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

Abstract

A soil drainage structure for saline-alkali land and desert soil and its construction method. This soil drainage structure introduces a water-retaining and breathable cloth as an isolation layer to block the penetration and migration of water and salts between the planting soil layer and the saline-alkali soil layer. It not only has excellent water-retaining performance but also good air permeability, which can provide sufficient oxygen supply for plant roots and avoid growth obstacles caused by lack of oxygen or salt accumulation. In addition, the construction process of this structure is simple and efficient. The surface soil is excavated according to the preset depth, and only the pre-cut water-retaining and breathable cloth needs to be laid in the dug pit and closely fitted with the pit wall, and finally the soil is backfilled to form a planting soil layer suitable for plant growth. After completing the above steps, irrigation and planting operations can be directly carried out, greatly reducing the construction difficulty and cost, and is especially suitable for ecological restoration and agricultural development in saline-alkali land or desert areas.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil ecological improvement, and particularly relates to a soil drainage structure for saline-alkali land and desert soil and a construction method thereof. Background Art

[0002] At present, during the process of soil improvement in saline-alkali land or desert areas, drainage measures are usually required to regulate the water and salt content in the soil. Existing improvement methods mainly include traditional underground pipe drainage method, gravel layer laying method, and continuous laying of waterproof layers, etc., but these methods all have certain limitations:

[0003] (1) The underground pipe drainage method buries drainage pipelines to guide excess water and salt to the outside of the ground surface, thereby reducing the salt content of the surface soil. However, this method has complex construction, the pipes are prone to blockage, and the later maintenance cost is relatively high.

[0004] (2) The gravel layer laying method lays a relatively thick layer of crushed stones or sand on the soil surface as an isolation belt to prevent rainwater from directly infiltrating into the high-salt formation. 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 relatively high.

[0005] (3) The method of continuously laying a waterproof layer (such as a plastic film) can quickly form an anti-seepage barrier in the short term and reduce the salt accumulation caused by water evaporation. However, long-term use will hinder the gas exchange inside the soil, resulting in hypoxia at the bottom, which in turn affects the normal development of plant roots.

[0006] The above methods all have obvious limitations in practical applications, especially in areas where the tillage mode needs to be frequently adjusted or extreme climate conditions are faced. For example, the traditional pipe drainage method not only has complex construction but is also easily damaged; while a completely enclosed waterproof treatment may cause problems such as secondary salinization and crop growth obstacles. In addition, common soil conditioners on the market mostly focus on single functions and lack comprehensive consideration of the change rules of soil properties, so they often fail to achieve the expected effect in practical applications.

[0007] In summary, although the existing methods can improve the soil conditions to a certain extent, due to their limitations, there is an urgent need for a solution that meets the requirements of efficient and economical large-scale soil improvement. Summary of the Invention

[0008] In view of the problems existing in the existing soil improvement technologies, such as complex construction, high construction and operation and maintenance costs, and obstruction of gas exchange resulting in oxygen deficiency in the roots, the present invention provides a soil drainage structure for saline-alkali land and desert soil and its construction method. The soil drainage structure uses a water-retaining and breathable cloth with optimized structure as an isolation layer to effectively separate the planting soil layer from the saline-alkali soil layer, blocking the water penetration and salt migration between the two. At the same time, the water-retaining and breathable cloth has good air permeability, which can ensure that the plant roots obtain sufficient oxygen and avoid adverse effects on the normal growth of plants. In addition, the structure is easy to construct. It only needs to dig the surface soil to form a concave pit according to the preset depth, lay the cut water-retaining and breathable cloth in the pit and make it closely fit with the bottom of the pit, and then backfill the soil in the groove enclosed by the water-retaining and breathable cloth to form a planting soil layer, and then the subsequent irrigation and planting work can be carried out.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A soil drainage structure for saline-alkali land and desert soil, comprising: a plurality of water-retaining and breathable cloths, a planting soil layer and a saline-alkali soil layer; the edges of the water-retaining and breathable cloths are turned up, and the cloth surface of the water-retaining and breathable cloths is sunken downward to form a groove for loading the planting soil layer; the outer ends of the edges of the water-retaining and breathable cloths are turned outwards to form turned-up edges, and there is a gap for water to infiltrate between adjacent turned-up edges; 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 and be able to block the penetration 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 turned-up edge is 3-4 cm; and / or, adjacent turned-up edges at least partially overlap; and / or,

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

[0013] A salt adsorption material is filled between adjacent turned-up edges.

