Soil remediation system and method for farmland reclamation

Abstract

The present invention relates to the technical field of soil remediation, and in particular to a soil remediation system and method for farmland reclamation, comprising a concealed pipe buried in the soil, the concealed pipe being distributed at fixed intervals inside the soil, the upper surface of the concealed pipe being provided with a mesh portion distributed continuously or at fixed intervals, the mesh portion being made of metal and having a supporting effect, the surface of the soil being provided with a water-retaining portion, and the interior of the concealed pipe being ventilated for a long period of time. In the present invention, the "surface aggregation phenomenon" is changed from the surface of the soil to the interior of the soil, reducing the repeated up and down migration of salt in the soil, making the soil moisture at the concealed pipe lower than the average soil moisture at the location of the concealed pipe, and under the action of capillary phenomenon, causing the salt in the soil to migrate toward the vicinity of the mesh portion and be locked near the mesh portion. During the rainy season or irrigation, saturated water passes through the vicinity of the mesh portion under the action of gravity, and carries the salt away through the interior of the concealed pipe and a drainage pipe, the drainage mode of the drainage pipe being gravity-driven or water pump-driven.

Description

Technical Field

[0001] The present invention relates to the technical field of soil remediation, and in particular to a soil remediation system and method for farmland reclamation. Background Art

[0002] Saline-alkali land refers to land affected by saline-alkali components in the soil. Saline-alkali land usually contains a large amount of saline-alkali ions, which affect the normal growth of crops.

[0003] Under the influence of surface aggregation phenomenon, salt will migrate to the surface of the soil. According to the movement characteristics of "salt follows water, water goes and salt remains", salt will migrate back and forth up and down in the soil. The upward migration of salt is mainly due to the rapid evaporation of the surface soil. After evaporation, the surface soil will experience capillary phenomenon and absorb water downward, which will continuously lead to salt accumulation and residue.

[0004] Various methods used in the existing technology, such as biological methods, have the disadvantage of slow effectiveness, chemical methods using the method of adding improvers are unsustainable, and soil turning and washing methods have the problems of large engineering workload and high cost. Therefore, to address the above problems, a soil remediation system and method for farmland reclamation are proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a soil remediation system and method for farmland reclamation. The present invention can continuously reduce the salt content in the soil, thereby realizing soil reclamation. The concealed pipes, water inlet pipes and other structures used in the remediation process can be used as irrigation channels for subsequent drip irrigation in reclamation, realizing the reuse of desalination and irrigation.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a soil remediation system for farmland reclamation, comprising a concealed pipe buried in the soil, the concealed pipes being arranged at fixed intervals within the soil, the upper surface of the concealed pipe being provided with a mesh portion arranged continuously or at fixed intervals, the mesh portion being made of metal and having a supporting effect, a water-retaining portion being provided on the surface of the soil, the interior of the concealed pipe being ventilated for a long period of time, so that the soil moisture at the location of the concealed pipe is lower than the average soil moisture at the location of the concealed pipe, a capillary phenomenon occurs near the concealed pipe, and the water-retaining portion is provided on the soil surface, reducing evaporation from the soil surface and causing salt in the soil to migrate toward the vicinity of the mesh portion;

[0007] Multiple concealed pipes are connected to the drainage pipes, and the water spraying caused by irrigation will carry away the salt near the net through the concealed pipes and drainage pipes.

[0008] In the present invention, the main method for desalting the soil is as follows: a concealed pipe is buried inside the soil, a water-retaining portion is provided on the surface of the soil to reduce evaporation from the soil surface, the interior of the concealed pipe is ventilated for a long time, and the "surface accumulation phenomenon" is changed from the surface of the soil to the interior of the soil, thereby reducing the repeated migration of salt in the soil. The soil moisture at the concealed pipe is lower than the average soil moisture at the location of the concealed pipe. Under the action of capillary phenomenon, the salt in the soil migrates to the vicinity of the mesh portion and is locked near the mesh portion. During the rainy season or irrigation, saturated water passes through the mesh portion under the action of gravity, carrying the salt away through the interior of the concealed pipe and the drain pipe. The drainage method of the drain pipe is gravity-driven or water pump-driven.

[0009] As a soil remediation system for farmland reclamation of the present invention, preferably, the water retention part is formed by laying straw on the soil surface or planting alkali-resistant plants on the soil surface.

