Root layer salt elimination system based on vacuum negative pressure porous seepage pipe and method thereof

Abstract

The invention discloses a root system layer salt elimination system and method based on vacuum negative pressure porous seepage pipes, an irrigation and drainage system (1) comprises a shallow ditch (11), a water distribution pit (12), a water storage tank (13), a plurality of seepage pipes (14), a pipeline (15) and a first solenoid valve (23), and a field control system (2) comprises an instrument storage pile (21), a central processor (22), a data transmission line (24) and a soil water and salt sensor (25). According to the requirements of field irrigation and salt elimination automation, dynamic and precise regulation and control of farmland water and salt are achieved by setting specific soil moisture and salt threshold values and combining a field control system. The deep leakage amount of water and solute in the vertical direction can be effectively reduced, the desalination amount under the unit leaching water amount is increased, and the effects of saving water, controlling salt and avoiding secondary pollution caused by leaching water are achieved.

Description

Technical Field

[0001] The invention relates to a root layer salt drainage system based on vacuum negative pressure porous seepage pipes and a method thereof, belonging to the technical field of farmland irrigation and drainage. Background Art

[0002] Subsurface irrigation is a micro-irrigation technology for farmland. It uses porous seepage pipes buried underground to divert irrigation water into the soil at a certain depth below the ground. By regulating the water supply pressure in the pipes, low-intensity and continuous irrigation of the crop root zone is achieved.

[0003] Currently, subsurface irrigation is gaining popularity in greenhouses due to its low material cost, water-saving properties, and minimal land occupation. However, compared to open fields, greenhouses lack natural rainfall, and the frequent application of fertilizers and pesticides can lead to salt accumulation in the root zone, which can harm crop growth in the long term.

[0004] Irrigation leaching is a common method of soil leaching and desalination. It mainly works by injecting excess fresh water into the target field, which infiltrates the salt in the soil into the deep soil layer, achieving the effect of water pressure salt. In addition, irrigation leaching is usually aimed at the entire farmland, while the localized wetting micro-irrigation method commonly used in greenhouse farmland will cause the accumulation of solutes in the field to be localized, ultimately resulting in a decrease in the desalination benefit of the leaching water. Therefore, for soil salt leaching in greenhouses, on the one hand, it is necessary to increase the lateral discharge of leached water, limit the accumulation and diffusion of solutes in the vertical profile of the soil, and prevent and control secondary soil pollution; on the other hand, it is necessary to focus on the targeted desalination of local soil to avoid ineffective leaching. Based on the mechanism of action of the infiltration pipe, during the soil leaching process, an attempt can be made to adjust the infiltration pipe to a negative pressure state, thereby forming suction around the pipe wall to offset the capillary force of the soil on water retention during the seepage process of the pipe wall, and extract the water in the saturated or near-saturated zone of the soil during the irrigation infiltration process, so as to achieve synchronization of vertical infiltration and lateral drainage, thereby reducing the deep vertical leakage of water and solutes, improving the desalination efficiency per unit leaching water volume, achieving the purpose of water saving and salt control, and reducing secondary pollution caused by leached water. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the existing technology and provide a root layer salt removal system and method based on vacuum negative pressure porous infiltration pipes, which can effectively reduce the deep vertical leakage of water and solutes, increase the desalination amount per unit leaching water volume, achieve the effect of saving water and controlling salt and avoiding secondary pollution caused by leaching water. Specifically, a root layer salt removal system and method based on vacuum negative pressure porous infiltration pipes are provided, including an irrigation and drainage system and a field control system.

[0006] Preferably, the present invention provides a root layer salt drainage system based on vacuum negative pressure porous seepage pipes, comprising an irrigation and drainage system and a field control system, wherein the field control system is installed on the irrigation and drainage system;

[0007] Among them, the irrigation and drainage system includes shallow ditches, water distribution pits, water storage tanks, several infiltration pipes, pipelines and a first solenoid valve. A water distribution pit and several shallow ditches arranged at equal intervals are opened on the target field. Infiltration pipes are laid in several shallow ditches arranged at equal intervals. The water storage tanks are connected to the infiltration pipes and water distribution pits through pipelines, and a first solenoid valve is installed on the pipelines.

[0008] Preferably, the irrigation and drainage system includes a second pipeline, a second solenoid valve, an air pump, a precipitator and a waste liquid barrel. The air pump is connected to the precipitator, the precipitator is connected to the seepage pipe through the second pipeline, a second solenoid valve is installed on the second pipeline, and the precipitator is connected to the waste liquid barrel.

[0009] Preferably, the field control system includes an instrument storage pile, a central processing unit, a data transmission line, and a soil water and salt sensor. The central processing unit is installed on the instrument storage pile, and the central processing unit is connected to the soil water and salt sensor via the data transmission line.

[0010] Preferably, the field control system includes a water flow sensor, which is installed on the pipeline and connected to the central processor.

[0011] Preferably, the first solenoid valve and the second solenoid valve are connected to the central processing unit.

