A method for coordinated regulation of water and salt in the root zone of jujube trees based on continuous vertical pipe irrigation

Abstract

This application relates to the field of agricultural irrigation and soil water and salt management technology, and discloses a method for coordinated regulation of water and salt in the root zone of jujube trees based on continuous vertical pipe irrigation. The method includes: deploying vertical pipes around the main root zone of the jujube tree to continuously supply slightly saline water; obtaining meteorological theoretical water consumption demand and headstock observation flow rate, identifying effective infiltration flow rate and calculating the total external salt mass; constructing surface state quantities, transient transitional inventory in the main root protection zone, and deep state quantities, disassembling the total external salt mass and updating the above state quantities; calculating the freshwater maintenance capacity factor and isolation integrity index, obtaining surface overload contribution items and deep overload contribution items; when the isolation state of the main root zone is determined to be ineffective, comparing the surface overload contribution item with the deep overload contribution item, and outputting a matching hydraulic regulation command. This invention overcomes the defect of soil sensors being prone to corrosion and failure, improves the accuracy of salt distribution measurement, achieves targeted hydraulic remediation, and avoids secondary hydrological hazards caused by flood irrigation.

Description

Technical Field

[0001] This invention relates to the field of agricultural irrigation and soil water and salt management technology, specifically a method for synergistic regulation of water and salt in the root zone of jujube trees based on continuous vertical pipe irrigation. Background Technology

[0002] In arid and semi-arid regions, where freshwater resources are severely scarce, the use of brackish water for agricultural irrigation has become a routine alternative for maintaining the growth of cash crops such as jujube trees. However, long-term input of brackish water can easily disrupt the original water-salt balance of the soil, leading to a large accumulation of salt in the crop root zone.

[0003] To monitor and control water and salt dynamics in the root zone, existing irrigation management systems typically rely heavily on water and salt sensors buried within the soil. However, in brackish water supply and high-salt-alkali soil environments, the probes of these in-situ sensors are highly susceptible to chemical corrosion and physical scaling, leading to data drift or complete hardware failure. This makes it difficult for the system to obtain long-term, continuous, and reliable underlying parameters. Furthermore, in the extrapolation and calculation of water and salt transport, existing methods often treat the root zone soil as a uniformly mixed space, failing to distinguish the differentiated effects of various boundary conditions—such as surface evaporation, root water absorption, and gravity excretion—on the retention of free salts. This results in significant deviations in the calculation of salt spatial distribution within non-uniform soil profiles.

[0004] Furthermore, when existing system assessments identify crops as suffering from high salt stress and requiring salt drainage, a single, large-volume flood irrigation method is often used for forced leaching. This extensive hydraulic operation, lacking an assessment of the specific spatial sources of salt overload, not only results in severe waste of water resources but also easily leads to insufficient drainage of groundwater, causing abnormal rises in the groundwater level. This, in turn, triggers secondary hydrological disasters such as the reverse intrusion of salts from the lower layers via capillary transport, making it difficult to effectively eliminate the threat of salinization at different levels.

[0005] Therefore, this invention proposes a method for coordinated regulation of water and salt in the root zone of jujube trees based on continuous vertical pipe irrigation to address the shortcomings of existing technologies. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for coordinated water and salt regulation in the root zone of jujube trees based on continuous vertical pipe irrigation. This method solves the problems of easy corrosion and failure of underground sensors, inaccurate calculation of salt distribution in root zone profiles, and the potential for secondary hydrological disasters caused by blind flooding and salt discharge in existing brackish water irrigation regulation.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for synergistic regulation of water and salt in the root zone of jujube trees based on continuous vertical pipe irrigation, comprising the following steps: A closed-walled vertical pipe with a single open bottom is installed around the main root area of ​​the jujube tree, and the outlet of the vertical pipe is buried in the set layer interface burial depth range. Slightly saline water is supplied in a continuous water supply mode through the vertical pipe; Obtain meteorological theoretical water consumption demand and head unit observation flow, identify and output effective infiltration flow; The effective infiltration flow rate is multiplied by the background salinity concentration of the irrigation water source to obtain the total external salinity mass; Construct surface state quantities, transient transition inventory quantities in the main root protection zone, and deep state quantities along the vertical profile; Disassemble the total external salt mass and update the surface state quantity, transient transition inventory of the main root protection zone, and deep state quantity; Calculate the freshwater maintenance capacity factor based on the effective infiltration flow and meteorological theoretical water demand. The isolation integrity index is calculated based on the surface state variables and deep state variables, and the surface overload contribution item and deep overload contribution item are obtained. When the isolation integrity index is lower than the isolation health judgment threshold and the freshwater maintenance capacity factor is lower than the freshwater safety maintenance threshold, the isolation status of the main root zone is determined to be invalid, and the routine brackish water supply operation is stopped. By comparing the numerical relationship between the surface overload contribution and the deep overload contribution, a matching hydraulic control command is output.

[0008] Preferably, identifying and outputting the effective infiltration flow rate includes: Set a minimum effective traffic threshold; When the head observation flow rate is less than or equal to the minimum effective flow rate threshold, the value of the head observation flow rate is assigned to the effective infiltration flow rate; When the observed flow rate at the head is greater than the minimum effective flow rate threshold, the ratio of the meteorological theoretical water consumption demand to the observed flow rate at the head is calculated to obtain the water consumption infiltration consistency discrimination index. Determine whether the water consumption and infiltration consistency discrimination index exceeds the limit; When the water consumption infiltration consistency discrimination index exceeds the limit, the effective infiltration flow rate is output through autoregressive interpolation correction.

[0009] Preferably, when the water consumption infiltration consistency discrimination index exceeds the limit, the effective infiltration flow rate is corrected and output through autoregressive interpolation, including: The cumulative actual infiltration volume of the previous 3 days was extracted to calculate the moving average value, and a dynamic theoretical flow decay hysteresis interval was constructed. When the water consumption infiltration consistency discrimination index exceeds the theoretical flow rate decay hysteresis range and the pipeline pressure simultaneously experiences an abnormal drop or rise, it is determined that an abnormal observed flow rate caused by non-soil factors has occurred. A time series autoregressive model was established by extracting the historical daily average effective infiltration flow series from the previous 7 to 14 days. The theoretical infiltration amount for the current period is predicted using the aforementioned time series autoregressive model; The effective infiltration flow rate after smoothing correction is output by replacing the head observation flow rate with the theoretical infiltration rate.

[0010] Preferably, the disassembly of the total external salt content includes: The ratio of the theoretical meteorological water demand to the effective infiltration flow is used to construct an upward evaporation traction weighting coefficient. Subtracting the evaporation traction weighting coefficient from the value 1 yields the downward infiltration drive weighting coefficient; Based on the evaporation traction weighting coefficient and the infiltration driving weighting coefficient, the total external salt mass is decomposed into the flux retained in the surface layer and the flux that penetrates downwards to the deeper layers with the water flow.

[0011] Preferably, updating the surface state quantities, the transient transition inventory in the primary root protection zone, and the deep state quantities includes: The safe salt tolerance threshold of the main root zone is calculated by multiplying the soil space volume, soil saturated water content and the preset critical salt tolerance concentration of crop roots. When the calculated transient transition inventory of the main root protection zone exceeds the safe salt tolerance threshold of the main root zone, the volume capping forced redistribution mechanism is triggered. The excess salt mass is forcibly allocated and accumulated to the deep state quantity through the volume-top forced redistribution mechanism.

