Method for inhibiting typical grassland Artemisia annua in Hagenberg temperate zone by mixed sowing configuration of indigenous dominant plants

Abstract

The invention discloses a method for inhibiting typical grassland artemisia annua of a Hagenberg temperate zone by mixed sowing configuration of indigenous dominant plants, and belongs to the technical field of grassland ecological restoration and vegetation regulation, and the technical scheme is as follows: spraying 70% saflufenacil water dispersible granule diluent for selective inhibition from the seedling stage to the initial branching stage of the artemisia annua; 30-45 days after spraying, a local dominant plant grass seed combination is resown, and the local dominant plant grass seed combination is composed of leymus chinensis, grass, elytrigia intermedium, astragalus melilotus and lespedeza daurica; 10-15 days after reseeding, 1 ton / mu of decomposed sheep manure organic fertilizer is applied. According to field verification, the biomass ratio of the artemisia annua is reduced by 76.71%, the biomass on the vegetation ground is increased by 73%-80% compared with a control group, the organic carbon on the soil surface layer is increased by 14.29%, and the rapidly available phosphorus is increased by 83.02%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of grassland ecological restoration and vegetation control, in particular to a method for inhibiting Artemisia vulgaris in a typical grassland in Hulun Buir by mixed sowing of native dominant plants. BACKGROUND

[0002] Xiwuzhuer Village, Chenbaerhu Banner, Hulun Buir City (geographical coordinates: 49°25'48"N, 118°37'12"E, altitude 582 m), belongs to the typical temperate continental climate zone. The long-term average temperature in this area is about -0.21°C, and the winter is long (extreme low temperature ≤-40°C). The annual precipitation is about 350 mm, mainly concentrated in summer from June to August. The soil type is chestnut soil, which is nutrient-poor, with soil organic matter content of 1.7% in the surface layer of 0-15 cm. The grass cover is 40%, and the original vegetation is mainly perennial grasses such as Leymus chinensis, Stipa grandis and Cleistogenes squarrosa. However, long-term unreasonable use (overgrazing, frequent mowing) has led to degradation of the ecosystem in this area, resulting in the following problems: (1) Soil degradation promotes the competitive advantage of A. vulgaris: continuous consumption of nutrients in the surface layer (0-15 cm) of the soil significantly reduces the overall nutrient supply capacity; at the same time, repeated trampling by livestock and frequent mechanical rolling increase the soil bulk density, reduce the porosity, and weaken the aeration and water permeability. A. vulgaris has strong adaptability to poor and compact degraded soil, and has a competitive advantage over high-quality native forage grasses such as L. chinensis, and gradually dominates the resource competition, exacerbating the deterioration of the community structure; (2) Deterioration of vegetation community structure exacerbates the expansion of A. vulgaris: the cover, average height and aboveground biomass of L. chinensis community continue to decrease, the tillering ability decreases, the community stability decreases, and the proportion of forbs increases significantly. A. vulgaris, with its strong reproductive ability and resource competition ability, becomes the dominant forbs in the community, further occupying the light, nutrient and water space of high-quality forage grasses; (3) Weakening of the stress resistance of high-quality vegetation indirectly promotes the expansion of A. vulgaris: the dual stress of soil nutrient imbalance and community structure deterioration leads to a significant decrease in the resistance of high-quality forage grasses such as L. chinensis to extreme weather conditions such as winter cold and late spring frost, with a delay of 5-7 days in the recovery period and a shortening of the effective growth period. A. vulgaris has stronger tolerance to extreme weather conditions, and its excessive growth not only further occupies the light, water and nutrient resources of high-quality forage grasses, but also inhibits the growth of L. chinensis and other forage grasses, forming a vicious cycle of "degradation-A. vulgaris expansion-redegradation", which seriously affects the yield and quality of high-quality forage grasses.

[0003] The existing Artemisia plant control technology has obvious regional adaptability defects when applied: (1) Chemical control technology has poor ecological compatibility and short-term effect. Although existing chemical herbicides can inhibit Artemisia plants in the short term, they do not inhibit specified Artemisia grass plants. Conventional single spraying of inhibitors to eliminate A. annua can cause phytotoxicity to high-quality grasses such as Leymus chinensis, weaken their competitiveness, create gaps for the secondary expansion of Artemisia plants, and have a short-term effect. (2) Plant regulation has insufficient adaptability and is limited in scale. Traditional physical control (manual / mechanical removal) is costly and inefficient, and frequent mechanical operations can increase soil bulk density and exacerbate the vicious cycle of degradation. Single plant regulation (single grass reseeding) lacks the synergistic effect of native plants, and the reseeded species have insufficient adaptability to severe cold and poor soil, and their competitiveness is weaker than that of Artemisia plants, resulting in a short-term inhibition effect and an inability to optimize the community structure from the essence. SUMMARY

