Intelligent irrigation and salinity regulation and control integrated system for cotton saline-alkali soil improvement

Abstract

The invention relates to the technical field of agricultural engineering, in particular to an intelligent irrigation and salinity regulation and control integrated system for cotton saline-alkali soil improvement, which comprises a plurality of irrigation pipes, the irrigation pipes are communicated with a plurality of branch pipes, the irrigation pipes are further sleeved with a plurality of regulation devices, and each regulation device comprises a plurality of stages of support rods which are sleeved end to end; water inlets for allowing saline water to enter the supporting rods are formed in the positions, close to the bottom ends, in the supporting rods, and buoyancy unfolding mechanisms for driving the next-stage supporting rods to be vertically unfolded through saline water injection are arranged in the supporting rods; a conversion assembly used for switching the drainage hole diameter of the branch pipe according to the lifting height of the supporting rod is arranged between the irrigation pipe and the last-stage supporting rod. Buoyancy expansion mechanisms of the multi-stage supporting rods in the adjusting device are linked with the conversion assemblies to automatically switch the drainage hole diameters of the branch pipes, and in combination with real-time sensing and dynamic strategies of the irrigation regulation and control system, full-period automatic salt regulation and control and precise irrigation of cotton saline-alkali soil in winter, uniform spreading and icing of saline water and salt return prevention of under-mulch drip irrigation in spring are achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of agricultural engineering, in particular to an intelligent irrigation and salt content regulation integrated system for cotton saline-alkali land improvement. BACKGROUND

[0002] Saline-alkali land is widely distributed in the world, and there is a considerable amount of saline-alkali land resources in China. Due to the high salt content in the soil of saline-alkali land, cotton growth is inhibited, the germination rate is low, the growth is slow, and even death, which greatly limits the agricultural utilization value of the land. In order to improve the productivity of the land, the improvement of saline-alkali land has become a key task in agricultural development. At present, using saline water ice layer to improve cotton saline-alkali land is an effective way, the principle is to irrigate saline water to the cotton field in winter, the saline water freezes in low temperature, and the saline water melts in spring when the temperature rises, the high-concentration saline water melts and infiltrates first to remove part of the salt, and the subsequent melting of the slightly salty water and fresh water further leaches the soil, so that the salt migrates to the deep soil, thereby reducing the salt content of the surface soil and creating suitable conditions for crop growth.

[0003] The document "Research Progress and Prospect of Saline Water Ice Irrigation for Saline-alkali Land Improvement" points out that high salinity saline water cannot be directly used for irrigation, so how to reasonably use these high salinity underground saline water for saline-alkali land improvement is a problem that needs to be solved in agricultural production in this area. Based on the above background, according to the regional climate conditions, soil water and salt transport law and plant growth and development law, based on the principle of saline water ice freezing and thawing separation, a winter saline water ice irrigation and saline-alkali land improvement technology is proposed, which fully utilizes the regional winter low temperature conditions and rich saline water resources. In winter, the saline-alkali land is irrigated with ice, and during the melting process of the saline water ice, the slightly salty water and fresh water that melts later has a good leaching effect on the soil salt, combined with subsequent salt inhibition measures and summer rainfall leaching salt, to create a low-salt soil condition for crop emergence and plant growth.

[0004] However, the existing technology for improving saline-alkali land by using saline water ice layer has many defects. When using saline water for regulation, large-scale saline water is usually injected through water pipes in winter to try to freeze the saline water on the soil surface to achieve subsequent improvement. However, in actual operation, it is difficult to uniformly distribute the saline water on the soil surface by water pipe flushing, so a large amount of manpower is needed to manually sweep the saline water to all parts of the soil surface to ensure relatively uniform distribution of salt, which not only results in high labor cost, but also low efficiency. At the same time, it is difficult to achieve complete uniformity by manual water sweeping, which will cause uneven distribution of soil salt and affect the subsequent improvement effect. Therefore, an intelligent irrigation and salt content regulation integrated system for saline-alkali land improvement is urgently needed. SUMMARY

[0005] To solve the above problems, the application provides a kind of intelligent irrigation and salt control integrated system for cotton saline-alkali land improvement, the drainage aperture of branch pipe is automatically switched by the buoyancy unfolding mechanism of multistage support rod in the adjusting device of irrigation pipe sleeve linkage conversion assembly, and the real-time sensing and dynamic strategy of irrigation control system are combined to realize the whole cycle automation of salt control and precision irrigation of saline-alkali land in winter salt water uniform spreading icing, spring film under drip irrigation salt return prevention.

[0006] In order to achieve the above purpose, the technical scheme of the present application is as follows: an intelligent irrigation and salt control integrated system for cotton saline-alkali land improvement, comprising a plurality of irrigation pipes and a variable frequency water pump, the irrigation pipes are communicated with the variable frequency water pump, a plurality of branch pipes are communicated with the irrigation pipes, an electromagnetic valve is arranged on each irrigation pipe, a partition valve is arranged at the connection between the electromagnetic valve and the irrigation pipe, and an irrigation control system is connected with the electromagnetic valve; a plurality of adjusting devices are sleeved on the irrigation pipes, each adjusting device comprises a plurality of support rods sleeved at the head and tail, a water inlet is formed in the support rod near the bottom end for allowing salt water to enter the inside of the support rod, a buoyancy unfolding mechanism is arranged in the support rod for driving the vertical unfolding of the next stage support rod by injecting salt water, and a conversion assembly is arranged between the irrigation pipe and the last stage support rod for switching the drainage aperture of the branch pipe according to the lifting height of the support rod.

[0007] The conversion assembly comprises a first fixed block fixedly connected to the outer side wall of any stage support rod, a crank connecting rod mechanism is hinged to the first fixed block, a conversion ring is hinged to the end of the crank connecting rod mechanism away from the first fixed block, the conversion ring is sleeved on the branch pipe and is rotatably connected with the branch pipe, a water outlet hole is formed in the branch pipe, the conversion ring is divided into a water injection area and a drip irrigation area, only a single first hole is formed in the water injection area, a plurality of second holes are formed in the drip irrigation area, and a pressure compensation diaphragm is arranged on the inner side wall of the drip irrigation area, the diameter of the water outlet hole is greater than the diameter of the first hole, and the diameter of the first hole is greater than the diameter of the second hole.

