An integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium

Abstract

The present invention relates to the field of agricultural irrigation technology, and more specifically, to an integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium. The system comprises a fertilizer irrigation machine, which integrates a soil monitoring unit, a dynamic decision-making control unit, a water and fertilizer delivery execution unit, and a remote monitoring unit. The soil monitoring unit obtains key soil parameters in real time through a soil parameter sensor group, generates a comprehensive soil state index, and transmits it to the dynamic decision-making control unit. The dynamic decision-making control unit generates a precise irrigation and fertilization strategy based on the soil parameters, and transmits it to the water and fertilizer delivery execution unit. The water and fertilizer delivery execution unit is connected to a switching valve through a main irrigation pipeline, and the switching valve is respectively connected to a pulse irrigation branch and an injection branch. The pulse irrigation branch performs pulse irrigation on the surface soil, and the injection branch directly injects the selenium fertilizer solution into the root-intensive area. The present invention significantly improves the utilization rate of selenium fertilizer by dynamically regulating the irrigation mode, and provides efficient technical support for rapeseed cultivation.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural irrigation, in particular to an integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium. Background Art

[0002] Rapeseed is an important oil crop that is widely cultivated around the world, but it often faces the dual challenges of cadmium (Cd) pollution and selenium (Se) deficiency during its growth. This problem is particularly prominent in arid areas. Due to the low soil moisture and high pH value under drought conditions, selenium fertilizers (such as sodium selenite) are easily combined with calcium and iron ions to form insoluble compounds after application, resulting in low selenium fertilizer utilization (usually <20%) and difficulty in migrating to the crop root area. Existing technologies usually adopt a water-fertilizer separation mode, that is, water is provided through flooding or drip irrigation, and selenium fertilizer is supplemented by surface application or foliar spraying.

[0003] Although existing technologies attempt to solve the problem of selenium fertilizer supplementation through water-fertilizer separation (such as flooding or foliar spraying), there are still significant problems with the efficiency of selenium fertilizer migration. Specifically, selenium fertilizer applied on the surface is difficult to dissolve under drought conditions. Moreover, due to low soil moisture and high pH, ​​selenium fertilizer easily combines with cations such as calcium and iron to form insoluble compounds, causing selenium fertilizer to be retained in the surface soil (0-5 cm) and unable to effectively migrate to the main root distribution layer (15-30 cm). This results in low selenium fertilizer utilization (usually <20%), making it difficult to meet the nutritional needs of crops for selenium, while also exacerbating the waste of selenium fertilizer and soil immobilization problems. Summary of the Invention

[0004] The present invention provides an integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium. The system connects a switching valve via a main irrigation pipe, which is then connected to a pulse irrigation branch and an injection branch. The pulse irrigation branch applies pulse irrigation to the surface soil (0-15 cm), while the injection branch injects a selenium fertilizer solution directly into the root-dense area (15-30 cm). The system automatically switches between a pulse injection composite mode and a root-targeted injection mode based on soil moisture and selenium concentration, achieving efficient utilization of selenium fertilizer. This solves the problem raised in the background art, namely, the low utilization rate of selenium fertilizer in arid areas due to inefficient soil immobilization and migration.

[0005] To achieve the above objectives, the system includes a fertilizer irrigation machine, which integrates a soil monitoring unit and a water and fertilizer delivery execution unit. The soil monitoring unit obtains key soil parameters in real time, including cadmium and selenium content, temperature, humidity, and pH value. The system also includes a dynamic decision control unit, which generates a first decision, wherein:

[0006] Generate the first fertigation strategy based on temperature and pH;

[0007] The water and fertilizer delivery execution unit performs temperature compensation, corrects the selenium effectiveness score, and optimizes the irrigation period based on the first fertigation strategy to inhibit the adsorption and passivation of selenium fertilizer in the soil at high temperature and high pH value;

[0008] Generate precision fertigation strategies based on cadmium and selenium levels and moisture;

[0009] The fertilizer irrigation machine includes a main irrigation pipe, which is connected to a switching valve. The switching valve includes a rotary valve and an electromagnetic three-way valve. The rotary valve adjusts the opening and closing of the main passage, and the electromagnetic three-way valve distributes the mixed mode flow. The switching valve is respectively connected to a pulse irrigation branch and an injection branch.