[0012] Preferably, the precipitator includes a precipitator frame, a triangular base, a turbidity sensor, a hinge, and a detachable surface, wherein the triangular base is fixedly arranged at the bottom of the precipitator frame, the turbidity sensor is fixedly arranged at the top of the precipitator frame, and the detachable surface is mounted on the precipitator frame via a hinge;

[0013] The bottom of the shallow ditch has a slope of 2° to 6° from the beginning to the end of the field, and the height of the bottom of the ditch at the beginning of the field is higher than that at the end of the field.

[0014] Preferably, a root zone salt removal method based on vacuum negative pressure porous seepage pipes is based on any one of the root zone salt removal systems based on vacuum negative pressure porous seepage pipes, performing the following steps:

[0015] If the crops in the target field are still growing, the central processor will take an emergency rinsing strategy;

[0016] If there is no crop growing in the target field, a maintenance rinsing strategy is adopted using the central processing unit;

[0017] Among them, emergency shower strategies include:

[0018] The central processing unit is used to control the first solenoid valve to open, and the water in the water storage tank is injected into the water distribution pit. The water in the water distribution pit flows along the shallow ditch to the end of the field.

[0019] If the soil water and salt sensor buried at the end of the field detects that the soil moisture data of the infiltration pipe reaches the saturated moisture content of the preset target field soil, the central processor controls the first solenoid valve to close;

[0020] When the soil moisture content fed back by the soil water and salt sensor at the end of the field and the same buried depth as the infiltration pipe reaches the preset field water holding capacity for the first time, the central processor controls the vacuum pump to start, and the negative pressure intensity in the precipitator connected to the vacuum pump gradually increases, thereby generating the same intensity of negative pressure inside the infiltration pipe;

[0021] When the capillary water suction around the seepage pipe is lower than the negative pressure strength inside the seepage pipe, the water around the seepage pipe enters the seepage pipe, and the seepage pipe is used to extract the leached water from the soil;

[0022] The leached water drawn from the seepage pipe enters the precipitator. The turbidity sensor is used to monitor the data of the granular sediment-like floating objects in the leached water in the precipitator. The central processing unit controls the second solenoid valve to open and discharge the water in the precipitator into the waste liquid barrel.

[0023] When the soil moisture content fed back by the soil water and salt sensor is lower than the field water holding capacity of the preset target field, the central processor is used to control the vacuum pump to be turned off.

[0024] Preferably, a maintenance rinse strategy includes:

[0025] Calculate the total amount of rinse water:

[0026]

[0027] Where: Q is the amount of water required for maintenance leaching; n is the number of shallow trenches; h1 is the distance between the bottom depth of the shallow trench at the beginning of the field and the buried depth of the infiltration pipe; w1 is the bottom width of the shallow trench at the beginning of the field; h2 is the distance between the bottom depth of the shallow trench at the end of the field and the buried depth of the infiltration pipe; w2 is the bottom width of the shallow trench at the end of the field; L is the length of the target field; θ s is the volume saturated moisture content of the soil in the target field;

[0028] The central processing unit is used to control the opening of the first solenoid valve, and the water flow sensor is used to accurately record the amount of water flowing through the first solenoid valve and feed it back to the central processing unit;

[0029] When the water flow sensor senses that the amount of water flowing through the first solenoid valve reaches a set water volume threshold, the central processing unit controls the first solenoid valve to close;

[0030] The water flowing out of the water storage tank is injected into the water distribution pit and then flows into each shallow ditch;

[0031] When the soil moisture content fed back by the soil water and salt sensor reaches the preset field water holding capacity for the first time, the central processor controls the vacuum pump to start, and the negative pressure intensity in the precipitator gradually increases, thereby generating the same intensity of negative pressure inside the infiltration tube;

[0032] When the capillary water suction around the seepage pipe is lower than the negative pressure strength inside the seepage pipe, the water around the seepage pipe enters the seepage pipe, and the seepage pipe is used to extract the leached water from the soil;

[0033] The leached water extracted from the seepage pipe enters the sedimentation tank through the water inlet;

[0034] Use turbidity sensors to monitor the floating particles of sediment in the leaching water in the precipitator;

[0035] Based on the data of the floating particles and sand fed back by the turbidity sensor, the central processor controls the second solenoid valve to open and discharge the leached water in the sedimentation tank into the waste liquid barrel;

[0036] When the soil moisture content fed back by the soil water and salt sensor is lower than the field water holding capacity of the preset target field, the central processor is used to control the vacuum pump to be turned off.

[0037] Prioritizing, after crops are planted, soil water and salt sensors are used to collect soil moisture data in real time and feed it back to the central processor;

[0038] If the soil moisture data received by the central processor from the soil water and salt sensor reaches the preset lower limit of crop drought tolerance, the central processor controls the first solenoid valve to open, allowing water in the water storage tank to flow into each infiltration pipe until the soil moisture data fed back by the soil water and salt sensor reaches between 70% and 75% of the field water holding capacity of the preset target field, and the first solenoid valve is closed.

