A high-altitude desert saline area comprehensive ecological restoration method based on salt discharge and alkali reduction hydraulic structure and mineral-based slow-release agent

Abstract

This invention relates to a comprehensive ecological restoration method for high-altitude desert saline-alkali areas based on a hydrodynamic structure for salt drainage and synergistic use of a mineral-based slow-release agent. The method includes: preparing and applying a mineral-based slow-release agent by mixing sulfur-containing minerals, acidifiers, crushed agricultural and forestry waste, clay minerals, and adhesives to prepare a slow-release matrix; constructing and implementing a hydrodynamic salt drainage activation system, building a periodic, high-efficiency drainage geotechnical structure in the area to be restored and coupling it with a drip irrigation system to form a hydrodynamic transport channel, achieving soil salt leaching and pre-activation of the slow-release agent through spraying; implementing microbial synergistic soil improvement by adding organic materials produced from the composting and fermentation of agricultural and livestock waste and electroactive functional microbial agents, activating the slow-release matrix through extracellular electron injection, and increasing soil organic matter content and microbial activity; and constructing a vegetation system by planting cold-resistant and salt-tolerant native herbaceous and shrub plants. This method solves the ecological restoration challenges in high-altitude desert saline-alkali areas.

Description

Technical Field

[0001] This invention relates to the field of ecological restoration technology, and in particular to a comprehensive ecological restoration method for high-altitude desert saline-alkali areas based on a hydrodynamic structure for desalination and alkali reduction, in conjunction with a mineral-based slow-release agent. Background Technology

[0002] Ecological restoration of high-altitude saline-alkali desert areas (such as the Qinghai-Tibet Plateau and arid Northwest China) is a global challenge. These areas have extremely fragile ecosystems and face multiple stresses, including soil salinization, drought and water scarcity, soil infertility, high evaporation, strong freeze-thaw cycles, and difficulties in vegetation establishment. As a result, traditional saline-alkali land improvement techniques are ineffective in these extreme environments and may even trigger secondary ecological problems.

[0003] Currently, common saline-alkali land management technologies have significant limitations in high-altitude desert environments. Traditional physical salt drainage techniques, such as open ditches or underground pipes, are more commonly used in low-altitude areas. However, in high-altitude and cold regions, the geotechnical structures used for salt drainage are easily limited by seasonal freeze-thaw cycles, making it difficult to maintain stable functionality in the long term. Furthermore, traditional salt drainage technologies rely solely on natural precipitation or flood irrigation, failing to effectively combine with artificially controlled pulsed leaching systems, resulting in salt accumulation that is difficult to drain, leading to low drainage efficiency. Regarding chemical amendments, conventional amendments (such as desulfurized gypsum and organic fertilizers) have low active ingredients, lack sustained improvement effects, and exhibit slow-acting results. They often focus on a single function of adjusting pH or supplementing nutrients, making it difficult to cope with the complex and continuous saline-alkali stress in high-altitude and cold desert environments. In terms of vegetation restoration, existing technologies focus on "soil improvement and suitable planting" or "selection of suitable plants for suitable soil," resulting in limited plant species selection. These species lack synergistic tolerance to the combined stresses of high altitude, strong ultraviolet radiation, and high salinity, leading to poor community stability and easy degradation. Meanwhile, the structure of saline-alkali soil has not been fundamentally improved, microbial activity is low, and plants are unable to take root and survive for a long time.

[0004] Existing technologies often employ single measures or simple combinations of technologies, lacking a systematic solution for the unique complex ecosystem of "high altitude-altitude-cold-desert-salinization," resulting in unsustainable restoration effects and difficulty in self-sustaining the vegetation system. Therefore, there is an urgent need for a comprehensive ecological restoration method for high-altitude desert saline-alkali areas based on a hydrodynamic structure for salt drainage and alkali reduction, in conjunction with mineral-based slow-release agents. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a comprehensive ecological restoration method for high-altitude desert saline-alkali areas based on a hydrodynamic structure for salt drainage and alkalinity reduction, in conjunction with mineral-based slow-release agents. The technical problems this method needs to solve include: 1) how to establish efficient and stable water transport and salt drainage / alkalinity reduction channels under conditions of high altitude, water scarcity, high evaporation, and strong freeze-thaw cycles; 2) how to continuously reduce soil salinity and alkalinity and improve soil particle structure and fertility through long-term slow-release technology using mineral-based materials; and 3) how to rapidly construct a soil environment suitable for native plant growth through the coupling of biological, physical, and chemical technologies, ultimately achieving self-sustaining and benign succession of the ecosystem.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] According to one aspect of the present invention, a comprehensive ecological restoration method for high-altitude desert saline-alkali areas based on a hydrodynamic structure for salt drainage and alkali reduction, synergistic with a mineral-based slow-release agent, is provided, comprising the following steps:

