Method for ecological restoration of degraded grassland

Abstract

This invention discloses a method for ecological restoration of degraded grassland, comprising the following steps: S1, degradation assessment; S2, initial division of the restoration area; S3, preliminary restoration; S4, secondary division of the restoration area; S5, in-depth restoration; and S6, regular sowing. This method uses contour lines as a reference to form a scientifically sound and comprehensive restoration plan. Ecological fences are laid along the contour lines as restoration boundaries, which not only improves water resource utilization but also strengthens the maintenance of healthy grassland within the area, ultimately forming a dynamically restored ecosystem. This significantly reduces the amount of fertilizers and other additives used, achieving excellent ecological restoration results for degraded grassland, and is particularly suitable for areas with significant altitude variations.

Description

Technical Field

[0001] This invention relates to the field of grassland ecological restoration technology, specifically to a method for ecological restoration of degraded grassland. Background Technology

[0002] Grasslands are the largest terrestrial ecosystems, playing vital roles in production, livelihood, and ecology, and are of great significance to global food and ecological security. However, due to global change and human activities, grassland ecosystems have experienced varying degrees of degradation. The restoration of degraded grasslands and the stability of their structure and function after restoration have become a pressing global concern.

[0003] Many factors contribute to grassland degradation, such as long-term grazing, invasive plants, mining, oilfield extraction, urban expansion, extreme rainfall, and frequent droughts. Grassland restoration is not a simple reversal of grassland degradation, but rather a process based on fundamental ecological concepts and principles, employing a series of grassland restoration measures to restore the ecosystem function and productivity of degraded grasslands to their original healthy levels. Grassland restoration technologies can be broadly categorized into natural force-based restoration techniques, artificially assisted restoration techniques, and artificial grassland establishment techniques.

[0004] Currently, most methods for restoring degraded grasslands employ a comprehensive approach combining multiple methods. For example, patent publication number CN118716131A discloses a method for restoring degraded grasslands through oxygen and nutrient regulation, comprising the following steps: Step 1, Sample Collection: Based on grassland degradation-related grading standards, three sampling areas are randomly selected from each degraded area, with five quadrats set up within each sampling area, spaced 50m apart, and each quadrat measuring 1m × 1m; Step 2, Data Measurement: Aboveground vegetation biomass (AGB), coverage, and height are measured in the four degraded sampling areas to calculate community diversity characteristics; Step 3, Index Analysis: The plant diversity, soil nutrients, and microbial biomass of grasslands with different degrees of degradation are compared and analyzed using the above indicators; Step 4, Implementation of Control Measures: Different measures are taken for grasslands with different degrees of degradation. This invention achieves good restoration results by comparing and analyzing plant diversity, soil nutrients, and microbial biomass of grasslands with different degrees of degradation and taking different measures for different degradation situations.

[0005] However, this method, as well as other existing methods, takes little into account the factor of grassland elevation. Yet, rainwater accumulation is greatly affected by elevation, and in this context, the restoration effect of such restoration methods fluctuates considerably. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a method for ecological restoration of degraded grassland.

[0007] The technical solution of this invention is:

[0008] A method for ecological restoration of degraded grassland includes the following steps:

[0009] S1. Degradation Assessment: Assess the degree of degradation of the grassland to be restored, classifying it into mild, moderate, and severe.

[0010] S2. First division of restoration area: The elevation of the grassland to be restored is measured, and a contour map of the grassland to be restored is drawn. The area enclosed by the contour lines is the contour area. The aboveground biomass of the grassland to be restored is counted. Plots with aboveground biomass >1800kg / ha are classified as healthy grassland. According to the degree of degradation, the first-stage restoration boundary is determined. The first-stage restoration boundary is a contour line in which the area of ​​healthy grassland accounts for 75-85% of the total area of ​​the contour area. The midpoint of the line connecting the point on the first-stage restoration boundary to the edge of the corresponding grassland to be restored is found. The line connecting each midpoint is used as the first-stage outer restoration boundary.

[0011] S3. Preliminary restoration: Excavate a drainage ditch on the boundary of the first-stage inner restoration, and set up an ecological fence inside the drainage ditch. Apply nutrient solution through the ecological fence, plant water-resistant plants between the boundary of the first-stage outer restoration and the boundary of the first-stage inner restoration, and apply restoration agent between the boundary of the first-stage outer restoration and the edge of the grassland to be restored.

[0012] S4. Secondary division of restoration area: 3 to 6 months after the initial restoration is completed, plots with aboveground biomass > 2000 kg / ha are divided into healthy grasslands. Based on the degree of degradation, the secondary inner restoration boundary is determined. The secondary inner restoration boundary is a contour line in which the area of ​​healthy grassland accounts for 80 to 90% of the total area of ​​the contour line area. The midpoint of the line connecting the point on the secondary inner restoration boundary to the edge of the corresponding grassland to be restored is found. The line connecting each midpoint is used as the secondary outer restoration boundary.