[0010] Laying straw on the soil surface or planting alkali-resistant plants can effectively reduce the evaporation of water from the soil surface and reduce the capillary phenomenon of the soil surface;

[0011] As a soil remediation system for farmland reclamation of the present invention, preferably, the buried depth of the concealed pipe is the maximum average depth of the root system of the selected crops after reclamation.

[0012] The depth of the concealed pipe is near the maximum average depth of the root system of the selected crops after reclamation. The existence of the concealed pipe can produce an effective capillary effect on the soil near the plant roots. As the area near the concealed pipe is ventilated, the soil moisture near the concealed pipe evaporates, and the soil near the concealed pipe will produce suction for the surrounding salty water, which then evaporates again, thereby accumulating salt near the concealed pipe. The concealed pipe is near the root system of crops, which greatly eliminates the impact of salt on the root system of crops and achieves reclamation.

[0013] As a preferred embodiment of the soil remediation system for farmland reclamation of the present invention, a valve is connected to the outlet of the drainage pipe to control the opening and closing of the drainage pipe. Each concealed pipe is upwardly connected to air ducts at the front and rear positions, one air duct is used for supplying air, and the other air duct is used for drawing air, thereby realizing long-term ventilation inside the concealed pipe.

[0014] When the valve is closed, there are only two air outlets in the concealed pipe, namely the two air ducts. When the air ducts are working, the soil near the concealed pipe will evaporate continuously.

[0015] As a preferred embodiment of the soil remediation system for farmland reclamation of the present invention, evenly spaced slots are provided on the upper side of the wind tube, a fan for supplying or inducing air is fixedly connected to the inner side of the wind tube, the fan is installed on the lower side of the slots, and a valve is provided at the slots, the opening and closing angle of the valve is 80 degrees; the opening and closing angle of the valve is less than 90 degrees, which is used to prevent the valve from being too open and causing the valve to be unable to close;

[0016] When the valve is arranged on the inner side of the wind tube, the wind tube is used to supply air and introduce air into the concealed duct;

[0017] When the valve is arranged on the outside of the wind tube, the wind tube is used to draw air and lead out the air in the concealed pipe.

[0018] In the present invention, one of the two air ducts on the concealed pipe is equipped with a fan for supplying air, and the other is equipped with a fan for inducing air, thereby achieving forced ventilation;

[0019] In the present invention, when the fan is not working, under windy conditions, a pressure difference can still be generated at the two air ducts on the concealed pipe, thereby achieving ventilation;

[0020] When wind passes through the air duct for supplying air, the valve on the windward side is in an open state, the empty slot on the windward side is open, and the valve on the leeward side is in a closed state, the empty slot is closed;

[0021] When the wind passes through the wind tube for inducing air, the valve on the windward side is in a closed state, and the empty slot on the windward side is closed. The valve on the leeward side is in an open state under the negative pressure of the airflow, and the empty slot is in an open state.

[0022] This allows wind to flow into the concealed pipe, and the presence of the valve can reduce the amount of rainfall entering the concealed pipe to a certain extent;

[0023] As a preferred embodiment of the soil remediation system for farmland reclamation of the present invention, the top end of the concealed pipe is fixedly connected to a mesh support portion via a support member, and a water absorption portion is fixedly connected between the mesh support portion and the upper mesh portion.

[0024] The outer sides of the mesh structures such as the mesh support portion and the air-permeable portion in the present invention can be fixedly connected with linen cloth, which is used to filter and intercept, thereby preventing the mesh structure from being blocked by soil.

[0025] As the soil remediation system for farmland reclamation of the present invention, preferably, the water absorption part is a sponge, fiber cloth, etc.

[0026] As a preferred embodiment of the soil remediation system for farmland reclamation of the present invention, the net portion is continuously distributed, a uniaxial telescopic rod is fixedly connected to the inner side of the bottom end of the concealed pipe, and the movable end of the uniaxial telescopic rod is fixedly connected to the bottom end of the net portion. When the movable end of the uniaxial telescopic rod rises, the water absorption portion between the mesh support portion and the net portion is compressed upward, the ventilation influence area of ​​the concealed pipe is increased, the evaporation area is increased, and the range of salt migration that can be affected is also increased, thereby increasing the salt migration effect, and the pressure on the water absorption portion will cause the pore diameter in the water absorption portion to decrease, and the reduction in the pore diameter will increase the capillary suction of the water absorption portion to the surrounding soil water, thereby increasing the effect of salt migration to the concealed pipe and increasing the evaporation effect;

[0027] When the movable end of the uniaxial telescopic rod descends, the water absorption part between the mesh support part and the upper part increases, the pore diameter of the water absorption part increases, the permeability increases, and the drainage effect during water sprinkling and drainage is enhanced.