[0010] The water and fertilizer delivery execution unit performs pulse irrigation on the surface soil through a pulse irrigation branch based on a precision irrigation and fertilization strategy, and performs a pulse injection composite mode and a root-targeted injection mode on the root-dense area through an injection branch, so as to migrate selenium fertilizer to the main distribution layer of the root system.

[0011] In the above technical solution, selenium fertilizer mainly penetrates into the root zone through the surface soil. However, due to low soil moisture and high pH, ​​selenium fertilizer easily combines with cations such as calcium and iron to form insoluble compounds, making it difficult for selenium fertilizer to migrate to the deep root zone (15-30 cm), affecting crop nutrient absorption and growth. The present invention generates a first fertigation strategy based on temperature and pH value to ensure that basic environmental conditions are suitable for the effective utilization of selenium fertilizer and the passivation of cadmium. Subsequently, a precision fertigation strategy is generated based on detailed parameters such as cadmium and selenium content and humidity. The dynamic decision control unit (700) uses a multi-objective optimization algorithm to determine the best irrigation mode, including pulse irrigation, root targeted injection and mixed mode, to balance the utilization rate of selenium fertilizer, cadmium passivation effect and water resource consumption. The main irrigation pipeline is equipped with a switching valve, which adopts a combination design of a rotary valve and an electromagnetic three-way valve. The rotary valve adjusts the opening and closing of the main passage to ensure the stability of the flow of the main irrigation pipeline; the electromagnetic three-way valve distributes the mixed mode flow to the pulse branch and the injection branch in a ratio of 7:3 in real time according to the instructions of the dynamic decision control unit, ensuring the coordinated operation of the pulse irrigation branch and the injection branch.

[0012] On this basis, a self-cleaning dripper is provided at the bottom of the pulse irrigation branch (300), and pulse irrigation is performed on the surface soil through the self-cleaning dripper to quickly increase the moisture of the surface soil and allow the selenium fertilizer to migrate to the root system.

[0013] In another technical solution, a micro pump and a retractable injection needle are provided at the bottom of the injection branch (400), and a pulse injection composite mode and a root-targeted injection mode are performed on the root-dense area through the micro pump and the retractable injection needle. The retractable injection needle head is integrated with an atomizing nozzle to accelerate the diffusion efficiency of selenium fertilizer in the rhizosphere soil.

[0014] This technical solution uses high-frequency pulse irrigation to quickly increase the moisture content of the surface soil, promoting the migration of selenium fertilizer to the root system. At the same time, through the precise positioning of the retractable injection needle and the diffusion effect of the atomizing nozzle, it ensures that the selenium fertilizer is directly delivered to the root-dense area, avoiding the problem of selenium fertilizer combining with cations such as calcium and iron in the surface soil to form insoluble compounds.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. Among the three injection methods used in the present invention, dynamic pulse irrigation, pulse injection composite mode, and root targeted injection, if only dynamic pulse irrigation and root targeted injection are used without the mixed mode, when the soil moisture and selenium concentration are insufficient at the same time, the system will fall into the dilemma of "water replenishment leading to selenium loss" or "selenium preservation and delayed water replenishment"; if only pulse irrigation and mixed mode are used without targeted injection, the selenium fertilizer in the low-selenium soil cannot bypass the surface oxide layer and reach the root system directly, and will still be ineffective due to soil adsorption; if only targeted injection and mixed mode are used without pulse irrigation, the accumulation of salt in the surface soil will hinder water infiltration, resulting in the inability to absorb the deeply injected selenium fertilizer. By effectively combining the three, the problem of difficult coordination among water management, selenium fertilizer supply and soil environment in traditional irrigation and fertilization is solved.

