Fertilization and irrigation two-way regulation system under coupling modeling of water and fertilizer requirements

Abstract

The application relates to the technical field of fertilization irrigation regulation, and discloses a fertilization irrigation two-way regulation system under water requirement and fertilizer requirement coupling modeling, which is centered on water requirement and fertilizer requirement coupling modeling and constructs a fertilization irrigation two-way regulation system. The system comprises a multi-source data acquisition module, through which soil, crop growth period and meteorological data are acquired through layered soil sensors, crop image acquisition equipment and meteorological acquisition points; a water and fertilizer scheme generation module, which calculates irrigation amount, fertilizer type and dosage based on data and adjusts intervals in combination with temperature; an operation execution module, which controls the operation of irrigation and fertilization equipment and records the state; and a data correction module, which compares sensor and sample data and generates a correction scheme. Through the closed loop of data acquisition, scheme generation, execution and correction, the system realizes accurate regulation, simultaneously covers equipment state monitoring and early warning, and guarantees that fertilization irrigation is efficiently adapted to crop requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fertilization irrigation regulation, in particular to a fertilization irrigation two-way regulation system under the coupling modeling of water requirement and fertilizer requirement. BACKGROUND

[0002] Fertilization irrigation is a core link in agricultural production to ensure crop yield and improve resource utilization efficiency. By providing suitable water and nutrient supply for crops, it meets the physiological needs of crops at different growth stages and is widely used in various crop planting scenarios such as food crops and economic crops. In the process of agricultural modernization, scientific fertilization irrigation can not only reduce the waste of water resources and chemical fertilizers and reduce the risk of agricultural non-point source pollution, but also significantly improve crop quality and yield, which is a key technical support for promoting green and sustainable development of agriculture.

[0003] However, traditional fertilization irrigation technology still has many deficiencies in practical application and is difficult to adapt to the needs of modern agriculture for precision and intelligence. First, water and fertilizer requirement decisions are separated and not coupled modeling: traditional methods mostly calculate irrigation or fertilizer amounts separately, ignoring the synergistic absorption effect between soil water and nutrients - for example, insufficient soil moisture will inhibit nutrient dissolution and root absorption efficiency, and excessive water will easily lead to nutrient leaching loss. This separate decision-making easily causes water and fertilizer imbalance, either wasting water resources and chemical fertilizers or failing to meet the actual needs of crops. Second, the data collection dimension is single and lacks multi-source collaboration: traditional systems mostly only collect surface soil moisture or single weather indicators, do not monitor soil at different depths to understand the distribution of water and nutrients at different depths, and do not integrate the dynamic changes of crop growth periods, resulting in low matching degree of water and fertilizer schemes with actual crop growth needs, often causing problems of water and fertilizer excess or deficiency in specific areas.

[0004] Therefore, it is necessary to design a fertilization irrigation two-way regulation system under the coupling modeling of water requirement and fertilizer requirement to solve the problems of water and fertilizer decision separation, one-sided data collection, lack of real-time feedback control, and low equipment regulation accuracy in traditional fertilization irrigation technology. SUMMARY

[0005] In view of this, the present application provides a fertilization irrigation two-way regulation system under the coupling modeling of water requirement and fertilizer requirement, aiming to solve the problems of water and fertilizer decision separation, one-sided data collection, lack of real-time feedback control, and low equipment regulation accuracy in traditional fertilization irrigation technology.

[0006] In one aspect, the present application provides a fertilization irrigation two-way regulation system under the coupling modeling of water requirement and fertilizer requirement, comprising:

[0007] Multi-source data acquisition module, for dividing the monitoring area according to the plot area, uniformly arranging soil monitoring points in each monitoring area, dividing the soil monitoring points into surface layer, middle layer and deep layer, and arranging moisture sensor, EC sensor and nutrient sensor in each layer for obtaining soil data, further arranging night lighting equipment and image acquisition equipment above each monitoring area, and the night lighting equipment and image acquisition equipment acquire crop overhead and side view images at intervals within a set period for judging whether the crop is in the growth period, and arranging meteorological acquisition points around the plot according to the density, and arranging rain gauge and temperature sensor at the meteorological acquisition points for obtaining meteorological data and connecting the meteorological service through the network interface;

[0008] Among them, all the devices of the multi-source data acquisition module are connected to the data storage node through wired or wireless connection, and the data are marked with monitoring area number and collection time;

[0009] Water and fertilizer scheme generation module, for extracting the latest soil data, crop growth period judgment result and meteorological data of the multi-source data acquisition module from the data storage node, calculating irrigation amount according to soil moisture difference value, setting fertilizer type and amount according to soil nutrient and crop growth period demand difference value, adjusting interval according to temperature average value, generating scheme containing irrigation time, fertilizer concentration, execution sequence and no-rain execution period, and storing the scheme information in the storage node;

[0010] Operation execution module, for laying irrigation pipe and fertilizer pipe in parallel in each monitoring area, the irrigation pipe and fertilizer pipe are respectively connected with valve and metering device, the valve and metering device are connected with control device, the control device takes scheme from the storage node, starts the equipment according to the execution period, the control device controls flow and fertilizer concentration, and records the equipment state to the storage node at regular intervals when running according to the scheme, and closes the equipment and marks the time when the operation is completed.

[0011] Further, it further includes data correction module;

[0012] The data correction module is used to arrange sample points in the monitoring area according to the set distribution at a set time after operation, collect soil samples of each soil layer to measure soil moisture, record crop leaf color and leaf length, transmit the collected data to the data storage node, compare with the synchronous soil sensor data of the multi-source data acquisition module, generate correction scheme, mark correction time, correction basis and associated initial scheme number, store to the data storage node, and call by the control device in the next operation.

[0013] Further, when comparing the sensor data and sample data, the data correction module includes:

[0014] The data correction module extracts synchronous soil moisture data of the multi-source data acquisition module and sample point measured soil moisture data, and calculates the soil moisture difference value.

[0015] The first soil condition difference threshold value, the second soil condition difference threshold value and the third soil condition difference threshold value are preset, and the first soil condition difference threshold value is smaller than the second soil condition difference threshold value, and the second soil condition difference threshold value is smaller than the third soil condition difference threshold value;

[0016] The data correction module compares the soil condition difference with the preset threshold value:

[0017] When the soil condition difference is less than or equal to the first soil condition difference threshold value, it is determined that the sensor data does not need to be corrected, and the original soil data validity is maintained;

[0018] When the soil condition difference is greater than the first soil condition difference threshold value and less than or equal to the second soil condition difference threshold value, a first correction coefficient is generated, the soil sensor data is corrected, and the corrected data is equal to the soil condition data multiplied by the first correction coefficient;

[0019] When the soil condition difference is greater than the second soil condition difference threshold value and less than or equal to the third soil condition difference threshold value, a second correction coefficient is generated, the soil sensor data is corrected, and the corrected data is equal to the soil condition data multiplied by the second correction coefficient;

[0020] When the soil condition difference is greater than the third soil condition difference threshold value, a third correction coefficient is generated, the soil sensor data is corrected, and the corrected data is equal to the soil condition data multiplied by the third correction coefficient;

[0021] The first correction coefficient is smaller than the second correction coefficient, and the second correction coefficient is smaller than the third correction coefficient. The corrected data is stored in the data storage node.

