Precise water and fertilizer integrated cotton cultivation method based on drip irrigation regulation and control

Abstract

The invention relates to the technical field of intelligent irrigation, in particular to a cotton precise water and fertilizer integrated cultivation method based on drip irrigation regulation, comprising the following steps: S1, monitoring soil moisture content and soil nutrient concentration of a cotton root zone; s2, determining a target soil moisture threshold value and a target nutrient application rate in combination with the current growth stage of cotton; s3, the irrigation starting time, the irrigation water amount and the fertilizer application amount of the drip irrigation system are calculated; s4, setting control parameters of the drip irrigation system; s5, performing water and fertilizer integrated application according to the control parameters set in S4; and S6, evaluating the water and fertilizer distribution uniformity of the cotton root zone, and outputting a water and fertilizer optimization report. According to the invention, accurate monitoring and dynamic regulation and control of the water and fertilizer state of the cotton root zone are realized, the water and fertilizer utilization efficiency and application uniformity are improved, and high efficiency and controllability of the whole water and fertilizer management process are ensured.

Description

Technical Field

[0001] This invention relates to the field of intelligent irrigation technology, and in particular to a precise water and fertilizer integration cultivation method for cotton based on drip irrigation control. Background Technology

[0002] In the current context of agricultural digitalization, drip irrigation, as an efficient water-saving irrigation technology, has been widely used in the cultivation of dryland cash crops such as cotton. Traditional water and fertilizer management methods mostly rely on experience and lack linkage analysis of soil moisture dynamics, crop nutrient requirements and irrigation system operating parameters, which often leads to problems such as inaccurate irrigation timing, excessive or insufficient fertilization, and uneven distribution of water and fertilizer in the root zone, thereby affecting cotton yield and resource utilization efficiency.

[0003] However, existing technologies generally suffer from the following problems: First, they lack high-frequency dynamic monitoring methods for root zone soil moisture and major nutrient concentrations, making it difficult to provide basic data for real-time regulation; second, they fail to integrate cotton growth stage characteristics with soil parameters for analysis, making it impossible to set reasonable water and fertilizer target values; and third, the setting of irrigation and fertilization parameters lacks systematic modeling support, resulting in low control precision and delayed adjustment response during the application process. Therefore, it is necessary to construct a precision water and fertilizer integration cultivation method for cotton based on drip irrigation regulation to achieve dynamic matching and intelligent application of water and fertilizer, thereby solving the core challenges in crop water and fertilizer management. Summary of the Invention

[0004] To achieve the above objectives, this invention provides a method for precise integrated water and fertilizer cultivation of cotton based on drip irrigation control.

[0005] A method for precise fertigation of cotton based on drip irrigation includes the following steps: S1: Monitor soil moisture content and soil nutrient concentration in the cotton root zone; S2: Based on the soil moisture content and soil nutrient concentration monitored in S1, and combined with the current growth stage of cotton, determine the target soil moisture threshold and target nutrient application rate. S3: Based on the target soil moisture threshold and target nutrient application rate determined in S2, calculate the irrigation start-up timing and irrigation water volume of the drip irrigation system, as well as the fertilizer application rate; S4: Based on the irrigation start-up timing, irrigation water volume, and fertilizer application rate calculated in S3, set the control parameters of the drip irrigation system, including dripper opening time, drip irrigation flow rate, and fertilizer injection rate; S5: Start the drip irrigation system and apply water and fertilizer in accordance with the control parameters set in S4; S6: After application, assess the uniformity of water and fertilizer distribution in the cotton root zone and generate a water and fertilizer optimization report.

[0006] Optionally, S1 specifically includes: S11: Multiple soil moisture sensors and ion-selective electrode soil nutrient sensors are installed along the drip irrigation tape in the cotton root zone to collect soil volumetric water content and soluble nutrient concentration values ​​at different times. S12: Perform time-moving average processing on the collected soil volumetric moisture content values ​​to eliminate single-point abnormal fluctuations and obtain the current soil moisture content value. S13: Perform calibration conversion on the electrical signal intensity output by the soil nutrient sensor, and combine it with soil temperature parameters to calculate the current soil nutrient concentrations of nitrate nitrogen, ammonium nitrogen, available potassium and available phosphorus. S14: Upload the soil moisture content and soil nutrient concentration obtained in S12 and S13 to the data management terminal, and establish data tags bound to time and spatial coordinates.

