Windproof sand-fixing structure

Abstract

This invention relates to a windbreak and sand-fixing structure, comprising a water-retaining layer laid on the ground and a multi-functional board inclinedly inserted into the water-retaining layer. The water-retaining layer includes, from bottom to top, a biodegradable mulch film, a composite water-retaining layer, and a vegetation layer. The composite water-retaining layer includes, from bottom to top, a deep layer, a shallow layer, and a surface layer. A water-absorbing net is laid in the middle of the shallow layer. The multi-functional board is composed of a PPS board, water-passing holes, a light-blocking plate, a stainless steel pipe, and a support plate. The two ends of the water-absorbing net are connected to the SAF fiber water-absorbing cotton at the bottom of the stainless steel pipe by rope-like SAF fiber water-absorbing cotton. The multi-functional board is inclined northward into the sand, forming an angle of 40° to 60° with the ground. This windbreak and sand-fixing structure achieves the goal of vegetation restoration in desert areas by establishing a water-retaining layer, setting up an inclined multi-functional board, and inoculating vegetation in stages, providing favorable conditions for vegetation growth.

Description

Technical Field

[0001] This invention relates to the field of wind and sand control, and in particular to a windbreak and sand-fixing structure. Background Technology

[0002] Existing windbreak and sand-fixing technologies can be broadly categorized into three types: mechanical sand fixation, chemical sand fixation, and biological sand fixation. Mechanical sand fixation primarily involves setting up sand barriers or covering the sand surface through methods such as stabilization, obstruction, transport, and guidance to reduce or eliminate wind and sand hazards. Common methods include setting up sand barriers, building three-dimensional fences, and laying fiber netting. While mechanical sand fixation is highly effective, it is costly, consumes significant human resources, and has a limited lifespan, making it suitable only as a temporary sand control measure in severely desertified areas. Chemical sand fixation refers to using chemical materials and processes to construct a solidified layer on the ground surface that prevents wind erosion while retaining moisture and improving the properties of the sand, thereby controlling and improving the sandy environment. Initially, chemical sand-fixing agents were mainly asphalt emulsions. With technological advancements, various high-molecular polymers have emerged. However, these inorganic materials generally have poor vegetation growth properties. Therefore, more research has focused on the development and improvement of organic chemical sand-fixing agents. Biological sand fixation is the most effective means of sand fixation, which aims to prevent desertification, stabilize oases, and improve the environmental quality and production potential of sandy areas through enclosure and planting. However, the types of sand-fixing plants are limited, their growth cycle is long, and they have high requirements for soil conditions. Direct planting of sand-fixing plants often fails to achieve survival, resulting in a waste of resources.

[0003] In recent years, researchers both at home and abroad have conducted extensive studies on microbial soil modification. Currently, the main method for applying microorganisms to the remediation of desertified soils is to utilize the biological crust formed by spore-bearing plant groups such as bacteria, fungi, algae, and mosses with the soil to stabilize the soil, thereby reducing wind erosion and dust particle production. It can also affect soil temperature, promote the input of soil carbon and nitrogen into the ecosystem, and provide favorable conditions for plant germination and establishment.

[0004] However, due to the high ultraviolet radiation, low rainfall, and high evaporation rates in most desertified areas, the soil salinity is excessively high, severely limiting biological activity. The formation of a fully functional biological crust is estimated to take at least several decades. Therefore, the appropriate materials or methods to achieve this in practical applications remain a subject requiring further research. Summary of the Invention

[0005] This invention addresses the challenge of sand fixation in wind-blown sandy areas by proposing a comprehensive sand-fixing structure integrating physical, chemical, and biological methods. First, the structure modifies the sandy land by adding water-retaining structures to prevent water infiltration. Simultaneously, water-retaining components and pH buffers are added to increase organic matter content, enhance the water retention capacity of the sandy soil, and maintain the acid-base balance of the plant growth environment. Second, replaceable, tilted, multi-functional panels are installed to collect water for initial plant growth, block sunlight, reduce UV damage, and decrease water evaporation, while also contributing to sand fixation and preventing burial by shifting sands. Finally, a vegetation-based sand-fixing agent is sprayed in three stages: algae, shallow-rooted plants, and deep-rooted plants, gradually improving soil conditions and achieving the goal of plant-based sand fixation.

