short-habitat meadow grassland ecosystem.

[0003] Due to long-term overgrazing, climate warming, and human disturbance, the meadow grassland in Huitengxile Mountain has suffered severe degradation: the soil has become compacted and fertility has declined; the grass height is only 8-25cm and the coverage is 40%-60%; the proportion of high-quality grasses and legumes has decreased significantly; and the proportion of miscellaneous grasses in the Asteraceae family has reached 30.30%. The community structure has become simple, which seriously restricts the local animal husbandry and grassland ecological security.

[0004] Existing technologies have proposed various restoration measures, mainly including single or simple combinations of methods such as fencing and grazing bans, soil loosening and improvement, simple reseeding, and surface fertilization. However, these existing technological solutions have the following significant shortcomings when applied to the alpine meadow-steppe habitat of Huitengxile: However, existing technologies for restoring degraded grasslands in cold regions have the following shortcomings: First, there is a lack of precise adaptation to the cold, short-lived habitat. The Huitengxile region has a frost-free period of less than 80 days and an average annual temperature close to 0°C, making low-temperature stress the primary factor limiting plant establishment. Current technologies mostly use normal-temperature forage varieties or unproven common cultivars, resulting in extremely low overwintering and seedling rates in the first year after sowing. Some schemes introduce annual fast-growing grasses such as oats, which may provide short-term greening but cannot survive the winter, degrading and disappearing from the second year onwards, failing to meet the needs for sustainable restoration. Second, the fragmented operation of multiple stages leads to excessive disturbance. Current technologies implement weed control, reseeding, and fertilization in separate steps, requiring repeated mechanical entry into the grassland. For alpine meadows with fragile soil structures, frequent compaction further exacerbates soil compaction and vegetation damage, leading to restorative secondary degradation. Summary of the Invention

[0005] To address the aforementioned shortcomings, this invention provides a grassland restoration method and restoration combination suitable for alpine short-habitat montane meadow-steppe in Huitengxile. Details are as follows: A grassland restoration method suitable for alpine short-habitat mountain meadow steppe in Huitengxile involves using no-till strip seeding on the target meadow steppe plot in mid-to-late June before the rainy season to simultaneously complete weed inhibitor spraying, grass seed reseeding, mineral fertilizer application, and light compaction. The grass species are described in the following weight ratios: Mongolian icegrass: Leymus chinensis: Xilingol edged bromegrass (variety registration number: 239; breeding unit: Inner Mongolia Agricultural University; approved by the National Forage Variety Approval Committee and registered as a wild cultivated variety): Mengnong No. 2 alfalfa (variety number: Mengshen-020-2020; applicant unit: College of Grassland and Resource Environment, Inner Mongolia Agricultural University) = 2:2:3:3, with a sowing rate of 1.5-2.5 kg / mu; The grass seeds were treated with Trichoderma harzianum (Trichoderma) before sowing. Trichoderma harzianum MCBC3 powder seed dressing treatment, with an inoculant dosage of 0.8-1.2 kg / mu; the Trichoderma harzianum ( Trichoderma harzianum MCBC3 is deposited at the China General Microbiological Culture Collection Center (CGMCC), accession number: CGMCC No. 41745, address: No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing. The method is applicable to alpine short-habited mountain meadow-steppe at 41°±1′N, altitude 2000±50m, average annual temperature 0±1℃, frost-free period <80d, annual precipitation 280-380mm, and soil type black calcareous soil or chestnut calcareous soil.

[0006] Preferably, the weed inhibitor is bentazon, and the application rate is 130-170 mL / mu; Preferably, the mineral fertilizer is grassland sheep manure organic fertilizer (trace element enhanced type), provided by Inner Mongolia Yufu Ecological Agriculture and Animal Husbandry Technology Co., Ltd. and the Grassland Health Center of Inner Mongolia University - Sunite Left Banner Base, with registration number: Mengnongfei (2024) Zhunzi 2581, and the application rate is 45-55 kg / mu.

[0007] Preferably, the row spacing for no-till row sowing is 25-35cm, and the sowing depth is 2-3cm.