[0007] Optionally, S13 specifically includes: S131: Collect the potential signal value output by the ion-selective electrode and record the corresponding soil temperature parameters. The electrodes include nitrate nitrogen electrode, ammonium nitrogen electrode, available potassium electrode and available phosphorus electrode. S132: Perform temperature compensation correction on the output signals of each electrode, and correct the potential value according to the sensor characteristic equation to make it conform to the measurement conditions at the standard temperature. S133: Call the pre-calibrated potential-concentration mapping table, convert the compensated potential value into an ion activity value, and convert it into a soil nutrient concentration value based on the ion strength parameters in the solution.

[0008] Optionally, S2 specifically includes: S21: Obtain the current growth stage of the cotton and retrieve the corresponding water requirement threshold and nutrient requirement parameters from the preset growth cycle database. S22: Compare the soil moisture content monitored in S1 with the water demand threshold for the target stage, and set the target soil moisture threshold for the current stage. S23: Based on the nutrient concentrations of nitrate nitrogen, ammonium nitrogen, available potassium, and available phosphorus obtained in S1, and combined with the target concentration requirements for each growth stage, set the target nutrient application rate.

[0009] Optionally, S23 specifically includes: S231: Read the target nutrient concentration parameters for the current stage from the reproductive cycle database, including the target concentration range values ​​for nitrate nitrogen, ammonium nitrogen, available potassium, and available phosphorus for the current stage; S232: Calculate the difference between the actual nutrient concentration obtained from monitoring S1 and the target concentration for the corresponding stage to obtain the concentration deviation value of each nutrient; S233: Based on the concentration deviation of each nutrient and its weighting coefficient in the physiological needs of cotton at the corresponding stage, a weighted analysis of the deviation is performed to determine the corresponding fertilization adjustment ratio. S234: Based on the fertilization adjustment ratio in S233, calculate the target nutrient application rate for the current stage and output the corresponding application parameters for nitrogen, potassium and phosphorus fertilizers respectively.

[0010] Optionally, S3 specifically includes: S31: Call the real-time soil moisture content value of the cotton root zone recorded in S1, compare it with the target soil moisture threshold set in S2, determine whether the current moisture content is lower than the set threshold, and determine whether irrigation needs to be started accordingly. S32: When the soil moisture content is below the threshold, calculate the required irrigation water volume based on the irrigation depth and effective root zone depth, combined with the current soil texture and water holding capacity of the field. ; S33: Based on the target nutrient application rate set in S2 and the irrigation water volume in S32, the total fertilizer application is calculated in combination with the fertilizer nutrient content. The formula is as follows: ,in, For the first The application rate of this type of fertilizer; For the first Target nutrient concentration; This refers to the total amount of water used for irrigation. For the first The proportion of effective nutrients in fertilizers.

[0011] Optionally, S4 specifically includes: S41: Use the irrigation start timing of S3 as the trigger threshold of the control system, and set the drip irrigation process to start automatically when the measured soil moisture content is lower than the threshold. S42: Based on the required irrigation water volume Based on the unit flow rate parameters of each dripper in the drip irrigation system and the total number of drippers in the irrigation area, calculate the corresponding dripper activation time. And configure it to the main control terminal; S43: Match the irrigation water volume with the drip irrigation flow rate per unit time, set the drip irrigation flow rate parameters required for the current irrigation operation, and use them as the execution reference for the control valves and flow regulation devices; S44: Allocate the application rates of various fertilizers obtained in S3 with the irrigation duration, combine the fertilizer solution concentration and the capacity of the fertilizer injection device, set the fertilizer injection rate, and write it into the fertilizer injection system controller.

