Wheat strip uniform planting drip irrigation water and fertilizer coordination precision control method and system

Abstract

The application relates to the field of agricultural irrigation technology and discloses a wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision regulation method and system. The method comprises the following steps: determining an interception efficiency difference coefficient according to four-row one-strip wide-narrow-row row spacing structure parameters, correcting the interception efficiency difference coefficient into a time-varying interception efficiency difference coefficient based on cumulative effective accumulated temperature, triggering an irrigation event by using a difference value of matric potential on the wide-row side and the narrow-row side, using a difference in water consumption to form an asymmetric gradient of matric potential to drive water and fertilizer to directionally diffuse to the root zone on the narrow-row side through a pre-wetting section, a stop section and a supplementary irrigation section, and iteratively correcting the length of the stop section at a convergence rate. The application improves the water and fertilizer interception uniformity of the densely planted area on the narrow-row side and the nitrogen fertilizer utilization efficiency in the whole growth period.

Description

Technical Field

[0001] This application relates to the field of agricultural irrigation technology, and in particular to a method and system for precise regulation of water and fertilizer synergy in wheat strip uniform sowing drip irrigation. Background Technology

[0002] Drip irrigation fertigation technology delivers irrigation water and soluble fertilizer simultaneously to the wheat root zone, achieving synergistic water and fertilizer supply. Compared with traditional flood irrigation, it saves 30% to 50% of water and increases nitrogen fertilizer utilization by 10% to 25%. Existing drip irrigation fertigation technology typically uses a single drip tape to cover multiple rows of wheat, employing a uniform row spacing planting pattern. It uses the absolute value of a single point from a soil moisture sensor or conductivity sensor as a feedback signal, combined with the crop's water and fertilizer requirements during its growth stages, to uniformly control the irrigation and fertilizer application rates. All rows within the coverage area of ​​a single drip tape are considered homogeneous control units, receiving the same amount of water and fertilizer uniformly.

[0003] However, the existing technologies have the following shortcomings: all existing technologies are based on uniform row spacing and do not consider the inherent differences in the ability of plants on both sides to intercept the moist front of the drip irrigation tape under non-uniform wide and narrow row planting structures; existing sensor deployment schemes use single-point absolute values ​​as feedback signals, and the signals themselves do not carry spatial location information between rows, making it impossible to distinguish the actual moisture status differences between the wide and narrow row sides; existing control strategies treat all rows within the coverage area of ​​a drip irrigation tape uniformly. Under symmetrical water supply conditions, densely planted narrow row plants have less water and fertilizer interception than sparsely planted wide row plants due to intense root competition and limited root expansion of individual plants. This results in a structural supply deviation of continuous water deficit on the narrow row side and relative surplus on the wide row side. This deviation accumulates as the growth period progresses, further affecting the uniformity of the population and the number of grains per ear. Summary of the Invention

[0004] This application provides a method and system for precise regulation of water and fertilizer synergy in wheat strip uniform sowing and drip irrigation, which solves the problem that the systematic deviation of water and fertilizer supply within the coverage area of ​​a single drip irrigation strip under non-uniform wide and narrow row planting structure cannot be eliminated by active control, and improves the uniformity of water and fertilizer interception and nitrogen fertilizer utilization efficiency of plants in narrow row lateral dense planting area.

[0005] In a first aspect, this application provides a method for precise regulation of water and fertilizer synergy in wheat strip uniform sowing drip irrigation, the method comprising: Step S1: Based on the four-row-one-wide-narrow-row-spacing structural parameters, determine the interception efficiency coefficient of the wide row side and the interception efficiency coefficient of the narrow row side by the ratio of the root domain width of a single plant to the width of the distributed moist front on the wide row side and the narrow row side respectively, and determine the difference between the two as the interception efficiency difference coefficient. Step S2: Based on the correspondence between accumulated effective temperature and root lateral expansion radius, the interception efficiency difference coefficient is corrected to a time-varying interception efficiency difference coefficient. Step S3: Soil matrix potential sensors are installed on both sides of the drip irrigation tape. The difference between the matrix potential on the wide row side and the narrow row side is determined as the matrix potential difference value. The irrigation event is initiated when the matrix potential on the narrow row side reaches the irrigation lower limit. During the irrigation event, the rest period is determined by the time-varying interception efficiency difference coefficient. By stopping water supply after the pre-wetting period and experiencing the rest period, the difference in water consumption caused by the difference in the time-varying interception efficiency difference coefficient between the plants on the wide row side and the narrow row side is used to form an asymmetric matrix potential gradient between the wide row side and the narrow row side. Water supply is restored in the supplementary irrigation section at a flow rate lower than that in the pre-wetting section, so that the supplementary irrigation water and fertilizer are directionally diffused to the root zone of the narrow row side under the drive of the asymmetric matrix potential gradient. The topdressing nitrogen fertilizer is embedded in the supplementary irrigation section and applied with water. Step S4: The convergence rate is determined by the time it takes for the matrix potential difference to converge from the peak value of the resting segment to the equilibrium value. The resting segment duration of the next irrigation event is iteratively corrected using the convergence rate.

[0006] Secondly, this application provides a wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control system, the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control system comprising: The analysis module is used to determine the interception efficiency coefficient of the wide row side and the narrow row side based on the four-row-one-wide-narrow-row spacing structure parameters, using the ratio of the root domain width of a single plant to the width of the distributed moist front on the wide row side and the narrow row side respectively, and the difference between the two is determined as the interception efficiency difference coefficient. The correction module is used to correct the interception efficiency difference coefficient to a time-varying interception efficiency difference coefficient based on the correspondence between the accumulated effective temperature and the lateral expansion radius of the root system. The driving module is used to deploy soil matrix potential sensors on both sides of the drip irrigation tape. The difference between the matrix potential on the wide row side and the narrow row side is used to determine the matrix potential difference value. The irrigation event is initiated when the matrix potential on the narrow row side reaches the irrigation lower limit. In the irrigation event, the duration of the rest period is determined by the time-varying interception efficiency difference coefficient. By stopping water supply after the pre-wetting period and experiencing the rest period, the difference in water consumption caused by the difference in the time-varying interception efficiency difference coefficient between the plants on the wide row side and the narrow row side is utilized to form an asymmetric matrix potential gradient between the wide row side and the narrow row side. Water supply is restored in the supplementary irrigation section at a flow rate lower than that in the pre-wetting section, so that the supplementary irrigation water and fertilizer are directionally diffused to the root zone of the narrow row side under the drive of the asymmetric matrix potential gradient, and the topdressing nitrogen fertilizer is embedded in the supplementary irrigation section and applied with water. An iterative module is used to determine the convergence rate by the time it takes for the matrix potential difference value to converge from the peak value of the resting segment to the equilibrium value, and to iteratively correct the resting segment duration of the next irrigation event using the convergence rate.

[0007] Thirdly, a wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control device is provided, comprising: a memory and at least one processor, wherein the memory stores instructions; the at least one processor calls the instructions in the memory to cause the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control device to execute the above-described wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control method.

[0008] Fourthly, a computer-readable storage medium is provided, wherein instructions are stored in the computer-readable storage medium, which, when executed on a computer, cause the computer to perform the above-described method for precise control of water and fertilizer synergy in wheat strip uniform sowing and drip irrigation.