[0017] 2. The combined design of a rotary valve and a solenoid three-way valve significantly improves irrigation continuity and stability, unlike traditional single-valve control or independent valves for each branch. Specifically, the rotary valve controls the opening and closing of the main channel, ensuring smooth switching of the overall water flow; while the solenoid three-way valve precisely adjusts the flow ratio between different branches, enabling dynamic adjustment of surface irrigation (0-15 cm) and deep injection (15-30 cm). Compared to existing technologies, this combined design can more effectively respond to changes in crop growth needs, optimize the utilization efficiency of water resources and selenium fertilizer, and avoid resource waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall process structure of the present invention;

[0019] Figure 2 A schematic diagram of a soil monitoring unit process according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the flow of the water and fertilizer delivery execution unit according to an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the water and fertilizer flow streamlines according to an embodiment of the present invention;

[0022] Figure 5 A front view of a mechanical support structure according to an embodiment of the present invention;

[0023] Figure 6 Schematic diagram of the structure of a soil parameter sensor group according to an embodiment of the present invention.

[0024] The meaning of each number in the figure is:

[0025] 100, main irrigation pipeline; 200, switching valve; 2001, electromagnetic three-way valve; 2002, rotary valve; 300, pulse irrigation branch; 400, injection branch; 500, drip irrigation belt; 600, soil monitoring unit; 6001, electrochemical sensor; 6002, temperature and humidity sensor; 6003, pH sensor; 6004, stainless steel probe; 6005, support arm; 6006, slide rail; 700, dynamic decision control unit; 800, water and fertilizer delivery execution unit; 900, remote monitoring unit. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] At the same time, some technical terms are explained here:

[0028] LoRa (LongRange) is a low-power wide area network (LPWAN) communication technology suitable for long-distance, low-power IoT applications. Known for its long-distance transmission (up to 10 kilometers) and low power consumption, LoRa is suitable for farmland monitoring in remote areas.

[0029] like Figure 6 As shown in the figure, the surface soil refers to the soil in the area 0 to 5 cm below the upper soil layer;

[0030] RS485 is an industrial standard differential serial communication protocol that supports long-distance (≤1200 meters) and multi-device (≤32 nodes) half-duplex data transmission.

[0031] At present, the problem of selenium fertilizer not being able to effectively migrate to the main distribution layer of the root system, resulting in low utilization rate of selenium fertilizer in rapeseed cultivation in arid areas, is addressed. The present invention provides an integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium, aiming to improve the migration efficiency and utilization rate of selenium fertilizer through precise water-fertilizer integration technology. Figure 1 As shown, the core problem of low efficiency of selenium fertilizer migration in arid areas is solved by the coordinated work of the fertilizer irrigation machine and its integrated soil monitoring unit 600, dynamic decision control unit 700, water and fertilizer delivery execution unit 800 and remote monitoring unit 900.

[0032] See also Figure 2 As shown, the soil monitoring unit 600 is the data acquisition core of the fertilizer irrigation machine, through the soil parameter sensor group (see Figure 5 As shown, the electrochemical sensor 6001, the temperature and humidity sensor 6002, and the pH sensor 6003 work together to obtain key soil parameters (including cadmium and selenium content, temperature, humidity, and pH value) in real time. Figure 6 As shown, the electrochemical sensor 6001 uses a stainless steel probe 6004 and a waterproof package. The probe length is adjustable (0 to 30 cm) and can adapt to soil layer detection at different depths. It is mainly used to detect the cadmium (Cd) and selenium (Se) content in the root distribution layer (15 to 30 cm) with a detection accuracy of ±0.01 mg / kg. The temperature and humidity sensor 6002 has a built-in thermistor and a capacitive humidity probe, which achieves close contact with the soil through a spring expansion mechanism. The bottom of the sensor is also equipped with a stainless steel probe 6004, which monitors the soil moisture (accuracy ±2%) and temperature (accuracy ±0.5°C) in the 0 to 30 cm layer in real time. The pH sensor 6003 uses an integrated probe that integrates a glass electrode and a reference electrode. The surface is covered with an anti-corrosion coating and is used to measure the pH value of the surface soil with an accuracy of ±0.2. The wireless transmission node uses a unitized metal shell, a built-in solar power supply panel and a lightning protection circuit. It is responsible for encrypting the sensor data and transmitting it to the control center via LoRa. Figure 5 As shown, the soil parameter sensor group realizes precise positioning and dynamic monitoring of the soil parameter sensor group through a modular mechanical support structure. The mechanical support structure includes an adjustable support arm 6005 and a slide rail 6006. The slide rail 6006 is provided with an electrochemical sensor 6001, a temperature and humidity sensor 6002, and a pH sensor 6003 from the outside to the inside. The bottom of the electrochemical sensor 6001 and the temperature and humidity sensor 6002 are both provided with a stainless steel probe 6004. The support arm 6005 is made of carbon fiber and can be raised and lowered to adjust the depth of the sensor probe. The sensor can be moved on the slide rail 6006 to cover different monitoring points.