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

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

[0016] In some embodiments, the cross-sectional shape of the groove is U-shaped.

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

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

[0019] Excavate the surface soil of the plot where the water-retaining and breathable cloth needs to be laid to ensure reaching the predetermined laying depth to form a pit;

[0020] Select the water-retaining and breathable cloth with corresponding sizes and quantities according to the specific dimensions of the pit;

[0021] Lay a number of the selected water-retaining and breathable cloths in the pit: the cloth surface of the water-retaining and breathable cloth is laid on the bottom surface of the pit, and the edge of the water-retaining and breathable cloth is folded upward. The cloth surface of the water-retaining and breathable cloth is recessed downward to form a groove, the bottom wall of the groove fits the bottom surface of the pit, and at the same time, the outer end of the edge of the water-retaining and breathable cloth is folded outward to form the folded edge. The adjacent folded edges at least partially overlap and maintain a certain gap for water infiltration;

[0022] Fill the groove with soil and irrigate it for subsequent planting work.

[0023] In some embodiments, the construction method further includes: after completing the laying of the water-retaining and breathable cloth, check the flatness of the laying and the tightness of the seams between adjacent water-retaining and breathable cloths; if there is a need for adjustment, corresponding corrective measures should be immediately implemented to ensure the laying quality.

[0024] In some embodiments, the construction method further includes: rinse the laid water-retaining and breathable cloth to remove impurities on the cloth surface.

[0025] In some embodiments, the construction method further includes: regularly check the water-retaining and breathable cloth. If any abnormal situation is found, find out the reason and take remedial measures. If the water-retaining and breathable cloth is damaged, replace it with a new one in time.

[0026] Compared with the prior art, the soil drainage structure of saline-alkali land and desert soil provided by the present invention and its construction method 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 achieve precise irrigation and fertilization, ensure that the irrigation water and fertilizer act precisely on the planting soil layer, effectively prevent them from infiltrating into the lower soil layer, reduce resource waste. At the same time, this structure also takes into account the gas exchange requirements 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 impact on the normal growth of plants;

[0028] 2. The present invention provides a dedicated water infiltration channel between adjacent water-retaining and breathable fabrics. In the case of excessive irrigation water, these gaps play a key role, enabling the excess water along with the dissolved minerals to move smoothly downward into the underlying soil by relying on natural osmotic force, thus completing the drainage process. Even in the extreme situation of continuous immersion, the excess water can be smoothly discharged through these gaps, effectively preventing waterlogging and ensuring the long-term reliability and stability of the drainage system. At the same time, a humidity-responsive gel strip is embedded at the folded edge of the water-retaining and breathable fabric. This gel strip enables the gap width between the folded edges to be automatically adjusted within the range of 0.2 - 1.2 cm according to the soil humidity, thereby dynamically optimizing the water infiltration rate to meet the drainage requirements under different humidity conditions. In addition, the space between the folded edges is filled with salt adsorption materials such as modified zeolite and activated carbon. These materials can adsorb the salts infiltrating with the water, effectively reducing the impact of salts on the planting soil layer, further improving the soil quality, and promoting the healthy growth of crops;

[0029] 3. Compared with the traditional pipeline drainage system, the soil drainage structure provided by the present invention does not require complex engineering design, making the maintenance work more convenient, significantly reducing the investment cost at the initial stage of construction, and at the same time reducing the burden of long-term operation and maintenance costs;

[0030] 4. The construction of the soil drainage structure provided by the present invention is also simple. It only requires digging the surface soil of the target plot to the designed depth, laying the water-retaining and breathable fabric, and then covering the soil. This process does not require complex pipeline layout, greatly improving the construction convenience and is suitable for large-scale mechanized operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the drawings and embodiments.

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

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

[0034] Figure 3 is a schematic structural diagram of part A;

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

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

[0037] The meanings of the reference symbols in the drawings are as follows:

[0038] 1 - Planting soil layer; 2 - Water - retaining and breathable cloth; 3 - Folded edge; 4 - Saline - alkali soil layer. Detailed implementation mode

[0039] The present invention will be further explained in detail below in combination with the description of the accompanying drawings and specific embodiments. However, the following description including the embodiments is only used to enable those of ordinary skill in the technical field to which the present invention belongs to more clearly understand the principles and essence of the present invention, and does not mean any form of limitation to the present invention.

