A method for effectively improving survival rate of cryptogamic plants in extremely arid sandy areas

Abstract

The application discloses a method for effectively improving survival rate of cryptogamic plants in an extremely arid sandy area, and relates to the field of biological soil crusts. The method comprises the following steps: establishing a crust nursery, selecting a complex microbial colony which is treated by simulating natural adversity as field inoculation material, adopting a fusional crust field breeding box arranged in a row and column mode to carry out field breeding, planting into drifting sand with the convex surface of the arc-shaped protective cover facing the wind direction, inoculating the complex microbial colony material on the first platform, and placing water-retaining slow-release fillers on the second platform; and planting special crown shrubs in the interspaces of the fusional crust field breeding box. The method solves the problems of insufficient traditional inoculation material, single variety, poor adaptability, extensive cryptogamic plant inoculation mode, simple breeding technology, poor habitat, and missing auxiliary materials, improves the survival rate of cryptogamic plants, promotes the formation of biological soil crusts, and is suitable for the extremely arid sandy area.

Description

Technical Field

[0001] This invention belongs to the field of ecological restoration technology in sandy areas, specifically a method for effectively improving the survival rate of cryptogams in the wild in extremely arid sandy areas. Background Technology

[0002] Desertification control is a key and challenging issue in global ecological environmental protection. Biological sand fixation technology, due to its combination of ecological restoration and sustainability, has always been a research hotspot and mainstream development direction in this field. Among these technologies, the use of biological soil crusts (BSCs, referring to a surface cover layer composed of soil particles and varying proportions of photosynthetic autotrophic organisms such as cyanobacteria, algae, lichens, and bryophytes, as well as heterotrophic microorganisms such as bacteria, fungi, and archaea) for sand fixation is a novel biological sand fixation technology that has attracted considerable attention in recent years. The core principle of this technology is to inoculate cryptogams (plants that reproduce by spores rather than seeds) such as cyanobacteria, lichens, and bryophytes onto the shifting sand surface, promoting their development into a structurally stable "biological protective shell." This shell not only fixes sand particles and slows down wind erosion but also improves the surface soil structure and enhances water and fertilizer retention capacity, acting as an ecosystem "engineer." It has broad application prospects in ecological restoration projects in arid and semi-arid sandy areas. Currently, this technology has been tested on a small scale in some areas with superior habitats such as desertified land and desertified grassland, becoming an important means to supplement traditional biological sand fixation, mechanical sand fixation and chemical sand fixation technologies, but it has not yet been promoted on a large scale.

[0003] Despite the significant ecological advantages of biological soil crusting sand control technology, its practical application in the field still faces numerous technical bottlenecks and natural constraints, failing to achieve a stable sand-fixing effect and thus significantly reducing its effectiveness, hindering large-scale promotion and application. The core problem lies in the poor adaptability of artificially cultivated cryptogamic plant populations and their extremely low survival rate in the wild, which is closely related to the extremely harsh habitat conditions in desert regions. Especially in extremely arid sandy areas, not only is the soil thin and lacking in the nutrients and organic matter required for cryptogamic plant growth, but the highly mobile sand matrix also cannot provide a stable growth point for seedlings or spores. Simultaneously, the harsh climate of these regions means that frequent strong winds in spring can easily blow away inoculated biological materials and topsand, the scorching summer sun rapidly depletes soil moisture, leading to dehydration of cryptogamic plants, and the severe winter cold can damage the cell structure of cryptogamic plants, causing irreversible frost damage. In such a complex and harsh environment, simply spraying or spreading spores or seedlings of cyanobacteria, lichens, and mosses onto the surface of quicksand is insufficient for cryptogams to survive and reproduce, let alone develop into structurally complete and stable biological soil crusts. Consequently, the desired windbreak, sand fixation, and ecological restoration effects cannot be achieved. Furthermore, large-scale field propagation techniques for lichens and mosses have not yet been successfully developed, and the lack of sufficient inoculation materials adapted to the wild environment further limits the widespread application of this technology.

[0004] To address the aforementioned technical challenges, researchers have conducted a series of studies attempting to optimize the bio-soil crusting desertification control technology. Regarding inoculation material improvement, they have artificially domesticated and cultivated autotrophic microorganisms such as cyanobacteria and mosses, screening out dominant strains or populations that are drought-resistant, cold-resistant, and heat-resistant to enhance their adaptability to adverse environments. In terms of material propagation technology, they have developed large-scale indoor cultivation systems tailored to the growth characteristics of lichens and mosses, achieving mass production of inoculation materials by controlling conditions such as temperature, humidity, and light, thus alleviating the shortage of inoculation materials in the field. Simultaneously, they are exploring the mixed inoculation of different types of cryptogams, utilizing the synergistic effects between species to resist damage and promote crust formation. Regarding inoculation methods, they have abandoned the traditional single spraying and broadcasting methods, using mulch such as straw and non-woven fabric to assist in inoculation, reducing wind and sand erosion and water evaporation, and providing temporary shelter for microbial growth. Some studies have also explored the inoculation method of mixing microbial agents with soil, mixing artificially cultivated microorganisms with improved soil (adding organic matter, water-retaining agents, etc.) and then laying it on the sand surface to improve the local micro-habitat and promote microbial reproduction.

