Method for inhibiting artemisia annua in hulunbuir typical grassland by using local dominant plant mixed sowing configuration

Abstract

The application discloses a method for inhibiting Artemisia annua in a Hulunbuir typical grassland by using mixed sowing of local dominant plants, and belongs to the technical field of grassland ecological restoration and vegetation regulation. The technical scheme is as follows: during the seedling stage to the initial branching stage of the Artemisia annua, 70% bensulfuron-methyl water dispersible granules are sprayed to perform selective inhibition; 30-45 days after the spraying, local dominant plant grass seeds are supplemented and sowed, and the local dominant plant grass seeds are composed of Leymus chinensis, Leymus mollis, Thinopyrum intermedium, Melilotus officinalis, and Lespedeza davurica; 10-15 days after the supplement and sowing, 1 ton of decomposed sheep manure organic fertilizer is applied per mu. Field verification shows that the application can reduce the biomass proportion of the Artemisia annua by 76.71%, increase the aboveground biomass of the vegetation by 73%-80% compared with a control, increase the organic carbon in the surface layer of the soil by 14.29%, and increase the available phosphorus by 83.02%.

Description

Technical Field

[0001] This invention relates to the field of grassland ecological restoration and vegetation regulation technology, specifically a method for suppressing Artemisia annua in the typical temperate grasslands of Hulunbuir by using mixed sowing of native dominant plants. Background Technology

[0002] Xiwuzhuer Sumu, Chenbalhu Banner, Hulunbuir City (geographical coordinates: 49°25' 48" N, 118°37'12" E, altitude 582 m), belongs to a typical temperate continental climate zone. The region has a long-term average annual temperature of approximately -0.21℃, with a severe winter lasting up to 6 months (extreme low temperature ≤ -40℃). The average annual precipitation is about 350 mm, mainly concentrated in the summer months of June to August. The soil type is chestnut calcareous soil, nutrient-poor, with an organic matter content of only 1.7% in the top 0-15cm soil layer. Grass cover is 40%, with native vegetation mainly consisting of perennial grasses such as sheepgrass, needlegrass, and rough grass. However, years of unreasonable utilization (overgrazing and frequent mowing) have led to the degradation of the ecosystem in this area, resulting in the following problems:

[0003] (1) Soil degradation gives Artemisia annua a competitive advantage: Nutrients in the top layer of soil (0-15cm) are continuously consumed, and the overall nutrient supply capacity is significantly reduced; at the same time, repeated trampling by livestock and frequent mechanical compaction lead to increased soil bulk density, reduced porosity, and weakened aeration and permeability. Artemisia annua is highly adaptable to barren and compacted degraded soils and has a competitive advantage over high-quality native forage grasses such as sheepgrass. It gradually occupies a dominant position in resource competition, which exacerbates the deterioration of community structure.

[0004] (2) The deterioration of vegetation community structure exacerbates the expansion of Artemisia annua: the coverage, average height and aboveground biomass of Leymus chinensis community continue to decrease, the tillering ability weakens, the community stability declines, and the proportion of miscellaneous grasses increases significantly. With its strong reproductive capacity and resource competition ability, Artemisia annua has become the dominant miscellaneous grass in the community, further squeezing out the light, nutrient and water space of high-quality forage grasses.

[0005] (3) The weakening of the stress resistance of high-quality vegetation indirectly promotes the expansion of Artemisia annua: The dual stress of soil nutrient imbalance and community structure degradation leads to a significant decrease in the resistance of high-quality forage grasses such as Leymus chinensis to extreme climates such as severe winter cold and late spring frost, delaying the greening period by 5-7 days and shortening the effective growth period; while Artemisia annua is more tolerant to extreme climates. Its excessive growth not only further squeezes the light, water and nutrient resources of high-quality forage grasses, but also inhibits the growth and recovery of Leymus chinensis and other grasses, forming a vicious cycle of "degradation- expansion of Artemisia annua-re-degradation", which seriously affects the yield and quality of high-quality forage grasses.