[0012] Preferably, the freshwater maintenance capacity factor is calculated based on the effective infiltration flow and meteorological theoretical water demand, including: Obtain the corrected interfacial water retention coefficient; Within a set statistical period, the downward resistance is obtained by time-step integration of the product of the effective infiltration flow rate and the corrected interfacial peristaltic coefficient. Within the statistical period, the total water consumption is obtained by time-step integration of the meteorological theoretical water consumption demand; Calculate the difference between the downward resistance and the total water consumption; Calculate the sum of the total water consumption and the set basic water consumption constant; Dividing the difference by the sum yields the freshwater maintenance capacity factor.

[0013] Preferably, the isolation integrity index is calculated based on the surface state variables and deep state variables, and the surface overload contribution term and deep overload contribution term are obtained, including: Set surface safety capacity thresholds and deep safety capacity thresholds; The surface back pressure weight is multiplied by the proportion of the surface state quantity to the surface safe capacity threshold to obtain the surface overload contribution term. The deep-layer retention and buoyancy weight is multiplied by the proportion of the deep-layer state quantity to the deep-layer safety capacity threshold to obtain the deep-layer overload contribution term. Furthermore, the sum of the surface backpressure weight and the deep retention and upward floating weight is a value of 1; Calculate the sum of the surface overload contribution term and the deep overload contribution term; The isolation integrity index is obtained by subtracting the sum from the value 1.

[0014] Preferably, the numerical relationship between the surface overload contribution and the deep overload contribution is compared, and a matching hydraulic control command is output, including: When the surface overload contribution is greater than or equal to the deep overload contribution, it is determined that the surface dominant failure branch is entered, and a high-pressure shell breaking and low-pressure flat pushing combination command is output. When the surface overload contribution is less than the deep overload contribution, it is determined that the deep dominant failure branch is entered, and an ultra-long cycle micro-flow infiltration command is output.

[0015] Preferably, the output of the high-pressure shell-breaking and low-pressure horizontal thrust combination command includes: High-pressure micro-jet water discharge operation is performed at the set high-pressure operating pressure to destroy the surface salt crust layer; The pipeline operating pressure is lowered to the set low-pressure operating pressure, and a low-pressure flat-push fresh water flow is continuously output to generate push water volume. The amount of water moved is equivalently converted into the amount of solute replacement of surface salts; The solute replacement amount is used as the negative desalination flux, and the surface state amount is deducted at daily steps.

[0016] Preferably, the output of ultra-long cycle micro-flow infiltration commands includes: Extend the single water supply cycle and control the outflow rate to a preset low flow rate; Calculate the ratio of the minute infiltration volume to the sum of the deep soil water volume and the minimum volume zero constant; The total amount of salt discharged is obtained by multiplying the ratio by the deep state quantity and performing time integration over an ultra-long period. The deep state quantity is reduced and updated based on the total amount of salt discharged; When the deep state quantity is less than the deep safety limit, the freshwater maintenance capacity factor exceeds the freshwater safety maintenance threshold, or the hydraulic gradient of the deep bottom layer changes from positive to negative, the ultra-long cycle micro-flow infiltration command is terminated.

[0017] This invention provides a method for synergistic regulation of water and salt in the root zone of jujube trees based on continuous vertical pipe irrigation. It has the following beneficial effects: 1. This invention involves deploying closed-walled pipes and single-bottom-opening vertical pipes around the main root zone of jujube trees, burying the outlets at a predetermined depth within the interlayer interface, and combining this with a brackish water continuous water supply mode to directly and directionally deliver irrigation water to the deep soil layers. This method physically prevents lateral seepage and intense evaporation of irrigation water in the surface soil, inhibiting surface salt accumulation. Simultaneously, the downward positive pressure water flow generated by continuous infiltration resists the upward intrusion of high-concentration salts from the subsoil, maintaining a stable low-salt isolation space for the main root system under brackish water irrigation conditions.

[0018] 2. This invention utilizes the ratio of meteorological theoretical water demand to the observed flow rate to construct a consistency index for water consumption and infiltration. Combined with a theoretical flow rate attenuation hysteresis interval set based on historical actual infiltration volume, it achieves automatic identification of non-soil factor data caused by pipeline anomalies. After determining data anomalies, the system calls a time-series autoregressive model to perform interpolation correction using historical anomaly-free time series. This mechanism overcomes the defect of underground in-situ sensors being prone to corrosion and failure in saline-alkali environments over long periods, ensuring the accuracy and consistency of the basic infiltration data upon which the system's long-term extrapolation relies.

[0019] 3. This invention constructs three independent zones along the vertical profile: surface state quantity, transient transitional stock quantity in the main root protection zone, and deep state quantity. It then decomposes the flux of newly added total salt based on evaporation traction and infiltration driving weights. Combined with a volumetric top-level forced redistribution mechanism, the system calculates the overflow and downward transfer of temporarily retained salt based on soil water-holding characteristics and the law of conservation of mass. This discretized three-layer calculation model solves the problem that traditional overall mixing models cannot quantify the stratified retention and non-uniform migration characteristics of salt, improving the accuracy of calculating the spatiotemporal distribution of salt in the root zone.

[0020] 4. This invention integrates the dynamics of water flow obstruction with the degree of salinity approach to calculate the freshwater maintenance capacity factor and the isolation integrity index, establishing a two-factor isolation failure judgment mechanism. Upon failure, it compares the overload contributions of the surface and deep layers to pinpoint the threat source. For surface-dominant failure caused by surface crust degradation, the system outputs a combination of high-pressure crust breaking and low-pressure pushing commands to restore infiltration channels and leach salt. For deep-dominant failure caused by deep overload, the system outputs ultra-long-cycle, low-flow infiltration commands to slowly dissipate free salt. This mechanism achieves targeted matching of hydraulic repair commands, avoiding secondary hydrological hazards such as groundwater level rise caused by solely relying on large-scale flooding. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the system architecture of the present invention; Figure 2 This is a schematic diagram of the method flow of the present invention; Figure 3 This is a schematic diagram illustrating the internal working principle of the state conservation calculation module of the present invention; Figure 4 This is a schematic diagram of the evolution curve of the system operating state variables of the present invention; Figure 5 This is a schematic diagram of the water-salt dual-factor assessment and remediation response trajectory of the present invention; Figure 6 The core indicators of this invention are verified by comparative bar graphs, where (a) is the comparison of average electrical conductivity in the main root zone, (b) is the comparison of relative irrigation water productivity, and (c) is the comparison of relative yield per plant. Figure 7 This is a schematic diagram illustrating the working principle of the vertical pipe irrigation device of the present invention; Figure 8 This is a schematic diagram of the vertical pipe layout method of the present invention.

[0022] Among them, 100 is the flux decoupling module; 200 is the state conservation calculation module; 300 is the evaluation and identification module; and 400 is the repair and self-recovery module. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] See attached document Figure 1 This invention provides a water-salt synergistic regulation system for the root zone of jujube trees based on continuous vertical pipe irrigation. The water-salt synergistic regulation system for the root zone of jujube trees includes: The flux decoupling module 100 is used to collect meteorological data and the head observation flow of the riser network, calculate discrimination indicators to identify the physical operating status, output the effective infiltration flow, and calculate the total external salt mass input to the system on the same day.

[0025] The state conservation calculation module 200 is used to establish system partition state quantities according to preset vertical spatial layering rules, separate external new flux and internal stock according to the principle of mass conservation, perform time-series update calculations and complete global mass balance bidirectional verification.

[0026] The assessment and identification module 300 is used to perform cross-seasonal state quantity calibration, and outputs the freshwater maintenance capacity factor and isolation integrity index based on time step integration calculation to determine whether the physical isolation status of the root region exceeds the preset safety limit.

[0027] The repair and self-recovery module 400 is used to determine the repair branch based on the weight distribution characteristics in the isolation integrity index, generate the corresponding pipeline flow control command, and determine the physical conditions for exiting the repair state based on the state evolution results of subsequent system time steps.

