Soil drainage structure for saline-alkali land and desert soil, and method for constructing same

Abstract

A soil drainage structure for saline-alkali land and desert soil, and a method for constructing same. The soil drainage structure blocks moisture infiltration and salt migration between a planting soil layer and a saline-alkali soil layer by introducing a water-retaining and breathable fabric as an isolation layer. The soil drainage structure has not only a superior water-retaining performance, but also good breathability, thereby supplying sufficient oxygen to plant roots and avoiding growth disorders caused by oxygen deficiency or salt accumulation. In addition, the construction process of the structure is simple and efficient. Surface soil is excavated according to a preset depth, and it is only necessary to spread a pre-cut water-retaining and breathable fabric inside each excavated pit and make same fit closely onto the pit wall; and finally the excavated pits are backfilled with soil, forming a planting soil layer suitable for plant growth. After said steps are completed, irrigation and planting operations can be directly performed, thereby greatly reducing construction difficulty and costs. Therefore, the present invention is particularly suitable for ecological restoration and agricultural development in saline-alkali land or desert areas.

Description

A soil drainage structure for saline-alkali land and desert soil and its construction method Technical Field

[0001] This invention belongs to the field of soil ecological improvement technology, specifically relating to a soil drainage structure and construction method for saline-alkali land and desert soil. Background Technology

[0002] Currently, in the process of soil improvement in saline-alkali land or desert areas, drainage measures are usually required to regulate the moisture and salinity content of the soil. Existing improvement methods mainly include traditional underground pipe drainage methods, gravel layer laying methods, and continuous waterproof layer laying, but these methods all have certain limitations.

[0003] (1) The underground pipeline drainage method guides excess water and salt to the surface by pre-burying drainage pipelines, thereby reducing the salt content of the topsoil. However, this method is complicated to construct, the pipeline is prone to blockage, and the later maintenance cost is high.

[0004] (2) Gravel layering method: A thick layer of gravel or sand is laid on the soil surface as an isolation zone to prevent rainwater from directly seeping into the high-salinity strata. Although this method can effectively block external water sources, it cannot fundamentally solve the salinization problem, and the construction and operation and maintenance costs are high.

[0005] (3) Although the method of continuously laying waterproof layers (such as plastic film) can quickly form an impermeable barrier in the short term and reduce the accumulation of salt caused by water evaporation, long-term use will hinder the gas exchange inside the soil, leading to oxygen deficiency at the bottom and thus affecting the normal development of plant roots.

[0006] The methods described above all have significant limitations in practical applications, especially in areas where farming patterns need to be frequently adjusted or where extreme climatic conditions are encountered. For example, traditional pipe drainage methods are not only complex to construct but also prone to damage; while completely sealed waterproofing treatments may lead to secondary salinization and crop growth obstacles. Furthermore, most commercially available soil conditioners focus on a single function and lack a comprehensive consideration of the changing patterns of soil properties, thus often failing to achieve the desired results in practical applications.

[0007] In summary, although existing methods can improve soil conditions to some extent, their limitations necessitate a solution that meets the needs of efficient and economical large-scale soil improvement. Summary of the Invention

[0008] To address the problems of complex construction, high construction and maintenance costs, and root hypoxia caused by hindered gas exchange in existing soil improvement technologies, this invention provides a soil drainage structure and its construction method for saline-alkali and desert soils. This soil drainage structure uses a structurally optimized water-retaining and breathable fabric as an isolation layer to effectively separate the planting soil layer from the saline-alkali soil layer, preventing water infiltration and salt migration between the two. Simultaneously, the water-retaining and breathable fabric has good air permeability, ensuring sufficient oxygen supply to plant roots and avoiding adverse effects on normal plant growth. Furthermore, the structure is simple to construct. Simply excavate the topsoil to a predetermined depth to form a pit, lay the pre-cut water-retaining and breathable fabric in the pit, ensuring it adheres tightly to the bottom, and then backfill the groove formed by the fabric to form the planting soil layer, ready for subsequent irrigation and planting.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A soil drainage structure for saline-alkali and desert soil includes: a plurality of water-retaining and breathable fabrics, a planting soil layer, and a saline-alkali soil layer; the edges of the water-retaining and breathable fabrics are folded upwards, and the fabric surface of the water-retaining and breathable fabrics is concave downwards to form a groove, the groove being used to hold the planting soil layer; the outer ends of the edges of the water-retaining and breathable fabrics are folded outwards to form folded edges, and there are gaps between adjacent folded edges for water infiltration; the saline-alkali soil layer is located below the groove, and the water-retaining and breathable fabrics are configured to allow gas to pass through while blocking the infiltration of water and the migration of salt between the planting soil layer and the saline-alkali soil layer.

