A construction method of a buried pipe drainage for saline-alkali farmland
By laying a crisscrossing infiltration network and a controllable drainage device in saline-alkali farmland, the problems of seepage failure and water layer regulation in underground drainage systems in saline-alkali farmland have been solved, achieving rapid infiltration and flexible water layer management, thereby improving soil quality and crop yield.
Patent Information
- Application Number
- CN202610854514.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Filing Date
- 2026-06-13
- Publication Date
- 2026-07-14
AI Technical Summary
Existing underground drainage technology for saline-alkali farmland fails to seep water after the following year or longer due to soil compaction caused by alternating wet and dry conditions. The underground pipes cannot drain water normally and cannot achieve flexible control of the water layer for rice cultivation.
An integrated laser pipe-laying machine is used to lay horizontal underground pipes, which are then combined with a cross-sectional and cross-sectional drainage trench filter layer. Combined with a controllable drainage device, a cross-sectional and cross-sectional drainage network is formed. A soft water hose with a switch valve is installed at the outlet of the underground pipe to achieve precise water layer control.
It enables rapid water infiltration and long-term unobstructed drainage in saline-alkali farmland, solves the problem of water infiltration failure after soil compaction, and allows for flexible regulation of water storage or drainage as needed to meet the planting needs of different crops.
Smart Images
Figure CN122382945A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of bait manufacturing technology, and in particular to a construction method for underground drainage in saline-alkali farmland. Background Technology
[0002] Saline-alkali land refers to arable land with excessively high levels of soluble salts or exchangeable sodium, leading to inhibited crop growth. This type of soil often exhibits characteristics such as compaction, poor permeability, and high pH, making crops prone to physiological drought and nutrient imbalance. Based on their harmful characteristics, it is classified into saline soil and alkaline soil. Saline-alkali land requires remediation through measures such as irrigation to leach salts, application of soil conditioners, and planting salt-tolerant crops to restore agricultural productivity. In existing technologies, due to the severe imbalance of pH and salinity in saline-alkali land, organic matter is almost completely depleted, resulting in extremely low organic matter content, the near disappearance of beneficial soil microorganisms, and fine, non-aggregated soil particles. Furthermore, while the initial drainage process allows for normal water infiltration due to the loosened soil in the pipe trenches, the soil hardens after the subsequent wetting and drying process, preventing normal infiltration. This leads to the problem that the underground pipe drainage system for saline-alkali land essentially stops draining water in the following year or even longer. Therefore, a construction method for underground pipe drainage in saline-alkali farmland is proposed. Summary of the Invention
[0003] To address the shortcomings of existing technologies, this invention provides the following technical solution: A construction method for underground drainage in saline-alkali farmland includes the following steps: S1: Conduct site leveling and geological surveys on the saline-alkali farmland to be improved, and determine the laying parameters of underground pipes and infiltration ditches; S2: An integrated laser pipe laying machine is used to lay horizontal underground pipes at a preset depth, and filter material is filled simultaneously to form a permeable filter material layer that wraps the underground pipes; S3: Vertical seepage trenches are laid perpendicular to the horizontal underground pipes. The bottom of the seepage trenches is flush with the top of the seepage filter material layer, and the top penetrates the plow layer and extends into the tillage layer. S4: Install a controllable drainage device at the outlet of the concealed pipe; S5: Backfill and compact the soil in the construction area; S6: Debug the controllable drainage device and verify its drainage and water storage functions.
[0004] As an improvement to the above technical solution: S11: Clear debris from the surface of cultivated land and level the land to a slope of ≤0.3%; S12: Survey the soil texture, salinity, and depth of the plow pan to determine the spacing of underground pipes (5 to 15 meters) and the burial depth (1 to 1.5 meters). The spacing of the drainage trenches should be consistent with that of the underground pipes.
[0005] As an improvement to the above technical solution: S21: PE single-wall corrugated pipe is selected as the concealed pipe, and the outer wall of the pipe is wrapped with DuPont geotextile. S22: Fill with filter media of the same particle size as the mixed sand to form a permeable filter media layer with a thickness of 20-40 cm; S23: The integrated laser pipe laying machine completes trenching, pipe laying, and filter material filling in one go.
[0006] As an improvement to the above technical solution: S31: The seepage channel is filled with the same filter material as the seepage filter layer, with a thickness of 0.3-0.5 meters; S32: The top of the seepage trench extends 15-20 cm into the plow layer, with an overall height of 30-60 cm; S33: The seepage channels and horizontal underground pipes are arranged at 90° angles to form a crisscrossing seepage network.