[0008] Preparation and application of mineral-based slow-release agent: Sulfur-containing minerals, acidifiers, crushed agricultural and forestry waste, clay minerals and adhesives are mixed and pelletized to prepare a slow-release matrix with long-term slow-release performance, and the mineral-based slow-release agent is applied to the area to be repaired;

[0009] Constructing and implementing a hydraulic desalination and activation system: In the area to be repaired where the mineral-based slow-release agent has been applied, a periodic, high-efficiency drainage geostructure is constructed and coupled with a spraying system to form an effective hydrodynamic transport channel; spraying is carried out through the spraying system to achieve the leaching and discharge of soil salts using water flow dynamics, while simultaneously achieving the physicochemical pre-activation of the mineral-based slow-release agent;

[0010] Implementing microbial synergistic soil improvement: adding organic materials and electroactive functional microbial agents produced by composting and fermenting agricultural and livestock waste; further activating the slow-release matrix through the extracellular electron injection of the mineral-based slow-release agent by the electroactive functional microbial agents; and simultaneously using the organic materials and functional microbial agents to increase soil organic matter content and microbial activity, thereby promoting the formation of soil aggregate structure.

[0011] Constructing a vegetation system: Selecting and combining native herbaceous and shrubby plants that are cold-resistant and salt-tolerant to complete ecological restoration.

[0012] Optionally, the mineral-based slow-release agent comprises the following components in parts by weight: 40-50 parts of sulfur-containing minerals, 5-10 parts of acidifying agent, 20-40 parts of clay and adhesive, and 10-20 parts of crushed agricultural and forestry waste.

[0013] The sulfur-containing minerals are pyrite, iron sulfide, or coal-based sulfides; the acidifying agent is urea phosphate or sulfur; and the pulverized agricultural and forestry waste provides the main attachment sites for the electroactive functional bacteria agent.

[0014] Optionally, the mineral-based slow-release agent can be slowly and directionally released over a long period through hydrodynamic physical action, with an effective release period of not less than 2 years; the periodic high-efficiency drainage geostructure includes a longitudinal guide ditch in the area to be repaired, the depth of which is set to 0.6-1.0 meters according to the root development depth of the target plants; the spraying regime of the sprinkler system is matched with the soil properties, salinity, infiltration rate and leaching water volume of the repair area.

[0015] Optionally, the electroactive functional microbial agent comprises salt- and alkali-resistant extracellular electroactive microorganisms, including one or more of *Geobacillus anodicus*, *Cookella rosea*, *Geobacillus spp.*, and *Aspergillus terreus* SYAT-1; the effective viable count of the microbial agent is not less than 1 × 10⁻⁶. 7 CFU / g.

[0016] Optionally, the implementation of synergistic microbial soil improvement also includes adding one or more of nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, potassium-solubilizing bacteria, Bacillus megaterium, and Bacillus licheniformis to the soil.

[0017] Optionally, the cold-resistant and salt-tolerant native herbaceous plants include one or more of the following: Leymus chinensis, Imperata cylindrica, Salicornia glutinosa, Kentucky bluegrass, and alfalfa; the cold-resistant and salt-tolerant shrubs include one or more of the following: Salicylum indicum, Hippophae rhamnoides, Tamarix chinensis, Amorpha fruticosa, and Rhus typha orientalis.

[0018] Optionally, during or after the construction of the vegetation system, a windproof and heat-insulating layer may be covered on the surface of the vegetation area; the windproof and heat-insulating layer may be composed of one or more materials selected from barley straw, coconut fiber mesh and non-woven fabric.

[0019] The advantages of implementing this invention are:

[0020] 1. First, it is a systematic innovation that integrates "hydraulic desalination → chemical slow-release alkali reduction → biological organic fertilization → wind protection and heat preservation → vegetation planting and restoration" into a complete technical system for high-altitude desert saline areas.

[0021] 2. High and stable salt removal efficiency: Based on the pulse leaching drainage-washing system, it effectively overcomes the problem of salt accumulation on the surface caused by high evaporation; the depth of the drainage ditch (0.6-1.0 meters) is set according to the depth of the plant root layer, which can more effectively protect the root zone environment, and the salt removal and alkali reduction effect is significant and long-lasting.