[0028] See attached document Figure 2 This invention provides a method for synergistic regulation of water and salt in the root zone of jujube trees based on continuous vertical pipe irrigation, comprising the following steps: S100, the flux decoupling module 100 acquires the meteorological theoretical water consumption demand and the head observation flow, uses the ratio of the two to identify and correct abnormal flow data, and calculates the total external salt mass of the day by combining the background salt concentration of the irrigation water source. S200, the state conservation calculation module 200 performs flux decomposition on the total external salt mass, calculates the stock transfer and temporary release amounts respectively in combination with the control events and soil moisture characteristics, updates the state quantities of each spatial partition and the system salt discharge amount, and performs global mass balance closed-loop verification. S300, the assessment and identification module 300 performs cross-seasonal initial state updates and system baseline alignment, calculates the freshwater maintenance capacity factor and isolation integrity index respectively, and determines whether the isolation status of the main root zone has failed based on the dual-factor joint constraint. S400, the repair and self-recovery module 400 identifies the failure mode based on weight distribution when determining isolation failure, outputs corresponding hydraulic repair commands for surface or deep dominant failures respectively, and terminates command output when the relevant status indicators recover to the set threshold.

[0029] To further clarify the implementation of each technical aspect of the present invention, the following will provide a detailed description of the implementation of each functional module involved above and its internal processing flow.

[0030] See attached document Figure 2 In this embodiment, the external flux decoupling and anchoring process performed by the flux decoupling module 100 aims to eliminate interference from non-soil factors, obtain true infiltration data, and establish the external boundary for newly added salinity by acquiring physical parameters and analyzing headwater flow. Specifically, this process includes the following steps: S110, the parameter acquisition unit of the flux decoupling module 100 defines the physical boundary of the vertical pipe and the burial depth parameters of the corresponding layer interface, which are laid out outside the main root area of ​​the jujube tree.

[0031] Combination Figure 7 and Figure 8As shown, as a preferred method, the physical boundary of the riser adopts a structure with a closed pipe wall and a single open bottom. In specific implementation, the riser emitter is composed of a vertically buried rigid PVC pipe with a diameter between 4cm and 20cm. The upper end of the riser emitter is connected to the water supply system, while the lower end is open and in direct contact with the soil. That is, the lower end of the riser emitter forms a circular water-soil interface parallel to the ground in the horizontal direction, and the diameter of the interface is the inner diameter of the riser. The physical principle of this structure is to use a physical barrier to forcibly cut off the lateral seepage of irrigation water in the surface soil, forcing the water flow directly to the designated depth.

[0032] The burial depth parameters of the layer interface are set according to the vertical distribution characteristics of the jujube tree's main root system, with a burial depth range of 0.4m to 0.5m. The horizontal distance between the vertical pipe and the jujube tree trunk is set at 0.3m, and the pipes are arranged around the trunk. The basis for setting this range is to avoid the strong evaporation and salt accumulation zone in the surface layer from 0 to 20cm, while ensuring that the outlet of the vertical pipe is precisely located in the physical space where the main root system has the highest water absorption efficiency.

[0033] The vertical pipe does not house control components such as solenoid valves and operates in a continuous water supply mode. Its working principle is as follows: when crop roots are short of water or soil moisture evaporates, the roots absorb water from the nearby soil to support crop growth and development or for water to be consumed through evaporation. This disrupts the original equilibrium at the soil-water interface, creating a potential energy difference. Under the influence of this soil potential energy, pressurized water from the supply pipe enters the vertical pipe irrigation device. As water enters the soil from the outlet, it gradually reaches saturation around the outlet, causing the soil potential energy to gradually decrease. This eventually reduces the flow rate of the irrigation device until the surrounding soil moisture is utilized by the plants or evaporated. The water then flows out and diffuses outwards under the influence of soil potential energy. The vertical pipe system operates in a continuous water supply mode, automatically delivering slightly saline water to the root zone based on the soil-water potential energy difference. Combined with the control method of this invention, it can achieve biennial leaching and salt-suppressing irrigation, resulting in a low salt content in the jujube tree root zone. For the selection of vertical pipe materials and the setting of pipe diameter, those skilled in the art can configure them according to farmland irrigation standards. The selection of pipe materials and fittings is a well-known technology in this field and will not be elaborated here.

[0034] S120, the anomaly troubleshooting unit obtains the meteorological theoretical water consumption demand and the head observation flow aligned on the same daily time scale, calculates the ratio of the meteorological theoretical water consumption demand to the head observation flow as the water consumption infiltration consistency judgment index, and introduces the minimum effective flow threshold to avoid the risk of division by zero anomaly.

[0035] To ensure the computational stability of hydraulic anomaly detection and avoid calculation anomalies where the denominator approaches zero under extremely low flow rates, the anomaly troubleshooting unit sets a minimum effective flow rate threshold. This minimum effective flow rate threshold represents the flow boundary value under conditions of irrigation equipment shutdown or power outage, or extreme low-flow leakage. The value of this threshold is typically calibrated based on the opening pressure of the anti-drip valves in the irrigation network or the minimum stable operating flow rate of the system pumps. When the observed flow rate at the head end exceeds the minimum effective flow rate threshold, the anomaly troubleshooting unit performs a ratio calculation. The formula for calculating the water consumption-infiltration consistency discrimination index is as follows: ; In the formula, For the first Daily water consumption and infiltration consistency criteria, dimensionless; For the first Daily meteorological theoretical water demand, in mm or m 3 ; For the first The daily head-up observation flow rate is kept in the same dimension as the water consumption demand. For calculating the meteorological theoretical water consumption demand, those skilled in the art can extrapolate it using the Penman formula based on ambient temperature, humidity, and wind speed data collected from standard meteorological stations. This meteorological water consumption demand calculation process is well-known in the field and will not be elaborated upon here. When the head-up observation flow rate is less than or equal to the minimum effective flow rate threshold, the system skips the hydraulic anomaly detection process, and the anomaly mitigation unit directly assigns the head-up observation flow rate value to the effective infiltration flow rate. .

[0036] S130, the abnormal obstacle removal unit constructs a theoretical flow decay hysteresis interval based on the historical real infiltration volume. When the water consumption infiltration consistency discrimination index exceeds the limit, it is determined that the observed flow abnormality is not caused by soil factors, and triggers autoregressive interpolation correction to output the effective infiltration flow.

[0037] In brackish water continuous water supply scenarios, the infiltration rate typically exhibits a non-linear decay characteristic due to the back pressure of the soil matrix potential. Therefore, the anomaly detection unit extracts the cumulative actual infiltration volume of the previous three days and constructs a dynamic theoretical flow decay hysteresis interval by combining the negative feedback response relationship between soil matrix potential and water supply flow. In specific implementation, a moving average value is calculated for the infiltration volume of the previous three days, and a set tolerance coefficient (e.g., a value range between 0.8 and 1.2) is introduced to define the dynamic upper and lower limits of this interval. This theoretical flow decay hysteresis interval defines the reasonable range of flow fluctuation at the head of the pipeline network under the current soil moisture state. When the direction or magnitude of the abrupt change in the water consumption infiltration consistency discrimination index exceeds the theoretical flow decay hysteresis interval, the anomaly detection unit determines that the observed data deviates from the soil resistance evolution law. To improve the robustness of the judgment and avoid one-sided judgment, the system simultaneously collects pressure sensor data at the head of the pipeline network for multi-dimensional verification. If the pipeline pressure synchronously experiences an abnormal drop or rise, it is ultimately determined that an anomaly in the observed flow is caused by factors other than soil. Abnormal flow rates not caused by soil factors include filter unit blockage, localized sludge suction in the pipeline network, pipeline pressure fluctuations, or pipeline rupture.