[0013] S5. Deep restoration: Excavate a drainage ditch on the boundary of the secondary inner restoration, and set up an ecological fence inside the drainage ditch. Apply nutrient solution through the ecological fence, plant water-resistant plants between the boundary of the secondary outer restoration and the boundary of the secondary inner restoration, and apply compound fertilizer between the boundary of the primary outer restoration and the edge of the grassland to be restored.

[0014] S6. Regular sowing: Sow seeds in the grassland to be restored 3 to 6 months after the completion of deep restoration.

[0015] Furthermore, in S1, the degree of degradation of the grassland to be restored is classified according to the coverage. When the coverage is >60%, the degree of degradation of the grassland to be restored is mild; when 30% ≤ coverage ≤ 60%, the degree of degradation of the grassland to be restored is moderate; and when the coverage is <30%, the degree of degradation of the grassland to be restored is severe.

[0016] Note: Introducing grassland cover as a standard for evaluating the degree of grassland degradation has a certain theoretical basis and provides guidance for subsequent specific restoration measures.

[0017] Furthermore, in S2, when the degradation of the grassland to be restored is mild, a contour line in which the area of ​​healthy grassland accounts for 75-80% of the total area of ​​the contour line region serves as the boundary for one-time restoration; when the degradation of the grassland to be restored is moderate, a contour line in which the area of ​​healthy grassland accounts for 77-83% of the total area of ​​the contour line region serves as the boundary for one-time restoration; and when the degradation of the grassland to be restored is severe, a contour line in which the area of ​​healthy grassland accounts for 80-85% of the total area of ​​the contour line region serves as the boundary for one-time restoration.

[0018] Note: By selecting different methods for defining the intra-one repair boundary based on varying degrees of degradation, the intra-one repair boundary definition method becomes more scientific and reasonable.

[0019] Furthermore, in S4, when the degradation of the grassland to be restored is mild, a contour line in which the area of ​​healthy grassland accounts for 80-85% of the total area of ​​the contour line region serves as the boundary for secondary internal restoration; when the degradation of the grassland to be restored is moderate, a contour line in which the area of ​​healthy grassland accounts for 83-86% of the total area of ​​the contour line region serves as the boundary for secondary internal restoration; and when the degradation of the grassland to be restored is severe, a contour line in which the area of ​​healthy grassland accounts for 85-90% of the total area of ​​the contour line region serves as the boundary for secondary internal restoration.

[0020] Note: By selecting different methods for defining the secondary inner repair boundary based on varying degrees of degradation, the method for defining the secondary inner repair boundary becomes more scientific and reasonable.

[0021] Furthermore, in S3 and S5, the nutrient solution composition and mass fraction are: 3-4% humic acid, 0.5-1% slow-release urea, 0.4-0.8% superphosphate, and the balance being water. The water-resistant plants are one or more of vetiver, bahia, and bermudagrass. In S3, the remediation agent composition and mass fraction are: 50-55% quicklime, 15-20% straw biochar, 3-5% magnesium sulfate, and the balance being hydrated lime. The amount of remediation agent applied is adjusted to ensure remediation. The pH of the soil after application is 6.5-7. The composition and mass fraction of the compound fertilizer in S5 are as follows: 3-5% microbial inoculant, 40-50% well-rotted livestock manure, 15-20% straw biochar, and the remainder is urea. The microbial inoculant is one or more of rhizobium, nitrogen-fixing spirochete, Bacillus megaterium, Pseudomonas, and Bacillus subtilis. The application rate of the compound fertilizer is 300-500 kg / ha, and the mixing depth during application is 10-15 cm.

[0022] Explanation: By applying nutrient solution and adding remedial agents, healthy grasslands are maintained, while the sequential application of improved remedial agents and compound fertilizers promotes faster recovery of severely degraded grasslands.

[0023] Preferably, when the degradation of the grassland to be restored is mild, the planting density of the water-resistant plants in S3 is 3-5 plants / m². 3 The planting density of water-resistant plants in S5 is 2-4 plants / m². 3 When the degradation level of the grassland to be restored is moderate, the planting density of water-resistant plants in S3 is 3-8 plants / m². 3 The planting density of water-resistant plants in S5 is 3-5 plants / m². 3 When the degradation of the grassland to be restored is severe, the planting density of water-resistant plants in S3 is 5-10 plants / m². 3 The planting density of water-resistant plants in S5 is 4–8 plants / m². 3 .

[0024] Note: The planting density of water-resistant plants is optimized and adjusted according to the different degrees of degradation to ensure the water-resistant effect.

[0025] Furthermore, the width of the water diversion ditch is 10-30cm, and the ecological fence includes hollow columns on both sides and several connecting rods between the two hollow columns. The two ends of the lowest connecting rod are connected to the interior of the two hollow columns. The bottom of the connecting rod is provided with several openings. The bottom of the hollow column is conical and has openings. The ecological fences are connected by several steel wire ropes. The length of the ecological fence is 80-120cm, and the interval between two adjacent ecological fences is 3-5m.