[0009] The technical solution provided in this application transforms the four-row, one-width, narrow-row spacing structural parameters into interception efficiency coefficients for the wide-row side and the narrow-row side, and determines the interception efficiency difference coefficient based on the difference between the two. This is the first time that non-uniform row spacing geometric parameters have been incorporated into the active control input of the water and fertilizer regulation system. This enables the regulation decision to perceive the spatial heterogeneity of the planting structure, fundamentally overcoming the inherent defect of existing technologies that treat all rows within the same drip irrigation tape coverage area as homogeneous control units. Furthermore, based on the correspondence between accumulated effective temperature and the lateral expansion radius of the root system, the interception efficiency difference coefficient is corrected to a time-varying interception efficiency difference coefficient. This allows the control parameters to be continuously updated with the dynamic expansion of the wheat root system throughout its entire growth period, avoiding the systematic bias of overestimating the interception efficiency difference between the two sides in the early growth stage and underestimating it in the middle and late growth stages. This ensures that the regulation commands remain consistent with the actual spatial distribution of the root system at each key growth stage: greening, jointing, heading, flowering, and grain filling. By deploying soil matrix potential sensors on both sides of the drip irrigation tape and determining the matrix potential difference between the wide row side and the narrow row side, a differential feedback signal carrying inter-row spatial location information is introduced. This enables the closed-loop control system to perceive the actual water imbalance on both sides in real time. The irrigation event is precisely initiated when the matrix potential on the narrow row side reaches the irrigation lower limit. The duration of the rest period is determined by the time-varying interception efficiency difference coefficient. Through a three-segment time sequence structure of pre-wetting, rest, and re-irrigation, without changing any physical structure of the drip irrigation tape, the differential water consumption of plants on both sides in the rest period is used to actively create an asymmetric gradient of matrix potential. This drives the directional diffusion of re-irrigated water and fertilizer to the root zone on the narrow row side. At the same time, topdressing nitrogen fertilizer is embedded in the re-irrigation section and applied with the directional diffusion water flow, achieving coordinated and precise delivery of water and fertilizer in the spatial dimension.

[0010] The core contribution of the aforementioned technical features lies in the interception efficiency difference coefficient, which serves as a bridge variable connecting the geometric parameters of the planting structure with water and fertilizer regulation commands. Its time-varying correction mechanism ensures that the calculation of the resting period duration is always based on weights consistent with the actual root expansion state throughout the entire growth period, rather than relying on fixed empirical values. This algorithmic feature's substantial contribution to the scheme lies in deeply coupling planting agronomic parameters with the irrigation control algorithm, enabling the regulation system to perceive crop growth dynamics. Furthermore, the convergence rate is determined by the time it takes for the matrix potential difference value to converge from the peak value of the resting period to the equilibrium value. This convergence rate is then used to iteratively correct the resting period duration for the next irrigation event, constructing an adaptive feedback loop with the actual water response behavior of the crop as the evaluation criterion. This allows the control parameters to continuously self-correct with the seasonal changes in the soil's water conductivity, ensuring the stability and parameter adaptability of the three-stage time-series control strategy across multiple irrigation events throughout the entire growth period. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of an embodiment of the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision regulation method in this application; Figure 2 This is a schematic diagram illustrating the dynamic change of the interception efficiency coefficient with the cumulative effective accumulated temperature in the embodiments of this application; Figure 3 This is a schematic diagram comparing the soil volumetric moisture content of each row before and after the supplementary irrigation section in this embodiment of the application. Detailed Implementation

[0013] This application provides a method and system for precise regulation of water and fertilizer synergy in drip irrigation for strip sowing of wheat. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0014] For ease of understanding, the specific process of the embodiments of this application is described below. Please refer to [link / reference]. Figure 1 One embodiment of the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision regulation method in this application includes: Step S1: Based on the four-row-one-wide-narrow-row-spacing structural parameters, determine the interception efficiency coefficient of the wide row side and the interception efficiency coefficient of the narrow row side by the ratio of the root domain width of a single plant to the width of the distributed moist front on the wide row side and the narrow row side respectively, and determine the difference between the two as the interception efficiency difference coefficient. Specifically, the "four-row, one-wide, narrow-row" row spacing structure refers to a planting configuration of three narrow rows and one wide row (15-15-15-30 cm). The narrow row spacing is 15 cm, the wide row spacing is 30 cm, and the drip irrigation tape is centrally placed in the center of the wide row. The effective wetting front radius measured in the field is 30 cm, and the wetting front extends symmetrically to both sides, with a coverage width of 60 cm. The allocated wetting front width refers to the value allocated per row, obtained by dividing the wetting front coverage width by the corresponding number of lateral rows: For the wide row side (2 rows), each row is allocated a wetting front width of 30 ÷ 2 = 15 cm; for the narrow row side (2 rows as well), each row is allocated a wetting front width of 15 cm. The expandable root zone width per plant refers to the maximum width that a single plant can independently occupy laterally, constrained by the competition boundary of root systems in adjacent rows. It is taken as half of the corresponding lateral row spacing: 7.5 cm for the narrow row side and 15 cm for the wide row side. Therefore, the interception efficiency coefficient on the narrow row side is 7.5 ÷ 15 = 0.50, the interception efficiency coefficient on the wide row side is 15 ÷ 15 = 1.00, and the interception efficiency difference coefficient is 1.00 - 0.50 = 0.50, which are stored in the control system parameter database. This coefficient quantitatively characterizes the inherent difference in the interception ability of plants on both sides of the drip irrigation tape moist front under a non-uniform row spacing structure, and serves as the starting point for subsequent time-varying corrections and time-series control.

[0015] Step S2: Based on the correspondence between accumulated effective temperature and root lateral expansion radius, the interception efficiency difference coefficient is corrected to a time-varying interception efficiency difference coefficient.

[0016] Specifically, the cumulative effective accumulated temperature is calculated using 0℃ as the baseline temperature for wheat growth. This is obtained by subtracting 0℃ from the daily average temperature collected by meteorological sensors and taking the non-negative value, which is then accumulated daily from the sowing date. The relationship between the root system's lateral expansion radius and the cumulative effective accumulated temperature is determined using a piecewise linear truncation model: before the cumulative effective accumulated temperature reaches the jointing stage threshold (600℃·d), the current root system lateral expansion radius increases linearly according to the product of the maximum lateral expansion radius (12 cm measured in the field) and the ratio of the cumulative effective accumulated temperature to the accumulated temperature threshold; after the cumulative effective accumulated temperature reaches 600℃·d, the root system lateral expansion radius stabilizes at 12 cm and no longer increases. The truncation correction logic is as follows: if the current root system lateral expansion radius does not exceed half the row spacing on the narrow row side (7.5 cm), then the time-varying root domain width on the narrow row side is taken as the current root system lateral expansion radius; if it exceeds, then the upper limit of 7.5 cm is taken; the same applies to the wide row side, with an upper limit of 15 cm. Taking the greening stage (cumulative effective temperature 400℃·d) as an example, the lateral expansion radius of the root system during this period is 12×(400÷600)=8cm. The time-varying root domain width on the narrow row side is taken as the upper limit of 7.5 cm, and the time-varying root domain width on the wide row side is taken as 8 cm. The time-varying interception efficiency coefficient on the narrow row side is 7.5÷15=0.50, and the time-varying interception efficiency coefficient on the wide row side is 8÷15=0.533. The time-varying interception efficiency difference coefficient is 0.533-0.50=0.033. By the jointing stage (cumulative effective temperature 600℃·d), the time-varying interception efficiency coefficient on the wide row side is 12÷15=0.800, and the time-varying interception efficiency difference coefficient is 0.800-0.50=0.300. The difference between the two sides has increased significantly, triggering the three-stage time sequence to enter the enhanced regulation mode.