[0004] Based on the above technical problems, the present application aims to address the unique high-latitude severe cold climate, the poor and compact soil characteristics of chestnut calcareous soil in the temperate typical grassland of Xiwuzhuer Village, Chenbargui Banner, Hulunbuir City, and the actual problems of excessive expansion of A. annua, decline of high-quality forage grasses, and insufficient regional adaptability of existing control technologies caused by grassland degradation. There is an urgent need for an ecologically friendly, locally adapted, and simultaneous A. annua precise inhibition and degraded grassland restoration synergistic technology to optimize the vegetation community structure, improve the productivity of high-quality forage grasses and the stability of the ecosystem, and ensure the sustainable use and production value of the grassland in this region. The specific steps are as follows: A method for inhibiting A. annua in Hulunbuir temperate typical grassland using native dominant plant mixed seeding, comprising the following steps: S1, spraying inhibitor: spraying an inhibitor to the degraded grassland to selectively inhibit A. annua during the seedling stage to the early branching stage of A. annua; The inhibitor is a benzenesulfonamide water dispersible granule dilution; S2, reseeding: 30-45 days after the inhibitor is sprayed, reseeding a native dominant plant grass seed combination; The native dominant plant grass seed combination is composed of the following proportions: Leymus chinensis 1-2 kg / acre, Daurian sagebrush 0.1-0.3 kg / acre, intermediate wildrye 0.2-0.4 kg / acre, Melilotus officinalis 0.4-0.6 kg / acre, and Daurian Huji 0.4-0.6 kg / acre; S3, fertilization: 10-15 days after reseeding, applying composted organic fertilizer.

[0005] Moreover, the dilution concentration of the benzenesulfonamide water dispersible granule dilution is 1:500-1:800, and the spraying amount is 10-15 L / acre.

[0006] Moreover, the benfuresate water dispersible granule is 70% benfuresate water dispersible granule, the dilution concentration is 1:600, and the spraying dosage is 12 L / mu; The native dominant plant grass seed combination is composed of the following proportions: Leymus chinensis 1.5 kg / mu, Aeluropus littoralis 0.2 kg / mu, Thinopyrum intermedium 0.3 kg / mu, Melilotoides ruthenica 0.5 kg / mu, and Hupehanshu 0.5 kg / mu.

[0007] Moreover, the specific spraying parameters of the benfuresate water dispersible granule diluent are adjusted according to the Artemisia rupestris coverage: When the Artemisia rupestris coverage is 20%-30%, the dilution concentration is 1:800, and the spraying dosage is 10 L / mu; When the Artemisia rupestris coverage is 30%-50%, the dilution concentration is 1:600, and the spraying dosage is 12 L / mu; When the Artemisia rupestris coverage is greater than or equal to 50%, the dilution concentration is 1:500, and the spraying dosage is 15 L / mu, and is sprayed twice with an interval of 7 days.

[0008] Moreover, the native dominant plant grass seed combination is a combination of Gramineae and Leguminosae, and the sowing method is strip sowing with a row spacing of 20-30 cm, a ditch depth of 1.5-2.5 cm, and a soil covering of 1-2 cm.

[0009] Moreover, the mature organic fertilizer is a mature sheep manure organic fertilizer from Hulunbuir, and the indexes meet the following requirements: organic matter content ≥ 30%, total nitrogen ≥ 1.5%, total phosphorus ≥ 0.8%, total potassium ≥ 1.0%, and pH value 7.0-8.0.

[0010] Moreover, the application amount of the mature organic fertilizer is 0.8-1.2 tons / mu, and the application method is manual throwing or uniform throwing by a fertilizer throwing machine.

[0011] Moreover, in step S1, when the inhibitor is sprayed: The flat area with a slope of less than or equal to 15° is sprayed by a multi-rotor unmanned aerial vehicle, the flight height is 1.5-2.0 m, the flight speed is 4-6 m / s, and the droplet particle size is 150-200 μm; The area within a range of 100 m from a water source is sprayed by a backpack electric sprayer, the distance between the nozzle and the Artemisia rupestris canopy is 30-50 cm, and the spraying angle is 45° with the canopy.

[0012] Moreover, before the supplemental sowing in step S2, for the Leymus chinensis, Melilotoides ruthenica, and Hupehanshu, a seed pretreatment process is further included: The Leymus chinensis seed is treated by mechanical friction and low-temperature stratification at 0-5 °C for 7-10 days; The Hupehanshu and Melilotoides ruthenica seeds are treated by soaking in 80 °C warm water for 5-10 minutes; After treatment, 0.5% of naphthalene acetic acid and 1% of rhizobium agent of leguminous plants were added in total mass of seeds.

[0013] Moreover, the method is applied to the temperate typical grassland degradation area of Xiwuzhuer Village, Chenbarhu Banner, Hulunbuir City, the soil type of the area is chestnut calcareous soil, the average annual temperature is-0.21 DEG C, the extreme low temperature is less than or equal to-40 DEG C, and the average annual precipitation is 350 mm.