[0028] As a preferred soil remediation system for farmland reclamation of the present invention, the top of the concealed pipe is fixedly connected to an air duct, and air permeable parts are evenly arranged on the outside of the air duct. The two ends of the air duct are also connected to the two air ducts of the concealed pipe. The center of the air duct is fixedly connected to a water inlet pipe, and the water inlet end of the water inlet pipe can be connected to a pressurized water pipe. The water inlet pipe is evenly provided with nozzles on the inside of the air duct. After the water inlet pipe is connected to the pressurized water pipe, the water inlet pipe can spray water to the air permeable part to achieve water sprinkling near the air duct. The saturated water carrying salt flows into the concealed pipe under the action of gravity to achieve salt discharge.

[0029] The air duct and the concealed pipe share the air tube. The air duct greatly increases the surface area involved in the surface accumulation phenomenon, increases the impact range of salt migration to the air duct and the concealed pipe, and the air duct has a larger surface accumulation area. After the water inlet pipe is connected to the pressurized water pipe, the water inlet pipe can spray water to the air permeable part to achieve water sprinkling near the air duct. The saturated water carries the salt and flows into the concealed pipe under the action of gravity to achieve salt discharge.

[0030] The soil remediation method for farmland reclamation comprises the following steps:

[0031] Step 1: Bury a concealed pipe inside the soil, set a water-retaining part on the soil surface to reduce evaporation from the soil surface, and ventilate the interior of the concealed pipe for a long time to make the soil humidity at the concealed pipe lower than the average soil humidity where the concealed pipe is located. Under the action of capillary phenomenon, the salt in the soil migrates to the vicinity of the net part;

[0032] Step 2: The water spraying operation will remove the salt near the net through the hidden pipes and drain pipes.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The soil remediation system for farmland reclamation of the present invention mainly desalinates the soil by burying a concealed pipe inside the soil, providing a water-retaining portion on the surface of the soil to reduce evaporation from the soil surface, and ventilating the interior of the concealed pipe for a long time to change the "surface accumulation phenomenon" from the surface of the soil to the interior of the soil, thereby reducing the repeated up and down migration of salt in the soil, migrating downward in the rainy season and upward in the dry season, so that the soil moisture at the concealed pipe is lower than the average soil moisture at the location of the concealed pipe. Under the action of capillary phenomenon, the salt in the soil migrates toward the vicinity of the net-surface portion and is locked near the net-surface portion. During the rainy season or irrigation, saturated water passes through the vicinity of the net-surface portion under the action of gravity, and carries away the salt through the interior of the concealed pipe and the drain pipe. The drainage method of the drain pipe is gravity-driven or water pump-driven.

[0035] 2. In the soil remediation system used for farmland reclamation, the depth of the concealed pipe is near the maximum average depth of the root system of the selected crops after reclamation. The existence of the concealed pipe can produce an effective capillary phenomenon on the soil near the plant roots. As the ventilation near the concealed pipe increases, the soil moisture near the concealed pipe evaporates, and the soil near the concealed pipe will generate suction for the surrounding salty water, which then evaporates again, thereby accumulating salt near the concealed pipe. The concealed pipe is near the root system of crops, thereby greatly eliminating the impact of salt on the root system of crops and achieving reclamation.

[0036] 3. The soil remediation system for farmland reclamation has two air ducts on the concealed pipe, one of which is equipped with a fan for supplying air and the other with a fan for induced air, to achieve forced ventilation. When the fan is not working, a pressure difference can still be generated at the two air ducts on the concealed pipe under windy conditions, thereby achieving ventilation. When wind passes through the air duct for supplying air, the valve on the windward side is in an open state, the empty slot on the windward side is open, the valve on the leeward side is in a closed state, and the empty slot is in a closed state. When wind passes through the air duct for induced air, the valve on the windward side is in a closed state, the empty slot on the windward side is closed, and the valve on the leeward side is in an open state under the action of negative pressure when the air flows through, and the empty slot is in an open state, so that wind can be poured into the concealed pipe. The existence of the valve can reduce the entry of rainfall into the concealed pipe to a certain extent.

