Soil remediation system and method for farmland reclamation

Abstract

The invention relates to the technical field of soil remediation, in particular to a soil remediation system and method for farmland reclamation, the soil remediation system comprises concealed pipes buried in soil, the concealed pipes are fixedly distributed in the soil at intervals, the upper surfaces of the concealed pipes are provided with upper net parts which are continuously or fixedly distributed at intervals, and the upper net parts are made of metal and have a supporting effect; according to the invention, the surface aggregation phenomenon is changed from the surface of the soil to the interior of the soil, so that the up-down repeated migration of salt in the soil is reduced, the soil humidity at the position of the underground pipe is lower than the average soil humidity of the underground pipe, and under the action of the capillarity, the water retention effect of the underground pipe is improved. Salt in the soil is migrated to the position near the upper net part and locked near the upper net part, in the rainy season or during irrigation, saturated water passes through the position near the upper net part under the action of gravity, the salt is taken away through the interior of the concealed pipe and the drainage pipe, and the drainage mode of the drainage pipe is a gravity mode or a water pump driving mode.

Description

Technical Field

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

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

[0003] Under the action of the surface accumulation phenomenon, salts will migrate to the soil surface layer. According to the movement characteristics of "salts follow water and water leaves salts behind", salts will reciprocally migrate up and down in the soil. The upward migration of salts is mainly because the evaporation of the surface soil is fast, and after evaporation, capillary phenomenon will occur in the surface soil, sucking water downward, thus continuously causing salt accumulation and residue.

[0004] In the prior art, various methods are adopted. For example, the biological method has the disadvantage of slow effect, the chemical method of adding modifiers is not sustainable, and the method of turning over the soil and washing the land has the problems of large engineering quantity and high cost. Therefore, a soil remediation system and method for farmland reclamation are proposed to solve the above problems. 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 salts in the soil, thereby realizing the reclamation of the soil. Structures such as the blind pipes and water inlet pipes used in the remediation process can be used as irrigation channels for drip irrigation in subsequent reclamation, realizing the repeated utilization of desalination and irrigation.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A soil remediation system for farmland reclamation, including blind pipes buried inside the soil. The blind pipes are fixedly spaced apart inside the soil. The upper surface of the blind pipes is provided with upper net parts distributed continuously or at fixed intervals. The upper net parts are made of metal and have a supporting effect. A water retention part is arranged on the surface of the soil. The inside of the blind pipes is ventilated for a long time, so that the soil humidity at the position of the blind pipes is lower than the average soil humidity where the blind pipes are located. Capillary phenomenon will occur near the blind pipes, and a water retention part is arranged on the soil surface to reduce the evaporation of the soil surface, so that the salts in the soil migrate near the upper net parts;

[0007] Multiple blind pipes are all communicated with a drain pipe. The water leaching effect brought by irrigation will take away the salts near the upper net parts through the blind pipes and the drain pipe.

[0008] In the present invention, the main method for desalinating the soil is as follows: burying a blind pipe inside the soil, arranging a water retention part on the soil surface to reduce the evaporation on the soil surface, keeping the inside of the blind pipe ventilated for a long time, changing the "surface accumulation phenomenon" from the soil surface to the inside of the soil, reducing the repeated up-and-down migration of salts in the soil, making the soil humidity at the position of the blind pipe lower than the average soil humidity where the blind pipe is located. Under the action of capillary action, the salts in the soil migrate upward to the vicinity of the upper net part and are locked there. During the rainy season or irrigation, the saturated water passes through the vicinity of the upper net part under the action of gravity and takes away the salts through the inside of the blind pipe and the drain pipe. The drainage method of the drain pipe is gravity type or driven by a water pump;

[0009] Preferably, as the soil remediation system for farmland reclamation of the present invention, the water retention part is formed by laying straw on the soil surface or planting alkali-tolerant plants on the soil surface layer.

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

[0011] Preferably, as the soil remediation system for farmland reclamation of the present invention, the burial depth of the blind pipe is the maximum average depth of the roots of the selected crops after reclamation.

