Furrow type dry salt elimination system and method for dry land saline-alkali soil improvement

Abstract

The invention relates to the technical field of saline-alkali soil treatment and improvement, in particular to a furrow type dry salt elimination system and method for dry land saline-alkali soil improvement, the furrow type dry salt elimination system for dry land saline-alkali soil improvement comprises ridges and furrows which are alternately arranged, the slope surface of each ridge is constructed to form an included angle of 40-50 degrees with the ground plane, and the slope surface of each ridge is constructed to form an inclined angle of 40-50 degrees with the ground plane. A layer of hydrophilic covering material is laid on the surface of the ridge platform; according to the technical scheme, due to the fact that the ridge structure with the specific slope angle is adopted, the system actively creates an optimal directional path for soil water and salt migration, under driving of natural evaporation potential, salt in a plough layer can be efficiently and continuously guided and enriched in a hydrophilic covering material on the surface of the ridge, and the salt content of the plough layer can be effectively and continuously enriched. The core purpose of the method is to thoroughly remove the salt out of the soil body instead of only inhibiting surface aggregation or temporary leaching downward movement of the salt, so that the fundamental problem that the salt is not thoroughly removed by a traditional method is solved.

Description

Technical Field

[0001] This invention relates to the field of saline-alkali land management and improvement technology, and in particular to a furrow-type dry salt drainage system and method for improving dryland saline-alkali soil. Background Technology

[0002] Soil salinization is a major obstacle to sustainable agricultural development and ecological security worldwide. Traditional saline-alkali land improvement techniques mainly include water conservancy engineering measures, such as irrigation and salt leaching, and underground drainage; agricultural cultivation measures, such as deep plowing, land leveling, and fertilization; and chemical improvement measures, such as the application of gypsum and desulfurization byproducts.

[0003] While these technologies are effective under certain conditions, they generally have the following limitations: 1) High dependence on water resources: Irrigation and salt leaching require a large amount of fresh water, making them difficult to promote and apply in arid and water-scarce areas; 2) Complex engineering and high costs: For example, underground drainage systems require complex engineering design, laying and maintenance, resulting in high initial investment and long-term management costs; 3) Incomplete improvement or easy recurrence: Many methods only leach salt to the lower soil layer or temporarily inhibit its accumulation on the surface, failing to completely remove salt from the soil, posing a serious risk of seasonal salt return; 4) Potential for secondary environmental problems: Drainage and salt discharge can easily lead to salinization pollution of downstream water bodies.

[0004] Ridge cultivation, by creating raised beds and furrows in the field, aims to provide a relatively loose and well-drained growing environment for crop roots. Its salt-suppressing logic is mainly based on two aspects: first, by increasing the surface area and altering local hydrothermal conditions, it inhibits the migration of salt from the lower layers to the top of the ridges to a certain extent ("salt suppression"); second, during rainfall or irrigation, it is hoped that water will leach some of the salt from the topsoil downwards and drain it through the furrows ("salt removal"). However, this technology has inherent flaws: Limitations of the objectives and principles: Its primary objective is crop cultivation. The so-called "salt suppression" aims to create a temporary low-salt microenvironment in the crop root zone, rather than actively and completely removing salt from the soil. A large amount of salt remains inside and below the ridge, and can easily rise back up once conditions are suitable (such as strong evaporation), making it a passive response mode.

[0005] Salt removal is inefficient and requires stringent conditions: its limited salt removal effect is highly dependent on sufficient irrigation water or rainfall for downward leaching. In arid and semi-arid inland saline-alkali areas lacking stable water sources, this mechanism is essentially ineffective. Furthermore, the dispersed distribution of salts in the soil, lacking efficient physical pathways for accumulation in designated areas, makes any subsequent form of "salt removal" inefficient and costly.

[0006] The core problem with existing technologies, especially the closest traditional raised-ridge cultivation techniques, is that they have failed to fundamentally solve the key issue of "how to efficiently, cost-effectively, and completely remove salt from the soil." Summary of the Invention

[0007] In view of the problems of existing technologies described in the background section, especially traditional raised-ridge cultivation techniques, such as passive salt suppression, incomplete salt removal, reliance on irrigation water, and lack of precise control, this invention aims to provide a novel solution for saline-alkali land improvement. The technical problem this invention seeks to solve is: how to actively and efficiently separate and remove salt from the topsoil without relying on large amounts of freshwater leaching or constructing complex underground engineering projects, while simultaneously achieving water conservation, low cost, and controllability in the improvement process.