[0008] The technical principle of the above scheme is as follows:

[0009] When irrigation starts, the irrigation control system controls the opening of the electromagnetic valve and the partition valve, and the variable frequency water pump delivers salt water to the irrigation pipe and the branch pipe. At this time, the drip irrigation area of the conversion ring is aligned with the water outlet hole of the branch pipe, and the plurality of second holes in the drip irrigation area cooperate with the pressure compensation diaphragm to make the water flow discharge at a small flow rate and a high flow rate.

[0010] With the continuous injection of salt water, part of the salt water enters the inside through the water inlet of the support rod, triggering the buoyancy unfolding mechanism. The float at the bottom end of the next stage support rod rises under the action of salt water buoyancy, driving the vertical unfolding of the next stage support rod from the top end of the upper stage support rod, and the support rods are unfolded stage by stage. In this process, when the support rod is lifted to a certain height, the water injection area is aligned with the water outlet hole of the branch pipe through the conversion assembly, the single first hole of the water injection area increases the water injection amount, and a 18-21cm salt water ice layer is quickly formed, which speeds up the ice layer construction speed.

[0011] When the salt water melts and infiltrates in spring, the salt water ice layer in the support rod disappears, the buoyancy unfolding mechanism loses buoyancy, and each level of support rod is retracted under the action of gravity. At the same time, the crank connecting rod mechanism drives the reverse rotation of the conversion ring, so that the drip irrigation area is aligned with the water outlet hole again, and the system switches to the small flow drip irrigation mode.

[0012] The above scheme has the following beneficial effects:

[0013] 1. In this scheme, the support rod is lifted by the buoyancy unfolding mechanism, and the conversion assembly is switched in parallel with the drainage hole diameter. The large and small hole conversion mechanism is constructed based on the salt control requirement, which can accurately control the water flow state and ensure uniform distribution of salt water and rapid formation of ice layer, and realize the self-adaptive switching of "small aperture high-speed water laying-big aperture rapid ice injection". The salt water is evenly expanded under the support of the ice layer, and the irrigation pipe is lifted away from the ice surface with the support rod, which completely avoids the freezing risk and significantly improves the ice layer construction efficiency.

[0014] 2. In this scheme, in spring, the system can automatically switch to the small flow drip irrigation mode according to the natural contraction of the support rod, dynamically adapt to the irrigation requirements at different stages, effectively inhibit the salt infiltration, and at the same time, the support rod after contraction drives the irrigation pipe close to the soil surface, so that the irrigation pipe is located below the mulch film during mulching, and the film drip irrigation after mulching can block the water evaporation path. The mechanical structure and salt control logic are deeply coupled to form a closed-loop regulation of "ice layer melting-mulching salt inhibition-film drip irrigation", which does not need external intervention.

[0015] Further, the elastic sealing strips are arranged between the conversion ring and the branch pipes.

[0016] Beneficial effect: When draining water in the drip irrigation area, the elastic sealing strip blocks the path of the water injection area, preventing salt water from leaking from the water injection area, ensuring the high flow rate and small flow characteristics of the pressure compensation diaphragm, and achieving uniform and rapid spreading of salt water in winter.

[0017] Further, the buoyancy unfolding mechanism includes a float fixedly connected to the bottom end of the next level support rod, and the top end of each level of support rod is provided with an opening, and a sealing ring is fixedly connected in the opening. The next level of support rod is in sliding connection with the sealing ring when it is unfolded or retracted.

[0018] Beneficial effects: The buoyancy during the saltwater injection is used as the driving force, and the float at the bottom end of the next level support rod is automatically lifted as the liquid level rises, without the need for additional power devices to vertically expand the support rod step by step; the sealing ring at the top end of each level support rod is slidingly connected with the next level support rod, which not only ensures the smoothness during the expansion and contraction process, but also isolates the inner and outer spaces of the support rod, preventing saltwater from leaking from the connection during the vertical expansion process, and ensuring the stability of the buoyancy drive; after the ice layer melts in spring, the support rod contracts under the action of gravity, and the sliding fit characteristics of the sealing ring avoid jamming, ensuring that the conversion assembly accurately switches to the drip irrigation mode when the support rod is retracted.

[0019] Further, a plurality of receiving grooves are formed on the end of the support rod, and a second fixed block is fixedly connected in each receiving groove. A first connecting plate and a second connecting plate are respectively hinged to the second fixed block. The outer bottom wall of the irrigation pipe is provided with an arc-shaped sliding rail. The first connecting plate and the second connecting plate are respectively hinged to a first sliding block and a second sliding block away from the second fixed block. The first sliding block and the second sliding block are located in the arc-shaped sliding rail and slidingly fit with the arc-shaped sliding rail.

[0020] Beneficial effects: The first connecting plate, the second connecting plate hinged to the second fixed block, and the sliding blocks in the arc-shaped sliding rail of the irrigation pipe form a four-bar linkage support mechanism. When the support rod is vertically expanded, the connecting plates are expanded from the receiving grooves, and the lifting force of the support rod is uniformly transmitted to the bottom of the irrigation pipe through the sliding of the first sliding block and the second sliding block in the arc-shaped sliding rail. This multi-point support structure avoids the tilting or displacement of the irrigation pipe that may be caused by traditional single-point support, ensuring the precise alignment of the branch pipe water outlet hole and the conversion ring.

[0021] Further, a damping assembly for reducing the impact when the first connecting plate and the second connecting plate expand or contract is arranged in the arc-shaped sliding rail. The damping assembly includes a first spring and a second spring. The first spring is fixedly connected between the first sliding block and the second sliding block. The second spring is fixedly connected between the second sliding block and the side wall of the arc-shaped sliding rail.