[0012] The depth of the blind pipe is near the maximum average depth of the roots of the selected crops after reclamation. The existence of the blind pipe can produce an effective capillary phenomenon on the soil near the plant roots. With the ventilation near the blind pipe, the soil moisture near the blind pipe evaporates, and the soil near the blind pipe will generate suction on the surrounding water with salts and then evaporate again, thus accumulating the salts near the blind pipe. And the blind pipe is near the crop roots, thus greatly eliminating the influence of salts on the crop roots and realizing reclamation;

[0013] Preferably, as the soil remediation system for farmland reclamation of the present invention, a valve is connected to the outlet of the drain pipe to control the opening and closing of the drain pipe. Each blind pipe is connected upward to a wind tunnel at the front and rear positions. One wind tunnel is used for air supply and the other wind tunnel is used for air extraction to realize long-term ventilation inside the blind pipe.

[0014] When the valve is closed, there are only two air outlets in the blind pipe, that is, at the two wind tunnels. When the wind tunnels work, continuous and uninterrupted evaporation occurs on the soil near the blind pipe;

[0015] Preferably, as the soil remediation system for farmland reclamation of the present invention, evenly arranged empty slots are opened on the upper side of the wind tunnel. A fan for air supply or air extraction is fixedly connected to the inner side of the wind tunnel. The fan is installed on the lower side of the empty slot. A valve flap is arranged at the empty slot, and the opening and closing angle of the valve flap is 80°; the opening and closing angle of the valve flap is less than 90° to prevent the valve flap from opening too much and causing the phenomenon of not being able to close;

[0016] When the valve is arranged inside the air duct, the air duct is used for air supply to introduce air into the blind pipe.

[0017] When the valve is arranged outside the air duct, the air duct is used for air extraction to extract the air inside the blind pipe.

[0018] In the present invention, one of the two air ducts on the blind pipe is installed with a blower for air supply, and the other is installed with a blower for air extraction to achieve forced ventilation.

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

[0020] When the wind passes through the air duct for air supply, 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.

[0021] When the wind passes through the air duct for air extraction, 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 negative pressure effect when the air flow passes through, and the empty slot is in an open state.

[0022] Thus, the wind can be poured into the blind pipe, and the presence of the valve can reduce the rainfall entering the blind pipe to a certain extent.

[0023] Preferably, as the soil remediation system for farmland reclamation of the present invention, the top end of the blind pipe is fixedly connected with a mesh support part through a support member, and a water absorption part is fixedly connected between the mesh support part and the upper net part.

[0024] On the outer side of the mesh structures such as the mesh support part and the air permeable part in the present invention, a linen cloth can be fixedly connected, and the linen cloth is used to play a role of filtering and intercepting to prevent the mesh structure from being blocked by soil.

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

[0026] Preferably, as the soil remediation system for farmland reclamation of the present invention, the upper net part is arranged in a continuous distribution, and a single-axis telescopic rod is fixedly connected to the inner side of the bottom end of the blind pipe. The movable end of the single-axis telescopic rod is fixedly connected to the bottom end of the upper net part. When the movable end of the single-axis telescopic rod rises, the water absorption part between the mesh support part and the upper net part is compressed upward. The ventilation influence area of the blind pipe increases, the evaporation area increases, and the range of salt migration that can be affected will also increase, thereby increasing the salt migration effect. Moreover, the compression of the water absorption part will cause the pore diameter inside the water absorption part to decrease, and the decrease in the pore diameter will increase the capillary suction of the water absorption part for the surrounding soil water, increasing the effect of salt migration towards the blind 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 netting part increases, the pore diameter of the water absorption part increases, and the permeability increases, enhancing the drainage effect during water spraying and drainage.

[0028] Preferably, for the soil remediation system for farmland reclamation of the present invention, an air duct is fixedly connected to the top of the blind pipe. The outer side of the air duct is evenly provided with a ventilation part. Both ends of the air duct are also communicated with the two air cylinders of the blind pipe. A water inlet pipe is fixedly connected to the center of the air duct. 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 spray heads inside the air duct. After the water inlet pipe is communicated with the pressurized water pipe inside, the water inlet pipe can spray water to the ventilation part to achieve water spraying near the air duct. The saturated water carrying salts flows into the blind pipe under the action of gravity to achieve salt drainage.

[0029] The air duct and the blind pipe share the air cylinder. The air duct greatly increases the surface area involved in the surface accumulation phenomenon, increasing the influence range of salt migration towards the air duct and the blind pipe. Moreover, the air duct has a larger surface area for surface accumulation. After the water inlet pipe is communicated with the pressurized water pipe inside, the water inlet pipe can spray water to the ventilation part to achieve water spraying near the air duct. The saturated water carrying salts flows into the blind pipe under the action of gravity to achieve salt drainage.