[0005] While existing technologies and methods have improved the conditions for the formation of biological soil crusts in the field to some extent, they still have many shortcomings and have not fundamentally solved the bottlenecks of low survival rates and difficulties in large-scale application of microorganisms such as cryptogams in the wild. Although the tolerance of artificially domesticated superior varieties has been improved, they are currently only applied to local sandy areas with superior micro-habitats, and the problems of low survival rates after inoculation in extremely arid sandy areas and the degradation of indoor-cultivated varieties in the wild have not been solved. Although mulch-assisted inoculation and inoculant-mixed soil methods can improve local micro-habitats, on the one hand, mulch is easily degraded in the natural environment or buried by wind and sand, and cannot play a long-term role; on the other hand, long-term covering can easily lead to poor development of effective microbial components and excessive growth of other polluting microorganisms. Indoor large-scale propagation technology is currently only applied to some species such as cyanobacteria, while large-scale propagation of plants such as lichens and mosses, which require long growth cycles and have strict habitat requirements, is still not possible, making it difficult to meet the material needs of large-scale desertification control projects. In summary, existing technologies still suffer from shortcomings such as insufficient material adaptability, difficulty in propagation, low survival rate in the wild, and unstable treatment effects. As a result, although bio-soil crust desertification control technology has received much research attention, it has not yet achieved a breakthrough and cannot be widely applied in desertification control practices. There is an urgent need for a technical solution that can supply inoculation materials on a large scale, systematically improve the wild breeding habitat of microorganisms, significantly improve the wild survival rate of cryptogams, and efficiently promote the formation of bio-soil crusts. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a method to effectively improve the survival rate of Cryptocoryne plants in the wild in extremely arid sandy areas. 1) By establishing a crust nursery and using a composite microbial community treated with crust as a field inoculation material, large-scale production is achieved, solving the problems of lack of traditional inoculation materials, single variety, and poor adaptability; 2) An integrated crust field propagation box is developed that can not only prevent wind erosion and fix sand, but also provide shelter for Cryptocoryne plants, making up for the lack of auxiliary materials and alleviating the harshness of the field habitat; 3) An integrated inoculation technology combining a composite microbial community, an integrated crust field propagation box, and a special crown-shaped shrub for shading is constructed to optimize the extensive inoculation method. The core purpose of the synergy of the three is to improve the field propagation rate and survival rate of Cryptocoryne plants, efficiently promote the formation of biological soil crust, and perfectly adapt to the environment of extremely arid sandy areas.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for effectively improving the survival rate of cryptogams in the wild in extremely arid sandy areas, the specific steps of which are as follows: The inoculation material is obtained by: cultivating a complex microbial community in a crust nursery and subjecting it to crust hardening treatment before leaving the nursery to obtain the complex microbial community inoculation material for inoculation; the crust hardening treatment is to simulate natural stress conditions and to lightly interrupt the nutrient and water supply to the inoculation material; the seed source of the complex microbial community is the crust seed source of cryptogamic plants in the lichen or moss stage collected nearby in the desertification control area. The composite microbial cluster was propagated in the field using a fusion-type crust field propagation box. Specifically, the fusion-type crust field propagation boxes were arranged in a row-and-column pattern on quicksand. Each fusion-type crust field propagation box included an arc-shaped protective cover, inside which a first platform and a second platform were horizontally arranged. The lower end of the arc-shaped protective cover was planted in the quicksand, with the protruding outer surface of the arc-shaped protective cover facing the wind direction. The composite microbial cluster inoculation material was inoculated on the first platform, and water-retaining slow-release packing material was placed in the second platform. The propagation of the composite microbial cluster inoculation material is assisted by using a biological shading method, specifically by planting special crown-shaped shrubs in the interrow area of ​​the fusion-type crust field propagation box.

[0008] Furthermore, the specific steps for obtaining the composite microbial cluster inoculation material for inoculation are as follows: Select a slightly acidic to slightly alkaline sandy loam, loam, or clay loam soil with sufficient transportation, labor, water, and power sources, flat terrain, good drainage, groundwater level ≤1.5m, and soil layer thickness ≥50cm as the crusting nursery site. Construct a shade shed that does not obstruct ventilation in the crusting nursery site. The area of ​​the crusting nursery is determined according to the requirements of the complex microbial community and the tillage system. Divide the crusting nursery into crusting beds according to the ridge cultivation method, and prepare the soil until the soil particles are fine and the surface is flat. The crusting beds constitute the cultivation unit of the crusting bed. Deeply cultivate and refine the soil corresponding to the crust bed in the crust nursery, and remove grass roots and stones. The cultivation depth should be ≥25cm in autumn / winter and ≥20cm in spring. After cultivation, harrow, level and compact the soil in time according to the local snow accumulation. Before cultivation, disinfect the soil with chemicals or burn the soil. Lay a plant fiber substrate or special culture medium on the crust bed, and lay a thick layer of pure sand on the substrate. After crushing the composite microbial cluster, spread it evenly on the surface of the pure sand and compact and spray water. Inoculate when the soil temperature at a depth of 5cm is stable at about 10℃. After inoculation, the crust bed should be shaded during the day. During the cultivation period, special microbial green manure should be the main fertilizer. For the first base fertilizer, the special microbial green manure should be mixed with the compound microbial cluster and spread. The top dressing should be diluted with water and sprayed onto the crust bed. Fully decomposed organic fertilizer and a small amount of inorganic phosphorus, potassium and inorganic nitrogen fertilizer should be applied in combination. The soil pH should be kept <6 throughout the process. Water should be applied daily for half a month after inoculation. Thirty days before transplanting, the inoculated material after cultivation should undergo a hardening treatment. Specifically, the shade structure should be gradually removed within one week. From 30 to 16 days before transplanting, the watering frequency should be adjusted to once every 3 days. From 15 days before transplanting to the day of transplanting, the watering frequency should be adjusted to once every 7 days, with a single watering amount of 0.1 kg / m³. 2 ~0.5kg / m 2 Furthermore, fertilization was completely stopped throughout the process; After the crusting treatment, the inoculation material is transported out of the nursery according to the sand fixation season. Specifically, the inoculation material is peeled off one by one from the crust bed according to the culture medium and stacked evenly. After peeling, it is transported in a timely manner with ventilation, and water loss and sun exposure are avoided during transportation to obtain composite microbial cluster inoculation material.

[0009] Furthermore, the surface of the crusted seedbed is 5cm to 15cm lower than the ridge, the seedbed is 60cm to 80cm wide, the seedbed is 3m to 5m long, and the ridge is 30cm wide. Before sowing, the crusted seedbed is prepared until the soil particles are fine and the surface is flat. A shade shed with a height of 2.5m to 4m is built in the crusted seedbed.

[0010] Furthermore, the width of the crust bed is set to 1-2 times the length of the fusion-type crust field breeding box, and the bed surface is 20-30cm lower than the embankment; a 0.5-1cm thick layer of pure sand is laid on the culture medium laid on the crust bed; the composite microbial cluster is crushed and evenly spread on the surface of the pure sand and compacted, with an inoculation amount of 0.05kg / m². 2 ~0.15kg / m 2 .

[0011] Furthermore, after inoculation, the crust bed should be shaded daily from 10:00 to 17:30. During the low-temperature season, a plastic film with a height of 10-15cm should be used to warm and moisturize the crust bed. The initial base fertilizer is 0.2kg / m². 2 ~0.4kg / m 2 The specialized microbial green manure is mixed with the compound microbial cluster and applied by broadcasting. For the first two weeks after inoculation, water daily using a spray system, for a cumulative total of 3-5 hours and a total water volume of 1.5 kg / m³. 2 ~2kg / m 2 From half a month after inoculation until the skin forms, spray for a total of 2-3 hours daily, with a total water volume of 0.1 kg / m². 2 ~0.5kg / m 2 .

[0012] Furthermore, in the step of using afforestation to assist in the propagation of the composite microbial cluster inoculation material, the afforestation technology follows the GB / T 51085 standard, and the special crown-shaped shrubs are selected from sandy shrubs with dense crowns, and the crown shape is elliptical or equilateral triangle; before the biological soil crust is formed, the desertification control area is strictly managed and human-caused damage is prohibited.

[0013] Furthermore, if inoculation and afforestation are completed during the dry season, the planted shrubs should be watered by irrigation, with a watering rate of 1 kg / shrub; the watering rate for the composite microbial cluster inoculation material should be 0.1 kg / m³. 2 ~0.5kg / m 2 .

[0014] Furthermore, the lower end of the arc-shaped protective cover is planted in the quicksand at a depth of 5cm to 8cm, with 12cm to 15cm exposed above the ground; the spacing between rows of the fusion-type crust field breeding box is determined according to the rainfall or the time of crust formation in the area to be treated.