[0006] To achieve the above objectives, this invention provides a windbreak and sand-fixing structure, comprising a water-retaining layer laid on the ground and a multifunctional board inclinedly inserted into the water-retaining layer. The water-retaining layer comprises, from bottom to top, a biodegradable mulch film, a composite water-retaining layer, and a vegetation layer. The composite water-retaining layer comprises, from bottom to top, a deep layer at a depth of 20-30 cm, a shallow layer at a depth of 0-20 cm, and a surface layer above the ground. A water-absorbing net is laid in the middle of the shallow layer, and the water-absorbing net is made of SAF fiber water-absorbing cotton with a mesh size of 25cm*25cm. The vegetation layer selects *Micrococcus septemlobus* and *Bryophytum esculentum* as initial sand-fixing plants. The multifunctional board is composed of PPS board and a water-absorbing material. The PPS board consists of a hole, a light-shielding plate, a stainless steel pipe, and a support plate. The PPS board has a continuous groove in the middle and hollow pipes on both sides with a bottom length greater than the middle. Water passage holes are staggered on the groove. The support plate is vertically welded to the upper part of the stainless steel pipe. The lower end of the hollow pipe is inserted into the stainless steel pipe. The bottom end of the stainless steel pipe is filled with SAF fiber absorbent cotton. The two ends of the absorbent net are connected to the SAF fiber absorbent cotton at the bottom of the stainless steel pipe through rope-like SAF fiber absorbent cotton. The light-shielding plate is set below and behind the water passage holes of the PPS board. The groove side of the PPS board is installed opposite to the support plate, with the groove surface facing south. The multi-functional board is inserted into the sand at a northward angle, forming an angle of 40° to 60° with the ground.

[0007] Preferably, the biodegradable mulch film is a polylactic acid film laid 30 cm below the ground.

[0008] Preferably, the composite water-retaining layer is formed by backfilling in layers after mixing biochar, organic-inorganic composite water-retaining agent and sand in a certain proportion, wherein the biochar is made by mixing biochar base material and pH buffer solution in a 5:1 ratio.

[0009] Preferably, the shallow layer contains biochar and organic-inorganic composite water-retaining agent at mass ratios of 1% and 0.4% respectively, and the surface layer is an organic-inorganic composite water-retaining agent layer sprayed onto the sand surface at a dosage of 30-60 kg / hm². 2 .

[0010] Preferably, the biochar base material is made from garden waste; the pH buffer solution is 4-hydroxyethylpiperazine ethanesulfonic acid buffer solution with an effective pH range of 6.8 to 8.2; the organic-inorganic composite water-retaining agent is a humic acid-acrylic acid-attapulgite water-retaining agent with a pH range of 6 to 8.

[0011] Preferably, the planting step of the vegetation layer includes:

[0012] Gametophytes of Microcoleopterus xanthoides and Bryophytum esculentum were expanded in BG11 medium and CT medium, respectively.

[0013] The gametophytes of the moss were mixed with the sheathed microsheath algae at a dry weight ratio of 1:8.

[0014] Garden waste was converted into wood pulp using a mechanical pulping method. 0.3–1.0 mg / L of 6-BA plant growth regulator was added to each ton of wood pulp. This pulp was then mixed with an algae-moss culture solution and sprayed onto the composite water-retaining layer, resulting in a coating thickness of 3–5 mm after drying. The inoculum amount of *Micrococcus sheathiensis* and *Bryophytum esculentum* was 1000 mg·DW / m³. 2 ;

[0015] After the biological crust has fully formed, select the seeds of local dominant herbaceous plants, mix them with wood pulp, and spray the mixture onto the surface. After the crust has formed, spray water in the early stages to promote seed germination.

[0016] Preferably, the PPS board is 1m long, 1.1m high, and 1-1.5cm thick; there are 2-3 water passage holes in each row, with a hole height of 3cm-5cm; the stainless steel pipe is 50cm high and has a pointed bottom.

[0017] Preferably, the multifunctional panels are laid in rows from east to west, and the angle between the multifunctional panels and the bottom surface is chosen to be as perpendicular as possible to the local solar altitude angle on the summer solstice.

[0018] Preferably, the interval between each row of multifunctional panels in the north-south direction is 1m, and the width of the light-shielding panel is 1.5 times the height of the water passage hole.

[0019] Preferably, shallow-rooted plants are inoculated when the biocrust coverage in the vegetation layer is >90%, the biomass of the biocrust is >2.0 mg / kg, and the biocrust thickness is >4 mm.

[0020] Deep-rooted plants should only be planted when the soil conditions meet the requirements.