[0012] Optionally, S44 specifically includes: S441: Apply the various fertilizer application rates calculated in S3. With the dripper opening time in S42 Perform matching and allocation, and calculate the target injection rate of each type of fertilizer throughout the irrigation process. The formula is: ; S442: Combined with the preset fertilizer solution concentration The formula for converting solid dosage to liquid injection volume is as follows: ,in, For the first The injection volume of the fertilizer-like solution; S443: Based on the maximum working capacity parameter of the fertilizer injection device, determine whether the current injection rate exceeds the limit; if it does not exceed the limit, directly set the injection rate parameter; if it exceeds the limit, perform proportional segmented injection control within a time period.

[0013] Optionally, S5 specifically includes: S51: Receives the dripper opening time, drip irrigation flow rate and fertilizer injection rate parameters set in S4, automatically wakes up the main control unit and starts the irrigation process; S52: Control the solenoid valve of the drip irrigation main pipeline to open at a set time to maintain a stable flow output of the system, and simultaneously start the fertilizer injection pump to inject fertilizer solution of the corresponding concentration in proportion; S53: During irrigation, the system monitors the operation status of the flow meter and fertilizer metering device in real time to ensure that the irrigation water volume and injected fertilizer are consistent with the set values; S54: After irrigation is completed, the control system automatically shuts down all actuators and records the water and fertilizer application parameters and operation time.

[0014] Optionally, S6 specifically includes: S61: After drip irrigation is completed, soil moisture content and soil nutrient concentration data are collected simultaneously at multiple points in the cotton root zone to obtain the distribution of soil water and fertilizer status after application. S62: Perform spatial variability analysis on the moisture content and nutrient concentration data at each sampling point, and calculate the standard deviation and coefficient of variation. ; S63: The coefficient of variation Compare the distribution with the target threshold standard for the current stage to determine whether the water and fertilizer distribution meets the set consistency requirements. If it does not meet the requirements, mark the areas with deviations. S64: Generate a water and fertilizer optimization report that includes distribution uniformity index, deviation area identification, water and fertilizer use efficiency assessment value, and historical comparative analysis charts.

[0015] The beneficial effects of this invention are: This invention establishes a drip irrigation regulation system that integrates monitoring, calculation, and control, enabling dynamic monitoring of soil moisture and nutrient concentration in the cotton root zone and determining target thresholds by combining growth stage parameters. Through coupled calculation of water and fertilizer data with growth stages, it can automatically calculate the timing of irrigation initiation, irrigation water volume, and fertilizer application rate under different meteorological and physiological conditions, and convert the results into control parameters for the drip irrigation system, thus achieving a precise integrated water and fertilizer management process.

[0016] This invention, through quantitative evaluation and optimization report output of water and fertilizer distribution uniformity, not only improves the water and fertilizer utilization efficiency and application uniformity in the cotton root zone, but also effectively reduces irrigation energy consumption and fertilizer waste, providing intelligent and scientific technical support for efficient cotton cultivation in arid areas. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the integrated water and fertilizer cultivation method according to an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the process of setting control parameters according to an embodiment of the present invention. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more comprehensive, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0020] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0021] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0022] like Figures 1-2 As shown, a precise fertigation method for cotton based on drip irrigation includes the following steps: S1: Monitor soil moisture content and soil nutrient concentration in the cotton root zone; S2: Based on the soil moisture content and soil nutrient concentration monitored in S1, and combined with the current growth stage of cotton, determine the target soil moisture threshold and target nutrient application rate. S3: Based on the target soil moisture threshold and target nutrient application rate determined in S2, calculate the irrigation start-up timing and irrigation water volume of the drip irrigation system, as well as the fertilizer application rate; S4: Based on the irrigation start-up timing, irrigation water volume, and fertilizer application rate calculated in S3, set the control parameters of the drip irrigation system, including dripper opening time, drip irrigation flow rate, and fertilizer injection rate; S5: Start the drip irrigation system and apply water and fertilizer in accordance with the control parameters set in S4; S6: After application, assess the uniformity of water and fertilizer distribution in the cotton root zone and generate a water and fertilizer optimization report.