[0026] Note: The specially designed ecological fence can facilitate the application and drainage of nutrient solution.

[0027] Furthermore, in S6, the grassland to be restored is divided into several blocks at equal intervals during sowing. Each block is separated by the ecological fence and wire rope. One block is selected as a grazing area within each block for grazing for 1 to 2 months. Sowing begins in the block after grazing ends, with grazing and sowing proceeding sequentially from one side of the grassland to be restored to the other.

[0028] Note: By further optimizing the timing of sowing and grazing, the dynamic restoration of grassland cycles can be ensured, and the ecological fence can be used repeatedly in different scenarios.

[0029] Furthermore, in S6, the seeding method is drone seeding, with a seeding density of 10–20 g / m². 3The crop species are one or more of the following: Kobresia, Festuca argyi, Barley grass, Iris septemlobus, Bergenia schreberi, Triangular grass, Imperata cylindrica, Zoysia japonica, Sedge grass, Ryegrass, and Artemisia annua.

[0030] Note: When selecting specific crops to sow, choose according to local climate conditions and suitable crops.

[0031] The beneficial effects of this invention are:

[0032] This invention provides a method for ecological restoration of degraded grassland. Using contour lines as a reference, a scientifically sound and comprehensive restoration plan is formed. Ecological fences are laid along the contour lines as restoration boundaries, which not only improves water resource utilization but also strengthens the maintenance of healthy grassland within the area. By spatially blocking rainwater runoff and extending the time of water infiltration, grassland restoration efficiency is significantly improved, strengthening the transition between the inside and outside of the degraded zone and preventing further degradation. Simultaneously, as restoration progresses, the restoration boundaries are adjusted. After adjustment, targeted deep restoration is carried out based on the initial restoration. The two restoration processes promote each other, ultimately forming a dynamically restored ecosystem. This greatly reduces the amount of fertilizers and other additives used, achieving excellent ecological restoration results for degraded grassland, and is particularly suitable for areas with significant altitude variations. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of healthy grassland after the S2 restoration area is divided once in an experimental example of a degraded grassland ecological restoration method of the present invention;

[0034] Figure 2 This is a schematic diagram of the contour lines after the S2 restoration area was divided once in an experimental example of a degraded grassland ecological restoration method of the present invention;

[0035] Figure 3 This is a schematic diagram of the restoration boundary after the S2 restoration area is divided once in an experimental example of a degraded grassland ecological restoration method of the present invention;

[0036] Figure 4 This is a schematic diagram of the healthy grassland after preliminary restoration in S3, an experimental example of a degraded grassland ecological restoration method of the present invention;

[0037] Figure 5 This is a schematic diagram of the contour lines after secondary division of the S4 restoration area in an experimental example of a degraded grassland ecological restoration method of the present invention;

[0038] Figure 6 This is a schematic diagram of the restoration boundary after secondary division of the S4 restoration area in an experimental example of a degraded grassland ecological restoration method of the present invention;

[0039] Figure 7This is a schematic diagram of the block unit and grazing area during periodic sowing in S6, an experimental example of a degraded grassland ecological restoration method of the present invention;

[0040] Figure 8 This is a schematic diagram of an ecological fence structure in a method for ecological restoration of degraded grassland according to the present invention. Detailed Implementation

[0041] Example 1

[0042] A method for ecological restoration of degraded grassland includes the following steps:

[0043] S1. Degradation Assessment: Assess the degree of degradation of the grassland to be restored, classifying it into mild, moderate, and severe.

[0044] The degree of degradation of grassland to be restored is classified according to its cover. When the cover is >60%, the grassland to be restored is classified as mild; when the cover is 30% ≤ cover ≤ 60%, the grassland to be restored is classified as moderate; and when the cover is <30%, the grassland to be restored is classified as severe.

[0045] S2. First division of restoration area: The elevation of the grassland to be restored is measured, and a contour map of the grassland to be restored is drawn. The area enclosed by the contour lines is the contour area. The aboveground biomass of the grassland to be restored is counted. The plots with aboveground biomass >1800 kg / ha are classified as healthy grassland. According to the degree of degradation, the inner restoration boundary is determined. The inner restoration boundary is a contour line in which the area of ​​healthy grassland accounts for 77-83% of the total area of ​​the contour area. The midpoint of the line connecting the point on the inner restoration boundary to the edge of the corresponding grassland to be restored is found. The line connecting all the midpoints is used as the outer restoration boundary.

[0046] When the degradation of the grassland to be restored is mild, a contour line in which the area of ​​healthy grassland accounts for 77% of the total area of ​​the contour line region is used as the boundary of the first restoration. When the degradation of the grassland to be restored is moderate, a contour line in which the area of ​​healthy grassland accounts for 80% of the total area of ​​the contour line region is used as the boundary of the first restoration. When the degradation of the grassland to be restored is severe, a contour line in which the area of ​​healthy grassland accounts for 83% of the total area of ​​the contour line region is used as the boundary of the first restoration.