[0011] In some embodiments, the width of the folded edge is 3-4 cm; and / or, adjacent folded edges at least partially overlap; and / or,

[0012] An adaptive gap adjustment element is provided at the gap to automatically adjust the rate of water infiltration; and / or,

[0013] Salt-absorbing material is filled between adjacent folded edges.

[0014] In some embodiments, the adaptive gap adjustment element is a humidity-responsive gel strip whose expansion rate is positively correlated with soil moisture and whose adjustment range is 0.2 to 1.2 cm.

[0015] In some embodiments, the water-retaining and breathable fabric is made of one or both of modified meltblown material and polypropylene.

[0016] In some embodiments, the groove has a U-shaped cross-section.

[0017] In some embodiments, the width of the water-retaining and breathable fabric is 2 to 6 m.

[0018] The present invention also provides a construction method for soil drainage structures in saline-alkali land and desert soil as described above, comprising the following steps:

[0019] For plots where water-retaining and breathable fabric needs to be laid, the surface soil is excavated to ensure that the predetermined laying depth is reached, forming a pit;

[0020] Based on the specific dimensions of the recess, select the appropriate size and quantity of the water-retaining and breathable fabric;

[0021] The selected water-retaining and breathable fabrics are laid in the recess: the fabric surface of the water-retaining and breathable fabric is laid on the bottom surface of the recess, and the edge of the water-retaining and breathable fabric is folded upward, and the fabric surface of the water-retaining and breathable fabric is recessed downward to form a groove. The bottom wall of the groove is in contact with the bottom surface of the recess. At the same time, the outer edge of the water-retaining and breathable fabric is folded outward to form the folded edge. Adjacent folded edges overlap at least partially and maintain a certain gap to allow water to seep in.

[0022] Soil is filled into the groove and irrigated to prepare for subsequent planting.

[0023] In some embodiments, the construction method further includes: after the water-retaining and breathable fabric is laid, checking the flatness of the laying and the tightness of the joints between adjacent water-retaining and breathable fabrics; if adjustments are needed, corresponding corrective measures should be implemented immediately to ensure the laying quality.

[0024] In some embodiments, the construction method further includes rinsing the laid water-retaining and breathable fabric to remove impurities from the fabric surface.

[0025] In some embodiments, the construction method further includes: regularly inspecting the water-retaining and breathable fabric; if any abnormality is found, identifying the cause and taking remedial measures; if the water-retaining and breathable fabric is damaged, replacing it with a new one in a timely manner.

[0026] Compared with existing technologies, the soil drainage structure and construction method for saline-alkali land and desert soil provided by this invention have the following beneficial effects:

[0027] 1. The soil drainage structure provided by the present invention uses a water-retaining and breathable cloth to isolate the planting soil layer and the saline-alkali soil layer, which can realize precise irrigation and fertilization, ensure that irrigation water and fertilizer are precisely applied to the planting soil layer, effectively prevent them from seeping into the lower soil layers, reduce resource waste, and at the same time, the structure also takes into account the gas exchange needs between the upper and lower soil layers. The water-retaining and breathable cloth can ensure that the plant roots can obtain sufficient oxygen and will not have an adverse effect on the normal growth of the plants.