[0017] Step S3: Soil matrix potential sensors are installed on both sides of the drip irrigation tape. The difference between the matrix potential on the wide row side and the narrow row side is determined as the matrix potential difference value. The irrigation event is initiated when the matrix potential on the narrow row side reaches the irrigation lower limit. During the irrigation event, the rest period is determined by the time-varying interception efficiency difference coefficient. By stopping water supply after the pre-wetting period and experiencing the rest period, the difference in water consumption caused by the difference in the time-varying interception efficiency difference coefficient between the plants on the wide row side and the narrow row side is used to form an asymmetric matrix potential gradient between the wide row side and the narrow row side. Water supply is restored in the supplementary irrigation section at a flow rate lower than that in the pre-wetting section, so that the supplementary irrigation water and fertilizer are directionally diffused to the root zone of the narrow row side under the drive of the asymmetric matrix potential gradient. The topdressing nitrogen fertilizer is embedded in the supplementary irrigation section and applied with water. Specifically, the formation mechanism of the asymmetric gradient of matrix potential is not common knowledge and must be explained as follows: During the rest period, the solenoid valve is closed and irrigation stops. The plants on both sides continue to absorb water from the soil. Due to the higher difference coefficient of interception efficiency and larger root area of ​​individual plants, the water consumption rate per unit time of the plants on the wide row side is lower than that of the plants on the narrow row side. This results in a continuous increase in the absolute value of the soil matrix potential on the narrow row side (soil tends to dry out) and a continuous decrease in the absolute value of the soil matrix potential on the wide row side (soil is relatively moist). A lateral matrix potential gradient difference is formed between the wide row side and the narrow row side. The formula for calculating the rest period duration is: Rest period duration = Target induced matrix potential difference value ÷ (Soil hydraulic conductivity coefficient × Time-varying interception efficiency difference coefficient), where the target induced matrix potential difference value is taken as 8 kPa (to ensure sufficient driving force for directional diffusion of supplemental irrigation water), and the initial value of the soil hydraulic conductivity coefficient is taken as 0.8 kPa / h (based on field measurement calibration of loam soil); substituting the time-varying interception efficiency difference coefficient of 0.300 at the jointing stage, the rest period duration = 8 ÷ (0.8 × 0.300) = 33 min. The flow rate of the supplemental irrigation section is one-third of the rated flow rate (0.5 L / h). The low flow rate ensures that water diffuses slowly and directionally towards the narrow row lateral root zone along the negative direction of the lateral coordinate axis driven by the matrix potential gradient, rather than expanding symmetrically again under high pressure. Topdressing nitrogen fertilizer is embedded in the supplemental irrigation section in the form of urea solution, which is enriched in the root zone of the narrow row dense planting area with the directional diffusion water flow. The urea concentration is calculated and determined based on the ratio of the current topdressing nitrogen amount to the supplemental irrigation flow rate.

[0018] Step S4: The convergence rate is determined by the time it takes for the matrix potential difference to converge from the peak value of the resting segment to the equilibrium value. The resting segment duration of the next irrigation event is iteratively corrected using the convergence rate.

[0019] Specifically, the convergence rate is defined as the time taken for the matrix potential difference to first fall from the peak value of the resting phase to the equilibrium threshold (2 kPa) after the supplementary irrigation phase ends, in minutes. Physically, it represents the speed at which the water difference between the two sides caused by asymmetric supply naturally dissipates to equilibrium. The target convergence rate range is set to 40 to 60 minutes, with a median of 50 minutes. This is based on the following: a convergence rate below 40 minutes indicates that the matrix potential gradient induced by the resting phase is insufficient to drive effective directional diffusion of supplementary irrigation water, requiring an increased resting phase duration; a convergence rate exceeding 60 minutes indicates that the asymmetric supply intensity exceeds the actual demand difference, requiring a shortened resting phase duration. In the proportional-integral iterative correction, the proportional coefficient is set to 0.3 and the integral coefficient to 0.05. The integral term accumulates the deviations of the five most recent consecutive irrigation events, and the corrected resting phase duration is constrained to the range of 10 to 60 minutes. When the convergence rate of three consecutive irrigation events deviates from the target range and the corrected rest period duration continues to change in the same direction, it is determined that the soil hydraulic conductivity coefficient has experienced seasonal drift. The soil hydraulic conductivity coefficient is recalibrated by dividing the target induced matrix potential difference value by the product of the corrected rest period duration and the time-varying interception efficiency difference coefficient. The updated value is written into the control system parameter database to ensure that the soil hydraulic conductivity coefficient on which the subsequent rest period duration calculation depends is consistent with the actual field conditions.

[0020] In one specific embodiment, step S1 includes: Using the location where the drip irrigation tape is laid as the origin of the coordinate system, a horizontal coordinate axis is established along the direction perpendicular to the sowing row. The wide row side is the positive direction and the narrow row side is the negative direction. Based on field measurements, the effective wetting front radius of the drip irrigation tape is determined, and the sum of the lengths of the wetting front radii in the positive and negative directions is determined as the wetting front coverage width. The width of the moist front allocated to each row on the wide row side is determined based on the ratio of the width of the moist front coverage to the number of rows on the wide row side; the width of the expandable root zone of each plant on the wide row side is determined based on half of the row spacing on the wide row side; the ratio of the width of the expandable root zone of each plant on the wide row side to the width of the moist front allocated to each row on the wide row side is determined as the interception efficiency coefficient on the wide row side. The width of the moist front allocated to each row on the narrow row side is determined based on the ratio of the width of the moist front coverage to the number of rows on the narrow row side; the width of the expandable root zone of each plant on the narrow row side is determined based on half of the row spacing on the narrow row side; the ratio of the width of the expandable root zone of each plant on the narrow row side to the width of the moist front allocated to each row on the narrow row side is determined as the interception efficiency coefficient on the narrow row side. The difference between the interception efficiency coefficient on the wide side and the interception efficiency coefficient on the narrow side is determined as the interception efficiency difference coefficient, and the interception efficiency difference coefficient is stored in the control system parameter database.

[0021] Specifically, establishing a horizontal coordinate axis with the drip irrigation tape laying position as the origin is to precisely locate the non-uniform row spacing structure of four rows and one tape in space, so that the lateral positional relationship of each row of plants relative to the drip irrigation tape on the wide row side and the narrow row side can be quantitatively expressed. The coverage width of the wetting front is determined by the effective radius of the wetting front measured in the field, that is, the drip irrigation tape extends to both positive and negative sides by the same radius, and the sum of the two sides constitutes the complete coverage width. In the three narrow and one wide (15-15-15-30 cm) planting configuration, there are 2 rows on the narrow row side and 2 rows on the wide row side within the coverage area of ​​the wetting front. The width of the wetting front allocated to each row is obtained by dividing the coverage width by the number of rows on the corresponding side. This division method ensures that each row of plants receives an equal amount of wetting front cross-section based on the principle of equal area allocation, which is a prerequisite for the subsequent comparison of interception efficiency coefficients. The maximum root zone width that a single plant can expand is taken as half the row spacing. This is based on the fact that the root systems of two adjacent rows compete with each other in the lateral direction along the midline between the rows. The maximum root zone width that a single plant can expand outward does not exceed this boundary. This value reflects the actual physical constraints on the lateral expansion of the root system under dense planting conditions.

[0022] The ratio of the expandable root zone width of each plant in the wide-row side to the width of its allocated moist front constitutes the interception efficiency coefficient for the wide-row side, and the same applies to the narrow-row side. The difference between the two is the interception efficiency difference coefficient. The physical meaning of this coefficient is: under symmetrical drip irrigation conditions, the difference in the actual interception capacity of individual plants on the wide-row side and the narrow-row side for the moist front. The larger the coefficient, the more significant the difference in water interception capacity between the two sides, and the more severe the water deficit on the narrow-row side and the relative water surplus on the wide-row side caused by symmetrical irrigation. Storing the interception efficiency difference coefficient in the control system parameter database allows for time-varying correction during the subsequent accumulated temperature accumulation process. The corrected value is then directly substituted into the rest period duration calculation formula to drive the parameter generation of the three-stage time-series control strategy, thereby continuously quantifying the impact of non-uniform row spacing structure on the balance of water and fertilizer supply throughout the entire growth period.

