Greenhouse water regulation methods and systems based on the root zone-plant-atmosphere system

Abstract

This application discloses a greenhouse water control method and system based on the root zone-plant-atmosphere system. The method includes: acquiring soil water potential, plant water potential, air temperature, and relative humidity information in real time through an information acquisition module; calculating atmospheric water potential based on the acquired air temperature and relative humidity; calculating transpiration pull and water supply power based on the atmospheric water potential, plant water potential, and soil water potential; determining the stomatal aperture of the greenhouse plant based on the ratio of transpiration pull to water supply power; and issuing control commands based on the stomatal aperture and the ratio of transpiration pull to water supply power to achieve water control of the greenhouse plant. The method adopted in this application is simple and efficient. By comprehensively controlling water based on the relative relationship between water supply power and transpiration pull, it can maintain the water supply and demand balance of the root zone-plant-atmosphere system, effectively reduce evaporation and conserve energy, and improve crop photosynthetic capacity, yield, and water use efficiency.

Description

Technical Field

[0001] This invention relates to the field of environmental control technology in facility horticulture, specifically to a greenhouse water control method and system based on the root zone-plant-atmosphere system. Background Technology

[0002] Water is an indispensable resource for plant growth. Reasonable water management can not only meet the physiological needs of crops, but also improve their disease resistance and yield.

[0003] Currently, traditional greenhouse water management often relies solely on irrigation based on soil moisture conditions to ensure sufficient water supply. However, this neglects the interactive influence of various elements within the soil-plant-atmosphere continuum. Greenhouses are mostly relatively enclosed spaces where large amounts of heat easily accumulate. Since atmospheric evaporation within greenhouses often far exceeds the water absorption capacity of crop roots, even with sufficient moisture in the root zone, plants are prone to water stress and photosynthetic inhibition, leading to reduced yields. Plant drought stress is not only caused by soil moisture deficit; the high intensity of atmospheric evaporation resulting in a "supply and demand imbalance" of water is also a significant factor contributing to plant drought stress.

[0004] Therefore, how to comprehensively regulate plants based on the relative relationship between root zone moisture and atmospheric evaporation intensity is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, this application proposes the following technical solution:

[0006] In a first aspect, embodiments of this application provide a greenhouse water regulation method based on a root zone-plant-atmosphere system, including:

[0007] The information acquisition module acquires information on soil water potential, plant water potential, air temperature, and relative humidity in real time.

[0008] The atmospheric water potential is calculated based on the obtained air temperature and relative humidity.

[0009] The transpiration pull and water supply power are calculated using atmospheric water potential, plant water potential, and soil water potential, respectively.

[0010] The stomatal opening of greenhouse plants is determined based on the ratio of transpiration pull to water supply force.

[0011] Control commands are issued based on the ratio of stomatal opening and transpiration pull to water supply force of the greenhouse plants to achieve water regulation of the greenhouse plants.

[0012] In one possible implementation, the formula for calculating atmospheric water potential based on the obtained air temperature and relative humidity is as follows:

[0013]

[0014] Among them, V w Let T be the partial molar volume of water, R be the gas constant, and T be the partial molar volume of water. k RH represents the absolute temperature of the air and the relative humidity of the air.

[0015] In one possible implementation, the formulas for calculating transpiration pull and water supply dynamics using atmospheric water potential, plant water potential, and soil water potential are as follows:

[0016]

[0017] in, These are soil water potential, plant water potential, and atmospheric water potential, respectively.

[0018] In one possible implementation, the formula for determining the stomatal aperture of greenhouse plants based on the ratio of transpiration pull to water supply force is as follows:

[0019]

[0020] Where g is the current stomatal conductance of the plant, g max For maximum porosity, g / g max Δ represents the stomatal opening, and Δ represents the ratio of transpiration pull to water supply force.

[0021] In one possible implementation, water regulation of the greenhouse plants is achieved by issuing control commands based on the ratio of stomatal opening and transpiration pull to water supply force, including:

[0022] Determine the stomatal opening of greenhouse plants;

[0023] When the ratio of stomatal opening of greenhouse plants is greater than or equal to the preset value, the plant's water status is suitable and the water supply and demand are balanced.