[0021] Based on the above technical solution, the advantages of the present invention are:

[0022] The windbreak and sand-fixing structure of this invention achieves the goal of vegetation restoration in desert areas by establishing a water-retaining layer, setting up inclined multi-functional panels, and inoculating plants in stages. The inoculation of plants is roughly divided into three stages: algae, shallow-rooted plants, and deep-rooted plants. During the inoculation and growth of different types of plants, the multi-functional panels and water-retaining layer structure are adjusted to maintain the plants. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0024] Figure 1 Schematic diagram of a windbreak and sand-fixing structure;

[0025] Figure 2 This is a schematic diagram of the water-retaining layer structure;

[0026] Figure 3 This is a schematic diagram of a water absorption net;

[0027] Figure 4 This is a schematic diagram of the multi-functional panel structure;

[0028] Figure 5 This is a side view of the multi-functional panel. Detailed Implementation

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0030] This invention provides a windbreak and sand-fixing structure, such as Figures 1-5 As shown, a preferred embodiment of the present invention is illustrated.

[0031] like Figure 1As shown, the windbreak and sand-fixing structure includes a water-retaining layer laid on the ground and a multi-functional board 9 inclinedly inserted into the water-retaining layer. The water-retaining layer includes, from bottom to top, a biodegradable mulch film 1, a composite water-retaining layer 2, and a vegetation layer 3. The composite water-retaining layer 2 includes, from bottom to top, a deep layer 4 at a depth of 20-30 cm, a shallow layer 5 at a depth of 0-20 cm, and a surface layer 6 above the ground. A water-absorbing net 7 is laid in the middle of the shallow layer 5. The water-absorbing net 7 is made of SAF fiber water-absorbing cotton 8 with a mesh size of 25cm*25cm. The vegetation layer 3 selects *Micrococcus septemlobus* and *Bryophytum comosum* as initial sand-fixing plants. The multi-functional board 9 consists of a PPS board 10, water-permeable holes 11, a light-blocking board 14, a stainless steel pipe 12, and... The PPS board 10 is composed of a support plate 13. The PPS board 10 has a continuous groove in the middle and hollow tubes on both sides with the bottom being longer than the middle. Water passage holes 11 are staggered on the groove. The support plate 13 is vertically welded to the upper part of the stainless steel tube 12. The lower end of the hollow tube is inserted into the stainless steel tube 12. The bottom end of the stainless steel tube 12 is filled with SAF fiber absorbent cotton 8. The two ends of the absorbent net 7 are connected to the SAF fiber absorbent cotton 8 at the bottom of the stainless steel tube 12 through rope-like SAF fiber absorbent cotton 8. The light-shielding plate 14 is set below the rear side of the water passage holes 11 of the PPS board 10. The groove side of the PPS board 10 is installed opposite to the support plate 13, with the groove surface facing south. The multi-functional plate 9 is inserted into the sand at a northward angle, forming an angle of 40° to 60° with the ground.

[0032] Biodegradable mulch film 1 is made of polylactic acid (PLA) and laid 30cm below the ground. Under normal room temperature and pressure conditions, PLA film degrades over several years, ensuring water retention in the early stages of sand fixation. In the later stages of sand fixation, due to better soil conditions and increased soil microbial content, the degradation of PLA film is accelerated.

[0033] The PLA membrane selected at the bottom of the water-retaining layer has a long degradation time under drought conditions, which can ensure water retention during the early growth of plants. At the same time, the final degradation products of this type of polymer are carbon dioxide and water, which will not have an impact on the environment.

[0034] The composite water-retaining layer 2 is formed by backfilling in layers after mixing biochar, organic-inorganic composite water-retaining agent and sand in a certain proportion. The biochar is made by mixing biochar base material and pH buffer in a 5:1 ratio to make biochar with pH buffering properties.

[0035] Preferably, in the shallow layer 5, the biochar and organic-inorganic composite water-retaining agent account for 1% and 0.4% of the sand by mass, respectively; in the top layer 5, the biochar and organic-inorganic composite water-retaining agent account for 1% and 0.6% of the sand by mass, respectively; and the surface layer is composed of organic-inorganic composite water-retaining agent. After backfilling the deep and shallow layers of sand, the organic-inorganic composite water-retaining agent is evenly spread on the surface layer at a rate of 30–60 kg / hm². 2 .