[0008] Preferably, the Trichoderma harzianum ( Trichoderma harzianum MCBC3 powder seed treatment is used to: improve the germination rate and uniformity of overseeded grass seeds under high-altitude and low-temperature conditions, promote the elongation of the radicle to enhance the seedling's drought and cold resistance, and enhance the competitiveness and overwintering survival rate of overseeded grass seeds in the Huitengxile high-altitude and short-lived habitat by inducing the accumulation of proline and soluble sugars and the increase of antioxidant enzyme activity in forage leaves.

[0009] Preferably, the Trichoderma harzianum ( Trichoderma harzianumMCBC3 powder seed dressing can promote root growth of reseeded vegetation, reduce the survival competition of pathogens, regulate soil microbial community structure, and increase vegetation coverage and the quantity of high-quality forage.

[0010] Preferably, in the grass species combination, Xilingol edged bromegrass is a cold-resistant, barren-tolerant, and stable-yielding grass for more than 10 years, while Mengnong No. 2 alfalfa is a drought-resistant, pest-resistant, salt-tolerant, and nitrogen-fixing legume. The two work together to achieve a long-term and stable restoration effect of complementary grass and legume, combining long-term and short-term effects, stabilizing seedlings in the first year, and continuously increasing yield from the second year onwards.

[0011] Preferably, the metribuzin is a selective contact herbicide that achieves precise weed control by inhibiting the photosynthesis, respiration, and water metabolism of broadleaf weeds, and is safe for humans and animals and environmentally friendly.

[0012] Preferably, the mineral fertilizer targets and replenishes soil nutrients, working synergistically with no-till strip seeding and weed suppression to achieve a high seedling rate under minimal soil disturbance conditions, forming a restoration process that simultaneously suppresses weeds, reseeds, and applies fertilizer.

[0013] Preferably, the restoration method, starting from the second year after reseeding, continuously increases the coverage, density, and yield of the target grass species combination, with a hay yield of 280-380 kg / mu, and simultaneously achieves ecological functions such as soil and nitrogen fixation, soil and water conservation, biodiversity enhancement, and carbon sequestration and water conservation.

[0014] Preferably, the method is applicable to the improvement of degraded grasslands in the Huitengxile Mountain meadow steppe. After restoration, the grassland vegetation coverage and the proportion of high-quality forage grasses are significantly increased, while the proportion of broadleaf miscellaneous grasses is significantly reduced.

[0015] Secondly, this invention provides a grass seed composition for the restoration of alpine short-habitat meadow steppes in Huitengxile, comprising the following grass seeds in parts by weight: Mongolian icegrass: Leymus chinensis: Xilingol edged bromegrass (registration number 239): Mengnong No. 2 alfalfa (Mengshen-020-2020) = 2:2:3:3, and using Trichoderma harzianum ( Trichoderma harzianum MCBC3 powder is used for seed treatment, with a dosage of 0.5 kg of inoculant per kilogram of grass seeds.

[0016] Preferably, the grass seed composition is used in synergistic application with metribuzin inhibitors and mineral fertilizers to achieve a one-time restoration operation of degraded alpine meadows under no-till strip seeding conditions.

[0017] Thirdly, the present invention provides a repair combination of the method, including the following quantitative parameters: Inhibitor: Bentazon, 150 mL / acre; Grass seed ratio: Composed of the following grass seeds in parts by weight: Mongolian ice grass: Leymus chinensis: Xilingol edged bromegrass (registration number 239): Mengnong No. 2 alfalfa (Meng Shen-020-2020) = 2:2:3:3; Grass seeding rate: 2.0 kg / mu; Microbial inoculant dosage: Trichoderma harzianum ( Trichoderma harzianum MCBC3, 1.0 kg / mu; Mineral fertilizer application rate: 50 kg / mu; Row spacing for strip seeding: 30cm; Sowing depth: 2-3cm; Application period: Mid to late June, before the rainy season; Suitable habitat: 41°±1′N, altitude 2000±50m, average annual temperature 0±1℃, frost-free period <80d, annual precipitation 280-380mm, black calcareous soil / chestnut calcareous soil.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention is designed for alpine meadows located at 41°N latitude, 2000m altitude, 0°C annual average temperature, <80d frost-free period, 380mm annual precipitation, and black / chestnut soil. It constructs a combination of cold-resistant native grasses, pest and weed control, micro-targeted fertilization, and no-till light compaction for remediation. This system is adapted to the parameterized scheme of the Huitengxile short habitat, solving the problem of existing technologies lacking precise adaptation to the special characteristics of alpine short habitats.