[0030] A soil remediation method for farmland reclamation, the steps of which are as follows:

[0031] Step 1: Bury a blind pipe inside the soil, and a water retention part is provided on the surface of the soil to reduce the evaporation on the soil surface. The inside of the blind pipe is ventilated for a long time, so that the soil humidity at the blind pipe is lower than the average soil humidity where the blind pipe is located. Under the action of capillary action, the salts in the soil migrate upwards near the upper netting part;

[0032] Step 2: The water spraying operation will carry away the salts near the upper netting part through the blind pipe and the drain pipe.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1. For the soil remediation system for farmland reclamation, in the present invention, the main method for desalinating the soil is to bury a blind pipe inside the soil, and a water retention part is provided on the surface of the soil to reduce the evaporation on the soil surface. The inside of the blind pipe is ventilated for a long time, changing the "surface accumulation phenomenon" from the soil surface to the soil interior, reducing the repeated up and down migration of salts in the soil (downward migration in the rainy season and upward migration in the dry season), making the soil humidity at the blind pipe lower than the average soil humidity where the blind pipe is located. Under the action of capillary action, the salts in the soil migrate upwards near the upper netting part and are locked near the upper netting part. During the rainy season or irrigation, the saturated water passes near the upper netting part under the action of gravity, and the salts are carried away through the inside of the blind pipe and the drain pipe. The drainage method of the drain pipe is gravity type or pump-driven.

[0035] 2. For the soil remediation system used in farmland reclamation, the depth of the blind pipes is near the maximum average depth of the roots of the selected crops after reclamation. The presence of the blind pipes can produce an effective capillary phenomenon in the soil near the plant roots. With the ventilation near the blind pipes, the soil moisture near the blind pipes evaporates. The soil near the blind pipes will generate suction on the surrounding water with salt, and then evaporate again, thus accumulating the salt near the blind pipes. Since the blind pipes are near the crop roots, the influence of salt on the crop roots can be greatly eliminated, realizing reclamation.

[0036] 3. For the soil remediation system used in farmland reclamation, one of the two air ducts on the blind pipes is installed with a blower for air supply, and the other is installed with a blower for air extraction to achieve forced ventilation. When the blowers are not working, under windy conditions, a pressure difference can still be generated at the two air ducts on the blind pipes, thus realizing ventilation. When the wind passes through the air duct for air supply, the valve on the windward side is in the open state, the empty slot on the windward side is open, the valve on the leeward side is in the closed state, and the empty slot is in the closed state. When the wind passes through the air duct for air extraction, the valve on the windward side is in the closed state, the empty slot on the windward side is closed, and the valve on the leeward side is in the open state under the negative pressure effect when the air flow passes through, and the empty slot is in the open state, so that the wind can be poured into the blind pipes. The presence of the valves can reduce the rainfall entering the blind pipes to a certain extent.

[0037] 4. For the soil remediation system used in farmland reclamation, when the movable end of the single-axis telescopic rod rises, the water absorption part between the mesh support part and the upper net part is compressed upward. The ventilation influence area of the blind pipes increases, the evaporation area increases, and the range of salt migration that can be affected will also increase, thus increasing the salt migration effect. And the compression of the water absorption part will cause the pore diameter inside the water absorption part to decrease. The decrease in the pore diameter will increase the capillary suction of the water absorption part on the surrounding soil water, increasing the effect of salt migration towards the blind pipes and increasing the evaporation effect. When the movable end of the single-axis telescopic rod descends, the water absorption part between the mesh support part and the upper net part increases, the pore diameter of the water absorption part increases, and the permeability increases, increasing the drainage effect during water leaching and drainage.

[0038] 5. For the soil remediation system used in farmland reclamation, the air duct shares the air duct with the blind pipes. The air duct greatly increases the surface area participating in the surface accumulation phenomenon, increasing the influence range of salt migration towards the air duct and the blind pipes. And the air duct has a larger surface accumulation area. After connecting the water inlet pipe with the pressurized water pipe, the water inlet pipe can spray water to the air permeable part, realizing water leaching near the air duct. The saturated water carrying salt flows into the blind pipes under the action of gravity to achieve salt drainage. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is the overall structural schematic diagram of the present invention;

[0040] Figure 2 is the external structural schematic diagram at the blind 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 Top view structural diagram of the air duct of the present invention when used for air supply;

[0043] Figure 5 Top view structural diagram of the air duct of the present invention when used for air extraction;

[0044] Figure 6 Schematic diagram of the structures of the concealed pipe and the air duct in the soil in the present invention;

[0045] Figure 7 Schematic diagram of the structures of the concealed pipe, the air duct and the water inlet pipe in the present invention;

[0046] Figure 8 Cross-sectional structural diagram of the concealed pipe and the air duct in the present invention;

[0047] Figure 9 Cross-sectional view structural diagram of the concealed pipe and the air duct in the soil in the present invention;

[0048] Figure 10 For the present invention Figure 9 Enlarged structural diagram at position A.