[0036] The biochar base is made from garden waste; the pH buffer is 4-hydroxyethylpiperazine ethanesulfonic acid buffer, with an effective pH range of 6.8–8.2; the organic-inorganic composite water-retaining agent is a humic acid-acrylic acid-attapulgite water-retaining agent, with a pH range of 6–8. The use of HEPES buffer adsorbed into the biochar solves the problem of excessively high pH levels in the environment being detrimental to microbial / plant growth, while also ensuring that the large temperature differences in the desert environment do not affect the effectiveness of the buffer, thus maintaining a stable pH value for a long time.

[0037] The biochar in the composite water-retaining layer is made from garden waste, realizing the resource utilization of waste and saving costs. At the same time, biochar is rich in nutrients such as N, P, K, Ca, and Mg, and has good water retention. When used in conjunction with water-retaining agents, it can improve the soil's water retention effect and provide favorable conditions for plant growth. The water-retaining agent content in the sandy soil decreases from top to bottom, which can stratify the water content and preferentially store water in the shallow layer for the initial use of algae and shallow-rooted plants.

[0038] For vegetation layer 3, *Microcoleus sheathus* and *Bryum dentatum* were selected as initial sand-fixing plants. Gametophytes of *Microcoleus sheathus* and *Bryum dentatum* were expanded on BG11 and CT media, respectively. The moss gametophytes were mixed with *Microcoleus sheathus* at a dry weight ratio of 1:8. Wood pulp was produced from garden waste using mechanical pulping technology. 0.3–1.0 mg / L of 6-BA plant growth regulator was added to each ton of wood pulp, and the mixture was then sprayed onto the composite water-retaining layer, ensuring a coating thickness of 3–5 mm after drying. The inoculum concentration of *Microcoleus sheathus* and *Bryum dentatum* was 1000 mg·DW / m². 2 Approximately [time period missing]. After the biological crust has fully formed, select seeds of local dominant herbaceous plants, mix them with wood pulp, and spray the mixture onto the surface. In the early stages after crust formation, spray with water appropriately to promote seed germination. Plant deep-rooted plants only after good soil conditions are achieved.

[0039] The gametophytes of algae and bryophytes were mixed with wood pulp and sprayed onto the pulp. The resulting crust after the pulp dried not only stabilized the shifting sand but also simplified the inoculation process. The addition of 6-BA plant growth regulator to the wood pulp further enhanced the stress resistance of desert algae, promoted their growth and chlorophyll synthesis, and accelerated the formation of biocrusts.

[0040] The multi-functional board 9 consists of a PPS board 10, water passage holes 11, a light-shielding plate 14, a stainless steel pipe 12, and a support plate 13, and serves the functions of water collection, light shading, windproofing, and sand fixation. The bottom end of the stainless steel pipe 12 is filled with absorbent fiber cotton and connected to the absorbent mesh 7 of the water-retaining layer.

[0041] like Figure 3 As shown, a water-absorbing net 7 made of SAF fiber absorbent cotton is laid in the middle of the shallow layer. The net size is 25cm*25cm. The two ends of the water-absorbing net 7 are connected to the multi-functional board 9 by rope-like SAF fiber absorbent cotton, which further diffuses the moisture and nutrient solution on the multi-functional board 9.

[0042] like Figure 4 , Figure 5 As shown, the main body of the multi-functional board 10 is made of PPS material. The main body is 1m long, 1.1m high, and 1-1.5cm thick. The center is grooved with staggered perforations forming drainage holes, 2-3 per row, with holes 3-5cm high, facilitating rainwater collection and even distribution to the ground. Both sides of the board are hollow tubes, approximately 20cm longer at the bottom than the grooved section, for insertion into the stainless steel tube 12 at the bottom. The stainless steel tube 12 has perforations at its bottom, connecting to the absorbent mesh 7, for dispersing the moisture / nutrients supplied through the hollow tube.

[0043] The multifunctional board body is made of PPS material with low water absorption, which can effectively collect rainwater and bring it to the ground. In addition, compared with natural materials, PPS board is also structurally stable, not easily deformed, and radiation resistant, making it suitable for long-term use in desert environments.

[0044] The installation of the multi-functional board is simplified by inserting stainless steel tubes, making it easier to disassemble and reinstall during periods when plants need sunlight. The stainless steel material also prevents corrosion, and its weight helps it hold firmly in the sand. Its connection to the water-absorbing net facilitates the replenishment of water and nutrient solution at the plant roots, improving the plant's utilization of water and nutrients.

