A method for improving soil and vegetation of a meadow steppe pasture of a temperate zone and application thereof

Abstract

The application discloses a temperate meadow steppe pasture grassland soil and vegetation synergic improvement method and application, and belongs to the technical field of grassland ecological restoration and degraded grassland improvement, and the method comprises the following steps: S1, pre-cutting roots to form narrow cracks; S2, forming an ice wedge, using winter natural cooling to make deep unfrozen water migrate to the cracks and expand by freezing, and the crack width is expanded; S3, hot melting and seeding, sowing the pasture grass seeds in the ice wedge cracks and applying a water-retaining agent when the surface soil is thawed in the next year; S4, spring root cutting, performing the root cutting operation when the soil layer thawing depth reaches 10-15 cm; and S5, applying a composite mixed fertilizer. Experiments show that the method can significantly improve the pasture grass community coverage, height and aboveground biomass, and simultaneously improve the contents of soil nutrient components, organic carbon and the like, and is suitable for the pasture grassland with the pasture grass as a dominant species, and has good ecological and economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of grassland ecological restoration technology, specifically relating to a method and application for the synergistic improvement of soil and vegetation in temperate meadow steppe grassland. Background Technology

[0002] Huhewenduer Gacha Pasture, Chenbalhu Banner, Hulunbuir City, Inner Mongolia Autonomous Region, with geographical coordinates of 119°30′10.38″E, 49°42′5.58″N, is located in the north-central part of the Hulunbuir Grassland. It has a typical temperate meadow-steppe climate with unique climatic characteristics brought about by its high latitude: the average annual temperature is -1.5℃ to 1℃, the severe winter lasts for up to 6 months, and the extreme low temperature can reach below -40℃. The soil thaws slowly in spring, with the thawing depth reaching 10-15cm concentrated in late May to late June. Summers are short, with concentrated rainfall and often accompanied by short-term heavy rainfall. Affected by the groundwater level of the Ergun River tributary, the surface soil moisture is maintained at 18%-22% year-round, slightly higher than that of similar grassland areas. The pasture has typical chernozem soil, with a deep topsoil layer. The initial organic carbon content is 3.0%-3.2%, and the total nitrogen content is 0.21%-0.23%. The native vegetation is dominated by sheepgrass, accompanied by perennial grasses such as icegrass and feathergrass. It is an important seasonal mowing area (cut once a year in mid-to-late August). However, long-term large-scale mowing has led to significant ecological and production problems in the area:

[0003] (1) Soil quality degradation: The nitrogen and phosphorus nutrients in the topsoil are consumed too quickly, and the total nitrogen content decreases by 15%-20% compared with the initial state. At the same time, frequent mechanical compaction increases the soil bulk density, reduces soil porosity, and weakens aeration and water permeability.

[0004] (2) Decreased vegetation productivity: The coverage, average height and aboveground biomass of Leymus chinensis community gradually decreased, and the tillering ability of Leymus chinensis weakened, while the proportion of miscellaneous grasses in the community increased.

[0005] (3) Reduced vegetation resistance: Due to soil nutrient imbalance and structural degradation, sheepgrass has reduced resistance to severe winter cold and late spring frost, delayed greening period by 5-7 days, and shortened vigorous growth period, which further affects the yield and quality of grass cutting.

[0006] There is an urgent need for a grassland improvement method that can adapt to its environmental conditions and solve practical problems, so as to achieve a synergistic improvement in soil fertility and vegetation productivity and ensure the sustainable use of the pasture for mowing. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention discloses a method and application for synergistic improvement of soil and vegetation in temperate meadow steppe grasslands covered with Leymus chinensis, as detailed below:

[0008] A method for synergistic improvement of soil and vegetation in temperate meadow steppe meadows covered with Leymus chinensis includes the following steps:

[0009] S1. Pre-cutting roots: When the topsoil is frozen to a depth of 5-8cm, pre-cutting roots in the frozen layer is carried out to form narrow cracks with a width of 1-2cm in the frozen layer.

[0010] S2. Formation of ice wedges: Utilizing the natural cooling process in winter, deep unfrozen water migrates to the cracks and freezes, expanding the crack width and forming ice wedge cracks. This was implemented at Li Songbin's ranch in Huhewenduer Gacha, Chenbalhu Banner. According to statistics, the ice volume expansion rate is about 8%-10%, which generates horizontal compressive stress on the soil on both sides of the crack, expanding the crack width to 3-5cm and forming a radial micro-crack network around the crack.