[0038] In this embodiment, after determining that an anomaly in the observed flow rate is not caused by soil factors, the anomaly mitigation unit initiates autoregressive interpolation correction. The autoregressive interpolation correction establishes a time-series autoregressive model by extracting the effective infiltration flow rate sequence from historical periods without anomalies. The input data consists of the historical daily average effective infiltration flow rate sequence from the 7 to 14 days prior to the current period. The system uses the least squares method to fit the model parameters, determines the order of the autoregressive model using the Akaike Information Criterion, and predicts the theoretical infiltration rate for the current period based on the time-series autoregressive model. This theoretical infiltration rate is then used to replace the abnormal initial observed flow rate, ultimately outputting the smoothed and corrected effective infiltration flow rate. .

[0039] S140, the external salt anchoring unit will effectively control the infiltration flow rate. Multiplying the concentration of the irrigation water source by the background salt concentration, the total external salt mass introduced into the system at the current time step is calculated.

[0040] The technical purpose of this calculation step is to quantify the absolute solute boundary load introduced into the root zone by a single water infiltration, thereby providing an accurate material input source for the subsequent two-layer conservation model within the system. The external salinity anchoring unit, combined with the salinity parameters of the brackish water source, determines the background salinity concentration of the irrigation water source. The formula for calculating the total external salinity mass is as follows: ; In the formula, For the first The total external salt mass introduced into the system daily is expressed in kg or g. For the first Daily effective infiltration flow rate, in m³ 3 Or L; Background salinity concentration of irrigation water, in kg / m³ 3 Or g / L.

[0041] See attached document Figure 2 and combined Figure 3 In this embodiment, the state space construction and two-layer conservation calculation process performed by the state conservation calculation module 200 aims to utilize temporal logic and various inventory constraint boundaries to complete the separation of old and new throughput, independent evolution of internal states, and bidirectional verification of global quality. Specifically, this process includes the following steps: S210, the variable definition unit of the state conservation calculation module 200 constructs three independent partition state variables along the vertical profile: surface state variable, deep state variable, and transient transition inventory of the main root protection zone used to store temporarily retained free salt. It also establishes a global total salt content verification variable that does not participate in the decision-making process.

[0042] As a preferred approach, to accurately describe the residence characteristics of salt in a non-uniform soil profile, the system employs a discretized state space for simulation. The variable definition unit divides the vertical space according to the set layer interface depth parameters. In this embodiment, the surface state variable is defined. The total soil salinity corresponds to the depth range from 0 to the interlayer interface, which is affected by both surface evaporation and irrigation infiltration. The transient transitional stockpile in the taproot protection zone is defined. The mass of dissolved free salts in the region between the burial depth of the corresponding layer interface and the lower limit of the main root distribution. This portion of salts exhibits strong rheological properties with fluctuations in soil moisture. Define the deep state quantity. This corresponds to the subsoil salinity below the lower limit of the taproot distribution, where material exchange is relatively slow. A global total salinity check variable is established. The technical objective is to construct a holistic quality ledger independent of the three-layer spatial interaction logic, specifically for subsequent quality conservation closed-loop verification. During system initialization, the initial values ​​of the state variables for each partition are allocated and set according to the hierarchical volume ratio based on offline soil background test data before the new irrigation season.

[0043] S220, the flux splitting unit decomposes the external new flux according to the meteorological theory of water consumption demand and the gravity constant, and calculates the stock transfer salt due to rainfall or shifting instructions based on the upper limit constraint of surface inventory shift.

[0044] Water transport is the kinetic carrier of solute migration. The flux decomposition unit obtains the external total salt mass calculated in the previous step and calculates the allocation weights based on the atmospheric evaporation-transpiration pull and downward gravitational potential energy at the current time step. In specific implementation, an upward evaporation pull weight coefficient is constructed by calculating the ratio of meteorological theoretical water demand to the current effective infiltration flow, and a downward infiltration drive weight coefficient is obtained by subtracting this coefficient from 1. Based on this, the external total salt mass is decomposed into the flux retained in the surface layer and the flux that directly penetrates downward to the deeper layers with the water flow. When natural rainfall occurs or artificial hydraulic thrust is executed, the infiltration of water will drive the state quantities originally retained in the surface layer. Some of the salt in the water is transferred to the lower space. To avoid generating negative mass inventory that violates the laws of physics when calculating high-flux flushing, the flux splitting unit applies an upper limit constraint on surface inventory transfer. The specific execution logic of the upper limit constraint on surface inventory transfer is as follows: the amount of salt transferred in the current time step must absolutely not exceed the surface state quantity at the end of the previous time step. The value. When the theoretically calculated stock transfer salt content is greater than the current surface state quantity. At that time, the system forcibly truncates the value of the transferred salt to be equal to the current surface state value. .

[0045] S230, the state update unit combines soil moisture characteristics to calculate the release amount of temporarily retained salt, and applies the upper limit constraint of transitional inventory release and the forced redistribution mechanism of volume limit to update the prior state quantities of each partition.

[0046] The soil water-holding capacity within the taproot protection zone determines the upper limit of solute retention. When soil moisture content exceeds field capacity, resulting in gravitational free water, the salts dissolved in this water will be released from the transient transitional stockpile within the taproot protection zone. Release downwards. The state update unit calculates the release amount of the temporarily retained salt and strictly applies a transitional stock release upper limit constraint during the calculation process, meaning that the release amount in a single calculation must not exceed the transient transitional stock in the main root protection zone. The current total inventory. To cope with extreme moisture accumulation conditions, the state update unit introduces a volume-limited forced redistribution mechanism. This mechanism is determined by setting a safe salt tolerance threshold for the main root zone. The safe salt tolerance threshold for the main root zone is calculated based on the product of the soil space volume of the main root protection zone, the soil saturated water content, and the preset critical salt tolerance concentration of the crop roots. When calculating the updated transient transition inventory of the main root protection zone... When the salt content exceeds the safe salt tolerance threshold of the main root region, the excess salt mass is forcibly allocated and accumulated in the deep state quantity. In this way, the timing update of the prior state variables of each partition is completed.

[0047] S240, the verification unit calculates the deep desalination amount based on the constraint that the deep discharge does not exceed the deep inventory to complete the deep state shaping. By comparing the spatial summation of the partitioned state variables with the time integral of the system's inflow and outflow fluxes, the closed-loop consistency of the two-layer mass conservation equation is verified.

[0048] Moisture in the deep soil layer is driven by the hydraulic gradient of the subsurface layer to drain further beyond the system's physical boundary, resulting in deep soil desalination. The verification unit calculates this desalination rate by combining the deep soil permeability coefficient and the subsurface hydraulic gradient. To ensure the conservation of subsurface material, the system simultaneously applies a constraint that the deep soil outflow does not exceed the deep soil stockpile, ensuring that the calculated deep soil desalination amount is always less than or equal to the current deep soil state quantity. Based on this, the deep state quantity after deduction is output and finalized. After completing the status updates of the three partitions, the verification unit initiates a dual verification mechanism. The formula for calculating the global mass conservation relative error is as follows: ; In the formula, For the first The global mass conservation relative error of the day is dimensionless. For the first The total mass of the spatial summation of the values ​​of the three regional state variables of the day, in kg; For the first Daily verification variables based on total global salt content The calculated total mass of the system's inflow and outflow flux over time is expressed in kg. This is a fundamental mass constant, expressed in kg, set to prevent the denominator from approaching zero. Typically, this value is set to 5% to 10% of the system's historical daily average input salt content. This is used to eliminate the computational divergence caused by the infinite amplification of minute absolute errors under extremely low inventory conditions. The technical purpose of this calculation step is to quantify the degree of deviation between the spatial discrete calculation results and the time continuous integration results, in order to monitor the state drift of the system during long-term operation.