[0047] S3. Preliminary restoration: Excavate a drainage ditch on the boundary of the first-stage inner restoration and set up an ecological fence inside the drainage ditch. Apply nutrient solution through the ecological fence. Plant water-impermeable plants between the boundary of the first-stage outer restoration and the boundary of the first-stage inner restoration. Apply restoration agent between the boundary of the first-stage outer restoration and the edge of the grassland to be restored.

[0048] The nutrient solution consists of the following components and mass fractions: humic acid 3.5%, slow-release urea 0.7%, superphosphate 0.65%, with the remainder being water. The plants used for water isolation are Bahia grass and Bermuda grass. The remediation agent consists of the following components and mass fractions: quicklime 52%, straw biochar 18%, magnesium sulfate 4%, with the remainder being hydrated lime. The amount of remediation agent applied is adjusted to ensure that the pH of the soil after remediation is 6.8.

[0049] When the degradation of the grassland to be restored is mild, the planting density of waterproof plants is 4 plants / m². 3 When the degradation level of the grassland to be restored is moderate, the planting density of water-resistant plants is 5 plants / m². 3 When the degradation of the grassland to be restored is severe, the planting density of water-resistant plants is 8 plants / m². 3 ;

[0050] The width of the water diversion ditch is 20cm. The ecological fence includes hollow columns on both sides and several connecting rods between the two hollow columns. The two ends of the bottom connecting rod are connected to the interior of the two hollow columns. The bottom of the connecting rod has several openings. The bottom of the hollow column is tapered and has openings. The ecological fences are connected by several steel wire ropes. The length of the ecological fence is 100cm. The interval between two adjacent ecological fences is 4m.

[0051] S4. Secondary division of restoration area: Four months after the completion of the initial restoration, plots with aboveground biomass >2000 kg / ha are classified as healthy grasslands. Based on the degree of degradation, the secondary inner restoration boundary is determined. The secondary inner restoration boundary is a contour line where the area of ​​healthy grassland accounts for 83-88% of the total area of ​​the contour line area. Find the midpoint of the line connecting the point on the secondary inner restoration boundary with the edge of the corresponding grassland to be restored, and use the line connecting each midpoint as the secondary outer restoration boundary.

[0052] When the degradation of the grassland to be restored is mild, a contour line in which the area of ​​healthy grassland accounts for 83% of the total area of ​​the contour line region is used as the secondary inner restoration boundary; when the degradation of the grassland to be restored is moderate, a contour line in which the area of ​​healthy grassland accounts for 85% of the total area of ​​the contour line region is used as the secondary inner restoration boundary; when the degradation of the grassland to be restored is severe, a contour line in which the area of ​​healthy grassland accounts for 88% of the total area of ​​the contour line region is used as the secondary inner restoration boundary.

[0053] S5. Deep restoration: Excavate a drainage ditch on the boundary of the secondary inner restoration and set up an ecological fence inside the drainage ditch. Apply nutrient solution through the ecological fence. Plant water-resistant plants between the boundary of the secondary outer restoration and the boundary of the secondary inner restoration. Apply compound fertilizer between the boundary of the primary outer restoration and the edge of the grassland to be restored.

[0054] The nutrient solution consists of the following components and mass fractions: humic acid 3.3%, slow-release urea 0.76%, superphosphate 0.66%, and the remainder is water. The water-resistant plants are Bahia grass and Bermuda grass. The compound fertilizer consists of the following components and mass fractions: microbial inoculant 4%, well-rotted livestock manure 46%, straw biochar 17%, and the remainder is urea. The microbial inoculant is composed of nitrogen-fixing spirobacter, Bacillus megaterium, and Pseudomonas aeruginosa mixed in equal mass. The compound fertilizer is applied at a rate of 400 kg / ha, and the mixing depth during application is 12 cm.

[0055] When the degradation of the grassland to be restored is mild, the planting density of waterproof plants is 3 plants / m². 3 When the degradation level of the grassland to be restored is moderate, the planting density of water-resistant plants is 4 plants / m². 3 When the degradation of the grassland to be restored is severe, the planting density of water-resistant plants is 6 plants / m². 3 ;

[0056] S6. Regular Sowing: Four months after the completion of deep restoration, sowing is carried out in the grassland to be restored. The grassland is divided into seven equally spaced blocks, separated by ecological fences and wire ropes. One block is selected as a grazing area for grazing for 1.5 months. Sowing begins in the blocks after grazing ends, proceeding sequentially from one side of the grassland to the other. Sowing is done by drone at a density of 15 g / m². 3 The crop species are Bergenia schreberi, Triangular grass, Imperata cylindrica, and Zoysia japonica.

[0057] Example 2

[0058] The difference between this embodiment and Embodiment 1 is that:

[0059] S2. First-level division of restoration area: Based on the degree of degradation, determine the boundary of restoration within one level. The boundary of restoration within one level is a contour line in which the area of ​​healthy grassland accounts for 80-85% of the total area of ​​the contour line area.

