A method and system for seedling cultivation in a flower greenhouse

Abstract

This invention belongs to the field of flower seedling technology, and relates to a method and system for flower greenhouse seedling cultivation. The method collects real-time electrical conductivity signals from the rhizosphere layer of the seedling substrate and determines the standard deviation of signal fluctuation based on signal amplitude changes. A triggering logic is established by combining the instantaneous cumulative light intensity in the greenhouse with the standard deviation of signal fluctuation to determine the diffusion resistance surface of carbon dioxide waste gas generated on the seedling root surface. In response to the determination result, a nonlinear variable pressure pulse sequence controlled by the substrate moisture content drives saturated humid air to permeate into the substrate pores. Through interphase displacement, the carbon dioxide waste gas layer is stripped away and dissolved oxygen is replaced. This scheme captures the diffusion characteristics of the surface interface during peak metabolic periods, restoring the mass transfer pathway of oxygen and nutrient ions while maintaining substrate water potential stability and moisture balance. This effectively avoids water loss stress caused by ventilation intervention and improves the respiratory activity and uniformity of seedling propagation.

Description

Technical Field

[0001] This invention relates to a method and system for cultivating seedlings in a greenhouse for fresh flowers, belonging to the field of fresh flower seedling technology. Background Technology

[0002] Currently, the field of industrialized flower seedling production employs automated greenhouse control methods. These methods provide the basic conditions for seedling growth by regularly replenishing water, irrigating with nutrient solutions, and regulating environmental factors such as temperature and humidity. This mainstream seedling production method can maintain the basic survival of seedlings under standard operating conditions, and its core logic lies in achieving large-scale configuration of environmental factors. High-value-added flower varieties such as roses and orchids are highly sensitive to light and heat during their critical root development stages. During peak photosynthesis, the transpiration pull generated by the seedlings drives the roots to rapidly absorb water, resulting in a high-speed flow field of water within the micropores on the root hair surface. Influenced by capillary forces within the substrate pores, this flow induces capillary locking at the interface. The carbon dioxide waste gas produced by root respiration is restricted by this locking effect, making it difficult for it to diffuse into the substrate. This forms a waste gas film on the root surface, blocking the penetration path of dissolved oxygen and inhibiting the diffusion rate of nutrient molecules due to changes in local osmotic pressure. Existing technologies attempt to address this problem by increasing irrigation frequency or implementing high-flow ventilation.

[0003] However, increased irrigation often leads to the substrate moisture content exceeding the saturation limit, inducing rhizosphere suffocation, while high-volume ventilation causes the roots to lose water too quickly, causing physiological drought and mechanical stress damage to the root hair cell walls. These conventional methods cannot specifically eliminate surface diffusion barriers on the root surface while maintaining rhizosphere water potential balance. For example, Chinese invention patent application CN119969246A discloses an irrigation control method and system based on changes in the conductivity of rhizosphere nutrient solution. It adjusts irrigation actions by monitoring the absolute deviation between the conductivity of rhizosphere nutrient solution and the conductivity of irrigation nutrient solution. The control logic is anchored to the overall feedback of nutrient content in the rhizosphere environment. The low-frequency EC value deviation signal it relies on reflects the overall salt concentration change of the substrate. Under high metabolic conditions of crops, carbon dioxide lock-up at the rhizosphere interface is a millisecond-level surface physical dynamic evolution. Its impact on the EC signal is manifested as a change in the discrete characteristics of the signal rather than a drastic fluctuation in the overall mean. The triggering mechanism based solely on EC value deviation cannot identify the physiological asphyxiation state induced by capillary lock-up. The activated irrigation action increases the thickness of the interfacial liquid film and exacerbates the physical lock-up of carbon dioxide, resulting in a mechanistic mismatch between the control logic and the physiological needs of the plant.

[0004] Therefore, the technical problem to be solved by this invention is how to accurately identify and eliminate diffusion barriers at the root surface under high metabolic conditions, and ensure root respiration activity while maintaining stable substrate water potential. Summary of the Invention

[0005] To address the problems in the background art, the technical solution of the present invention is as follows: A method for cultivating seedlings in a flower greenhouse, comprising: Step 101: Using the nutrient parameter acquisition unit arranged in the rhizosphere layer of the seedling substrate, the real-time signal of substrate conductivity is acquired at a frequency of 5Hz to 10Hz, and the standard deviation of signal fluctuation characterizing the ion mass transfer resistance is calculated based on the signal amplitude change of adjacent sampling points. Step 102: Real-time acquisition of instantaneous cumulative light intensity in the greenhouse, and introduction of signal fluctuation standard deviation and instantaneous cumulative light intensity into the rhizosphere gas replacement trigger logic; when the instantaneous cumulative light intensity is higher than 800 Lux·h and the signal fluctuation standard deviation is lower than the preset stability threshold for 60s, it is determined that a gas diffusion resistance surface composed of a high-concentration carbon dioxide waste gas layer is generated on the root surface of the flower seedlings. Step 103: In response to the determination result of the gas diffusion resistance surface, saturated humid air is driven to penetrate into the pores of the seedling substrate through a nonlinear variable pressure pulse sequence. The output pressure of the saturated humid air is superimposed on the initial pressure of 0.04 MPa, and its pulse amplitude is controlled by the real-time moisture content of the seedling substrate and is inversely proportional to the real-time moisture content. By utilizing the interphase displacement effect between the saturated humid air and the pore water of the substrate, the high-concentration carbon dioxide waste gas layer is stripped off by periodic shear force and dissolved oxygen replacement is completed.