[0006] Existing Artemisia species control technologies suffer from significant regional adaptability deficiencies:

[0007] (1) Chemical control technology has poor ecological compatibility and its effects are difficult to sustain. Although existing chemical herbicides can inhibit Artemisia species in the short term, they do not inhibit specific Artemisia species. Conventional single spraying of inhibitors to eliminate Artemisia annua can easily cause phytotoxicity to high-quality forage grasses such as Leymus chinensis, weakening their competitiveness and leaving room for secondary expansion of Artemisia species, making it difficult to achieve long-term effectiveness.

[0008] (2) Insufficient adaptability of plant regulation and limited scale. Traditional physical control (manual / mechanical removal) is costly and inefficient, and frequent mechanical operations will aggravate soil bulk density problems and exacerbate the vicious cycle of degradation; single plant regulation (single grass reseeding) lacks the synergistic effect of native plants, the reseeded species are not well adapted to cold and barren soils, are less competitive than Artemisia species, the inhibitory effect is short-lived, and it cannot fundamentally optimize the community structure. Summary of the Invention

[0009] Based on the aforementioned technical problems, this invention addresses the unique high-latitude, frigid climate and poor, compact chestnut-calcareous soil characteristics of the typical temperate grassland in Xiwuzhuer Sumu, Chenbalhu Banner, Hulunbuir City. It also addresses the practical problems of excessive expansion of Artemisia annua, decline in high-quality forage grasses, and insufficient regional adaptability of existing control technologies caused by grassland degradation. Therefore, an eco-friendly, local habitat-adaptable, and synergistic technical solution is urgently needed to simultaneously achieve precise suppression of Artemisia annua and restoration of degraded grasslands. This solution aims to optimize vegetation community structure, enhance the productivity of high-quality forage grasses and ecosystem stability, and ensure the sustainable utilization and production value of the grasslands in this region. Specifically, the following is a detailed explanation:

[0010] A method for suppressing Artemisia annua in typical temperate grasslands of Hulunbuir by using mixed sowing of native dominant plants includes the following steps:

[0011] 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;

[0012] The inhibitor is a diluted solution of benzosulfuron-methyl water-dispersible granules;

[0013] S2. Reseeding: 30-45 days after the inhibitor is sprayed, reseed a combination of native and dominant grass species.

[0014] The native dominant grass species combination consists of the following proportions:

[0015] 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;

[0016] S3. Fertilization: Apply well-rotted organic fertilizer 10-15 days after reseeding.

[0017] Furthermore, 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.

[0018] Moreover, the bensulfuron-methyl water-dispersible granules are 70% bensulfuron-methyl water-dispersible granules with a dilution concentration of 1:600 ​​and a spraying dosage of 12L / mu;

[0019] The native dominant grass species combination consists of the following proportions:

[0020] 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.

[0021] Furthermore, the specific spraying parameters of the benzosulfanilamide water-dispersible granule dilution should be adjusted according to the coverage of Artemisia annua:

[0022] When the coverage of Artemisia annua is 20%-30%, the dilution concentration is 1:800, and the spraying dosage is 10L / mu;

[0023] When the coverage of Artemisia annua is 30%-50%, the dilution concentration is 1:600, and the spraying dosage is 12L / mu;

[0024] 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.

[0025] Moreover, the native dominant plant species combination is a mixed sowing combination of grass family and leguminous family, and the sowing method is row sowing with a row spacing of 20-30cm, a furrow depth of 1.5-2.5cm, and a soil covering of 1-2cm.

[0026] Moreover, 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.

[0027] Moreover, the amount of the decomposed organic fertilizer applied is 0.8-1.2 tons per mu, and the application method is manual spreading or uniform spreading by a fertilizer spreader.

[0028] Furthermore, in step S1, when spraying the inhibitor:

[0029] 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.

[0030] 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.

[0031] Furthermore, before reseeding in step S2, seed pretreatment is also included for Leymus chinensis, Astragalus membranaceus, and Lespedeza dauricum.

[0032] Sheepgrass seeds were treated with mechanical friction and low-temperature stratification at 0-5℃ for 7-10 days;

[0033] Seeds of Lespedeza dauricum and Astragalus membranaceus were treated by soaking in 80℃ warm water for 5-10 minutes.

[0034] After treatment, add 0.5% naphthaleneacetic acid and 1% leguminous rhizobium agent by total seed weight.