[0014] Moreover, the method achieves the following technical effects: The proportion of artemisia annua biomass is reduced by more than 76.71%; The above-ground biomass of vegetation is increased by 73%-80% compared with the control; The organic carbon content of the soil surface layer 0-15 cm is increased by more than 14.29%, and the available phosphorus content is increased by more than 83.02%.

[0015] Compared with the prior art, the method has the beneficial effects that: 1. The prior art usually adopts single herbicide spraying or single grass seed reseeding, and often falls into the dilemma of short-term inhibition, rebound expansion, low reseeding survival rate and insufficient competitiveness, the method is aimed at the typical grassland degradation core area of Xiwuzhuer Village, Chenbarhu Banner, Hulunbuir, first, selective suppression is carried out on artemisia annua seedlings by using bensulfuron-methyl, without damaging high-quality gramineous forage; then, the native dominant grass species combination suitable for the severe cold and poor habitat is reseeded in the drug efficacy window period; finally, the reseeded grass species is supported to form a community through the slow-release nutrient of organic fertilizer; through field measurement, the biomass proportion of artemisia annua is reduced from 39.11% to 9.11%, which is significantly better than conventional chemical control or single grass treatment.

[0016] 2. The prior physical and chemical control technologies pay more attention to above-ground vegetation inhibition, ignore the root cause of soil degradation, and even aggravate soil compaction due to mechanical rolling, the method is implemented by no-tillage reseeding + organic fertilizer surface application, without disturbing the soil structure, the above-ground biomass of the community reaches 387.86 g / m2 in the current year, and still maintains 344.68 g / m2 in the next year, which is significantly better than the commercial grass combination in persistence; the soil organic carbon content of the soil surface layer is increased by 14.29% compared with the control, the available phosphorus content is increased by 83.02% compared with the control, the soil pH is restored from weak acid to neutral, and the nutrient supply capacity of chestnut calcareous soil is improved.

[0017] 3. The method is aimed at the special habitat of Hulunbuir with an average annual temperature of-0.21 DEG C, an extreme low temperature of less than or equal to-40 DEG C, a short frost-free period and poor soil, and native dominant plants such as dandelion, dandelion, intermediate wildrye, herbaceous astragalus, daurian hujiuzi and the like are selected, and the overwintering rate and greening rate are significantly higher than those of commercial grass species. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a test design diagram of example 1. Figure 2 Effects of fertilization and soil layer on soil nutrient characteristics in Example 5. DETAILED DESCRIPTION

[0019] Test design and grass seed combination configuration in Example 1 This example is based on the setting of 36 test plots in the enclosed sample plot, which specifically includes reseeding and fertilization. Select 1.5 mu of degraded grassland in Xiwuzhuer Village, Chenbaerhu Banner to set up test plots (install fences, barbed wire and doors). A 2x2 split plot test design is used, with 5 different grass seed combinations (R1-R5) and 1 no reseeding treatment (R0) in the main area. The specific combinations are as follows: Grass seed combination 1 (R1): 1.5 kg / mu of Dalurian Huji, 0.5 kg / mu of Sophora flavescens, 0.5 kg / mu of oblique stem Astragalus, and 0.5 kg / mu of Medicago ruthenica; Grass seed combination 2 (R2): 1.5 kg / mu of Leymus chinensis, 1.0 kg / mu of Agropyron cristatum, 0.4 kg / mu of Achnatherum splendens, and 0.1 kg / mu of Thinopyrum intermedium; Grass seed combination 3 (R3): 1.5 kg / mu of Leymus chinensis, 0.2 kg / mu of Achnatherum splendens, 0.3 kg / mu of Thinopyrum intermedium, 0.5 kg / mu of Melilotus officinalis, and 0.5 kg / mu of Dalurian Huji; Grass seed combination 4 (R4): 1.0 kg / mu of Agropyron cristatum, 1.0 kg / mu of Elymus nutans, 0.4 kg / mu of Achnatherum splendens, and 0.6 kg / mu of Thinopyrum intermedium; Grass seed combination 5 (R5): 1.0 kg / mu of Dalurian Huji, 0.7 kg / mu of Sophora flavescens, 0.8 kg / mu of Medicago polymorpha, and 0.5 kg / mu of Medicago sativa.

[0020] Among them, R1 is a native grass seed combination of Gramineae, R2 is a native legume seed combination, R3 is a native grass seed combination of Gramineae + legume, R4 is a commercially available grass seed combination of Gramineae, and R5 is a commercially available legume seed combination.

[0021] The sub-area is set up with no fertilization (F1) and organic fertilizer (F2) two treatments. The test sets up 12 treatments (R1F1, R2F1, R3F1, R4F1, R5F1, R0F, R1F2, R2F2, R3F2, R4F2, R5F2 and CK), each treatment 3 repeats, a total of 36 test plots, each plot 4m long x 4m wide, 1m wide isolation belt between plots to avoid interference between different treatments Figure 1 ). Sowing in July 2024, sowing amount is 3 kg / mu by strip sowing, and 1 ton / mu of organic fertilizer is evenly applied in the fertilization area after sowing.