[0019] 2. This invention employs a high-altitude, stable-yield combination of Mongolian icegrass: crested wheatgrass: Xilingol edged hairy bromegrass (registration number 239): Mengnong No. 2 alfalfa (Mengshen-020-2020) = 2:2:3:3. Among them, Xilingol edged hairy bromegrass (registration number 239) is a cold-resistant, barren-tolerant, and stable-yielding grass variety with a lifespan of over 10 years, significantly enriching the selection of high-yielding grasses for alpine meadows. Mengnong No. 2 alfalfa (Mengshen-020-2020) is a drought-resistant, pest-resistant, salt-tolerant, and nitrogen-fixing legume, suitable for arid and cold regions of Inner Mongolia with annual precipitation above 250mm and soil pH ≤ 8.6, and is well-suited to local soil conditions. The synergistic effect of these two grasses achieves complementary benefits between grasses and legumes, combining long-term and short-term effects, ensuring stable seedling emergence in the first year, continuous yield increases from the second year onwards, and long-term stable restoration, distinguishing it from short-term, high-yield combinations containing oats.

[0020] 3. This invention uses 150 mL / mu of metribuzin for precise control of broadleaf weeds, and employs no-till row sowing combined with Trichoderma harzianum (…). Trichoderma harzianumMCBC3 powder was used for seed dressing, and 50 kg / mu of mineral fertilizer was applied simultaneously to target and replenish soil nutrients. Finally, light compaction was performed to complete the operation. Bentazon, as a selective contact herbicide, achieves precise weed control by inhibiting the photosynthesis, respiration, and water metabolism of broadleaf weeds, and is safe for humans and animals and environmentally friendly; Trichoderma harzianum ( Trichoderma harzianum MCBC3 powder seed dressing can promote root growth of reseeded vegetation, reduce the survival competition of pathogens, regulate soil microbial community structure, and increase vegetation coverage and the quantity of high-quality forage. Attached Figure Description

[0021] Figure 1 Bar chart showing the changes in plant height for different combinations of grass species in different years; Figure 2 Bar chart showing the changes in vegetation cover for different grass species combinations in different years; Figure 3 Bar chart showing the changes in population density for different grass species combinations in different years; Figure 4 Bar chart showing the changes in aboveground hay yield for different combinations of grass species in different years; Figure 5 This is a field photo showing the actual growth of grass seed combination I in 2024. Figure 6 This is a field photo showing the actual growth of grass seed combination I in 2025. Figure 7 This is a field photo showing the actual growth of grass seed combination II in 2024. Figure 8 This is a close-up photo of the plants from the 2025 grass seed combination II. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to embodiments and comparative examples, but the implementation of the present invention is not limited thereto.

[0023] Example 1 1. Overview of the test site The experimental plot is located in the alpine meadow grassland of Huitengxile Mountain in Chayouzhong Banner, Ulanqab City, at 41°14′57″N, 112°54′53″E, at an altitude of 2004 meters. The climate is classified as humid to semi-humid mountain cold-temperate type, with an average annual temperature of 0℃, a frost-free period of less than 80 days, and annual precipitation of approximately 400 mm. The soil is black calcareous soil or chestnut calcareous soil. The grass height is 8-25 cm, with a grass cover of 40-60%. The grassland type is sedge + Kentucky bluegrass, and the main native vegetation is sedge (…). Carex spp. Kentucky bluegrass ( ) Poa pratensis ), celery ( Sphallerocarpus gracilis ), Edelweiss ( Leontopodium leontopodioides), Sanguisorba officinalis ( Sanguisorba officinalis Artemisia selengensis ( ), Artemisia selengensis Artemisia tanacetifolia ), star-haired purslane ( Potentilla acaulis ), dandelion ( Taraxacum mongolicum ), Xingan Bupleurum ( Bupleurum sibiricum ), pigweed ( Salsola collina )wait.