[0023] S1 specifically includes: S11: Multiple soil moisture sensors and ion-selective electrode soil nutrient sensors are installed along the drip irrigation tape in the cotton root zone to collect soil volumetric water content and soluble nutrient concentration values ​​at different times. S12: Perform time-moving average processing on the collected soil volumetric moisture content values ​​to eliminate single-point abnormal fluctuations and obtain a stable current soil moisture content value. S13: Perform calibration conversion on the electrical signal intensity output by the soil nutrient sensor, and combine it with soil temperature parameters to calculate the current soil nutrient concentrations of nitrate nitrogen, ammonium nitrogen, available potassium and available phosphorus. S14: Upload the soil moisture content and soil nutrient concentration obtained in S12 and S13 to the data management terminal, and establish data tags bound to time and spatial coordinates for subsequent cultivation parameter decision input; the above steps, by coordinating the deployment of soil moisture sensors and nutrient electrode probes, and combining moving average and temperature calibration processing, can achieve high-precision dynamic monitoring of soil water and fertilizer status in the cotton root zone, providing real-time and reliable basic data support for subsequent target threshold calculation and water and fertilizer regulation.

[0024] S13 specifically includes: S131: Collect the potential signal value output by the ion-selective electrode and record the corresponding soil temperature parameters. The electrodes include nitrate nitrogen electrode, ammonium nitrogen electrode, available potassium electrode and available phosphorus electrode. S132: Perform temperature compensation correction on the output signals of each electrode, and correct the potential value according to the sensor characteristic equation to make it conform to the measurement conditions at the standard temperature. The temperature compensation equation expression is: ,in, This is the potential value after temperature compensation; This is the measured potential value; This is the electrode temperature compensation coefficient; For actual soil temperature measurement; Standard temperature; S133: Call the pre-calibrated potential-concentration mapping table to convert the compensated potential value into an ion activity value, and then convert it into a soil nutrient concentration value based on the ion strength parameters in the solution. The calculation formula is as follows: ,in, For the first The concentration of nutrients; This represents the currently measured electrode potential value; This represents the standard potential value of the corresponding electrode; The slope coefficient of the electrode; is the electrode calibration coefficient, and is a dimensionless constant.

[0025] Table 1 Potential-Concentration Mapping Table Potential range of each electrode in Table 1 above With concentration range Established through a logarithmic linear relationship, satisfying the formula: The output potential of the electrode changes linearly with the logarithmic change of the ion concentration in the solution, which conforms to the Nernst response model. The reference potential at a standard solution (of known concentration) is used to determine the zero-point offset; when the system acquires the real-time potential of the electrode output... Then, it is first corrected according to the temperature compensation formula. Then substitute the corresponding electrode parameters into the table above, and use the conversion formula: It can calculate the current nutrient concentration; by establishing a potential-concentration mapping table, it can achieve unified calibration and rapid conversion of different types of nutrient electrodes; it can be reused in different cotton planting plots, significantly improving the standardization and accuracy of soil nutrient monitoring, and providing a data consistency basis for subsequent target fertilization rate determination.

[0026] S2 specifically includes: S21: Obtain the current growth stage of the cotton and retrieve the corresponding water requirement threshold and nutrient requirement parameters from the preset growth cycle database. Table 2 Fertility Cycle Database In Table 2 above, the growth stages are divided into seedling stage, budding stage, boll-forming stage, and boll-opening stage according to the cotton development process, reflecting the physiological characteristics and different needs of different stages; the start and end days of each stage indicate the standard duration range of each stage, starting from the sowing time, to facilitate real-time positioning of the cotton's current stage; the target soil moisture threshold indicates the range of soil volumetric moisture content that should be maintained in the root zone at this stage, used for setting the target threshold in S2; the target nutrient concentration indicates a reasonable concentration range set according to the nutrient absorption characteristics of cotton at each stage; by establishing a water and fertilizer target database covering the entire cotton growth period, the system can automatically match the corresponding water and fertilizer demand range based on the current number of days and the growth stage, thereby providing a scientific basis for setting the target threshold, ensuring that irrigation and fertilization operations are highly matched with the crop's water and fertilizer requirements, and improving the effect of precision cultivation.