[0035] Moreover, the method was applied to the degraded temperate typical grassland area of ​​Xiwuzhuersumu, Chenbalhu Banner, Hulunbuir City. The soil type in this area is chestnut calcareous soil, with an average annual temperature of -0.21℃, an extreme low temperature of ≤-40℃, and an average annual precipitation of 350mm.

[0036] Moreover, the method achieves the following technical effects:

[0037] The biomass share of Artemisia annua decreased by more than 76.71%;

[0038] Aboveground biomass of vegetation increased by 73%-80% compared to the control;

[0039] The organic carbon content in the top 0-15cm layer of soil increased by more than 14.29%, and the available phosphorus content increased by more than 83.02%.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] 1. Existing technologies often employ single-type herbicide spraying or single-grass-species reseeding, which frequently leads to short-term suppression, rebound expansion, or low reseeding survival rates and insufficient competitiveness. This invention targets Xiwuzhuer Sumu in Chenbalhu Banner, a core area of ​​typical grassland degradation in Hulunbuir. It first uses bensulfuron-methyl to selectively suppress Artemisia annua seedlings without harming high-quality gramineous forage grasses. Then, during the efficacy window, it reseeds a combination of native dominant grass species suitable for cold and barren habitats. Finally, it uses slow-release organic fertilizer to support the reseeded grass species to form communities. Field tests showed that this model reduced the biomass percentage of Artemisia annua from 39.11% to 9.11%, which is significantly better than conventional chemical control or single-grass-species treatment.

[0042] 2. Existing physical and chemical control technologies mostly focus on suppressing aboveground vegetation, neglecting the root causes of soil degradation. In fact, mechanical compaction can even exacerbate soil compaction. This invention, through no-till reseeding and surface application of organic fertilizer, achieves a biomass of 387.86 g / m² in the first year of implementation without disturbing the soil structure, and maintains 344.68 g / m² in the second year, demonstrating significantly better sustainability than commercial grass combination. The surface soil organic carbon content is increased by 14.29% compared to the control, the available phosphorus content is increased by 83.02% compared to the control, and the soil pH is restored from slightly acidic to neutral, improving the nutrient supply capacity of chestnut soil.

[0043] 3. This invention targets the special habitat of Hulunbuir, where the average annual temperature is -0.21℃, the extreme low temperature is ≤-40℃, the frost-free period is short, and the soil is barren. It selects native dominant plants that have been naturally domesticated for a long time, such as sheepgrass, sedge, intermediate wheatgrass, osmanthus-like astragalus, and Daurian lespedeza, which have significantly higher overwintering rate and greening rate than commercial grass species. Attached Figure Description

[0044] Figure 1 This is the experimental design diagram for Example 1;

[0045] Figure 2 The effects of fertilization treatment and soil layer on soil nutrient characteristics in Example 5. Detailed Implementation

[0046] Example 1: Experimental Design and Grass Seed Combination Configuration

[0047] This embodiment established 36 experimental plots based on enclosed sample plots, specifically including reseeding and fertilization. A 1.5-mu (approximately 0.067 hectares) degraded grassland in Xiwuzhuer Sumu, Chenbalhu Banner, was selected for enclosed experimental plots (with fencing, barbed wire, and gates installed). A 2×2 split-plot experimental design was adopted, with the main plot containing 5 different grass species combinations (R1-R5) and 1 no-reseeding treatment (R0). The specific combinations are as follows:

[0048] Grass species combination 1 (R1): Lespedeza dauricum 1.5 kg / mu + Astragalus membranaceus 0.5 kg / mu + Astragalus membranaceus 0.5 kg / mu + Alfalfa 0.5 kg / mu;

[0049] Grass species combination 2 (R2): Sheepgrass 1.5kg / mu + ice grass 1.0kg / mu + edible grass 0.4kg / mu + intermediate wheatgrass 0.1kg / mu;

[0050] Grass species combination 3 (R3): Leymus chinensis 1.5kg / mu + Leymus chinensis 0.2kg / mu + Leymus chinensis 0.3kg / mu + Astragalus membranaceus 0.5kg / mu + Lespedeza bicolor 0.5kg / mu;

[0051] Grass species combination 4 (R4): 1.0 kg / mu of ice grass + 1.0 kg / mu of crested wheatgrass + 0.4 kg / mu of water hyacinth + 0.6 kg / mu of intermediate wheatgrass;

[0052] Grass species combination 5 (R5): Daurian Lespedeza 1.0 kg / mu + Astragalus membranaceus 0.7 kg / mu + Alfalfa 0.8 kg / mu + Alfalfa 0.5 kg / mu.