[0015] Furthermore, the inner wall of the arc-shaped protective cover has a honeycomb structure, and an arc-shaped groove is set at the bottom edge of the arc-shaped protective cover. All areas above the groove have an arc-shaped structure, and a through hole is opened at the lowest point of the groove along the vertical direction of the arc-shaped protective cover, connecting the inside and outside of the arc-shaped protective cover.

[0016] Furthermore, the water-retaining slow-release filler is a composite water-retaining agent material based on cotton stalk cellulose.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: This invention provides a method to effectively improve the survival rate of Cryptogams in the wild in extremely arid sandy areas. By integrating optimized inoculation materials, innovative fusion-type soil crust field propagation boxes, and ecological synergy with special crown-shaped shrubs providing shade, this method fundamentally solves the problems of low survival rates and unstable effects of existing biological soil crusting desertification control technologies in extremely arid sandy areas, achieving multi-dimensional synergistic benefits. Firstly, this method abandons the traditional single inoculation material model, using a composite microbial community cultivated in a soil crusting nursery and treated with crusting hardening as the inoculation material. This inoculation material uses a composite microbial community cultivated in a local soil crusting nursery in the area to be treated as the seed source. After being treated with crusting hardening under simulated natural adversity, it has initially acquired environmental adaptability and crusting plasticity suitable for extremely arid sandy areas, effectively tolerating harsh environments such as barren soil, drastic temperature differences, and sandstorms, providing a reliable material basis for the survival of Cryptogams in the wild. Simultaneously, the soil crusting nursery cultivation enables large-scale production of the inoculation material, solving the problem of insufficient supply of traditional inoculation materials. Secondly, this method uses a row-and-column arrangement of integrated crust-forming field propagation boxes as the core carrier for field propagation. The arc-shaped protective cover, combined with directional planting, effectively blocks wind and sand erosion, stabilizes the shifting sand matrix, and prevents the inoculation material from being swept away by strong winds. The double-platform arrangement within the box holds the inoculation material and water-retaining slow-release filler, respectively. The water-retaining slow-release filler continuously provides moisture support for the propagation of cryptogams, alleviating the environmental stress of extreme drought and significantly improving the micro-habitat for the field propagation of cryptogams, thus laying a solid protective foundation for the formation of biological soil crusts. Thirdly, this method combines the protective function of the integrated crust-forming field propagation boxes with the planting of special crown-shaped shrubs between rows, forming a synergistic ecological system of dual protection: propagation boxes and shrubs. The shrubs not only further weaken the impact of wind and sand on the propagation boxes and inoculation materials but also improve the local ecological environment of the sandy areas to be treated, assisting in the propagation of the composite microbial community inoculation material, achieving simultaneous advancement of cryptogam propagation and vegetation restoration in sandy areas. Fourth, this method organically combines optimized inoculation materials, innovative propagation devices, and standardized inoculation procedures, solving the industry problem that a single technical means cannot simultaneously address inoculation adaptability, environmental protection, and soil crust integrity. It achieves synergistic adaptation of inoculation materials, protective facilities, and inoculation processes, significantly improving the field adaptability and preservation effect of cryptogams in extremely arid sandy areas. This promotes the advancement of biological soil crust desertification control technology from small-scale trials to large-scale applications, providing an efficient and stable technical path for desertification control in extremely arid sandy areas, and possessing both outstanding ecological value and broad application prospects.

[0018] Furthermore, by precisely defining the site selection and specifications of the crust nursery, crust bed, and crust ridge, this invention creates a suitable cultivation environment for the complex microbial community. The site selection requirements, such as terrain, soil, and soil layer thickness, ensure the stability of the cultivation substrate. The height and ventilation design of the shade shed take into account both shading needs and air circulation. The size and specifications of the crust bed and crust ridge are adapted to the integrated crust field propagation box, providing process assurance for the large-scale and standardized production of subsequent inoculation materials.

[0019] Furthermore, by limiting the steps of soil cultivation, disinfection, and substrate laying, this invention effectively eliminates interfering factors such as weeds and stones in the cultivation environment, reducing the risk of soil-borne diseases and pests. The method of laying plant fiber substrate or special culture medium with 0.5cm to 1cm thick pure sand provides a suitable attachment carrier for the growth of complex microbial communities, while ensuring the permeability and water retention of the substrate. Precise inoculation amount and inoculation temperature limits ensure the initial growth density and germination rate of the inoculated material.

[0020] Furthermore, this invention achieves scientific regulation of the growth process of the composite microbial community by specifying refined parameters for cultivation and management measures such as shading, warming and moisturizing, fertilization, and watering during the seedling stage. The fertilization scheme of special microbial green manure combined with decomposed organic fertilizer and inorganic fertilizer controls the soil pH to <6 throughout the process, providing a balanced nutrient supply for the growth of the inoculated material. The staged spraying watering method and precise watering volume and time limits not only meet the water requirements of the inoculated material at different growth stages, but also avoid the adverse effects of too much or too little water on its growth. The greenhouse film warming and moisturizing measures in the low-temperature season effectively solve the problem of low temperature environment inhibiting the growth of inoculated material, ensuring the stable growth of inoculated material under different climatic conditions. Furthermore, by defining specific parameters and operational steps for the bark-refining treatment, this invention achieves standardized operation that simulates natural adversity. By gradually removing the shade structure and reducing the frequency of watering in stages, the inoculated material gradually adapts to the arid and nutrient-poor field environment. The precise amount of watering per application and the cessation of fertilization further enhance the drought resistance and tolerance to poor soil of the inoculated material, making the bark-refining treatment more controllable and significant. The cultivated inoculated material can better adapt to the field environment of extremely arid sandy areas, further improving the field survival rate of cryptogams from the inoculated material cultivation stage.