[0007] As an improvement to the above technical solution: S41: Install a soft water hose of the same diameter as the pipe at the outlet of the concealed pipe; S42: A switch valve is installed at the end of the soft water hose to control the flow rate and the on / off state of drainage.
[0008] As an improvement to the above technical solution: S51: The original soil is used to backfill the seepage trench and the underground pipe trench in layers, with each layer being ≤20 cm thick; S52: Lightly compact the backfill soil to avoid damaging the structure of the seepage ditch and filter layer.
[0009] As an improvement to the above technical solution: S61: Close the switch valve and conduct a water storage test to verify that the water layer leakage is ≤5 cm within 24 hours; S62: Open the valve to conduct a drainage test and verify that the water level in the topsoil layer can drop to the target height within 48 hours.
[0010] As an improvement to the above technical solution: The method is applicable to clay, silt and soda saline-alkali land. The filter media can be replaced with sand, gravel, furnace ash or manufactured sand. The controllable drainage device can be replaced with a pneumatic control valve.
[0011] The beneficial effects of this invention are: 1. In this invention, a horizontal underground pipe is laid in one go by an integrated laser pipe laying machine and paired with a filter material layer of horizontal and vertical orthogonal seepage trenches. This achieves the effect of rapid water infiltration in the topsoil and long-term unobstructed drainage of the underground pipes, solving the problem of water seepage failure and drainage failure of underground pipes in the treatment of clay, silt and soda saline-alkali soils after dry and wet compaction.
[0012] 2. In this invention, by installing a controllable drainage device with a switch valve and an equal-diameter soft water hose at the outlet of the underground pipe, the precise water layer control effect of storing water in drought and draining water in flood is achieved, solving the problems of water storage in single-stage direct discharge of underground pipes and difficulty in flexibly controlling the water layer in rice planting in the prior art. Attached Figure Description
[0013] Figure 1 This is a flowchart of the present invention; Figure 2 This is a schematic diagram illustrating the layout of the method of the present invention. Detailed Implementation
[0014] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.
[0015] See appendix Figures 1-2 A construction method for underground drainage in saline-alkali farmland includes the following steps: S1: Conduct site leveling and geological surveys on the saline-alkali farmland to be improved, and determine the laying parameters for underground pipes and infiltration ditches.
[0016] S2: An integrated laser pipe laying machine is used to lay horizontal underground pipes at a preset depth, and filter media is filled simultaneously to form a permeable filter media layer that wraps the underground pipes.
[0017] S3: Vertical seepage trenches are laid perpendicular to the horizontal underground pipes. The bottom of the seepage trenches is flush with the top of the seepage filter material layer, and the top penetrates the plow layer and extends into the tillage layer.
[0018] S4: Install a controllable drainage device at the outlet of the concealed pipe.
[0019] S5: Backfill and compact the soil in the construction area.
[0020] S6: Debug the controllable drainage device and verify its drainage and water storage functions.
[0021] See appendix Figures 1-2 S11: Clear debris from the surface of cultivated land and level the land to a slope of ≤0.3%.
[0022] S12: Survey the soil texture, salinity, and depth of the plow pan to determine the spacing of underground pipes (5 to 15 meters) and the burial depth (1 to 1.5 meters). The spacing of the drainage trenches should be consistent with that of the underground pipes.
[0023] See appendix Figures 1-2 S21: PE single-wall corrugated pipe is selected as the concealed pipe, and the outer wall of the pipe is wrapped with DuPont geotextile.
[0024] S22: Fill with filter media of the same particle size as the mixed sand to form a permeable filter media layer with a thickness of 20-40 cm.
[0025] S23: The integrated laser pipe laying machine completes trenching, pipe laying, and filter material filling in one go.
[0026] See appendix Figures 1-2 S31: The seepage channel is filled with the same filter material as the seepage filter layer, with a thickness of 0.3-0.5 meters.
[0027] S32: The top of the seepage trench extends 15-20 cm into the plow layer, with an overall height of 30-60 cm.
[0028] S33: The seepage channels and horizontal underground pipes are arranged at 90° angles to form a crisscrossing seepage network.
[0029] See appendix Figures 1-2 S41: Install a soft water hose of the same diameter as the pipe at the outlet of the concealed pipe.
[0030] S42: A switch valve is installed at the end of the soft water hose to control the flow rate and the on / off state of drainage.
[0031] See appendix Figures 1-2 S51: The original soil is used to backfill the seepage trench and the underground pipe trench in layers, with each layer having a thickness of ≤20 cm.