[0008] In view of this, the present invention provides a furrow-type dry salt drainage system for improving saline-alkali soil in dryland areas. The system comprises alternating ridges and furrows, with the slope of each ridge constructed at an angle of 40-50° to the ground plane. This specific angle design aims to optimize the synergistic relationship between soil capillary action and surface evaporation area, creating an optimal physical path for water and salt transport. Furthermore, a hydrophilic covering material is laid on the surface of the ridges. This covering layer not only enhances capillary water transport but also serves as a carrier for the accumulation of salts after evaporation and precipitation, providing a key interface for achieving salt "phase separation" and subsequent convenient removal.

[0009] Preferably, the thickness of the hydrophilic covering material is 2-5 cm.

[0010] Preferably, the hydrophilic covering material can be selected from natural fiber materials or synthetic hydrophilic nonwoven fabrics to achieve a good balance between water delivery performance and salt enrichment capacity.

[0011] Preferably, the height of the raised bed is set to 25cm to 35cm to adapt to different soil types and initial salinity conditions, ensuring sufficient space for salt accumulation.

[0012] As a further optimization, a salt-tolerant plant system can also be configured within the furrows. The transpiration of salt-tolerant plants helps regulate local moisture conditions, enhances evaporation drive, and can generate certain economic or ecological benefits.

[0013] Secondly, the present invention provides a dry salt drainage method for improving dry saline-alkali soil using the above-mentioned furrow-type dry salt drainage system.

[0014] The method includes the following steps: System construction steps: On the plot to be improved, construct the furrow-type dry salt drainage system as described above. Specifically, this may include preliminary land leveling, layout and positioning according to the design, using ridging machinery to create ridges with specific slope angles, and laying hydrophilic covering material on the surface of the ridges. Optionally, salt-tolerant plants may be sown or planted in the furrows.

[0015] System Operation and Monitoring Steps: After the system is constructed, driven by natural evaporation potential, soil moisture carrying soluble salts will be directionally transported to the ridge surface along optimized capillary paths. Moisture evaporates on or within the cover material, and salts precipitate and gradually accumulate. During this process, the salt content of the topsoil (e.g., the furrow area or a representative area of ​​the system) is monitored regularly, and its changes over time are recorded.

[0016] Termination Determination and Salt Removal Steps: Analyze the monitored soil salinity change curve. When the curve shows an inflection point where it changes from a continuous decline to an upward trend, this is scientifically determined to be the optimal termination point after the system's salt removal efficiency has reached its peak. At this time, remove the hydrophilic covering material that has accumulated a large amount of salt on the ridge surface, thereby achieving the physical stripping of salt from the soil. As a further improvement to this method, after salt removal, the plot can also be leveled to quickly restore it to a state suitable for conventional agricultural cultivation.

[0017] Compared with existing technologies, the technical solution of this invention, by employing a ridge structure with a specific slope angle, actively creates an optimal directional path for soil water and salt transport. This allows topsoil salts to be efficiently and continuously guided and enriched in the hydrophilic cover material on the ridge surface under the drive of natural evaporation potential. Its core purpose is to completely remove salts from the soil, rather than merely inhibiting their surface accumulation or temporary leaching downwards, thus solving the fundamental problem of incomplete salt removal in traditional methods. The entire salt enrichment process relies entirely on the driving force of natural evaporation; the system itself does not require irrigation water for leaching. Therefore, this technology is particularly suitable for arid and semi-arid saline-alkali areas with scarce freshwater, breaking through the limitations of traditional methods. The heavy reliance on water resources in traditional salt leaching methods greatly expands the applicability of the technology. The system of this invention only involves the structural modification of the surface micro-topography and the laying of covering materials, without the need for excavation, laying, and maintenance of expensive and complex underground drainage networks. This significantly reduces initial construction investment and long-term operation and maintenance costs, making the technology easier to promote and apply on a large scale in vast farmlands. By using the method defined in the claims, namely monitoring soil salinity dynamics and identifying the inflection point of its change curve to determine the termination time, the salt removal process is transformed from relying on experience-based judgment to data-driven scientific decision-making. This effectively avoids undertreatment or overtreatment, ensuring the high efficiency of the entire improvement process and the optimization of resource utilization.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of a furrow-type dry salt drainage system for improving saline-alkali soil in dryland, according to one embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the water and salt transport principle of a furrow-type dry salt drainage system for improving dryland saline-alkali soil according to one embodiment of the present invention. Figure 3 This is a schematic diagram of the dynamic salt content change curve of a furrow-type dry salt drainage method for improving saline-alkali soil in dryland, according to one embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: Detailed Implementation