[0022] Further, when the data correction module generates the correction scheme, it includes:

[0023] The data correction module obtains the crop leaf color parameter and the leaf length, and presets the standard color parameter and the standard length;

[0024] The color deviation and the length deviation are calculated, and the color deviation and the length deviation are compared with the standard color deviation threshold value and the standard length deviation threshold value respectively, to determine whether the crop growth state meets the expectation;

[0025] When the color deviation is less than or equal to the standard color deviation threshold value and the length deviation is less than or equal to the standard length deviation threshold value at the same time, it is determined that the crop growth state meets the expectation, and the correction scheme only includes the sensor data correction value;

[0026] When the color deviation is greater than the standard color deviation threshold value or the length deviation is greater than the standard length deviation threshold value, it is determined that the crop growth state deviates from the expectation, and the correction scheme includes the fertilizer concentration adjustment amount and the irrigation time adjustment amount in addition to the sensor data correction value.

[0027] Furthermore, when the water and fertilizer scheme generation module calculates the irrigation amount, it includes:

[0028] The water and fertilizer scheme generation module extracts soil moisture data from each soil layer, calculates the average surface soil moisture, average middle soil moisture, and average deep soil moisture, and presets the target moisture value for each soil layer.

[0029] Calculate the surface moisture difference between the average surface soil moisture value and the target surface soil moisture value, the middle soil moisture difference between the average middle soil moisture value and the target middle soil moisture value, and the deep soil moisture difference between the average deep soil moisture value and the target deep soil moisture value.

[0030] The comprehensive irrigation demand is calculated based on the preset surface moisture weight coefficient, middle layer moisture weight coefficient, and deep layer moisture weight coefficient. The comprehensive irrigation demand is the sum of the surface moisture difference multiplied by the surface moisture weight coefficient, the middle layer moisture difference multiplied by the middle layer moisture weight coefficient, and the deep layer moisture difference multiplied by the deep layer moisture weight coefficient.

[0031] Preset minimum irrigation demand threshold and maximum irrigation demand threshold:

[0032] When the total irrigation demand is less than or equal to the minimum irrigation demand threshold, it is determined that no irrigation is needed and the irrigation amount is set to zero.

[0033] When the total irrigation demand is greater than the minimum irrigation demand threshold and less than or equal to the maximum irrigation demand threshold, the irrigation amount is the total irrigation demand multiplied by the area of ​​the monitoring area.

[0034] When the total irrigation demand exceeds the maximum irrigation demand threshold, the irrigation amount is the maximum irrigation demand threshold multiplied by the area of ​​the monitored area, and the remaining unmet irrigation demand is included in the calculation of the next water and fertilizer plan.

[0035] The sum of the surface moisture weighting coefficient, the middle moisture weighting coefficient, and the deep moisture weighting coefficient is equal to one.

[0036] Furthermore, when setting the type and amount of fertilizer, the water and fertilizer program generation module includes:

[0037] The water and fertilizer scheme generation module extracts the nutrient requirement parameters corresponding to the crop growth stage based on the crop growth stage determination results. The nutrient requirement parameters include nitrogen, phosphorus and potassium requirements.

[0038] Obtain the actual nitrogen, phosphorus, and potassium content in the soil as detected by the soil nutrient sensor;

[0039] Calculate the difference between the required nitrogen content and the actual nitrogen content, the difference between the required phosphorus content and the actual phosphorus content, and the difference between the required potassium content and the actual potassium content.

[0040] Preset nutrient sufficiency threshold range:

[0041] When the nitrogen difference is within the nitrogen sufficiency threshold range, the phosphorus difference is within the phosphorus sufficiency threshold range, and the potassium difference is within the potassium sufficiency threshold range, it is determined that no fertilization is required.

[0042] When any nutrient difference is greater than zero, the priority fertilizer type is determined according to the proportion of the absolute values ​​of each nutrient difference. The amount of fertilizer applied is the maximum value among the nutrient differences multiplied by the area of ​​the monitoring area and then multiplied by the nutrient conversion coefficient.

[0043] Furthermore, when the water and fertilizer solution generation module adjusts the interval based on the average temperature, it includes:

[0044] The water and fertilizer scheme generation module extracts temperature data from meteorological collection points and calculates the average daily temperature of the monitoring area.

[0045] A first temperature range, a second temperature range, and a third temperature range are preset, wherein the first temperature range is less than the second temperature range and the third temperature range;

[0046] When the average daily temperature is within the first temperature range, the fertilization and irrigation interval is set as the first fertilization and irrigation interval.

[0047] When the average daily temperature is within the second temperature range, the fertilization and irrigation interval is set as the second fertilization and irrigation interval.

[0048] When the average daily temperature is within the third temperature range, the fertilization and irrigation interval is set as the third fertilization and irrigation interval.

[0049] The first fertilization and irrigation interval is longer than the second fertilization and irrigation interval, which is longer than the third fertilization and irrigation interval. The interval adjustment needs to be combined with rainfall forecast data. If the rainfall in the next 24 hours is greater than the preset rainfall threshold, the fertilization and irrigation interval will be extended by the preset time.

[0050] Furthermore, when the operation execution module controls the flow rate and fertilizer concentration, it includes:

[0051] The control device obtains preset target values ​​for fertilizer concentration and irrigation flow rate from the data storage node;

[0052] The metering device collects the current fertilizer concentration and current irrigation flow rate in real time.

[0053] Calculate the concentration deviation between the current fertilizer concentration and the target fertilizer concentration, and the flow deviation between the current irrigation flow rate and the target irrigation flow rate;

[0054] Preset allowable deviation values ​​for concentration and flow rate:

[0055] When the concentration deviation exceeds the allowable concentration deviation value, adjust the valve opening of the fertilizer application pipe;

[0056] When the flow deviation exceeds the allowable flow deviation value, adjust the valve opening of the irrigation pipe.

[0057] Furthermore, when the job execution module periodically records the device status, it includes:

[0058] The control device records the valve operating current, pipeline pressure, and metering device error at preset time intervals.