[0033] During operation, the electrochemical sensor 6001 detects the cadmium and selenium content; the temperature and humidity sensor 6002 collects humidity and temperature data; the pH sensor 6003 measures the pH of the surface soil. The collected raw data is subjected to noise filtering and temperature compensation by the built-in MCU, and then data fusion is performed to generate comprehensive soil status indicators (such as selenium effectiveness score and cadmium activity index). The calibrated comprehensive soil status indicators are packaged and sent to the dynamic decision control unit 700 via the wireless transmission node, with a transmission interval of no more than 5 minutes. Finally, the soil monitoring unit 600 outputs the calibrated comprehensive soil status indicators, including soil moisture (0-30cm layered data), cadmium / selenium content (root distribution layer, 15-30cm), pH value and temperature (surface soil, 0-5cm).

[0034] The dynamic decision control unit 700 generates a precise irrigation and fertilization strategy by receiving the comprehensive soil status indicators transmitted by the soil multi-parameter monitoring unit and combining it with the preset control logic and algorithm. It includes an embedded processor, data storage, a control signal output interface and a mechanical operation panel. The embedded processor adopts a high-performance ARM architecture and has built-in multi-threaded processing capabilities. The data storage uses a solid-state drive (SSD) to store historical data and model parameters, supporting fast reading and writing and data backup. The control signal output interface is connected to the actuator (rotary valve, electromagnetic three-way valve, etc.) via RS485 to ensure the stability and real-time performance of signal transmission. The mechanical operation panel adopts a waterproof and dustproof design, equipped with physical buttons and LCD display, and supports manual mode switching and parameter adjustment.

[0035] During operation, the dynamic decision control unit 700 first receives the calibration data transmitted by the soil multi-parameter monitoring unit, including soil moisture (0-30 cm layered data), cadmium / selenium content (root distribution layer, 15-30 cm), pH value and temperature (surface soil, 0-5 cm), and then the embedded processor further processes the data.

[0036] The embedded processor first performs temperature compensation on the cadmium / selenium data collected by the electrochemical sensor 6001. Based on real-time temperature data from the 0-30 cm layer (accuracy of ±0.5°C), the system applies a 0.5% offset to the selenium reading for every 1°C increase in temperature. Simultaneously, surface soil pH data from the pH sensor 6003 (0-5 cm, accuracy of ±0.2°C) is used to modify the selenium availability score. When the pH exceeds 7.5, the system automatically adjusts the selenium availability score downward by 20% and triggers a high-frequency pulse irrigation mode (7Hz) to enhance selenium migration in alkaline soils. When the pH falls below 6.0, an acidic soil optimization program is initiated, increasing the target selenium / cadmium ratio (Se / Cd) from 5 to 8 and increasing the selenium fertilizer injection rate by 20% to offset the selenium fixation effect of acidic soils. Temperature data is also used to optimize irrigation timing. When the surface temperature exceeds 30°C, the system automatically shifts irrigation to early morning or late evening to prevent water evaporation and selenium fertilizer decomposition caused by high temperatures.