[0028] 2. This invention incorporates dedicated water infiltration channels between adjacent water-retaining and breathable fabrics. In cases of excessive irrigation, these gaps play a crucial role, allowing excess water, along with dissolved minerals, to smoothly move downwards into the soil layer via natural permeability, thus completing the drainage process. Even in extreme situations of continuous soaking, excess water can drain smoothly through these gaps, effectively preventing waterlogging and ensuring the long-term reliability and stability of the drainage system. Simultaneously, humidity-responsive gel strips are embedded in the folded edges of the water-retaining and breathable fabrics. These gel strips allow the gap width between the folded edges to automatically adjust according to soil moisture within a range of 0.2–1.2 cm, dynamically optimizing the water infiltration rate and adapting to drainage needs under varying humidity conditions. Furthermore, modified zeolite, activated carbon, and other salt-absorbing materials are filled between the folded edges. These materials adsorb salts that infiltrate with the water, effectively reducing the impact of salts on the planting soil layer, further improving soil quality, and promoting healthy crop growth.

[0029] 3. Compared with traditional pipeline drainage systems, the soil drainage structure provided by this invention does not require complex engineering design, making maintenance work more convenient, significantly reducing the initial investment cost, and also alleviating the long-term operation and maintenance cost burden.

[0030] 4. The soil drainage structure provided by this invention is also simple to construct. It only requires digging up the surface soil of the target plot to the designed depth, laying a water-retaining and breathable cloth, and then covering it with soil. This process does not require a complicated pipeline layout, which greatly improves the convenience of construction and is suitable for large-scale mechanized operations. Attached Figure Description

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] Figure 1 is a schematic diagram of the soil drainage structure provided by the present invention;

[0033] Figure 2 is a schematic diagram of a soil drainage structure provided in another embodiment of the present invention;

[0034] Figure 3 is a schematic diagram of the structure at point A;

[0035] Figure 4 is a schematic diagram of a soil drainage structure provided in another embodiment of the present invention;

[0036] Figure 5 is a schematic diagram of the structure of the water-retaining and breathable membrane provided by the present invention.

[0037] The symbols in the attached diagram have the following meanings: 1—planting soil layer; 2—water-retaining and breathable fabric; 3—folded edge; 4—saline-alkali soil layer. Detailed Implementation

[0038] The present invention will be further explained in detail below with reference to the accompanying drawings and specific embodiments. However, the following description of the embodiments is only intended to enable those skilled in the art to more clearly understand the principles and essence of the present invention, and does not imply any limitation on the present invention.

[0039] Example 1

[0040] This invention provides a soil drainage structure for saline-alkali and desert soils, as shown in Figures 1-5. The structure includes several water-retaining and breathable fabrics 2, a planting soil layer 1, and a saline-alkali soil layer 4. The edges of the water-retaining and breathable fabrics 2 are folded upwards, and the fabric surface of the fabric 2 is concave downwards to form a groove. This groove is used to hold the planting soil layer 1, allowing planting to take place within it. The outer ends of the edges of the water-retaining and breathable fabrics 2 are folded outwards to form folded edges 3. Preferably, the folded edges 3 are flush with the horizontal plane, and there are gaps between adjacent folded edges 3 to allow water to infiltrate downwards. These gaps refer to the vertical distance between the folded edges 3, as shown in Figure 1. The size of these gaps is L > 0 cm and L ≤ 0.5 cm. The overlapping design of the folded edges 3 cleverly plays a guiding role, directing irrigation water along a specific path. The water is confined within the groove and irrigates the planting soil layer 1, avoiding direct downward infiltration through the gaps. Only after the planting soil layer 1 has fully absorbed the necessary water will the excess water accumulated on the surface be guided by the folded edge 3, slowly flow into the gaps, and eventually seep into the underlying saline-alkali soil.