[0049] S250, when the deviation recalculation unit exceeds the tolerance in the global dual-track verification, calls the weight parameters or moving average parameters of the recent time step and recalculates the new throughput split and inventory release process using historical smoothing weights.

[0050] In this embodiment, the system sets a conservation tolerance threshold, which is typically set between 0.03 and 0.05. When the global mass conservation relative error... When the deviation exceeds the conservation tolerance threshold, the deviation reassessment unit determines that a global dual-track verification error has occurred at the current time step. The physical cause of the error is usually a sudden change in the input meteorological data, leading to nonlinear weight distribution distortion. After identifying the error, the deviation reassessment unit terminates the state saving of the current time step, extracts the newly added flux split weight parameters from the previous 5 historical time steps, performs a moving average calculation, and replaces the current abnormal parameters with the obtained smoothed weight parameters. To avoid the system falling into a computational dead zone due to insufficient effective historical time steps during the initial startup phase or when encountering consecutive extreme weather events, when there are fewer than 3 available anomaly-free historical time steps, the system directly calls the built-in local typical soil background experience allocation coefficient as a fallback replacement parameter. Using the replaced weight parameters, the system calculates the current error at the first time step. The values ​​of the state variables of each partition on a given day are used as the initial state. The calculation logic from S220 to S240 is executed sequentially until the global mass conservation relative error is reached. The value is reduced to within the conservation tolerance threshold, thereby ensuring the stability and reliability of the water-salt evolution calculation trajectory in the root zone.

[0051] See attached document Figure 2 In this embodiment, the water-salt dual-factor assessment and failure identification process performed by the assessment and identification module 300 aims to overcome the cumulative integration error under long-term sensorless conditions and quantify the health of the root zone physical barrier. Specifically, the process includes the following steps: S310, the background calibration unit executed by the evaluation and identification module 300 performs cross-seasonal state inheritance based on the precipitation evaporation attenuation function during the non-irrigation season, and introduces offline soil background test data to perform offline background calibration of the global total salinity before the start of the new irrigation season, eliminating the integral drift of long-term simulation.

[0052] During the fallow period in the non-irrigation season, the system suspends active irrigation operations, and the evolution of soil water and salt is driven by meteorological conditions. The background calibration unit performs cross-seasonal state inheritance. In specific implementation, the precipitation evaporation attenuation function calculates the net water exchange flux by obtaining the actual daily snowfall or rainfall, deducting the potential evaporation during the same period, and combining it with the soil water storage coefficient. This flux is converted into a proportional coefficient for salt leaching or surface accumulation, and the values ​​of each zone's state quantity at the end of the previous irrigation season are accumulated or decreased according to the daily step size to maintain the continuity of the zone's state quantity values. Since relying solely on the model's time-step integration calculation over long periods will produce cumulative errors, in this embodiment, to establish a reliable quality starting point for the new round of regulation, the system introduces offline soil background test data for calibration before the start of the new irrigation season. As a preferred method, the offline soil background test data is obtained through field physical sampling and conversion by laboratory conductivity measurement. The background calibration unit replaces the zone state quantity values ​​after cross-seasonal evolution with the offline soil background test data, and updates the global total salt content synchronously accordingly, thereby correcting the calculation deviation caused by the long-term lack of probe feedback.

[0053] S320, the maintenance assessment unit calculates the freshwater maintenance capacity factor to quantify the hydraulic retention maintenance degree based on the time-step integral of the effective infiltration flow, the corrected interfacial peristaltic coefficient, and the theoretical water consumption demand.

[0054] To prevent the taproot zone from being infiltrated by high-concentration saline water under a continuous brackish water supply, the system needs to create a water-isolation space around the taproot zone using a continuous net downward water flow. The technical principle behind this process is that effective physical resistance can only be maintained when the downward pressure of the external water flow is greater than the upward suction force of the crop roots. The maintenance assessment unit calculates the water surplus / deficit status over a certain period through time-step integration. As a preferred method, this calculation process introduces a modified interfacial water retention coefficient to characterize the degree of mechanical resistance of the deep soil physical structure to the downward transport of water. The value of this coefficient is mainly obtained empirically from tables based on the clay content and bulk density of the soil at the bottom of the taproot zone, and its value is set between 0.8 and 0.95. The formula for calculating the freshwater retention capacity factor is: ; In the formula, For the first Freshwater sustainability factor for each statistical period, dimensionless; For the first Daily effective infiltration flow rate, in m³ 3 ; The corrected interfacial permeability coefficient is dimensionless. For the first Daily meteorological theoretical water demand, in m³ 3 ; The total number of days in the statistical period, expressed in days (d). The basic water consumption constant set to prevent the denominator from approaching 0, with units of m³. 3 Basic water consumption constant The value is set to 1% to 5% of the system's historical daily average meteorological theoretical water demand. The technical purpose of this calculation step is to evaluate in the long term whether the hydraulic input can offset the local water deficit caused by crop transpiration.

[0055] S330, the integrity evaluation unit calculates the isolation integrity index based on the ratio of surface state variables and deep state variables to their safe capacity threshold, combined with the surface back pressure weight and the deep retention and floating weight.

[0056] Besides the positive pressure effect of water flow, the degree of physical retention and approach of salt also reflects the safety status of the taproot zone. Excessive accumulation of surface salt may generate downward concentration back pressure, while overload of deep salt may trigger upward capillary buoyancy. The integrity assessment unit quantifies the risk of high-concentration salts approaching the taproot zone from both the top and bottom. The system sets surface and deep safety capacity thresholds. The surface safety capacity threshold is determined based on the saturated bulk density of the surface soil and the set salt tolerance limit concentration, while the deep safety capacity threshold is determined based on the subsoil porosity and the critical concentration of the groundwater level. The formula for calculating the isolation integrity index is: ; In the formula, The isolation integrity index is dimensionless. The surface back pressure weight is dimensionless. The weight for deep retention and upward floating is dimensionless and satisfies... The constraint relationship; The surface state quantity at the current time step, in kg; This represents the surface safety capacity threshold, in kg. This represents the deep state quantity at the current time step, in kg. The threshold value for deep-layer safety capacity is expressed in kg. Considering that the direct harm of surface evaporation and salt return to the shallow root system in arid regions is generally greater than the risk of slow upwelling in deeper layers, in this embodiment, the surface backpressure weight is set to 0.6, and the deep retention and upwelling weight is set to 0.4. To avoid the calculated value within the brackets on the right side of the formula being greater than 1 under extreme salinity overload conditions, which could lead to a negative isolation integrity index, the system applies a bottom-line truncation constraint: when the calculated isolation integrity index is less than 0, it is forcibly assigned a value of 0. This technical logic integrates the bidirectional salinity threat in space into a scalar with a value range of 0 to 1; the closer the value is to 1, the more complete the isolation state.

[0057] S340, when the isolation integrity index and the freshwater maintenance capacity factor are both below their respective preset safety thresholds, the failure determination unit determines that the isolation status of the main root zone of the system has failed, stops the normal water supply, and switches to the repair water supply mode.