[0037] The dynamic decision-making control unit 700 first generates a preliminary first fertigation strategy based on preliminary assessments of soil temperature and pH. This phase primarily ensures that basic environmental conditions are suitable for the effective utilization of selenium fertilizer and the deactivation of cadmium. Based on these initial conditions, the system can make preliminary adjustments, such as optimizing irrigation frequency or selecting appropriate irrigation time periods, to address the impact of varying environmental factors on crop growth.

[0038] Subsequently, the dynamic decision control unit 700 further runs a multi-objective optimization algorithm, taking into account more parameters, including soil moisture, selenium and cadmium content, etc., to refine the first fertigation strategy. The algorithm aims to balance the utilization rate of selenium fertilizer, the passivation effect of cadmium and water resource consumption, and determine the optimal irrigation mode (pulse irrigation, root targeted injection and mixed mode), irrigation frequency and water volume, and the specific application amount of selenium fertilizer and passivator. In this way, the system can not only adapt to different soil and crop conditions, but also ensure that every drop of water and every piece of fertilizer is used efficiently. Finally, the generated precision fertigation strategy is converted into an execution instruction through the control signal output interface and passed to the water and fertilizer delivery execution unit 800 for implementation.

[0039] The water and fertilizer delivery execution unit 800 is the core executive component of the fertilization and irrigation machine. It is responsible for achieving efficient delivery and precise control of selenium fertilizer and irrigation water according to the precise irrigation and fertilization strategy transmitted by the dynamic decision-making control unit 700. This unit receives the strategy transmitted by the dynamic decision-making control unit 700, including the irrigation mode (dynamic pulse irrigation, pulse injection combined mode, root-targeted injection), irrigation frequency and water volume, and the application amount of selenium fertilizer and passivation agent, and executes the corresponding operations according to the strategy.

[0040] See also Figure 3 、 Figure 4As shown, the fertilizer irrigation machine of the present invention connects a main irrigation pipe 100 to a switching valve 200, which in turn connects to a pulse irrigation branch 300 and an injection branch 400, respectively, through the switching valve 200, achieving efficient water and fertilizer delivery and precise control. The main irrigation pipe 100 is made of corrosion-resistant stainless steel with a smooth interior. The switching valve 200 controls the flow of water and fertilizer through a combination of a rotary valve 2002 and a solenoid three-way valve 2001. The rotary valve 2002 regulates the opening and closing of the main flow path, while the solenoid three-way valve 2001 distributes the flow in a mixed mode. The solenoid three-way valve 2001 opens and closes according to commands at a frequency of 5 Hz, driving the drip irrigation tape 500 to provide surface irrigation of 0 to 15 cm. The injection branch 400 uses a micropump to drive a retractable injection needle with an integrated atomizing nozzle. The injection depth is controlled by a stepper motor from 0 to 30 cm, and the injection frequency is 2 Hz. A root location sensor 6 is deployed near the injection needle, providing real-time feedback on the location of dense root areas through soil resistivity measurements.

[0041] When soil moisture is low (less than 40% field capacity), the system activates dynamic pulse irrigation mode. At this point, the water-fertilizer mixture enters the pulse irrigation branch 300 through the main irrigation pipe 100. The electromagnetic three-way valve 2001 controls the water flow with a 5Hz high-frequency pulse, with a single water volume of 0.1L, driving the self-cleaning drippers to perform surface irrigation (0-15cm). The high-frequency pulse water flow can quickly penetrate the selenium fertilizer solution into the root zone, while the backwash function prevents dripper clogging. This mode is suitable for the early stages of drought, quickly increasing surface soil moisture and promoting the migration of selenium fertilizer to the root system. In this state, the rotary valve 2002 remains fully open to ensure smooth water flow in the main irrigation pipe 100. At this time, the electromagnetic three-way valve 2001 completely closes the channel of the injection branch 400, directing all water and fertilizer flow to the pulse irrigation branch 300. This high-frequency pulse design can both quickly increase surface moisture and effectively prevent dripper clogging.