[0059] Preset the normal range of valve operating current, the normal range of pipeline pressure, and the allowable error value of the metering device;

[0060] When the valve operating current is within the normal current range, the pipeline pressure is within the normal pressure range, and the metering device error is less than or equal to the allowable error value, the equipment is judged to be in normal condition, and the equipment is marked as operating well in the data storage node.

[0061] When any parameter exceeds the corresponding normal range or allowable value, the device status is determined to be abnormal, the abnormality type is marked in the data storage node, and the system early warning mechanism is triggered.

[0062] Furthermore, when the multi-source data acquisition module determines whether a crop is in its growth stage, it includes:

[0063] The image acquisition device acquires top-view and side-view images of the crop and extracts plant height and leaf area index.

[0064] The crop growth period start threshold and growth period end threshold are preset. The crop growth period start threshold includes the start plant height and the start leaf area index. The growth period end threshold includes the end plant height and the end leaf area index.

[0065] When the crop plant height is greater than or equal to the initial plant height and the crop leaf area index is greater than or equal to the initial leaf area index, the crop is determined to have entered the growth period.

[0066] When the crop plant height is greater than or equal to the final plant height and the crop leaf area index is greater than or equal to the final leaf area index, the crop is determined to be in the vigorous growth period.

[0067] When the crop height decreases for two consecutive collection cycles compared to the previous collection cycle, and the crop leaf area index is less than the initial leaf area index, the crop is determined to have exited the growth period.

[0068] The crop growth period determination result is stored in the data storage node after being correlated with the image acquisition time.

[0069] Compared with existing technologies, the beneficial effects of this invention are as follows: This system constructs a layered, multi-dimensional data acquisition system through a multi-source data acquisition module, enabling precise monitoring of soil moisture and nutrients (top, middle, and deep layers). Combined with dynamic judgment of crop growth stages and collaborative analysis of meteorological data (temperature and rainfall), it breaks through the limitations of traditional fertilization and irrigation methods, which suffer from "separation of water and nutrient decisions" and "partial data acquisition." Simultaneously, the water and fertilizer scheme generation module is based on coupled modeling of water and fertilizer requirements. It dynamically optimizes irrigation volume, fertilizer type and dosage, and execution intervals based on soil moisture differences, nutrient and crop demand differences, and average temperature, ensuring that water and fertilizer configuration is highly adapted to the physiological needs of crops at different growth stages. This effectively reduces the waste of water and fertilizer resources, avoids crop growth imbalances caused by localized water and fertilizer shortages or over-fertilization, and significantly improves the efficiency of water and fertilizer resource utilization.

[0070] The operation execution module, through the parallel laying of irrigation and fertilization pipelines in different zones, coupled with closed-loop control of valves, metering devices, and control devices, achieves differentiated water and fertilizer supply in different monitoring areas. This solves the problem of "uniform parameter control and poor regional adaptability" in traditional equipment, ensuring the uniformity and accuracy of water and fertilizer application in each area. Simultaneously, the timed recording of equipment operation status and the association of information from data storage nodes not only provide traceable evidence for the fertilization and irrigation process but also accumulate basic data for subsequent data correction and scheme optimization. The entire system forms a complete closed loop of "data acquisition - scheme generation - precise execution - data storage," promoting the transformation of fertilization and irrigation from traditional extensive management to intelligent and precise management, helping to reduce costs and increase efficiency in agricultural production, and providing reliable technical support for stable crop growth and quality improvement. Attached Figure Description

[0071] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0072] Figure 1 The first functional block diagram of the bidirectional fertilization and irrigation control system under coupled modeling of water demand and fertilizer demand provided in the embodiments of the present invention;

[0073] Figure 2 This is a second functional block diagram of a two-way fertilization and irrigation control system under coupled modeling of water demand and fertilizer demand, provided in an embodiment of the present invention. Detailed Implementation

[0074] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0075] See Figure 1 As shown in the figure, this embodiment of the invention proposes a bidirectional control system for fertilization and irrigation under coupled modeling of water demand and fertilizer demand, including: a multi-source data acquisition module, a water and fertilizer scheme generation module, and an operation execution module.

[0076] Specifically, the multi-source data acquisition module is used to divide the monitoring area according to the plot area. Soil monitoring points are evenly distributed in each monitoring area, and the soil monitoring points are divided into surface, middle and deep layers. Each layer is equipped with a moisture sensor, EC sensor and nutrient sensor to acquire soil data. Night lighting equipment and image acquisition equipment are also deployed above each monitoring area. The night lighting equipment and image acquisition equipment acquire crop top and side view images at intervals within a set time period to determine whether the crop is in the growth stage. Meteorological collection points are deployed around the plot according to density. Rain gauges and temperature sensors are set at the meteorological collection points to acquire meteorological data and connect to meteorological services through a network interface.

[0077] In this module, all devices are connected to the data storage node via wired or wireless means, and all data are labeled with the monitoring area number and the collection time.

[0078] The water and fertilizer plan generation module is used to extract the latest soil data, crop growth period judgment results and meteorological data from the multi-source data acquisition module from the data storage node, calculate the irrigation amount based on the soil moisture difference, set the fertilizer type and amount based on the difference between soil nutrients and crop growth period requirements, adjust the interval based on the average temperature, generate a plan containing irrigation duration, fertilizer concentration, execution order and no rainfall execution period, and store the plan annotation information in the node.

[0079] The operation execution module is used to lay irrigation pipes and fertilizer pipes in parallel in each monitoring area. The irrigation pipes and fertilizer pipes are connected to valves and metering devices, respectively. The valves and metering devices are connected to a control device. The control device retrieves the plan from the storage node, starts the equipment according to the execution period, controls the flow rate and fertilizer concentration, and records the equipment status and transmits it to the storage node at regular intervals when running according to the plan. When the operation ends, the equipment is shut down and the time is marked.

[0080] The above embodiments construct a layered, multi-dimensional data acquisition system through a multi-source data acquisition module, enabling precise monitoring of soil moisture and nutrients (top, middle, and deep layers). Combined with dynamic crop growth stage assessment and collaborative analysis of meteorological data (temperature and rainfall), this overcomes the limitations of traditional fertilization and irrigation methods, which often involve "separate decisions on water and nutrients" and "partial data acquisition." Simultaneously, the water and fertilizer plan generation module uses coupled modeling of water and fertilizer requirements. Based on soil moisture differences, nutrient and crop demand differences, and average temperature, it dynamically optimizes irrigation volume, fertilizer type and dosage, and execution intervals. This ensures that water and fertilizer configurations are highly adapted to the physiological needs of crops at different growth stages, effectively reducing water and fertilizer waste, avoiding crop growth imbalances caused by localized water and fertilizer shortages or over-fertilization, and significantly improving water and fertilizer resource utilization efficiency.