[0049] In the figure: 1, soil; 2, concealed pipe; 21, upper netting part; 3, drain pipe; 4, valve; 5, air duct; 51, empty slot; 52, fan; 53, valve flap; 6, water retention part; 7, air duct; 71, air permeable part; 72, water inlet pipe; 8, mesh support part; 9, single-axis telescopic rod; 10, water absorption part. Detailed implementation manners

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

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

[0052] A soil remediation system for farmland reclamation, including a buried blind pipe 2 inside the soil 1. The blind pipes 2 are fixedly spaced inside the soil 1. The upper surface of the blind pipe 2 is provided with an upper net part 21 distributed continuously or at fixed intervals. The upper net part 21 is made of metal and has a supporting effect. A water retention part 6 is arranged on the surface of the soil 1. The inside of the blind pipe 2 is ventilated for a long time, so that the soil humidity at the blind pipe 2 is lower than the average soil humidity where the blind pipe 2 is located. Capillary phenomenon will occur near the blind pipe 2. By arranging the water retention part 6 on the surface of the soil 1, the evaporation on the surface of the soil 1 is reduced, and the salt in the soil migrates upward near the upper net part 21;

[0053] Multiple blind pipes 2 are all connected to the drain pipe 3. The water leaching effect brought by irrigation will carry away the salt near the upper net part 21 through the blind pipe 2 and the drain pipe 3.

[0054] In the present invention, the main method for desalting the soil 1 is as follows: bury blind pipes 2 inside the soil 1, arrange a water retention part 6 on the surface of the soil 1 to reduce the evaporation on the surface of the soil 1, ventilate the inside of the blind pipe 2 for a long time, change the "surface accumulation phenomenon" from the surface of the soil 1 to the inside of the soil 1, reduce the repeated migration of salt up and down in the soil 1 (downward migration in the rainy season and upward migration in the dry season), make the soil humidity at the blind pipe 2 lower than the average soil humidity where the blind pipe 2 is located. Under the action of capillary phenomenon, the salt in the soil migrates upward near the upper net part 21 and is locked near the upper net part 21. In the rainy season or during irrigation, the saturated water passes near the upper net part 21 under the action of gravity, and the salt is carried away through the inside of the blind pipe 2 and the drain pipe 3. The drainage method of the drain pipe 3 is gravity type or driven by a water pump;

[0055] In an optional embodiment, the water retention part 6 is formed by laying straw on the surface of the soil 1 or by planting alkali-tolerant plants in the surface layer of the soil 1.

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

[0057] In an optional embodiment, the burial depth of the blind pipe 2 is the maximum average depth of the roots of the selected crops after reclamation.

[0058] The depth of the blind pipe 2 is near the maximum average depth of the roots of the selected crops after reclamation. The existence of the blind pipe 2 can produce an effective capillary phenomenon on the soil near the plant roots. With the ventilation near the blind pipe 2, the soil moisture near the blind pipe 2 evaporates. The soil near the blind pipe 2 will generate suction on the surrounding water with salt, and then evaporate again, so as to accumulate the salt near the blind pipe 2. And the blind pipe 2 is near the crop roots, thus greatly eliminating the influence of salt on the crop roots and realizing reclamation;

[0059] In an alternative embodiment, a valve 4 is connected to the outlet of the drain pipe 3 to control the opening and closing of the drain pipe 3. Each concealed pipe 2 is connected upward to a ventilation duct 5 at both the front and rear positions. One ventilation duct 5 is for air supply, and the other ventilation duct 5 is for air extraction, to achieve long-term ventilation inside the concealed pipe 2.

[0060] When the valve 4 is closed, there are only two air inlets in the concealed pipe 2, namely at the two ventilation ducts 5. When the ventilation ducts 5 are operating, it causes continuous and uninterrupted evaporation of the soil 1 near the concealed pipe 2.