[0022] Beneficial effects: Through the joint action of the first spring and the second spring, the impact force caused by the instantaneous vertical expansion or contraction of the first sliding block and the second sliding block in the arc-shaped sliding rail can be inhibited, avoiding damage to the irrigation pipe.

[0023] Further, the inner walls of the irrigation pipe, the branch pipe, and the support rod are coated with a fusion epoxy powder coating and a polyethylene coating from the inside to the outside.

[0024] Beneficial effects: The fusion epoxy powder coating has extremely strong chemical stability and can effectively resist the corrosion of high-concentration salt, acid, and alkali substances in saline-alkali soil, forming the first anti-corrosion barrier. The outer polyethylene coating further isolates water and air, preventing the coating from aging and permeating. The double protection significantly prolongs the corrosion resistance of the pipe material and extends the service life of the equipment, avoiding the impact of pipe corrosion and leakage on irrigation and salt regulation.

[0025] Further, the branch pipes are each embedded with symmetrically arranged magnetic positioning sheets, and the conversion ring is embedded with iron induction sheets corresponding to the magnetic positioning sheets.

[0026] Beneficial effects: when the conversion ring rotates to switch the drainage hole diameter, the iron induction sheet will be attracted by the magnetic force at the moment of approaching the magnetic positioning sheet, and will be accurately positioned at the preset position, avoiding the position deviation caused by mechanical errors or water flow impact. When the conversion ring is rotated to the correct position, the iron induction sheet completely corresponds to the magnetic positioning sheet, and a specific magnetic field change signal is generated and transmitted to the irrigation control system. The system determines whether the conversion assembly is in the correct working state according to the signal, and if the expected signal is not detected, a fault warning can be sent in time.

[0027] Further, the irrigation control system includes a sensing unit, a data acquisition and processing module, a strategy generation module, and an execution control module, wherein:

[0028] The sensing unit is respectively connected with the frequency conversion water pump, the electromagnetic valve and the iron induction sheet signal, and the sensing unit includes a plurality of soil sensors, flow rate sensors and displacement sensors arranged on the irrigation pipe and the support rod. The sensing unit transmits the data of the sensors to the data acquisition module;

[0029] The data acquisition module is used to receive the frequency conversion water pump frequency, the electromagnetic valve opening degree, the conversion ring position data, the soil salt concentration, the soil surface temperature, the soil surface humidity, the water flow rate data in the irrigation pipe and the vertical expansion height of the support rod, and adopts data filtering and normalization processing to obtain the processed environmental data set and equipment data set, and transmits them to the strategy generation module and the execution control module respectively;

[0030] The strategy generation module is used to receive the environmental data set and the equipment data set, calculate the ice layer formation speed by extracting the soil surface temperature and the vertical expansion height of the support rod, generate the water injection amount adjustment instruction, obtain the dynamic salt concentration value by extracting the soil salt concentration, match the drip irrigation rate according to the dynamic salt concentration value and the soil surface humidity, and transmit the water injection amount adjustment instruction and the drip irrigation rate to the execution control module;

[0031] The execution control module is used to receive the water injection amount adjustment instruction and the drip irrigation rate, compare the real-time frequency conversion water pump frequency, the electromagnetic valve opening degree, the conversion ring position data and the water flow rate data, and control the adjustment of the frequency conversion water pump frequency and the electromagnetic valve opening degree according to the water injection amount adjustment instruction and the drip irrigation rate.

[0032] Further, the strategy generation module includes an ice layer construction control unit, which is used to calculate the ice layer thickness according to the vertical expansion height data of the support rod and the soil surface temperature data by using the ice layer growth rate formula:

[0033]

[0034] V1=K*(H-h / T)

[0035] Wherein, V0 represents the freezing rate in the interval of ice layer thickness less than 2-3cm, K is the correction coefficient, T0 is the freezing point temperature, T s is the soil surface temperature, t is the real-time water injection time, by calculating the freezing rate in the interval of ice layer thickness reaching 2-3cm, when the freezing rate is lower than the set threshold, the water injection amount adjustment instruction of water injection amount promotion is generated and transmitted to the execution control module;

[0036] V1 represents the freezing rate when the ice layer thickness is greater than the interval of 2-3cm, H represents the vertical development height data, h represents the initial height difference between the displacement sensor and the ground, T is the current temperature, by calculating the freezing rate when the ice layer thickness is greater than the interval of 2-3cm, when the freezing rate is lower than the set threshold, the water injection amount adjustment instruction of water injection amount promotion is generated and transmitted to the execution control module; when the ice layer thickness H-h is between 20cm-25cm, the water injection amount adjustment instruction of closing water injection is generated to the execution control module.

[0037] Further, the strategy generation module further includes a drip irrigation regulation unit, the drip irrigation regulation unit is used for receiving soil salt concentration C s , adopting a gradient dilution model:

[0038] Q=Q0*(C s / C max ) n

[0039] Wherein Q0 is the reference drip irrigation amount, C max is the upper limit of salt concentration, n is the dilution gradient coefficient, when C s ≥C max , the target drip irrigation amount is calculated by the gradient dilution model, the drip irrigation rate is generated to the execution control module, and the execution control module generates the speed adjustment instruction and transmits it to the variable frequency water pump to adjust the water flow.

[0040] Beneficial effects: 1, the sensing unit integrates multiple types of sensors such as soil, flow rate and displacement, and can capture real-time environmental and equipment state data, covering key indicators such as soil salt concentration, ice layer growth and water flow rate. Compared with traditional single-point monitoring, the system can accurately depict the whole cycle change of saline-alkali soil improvement through fusion analysis of multi-source information by the data acquisition and processing module, and provide comprehensive basis for decision-making, avoiding the lag or failure of regulation caused by monitoring blind area.