[0042] When soil moisture is moderate (40% to 70% field capacity) and selenium concentration is low (0.03 to 0.05 mg / kg), the system switches to pulse injection combined mode. At this point, the water-fertilizer mixture flows through the main irrigation pipe 100 and simultaneously enters the pulse irrigation branch 300 and injection branch 400. Pulse irrigation branch 300 delivers 0.3 L of water-fertilizer mixture at a 3 Hz frequency to the surface layer (0 to 15 cm), further replenishing the surface selenium fertilizer. Injection branch 400, using a micropump to drive a retractable injection needle, injects selenium fertilizer solution directly into the dense root zone (15 to 30 cm) at a 1 Hz frequency. In this state, rotary valve 2002 remains fully open, while the solenoid three-way valve (2001) intelligently distributes the flow in a 7:3 ratio: 70% of the flow enters pulse irrigation branch 300, delivering 0.3 L of water-fertilizer mixture at a 3 Hz frequency for surface irrigation; 30% of the flow enters injection branch 400. This mode combines surface pulses with deep injections, ensuring continuous penetration of surface selenium fertilizers while achieving precise supplementation of the root zone. It is suitable for growth periods with higher demands for selenium fertilizers.

[0043] When the soil moisture is moderate (40% to 70% field water holding capacity) and the selenium concentration is extremely low (<0.03 mg / kg), the system switches to the root-targeted injection mode. In this state, the rotary valve 2002 continues to remain fully open, and the electromagnetic three-way valve 2001 completely closes the pulse irrigation branch 300, concentrating all flows to the injection branch 400. At this time, the water-fertilizer mixture enters the injection branch 400 in full through the main irrigation pipe 100. The retractable injection needle automatically adjusts the telescopic depth (15 to 30 cm) according to the root density data fed back by the soil resistivity sensor, and injects 0.5 L / time of selenium fertilizer solution at a frequency of 2 Hz. The injection needle is integrated with an atomizing nozzle to further improve the diffusion efficiency of selenium fertilizer in the rhizosphere soil. This mode focuses on the precise supplementation of root-dense areas and is suitable for scenarios where the demand for selenium fertilizer is extremely high and the surface supplementation effect is limited.

[0044] Furthermore, the system dynamically adjusts its injection strategy based on real-time soil temperature and pH monitoring. When the root zone temperature exceeds 28°C, the injection frequency is automatically reduced from the standard 2Hz to 1Hz to minimize pyrolysis of the selenium solution, while the single injection volume is increased from 0.5L to 0.8L to maintain the total selenium fertilizer supply. Under low-temperature conditions (<15°C), the injection frequency is increased to 3Hz and the single injection volume is reduced to 0.3L to enhance the diffusion efficiency of the selenium fertilizer in cold soil. For abnormal pH values, when acidic soil (pH <6.0) is detected, the system increases the injection volume by 20% to overcome soil selenium fixation. Under alkaline conditions (pH >8.0), a deep injection mode is activated, adjusting the injection depth from the standard 15-30cm to 20-35cm to avoid the high-pH surface soil. These parameter adjustments are achieved through the micropump's PID control system and precise stepper motor positioning, ensuring that the optimal selenium-cadmium ratio (Se / Cd ≥ 5) is maintained under various environmental conditions. The atomizing nozzle integrated in the injection needle will automatically change the atomization particle size according to the adjusted flow rate. In the high-temperature and high-flow mode, large-particle atomization of 150μm is used to reduce drift, and in the low-temperature and high-frequency mode, it switches to fine mist of 80μm to enhance diffusion uniformity.

[0045] At the same time, the system achieves precise control of the selenium-cadmium ratio (Se / Cd≥5) by dynamically adjusting the amount of selenium fertilizer applied. When the cadmium activity index is ≥0.8, the injection branch 400 automatically increases the injection volume of selenium fertilizer by 20% (up to 0.6L / time), and suppresses the absorption of cadmium by increasing the effective concentration of selenium. In the pulsed coordinated injection mode, the system monitors the Se / Cd ratio in real time. If Se / Cd is detected to be less than 5, the injection frequency of selenium fertilizer in the root-dense area is increased (from 1Hz to 2Hz); in the root-targeted injection mode, the maximum injection volume (0.6L / time) is directly used to quickly increase the selenium concentration in the root zone. This dynamic control mechanism based on the selenium-cadmium ratio ensures the efficient utilization of selenium fertilizer and effectively controls the absorption of cadmium by rapeseed without the need for additional cadmium passivation agents.