[0024] 2. Species Composition Analysis of the Experimental Plot A total of 14 different plant families were found in the experimental plot, namely Poaceae, Fabaceae, Asteraceae, Rosaceae, Apiaceae, Ranunculaceae, Brassicaceae, Amaranthaceae, Chenopodiaceae, Plantaginaceae, Gentianaceae, Cyperaceae, Caryophyllaceae, and Papaveraceae. Among them, Asteraceae had the highest proportion of species, at 30.30%; Poaceae, Fabaceae, and Rosaceae also had relatively high proportions, each at 12.12%. The natural grassland plant life forms were dominated by perennial herbs, accounting for 81.82%, annual herbs accounted for 15.15%, and shrubs and subshrubs accounted for only 3.03%. See Tables 1 and 2.

[0025] Table 1. Family composition of dominant plant species in natural grasslands

[0026] Table 2 Basic Groups of Life Forms of Natural Grassland Plants

[0027] 3. Test methods To improve the quality of high-quality forage grasses in grasslands, a combination of grasses and leguminous grasses was overseeded. The specific experimental groups are as follows: Combination I (Common Grass Seed Combination Control): Select seeds that are currently available in large quantities on the market, a combination of Psammophytic Agrostis + Elymus sibiricum + Oats + Alfalfa in a ratio of 2:2:3:3.

[0028] Combination II (this invention): Select seeds readily available in the market and seeds from varieties approved for transformation and propagation in Inner Mongolia Autonomous Region. The combination is: *Mongolian icegrass* + *Leymus chinensis* + *Bryophytum comosum* (registration number 239) + *Alfalfa* No. 2 (Mongolian Approval-020-2020), in a ratio of 2:2:3:3. Before sowing, *Trichoderma harzianum* (…) is used… Trichoderma harzianum MCBC3 powder can be used for seed dressing at a rate of 1 kg / mu.

[0029] CK (Blank Control): No reseeding was performed.

[0030] In mid-to-late June 2024, a combined herbicide-suppressing and fertilizing machine was used to reseed and fertilize the experimental area. Spraying herbicides, reseeding, fertilizing, and compaction were completed simultaneously. Metfluthrin was sprayed at a rate of 150 mL / mu to reduce disturbance from annual and biennial native vegetation. A combination of legume and grass species was reseeded at a rate of 2.0 kg / mu. 50 kg / mu of mineral fertilizer (Mongolian Agricultural Fertilizer (2024) Approval No. 2581) was applied, and row sowing was performed using a no-till reseeder with a row spacing of 30 cm and a depth of 2-3 cm. Three replicates were set up for each combination.

[0031] In late August 2025, the quadrat method (quadrat size 1m×1m) was used to investigate vegetation species, abundance, coverage, and height using visual inspection and folding rulers. Aboveground biomass was measured using the harvesting, drying, and weighing method.

[0032] 4. Evaluation of recovery effect After planting, the seedling emergence rate of the grass seed combination was highly consistent with that of the original plant configuration. Plant information for experimental plots from different years is shown in Table 3.

[0033] Table 3 Plant Information Table for Experimental Plots in Different Years

[0034] Note: "√" indicates that the species appeared in the quadrat.

[0035] The growth patterns of combination I, combination II, and control (CK) showed some differences over two years, as shown in the figure. Figure 1-4 .

[0036] (1) Height: In the first year, the height of combination I was significantly higher than that of CK and combination II; in the second year, the heights of combination I, combination II and CK were close.

[0037] (2) Coverage: In the first year, the coverage of combination I was significantly higher than that of CK and combination II; in the second year, the coverage of combination II was higher than that of CK and combination I.

[0038] (3) Density: In the first year, the densities of combination I and combination II were higher than those of CK; in the second year, the density of combination II was higher than that of combination I and higher than that of CK.

[0039] (4) Output: In the first year, the output of combination I was higher than that of CK and combination II; in the second year, the output of combination II increased and was higher than that of CK and combination I.