[0021] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first," "second," "third," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0024] Implementation Method 1: Construction of a furrow-type dry salt drainage system This embodiment details the construction process of a furrow-type dry salt drainage system. The specific steps are as follows, which can be referred to... Figure 1 To understand: Site selection and pretreatment: Select a dryland site with moderate salinity and a soil electrical conductivity (ECe) of 8-15 dS / m to be improved. Remove large weeds and crop residues from the surface, and use a rotary tiller or plow to perform preliminary tillage and leveling to break up soil compaction and loosen the topsoil. In the above, soil electrical conductivity (ECe) refers to the electrical conductivity of the saturated soil paste extract.

[0025] Design and layout: Determine the orientation of ridge 1, generally recommending it to be perpendicular to or at an angle to the prevailing wind direction or terrain slope to optimize ventilation and drainage. Design the center-to-center spacing of ridge 1 to be 1.2 meters. Use lime powder or stakes and lines to clearly mark the center line of ridge 1 on the leveled land.

[0026] Shaping Ridge 1: Using a ridging machine with an adjustable forming plate, ridging is performed along the marked lines. Adjust the ridging machine to shape ridge 1 into an isosceles trapezoid with a cross-section of approximately 30 cm at the top and 80 cm at the bottom. The angle (α) between the slope of ridge 1 and the horizontal ground plane should be adjusted to 45°, and the vertical height (H) of ridge 1 should be controlled at 30 cm. Adjacent to this ridge, a furrow 2 with a width of approximately 40 cm is formed. After ridging, the slope of ridge 1 is lightly compacted and smoothed using a wooden board or a special scraper to ensure a flat surface and stable angle, facilitating continuous capillary rise of moisture.

[0027] Apply hydrophilic mulch material 3: Select corn stalks crushed to a length of 5cm-10cm as the natural fiber hydrophilic mulch material 3. Spread the stalks evenly over the entire surface of the ridge 1 (including the top and two slopes), with a thickness of approximately 3cm. When laying, ensure that the mulch layer is loose and permeable, without forming a dense, compacted layer, in order to maintain good capillary water absorption and evaporation surface area.

[0028] Optionally, a salt-tolerant plant system 4 can be configured: Shallow furrows are manually dug at the bottom of the formed ridges 2, and Suaeda salsa seeds are sown at a density of 20 cm row spacing and 15 cm plant spacing. After sowing, a thin layer of soil is covered and lightly pressed down. This step is an optimization step designed to utilize plant transpiration to assist in salt removal and provide biomass.

[0029] At this point, a complete furrow-type dry salt drainage system is constructed. When the system is running, soil water and salt will be transported along the optimized 45° slope capillary path to the top area of ​​ridge 1, driven by evaporation potential, and will eventually be enriched in the straw mulch layer.

[0030] Implementation Method 2: Dry Salt Removal Method This embodiment, in conjunction with the system constructed in Example 1, details the complete implementation process of the dry salt removal method of the present invention, which can be combined with... Figure 2 and Figure 3 To understand.

[0031] System runtime: Driving and Enrichment: After the system is constructed, it enters the natural operation phase. Under the influence of sunlight and wind, soil moisture continuously migrates to the surface of ridge 1, where the evaporation potential is stronger, through capillary action, carrying dissolved salts to the straw mulch layer. Moisture evaporates and dissipates in the mulch layer, while salts gradually crystallize and accumulate between the straw fibers.

[0032] Dynamic monitoring: On the first day after the system starts operating, select 3-5 representative monitoring points, typically located in the middle of furrow 2. Use a portable soil conductivity meter to measure the soil solution electrical conductivity (ECe) value of the 0cm to 20cm tillage layer. This value effectively reflects the soil salinity content. Thereafter, repeat the measurement at the same monitoring point every 7-10 days, recording the measurement date and the corresponding ECe value.

[0033] Data analysis and termination determination: Plot the change curve: Take a series of monitored ECe values, preferably the average of multiple measurements, as the vertical axis and time as the horizontal axis to plot the "soil salinity content-time" change curve.

[0034] Identifying inflection points: such as Figure 3 As shown, in the initial stage of operation, the curve typically shows a continuous downward trend as salt is continuously directed and "extracted" from the topsoil. With prolonged operation, when most of the easily migratable salts in the topsoil have been removed, and the high concentration in the salt-rich area of ​​ridge 1 may begin to have a slight salt diffusion and backflow effect on adjacent soils, the system's net salt removal efficiency reaches its peak and then begins to decline. At this point, the monitoring curve will show a clear "inflection point," meaning the curve changes from a downward trend to a stable state or begins to rise slowly.