[0022] Example 2 Spray inhibitor

[0023] This example is applicable to all test plots in Example 1. Based on the characteristics of Hulunbuir climate, soil type, community structure, etc., 70% bensulfuron-methyl water dispersible granules (trade name: Ba Bajin®, registration certificate number: PD20131930) are selected as the inhibitor. The specific operation is as follows: (1) Inhibitor selection and pretreatment The selected inhibitor meets the following technical indicators: ① Through indoor pot toxic force determination, the safety threshold of the inhibitor to native high-quality forage grasses such as Leymus chinensis, Agropyron cristatum, and Spiraea salicifolia is ≥ 90%, and there is no risk of leaf yellowing and tillering inhibition after spraying on seedlings; ② Low toxicity and low residual, half-life in soil ≤ 30 days, and good chemical stability in the temperature range of -40°C-35°C, suitable for the extreme climate of grassland overwintering and summer high temperature; ③ No significant inhibition effect on bacterial, fungal, and other microbial communities in chestnut soil (P>0.05), and no effect on soil aeration, water permeability, and nutrient conversion efficiency. P

[0024] Before use, the inhibitor is pretreated: dilute (replace deionized water to improve on-site operability) with clean water (pH 6.5-7.5) meeting the agricultural field irrigation water quality standard (GB 5084-2021) at a ratio of 1:500-1:800, stir uniformly, and stand for 10-15 minutes; During this period, add 0.1% non-ionic surfactant (such as polyoxyethylene sorbitan ester, trade name: Tween-80) of the total amount of the inhibitor, stir thoroughly until completely dissolved, to improve the adhesion and rainwater erosion resistance of the pesticide on the leaves of Artemisia annua, and avoid loss of the pesticide due to summer heavy rainfall.

[0025] (2) Spray timing determination Based on the results of continuous monitoring of grassland phenology, spraying is carried out during the seedling stage to the early branching stage of Artemisia annua (mid-to late May to early June), which needs to meet the following conditions: ① The plant height of Artemisia annua is ≤ 15 cm, the cuticle layer of the leaves has not yet fully formed, the sensitivity to the inhibitor is high, and the dense community has not yet formed, making it easy for the pesticide to uniformly contact the target; ② High-quality forage grasses such as Leymus chinensis are in the peak regreening period, with well-developed root systems and strong stress resistance, significantly improving the tolerance to the inhibitor; ③ Choose a day with an average rainfall of ≤ 5 mm, and avoid extreme low temperatures (≥ 5°C) and high temperatures (≤ 30°C) to ensure stable pesticide action period. Before spraying, meteorological forecasts and actual measurement data should be checked 3 days in advance to avoid periods of strong wind (wind speed ≥ 4 m / s) and rainfall warning, and preferentially choose sunny days between 9:00-11:00 (leaf dew has evaporated) or 16:00-18:00 (temperature drops, evaporation is small) for operation.

[0026] (3) Spray dosage and concentration control​ For the area with 20-30% coverage of artemisia, the inhibitor with dilution concentration of 1:800 was used at a dosage of 10 L / acre; for the area with 30-50% coverage of artemisia, the inhibitor with dilution concentration of 1:600 was used at a dosage of 12 L / acre; for the area with coverage of artemisia ≥ 50%, the inhibitor with dilution concentration of 1:500 was used at a dosage of 15 L / acre, and the spraying was performed twice (the second spraying was performed 7 days after the first spraying) to avoid potential impact of single high-dose spraying on the soil and associated pasture.

[0027] (4) Spraying mode and operation specification The "backpack electric sprayer + unmanned aerial vehicle cooperative spraying" mode was adopted to adapt to the large-scale operation and fine prevention and control requirements of grassland: ① For the flat area with slope ≤ 15°, multi-rotor unmanned aerial vehicle (carrying centrifugal spray head) was selected for spraying. The flight height was controlled at 1.5-2.0 m, the spray head spacing was 50 cm, the flight speed was 4-6 m / s, the droplet size was 150-200 μm, and the drift distance was ≤ 50 cm to ensure that the pesticide was evenly covered on the artemisia canopy and did not affect the surrounding high-quality pasture area. ② For the fine areas such as the surrounding of the fence and within 100 m of the water source, the backpack electric sprayer (carrying fan-shaped spray head) was used for directional spraying. The spray head was 30-50 cm away from the artemisia canopy, the spraying angle was 45° to the canopy, and the spraying was gradually pushed from the edge to the center of the artemisia community to avoid a large amount of pesticide penetrating into the soil surface below 0-5 cm (to prevent affecting the subsequent seed germination).