[0060] When the degradation of the grassland to be restored is mild, a contour line in which the area of ​​healthy grassland accounts for 80% of the total area of ​​the contour line region is used as the boundary for one-time restoration. When the degradation of the grassland to be restored is moderate, a contour line in which the area of ​​healthy grassland accounts for 83% of the total area of ​​the contour line region is used as the boundary for one-time restoration. When the degradation of the grassland to be restored is severe, a contour line in which the area of ​​healthy grassland accounts for 85% of the total area of ​​the contour line region is used as the boundary for one-time restoration.

[0061] Example 3

[0062] The difference between this embodiment and Embodiment 1 is that:

[0063] S2. First-level division of restoration area: Based on the degree of degradation, determine the boundary of restoration within one level. The boundary of restoration within one level is a contour line in which the area of ​​healthy grassland accounts for 75-80% of the total area of ​​the contour line area.

[0064] When the degradation of the grassland to be restored is mild, a contour line with healthy grassland covering 75% of the total area of ​​the contour line region is used as the boundary for one-time restoration. When the degradation of the grassland to be restored is moderate, a contour line with healthy grassland covering 77% of the total area of ​​the contour line region is used as the boundary for one-time restoration. When the degradation of the grassland to be restored is severe, a contour line with healthy grassland covering 80% of the total area of ​​the contour line region is used as the boundary for one-time restoration.

[0065] Example 4

[0066] The difference between this embodiment and Embodiment 1 is that:

[0067] S3. Preliminary remediation: The nutrient solution consists of the following components and mass fractions: humic acid 3%, slow-release urea 0.5%, superphosphate 0.4%, with the remainder being water. The plant used for water isolation is vetiver. The remediation agent consists of the following components and mass fractions: quicklime 50%, straw biochar 15%, magnesium sulfate 3%, with the remainder being hydrated lime. The amount of remediation agent applied is adjusted to ensure that the pH of the soil after remediation is 6.5.

[0068] Example 5

[0069] The difference between this embodiment and Embodiment 1 is that:

[0070] S3. Preliminary remediation: The nutrient solution consists of the following components and mass fractions: humic acid 4%, slow-release urea 1%, superphosphate 0.8%, with the remainder being water. The plant used for water isolation is Bermuda grass. The remediation agent consists of the following components and mass fractions: quicklime 55%, straw biochar 20%, magnesium sulfate 5%, with the remainder being hydrated lime. The amount of remediation agent applied is adjusted to ensure that the pH of the soil after remediation is 7.

[0071] Example 6

[0072] The difference between this embodiment and Embodiment 1 is that:

[0073] S3. Preliminary Restoration: When the degradation of the grassland to be restored is mild, the planting density of waterproof plants is 3 plants / m². 3 When the degradation level of the grassland to be restored is moderate, the planting density of water-resistant plants is 3 plants / m². 3 When the degradation of the grassland to be restored is severe, the planting density of water-resistant plants is 5 plants / m². 3 .

[0074] Example 7

[0075] The difference between this embodiment and Embodiment 1 is that:

[0076] S3. Preliminary Restoration: When the degradation of the grassland to be restored is mild, the planting density of waterproof plants is 5 plants / m². 3 When the degradation level of the grassland to be restored is moderate, the planting density of water-resistant plants is 8 plants / m². 3 When the degradation of the grassland to be restored is severe, the planting density of water-resistant plants is 10 plants / m². 3 .

[0077] Note: The planting density of water-resistant plants should be adjusted according to the degree of degradation of the degraded grassland and the local rainfall. When the degradation is severe, the density should be increased appropriately, and when the rainfall is low, the density should be decreased appropriately.

[0078] Example 8

[0079] The difference between this embodiment and Embodiment 1 is that:

[0080] The width of the water diversion ditch is 10cm. The ecological fence includes hollow posts on both sides and several connecting rods between the two hollow posts. The two ends of the bottom connecting rod are connected to the interior of the two hollow posts. The bottom of the connecting rod has several openings. The bottom of the hollow posts is conical and has openings. The ecological fences are connected by several steel wire ropes. The length of the ecological fence is 80cm and the interval between two adjacent ecological fences is 3m.

[0081] Example 9

[0082] The difference between this embodiment and Embodiment 1 is that:

[0083] The width of the water diversion ditch is 30cm. The ecological fence includes hollow columns on both sides and several connecting rods between the two hollow columns. The bottom connecting rod is connected to the interior of the two hollow columns at both ends. The bottom of the connecting rod has several openings. The bottom of the hollow column is tapered and has openings. The ecological fences are connected by several steel wire ropes. The length of the ecological fence is 120cm. The interval between two adjacent ecological fences is 5m.

[0084] Note: When the area of ​​grassland to be restored is large, a longer ecological fence and a wider spacing between ecological fences can be used.