[0053] Among them, R1 is a combination of native grass species, R2 is a combination of native potato species, R3 is a combination of native grass and legume species, R4 is a combination of commercial grass species purchased from the market, and R5 is a combination of commercial legume species purchased from the market.

[0054] The subplot included two treatments: no fertilization (F1) and fertilization with organic fertilizer (F2). A total of 12 treatments were included in the experiment (R1F1, R2F1, R3F1, R4F1, R5F1, R0F, R1F2, R2F2, R3F2, R4F2, R5F2 and CK), with three replicates for each treatment, resulting in a total of 36 experimental plots. Each plot was 4m long × 4m wide, with a 1m wide buffer zone between plots to prevent interference between different treatments. Figure 1 Sowing will take place in July 2024, using row sowing at a rate of 3 kg / mu. After sowing, powdered organic fertilizer will be evenly spread in the fertilization plots at a rate of 1 ton / mu.

[0055] Example 2 Spraying inhibitors

[0056] This embodiment applies to all experimental plots in Example 1. Considering the climate characteristics, soil type, and community structure of Hulunbuir, 70% bensulfuron-methyl water-dispersible granules (trade name: Babaijin®, registration certificate number: PD20131930) were selected as the inhibitor. The specific operation is as follows:

[0057] (1) Inhibitor selection and pretreatment

[0058] The selected inhibitors meet the following technical indicators: ① Indoor pot toxicity tests show a safety threshold of ≥90% for native high-quality forage grasses such as Leymus chinensis, Leymus chinensis, and Lespedeza dauricum, with no risk of phytotoxicity such as leaf yellowing or tillering inhibition after spraying during the seedling stage; ② Low toxicity and low residue, with a half-life of ≤30 days in the soil, and good chemical stability within a temperature range of -40℃ to 35℃, suitable for the extreme climate of grasslands during harsh winters and hot summers; ③ No significant inhibitory effect on bacteria, fungi, and other microbial communities in chestnut soil. P >0.05), which does not affect soil aeration, water permeability, or nutrient conversion efficiency.

[0059] Pre-treat the inhibitor before use: Dilute it with clean water (pH 6.5-7.5) that meets the farmland irrigation water quality standards (GB 5084-2021) at a mass-to-volume ratio of 1:500-1:800 (to replace deionized water and improve on-site operability), stir evenly and let it stand for 10-15 minutes; during this time, add 0.1% of the total amount of inhibitor with a nonionic surfactant (such as polyoxyethylene sorbitan ester, trade name: Tween-80), stir thoroughly until completely dissolved, so as to improve the adhesion of the agent to the surface of Artemisia annua leaves and its resistance to rain washout, and avoid the loss of the agent due to concentrated summer rainfall.

[0060] (2) Determining the timing of spraying

[0061] Based on continuous monitoring of grassland phenology, spraying was selected during the seedling stage to early branching stage of Artemisia annua (mid-to-late May to early June). This period required the following conditions to be met simultaneously: ① Artemisia annua plant height ≤15cm, leaf cuticle not fully formed, high sensitivity to inhibitors, and no dense community yet, allowing for easy and even contact of the pesticide with the target; ② High-quality forage grasses such as Leymus chinensis were in their peak greening stage, with well-developed root systems and strong resistance, significantly improving their tolerance to inhibitors; ③ Daily average rainfall ≤5mm was selected, avoiding periods of extreme low temperatures (≥5℃) and high temperatures (≤30℃) to ensure a stable pesticide action period. Weather forecasts and measured data should be checked 3 days in advance, avoiding periods of strong winds (≥4m / s) and rain warnings. Priority should be given to sunny days from 9:00-11:00 (when dew on leaves has evaporated) or 16:00-18:00 (when temperatures drop and evaporation is low) for spraying.