[0022] 3. The amendment has strong environmental adaptability. The core mineral-based slow-release agent utilizes the slow acidification characteristics of sulfide minerals under microbial action and freeze-thaw cycles, which solves the problem of inhibited activity of conventional amendments in high-altitude and cold regions and realizes long-term dynamic adjustment of salinity index.

[0023] 4. The ecological restoration effect is good. By combining organic-microbial agents to improve the soil and specially selected plants, and combined with windbreak and heat preservation measures, the survival rate and community stability of plants under high-altitude and cold desert conditions have been greatly improved, realizing the leap from soil improvement to ecological reconstruction. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart illustrating the method described in this invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] like Figure 1 As shown, a comprehensive ecological restoration method for high-altitude desert saline-alkali areas based on a hydrodynamic structure for salt drainage and alkali reduction, synergistic with mineral-based slow-release agents, includes the following steps:

[0029] Preparation and application of mineral-based slow-release agents: Using sulfur-containing minerals, acidifiers, crushed agricultural and forestry waste, clay minerals, and adhesives, a slow-release matrix with long-term slow-release properties is prepared by pelleting. Through physicochemical pre-activation by hydraulic action and the synergistic effect of electroactive microorganisms, the pH value and electrical conductivity (EC value) of saline-alkali soil are effectively regulated, effectively reducing soil salinity and alleviating saline-alkali stress.

[0030] Constructing and implementing a hydraulic desalination activation system: In the remediation area where mineral-based slow-release agents have been applied, a periodic and efficient drainage geostructure is constructed and coupled with a spraying system to form an effective hydrodynamic transport channel. The mineral slow-release matrix is ​​pre-activated through the physicochemical action of water flow.

[0031] Implementing soil improvement through microbial synergy: Adding organic materials and electroactive functional microbial agents produced by the composting and fermentation of agricultural and livestock waste, and realizing the extracellular electron injection of mineral matrix based on electroactive microorganisms, thereby activating and slowly releasing mineral matrix through the action of exogenous electrons; utilizing functional microorganisms and composting fermentation materials to increase soil organic matter content and microbial activity, promote the formation of soil aggregate structure, and improve soil nutrient level in situ.

[0032] Constructing a vegetation system: Selecting and combining native herbaceous and shrubby plant germplasm resources that are cold-resistant and salt-tolerant to achieve long-term ecological stability and restoration.

[0033] Furthermore, the mineral-based slow-release agent comprises the following components in parts by weight: 40-50 parts sulfur-containing minerals, 5-10 parts acidifier, 20-40 parts clay and binder, and 10-20 parts crushed agricultural and forestry waste. The sulfur-containing minerals include pyrite, iron sulfide, or coal-based sulfides; the acidifier is urea phosphate or sulfur, which mainly provides the proton source for the acidification process; the clay and binder mainly provide the binding force for the preparation of the slow-release agent and are the main components for forming the pellet structure; the crushed agricultural and forestry waste mainly provides the main attachment sites for extracellular electroactive microorganisms and is a key substance for forming a microorganism-mineral interaction system; the mineral-based slow-release agent is prepared by pelleting and has long-term slow-release performance, and can form a microorganism-slow-release agent interaction complex during the application process.

[0034] Furthermore, the long-term, slow, and directional exfoliation of the mineral-based slow-release agent is achieved through hydrodynamic physical action, with a release cycle of no less than 2 years; surface oxidation and slow release are achieved through the erosive action of oxygen and ions carried by the hydrodynamic force; the hydrodynamic geostructure includes longitudinal guide ditches and a surface source sprinkler system in the remediation area, which can ensure the effective storage and return of water sources; the depth of the longitudinal guide ditches is determined according to the development of plant roots and is set at 0.6-1.0 meters; the sprinkler system spray regime is matched with soil properties, salinity, infiltration rate, and leaching water volume to form an effective hydrodynamic transport channel.

[0035] Before constructing the geotechnical structure, the soil in the area to be repaired must first be tilled. The tilling depth should be determined based on the root extension depth of the plants, generally within the range of 0.2-0.5 m. After tilling, periodic, high-efficiency drainage ditches should be constructed in the longitudinal area, with an interval of 5-8 m and a depth of 0.6-1.0 m. The drainage ditches should have both drainage and water storage functions. For the sprinkler system, a pulse sprinkler system or a long-cycle sprinkler system can be adopted. During the sprinkler process, the changes in salt content in the aqueous solution and soil should be monitored regularly, and the sprinkler regime should be adjusted according to the salt leaching. The sprinkler system should ultimately be optimized to achieve the fastest salt spraying speed and the most thorough leaching and dissolution, establishing an effective water and salt transport channel to promote salt discharge, with a final salt discharge rate of not less than 60%.