[0046] In this embodiment, the mechanical structure achieves efficient functional coordination through modular design: the main irrigation pipe 100 and the switching valve 200 together constitute the water delivery center, while the pulse irrigation branch 300 and the injection branch 400 are optimized for surface penetration and deep targeted delivery respectively, ensuring that water and nutrients can accurately reach the areas required by the crop roots. In particular, the combined design of the rotary valve 2002 and the electromagnetic three-way valve 2001 plays a key role in this system. Compared with the traditional single valve or the method of independently setting valves for each branch, this combination not only simplifies the complexity of the system and reduces maintenance costs, but also can more flexibly and accurately control the direction and distribution ratio of water flow, thereby improving the utilization efficiency of water resources and fertilizers. In addition, the application of root positioning sensors further ensures execution accuracy, making the entire fertilization and irrigation process more intelligent and refined. All mechanical units are integrated with the signal line through rigid connections to form a compact and efficient fertilizer irrigation machine body, providing strong support for rapeseed growth.

[0047] Ultimately, the water and fertilizer delivery execution unit 800 executes the corresponding irrigation and fertilization operations according to the strategy of the dynamic decision control unit 700 and transmits the execution results (irrigation water volume, fertilizer application amount, and mode status) to the remote monitoring unit 900 via the control signal output interface. Through the design of the water and fertilizer delivery execution unit 800, the present invention achieves efficient utilization and precise delivery of selenium fertilizer, solving the core problem of low selenium fertilizer migration efficiency in arid areas.

[0048] The remote monitoring unit 900 is responsible for receiving the execution results (irrigation water volume, fertilizer application amount, and mode status) transmitted by the dynamic decision control unit 700 and optimizing system operation through data analysis and feedback. This unit is integrated into the control box of the fertilizer irrigation machine and includes a wireless transmission node, data storage, a remote communication module, and a mechanical operation panel. The wireless transmission node uses LoRa technology to encrypt the execution results and transmit them to the remote monitoring platform; the data storage uses a solid-state drive (SSD) to store historical data and model parameters; the remote communication module supports 4G / 5G networks to ensure real-time and stable data transmission; the mechanical operation panel is equipped with physical buttons and an LCD display, supporting manual mode switching and parameter adjustment.

[0049] During operation, the remote monitoring unit 900 first receives the execution results transmitted by the dynamic decision control unit 700, including data such as irrigation water volume, fertilizer application amount, and mode status. Subsequently, the built-in MCU analyzes the data and calculates the system operation efficiency and selenium fertilizer utilization rate using the following formula:

[0050]

[0051] Where η represents the system operation efficiency;

[0052] Q实际 Indicates the actual amount of irrigation water;

[0053] Q 理论 Indicates theoretical water absorption.

[0054]

[0055] Where U Se It indicates the utilization rate of selenium fertilizer;

[0056] S 吸收 Indicates the amount of selenium fertilizer absorbed by crops;

[0057] S 施用量 Indicates the amount of selenium fertilizer applied to the system.

[0058] Based on the analysis results, the remote monitoring unit 900 generates optimization recommendations (such as adjusting irrigation frequency and fertilizer application rate) and transmits these recommendations to the fertilization irrigation machine via a wireless transmission node. Simultaneously, a mechanical operation panel displays the current system status and optimization recommendations, supporting manual intervention and adjustments. Ultimately, through real-time data collection, analysis, and feedback, the remote monitoring unit 900 achieves intelligent management of the fertilization irrigation machine, significantly improving selenium fertilizer utilization and system operational efficiency.

[0059] In summary, through the mechanical design of the multi-mode linkage switching valve and the dynamic regulation of the system process, the present invention realizes the precise switching and flow distribution of three modes: dynamic pulse irrigation, pulse injection composite mode, and root targeted injection. It solves the problem of low utilization rate of selenium fertilizer in arid areas due to low soil immobilization and migration efficiency, and provides efficient and precise technical support for rapeseed cultivation.