[0039] The beneficial effects achieved by the present invention are:

[0040] (1) The present invention can effectively reduce the vertical leakage of water and solutes into deep layers, increase the desalination rate per unit leaching water volume, achieve the effects of water conservation and salt control, and avoid secondary pollution caused by leached water. Specifically, a root layer salt removal system and method based on vacuum negative pressure porous seepage pipes is provided, including an irrigation and drainage system and a field control system. Under the premise of meeting desalination requirements, the present invention utilizes the irrigation and drainage system and the field control system to reduce dependence on freshwater resources and improve the desalination efficiency of farmland.

[0041] (2) There is no need to re-lay out the pipelines related to desalination. Only infiltration pipes need to be set up under the fields. The present invention does not cause a reduction in the original planting area.

[0042] (3) The present invention monitors and regulates soil water and salt in real time, and the dynamic accuracy of soil water and salt management is high.

[0043] (4) The system of the present invention operates fully automatically, saving manpower.

[0044] (5) The present invention has the function of collecting sewage, thus avoiding secondary pollution caused by the extracted leaching water. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0046] Figure 1 Schematic diagram of the overall system structure;

[0047] Figure 2 This is a schematic diagram of the field structure;

[0048] Figure 3 This is a bird's-eye view of the field;

[0049] Figure 4 It is a schematic diagram of the cross section AA of the field;

[0050] Figure 5 It is a schematic diagram of the BB section of the field longitudinal section;

[0051] Figure 6 Schematic diagram of the precipitator structure;

[0052] Figure 7 Run the flowchart for the system.

[0053] In the figure: 11: shallow ditch; 12: water distribution pit; 13: water storage tank; 14: seepage pipe; 15: pipeline; 16: vacuum pump; 17: sedimentation tank; 171: water inlet; 172: water outlet; 173: exhaust port; 174: triangular base; 175: turbidity sensor; 176: hinge; 177: detachable panel; 18: waste liquid barrel; 21: instrument storage pile; 22: central processing unit; 23: first solenoid valve; 24: data transmission line; 25: soil water and salt sensor; 26: water flow sensor. DETAILED DESCRIPTION

[0054] To facilitate the technical solution of the application, some concepts involved in this application are first explained below.

[0055] It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention, they are only used to explain the relative position relationship and movement status of the various components under a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0056] In addition, if the descriptions of "first" and "second" are involved in the present invention, they are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0057] See also Figure 1 The present application provides a schematic structural diagram of a root zone salt drainage system based on vacuum negative pressure porous infiltration pipes, which includes an irrigation and drainage system 1 and a field control system 2. According to the present invention, a root zone salt drainage system and method based on vacuum negative pressure porous infiltration pipes are provided. The irrigation and drainage system 1 includes a shallow ditch 11, a water distribution pit 12, a water storage tank 13, an infiltration pipe 14, a hard plastic pipe 15, an air pump 16, a precipitator 17, and a waste liquid tank 18.

[0058] refer to Figures 2 to 5 The shallow trench 11 is a channel for rinsing water from the beginning to the end of the field. The cross-section of the shallow trench 11 is an inverted trapezoid, with a height of 10 to 15 cm, a width of 5 to 10 cm at the upper base, and a width of 10 to 20 cm at the lower base. The length of the trapezoid matches the length of the target field. To ensure that water flows from the beginning to the end of the field within the shallow trench, a slope of 2° to 6° is required from the beginning to the end of the field during the digging process.

[0059] The water distribution pit 12 is connected to the shallow ditch 11 at the head of the field and is mainly used to distribute water for washing. The depth of the water distribution pit 12 is consistent with the bottom depth of the shallow ditch 11 at the head of the field, and the width of the water distribution pit 12 is consistent with the width of the actual planting field. The length of the water distribution pit 12 is 1.0 to 1.2 meters.

[0060] The spacing between the shallow trenches 11 is determined by the spacing of the crops. The water storage tank 13 has a water inlet near the top and two outlets near the bottom: a first outlet and a second outlet. The first outlet is connected to the seepage pipe 14 via a rigid plastic tube, while the second outlet is connected to the water distribution pit 12 via a pipe 15. A water flow sensor 26 is installed on the second outlet to record the total amount of water discharged from the second outlet.

[0061] The seepage pipe 14 is a porous seepage pipe made of plastic or rubber recycled from waste tires. The seepage pipe 14 is buried 20 to 30 cm below the ground surface, and the specific burial depth is determined according to the depth of the root layer of the crops. The pipe spacing of the seepage pipe 14 is determined according to the spacing of the shallow trenches dug. Crops are planted directly above the seepage pipe 14, which is conducive to irrigation or salt drainage operations. In order to ensure that the seepage pipe buried underground is not affected by planting equipment or human trampling, which may cause the pipe to be crushed, a hard material can be added to the outside of the seepage pipe 14 for fixation in the embodiment of the present application. In order to prevent the seepage pipe 14 from being blocked by soil particles during use, a layer of flexible metal stretch mesh that has been impregnated with plastic can be wrapped around the outside of the seepage pipe 14 to block direct contact between the seepage pipe 14 itself and the soil, thereby reducing the risk of the water-permeable pores of the seepage pipe 14 being blocked.