[0035] Scientific decision-making: When the "inflection point" is identified, it can be scientifically determined as the optimal time to terminate the current desalination operation. For example, in Example 1, the curve shows an inflection point around day 42, so this time is selected for subsequent operations.

[0036] Salt removal and land restoration: Removal of salt-rich material: After determining the termination, use a shovel or small machinery to completely remove the straw mulch layer on the surface of ridge 1 that has accumulated a large amount of salt crystals, and transport it away from the field for harmless treatment or resource utilization. This operation directly removes most of the salt separated from the soil.

[0037] Leveling the land: Use a rotary tiller or leveling machinery to flatten the original ridge 1 and furrow 2 structure, so that the plot is restored to a roughly flat state.

[0038] Restoring cultivation: After leveling the land, it can be plowed and fertilized, and conventional crops such as wheat and corn can be sown directly, realizing a rapid conversion from saline-alkali land to normal arable land.

[0039] Implementation Method 3: Variation of System Parameters This embodiment aims to illustrate that, without departing from the core concept of the present invention, the key parameters of the system can be adjusted within a certain range to achieve the purpose of the present invention.

[0040] Variations in the angle of ridge 1: In sandy soils with weak capillary action, the slope angle of ridge 1 can be adjusted to 40° to increase the evaporation area and compensate for capillary driving force; in heavy clay soils, it can be adjusted to 50° to enhance the vertical component of capillary upward force. Experiments have shown that the directional salt drainage effect is significantly better than that of traditional flat or gently sloping ridges within the range of 40° to 50°.

[0041] Variations in covering materials: Hydrophilic covering material 3 can also be corn stalks, coconut coir, hydrophilically treated waste cotton fabrics, or non-woven fabrics. For example, using a layer of polyester hydrophilic non-woven fabric with a unit area weight of 150 g / m² (approximately equivalent thickness of 2 cm) can also effectively guide and enrich water and salt.

[0042] System size variations: For plots with extremely high salinity, the height of ridge 1 can be increased to 35 cm to provide greater salt accumulation capacity and a longer transport path. The width of furrow 2 can be adjusted from 30 cm to 60 cm depending on the type of salt-tolerant plants subsequently planted or field management needs.

[0043] Example 1 Construct raised beds 1 with a 45° slope, and cover the surface with a 3cm thick layer of corn stalks as a hydrophilic mulch material 3. No additional irrigation is required; the system operates solely on natural evaporation. Soil salinity is monitored regularly, and when the salinity curve shows an inflection point (a change from decreasing to increasing), indicating an inflection point, the system is terminated and the salt-rich mulch is removed around day 42.

[0044] Implementation results: Salt removal rate: After the operation was completed, the average ECe of the soil in the 0cm to 20cm topsoil layer dropped to 4.8 dS / m, and the salt removal rate reached 60%.

[0045] Water consumption: Zero irrigation throughout the entire process, relying solely on natural rainfall and initial soil moisture.

[0046] Improvement cycle: From construction to removal of cover and leveling of land, the total time is approximately 45 days.

[0047] Duration of effect: After planting conventional crops for one season following the improvement, monitoring showed that the salt return rate at the end of the season was less than 8%.

[0048] Example 2 Based on the system of Example 1, Suaeda salsa is planted in furrow 2. The rest is the same as in Example 1.

[0049] Implementation results: Salt removal rate: The average ECe in the topsoil decreased to 4.5 dS / m, with a removal rate of approximately 62.5%. Salt-tolerant plants generated additional water transport drive through transpiration.

[0050] Additional benefits: Harvesting Suaeda salsa biomass in saline-alkali land brings direct economic benefits of approximately RMB 1,800 per hectare, demonstrating the synergistic benefits of "improving while producing".

[0051] Comparative Example 1 The common form of traditional raised-ridge cultivation was adopted, with the slope angle of ridge 1 being approximately 20° (gentle slope). The surface of ridge 1 was covered with the same corn stalk mulch material. The cultivation was not based on inflection point criteria, but rather operated on a fixed cycle (60 days).

[0052] Implementation results: Salt removal rate: After 60 days of operation, the average ECe of the topsoil was 8.4 dS / m, with a removal rate of only 30%. The efficiency of salt directional enrichment was significantly lower than that at a slope angle of 45°, demonstrating that a specific steep slope angle is crucial for creating efficient water and salt transport pathways.