[0062] (3) Control of spraying dosage and concentration

[0063] For areas with Artemisia annua cover of 20%-30%, use an inhibitor diluted 1:800 at a rate of 10 L / mu; for areas with cover of 30%-50%, use an inhibitor diluted 1:600 ​​at a rate of 12 L / mu; and for areas with cover ≥50%, use an inhibitor diluted 1:500 at a rate of 15 L / mu. Spray twice (once on the 7th day after the first spray) to avoid potential impacts of a single high dose on the soil and associated pasture grasses.

[0064] (4) Spraying method and operating procedures

[0065] The "backpack electric sprayer + drone coordinated spraying" mode is adopted to meet the needs of large-scale grassland operations and refined pest control: ① For gentle areas with a slope of ≤15°, multi-rotor drones (equipped with centrifugal nozzles) are used for spraying. Before operation, the flight path is planned by GPS positioning, the flight altitude is controlled at 1.5~2.0m, the nozzle spacing is 50cm, the flight speed is 4~6m / s, and the droplet size is 150~200μm to ensure that the pesticide evenly covers the Artemisia canopy and the drift distance is ≤50cm, so as not to affect the surrounding high-quality forage concentrated areas; ② For refined areas such as around the fence and within 100m of the water source, backpack electric sprayers (equipped with fan-shaped nozzles) are used for directional spraying. The distance between the nozzle and the Artemisia canopy is 30-50cm, the spraying angle is 45° with the canopy, and the spraying is gradually advanced from the edge of the Artemisia community towards the center to avoid a large amount of pesticide seeping into the soil surface 0-5cm below (to prevent affecting the germination of subsequent reseeding seeds).

[0066] (5) Post-spraying maintenance and effect monitoring

[0067] If a single rainfall of ≥10mm occurs within 7 days after spraying, the area should be re-sprayed within 3 days after the rain (dilution concentration remains the same, dosage is halved); 15 days after spraying, monitor the plant height and fresh weight inhibition rate of Artemisia annua using the quadratic method (inhibition rate calculation formula: inhibition rate = (control group index - treatment group index) / control group index × 100%), and monitor the change in canopy cover after 25 days. When the plant height / fresh weight inhibition rate is ≤60% or the canopy cover reduction rate is ≤50%, apply an additional low-dose spray (dilution concentration 1:800, dosage 6.5L / acre).

[0068] Simultaneously conduct ecological safety monitoring: measure the growth indicators (plant height, number of tillers, aboveground biomass) of high-quality forage grasses such as sheepgrass once 30 days after spraying, and measure the soil physicochemical properties (pH, organic matter content, bulk density, porosity) once 60 days after spraying to ensure that the inhibitor has no negative impact on soil and vegetation.

[0069] Example 3: Re-broadcast

[0070] This embodiment applies to all test cells in Embodiment 1, specifically including R1F1, R2F1, R3F1, R4F1, and R5F1. 1, Ten experimental treatments, including R1F2, R2F2, R3F2, R4F2, and R5F2:

[0071] (1) Seed treatment: Seeds of Leymus chinensis and Leymus chinensis were treated with "mechanical friction + low temperature stratification". Mechanical friction removed the cuticle layer of the seed coat (increasing water absorption rate), and then stratified at a low temperature of 0-5℃ for 7-10 days to simulate the low temperature environment of the grassland in winter and break dormancy. Seeds of Lespedeza dauricum and Astragalus membranaceus were soaked in 80℃ warm water for 5-10 minutes (natural cooling) to break the hard seed rate (hard seed rate ≥80%), and then drained and dried in a cool place until semi-dry. The seeds treated above were mixed evenly, and 0.5% of the total seed mass of naphthaleneacetic acid and 1% of leguminous rhizobium agent were added. Then, an appropriate amount of clay (accounting for 30% of the seed mass) was added to make a paste to improve the adhesion between the seeds and the soil and prevent wind erosion.