[0021] This invention further refines the technical solution of the independent claims by precisely defining the technical features of the integrated crust-forming field propagation box, the arc-shaped protective cover structure, the water-retaining and slow-release filler material, afforestation assistance, and post-planting management. It achieves synergistic adaptation of each technical link and superimposed upgrades in technical effects, making the improvement in the field survival rate of Cryptogams in extremely arid sandy areas more significant and stable. Firstly, the limitation on the planting depth and ground exposure height of the arc-shaped protective cover balances the windbreak and sand-fixing stability of the propagation box with the protection range of the inoculation material. The row spacing is designed based on the rainfall or crust formation time in the area to be treated, allowing the arrangement of the propagation boxes to be more adapted to the environmental characteristics of different sandy areas, achieving site-specific protective effects. Secondly, the design of the honeycomb-shaped inner wall, arc-shaped grooves, and through-hole structure of the arc-shaped protective cover further optimizes the protective and water-retention performance of the breeding box. The honeycomb-shaped inner wall enhances the adsorption of air moisture and increases air circulation, while the arc-shaped grooves effectively collect rainwater from the outside of the sand barrier and guide the water into the box through the through-holes, increasing the water content of the effective area, supplementing the inoculation material with natural water sources, alleviating the water scarcity problem in extremely arid sandy areas, and making the micro-habitat improvement effect of the breeding box more prominent. Thirdly, the water-retaining slow-release filler is limited to a composite water-retaining agent material based on cotton stalk cellulose. This filler not only has excellent water retention and slow water release performance, continuously providing moisture support for the inoculation material, but also realizes the resource utilization of agricultural straw. Its decomposition products will not cause secondary pollution to the sandy area, combining ecological, economic, and environmental value. It works synergistically with the structural design of the breeding box to further improve water use efficiency. Fourth, the standardization of afforestation auxiliary links makes the auxiliary propagation effect of shrub afforestation more significant. The implementation of the national standard GB / T 51085 afforestation technology ensures the survival rate of shrub planting. The selection of special crown-shaped sandy shrub varieties with dense canopies and elliptical or equilateral triangular crowns can maximize the windbreak and sand fixation function of shrubs and avoid adverse effects such as competition for light and nutrients for the propagation of cryptogamic plants. The strict management requirements before the formation of biological soil crust effectively avoid human interference with the inoculation material and shrub growth, and ensure the technical effect of early cultivation and planting. Fifth, the precise definition of water replenishment methods and amounts during the dry season addresses the environmental characteristics of water scarcity in extremely arid sandy areas. Differentiated water replenishment for shrubs and inoculation materials is achieved, with irrigation and sprinkler irrigation methods adapted to the growth needs of shrubs and cryptogamic inoculation materials, respectively. The precise water replenishment not only meets the water requirements of both but also avoids water waste, effectively improving the survival rate of cryptogamic plants and shrubs after construction in the dry season. This allows the synergistic system of propagation boxes, inoculation materials, and shrub afforestation to function stably during the dry season, further enhancing the adaptability and application effect of this invention in extremely arid sandy areas. Attached Figure Description

[0022] Figure 1 A schematic diagram of the layout of a fusion-type crust field breeding box.

[0023] Figure 2 This is a schematic diagram of the construction of a fusion-type crust field breeding box.

[0024] Figure 3 This is a schematic diagram of the structure of a fusion-type crust field breeding box.

[0025] In the attached diagram: 11-arc-shaped protective cover; 12-first end; 13-second end; 14-first platform; 15-partition; 16-second platform; 17-through hole; 2-composite microbial cluster; 3-water-retaining slow-release filler. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] Definitions: Extremely arid sandy areas are defined as regions with an aridity index (AI) below 0.05, meaning annual precipitation is less than 5% of potential evapotranspiration.

[0028] This invention provides a method for effectively improving the survival rate of cryptogams in the wild in extremely arid sandy areas, the specific steps of which are as follows: Step 1: Cultivation of inoculated materials.

[0029] To address the shortage of inoculation materials and the limited adaptation of single species such as algae, lichens, and mosses to harsh natural habitats, this invention proposes the construction of a crust nursery for large-scale production of inoculation materials. From the outset, a complex microbial community is cultivated within the crust nursery. The seed source for this community is the crust of cryptogams (lichens or mosses) collected locally from the desertification control area, leveraging a multi-species synergistic resistance model. Furthermore, measures such as propagation and crust hardening within the crust nursery enhance the resilience of the inoculation materials, laying a solid material foundation for the later survival of the complex microbial community in the wild. Key points include: 1) Construction of the Crust Cultivation Nursery. The crust cultivation nursery should be located in a place with convenient transportation, sufficient labor, and access to water and electricity. It should generally be equipped with ventilation and shading facilities. The size of the nursery area depends on the required amount of complex microbial communities and the cultivation system. The nursery should be situated on flat terrain with good drainage; the groundwater level should not exceed 1.5m; the soil layer should generally be at least 50cm thick; and the soil should be slightly acidic to slightly alkaline sandy loam, loam, or clay loam. The nursery should have a shade structure. The height of the shade structure should be 2.5~4m, and the shade structure should not obstruct ventilation.

[0030] 2) Management of the crust bed. Deep tillage and thorough preparation are required, removing weeds, stones, and ensuring the soil is level and broken up. In autumn (winter), tillage depth should be at least 25cm. In areas without snow accumulation in winter, harrowing should be done immediately after tilling. In areas with moist soil, heavy clay soil, or snow accumulation in winter, the crust bed must be prepared before cultivating the complex microbial community, including tilling, harrowing, leveling, and compaction. In areas with snow accumulation, harrowing is not necessary after tilling; harrowing should be done in early spring of the following year. In spring, tillage depth should be at least 20cm, followed by harrowing, leveling, and compaction. When preparing the soil, the width of the crust bed should be 1-2 times the length of the fusion-type crust field breeding box, and the bed surface should be approximately 20-30cm below the embankment. Before cultivating the complex microbial community, soil treatment methods such as chemical disinfection and soil burning should be used, depending on the specific circumstances. For commonly used soil treatment agents, refer to the "Gansu Province Forest Tree Seedling Cultivation Technical Regulations" (DB62 / T1 91-92). After compaction, lay a culture medium on the crust bed. The substrate can be plant fiber materials such as non-woven fabric or burlap, or a special substrate. Spread a layer of pure sand on the culture medium, with a thickness of 0.5cm to 1cm. Then, mix and crush the seed source, evenly spread it on the substrate, and compact it. The first seed source can be collected from the wild. When collecting inoculation material seed sources in the wild, it is generally advisable to follow the principle of proximity to the sand-affected area, selecting crusts at the lichen or moss stage for collection. Subsequent inoculation material seed sources cultivated in the crust nursery should be retained; it is not advisable to collect inoculation seed sources from the wild again.

[0031] 3) Work Method. The work method is ridge planting. The ridge surface should be 5-15cm lower than the ridge edge, 60-80cm wide, 3-5m long, and the ridge edge 30cm wide. The ridge should be prepared before sowing. The soil particles should be finely broken and the surface should be flat.

[0032] 4) Inoculation and Cultivation. Inoculation site selection: The site should be located in a production area with good soil quality, convenient irrigation, good drainage, and easy management. There are no special requirements for the inoculation period, but in Northwest China, spring is preferable. Inoculation can begin when the soil temperature at a depth of 5cm stabilizes at around 10℃. The inoculation rate is determined based on the quality of the seed material, generally using 0.05~0.15 kg / m³. 2 .

[0033] 5) Inoculation method. Broadcasting is used. After broadcasting, the seedbed should be compacted, and water should be sprayed immediately after compaction. The amount of water should be just enough to moisten the seedbed after spraying.

[0034] 6) Seedling management. After inoculation, shading should be provided daily from 10:00 to 17:30, depending on the specific circumstances. During cold seasons, measures should be taken to warm and moisturize the seedbed. This can be achieved by covering it with plastic film, with the film height preferably 10-15cm.