[0085] Example 10

[0086] The difference between this embodiment and Embodiment 1 is that:

[0087] S4. Secondary division of restoration area: Three months after the completion of the initial restoration, the boundary of the secondary restoration is determined according to the degree of degradation. The boundary of the secondary restoration is a contour line in which the area of ​​healthy grassland accounts for 80-95% of the total area of ​​the contour line area.

[0088] When the degradation of the grassland to be restored is mild, a contour line with healthy grassland covering 80% of the total area of ​​the contour line region is used as the secondary inner restoration boundary. When the degradation of the grassland to be restored is moderate, a contour line with healthy grassland covering 83% of the total area of ​​the contour line region is used as the secondary inner restoration boundary. When the degradation of the grassland to be restored is severe, a contour line with healthy grassland covering 85% of the total area of ​​the contour line region is used as the secondary inner restoration boundary.

[0089] Example 11

[0090] The difference between this embodiment and Embodiment 1 is that:

[0091] S4. Secondary division of restoration area: Six months after the completion of the initial restoration, the boundary of the secondary restoration is determined according to the degree of degradation. The boundary of the secondary restoration is a contour line in which the area of ​​healthy grassland accounts for 85-90% of the total area of ​​the contour line area.

[0092] When the degradation of the grassland to be restored is mild, a contour line with healthy grassland covering 85% of the total area of ​​the contour line region is used as the secondary inner restoration boundary. When the degradation of the grassland to be restored is moderate, a contour line with healthy grassland covering 86% of the total area of ​​the contour line region is used as the secondary inner restoration boundary. When the degradation of the grassland to be restored is severe, a contour line with healthy grassland covering 90% of the total area of ​​the contour line region is used as the secondary inner restoration boundary.

[0093] Example 12

[0094] The difference between this embodiment and Embodiment 1 is that:

[0095] S5. Deep Repair: The nutrient solution consists of the following components and mass fractions: humic acid 3%, slow-release urea 0.5%, superphosphate 0.4%, and the remainder is water. The water-resistant plants are one or more of vetiver, bahia grass, and bermudagrass. The compound fertilizer consists of the following components and mass fractions: microbial inoculant 3%, well-rotted livestock manure 40%, straw biochar 15%, and the remainder is urea. The microbial inoculant is rhizobium. The compound fertilizer application rate is 300 kg / ha, and the mixing depth during application is 10 cm.

[0096] Example 13

[0097] The difference between this embodiment and Embodiment 1 is that:

[0098] S5. Deep Repair: The nutrient solution consists of the following components and mass fractions: humic acid 4%, slow-release urea 1%, superphosphate 0.8%, with the remainder being water. The water-resistant plants are one or more of vetiver, bahia grass, and bermudagrass. The compound fertilizer consists of the following components and mass fractions: microbial agent 5%, well-rotted livestock manure 50%, straw biochar 20%, with the remainder being urea. The microbial agent is Bacillus subtilis. The compound fertilizer application rate is 500 kg / ha, and the mixing depth during application is 15 cm.

[0099] Note: The amount of compound fertilizer applied should be adjusted according to the degree of degradation of the degraded grassland. When the degradation is severe, the amount applied should be increased, and the depth of mixing should be increased appropriately.

[0100] Example 14

[0101] The difference between this embodiment and Embodiment 1 is that:

[0102] S5. Deep Restoration: When the degradation of the grassland to be restored is mild, the planting density of water-resistant plants is 2 plants / m². 3 When the degradation level of the grassland to be restored is moderate, the planting density of water-resistant plants is 3 plants / m². 3 When the degradation of the grassland to be restored is severe, the planting density of water-resistant plants is 4 plants / m². 3 .

[0103] Example 15

[0104] The difference between this embodiment and Embodiment 1 is that:

[0105] S5. Deep Restoration: When the degradation of the grassland to be restored is mild, the planting density of water-resistant plants is 4 plants / m². 3 When the degradation level of the grassland to be restored is moderate, the planting density of water-resistant plants is 5 plants / m². 3 When the degradation of the grassland to be restored is severe, the planting density of water-resistant plants is 8 plants / m². 3 .

[0106] Example 16

[0107] The difference between this embodiment and Embodiment 1 is that:

[0108] S6. Regular Sowing: Three months after the completion of deep restoration, sow seeds in the grassland to be restored. Divide the grassland into four equally spaced blocks, separating them with ecological fences and wire ropes. Select one block as a grazing area for grazing for two months. After grazing, sowing begins in the selected block, proceeding sequentially from one side of the grassland to the other. Sowing is done using drones at a density of 10 g / m². 3The crop species are Kobresia, Fescue, Barley grass, and Southwest Iris.

[0109] Example 17

[0110] The difference between this embodiment and Embodiment 1 is that:

[0111] S6. Regular Sowing: Six months after the completion of deep restoration, sowing is carried out in the grassland to be restored. The grassland is divided into 12 equally spaced blocks, separated by ecological fences and wire ropes. One block is selected as a grazing area for grazing for one month. Sowing begins in the selected blocks after grazing, proceeding sequentially from one side of the grassland to the other. Sowing is done by drone at a density of 20 g / m². 3 The crop species are sedge, ryegrass, and artemisia.