[0072] (2) Determine the rebroadcast time

[0073] Reseeding should be done 30-45 days after the first spraying of the inhibitor (early July), at which time the following conditions must be met: ① The inhibition rate of Artemisia annua plant height is ≥60%, its growth is significantly inhibited, and it has not formed a competitive advantage, leaving space for the germination of reseeded seeds; ② The grassland soil moisture is good (the top 0-15cm soil moisture content is 15%-20%), and it avoids late frost (no extreme low temperatures after late June), with suitable temperature (daily average temperature 15-25℃), which meets the germination requirements of native grass species; ③ It is close to the concentrated summer rainfall period, which can reduce artificial watering and improve the survival rate of seedlings. Before reseeding, the soil moisture content should be monitored. If it is lower than 15%, irrigation should be carried out 1-2 days before reseeding (at a rate of 10-15 m³ / mu) to ensure the water requirements for seed germination.

[0074] (3) Sowing

[0075] Before sowing, manually remove Artemisia annua stalks, stones, and other debris from the reseeding area to reduce seed germination obstacles. In the experimental plots, manual row sowing was used, with a row spacing of 20-30 cm and a furrow depth of 2 cm. The mixed seeds were evenly scattered into the furrows, then covered with 1-2 cm of soil and lightly compacted with the feet to prevent seeds from being exposed to the surface and eroded by wind or eaten by birds. For large areas of degraded grassland, no-till reseeding was used, with a row spacing of 20-30 cm and a furrow depth of 2 cm. The seeding rate was 3 kg / mu.

[0076] Example 4 Fertilization

[0077] This embodiment applies to all test cells in Embodiment 1, specifically including six test processes: R0F2, R1F2, R2F2, R3F2, R4F2, and R5F2.

[0078] (1) Screening of organic fertilizers: Priority should be given to well-rotted sheep manure organic fertilizer (resource utilization of grassland livestock waste, strong adaptability, powder form) which is widely available in Hulunbuir. It should 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; the degree of decomposition should meet the standards: high temperature decomposition (55~65℃) ≥15 days, pH value 7.0~8.0, no foul odor, ascarid egg mortality rate ≥95%, and fecal coliform count ≤10. 5 Particles per gram; particle size ≤ 2 cm; free of impurities such as stones, weed seeds, and Artemisia annua residues, to avoid introducing new invasion risks.

[0079] (2) Organic fertilizer application rate: 1 ton / mu.

[0080] (3) Fertilization time: 10-15 days after reseeding. At this time, the soil structure is loose after shallow turning, and organic fertilizer can be fully mixed with the topsoil. This can provide stable basic nutrients for seed germination, improve the compact structure of chestnut soil, and enhance the soil's water retention capacity. At the same time, the roots of the reseeded grass seeds expand rapidly and need to be supplemented with nutrients to promote growth. However, the remaining plants of Artemisia annua are weakened by the inhibitor and cannot compete for nutrients in large quantities. Before fertilization, meteorological data should be monitored to avoid periods of heavy rain (24-hour rainfall ≥20mm) and strong winds (wind speed ≥4m / s) to avoid fertilizer loss or drift.

[0081] (4) Fertilization method: manual spreading was used in the experimental plots, and fertilizer spreaders were used to spread fertilizer evenly on large areas of degraded grassland.

[0082] (5) Quality standards: The blended fertilizer shall meet the requirements of NY / T 1868-2021 Organic Fertilizer. The content of heavy metals (lead, cadmium, mercury, arsenic and chromium) shall meet the national standard limits. The moisture content of the decomposed sheep manure granules shall be controlled at 20%-25% (to avoid clumping and affecting the uniformity of application).

[0083] Example 5: Field Verification and Application Results

[0084] (1) Spraying inhibitors (all experimental treatments): From May 25 to June 5, 2024 (soil thawing depth 25cm, good soil moisture, no heavy rainfall during the period), 70% benzoyl permethrin water-dispersible granules were sprayed directionally using a backpack electric sprayer (equipped with a fan-shaped nozzle). The distance between the nozzle and the Artemisia canopy was 30-50cm, and the spraying angle was 45° with the canopy. The spraying was gradually advanced from the edge of the Artemisia community towards the center to avoid the pesticide penetrating into the top 0-5cm of the soil. The cover of the experimental area was investigated and found to be about 50%. The inhibitor was diluted 1:600 ​​and the dosage was 12L / mu.