[0053] Results analysis: The gentle slope structure makes the direction of capillary action more vertical, and the lateral transport component is insufficient, which makes it impossible to efficiently "push" salt to the enrichment area at the top of the ridge.

[0054] Comparative Example 2 Construct ridges 1 with a 45° slope, but leave the surface of ridges 1 bare without any covering material. The operation and monitoring methods are the same as in Example 1.

[0055] Implementation results: Salt removal rate: When the inflection point appeared (around day 38), the average soil ECe dropped to 6.9 dS / m, with a removal rate of 42.5%.

[0056] Key issue: Salt precipitates directly on the soil surface, forming a salt crust, which hinders continuous water evaporation and further upward migration of salt, reducing enrichment efficiency. Simultaneously, salt crystallizes within the soil and cannot be removed entirely through simple physical methods, making subsequent desalination operations difficult and posing a high risk of salt return. This comparison demonstrates the necessity of a hydrophilic capping layer as a "removable salt collector."

[0057] Comparative Example 3 The system is the same as in Example 1, but instead of dynamic monitoring of salinity, it is evaluated after 60 days of system operation based on traditional experience.

[0058] Implementation results: The operation was terminated after 30 days: the soil salinity removal rate was 45%, the treatment was incomplete, and the premature termination meant that the potential was not fully realized.

[0059] The operation was terminated after 60 days: the soil salinity removal rate was 61%, which was comparable to the effect of Example 1, but it consumed 18 more days of ineffective operation time, which increased the time cost and the potential risk of excessive water evaporation.

[0060] Results analysis: This comparison highlights the outstanding value of scientific criteria based on the inflection point of the salinity change curve in achieving efficiency optimization, and avoids the waste of resources or insufficient results caused by empiricism.

[0061] Comparative Example 4 The most common method of salt leaching is used. After leveling the land, flood irrigation is carried out, with an irrigation volume of about 600 cubic meters per acre. This allows the water to seep down and leach the salt to deeper layers, and some of the leachate is discharged through excavated open ditches.

[0062] Implementation results: Salt removal rate: Seven days after irrigation, the salt content in the topsoil decreased significantly, with ECe dropping to approximately 5 dS / m.

[0063] Water consumption: The water consumption is enormous, making it difficult to implement in arid areas.

[0064] Main drawbacks: Severe salinization occurs; within 30 days after irrigation is stopped, due to evaporation and the upward flow of groundwater salts, ECe rises to over 9 dS / m, making the effect short-lived. Furthermore, digging drainage ditches damages the land, and drainage causes secondary pollution.

[0065] Comparative Example 5 Construct a gentle slope ridge 1 with a slope angle of 20° and a height of 30cm, and cover the surface with a 3cm thick layer of corn stalks. The operation and monitoring are the same as in Example 1.

[0066] Implementation results: Salt removal rate: When the salt curve reached an inflection point (around day 55), the average ECe of the soil in the 0cm to 20cm topsoil layer was 7.8 dS / m, with a removal rate of only 35%.

[0067] Results Analysis: A small slope angle resulted in a severe deficiency of the "lateral force" for the directional transport of water and salt. The capillary ascent path of water was closer to vertical, and a large amount of salt evaporated and precipitated in the lower part of the slope of ridge 1, failing to be efficiently "transported" to the enrichment area at the top of the ridge. Salt was dispersed and deposited within the soil, leading to: (1) low overall salt removal efficiency; (2) non-concentrated salt enrichment, making it impossible to remove effectively afterward; and (3) the easy formation of salt crusts on the slope, hindering subsequent water and salt transport. This result proves that when the slope angle is less than 40°, the system loses its core function of efficient "salt conduction-salt accumulation".

[0068] Comparative Example 6 Construct a steep slope ridge 1 with a slope angle of 60° and a height of 30cm, and lay the same covering layer on the surface.

[0069] Implementation results: Salt removal rate: Salt levels decreased rapidly in the early stages of operation (approximately 30 days), but the system was extremely unstable. Around the 35th day of operation, localized slope collapses occurred due to rainfall, damaging the system.

[0070] Results Analysis: While a large slope angle theoretically provides strong lateral capillary driving force, it severely compromises the physical stability of the structure. Steep slopes are highly susceptible to soil erosion and collapse under alternating wet and dry conditions, wind, or even minor disturbances, making it impossible for the system to operate continuously until its design life. Furthermore, an excessively large slope angle reduces the effective evaporation enrichment area per unit area. These results demonstrate that when the slope angle exceeds 50°, the system's engineering reliability and sustainable operation capability are significantly reduced, rendering it impractical for application.