[0040] Monitoring of key indicators for reseeding and establishment: In 2024, the emergence of hybrid seedling II was good. A seedling emergence rate survey was conducted in mid-August, with an average emergence rate of 87.3% for reseeded grass seeds in the sample plots. A survey conducted in late May 2025 during the greening-up period showed that the overwintering greening-up rate of hybrid seedling II reached 83.6%, with well-developed root systems and normal tillering, indicating that *Trichoderma harzianum* (…) Trichoderma harzianumMCBC3 seed treatment effectively enhanced the establishment ability and overwintering survival rate of reseeded grass seeds under high-altitude and low-temperature conditions. In combination II, both Xilingol edged bromegrass and Mengnong No. 2 alfalfa showed good cold resistance and rapid growth after greening up, laying a solid population foundation for the yield to surpass that of combination I in the second year.

[0041] In the first year, combination I exhibited higher height, cover, density, and yield due to the presence of annual oats, which have a faster growth rate. From the second year onwards, combination II showed better recovery results. The Xilingol edge-haired bromegrass (registration number 239) and Mengnong No. 2 alfalfa (Meng Shen-020-2020) in combination II are suitable for growth in the Huitengxile alpine meadow grassland region. Xilingol edge-haired bromegrass in combination II is a cold-resistant and barren-tolerant grass variety, while Mengnong No. 2 alfalfa is a drought-resistant, pest-resistant, salt-tolerant, and nitrogen-fixing legume. The synergistic effect of these two varieties achieved complementary benefits between grasses and legumes, combining short-term and long-term effects, ensuring stable seedling growth in the first year and continuous yield increases from the second year onwards, resulting in a long-term stable recovery effect.

[0042] See the growth status of Combination I and Combination II in 2024 and 2025. Figure 5-8 .

[0043] The experimental results show that from the second year onwards, the coverage, density and yield of combination II (the present invention) continue to increase, with a hay yield of 280-380 kg / mu. It has dual value for both forage and ecology (soil fixation, nitrogen fixation, water and soil conservation, and biodiversity enhancement), and can achieve the restoration of degraded alpine meadows by "improving quality, increasing quantity, stabilizing yield, fixing carbon and conserving water".

[0044] Example 2 Based on combination II of Example 1, three treatments were set up with grass seeding rates of 1.5 kg / mu, 2.0 kg / mu, and 2.5 kg / mu, respectively, while other parameters remained the same as in Example 1.

[0045] The results showed that at a seeding rate of 1.5 kg / mu, the number of seedlings per unit area was insufficient, the community establishment rate was slow, and the first-year coverage was low. At a seeding rate of 2.5 kg / mu, although the seedling density was higher, intraspecific competition intensified, resulting in a decrease in plant height and biomass, and an increase in seed costs. At a seeding rate of 2.0 kg / mu, the seedling density was moderate, the plants grew vigorously, and the yield per unit area was the highest. Therefore, 2.0 kg / mu is the optimal seeding rate.

[0046] Example 3 Based on combination II of Example 1, three treatments were set up with a benzimidox spraying rate of 130 mL / mu, 150 mL / mu, and 170 mL / mu, respectively, while other parameters remained the same as in Example 1.

[0047] Bentazon is a selective and contact herbicide that primarily kills weeds by inhibiting the physiological mechanisms of green plants, such as photosynthesis, respiration, and water metabolism, thereby exacerbating the death of plant cells. It is characterized by its rapid effectiveness, low toxicity, safety for humans and animals, and environmental friendliness.

[0048] The results showed that when the application rate of bentazon was 130 mL / mu, the inhibition rate of broadleaf weeds was approximately 70%, with some highly competitive weeds (such as Asteraceae plants) still having residues. At a application rate of 150 mL / mu, the inhibition rate of broadleaf weeds reached over 85%, and there was no significant phytotoxicity to reseeded gramineous and leguminous forage grasses. At a application rate of 170 mL / mu, the weed-suppressing effect was further improved, but the cost increased, and there was a potential risk of residue in cold environments. Considering all factors, 150 mL / mu was the optimal application rate, balancing weed-suppressing effect, ecological safety, and cost-effectiveness.

[0049] Example 4 Based on combination II of Example 1, three treatments were set up with mineral fertilizer (Mongolian Agricultural Fertilizer (2024) Approval No. 2581) application rates of 45 kg / mu, 50 kg / mu, and 55 kg / mu, respectively, with other parameters remaining the same as in Example 1.