[0028] (5) Post-spraying maintenance and effect monitoring If the single rainfall is ≥ 10 mm within 7 days after spraying, the area needs to be sprayed again within 3 days after the rain (the dilution concentration remains unchanged, and the dosage is halved); 15 days after spraying, the sample method is used to monitor the artemisia plant height and fresh weight inhibition rate (inhibition rate calculation formula: inhibition rate = (control group index - treatment group index) / control group index x 100%); 25 days after spraying, the coverage change is monitored. When the plant height / fresh weight inhibition rate is ≤ 60% or the coverage reduction rate is ≤ 50%, additional low-dose spraying (dilution concentration 1:800, dosage 6.5 L / acre) is performed.

[0029] Simultaneous ecological safety monitoring: 30 days after spraying, the growth indicators (plant height, tiller number, and aboveground biomass) of sheep grass and other high-quality pastures are measured; 60 days after spraying, the soil physical and chemical properties (pH, organic matter content, bulk density, and porosity) are measured to ensure that the inhibitor has no negative impact on the soil and vegetation.

[0030] Example 3: Supplementary planting

[0031] This example is applicable to all test plots in Example 1, specifically including R1F1, R2F1, R3F1, R4F1, R5F 1,R1F2, R2F2, R3F2, R4F2, R5F2, and 10 other test treatments: (1) Seed treatment: The seeds of Leymus chinensis and Agropyron cristatum were treated by "mechanical friction + low-temperature stratification". The seed coat cutin layer was removed by mechanical friction (to improve water absorption), and then the seeds were stratified at 0-5°C for 7-10 days to simulate the low-temperature environment of the grassland in winter and break dormancy. The seeds of Potentilla davidii and Melilotus officinalis were soaked in warm water at 80°C for 5-10 minutes (natural cooling) to break the hard seed rate (hard seed rate ≥ 80%), and then the water was drained and the seeds were dried in the shade. The treated seeds were mixed uniformly, 0.5% naphthalene acetic acid and 1% rhizobium agent were added to the total mass of the seeds, and then an appropriate amount of clay (30% of the mass of the seeds) was added to make a paste to improve the adhesion of the seeds to the soil and prevent wind erosion and loss.

[0032] (2) Determining the time of supplemental planting The time of supplemental planting was selected 30-45 days after the first spraying of the inhibitor (early July), which met the following conditions: ① The inhibition rate of the height of Artemisia rupestris was ≥ 60%, and the growth was significantly inhibited, which did not form a competitive advantage, leaving space for the germination of the seeds of the supplemental planting; ② The soil moisture content of the grassland was good (the soil moisture content of the surface layer was 15%-20%), and the late frost was avoided (there was no extreme low temperature after late June), and the temperature was suitable (the daily mean temperature was 15-25°C), which met the germination requirements of the native grass seeds; ③ It was close to the period of concentrated rainfall in summer, which could reduce artificial irrigation and improve the survival rate of seedlings. Before supplemental planting, the soil moisture content was monitored, and if it was less than 15%, irrigation (amount: 10-15 m³ / acre) was carried out 1-2 days before supplemental planting to ensure the water requirement for seed germination.

[0033] (3) Seeding Before seeding, the residues of Artemisia rupestris, stones, and other obstacles to seed germination were removed by hand to reduce the obstacles to seed germination. The test plots were seeded by hand using the strip seeding method, with a row spacing of 20-30 cm and a depth of 2 cm. The mixed seeds were evenly spread into the ditch, and then covered with 1-2 cm of soil. The seeds were lightly compacted with the foot to prevent them from being exposed to the surface and being eroded by the wind or eaten by birds. For large areas of degraded grassland, the supplemental planting was carried out by no-tillage, with a row spacing of 20-30 cm and a depth of 2 cm. The seeding rate was 3 kg / acre.

[0034] Example 4 Fertilization

[0035] This example is applicable to all test plots in Example 1, specifically including R0F2, R1F2, R2F2, R3F2, R4F2, R5F2, and 6 other test treatments:

[0036] (1) Organic fertilizer selection: Preferentially select Hulun Buir's local source of mature sheep manure organic fertilizer (grassland livestock waste resource utilization, strong adaptability, powder form), which needs to meet the following technical indicators: organic matter content ≥ 30%, total nitrogen (N) ≥ 1.5%, total phosphorus (P2O5) ≥ 0.8%, total potassium (K2O) ≥ 1.0%, balanced nutrients and slow release; maturity standards: high-temperature maturity (55-65°C) ≥ 15 days, pH value 7.0-8.0, no foul odor, roundworm egg mortality rate ≥ 95%, fecal coliform count ≤ 10 5

[0037] (2) Organic fertilizer dosage: 1 ton / acre.

[0038] (3) Fertilization time: 10-15 days after reseeding, at which time the soil structure is loose after shallow plowing, and the organic fertilizer can be fully mixed with the surface soil, providing stable basic nutrients for seed germination, improving the compact structure of chestnut soil, and improving the soil water and moisture conservation capacity; At the same time, the reseeding grass seedling roots expand rapidly, and nutrients need to be supplemented to promote growth, while the growth of artemisia annua residues is weakened by the influence of the inhibitor and cannot compete for nutrients in large quantities. Before fertilization, meteorological data need to be monitored to avoid heavy rain (24-hour rainfall ≥ 20 mm) and strong wind (wind speed ≥ 4 m / s) periods to avoid fertilizer loss or drift.