[0081] The above-described embodiment's operation execution module, through the parallel laying of irrigation and fertilization pipelines in zones, coupled with closed-loop control of valves, metering devices, and control devices, achieves differentiated water and fertilizer supply to different monitoring areas. This solves the problem of "uniform parameter control and poor regional adaptability" in traditional equipment, ensuring the uniformity and accuracy of water and fertilizer application in each area. Simultaneously, the timed recording of equipment operation status and the association of information from data storage nodes not only provide traceable evidence for the fertilization and irrigation process but also accumulate basic data for subsequent data correction and scheme optimization. The entire system forms a complete closed loop of "data acquisition - scheme generation - precise execution - data storage," promoting the transformation of fertilization and irrigation from traditional extensive management to intelligent and precise management, helping to reduce costs and increase efficiency in agricultural production, and providing reliable technical support for stable crop growth and quality improvement.

[0082] See Figure 2 As shown, the system also includes a data correction module;

[0083] Specifically, the data correction module is used to set up sample points in the monitoring area according to a set time and distribution after the operation, collect soil samples from each soil layer to measure soil moisture, and record the color and length of crop leaves; transmit the collected data to the data storage node and compare it with the soil sensor data of the multi-source data acquisition module at the same time; generate a correction plan, mark the correction time, correction basis and associated initial plan number, and store it in the data storage node for the control device to call during the next operation.

[0084] The data correction module in the above embodiment collects on-site samples at specific time points after the operation, selecting sample points according to a preset spatial distribution. This not only obtains measured data on soil moisture in each soil layer to verify the monitoring accuracy of the soil sensor, but also records phenotypic characteristics such as crop leaf color and length to intuitively reflect the effect of fertilization and irrigation. By comparing the measured soil moisture with sensor data from the same period, sensor deviation can be quantified and corresponding correction coefficients can be generated, avoiding data distortion caused by sensor drift over long-term use. At the same time, by combining the differences between crop leaf phenotypes and standard parameters, the actual adaptability of the water and fertilizer program can be judged. If the crop growth status deviates from expectations, adjustments to fertilizer concentration and irrigation duration are added to the correction program. The correction program generated by this module is stored in association with the initial program, allowing the control device to directly call the corrected parameters during the next operation, forming a closed loop of "execution-verification-correction-optimization". This effectively improves the system's adaptability to changes in soil characteristics and crop growth dynamics, further ensuring the accuracy of fertilization and irrigation.

[0085] Specifically, when the data correction module compares sensor data with sample data, it includes:

[0086] The data correction module extracts the soil moisture data from the multi-source data acquisition module and the measured soil moisture data from the sample points, and calculates the soil moisture difference.

[0087] A first moisture difference threshold, a second moisture difference threshold, and a third moisture difference threshold are preset, and the first moisture difference threshold is less than the second moisture difference threshold and less than the third moisture difference threshold;

[0088] The data correction module compares the soil moisture difference with a preset threshold:

[0089] When the moisture difference is less than or equal to the first moisture difference threshold, the sensor data is determined to be without correction, and the validity of the original soil data is maintained.

[0090] When the soil moisture difference is greater than the first soil moisture difference threshold and less than or equal to the second soil moisture difference threshold, a first correction coefficient is generated to correct the soil sensor data. The corrected data is equal to the soil moisture data multiplied by the first correction coefficient.

[0091] When the soil moisture difference is greater than the second soil moisture difference threshold and less than or equal to the third soil moisture difference threshold, a second correction coefficient is generated to correct the soil sensor data. The corrected data is equal to the soil moisture data multiplied by the second correction coefficient.

[0092] When the soil moisture difference exceeds the third soil moisture difference threshold, a third correction coefficient is generated to correct the soil sensor data. The corrected data is equal to the soil moisture data multiplied by the third correction coefficient.

[0093] Where the first correction coefficient is less than the second correction coefficient is less than the third correction coefficient, the corrected data is stored in the data storage node.

[0094] Specifically, the preset threshold for the first soil moisture difference is 1% (volume water content percentage, the same below), the second threshold is 3%, and the third threshold is 5%. The corresponding correction coefficients are set as follows: the first correction coefficient is 0.95, the second is 0.90, and the third is 0.85. That is, when the soil moisture difference is ≤1%, no correction is needed for the sensor data; when 1% < soil moisture difference ≤3%, correction is performed by multiplying the soil moisture data by 0.95; when 3% < soil moisture difference ≤5%, correction is performed by multiplying the soil moisture data by 0.90; and when the soil moisture difference >5%, correction is performed by multiplying the soil moisture data by 0.85.

[0095] The above embodiments make sensor data correction more practical by setting step-by-step thresholds and corresponding coefficients. This avoids overcorrection caused by minor deviations and allows for targeted calibration of larger deviations, ensuring the accuracy of soil data.

[0096] Specifically, when the data correction module generates a correction scheme, it includes:

[0097] The data correction module obtains crop leaf color parameters and leaf length, and presets standard color parameters and standard length.

[0098] Calculate the color deviation and length deviation, and compare them with the standard color deviation threshold and standard length deviation threshold, respectively, to see if the crop growth status meets expectations.

[0099] When both the color deviation and the length deviation are less than or equal to the standard color deviation threshold and the length deviation is less than or equal to the standard length deviation threshold, the crop growth status is determined to be in line with expectations, and the correction scheme only includes sensor data correction values.

[0100] When the color deviation is greater than the standard color deviation threshold or the length deviation is greater than the standard length deviation threshold, the crop growth status is determined to be deviating from the expected value. In addition to the sensor data correction value, the correction scheme also includes the fertilizer concentration adjustment and irrigation duration adjustment.

[0101] Specifically, the preset standard color parameters are the green RGB values ​​(50, 150, 50) of healthy leaves, and the standard color deviation threshold is ±20 for each RGB channel (i.e., color deviation within this range is considered normal). The standard length is set as the average leaf length at the corresponding growth stage (e.g., the standard leaf length at the wheat jointing stage is 20 cm), and the standard length deviation threshold is ±2 cm. When the color deviation is ≤ ±20 and the length deviation is ≤ ±2 cm, the correction scheme only includes the sensor data correction value; if the color deviation is > ±20 (e.g., leaves are yellowish, RGB values ​​deviate from the standard) or the length deviation is > ±2 cm (e.g., leaves are too short), the fertilizer concentration adjustment is set to ±5% (increase by 5% when fertilizer is insufficient, decrease by 5% when fertilizer is excessive), and the irrigation duration adjustment is set to ±10% (increase by 10% when water is insufficient, decrease by 10% when water is excessive).

[0102] The above embodiments make the judgment and correction of crop growth status more practical by quantifying parameters, and ensure that water and fertilizer adjustments are accurately matched to the actual needs of crops.