[0032] S52: Lightly compact the backfill soil to avoid damaging the structure of the seepage ditch and filter layer.
[0033] See appendix Figures 1-2 S61: Close the switch valve and conduct a water storage test to verify that the water layer leakage is ≤5 cm within 24 hours.
[0034] S62: Open the valve to conduct a drainage test and verify that the water level in the topsoil layer can drop to the target height within 48 hours.
[0035] See appendix Figures 1-2 The method is applicable to clay, silt and soda saline-alkali land. The filter media can be replaced with sand, gravel, furnace ash or manufactured sand. The controllable drainage device can be replaced with a bladder control valve.
[0036] Example 1:
[0037] Construction site: A 50-mu (approximately 3.3 hectares) soda-saline-alkali farmland in the Songnen Plain. The soil type is clay, with a pH of 9.2, a salt content of 0.45%, a plow pan depth of 18-22 cm from the surface, and an organic matter content of 0.8%. Soybeans are planned to be planted there.
[0038] The construction steps are as follows: S1 Site Leveling and Surveying: Remove weeds and debris from the farmland surface and level the land to a slope of 0.2%. Geological survey determined the soil texture to be silty clay with a plow pan thickness of approximately 5 cm. The spacing between underground pipes was determined to be 12 meters, with a burial depth of 1.3 meters; the spacing between drainage ditches was also 12 meters, arranged at a 90° angle to the underground pipes.
[0039] S2 Horizontal Conduit Pipe Laying and Permeable Filter Layer: 110mm outer diameter PE single-wall corrugated pipes are selected, wrapped with DuPont geotextile. An integrated laser pipe-laying machine is used to complete trenching and pipe laying in one operation. Simultaneously, 2-5mm diameter river sand is filled as filter material, forming a 30cm thick permeable filter layer around and above the pipe.
[0040] S3. Laying Vertical Infiltration Trenches: An infiltration trench is excavated above the underground pipe filter layer, perpendicular to the direction of the underground pipe. The trench is 20 cm wide, with its bottom flush with the top of the infiltration filter layer. The top of the trench extends upwards, penetrating the plow layer and into the cultivated layer by 18 cm. The overall height of the infiltration trench is 50 cm. The same river sand filter material as the underground pipe filter layer is filled into the trench to a thickness of 0.4 meters, forming a vertical infiltration channel. The infiltration trenches and the underground pipe form a crisscrossing infiltration network.
[0041] S4 Install a controllable drainage device: At the outlet of each concealed pipe extending into the drainage ditch, attach a 110mm flexible hose of the same diameter as the pipe. The flexible hose is 3 meters long and has a ball valve switch at the end. The flexible hose can be freely raised or lowered.
[0042] S5 Soil Backfilling and Compaction: The original soil is used for layered backfilling of the underground pipe trench and seepage trench. The loose thickness of each layer is controlled at 15 cm. The soil is lightly compacted manually to avoid damage to the filter material layer structure by strong mechanical rolling.
[0043] S6 Debugging and Verification: A water storage test was conducted with the ball valve closed, irrigating the field to a 15 cm water layer. After 24 hours, the water level dropped by 2.8 cm, meeting the water storage requirements. A drainage test was then conducted with the ball valve open. Within 48 hours, the entire surface water layer was drained, and the soil moisture content in the topsoil layer dropped to 65% of field capacity.
[0044] Treatment Results: After three consecutive years of use, the underground pipes could drain normally during spring irrigation and salt leaching each year. In the third year, the soil salinity in the topsoil dropped to 0.08%, the pH value dropped to 8.1, the organic matter content increased to 1.5%, and the soybean yield reached 180 kg per mu, an increase of 220% compared to before the treatment.
[0045] Example 2:
[0046] Construction site: A soda-saline-alkali farmland in the Songnen Plain, covering an area of 80 mu (approximately 5.3 hectares). The soil type is silt, with a pH value of 9.5 and a salt content of 0.52%. The plow pan is 15-18 cm deep from the surface. Rice is planned to be planted there.
[0047] The construction steps are as follows: S1 Site Leveling and Surveying: Level the land to a slope of 0.1%. The survey determined that the plow pan layer was approximately 4 cm thick, with extremely low soil permeability, making it almost impermeable. The spacing of the underground pipes was determined to be 8 meters, with a burial depth of 1.5 meters; the spacing of the drainage ditches was also determined to be 8 meters.