[0050] The results showed that when the application rate was 45 kg / mu, the increase in available nutrients in the soil was limited, and the yield increase in the second year was small. When the application rate was 50 kg / mu, the content of soil organic matter and available nitrogen, phosphorus and potassium were significantly increased, and the yield and quality of forage were optimal. When the application rate was 55 kg / mu, the yield increase was not significantly different from that of 50 kg / mu, but the fertilizer cost increased. Therefore, 50 kg / mu is the optimal application rate.

[0051] Example 5 Based on combination II of Example 1, Trichoderma harzianum ( Trichoderma harzianum The dosage of MCBC3 inoculant was 0.8 kg / mu, 1.0 kg / mu, and 1.2 kg / mu for three treatments, with other parameters remaining the same as in Example 1.

[0052] Trichoderma harzianum ( Trichoderma harzianum MCBC3 powder seed dressing can promote plant root growth, reduce the survival competition of pathogens, regulate soil microbial community structure, and increase vegetation coverage and the quantity of high-quality forage.

[0053] The results showed that when the inoculant dosage was 0.8 kg / mu, the amount of inoculant adhering to the seed surface was insufficient, the rhizosphere colonization effect was poor, and the improvement in seedling emergence rate was limited. When the inoculant dosage was 1.0 kg / mu, the seedling emergence rate was significantly improved, the seedling root system was well developed, the proline and soluble sugar content in the leaves increased, the antioxidant enzyme activity was enhanced, and the overwintering greening rate was significantly improved. When the inoculant dosage was 1.2 kg / mu, the effect was not significantly different from that of 1.0 kg / mu. Therefore, 1.0 kg / mu is the optimal inoculant dosage.

[0054] Example 6 The preferred parameters from Examples 1 to 5 are integrated to form a complete repair combination, with the specific parameters as follows: Inhibitor: Bentazon, 150 mL / acre; Grass seed ratio: Mongolian icegrass: Leymus chinensis: Xilingol edged bromegrass (registration number 239): Mengnong No. 2 alfalfa (Meng Shen-020-2020) = 2:2:3:3; Grass seeding rate: 2.0 kg / mu; Microbial inoculant dosage: Trichoderma harzianum ( Trichoderma harzianum MCBC3, 1.0 kg / mu; Mineral fertilizer application rate: 50 kg / mu; Row spacing for strip seeding: 30cm; Sowing depth: 2-3cm; Application period: Mid to late June, before the rainy season; Suitable habitat: 41°±1′N, altitude 2000±50m, average annual temperature 0±1℃, frost-free period <80d, annual precipitation 280-380mm, black calcareous soil / chestnut calcareous soil.

[0055] The above-mentioned restoration combination was used to restore degraded alpine meadow-steppe plots in Huitengxile. The monitoring results in the second year (2025) showed that the vegetation coverage in the restored area reached 75%-85%, an increase of 25-35 percentage points compared with that before restoration; the proportion of reseeded grass species exceeded 60%, and the proportion of high-quality grass and legume forage grasses increased significantly; the proportion of broadleaf miscellaneous grasses (Asteraceae, Rosaceae, etc.) decreased from more than 30% before restoration to less than 10%; and the aboveground biomass dry weight reached 280-380 kg / mu.

[0056] Comparative Example 1 On the same plot as in Example 1, no Trichoderma harzianum (Trichoderma harzianum) was introduced. Trichoderma harzianum The control experiment of seed dressing treatment with MCBC3 powder was conducted, and other parameters were kept the same as in Example 1.

[0057] The results showed that the germination rate of reseeded grass seeds without seed dressing treatment was only 68.5% in the first year, about 18.8 percentage points lower than that in Example 1; the root length of seedlings was about 30% shorter than that in Example 1; and the regrowth rate after overwintering was only 61.2%, about 22.4 percentage points lower than that in Example 1. This indicates that *Trichoderma harzianum* (…) Trichoderma harzianum MCBC3 powder seed dressing can effectively promote the elongation of the radicle of resown grass seeds under low temperature conditions, enhance the drought and cold resistance of seedlings, and reduce the survival competition of soil-borne pathogens by colonizing the rhizosphere and regulating the soil microbial community structure, thereby significantly improving the establishment competitiveness and overwintering survival rate of resown grass seeds in high-altitude and short-lived habitats.