[0103] Specifically, when the water and fertilizer scheme generation module calculates the irrigation amount, it includes:

[0104] The water and fertilizer scheme generation module extracts soil moisture data from each soil layer, calculates the average surface soil moisture, average middle soil moisture, and average deep soil moisture, and presets the target moisture value for each soil layer.

[0105] Calculate the surface moisture difference between the average surface soil moisture value and the target surface soil moisture value, the middle soil moisture difference between the average middle soil moisture value and the target middle soil moisture value, and the deep soil moisture difference between the average deep soil moisture value and the target deep soil moisture value.

[0106] Based on the preset surface water weight coefficient, middle water weight coefficient, and deep water weight coefficient, the comprehensive irrigation demand is calculated. The comprehensive irrigation demand is the sum of the surface water difference multiplied by the surface water weight coefficient, the middle water difference multiplied by the middle water weight coefficient, and the deep water difference multiplied by the deep water weight coefficient.

[0107] Preset minimum irrigation demand threshold and maximum irrigation demand threshold:

[0108] When the total irrigation demand is less than or equal to the minimum irrigation demand threshold, it is determined that no irrigation is needed and the irrigation amount is set to zero.

[0109] When the total irrigation demand is greater than the minimum irrigation demand threshold and less than or equal to the maximum irrigation demand threshold, the irrigation amount is the total irrigation demand multiplied by the area of ​​the monitoring area.

[0110] When the total irrigation demand exceeds the maximum irrigation demand threshold, the irrigation amount is the maximum irrigation demand threshold multiplied by the area of ​​the monitored area, and the remaining unmet irrigation demand is included in the calculation of the next water and fertilizer plan.

[0111] Among them, the weight coefficients of surface water, middle water, and deep water are added together to equal one.

[0112] Specifically, the target moisture values ​​for each soil layer increase and decrease with depth: 25% (volume water content) for the surface layer (0-20cm), 22% for the middle layer (20-40cm), and 20% for the deep layer (40-60cm). The corresponding weighting coefficients are 0.3 for the surface layer, 0.5 for the middle layer (as this is the main water absorption area for crop roots), and 0.2 for the deep layer, totaling 1. The minimum irrigation demand threshold is set at 5% (volume water content), meaning no irrigation is needed when the overall irrigation demand is ≤5%. The maximum irrigation demand threshold is set at 20% to avoid excessive irrigation in a single instance. If the monitored area is 100 square meters, when the overall irrigation demand is 10%, the irrigation volume = 10% × 100 = 10 cubic meters; if the overall irrigation demand is 25% (exceeding the maximum threshold), the irrigation volume for this instance = 20% × 100 = 20 cubic meters, with the remaining 5% demand included in the next calculation.

[0113] The above embodiments quantify various parameters to make irrigation calculations more closely match the root water absorption patterns of plants and the water-holding characteristics of the soil, ensuring precise and appropriate irrigation.

[0114] Specifically, when setting the type and amount of fertilizer in the water and fertilizer solution generation module, it includes:

[0115] The water and fertilizer solution generation module extracts the nutrient requirement parameters corresponding to the crop growth stage based on the crop growth stage determination results. The nutrient requirement parameters include the nitrogen, phosphorus and potassium requirements.

[0116] Obtain the actual nitrogen, phosphorus, and potassium content in the soil as detected by the soil nutrient sensor;

[0117] Calculate the difference between the required nitrogen content and the actual nitrogen content, the difference between the required phosphorus content and the actual phosphorus content, and the difference between the required potassium content and the actual potassium content.

[0118] Preset nutrient sufficiency threshold range:

[0119] When the nitrogen difference is within the nitrogen sufficiency threshold range, the phosphorus difference is within the phosphorus sufficiency threshold range, and the potassium difference is within the potassium sufficiency threshold range, it is determined that no fertilization is required.

[0120] When any nutrient difference is greater than zero, the priority fertilizer type is determined according to the proportion of the absolute values ​​of each nutrient difference. The amount of fertilizer applied is the maximum value among the nutrient differences multiplied by the area of ​​the monitoring area and then multiplied by the nutrient conversion coefficient.

[0121] Specifically, if the crop growth period is determined to be the jointing stage of corn, the corresponding nutrient requirement parameters are set as follows: nitrogen requirement value 120 mg / kg, phosphorus requirement value 60 mg / kg, and potassium requirement value 80 mg / kg; the actual content detected by the soil nutrient sensor is set as the actual nitrogen content 80 mg / kg, the actual phosphorus content 50 mg / kg, and the actual potassium content 70 mg / kg.

[0122] Specifically, the nutrient difference is calculated as follows: nitrogen difference = 120 - 80 = 40 mg / kg, phosphorus difference = 60 - 50 = 10 mg / kg, and potassium difference = 80 - 70 = 10 mg / kg. Preset nutrient sufficiency threshold ranges are: nitrogen sufficiency threshold range is [-20 mg / kg, 0 mg / kg] (i.e., actual nitrogen content is considered sufficient if it is within 20 mg / kg higher than the required value), phosphorus sufficiency threshold range is [-15 mg / kg, 0 mg / kg], and potassium sufficiency threshold range is [-18 mg / kg, 0 mg / kg].

[0123] Specifically, since the differences in nitrogen, phosphorus, and potassium element values ​​are all greater than 0 (exceeding the sufficient range), and the absolute value of the nitrogen element difference (40 mg / kg) is the largest, nitrogen fertilizer is prioritized for application. The monitoring area is set at 1 mu (approximately 667㎡). Considering the actual utilization rate of chemical fertilizers (e.g., the utilization rate of urea nitrogen is approximately 30%-40%), the nutrient conversion coefficient is set at 0.8 (a correction coefficient that converts the soil nutrient difference into the actual amount of fertilizer required). The soil tillage layer thickness (e.g., 20cm = 0.2m) and soil bulk density (e.g., 1.2g / cm³ = 1200kg / m³) are also considered. The soil mass is calculated by "area × thickness × bulk density," and then multiplied by the nutrient difference and the conversion coefficient.

[0124] Soil mass = 667㎡ × 0.2m × 1200kg / m³ ≈ 160080kg;

[0125] Fertilizer application rate (nutrient requirement) = 40mg / kg × 160080kg × 0.8 = 5122560mg ≈ 5.12kg.

[0126] The above embodiments ensure that the type of fertilizer matches the needs of the growth period and the amount of fertilizer is precisely matched to the soil nutrient gap by quantifying parameters, so as to avoid nutrient waste or deficiency.

[0127] Specifically, when the water and fertilizer solution generation module adjusts the interval based on the average temperature, it includes:

[0128] The water and fertilizer scheme generation module extracts temperature data from meteorological collection points and calculates the average daily temperature of the monitored area.