[0040] Embodiment 1

[0041] The present invention provides a soil drainage structure for saline - alkali land and desert soil. As Figures 1-5 shown, the structure includes: a plurality of water - retaining and breathable cloths 2, a planting soil layer 1, and a saline - alkali soil layer 4. The edge of the water - retaining and breathable cloth 2 is folded upwards, and the cloth surface of the water - retaining and breathable cloth 2 is sunken downwards to form a groove for loading the planting soil layer 1, and then planting is carried out in the planting soil layer 1. The outer end of the edge of the water - retaining and breathable cloth 2 is folded outwards to form a folded edge 3. The folded edge 3 is preferably flush with the horizontal plane, and there is a gap for water infiltration between adjacent folded edges 3. At this time, the gap refers to the vertical distance between the folded edges 3, that is Figure 1 as shown in. At this time, the size L of the gap satisfies L > 0 cm and L ≤ 0.5 cm. The overlapping design of the folded edge 3 cleverly plays a guiding role, guiding the irrigation water body to flow along a specific path. The water is restricted in the groove and irrigated into the planting soil layer 1, avoiding direct downward penetration through the gap. Only when the planting soil layer 1 has fully absorbed the necessary water, the surplus water accumulated on the surface layer will be guided by the folded edge 3, slowly flow into the gap, and finally infiltrate into the underlying saline - alkali soil.

[0042] The saline - alkali soil layer 4 is located below the groove. The water - retaining and breathable cloth 2 can allow gas to pass through, ensuring that the plant roots will not be affected by lack of oxygen due to root hypoxia, and can block the infiltration of water and the migration of salts between the planting soil layer 1 and the saline - alkali soil layer 4. That is, under the action of rain or irrigation, the planting soil layer 1 in the groove fully absorbs the required water. Thanks to the characteristics of the water - retaining and breathable cloth 2, these waters will not penetrate through the cloth surface into the saline - alkali soil layer 4. When the water is excessive, resulting in the accumulation of more water than its capacity on the surface layer of the planting soil layer 1, these excess waters will flow to the gap between adjacent folded edges 3, and these water flows will gradually infiltrate into the saline - alkali soil layer 4 below the groove, and may even penetrate deeper into the saline - alkali soil layer 4. However, the salts in the saline - alkali soil layer 4 will be effectively blocked by the water - retaining and breathable cloth 2, preventing them from flowing back upwards and invading the planting soil layer 1, protecting the plants from saline - alkali damage, and ensuring the stability and health of the plant growth environment.

[0043] The soil drainage system provided by the present invention has obvious advantages over the hard components commonly used for drainage in the prior art: the innovative use of water-retaining and breathable cloth 2 ensures that irrigation water and applied fertilizers act accurately on the planting soil layer 1, effectively preventing them from penetrating into the lower soil layer, thereby avoiding resource loss. Even in extreme cases of continuous immersion, excess water flows out through the gaps to prevent water accumulation, and natural osmosis is used to remove excess water and dissolved minerals, ensuring the long-term effectiveness and stability of the soil drainage process. In addition, the structure takes into account the gas exchange needs between the upper and lower layers of the soil, and will not cause any adverse effects on the normal growth of plants.

[0044] More importantly, the soil drainage structure of the present invention completely abandons the traditional complex and cumbersome pipeline layout, and greatly simplifies the structure. This improvement not only significantly reduces the difficulty of installation and subsequent maintenance, but also greatly improves the overall efficiency and reliability of the drainage system.

[0045] In some embodiments, an adaptive gap adjustment element is provided at the gap to achieve automatic adjustment of the water infiltration rate. In a specific implementation, a moisture-responsive gel strip is embedded in the gap reserved between the folded edges. The expansion rate of the moisture-responsive gel strip is proportional to the humidity of the surrounding soil. When the soil humidity increases, the gel strip expands, automatically reducing the gap width to a minimum of about 0.2 cm, thereby slowing down the water infiltration rate; and when the soil humidity decreases, the gel strip contracts, expanding the gap width to a maximum of about 1.2 cm, promoting water infiltration and deployment. This design can not only accurately control the discharge and retention of water according to the real-time changes in environmental humidity, but also effectively prevent water accumulation or drought problems caused by too fast or too slow water infiltration, further improving the adaptability and regulation efficiency of the entire soil drainage structure.