[0041] 2、Strategy generation module built-in ice layer growth rate model and gradient dilution algorithm, based on real-time data dynamic calculation of water injection and drip irrigation rate. For example, through the double-stage formula of the ice layer construction control unit, the system can accurately regulate the freezing process according to the soil temperature and support rod height, automatically increase the water injection when the freezing rate is lower than the threshold, and ensure that the ice layer thickness meets the standard; the drip irrigation control unit adjusts the drip irrigation amount according to the soil salt concentration gradient, so that the salt dilution is more uniform and efficient.

[0042] 3、The execution control module compares the strategy instruction with the real-time state of the equipment, and dynamically adjusts the opening degree of the frequency conversion water pump and the electromagnetic valve. For example, when the conversion ring switches the aperture, through the position signals fed back by the ferrous induction sheet and the magnetic positioning sheet, the system can verify whether the aperture switching is in place, and if there is deviation, it will be corrected immediately to avoid irrigation failure caused by mechanical failure or environmental interference.

[0043] 4、From winter ice layer construction to spring anti-return salt drip irrigation, the system automatically switches the control strategy according to the seasonal change and soil state without manual intervention. Through the continuous "data acquisition-strategy generation-execution feedback" cycle, the dynamic balance of salt and water resources in saline-alkali soil is realized.

[0044] Additional aspects and advantages of the application will be in part apparent and in part pointed out hereinafter in the description. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 It is a perspective view of the embodiment of the intelligent irrigation and salt regulation integrated system for cotton saline-alkali land improvement of the application;

[0046] Figure 2 It is a perspective view of the embodiment of the intelligent irrigation and salt regulation integrated system for cotton saline-alkali land improvement of the application; Figure 1 It is a perspective view of the embodiment of the intelligent irrigation and salt regulation integrated system for cotton saline-alkali land improvement of the application;

[0047] Figure 3 It is a perspective view of the embodiment of the intelligent irrigation and salt regulation integrated system for cotton saline-alkali land improvement of the application;

[0048] The reference signs in the drawings of the specification include: 1, irrigation pipe; 2, branch pipe; 3, conversion ring; 4, first hole; 5, crank connecting rod mechanism; 6, first fixed block; 7, water inlet; 8, support rod; 9, storage groove; 10, second connecting plate; 11, first connecting plate; 12, sealing ring; 13, elastic sealing strip; 14, second hole; 15, drip irrigation area; 16, water injection area; 17, water outlet hole. DETAILED DESCRIPTION

[0049] The technical solutions of the present application will be described clearly and completely in connection with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0050] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0051] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0052] The specific embodiments will be described in detail below:

[0053] Embodiment 1:

[0054] As shown in the accompanying drawings Figure 1As shown: when the existing saline-alkali soil improvement adopts salt water regulation, the ice formation in winter needs to rely on artificial salt water sweeping to the soil surface to distribute uniformly, which has the problems of low operation efficiency, high labor intensity and uneven salt water distribution; at the same time, the traditional irrigation system is difficult to automatically adjust the irrigation mode according to the seasonal change and the soil state, which is easy to lead to the salt in the deep soil returning to the surface with evaporation in spring, affecting the improvement effect, therefore, an intelligent irrigation and salt regulation integrated system for cotton saline-alkali soil improvement is proposed, which comprises a plurality of irrigation pipes 1 and a variable frequency water pump, the irrigation pipes 1 are communicated with the variable frequency water pump, a plurality of branch pipes 2 are communicated with the irrigation pipes 1, an electromagnetic valve is arranged on each irrigation pipe 1, a partition valve is arranged at the connection between the electromagnetic valve and the irrigation pipe 1, and the electromagnetic valve is signal connected with an irrigation control system; a plurality of adjusting devices are sleeved on the irrigation pipes 1, the adjusting device comprises a plurality of support rods 8 which are sleeved at the tail end, a water inlet 7 is formed in the support rod 8 near the bottom end for allowing salt water to enter the inside of the support rod 8, a buoyancy unfolding mechanism is arranged in the support rod 8 for driving the next support rod 8 to unfold vertically by the injection of salt water, and a conversion assembly is arranged between the irrigation pipe 1 and the last support rod 8 for switching the drain hole diameter of the branch pipe 2 according to the lifting height of the support rod 8. When the salt injection ice formation, first need to fill 2-3cm thick salt water, so that the soil surface is frozen, at the same time, in order to prevent the water flow from being too large to cause resource waste and a large amount of salt water to infiltrate into the soil, it is necessary to control the water flow in the initial water injection stage, and it is necessary to spread the water to the soil surface, but because the existing technology adopts artificial water sweeping with low efficiency and unevenness, the irrigation control system adjusts the water pressure by controlling the variable frequency water pump, and controls the water quantity by the electromagnetic valve and the partition valve, so that the conversion assembly is in the small aperture drainage state when the initial thin ice layer (2-3cm) is laid.

[0055] Specifically, the conversion assembly each comprises a first fixed block 6 fixedly connected to the outer side wall of any first-stage support rod 8, a crank link mechanism 5 hinged to the first fixed block 6, and a conversion ring 3 hinged to the end of the crank link mechanism 5 away from the first fixed block 6, the conversion ring 3 being sleeved on the branch pipe 2 and rotationally connected with the branch pipe 2, the branch pipe 2 being provided with a water outlet hole 17, the conversion ring 3 being divided into a water injection area 16 and a drip irrigation area 15, the water injection area 16 being provided with only a single first hole 4, the drip irrigation area 15 being provided with a plurality of second holes 14, and the inner side wall of the drip irrigation area 15 being provided with a pressure compensation diaphragm, the diameter of the water outlet hole 17 being greater than the diameter of the first hole 4 and the diameter of the second hole 14, and an elastic sealing strip 13 being arranged between the conversion ring 3 and the branch pipe 2 to close and separate the water injection area 16 and the drip irrigation area 15. When a thin ice layer initially in direct contact with the soil is laid, the rotation of the conversion ring 3 on the branch pipe 2 can align the drip irrigation area 15 with the water outlet hole 17. Since it is necessary to quickly spread brine on the surface of the soil, a large flow of water needs to be provided to meet the condition. To prevent the water pressure fluctuation between the small-diameter second hole 14 and the high-pressure water flow from causing the conversion ring 3 and the branch pipe 2 to break, a pressure compensation diaphragm is used to balance the water pressure fluctuation at the second hole 14 and the water outlet hole 17. Since the diameter of the second hole 14 is smaller than the diameter of the water outlet hole 17, according to the Venturi principle, the flow rate of fluid will increase when it flows from a large space to a small space. Therefore, the brine can be quickly sprayed from the branch pipe 2 to the second hole 14, and the brine is sent as far as possible to the soil at the middle part of the adjacent irrigation pipe 1, so as to quickly spread the brine on the surface of the soil without manual intervention.