[0041] The saline-alkali soil layer 4 is located below the groove. The water-retaining and breathable cloth 2 allows gas to pass through, ensuring that the plant roots do not suffer from root hypoxia due to lack of oxygen, which affects growth. It also blocks the penetration of water and the migration of salt between the planting soil layer 1 and the saline-alkali soil layer 4. Specifically, under the influence of rain or irrigation, the planting soil layer 1 in the groove fully absorbs the required water, and thanks to the properties of the water-retaining and breathable cloth 2, this water will not seep through the cloth surface into the saline-alkali soil layer 4. When there is excessive water, causing the surface of the planting soil layer 1 to accumulate water exceeding its capacity, this excess water will flow into the gaps between adjacent folded edges 3. This water flow will gradually seep into the saline-alkali soil layer 4 below the groove, and may even penetrate into the lower layers of saline-alkali soil 4. However, the salt in the saline-alkali soil layer 4 is effectively blocked by the water-retaining and breathable cloth 2, preventing it from flowing back up and invading the planting soil layer 1, protecting the plants from salinity and ensuring the stability and health of the plant's growth environment.

[0042] The soil drainage system provided by this invention has significant advantages over the rigid components commonly used in existing drainage technologies: it innovatively employs a water-retaining and breathable fabric 2, ensuring that irrigation water and applied fertilizer are precisely applied to the planting soil layer 1, effectively preventing their seepage into the lower soil layers and thus avoiding resource loss. Even in extreme cases of continuous soaking, excess water flows out through gaps, preventing waterlogging, and relies on natural osmosis to remove excess water and dissolved minerals, ensuring the long-term effectiveness and stability of the soil drainage process. Furthermore, this structure takes into account the gas exchange needs between the upper and lower soil layers, and will not have any adverse effects on the normal growth of plants.

[0043] More importantly, the soil drainage structure of this invention completely eliminates the traditional complex and cumbersome pipeline layout, achieving a significant simplification of the structure. This improvement not only significantly reduces the difficulty of installation and subsequent maintenance, but also greatly enhances the overall efficiency and reliability of the drainage system.

[0044] In some implementations, an adaptive gap adjustment element is provided at the gap to automatically adjust the water infiltration rate. In a specific implementation, a humidity-responsive gel strip is embedded within the gap between the folded edges. The expansion rate of this gel strip is proportional to the moisture content of the surrounding soil. When soil moisture increases, the gel strip expands, automatically reducing the gap width to a minimum of approximately 0.2 cm, thereby slowing the water infiltration rate. Conversely, when soil moisture decreases, the gel strip contracts, expanding the gap width to a maximum of approximately 1.2 cm, promoting water infiltration and distribution. This design not only precisely controls water discharge and retention based on real-time changes in environmental humidity but also effectively prevents waterlogging or drought caused by excessively rapid or slow water infiltration, further improving the adaptability and regulation efficiency of the entire soil drainage structure.

[0045] In some implementations, salt-absorbing materials (such as modified zeolite, activated carbon, etc.) are filled between adjacent folded edges. This design actively intercepts and adsorbs dissolved salts during water infiltration. Specifically, when irrigation water or excess water infiltrates through the gaps in the water-retaining and breathable fabric, it flows through the filled salt-absorbing materials. Due to their high specific surface area and porous structure, these materials can effectively capture and fix salt ions carried in the water, reducing the concentration of salt entering the planting soil layer. This prevents salt accumulation on the surface, reduces salt damage to crop roots, and improves the physicochemical properties of the soil, providing a more ideal growing environment for crops.

[0046] In some embodiments, the above-mentioned water-retaining and breathable fabric 2 is made of one or both of modified meltblown material and polypropylene.

[0047] In some embodiments, the groove has a U-shaped cross-section.

[0048] In practical applications, the present invention does not strictly limit the shape of the groove, and can be adjusted according to the shape of the specific plot to be laid. Thanks to the shape plasticity of the water-retaining and breathable cloth 2, it can flexibly adapt to various terrain features and easily cope with terrain undulations.

[0049] In some embodiments, as shown at point A in Figure 2, the folded edges 3 of adjacent water-retaining and breathable fabrics 2 at least partially overlap, and the gap joint structure is shown in Figure 3, with a dimension L > 0 cm and L ≤ 0.5 cm.