[0011] S3. Thermal thawing sowing: When the surface soil begins to thaw the following year, sow sheepgrass seeds in the cracks formed after the ice wedges melt and apply a water-retaining agent (any water-retaining agent commonly used in this field is acceptable).

[0012] S4. Spring root cutting: When the soil thaws to a depth of 10-15cm, use a grassland restoration machine to cut roots to a depth of 8-15cm.

[0013] S5. Application of compound blended fertilizer: This is carried out simultaneously with root cutting. The compound blended fertilizer, by mass percentage, includes: 12-18 parts of fast-acting nitrogen fertilizer; 18-22 parts of slow-release nitrogen fertilizer; 7-12 parts of phosphate fertilizer; 12-18 parts of potassium fertilizer; and 35-45 parts of well-rotted sheep manure granules.

[0014] Furthermore, in step S1, the specific conditions for freezing the topsoil to 5-8cm are: early November, with a daily average temperature of -5℃ to -10℃.

[0015] Furthermore, in step S1, a soil deep tillage machine (such as the 1S-150 type deep tillage machine) is used to perform pre-cutting of roots in the frozen layer. The pre-cutting depth is 12-15cm, the tooth width is 1.5-2.5cm, and the tooth spacing is 35-45cm.

[0016] Furthermore, in step S3, the specific conditions for the surface soil to begin thawing the following year are: in early April of the following year, the average daily temperature exceeds 0°C.

[0017] Furthermore, in step S4, the soil thawing depth reaches 10-15cm from late May to late June; the root cutting row spacing is 28-32cm, and the operation is carried out 1-2 times.

[0018] Furthermore, in step S4, a 9QP-830 grassland restoration machine (Chifeng Tianfeng Agricultural and Forestry Machinery Manufacturing Plant) is used to cut the roots. The cutting blade rotation speed is 250-260 r / min, and the equipment travel speed is 5-8 km / h.

[0019] Further, in step S5, the fast-acting nitrogen fertilizer is urea with an effective nitrogen content ≥46%; the slow-release nitrogen fertilizer is coated urea with an effective nitrogen content ≥42%; the phosphate fertilizer is superphosphate with an effective P2O5 content ≥12%; the potassium fertilizer is potassium chloride with an effective K2O content ≥50%; and the organic carbon content of the decomposed sheep manure granules is ≥45%, and the moisture content is controlled at 20%-25% after high-temperature decomposition and sterilization.

[0020] Furthermore, in step S5, the application rate of compound blended fertilizer is 130 kg / ha to 170 kg / ha (preferably 150 kg / ha).

[0021] On the other hand, the present invention provides the application of the above-mentioned improved method in high-latitude temperate meadow grasslands to improve vegetation productivity and soil quality in sheepgrass-cut grasslands.

[0022] It can also be used for mowing grasslands where sheepgrass is the dominant species, where the mowing grassland is mowed once a year in mid-to-late August, with a stubble height of 5cm.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. This invention addresses the climatic characteristics of high-latitude temperate meadow grasslands, characterized by severe winters, frequent freeze-thaw cycles, and slow spring thawing. For the first time, it combines pre-root cutting, ice wedge formation, thermo-thaw sowing, and spring root cutting and fertilization. By pre-cutting roots in the frozen winter layer, the natural force of the expansion of deep unfrozen water is used to form ice wedge fissures and a radial micro-fissure network in the soil, achieving in-situ improvement of soil physical structure. This avoids the damage to soil structure caused by traditional deep mechanical tillage. The fissures formed after the ice wedges melt in the following spring provide a good micro-habitat for seed germination, achieving synergy between sowing and soil improvement.

[0025] 2. This invention, through winter soil loosening, spring sowing, and root cutting fertilization, is tailored to the region's late soil thawing, short greening period, and concentrated rainfall. Experimental results show that the treatment group using the complete method of this invention exhibits increased total nitrogen content, significantly increased organic carbon content, decreased soil bulk density, and increased porosity. The aboveground biomass of vegetation also shows a significant increase, with the Leymus chinensis community coverage, height, and density all significantly better than the control group and the root cutting treatment group. This method can effectively extend the utilization life of mowed grasslands and provides reliable technical support for the sustainable utilization of Leymus chinensis mowed grasslands in high-latitude temperate meadow steppes.