[0027] S22: Compare the soil moisture content monitored in S1 with the water demand threshold for the target stage, and set the target soil moisture threshold for the current stage; the threshold is calculated according to the following formula: ,in, The target soil moisture threshold for the current stage; Recommend the lower limit value of moisture for the corresponding stage in the database; This is a correction factor used to adjust the water safety margin under different climatic conditions; This represents the current evapotranspiration requirement of the crop. This is the historical average evaporation rate; S23: Based on the nutrient concentrations of nitrate nitrogen, ammonium nitrogen, available potassium and available phosphorus obtained in S1, and combined with the target concentration requirements of each growth stage, the target nutrient application rate is set; the above steps link the cotton growth stage with the water and fertilizer demand standards, realize the precise setting of irrigation and fertilization target values ​​in stages, and improve the adaptability and accuracy of water and fertilizer regulation strategies.

[0028] S23 specifically includes: S231: Read the target nutrient concentration parameters for the current stage from the reproductive cycle database, including the target concentration range values ​​for nitrate nitrogen, ammonium nitrogen, available potassium, and available phosphorus for the current stage; S232: Calculate the difference between the actual nutrient concentration obtained from monitoring S1 and the target concentration for the corresponding stage to obtain the concentration deviation value for each nutrient. The calculation formula is as follows: ,in, For the first Concentration deviation of nutrient types; For the current stage Class target concentration; For the actual measurement Nutrient concentration; S233: Based on the concentration deviations of each nutrient and their weighting coefficients in the physiological requirements of cotton at the corresponding stage, a weighted analysis is performed on the deviations to determine the corresponding fertilization adjustment ratio. The calculation formula is as follows: ,in: Adjust the total fertilization index; For the first Nutrient requirement weighting coefficient; For the first Concentration deviation of nutrient types; S234: Based on the fertilization adjustment ratio in S233, calculate the target nutrient application rate for the current stage, and output the corresponding application parameters for nitrogen, potassium, and phosphorus fertilizers respectively. The calculation formula is as follows: ,in: For the first Application rates corresponding to different types of nutrients; For the first The conversion coefficient for unit concentration application of various nutrients; the above steps, by introducing difference calculation, weighting and fertilizer application conversion, can improve the accuracy and controllability of decision response, thereby optimizing the allocation of water and fertilizer resources and ensuring the nutritional balance of cotton throughout its growth process.

[0029] S3 specifically includes: S31: Call the real-time soil moisture content value of the cotton root zone recorded in S1, compare it with the target soil moisture threshold set in S2, determine whether the current moisture content is lower than the set threshold, and determine whether irrigation needs to be started accordingly. S32: When the soil moisture content is below the threshold, calculate the required irrigation water volume based on the irrigation depth and effective root zone depth, combined with the current soil texture and water holding capacity of the field. The specific calculation formula is as follows: ,in: For irrigated area; Effective root depth; The target volumetric moisture content; This represents the current measured volumetric moisture content. S33: Based on the target nutrient application rate set in S2 and the irrigation water volume in S32, the total fertilizer application is calculated in combination with the fertilizer nutrient content. The formula is as follows: ,in, For the first The application rate of this type of fertilizer; For the first Target nutrient concentration; This refers to the total amount of water used for irrigation. For the first The effective nutrient content ratio of fertilizers; the above steps, by introducing root zone water compensation calculation and fertilizer-water linkage ratio formula, realize the quantitative calculation of irrigation start time, water volume and fertilizer application, which can ensure that water and fertilizer input is accurately matched with crop root zone gap, and improve the scientific nature of drip irrigation system response and operational efficiency.

[0030] S4 specifically includes: S41: Use the irrigation start timing of S3 as the trigger threshold of the control system, and set the drip irrigation process to start automatically when the measured soil moisture content is lower than the threshold. S42: Based on the required irrigation water volume Based on the unit flow rate parameters of each dripper in the drip irrigation system and the total number of drippers in the irrigation area, calculate the corresponding dripper activation time. It is configured to the main control terminal to ensure accurate injection of the target water volume. The calculation formula is as follows: ,in: This refers to the dripper activation time; The working flow rate for a single dripper; The number of drippers within the irrigation area; S43: Match the irrigation water volume with the drip irrigation flow rate per unit time, set the drip irrigation flow rate parameters required for the current irrigation operation, and use this as the execution reference for the control valves and flow regulation devices. The calculation formula is as follows: ,in, The set drip irrigation flow rate; This refers to the total amount of water used for irrigation. This refers to the dripper activation time; S44: Allocate the application rates of various fertilizers obtained in S3 with the irrigation duration, combine the fertilizer solution concentration and the capacity of the fertilizer injection device, set the fertilizer injection rate, and write it into the fertilizer injection system controller to achieve quantitative fertilizer injection throughout the process; the above steps establish a quantitative relationship between the dripper opening time and the system flow rate based on water volume and flow parameters, which can effectively control the consistency between the actual irrigation output and the target setting, and improve the operational accuracy and control stability of the drip irrigation system.

