Greenhouse moisture regulation and control method and system based on root zone-plant-atmosphere system

Abstract

The invention discloses a greenhouse moisture regulation and control method and system based on a root zone-plant-atmosphere system, and the method comprises the steps: carrying out the real-time obtaining of soil water potential, plant water potential, air temperature and air relative humidity information through an information collection module; the atmospheric water potential is calculated according to the obtained air temperature and air relative humidity; respectively calculating transpiration pulling force and water supply power through the atmospheric water potential, the plant water potential and the soil water potential; determining the pore opening of the greenhouse plant according to the ratio of the transpiration tension to the water supply power; according to the pore opening degree of the greenhouse plant and the ratio of the transpiration pulling force to the water supply power, a control instruction is sent out to achieve water regulation and control of the greenhouse plant. The mode adopted in the method is simple and efficient, comprehensive moisture regulation and control are conducted according to the relative relation between water supply power and transpiration pulling force, moisture supply and demand balance of a root zone-plant-atmosphere system can be maintained, evaporation and throttling are effectively reduced, and the photosynthetic capacity, the yield and the moisture utilization efficiency of crops are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental regulation of facility horticulture, and in particular to a greenhouse moisture regulation method and system based on a root zone-plant-atmosphere system. Background Art

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

[0003] At present, traditional greenhouse water control usually unilaterally irrigates according to soil moisture conditions to ensure sufficient water supply, but ignores the interaction of various elements within the soil-plant-atmosphere continuum system. Most greenhouses are relatively closed spaces, and a large amount of heat is easily accumulated inside. Since the evaporation capacity of the atmosphere in the greenhouse is often much greater than the water absorption capacity of the crop roots, even if the root zone has sufficient water, the plants are prone to water stress and photosynthetic inhibition, thereby reducing yields. Plant drought stress is not only caused by soil moisture deficit, but also the "supply and demand" of water caused by high atmospheric evaporation intensity is also an important factor leading 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 technical problems, this application proposes the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a greenhouse moisture control method based on a root zone-plant-atmosphere system, comprising:

[0007] The information acquisition module is used to obtain the soil water potential, plant water potential, air temperature and air relative humidity information in real time;

[0008] Calculate the atmospheric water potential based on the obtained air temperature and relative air humidity;

[0009] The transpiration pull and the water supply power are calculated respectively by the atmospheric water potential, the plant water potential and the soil water potential;

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

[0011] According to the ratio of the stomatal opening of the greenhouse plants and the transpiration pull to the water supply power, a control instruction is issued to achieve moisture regulation of the greenhouse plants.

[0012] In a possible implementation, the formula for calculating the atmospheric water potential according to the acquired air temperature and air relative humidity is:

[0013]

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

[0015] In a possible implementation, the formulas for calculating the transpiration pull and the water supply power respectively by the atmospheric water potential, the plant water potential and the soil water potential are:

[0016]

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

[0018] In a possible implementation, the calculation formula for determining the stomatal aperture of greenhouse plants according to the ratio of transpiration pull to water supply power is:

[0019]

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

[0021] In a possible implementation, a control instruction is issued according to the ratio of the stomatal opening of the greenhouse plants and the transpiration tension to the water supply power to achieve moisture regulation of the greenhouse plants, including:

[0022] Determine the stomatal opening of greenhouse plants;

[0023] When the ratio of the stomatal opening of greenhouse plants is greater than or equal to the preset value, the water status of the plants is appropriate and the water supply and demand are balanced;

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

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

[0026] In a possible implementation, the water supply and demand relationship is determined according to the determined ratio of transpiration pull to water supply power to achieve water regulation of greenhouse plants, including:

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

[0028] If the drought in the root zone of the plant is caused by excessive transpiration tension, spray humidification should be performed;

[0029] If the root zone drought condition of the plant is root zone water supply limiting drought, perform root zone irrigation;

[0030] If the root zone drought condition of the plant is a root zone water-transpiration pull co-limiting drought, root zone irrigation and spray humidification should be performed simultaneously.