[0006] Preferably, step 101 specifically includes: step 1011, simultaneously acquiring multi-channel real-time matrix conductivity signals through multiple electrolyte sensing probes embedded in the seedling substrate and distributed in an equally spaced array; step 1012, performing noise reduction processing on the real-time matrix conductivity signals, and calculating the standard deviation of the processed sampling points within the sliding sampling window as the signal fluctuation standard deviation, which is used to characterize the degree of surface disturbance of the electrolyte movement rate in the pores of the seedling substrate.

[0007] Preferably, in step 102, the rhizosphere gas replacement triggering logic is established as follows: the instantaneous cumulative light intensity is defined as a positive variable that drives the increase of root physiological oxygen demand, and the standard deviation of signal fluctuation is defined as a negative variable that reflects the interface mass transfer efficiency; when the instantaneous cumulative light intensity exceeds the photosynthetic metabolism threshold and the standard deviation of signal fluctuation shows a downward trend induced by gas lock-in, it is determined that the seedling substrate has entered a state of physiological asphyxiation.

[0008] Preferably, in step 103, the saturated humid air is generated by an ultrasonic generator, and its relative humidity is maintained in the range of 95% to 99% to maintain the root surface water potential stable when stripping the high-concentration carbon dioxide exhaust gas layer and to avoid root water loss damage caused by dry air ventilation.

[0009] Preferably, the pulse frequency of the nonlinear variable pressure pulse sequence is 0.1Hz to 1.0Hz. Through the periodic fluctuation of pressure in the micropores of the seedling substrate, kinetic energy is generated to destroy the surface tension of the waste gas membrane, thereby realizing the emission of waste gas into the greenhouse atmosphere.

[0010] Preferably, the method for raising seedlings in a flower greenhouse also includes: step 104, monitoring the recovery slope of the standard deviation of the signal fluctuation after being treated with saturated humid air replacement, and when the recovery slope reaches the equilibrium threshold, stopping the output of saturated humid air and starting the nutrient solution supply system to improve the nutrient ion absorption efficiency by utilizing the mass transfer path after gas removal.

[0011] Preferably, the instantaneous cumulative light intensity is acquired by a photonic quantum sensor, and its sampling period is synchronized with the signal acquisition period in step 101 to ensure that the energy input and physiological response are matched in temporal logic.

[0012] Preferably, the seedling substrate includes peat, perlite and vermiculite in a volume ratio of 3:1:1, and the total porosity of the seedling substrate is 65% to 75%, which is used to provide a physical medium for the transmission of pressure waves of saturated humid air.

[0013] Preferably, during the determination process, the stability threshold is dynamically corrected by acquiring the deviation characteristics of real-time ambient temperature and light intensity to compensate for signal judgment deviation caused by sensor temperature drift.

[0014] A seedling cultivation system for a flower greenhouse, comprising: The nutrient parameter acquisition unit includes multiple electrolyte sensing probes embedded in the seedling substrate and arranged in an equally spaced array, which are used to simultaneously acquire real-time signals of substrate conductivity from multiple channels. The light environment monitoring unit includes a light quantum sensor for acquiring the instantaneous cumulative light quantity synchronized with the sampling period of the real-time matrix conductivity signal; The signal processing and determination module is used to receive the real-time matrix conductivity signal at a frequency of 5Hz to 10Hz and calculate the standard deviation of signal fluctuation within a sliding sampling window. The signal processing and determination module is also used to execute the rhizosphere gas replacement trigger logic. When the instantaneous cumulative light intensity is higher than 800 Lux·h and the standard deviation of signal fluctuation is lower than the preset stability threshold for 60s, it determines that a gas diffusion resistance surface composed of a high-concentration carbon dioxide exhaust gas layer is generated and outputs a replacement trigger signal. The gas replacement execution module includes an ultrasonic generator and a variable pressure drive assembly. The ultrasonic generator generates saturated humid air with a relative humidity of 95% to 99%. In response to a replacement trigger signal, the gas replacement execution module outputs a nonlinear variable pressure pulse sequence with a frequency of 0.1 Hz to 1.0 Hz through the variable pressure drive assembly, driving the saturated humid air to permeate into the pores of the seedling substrate. The initial pressure reference of the nonlinear variable pressure pulse sequence is 0.04 MPa, and the pulse amplitude is controlled by and inversely proportional to the real-time moisture content of the seedling substrate. The collaborative liquid supply module includes a nutrient solution supply system; the signal processing and judgment module is also used to monitor the recovery slope of the standard deviation of the signal fluctuation after saturated humid air replacement treatment, and to control the start of the nutrient solution supply system when the recovery slope reaches the equilibrium threshold.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. In the seedling cultivation of flowers in greenhouses, by monitoring the characteristic dispersion fluctuation of the substrate conductivity signal, the diffusion barrier of the surface interface formed by the seedling during the peak metabolic period is captured. By utilizing the immiscible flow characteristics of saturated humid air and substrate pore water, a phase displacement effect is generated, which physically peels off the carbon dioxide waste gas film attached to the surface of the root hairs, restores the mass transfer pathway of oxygen and nutrient ions, and enables the root system to maintain respiration without changing the overall physical structure of the substrate.

[0016] 2. The nonlinear variable pressure sequence drives the output of saturated humid air. The pressure pulse generates periodic interfacial shear force in the micropores of the matrix, realizing in-situ emission of exhaust gas and in-situ exchange of dissolved oxygen. At the same time, the saturated humid air maintains a constant water potential on the root surface, avoiding the microenvironment water loss stress caused by traditional dry air ventilation, and maintaining the water balance of high-value seedlings during the peak of physiological metabolism.