[0031] S44 specifically includes: S441: Apply the various fertilizer application rates calculated in S3. With the dripper opening time in S42 Perform matching and allocation, and calculate the target injection rate of each type of fertilizer throughout the irrigation process. The formula is: ; S442: Combined with the preset fertilizer solution concentration The solid application rate is converted into liquid injection volume to align with the flow control parameters of the fertilizer injection pump. The formula is as follows: ,in, For the first The injection volume of the fertilizer-like solution; S443: Based on the maximum working capacity parameter of the fertilizer injection device, determine whether the current injection rate exceeds the limit; if it does not exceed the limit, directly set the injection rate parameter; if it exceeds the limit, perform proportional segmented injection control within a time period; write the injection rate parameters of various fertilizers into the fertilizer injection control system to realize synchronous fertilizer injection operation during drip irrigation; the above steps, by introducing quantitative ratio calculation of application amount and time and solid-liquid conversion relationship, can realize dynamic setting and systematic control of fertilizer injection rate, so that the water and fertilizer application process has precise controllability in both time and concentration dimensions.

[0032] S5 specifically includes: S51: Receives the dripper opening time, drip irrigation flow rate and fertilizer injection rate parameters set in S4, automatically wakes up the main control unit and starts the irrigation process; S52: Control the solenoid valve of the drip irrigation main pipeline to open at a set time to maintain a stable flow output of the system, and simultaneously start the fertilizer injection pump to inject fertilizer solution of the corresponding concentration in proportion; S53: During irrigation, the system monitors the operation status of the flow meter and fertilizer metering device in real time to ensure that the irrigation water volume and injected fertilizer are consistent with the set values; S54: After irrigation is completed, the control system automatically shuts down all actuators and records the water and fertilizer application parameters and operation time, completing the data archiving of the entire process; the above steps achieve simultaneous water and fertilizer application by automatically executing the set flow rate and fertilizer injection parameters, improving irrigation efficiency and fertilizer utilization, and ensuring that the application process is efficient, stable, and data is traceable.

[0033] S6 specifically includes: S61: After drip irrigation is completed, soil moisture content and soil nutrient concentration data are collected simultaneously at multiple points in the cotton root zone to obtain the distribution of soil water and fertilizer status after application. S62: Perform spatial variability analysis on the moisture content and nutrient concentration data at each sampling point, and calculate the standard deviation and coefficient of variation. Based on this, the uniformity of water and fertilizer distribution in the root zone in both the horizontal and vertical directions can be determined. The calculation formula is as follows: ,in, The standard deviation is the sample standard deviation. The average value of the sample points; when The smaller the value, the more evenly the water and fertilizer are distributed; S63: The coefficient of variation Compare the water and fertilizer distribution with the target threshold standard for the current stage to determine whether it meets the set consistency requirements. If it does not, mark the areas with deviations. The judgment formula is: ,in, This represents the deviation value of the distribution uniformity. The target distribution uniformity standard; when When the distribution is uniform, it is determined that the distribution is uniform; among which This is the allowable deviation threshold; S64: Generate a water and fertilizer optimization report that includes distribution uniformity index, deviation area identification, water and fertilizer use efficiency assessment value and historical comparison analysis charts, and automatically output it to the terminal management system; the above steps realize the quantitative evaluation of water and fertilizer application effect through multi-point data collection and spatial distribution analysis, and provide a basis for subsequent irrigation strategy adjustment through the optimization report.