[0037] 4. In the soil remediation system for farmland reclamation, when the movable end of the uniaxial telescopic rod rises, the water absorption part between the mesh support part and the upper part is compressed upward, the ventilation influence area of ​​the concealed pipe increases, the evaporation area increases, and the range of salt migration that can be affected also increases, thereby increasing the salt migration effect. The pressure on the water absorption part will cause the pore diameter in the water absorption part to decrease. The decrease in pore diameter will increase the capillary suction of the water absorption part to the surrounding soil water, increase the effect of salt migration to the concealed pipe, and increase the evaporation effect. When the movable end of the uniaxial telescopic rod descends, the water absorption part between the mesh support part and the upper part increases, the pore diameter of the water absorption part increases, the permeability increases, and the drainage effect during water sprinkling and drainage is increased.

[0038] 5. In the soil remediation system used for farmland reclamation, the air duct and the concealed pipe share the air tube. The air duct greatly increases the surface area involved in the surface accumulation phenomenon, increases the impact range of salt migration to the air duct and the concealed pipe, and the air duct has a larger surface accumulation area. After the water inlet pipe is connected to the pressurized water pipe, the water inlet pipe can spray water to the air permeable part to achieve water sprinkling near the air duct. The saturated water carries the salt and flows into the concealed pipe under the action of gravity to achieve salt discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0040] Figure 2 This is a schematic diagram of the appearance structure of the concealed pipe of the present invention;

[0041] Figure 3 Schematic diagram of the buried position of the concealed pipe in the present invention;

[0042] Figure 4 This is a schematic diagram of the structure of the fan of the present invention when it is used for air supply;

[0043] Figure 5 This is a schematic diagram of the structure of the fan duct of the present invention when used for air induction;

[0044] Figure 6 This is a schematic diagram of the structure of the concealed pipe and the air duct in the soil in the present invention;

[0045] Figure 7 This is a schematic structural diagram of the concealed pipe, air duct and water inlet pipe of the present invention;

[0046] Figure 8 Schematic diagram of the cross-sectional structure of the concealed pipe and the air duct of the present invention;

[0047] Figure 9 This is a schematic diagram of the cross-sectional structure of the concealed pipe and the air duct in the soil of the present invention;

[0048] Figure 10 For the present invention Figure 9 A in the figure is an enlarged structural diagram.

[0049] In the figure: 1. Soil; 2. Concealed pipe; 21. Net-mounted part; 3. Drain pipe; 4. Valve; 5. Air duct; 51. Empty slot; 52. Fan; 53. Valve; 6. Water-retaining part; 7. Air duct; 71. Breathable part; 72. Water inlet pipe; 8. Mesh support part; 9. Single-axis telescopic rod; 10. Water absorption part. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] Example 1, please refer to Figure 1-5 , the present invention provides a technical solution:

[0052] A soil remediation system for farmland reclamation includes a concealed pipe 2 buried within soil 1. The concealed pipes 2 are arranged at fixed intervals within the soil 1. A continuous or fixed-interval mesh portion 21 is provided on the upper surface of the concealed pipe 2. The mesh portion 21 is made of metal and has a supporting effect. A water-retaining portion 6 is provided on the surface of the soil 1. The interior of the concealed pipe 2 is ventilated for a long time, so that the soil moisture at the location of the concealed pipe 2 is lower than the average soil moisture at the location of the concealed pipe 2. Capillary action occurs near the concealed pipe 2. The water-retaining portion 6 is provided on the surface of the soil 1 to reduce evaporation from the surface of the soil 1, causing salt in the soil to migrate toward the mesh portion 21.

[0053] The multiple concealed pipes 2 are all connected to the drainage pipe 3 , and the water spraying effect brought by irrigation will carry away the salt near the net part 21 through the concealed pipes 2 and the drainage pipe 3 .