[0056] The magnetic positioning piece is symmetrically arranged in the branch pipe 2, the ferrous induction piece corresponding to the magnetic positioning piece is embedded on the conversion ring 3, and the magnetic positioning piece in the branch pipe 2 cooperates with the ferrous induction piece on the conversion ring 3 to ensure the accurate position of the conversion ring 3 and realize stable switching of the drainage hole diameter.

[0057] After the initial thin ice layer freezes, the thin ice layer can prevent salt water from infiltrating into the soil, so at this time the water injection amount can be increased. Specifically, the buoyancy expansion mechanism includes a float fixedly connected to the bottom end of the support rod 8. As the salt water continues to be injected, part of the salt water enters the interior through the water inlet 7 of the support rod 8, and the buoyancy expansion mechanism begins to function. The float at the bottom end of the next level of support rod 8 is lifted under the action of the salt water buoyancy. The top end of each level of support rod 8 is provided with an opening, and a sealing ring 12 is fixedly connected in the opening. Each level of support rod 8 is in sliding connection with the sealing ring 12 when it is expanded or contracted, thereby driving the next level of support rod 8 to be vertically expanded from the opening at the top end of the upper level of support rod 8. The irrigation pipe 1 is raised along with the lifting of the support rod 8, thereby preventing the irrigation pipe 1 and the branch pipe 2 from being gradually frozen in the ice layer during the water injection process. The frozen irrigation pipe 1 and the branch pipe 2 can be deformed and broken due to the stress generated by the contraction of the ice layer. The sealing ring 12 ensures the sealing property during the sliding connection. During the vertical expansion of the support rod 8, the first fixed block 6 fixed to the outer side wall of the support rod 8 pulls the conversion ring 3 to rotate through the crank linkage mechanism 5. When the support rod 8 is lifted to a certain height, the conversion ring 3 can be rotated to align the water injection area 16 with the water outlet hole 17. Since the diameter of the first hole 4 is greater than that of the second hole 14, the water injection amount and the water pressure remain unchanged at this time. When the salt water flows out from the water injection area 16, the flow rate is slowed down. A salt water ice layer of 18-21 cm is rapidly formed on the top of the thin ice layer without causing a large impact force on the thin ice layer. When the ice layer is frozen, the first fixed block 6 and part of the crank linkage mechanism 5 located outside the support rod 8 are frozen in the ice layer, thereby achieving physical self-locking of the conversion ring 3.

[0058] Since the salt in the salt water irrigation is prone to accumulate in the pipe, which can cause corrosion inside the irrigation pipe 1, the branch pipe 2 and the support rod 8, the inner walls of the irrigation pipe 1, the branch pipe 2 and the support rod 8 are coated with a fusion epoxy powder coating and a polyethylene coating from the inside to the outside. The fusion epoxy powder coating and the polyethylene coating have corrosion resistance, thereby ensuring that the salt water can be stably delivered for a long time.

[0059] When the salt water infiltrates into the soil after the salt water ice layer melts in the spring, in order to reduce the soil surface evaporation caused by the temperature rise and to avoid the deep salt returning to the soil surface with the water evaporation, the soil surface needs to be covered with a film. At the same time, the plants need to be irrigated by using the film mulching drip irrigation method. Therefore, when the salt water infiltrates into the soil after the salt water ice layer melts, the float in the support rod 8 loses buoyancy, and each level of support rod 8 is sequentially retracted under the action of its own gravity. As the support rod 8 is retracted, the irrigation pipe 1 is close to the ground, the crank linkage mechanism 5 drives the conversion ring 3 to rotate in the opposite direction, and the drip irrigation area 15 is again aligned with the water outlet hole 17. At this time, after the ground film is laid, the irrigation pipe 1 can be located below the ground film, and by using the film mulching drip irrigation method, the small pore size drainage can minimize the water injection amount, and the water is slowly supplied in the form of drip irrigation. This method effectively solves the problem of spring salt return in the prior art.

[0060] Example 2:

[0061] As shown in the accompanying drawings, the difference between the embodiment 1 is that the end of the support rod 8 is provided with a plurality of receiving grooves 9, the second fixing block is fixedly connected in the receiving groove 9, the first connecting plate 11 and the second connecting plate 10 are respectively hinged on the second fixing block, the arc-shaped slide rail is opened on the outer bottom wall of the irrigation pipe 1, the first slide block and the second slide block are respectively hinged on the end of the first connecting plate 11 and the second connecting plate 10 away from the second fixing block, and the first slide block and the second slide block are located in the arc-shaped slide rail and are in sliding fit with the arc-shaped slide rail. Figure 1 The difference between the embodiment 1 is that the end of the support rod 8 is provided with a plurality of receiving grooves 9, the second fixing block is fixedly connected in the receiving groove 9, the first connecting plate 11 and the second connecting plate 10 are respectively hinged on the second fixing block, the arc-shaped slide rail is opened on the outer bottom wall of the irrigation pipe 1, the first slide block and the second slide block are respectively hinged on the end of the first connecting plate 11 and the second connecting plate 10 away from the second fixing block, and the first slide block and the second slide block are located in the arc-shaped slide rail and are in sliding fit with the arc-shaped slide rail.