[0023] In one specific embodiment, step S2 includes: Based on the difference between the daily average temperature collected in real time by meteorological sensors and the basic temperature for wheat growth, the non-negative difference values ​​of each collection day are accumulated day by day to obtain the cumulative effective accumulated temperature from the sowing date. Based on the ratio of accumulated effective temperature to the accumulated temperature threshold at the jointing stage, the maximum lateral expansion radius of wheat roots is linearly truncated to obtain the lateral expansion radius of the roots at the current stage. Based on the current lateral expansion radius of the root system, the width of the time-varying root domain on the narrow row side and the width of the time-varying root domain on the wide row side are respectively determined by the fact that the current lateral expansion radius of the root system does not exceed half of the row spacing on the narrow row side and the width of the time-varying root domain on the wide row side. The ratio of the time-varying root domain width on the narrow row side to the width of the moistening front allocated to each row on the narrow row side is determined as the time-varying narrow row side interception efficiency coefficient. The ratio of the time-varying root domain width on the wide row side to the width of the moistening front allocated to each row on the wide row side is determined as the time-varying wide row side interception efficiency coefficient. The difference between the time-varying wide row side interception efficiency coefficient and the time-varying narrow row side interception efficiency coefficient is determined as the time-varying interception efficiency difference coefficient.

[0024] Specifically, the baseline temperature for wheat growth was set at 0℃, which is the generally accepted standard for the lower limit of wheat physiological development temperature. When the daily average temperature is below 0℃, the contribution of effective accumulated temperature is zero. Therefore, the cumulative effective accumulated temperature obtained by summing the non-negative differences of each collection day accurately reflects the total amount of heat accumulated by wheat since sowing. The accumulated temperature threshold at the jointing stage was set at 600℃·d, based on the empirical statistical value of accumulated temperature from sowing to the jointing stage in the standard growth process of winter wheat in the North China Plain. This threshold marks the stable stage of lateral root expansion. The maximum lateral expansion radius of wheat roots was set at 12 cm, which was the actual measured value from root excavation in the field. The calculation logic of the linear proportional truncation treatment is as follows: when the cumulative effective accumulated temperature is less than 600℃·d, the current root lateral expansion radius is equal to the product of 12 cm and the ratio of the cumulative effective accumulated temperature to 600℃·d, and increases linearly with the accumulated temperature; when the cumulative effective accumulated temperature reaches or exceeds 600℃·d, the current root lateral expansion radius is fixed at 12 cm and no longer increases. This truncation treatment reflects the physiological law that the lateral expansion of the root system tends to stabilize after the jointing stage.

[0025] The time-varying root domain width is a dynamic correction to the expandable root domain width of a single plant in step S1: Step S1 uses half of the row spacing as the static upper limit of the expandable root domain width of a single plant, which reflects the maximum possible width occupied after the root system is fully developed; while in the early stage of growth, when the root system has not yet expanded to the inter-row competition boundary, the actual expandable root domain width of a single plant should be taken as the lateral expansion radius of the root system in the current period rather than the static upper limit. Therefore, the time-varying root domain width in the current period is taken as the difference between the lateral expansion radius of the root system in the current period and half of the row spacing, ensuring that the interception efficiency coefficient remains consistent with the actual root expansion state throughout the entire growth period. The time-varying interception efficiency difference coefficient is obtained by subtracting the time-varying narrow row interception efficiency coefficient from the time-varying wide row interception efficiency coefficient. This value changes dynamically with the progress of the growth period: in the early growth stage, when neither side of the root system has reached the inter-row competition boundary, the time-varying root domain widths on both sides are equal, the time-varying interception efficiency difference coefficient approaches zero, and the three-stage time-series control degenerates into uniform irrigation; as the accumulated effective temperature increases, the narrow row side root system reaches the 7.5 cm competition boundary first, while the wide row side has not yet reached the 15 cm boundary, the interception efficiency difference between the two sides gradually widens, the time-varying interception efficiency difference coefficient increases accordingly, the driving rest period duration is correspondingly extended, and the intensity of asymmetric regulation continues to increase.

[0026] Figure 2 This is a schematic diagram illustrating the dynamic change of the interception efficiency coefficient with accumulated effective temperature in an embodiment of this application. Figure 2 As shown, the interception efficiency coefficient on the wide-row side increases linearly with the accumulated temperature before reaching 600℃·d, and stabilizes at 0.80 after reaching 600℃·d. The interception efficiency coefficient on the narrow-row side stops increasing due to the smaller row spacing and the root system extending to the competition boundary, and stabilizes at 0.50 when the accumulated effective temperature reaches 400℃·d. The interception efficiency difference coefficient is the difference between the two, and it increases with the accumulated temperature when the accumulated effective temperature is below 400℃·d, continues to expand in the stage from 400℃·d to 600℃·d, and stabilizes at 0.30 after 600℃·d. This stable value is directly substituted into the formula for calculating the rest period duration, driving the three-stage time sequence control to enter the enhanced regulation mode after the jointing period.

[0027] In one specific embodiment, step S3 involves deploying soil matrix potential sensors on both sides of the drip irrigation tape, determining the matrix potential difference value as the difference between the matrix potential on the wide row side and the narrow row side, and initiating an irrigation event when the matrix potential on the narrow row side reaches the irrigation lower limit, including: The soil matrix potential sensor on the narrow row side is set up at the location of the center line of the narrow row side and the root active layer depth with the drip irrigation tape as the coordinate origin. The soil matrix potential sensor on the wide row side is set up at the location of the center line of the wide row side and the root active layer depth with the coordinate origin as the reference. The readings of the soil matrix potential sensors on the narrow row side and the wide row side are collected at a preset collection period to obtain the matrix potential of the narrow row side and the matrix potential of the wide row side. The difference between the matrix potential on the wide row side and the matrix potential on the narrow row side is defined as the matrix potential difference value; The irrigation event is initiated when the absolute value of the matrix potential on the narrow row side reaches the lower limit threshold of irrigation. The current matrix potential difference value and the time-varying interception efficiency difference coefficient are read for use in the calculation of the subsequent rest period duration.

[0028] Specifically, soil matrix potential sensors on the narrow-row side were positioned 15 cm from the origin on the negative direction of the horizontal coordinate axis (i.e., the center line between the two rows of plants on the narrow-row side), while those on the wide-row side were positioned 22.5 cm from the origin on the positive direction of the horizontal coordinate axis (i.e., the center line between the two rows of plants on the wide-row side). Both sensors were buried at a depth of 15 cm into the active root layer, which corresponds to the field-measured concentration depth of the wheat's main root water absorption layer. These placement locations correspond to the most intense root competition area on the narrow-row side and the central area of ​​root zone expansion for a single plant on the wide-row side, ensuring that sensor readings accurately reflect the actual soil moisture status experienced by the plants on both sides. A preset acquisition period of 30 minutes was used to ensure timely capture of dynamic changes in matrix potential while avoiding data redundancy caused by excessively frequent acquisitions. The matrix potential difference is defined as the matrix potential of the wide row side minus the matrix potential of the narrow row side. Since the matrix potential is represented by a negative value (the larger the absolute value, the drier the soil), under the condition of symmetrical water supply from the drip irrigation tape, the narrow row side has a higher water consumption intensity and drier soil due to dense planting, so its absolute matrix potential is greater than that of the wide row side. Therefore, the matrix potential difference is positive under normal conditions, and the larger the positive value, the more serious the water imbalance between the two sides.