[0050] Preferably, the width d of the folded edge 3 is 3 to 4 cm.

[0051] Furthermore, during the laying of the water-retaining and breathable fabric 2, the plot usually has a specific length, width, and depth. In order to ensure the best water-retaining and breathable effect, the width of the fabric is usually designed to be the sum of the plot width plus twice the laying depth and twice the folded edge width d, while the length is designed to be the sum of the plot length plus twice the laying depth and twice the folded edge width d. In this embodiment, the width of a single piece of water-retaining and breathable fabric 2 is preferably 2 to 6 m.

[0052] In some implementations, in the area adjacent to the sidewall of the pit (here, the pit refers to a depression formed by excavation in the paved area), the edges of the two key water-retaining and breathable fabrics 2 are folded upwards, with the fold width consistent with the depth of the fabric laying, to ensure optimal results. As shown in Figure 3, the fabric surface adhering to the pit wall should extend vertically to be flush with the surface of the planting soil layer 1, or ideally, slightly beyond the surface of the planting soil layer, thereby enhancing the barrier effect between the sides of the pit and the saline-alkali soil.

[0053] Example 2

[0054] Based on Example 1, the present invention also provides a construction method for the soil drainage structure, comprising the following steps:

[0055] S1. Excavate the surface soil of the plot where water-retaining and breathable cloth 2 needs to be laid to ensure that the predetermined laying depth is reached and a pit is formed.

[0056] S2. Select the appropriate size and quantity of water-retaining and breathable fabric 2 according to the specific dimensions of the pit. Preferably, each piece of fabric is cut into shape according to the specified method and then sewn together for reinforcement.

[0057] S3. Lay the selected water-retaining and breathable fabrics 2 one by one in the pit: First, lay the surface of the water-retaining and breathable fabric 2 on the bottom surface of the pit, and fold the edge of the water-retaining and breathable fabric 2 upwards. The surface of the water-retaining and breathable fabric 2 is recessed downwards to form a groove, and the bottom wall of the groove is in contact with the bottom surface of the pit.

[0058] Preferably, the process of laying the water-retaining and breathable fabric 2 can be carried out by tractor or other mechanical equipment to ensure the convenience and precision of construction.

[0059] S6. Then, the excavated soil is backfilled or new soil is added to form planting soil layer 1. Planting soil layer 1 is then irrigated to prepare for subsequent planting work.

[0060] Furthermore, the construction method also includes: S4, after the water-retaining and breathable fabric 2 is laid, checking the flatness of the laying and the tightness of the joints between adjacent water-retaining and breathable fabrics 2. If adjustments are needed, corresponding corrective measures should be implemented immediately to ensure the laying quality.

[0061] The construction method also includes: S5, rinsing the laid water-retaining and breathable cloth 2 several times to remove impurities from the cloth surface so as to facilitate subsequent normal agricultural operations.

[0062] The construction method also includes: S7. Regularly inspect the water-retaining and breathable fabric 2. If any abnormality is found, find out the cause and take remedial measures. If the water-retaining and breathable fabric 2 is damaged, replace it with a new water-retaining and breathable fabric 2 in a timely manner. Select a water-retaining and breathable fabric 2 of the same material as the replacement. However, the original design specifications must be strictly followed in the processing and manufacturing.

[0063] In step S6, when irrigating the planting soil layer 1, adding an appropriate amount of nutrient solution can promote vegetation growth and improve the overall ecological environment quality. For crops on saline-alkali land, the recommended nutrient solution contains potassium silicate (K2SiO3, concentration approximately 0.1 mmol / L) and proline (concentration approximately 0.5 g / L) to enhance the plant's ability to resist harsh environments. In desert environments, it is recommended to select appropriate hydroponics-specific liquid fertilizers according to the actual conditions.