[0034] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0035] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A cotton precise water and fertilizer integrated cultivation method based on drip irrigation regulation, characterized in that, The method comprises the following steps: S1: monitoring the soil moisture content and soil nutrient concentration in the cotton root zone; S2: determining the target soil moisture threshold and target nutrient application rate according to the soil moisture content and soil nutrient concentration monitored in S1, combined with the current growth stage of cotton; S3: calculating the irrigation start time and irrigation water volume of the drip irrigation system, and the fertilizer application amount according to the target soil moisture threshold and target nutrient application rate determined in S2; S4: setting the control parameters of the drip irrigation system, including the dripper opening time, drip irrigation flow and fertilizer injection rate, based on the irrigation start time, irrigation water volume and fertilizer application amount calculated in S3; S5: starting the drip irrigation system and applying water and fertilizer in an integrated manner according to the control parameters set in S4; S6: after the application is completed, evaluating the water and fertilizer distribution uniformity in the cotton root zone, and outputting a water and fertilizer optimization report.

2. The cotton precision water and fertilizer integrated cultivation method based on drip irrigation regulation according to claim 1, characterized in that, The S1 specifically comprises: S11: arranging multi-point soil moisture sensors and ion-selective electrode soil nutrient sensors in the cotton root zone along the drip irrigation belt to collect soil volume water content and soluble nutrient concentration values at different times; S12: performing time sliding average processing on the collected soil volume water content values to eliminate single-point abnormal fluctuations and obtain the current soil moisture content value; S13: performing calibration conversion on the electrical signal intensity output by the soil nutrient sensor, and converting to obtain the soil nutrient concentration of the current nitrate nitrogen, ammonium nitrogen, available potassium and available phosphorus indicators combined with the soil temperature parameter; S14: uploading the soil moisture content and soil nutrient concentration obtained in S12 and S13 to a data management terminal, and establishing a data tag bound with time and space coordinates.

3. The cotton precision water and fertilizer integrated cultivation method based on drip irrigation regulation according to claim 2, characterized in that, The S13 specifically comprises: S131: collecting the potential signal value output by the ion-selective electrode and recording the corresponding soil temperature parameter, the electrode including a nitrate nitrogen electrode, an ammonium nitrogen electrode, an available potassium electrode and an available phosphorus electrode; S132: performing temperature compensation correction on the output signals of each electrode, correcting the potential value according to the sensor characteristic equation to make it meet the measurement conditions at the standard temperature; S133: calling the pre-calibrated potential-concentration mapping table to convert the compensated potential value into ion activity value, and converting into soil nutrient concentration value according to the ion strength parameter in the solution.

4. The cotton precision water and fertilizer integrated cultivation method based on drip irrigation regulation according to claim 1, characterized in that, The S2 specifically comprises: S21: obtaining the current growth stage of cotton and calling the water requirement critical value and nutrient demand parameter of the corresponding stage from the preset growth cycle database; S22: comparing the soil moisture content monitored in S1 with the water requirement critical value of the target stage to set the target soil moisture threshold corresponding to the current stage; S23: setting the target nutrient application rate according to the nutrient concentration of nitrate nitrogen, ammonium nitrogen, available potassium and available phosphorus obtained in S1, combined with the target concentration demand of each growth stage.

5. The drip irrigation regulated cotton precise water and fertilizer integrated cultivation method according to claim 4, characterized in that, The S23 specifically comprises: S231: reading the target nutrient concentration parameter of the current stage from the growth cycle database, including the stage target concentration interval value of nitrate nitrogen, ammonium nitrogen, available potassium and available phosphorus; S232: calculating the concentration deviation value of each nutrient by difference between the actual nutrient concentration obtained by monitoring in S1 and the target concentration of the corresponding stage; S233: According to the concentration deviation value of each nutrient, combined with its weight coefficient in the physiological demand of cotton at the corresponding stage, the deviation is weighted and analyzed to determine the corresponding fertilization adjustment ratio; S234: According to the fertilization adjustment ratio of S233, the target nutrient application rate of the current stage is calculated, and the application parameters of corresponding nitrogen fertilizer, potassium fertilizer and phosphorus fertilizer are output respectively.