[0039] (4) Fertilization method: The test plot uses manual throwing method, and the large-area degraded grassland uses throwing fertilizer machine for uniform throwing.

[0040] (5) Quality standards: The mixed fertilizer as a whole meets the requirements of NY / T 1868-2021 "Organic Fertilizer", among which the heavy metal content (lead, cadmium, mercury, arsenic, chromium) needs to meet the national standard limit, and the moisture content of mature sheep manure particles is controlled at 20%-25% (to avoid clumping and affect uniformity of throwing).

[0041] Example 5 Field verification and application effect (1) Spray inhibitor (all test treatments): May 25, 2024-June 5, 2024 (soil layer thawing depth 25 cm, good moisture regime, no heavy rain during the period), use a backpack electric sprayer (with fan-shaped nozzles) to spray 70% bensulfuron-methyl water dispersible granules, the nozzle distance from the artemisia annua canopy is 30-50 cm, the spraying angle is 45° with the canopy, and the center is gradually pushed along the edge of the artemisia annua community to avoid a large amount of pesticide penetrating into the soil surface below 0-5 cm. Investigate the coverage of the test area, find that the grass coverage is about 50%, use the inhibitor with a dilution concentration of 1:600, and the dosage is 12 L / acre; ​(2) Sowing (all sowing plots, including R1F1, R2F1, R3F1, R4F1, R5F1, R1F2, R2F2, R3F2, R4F2, R5F2, etc. 10 test treatments): From July 4, 2024 to July 6, 2024 (30 days after spraying the inhibitor), artificial strip sowing is used to make up for the sowing, the row spacing is 20-30 cm, the ditch depth is 2 cm, the mixed seeds are evenly scattered into the ditch, and then the soil is covered by 1-2 cm, and the soil is lightly compacted by foot.

[0042] (3) Fertilization (fertilization plots, including R0F2, R1F2, R2F2, R3F2, R4F2, R5F2, etc. 6 test treatments): Around July 15, 2024, the powder organic fertilizer is scattered by artificial throwing, and the fertilizer is evenly covered in the plot, and the amount is 1 ton / acre.

[0043] (4) Daily management: During the test period, the 12 groups of treatments are managed according to the local conventional way, and only once irrigation is carried out (15 m 3 ).

[0044] (5) Data collection: In August 2024 and August 2025 (growing season), 1 m x 1 m quadrat is used to monitor the vegetation community height, coverage, density and ground cutting of each test plot, and the species in each quadrat are cut, dried and weighed to calculate the aboveground biomass; in August 2025 (one year after implementation), 0-15 cm and 15-30 cm soil samples are collected in each test plot by soil drill 3 drill mixing 1 drill, and soil pH, total and available nutrients are measured.

[0045] Figure 2 The comparative changes of pH, organic carbon and available phosphorus in 0-15 cm and 15-30 cm soil layers under fertilization and non-fertilization treatments are shown in the figure, F1 is non-fertilization treatment, and F2 is fertilization treatment. Different lowercase letters represent significant differences (P<0.05) between non-fertilization and fertilization treatments To further analyze the effects of reseeding, fertilization and soil depth on the recovery of soil nutrients one year after implementation (2025), linear mixed effect model is used for analysis, and the main effects and interactions of each factor are evaluated, and the results are shown in Table 1. Table 2 compares the dynamic changes of vegetation height, coverage, density and aboveground biomass under different reseeding grass species combinations in 2024-2025, aiming to identify the dominant grass species combination and its time persistence. Table 3 further quantifies the composition structure of Poaceae, Leguminosae, Artemisia annua and other miscellaneous grasses under each treatment from the perspective of functional group biomass ratio, to directly evaluate the inhibition effect of the present application on Artemisia annua and the recovery level of high-quality forage grass.

[0046] Table 1. Results of linear mixed-effects model analysis (F-value) of the effects of reseeding, fertilization, soil depth and their interactions on soil nutrient characteristics.

[0047] Note: DF1 and DF2 represent the numerator and denominator degrees of freedom, respectively. P <0.01, * indicates P <0.05, significance is indicated by italics and bold.

[0048] Table 2. Changes in vegetation height, cover, density, and aboveground biomass under different grass species combinations reseeded in 2024 and 2025.

[0049] Note: Different capital letters in the same column indicate significant differences between treatments in different years. P <0.05, different lowercase letters indicate significant differences between different treatments ( P <0.05). R0, R1, R2, R3, R4 and R5 represent no reseeding, reseeding with native grass species, reseeding with native potato species, reseeding with native grass and legume species, reseeding with commercial grass species, and reseeding with commercial legume species, respectively.