[0036] Furthermore, the electroactive functional microbial agent contains salt- and alkali-resistant extracellular electroactive microorganisms, including one or more of the following: *Geobacterium anolysinus*, *Cookella roseum*, *Geobacterium spp.*, and *Aspergillus terreus* SYAT-1; the effective viable count of the microbial agent is not less than 1 × 10⁻⁶. 7 CFU / g.

[0037] Furthermore, implementing microbial synergistic soil improvement also includes adding one or more of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, potassium-solubilizing bacteria, Bacillus megaterium, and Bacillus licheniformis to the soil.

[0038] Furthermore, the cold-resistant and salt-tolerant native herbaceous plants include one or more of the following: Leymus chinensis, Imperata cylindrica, Salicornia glutinosa, Kentucky bluegrass, and Alfalfa; the cold-resistant and salt-tolerant shrubs include one or more of the following: Salicyla spp., Hippophae rhamnoides, Tamarix chinensis, Amorpha fruticosa, and Rhus typha orientalis; the combination ratio of plant seeds is adjusted according to the degree of soil salinization and climatic conditions in high-altitude desert saline areas.

[0039] Furthermore, during or after the construction of the vegetation system, a windproof and heat-insulating layer is covered on the surface of the vegetation area; the windproof and heat-insulating layer is composed of one or more materials selected from barley straw, coconut fiber mesh, and non-woven fabric.

[0040] Example 2: Restoration of a severely saline meadow in a river valley on the Qinghai-Tibet Plateau

[0041] 1. Overview of the area to be restored: Altitude 3000 meters, soil is heavily sulfate-chloride type saline soil, average salt content of 1.2% in the 0-20cm soil layer, pH value 9.5, vegetation cover less than 10%.

[0042] 2. Repair Implementation:

[0043] Hydrodynamic salt removal: First, longitudinal drainage ditches with a depth of 0.8 meters and a width of 0.5 meters are excavated at 5-meter intervals, and the ditches are backfilled with sand and gravel filter media. Then, a pulse sprinkler system with a sprinkler intensity of 8 mm / h is installed, and the sprinkler operation is carried out twice a week for 2 hours each time, which promotes the downward migration of salt and its discharge into the drainage ditches.

[0044] Application of mineral-based slow-release agent: Two weeks after the desalination process is implemented, apply mineral-based slow-release agent (components: 50 parts pyrite, 30 parts modified mineral matrix, 15 parts humic acid, and 5 parts sulfur) evenly at a rate of 5 tons / hectare (approximately 5% of the soil mass).

[0045] Soil structure improvement and nutrient enhancement: One week after applying the slow-release agent, spread cow and sheep manure compost (20 tons / hectare) and compound functional microbial agents (nitrogen-fixing bacteria, phosphate-solubilizing bacteria, etc., with an effective viable count ≥2×10⁻⁶). 7 CFU / g), and mix it with the topsoil by shallow rotary tillage (15cm depth).

[0046] Vegetation system construction and insulation: After soil improvement, a mixture of seeds of Leymus chinensis (30%), Imperata cylindrica (30%), Kentucky bluegrass (20%), and alfalfa (20%) was sown and planted with one-year-old container seedlings of Hippophae rhamnoides (1.5m × 2m spacing). Immediately after sowing and planting, a windproof and heat-insulating layer composed of barley straw (bottom layer) and coconut fiber netting (top layer) was applied.

[0047] 3. Restoration effect: One year after restoration, the soil salinity in the 0-20cm layer dropped to below 0.3%, the pH value dropped to around 8.2, and the soil organic matter content increased by 35%. The vegetation cover recovered to over 65%, the survival rate of sea buckthorn reached 90%, and a stable grass-shrub community was formed.

[0048] Example 3: Restoration of moderately salinized and degraded grasslands on the edge of arid desert regions in Northwest China

[0049] 1. Overview of the area to be restored: Altitude 2500 meters, soil is moderately saline-alkali, average salt content of 0.6% in the 0-20cm soil layer, pH value 9.0, and soil compaction is severe.