[0085] (2) Sowing (all sowing plots, specifically including 10 experimental treatments such as R1F1, R2F1, R3F1, R4F1, R5F1, R1F2, R2F2, R3F2, R4F2, and R5F2): From July 4 to July 6, 2024 (30 days after spraying the inhibitor), re-sowing was carried out by manual row sowing with a row spacing of 20-30cm and a furrow depth of 2cm. The mixed seeds were evenly scattered into the furrows, and then covered with 1-2cm of soil and lightly compacted with feet.

[0086] (3) Fertilization (fertilization plots, specifically including 6 experimental treatments such as R0F2, R1F2, R2F2, R3F2, R4F2, and R5F2): Around July 15, 2024, powdered organic fertilizer was applied by manual spreading to ensure that the fertilizer evenly covered the plots, with a dosage of 1 ton / mu.

[0087] (4) Daily management: During the experiment, all 12 treatments were managed according to local routine methods, with irrigation only carried out once during extreme drought (15 consecutive days without rainfall) (15 m³ of water per mu). 3 ).

[0088] (5) Data collection: In August 2024 and August 2025 (peak growing season), the height, cover, density of vegetation community in each experimental plot were monitored using 1m×1m quadrats. The species in each quadrats were cut at ground level, dried, weighed, and the aboveground biomass was calculated. In August 2025 (one year after implementation), soil samples of 0-15cm and 15cm-30cm were collected in each experimental plot using a soil drill with 3 drills and 1 drill. Soil pH, total soil nutrients, and available nutrients were measured.

[0089] Figure 2 The figure shows the comparative changes in pH, organic carbon, and available phosphorus in the 0-15 cm and 15-30 cm soil layers under fertilized and unfertilized treatments. In the figure, F1 represents the unfertilized treatment, and F2 represents the fertilized treatment. Different lowercase letters indicate significant differences between the unfertilized and fertilized treatments (P<0.05).

[0090] To further analyze the impact of reseeding, fertilization, and soil depth on soil nutrient recovery one year after implementation (2025), a linear mixed-effects model was used to evaluate the main effects and interactions of each factor. The results are shown in Table 1. Table 2 compares the dynamic changes in vegetation height, cover, density, and aboveground biomass under different reseeding grass species combinations from 2024 to 2025, aiming to identify dominant grass species combinations and their temporal persistence. Table 3 further quantifies the composition structure of grasses, leguminous grasses, Artemisia annua, and other miscellaneous grasses under each treatment by focusing on the biomass proportion of functional groups, in order to directly evaluate the inhibitory effect of this invention on Artemisia annua and the recovery level of high-quality forage.

[0091] 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.

[0092]

[0093] 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.

[0094] Table 2. Changes in vegetation height, cover, density, and aboveground biomass under different grass species combinations reseeded in 2024 and 2025.

[0095]

[0096] 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.

[0097] Table 3. Changes in biomass percentage under different treatment combinations (percentage)

[0098]

[0099] 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.

[0100] I. Results and Analysis of Soil Indicators

[0101] (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); Significant differences were observed in soil pH, total carbon, total nitrogen, total phosphorus, soil organic carbon, ammonium nitrogen, nitrate nitrogen, and available phosphorus content among different soil layers (Table 1, P <0.05).

[0102] (2) Interaction effect:

[0103] A. Reseeding × Fertilization: Significant differences were observed in soil ammonium nitrogen and available phosphorus, indicating that both reseeding and fertilization had a significant impact on ammonium nitrogen and available phosphorus.

[0104] B. Reseeding × Soil layer: Significant differences were observed in total soil carbon and total nitrogen, indicating that there were significant differences in total soil carbon and total nitrogen among different soil layers under the reseeding treatment.

[0105] C. Fertilization × Soil layer: There were no significant differences in soil pH, total soil nutrients, and readily available nutrients, indicating that there is a trade-off between the two.

[0106] D. Reseeding × Fertilization × Soil layer: No significant differences were found in soil pH, total soil nutrients, and available nutrients, indicating that the interaction of the three factors is relatively complex.