[0064] When implementing the design scheme provided by this invention, local geographical characteristics and socio-economic development levels should be fully considered and integrated to adjust the design scheme accordingly. For example, in areas with abundant water resources, increasing the frequency of irrigation can promote the rapid removal of salts from the soil, thereby optimizing the soil environment. Conversely, in areas with scarce water resources, it is necessary to carefully control the irrigation cycle and appropriately extend the time between irrigations to maximize water conservation. Furthermore, to more accurately adapt to the growth habits of various plants, the applied nutrient combination and ratio should be carefully adjusted and optimized in a timely manner according to the actual situation to ensure that plants receive the most suitable nutrient supply to promote their healthy growth.

[0065] The preferred embodiments of the present invention are for inspiration. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of the present invention.

[0066] The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A soil drainage structure for saline-alkali land and desert soil, characterized in that, include: Several layers of water-retaining and breathable fabric, planting soil layer and saline-alkali soil layer; The edge of the water-retaining and breathable fabric is folded upwards, and the fabric side of the water-retaining and breathable fabric is recessed downwards to form a groove, which is used to hold the planting soil layer; The outer edge of the water-retaining and breathable fabric is folded outward to form a folded edge, and there is a gap between adjacent folded edges to allow water to seep down. The saline-alkali soil layer is located below the groove, and the water-retaining and breathable cloth is configured to allow gas to pass through while blocking the infiltration of water and the migration of salt between the planting soil layer and the saline-alkali soil layer.

2. The soil drainage structure according to claim 1, characterized in that, The width of the folded edge is 3-4 cm; and / or, Adjacent folded edges at least partially overlap; and / or, An adaptive gap adjustment element is provided at the gap to automatically adjust the rate of water infiltration; and / or, Salt-absorbing material is filled between adjacent folded edges.

3. The soil drainage structure according to claim 2, characterized in that, The adaptive gap adjustment element is a humidity-responsive gel strip, whose expansion rate is positively correlated with soil moisture, and its adjustment range is 0.2 to 1.2 cm.

4. The soil drainage structure according to any one of claims 1-3, characterized in that, The water-retaining and breathable fabric is made of one or both of modified meltblown material and polypropylene.

5. The soil drainage structure according to claim 1, characterized in that, The groove has a U-shaped cross-section.

6. The soil drainage structure according to claim 1, characterized in that, The width of the water-retaining and breathable fabric is 2 to 6 meters.

7. A construction method for a soil drainage structure for saline-alkali land and desert soil as described in any one of claims 1-6, characterized in that: Includes the following steps: For plots where water-retaining and breathable fabric needs to be laid, the surface soil is excavated to ensure that the predetermined laying depth is reached, forming a pit; Based on the specific dimensions of the recess, select the appropriate size and quantity of the water-retaining and breathable fabric; The selected water-retaining and breathable fabrics are laid in the recess: the fabric surface of the water-retaining and breathable fabric is laid on the bottom surface of the recess, and the edge of the water-retaining and breathable fabric is folded upward, and the fabric surface of the water-retaining and breathable fabric is recessed downward to form a groove. The bottom wall of the groove is in contact with the bottom surface of the recess. At the same time, the outer edge of the water-retaining and breathable fabric is folded outward to form the folded edge. Adjacent folded edges overlap at least partially and maintain a certain gap to allow water to seep in. Soil is filled into the groove and irrigated to prepare for subsequent planting.

8. The construction method according to claim 7, characterized in that, It also includes: after the water-retaining and breathable fabric is laid, checking the flatness of the laying and the tightness of the joints between adjacent water-retaining and breathable fabrics; if there is a need for adjustment, the corresponding corrective measures should be implemented immediately to ensure the laying quality.

9. The construction method according to claim 7, characterized in that, Also includes: After the water-retaining and breathable fabric has been laid, it should be rinsed to remove impurities from the fabric surface.

10. The construction method according to claim 7, characterized in that, It also includes: regularly inspecting the water-retaining and breathable fabric; if any abnormality is found, identifying the cause and taking remedial measures; if the water-retaining and breathable fabric is damaged, replacing it with a new one in a timely manner.

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