[0026] 3. This invention fully considers the climate and soil characteristics of high-latitude temperate meadow grasslands: S1 pre-root cutting is carried out in early November when the topsoil is frozen to 5-8cm, taking advantage of the off-season; S2 ice wedge formation relies on the natural cooling process in winter, requiring no additional energy consumption; S3 thermo-thaw sowing is carried out in early April when the topsoil thaws, matching the soil moisture before greening; S4 root cutting and S5 fertilization are carried out simultaneously from late May to late June when the soil thaws to a depth of 10-15cm, effectively reducing nutrient loss and combining natural rhythms to save costs and increase efficiency. Detailed Implementation

[0027] Example 1

[0028] A method for synergistic improvement of soil and vegetation in temperate meadow steppe meadows covered with Leymus chinensis includes the following steps:

[0029] S1. Pre-cutting roots: When the topsoil is frozen to 5cm, pre-cutting roots in the frozen layer is carried out to form a narrow crack with a width of 1cm in the frozen layer.

[0030] S2. Formation of ice wedges: Utilizing the natural cooling process in winter, deep unfrozen water migrates to the fissures and freezes, expanding the fissure width and forming ice wedge fissures;

[0031] S3. Hot-melt sowing: When the surface soil begins to thaw the following year, sow sheepgrass seeds in the cracks formed after the ice wedges melt and apply polyacrylamide water-retaining agents.

[0032] S4. Spring root cutting: When the soil thaws to a depth of 10cm, use a grassland restoration machine to cut roots to a depth of 15cm.

[0033] S5. Application of compound blended fertilizer: This is carried out simultaneously with root cutting. The compound blended fertilizer, by mass percentage, includes: 12 parts fast-acting nitrogen fertilizer; 18 parts slow-release nitrogen fertilizer; 7 parts phosphorus fertilizer; 12 parts potassium fertilizer; and 35 parts well-rotted sheep manure granules.

[0034] Preferably, in step S1, the specific conditions for freezing the topsoil to 5cm are: early November, with an average daily temperature of -5℃.

[0035] Preferably, in step S1, a soil deep tillage machine is used to perform pre-cutting of roots in the frozen layer, with a pre-cutting depth of 12cm, a tooth width of 1.5cm, and a tooth spacing of 35cm.

[0036] Preferably, in step S3, the specific conditions for the surface soil to begin thawing the following year are: in early April of the following year, the average daily temperature exceeds 0°C.

[0037] Preferably, in step S4, the soil thawing depth reaches 10-15cm from late May to late June; the root cutting row spacing is 28cm, and the operation is carried out once.

[0038] Preferably, in step S4, a 9QP-830 grassland restoration machine is used for root cutting, with a blade rotation speed of 250 r / min and a machine travel speed of 5 km / h.

[0039] Preferably, in step S5, the fast-acting nitrogen fertilizer is urea with an effective nitrogen content ≥46%; the slow-release nitrogen fertilizer is coated urea with an effective nitrogen content ≥42%; the phosphate fertilizer is superphosphate with an effective P2O5 content ≥12%; the potassium fertilizer is potassium chloride with an effective K2O content ≥50%; and the organic carbon content of the decomposed sheep manure granules is ≥45%, and the moisture content is controlled at 20% after high-temperature decomposition and sterilization.

[0040] Preferably, in step S5, the amount of compound fertilizer applied is 130 kg / ha.

[0041] Example 2

[0042] A method for synergistic improvement of soil and vegetation in temperate meadow steppe meadows covered with Leymus chinensis includes the following steps:

[0043] S1. Pre-cutting roots: When the topsoil is frozen to 8cm, pre-cutting roots in the frozen layer is carried out to form a narrow crack with a width of 2cm in the frozen layer.

[0044] S2. Formation of ice wedges: Utilizing the natural cooling process in winter, deep unfrozen water migrates to the fissures and freezes, expanding the fissure width and forming ice wedge fissures;

[0045] S3. Hot-melt sowing: When the surface soil begins to thaw the following year, sow sheepgrass seeds in the cracks formed after the ice wedges melt and apply polyacrylamide water-retaining agents.

[0046] S4. Spring root cutting: When the soil thaws to a depth of 15cm, use a grassland restoration machine to cut roots to a depth of 8cm.

[0047] S5. Application of compound blended fertilizer: This is carried out simultaneously with root cutting. The compound blended fertilizer, by mass percentage, includes: 18 parts of fast-acting nitrogen fertilizer; 22 parts of slow-release nitrogen fertilizer; 12 parts of phosphate fertilizer; 18 parts of potassium fertilizer; and 45 parts of well-rotted sheep manure granules.