[0024] When the ratio of stomatal opening to volume in greenhouse plants is less than a preset value, the plants experience water stress.

[0025] The water supply and demand relationship is determined by the ratio of transpiration pull to water supply power, thereby enabling water regulation of greenhouse plants.

[0026] In one possible implementation, the determination of water supply and demand based on the ratio of transpiration pull to water supply force to achieve water regulation for greenhouse plants includes:

[0027] When the ratio of transpiration pull to water supply force exceeds the critical value of plant water deficit, the cause of drought in the root zone of the plant is determined.

[0028] If the drought in the root zone of the plant is due to excessive transpiration pull, then spray humidification should be implemented;

[0029] If the drought in the root zone of the plant is a root zone water-limiting drought, then root zone irrigation should be implemented;

[0030] If the drought in the plant's root zone is a root zone water-transpiration pull-limiting drought, then root zone irrigation and misting humidification should be carried out simultaneously.

[0031] Secondly, embodiments of this application provide a greenhouse water control system based on a root zone-plant-atmosphere system, including: a water integrated management decision module and an information acquisition module and a water control module electrically connected to the water integrated management decision module;

[0032] The integrated water management decision module calculates the ratio of transpiration pull to water supply force and stomatal aperture based on the soil water potential, plant water potential, air temperature and relative humidity information collected by the information collection module.

[0033] The water regulation module regulates the water supply of greenhouse plants based on the stomatal opening and the ratio of transpiration pull to water supply power calculated by the water integrated management decision module.

[0034] In one possible implementation, the information acquisition module includes a soil water potential sensor, an air temperature sensor, an air relative humidity sensor, and a plant water potential sensor; the soil water potential sensor is used to acquire the water potential of the soil; the air temperature sensor and the air relative humidity sensor acquire the air temperature and relative humidity in real time, respectively; and the plant water potential sensor is used to acquire the water potential of the plant.

[0035] In one possible implementation, the integrated water management decision module controls a solenoid valve via a relay connection. The solenoid valve is electrically connected to the water control module, which includes a root zone irrigation submodule and an air humidification submodule.

[0036] In one possible implementation, it further includes: a power supply module and an input / output module, both of which are electrically connected to the integrated water management decision module. The integrated water management decision module is a microcontroller, and the input / output module includes a keyboard and a display.

[0037] Compared with the prior art, the beneficial effects of this application are as follows:

[0038] The method used in this application is simple and efficient. It comprehensively regulates water based on the relative relationship between the root zone-plant water supply dynamics and the plant-atmosphere transpiration pull, which can maintain the water supply and demand balance of the root zone-plant-atmosphere system, effectively reduce evaporation and save water, and improve crop photosynthetic capacity, yield and water use efficiency.

[0039] The integrated decision-making system for greenhouse root zone and atmospheric moisture provided in this application uses a microcontroller as a data processing and control platform. It performs feedback control based on plant moisture status and drought causes, and coordinates the regulation of root zone and atmospheric moisture to maintain a dynamic balance of "root water absorption - plant water transport - atmospheric evaporation demand", so that the plant is in a suitable moisture state. Attached Figure Description

[0040] Figure 1 A schematic flowchart illustrating a greenhouse water regulation method based on a root zone-plant-atmosphere system provided in this application embodiment;

[0041] Figure 2 A general block diagram of a greenhouse water regulation method based on a root zone-plant-atmosphere system provided in this application embodiment;

[0042] Figure 3 A graph showing the relationship between stomatal opening and transpiration pull / water supply power ratio in tomatoes, provided in an embodiment of this application;

[0043] Figure 4 This is a schematic diagram of a greenhouse water control system based on the root zone-plant-atmosphere system, provided as an embodiment of this application. Detailed Implementation

[0044] The present solution will now be described in conjunction with the accompanying drawings and specific embodiments.