[0029] The lower threshold for irrigation is set at 40 kPa, the absolute value of the matrix potential on the narrow row side. This value represents the critical matrix potential at which wheat roots begin to experience water stress under loam soil conditions. The matrix potential on the narrow row side, rather than the matrix potential on the wide row side, is used as the trigger condition because the plant density on the narrow row side is higher, the root zone of each plant is narrower, and the water consumption rate is faster. The narrow row side always reaches the water deficit critical point before the wide row side. Triggering irrigation with the matrix potential on the narrow row side ensures that plants in densely planted areas do not experience water stress. Simultaneously with triggering the irrigation event, the current matrix potential difference value and the time-varying interception efficiency difference coefficient are read. The former reflects the degree of actual water imbalance on both sides at the trigger time, while the latter reflects the theoretical difference in interception efficiency between the plants on both sides at the current growth stage. Both serve as input parameters for the rest period duration calculation formula. The time-varying interception efficiency difference coefficient determines the intensity of differential water consumption on both sides during the rest period, while the matrix potential difference value is used to determine whether an asymmetric control mode needs to be activated (uniform irrigation is performed when the matrix potential difference value is below 5 kPa, and three-stage time-series asymmetric control is activated when it reaches or exceeds 5 kPa).

[0030] In one specific embodiment, step S3, by stopping water supply after the pre-wetting phase and allowing for a rest period, utilizes the difference in water consumption caused by the difference in the time-varying interception efficiency coefficient between plants on the wide-row and narrow-row sides to create an asymmetric gradient of matrix potential between them, including: The rest period duration is calculated based on the ratio of the target induced matrix potential difference to the soil hydraulic conductivity coefficient and the time-varying interception efficiency difference coefficient. The rest period duration is determined by the quotient of the product of the target induced matrix potential difference, the soil hydraulic conductivity coefficient, and the time-varying interception efficiency difference coefficient. Water is supplied to the seedling root zone at the rated flow rate for a pre-wetting phase until the wetting front symmetrically expands to the preset coverage radius, and then water supply is stopped for the rest period. During the resting period, the plants on the wide row side have a higher coefficient of difference in time-varying interception efficiency and a larger root zone area per plant. Their water consumption rate per unit time is lower than that of the plants on the narrow row side. The absolute value of the matrix potential on the narrow row side continues to increase, while the absolute value of the matrix potential on the wide row side continues to decrease, thus forming an asymmetric gradient of matrix potential between the wide row side and the narrow row side.

[0031] Specifically, the target induced matrix potential difference value is set at 8 kPa. This value represents the minimum matrix potential gradient required to drive measurable directional diffusion of supplemental irrigation water along the lateral direction under loam conditions. Below this value, the lateral directional diffusion effect of supplemental irrigation water is not significant; above this value, an excessively long rest period will lead to water stress in plants on the narrow row side during the rest period. 8 kPa is the engineering equilibrium value between the two. The initial value of the soil hydraulic conductivity coefficient is set at 0.8 kPa / h, based on the field measurement calibration value of loam. This coefficient characterizes the increment of matrix potential difference that can be induced per hour during the rest period under the condition of unit time-varying interception efficiency difference coefficient. Its dimension determines the dimensional consistency of the rest period calculation formula. The resting period duration = target induced matrix potential difference value ÷ (soil hydraulic conductivity coefficient × time-varying interception efficiency difference coefficient). The physical meaning of this formula is: given soil hydraulic conductivity and the difference in interception efficiency on both sides, the shortest resting time required to reach the target induced matrix potential difference value. A larger time-varying interception efficiency difference coefficient indicates a higher intensity of differential water consumption on both sides, and a shorter resting time required to reach the same target induced matrix potential difference value; the two are inversely proportional. The rated flow rate is 1.5 L / h (single dripper), and the preset coverage radius is 30 cm, consistent with the field-measured wetting front radius in step S1. Water is continuously supplied during the pre-wetting period until the wetting front expands to this radius, ensuring that the initial water content on both sides is symmetrical and uniform at the end of the pre-wetting period, providing consistent initial moisture conditions for the differential water consumption in the subsequent resting period.

[0032] The formation mechanism of the asymmetric matrix potential gradient is as follows: During the resting period, the solenoid valve is completely closed and the external water supply is interrupted. The roots of plants on both sides continuously absorb water from the root zone soil. The amount of water extracted from the soil per unit time depends on the product of the root zone area of ​​a single plant and the transpiration intensity of the plant. Plants on the wide row side have a larger row spacing and a higher difference coefficient of time-varying interception efficiency, resulting in a larger usable root zone area per plant. Under the same transpiration intensity, less water is extracted per unit soil volume, and the absolute value of the soil matrix potential rises slowly. Plants on the narrow row side have a smaller row spacing and more intense root competition, resulting in a limited usable root zone area per plant. More water is extracted per unit soil volume, and the absolute value of the soil matrix potential rises rapidly. The difference in the absolute value of the soil matrix potential on both sides continues to accumulate with the extension of the resting time, forming a transverse matrix potential gradient from the positive direction to the negative direction between the wide row side (lower absolute value of matrix potential, relatively moist soil) and the narrow row side (higher absolute value of matrix potential, relatively dry soil), i.e., the asymmetric matrix potential gradient. Under low-flow water supply conditions in the supplementary irrigation section, this gradient becomes the physical driving force for the directional diffusion of supplementary irrigation water and fertilizer into the narrow row lateral root zone. The low flow rate (one-third of the rated flow rate, i.e., 0.5 L / h) ensures that the supplementary irrigation water diffuses slowly laterally under the drive of the matrix potential gradient, rather than expanding symmetrically to cover both sides under high flow pressure.

[0033] In one specific embodiment, step S3 involves restoring water supply in the supplementary irrigation section at a lower flow rate than in the pre-wetting section, allowing the supplementary irrigation fertilizer to diffuse directionally towards the narrow-row lateral root zone under the drive of the matrix potential asymmetric gradient, and embedding the topdressing nitrogen fertilizer into the supplementary irrigation section for application with the irrigation water, including: After the rest period ends, water supply is restored at a supplemental irrigation flow rate lower than the rated flow rate. The supplemental irrigation water and fertilizer diffuse directionally into the narrow row lateral root zone along the negative direction of the lateral coordinate axis under the drive of the asymmetric gradient of the matrix potential. Based on the ratio of the amount of nitrogen applied during the current growth period to the amount of supplemental irrigation, the concentration of nitrogen fertilizer for topdressing is determined. The nitrogen fertilizer is then dissolved in the irrigation water at the concentration of nitrogen fertilizer for topdressing and embedded in the supplemental irrigation section for simultaneous application with the supplemental irrigation water and fertilizer, so that the nitrogen fertilizer for topdressing diffuses directionally towards the narrow row lateral root zone with the supplemental irrigation water and fertilizer. The concentration of topdressing nitrogen fertilizer is verified by the difference between the reading of the matrix potential difference at the end of the supplementary irrigation section and the target induced matrix potential difference. The verified topdressing nitrogen fertilizer concentration is stored in the control system parameter database for use in the next irrigation event.

[0034] Specifically, the supplemental irrigation flow rate is one-third of the rated flow rate, i.e., 0.5 L / h. The basis for setting the low flow rate is as follows: the core purpose of the supplemental irrigation section is to allow water and fertilizer to slowly and directionally diffuse along the negative direction of the transverse coordinate axis towards the narrow row lateral root zone under the drive of the asymmetric gradient of the matrix potential. If the supplemental irrigation flow rate is too high, the pipeline pressure will dominate the direction of water diffusion, the directional driving effect of the matrix potential gradient will be covered by the pressure drive, the water will expand symmetrically again, and the asymmetric supply effect will disappear. 0.5 L / h is the critical engineering value that ensures continuous water supply and that the pipeline pressure does not exceed the driving force of the matrix potential gradient. The current topdressing nitrogen amount during the growing season is allocated to each growth stage according to the following proportions: 40% for the jointing stage, 25% for the booting stage, 20% for the flowering stage, and 15% for the grain-filling stage. After the topdressing nitrogen amount for each stage is determined, urea (containing 46% nitrogen) is used as the application carrier. The topdressing nitrogen amount for each stage is divided by 46% to obtain the urea amount for each stage. Then, it is divided by the product of the supplementary irrigation flow rate and the supplementary irrigation period duration for the corresponding irrigation event to obtain the topdressing nitrogen fertilizer concentration, in grams per liter. The fertilizer injection pump injects urea stock solution into the supplementary irrigation water flow in real time according to this concentration to ensure that nitrogen diffuses and accumulates in a directional manner to the narrow row lateral root zone simultaneously with the supplementary irrigation water and fertilizer.