[0046] In some embodiments, salt adsorption materials (such as modified zeolite, activated carbon, etc.) are filled between adjacent folded edges. This design can actively intercept and adsorb 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 adsorption materials. These materials, due to their high specific surface area and porous structure, can effectively capture and fix salt ions carried in the water, reduce the concentration of salt entering the planting soil layer, thereby preventing salt accumulation in the surface layer, reducing the damage to the crop root system caused by salt damage, and at the same time improving the physical and chemical properties of the soil, providing a more ideal growth environment for crops.

[0047] In some embodiments, the water-retaining and breathable fabric 2 is made of one or both of modified meltblown material and polypropylene.

[0048] In some embodiments, the cross-sectional shape of the groove is U-shaped.

[0049] In practical applications, the shape of the groove in the present invention is not strictly limited and can be adjusted accordingly 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.

[0050] In some embodiments, as Figure 2 shown at A in the figure, at least part of the folded edges 3 of the adjacent water-retaining and breathable cloths 2 overlap. At this time, the gap joint structure is as Figure 3 shown, and its size L > 0 cm and L ≤ 0.5 cm.

[0051] Preferably, the width d of the above-mentioned folded edge 3 is 3 - 4 cm.

[0052] Furthermore, during the process of laying the water-retaining and breathable cloth 2, the plot usually has a specific length, width, and depth. To ensure the best water-retaining and breathable effect, the width of the cloth is usually designed as the sum of the plot width, twice the laying depth, and twice the width d of the folded edge. And the length is designed as the sum of the plot length, twice the laying depth, and twice the width d of the folded edge. In this embodiment, the width of a single water-retaining and breathable cloth 2 is preferably 2 - 6 m.

[0053] In some embodiments, in the area adjacent to the side wall of the soil pit (here, the soil pit refers to the concave pit formed by excavating in the plot to be laid), the edges of two key water-retaining and breathable cloths 2 are folded upward, and the folding width is the same as the laying depth of the cloth to ensure the best effect. That is Figure 3 as shown, the cloth surface close to the pit wall should extend vertically to be flush with the surface of the planting soil layer 1, or more ideally, slightly exceed the surface layer of the planting soil, so as to enhance the isolation effect between both sides of the soil pit and the saline-alkali soil.

[0054] Embodiment 2

[0055] Based on Embodiment 1, the present invention also provides a construction method for the soil drainage structure, including the following steps:

[0056] S1. Excavate the surface soil of the plot where the water-retaining and breathable cloth 2 needs to be laid to ensure reaching the predetermined laying depth to form a concave pit.

[0057] S2. Select the water-retaining and breathable cloth 2 with corresponding size and quantity according to the specific size of the concave pit. Preferably, cut the shape of each piece of cloth in the specified manner and sew and reinforce it.

[0058] S3. Lay the selected several water-retaining and breathable cloths 2 one by one in the concave pit: first, lay the cloth surface of the water-retaining and breathable cloth 2 on the bottom surface of the concave pit, and fold the edge of the water-retaining and breathable cloth 2 upward. The cloth surface of the water-retaining and breathable cloth 2 is sunken downward to form a groove, and the bottom wall of the groove fits the bottom surface of the concave pit.

[0059] Preferably, the process of laying the water-retaining and breathable cloth 2 can be implemented by a tractor or other mechanical equipment to ensure the convenience and precision of construction.

[0060] S6. Then, refill the excavated soil or fill in new soil to form the planting soil layer 1, and irrigate the planting soil layer 1 for subsequent planting work.

[0061] Furthermore, the construction method further includes: S4. After the laying of the water-retaining and breathable cloth 2 is completed, check the flatness of the laying and the tightness of the seams between adjacent water-retaining and breathable cloths 2. If adjustment is required, corresponding corrective measures should be immediately implemented to ensure the laying quality.

[0062] The construction method further includes: S5. Rinse the laid water-retaining and breathable cloth 2 several times to remove impurities on the cloth surface for subsequent normal agricultural operations.

[0063] The construction method further includes: S7. Regularly check the water-retaining and breathable cloth 2. If any abnormal situation is found, find out the reason and take remedial measures. If the water-retaining and breathable cloth 2 is damaged, replace it with a new one in time. Select a water-retaining and breathable cloth 2 of the same material for replacement, but it must be strictly processed and manufactured in accordance with the original design specifications.