[0045] Figure 1 A flowchart illustrating a greenhouse water regulation method based on a root zone-plant-atmosphere system provided in this application embodiment is shown below. Figure 1 and Figure 2 This embodiment of a greenhouse water regulation method based on a root zone-plant-atmosphere system includes:

[0046] S101 acquires information on soil water potential, plant water potential, air temperature, and relative humidity in real time through an information acquisition module.

[0047] In this embodiment, the information acquisition module acquires soil water potential, plant water potential, air temperature and relative humidity in real time every 1 minute, and the acquired data is transmitted to the water integrated management decision module via a data cable.

[0048] S102, calculate the atmospheric water potential based on the obtained air temperature and relative humidity.

[0049] In this embodiment, the formula for calculating atmospheric water potential based on the obtained air temperature and relative humidity is as follows:

[0050]

[0051] Among them, V w Let be the partial molar volume of water, with a value of 0.018 × 10⁻⁶. -3 m -3 mol -1 R is the gas constant, with a value of 8.31 Pa·m. -3 ·mol -1 ·°K, T k RH represents the absolute temperature of the air and the relative humidity of the air.

[0052] S103, the transpiration pull and water supply power are calculated using the atmospheric water potential, plant water potential and soil water potential, respectively.

[0053] In this embodiment, the formulas for calculating transpiration pull and water supply dynamics using atmospheric water potential, plant water potential, and soil water potential are as follows:

[0054]

[0055] in, These are soil water potential, plant water potential, and atmospheric water potential, respectively.

[0056] S104, the stomatal opening of greenhouse plants is determined based on the ratio of transpiration pull to water supply force.

[0057] In this embodiment, the formula for calculating the stomatal aperture of greenhouse plants based on the ratio of transpiration pull to water supply force is as follows:

[0058]

[0059] Where g is the current stomatal conductance of the plant, g max For maximum porosity, g / g max Δ represents the stomatal opening, and Δ represents the ratio of transpiration pull to water supply force.

[0060] In this embodiment, tomato plants are used. As water stress in tomato plants increases, stomata gradually close. The water stress status of the plant can be judged based on the stomatal opening. Stomatal opening can be determined by comparing the plant's current stomatal conductance g with its maximum stomatal conductance g. max The ratio is determined based on g / g max The relationship between the transpiration pull / water supply force ratio Δ and the threshold for inducing water stress can be determined, such as... Figure 3 As shown, as Δ increases, the stomatal aperture gradually decreases, exhibiting an S-shaped curve, which can be fitted using the logistic function:

[0061]

[0062] S105, based on the ratio of stomatal opening and transpiration pull to water supply force of the greenhouse plants, control commands are issued to regulate the water content of the greenhouse plants.

[0063] In this embodiment, the stomatal opening of the greenhouse plants is first determined. When the ratio of the stomatal opening of the greenhouse plants is greater than or equal to a preset value, the plant's water status is suitable and the water supply and demand are balanced. When the ratio of the stomatal opening of the greenhouse plants is less than the preset value, the plant is in a state of water stress. The water supply and demand relationship is determined based on the determined ratio of transpiration pull to water supply force, thereby realizing the water regulation of the greenhouse plants.

[0064] When the ratio of transpiration pull to water supply exceeds the critical value of plant water deficit, the cause of drought in the plant root zone is determined. If the drought in the plant root zone is due to excessive transpiration pull, spray humidification is implemented. If the drought in the plant root zone is due to water supply limitation in the root zone, root zone irrigation is implemented. If the drought in the plant root zone is due to both water and transpiration pull limitation in the root zone, root zone irrigation and spray humidification are implemented simultaneously.