[0035] The physical meaning of the verification logic is as follows: the matrix potential difference reading at the end of the supplementary irrigation period reflects the recovery status of soil moisture balance on both sides after the actual delivery of water and fertilizer to the narrow row side during this supplementary irrigation. If the reading is still significantly higher than the target induced matrix potential difference value, it indicates that the amount of water used for this supplementary irrigation is insufficient to fully compensate for the water deficit on the narrow row side, and the corresponding nitrogen fertilizer concentration is also too low, requiring appropriate adjustment in the next irrigation event. If the reading is lower than the target induced matrix potential difference value, it indicates that the amount of water used for supplementary irrigation exceeds the actual needs of the narrow row side, and the nitrogen fertilizer concentration is too high, requiring appropriate adjustment. The difference between the matrix potential difference reading at the end of the supplementary irrigation period and the target induced matrix potential difference value is used as the verification quantity. This is then proportionally correlated with the nitrogen fertilizer concentration to obtain the verified nitrogen fertilizer concentration, which is written into the control system parameter database. In the supplementary irrigation period of the next irrigation event, this value is directly called as the initial concentration setting value, thereby ensuring that the nitrogen fertilizer concentration continuously approaches the target value that precisely matches the actual nitrogen requirement intensity of the narrow row side during each irrigation event throughout the entire growth period.

[0036] Figure 3 This is a schematic diagram comparing the soil volumetric moisture content of each row before and after the irrigation process in an embodiment of this application. Figure 3As shown, before supplemental irrigation, the soil volumetric moisture content of the outer and inner rows of the narrow row was 28.5% and 27.2%, respectively, significantly lower than that of the wide row side (33.1% and 34.8%). The difference in moisture content between the two sides was 5.6 to 7.6 percentage points, reflecting the systemic water deficit on the narrow row side under symmetrical water supply conditions. After the supplemental irrigation was implemented, the moisture content of the outer and inner rows of the narrow row increased to 34.2% and 33.8%, respectively, which was consistent with that of the wide row side (34.5% and 34.9%). The difference narrowed to 0.3 to 0.7 percentage points, verifying the actual effect of the asymmetric gradient of matrix potential driving the directional diffusion of supplemental irrigation water and fertilizer to the root zone on the narrow row side.

[0037] In one specific embodiment, step S4 includes: After the supplementary irrigation period of the irrigation event ends, the readings of the soil matrix potential sensor on the narrow row side and the soil matrix potential sensor on the wide row side are continuously collected at a preset monitoring cycle. The dynamic changes of the matrix potential difference are continuously recorded. The reading of the matrix potential difference at the end of the rest period is determined as the peak value of the rest period. The difference between the time when the matrix potential difference first falls back to the equilibrium threshold and the end of the supplementary irrigation period is determined as the convergence rate. Based on the deviation between the convergence rate and the target convergence rate range, and the cumulative value of the difference between the convergence rate and the median of the target convergence rate range in the five most recent consecutive irrigation events, the duration of the pause in the next irrigation event is iteratively corrected by proportional integral to obtain the corrected pause duration, and the corrected pause duration is constrained within a preset duration range. When the convergence rate of three consecutive irrigation events deviates from the target convergence rate range and the duration of the corrected pause period continues to change in the same direction, the soil hydraulic conductivity coefficient is recalibrated by taking the quotient of the product of the target induced matrix potential difference value, the duration of the corrected pause period, and the time-varying interception efficiency difference coefficient. The corrected rest period duration and the recalibrated soil hydraulic conductivity coefficient are stored in the control system parameter database for use in calculating the rest period duration of the next irrigation event.

[0038] Specifically, the preset monitoring period is 10 minutes, which is shorter than the typical convergence time of the matrix potential difference after the supplementary irrigation period (40 to 60 minutes), ensuring that the convergence process can be fully captured without missing the critical moment of peak fall. The peak value of the resting period is the reading of the matrix potential difference at the end of the resting period. This moment is the maximum value reached after the asymmetric gradient of matrix potential has fully developed in the resting period, and it is the direct basis for measuring whether the parameters of this resting period have achieved the target induced matrix potential difference value. The equilibrium threshold is 2 kPa. This value is the judgment boundary when the matrix potential difference between the wide row side and the narrow row side falls back to the sensor error range. When it is lower than this value, it is considered that the water on both sides has tended to be balanced, and the convergence process ends. The physical meaning of the convergence rate is the time required for the soil water on both sides to tend to be balanced again after the supplementary irrigation water and fertilizer diffuses directionally to the root zone of the narrow row side. The longer this value is, the stronger the retention capacity of the narrow row side for supplementary irrigation water and fertilizer and the more lasting the asymmetric supply effect. The target convergence rate range is 40 to 60 minutes, with a median of 50 minutes. A convergence rate below 40 minutes indicates insufficient matrix potential gradient induced by the rest period and that the directional diffusion effect of supplemental irrigation water and fertilizer is not as expected. A convergence rate above 60 minutes indicates that the asymmetric supply intensity exceeds the actual absorption capacity of the narrow row side. In the proportional-integral iterative correction, the proportional coefficient is 0.3 and the integral coefficient is 0.05. The integral term accumulates the deviation of the five most recent consecutive irrigation events. The five events are based on the four major irrigation events throughout the growth period, taking into account the historical depth of the seedling water. After correction, the rest period duration is constrained to 10 to 60 minutes. The lower limit of 10 minutes is the shortest effective duration to ensure the existence of the rest period, and the upper limit of 60 minutes is the safety boundary to prevent water stress on the narrow row side during the rest period.

[0039] The convergence rate of three consecutive irrigation events deviated from the target range, and the corrected rest period duration continued to change in the same direction. This indicates that simply adjusting the rest period duration is no longer sufficient to bring the convergence rate back to the target range. The root cause of the deviation lies in the seasonal drift of the soil hydraulic conductivity coefficient (e.g., changes in soil bulk density due to tillage or rainfall), which requires recalibration. The recalibration formula is: Recalibrated soil hydraulic conductivity coefficient = Target induced matrix potential difference value ÷ (Corrected rest period duration × Time-varying interception efficiency difference coefficient). This formula is derived by reversing the rest period duration calculation formula in step S3. The corrected rest period duration is used as an estimate of the current effective rest period duration, and the soil hydraulic conductivity coefficient that matches the current actual soil hydraulic conductivity characteristics is solved. The recalibrated value replaces the original soil hydraulic conductivity coefficient in the control system parameter database and is directly called in the calculation of the rest period duration of the next irrigation event. This ensures that the rest period duration calculation is always based on the soil hydraulic conductivity coefficient consistent with the actual field conditions, and that the target induced matrix potential difference value can be accurately reproduced in subsequent irrigation events.