[0058] Comparative Example 2 On the same plot as in Example 1, a control experiment was set up without spraying metribuzin, with other parameters remaining the same as in Example 1.

[0059] The results showed that in the experimental plots without weed suppression treatment, broadleaf weeds such as those from the Asteraceae family (accounting for as much as 30.30%) and the Rosaceae family, with their strong seed reproduction and resource competition capabilities, exerted significant competitive inhibition during the seedling stage of the reseeded grass seeds. This resulted in a reduction of approximately 30% in the emergence rate of the reseeded grass seeds, and the first-year cover was about 20 percentage points lower than in Example 1. This indicates that precise suppression of broadleaf weeds by metribuzin is a key factor in ensuring the successful establishment of reseeded grass seeds.

[0060] Comparative Example 3 On the same plot as in Example 1, a control experiment was set up with combination I (Psammophytic icegrass + Leymus chinensis + oats + alfalfa = 2:2:3:3), without Trichoderma harzianum seed treatment, and other operations were kept the same as in Example 1.

[0061] The results showed that in the first year, the height, cover, density, and yield of combination I were significantly higher than those of combination II of this invention. This is because combination I contained the annual plant oats, which grows rapidly and represents a "short-term effective" restoration mode. However, oats cannot survive the winter and degenerate and disappear from the second year onwards. The reseeded grass species in combination I, including *Agrostis pilosa*, *Leymus chinensis*, and alfalfa, resulted in a significant decrease in the yield of combination I. In contrast, combination II of this invention showed better recovery effects from the second year onwards, with cover, density, and yield all surpassing those of combination I. *Bryophytum comosum* (registration number 239) from Xilingol and *Alfalfa 'Mongolia No. 2' (Mongolian Approval-020-2020)* are suitable for growth in the alpine meadow grassland area of ​​Huitengxile, achieving a long-term and stable restoration effect. This fully demonstrates that combination II of this invention differs from short-term high-yield combinations containing oats and belongs to a unique ratio scheme of perennial cold-resistant native grass species that is "complementary to grasses and beans, combining short-term and long-term effects, stabilizing seedlings in the first year, continuously increasing yield from the second year onwards, and long-term stability."

[0062] Comparative Example 4 On the same plot as in Example 1, a traditional step-by-step operation control was set up: first, pine barnyardgrass was sprayed, then no-till row sowing was carried out after an interval of 7 days, and then fertilization and compaction were carried out after an interval of 7 days. That is, all procedures were completed by three mechanical operations, and other parameters were kept the same as in Example 1.

[0063] The results showed that traditional step-by-step operations, due to repeated mechanical compaction, resulted in an approximately 12% increase in soil bulk density and a 25% increase in the area of ​​damaged native vegetation in the experimental area compared to Example 1. The germination rate of reseeded grass seeds was only 74.2%, approximately 13.1 percentage points lower than that of Example 1 (87.3%), indicating a significant remedial secondary degradation phenomenon. In contrast, the process of this invention achieves a single operation with minimal disturbance and maximizes the germination rate. Its parameters are precisely matched to the characteristics of alpine meadow soil compaction, low temperature and low fertility, and strong weed competition, effectively avoiding the drawbacks of traditional step-by-step operations.

[0064] Comparative Example 5 On the same plot as in Example 1, a control experiment of common grass species combinations was set up: common cultivated species that had not been screened for high-altitude cold environments were selected and mixed in a ratio of Mongolian ice grass + crested wheatgrass + awnless brome + alfalfa = 2:2:3:3. Trichoderma harzianum was not used for seed treatment, and other parameters were kept the same as in Example 1.

[0065] The results showed that the overwintering rate of the common grass species combination in the first year was only 44.7%, far lower than that of Example 1; after greening up in the second year, some varieties degenerated and died, resulting in poor community stability. In contrast, the Xilingol edged bromegrass (registration number 239) and Mengnong No. 2 alfalfa (Mengshen-020-2020) selected in Example 1 are varieties approved and registered in Inner Mongolia Autonomous Region. After regional adaptability verification, they showed good overwintering ability and continuous yield increase characteristics in high-altitude and short-lived habitats.