[0065] In this embodiment, when g / g max When the moisture content is ≥60%, the plant's water status is suitable, and the water supply and demand are relatively balanced. Based on the logistic function, Δ≤37 can be determined. When g / g max When the soil moisture content is less than 60%, the plant exhibits water stress. Based on the logistic function, Δ > 37. Further analysis of soil and atmospheric water potential determines the drought inducing factor, triggering irrigation or misting commands to maintain the balance between transpiration pull and water supply dynamics, ensuring adequate plant moisture. When the ratio Δ of transpiration pull to water supply dynamics exceeds 37, the threshold for inducing water stress in tomato plants is reached. Water regulation is then implemented based on the drought inducing factor: if soil water potential is < -0.25 MPa and atmospheric water potential is > -80 MPa, it indicates root zone water deficit drought. A signal is sent to the solenoid valve, executing the soil moisture regulation submodule and initiating the irrigation system until Δ drops below 37, at which point irrigation ceases. If soil water potential > -0.25 MPa and atmospheric water potential < -80 MPa, it is a drought caused by excessive atmospheric evaporation intensity and transpiration pull. A signal is sent to the solenoid valve to execute the air moisture control submodule, start the spray humidification system, and stop spray humidification until Δ drops below 37. If soil water potential ≤ -0.25 MPa and atmospheric water potential ≤ -80 MPa, it is a drought caused by a combination of root zone water deficit and excessive transpiration pull. The soil and air moisture control submodules are executed to start the irrigation and spray humidification systems until Δ drops below 37.

[0066] Corresponding to the greenhouse water control method based on the root zone-plant-atmosphere system provided in the above embodiments, this application also provides an embodiment of a greenhouse water control system based on the root zone-plant-atmosphere system.

[0067] See Figure 4 This application provides a greenhouse water control system based on a root zone-plant-atmosphere system, comprising: a water integrated management decision module, an information acquisition module, and a water control module electrically connected to the water integrated management decision module. The water integrated management decision module calculates the ratio of transpiration pull to water supply force and stomatal aperture based on soil water potential, plant water potential, air temperature, and relative humidity information acquired by the information acquisition module. The water control module controls the water supply of the greenhouse plants based on the stomatal aperture and the ratio of transpiration pull to water supply force calculated by the water integrated management decision module.

[0068] In this embodiment, the information acquisition module includes a soil water potential sensor, an air temperature sensor, an air relative humidity sensor, and a plant water potential sensor. The soil water potential sensor acquires the soil water potential, the air temperature and relative humidity sensors acquire the air temperature and relative humidity in real time, respectively, and the plant water potential sensor acquires the plant water potential. The integrated water management decision module controls a solenoid valve via a relay connection. The solenoid valve is electrically connected to the water regulation module, which includes a root zone irrigation submodule and an air humidification submodule.

[0069] The greenhouse water control system based on the root zone-plant-atmosphere system in this embodiment further includes a power supply module and an input / output module. Both the power supply module and the input / output module are electrically connected to the integrated water management decision module. The integrated water management decision module adopts a microcontroller, and the input / output module includes a keyboard and a display.

[0070] This embodiment provides a method for synergistic regulation of root zone and atmospheric water based on the relative relationship between transpiration pull and water supply dynamics. This method integrates the water potential energy of the root zone, plant, and atmosphere, quantifies transpiration pull, water supply dynamics, and supply-demand relationship, and uses feedback to regulate root zone and atmospheric water. This can achieve a dynamic balance between root zone-plant water supply and plant-atmosphere transpiration pull, thereby maintaining the plant in a suitable water state, inhibiting excessive transpiration and water consumption, and improving photosynthetic rate, yield, and water use efficiency.

[0071] In this embodiment, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0072] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0073] The above description is merely a specific embodiment of this application. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application. The protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A greenhouse water regulation method based on the root zone-plant-atmosphere system, characterized in that, include: The information acquisition module acquires information on soil water potential, plant water potential, air temperature, and relative humidity in real time. The atmospheric water potential is calculated based on the obtained air temperature and relative humidity. The transpiration pull and water supply force are calculated using atmospheric water potential, plant water potential, and soil water potential, respectively. The calculation formula is as follows: ； in, , , These are soil water potential, plant water potential, and atmospheric water potential, respectively. The stomatal aperture of greenhouse plants is determined based on the ratio of transpiration pull to water supply force. The calculation formula is as follows: Where g is the current stomatal conductance of the plant. For maximum porosity, For pore opening, It is the ratio of transpiration pull to water supply force; Based on the ratio of stomatal opening and transpiration pull to water supply force of the greenhouse plants, control commands are issued to regulate the water supply of the greenhouse plants, including: Determine the stomatal opening of greenhouse plants; When the ratio of stomatal opening of greenhouse plants is greater than or equal to the preset value, the plant's water status is suitable and the water supply and demand are balanced. When the ratio of stomatal opening to volume in greenhouse plants is less than a preset value, the plants experience water stress. The water supply and demand relationship is determined based on the established ratio of transpiration pull to water supply force, thereby enabling water regulation of greenhouse plants, including: When the ratio of transpiration pull to water supply force exceeds the critical value of plant water deficit, the cause of drought in the root zone of the plant is determined. If the drought in the root zone of the plant is due to excessive transpiration pull, then spray humidification should be implemented; If the drought in the root zone of the plant is a root zone water-limiting drought, then root zone irrigation should be implemented; If the drought in the plant's root zone is a root zone water-transpiration pull-limiting drought, then root zone irrigation and misting humidification should be carried out simultaneously.