[0048] Preferably, in step S1, the specific conditions for freezing the topsoil to 8cm are: early November, with an average daily temperature of -10℃.

[0049] Preferably, in step S1, a soil deep tillage machine is used to perform pre-cutting of roots in the frozen layer, with a pre-cutting depth of 15cm, a tooth width of 2.5cm, and a tooth spacing of 45cm.

[0050] Preferably, in step S3, the specific conditions for the surface soil to begin thawing the following year are: in early April of the following year, the average daily temperature exceeds 0°C.

[0051] Preferably, in step S4, the soil thawing depth reaches 15cm between late May and late June; the root cutting row spacing is 32cm, and the operation is carried out twice.

[0052] Preferably, in step S4, a 9QP-830 grassland restoration machine is used for root cutting, with a blade rotation speed of 260 r / min and a machine travel speed of 8 km / h.

[0053] Preferably, in step S5, the fast-acting nitrogen fertilizer is urea with an effective nitrogen content ≥46%; the slow-release nitrogen fertilizer is coated urea with an effective nitrogen content ≥42%; the phosphate fertilizer is superphosphate with an effective P2O5 content ≥12%; the potassium fertilizer is potassium chloride with an effective K2O content ≥50%; and the organic carbon content of the decomposed sheep manure granules is ≥45%, and the moisture content is controlled at 25% after high-temperature decomposition and sterilization.

[0054] Preferably, in step S5, the amount of compound fertilizer applied is 170 kg / ha.

[0055] Example 3

[0056] A method for synergistic improvement of soil and vegetation in temperate meadow steppe meadows covered with Leymus chinensis includes the following steps:

[0057] S1. Pre-cutting roots: When the topsoil is frozen to a depth of 6.5cm, pre-cutting roots in the frozen layer is carried out to form a narrow crack with a width of 1.5cm in the frozen layer.

[0058] S2. Formation of ice wedges: Utilizing the natural cooling process in winter, deep unfrozen water migrates to the fissures and freezes, expanding the fissure width and forming ice wedge fissures;

[0059] S3. Hot-melt sowing: When the surface soil begins to thaw the following year, sow sheepgrass seeds in the cracks formed after the ice wedges melt and apply polyacrylamide water-retaining agents.

[0060] S4. Spring root cutting: When the soil thaws to a depth of 13cm, use a grassland restoration machine to cut roots to a depth of 11cm.

[0061] S5. Application of compound blended fertilizer: This is carried out simultaneously with root cutting. The compound blended fertilizer, by mass percentage, includes: 16 parts of fast-acting nitrogen fertilizer; 20 parts of slow-release nitrogen fertilizer; 10 parts of phosphate fertilizer; 16 parts of potassium fertilizer; and 40 parts of well-rotted sheep manure granules.

[0062] Preferably, in step S1, the specific conditions for freezing the topsoil to 6.5cm are: early November, with an average daily temperature of -8℃.

[0063] Preferably, in step S1, a soil deep tillage machine is used to perform pre-cutting of roots in the frozen layer, with a pre-cutting depth of 13cm, a tooth width of 2cm, and a tooth spacing of 40cm.

[0064] Preferably, in step S3, the specific conditions for the surface soil to begin thawing the following year are: in early April of the following year, the average daily temperature exceeds 0°C.

[0065] Preferably, in step S4, the soil thawing depth reaches 10-15cm from late May to late June; the root cutting row spacing is 30cm, and the operation is carried out twice.

[0066] Preferably, in step S4, a 9QP-830 grassland restoration machine is used for root cutting, with a blade rotation speed of 254 r / min and a machine travel speed of 6 km / h.

[0067] Preferably, in step S5, the fast-acting nitrogen fertilizer is urea with an effective nitrogen content ≥46%; the slow-release nitrogen fertilizer is coated urea with an effective nitrogen content ≥42%; the phosphate fertilizer is superphosphate with an effective P2O5 content ≥12%; the potassium fertilizer is potassium chloride with an effective K2O content ≥50%; and the organic carbon content of the decomposed sheep manure granules is ≥45%, and the moisture content is controlled at 23% after high-temperature decomposition and sterilization.

[0068] Preferably, in step S5, the amount of compound fertilizer applied is 150 kg / ha.