[0048] S2 lays horizontal underground pipes and a permeable filter layer: 90mm outer diameter PE single-wall corrugated pipes are used, wrapped with DuPont geotextile. An integrated laser pipe-laying machine completes trenching, pipe laying, and filter filling in one operation. The filter material is manufactured sand with a particle size of 2-4mm, with a filling thickness of 40cm.
[0049] S3. Laying Vertical Infiltration Trench: Excavate an infiltration trench perpendicular to the direction of the underground pipe. The bottom of the trench should be flush with the top of the infiltration filter media layer, and the top of the trench should extend 20 cm above the plow layer, with an overall height of 60 cm. Fill with manufactured sand filter media to a thickness of 0.5 meters to form a vertical infiltration channel.
[0050] S4. Install a controllable drainage device: Install a soft water hose of equal diameter at the outlet of the concealed pipe, with a switch valve at the end. The soft water hose is 5 meters long and can be raised and fixed above the drainage ditch bank or placed inside the ditch as needed.
[0051] S5 Soil Backfilling and Compaction: The original soil is backfilled in layers, with each layer not exceeding 20 cm in thickness, and lightly compacted manually.
[0052] S6 debugging and verification: Water storage test: Close the valve and fill the paddy field with water to a depth of 10 cm. After 24 hours, the water level drops by 1.5 cm, which meets the water storage requirements for paddy fields.
[0053] Drainage test: Open the valve and drain the water layer completely within 48 hours.
[0054] Verification of rice growth cycle management: During the tillering stage, the valve was closed to store water to a depth of 5 cm; during the heading and flowering stage, a water layer of 10 cm was maintained; during the waxy ripening stage, the valve was opened to gradually drain the water. The water layer could be precisely controlled at each stage, meeting the standards for rice planting management.
[0055] Results: In the first year, the rice yield reached 420 kg per mu, and in the second year it increased to 480 kg per mu. The salt content of the topsoil decreased from 0.52% to 0.06%. Within three years, the underground pipes maintained normal drainage without any hardening or blockage.
[0056] Comparative Example 1: Construction site: The plot of land adjacent to Example 1, covering an area of 50 mu, is also a soda saline-alkali clay farmland with basically the same soil conditions.
[0057] Construction method: Excavate underground pipe trenches 1.3 meters deep and spaced 15 meters apart, lay PE single-wall corrugated pipes (without geotextile wrapping), and backfill the surrounding area with a small amount of sand and gravel filter material, approximately 5 cm thick. No seepage channel is installed. The outlet is a direct discharge pipe with no controllable drainage device.
[0058] Results: After the first year of irrigation and salt leaching, the underground pipes discharged water normally, and the salt content of the topsoil decreased from 0.44% to 0.18%, showing significant results.
[0059] During irrigation in the second spring, the water output from the underground pipe decreased significantly, to only about 20% of the first year's output. Upon excavation and inspection, it was found that the soil around the underground pipe was compacted and hardened, preventing water from penetrating into the pipe.
[0060] In the third year, the underground pipes stopped producing water altogether, and the salinity of the topsoil rebounded to 0.35%. The rice yield per mu plummeted from 350 kg in the first year to less than 80 kg in the third year, and the system completely failed.
[0061] Reasons for failure: The lack of drainage trenches disrupted the plow pan, causing the soil to harden after alternating wet and dry periods, thus eliminating the seepage channels; the absence of geotextile protection resulted in the pipe holes being blocked by fine soil particles; and the lack of a controllable drainage device made it impossible for the paddy field to retain water, making rice planting and management difficult.
[0062] Comparative Example 2: Construction site: The plot of land adjacent to Example 2, covering an area of 30 mu, with the same soil conditions.
[0063] Construction method: The method of laying the underground pipe is the same as in Example 2, and a ball valve is installed at the outlet for controllable drainage. However, no seepage trench is set up, and the drainage relies solely on the natural infiltration of the filter layer above the underground pipe.
[0064] Results: In the first year, the drainage effect was good, the water storage and drainage in the paddy fields were controlled normally, the salt content was reduced to 0.10%, and the rice yield was 400 kg per mu.
[0065] Starting in the second year, the rate of water infiltration from the field surface slowed significantly. Water storage tests showed that the water level dropped by only 0.3 cm in 24 hours, indicating that the soil between the topsoil and the underground pipes had hardened, obstructing the infiltration channels.
[0066] In the third year, drainage efficiency further decreased, the salt leaching effect was greatly reduced, the salt content rose back to 0.20%, and the rice yield per mu dropped to 250 kg.