[0062] The damping assembly for slowing down the impact when the first connecting plate 11 and the second connecting plate 10 are expanded or contracted is arranged in the arc-shaped slide rail, and the damping assembly comprises a first spring and a second spring, the two ends of the first spring are fixedly connected between the first slide block and the second slide block, and the two ends of the second spring are fixedly connected with the second slide block and the side wall of the arc-shaped slide rail.

[0063] The specific implementation process is as follows: in the process of continuously injecting salt water to make the support rod 8 vertically expand, the second fixing block in the receiving groove 9 at the end of the support rod 8 also rises with the support rod 8, the first connecting plate 11 and the second connecting plate 10 are released from the constraint of the previous stage support rod 8 and expanded in the rising process, and the first connecting plate 11 and the second connecting plate 10 drive the first slide block and the second slide block to slide in the arc-shaped slide rail of the outer bottom wall of the irrigation pipe 1. This linkage design makes the support rod 8 provide stable support for the irrigation pipe 1 during the vertical expansion process, avoiding displacement or deformation of the irrigation pipe 1 due to uneven force. At the same time, the first spring and the second spring jointly slow down the impact when the first connecting plate 11 and the second connecting plate 10 are expanded, avoiding damage to the components due to excessive instantaneous impact force, and ensuring the stable support of the support rod 8 to the irrigation pipe 1 during the vertical expansion or contraction. At the same time, the traditional technology usually needs to form a 20-25cm salt water ice layer, but there is still rainfall and snowfall in winter, and considering that the secondary freezing of part of the support rod 8 after rainfall and snowfall may cause the irrigation pipe 1 and the branch pipe 2 to be frozen in the snow layer or ice layer, therefore, through the support of the first connecting plate 11 and the second connecting plate 10 to the irrigation pipe 1, and through the design of the 18-21cm ice layer in the present scheme, 2-4cm of height error is reserved, which not only avoids the irrigation pipe 1 and the branch pipe 2 from being frozen in the ice layer during the secondary freezing, but also further collects the fresh water located in the upper part of the ice layer, providing fresh water resources for subsequent soil salt washing after thawing.

[0064] When the salt water melts and infiltrates into the soil in spring, the salt water ice layer in the support rod 8 melts, the buoy loses buoyancy, and each level of the support rod 8 is retracted under the action of its own gravity. At the same time, the first connecting plate 11 and the second connecting plate 10 are driven by the support rod 8 to retract by reversely sliding in the arc-shaped sliding rail through the first sliding block and the second sliding block, and are re-stored in the storage groove 9 at the end of the support rod 8. When the support rod 8 and its linkage structure are quickly retracted under the action of gravity, if there is no buffering, the first connecting plate 11 and the second connecting plate 10 will produce a transient impact force on the arc-shaped sliding rail of the outer bottom wall of the irrigation pipe 1 through the sliding block, and the irrigation pipe 1 as a main channel for carrying water flow is prone to stress fatigue under the transient impact, resulting in thinning of the pipe wall, loosening of the interface, and even rupture. In addition, if the retraction impact causes the irrigation pipe to shake or displace, it may cause the branch pipe water outlet hole to be misaligned with the small hole diameter area of the conversion ring, causing unstable drip irrigation flow. The buffering effect of the first spring and the second spring allows the support rod 8 to retract uniformly, and the precise alignment of the magnetic positioning sheet and the ferrous induction sheet can control the repositioning error of the irrigation pipe 1 to within ±2 mm, ensuring stable output of water flow through the pressure compensation diaphragm in the drip irrigation mode.

[0065] Example 3:

[0066] As shown in the accompanying drawings, Figure 1 different from example 2, the irrigation control system comprises a sensing unit, a data acquisition and processing module, a strategy generation module and an execution control module, wherein:

[0067] The sensing unit is signal-connected with the variable frequency water pump, the electromagnetic valve and the ferrous induction sheet, respectively. The sensing unit comprises a plurality of soil sensors, flow rate sensors and displacement sensors arranged on the irrigation pipe 1 and the support rod 8, and transmits the sensors of a plurality of channels to the data acquisition module.

[0068] The data acquisition module is used for receiving the variable frequency water pump frequency, the electromagnetic valve opening degree, the conversion ring 3 position data, the soil salt concentration, the soil surface temperature, the soil surface humidity, the water flow rate data in the irrigation pipe 1 and the vertical deployment height of the support rod 8 transmitted by the sensing unit, and adopting data filtering and normalization processing to obtain processed environmental data set and equipment data set, and transmitting them to the strategy generation module and the execution control module, respectively.

[0069] The strategy generation module is used for receiving the environmental data set and the equipment data set, calculating the ice layer formation speed by extracting the soil surface temperature and the vertical deployment height of the support rod 8, generating a water injection amount adjustment instruction; obtaining a dynamic salt concentration value by extracting the soil salt concentration, matching a drip irrigation rate according to the dynamic salt concentration value and the soil surface humidity; and transmitting the water injection amount adjustment instruction and the drip irrigation rate to the execution control module.

[0070] The strategy generation module comprises an ice layer construction control unit, which is configured to calculate the ice layer thickness by using an ice layer growth rate formula according to the vertical development height data of the support rod 8 and the soil surface temperature data:

[0071]

[0072] V1=K*(H-h / T)

[0073] wherein V0 represents the freezing rate in the interval in which the ice layer thickness is less than 2-3 cm, K is a correction coefficient, T0 is the freezing point temperature, T is the soil surface temperature, and t is the real-time water injection time. s The freezing rate in the interval in which the ice layer thickness is less than 2-3 cm is calculated, and when the freezing rate is lower than a set threshold, a water injection amount adjustment instruction for increasing the water injection amount is generated and transmitted to the execution control module;

[0074] V1 represents the freezing rate in the interval in which the ice layer thickness is greater than 2-3 cm, H represents the vertical development height data, h represents the initial height difference between the displacement sensor and the ground, and T is the current temperature. The freezing rate in the interval in which the ice layer thickness is greater than 2-3 cm is calculated, and when the freezing rate is lower than a set threshold, a water injection amount adjustment instruction for increasing the water injection amount is generated and transmitted to the execution control module; when the ice layer thickness H-h is between 20 cm and 25 cm, a water injection amount adjustment instruction for closing the water injection is generated and transmitted to the execution control module;

[0075] The strategy generation module further comprises a drip irrigation control unit, which is configured to receive the soil salt concentration C s , and calculate the target drip irrigation amount by using a gradient dilution model:

[0076] Q=Q0*(C s / C max ) n

[0077] wherein Q0 is the reference drip irrigation amount, C max is the upper limit of the salt concentration, and n is the dilution gradient coefficient. When C s ≥C max , the target drip irrigation amount is calculated by using the gradient dilution model, a drip irrigation rate is generated and transmitted to the execution control module, and the execution control module generates a rotation speed adjustment instruction and transmits it to the variable frequency water pump to adjust the water flow.