[0054] In the present invention, the main method for desalting the soil 1 is as follows: a concealed pipe 2 is buried inside the soil 1, a water-retaining portion 6 is provided on the surface of the soil 1 to reduce evaporation from the surface of the soil 1, the interior of the concealed pipe 2 is ventilated for a long time, and the "surface accumulation phenomenon" is changed from the surface of the soil 1 to the interior of the soil 1, thereby reducing the repeated migration of salt in the soil 1 up and down, migrating downward in the rainy season and upward in the dry season, so that the soil moisture at the concealed pipe 2 is lower than the average soil moisture at the location of the concealed pipe 2. Under the action of capillary phenomenon, the salt in the soil migrates to the vicinity of the net-surface portion 21 and is locked near the net-surface portion 21. During the rainy season or irrigation, saturated water passes through the vicinity of the net-surface portion 21 under the action of gravity, and carries the salt away through the interior of the concealed pipe 2 and the drain pipe 3. The drainage method of the drain pipe 3 is gravity-driven or water pump-driven.

[0055] In an optional embodiment, the water retaining portion 6 is formed by laying straw on the surface of the soil 1 or planting alkali-resistant plants on the surface of the soil 1 .

[0056] Laying straw or planting alkali-resistant plants on the surface of the soil 1 can effectively reduce the evaporation of water on the surface of the soil and reduce the capillary phenomenon on the surface of the soil 1;

[0057] In an optional embodiment, the buried depth of the concealed pipe 2 is the maximum average depth of the root system of the selected crops after reclamation.

[0058] The depth of the hidden pipe 2 is near the maximum average depth of the root system of the selected crops after reclamation. The presence of the hidden pipe 2 can produce an effective capillary effect on the soil near the plant roots. As the area near the hidden pipe 2 is ventilated, the soil moisture near the hidden pipe 2 evaporates, and the soil near the hidden pipe 2 generates suction for the surrounding salty water, which then evaporates again, thereby accumulating salt near the hidden pipe 2. The hidden pipe 2 is near the root system of the crops, thereby greatly eliminating the impact of salt on the root system of the crops and achieving reclamation.

[0059] In an optional embodiment, a valve 4 is connected to the outlet of the drain pipe 3 for controlling the opening and closing of the drain pipe 3. Each concealed pipe 2 is upwardly connected to an air duct 5 at the front and rear positions, one air duct 5 is used for supplying air, and the other air duct 5 is used for drawing air, thereby achieving long-term ventilation inside the concealed pipe 2.

[0060] When the valve 4 is closed, the concealed pipe 2 has only two air outlets, namely, the two air ducts 5. When the air ducts 5 are working, the soil 1 near the concealed pipe 2 evaporates continuously and uninterruptedly.

[0061] In an optional embodiment, evenly spaced slots 51 are provided on the upper side of the air duct 5. A fan 52 for supplying or inducing air is fixedly connected to the inner side of the air duct 5. The fan 52 is installed on the lower side of the slots 51. A valve 53 is provided at the slots 51. The opening and closing angle of the valve 53 is 80°. The opening and closing angle of the valve 53 is less than 90° to prevent the valve 53 from being over-opened and unable to close.

[0062] When the valve 53 is arranged on the inner side of the wind tube 5, the wind tube 5 is used to supply air and introduce air into the concealed tube 2;

[0063] When the valve 53 is arranged on the outside of the wind tube 5 , the wind tube 5 is used to draw air and lead the air in the concealed tube 2 out.

[0064] The valve is made of a plastic sheet;

[0065] In the present invention, one of the two air ducts 5 on the concealed pipe 2 is equipped with a fan 52 for supplying air, and the other is equipped with a fan 52 for inducing air, so as to realize forced ventilation;

[0066] In the present invention, when the fan 52 is not working, under windy conditions, a pressure difference can still be generated at the two air ducts 5 on the concealed pipe 2, thereby achieving ventilation;

[0067] When wind passes through the air duct 5 for supplying air, the valve 53 on the windward side is in an open state, the empty slot 51 on the windward side is open, and the valve 53 on the leeward side is in a closed state, and the empty slot 51 is in a closed state;

[0068] When wind passes through the wind tube 5 for inducing air, the valve 53 on the windward side is in a closed state, and the empty slot 51 on the windward side is closed. The valve 53 on the leeward side is in an open state under the negative pressure of the airflow, and the empty slot 51 is in an open state.

[0069] Thus, wind can flow into the concealed pipe 2, and the presence of the valve 53 can reduce the amount of rainfall entering the concealed pipe 2 to a certain extent;

[0070] Example 2: This example is a further improvement of Example 1. Figures 1-10The top end of the concealed pipe 2 is fixedly connected to a mesh support portion 8 through a support member, and a water absorption portion 10 is fixedly connected between the mesh support portion 8 and the upper net portion 21 .