[0050] 2. Repair Implementation:

[0051] The steps in this embodiment are basically the same as in Embodiment 1, except that, given the low local rainfall (annual rainfall <150mm), the drainage ditch depth is set to 0.6 meters to facilitate the collection of limited rainwater. The application rate of the mineral-based slow-release agent is adjusted to 3 tons / hectare (approximately 3% of the soil mass). More drought-resistant species such as *Haworthia cochinchinensis* and *Tamarix chinensis* are selected as the dominant shrubs. A single layer of coconut fiber mesh is used for the windbreak and insulation layer to balance insulation and permeability.

[0052] 3. Restoration effect: After 18 months of restoration, soil salinity and pH value decreased significantly, and tamarisk and saltwort trees grew well, forming an effective windbreak and sand-fixing community.

[0053] Example 4: Rapid Improvement of Severely Saline-Alkali Land and Forage Production

[0054] Target area: Delingha, Qinghai, and other areas with severely sulfate-type saline soil, serious soil compaction, and almost no vegetation.

[0055] Technical parameters configuration:

[0056] Salt drainage system: Excavate drainage blind ditches with a depth of 0.8 meters and a spacing of 8 meters. Backfill the ditches with sand and gravel filter material and lay perforated underground pipes (corrugated plastic pipes can be used). The slope of the ditch bottom should not be less than 0.2%. Couple a mobile sprinkler irrigation machine for periodic rinsing. The irrigation quota is 1000-1200 cubic meters / hectare·time. Based on soil salinity monitoring data, carry out 2-3 pulse rinsings in spring and autumn.

[0057] Chemical amendment: Apply a mineral-based slow-release agent at a rate of 5 tons per hectare. Thoroughly mix it with the top 0-20cm of soil using a rotary tiller.

[0058] Biological improvement: Apply 30 tons / hectare of well-rotted cow and sheep manure compost and inoculate with a compound functional microbial agent (nitrogen-fixing bacteria, phosphate-solubilizing bacteria, etc.), with an effective viable count ≥10. 7 CFU / g.

[0059] Vegetation setup: Salt-tolerant forage grasses such as alkali grass (40%), alfalfa (30%), and lysimachia (30%) were mixed in. After sowing, a windproof and heat-insulating layer composed of barley straw and biodegradable non-woven fabric was laid on top.

[0060] Expected results: After one year of implementation, the salinity of the topsoil layer (0-20cm) can be reduced from over 1.5% to below 0.5%. High-quality forage can be harvested in the same year, with an annual hay yield of over 700 kg / mu, achieving a combination of ecological restoration and economic benefits.

[0061] Example 5: Prevention and Control of Secondary Salinization and Production Capacity Enhancement in Irrigation Areas

[0062] Target area: Downstream of large irrigation areas such as Gansu, where improper irrigation has led to a rise in groundwater levels and secondary salinization of farmland.

[0063] Technical parameters configuration:

[0064] Salt drainage system: shallow, dense open ditches with a depth of 0.6 meters are used in the field to collect the high salinity of the surface water.

[0065] Chemical and biological improvement: Combine autumn plowing and winter irrigation, apply 300 kg of mineral-based slow-release agent (selected from coal-based sulfides) and 1000 kg of organic fertilizer per mu, and plow them into the soil to improve the basic soil fertility.

[0066] Vegetation management: Implement a cotton-alfalfa crop rotation system. Utilize alfalfa's strong root system and biological nitrogen-fixing capacity to further improve soil structure and consolidate desalination effects.

[0067] Expected results: By preventing salt accumulation in the topsoil and combining it with biological improvement, the productivity of low- and medium-yield fields will be increased by 20%-30% within 3 years, achieving sustainable development of agriculture in the irrigation area.

[0068] Example 6: Rapid revegetation and reinforcement of saline soil on roadside slopes

[0069] Target area: Saline soil areas along highway and railway roadbeds, such as the Chaka Salt Lake area in Qinghai Province, which face problems of salt weathering, erosion, and stability.

[0070] Technical parameters configuration:

[0071] Salt-blocking and salt-removing structure: A gravel-filled salt-blocking barrier layer is installed inside the roadbed slope and below the shoulder. The barrier layer uses gravel with a particle size of 2.0-5.0 mm and a thickness of 50-80 cm, effectively preventing capillary water from carrying salt upwards. The hydrodynamic module uses a drip irrigation system for precise, small-volume, multiple rinsing, which saves water and avoids slope erosion. Soil conditioner is mixed with grass and shrub seeds, water-retaining agents, etc., and then sprayed using hydraulic spraying technology to ensure adhesion and uniformity on steep slopes.