[0078] The execution control module is configured to receive the water injection amount adjustment instruction and the drip irrigation rate, compare the real-time variable frequency water pump frequency, the electromagnetic valve opening degree, the conversion ring 3 position data and the water flow rate data, and control the adjustment of the variable frequency water pump frequency and the electromagnetic valve opening degree according to the water injection amount adjustment instruction and the drip irrigation rate.

[0079] The specific implementation process is as follows: after the irrigation control system is started, the strategy generation module determines that the ambient temperature is below the freezing point according to the soil surface temperature, starts to inject water through the drip irrigation area 15, the initial water volume is 5 m 3 / h, the water flow rate is 2.5 m / s, the coverage radius reaches 8 m, when the time for the ice layer thickness to reach 2-3 cm is calculated by calculating the ice formation rate, until the support rod 8 is expanded and lifted due to the buoyancy of the irrigation pipe 1, the conversion ring 3 is switched to the water injection area 16, and the support rod 8 starts to expand vertically, at this time, the partition valve is switched by the electromagnetic valve, the water injection volume is increased to 20 m 3 / h, the salt ice layer is formed at a speed of 18-21 cm, the strategy generation module is switched to calculate the ice layer growth rate under the current water injection volume to calculate the time required for water injection, and whether the water injection needs to be continued is determined again when the current ice layer thickness H-h reaches the preset ice layer thickness.

[0080] When the soil surface temperature rises to 5°C, the internal ice layer of the support rod 8 melts and retracts, the conversion ring 3 is reset to the drip irrigation area 15, the strategy generation module generates a drip irrigation rate instruction according to the soil salt concentration, the frequency conversion water pump adjusts the speed to 1800 rpm, and the film drip irrigation is started to inhibit the salt seepage.

[0081] In order to verify the innovation of the scheme, two adjacent saline-alkali lands (each with an area of 1000 m2 and an initial salt content of 8-10 g / kg) are selected and respectively used:

[0082] Control group: traditional manual salt water sweeping + fixed drip irrigation system;

[0083] Experimental group: intelligent irrigation and salt content control integrated system of the scheme.

[0084] Test period: 2 complete years (including winter freezing period and spring salt return period).

[0085] Monitoring index:

[0086] Winter operation efficiency (labor input time, time required to complete the same area);

[0087] Ice layer thickness uniformity (1 measurement point per 10 m2, a total of 100 points);

[0088] Spring soil surface layer (0-20 cm) salt content change;

[0089] Improved cotton yield (statistical per year).

[0090] Experimental results:

[0091]

[0092] Conclusion: Through the comparison test data, compared with the traditional artificial salt scanning combined with fixed irrigation, the intelligent irrigation and salt control integrated system shows significant advantages in manpower investment, ice layer uniformity, salt control and crop yield increase in multiple dimensions. It saves manpower, improves 65% ice layer uniformity, reduces more than 50% surface layer salt, and increases cotton yield by 10%. It fully verifies the innovation value of automation, precision and high efficiency in saline-alkali soil improvement, and provides a more scientific and reliable solution for saline-alkali soil treatment.

[0093] Obviously, the above embodiments are only examples for clearly illustrating, but not limiting the embodiments. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. An integrated intelligent irrigation and salinity control system for improving saline-alkali land for cotton cultivation, comprising several irrigation pipes (1) and a variable frequency water pump, wherein each irrigation pipe (1) is connected to the variable frequency water pump, and several branch pipes (2) are connected to each irrigation pipe (1), each irrigation pipe (1) is equipped with a solenoid valve, and a zone valve is provided at the connection between the solenoid valve and the irrigation pipe (1), characterized in that, The solenoid valve signal is connected to the irrigation control system; the irrigation pipe (1) is also fitted with several adjustment devices, each of which includes several levels of support rods (8) that are connected end to end. The support rods (8) are all opened near the bottom end to allow brine to enter the support rods (8). The support rods (8) are all equipped with a buoyancy deployment mechanism for driving the next level support rod (8) to unfold vertically by injecting brine. The irrigation pipe (1) and the last level support rod (8) are all equipped with a conversion component for switching the drainage hole diameter at the branch pipe (2) according to the lifting height of the support rod (8). Each conversion component includes a first fixed block (6) fixedly connected to the outer wall of any first-level support rod (8). A crank-connecting rod mechanism (5) is hinged on the first fixed block (6). A conversion ring (3) is hinged to the end of the crank-connecting rod mechanism (5) away from the first fixed block (6). The conversion ring (3) is sleeved on the branch pipe (2) and rotatably connected to the branch pipe (2). A water outlet hole (17) is opened on the branch pipe (2). The conversion ring (3) is divided into a water injection area (16) and a drip irrigation area (15). The water injection area (16) has only a single first hole (4). The drip irrigation area (15) has several second holes (14). A pressure compensation diaphragm is provided on the inner wall of the drip irrigation area (15). The diameter of the water outlet hole (17) is ≥ the diameter of the first hole (4) > the diameter of the second hole (14).

2. The integrated intelligent irrigation and salinity control system for improving saline-alkali land for cotton cultivation according to claim 1, characterized in that, An elastic sealing strip (13) is provided around both the conversion ring (3) and the branch pipe (2). The elastic sealing strip (13) is used to seal and separate the water injection area (16) and the drip irrigation area (15).