[0017] 3. By combining the characteristics of light accumulation and signal dispersion, a coupled judgment logic is constructed to accurately identify the surface interface locking state induced by high-speed water absorption, triggering a targeted phase displacement execution procedure. This avoids the blind irrigation caused by the inability of traditional control schemes to distinguish between environmental hypoxia and physiological interface blockage, reduces the risk of secondary root suffocation caused by excessive substrate moisture, and improves the uniformity of seedling development during factory propagation. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the overall process of rhizosphere gas replacement and synergistic liquid supply for fresh flower seedling cultivation according to the present invention. Figure 2 This is a state transition diagram for determining and triggering the diffusion resistance at the root interface in this invention.

[0019] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0021] A method for cultivating seedlings in a flower greenhouse includes: Step 101: Using the nutrient parameter acquisition unit arranged in the rhizosphere layer of the seedling substrate, the real-time signal of substrate conductivity is acquired at a frequency of 5Hz to 10Hz, and the standard deviation of signal fluctuation characterizing the ion mass transfer resistance is calculated based on the signal amplitude change of adjacent sampling points. Step 102: Real-time acquisition of instantaneous cumulative light intensity in the greenhouse, and introduction of signal fluctuation standard deviation and instantaneous cumulative light intensity into the rhizosphere gas replacement trigger logic; when the instantaneous cumulative light intensity is higher than 800 Lux·h and the signal fluctuation standard deviation is lower than the preset stability threshold for 60s, it is determined that a gas diffusion resistance surface composed of a high-concentration carbon dioxide waste gas layer is generated on the root surface of the flower seedlings. Step 103: In response to the determination result of the gas diffusion resistance surface, saturated humid air is driven to penetrate into the pores of the seedling substrate through a nonlinear variable pressure pulse sequence. The output pressure of the saturated humid air is superimposed on the initial pressure of 0.04 MPa, and its pulse amplitude is controlled by the real-time moisture content of the seedling substrate and is inversely proportional to the real-time moisture content. By utilizing the interphase displacement effect between the saturated humid air and the pore water of the substrate, the high-concentration carbon dioxide waste gas layer is stripped off by periodic shear force and dissolved oxygen replacement is completed.

[0022] Preferably, step 101 specifically includes: step 1011, simultaneously acquiring multi-channel real-time matrix conductivity signals through multiple electrolyte sensing probes embedded in the seedling substrate and distributed in an equally spaced array; step 1012, performing noise reduction processing on the real-time matrix conductivity signals, and calculating the standard deviation of the processed sampling points within the sliding sampling window as the signal fluctuation standard deviation, which is used to characterize the degree of surface disturbance of the electrolyte movement rate in the pores of the seedling substrate.

[0023] Preferably, in step 102, the rhizosphere gas replacement triggering logic is established as follows: the instantaneous cumulative light intensity is defined as a positive variable that drives the increase of root physiological oxygen demand, and the standard deviation of signal fluctuation is defined as a negative variable that reflects the interface mass transfer efficiency; when the instantaneous cumulative light intensity exceeds the photosynthetic metabolism threshold and the standard deviation of signal fluctuation shows a downward trend induced by gas lock-in, it is determined that the seedling substrate has entered a state of physiological asphyxiation.

[0024] Preferably, in step 103, the saturated humid air is generated by an ultrasonic generator, and its relative humidity is maintained in the range of 95% to 99% to maintain the root surface water potential stable when stripping the high-concentration carbon dioxide exhaust gas layer and to avoid root water loss damage caused by dry air ventilation.

[0025] Preferably, the pulse frequency of the nonlinear variable pressure pulse sequence is 0.1Hz to 1.0Hz. Through the periodic fluctuation of pressure in the micropores of the seedling substrate, kinetic energy is generated to destroy the surface tension of the waste gas membrane, thereby realizing the emission of waste gas into the greenhouse atmosphere.

[0026] Preferably, the method for raising seedlings in a flower greenhouse also includes: step 104, monitoring the recovery slope of the standard deviation of the signal fluctuation after being treated with saturated humid air replacement, and when the recovery slope reaches the equilibrium threshold, stopping the output of saturated humid air and starting the nutrient solution supply system to improve the nutrient ion absorption efficiency by utilizing the mass transfer path after gas removal.

[0027] Preferably, the instantaneous cumulative light intensity is acquired by a photonic quantum sensor, and its sampling period is synchronized with the signal acquisition period in step 101 to ensure that the energy input and physiological response are matched in temporal logic.

[0028] Preferably, the seedling substrate includes peat, perlite and vermiculite in a volume ratio of 3:1:1, and the total porosity of the seedling substrate is 65% to 75%, which is used to provide a physical medium for the transmission of pressure waves of saturated humid air.

[0029] Preferably, during the determination process, the stability threshold is dynamically corrected by acquiring the deviation characteristics of real-time ambient temperature and light intensity to compensate for signal judgment deviation caused by sensor temperature drift.