[0031] In a second aspect, an embodiment of the present application provides a greenhouse moisture control system based on a root zone-plant-atmosphere system, including: a moisture comprehensive management decision module, and an information collection module and a moisture control module electrically connected to the moisture comprehensive management decision module;

[0032] The water comprehensive management decision module calculates the ratio of transpiration pull to water supply power and stomatal aperture according to the soil water potential, plant water potential, air temperature and air relative humidity information collected by the information collection module;

[0033] The moisture control module controls the moisture of greenhouse plants according to the stomatal aperture and the ratio of transpiration tension to water supply power calculated by the moisture comprehensive management decision module.

[0034] In a 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 obtain the water potential of the soil; the air temperature sensor and the air relative humidity sensor respectively obtain the temperature and relative humidity of the air in real time, and the plant water potential sensor is used to obtain the water potential of the plant.

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

[0036] In a possible implementation, it also includes: a power supply module and an input-output module, both of which are electrically connected to the comprehensive moisture management decision module, the comprehensive moisture management decision module uses a single-chip microcomputer, and the input-output module includes a keyboard and a display.

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

[0038] The method adopted in the present application is simple and efficient. It performs comprehensive water regulation 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 money, and improve crop photosynthetic capacity, yield and water use efficiency.

[0039] The greenhouse root zone and atmospheric moisture comprehensive decision-making system provided in the present application uses a single-chip microcomputer as a data processing and control platform, performs feedback control according to the moisture status of the plants and drought inducements, coordinates the regulation of the root zone and atmospheric moisture, maintains a dynamic balance of "root water absorption - plant water delivery - atmospheric evaporation demand", and keeps the plants in a suitable moisture state. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of a flow chart of a greenhouse moisture control method based on a root zone-plant-atmosphere system provided in an embodiment of the present application;

[0041] Figure 2 An overall block diagram of a greenhouse moisture control method based on a root zone-plant-atmosphere system provided in an embodiment of the present application;

[0042] Figure 3 A relationship diagram between the tomato stomatal aperture and the transpiration pull / water supply power ratio provided in the embodiment of the present application;

[0043] Figure 4 A schematic diagram of a greenhouse moisture control system based on a root zone-plant-atmosphere system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The present solution is described below in conjunction with the accompanying drawings and specific implementation methods.

[0045] Figure 1 A schematic diagram of a greenhouse water control method based on a root zone-plant-atmosphere system provided in an embodiment of the present application, see Figure 1 and Figure 2 In this embodiment, a greenhouse moisture control method based on the root zone-plant-atmosphere system includes:

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

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

[0048] S102, calculating the atmospheric water potential according to the acquired air temperature and air relative humidity.

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

[0050]

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

[0052] S103, respectively calculating the transpiration pull and the water supply power through the atmospheric water potential, the plant water potential and the soil water potential.

[0053] In this embodiment, the formulas for calculating the transpiration pull and water supply power respectively by atmospheric water potential, plant water potential and soil water potential are:

[0054]

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

[0056] S104, determining the stomatal opening of the greenhouse plants according to the ratio of transpiration pull to water supply power.

[0057] In this embodiment, the calculation formula for determining the stomatal aperture of greenhouse plants according to the ratio of transpiration pull to water supply power is:

[0058]

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

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

[0061]

[0062] S105, issuing control instructions according to the stomatal opening of the greenhouse plants and the ratio of transpiration tension to water supply power to achieve moisture regulation of the greenhouse plants.

[0063] In this embodiment, the stomatal opening of the greenhouse plants is first judged. When the ratio of the stomatal opening of the greenhouse plants is greater than or equal to the preset value, the moisture state of the plants is appropriate 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 plants are in a state of water stress. The water supply and demand relationship is judged based on the determined ratio of transpiration pull and water supply power to achieve moisture regulation of the greenhouse plants.