[0062] The rigid plastic pipe 15 is a plastic pipe directly connected to the seepage pipe 14. The rigid plastic pipe 15 includes a rigid plastic main pipe and a rigid plastic water distribution pipe. There are two rigid plastic main pipes, which are vertically connected to the rigid plastic water distribution pipe which is also placed horizontally. The rigid plastic water distribution pipe is arranged horizontally and is evenly provided with the same number of through holes as the seepage pipe 14. The connection between the rigid plastic main pipe and the rigid plastic water distribution pipe is treated with a sealing ring to ensure the sealing of the system. The vacuum pump 16 is a conventional air pump, which generates negative pressure in the sealed container by extracting the air in the sealed container.

[0063] refer to Figure 6 The precipitator 17 further includes a water inlet 171, a water outlet 172, an exhaust port 173, a triangular base 174, a turbidity sensor 175, and a hinge 176. The precipitator 17 is a rectangular parallelepiped as a whole, and its dimensions are 1 meter in length, width, and height. The water inlet 171 is a through hole provided on the precipitator, which is connected to the infiltration pipe 14 through a pipe 15. When there is a working negative pressure inside the precipitator, the same intensity of negative pressure also exists in the infiltration pipe 14 connected to the precipitator through the second pipe. The second pipe can adopt the pipe 15, so that the elution waste liquid extracted from the infiltration pipe 14 can enter the precipitator through the pipe 15.

[0064] The water outlet 172 is another through hole provided on the filter, which is mainly used to transport the water in the precipitator to the waste liquid barrel 18 through the pipe 15. The exhaust port 173 is a through hole provided at the top of the precipitator near the top corner, which is mainly connected to the vacuum pump 16 through a hard plastic pipe. The triangular base 174 is a wedge-shaped plastic plate, the length, width and height of which are determined by the length and width of the precipitator, and the height is determined by the height of the water inlet. The turbidity sensor 175 is used to monitor the suspended particles in the water, and mainly determines whether the liquid in the precipitator can be discharged into the waste liquid barrel based on the data it feedbacks. The hinge 176 is a fixed component that fixes the detachable surface to the entire device. The detachable surface 177 is a side surface of the precipitator without a through hole. It is fixed to the precipitator 17 by the hinge 176, which facilitates the cleaning of the interior of the precipitator 17 after the salt removal system is completed. The detachable connection surface of the precipitator is connected with a sealing strip to ensure its internal sealing.

[0065] The waste liquid bucket 18 is a rectangular water collection bucket with dimensions of 1 x 1 x 1.5 m in length x width x height. According to the present invention, a root zone salt drainage system and method based on vacuum negative pressure porous infiltration pipes is provided. The field control system 2 includes: an instrument storage pile 21, a central processing unit 22, a first solenoid valve 23, a data transmission line 24, a soil water and salt sensor 25, a water flow sensor 26, and a second solenoid valve.

[0066] The instrument storage pile 21 is a storage component for storing some components. The central processing unit 22 is the core component of the control system, providing functions such as inputting control thresholds, data comparison, data feedback, converting data signals, and data storage. The first solenoid valve 23 is installed at the pipeline outlet of some components and closes and connects the pipeline under the control of the central processing unit 22. The data transmission line 24 connects the electrical wires of each component.

[0067] The soil water and salt sensor 25 is composed of multiple time domain reflectometers buried at fixed vertical intervals, starting from 5 to 10 cm below the soil surface. The burial depth of the lowest time domain reflectometer is consistent with the burial depth of the infiltration pipe, and is used to measure soil water and salt data at different depths.

[0068] The central processor 22 controls the system's operation based on data from the soil water and salt sensors 25. When the central processor 22 controls the irrigation system, it uses the average soil moisture data collected by all time-domain reflectometers in the soil water and salt sensors. When the central processor 22 controls the salt removal system, it uses the average soil salinity data collected by all time-domain reflectometers in the soil water and salt sensors 25. The central processor 22 controls the opening and closing of the vacuum pump 16 based on the soil moisture data collected by the lowest time-domain reflectometer in the soil water and salt sensors.

[0069] Multiple soil water and salt sensors 25 are embedded between the two infiltration pipes, located in the middle of the target field's central axis and at the end of the field. A water flow sensor 26 is mounted on the pipe leading to the second outlet of the water storage tank to record the amount of water flowing through the second outlet of the water storage tank 13.