[0030] A flower greenhouse seedling cultivation system includes: The nutrient parameter acquisition unit includes multiple electrolyte sensing probes embedded in the seedling substrate and arranged in an equally spaced array, which are used to simultaneously acquire real-time signals of substrate conductivity from multiple channels. The light environment monitoring unit includes a light quantum sensor for acquiring the instantaneous cumulative light quantity synchronized with the sampling period of the real-time matrix conductivity signal; The signal processing and determination module is used to receive the real-time matrix conductivity signal at a frequency of 5Hz to 10Hz and calculate the standard deviation of signal fluctuation within a sliding sampling window. The signal processing and determination module is also used to execute the rhizosphere gas replacement trigger logic. When the instantaneous cumulative light intensity is higher than 800 Lux·h and the standard deviation of signal fluctuation is lower than the preset stability threshold for 60s, it determines that a gas diffusion resistance surface composed of a high-concentration carbon dioxide exhaust gas layer is generated and outputs a replacement trigger signal. The gas replacement execution module includes an ultrasonic generator and a variable pressure drive assembly. The ultrasonic generator generates saturated humid air with a relative humidity of 95% to 99%. In response to a replacement trigger signal, the gas replacement execution module outputs a nonlinear variable pressure pulse sequence with a frequency of 0.1 Hz to 1.0 Hz through the variable pressure drive assembly, driving the saturated humid air to permeate into the pores of the seedling substrate. The initial pressure reference of the nonlinear variable pressure pulse sequence is 0.04 MPa, and the pulse amplitude is controlled by and inversely proportional to the real-time moisture content of the seedling substrate. The collaborative liquid supply module includes a nutrient solution supply system; the signal processing and judgment module is also used to monitor the recovery slope of the standard deviation of the signal fluctuation after saturated humid air replacement treatment, and to control the start of the nutrient solution supply system when the recovery slope reaches the equilibrium threshold.

[0031] Example 1: In an intelligent multi-span greenhouse environment for the mass cultivation of high-value Phalaenopsis orchid seedlings, the system faces the condition of fluctuating strong light intensity during midday in spring, due to the instantaneous accumulation of light... When the concentration reaches over 1200 Lux·h, the transpiration of the seedling canopy is enhanced by radiation, and the roots perform high-speed water absorption to compensate for water loss from the leaves. This leads to a significant increase in the standard deviation of the real-time substrate conductivity signal collected by the nutrient parameter acquisition units located in the rhizosphere of the seedling substrate. It exhibits nonlinear contraction and remains below a preset stability threshold for 60 seconds. This smoothing characteristic of signal fluctuations indicates capillary locking within the micron-sized pores on the surface of seedling root hairs. This prevents the diffusion of carbon dioxide generated by root respiration and metabolism, forming a layer of carbon dioxide waste gas. This interfacial diffusion resistance surface physically isolates the penetration path of dissolved oxygen and alters the electrolyte diffusion coefficient at the local interface. This results in the seedlings being in a state of physiological asphyxiation in a mixed substrate of peat, perlite, and vermiculite with sufficient overall oxygen content, leading to technical problems such as root-to-stem ratio imbalance and limited growth uniformity. The standard deviation of the real-time substrate conductivity signal is also relevant. The physical mechanism by which this sensor can characterize surface interface closure lies in the following: Under high-frequency sampling of 5Hz to 10Hz, the conductivity sensor acquires not only the overall average ion concentration of the matrix pore water, but also the transient signals of surface electrical properties generated by random perturbations along the ion migration path. When the seedling is in a high metabolic state and carbon dioxide closure has not occurred, the capillary pores on the root surface are in a fully liquid-connected state. The ion convection and collision induced by transpiration pull generate high-frequency signal discrete outliers, which are manifested as a large standard deviation. However, once the root hair surface is covered by a carbon dioxide waste gas film, the local interface changes from a conductive liquid phase to an insulating gas phase. The ion mass transfer path is physically isolated or narrowed, resulting in a drastic compression of the space for random perturbations in charge migration. This physical evolution from a turbulent state to a laminar or static state is reflected in the convergence of the signal fluctuation amplitude at the sensor output, which is manifested as a standard deviation. It experienced a precipitous drop and remained at a low level.

[0032] In response to the determination of the gas diffusion resistance surface, the system implements an interphase displacement procedure. The current nutrient solution irrigation program is interrupted via the coordinated liquid supply module to prevent an increase in the interfacial liquid film thickness. Saturated humid air with a relative humidity maintained between 95% and 99% is generated by an ultrasonic generator. A nonlinear variable pressure pulse sequence with a frequency of 0.1Hz to 1.0Hz is output from the variable pressure drive component to drive the saturated humid air to permeate into the pores of the seedling substrate. This process utilizes the immiscible flow characteristics between the saturated humid air and the substrate pore water, and its output pressure... Follow the formula below: ,in, To output pressure, in actual execution, a nonlinear variable pressure pulse sequence overcomes the viscous fingering effect in heterogeneous porous media through periodic pressure changes. Due to the uneven pore distribution of peat and perlite matrices, constant pressure airflow often only forms channels through large pores and cannot reach the rhizosphere micropores. This invention utilizes variable pressure pulses of 0.1Hz to 1.0Hz to generate inertial wave energy. On the pressure rising edge, it drives saturated moist air to overcome the capillary entry pressure threshold and be forced into the micropores. On the pressure falling edge, the original capillary rebound force of the matrix causes instantaneous shear displacement of the liquid film. This periodic reciprocating compression generates a disturbance mechanical wave at the gas-liquid interface, allowing the saturated moist air to uniformly cover the rhizosphere region through an unsteady wavefront propulsion mode, like a gas plug piston, rather than penetrating along a single path. This achieves physical stripping of the carbon dioxide waste gas layer on the surface of the entire root hair. The initial pressure reference is set to 0.04 MPa; The amplitude of the pulse is inversely proportional to the real-time moisture content of the seedling substrate. ω is the angular frequency, which corresponds to the frequency of the nonlinear transformer pulse sequence; When the high-humidity gaseous medium is output, the gas replacement execution module reads the current instantaneous absolute pressure of the variable pressure drive component, activates the pre-enthalpy temperature rise compensation procedure, and calculates the theoretical cooling range of throttling expansion by combining the Joule-Thomson coefficient of the humid air with the absolute ambient pressure difference. The heating wire set on the periphery of the gas pipeline is instructed to apply a matching heat flux to the injected gas flow. The thermodynamic boundary compensation action counteracts the phenomenon of dew point phase change downward caused by the high-pressure saturated humid air squeezing into the pores and expanding with the pulse pressure drop, inhibits the condensation and precipitation of water vapor inside the granular microstructure, and maintains the physical stripping property of saturated humid air as a gas plug piston. This periodic micro-pressure pulse generates interfacial shear force in the matrix micropores, and replaces the original position of carbon dioxide microbubbles attached to the root hair surface with a high dissolved oxygen phase through physical interphase displacement. Moreover, since saturated humid air is used as the displacement medium, mechanical stress damage to the root hair cell wall caused by the fluctuation of rhizosphere water potential is avoided in the ventilation process.