6. The cotton precision water and fertilizer integrated cultivation method based on drip irrigation regulation according to claim 1, characterized in that, The S3 specifically includes: S31: Call the real-time soil moisture content value of the cotton root zone recorded in S1, and compare it with the target soil moisture threshold value set in S2 to determine whether the current water content is lower than the set threshold value, and determine whether irrigation needs to be started accordingly; S32: When the soil moisture content is lower than the threshold value, calculate the required irrigation water volume according to the irrigation depth and the effective root layer depth, combined with the current field soil texture and water holding capacity ; S33: Based on the target nutrient application rate set in S2 and the irrigation water amount in S32, the total amount of fertilizer is calculated in combination with the nutrient content of the fertilizer, the formula is: wherein, is the application amount of the first class of fertilizer; is the target nutrient concentration of the first class; is the total irrigation water amount; is the effective nutrient content ratio of the first class of fertilizer.

7. The cotton precision water and fertilizer integrated cultivation method based on drip irrigation regulation according to claim 6, characterized in that, The S4 specifically includes: S41: Take the irrigation starting time of S3 as the trigger threshold of the control system, and set to automatically start the drip irrigation process when the measured soil moisture content is lower than the threshold value; S42: according to the required irrigation water quantity and the unit flow parameter of each dripper in the drip irrigation system, combined with the total number of drippers in the irrigation area, the corresponding dripper opening time is calculated , and configured to the master terminal; S43: Match the irrigation water volume with the drip irrigation flow per unit time, set the drip irrigation flow parameter required for the current irrigation operation as the execution reference of the control valve and flow regulating device; S44: Match and distribute the application amount of each type of fertilizer obtained in S3 with the irrigation duration, set the fertilizer injection rate in combination with the fertilizer solution concentration and the injection device capacity, and write it into the fertilizer injection system controller.

8. The cotton precision water and fertilizer integrated cultivation method based on drip irrigation regulation according to claim 7, characterized in that, The S44 specifically includes: S441: match the calculated application amount of each type of fertilizer in S3 with the opening time of the dripper in S42 ;​​​ S442: combining the preset fertilizer solution concentration The solid application amount is converted into the liquid injection volume, and the formula is: Wherein, is the injection volume of the first class fertilizer solution; S443: According to the maximum working capacity parameter of the fertilizer injection device, determine whether the current injection rate is out of limit; if not, directly set the injection rate parameter, if out of limit, perform proportional segmented injection control within the time period.

9. The drip irrigation regulated cotton precise water and fertilizer integrated cultivation method according to claim 1, characterized in that, The S5 specifically includes: S51: Receive the dripper opening time, drip irrigation flow and fertilizer injection rate parameters set in S4, automatically wake up the main control unit and start the irrigation process; S52: Control the electromagnetic valve of the drip irrigation main pipeline to open according to the set time, maintain stable flow output of the system, and simultaneously start the fertilizer injection pump to inject fertilizer solution with corresponding concentration in proportion; S53: During the irrigation process, the system monitors the running state of the flow meter and the fertilizer injection metering device in real time to ensure that the irrigation water volume and the injected fertilizer are consistent with the set values; S54: After irrigation, the control system automatically closes all actuators, records the water and fertilizer application parameters and operation time of this time.

10. The method according to claim 1, wherein the method is characterized in that, The S6 specifically includes: S61: After the completion of drip irrigation application, the soil moisture content and soil nutrient concentration data are collected at multiple points in the cotton root zone to obtain the soil water and fertilizer state distribution after application; S62: Perform spatial difference analysis on the moisture content and nutrient concentration data of each sampling point, calculate the standard deviation and coefficient of variation ; S63: Calculate the coefficient of variation of the water and fertilizer distribution in the current stage Compare the target threshold distribution standard of the current stage with the water and fertilizer distribution, and determine whether the water and fertilizer distribution meets the set consistency requirement. If not, mark the area with deviation. S64: Generate a water and fertilizer optimization report containing distribution uniformity index, deviation area identification, water and fertilizer utilization efficiency evaluation value and historical comparison analysis chart.

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