[0069] Experimental Section

[0070] The experimental site (1000 mu) was fenced off (with fencing, barbed wire, and gates installed), and divided into 20 experimental plots (5 replicates for each treatment). Each plot measured 1000m long × 215.6m wide, with a 10m wide isolation zone between plots to prevent interference between different treatments. The following four treatment groups were set up:

[0071] C1: Control group, without root cutting or fertilization, using natural mowing, mowing once a year in mid-to-late August, leaving a stubble height of 5cm.

[0072] C2: The difference from Example 3 is that the S1, S2, and S3 treatments are not performed, and root cutting and fertilization are carried out directly in spring.

[0073] C3: The method described in Example 3 is used for processing.

[0074] C4: The difference from Example 3 is that S1, S2, and S3 treatments are not performed. Root cutting and fertilization are carried out directly in spring, and the application rate of compound fertilizer is increased to 300 kg / ha.

[0075] All the above-mentioned schemes were implemented starting in November 2022, with fertilization completed in late June. Data collection was conducted in August 2023, August 2024, and August 2025, respectively. Five 1m×1m quadrats were randomly selected from each replicate plot to measure vegetation height, cover, density, and aboveground biomass. The results are shown in Table 1. Three-way ANOVA was used to test the effects of year, treatment, and soil depth on soil indicators. The results are shown in Table 2. The changes in total nitrogen, organic carbon, microbial biomass (C nitrogen), available phosphorus and potassium, and pH under different years and treatment combinations are shown in Table 3. The differences in each indicator between the 0-15cm and 15-30cm soil depths are shown in Table 4.

[0076] Table 1. Effects of different treatments on vegetation height, cover, density, and aboveground biomass in different years.

[0077]

[0078] 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).

[0079] Table 1 shows that from 2023 to 2025, the vegetation height, cover, and aboveground biomass of group C1 increased year by year, indicating that the grassland itself has a certain recovery capacity; however, the improvement of the treatment groups was much greater than that of group C1, reflecting the promoting effect of artificial measures. Compared with C1, treatment C2 showed improvements in vegetation height, cover, and aboveground biomass from 2023 to 2025, but the effect was weaker than that of C3 and C4. Treatment C3 had the best effect, with vegetation height, cover, and aboveground biomass significantly higher than other groups from 2024 to 2025. Although the improvement was not significant in 2023, the advantage gradually became more prominent in subsequent years. Treatment C4 was slightly less effective than group C3, possibly due to the diminishing marginal effect of excessive fertilization.

[0080] Table 2. Three-factor ANOVA of soil parameters by year, treatment, and soil depth.

[0081]

[0082] Note: ** indicates that the significance level is reached at 0.01.

[0083] Table 3. Effects of different years and treatments on soil indices in temperate meadow steppe meadows with sheepgrass mowing.

[0084]

[0085] 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).

[0086] According to the results in Tables 2 and 3, year, treatment, and soil depth all had a significant impact on soil indicators. Among them, treatment C3 showed the best effect in improving soil nutrients and microbial activity: its total nitrogen, organic carbon, available phosphorus, available potassium, and microbial biomass C nitrogen contents all increased continuously with the year, reaching 0.28%, 3.00%, 3.75 mg / kg, 152.50 mg / kg, and 675.68 mg / kg respectively in 2025, significantly higher than other treatments; while treatment C4 showed a decrease in nutrients, indicating that high fertilization may have an inhibitory effect. Furthermore, the interaction between treatment and soil depth had a significant impact on organic carbon and microbial biomass C, with the topsoil being more sensitive to amendment measures.

[0087] Table 4. Effects of different soil depths on various soil parameters

[0088]

[0089] Note: Different lowercase letters in the same column indicate significant differences (P<0.05), and different uppercase letters indicate significant differences between different treatments. P <0.05).

[0090] According to Table 4, there are significant differences in the effects of different soil depths on soil indicators. The total nitrogen content, organic carbon content, available phosphorus, and available potassium content in the 0-15cm soil layer are significantly higher than those in the 15-30cm soil layer (P<0.05), indicating that nutrients are mainly concentrated in the topsoil. However, there are no significant differences in microbial biomass C and nitrogen between the two layers (P>0.05), indicating that the distribution of microorganisms is relatively uniform. The pH value is significantly higher in the deeper soil layers than in the topsoil layer, which may be related to the fact that the topsoil layer is more affected by fertilization and vegetation root activity.