[0129] A first temperature range, a second temperature range, and a third temperature range are preset, wherein the first temperature range is less than the second temperature range and the third temperature range;

[0130] When the average daily temperature is within the first temperature range, the fertilization and irrigation interval is set as the first fertilization and irrigation interval.

[0131] When the average daily temperature is within the second temperature range, the fertilization and irrigation interval is set as the second fertilization and irrigation interval.

[0132] When the average daily temperature is within the third temperature range, the fertilization and irrigation interval is set as the third fertilization and irrigation interval.

[0133] The first fertilization and irrigation interval is longer than the second fertilization and irrigation interval, which is longer than the third fertilization and irrigation interval. The interval adjustment needs to be combined with rainfall forecast data. If the rainfall in the next 24 hours is greater than the preset rainfall threshold, the fertilization and irrigation interval will be extended by the preset time.

[0134] Specifically, the first temperature range is set at 5℃-15℃ (low temperature range, when wheat grows slowly and water evaporation and nutrient consumption are low), the second temperature range is set at 15℃-25℃ (suitable temperature range, during the key growth stages of wheat such as jointing and booting, when metabolism is vigorous), and the third temperature range is set at 25℃-35℃ (high temperature range, around the grain-filling stage of wheat, when transpiration is strong and water and nutrient consumption is rapid).

[0135] Specifically, the corresponding fertilization and irrigation intervals are set as follows: the first fertilization and irrigation interval (suitable for low temperatures) is set to 7 days, the second fertilization and irrigation interval (suitable for moderate temperatures) is set to 5 days, and the third fertilization and irrigation interval (suitable for high temperatures) is set to 3 days, satisfying the logic of "first interval > second interval > third interval," which aligns with the growth pattern that crops require more water and fertilizer as temperatures rise. Simultaneously, a preset rainfall threshold of 10mm (i.e., moderate to heavy rainfall, which can effectively replenish soil moisture) is set. If the weather service indicates that the rainfall in the next 24 hours will be greater than 10mm, the current fertilization and irrigation interval will be extended by the preset duration of 2 days—for example, if the current temperature range is the second range (15℃-25℃), the original interval of 5 days will be extended to 7 days; if the current temperature range is the third range (25℃-35℃), the original interval of 3 days will be extended to 5 days.

[0136] The above embodiments quantify temperature ranges, interval durations, and rainfall thresholds to ensure that interval adjustments are adapted to crop growth rhythms while avoiding resource waste caused by repeated irrigation and fertilization after rain.

[0137] Specifically, when the operation execution module controls the flow rate and fertilizer concentration, it includes:

[0138] The control device obtains the preset target values ​​for fertilizer concentration and irrigation flow rate from the data storage node;

[0139] The current fertilizer concentration and irrigation flow rate are collected in real time through metering devices;

[0140] Calculate the concentration deviation between the current fertilizer concentration and the target fertilizer concentration, and the flow deviation between the current irrigation flow rate and the target irrigation flow rate;

[0141] Preset allowable deviation values ​​for concentration and flow rate:

[0142] When the concentration deviation exceeds the allowable concentration deviation value, adjust the valve opening of the fertilizer application pipe;

[0143] When the flow deviation exceeds the allowable flow deviation value, adjust the valve opening of the irrigation pipe.

[0144] Specifically, the target concentration for pre-fertilizer application is 3% (i.e., the percentage of fertilizer solution by mass in the total solution, applicable to topdressing concentrations for most crops), with an allowable concentration deviation of 0.3% (i.e., the deviation between the actual concentration and the target value must be controlled within ±0.3%); the target irrigation flow rate is set at 50 liters / minute (suitable for irrigation efficiency in medium-sized monitoring areas), with an allowable flow rate deviation of 5 liters / minute (i.e., the actual flow rate must be controlled within the range of 45-55 liters / minute).

[0145] Specifically, when the metering device detects that the current fertilizer concentration is 3.5% (concentration deviation = 3.5% - 3% = 0.5% > 0.3%), the control device reduces the opening of the fertilizer pipe valve (the opening is reduced by 2% for every 0.1% deviation); if the current irrigation flow rate is 62 liters / minute (flow rate deviation = 62 - 50 = 12 liters / minute > 5 liters / minute), the irrigation pipe valve opening is reduced (the opening is reduced by 1.5% for every 1 liter / minute deviation).

[0146] The above embodiments achieve precise closed-loop control of flow rate and concentration by quantifying target values, allowable deviations, and adjustment ranges, thus avoiding imbalances in water and fertilizer supply caused by fluctuations in equipment output.

[0147] Specifically, when the job execution module periodically records the device status, it includes:

[0148] The control device records the valve operating current, pipeline pressure, and metering device error at preset time intervals;

[0149] Preset the normal range of valve operating current, the normal range of pipeline pressure, and the allowable error value of the metering device;

[0150] When the valve operating current is within the normal current range, the pipeline pressure is within the normal pressure range, and the metering device error is less than or equal to the allowable error value, the equipment is judged to be in normal condition, and the equipment is marked as operating well in the data storage node.

[0151] When any parameter exceeds the corresponding normal range or allowable value, the device status is determined to be abnormal, the abnormality type is marked in the data storage node, and the system early warning mechanism is triggered.

[0152] Specifically, the preset recording interval is 30 minutes (balancing real-time performance and data storage efficiency); the normal range of valve operating current is set to 0.5A-2A (to adapt to the operating current characteristics of small and medium-sized solenoid valves); the normal range of pipeline pressure is set to 0.2MPa-0.6MPa (meeting the conventional pressure-bearing capacity of farmland irrigation pipelines); and the allowable error value of the metering device is set to ±2% (to meet the accuracy requirements of flow and concentration measurement).

[0153] Specifically, when the control device records a valve operating current of 1.2A (within 0.5A-2A), a pipeline pressure of 0.4MPa (within 0.2MPa-0.6MPa), and a metering device error of 1.5% (≤±2%), the equipment is considered to be in normal condition and marked as "operating well." If the valve operating current is 2.5A (exceeding the upper limit), it is marked as "valve current over-limit." If the pipeline pressure is 0.15MPa (below the lower limit), it is marked as "pipeline pressure insufficient." If the metering device error is 3% (exceeding the allowable value), it is marked as "metering error too large." All of the above abnormal situations trigger system warnings (such as audible and visual alarms or remote notifications) to ensure timely troubleshooting of equipment malfunctions.

[0154] Specifically, when the multi-source data acquisition module determines whether a crop is in its growth stage, it includes:

[0155] Image acquisition equipment acquires top-view and side-view images of crops and extracts plant height and leaf area index;

[0156] Preset crop growth period start threshold and growth period end threshold. The crop growth period start threshold includes the start plant height and start leaf area index, and the growth period end threshold includes the end plant height and end leaf area index.