[0035] 7) Fertilization. During the seedling stage, fertilization should primarily use specialized microbial green manure. Compost, manure, oilseed cake, and human excrement can be applied as needed, but these must be fully decomposed before application. During fertilization, soil pH should be measured regularly to ensure it is below 6. To adjust the proportions of various nutrients, inorganic phosphorus and potassium fertilizers and a small amount of inorganic nitrogen fertilizer can also be applied. The first basal fertilizer application should be combined with inoculation, with the fertilizer evenly mixed with the seed source and broadcast. The dosage of specialized microbial green manure is 0.2~0.4 kg / m². 2 Topdressing is also done by diluting the fertilizer with water and spraying it evenly onto the crust bed. The frequency, timing, type, and amount of topdressing are determined based on the growth needs of the inoculated material and soil fertility.

[0036] 8) Watering. Watering during the seedling stage is divided into two phases. The first phase is within half a month after inoculation, and watering is done by spraying. The total watering time per day should not be less than 2 hours, preferably 3-5 hours; the total water volume per day should not be less than 0.5 kg / m³. 2 The appropriate value is 1.5~2 kg / m³. 2 The second stage, from half a month after inoculation until the crusting process, continues with watering by spraying, with a cumulative watering time of 2-3 hours per day and a cumulative watering volume of 0.1-0.5 kg / m³ per day. 2 .

[0037] 9) Strengthening the inoculum. Strengthening the inoculum means simulating natural adverse conditions by slightly restricting its nutrients and water supply, enabling it to develop some drought and poor soil tolerance, thus improving its resilience in the wild. Specifically, after the inoculum has grown to a certain stage (generally 30 days before transplanting), the shade structure can be gradually removed (this should not be done too quickly, about a week is ideal). The watering frequency is reduced twice, to once a week (the first stage is 30-16 days before transplanting, watering frequency is reduced to once every three days; the second stage is 15 days before transplanting to the day of transplanting, watering frequency is reduced to once every seven days). Each watering should be 0.1~0.5 kg / m³. 2 Measures such as stopping fertilization were taken to ultimately make the conditions of the bark nursery as close as possible to natural adversity.

[0038] 10) Crust Survey and Removal from the Crust. The removal of inoculated materials should be coordinated with the sand-fixing season. When removing the inoculated materials, peel them off one strip at a time from the crust bed, stacking them evenly. There are no specific requirements for the number of layers; the key is to facilitate the work. After removal, the inoculated materials should be transported promptly, ensuring good ventilation during transport. Avoid water loss and direct sunlight during transport to prevent the inoculated materials from overheating and drying out; watering may be necessary in some cases.

[0039] Step 2: Laying inoculation materials in the field To address the shortcomings of existing technologies, such as the lack of facilities for assisting inoculation material development in the field and the limited protective effects, this invention develops an integrated crust-forming field propagation box. This significantly improves the micro-habitat, alleviates environmental stresses such as extreme drought, high temperature, and severe cold, and provides a sheltered environment for cryptogams. Furthermore, addressing the limitations of traditional artificial cultivation methods for cryptogams (algae, lichens, mosses) that are simplistic and inefficient in forming complete biological soil crusts, this invention proposes an integrated field inoculation technology combining a composite microbial community and an integrated crust-forming field propagation box. This achieves synergistic adaptation of inoculation materials, protective facilities, and inoculation processes, significantly improving the survival rate of cryptogams in arid sandy areas, especially extremely arid sandy areas. Key points include: 1) Setting up auxiliary facilities.

[0040] The auxiliary facilities use integrated crust-type field breeding boxes, such as... Figure 3 As shown, a hybrid crust-forming field breeding box includes an arc-shaped protective cover 11. The first end 12 of the arc-shaped protective cover 11 is higher than the second end 13. The bottom end of the second end 13 can be inserted into quicksand. When set up, two adjacent arc-shaped protective covers 11 are placed side by side and close to each other to form a strip-shaped barrier that can block wind and sand flow. A first platform 14 is horizontally set on the inner wall of the arc-shaped protective cover 11 facing the desert. The first platform 14 is used to inoculate a composite microbial cluster 2. The composite microbial cluster 2 is inoculated on the first platform 14 as a seed source for crust formation and cultivation. The arc-shaped protective cover 11 can protect the composite microbial cluster 2, preventing the crust from being directly exposed to light and reducing the rate of water loss. Therefore, it can improve the survival rate of the crust. By improving the survival rate of the crust, the control effect is improved. In addition, the hybrid crust-forming field breeding box itself, when laid on the desert surface, can also play a certain role in sand prevention. Combined with crust control, the control effect is further improved.

[0041] A baffle 15 is provided on the inner wall of the arc-shaped protective cover 11 near the inner ring end 12. By setting the baffle 15, the water evaporated by the composite microbial cluster 2 on the first platform 14 can be blocked, so that the steam can flow back into the first platform 14, thereby reducing the rate of water loss from the crust. It can also prevent severe weather such as wind and sand from directly impacting the crust to a certain extent. The baffle 15 can further improve the survival rate of the crust and further improve the prevention and control effect.

[0042] The inner wall of the arc-shaped protective cover 11 is provided with a second platform 16, which is located below the first platform 14. A water-retaining and slow-release packing 3 is placed on the second platform 16. By setting the water-retaining and slow-release packing 3, water can be absorbed and slowly released to meet the growth needs of the composite microbial cluster 2.

[0043] A further improvement involves carving an arc-shaped groove 7cm below the ground edge of the arc-shaped protective cover 11. A hole is made in the center of the groove, perpendicular to the arc-shaped protective cover 11, connecting to the interior. This hole collects rainwater from the surface of the arc-shaped protective cover 11 during rainfall and replenishes the interior through the small hole. The entire upper part of the groove in the arc-shaped protective cover 11 has an arc-shaped structure, with the lowest point being the newly opened hole, facilitating rainwater collection.

[0044] Further improvements include: adopting a honeycomb structure on the inner wall of the arc-shaped protective cover 11, which increases the contact area between the inner wall and the air, and serves to collect condensed water in the air at night and in the early morning, and replenish the water required by the complex microbial cluster during the day.

[0045] Further improvements include: the water-retaining slow-release filler can be configured as the cotton straw cellulose composite water-retaining agent material provided in patent application CN115948168A, which maintains the moisture required for crust growth through its own water absorption, water retention, and water release processes; in addition, other conventional water-retaining slow-release fillers capable of water absorption, water retention, and water release can also be used.

[0046] like Figure 1 As shown, the fusion-type crust-forming field breeding boxes are set up in rows and columns on shifting sand. When setting them up, the convex side of the arc-shaped protective cover 11 faces the wind direction to protect the complex microbial clusters inside the breeding box. The lower end of the arc-shaped protective cover 11 is planted into the shifting sand at a depth of 5cm-8cm, with 12cm-15cm protruding above the ground, effectively intercepting near-surface windblown sand. The row spacing of the breeding boxes is determined according to the specific climatic characteristics of the area to be treated. In areas with high rainfall, the row spacing can be appropriately increased, while in areas with low rainfall, the row spacing should be appropriately decreased. In areas on the southeastern edge of the Badain Jaran Desert with an annual rainfall of 110mm, a row spacing of 1m-1.5m is recommended. For every 50mm increase (decrease) in annual rainfall, the row spacing should be increased (decrease) by 50cm. Furthermore, the row spacing should be designed according to the planned crust formation time; the shorter the required time, the smaller the row spacing. The southeastern edge of the Badain Jaran Desert requires 3-5 years for the biological soil crust to form. The row spacing should be 1-1.5 meters. For every year the formation period increases (decreases), the row spacing of the breeding boxes should increase (decrease) by 50cm. Specific construction details are as follows... Figure 2 As shown.