[0050] Table 3. Changes in biomass percentage under different treatment combinations (percentage)

[0051] Note: Different lowercase letters in the same column indicate significant differences between treatments in different years. P <0.05, different capital letters indicate significant differences between different treatments ( P <0.05). R0, R1, R2, R3, R4 and R5 represent no reseeding, reseeding with native grass species, reseeding with native potato species, reseeding with native grass and legume species, reseeding with commercial grass species, and reseeding with commercial legume species, respectively; F1 and F2 represent no fertilization and fertilization, respectively.

[0052] I. Results and Analysis of Soil Indicators (1) Main effects: Fertilization has a significant impact on soil pH, soil organic carbon, and available phosphorus (Table 1, P <0.05); reseeding did not produce significant differences in soil pH, total soil nutrients, and available nutrients (Table 1, P＞0.05); the soil pH, total carbon, total nitrogen, total phosphorus, soil organic carbon, ammonium nitrogen, nitrate nitrogen, and available phosphorus contents were significantly different among different soil layers (Table 1, P <0.05).

[0053] (2) Interactive effects: A. Supplemental seeding x fertilization: Significant differences in soil ammonium nitrogen and available phosphorus were observed, indicating that supplemental seeding and fertilization jointly had a significant effect on ammonium nitrogen and available phosphorus.

[0054] B. Supplemental seeding x soil layer: Significant differences in soil total carbon and total nitrogen were observed, indicating that there were significant differences in soil total carbon and total nitrogen among different soil layers under supplemental seeding treatment.

[0055] C. Fertilization x soil layer: Soil pH, total nutrients, and available nutrients did not show significant differences, indicating that the interaction between the two factors was a trade-off.

[0056] D. Supplemental seeding x fertilization x soil layer: Soil pH, total nutrients, and available nutrients did not show significant differences, indicating that the interaction of the three factors was complex.

[0057] Further analysis showed that fertilization had a significant effect on surface soil nutrients: compared with the unfertilized treatment, the pH value, soil organic carbon (SOC), and available phosphorus (AP) in the 0-15 cm surface soil layer were significantly increased by 2.95%, 14.29%, and 83.02%, respectively; in contrast, there were no significant differences in the measured nutrient indicators between the fertilized and unfertilized treatments in the 15-30 cm soil layer (P > 0.05). Figure 1 , P <0.05).

[0058] II. Results and analysis of vegetation indicators As shown in Table 2, the year and different grass species supplemental seeding combinations had a significant impact on vegetation height, coverage, density, and biomass: 1. Time dimension (year): In 2024-2025, different grass species supplemental seeding combinations showed an increasing trend in vegetation density (an increase of 206.53%), indicating that supplemental seeding is an efficient technical means to improve the vegetation structure and enhance the vegetation coverage of degraded grassland; however, the density improvement rate of the treatment group was much higher than that of the control group, demonstrating that artificial supplemental seeding played a promoting role in community density.

[0059] 2. The effect of treatment measures: In 2024, the height, coverage and density of plant community under the grass seed combination R3 treatment were significantly higher than those under other treatments, and the biomass of plant community under the grass seed combination R3 treatment was significantly higher than that under the control and R1 treatment, but there was no significant difference between the grass seed combinations (R2, R4, R5) (Table 2).

[0060] In 2025, the height and density of plant community under the grass seed combination R3 treatment were significantly higher than those under other treatments, and the coverage of plant community under all the reseeding combination treatments (R1, R2, R3, R4, R5) was significantly higher than that under the control, although there was no significant difference in the biomass of plant community under different grass seed combination treatments, the biomass of plant community under the grass seed combination R3 treatment was significantly higher than that under other treatments (R1, R2, R4, R5) and the control (Table 2).

[0061] III. The inhibitory effect of reseeding and fertilization on Artemisia annua To clarify the inhibitory effect of reseeding and fertilization on Artemisia annua, the biomass proportion of Gramineae, Leguminosae, Artemisia annua and other miscellaneous grasses under different treatment combinations was calculated (Table 3). The results showed that under the fertilization treatment (F2), the proportion of Gramineae and Leguminosae under different grass seed combinations was significantly higher than that under the fertilization treatment (F1), and the proportion of Artemisia annua decreased; and under the grass seed combination R3 treatment, the proportion of Artemisia annua decreased most obviously. This result indicates that reseeding the grass seed combination R3 and applying organic fertilizer can effectively inhibit the growth of Artemisia annua.