[0070] The following describes the arrangement of a root zone salt drainage system and method based on vacuum negative pressure porous seepage pipes according to an embodiment of the present invention: First, a water distribution pit 12 is dug at the head of the field, with a length consistent with the width of the target field, a width of 10 to 20 cm, and a depth of 10 to 15 cm. Then, a shallow trench 11 with a certain slope (which can be 2° to 6°) is dug from the head of the field to the end of the field. The length of the shallow trench 11 is consistent with the length of the target field, and the cross-section of the shallow trench 11 is trapezoidal, with a height of 10 to 15 cm, a width of 5 to 10 cm on the upper base, and a width of 10 to 20 cm on the lower base. Fresh water is then connected to the water inlet of the water storage tank 13 to replenish water into the water storage tank 13.

[0071] Subsequently, the infiltration tube 14 is buried in the shallow trench 11. The burial depth of the infiltration tube 14 is between 20 and 30 cm, depending on the root zone depth of the crops planted in the target field. The soil water and salt sensor 25 is buried simultaneously with the infiltration tube 14. The soil water and salt sensor 25 is buried on the central axis of the target field from the beginning to the end of the field, specifically in the middle and end of the central axis of the field, that is, in the middle and end of the field. The soil water and salt sensor 25 is buried between two adjacent infiltration tubes 14 near the central axis of the target field, and the burial depth must be consistent with that of the infiltration tube 14.

[0072] After the infiltration pipe 14 and soil water and salinity sensor 25 are buried, the control system is deployed. Instrument storage piles 21 are installed on the outermost ridge of the target field, and the central processing unit 22 is placed inside them. A control program is installed on the central processing unit 22, connecting the data transmission line 245 of the soil water and salinity sensor 25 and the first solenoid valve to the central processing unit 22. The central processing unit 22 processes the data collected by the soil water and salinity sensor 25 in real time, compares and analyzes the processing results with the input control information, and then controls the opening and closing of the first solenoid valve 23 to connect and disconnect the pipeline.

[0073] The following is an explanation of the specific workflow of an embodiment of the present invention for a root layer salt drainage system and method based on vacuum negative pressure porous seepage pipes: After planting crops in the target field, the target crops need to be irrigated. The soil moisture content for starting irrigation is determined based on the lower limit of drought tolerance of different crops, and irrigation is stopped when the soil moisture content reaches 70% to 75% of the field water holding capacity of the target field. Table 1 lists the lower limits of drought tolerance of some common crops planted in greenhouses. The relative soil moisture content in the table is the ratio of soil moisture content to the field water holding capacity of the soil.

[0074] Table 1 Drought tolerance lower limit of some crops

[0075] Crop name celery tomato Potato eggplant green onions Soil relative moisture content% 70～80 50～55 60～65 50～55 60～70

[0076] After crop planting, soil water and salt sensors 25 embedded in the target field collect soil moisture data in real time and feed it back to the central processing unit 22. After comparison and analysis of the data, the central processing unit 22 controls the system to irrigate. If the soil moisture data received from the soil water and salt sensors 25 in the root zone reaches the lower limit of crop drought tolerance, the central processing unit 22 controls the first solenoid valve 23 to connect the pipeline, allowing the water in the water storage tank 13 to be distributed to each infiltration tube 14 through the first outlet and the pipeline. Irrigation is terminated when the soil moisture data fed back by the soil water and salt sensors 25 in the root zone reaches between 70% and 75% of the field water holding capacity of the target field.

[0077] The use of pesticides and fertilizers, water absorption by crop roots, and soil evaporation can cause salt accumulation in shallow soil layers and upward migration of salt from deeper soil layers. This creates a high-salinity environment within the crop root zone, causing salt stress to crop growth. To reduce this stress, salt removal from the root zone is necessary. Table 2 provides the upper salt tolerance limits for some crops. When the soil salt data fed back by the soil water and salt sensor 25 exceeds the upper salt tolerance limits for some crops as shown in Table 2, the central processor 22 controls the operation of the salt removal system.

[0078] Table 2 Upper limit of salt tolerance of some crops

[0079] Crop name celery tomato Potato eggplant green onions Total soluble salt in soil g / kg 3.4 2.0 3.0 1.5 4.3

[0080] In the embodiment of the present invention, the operation of the salt removal system requires the early closure of the irrigation system. The conversion between the irrigation system and the salt removal system lies in the first solenoid valve 23. The central processing unit 22 controls the first solenoid valve 23 on the pipe connected to the first water outlet of the water storage tank to close, and the second solenoid valve on the hard plastic main pipe connected to the water inlet 171 of the sedimentator 17 to open, thereby completing the conversion between the systems. If the central processing unit 22 is running the irrigation system before the system is converted, after the irrigation system is finished running, the central processing unit 22 controls the first solenoid valve 23 on the first water outlet of the water storage tank to close. If the irrigation system is not running before the system is converted, the central processing unit 22 directly controls the first solenoid valve 23 on the hard plastic main pipe 151 in front of the water storage tank to close, and the central processing unit 22 controls the second solenoid valve on the hard plastic main pipe 151 connected to the water inlet 171 of the sedimentator to open.