[0064] When the ratio of transpiration pull to water supply power exceeds the critical value of plant water deficit, the cause of plant root zone drought is judged. If the root zone drought is excessive transpiration pull type drought, spray humidification is performed. If the root zone drought is root zone water supply limiting drought, root zone irrigation is performed. If the root zone drought is root zone water-transpiration pull co-limiting drought, root zone irrigation and spray humidification are performed simultaneously.

[0065] In this embodiment, when g / g max When ≥60%, the water status of the plant is suitable, the water supply and demand are relatively balanced, and according to the logistic function, Δ≤37 can be determined; when g / g max <60%, the plant is in a state of water stress. According to the logistic function, it can be determined that Δ>37. The drought cause is further determined according to the soil water potential and atmospheric water potential, and irrigation or spray humidification instructions are issued to maintain the transpiration tension-water supply dynamic balance and the plant water in an appropriate state. When the ratio of transpiration tension to water supply dynamics Δ exceeds 37, the threshold for inducing water stress in tomato plants is reached, and water regulation is carried out according to the drought cause: if the soil water potential is <-0.25MPa and the atmospheric water potential is >-80MPa, it is a root zone water deficit drought, and a signal is output to the solenoid valve to execute the soil water regulation submodule, start the irrigation system, and end irrigation until Δ drops below 37. If the soil water potential is >-0.25MPa and the atmospheric water potential is <-80MPa, it is a drought caused by excessive atmospheric evaporation intensity and transpiration pull. A signal is output to the solenoid valve to execute the air moisture control submodule, start the spray humidification system, and end the spray humidification until Δ drops below 37; if the soil water potential is ≤-0.25MPa and the atmospheric water potential is ≤-80MPa, it is a drought caused by water deficit in the root zone and excessive transpiration pull. The soil and air moisture control submodule is executed to start the irrigation and spray humidification system until Δ drops below 37.

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

[0067] See also Figure 4 A greenhouse moisture control system based on a root zone-plant-atmosphere system is provided in an embodiment of the present application, comprising: a moisture comprehensive management decision module and an information collection module and a moisture control module electrically connected to the moisture comprehensive management decision module, wherein the moisture comprehensive management decision module calculates the ratio of transpiration pull to water supply power and the stomatal aperture according to the soil water potential, plant water potential, air temperature and air relative humidity information collected by the information collection module, and the moisture control module controls the moisture of greenhouse plants according to the stomatal aperture and the ratio of transpiration pull to water supply power calculated by the moisture comprehensive management decision module.

[0068] In this embodiment, the information collection module includes a soil water potential sensor, an air temperature sensor, an air relative humidity sensor and a plant water potential sensor, wherein the soil water potential sensor is used to obtain the water potential of the soil, the air temperature sensor and the air relative humidity sensor respectively obtain the temperature and relative humidity of the air in real time, and the plant water potential sensor is used to obtain the water potential of the plant. The water comprehensive management decision module is connected to the control solenoid valve through a relay, and the solenoid valve is electrically connected to the water control module, and the water control module includes a root zone irrigation submodule and an air humidification submodule.

[0069] A greenhouse moisture control system based on the root zone-plant-atmosphere system in this embodiment also includes: a power supply module and an input-output module, wherein the power supply module and the input-output module are electrically connected to the comprehensive moisture management decision module, the comprehensive moisture management decision module adopts a single-chip microcomputer, and the input-output module includes a keyboard and a display.

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

[0071] In the embodiments of the present application, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0072] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0073] The above is only a specific implementation of the present application. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A greenhouse water control method based on the root zone-plant-atmosphere system, characterized in that: include: The information acquisition module is used to obtain the soil water potential, plant water potential, air temperature and air relative humidity information in real time; Calculate the atmospheric water potential based on the obtained air temperature and relative air humidity; The transpiration pull and the water supply power are calculated respectively by the atmospheric water potential, the plant water potential and the soil water potential; The stomatal opening of greenhouse plants is determined based on the ratio of transpiration pull to water supply power; According to the ratio of the stomatal opening of the greenhouse plants and the transpiration pull to the water supply power, a control instruction is issued to achieve moisture regulation of the greenhouse plants.