[0033] After 180 seconds of continuous inverse pulse adjustment, the signal processing and judgment module monitored the standard deviation of the signal fluctuation after the permutation process. When the recovery slope reaches the equilibrium threshold, the mass transfer pathway at the rhizosphere interface is physically reconstructed and diffusion barriers are eliminated. The system then restores the nutrient solution supply system and utilizes the diffusion channels after gas removal to improve the absorption efficiency of nutrient ions. The final production statistics show that the root-to-stem ratio of seedlings increased by 17%, seedling etiolation was controlled, the development cycle was shortened by 4 days, and the survival rate after transplanting increased by 4.2%. This scheme achieves a breakthrough in the mass transfer limit of the root interface without changing the physical structure of the matrix by coupling environmental parameters with interface mass transfer characteristics, and converts the respiration pressure during the peak metabolic period into a driving force for improved growth performance.

[0034] Example 2: The experimental platform is currently deployed in an intelligent multi-span greenhouse containing Phalaenopsis orchid seedlings. The seedling substrate is a mixture of peat, perlite, and vermiculite in a mass ratio of 3:1:1. The experimental platform includes an electrolyte sensing probe with a measurement range of 0 mS / cm to 20 mS / cm and a measurement accuracy of 0.05 mS / cm, combined with a data acquisition module with a sampling frequency set to 10 Hz to acquire real-time signals of substrate conductivity. The sampling frequency is set to balance capturing the transient characteristics of liquid phase disturbances within micropores with suppressing high-frequency random noise in the signal. Since the evolution period of rhizosphere gas diffusion rate is typically on the order of seconds, the sampling period is set to 100 ms to ensure that the signal fluctuation characteristics can be restored according to the Nyquist sampling theorem without generating redundant computational load. During the experiment, a signal-to-noise ratio of 22 dB is superimposed on the data stream. Gaussian white noise was used to simulate the mechanical vibration interference generated by the operation of the irrigation pump. A control group and an experimental group were set up for comparison. The control group adopted a periodic venting method, while the experimental group adopted a nonlinear variable pressure pulse drive scheme for saturated humid air. When acquiring the real-time signal of substrate conductivity, the nutrient parameter acquisition unit outputs a bipolar AC square wave with a fundamental frequency of 1kHz as the measurement excitation source. The electrochemical polarization accumulation phenomenon at the probe metal interface is suppressed by a high-frequency reverse alternating electric field. The system simultaneously acquires the mass moisture content of the seedling substrate and executes a multivariable physical state decoupling procedure. When the mass moisture content value is within the liquid phase mass transfer range of 65% to 75% and the standard deviation of the signal fluctuation shows a step-like contraction characteristic, the signal processing and judgment module outputs the carbon dioxide gas phase lock-in judgment result. The ion mobility decrease disturbance caused by the overall moisture depletion of the substrate is removed at the logic layer.

[0035] Under conditions where strong light radiation continuously accumulates to 850 Lux·h, the raw values ​​of the real-time matrix conductivity signal were monitored to exhibit high-frequency, slight fluctuations between 1.25 mS / cm and 1.32 mS / cm. The standard deviation of the signal fluctuation was calculated. The initial baseline value was 2.15; as the seedling metabolic intensity increased, the standard deviation of signal fluctuation increased. The pressure decreased from 2.15 to 0.48 within 60 seconds, indicating that the movement of electrolytes was hindered due to carbon dioxide lock-in at the rhizosphere interface. The system introduced saturated humid air with a relative humidity of 98% into the experimental group and drove a nonlinear pressure pulse. The initial pressure reference was... Set to 0.04 MPa, depending on the pressure amplitude As the output pressure increases, the gas displacement within the matrix pores exhibits a non-linear growth trend; The standard deviation of signal fluctuation is between 0.04 MPa and 0.08 MPa. The recovery slope increases from 0.02 / s to 0.15 / s, and the interfacial shear force generated in this range overcomes capillary locking and strips off the carbon dioxide exhaust gas layer.

[0036] When pulse amplitude Increase output pressure When the pressure exceeds 0.12 MPa, the standard deviation of signal fluctuation... The recovery rate tended to saturate, and the microscopic characterization of the in vitro samples showed physical folds in the root hair cell walls induced by micromechanical impact, confirming that excessive driving pressure caused mechanical stress damage; the standard deviation of signal fluctuation in the experimental group At the end of the replacement treatment, the root respiration activity index recovered to 1.98, which was 12.6% higher than that of the control group using traditional dry air ventilation, and the matrix water potential fluctuation was maintained within a steady state range of less than 0.05 MPa. This data confirms that by using saturated humid air as the displacing phase in combination with nonlinear pressure swing control logic, the interfacial diffusion resistance surface during the peak metabolic period can be eliminated without disrupting the matrix water balance, thereby achieving a physical transformation of the rhizosphere environment from a suffocated state to a mass transfer state.