[0081] In an embodiment of the present invention, when the salt removal system is running, if crops are still growing in the target field, the central processor 22 will adopt an emergency rinsing strategy; if no crops are growing in the target field, the central processor 22 will adopt a maintenance rinsing strategy.

[0082] In an embodiment of the present invention, when the central processing unit 22 adopts an emergency rinsing strategy, the central processing unit 22 controls the first solenoid valve 23 in front of the second water outlet of the water storage tank 13 to open, and the water in the water storage tank 13 is injected into the water distribution pit 12 through the second water outlet. The water in the water distribution pit 12 flows to the end of the field along the slope of the shallow trench 11. In this rinsing mode, the water flow sensor 26 is not required to monitor water volume data. When the soil water and salt sensor 25 buried at the end of the field detects that the soil water content data from the infiltration tube 13 reaches the saturated water content of the target field soil, the central processing unit 22 controls the first solenoid valve 23 above the second water outlet of the water storage tank 13 to close. During the process of irrigating the target field, when the soil water content reported by the soil water and salt sensor 25 at the end of the field, buried at the same depth as the infiltration tube, reaches the field water holding capacity of the target field for the first time, the central processing unit 22 controls the vacuum pump 16 to open. During the operation of the vacuum pump, it is necessary to ensure that the negative pressure head it generates is higher than 10% of the negative pressure head corresponding to the field water holding capacity of the target field. The negative pressure inside the precipitator 17 connected to the vacuum pump 16 gradually increases, generating a negative pressure of the same intensity inside the infiltration tube 14. When the capillary water suction of the soil around the infiltration tube 14 is lower than the negative pressure inside the tube, the water around the tube body will enter the tube through the pores of the infiltration tube 14, extracting the leached water from the soil. The leached water extracted by the infiltration tube enters the precipitator 17 through the water inlet 171. The turbidity sensor 175 installed at the top of the precipitator 17 can monitor the floating particles of sediment in the water body. Based on the data fed back by the turbidity sensor 175, the central processing unit 22 will control the second solenoid valve at the precipitator drain port to open, discharging the water in the precipitator 17 into the waste liquid barrel 18 for subsequent processing. When the soil water content reported by the soil water-salt sensor 25 at the end of the field, which is buried at the same depth as the infiltration tube 14, is lower than the field water holding capacity of the target field, the central processing unit controls the vacuum pump 16 to shut down and terminate the operation of the emergency leaching system.

[0083] In the embodiment of the present invention, when the central processor 22 adopts a maintenance rinsing strategy, the total amount of rinsing water is the total water volume determined by the product of the total volume of the space directly above the bottom surface of all shallow trenches 11 and the corresponding infiltration pipes 14 and the saturated moisture content of the soil in the target field. The calculation formula is as follows:

[0084]

[0085] Where: Q is the amount of water required for maintenance washing, m 3 ; n is the number of shallow trenches; h1 is the distance between the bottom depth of the shallow trench at the head of the field and the buried depth of the infiltration pipe, m; w1 is the width of the bottom of the shallow trench at the head of the field, m; h2 is the distance between the bottom depth of the shallow trench at the tail of the field and the buried depth of the infiltration pipe, m; w2 is the width of the bottom of the shallow trench at the tail of the field, m; L is the length of the target field, m; θ s is the volume saturated moisture content of the soil in the target field.

[0086] Central processing unit 22 controls the opening of first solenoid valve 23 above the second water outlet of water storage tank 13. Water flow sensor 26 above the second water outlet accurately records the amount of water flowing through and feeds it back to central processing unit 22. When water flow sensor 26 detects that the water volume has reached a set threshold, it transmits a signal to close first solenoid valve 23 to central processing unit 22, which then controls the closing of first solenoid valve 23 above the second water outlet of water storage tank 13. Water flowing out of the second water outlet of the water storage tank is directly injected into the water distribution pit 12, where it is then diverted to each shallow trench 11.

[0087] During the process of the water storage tank injecting water into the target field, when the soil water content fed back by the soil water-salt sensor 25 at the end of the field, which is buried at the same depth as the infiltration pipe 14, reaches the field water holding capacity of the target field for the first time, the central processing unit 22 controls the vacuum pump 16 to start. During the operation of the vacuum pump, it is necessary to ensure that the negative pressure head generated by it is higher than 10% of the negative pressure head corresponding to the field water holding capacity of the target field. The negative pressure intensity in the precipitator 17 connected to the vacuum pump 16 gradually increases, thereby generating the same intensity negative pressure inside the infiltration pipe 14. When the capillary water suction of the soil around the infiltration pipe 14 is lower than the negative pressure intensity inside the pipe, the moisture around the pipe body will enter the pipe through the pores of the infiltration pipe 14, and extract the leached water from the soil body. The leached water extracted by the infiltration pipe enters the precipitator 17 through the water inlet 171. A turbidity sensor 175 mounted on top of the precipitator 17 monitors floating particles of sediment in the water. Based on the data from the turbidity sensor 175, the central processing unit 22 controls the opening of the second solenoid valve at the precipitator's outlet, draining the water from the precipitator 17 into the waste liquid tank 18 for subsequent processing. When the soil water and salt sensor 25 at the end of the field, buried at the same depth as the infiltration tube 14, reports that the soil moisture content is lower than the field water holding capacity of the target field, the central processing unit 22 controls the air pump 16 to shut down, terminating the maintenance leaching system.