2. The greenhouse moisture control method based on the root zone-plant-atmosphere system according to claim 1, characterized in that: Including, the formula for calculating the atmospheric water potential based on the obtained air temperature and relative air humidity is: Among them, V w is the partial molar volume of water, R is the gas constant, T k is the absolute temperature of air and RH is the relative humidity of air.

3. The greenhouse moisture control method based on the root zone-plant-atmosphere system according to claim 1, characterized in that: The formulas for calculating the transpiration pull and water supply power respectively by the atmospheric water potential, plant water potential and soil water potential are: in, They are soil water potential, plant water potential and atmospheric water potential.

4. The greenhouse moisture control method based on the root zone-plant-atmosphere system according to claim 1, characterized in that: The calculation formula for determining the stomatal aperture of greenhouse plants based on the ratio of transpiration pull to water supply power is: Where g is the current stomatal conductance of the plant, g max is the maximum stomatal conductance, g / g max is the stomatal opening, and Δ is the ratio of transpiration pull to water supply power.

5. The greenhouse water control method based on the root zone-plant-atmosphere system according to claim 1, characterized in that: The method includes issuing a control instruction according to the ratio of the stomatal opening of the greenhouse plants and the transpiration pull to the water supply power to realize the moisture regulation of the greenhouse plants, including: Determine the stomatal opening of greenhouse plants; When the ratio of the stomatal opening of greenhouse plants is greater than or equal to the preset value, the water status of the plants is appropriate and the water supply and demand are balanced; When the ratio of the stomatal opening of greenhouse plants is less than the preset value, the plants are 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 power, thereby achieving water regulation for greenhouse plants.

6. The greenhouse moisture control method based on the root zone-plant-atmosphere system according to claim 5, wherein the water supply and demand relationship is determined according to the ratio of the determined transpiration pull to the water supply power to achieve moisture control of greenhouse plants, comprising: When the ratio of transpiration pull to water supply power exceeds the critical value of plant water deficit, the cause of drought in the plant root zone is judged; If the drought in the root zone of the plant is caused by excessive transpiration tension, spray humidification should be performed; If the root zone drought condition of the plant is root zone water supply limiting drought, perform root zone irrigation; If the root zone drought condition of the plant is a root zone water-transpiration pull co-limiting drought, root zone irrigation and spray humidification should be performed simultaneously.

7. A greenhouse moisture control system based on a root zone-plant-atmosphere system, implementing the control method according to any one of claims 1 to 6, characterized in that: include: A moisture comprehensive management decision module and an information collection module and a moisture control module electrically connected to the moisture comprehensive management decision module; The water comprehensive management decision module calculates the ratio of transpiration pull to water supply power and stomatal aperture according to the soil water potential, plant water potential, air temperature and air relative humidity information collected by the information collection module; The moisture control module controls the moisture of greenhouse plants according to the stomatal aperture and the ratio of transpiration tension to water supply power calculated by the moisture comprehensive management decision module.

8. The greenhouse water control system based on the root zone-plant-atmosphere system according to claim 7, 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 obtain the water potential of the soil; the air temperature sensor and the air relative humidity sensor respectively obtain the temperature and relative humidity of the air in real time, and the plant water potential sensor is used to obtain the water potential of the plant.

9. The greenhouse water control system based on the root zone-plant-atmosphere system according to claim 7, characterized in that: The integrated moisture management decision module is connected to a control solenoid valve via a relay, and the solenoid valve is electrically connected to a moisture control module, and the moisture control module includes a root zone irrigation submodule and an air humidification submodule.

10. The greenhouse water control system based on the root zone-plant-atmosphere system according to claim 7, characterized in that: Also includes: A power supply module and an input-output module, wherein the power supply module and the input-output module are both electrically connected to the comprehensive moisture management decision module, the comprehensive moisture management decision module adopts a single-chip microcomputer, and the input-output module includes a keyboard and a display.

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