[0037] Example 3: In a smart plant factory with a 1500-square-meter Phalaenopsis orchid seedling propagation area, the system implements a parameter calibration procedure for the physical properties of the seedling substrate for different production batches to determine the judgment criteria; this procedure determines the stability threshold. The values ​​are determined as follows: During the seedling dormancy stage when greenhouse light intensity is below 200 Lux, the data acquisition module continuously collects real-time matrix conductivity signals for 30 minutes, obtains the background noise fluctuation amplitude sequence of the signal under natural diffusion conditions, and calculates the mean standard deviation of the sequence; the system identifies 1.2 times this mean as the stability threshold of the rhizosphere environment for this batch of seedlings. This eliminates the influence of different matrix ratios on interfacial mass transfer determination; the stability threshold of a certain batch of peat matrix was experimentally determined. The value is 0.35, which serves as the quantitative benchmark for the system to judge gas-locking action. The initial state definition procedure quantifies the physical background fluctuation boundary when the substrate is in a dormant period and there is no pore water seepage. During the normal metabolic active period, the transpiration pull of the plant drives the substrate water to form capillary jets in the micropores, carrying free ions and generating violent local potential transitions. The measured signal fluctuation standard deviation is maintained in the high-frequency discrete range above 2.0. When the micropores of the root epidermis are completely occupied by carbon dioxide microbubbles generated by metabolism and form an insulating gas-locking layer, the cross-sectional area of ​​the conductive liquid phase in the local pores is drastically reduced. The physical collision phenomenon of ions caused by fluid drag is isolated by interfacial tension, causing the surface dispersion of the substrate conductivity signal to drop sharply and approach the stability threshold. The signal processing and determination module relies on the convergence of eigenvectors to define the boundary of the surface resistance surface.

[0038] Response to instantaneous cumulative light intensity in the greenhouse Reaching 1050 Lux·h and signal fluctuation standard deviation Trigger preset stability threshold Based on the judgment result, the system adjusts the output state of the transformer drive component through the following compensation method: the nutrient parameter acquisition unit acquires the mass moisture content of the seedling substrate in real time. The pulse amplitude is calculated according to the following linear compensation formula. : It should be noted that the linear compensation formula used here is essentially a local linear approximation of the physical trend that the pulse amplitude is inversely proportional to the moisture content within the suitable moisture content range for seedling cultivation (65% to 75%). In actual control, as the moisture content... As the water film thins, the gas permeation resistance increases non-linearly. According to the inverse logic requirement, the pulse intensity is increased to maintain the displacement kinetic energy. Within this specific operating range, by setting a compensation coefficient k=0.002, this linear relationship can accurately map the slope of the inverse trend, thus simplifying the computational load of the real-time controller. Simultaneously, it ensures the control objective of a monotonically increasing pulse amplitude as moisture decreases, conforming to the technical essence of inverse drive. To calculate the pulse amplitude, This is the pressure compensation coefficient, with a value of 0.002. This represents the current percentage of saturated moisture content in the seedling substrate. The percentage of moisture content in the mass is monitored in real time. The base pulse amplitude is set to 0.015 MPa. This logic enables the system to automatically increase the pulse amplitude to maintain interfacial shear force and achieve the stripping of the carbon dioxide exhaust layer when the moisture content of the seedling substrate is high and the water film resistance in the micropores is large. The variable pressure drive component outputs a sinusoidal pressure pulse with a frequency of 0.5 Hz according to the calculation results, driving saturated humid air into the rhizosphere layer, so that the local oxygen partial pressure increases from the asphyxiated state of 2 kPa to more than 18 kPa.

[0039] The system monitors the standard deviation of signal fluctuations. The recovery trend is used to dynamically block the phase-to-phase displacement procedure. When the signal processing and judgment module detects the standard deviation of signal fluctuations... When the real-time growth rate exceeds 0.1 / s for three consecutive sampling cycles, the root surface water-air exchange channel is determined to have completed reconstruction. The system automatically issues a liquid supply recovery command, and the liquid supply module restarts the micro-sprinkler system within 15 seconds after the gas replacement ends. The low-resistance path generated by the gas replacement guides the ions in the nutrient solution to migrate directionally to the root surface. The final comparative data shows that the relative chlorophyll content of the seedling leaves using this adaptive adjustment scheme increased by 14.5%, and there was no structural collapse phenomenon in the seedling substrate due to pressure overload. This scheme eliminates the influence of environmental fluctuations on control accuracy by calibrating the judgment threshold on-site and compensating for the execution parameters in real time, and transforms the physicochemical evolution process of the rhizosphere interface into a definite sensor feedback action.

[0040] Example 4: In a seedling substrate environment using a mixture of peat and perlite at a mass ratio of 4:1, the system initiates a pre-processing physical resistance calibration program. Under no-load conditions, a constant flow of dry air is injected into the seedling substrate. The nutrient parameter acquisition unit collects the real-time pressure loss as the airflow penetrates the substrate layers, and converts this resistance characteristic value into an initial pressure benchmark. The system adjusts the step size; the system maintains the seedling substrate at saturated moisture content. Repeat the airflow injection action under the condition and record the standard deviation of signal fluctuation. The critical pressure at which a nonlinear shift occurs from the steady-state point; the system identifies 0.85 times this critical pressure value as the upper limit of the operating pressure of the variable-pressure drive component, thereby establishing the component-level pressure safety boundary for matrices with different physical properties when interphase displacement is initiated. At the end of the interphase displacement process, the signal processing and judgment module detects the standard deviation of signal fluctuations. If the background noise level recovers to within 1.1 times the initial mean, and this state lasts for more than 30 seconds, the reset criterion is consistent with the trigger threshold. The two layers form a 0.1 standard deviation ladder, which avoids frequent start-stop of the control actuator due to drastic phase changes at the interface by physical hysteresis. The seedling substrate after the carbon dioxide waste gas layer in the rhizosphere is removed is thus restored to the preset stable electrolyte diffusion state.