[0088] After the salt drainage system completes its operation, the central processing unit switches back to the irrigation system, monitoring data and controlling irrigation. After the irrigation system switchover is complete, the sediment remaining inside the sedimentation vessel 17 needs to be cleaned. The hinge 176 on the removable surface 177 is opened, and the accumulated sediment inside is cleaned with a tool. The hinge 176 is then re-secured, preparing for the next operation of the salt drainage system.

[0089] There are many models of water storage tank 13, seepage pipe 14, pipeline 15, air pump 16, precipitator 17, triangular base 174, turbidity sensor 175, hinge 176, detachable panel 177, waste liquid barrel 18, instrument storage pile 21, central processing unit 22, first solenoid valve 23, data transmission line 24, soil water and salt sensor 25, and water flow sensor 26 that can be used in the prior art. Those skilled in the art can choose according to actual needs, and no examples are given in this embodiment.

[0090] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0091] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not invented herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the claims.

[0092] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," "connected," and "matched" should be understood in a broad sense, and may refer to mechanical or electrical connections, internal communication between two elements, or direct connection. "Up," "down," "left," and "right" are only used to indicate relative positional relationships. When the absolute positions of the objects being described change, the relative positional relationships may also change.

[0093] Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures involved in the embodiments disclosed in the present invention are involved, and other structures can refer to the general design; the above specific implementation methods further explain the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above are only specific implementation methods of the present application and are not used to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of the present application should be included in the scope of protection of the present application.

Claims

1. A root layer salt removal system based on vacuum negative pressure porous infiltration pipe, characterized in that: It comprises an irrigation and drainage system (1) and a field control system (2), wherein the field control system (2) is installed on the irrigation and drainage system (1); The irrigation and drainage system (1) comprises a shallow ditch (11), a water distribution pit (12), a water storage tank (13), a plurality of infiltration pipes (14), a pipeline (15) and a first electromagnetic valve (23). A water distribution pit (12) and a plurality of shallow ditches (11) arranged at equal intervals are provided on the target field. Infiltration pipes (14) are laid in the plurality of shallow ditches (11) arranged at equal intervals. The water storage tank (13) is connected to the infiltration pipes (14) and the water distribution pit (12) through the pipeline (15). The first electromagnetic valve (23) is installed on the pipeline (15).

2. The root layer salt removal system based on vacuum negative pressure porous infiltration pipe according to claim 1 is characterized in that: The irrigation and drainage system (1) comprises a second pipeline, a second electromagnetic valve, an air pump (16), a precipitator (17) and a waste liquid barrel (18); the air pump (16) is connected to the precipitator (17); the precipitator (17) is connected to the seepage pipe (14) through the second pipeline; a second electromagnetic valve is installed on the second pipeline; and the precipitator (17) is connected to the waste liquid barrel (18).

3. The root layer salt removal system based on vacuum negative pressure porous infiltration pipe according to claim 2 is characterized in that: The field control system (2) comprises an instrument storage pile (21), a central processing unit (22), a data transmission line (24), and a soil water and salt sensor (25). The central processing unit (22) is installed on the instrument storage pile (21), and the central processing unit (22) is connected to the soil water and salt sensor (25) via the data transmission line (24).

4. The root layer salt removal system based on vacuum negative pressure porous infiltration pipe according to claim 3 is characterized in that: The field control system (2) comprises a water flow sensor (26), which is installed on the pipeline (15) and connected to the central processor (22).

5. The root layer salt removal system based on vacuum negative pressure porous infiltration pipe according to claim 4 is characterized in that: The first solenoid valve (23) and the second solenoid valve are connected to the central processing unit (22).

6. The root layer salt removal system based on vacuum negative pressure porous infiltration pipe according to claim 5 is characterized in that: The precipitator (17) comprises a precipitator frame (178), a triangular base (174), a turbidity sensor (175), a hinge (176), and a detachable surface (177); the triangular base (174) is fixedly arranged at the bottom of the precipitator frame (178); the turbidity sensor (175) is fixedly arranged at the top of the precipitator frame (178); and the detachable surface (177) is installed on the precipitator frame (178) through the hinge (176); The bottom of the shallow ditch (11) has a slope of 2° to 6° from the beginning to the end of the field, and the height of the bottom of the ditch at the beginning of the field is higher than that of the bottom of the ditch at the end of the field.