[0157] When the crop plant height is greater than or equal to the initial plant height and the crop leaf area index is greater than or equal to the initial leaf area index, the crop is determined to have entered the growth period.

[0158] When the crop plant height is greater than or equal to the final plant height and the crop leaf area index is greater than or equal to the final leaf area index, the crop is determined to be in the vigorous growth period.

[0159] When the crop height decreases for two consecutive collection cycles compared to the previous collection cycle, and the crop leaf area index is less than the initial leaf area index, the crop is determined to have exited the growth period.

[0160] The crop growth period determination result is stored in the data storage node after being correlated with the image acquisition time.

[0161] Specifically, the preset image acquisition cycle is 7 days / time (balancing crop growth rate and data acquisition efficiency); in the crop growth period start threshold, the initial plant height is set to 30 cm (corresponding to the early jointing stage of wheat, when the plant height exceeds the creeping growth state of the tillering stage), and the initial leaf area index (LAI) is set to 1.0 (when leaves begin to densely cover the ground surface and photosynthesis is enhanced); in the growth period end threshold, the end plant height is set to 80 cm (corresponding to the grain filling stage of wheat, when the plant height reaches its peak), and the end leaf area index is set to 4.0 (when leaf growth is most vigorous and the leaf layer structure is most complex).

[0162] Specifically, when the wheat plant height extracted from the image is ≥30 cm and LAI ≥1.0, it is determined to have entered the growth period; when the plant height is ≥80 cm and LAI ≥4.0, it is determined to be in the vigorous growth period (such as the booting to grain filling stage); when the plant height continuously decreases within two consecutive collection cycles (14 days) (such as from 80 cm to 75 cm and then to 70 cm), and LAI <1.0 (such as decreasing to 0.8), it is determined to have exited the growth period (corresponding to the late maturity stage of wheat, when the leaves wither and fall off).

[0163] The above embodiments quantify the thresholds of plant height and leaf area index to ensure that the growth period is determined in accordance with the key nodes of wheat growth, providing a precise basis for the generation of water and fertilizer programs.

[0164] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0165] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0166] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0167] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0168] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A bidirectional fertilization and irrigation control system based on coupled modeling of water demand and fertilizer demand, characterized in that, include: A multi-source data acquisition module is used to divide monitoring areas according to the plot area. Soil monitoring points are evenly distributed in each monitoring area, and the soil monitoring points are divided into surface, middle and deep layers. Each layer is equipped with a moisture sensor, EC sensor and nutrient sensor to acquire soil data. Night lighting equipment and image acquisition equipment are also deployed above each monitoring area. The night lighting equipment and image acquisition equipment acquire crop top and side view images at intervals within a set time period to determine whether the crop is in the growth stage. Meteorological collection points are deployed around the plot according to density. Rain gauges and temperature sensors are installed at the meteorological collection points to acquire meteorological data and connect to meteorological services through a network interface. All devices in the multi-source data acquisition module are connected to the data storage node via wired or wireless means, and the data are labeled with the monitoring area number and the acquisition time. The water and fertilizer scheme generation module is used to extract the most recent soil data, crop growth period judgment results and meteorological data from the multi-source data acquisition module from the data storage node, calculate the irrigation amount based on the soil moisture difference, set the fertilizer type and amount based on the difference between soil nutrients and crop growth period requirements, adjust the interval based on the average temperature, generate a scheme containing irrigation duration, fertilizer concentration, execution order and no rainfall execution period, and store the scheme annotation information in the node. The operation execution module is used to lay irrigation pipes and fertilizer pipes in parallel in each monitoring area. The irrigation pipes and fertilizer pipes are respectively connected to valves and metering devices. The valves and metering devices are connected to a control device. The control device retrieves the plan from the storage node, starts the equipment according to the execution period, controls the flow rate and fertilizer concentration, and records the equipment status and transmits it to the storage node at regular intervals when running according to the plan. When the operation ends, the equipment is turned off and the time is marked. The data correction module is used to set up sample points in the monitoring area according to a set time and distribution after the operation, collect soil samples from each soil layer to measure soil moisture, and record crop leaf color and leaf length; transmit the collected data to the data storage node and compare it with the soil sensor data of the multi-source data acquisition module at the same time; generate a correction plan, mark the correction time, correction basis and associated initial plan number, and store it in the data storage node for the control device to call during the next operation; When the data correction module generates a correction scheme, it includes: The data correction module acquires crop leaf color parameters and leaf length, and presets standard color parameters and standard length. Calculate the color deviation and length deviation, and compare them with the standard color deviation threshold and standard length deviation threshold, respectively, to see if the crop growth status meets expectations. When both the color deviation and the length deviation are less than or equal to the standard color deviation threshold and the length deviation is less than or equal to the standard length deviation threshold, the crop growth status is determined to be in line with expectations, and the correction scheme only includes sensor data correction values. When the color deviation is greater than the standard color deviation threshold or the length deviation is greater than the standard length deviation threshold, the crop growth status is determined to be deviating from the expected value. In addition to the sensor data correction value, the correction scheme also includes the fertilizer concentration adjustment and irrigation duration adjustment.

2. The bidirectional fertilization and irrigation control system based on coupled water demand and fertilizer demand modeling according to claim 1, characterized in that, When the data correction module compares sensor data with sample data, it includes: The data correction module extracts the soil moisture data from the multi-source data acquisition module and the measured soil moisture data from the sample points, and calculates the moisture difference. A first moisture difference threshold, a second moisture difference threshold, and a third moisture difference threshold are preset, and the first moisture difference threshold is less than the second moisture difference threshold and less than the third moisture difference threshold; The data correction module compares the moisture difference with a preset threshold: When the moisture difference is less than or equal to the first moisture difference threshold, the sensor data is determined to be without correction, and the validity of the original soil data is maintained. When the soil moisture difference is greater than the first soil moisture difference threshold and less than or equal to the second soil moisture difference threshold, a first correction coefficient is generated to correct the soil sensor data. The corrected data is equal to the soil moisture data multiplied by the first correction coefficient. When the soil moisture difference is greater than the second soil moisture difference threshold and less than or equal to the third soil moisture difference threshold, a second correction coefficient is generated to correct the soil sensor data. The corrected data is equal to the soil moisture data multiplied by the second correction coefficient. When the soil moisture difference exceeds the third soil moisture difference threshold, a third correction coefficient is generated to correct the soil sensor data. The corrected data is equal to the soil moisture data multiplied by the third correction coefficient. Where the first correction coefficient is less than the second correction coefficient is less than the third correction coefficient, the corrected data is stored in the data storage node.