[0061] In an alternative embodiment, evenly arranged empty slots 51 are provided on the upper side of the ventilation duct 5. A blower 52 for air supply or air extraction is fixedly connected to the inner side of the ventilation duct 5. The blower 52 is installed below the empty slots 51. A valve flap 53 is provided at the empty slots 51, and the opening and closing angle of the valve flap 53 is 80°; the opening and closing angle of the valve flap 53 is less than 90° to prevent the valve flap 53 from opening too much and causing a situation where it cannot be closed.

[0062] When the valve flap 53 is arranged on the inner side of the ventilation duct 5, this ventilation duct 5 is for air supply, introducing air into the concealed pipe 2.

[0063] When the valve flap 53 is arranged on the outer side of the ventilation duct 5, this ventilation duct 5 is for air extraction, extracting the air inside the concealed pipe 2.

[0064] The valve flap is made of a plastic sheet.

[0065] In the present invention, one of the two ventilation ducts 5 on the concealed pipe 2 is installed with a blower 52 for air supply, and the other is installed with a blower 52 for air extraction to achieve forced ventilation.

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

[0067] When the wind passes through the ventilation duct 5 for air supply, the valve flap 53 at the windward side is in an open state, the empty slot 51 at the windward side is open, and the valve flap 53 at the leeward side is in a closed state, and the empty slot 51 is in a closed state.

[0068] When the wind passes through the ventilation duct 5 for air extraction, the valve flap 53 at the windward side is in a closed state, the empty slot 51 at the windward side is closed, and the valve flap 53 at the leeward side is in an open state under the negative pressure effect when the air flow passes through, and the empty slot 51 is in an open state.

[0069] Thus, the wind can be introduced into the concealed pipe 2, and the presence of the valve flap 53 can reduce the rainfall entering the concealed pipe 2 to a certain extent.

[0070] Embodiment 2, this embodiment is a further improvement of Embodiment 1, please refer to Figures 1-10, the top end of the buried pipe 2 is fixedly connected with a mesh support part 8 through a support member, and a water absorption part 10 is fixedly connected between the mesh support part 8 and the upper netting part 21.

[0071] In the present invention, a linen cloth can be fixedly connected to the outer side of the mesh structures such as the mesh support part 8 and the air permeable part 71. The linen cloth is used to play a role of filtering and intercepting to prevent the mesh structure from being blocked by soil.

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

[0073] In an alternative embodiment, the upper netting part 21 is arranged in a continuous distribution. A single-axis telescopic rod 9 is fixedly connected to the inner side of the bottom end of the buried pipe 2, and the movable end of the single-axis telescopic rod 9 is fixedly connected to the bottom end of the upper netting part 21. When the movable end of the single-axis telescopic rod 9 rises, the water absorption part 10 between the mesh support part 8 and the upper netting part 21 is compressed upward. The ventilation influence area of the buried pipe increases, the evaporation area increases, and the range of salt migration that can be affected will also increase, thereby increasing the salt migration effect. Moreover, the compression of the water absorption part 10 will cause the pore diameter inside the water absorption part 10 to decrease. The decrease in the pore diameter will increase the capillary suction of the water absorption part 10 for the surrounding soil water, increasing the effect of salt migration towards the buried pipe 2 and increasing the evaporation effect;

[0074] When the movable end of the single-axis telescopic rod 9 descends, the water absorption part 10 between the mesh support part 8 and the upper netting part 21 increases, the pore diameter of the water absorption part 10 increases, and the permeability increases, increasing the drainage effect during water leaching and drainage.

[0075] In an alternative embodiment, an air pipe 7 is fixedly connected to the top end of the buried pipe 2. The air permeable part 71 is evenly arranged on the outer side of the air pipe 7. The two ends of the air pipe 7 are also connected to the two air cylinders 5 of the buried pipe 2. A water inlet pipe 72 is fixedly connected to the center of the air pipe 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 spray heads inside the air pipe 7. After the water inlet pipe 72 is connected to the pressurized water pipe inside, the water inlet pipe 72 can spray water to the air permeable part 71 to realize water leaching near the air pipe 7. The saturated water carrying salt flows into the buried pipe 2 under the action of gravity to realize salt drainage.

[0076] The air pipe 7 shares the air cylinder 5 with the buried pipe 2. The air pipe 7 greatly increases the surface area participating in the surface accumulation phenomenon, increasing the influence range of salt migration towards the air pipe 7 and the buried pipe 2. Moreover, the air pipe 7 has a larger surface accumulation area. After the water inlet pipe 72 is connected to the pressurized water pipe inside, the water inlet pipe 72 can spray water to the air permeable part 71 to realize water leaching near the air pipe 7. The saturated water carrying salt flows into the buried pipe 2 under the action of gravity to realize salt drainage.