[0064] In step S6, when irrigating the planting soil layer 1, the growth of vegetation can be promoted by adding an appropriate amount of nutrient solution to improve the overall ecological environment quality. For crops on saline-alkali land, the recommended nutrient solution contains potassium silicate (K2SiO3, concentration about 0.1 mmol / L) and proline (concentration about 0.5 g / L) to enhance the ability of plants to resist harsh environments. In a desert environment, it is recommended to select an appropriate soilless cultivation special liquid fertilizer according to the actual situation.

[0065] When implementing the design solution provided by the present invention, the local geographical characteristics and social and economic development level should also be fully considered and integrated to adjust the design solution. For example, in areas with relatively abundant water resources, the frequency of irrigation can be increased to promote the rapid discharge of salts in the soil, thereby optimizing the soil environment. On the contrary, in areas with relatively scarce water resources, the irrigation cycle needs to be carefully controlled, and the time between two irrigations should be appropriately extended to save water resources to the greatest extent. At the same time, in order to more precisely adapt to the growth habits of various plants, the nutrient combination and ratio applied should be carefully adjusted and optimized according to the actual situation to ensure that plants can obtain the most suitable nutrient supply to promote their healthy growth.

[0066] Based on the ideal embodiments of the present invention, through the above description, relevant staff can make various changes and modifications completely within the scope of not deviating from the technical idea of this invention.

[0067] The technical scope of the present invention is not limited to the content in the specification, and its technical scope 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 it includes: Several water-retaining and breathable fabrics, a planting soil layer, and a saline-alkali soil layer; The edge of the water-retaining and breathable fabric is turned up, and the fabric surface of the water-retaining and breathable fabric is sunken downward to form a groove for loading the planting soil layer; The outer end of the edge of the water-retaining and breathable fabric is turned outwards to form a turned edge, and there is a gap for water infiltration between adjacent turned edges. An adaptive gap adjustment element is arranged at the gap to automatically adjust the water infiltration rate. The adaptive gap adjustment element is a humidity-responsive gel strip, and its swelling rate is positively correlated with soil humidity. It adjusts the gap width between the turned edges within the range of 0.2-1.2 cm; at least part of adjacent turned edges overlap; a salt adsorption material is filled between adjacent turned edges; The saline-alkali soil layer is located below the groove, and the water-retaining and breathable fabric is configured to allow gas to pass through and be able to block 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 turned edge is 3-4 cm.

3. The soil drainage structure according to claim 1 or 2, characterized in that The water-retaining and breathable fabric is made of one or two of modified meltblown material and polypropylene.

4. The soil drainage structure according to claim 1, characterized in that The cross-sectional shape of the groove is U-shaped.

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

6. A construction method for the soil drainage structure of saline-alkali land and desert soil as described in any one of claims 1-5, characterized in that: It includes the following steps: Excavate the surface soil of the plot where the water-retaining and breathable fabric needs to be laid to ensure that the predetermined laying depth is reached to form a pit; Select the water-retaining and breathable fabrics with corresponding sizes and quantities according to the specific dimensions of the pit; Lay several selected water-retaining and breathable fabrics in the pit: the fabric surface of the water-retaining and breathable fabric is laid on the bottom surface of the pit, and the edge of the water-retaining and breathable fabric is turned up. The fabric surface of the water-retaining and breathable fabric is sunken downward to form a groove, and the bottom wall of the groove fits with the bottom surface of the pit. At the same time, the outer end of the edge of the water-retaining and breathable fabric is turned outwards to form the turned edge, and at least part of adjacent turned edges overlap and maintain a certain gap for water infiltration; Fill the groove with soil and irrigate it for subsequent planting work.

7. The construction method according to claim 6, characterized in that It also includes: after the laying of the water-retaining and breathable fabric is completed, check the flatness of the laying and the tightness of the seams between adjacent water-retaining and breathable fabrics; if there is a need for adjustment, corresponding correction measures should be immediately implemented to ensure the laying quality.

8. The construction method according to claim 6, characterized in that It also includes: Flush the laid water-retaining and breathable fabric to remove impurities on the fabric surface.

9. The construction method according to claim 6, characterized in that It also includes: regularly checking the water-retaining and breathable fabric, if any abnormal situation is found, finding out the cause and taking remedial measures, and if the water-retaining and breathable fabric is damaged, promptly replacing it with a new one.

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