[0058] To avoid frequent false alarms caused by sudden changes in single meteorological data or fluctuations in local parameters, this invention employs cross-validation using both hydrodynamics and solute statics. The failure determination unit acquires the real-time calculated freshwater maintenance capacity factor and isolation integrity index, and sets freshwater safety maintenance threshold and isolation health determination threshold respectively. In this embodiment, the freshwater safety maintenance threshold is set between 0.1 and 0.2, and the isolation health determination threshold is set between 0.3 and 0.5. When the isolation integrity index is less than the isolation health determination threshold, and the freshwater maintenance capacity factor is less than the freshwater safety maintenance threshold, the failure determination unit determines that the isolation status of the system's main root zone has failed. After determining the failure, the system suspends the current control events. The execution logic of stopping regular water supply and switching to the repair water supply mode is manifested as the system automatically interrupting the regular brackish water supply operation and triggering the repair and self-recovery module 400 to execute the corresponding hydraulic repair command. To ensure system logic closed-loop and long-term availability, as a preferred approach, the system simultaneously initiates a recovery monitoring process. Once the system detects that the repair and self-recovery module 400 has completed executing its instructions and re-entered new offline soil background test data, it will release the suspended state, reset all partition status variables and accumulated variables, and thus resume normal monitoring and calculation cycles.

[0059] See attached document Figure 2 In this embodiment, the physical repair mapping and state self-recovery process executed by the repair and self-recovery module 400 aims to automatically match and output the corresponding pipeline hydraulic commands based on the specific physical cause of the system's main root zone isolation state failure, and exit the repair state based on the temporal evolution of physical parameters. Specifically, this process includes the following steps: S410, the weight identification unit executed by the repair and self-recovery module 400 compares the contribution ratio of the surface back pressure weight and the deep retention and floating weight in the isolation integrity index to identify the branch destination of the system failure mode.

[0060] In this embodiment, when the isolation status of the main root zone of the system fails, the system needs to determine the specific physical source of the failure in order to output matching hydraulic control commands. The weight identification unit extracts the surface overload contribution item and the deep overload contribution item from the previous calculation steps. As a specific implementation, the value of the surface overload contribution item is calculated by multiplying the surface back pressure weight by the proportion of the surface state quantity to the surface safety capacity threshold. The value of the deep overload contribution item is calculated by multiplying the deep retention and buoyancy weight by the proportion of the deep state quantity to the deep safety capacity threshold. The system compares the magnitude of the above two values. When the surface overload contribution item is greater than or equal to the deep overload contribution item, the weight identification unit identifies that the current salinity threat mainly comes from the surface accumulation of high concentrations of salinity, and thus determines that the system has entered the surface-dominant failure branch. When the surface overload contribution is less than the deep overload contribution, the weight identification unit identifies that the salt threat mainly comes from the overload accumulation of bottom salt and the risk of upward capillary migration, and determines that the system enters the deep dominant failure branch.

[0061] S420, when the surface layer weight is dominant, the surface repair unit outputs a combination of high-pressure shell breaking and low-pressure pushing commands, and feeds the resulting water displacement amount into the state conservation calculation module 200 to calculate the continuous moving average value until the freshwater barrier completes physical remodeling.

[0062] For branch conditions where surface soil failure is the primary concern, the surface soil is prone to physical degradation due to long-term salt erosion, leading to surface crusting and decreased infiltration. Simply applying large volumes of conventional water is insufficient to achieve effective downward hydraulic leaching. As a preferred approach, the surface remediation unit directly outputs a combination of high-pressure crust breaking and low-pressure horizontal thrusting commands. Specifically, the system controls the irrigation network to operate at a pressure of 0.3 MPa to 0.4 MPa, executing high-pressure micro-jet water output for 1 to 2 hours. The technical objective of this operation is to utilize concentrated hydraulic kinetic energy to break down the surface salt crust layer and restore the physical infiltration channels of the topsoil. After the crust structure is destroyed, the system lowers the network operating pressure to 0.1 MPa to 0.15 MPa, continuously outputting a large flow of low-pressure horizontal thrusting freshwater, using gravitational potential energy to drive the salt layer downwards. Based on the principle of solute mixing and replacement in the unsaturated zone, the surface remediation unit converts the volume of water pushed by the low-pressure horizontal thrusting into an equivalent solute replacement volume of the surface salt. The calculation formula is as follows: ; In the formula, For the first The daily solute replacement amount is calculated in kg. For the first The volume of water pushed forward under the daily low-pressure thrust command is measured in cubic meters. 3 ; The surface soil leaching efficiency coefficient is dimensionless and its value is mainly determined by field sampling based on the sand content of the surface soil, and is set between 0.6 and 0.8. The surface state quantity at the current time step, in kg; This represents the current water content of the topsoil, in meters (m³). 3 Its value is obtained by multiplying the total spatial volume of the surface soil by the surface volume moisture content calculated by real-time monitoring or model. The basic water volume constant set to prevent the denominator from approaching 0, with units of m. 3 Its value is set at 5% of the baseline porosity data of the surface soil. This solute replacement amount is fed back as a negative desalination flux to the state conservation calculation module 200, and the surface state quantity is deducted on a daily basis. When the moving average of the surface state quantity over three consecutive days falls below 50% of the surface safety capacity threshold, the surface remediation unit determines that the freshwater barrier has completed physical remodeling and stops outputting this combined instruction.

[0063] S430, when the deep remediation unit is dominant in the deep layer weight, outputs an ultra-long cycle micro-flow infiltration command, calculates the deep layer outflow desalination flux based on the time integral driven by the micro-flow, and updates the deep layer state variables accordingly.

[0064] When the system identifies and enters the deep dominant failure branch, it indicates that the salt content carried by the deep soil has approached its physical carrying capacity limit. In this state, if a large-flow forced flush is used, excess water will accumulate at the bottom, causing the groundwater level to rise, which will exacerbate the harm caused by salt diffusion and penetration upwards with the water. To avoid such secondary hydrological disasters, the deep remediation unit outputs ultra-long-cycle, micro-flow infiltration commands to the pipe network by controlling the hydraulic potential energy gradient. In this embodiment, the command requires the pipe network outflow to be controlled within 30% to 40% of the standard flow for conventional brackish water irrigation, and the single water supply cycle to be extended to 2 to 3 times that of conventional operation. The technical purpose of this operation is to maintain the downward positive pressure stagnant state of the deep layers of the system using micro-flow, while providing time and space for high-concentration free salt to dissolve out of the system boundary with the slow water flow. Based on the convection mixing and displacement assumption, the deep remediation unit calculates the deep outflow desalination flux. The specific calculation logic is as follows: The sum of the minute infiltration water volume per unit time step and the deep soil water volume plus a very small volume constant is calculated. This ratio is then multiplied by the deep soil state variables, and finally integrated over a very long period to obtain the total amount of salt discharged. The system then successively deducts from and updates the deep soil state variables based on the calculated deep soil desalination flux, thus completing the simulation of salt discharge and decompression in the deep space.

[0065] S440, the repair exit unit monitors physical indicators in real time, and automatically terminates the hydraulic dredging command when the absolute amount of deep stock falls back to the safety limit, the freshwater maintenance capacity factor exceeds the safety limit due to continuous flow replenishment, or the deep net downward water migration flux reverses.