[0107] Further analysis showed that fertilization only had a significant effect on nutrients in the topsoil: compared with the unfertilized treatment, the pH, soil organic carbon (SOC), and available phosphorus (AP) in the 0-15 cm topsoil layer were significantly increased by 2.95%, 14.29%, and 83.02%, respectively; conversely, there were no significant differences in any of the measured nutrient indices in the 15-30 cm soil layer between the fertilized and unfertilized treatments. Figure 1 , P <0.05).

[0108] II. Results and Analysis of Vegetation Indicators

[0109] As shown in Table 2, the year and different grass species reseeding combinations all had a significant impact on vegetation height, cover, density, and biomass:

[0110] 1. Time dimension (year): From 2024 to 2025, different grass species reseeding combinations showed an increasing trend in vegetation density year by year (an increase of 206.53%), which indicates that reseeding is an efficient technical means to improve the vegetation structure of degraded grassland and increase vegetation coverage; however, the density increase in the treatment group was much greater than that in the control group, which shows that artificial reseeding has a promoting effect on community density.

[0111] 2. Effects of the treatment measures: In 2024, the height, cover and density of the plant community were significantly higher under the grass species combination R3 treatment than other treatments. The community biomass was significantly higher under the grass species combination R3 treatment than the control and R1 treatment, but there were no significant differences with other grass species combinations (R2, R4, R5) (Table 2).

[0112] In 2025, the height and density of the plant community were significantly higher under the grass species combination R3 treatment than other treatments. The plant community cover under all reseeding treatment combinations (R1, R2, R3, R4, R5) was significantly higher than the control group. Although there was no significant difference in community biomass under different grass species combination treatments, the community biomass under the grass species combination R3 treatment was significantly higher than other treatments (R1, R2, R4, R5) and the control (Table 2).

[0113] III. The Inhibitory Effects of Reseeding and Fertilization on Artemisia annua

[0114] To clarify the inhibitory effects of reseeding and fertilization on Artemisia annua, the biomass proportions of grasses, legumes, Artemisia annua, and other miscellaneous weeds under different treatment combinations were calculated (Table 3). The results showed that under the fertilization treatment (F2), the proportions of grasses and legumes were significantly higher under different grass species combinations compared to the fertilization treatment (F1), while the proportion of Artemisia annua decreased. Furthermore, the decrease in the proportion of Artemisia annua was most significant under grass species combination R3. This result indicates that reseeding grass species combination R3, along with the application of organic fertilizer, can effectively inhibit the growth of Artemisia annua.

[0115] IV. Conclusion:

[0116] The above experiments show that spraying 70% pyrimisulfuron-methyl water-dispersible granules (a 1:600 ​​dilution of the inhibitor, applied at 12 L / mu) on typical grasslands of Hulunbuir, along with overseeding the aforementioned experimental combination R3 (i.e., native dominant grasses + leguminous plants: 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), and applying 1 ton / mu of powdered organic fertilizer, can effectively inhibit the growth of Artemisia annua. This combination scheme can achieve a synergistic improvement in vegetation productivity (biomass increased by 80.24% in 2024 and 73.76% in 2025 compared to the control) and soil quality (soil organic carbon and available phosphorus increased by 14.29% and 83.02% respectively compared to the control); while reducing the biomass proportion of Artemisia annua (a decrease of 76.71% compared to the control). This technological model achieves multi-objective synergistic optimization of degraded grassland ecosystems and is an efficient ecological governance solution suitable for typical grassland areas in Hulunbuir.

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, The method is applied to the degraded temperate typical grassland area of ​​Xiwuzhuer Sumu, Chenbalhu Banner, Hulunbuir City, and 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 bensulfuron-methyl water-dispersible granules; the dilution concentration of the bensulfuron-methyl water-dispersible granules is 1:500-1:800, and the spraying dosage is 10-15 L / mu; 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. In step S1, the specific spraying parameters of the diluent for bensulfuron-methyl water-dispersible granules are adjusted 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 amount is 15L / mu, and it is sprayed twice with an interval of 7 days. 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.

2. The method according to claim 1, 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.

3. 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.

4. 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.

5. The method according to claim 4, characterized in that, The application rate of the decomposed organic fertilizer is 0.8-1.2 tons per mu.

6. 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.

7. 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.

Images