[0041] In cultivation conditions aimed at strengthening the root system of high-density rose seedlings, the system is based on the equivalent median pore diameter of the seedling substrate. Dynamically adjust the excitation parameters and excitation frequency of the ultrasonic generator. The value of follows the following physical mapping relationship: ,in, The excitation frequency of the ultrasonic generator. The surface tension of the matrix liquid phase; The density of the liquid; The target droplet diameter; this procedure is based on the detected median pore diameter of the peat matrix. When the value is 45μm, the excitation frequency is automatically adjusted. To generate median diameter The 12μm fine droplets allow saturated humid air to push the liquid film forward as an air plug when entering the matrix pores. This physical matching logic between the droplet diameter and the pore size ensures that the gas can penetrate the interfacial resistance surface and complete the in-situ displacement of the root surface while maintaining a low pressure of 0.05MPa.

[0042] Example 5: In a factory-scale deployment scenario for Phalaenopsis orchid seedling cultivation using coconut coir substrate with high porosity fluctuation characteristics, the system implements a substrate mechanical response calibration procedure to determine the initial pressure baseline. The procedure includes measuring the mass of a unit volume of seedling substrate in a completely dry state. Deionized water was injected into the seedling substrate until no more water seeped in, in order to determine the saturated moisture content. And the standard deviation of signal fluctuation is detected using a linear step pressure signal. The critical pressure value at which a nonlinear abrupt change occurs; where, For drying quality, This represents the percentage of saturated moisture content. The standard deviation of signal fluctuation; the system records the standard deviation of signal fluctuation. The ratio between the increment and the pressure increment, and the initial pressure reference. The pressure is locked at 1.15 times the critical pressure value, thereby driving the energy generated by the interphase displacement action to overcome the interfacial tension and protect the matrix microstructure.

[0043] Under continuous system operation, to address the particle size shift in saturated humid air caused by physical losses or changes in ambient temperature in the ultrasonic generator, a closed-loop frequency tuning procedure is implemented to maintain the stability of the phase distribution. This procedure determines the mechanical resonant frequency of the transducer by monitoring the amplitude of the feedback current of the ultrasonic power supply. The system performs phase compensation on the drive frequency based on temperature variables fed back from the ambient temperature sensor, ensuring that the generated saturated humid air particle size is within the range of 10μm to 15μm. Measurement data shows that after 500 hours of continuous operation, the system's pre-test program reduces the standard deviation of signal fluctuations. The baseline offset was controlled within 5% of the initial calibration value, the rhizosphere carbon dioxide replacement efficiency was maintained above 92%, and the coefficient of variation of seedling population development was reduced from 0.12 to below 0.04. This procedure eliminated the impact of hardware loss on process precision by converting and compensating for physical feedback signals, and achieved physical alignment of the seedling environment control logic under different production batches of substrate.

[0044] The system has a built-in time constant when executing the phase displacement procedure. The safety interlocking logic under constraints is used to address signal fluctuations caused by random electromagnetic interference encountered in the sensor sampling channel. To protect the physiological safety of seedlings in the event of non-realistic offsets, the logic sets the upper limit of the single continuous working time of the transformer drive component to τ=300s. If the signal processing and judgment module fails to obtain the recovery criterion that meets the balance threshold within this time window, the system automatically cuts off the output of saturated humid air and drives the cooperative liquid supply module to perform compensatory spraying at 50% of the rated flow rate. This logic procedure based on hard truncation in the time domain eliminates the risk of excessive substrate aeration caused by the interruption of the signal feedback link, and keeps the seedling development variation coefficient within 0.05 when the system encounters complex electromagnetic interference, thus achieving deterministic control over the physical evolution limit of the seedling process.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for cultivating seedlings in a flower greenhouse, characterized in that, include: Step 101: Using the nutrient parameter acquisition unit arranged in the rhizosphere layer of the seedling substrate, the real-time signal of substrate conductivity is acquired at a frequency of 5Hz to 10Hz, and the standard deviation of signal fluctuation characterizing the ion mass transfer resistance is calculated based on the signal amplitude change of adjacent sampling points. Step 102: Real-time acquisition of instantaneous cumulative light intensity in the greenhouse, and introduction of signal fluctuation standard deviation and instantaneous cumulative light intensity into the rhizosphere gas replacement trigger logic; when the instantaneous cumulative light intensity is higher than 800 Lux·h and the signal fluctuation standard deviation is lower than the preset stability threshold for 60s, it is determined that a gas diffusion resistance surface composed of a high-concentration carbon dioxide waste gas layer is generated on the root surface of the flower seedlings. Step 103: In response to the determination result of the gas diffusion resistance surface, saturated humid air is driven to penetrate into the pores of the seedling substrate through a nonlinear variable pressure pulse sequence. The output pressure of the saturated humid air is superimposed on the initial pressure of 0.04 MPa, and its pulse amplitude is controlled by the real-time moisture content of the seedling substrate and is inversely proportional to the real-time moisture content. By utilizing the interphase displacement effect between the saturated humid air and the pore water of the substrate, the high-concentration carbon dioxide waste gas layer is stripped off by periodic shear force and dissolved oxygen replacement is completed.