[0062] IV. Conclusion: Through the above experiments, it can be seen that spraying 70% bensulfuron-methyl water dispersible granules (dilution concentration 1:600, inhibitor, dosage 12 L / acre) and reseeding the above test R3 combination (i.e. native dominant Gramineae + Leguminosae plants: Leymus chinensis 1.5 kg / acre + Daurian wildrye 0.2 kg / acre + Thinopyrum intermedium 0.3 kg / acre + Melilotus officinalis 0.5 kg / acre + Humulus japonicus 0.5 kg / acre) and spreading 1 ton / acre of powdered organic fertilizer can effectively inhibit the growth of Artemisia annua. This combination scheme can achieve the synergistic improvement of vegetation productivity (the biomass in 2024 increased by 80.24% compared with the control, and the biomass in 2025 increased by 73.76% compared with the control) and soil quality (soil organic carbon and available phosphorus increased by 14.29% and 83.02% respectively compared with the control), and at the same time, the proportion of Artemisia annua biomass was reduced (by 76.71% compared with the control). This technical mode realizes the multi-objective synergistic optimization of degraded grassland ecosystem, and is an efficient ecological management scheme suitable for Hulun Buir typical grassland area.

Claims

1. A method for suppressing Artemisia annua in the typical temperate grasslands of Hulunbuir by using mixed sowing of native dominant plants, characterized in that, Includes the following steps: S1. Spraying inhibitors: Spraying inhibitors onto degraded grasslands during the seedling stage to the early branching stage of Artemisia annua to selectively inhibit Artemisia annua; The inhibitor is a diluted solution of benzosulfuron-methyl water-dispersible granules; S2. Reseeding: 30-45 days after the inhibitor is sprayed, reseed a combination of native and dominant grass species. The native dominant grass species combination consists of the following proportions: Leymus chinensis 1-2 kg / mu, Leymus chinensis 0.1-0.3 kg / mu, Leymus chinensis 0.2-0.4 kg / mu, Astragalus membranaceus 0.4-0.6 kg / mu, Lespedeza bicolor 0.4-0.6 kg / mu; S3. Fertilization: Apply well-rotted organic fertilizer 10-15 days after reseeding.

2. The method according to claim 1, characterized in that, The dilution concentration of the phenylsulfuron-methyl water-dispersible granule solution is 1:500-1:800, and the spraying dosage is 10-15 L / mu.

3. The method according to claim 2, characterized in that, The bensulfuron-methyl water-dispersible granules are 70% bensulfuron-methyl water-dispersible granules with a dilution concentration of 1:600 ​​and a spraying rate of 12L / mu; The native dominant grass species combination consists of the following proportions: Leymus chinensis 1.5 kg / mu, Leymus chinensis 0.2 kg / mu, Leymus chinensis 0.3 kg / mu, Astragalus membranaceus 0.5 kg / mu, Lespedeza bicolor 0.5 kg / mu.

4. The method according to claim 2, characterized in that, Adjust the specific spraying parameters of the benzosulfuron-methyl water-dispersible granule dilution according to the coverage of Artemisia annua: When the coverage of Artemisia annua is 20%-30%, the dilution concentration is 1:800, and the spraying dosage is 10L / mu; When the coverage of Artemisia annua is 30%-50%, the dilution concentration is 1:600, and the spraying dosage is 12L / mu; When the coverage of Artemisia annua is ≥50%, the dilution concentration is 1:500, the spraying dosage is 15L / mu, and it is sprayed twice with an interval of 7 days.

5. The method according to claim 1, characterized in that, The native dominant plant species combination is a mixed sowing combination of grass family and leguminous family, sown by row sowing with a row spacing of 20-30cm, a furrow depth of 1.5-2.5cm, and a soil covering of 1-2cm.

6. The method according to claim 1, characterized in that, The decomposed organic fertilizer is decomposed sheep manure organic fertilizer from Hulunbuir, and its indicators meet the following requirements: organic matter content ≥30%, total nitrogen ≥1.5%, total phosphorus ≥0.8%, total potassium ≥1.0%, and pH value 7.0-8.

0.

7. The method according to claim 6, characterized in that, The application rate of the decomposed organic fertilizer is 0.8-1.2 tons per mu.

8. The method according to claim 1, characterized in that, In step S1, when spraying the inhibitor: For gentle slopes ≤15°, multi-rotor drones are used for spraying, with a flight altitude of 1.5-2.0m, a flight speed of 4-6m / s, and a droplet size of 150-200μm. Within 100m of the water source, use a backpack electric sprayer for directional spraying, with the nozzle 30-50cm away from the canopy of Artemisia annua and the spraying angle at 45° to the canopy.

9. The method according to claim 1, characterized in that, Before reseeding in step S2, for Leymus chinensis, Astragalus membranaceus, and Lespedeza dauricum, a seed pretreatment process is also included: Sheepgrass seeds were treated with mechanical friction and low-temperature stratification at 0-5℃ for 7-10 days; The seeds of Lespedeza dauricum and Astragalus membranaceus were treated by soaking them in 80℃ warm water for 5-10 minutes. After treatment, add 0.5% naphthaleneacetic acid and 1% leguminous rhizobium agent by total seed weight.

10. The method according to claim 1, characterized in that, The method was applied to the degraded temperate typical grassland area of ​​Xiwuzhuersumu, Chenbalhu Banner, Hulunbuir City.

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