[0112] Note: When the area of ​​grassland to be restored is large, more block units can be divided.

[0113] Experimental Example

[0114] Following the method in Example 1, we conducted on-site restoration of degraded grassland in a mountainous area in the southwest, such as... Figures 1-7 As shown, the region has an altitude of 500-600m, with relatively low mountains and a gradually gentler terrain. It is a subtropical region, and the complex geographical conditions have led to the formation of various types of grassland vegetation and pasture resources.

[0115] First, the degradation assessment was carried out according to the method in S1. The coverage of the grassland to be restored was 46%, and the degree of degradation was moderate. Therefore, in the subsequent restoration process, the restoration was carried out according to the restoration parameters for severe degradation given in Example 1.

[0116] Subsequently, a schematic diagram showing the repair area divided according to S2 is shown below. Figure 2 and Figure 3 As shown, based on the contour lines, an inner and outer restoration boundary were obtained. After restoration according to the parameters of the initial restoration in S3, the resulting grassland condition is as follows. Figure 4 As shown, it can be seen that the number of healthy grasslands has increased significantly at this time. Moreover, the assessment standard for healthy grasslands (aboveground biomass > 2000 kg / ha) has increased compared to S2 (aboveground biomass > 1800 kg / ha). This means that grassland degradation has been controlled and has begun to recover, with the coverage rate reaching 59%.

[0117] Subsequently, the repair was performed again using the S5 deep repair method, such as... Figure 5 and Figure 6As shown, at this point, we add compound fertilizer to the outside of the corrected outer repair boundary instead of the repair agent. This is because in the initial repair, the repair agent mainly plays the role of adjusting soil pH and eliminating pests and diseases. However, in the deep repair, we begin to prepare for vegetation restoration. Therefore, the application of the two additives before and after the repair achieves a more scientific and reasonable soil conditioning effect. The adjustment location is allocated according to the condition after repair, which can greatly reduce the amount of the two regulators used. In conjunction with water storage in the irrigation ditch and the addition of nutrient solution, we ensure the maintenance of healthy grassland. The amount of nutrient solution added is 0.2-0.3 L / m of the inner repair boundary, and the frequency of addition is once a week.

[0118] Ultimately, by the time S6 regular sowing began—four months after the deep remediation ended—the grassland cover in the area had reached 86%. According to the healthy grassland assessment criteria in S4, the area of ​​healthy grassland had reached 81%, allowing for moderate grazing. Therefore, we implemented intermittent grazing as outlined in S6. Figure 7 As shown, this method can ensure the continuous restoration of grasslands and generate certain economic value, ultimately achieving dynamic ecological restoration of degraded grasslands.

Claims

1. A method for ecological restoration of degraded grassland, characterized in that, Includes the following steps: S1. Degradation Assessment: Assess the degree of degradation of the grassland to be restored, classifying it into mild, moderate, and severe. S2. First division of restoration area: The elevation of the grassland to be restored is measured, and a contour map of the grassland to be restored is drawn. The area enclosed by the contour lines is the contour area. The aboveground biomass of the grassland to be restored is counted. Plots with aboveground biomass >1800kg / ha are classified as healthy grassland. According to the degree of degradation, the first-stage restoration boundary is determined. The first-stage restoration boundary is a contour line in which the area of ​​healthy grassland accounts for 75-85% of the total area of ​​the contour area. The midpoint of the line connecting the point on the first-stage restoration boundary to the edge of the corresponding grassland to be restored is found. The line connecting each midpoint is used as the first-stage outer restoration boundary. S3. Preliminary restoration: Excavate a drainage ditch on the boundary of the first-stage inner restoration, and set up an ecological fence inside the drainage ditch. Apply nutrient solution through the ecological fence, plant water-resistant plants between the boundary of the first-stage outer restoration and the boundary of the first-stage inner restoration, and apply restoration agent between the boundary of the first-stage outer restoration and the edge of the grassland to be restored. S4. Secondary division of restoration area: 3 to 6 months after the initial restoration is completed, plots with aboveground biomass > 2000 kg / ha are divided into healthy grasslands. Based on the degree of degradation, the secondary inner restoration boundary is determined. The secondary inner restoration boundary is a contour line in which the area of ​​healthy grassland accounts for 80 to 90% of the total area of ​​the contour line area. The midpoint of the line connecting the point on the secondary inner restoration boundary to the edge of the corresponding grassland to be restored is found. The line connecting each midpoint is used as the secondary outer restoration boundary. S5. Deep restoration: Excavate a drainage ditch on the boundary of the secondary inner restoration, and set up an ecological fence inside the drainage ditch. Apply nutrient solution through the ecological fence, plant water-resistant plants between the boundary of the secondary outer restoration and the boundary of the secondary inner restoration, and apply compound fertilizer between the boundary of the primary outer restoration and the edge of the grassland to be restored. S6. Regular sowing: Sow seeds in the grassland to be restored 3 to 6 months after the completion of deep restoration.