[0071] The outer sides of the mesh structures such as the mesh support portion 8 and the air-permeable portion 71 in the present invention may be fixedly connected with linen, which is used to filter and intercept to prevent the mesh structure from being blocked by soil.

[0072] In an optional embodiment, the water absorbing part 10 is a sponge, fiber cloth, etc.

[0073] In an optional embodiment, the net portion 21 is continuously distributed, and a uniaxial telescopic rod 9 is fixedly connected to the inner side of the bottom end of the concealed tube 2, and the movable end of the uniaxial telescopic rod 9 is fixedly connected to the bottom end of the net portion 21. When the movable end of the uniaxial telescopic rod 9 rises, the water absorption portion 10 between the mesh support portion 8 and the net portion 21 is compressed upward, the ventilation influence area of ​​the concealed tube increases, the evaporation area increases, and the range of salt migration that can be affected also increases, thereby increasing the salt migration effect, and the pressure on the water absorption portion 10 will cause the pore diameter in the water absorption portion 10 to decrease. The reduction in pore diameter will increase the capillary suction of the water absorption portion 10 on the surrounding soil water, thereby increasing the effect of salt migration to the concealed tube 2 and increasing the evaporation effect;

[0074] When the movable end of the uniaxial telescopic rod 9 descends, the water absorption part 10 between the mesh support part 8 and the net part 21 increases, the pore diameter of the water absorption part 10 increases, and the permeability increases, thereby increasing the drainage effect during water spraying and drainage.

[0075] In an optional embodiment, the top of the concealed pipe 2 is fixedly connected to an air duct 7, and a ventilating portion 71 is evenly provided on the outside of the air duct 7. Both ends of the air duct 7 are also connected to the two air tubes 5 of the concealed pipe 2. A water inlet pipe 72 is fixedly connected to the center of the air duct 7. The water inlet end of the water inlet pipe 72 can be connected to a pressurized water pipe. The water inlet pipe 72 is evenly provided with nozzles on the inner side of the air duct 7. After the water inlet pipe 72 is connected to the pressurized water pipe, the water inlet pipe 72 can spray water toward the ventilating portion 71 to achieve water sprinkling near the air duct 7. The saturated water carrying salt flows into the concealed pipe 2 under the action of gravity to achieve salt discharge.

[0076] The air duct 7 and the concealed pipe 2 share the air tube 5. The air duct 7 greatly increases the surface area involved in the surface accumulation phenomenon, increases the influence range of salt migration to the air duct 7 and the concealed pipe 2, and the air duct 7 has a larger surface accumulation area. After the water inlet pipe 72 is connected to the pressurized water pipe, the water inlet pipe 72 can spray water to the air permeable part 71 to achieve water sprinkling near the air duct 7. The saturated water carries salt and flows into the concealed pipe 2 under the action of gravity to achieve salt discharge.

[0077] The present invention also discloses a soil remediation method for farmland reclamation, which comprises the following steps:

[0078] Step 1: Bury a concealed pipe 2 inside the soil 1. A water-retaining portion 6 is provided on the surface of the soil 1 to reduce evaporation from the surface of the soil 1. The interior of the concealed pipe 2 is ventilated for a long period of time to make the soil humidity at the location of the concealed pipe 2 lower than the average soil humidity at the location of the concealed pipe 2. Capillary action causes salt in the soil to migrate toward the net portion 21.

[0079] Step 2: The water spraying operation will remove the salt near the net part 21 through the hidden pipe 2 and the drain pipe 3.