[0072] Vegetation setup: Select salt-tolerant, deep-rooted shrubs such as tamarisk and sea buckthorn for planting, and combine them with herbaceous plants such as lysimachia to stabilize the soil. Use container seedlings and top-fill soil for planting to improve the survival rate.

[0073] Water management: Install a drip irrigation system and use reclaimed water or brackish water for precise irrigation to ensure plant survival and avoid secondary salinization.

[0074] Expected results: By combining engineering and biological measures, and focusing on the engineering goals of "fast", "stable" and "low maintenance", the slope will be quickly revegetated (coverage rate >80% within one year), the roadbed stability will be enhanced, and a good roadside landscape will be formed.

[0075] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A comprehensive ecological restoration method for high-altitude desert saline-alkali areas based on a hydrodynamic structure for salt drainage and alkali reduction, synergistic with mineral-based slow-release agents, characterized in that... Includes the following steps: Preparation and application of mineral-based slow-release agent: Sulfur-containing minerals, acidifiers, crushed agricultural and forestry waste, clay minerals and adhesives are mixed and pelletized to prepare a slow-release matrix with long-term slow-release performance, and the mineral-based slow-release agent is applied to the area to be repaired; Constructing and implementing a hydraulic desalination and activation system: In the area to be repaired where the mineral-based slow-release agent has been applied, a periodic, high-efficiency drainage geostructure is constructed and coupled with a spraying system to form an effective hydrodynamic transport channel; spraying is carried out through the spraying system to achieve the leaching and discharge of soil salts using water flow dynamics, while simultaneously achieving the physicochemical pre-activation of the mineral-based slow-release agent; Implementing microbial synergistic soil improvement: adding organic materials and electroactive functional microbial agents produced by composting and fermenting agricultural and livestock waste; further activating the slow-release matrix through the extracellular electron injection of the mineral-based slow-release agent by the electroactive functional microbial agents; and simultaneously using the organic materials and functional microbial agents to increase soil organic matter content and microbial activity, thereby promoting the formation of soil aggregate structure. Constructing a vegetation system: Selecting and combining native herbaceous and shrubby plants that are cold-resistant and salt-tolerant to complete ecological restoration; The mineral-based slow-release agent comprises the following components in parts by weight: 40-50 parts sulfur-containing minerals, 5-10 parts acidifier, 20-40 parts clay and adhesive, and 10-20 parts crushed agricultural and forestry waste. The sulfur-containing minerals are pyrite, iron sulfide, or coal-based sulfides; the acidifying agent is urea phosphate or sulfur; and the pulverized agricultural and forestry waste provides the main attachment sites for the electroactive functional bacteria agent.

2. The method according to claim 1, characterized in that, The mineral-based slow-release agent is released slowly and directionally over a long period through hydrodynamic physical action, with an effective release period of not less than 2 years. The periodic high-efficiency drainage geostructure includes a longitudinal guide ditch in the area to be repaired, with a depth of 0.6-1.0 meters set according to the root development depth of the target plants. The spraying regime of the spraying system is matched with the soil properties, salinity, infiltration rate and leaching water volume of the repair area.

3. The method according to claim 1, characterized in that, The electroactive functional microbial agent contains salt- and alkali-resistant extracellular electroactive microorganisms, including one or more of *Geobacillus anodicus*, *Cookella rosea*, *Geobacillus stolonifera*, and *Aspergillus terreus* SYAT-1; the effective viable count of the microbial agent is not less than 1 × 10⁻⁶. 7 CFU / g.

4. The method according to claim 1 or 3, characterized in that, The soil improvement through microbial synergy also includes adding one or more of nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, potassium-solubilizing bacteria, Bacillus megaterium, and Bacillus licheniformis to the soil.

5. The method according to claim 1, characterized in that, The cold-resistant and salt-tolerant native herbaceous plants include one or more of the following: Leymus chinensis, Imperata cylindrica, Salicornia glutinosa, Kentucky bluegrass, and Alfalfa; the cold-resistant and salt-tolerant shrubs include one or more of the following: Salicyla spp., Hippophae rhamnoides, Tamarix chinensis, Amorpha fruticosa, and Rhus typhina.

6. The method according to claim 1, characterized in that, During or after the construction of the vegetation system, a windproof and heat-insulating layer is covered on the surface of the vegetation area; the windproof and heat-insulating layer is composed of one or more materials selected from barley straw, coconut fiber mesh and non-woven fabric.

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