2. The method for ecological restoration of degraded grassland according to claim 1, characterized in that, In S1, the degree of degradation of the grassland to be restored is classified according to the coverage. When the coverage is >60%, the degree of degradation of the grassland to be restored is mild; when 30% ≤ coverage ≤ 60%, the degree of degradation of the grassland to be restored is moderate; and when the coverage is <30%, the degree of degradation of the grassland to be restored is severe.

3. The method for ecological restoration of degraded grassland according to claim 2, characterized in that, In S2, when the degradation of the grassland to be restored is mild, a contour line in which the area of ​​healthy grassland accounts for 75-80% of the total area of ​​the contour line region serves as the boundary of the first-level restoration. When the degradation of the grassland to be restored is moderate, a contour line in which the area of ​​healthy grassland accounts for 77-83% of the total area of ​​the contour line region serves as the boundary of the first-level restoration. When the degradation of the grassland to be restored is severe, a contour line in which the area of ​​healthy grassland accounts for 80-85% of the total area of ​​the contour line region serves as the boundary of the first-level restoration.

4. The method for ecological restoration of degraded grassland according to claim 2, characterized in that, In S4, when the degradation of the grassland to be restored is mild, a contour line in which the area of ​​healthy grassland accounts for 80-85% of the total area of ​​the contour line region serves as the secondary inner restoration boundary. When the degradation of the grassland to be restored is moderate, a contour line in which the area of ​​healthy grassland accounts for 83-86% of the total area of ​​the contour line region serves as the secondary inner restoration boundary. When the degradation of the grassland to be restored is severe, a contour line in which the area of ​​healthy grassland accounts for 85-90% of the total area of ​​the contour line region serves as the secondary inner restoration boundary.

5. A method for ecological restoration of degraded grassland according to claim 2, characterized in that, In S3 and S5, the nutrient solution composition and mass fraction are: humic acid 3-4%, slow-release urea 0.5-1%, superphosphate 0.4-0.8%, with the remainder being water. The insulated plants are one or more of vetiver, bahia, and bermudagrass. In S3, the remediation agent composition and mass fraction are: quicklime 50-55%, straw biochar 15-20%, magnesium sulfate 3-5%, with the remainder being hydrated lime. The amount of remediation agent applied is adjusted to ensure the soil remains intact after remediation. The pH is 6.5-7. The composition and mass fraction of the compound fertilizer in S5 are: 3-5% microbial inoculant, 40-50% well-rotted livestock manure, 15-20% straw biochar, and the balance is urea. The microbial inoculant is one or more of rhizobium, nitrogen-fixing spirochete, Bacillus megaterium, Pseudomonas, and Bacillus subtilis. The application rate of the compound fertilizer is 300-500 kg / ha, and the mixing depth during application is 10-15 cm.

6. A method for ecological restoration of degraded grassland according to claim 5, characterized in that, When the degradation of the grassland to be restored is mild, the planting density of water-resistant plants in S3 should be 3–5 plants / m². 3 The planting density of water-resistant plants in S5 is 2-4 plants / m². 3 When the degradation level of the grassland to be restored is moderate, the planting density of water-resistant plants in S3 is 3-8 plants / m². 3 The planting density of water-resistant plants in S5 is 3-5 plants / m². 3 When the degradation of the grassland to be restored is severe, the planting density of water-resistant plants in S3 is 5-10 plants / m². 3 The planting density of water-resistant plants in S5 is 4–8 plants / m². 3 .

7. The method for ecological restoration of degraded grassland according to claim 1, characterized in that, The width of the water diversion ditch is 10-30cm. The ecological fence includes hollow columns on both sides and several connecting rods between the two hollow columns. The two ends of the lowest connecting rod are connected to the interior of the two hollow columns. The bottom of the connecting rod is provided with several openings. The bottom of the hollow column is conical and has openings. The ecological fences are connected by several steel wire ropes. The length of the ecological fence is 80-120cm. The interval between two adjacent ecological fences is 3-5m.

8. A method for ecological restoration of degraded grassland according to claim 7, characterized in that, In S6, the grassland to be restored is divided into several blocks at equal intervals during sowing. Each block is separated by an ecological fence and wire rope. One block is selected as a grazing area within each block for grazing for 1 to 2 months. After grazing, sowing begins in the block. The grazing and sowing direction is from one side of the grassland to be restored to the other side in sequence.

9. A method for ecological restoration of degraded grassland according to claim 1, characterized in that, In step S6, the seeding method is drone seeding, and the seeding density is 10-20 g / m². 3 The crop species are one or more of the following: Kobresia, Festuca argyi, Barley grass, Iris septemlobus, Bergenia schreberi, Triangular grass, Imperata cylindrica, Zoysia japonica, Sedge grass, Ryegrass, and Artemisia annua.

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