2. The method for raising seedlings in a greenhouse for fresh flowers according to claim 1, characterized in that, Step 101 specifically includes: Step 1011, simultaneously acquiring multi-channel real-time matrix conductivity signals by using multiple electrolyte sensing probes embedded in the seedling substrate and arranged in an equally spaced array; Step 1012, performing noise reduction processing on the real-time matrix conductivity signals, and calculating the standard deviation of the processed sampling points within the sliding sampling window as the signal fluctuation standard deviation, which is used to characterize the degree of surface disturbance of the electrolyte movement rate in the pores of the seedling substrate.

3. The method for raising seedlings in a greenhouse for fresh flowers according to claim 1, characterized in that, In step 102, the rhizosphere gas replacement triggering logic is established as follows: instantaneous cumulative light intensity is defined as a positive variable that drives the increase of root physiological oxygen demand, and the standard deviation of signal fluctuation is defined as a negative variable that reflects the interface mass transfer efficiency; when the instantaneous cumulative light intensity exceeds the photosynthetic metabolism threshold and the standard deviation of signal fluctuation shows a downward trend induced by gas lock-in, it is determined that the seedling substrate has entered a state of physiological asphyxiation.

4. The method for raising seedlings in a greenhouse for fresh flowers according to claim 1, characterized in that, In step 103, saturated humid air is generated by an ultrasonic generator, and its relative humidity is maintained in the range of 95% to 99%. This is used to maintain the root surface water potential stable when stripping the high-concentration carbon dioxide exhaust gas layer and to avoid root water loss damage caused by dry air ventilation.

5. The method for raising seedlings in a greenhouse for fresh flowers according to claim 1, characterized in that, The nonlinear variable pressure pulse sequence has a pulse frequency of 0.1Hz to 1.0Hz. Through the periodic fluctuation of pressure in the micropores of the seedling substrate, it generates kinetic energy to break the surface tension of the waste gas film, thereby realizing the emission of waste gas into the greenhouse atmosphere.

6. The method for raising seedlings in a greenhouse for fresh flowers according to claim 1, characterized in that, The method for raising seedlings in a flower greenhouse also includes: Step 104, monitoring the standard deviation recovery slope of the signal fluctuation after saturated humid air replacement treatment. When the recovery slope reaches the equilibrium threshold, the output of saturated humid air is stopped, and the nutrient solution supply system is turned on to improve the nutrient ion absorption efficiency by utilizing the mass transfer path after gas removal.

7. The method for raising seedlings in a greenhouse for fresh flowers according to claim 1, characterized in that, The instantaneous cumulative light intensity is acquired by a photonic quantum sensor, and its sampling period is synchronized with the signal acquisition period in step 101 to ensure that the energy input and physiological response are matched in temporal logic.

8. The method for raising seedlings in a greenhouse for fresh flowers according to claim 1, characterized in that, The seedling substrate consists of peat, perlite, and vermiculite in a volume ratio of 3:1:

1. The total porosity of the seedling substrate is 65% to 75%, which is used to provide a physical medium for the transmission of pressure waves from saturated humid air.

9. The method for raising seedlings in a greenhouse for fresh flowers according to claim 1, characterized in that, During the determination process, the stability threshold is dynamically corrected by acquiring the deviation characteristics of real-time ambient temperature and light intensity to compensate for signal judgment deviation caused by sensor temperature drift.

10. A greenhouse seedling cultivation system for fresh flowers, used to implement the greenhouse seedling cultivation method for fresh flowers as described in claim 1, characterized in that, include: The nutrient parameter acquisition unit includes multiple electrolyte sensing probes embedded in the seedling substrate and arranged in an equally spaced array, which are used to simultaneously acquire real-time signals of substrate conductivity from multiple channels. The light environment monitoring unit includes a light quantum sensor for acquiring the instantaneous cumulative light quantity synchronized with the sampling period of the real-time matrix conductivity signal; The signal processing and determination module is used to receive the real-time matrix conductivity signal at a frequency of 5Hz to 10Hz and calculate the standard deviation of signal fluctuation within a sliding sampling window. The signal processing and determination module is also used to execute the rhizosphere gas replacement trigger logic. When the instantaneous cumulative light intensity is higher than 800 Lux·h and the standard deviation of signal fluctuation is lower than the preset stability threshold for 60s, it determines that a gas diffusion resistance surface composed of a high-concentration carbon dioxide exhaust gas layer is generated and outputs a replacement trigger signal. The gas replacement execution module includes an ultrasonic generator and a variable pressure drive assembly. The ultrasonic generator generates saturated humid air with a relative humidity of 95% to 99%. In response to a replacement trigger signal, the gas replacement execution module outputs a nonlinear variable pressure pulse sequence with a frequency of 0.1 Hz to 1.0 Hz through the variable pressure drive assembly, driving the saturated humid air to permeate into the pores of the seedling substrate. The initial pressure reference of the nonlinear variable pressure pulse sequence is 0.04 MPa, and the pulse amplitude is controlled by and inversely proportional to the real-time moisture content of the seedling substrate. The collaborative liquid supply module includes a nutrient solution supply system; the signal processing and judgment module is also used to monitor the recovery slope of the standard deviation of the signal fluctuation after saturated humid air replacement treatment, and to control the start of the nutrient solution supply system when the recovery slope reaches the equilibrium threshold.

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