[0040] The above describes the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control method in the embodiments of this application. The following describes the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control system in the embodiments of this application. One embodiment of the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control system in the embodiments of this application includes: The analysis module is used to determine the interception efficiency coefficient of the wide row side and the narrow row side based on the four-row-one-wide-narrow-row spacing structure parameters, using the ratio of the root domain width of a single plant to the width of the distributed moist front on the wide row side and the narrow row side respectively, and the difference between the two is determined as the interception efficiency difference coefficient. The correction module is used to correct the interception efficiency difference coefficient to a time-varying interception efficiency difference coefficient based on the correspondence between the accumulated effective temperature and the lateral expansion radius of the root system. The driving module is used to deploy soil matrix potential sensors on both sides of the drip irrigation tape. The difference between the matrix potential on the wide row side and the narrow row side is used to determine the matrix potential difference value. The irrigation event is initiated when the matrix potential on the narrow row side reaches the irrigation lower limit. In the irrigation event, the duration of the rest period is determined by the time-varying interception efficiency difference coefficient. By stopping water supply after the pre-wetting period and experiencing the rest period, the difference in water consumption caused by the difference in the time-varying interception efficiency difference coefficient between the plants on the wide row side and the narrow row side is utilized to form an asymmetric matrix potential gradient between the wide row side and the narrow row side. Water supply is restored in the supplementary irrigation section at a flow rate lower than that in the pre-wetting section, so that the supplementary irrigation water and fertilizer are directionally diffused to the root zone of the narrow row side under the drive of the asymmetric matrix potential gradient, and the topdressing nitrogen fertilizer is embedded in the supplementary irrigation section and applied with water. An iterative module is used to determine the convergence rate by the time it takes for the matrix potential difference value to converge from the peak value of the resting segment to the equilibrium value, and to iteratively correct the resting segment duration of the next irrigation event using the convergence rate.

[0041] This invention also provides a wheat strip uniform drip irrigation water and fertilizer synergistic precision control device, which can be a server. The device includes a processor, memory, display screen, input device, network interface, and database connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operating system and computer programs in the non-volatile storage medium. The database stores the data corresponding to this embodiment. The network interface communicates with external terminals via a network connection. The computer program is executed by the processor to implement the above-described method.

[0042] The present invention also provides a computer-readable storage medium, which can be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium, wherein the computer-readable storage medium stores instructions that, when the instructions are executed on a computer, cause the computer to perform the steps of the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control method.

[0043] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0044] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a wheat strip uniform drip irrigation water and fertilizer coordinated precision control device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: USB flash drive, portable hard drive, read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk, and other media capable of storing program code.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for precise regulation of water and fertilizer synergy in drip irrigation and strip sowing of wheat, characterized in that, The method includes: Step S1: Based on the four-row, one-width, narrow-row row spacing structure parameters, determine the interception efficiency coefficient for the wide-row side and the narrow-row side by using the ratio of the root zone width of a single plant to the width of the allocated moist front on both the wide-row and narrow-row sides. The difference between these two coefficients is then determined as the interception efficiency difference coefficient. This includes: establishing a horizontal coordinate axis perpendicular to the sowing row direction, with the drip irrigation tape laying position as the origin, the wide-row side as the positive direction and the narrow-row side as the negative direction; determining the effective moist front radius of the drip irrigation tape based on field measurements; and determining the moist front coverage width by summing the lengths of the moist front radii in both positive and negative directions; determining the allocated moist front width for each row on the wide-row side based on the ratio of the moist front coverage width to the number of rows on the wide-row side; and determining the interception efficiency coefficient for the narrow-row side based on half the row spacing on the wide-row side. The root zone width of each plant in each row on the wide row side is determined as the interception efficiency coefficient. The width of the wet front allocated to each row on the wide row side is determined based on the ratio of the wet front coverage width to the number of rows on the narrow row side. The root zone width of each plant in each row on the narrow row side is determined based on half the row spacing on the narrow row side. The ratio of the root zone width of each plant in each row on the narrow row side to the wet front allocated to each row on the narrow row side is determined as the interception efficiency coefficient. The difference between the interception efficiency coefficient on the wide row side and the interception efficiency coefficient on the narrow row side is determined as the interception efficiency difference coefficient, and the interception efficiency difference coefficient is stored in the control system parameter database. Step S2: Based on the correspondence between the accumulated effective temperature and the lateral expansion radius of the root system, the interception efficiency difference coefficient is corrected to a time-varying interception efficiency difference coefficient. Step S3: Soil matrix potential sensors are installed on both sides of the drip irrigation tape. The difference between the matrix potential on the wide row side and the narrow row side is determined as the matrix potential difference value. The irrigation event is initiated when the matrix potential on the narrow row side reaches the irrigation lower limit. In the irrigation event, the duration of the rest period is determined by the time-varying interception efficiency difference coefficient. By stopping water supply after the pre-wetting period and experiencing the rest period, the difference in water consumption caused by the difference in the time-varying interception efficiency difference coefficient between the plants on the wide row side and the narrow row side is utilized to form an asymmetric gradient of matrix potential between the wide row side and the narrow row side. Water supply is restored in the supplementary irrigation section at a flow rate lower than that in the pre-wetting section, so that the supplementary irrigation water and fertilizer are directionally diffused to the root zone of the narrow row side under the drive of the asymmetric gradient of matrix potential. The topdressing nitrogen fertilizer is embedded in the supplementary irrigation section and applied with water. Step S4: The time taken for the matrix potential difference value to converge from the peak value of the resting segment to the equilibrium value is determined as the convergence rate, and the resting segment duration of the next irrigation event is iteratively corrected using the convergence rate.

2. The method for precise regulation of water and fertilizer synergy in wheat strip uniform sowing and drip irrigation according to claim 1, characterized in that, Step S2 includes: Based on the difference between the daily average temperature collected in real time by meteorological sensors and the basic temperature for wheat growth, the non-negative difference values ​​of each collection day are accumulated day by day to obtain the cumulative effective accumulated temperature from the sowing date. Based on the ratio of the accumulated effective temperature to the accumulated temperature threshold at the jointing stage, the maximum lateral expansion radius of wheat roots is linearly truncated to obtain the lateral expansion radius of the roots at the current stage. Based on the current root system lateral expansion radius, the width of the time-varying root domain on the narrow row side and the width of the time-varying root domain on the wide row side are respectively determined as the lateral expansion radius of the current root system not exceeding half of the row spacing on the narrow row side and the lateral expansion radius of the current root system not exceeding half of the row spacing on the wide row side. The ratio of the time-varying root domain width on the narrow row side to the width of the wetted front allocated to each row on the narrow row side is determined as the time-varying narrow row side interception efficiency coefficient. The ratio of the time-varying root domain width on the wide row side to the width of the wetted front allocated to each row on the wide row side is determined as the time-varying wide row side interception efficiency coefficient. The difference between the time-varying wide row side interception efficiency coefficient and the time-varying narrow row side interception efficiency coefficient is determined as the time-varying interception efficiency difference coefficient.

3. The method for precise regulation of water and fertilizer synergy in wheat strip uniform sowing and drip irrigation according to claim 1, characterized in that, Step S3 involves deploying soil matrix potential sensors on both sides of the drip irrigation tape, determining the matrix potential difference value as the difference between the matrix potential on the wide row side and the narrow row side, and initiating an irrigation event when the matrix potential on the narrow row side reaches the lower limit of irrigation. This includes: The soil matrix potential sensor on the narrow row side is set up at the location of the center line of the narrow row side and the root active layer depth, with the drip irrigation tape as the coordinate origin. The soil matrix potential sensor on the wide row side is set up at the location of the center line of the wide row side and the root active layer depth, with the coordinate origin as the reference. The readings of the soil matrix potential sensor on the narrow row side and the soil matrix potential sensor on the wide row side are collected at a preset collection period to obtain the matrix potential of the narrow row side and the matrix potential of the wide row side. The difference between the matrix potential on the wide row side and the matrix potential on the narrow row side is defined as the matrix potential difference value; The irrigation event is initiated when the absolute value of the matrix potential on the narrow row side reaches the lower limit threshold of irrigation. The difference between the current matrix potential difference and the time-varying interception efficiency is read for use in the calculation of the subsequent rest period duration.