[0071] Comparative Example 7 Construct a ridge 1 with a slope angle of 45°, but the height of the ridge 1 is only 15cm, and the surface is covered with a covering layer.

[0072] Implementation results: Salt removal rate: The inflection point appeared relatively early (around day 25), but the final average soil ECe only dropped to 6.3 dS / m, with a removal rate of about 47.5%.

[0073] Results Analysis: Insufficient height limits both "salt enrichment capacity" and "water-salt transport path length." Small ridge volume results in a limited initial amount of transportable water and salt. Once salt rapidly accumulates to saturation, the system fails, unable to adequately extract salt from deeper or wider areas. This is analogous to a "salt suction pump" with too small a capacity, stopping prematurely and resulting in incomplete improvement. This demonstrates that when the height is below 25cm, the system is ill-suited to address the improvement needs of moderately to severely saline-alkali soils.

[0074] Comparative Example 8 Construct a ridge 1 with a slope angle of 45°, increase the height of the ridge 1 to 40cm, and lay a covering layer on the surface.

[0075] Implementation results: Salt removal rate: When the operation reached the inflection point (around day 55), the average soil ECe dropped to 4.2 dS / m, with a removal rate of about 65%.

[0076] Results Analysis: Although the final desalination effect was slightly better than in Example 1, the marginal benefits diminished, and the cost increased significantly. The amount of earthwork and covering material used for ridging increased by more than 33% year-on-year, and the time required was longer, but the salt removal rate only improved by about 5 percentage points. Excessively high ridges may also affect field machinery operations. These results demonstrate that when the ridge height exceeds 35cm, the improvement in technical effect cannot offset the disproportionate increase in cost and workload, and from the perspective of economic efficiency, it is not the optimal choice.

[0077] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0078] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0079] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A furrow-type dry salt drainage system for improving saline-alkali soil in dryland areas, characterized in that, include: Alternating ridges (1) and furrows (2); The slope of the ridge (1) forms an angle of 40°-50° with the ground plane; The surface of the ridge (1) is covered with a layer of hydrophilic covering material (3).

2. The furrow-type dry salt drainage system according to claim 1, characterized in that, The thickness of the hydrophilic covering material (3) is 2 cm - 5 cm.

3. The furrow-type dry salt drainage system according to claim 1, characterized in that, The hydrophilic covering material (3) is a natural fiber material or a synthetic hydrophilic nonwoven fabric.

4. The furrow-type dry salt drainage system according to claim 1, characterized in that, The height of the ridge (1) is 25cm-35cm.

5. The furrow-type dry salt drainage system according to claim 1 or 2, characterized in that, The furrow (2) is equipped with a salt-tolerant plant system (4).

6. A dry desalination method for improving dry saline-alkali soil using the furrow-type dry desalination system according to any one of claims 1-5, characterized in that, Includes the following steps: S1. System Construction: Construct the furrow-type dry salt drainage system on the plot to be improved; S2. System operation and monitoring: The natural evaporation potential is used to drive the water in the soil to carry soluble salts to the surface of the ridge (1) and to accumulate them, while the salt content of the topsoil is monitored. S3. Termination determination and salt removal: When the monitored soil salt content change curve shows an inflection point from decreasing to increasing, it is determined as the time to terminate salt removal, and the hydrophilic covering material (3) enriched with salt on the surface of the ridge (1) is removed.

7. The dry salt removal method according to claim 6, characterized in that, In step S1, the system construction includes: after the land is initially leveled, the lines are laid out according to the design spacing, and a ridge machine is used to shape a ridge (1) with a slope angle of 40-50°. Then, the hydrophilic covering material (3) is evenly laid on the surface of the ridge (1).

8. The dry salt removal method according to claim 7, characterized in that, In step S1, salt-tolerant plants are sown or planted in the furrow (2) to form the salt-tolerant plant system.

9. The dry salt removal method according to claim 6, characterized in that, In step S2, the soil salinity content of the furrow (2) area or the representative area of ​​the system as a whole is monitored periodically using an electrical conductivity meter, and the change curve of soil salinity content over time is plotted.

10. The dry salt removal method according to claim 6, characterized in that, Step S3 is followed by step S4: leveling the land after removing the salt-rich cover material to restore it to a state suitable for conventional agricultural cultivation.

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