[0047] 2) Inoculation Material Laying. Lay the inoculation material of the composite microbial community cultured in the crust nursery in step one into the first platform of the prepared fusion-type crust field propagation box. Lay one strip of inoculation material inside each propagation box. Handle the inoculation material gently and avoid piling up too much material at once.

[0048] 3) Assisted Afforestation. After the fusion-type field propagation boxes and inoculation materials are laid out, afforestation (afforestation techniques shall be implemented in accordance with GB / T 51085—2015) is adopted to assist the propagation of cryptogamic plants. The special crown-shaped shrubs used generally need to have dense crowns and elliptical or equilateral triangular tree shapes. In the southeastern edge of the Badain Jaran Desert, shrubs such as Caragana korshinskii and Caragana sinica can be selected. The planting location is selected between the rows of the fusion-type field propagation boxes.

[0049] 4) Post-inoculation management. After inoculation and afforestation, during the dry season, it is necessary to replenish the water for the special crown-shaped shrubs and inoculation materials. The replenishment amount for the special crown-shaped shrubs is 1 kg / shrub, and the watering method is irrigation; the replenishment amount for the inoculation materials is 0.1~0.5 kg / m². 2 The irrigation method is sprinkler irrigation. After inoculation, before the biological soil crust forms, the desertification control area should be strictly managed, and all logging, grazing and other activities should be prohibited to prevent human damage.

[0050] Example 1 This embodiment uses the Minqin Xishawo area on the southeastern edge of the Badain Jaran Desert as the experimental area. Combined with a semi-controlled soil crusting experiment, it conducts field survival experiments of cryptogams and bio-soil crusting cultivation experiments to verify the practical application effect of the method of this invention in extremely arid sandy areas. The specific implementation process is as follows: 1. Basic experimental conditions 1.1 Test period: March 2023 - November 2025.

[0051] 1.2 Experimental Site: The Minqin Xishawo area on the southeastern edge of the Badain Jaran Desert was selected as the experimental site on the edge of a typical oasis in an extremely arid sandy area (the climate, soil and other environmental conditions of this area are highly consistent with the target application scenario of this invention, and have the core characteristics of extremely arid sandy areas such as barren soil, scarce rainfall, frequent sandstorms and large diurnal temperature differences, which can meet the requirements of this invention for the cultivation of inoculated materials and field survival rate test). The seed source of the inoculated materials was collected from the calyx nursery, which has the same environmental conditions as this experimental area.

[0052] 1.3 Experimental materials: Composite microbial communities (BSCA) treated with soil crust (BSCs), ordinary biological soil crusts (BSCs), Microcoleus vaginatus (MV), and Scytonemajavanicum (SJ). Microcoleus vaginatus was inoculated alone without the aid of a fusion-type soil crust field breeding box and biological shading method. Microcoleus vaginatus by no supplementary measures, MVu); single inoculation of Java pseudocladophyte without auxiliary fusion-type scab field breeding box + biological shading method ( Scytonema javanicumby nosupplementary measures, SJu); straight-pipe sprayer, micro-spray watering device, portable refrigerator, stainless steel circular sampler with inner diameter of 7.08mm, spectrophotometer, ethanol and other test reagents.

[0053] 1.4 Sandy substrate for the experiment: In the Xishawo area on the southeastern edge of the Badain Jaran Desert, the windward slope of a typical crescent-shaped exposed sand dune was selected. There was no vegetation on the surface and sand was flowing.

[0054] 2. Cultivation and Skin Formation of Inoculation Material Following the inoculation material cultivation method in step one of this invention, the construction of the crust nursery, management of the crust bed, inoculation cultivation, and crust hardening treatment are completed. The key operations are as follows: 2.1 Setting up the crust nursery and crust bed: The crust nursery is equipped with ventilation and shading devices, with a shading shed height of 3m; the crust bed is deeply tilled and finely prepared into raised beds, with the bed surface 10cm lower than the bed ridge, the bed width 70cm, the bed length 4m, and the bed ridge width 30cm; the bed surface is covered with non-woven fabric culture medium, and then covered with 0.8cm thick pure sand, and the soil is disinfected with chemicals.

[0055] 2.2 Inoculation and Cultivation: In spring, when the soil temperature at a depth of 5cm is stable at 10℃, sow the seeds by broadcasting at a rate of 0.1kg / m³. 2 After sowing, compact the seedbed; provide shade from 10:00 to 17:30 daily after inoculation; apply 0.3 kg / m² of special microbial green manure during the seedling stage. 2 As a base fertilizer, it can be combined with well-rotted compost as a top dressing to maintain the soil pH value below 6.

[0056] 2.3 Seedling watering: Water by spraying for 4 hours daily for the first half month after inoculation, at a rate of 1.8 kg / m². 2 From half a month after inoculation until the skin forms, spray water for 2.5 hours daily, with a watering rate of 0.3 kg / m². 2 .

[0057] 2.4 Bark Formation Treatment: Bark formation treatment should be carried out 30 days before transplanting, and the shade structure should be gradually removed weekly. From 30 to 16 days before transplanting, the watering frequency should be reduced to once every three days. From 15 days before transplanting to the day of transplanting, the watering frequency should be reduced to once every seven days, with a single watering volume of 0.3 kg / m³. 2 Fertilization was stopped throughout the process to simulate natural stress and enhance the resilience of the inoculum material. The final inoculum material obtained was a composite microbial community (BSCA) treated with soil crust formation. Simultaneously, dried algal strains of common biological soil crusts (BSCs), microsheathed algae (MV), and Javan pseudoclade algae (SJ) were prepared as controls. All algal strains were sourced from cultures preserved in the soil crust nursery and were not collected again from the field.

[0058] 3. Field inoculation trial and grouping 3.1 Experimental Groups: This experiment consists of six groups, divided into two categories.

[0059] The first category is the structural support group (four groups): BSCA, BSCs, MV, and SJ, all of which are laid in the fusion-type crust field breeding box, with Caragana korshinskii planted between the rows of the breeding box.

[0060] The second category is the unstructured auxiliary group (two groups): Microcoleiscus var. sheathii (MVu) and Microcoleiscus javanica (SJu) without auxiliary measures, which were directly inoculated on bare sand.