4. The method for precise regulation of water and fertilizer synergy in wheat strip uniform sowing and drip irrigation according to claim 3, characterized in that, Step S3, by stopping water supply after the pre-wetting phase and allowing the duration of the rest period, utilizes the differential water consumption caused by the difference in the time-varying interception efficiency coefficient between the wide-row and narrow-row plants to create an asymmetric matrix potential gradient between the wide-row and narrow-row sides, including: The rest period duration is calculated based on the ratio of the target induced matrix potential difference value to the soil hydraulic conductivity coefficient and the time-varying interception efficiency difference coefficient. The rest period duration is determined by the quotient of the product of the target induced matrix potential difference value, the soil hydraulic conductivity coefficient, and the time-varying interception efficiency difference coefficient. Water is supplied to the root zone of the seedling at a rated flow rate for a pre-wetting phase until the wetting front symmetrically expands to the preset coverage radius, and then the water supply is stopped for the duration of the pause phase. During the rest period, the plants on the wide row side have a higher coefficient of difference in time-varying interception efficiency and a larger root zone area per plant, resulting in a lower water consumption rate per unit time compared to the plants on the narrow row side. Consequently, the absolute value of the matrix potential on the narrow row side continuously increases while the absolute value of the matrix potential on the wide row side continuously decreases, thus creating an asymmetric gradient of matrix potential between the wide row side and the narrow row side.

5. The method for precise regulation of water and fertilizer synergy in wheat strip uniform sowing and drip irrigation according to claim 4, characterized in that, Step S3 involves restoring water supply in the supplementary irrigation section at a lower flow rate than in the pre-wetting section, allowing the supplementary irrigation fertilizer to diffuse directionally towards the narrow-row lateral root zone under the drive of the asymmetric gradient of the substrate potential, and embedding the topdressing nitrogen fertilizer into the supplementary irrigation section for application with the irrigation water, including: After the pause period ends, water supply is resumed at a replenishment flow rate lower than the rated flow rate. The replenished water and fertilizer diffuse directionally into the narrow row lateral root zone along the negative direction of the lateral coordinate axis under the drive of the asymmetric gradient of the matrix potential. Based on the ratio of the current nitrogen application rate during the growing season to the irrigation flow rate, the nitrogen fertilizer concentration is determined. The nitrogen fertilizer is then dissolved in the irrigation water at the specified concentration and embedded in the irrigation section for simultaneous application with the irrigation water and fertilizer, allowing the nitrogen fertilizer to diffuse directionally towards the narrow row lateral root zone along with the irrigation water and fertilizer. The concentration of topdressing nitrogen fertilizer is verified by the difference between the reading of the matrix potential difference at the end of the supplementary irrigation section and the target induced matrix potential difference. The verified concentration of topdressing nitrogen fertilizer is then stored in the control system parameter database for use in the next irrigation event.

6. The method for precise regulation of water and fertilizer synergy in wheat strip uniform sowing and drip irrigation according to claim 5, characterized in that, Step S4 includes: After the supplementary irrigation period of the irrigation event ends, the readings of the soil matrix potential sensor on the narrow row side and the soil matrix potential sensor on the wide row side are continuously collected at a preset monitoring cycle. The dynamic changes of the matrix potential difference value are continuously recorded. The reading of the matrix potential difference value at the end of the rest period is determined as the peak value of the rest period. The difference between the time when the matrix potential difference value first falls back to the equilibrium threshold and the end of the supplementary irrigation period is determined as the convergence rate. Based on the deviation between the convergence rate and the target convergence rate range, and the cumulative value of the difference between the convergence rate and the median of the target convergence rate range in the five most recent consecutive irrigation events, the duration of the pause in the next irrigation event is iteratively corrected by proportional integral to obtain the corrected pause duration, and the corrected pause duration is constrained within a preset duration range. When the convergence rate of three consecutive irrigation events deviates from the target convergence rate range and the duration of the corrected pause period continues to change in the same direction, the soil hydraulic conductivity coefficient is recalibrated by the quotient of the product of the target induced matrix potential difference value, the duration of the corrected pause period, and the time-varying interception efficiency difference coefficient, to obtain the recalibrated soil hydraulic conductivity coefficient. The corrected pause duration and the recalibrated soil hydraulic conductivity coefficient are stored in the control system parameter database for use in calculating the pause duration of the next irrigation event.

7. A wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control system, characterized in that, For implementing the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control method as described in any one of claims 1 to 6, the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control system comprises: The analysis module is used to determine the interception efficiency coefficients for the wide-row side and the narrow-row side based on the four-row-one-width-narrow-row spacing structure parameters, using the ratio of the root zone width of a single plant to the width of the allocated moist front on both the wide-row and narrow-row sides. The difference between the two is determined as the interception efficiency difference coefficient. This includes: establishing a horizontal coordinate axis perpendicular to the sowing row direction with the drip irrigation tape laying position as the origin, with the wide-row side as the positive direction and the narrow-row side as the negative direction; determining the effective moist front radius of the drip irrigation tape based on field measurements; and determining the moist front coverage width by summing the lengths of the moist front radii in the positive and negative directions; determining the allocated moist front width for each row on the wide-row side based on the ratio of the moist front coverage width to the number of rows on the wide-row side; and determining the interception efficiency coefficient for the narrow-row side based on half of the row spacing on the wide-row side. The following steps are taken: First, determine the root zone width of each plant in each row on the wide-row side. Second, determine the root zone width of each plant in each row on the wide-row side to the width of the moist front allocated to each row on the wide-row side, which is the interception efficiency coefficient for the wide-row side. Third, determine the width of the moist front allocated to each row on the narrow-row side based on the ratio of the moist front coverage width to the number of rows on the narrow-row side. Fourth, determine the root zone width of each plant in each row on the narrow-row side based on half the row spacing on the narrow-row side. Fifth, determine the root zone width of each plant in each row on the narrow-row side to the width of the moist front allocated to each row on the narrow-row side, which is the interception efficiency coefficient for the narrow-row side. Sixth, determine the difference between the interception efficiency coefficient for the wide-row side and the interception efficiency coefficient for the narrow-row side, which is the interception efficiency difference coefficient. Finally, store the interception efficiency difference coefficient in the control system parameter database. The correction module is used to correct the interception efficiency difference coefficient to a time-varying interception efficiency difference coefficient based on the correspondence between the accumulated effective temperature and the lateral expansion radius of the root system. The driving module is used to deploy soil matrix potential sensors on both sides of the drip irrigation tape. The difference between the matrix potential on the wide row side and the narrow row side is used to determine the matrix potential difference value. The irrigation event is initiated when the matrix potential on the narrow row side reaches the irrigation lower limit. In the irrigation event, the duration of the rest period is determined by the time-varying interception efficiency difference coefficient. By stopping water supply after the pre-wetting period and experiencing the rest period, the difference in water consumption caused by the difference in the time-varying interception efficiency difference coefficient between the plants on the wide row side and the narrow row side is utilized to form an asymmetric matrix potential gradient between the wide row side and the narrow row side. Water supply is restored in the supplementary irrigation section at a flow rate lower than that in the pre-wetting section, so that the supplementary irrigation water and fertilizer are directionally diffused to the root zone of the narrow row side under the drive of the asymmetric matrix potential gradient, and the topdressing nitrogen fertilizer is embedded in the supplementary irrigation section and applied with water. An iterative module is used to determine the convergence rate by taking the time for the matrix potential difference value to converge from the peak value of the resting segment to the equilibrium value, and to iteratively correct the resting segment duration of the next irrigation event using the convergence rate.

8. A precise control device for drip irrigation and water and fertilizer coordination in wheat strip uniform sowing, characterized in that, The method includes a memory and a processor, wherein the memory stores a computer program that runs on the processor, and the processor executes the computer program to implement the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control method as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is run by the processor, it causes the processor to execute the wheat strip uniform sowing drip irrigation water and fertilizer synergistic precision control method as described in any one of claims 1 to 6.

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