7. A method for removing salt from the root layer based on vacuum negative pressure porous infiltration pipes, characterized in that: Based on the root layer salt removal system based on vacuum negative pressure porous infiltration pipe according to any one of claims 1 to 6, the following steps are performed: If the crops in the target field are still growing, an emergency washing strategy is adopted by the central processor (22); If there is no crop growing in the target field, a maintenance rinsing strategy is adopted by the central processor (22); Among them, emergency shower strategies include: The central processing unit (22) is used to control the first electromagnetic valve (23) to open, and the water in the water storage tank (13) is injected into the water distribution pit (12), and the water in the water distribution pit (12) flows to the end of the field along the shallow ditch (11); If the soil water-salt sensor (25) buried at the end of the field detects that the soil moisture data around the infiltration pipe (14) reaches the saturated moisture content of the preset target field soil, the central processor (22) controls the first electromagnetic valve (23) to close; When the soil water content fed back by the soil water-salt sensor (25) at the end of the field and buried at the same depth as the infiltration pipe (14) reaches the field water holding capacity of the preset target field for the first time, the central processor (22) controls the vacuum pump (16) to start, and the negative pressure intensity in the precipitator (17) connected to the vacuum pump (16) gradually increases, thereby generating the same negative pressure intensity inside the infiltration pipe (14); When the capillary water suction force of the soil around the infiltration pipe (14) is lower than the negative pressure strength in the infiltration pipe (14), the water around the infiltration pipe (14) enters the infiltration pipe (14), and the leached water is extracted from the soil body by using the infiltration pipe (14); The leached water extracted from the seepage pipe (14) enters the sedimentation tank (17), and the turbidity sensor (175) is used to monitor the data of the granular silt-like floating objects in the leached water in the sedimentation tank (17). The central processing unit (22) controls the second solenoid valve to open, and discharges the water in the sedimentation tank (17) into the waste liquid bucket (18); When the soil water content fed back by the soil water-salt sensor (25) is lower than the field water holding capacity of the preset target field, the central processor (22) controls the vacuum pump (16) to be turned off.

8. The root layer salt removal method based on vacuum negative pressure porous infiltration pipe according to claim 7 is characterized in that: Maintenance rinsing strategies include: Calculate the total amount of rinse water: Where: Q is the amount of water required for maintenance leaching; n is the number of shallow trenches; h1 is the distance between the bottom depth of the shallow trench (11) at the beginning of the field and the buried depth of the infiltration pipe (14); w1 is the bottom width of the shallow trench (11) at the beginning of the field; h2 is the distance between the bottom depth of the shallow trench (11) at the end of the field and the buried depth of the infiltration pipe; w2 is the bottom width of the shallow trench (11) at the end of the field; L is the length of the target field; θ s is the volume saturated moisture content of the soil in the target field; The central processing unit (22) is used to control the opening of the first electromagnetic valve (23), and the water flow sensor (26) is used to accurately record the amount of water flowing through the first electromagnetic valve (23) and feed it back to the central processing unit (22); When the water flow sensor (26) senses that the amount of water flowing through the first solenoid valve (23) reaches a set water volume threshold, the central processing unit (22) controls the first solenoid valve (23) to close; The water flowing out of the water storage tank (13) is injected into the water distribution pit (12) and then flows into each shallow ditch (11); When the soil water content fed back by the soil water-salt sensor (25) reaches the field water holding capacity of the preset target field for the first time, the central processor (22) is used to control the vacuum pump (16) to start, and the negative pressure intensity in the sedimentation tank (17) gradually increases, thereby generating a negative pressure of the same intensity inside the infiltration pipe (14); When the capillary water suction force of the soil around the infiltration pipe (14) is lower than the negative pressure strength in the infiltration pipe (14), the water around the infiltration pipe (14) enters the infiltration pipe (14), and the leached water is extracted from the soil body by using the infiltration pipe (14); The leached water extracted from the seepage pipe (14) enters the sedimentation vessel (17) through the water inlet (171); Using a turbidity sensor (175) to monitor the granular silt-like floating matter in the leached water in the sedimentation tank (17); Based on the particle silt floating matter data fed back by the turbidity sensor (175), the central processor (22) controls the second solenoid valve to open, so as to discharge the leached water in the sedimentation tank (17) into the waste liquid barrel (18); When the soil water content fed back by the soil water-salt sensor (25) is lower than the field water holding capacity of the preset target field, the central processor (22) is used to control the vacuum pump (16) to be turned off.

9. The root layer salt removal method based on vacuum negative pressure porous infiltration pipe according to claim 7 is characterized in that: After the crops are planted, soil water and salt sensors (25) are used to collect soil moisture data in real time and feed it back to the central processor (22); If the soil moisture data received by the central processor (22) from the soil moisture and salt sensor (25) reaches the preset lower limit of crop drought tolerance, the central processor (22) controls the first electromagnetic valve (23) to open, so that the water in the water storage tank (13) flows into each infiltration pipe (14), until the soil moisture data fed back by the soil moisture and salt sensor (25) reaches between 70% and 75% of the field water holding capacity of the preset target field, and then the first electromagnetic valve (23) is closed.

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