[0061] 3.2 The first type of inoculation was carried out in a fusion-type condylar field breeding box, as follows: 3.2.1 Deployment of the Integrated Crust Field Breeding Box: The breeding box adopts a protective cover structure with an arc-shaped groove and a honeycomb-shaped inner wall. The first platform of the protective cover is used to lay the inoculation material, and the second platform is used to place a composite water-retaining and slow-release filler based on cotton stalk cellulose. The arc-shaped groove and water holes at 7cm below the ground of the protective cover are used to collect rainwater, and the honeycomb-shaped inner wall is used to collect condensate. The partition is used to block water evaporation and reduce wind and sand impact. The integrated crust field breeding boxes of this invention are deployed in rows and columns in the test bare sand area. The arc side of the breeding box faces the prevailing wind direction, the bottom is embedded 6cm into the quicksand, and 13cm is exposed above the ground. Considering the annual rainfall of 110mm in the test area and the crust formation design time of 3-5 years, the row spacing of the breeding boxes is set to 1.2m.

[0062] 3.2.2 Preparation and Quantitative Inoculation of Inoculation Materials: The standard inoculation amounts of the four inoculation materials (BSCA, BSCs, MV, and SJ) were weighed according to the experimental design and laid in the first platform of the prepared fusion-type crust-forming field breeding box. One strip of inoculation material was laid inside each breeding box. The uniform inoculation amount was 12 μg·cm³. -2 .

[0063] 3.2.3 Auxiliary Afforestation Configuration: *Caragana korshinskii* shrubs (dense crown, elliptical tree shape) were planted between rows in the integrated bark-forming field propagation boxes. The afforestation techniques conformed to GB / T 51085—2015 standards. After planting, the *Caragana korshinskii* were irrigated with 1 kg of water per tree, and all inoculated materials were sprinkled with 0.3 kg of water per m². 2 .

[0064] 3.3 The second type of inoculation was carried out in the bare sand adjacent to the first type of structure-assisted test area, as follows: 3.3.1 Except for not using the fusion-type crust-forming field breeding box and not planting Caragana korshinskii, the surface characteristics, soil moisture content, and physical properties of the experimental area were completely consistent with those of the structure-assisted group experimental area.

[0065] 3.3.2 During inoculation, the standard inoculation amounts of both MVu and SJu materials were weighed according to the experimental design, crushed, and evenly spread on the surface of the quicksand. The mixture was then compacted using a tool, and immediately watered with a micro-sprayer. The watering amount was sufficient to moisten the surface. The uniform inoculation amount was 12 μg / cm³. -2 .

[0066] 3.4 Experimental Care: The first 30 days after inoculation were the artificial care phase. After 30 days, the experiment entered the natural acclimatization phase, during which artificial watering was stopped, and only experimental sampling was conducted. During the artificial care phase, watering was carried out using a micro-spraying method, with a uniform water volume of 1000 ml / m³. -2 Watering times are 8:00-8:30 AM, 11:30-12:00 PM, and 5:30-6:00 PM daily, with the specific watering frequencies as follows: (1) Days 1-10: Water daily; (2) Days 11-20: Water every other day; (3) Days 21-30: Water every 2 days.

[0067] 3.5 Post-planting management: After inoculation and afforestation are completed, human activities such as logging and grazing are strictly prohibited in the experimental area until the biological soil crust is formed.

[0068] 4. Biomass measurement and crust development characterization In this embodiment, the chlorophyll a content per unit volume of soil sample was used as the characterization index of the survival rate of cryptogams in the wild. Sampling and testing were carried out at 10 time points after inoculation: 0d, 1d, 4d, 7d, 10d, 13d, 16d, 21d, 26d, and 60d. Sampling continued for 60 days. The specific operation is as follows: 4.1 Sampling procedure: Sampling is carried out every morning from 7:30 to 8:00. Before collection, remove impurities such as dead branches and leaves, and animal feces from the ground. Peel off the crust completely, remove the attached loose soil and gravel with a brush, mix them, put them into a sterile bag, place them in a portable refrigerator, and quickly bring them back to the laboratory. At the same time, use a stainless steel circular sampler with an inner diameter of 7.08 mm to collect crust samples for the determination of chlorophyll a content.

[0069] 4.2 Chlorophyll a content detection: The chlorophyll a content was determined using the ethanol extraction method. The absorbance of the extract at 665 nm (A665) was measured under a spectrophotometer, and the chlorophyll a content was calculated using the following formula: Chlorophyll a (μg / cm) 2 = [11.9035 × ethanol volume (mL) × A665] / sampling area (cm²) 2 ) 4.3 Experimental Results: Chlorophyll a content (μg / cm³) at each time point for the six treatments (BSCA, BSCs, MV, SJ, MVu, SJu).2 The measurement results are shown in the table below: Chlorophyll a content in the bark of different inoculums (μg / cm) 2 Change Table

[0070] The experimental results of this embodiment show that in extremely arid sandy areas, the chlorophyll a content of the composite microbial community (BSCA) treated with the soil crust of this invention is much higher than that of single algal species (MV, SJ) and ordinary biological soil crusts (BSCs), and shows a continuous upward trend during the 60-day experimental period, reaching 24.29 μg / cm³ at 60 days. 2 It was significantly higher than other inoculums.

[0071] The above results demonstrate that the composite microbial community cultivated by this invention after undergoing crust formation treatment has stronger survival and growth capabilities in extremely arid sandy areas, and exhibits better crust formation.

[0072] Furthermore, on the third day of the experiment, a strong wind occurred in the experimental area. The inoculation material of the single algal species (MVu, SJu) experimental groups, which did not use the auxiliary fusion-type crust-forming field propagation box and the special canopy shrub afforestation protection, was blown away, causing the chlorophyll a content of these two experimental groups to be lower than the minimum detection unit from 4d to 60d, showing a value of 0. However, the chlorophyll a content of the composite microbial community (BSCA) cultivated by the crust-forming treatment of this invention + fusion-type crust-forming field propagation box + biological shading method was significantly higher than that of the single algal species (MVu, SJu) without the auxiliary fusion-type crust-forming field propagation box and the special canopy shrub afforestation protection during the 4d-60d period.

[0073] The above results demonstrate that the soil crust treatment, combined with the integrated soil crust field propagation box and biological shading method of this invention effectively solves the problems of wind and sand erosion, water scarcity, and drastic temperature differences in extremely arid sandy areas, providing a stable micro-habitat for cryptogams and significantly improving the survival rate of cryptogams in the wild. This proves that the method of this invention has good application effects in the cultivation of biological soil crusts in extremely arid sandy areas and can effectively promote the large-scale application of biological soil crust sand control technology.