3. The bidirectional fertilization and irrigation control system based on coupled modeling of water demand and fertilizer demand as described in claim 1, characterized in that, When the water and fertilizer scheme generation module calculates the irrigation amount, it includes: The water and fertilizer scheme generation module extracts soil moisture data from each soil layer, calculates the average surface soil moisture, average middle soil moisture, and average deep soil moisture, and presets the target moisture value for each soil layer. Calculate the surface moisture difference between the average surface soil moisture value and the target surface soil moisture value, the middle soil moisture difference between the average middle soil moisture value and the target middle soil moisture value, and the deep soil moisture difference between the average deep soil moisture value and the target deep soil moisture value. The comprehensive irrigation demand is calculated based on the preset surface moisture weight coefficient, middle layer moisture weight coefficient, and deep layer moisture weight coefficient. The comprehensive irrigation demand is the sum of the surface moisture difference multiplied by the surface moisture weight coefficient, the middle layer moisture difference multiplied by the middle layer moisture weight coefficient, and the deep layer moisture difference multiplied by the deep layer moisture weight coefficient. Preset minimum irrigation demand threshold and maximum irrigation demand threshold: When the total irrigation demand is less than or equal to the minimum irrigation demand threshold, it is determined that no irrigation is needed and the irrigation amount is set to zero. When the total irrigation demand is greater than the minimum irrigation demand threshold and less than or equal to the maximum irrigation demand threshold, the irrigation amount is the total irrigation demand multiplied by the area of ​​the monitoring area. When the total irrigation demand exceeds the maximum irrigation demand threshold, the irrigation amount is the maximum irrigation demand threshold multiplied by the area of ​​the monitored area, and the remaining unmet irrigation demand is included in the calculation of the next water and fertilizer plan. The sum of the surface moisture weighting coefficient, the middle moisture weighting coefficient, and the deep moisture weighting coefficient is equal to one.

4. The bidirectional fertilization and irrigation control system based on coupled modeling of water demand and fertilizer demand as described in claim 3, is characterized in that... When setting the fertilizer type and dosage in the water and fertilizer program generation module, the following are included: The water and fertilizer scheme generation module extracts the nutrient requirement parameters corresponding to the crop growth stage based on the crop growth stage determination results. The nutrient requirement parameters include nitrogen, phosphorus and potassium requirements. Obtain the actual nitrogen, phosphorus, and potassium content in the soil as detected by the soil nutrient sensor; Calculate the difference between the required nitrogen content and the actual nitrogen content, the difference between the required phosphorus content and the actual phosphorus content, and the difference between the required potassium content and the actual potassium content. Preset nutrient sufficiency threshold range: When the nitrogen difference is within the nitrogen sufficiency threshold range, the phosphorus difference is within the phosphorus sufficiency threshold range, and the potassium difference is within the potassium sufficiency threshold range, it is determined that no fertilization is required. When any nutrient difference is greater than zero, the priority fertilizer type is determined according to the proportion of the absolute values ​​of each nutrient difference. The amount of fertilizer applied is the maximum value among the nutrient differences multiplied by the area of ​​the monitoring area and then multiplied by the nutrient conversion coefficient.

5. The bidirectional fertilization and irrigation control system based on coupled modeling of water demand and fertilizer demand as described in claim 4, characterized in that, When the water and fertilizer solution generation module adjusts the interval based on the average temperature, it includes: The water and fertilizer scheme generation module extracts temperature data from meteorological collection points and calculates the average daily temperature of the monitoring area. A first temperature range, a second temperature range, and a third temperature range are preset, wherein the first temperature range is less than the second temperature range and the third temperature range; When the average daily temperature is within the first temperature range, the fertilization and irrigation interval is set as the first fertilization and irrigation interval. When the average daily temperature is within the second temperature range, the fertilization and irrigation interval is set as the second fertilization and irrigation interval. When the average daily temperature is within the third temperature range, the fertilization and irrigation interval is set as the third fertilization and irrigation interval. The first fertilization and irrigation interval is longer than the second fertilization and irrigation interval, which is longer than the third fertilization and irrigation interval. The interval adjustment needs to be combined with rainfall forecast data. If the rainfall in the next 24 hours is greater than the preset rainfall threshold, the fertilization and irrigation interval will be extended by the preset time.

6. The bidirectional fertilization and irrigation control system based on coupled modeling of water demand and fertilizer demand as described in claim 5, characterized in that, When the operation execution module controls the flow rate and fertilizer concentration, it includes: The control device obtains preset target values ​​for fertilizer concentration and irrigation flow rate from the data storage node; The metering device collects the current fertilizer concentration and current irrigation flow rate in real time. Calculate the concentration deviation between the current fertilizer concentration and the target fertilizer concentration, and the flow deviation between the current irrigation flow rate and the target irrigation flow rate; Preset allowable deviation values ​​for concentration and flow rate: When the concentration deviation exceeds the allowable concentration deviation value, adjust the valve opening of the fertilizer application pipe; When the flow deviation exceeds the allowable flow deviation value, adjust the valve opening of the irrigation pipe.

7. The bidirectional fertilization and irrigation control system based on coupled modeling of water demand and fertilizer demand as described in claim 6, characterized in that, When the job execution module periodically records the device status, it includes: The control device records the valve operating current, pipeline pressure, and metering device error at preset time intervals. Preset the normal range of valve operating current, the normal range of pipeline pressure, and the allowable error value of the metering device; When the valve operating current is within the normal current range, the pipeline pressure is within the normal pressure range, and the metering device error is less than or equal to the allowable error value, the equipment is judged to be in normal condition, and the equipment is marked as operating well in the data storage node. When any parameter exceeds the corresponding normal range or allowable value, the device status is determined to be abnormal, the abnormality type is marked in the data storage node, and the system early warning mechanism is triggered.

8. The bidirectional fertilization and irrigation control system based on coupled modeling of water demand and fertilizer demand according to claim 7, characterized in that, When the multi-source data acquisition module determines whether a crop is in its growth stage, it includes: The image acquisition device acquires top-view and side-view images of the crop and extracts plant height and leaf area index. The crop growth period start threshold and growth period end threshold are preset. The crop growth period start threshold includes the start plant height and the start leaf area index. The growth period end threshold includes the end plant height and the end leaf area index. When the crop plant height is greater than or equal to the initial plant height and the crop leaf area index is greater than or equal to the initial leaf area index, the crop is determined to have entered the growth period. When the crop plant height is greater than or equal to the final plant height and the crop leaf area index is greater than or equal to the final leaf area index, the crop is determined to be in the vigorous growth period. When the crop plant height decreases compared to the previous collection cycle and continues for two collection cycles, and the crop leaf area index is less than the initial leaf area index, the crop is determined to have exited the growth period. The crop growth period determination result is stored in the data storage node after being correlated with the image acquisition time.

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