[0067] Performance Difference: Compared with Example 2, the lack of drainage trenches led to soil compaction between the plow pan and the topsoil. Even with an intact filter layer in the underground pipes, water could not quickly infiltrate from the topsoil to the pipes. This demonstrates that orthogonal drainage trenches are a crucial structure for ensuring the long-term operation of the system and cannot be omitted.
[0068] The following table compares the solutions for treating sodium-alkali saline-alkali farmland: In summary, effective treatment of soda-saline-alkali farmland relies on three core structures: a horizontal and vertical orthogonal infiltration network, a filter layer for protection, and controllable drainage. Examples 1 and 2, based on these structures, adjusted parameters to suit different soil types and crops. After three years of treatment, soil indicators met standards, crop yields steadily increased, and the underground drainage system operated effectively for an extended period. Comparative Example 1, lacking all key structures, completely failed after three years. Comparative Example 2, omitting the infiltration trenches, experienced a continuous decline in effectiveness. Both examples exhibited soil compaction, obstructed drainage from the underground pipes, and a rebound in treatment results, fully demonstrating the irreplaceable nature of these key structures.
[0069] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Anyone skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.
Claims
1. A construction method for underground drainage in saline-alkali farmland, characterized in that, Includes the following steps: S1: Conduct site leveling and geological surveys on the saline-alkali farmland to be improved, and determine the laying parameters of underground pipes and infiltration ditches; S2: An integrated laser pipe laying machine is used to lay horizontal underground pipes at a preset depth, and filter material is filled simultaneously to form a permeable filter material layer that wraps the underground pipes; S3: Vertical seepage trenches are laid perpendicular to the horizontal underground pipes. The bottom of the seepage trenches is flush with the top of the seepage filter material layer, and the top penetrates the plow layer and extends into the tillage layer. S4: Install a controllable drainage device at the outlet of the concealed pipe; S5: Backfill and compact the soil in the construction area; S6: Debug the controllable drainage device and verify its drainage and water storage functions.
2. The construction method for underground drainage in saline-alkali farmland according to claim 1, characterized in that, S1 specifically includes: S11: Clear debris from the surface of cultivated land and level the land to a slope of ≤0.3%; S12: Survey the soil texture, salinity, and depth of the plow pan to determine the spacing of underground pipes (5 to 15 meters) and the burial depth (1 to 1.5 meters). The spacing of the drainage trenches should be consistent with that of the underground pipes.
3. The construction method for underground drainage in saline-alkali farmland according to claim 2, characterized in that, S2 specifically includes: S21: PE single-wall corrugated pipe is selected as the concealed pipe, and the outer wall of the pipe is wrapped with DuPont geotextile. S22: Fill with filter media of the same particle size as the mixed sand to form a permeable filter media layer with a thickness of 20-40 cm; S23: The integrated laser pipe laying machine completes trenching, pipe laying, and filter material filling in one go.
4. The construction method for underground drainage in saline-alkali farmland according to claim 3, characterized in that, S3 specifically includes: S31: The seepage channel is filled with the same filter material as the seepage filter layer, with a thickness of 0.3-0.5 meters; S32: The top of the seepage trench extends 15-20 cm into the plow layer, with an overall height of 30-60 cm; S33: The seepage channels and horizontal underground pipes are arranged at 90° angles to form a crisscrossing seepage network.
5. The construction method for underground drainage in saline-alkali farmland according to claim 4, characterized in that, S4 specifically includes: S41: Install a soft water hose of the same diameter as the pipe at the outlet of the concealed pipe; S42: A switch valve is installed at the end of the soft water hose to control the flow rate and the on / off state of drainage.
6. The construction method for underground drainage in saline-alkali farmland according to claim 4, characterized in that, S5 specifically includes: S51: The original soil is used to backfill the seepage trench and the underground pipe trench in layers, with each layer being ≤20 cm thick; S52: Lightly compact the backfill soil to avoid damaging the structure of the seepage ditch and filter layer.
7. The construction method for underground drainage in saline-alkali farmland according to claim 4, characterized in that, S6 specifically includes: S61: Close the switch valve and conduct a water storage test to verify that the water layer leakage is ≤5 cm within 24 hours; S62: Open the valve to conduct a drainage test and verify that the water level in the topsoil layer can drop to the target height within 48 hours.
8. The construction method for underground drainage in saline-alkali farmland according to claim 4, characterized in that: The method is applicable to clay, silt and soda saline-alkali land. The filter media can be replaced with sand, gravel, furnace ash or manufactured sand. The controllable drainage device can be replaced with a pneumatic control valve.