[0091] To clarify the correlation between vegetation and soil indicators, Pearson correlation analysis was used to calculate the correlation coefficients (r) between vegetation biomass and soil indicators under all treatments from 2023 to 2025. The results are shown in Table 5.

[0092] Table 5. Pearson correlation analysis between vegetation biomass and soil indicators

[0093]

[0094] Note: P A value <0.05 is considered "significantly positively correlated"; P A value <0.01 is considered "highly significant positive correlation".

[0095] The above results show that the correlation coefficients between vegetation biomass and soil core nutrients (total nitrogen, organic carbon, and available phosphorus) are all >0.9 and PThe value of <0.01 indicates that the improvement of soil nutrients directly drives the enhancement of vegetation productivity; at the same time, the increase in vegetation biomass will replenish soil organic carbon and nitrogen through litter.

[0096] In summary, C3 (Example 3 of this invention) is the optimal improvement scheme for mowed meadow steppe: this treatment can simultaneously improve vegetation productivity and soil quality; C3 is a precise and optimal dosage, avoiding the nutrient inhibition effect of high dosage; the technical effect is stable and sustainable, and the soil-vegetation index shows a continuous improvement trend from 2023 to 2025, which can extend the utilization life of mowed grassland.

Claims

1. A method for synergistic improvement of soil and vegetation in temperate meadow steppe grasslands covered with Leymus chinensis, characterized in that, Includes the following steps: S1. Pre-cutting roots: When the topsoil is frozen to a depth of 5-8cm, pre-cutting roots in the frozen layer is carried out to form narrow cracks with a width of 1-2cm in the frozen layer. S2. Formation of ice wedges: Utilizing the natural cooling process in winter, deep unfrozen water migrates to the fissures and freezes and expands, widening the fissures and forming ice wedge fissures; S3. Thermal thawing: When the surface soil begins to thaw the following year, sow sheepgrass seeds in the cracks formed after the ice wedges melt and apply a water-retaining agent. S4. Spring root cutting: When the soil thaws to a depth of 10-15cm, use a grassland restoration machine to cut roots to a depth of 8-15cm. S5. Application of compound blended fertilizer: This is carried out simultaneously with root cutting. The compound blended fertilizer, by mass percentage, includes: 12-18 parts of fast-acting nitrogen fertilizer; 18-22 parts of slow-release nitrogen fertilizer; 7-12 parts of phosphate fertilizer; 12-18 parts of potassium fertilizer; and 35-45 parts of well-rotted sheep manure granules.

2. The improved method according to claim 1, characterized in that, In step S1, the specific conditions for freezing the topsoil to 5-8cm are: early November, with a daily average temperature of -5℃ to -10℃.

3. The improved method according to claim 1, characterized in that, In step S1, a soil deep tillage machine is used to pre-cut roots in the frozen layer. The pre-cut root depth is 12-15cm, the tooth width is 1.5-2.5cm, and the tooth spacing is 35-45cm.

4. The improved method according to claim 1, characterized in that, In step S3, the specific conditions for the surface soil to begin thawing the following year are: in early April of the following year, the average daily temperature exceeds 0°C.

5. The improved method according to claim 1, characterized in that, In step S4, the soil thawing depth reaches 10-15cm from late May to late June; the root cutting row spacing is 28-32cm, and the operation is carried out 1-2 times.

6. The improved method according to claim 1, characterized in that, In step S4, a grassland restoration machine is used to cut the roots. The blade rotation speed is 250-260 r / min, and the equipment travel speed is 5-8 km / h.

7. The improved method according to claim 1, characterized in that, In step S5, the fast-acting nitrogen fertilizer is urea with an effective nitrogen content ≥46%; the slow-release nitrogen fertilizer is coated urea with an effective nitrogen content ≥42%; the phosphate fertilizer is superphosphate with an effective P2O5 content ≥12%; the potassium fertilizer is potassium chloride with an effective K2O content ≥50%; and the organic carbon content of the decomposed sheep manure granules is ≥45%, and the moisture content is controlled at 20%-25% after high-temperature decomposition and sterilization.

8. The improved method according to claim 1, characterized in that, In step S5, the application rate of compound blended fertilizer is 130 kg / ha to 170 kg / ha.

9. The application of the improved method according to any one of claims 1-8, characterized in that, Used in high-latitude temperate meadow grasslands to improve vegetation productivity and soil quality in sheepgrass-cut grasslands.

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