[0080] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A soil remediation system for farmland reclamation, comprising a concealed pipe (2) buried in the soil (1), characterized in that: The concealed pipes (2) are distributed at fixed intervals inside the soil (1). The upper surface of the concealed pipes (2) is provided with a continuous or fixed-interval distributed net portion (21). The net portion (21) is made of metal and has a supporting effect. The surface of the soil (1) is provided with a water retaining portion (6). The interior of the concealed pipes (2) is ventilated for a long time, so that the soil moisture at the concealed pipes (2) is lower than the average soil moisture at the location of the concealed pipes (2). Capillary phenomenon occurs near the concealed pipes (2). The water retaining portion (6) is provided on the surface of the soil (1), reducing evaporation from the surface of the soil (1) and causing salt in the soil to migrate to the vicinity of the net portion (21). The plurality of concealed pipes (2) are all connected to the drainage pipe (3). The water spraying effect brought by irrigation will carry away the salt near the net portion (21) through the concealed pipes (2) and the drainage pipe (3). The top of the concealed pipe (2) is fixedly connected to a mesh support portion (8) through a support member. A water absorption portion (10) is fixedly connected between the mesh support portion (8) and the net portion (21). The outlet of the drainage pipe (3) is connected to a valve (4) for controlling the opening and closing of the drainage pipe (3). Each concealed pipe (2) is upwardly connected to an air duct (5) at the front and rear positions. One air duct (5) is used for supplying air, and the other air duct (5) is used for drawing air, thereby achieving long-term ventilation inside the concealed pipe (2); The upper side of the wind tube (5) is provided with evenly arranged empty slots (51), and the inner side of the wind tube (5) is fixedly connected with a fan (52) for supplying or inducing air. The fan (52) is installed on the lower side of the empty slot (51). A valve (53) is provided at the empty slot (51). The opening and closing angle of the valve (53) is 80 degrees. When the valve (53) is provided on the inner side of the wind tube (5), the wind tube (5) is used for supplying air and introducing air into the concealed pipe (2). When the valve (53) is provided on the outer side of the wind tube (5), the wind tube (5) is used for inducing air and leading the air in the concealed pipe (2) out. The net portion (21) is continuously distributed. A uniaxial telescopic rod (9) is fixedly connected to the inner side of the bottom end of the concealed pipe (2). The movable end of the uniaxial telescopic rod (9) is fixedly connected to the bottom end of the net portion (21). When the movable end of the uniaxial telescopic rod (9) rises, the water absorption portion (10) between the mesh support portion (8) and the net portion (21) is compressed upward, the ventilation influence area of ​​the concealed pipe increases, the water absorption portion (10) is compressed, resulting in a decrease in the pore diameter in the water absorption portion (10), an increase in the water suction force of the water absorption portion (10) on the surrounding soil, and an increase in the effect of salt migration to the concealed pipe (2). When the movable end of the uniaxial telescopic rod (9) falls, the water absorption portion (10) between the mesh support portion (8) and the net portion (21) increases, the pore diameter of the water absorption portion (10) increases, the permeability increases, and the drainage effect during water sprinkling and drainage is increased. The top of the concealed pipe (2) is fixedly connected to the air duct (7), and the outside of the air duct (7) is evenly provided with a ventilating portion (71). The two ends of the air duct (7) are also connected to the two air ducts (5) of the concealed pipe (2). The center of the air duct (7) is fixedly connected to the water inlet pipe (72). The water inlet end of the water inlet pipe (72) can be connected to the pressurized water pipe. The water inlet pipe (72) is evenly provided with nozzles on the inside of the air duct (7). After the water inlet pipe (72) is connected to the pressurized water pipe, the water inlet pipe (72) can spray water to the ventilating portion (71), thereby achieving water spraying near the air duct (7). The saturated water carries salt and flows into the concealed pipe (2) under the action of gravity to achieve salt discharge.

2. The soil remediation system for farmland reclamation according to claim 1, characterized in that: The water-retaining part (6) is formed by laying straw on the surface of the soil (1) or by planting alkali-resistant plants on the surface of the soil (1).

3. The soil remediation system for farmland reclamation according to claim 1, characterized in that: The buried depth of the concealed pipe (2) is the maximum average depth of the root system of the selected crops after reclamation.

4. The soil remediation system for farmland reclamation according to claim 1, characterized in that: The water absorbing part (10) is a sponge or a fiber cloth.

5. A soil remediation method for farmland reclamation, using the soil remediation system according to claim 1, characterized in that: The steps are: Step 1: Bury a concealed pipe (2) inside the soil (1), and provide a water-retaining portion (6) on the surface of the soil (1) to reduce evaporation from the surface of the soil (1). The interior of the concealed pipe (2) is ventilated for a long time, so that the soil moisture at the concealed pipe (2) is lower than the average soil moisture at the location of the concealed pipe (2). Under the action of capillary action, salt in the soil migrates to the vicinity of the net portion (21); Step 2: The water spraying operation will remove the salt near the net-surface part (21) through the hidden pipe (2) and the drainage pipe (3).

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