Claims

1. A method for effectively improving the survival rate of cryptogams in the wild in extremely arid sandy areas, characterized in that, The specific steps are as follows: The inoculation material is obtained by: cultivating a complex microbial community in a crust nursery and subjecting it to crust hardening treatment before leaving the nursery to obtain the complex microbial community inoculation material for inoculation; the crust hardening treatment is to simulate natural stress conditions and to lightly interrupt the nutrient and water supply to the inoculation material; the seed source of the complex microbial community is the crust seed source of cryptogamic plants in the lichen or moss stage collected nearby in the desertification control area. The composite microbial cluster was propagated in the field using a fusion-type crust field propagation box. Specifically, the fusion-type crust field propagation boxes were arranged in a row-column pattern on quicksand. The fusion-type crust field propagation box included an arc-shaped protective cover (11). The arc-shaped protective cover (11) had a first platform (14) and a second platform (16) located below it. The lower end of the arc-shaped protective cover (11) was planted in the quicksand, and the protruding outer surface of the arc-shaped protective cover (11) faced the wind direction. The composite microbial cluster inoculation material was inoculated on the first platform (14), and water-retaining slow-release packing material (3) was placed in the second platform (16). The propagation of the composite microbial cluster inoculation material is assisted by a biological shading method, specifically by planting special crown-shaped shrubs in the interrow area of ​​the fusion-type crust field propagation box; The special crown-shaped shrubs are selected from sandy shrubs with dense crowns, and the crown shape is elliptical or equilateral triangle.

2. The method for effectively improving the survival rate of cryptogams in extremely arid sandy areas according to claim 1, characterized in that, The specific steps for obtaining the inoculation material for the composite microbial cluster are as follows: Select a slightly acidic to slightly alkaline sandy loam, loam, or clay loam soil with sufficient transportation, labor, water, and power sources, flat terrain, good drainage, groundwater level ≤1.5m, and soil layer thickness ≥50cm as the crusting nursery site. Construct a shade shed that does not obstruct ventilation in the crusting nursery site. The area of ​​the crusting nursery is determined according to the requirements of the complex microbial community and the tillage system. Divide the crusting nursery into crusting beds according to the ridge cultivation method, and prepare the soil until the soil particles are fine and the surface is flat. The crusting beds constitute the cultivation unit of the crusting bed. Deeply cultivate and refine the soil corresponding to the crust bed in the crust nursery, and remove grass roots and stones. The cultivation depth should be ≥25cm in autumn / winter and ≥20cm in spring. After cultivation, harrow, level and compact the soil in a timely manner according to the local snow accumulation. Before cultivation, disinfect the soil with chemicals or burn the soil. Lay a plant fiber substrate or special culture medium on the crust bed, and spread a 0.5cm~1cm thick layer of pure sand on the substrate. After crushing the composite microbial cluster, spread it evenly on the surface of the pure sand and compact and spray water. Inoculate when the soil temperature at a depth of 5cm is stable at about 10℃. After inoculation, the crust bed should be shaded during the day. During the cultivation period, special microbial green manure should be the main fertilizer. For the first base fertilizer, the special microbial green manure should be mixed with the compound microbial cluster and spread. The top dressing should be diluted with water and sprayed onto the crust bed. Fully decomposed organic fertilizer and a small amount of inorganic phosphorus, potassium and inorganic nitrogen fertilizer should be applied in combination. The soil pH should be kept <6 throughout the process. Water should be applied daily for half a month after inoculation. Thirty days before transplanting, the inoculated material after cultivation should undergo a hardening treatment. Specifically, the shade structure should be gradually removed within one week. From 30 to 16 days before transplanting, the watering frequency should be adjusted to once every 3 days. From 15 days before transplanting to the day of transplanting, the watering frequency should be adjusted to once every 7 days, with a single watering amount of 0.1 kg / m³. 2 ~0.5kg / m 2 Furthermore, fertilization was completely stopped throughout the process; After the crusting treatment, the inoculation material is transported out of the nursery according to the sand fixation season. Specifically, the inoculation material is peeled off one by one from the crust bed according to the culture medium and stacked evenly. After peeling, it is transported in a timely manner with ventilation, and water loss and sun exposure are avoided during transportation to obtain composite microbial cluster inoculation material.

3. The method for effectively improving the survival rate of cryptogams in extremely arid sandy areas according to claim 2, characterized in that, The surface of the crusted seedbed is 5cm to 15cm lower than the ridge, the seedbed is 60cm to 80cm wide, the seedbed is 3m to 5m long, and the ridge is 30cm wide. Before sowing, the crusted seedbed should be prepared until the soil particles are fine and the surface is flat. A shade shed with a height of 2.5m to 4m should be built in the crusted seedbed.

4. The method for effectively improving the survival rate of cryptogams in extremely arid sandy areas according to claim 2, characterized in that, The width of the crust bed should be 1-2 times the length of the fusion-type crust field breeding box, and the bed surface should be 20-30cm lower than the embankment. The composite microbial clusters should be crushed and evenly spread on the surface of pure sand and compacted. The inoculum amount is 0.05kg / m². 2 ~0.15kg / m 2 .

5. The method for effectively improving the survival rate of cryptogams in extremely arid sandy areas according to claim 2, characterized in that, Shade the crusting bed daily from 10:00 to 17:30 after inoculation. During cold seasons, use a plastic film 10-15cm high to warm and moisturize the crusting bed. The initial base fertilizer is 0.2kg / m². 2 ~0.4kg / m 2 The specialized microbial green manure is mixed with the compound microbial cluster and applied by broadcasting. For the first two weeks after inoculation, water daily using a spray system, for a cumulative total of 3-5 hours and a total water volume of 1.5 kg / m³. 2 ~2kg / m 2 From half a month after inoculation until the skin forms, spray for a total of 2-3 hours daily, with a total water volume of 0.1 kg / m². 2 ~0.5kg / m 2 .

6. The method for effectively improving the survival rate of cryptogams in extremely arid sandy areas according to claim 1, characterized in that, In the step of using afforestation to assist in the propagation of the composite microbial cluster inoculation material, the afforestation technology shall comply with the GB / T 51085 standard; before the formation of biological soil crust, the desertification control area shall be strictly managed and protected, and human-caused damage shall be prohibited.

7. A method for effectively improving the survival rate of cryptogams in extremely arid sandy areas according to claim 6, characterized in that, If inoculation and afforestation are completed during the dry season, the planted shrubs should be watered by irrigation at a rate of 1 kg / shrub; the watering rate for the composite microbial cluster inoculation material should be 0.1 kg / m³. 2 ~0.5kg / m 2 .

8. The method for effectively improving the survival rate of cryptogams in extremely arid sandy areas according to claim 1, characterized in that, The lower end of the arc-shaped protective cover (11) is planted in the quicksand at a depth of 5cm~8cm, with 12cm~15cm exposed above the ground; the spacing between rows of the fusion-type crust field breeding box is determined according to the rainfall or the time of crust formation in the area to be treated.

9. A method for effectively improving the survival rate of cryptogams in extremely arid sandy areas according to claim 1, characterized in that, The inner wall of the arc-shaped protective cover (11) has a honeycomb structure. An arc-shaped groove is engraved at the bottom edge of the arc-shaped protective cover (11). All areas above the groove have an arc-shaped structure. A through hole is opened at the lowest point of the groove along the vertical direction of the arc-shaped protective cover (11), connecting the inside and outside of the arc-shaped protective cover (11).

10. A method for effectively improving the survival rate of cryptogams in extremely arid sandy areas according to claim 1, characterized in that, The water-retaining slow-release filler is a composite water-retaining agent material based on cotton stalk cellulose.

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