[0077] The present invention also discloses a soil remediation method for farmland reclamation, and its steps are as follows:

[0078] Step 1: Bury a buried pipe 2 inside the soil 1, and a water retention part 6 is arranged on the surface of the soil 1 to reduce the evaporation on the surface of the soil 1. The inside of the buried pipe 2 is ventilated for a long time, so that the soil humidity at the position of the buried pipe 2 is lower than the average soil humidity where the buried pipe 2 is located. Under the action of capillary action, the salts in the soil migrate upward near the upper net part 21;

[0079] Step 2: The water spraying operation will carry away the salts near the upper net part 21 through the buried pipe 2 and the drain pipe 3.

[0080] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present 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 inside the soil (1), characterized in that: The concealed pipes (2) are arranged at fixed intervals inside the soil (1). The upper surface of the concealed pipes (2) is provided with web-covered portions (21) which are arranged continuously or at fixed intervals. The web-covered portions (21) are made of metal and have 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 phenomena occur near the concealed pipes (2). The water-retaining portions (6) are provided on the surface of the soil (1), so that evaporation from the surface of the soil (1) is reduced, and salt in the soil migrates to the vicinity of the web-covered portion (21). The plurality of 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-surface part (21) through the concealed pipes (2) and the drainage pipe (3).

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 any one of claims 1 to 3, characterized in that: 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, so as to achieve long-term ventilation inside the concealed pipe (2).

5. The soil remediation system for farmland reclamation according to claim 4, characterized in that: The upper side of the wind tube (5) is provided with evenly arranged empty slots (51); 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 at the lower side of the empty slot (51); a valve (53) is provided at the empty slot (51); and the opening and closing angle of the valve (53) is 80 degrees; 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 pipe (2); When the valve (53) is arranged on the outside of the wind tube (5), the wind tube (5) is used to draw air and draw out the air in the concealed pipe (2).

6. The soil remediation system for farmland reclamation according to any one of claims 1 to 3, characterized in that: The top end of the concealed pipe (2) is fixedly connected to a mesh support portion (8) via a support member, and a water absorbing portion (10) is fixedly connected between the mesh support portion (8) and the upper net portion (21).

7. The soil remediation system for farmland reclamation according to claim 6, characterized in that: The water absorbing part (10) is a sponge or a fiber cloth.

8. The soil remediation system for farmland reclamation according to claim 6, characterized in that: The web-surface portion (21) is arranged in a continuous distribution. 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 web-surface 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 web-surface portion (21) is compressed upward, the ventilation influence area of ​​the concealed pipe is increased, the water absorption portion (10) is compressed, resulting in a decrease in the pore diameter in the water absorption portion (10), and the water absorption force of the water absorption portion (10) on the surrounding soil is increased, thereby increasing the effect of salt migration to the concealed pipe (2); When the movable end of the uniaxial telescopic rod (9) descends, the water absorbing part (10) between the mesh support part (8) and the net-mounted part (21) increases, the pore diameter of the water absorbing part (10) increases, the permeability increases, and the drainage effect during water spraying and drainage is enhanced.

9. The soil remediation system for farmland reclamation according to claim 6, characterized in that: The top of the concealed pipe (2) is fixedly connected with an air duct (7), and the outer side of the air duct (7) is evenly provided with a ventilating portion (71). The two ends of the air duct (7) are also connected with the two air tubes (5) of the concealed pipe (2). The center of the air duct (7) is fixedly connected with a water inlet pipe (72), and the water inlet end of the water inlet pipe (72) can be connected with 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 with the pressurized water pipe, the water inlet pipe (72) can spray water to the ventilating portion (71) to achieve water spraying 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.

10. A soil remediation method for farmland reclamation, using the soil remediation system according to claim 1, characterized in that: The steps are: Step 1: a concealed pipe (2) is buried inside the soil (1), a water-retaining portion (6) is provided on the surface of the soil (1), evaporation from the surface of the soil (1) is reduced, the interior of the concealed pipe (2) is ventilated for a long time, the soil moisture at the concealed pipe (2) is lower than the average soil moisture at the location of the concealed pipe (2), and the salt in the soil migrates to the vicinity of the net portion (21) under the action of capillary phenomenon; 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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