[0066] Comparative Example 6 On the same plot as in Example 1, a control experiment was conducted in which ordinary commercial organic fertilizer (50 kg / mu) was used to replace the special mineral fertilizer, and other parameters remained the same as in Example 1.

[0067] The results showed that ordinary commercial organic fertilizer decomposed slowly under high-altitude and low-temperature conditions, resulting in insufficient release of readily available nutrients. The absorption and utilization rate of reseeded grass seeds during the growing season was significantly lower than that of specialized mineral fertilizers. Yield measurements showed that the aboveground hay yield in Comparative Example 6 was only 312 kg / mu in the second year, significantly lower than that in Example 1. Furthermore, the reseeded grass seeds in Comparative Example 6 were approximately 10 cm shorter than those in Example 1, and their leaves were more yellowish-green, exhibiting obvious nutrient deficiency symptoms. This indicates that ordinary organic fertilizer cannot meet the nutrient requirements for rapid pasture growth under high-altitude and short-lived habitats.

[0068] Compared with traditional technologies, this invention has the following advantages: it uses metribuzin to precisely suppress broadleaf weeds, is fast-acting, has low toxicity, is safe for humans and animals, and is environmentally friendly; it uses Trichoderma harzianum (… Trichoderma harzianum MCBC3 powder seed dressing promotes germination and emergence of reseeded grass seeds under high-altitude and low-temperature conditions, enhancing seedling drought and cold resistance; mineral fertilizers are used to target and supplement soil nutrients, avoiding the problem of slow decomposition of ordinary organic fertilizers under high-altitude and cold conditions; no-till row sowing is used to simultaneously complete weed suppression, reseeding, fertilization, and compaction in one go, minimizing disturbance and achieving a high seedling survival rate; a special formula for perennial cold-resistant native registered varieties is used, with complementary grasses and beans, combining long-term and short-term effects, ensuring stable seedlings in the first year, continuous yield increase from the second year onwards, and stable yield for more than 10 years.

Claims

1. A grassland restoration method suitable for alpine short-habitat mountain meadow-steppe in Huitengxile, characterized in that, Before the rainy season in mid-to-late June, no-till strip seeding was used on the target meadow grassland plots to simultaneously complete weed inhibitor spraying, grass seed reseeding, mineral fertilizer application, and compaction. The grass seeds are in the following weight ratios: Mongolian icegrass: crested wheatgrass: Xilingol edged bromegrass: Mengnong No. 2 alfalfa = 2:2:3:3, and the sowing rate is 1.5-2.5 kg / mu; The grass seeds were treated with Trichoderma harzianum MCBC3 before sowing, with an inoculant dosage of 0.8-1.2 kg / mu. The aforementioned Trichoderma harzianum MCBC3 is deposited at the China General Microbiological Culture Collection Center, accession number: CGMCC No. 41745; The method is applicable to alpine short-habited mountain meadow-steppe at 41°±1′N, altitude 2000±50m, average annual temperature 0±1℃, frost-free period <80d, annual precipitation 280-380mm, and soil type black calcareous soil or chestnut calcareous soil.

2. The method according to claim 1, characterized in that, The weed suppressant is metribuzin, and the application rate is 130-170 mL / mu.

3. The method according to claim 1, characterized in that, The application rate of the mineral fertilizer is 45-55 kg / mu.

4. The method according to claim 1, characterized in that, The row spacing for no-till row sowing is 25-35cm, and the sowing depth is 2-3cm.

5. A repair combination for the method of claim 1, characterized in that, Including the following quantitative parameters: Inhibitor: Bentazon, 150 mL / acre; Grass seed ratio: Composed of the following grass species in parts by weight: Mongolian ice grass: Leymus chinensis: Xilingol edged bromegrass: Mengnong No. 2 alfalfa = 2:2:3:3; Grass seeding rate: 2.0 kg / mu; Microbial inoculant application rate: Trichoderma harzianum MCBC3, 1.0 kg / mu; Mineral fertilizer application rate: 50 kg / mu; Row spacing for strip seeding: 30cm; Sowing depth: 2-3cm; Application period: Mid to late June, before the rainy season; Suitable habitat: 41°±1′N, altitude 2000±50m, average annual temperature 0±1℃, frost-free period <80d, annual precipitation 280-380mm, black calcareous soil / chestnut calcareous soil.

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