2. The greenhouse water regulation method based on the root zone-plant-atmosphere system according to claim 1, characterized in that, The formula for calculating atmospheric water potential based on the obtained air temperature and relative humidity is as follows: in, Let R be the partial molar volume of water, and R be the gas constant. RH represents the absolute temperature of the air and the relative humidity of the air.

3. A greenhouse water regulation system based on a root zone-plant-atmosphere system, implementing the regulation method according to any one of claims 1-2, characterized in that, include: A water integrated management decision module, and an information acquisition module and a water control module electrically connected to the water integrated management decision module; The integrated water management decision module calculates the ratio of transpiration pull to water supply force and stomatal aperture based on soil water potential, plant water potential, air temperature, and relative humidity information collected by the information acquisition module. The calculation formula is as follows: ； ； in, , , These represent soil water potential, plant water potential, and atmospheric water potential, respectively, with g representing the current stomatal conductance of the plant. For maximum porosity, For pore opening, It is the ratio of transpiration pull to water supply force; The water regulation module regulates the water supply of greenhouse plants based on the stomatal aperture and the ratio of transpiration pull to water supply force calculated by the comprehensive water management decision module, including: Determine the stomatal opening of greenhouse plants; When the ratio of stomatal opening of greenhouse plants is greater than or equal to the preset value, the plant's water status is suitable and the water supply and demand are balanced. When the ratio of stomatal opening to volume in greenhouse plants is less than a preset value, the plants experience water stress. The water supply and demand relationship is determined based on the established ratio of transpiration pull to water supply force, thereby enabling water regulation of greenhouse plants, including: When the ratio of transpiration pull to water supply force exceeds the critical value of plant water deficit, the cause of drought in the root zone of the plant is determined. If the drought in the root zone of the plant is due to excessive transpiration pull, then spray humidification should be implemented; If the drought in the root zone of the plant is a root zone water-limiting drought, then root zone irrigation should be implemented; If the drought in the plant's root zone is a root zone water-transpiration pull-limiting drought, then root zone irrigation and misting humidification should be carried out simultaneously.

4. The greenhouse water regulation system based on the root zone-plant-atmosphere system according to claim 3, characterized in that, The information acquisition module includes a soil water potential sensor, an air temperature sensor, an air relative humidity sensor, and a plant water potential sensor; the soil water potential sensor is used to acquire the water potential of the soil; the air temperature sensor and the air relative humidity sensor acquire the air temperature and relative humidity in real time, respectively; and the plant water potential sensor is used to acquire the water potential of the plant.

5. The greenhouse water regulation system based on the root zone-plant-atmosphere system according to claim 3, characterized in that, The integrated water management decision module controls the solenoid valve via a relay connection. The solenoid valve is electrically connected to the water regulation module, which includes a root zone irrigation submodule and an air humidification submodule.

6. The greenhouse water regulation system based on the root zone-plant-atmosphere system according to claim 3, characterized in that, Also includes: The system includes a power supply module and an input / output module, both of which are electrically connected to the integrated water management decision module. The integrated water management decision module uses a microcontroller, and the input / output module includes a keyboard and a display.

Images