3. The integrated intelligent irrigation and salinity control system for improving saline-alkali land for cotton cultivation according to claim 2, characterized in that, Each buoyancy deployment mechanism includes a float fixedly connected to the bottom of the next-level support rod (8). Each support rod (8) has an opening at its top, and a sealing ring (12) is fixedly connected inside the opening. The next-level support rod (8) is slidably connected to the sealing ring (12) when it is deployed or retracted.

4. The integrated intelligent irrigation and salinity control system for improving saline-alkali land for cotton cultivation according to claim 3, characterized in that, Several storage slots (9) are opened at the ends of the support rods (8). A second fixing block is fixedly connected in each storage slot (9). A first connecting plate (11) and a second connecting plate (10) are respectively hinged on the second fixing block. An arc-shaped slide rail is opened on the bottom wall of the irrigation pipe (1). A first slider and a second slider are respectively hinged at the ends of the first connecting plate (11) and the second connecting plate (10) away from the second fixing block. The first slider and the second slider are both located in the arc-shaped slide rail and slide in cooperation with the arc-shaped slide rail.

5. The integrated intelligent irrigation and salinity control system for improving saline-alkali land for cotton cultivation according to claim 4, characterized in that, The curved slide rail is equipped with a damping component to reduce the impact when the first connecting plate (11) and the second connecting plate (10) expand or contract. The damping component includes a first spring and a second spring. The two ends of the first spring are fixedly connected between the first slider and the second slider, respectively, and the two ends of the second spring are fixedly connected to the second slider and the side wall of the curved slide rail, respectively.

6. The integrated intelligent irrigation and salinity control system for improving saline-alkali land for cotton cultivation according to claim 5, characterized in that, The inner walls of the irrigation pipe (1), branch pipe (2) and support rod (8) are coated with fusion-bonded epoxy powder coating and polyethylene coating from the inside out.

7. The integrated intelligent irrigation and salinity control system for improving saline-alkali land for cotton cultivation according to claim 6, characterized in that, Each branch pipe (2) is embedded with symmetrically arranged magnetic positioning plates, and each conversion ring (3) is embedded with an iron induction plate corresponding to the magnetic positioning plate.

8. The integrated intelligent irrigation and salinity control system for improving saline-alkali land for cotton cultivation according to claim 7, characterized in that, The irrigation control system includes a sensing unit, a data acquisition and processing module, a strategy generation module, and an execution control module, wherein: The sensing unit is connected to the variable frequency water pump, the solenoid valve and the iron induction plate respectively. The sensing unit includes several soil sensors, flow rate sensors and displacement sensors installed on the irrigation pipe (1) and the support rod (8). The sensing unit transmits the sensors through several paths to the data acquisition module. The data acquisition module is used to receive data from the sensor unit, including the frequency of the variable frequency water pump, the opening degree of the solenoid valve, the position data of the switching ring (3), the soil salt concentration, the soil surface temperature, the soil surface humidity, the water flow rate data in the irrigation pipe (1), and the vertical unfolding height of the support rod (8). The module uses data filtering and normalization to obtain the processed environmental dataset and equipment dataset, and transmits them to the strategy generation module and the execution control module, respectively. The strategy generation module is used to receive environmental datasets and equipment datasets, calculate the ice formation rate by extracting soil surface temperature and vertical unfolding height of support rod (8), and generate water injection adjustment instructions; obtain dynamic salt concentration values ​​by extracting soil salt concentration, and match drip irrigation rate according to dynamic salt concentration values ​​and soil surface humidity; transmit water injection adjustment instructions and drip irrigation rate to execution control module. The execution control module is used to receive water injection volume adjustment instructions and drip irrigation rate. By extracting real-time variable frequency pump frequency, solenoid valve opening, conversion ring (3) position data and water flow rate data for comparison, the variable frequency pump frequency and solenoid valve opening are controlled and adjusted according to the water injection volume adjustment instructions and drip irrigation rate.

9. The integrated intelligent irrigation and salinity control system for improving saline-alkali land for cotton cultivation according to claim 8, characterized in that, The strategy generation module includes an ice layer construction control unit, which calculates the ice layer thickness using the ice layer growth rate formula based on the vertical unfolding height data of the support rod (8) and the soil surface temperature data. V1 = K*(Hh / T) Where V0 represents the freezing rate in the range where the ice thickness is less than 2-3 cm, K is a correction factor, T0 is the freezing point temperature, and T s The soil surface temperature is t, and the real-time water injection time is t. The freezing rate is calculated when the ice layer thickness reaches 2-3 cm. When the freezing rate is lower than the set threshold, a water injection volume adjustment command is generated and transmitted to the execution control module. V1 represents the icing rate when the ice thickness is greater than 2-3cm, H represents the vertical deployment height data, h represents the initial height difference between the displacement sensor and the ground, and T is the current temperature. By calculating the icing rate when the ice thickness is greater than 2-3cm, when the icing rate is lower than the set threshold, a water injection adjustment command to increase the water injection volume is generated and transmitted to the execution control module; when the ice thickness Hh is between 20cm and 25cm, a water injection adjustment command to shut off the water injection volume is generated and transmitted to the execution control module.

10. The integrated intelligent irrigation and salinity control system for improving saline-alkali land for cotton cultivation according to claim 9, characterized in that, The strategy generation module also includes a drip irrigation control unit, which receives soil salinity C. s A gradient dilution model is used: Q=Q0*(C s / C max ) n Where Q0 is the baseline drip irrigation volume, and C max Where C is the upper limit of salt concentration, n is the dilution gradient coefficient, and C is the upper limit of salt concentration. s ≥C max At that time, the target drip irrigation volume is calculated through the gradient dilution model, and the drip irrigation rate is generated and sent to the execution control module. The execution control module generates a speed adjustment command and transmits it to the variable frequency water pump to adjust the water flow.

Images