[0066] Hydraulic dredging operations span a long period, requiring the system to establish a multi-dimensional monitoring and exit mechanism to prevent excessive leaching from deteriorating the hydrological conditions of the bottom layer. The repair and exit unit monitors three core physical indicators in real time during the execution of ultra-long-cycle, low-flow infiltration commands. As a preferred approach, the repair and exit unit sets a deep-layer safety limit based on 60% of the deep-layer safety capacity threshold. When the calculated and updated deep-layer state quantity is less than the deep-layer safety limit, it indicates that the absolute amount of deep-layer stock has returned to a safe level. The repair and exit unit simultaneously reads the freshwater maintenance capacity factor; when this factor rises under continuous water replenishment and exceeds the freshwater safety maintenance threshold, it indicates that the hydraulic resistance maintenance degree meets the system's operational requirements. Furthermore, the repair and exit unit monitors the hydraulic gradient data at the deep soil bottom boundary. In this embodiment, the system sets the vertically downward water flow direction as positive. For the monitoring and acquisition of the deep bottom-layer hydraulic gradient, those skilled in the art can use a combination of groundwater level gauges and soil matrix potential sensors for measurement and calculation; the relevant calculation principles are well-known in the field and will not be elaborated here. When the hydraulic gradient value of the deep subsurface changes from positive to negative, it indicates a dynamic reversal in the net downward water migration flux of the deep subsurface, suggesting a risk of upward backflow of bottom water. The repair exit unit determines that physical repair has achieved the expected effect or reached the bottom safety limit when any one of the following three conditions is met: the absolute amount of deep subsurface water storage falls back to the safety limit, the freshwater maintenance capacity factor exceeds the freshwater safety maintenance threshold, or a dynamic reversal occurs in the net downward water migration flux of the deep subsurface. To avoid the system falling into an indefinite dredging cycle dead zone due to various monitoring indicators remaining in abnormal ranges, the repair exit unit adds a forced exit mechanism for a maximum dredging duration timeout. After triggering the above exit conditions or timeout mechanism, the system immediately terminates the hydraulic dredging command, drives the system state to self-recover, and re-enters the conventional brackish water irrigation scheduling cycle.

[0067] To further aid in understanding the present invention and verify its feasibility and advancement in actual agricultural production, a specific application example is provided below, along with an additional section on experimental verification and effect comparison for detailed explanation.

[0068] This embodiment selects a severely saline jujube orchard in southern Xinjiang as the application scenario. The typical characteristics of this area are strong evaporation, scarce rainfall, and the irrigation water source is slightly saline water (the background salt concentration is calibrated to be 3.2 g / L). The soil type is sandy loam.

[0069] System physical boundary parameter settings: The main root system of jujube trees is concentrated between 0.2m and 0.6m, so the burial depth parameter of the vertical pipe layer interface is set to 0.45m. Before the system starts, offline soil background test data is measured by field physical sampling to initialize the surface state quantity, transient transition inventory of the main root protection zone, and deep state quantity, and complete the system baseline alignment.

[0070] See attached document Figure 4 During the first 30 days after the start of the new irrigation season, the system is in a state of continuous supply of brackish water.

[0071] The flux decoupling module 100 acquires the meteorological theoretical water consumption demand and the headworks observation flow rate daily. On the 12th day, the headworks observation flow rate suddenly dropped. The system calculated the water consumption infiltration consistency discrimination index and found that it exceeded the limit. Combined with the pipeline pressure, it determined that the filter unit was slightly blocked. The system immediately triggered autoregressive interpolation correction, using data from historical periods without anomalies to smoothly output the effective infiltration flow rate, avoiding integral divergence and distortion in the external input salinity calculation caused by a brief hardware failure.

[0072] The state conservation calculation module 200 updates the appendix daily based on the weights of water infiltration and evaporation traction. Figure 4 The three curves in the figure (corresponding to surface state quantities, transient transitional inventory in the main root protection zone, and deep state quantities, respectively). From the appendix... Figure 4 During the normal operation period, the surface state quantity showed a slow fluctuating upward trend, while the transient transition inventory in the main root protection zone remained at a low and stable level, proving that the main root zone was in a safe physical isolation state; excess salt gradually transferred to the deeper state quantity through the forced redistribution mechanism of volume top.

[0073] See attached document Figure 5 During the 35th to 40th day of operation, the theoretical meteorological water demand surged due to continuous extreme high temperatures and drought. (See attached...) Figure 5 The trajectory shows that the freshwater maintenance capacity factor (solid line) continuously decreased, falling below the preset freshwater safety maintenance threshold (0.15) on day 41. Simultaneously, due to rapid surface water evaporation leading to rapid salt accumulation, the isolation integrity index (dashed line) also fell below the isolation health assessment threshold (0.4). After cross-validating both factors as failing on day 41, the failure assessment unit formally determined that the system's main root region isolation status had failed. The weight identification unit compared the surface and deep layer contributions and found that the surface overload contribution was significantly greater than the deep layer, indicating that the system had entered the surface-dominated failure branch. The system then suspended conventional brackish water supply and output a combination of high-pressure bursting and low-pressure pushing commands.

[0074] In the appendix Figure 5During the 42nd to 44th day of the repair period, the system first uses a high pressure of 0.35 MPa to break up the surface crust, followed by a low pressure and high flow rate of 0.12 MPa for horizontal dredging. The state conservation calculation module 200 equates the horizontal dredging volume to the solute replacement volume and deducts the surface state quantity. When the surface salinity inventory is continuously monitored to fall back to the safe limit, and the freshwater maintenance capacity factor rises again above 0.15 due to the low-pressure large water replenishment, the repair exit unit automatically terminates the hydraulic dredging command, stops the repair water supply after the repair is completed, and restores the normal continuous water supply. Figure 5 After 45 days, the two-factor curve returned to the high-level safe zone.

[0075] To verify the advantages of the present invention over the prior art, a comparative experiment was conducted on the same plot of land for a full reproductive period (120 days).

[0076] Experimental Groups: Experimental group (system of this invention): adopts fully automatic scheduling based on vertical pipe continuous irrigation and the aforementioned water-salt synergistic regulation logic.

[0077] Control group A (traditional surface micro-irrigation system): surface drip irrigation was used, and intermittent slightly saline water irrigation was carried out based on the upper and lower limits set by traditional soil moisture sensors.

[0078] Control group B (conventional non-sensory vertical pipe irrigation): uses the same vertical pipe hardware as the present invention, but does not have water-salt flux decoupling and dual-factor repair logic, and only performs constant flow continuous water supply.

[0079] See attached document Figure 6 In the experimental group, the average electrical conductivity (EC value) of the primary root zone soil was maintained at approximately 2.1 dS / m. In control group A, due to surface point source infiltration and intermittent water supply, a high-concentration salt crust formed around the root zone, with an EC value as high as 6.4 dS / m. Control group B, lacking state-space conservation calculations and dynamic remediation mechanisms, could not detect the approaching accumulated salt front, resulting in salt reverse intrusion into the primary root zone during periods of extreme drought, with an EC value reaching 4.8 dS / m. The data indicate that the combined mechanism of state conservation separation and two-factor failure assessment in this invention can maintain a low-salt environment in the primary root zone and inhibit salt front intrusion under continuous brackish water supply conditions.

[0080] Throughout the growing season, control group A experienced four erroneous irrigation stoppages due to long-term salt and alkali corrosion of the sensor probes. In contrast, the system of this invention, without relying on in-situ sensors in the root zone, achieved 120 days of continuous operation through flux decoupling and time-step conservation calculation logic, even without deploying in-situ electronic sensors in the root zone. Furthermore, compared to control group B's indiscriminate flooding to leach salt after discovering dead trees, the targeted combined repair instructions of this invention reduced the water consumption per salt leaching cycle by 34.5%.

[0081] As attached Figure 6 As shown, the irrigation water productivity of the experimental group was 28.2% higher than that of the control group A. In the final jujube yield measurement, thanks to the fact that the root zone was always free from high salt stress and long-term waterlogging and hypoxia, the average yield per jujube tree in the experimental group was significantly higher than that of the control groups A and B by 18.5% and 11.2%, respectively, and the rate of first-grade fruit was greatly improved.