[0045] The stainless steel pipe 12 has a main body height of 50cm and a pointed lower end for easy insertion into the ground. A 15-20cm long support plate 13, perpendicular to the pipe, is welded to the top of the pipe to reinforce the PPS board 10, resist wind force, and facilitate disassembly. The PPS board 10 is inserted into the soil to a depth of approximately 10cm, preventing the movement of surface sand and acting as a sand-fixing agent before a crust forms. The water passage holes 11 on the PPS board 10 reduce wind resistance. Since the wind direction in desert areas is predominantly northerly, a light-shielding plate 14 is placed below and behind the water passage holes 11 on the PPS board 10 to apply a downward force to the multi-functional board 9, preventing it from being blown over.

[0046] The PPS board 10 is installed opposite to the support board 13 on its grooved side, with the grooved surface facing south. The entire board is tilted northward and inserted into the sand about 40cm deep, forming an angle of 40° to 60° with the ground. The specific angle should be chosen to be as perpendicular as possible to the local summer solstice solar altitude angle. It is laid in rows from east to west. To ensure good shading effect, the spacing between each row of multi-functional boards 9 in the north-south direction is about 1m. A shading plate 14, 1.5 times the height of the drainage hole 11, is installed below and behind it to prevent direct sunlight from hitting the ground.

[0047] The multi-functional panels, placed at an angle, maximize the shading area, reducing ultraviolet radiation and water evaporation, thus protecting plant growth. Additionally, similar to vertical sand barriers, they act as windbreaks and sand stabilizers, preventing seedlings from being buried by sand.

[0048] The windbreak and sand-fixing structure of this invention achieves the goal of vegetation restoration in desert areas by establishing a water-retaining layer, setting up inclined multi-functional panels, and inoculating plants in stages. The inoculation of plants is roughly divided into three stages: algae, shallow-rooted plants, and deep-rooted plants. During the inoculation and growth of different types of plants, the multi-functional panels and water-retaining layer structure are adjusted to maintain the plants.

[0049] Algal growth stage: This windbreak and sand-fixing structure is constructed during the rainy season. While laying the mulch film, multi-functional panels are installed, and the composite water-retaining layer is constructed. The backfilled composite water-retaining layer is sprayed with water, followed by a spray of wood pulp containing gametophytes of *Micrococcus sheathii* and *Bryophytum dentatum*. During the initial drying and crusting stage of the wood pulp, appropriate watering is applied to keep the crust moist until the microalgae and moss sprout.

[0050] Shallow-rooted plants can be inoculated when the biocrust coverage is >90%, the biomass of the biocrust is >2.0 mg / kg, and the biocrust thickness is >4 mm.

[0051] Shallow-rooted plant stage: After the biological crust has fully formed, select local perennial herb seeds and mix them with wood pulp. Spray this mixture in spring, ensuring the wood pulp crust thickness does not exceed 1mm. Once the herbaceous plants have passed the seedling stage, remove the shade plate from the stainless steel pipe to allow the plants to receive sufficient sunlight. During the high temperatures of summer, insert the shade plate back into the stainless steel pipe to prevent sunburn. During the growth of shallow-rooted plants, nutrient solution can be added to the hollow tubes on both sides of the multi-functional board, depending on the plant's growth. The nutrients are then delivered to the plant roots via SAF fiber absorbent cotton and a water-absorbing net.

[0052] Deep-rooted plant stage: After obtaining good soil conditions, select drought-resistant woody plants for planting, and install water collection and shading boards for maintenance during the seedling stage.

[0053] This invention combines chemical sand fixation with physical sand fixation and plant sand fixation. The water-retaining agent and wood pulp used in the construction process not only have water-retaining effects, but also promote sand agglomeration, prevent sand movement, further strengthen the multifunctional board, and provide favorable conditions for vegetation growth.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A windbreak and sand-fixing structure, characterized in that: The system includes a water-retaining layer laid on the ground and a multi-functional board (9) inserted at an angle into the water-retaining layer. The water-retaining layer includes a biodegradable mulch film (1), a composite water-retaining layer (2), and a vegetation layer (3) arranged sequentially from bottom to top. The composite water-retaining layer (2) includes a deep layer (4) at a depth of 20-30cm underground, a shallow layer (5) at a depth of 0-20cm underground, and a surface layer (6) above the ground, arranged sequentially from bottom to top. A water-absorbing net (7) is laid in the middle of the shallow layer (5), and the water-absorbing net (7) has a mesh size of 25cm*25cm. The SAF fiber absorbent cotton (8) is laid out. The vegetation layer (3) selects *Micrococcus septemlobus* and *Bryophytum dentatum* as the initial sand-fixing plants. The composite water-retaining layer (2) is formed by mixing biochar, organic-inorganic composite water-retaining agent and sand in proportion and then backfilling in layers. The biochar is made by mixing biochar base material and pH buffer in a ratio of 5:

1. The multifunctional board (9) is composed of PPS board (10), water passage holes (11), light-shielding plate (14), stainless steel pipe (12) and support plate (13). The PPS board (10) has a continuous groove in the middle and hollow pipes on both sides with the bottom being longer than the middle. The groove has staggered water passage holes (11). The support plate (13) is vertically welded to the upper part of the stainless steel pipe (12). The lower end of the hollow pipe is inserted into the stainless steel pipe (12). The bottom end of the stainless steel pipe (12) is filled with SAF fiber absorbent cotton (8). The two ends of the absorbent net (7) are connected to the SAF fiber absorbent cotton (8) at the bottom of the stainless steel pipe (12) through rope-like SAF fiber absorbent cotton (8). The light shield (14) is set below the back side of the water passage hole (11) of the PPS plate (10). The groove side of the PPS plate (10) is installed opposite to the support plate (13), with the groove surface facing south. The multi-functional plate (9) is inserted into the sand at a northward angle to the ground, forming an angle of 40°~60°.

2. The windbreak and sand-fixing structure according to claim 1, characterized in that: The biodegradable mulch film (1) is a polylactic acid film laid 30cm below the ground.

3. The windbreak and sand-fixing structure according to claim 1, characterized in that: The mass ratio of biochar and organic-inorganic composite water retaining agent in the deep layer (4) is 1% and 0.4% respectively, the mass ratio of biochar and organic-inorganic composite water retaining agent in the shallow layer (5) is 1% and 0.6% respectively, and the surface layer (6) is a layer of sprayed organic-inorganic composite water retaining agent, with a dosage of 30-60 kg / hm 2 4. The windbreak and sand-fixing structure according to claim 1, characterized in that: The biochar base material is made from garden waste; the pH buffer solution is 4-hydroxyethylpiperazine ethanesulfonic acid buffer solution with an effective pH range of 6.8~8.2; the organic-inorganic composite water-retaining agent is a humic acid-acrylic acid-attapulgite water-retaining agent with a pH range of 6~8.

5. The windbreak and sand-fixing structure according to claim 1, characterized in that: The planting steps for the vegetation layer (3) include: Gametophytes of Microcolepidium and Rhizophora dentata were expanded in BG11 medium and CT medium, respectively. The gametophytes of the moss were mixed with the sheathed microsheath algae at a dry weight ratio of 1:

8. Garden waste is processed into wood pulp, and 0.3-1.0 mg / L of 6-BA plant growth regulator is added to each ton of wood pulp. This pulp is then mixed with an algae-moss culture solution and sprayed onto the composite water-retaining layer, resulting in a coating thickness of 3-5 mm after drying. The inoculation amount of *Micrococcus sheathiensis* and *Bryophytum esculentum* is 1000 mg·DW / m³. 2 ; After the biological crust has fully formed, select the seeds of local dominant herbaceous plants, mix them with wood pulp, and spray the mixture onto the surface. After the crust has formed, spray water in the early stages to promote seed germination.

6. The windbreak and sand-fixing structure according to claim 1, characterized in that: The PPS board (10) is 1m long, 1.1m high, and 1~1.5cm thick; there are 2~3 water passage holes (11) in each row, with a hole height of 3cm~5cm; the stainless steel pipe (12) is 50cm high and the lower end is made into a pointed shape.

7. The windbreak and sand-fixing structure according to claim 1, characterized in that: The multifunctional panels (9) are laid in rows from east to west, and the angle between the multifunctional panels (9) and the bottom surface is chosen to be perpendicular to the local solar altitude angle on the summer solstice.

8. The windbreak and sand-fixing structure according to claim 1, characterized in that: The interval between each row of multifunctional panels (9) in the north-south direction is 1m, and the width of the light-shielding plate (14) is 1.5 times the height of the water passage hole (11).

9. The windbreak and sand-fixing structure according to claim 5, characterized in that: When the biocrust coverage in the vegetation layer (3) is >90%, the biomass of the biocrust is >2.0 mg / kg, and the biocrust thickness is >4 mm, shallow-rooted plants are inoculated. Deep-rooted plants should only be planted when the soil conditions meet the requirements.

Images