[0060] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A rapeseed selenium and cadmium coordinated fertilization and irrigation integrated system, comprising a fertilization and irrigation machine, wherein the fertilization and irrigation machine integrates a soil monitoring unit (600) and a water and fertilizer delivery execution unit (800), wherein the soil monitoring unit (600) obtains key soil parameters in real time, wherein the key soil parameters include cadmium and selenium content, temperature, humidity, and pH value, and is characterized in that: It also includes a dynamic decision control unit (700), which generates a first decision, wherein: Generate the first fertigation strategy based on temperature and pH; Temperature compensation, revised selenium effectiveness scores, and optimized irrigation periods were performed based on the first fertigation strategy to inhibit the adsorption and passivation of selenium fertilizer in the soil at high temperatures and high pH values. Generate precision fertigation strategies based on cadmium and selenium levels and moisture; The fertilizer irrigation machine comprises a main irrigation pipe (100), wherein the main irrigation pipe (100) is connected to a pulse irrigation branch (300) and an injection branch (400). The water and fertilizer delivery execution unit (800) performs pulse irrigation on the surface soil through the pulse irrigation branch (300) based on the precision irrigation and fertilization strategy, and performs a pulse injection composite mode and a root-targeted injection mode on the root-intensive area through the injection branch (400), so as to migrate the selenium fertilizer to the main root distribution layer.

2. The integrated fertilization and irrigation system for rapeseed with selenium and cadmium coordinated regulation according to claim 1, characterized in that: The fertilizer irrigation machine is provided with a slide rail (6006), on which an electrochemical sensor (6001), a temperature and humidity sensor (6002) and a pH sensor (6003) are arranged in sequence from the outside to the inside, thereby obtaining key soil parameters in real time and generating a comprehensive soil status index.

3. The integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium according to claim 1, characterized in that: The soil monitoring unit (600) transmits the comprehensive soil state index to the dynamic decision control unit (700), prompting it to generate a precise irrigation and fertilization strategy.

4. The integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium according to claim 1, characterized in that: The dynamic decision control unit (700) is provided with an embedded processor, which receives temperature data and performs temperature compensation thereon, and receives surface soil pH data to correct the selenium effectiveness score.

5. The integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium according to claim 1, characterized in that: The dynamic decision control unit (700) uses a multi-objective optimization algorithm to balance selenium fertilizer utilization, cadmium passivation effect and water resource consumption, and transmits the precise irrigation and fertilization strategy to the water and fertilizer delivery execution unit (800).

6. The integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium according to claim 2, characterized in that: The bottom ends of the electrochemical sensor (6001) and the temperature and humidity sensor (6002) are both provided with stainless steel probes (6004) for detecting the cadmium and selenium content, temperature and humidity data in the soil at different depths.

7. The integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium according to claim 1, characterized in that: A self-cleaning dripper is provided at the bottom of the pulse irrigation branch (300), and pulse irrigation is performed on the surface soil through the self-cleaning dripper, so as to quickly increase the moisture of the surface soil and allow the selenium fertilizer to migrate to the root system.

8. The integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium according to claim 1, characterized in that: A micro pump and a retractable injection needle are provided at the bottom of the injection branch (400), and a pulse injection composite mode and a root targeted injection mode are performed in the root-dense area through the micro pump and the retractable injection needle. The retractable injection needle head is integrated with an atomizing nozzle to accelerate the diffusion efficiency of selenium fertilizer in the rhizosphere soil.

9. The integrated fertilization and irrigation system for rapeseed with coordinated regulation of selenium and cadmium according to claim 1, characterized in that: The main irrigation pipe (100) is connected to a switching valve (200), and the switching valve (200) includes a rotary valve (2002) and an electromagnetic three-way valve (2001). The rotary valve (2002) adjusts the opening and closing of the main passage, and the electromagnetic three-way valve (2001) distributes the mixed mode flow.

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