[0082] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for synergistic regulation of water and salt in the root zone of jujube trees based on continuous vertical pipe irrigation, characterized in that, Includes the following steps: A closed-walled vertical pipe with a single open bottom is installed around the main root area of ​​the jujube tree, and the outlet of the vertical pipe is buried in the set layer interface burial depth range. Slightly saline water is supplied in a continuous water supply mode through the vertical pipe; Obtain meteorological theoretical water consumption demand and head unit observation flow, identify and output effective infiltration flow; The effective infiltration flow rate is multiplied by the background salinity concentration of the irrigation water source to obtain the total external salinity mass; Construct surface state quantities, transient transition inventory quantities in the main root protection zone, and deep state quantities along the vertical profile; Disassemble the total external salt mass and update the surface state quantity, transient transition inventory of the main root protection zone, and deep state quantity; Calculate the freshwater maintenance capacity factor based on the effective infiltration flow and meteorological theoretical water demand. The isolation integrity index is calculated based on the surface state variables and deep state variables, and the surface overload contribution item and deep overload contribution item are obtained. When the isolation integrity index is lower than the isolation health judgment threshold and the freshwater maintenance capacity factor is lower than the freshwater safety maintenance threshold, the isolation status of the main root zone is determined to be invalid, and the routine brackish water supply operation is stopped. By comparing the numerical relationship between the surface overload contribution and the deep overload contribution, a matching hydraulic control command is output.

2. The method for coordinated water and salt regulation in the root zone of jujube trees based on continuous vertical pipe irrigation according to claim 1, characterized in that, Identify and output effective infiltration flow rates, including: Set a minimum effective traffic threshold; When the head observation flow rate is less than or equal to the minimum effective flow rate threshold, the value of the head observation flow rate is assigned to the effective infiltration flow rate; When the observed flow rate at the head is greater than the minimum effective flow rate threshold, the ratio of the meteorological theoretical water consumption demand to the observed flow rate at the head is calculated to obtain the water consumption infiltration consistency discrimination index. Determine whether the water consumption and infiltration consistency discrimination index exceeds the limit; When the water consumption infiltration consistency discrimination index exceeds the limit, the effective infiltration flow rate is output through autoregressive interpolation correction.

3. The method for coordinated water and salt regulation in the root zone of jujube trees based on continuous vertical pipe irrigation according to claim 2, characterized in that, When the water consumption infiltration consistency discrimination index exceeds the limit, the effective infiltration flow rate is output through autoregressive interpolation correction, including: The cumulative actual infiltration volume of the previous 3 days was extracted to calculate the moving average value, and a dynamic theoretical flow decay hysteresis interval was constructed. When the water consumption infiltration consistency discrimination index exceeds the theoretical flow rate decay hysteresis range and the pipeline pressure simultaneously experiences an abnormal drop or rise, it is determined that an abnormal observed flow rate caused by non-soil factors has occurred. A time series autoregressive model was established by extracting the historical daily average effective infiltration flow series from the previous 7 to 14 days. The theoretical infiltration amount for the current period is predicted using the aforementioned time series autoregressive model; The effective infiltration flow rate after smoothing correction is output by replacing the head observation flow rate with the theoretical infiltration rate.

4. The method for coordinated water and salt regulation in the root zone of jujube trees based on continuous vertical pipe irrigation according to claim 1, characterized in that, The total external salt content is analyzed, including: The ratio of the theoretical meteorological water demand to the effective infiltration flow is used to construct an upward evaporation traction weighting coefficient. Subtracting the evaporation traction weighting coefficient from the value 1 yields the downward infiltration drive weighting coefficient; Based on the evaporation traction weighting coefficient and the infiltration driving weighting coefficient, the total external salt mass is decomposed into the flux retained in the surface layer and the flux that penetrates downwards to the deeper layers with the water flow.

5. The method for coordinated water and salt regulation in the root zone of jujube trees based on continuous vertical pipe irrigation according to claim 1, characterized in that, Updating the surface state quantities, the transient transition inventory in the primary root protection zone, and the deep state quantities includes: The safe salt tolerance threshold of the main root zone is calculated by multiplying the soil space volume, soil saturated water content and the preset critical salt tolerance concentration of crop roots. When the calculated transient transition inventory of the main root protection zone exceeds the safe salt tolerance threshold of the main root zone, the volume capping forced redistribution mechanism is triggered. The excess salt mass is forcibly allocated and accumulated to the deep state quantity through the volume-top forced redistribution mechanism.

6. The method for coordinated water and salt regulation in the root zone of jujube trees based on continuous vertical pipe irrigation according to claim 1, characterized in that, The freshwater maintenance capacity factor is calculated based on the effective infiltration flow and meteorological theoretical water demand, including: Obtain the corrected interfacial water retention coefficient; Within a set statistical period, the downward resistance is obtained by time-step integration of the product of the effective infiltration flow rate and the corrected interfacial peristaltic coefficient. Within the statistical period, the total water consumption is obtained by time-step integration of the meteorological theoretical water consumption demand; Calculate the difference between the downward resistance and the total water consumption; Calculate the sum of the total water consumption and the set basic water consumption constant; Dividing the difference by the sum yields the freshwater maintenance capacity factor.

7. The method for coordinated water and salt regulation in the root zone of jujube trees based on continuous vertical pipe irrigation according to claim 1, characterized in that, The isolation integrity index is calculated based on the surface state variables and deep state variables, and the surface overload contribution term and deep overload contribution term are obtained, including: Set surface safety capacity thresholds and deep safety capacity thresholds; The surface back pressure weight is multiplied by the proportion of the surface state quantity to the surface safe capacity threshold to obtain the surface overload contribution term. The deep-layer retention and buoyancy weight is multiplied by the proportion of the deep-layer state quantity to the deep-layer safety capacity threshold to obtain the deep-layer overload contribution term. Furthermore, the sum of the surface backpressure weight and the deep retention and upward floating weight is a value of 1; Calculate the sum of the surface overload contribution term and the deep overload contribution term; The isolation integrity index is obtained by subtracting the sum from the value 1.

8. The method for coordinated water and salt regulation in the root zone of jujube trees based on continuous vertical pipe irrigation according to claim 1, characterized in that, Compare the numerical relationship between the surface overload contribution and the deep overload contribution, and output matching hydraulic control commands, including: When the surface overload contribution is greater than or equal to the deep overload contribution, it is determined that the surface dominant failure branch is entered, and a high-pressure shell breaking and low-pressure flat pushing combination command is output. When the surface overload contribution is less than the deep overload contribution, it is determined that the deep dominant failure branch is entered, and an ultra-long cycle micro-flow infiltration command is output.

9. The method for coordinated water and salt regulation in the root zone of jujube trees based on continuous vertical pipe irrigation according to claim 8, characterized in that, Output a combination of high-pressure shell bursting and low-pressure horizontal thrust commands, including: High-pressure micro-jet water discharge operation is performed at the set high-pressure operating pressure to destroy the surface salt crust layer; The pipeline operating pressure is lowered to the set low-pressure operating pressure, and a low-pressure flat-push fresh water flow is continuously output to generate push water volume. The amount of water moved is equivalently converted into the amount of solute replacement of surface salts; The solute replacement amount is used as the negative desalination flux, and the surface state amount is deducted at daily steps.

10. The method for coordinated water and salt regulation in the root zone of jujube trees based on continuous vertical pipe irrigation according to claim 8, characterized in that, Output ultra-long cycle, small flow rate infiltration commands, including: Extend the single water supply cycle and control the outflow rate to a preset low flow rate; Calculate the ratio of the minute infiltration volume to the sum of the deep soil water volume and the minimum volume zero constant; The total amount of salt discharged is obtained by multiplying the ratio by the deep state quantity and performing time integration over an ultra-long period. The deep state quantity is reduced and updated based on the total amount of salt discharged; When the deep state quantity is less than the deep safety limit, the freshwater maintenance capacity factor exceeds the freshwater safety maintenance threshold, or the hydraulic gradient of the deep bottom layer changes from positive to negative, the ultra-long cycle micro-flow infiltration command is terminated.

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