JP7395165B1 - Water supply control system, water supply control method, and water supply control program - Google Patents

Abstract

[Problem] To provide a water supply control system, etc. that can smooth transpiration from leaves and efficiently prepare an optimal cultivation environment for plants. [Solution] A leaf temperature sensor 1 that measures leaf temperature, a leaf moisture sensor 2 that measures the moisture content of leaves L, an underground irrigation device 4 that sprinkles water into a solid medium 204 that supports plants PL, and a leaf temperature sensor 1 that measures leaf temperature. The control device 7 controls the operation of the underground irrigation system 4 based on the measured values of the sensor 1 and the leaf moisture sensor 2. When the rate of increase in the measured value of the leaf temperature sensor 1 is equal to or higher than the upper limit leaf temperature increase rate Vuth, the underground irrigation device 4 is operated to start irrigation into the solid medium 204, and the leaf moisture sensor When the measured value of No. 2 exceeds the first leaf moisture lower limit value Whth1, the operation of the underground irrigation device 4 is stopped and irrigation into the solid culture medium 204 is ended. [Selection diagram] Figure 1

Description

The present invention relates to a water supply control system, a water supply control method, and a water supply control program for controlling water supply to plants.

Traditionally, when growing plants, especially crops, in greenhouses, the amount of watering, environmental temperature and humidity, amount of sunlight, and soil temperature have been adjusted in order to keep the plants healthy, improve the quality of the harvest, and maximize the yield. Efforts are being made to control environmental conditions such as: In recent years, the state of the plants themselves has been sensed, and the environmental conditions within the greenhouse have been controlled to keep the plants in optimal conditions based on the state of the plants themselves.

Here, Patent Document 1 discloses that leaf temperature, which is one of the indicators indicating the state of the plant itself, is sensed, and the leaf temperature is controlled by adjusting the growing environment of the plant based on the leaf temperature, thereby increasing the yield. The technology aimed at achieving this is described. If the leaf temperature is too high, the efficiency of photosynthesis decreases, so leaf temperature is extremely important as an indicator of the state of the plant itself.

Patent No. 6886656

By the way, as described in Patent Document 1, leaves of plants are provided with stomata. Plants have the ability to cool their leaves using the heat of evaporation when water is released from their stomata, keeping the leaf temperature as constant as possible, so normally the leaf temperature does not rise too much. However, in high-temperature environments such as midsummer, leaves are irradiated with a large amount of ultraviolet rays, and the leaves tend to reach high temperatures, which increases the amount and speed of transpiration from the leaves. As a result, the water supply to the leaves may not be able to keep up with the amount and speed of transpiration from the leaves, and the leaves may not be able to be sufficiently cooled by the heat of vaporization from transpiration.

Therefore, the present invention provides a water supply control system, a water supply control method, and a water supply control program that can smooth transpiration from leaves and efficiently prepare an optimal cultivation environment for plants.

A water supply control system according to one aspect of the present invention is a water supply control system that controls water supply to plants, and includes a leaf temperature sensor that measures the leaf temperature of the plants, and a leaf temperature sensor that measures the water content of the leaves of the plants. a moisture sensor; an underground irrigation device that irrigate the solid medium supporting the plants; and a control device that controls the operation of the underground irrigation device based on the measured values of the leaf temperature sensor and the leaf moisture sensor. , the control device is configured such that the measured value of the leaf temperature sensor is equal to or higher than a predetermined upper limit of leaf temperature, and the rate of increase of the measured value of the leaf temperature sensor is equal to or higher than the predetermined upper limit of leaf temperature increase rate. an underground irrigation start command unit that operates the underground irrigation device to start irrigation into the solid culture medium; and after operating the underground irrigation device, the measured value of the leaf moisture sensor is an underground irrigation termination command unit that stops the operation of the underground irrigation device and terminates irrigation into the solid medium when the first lower limit of leaf moisture exceeds the first leaf moisture lower limit value.

The above-mentioned irrigation control system further includes a surface irrigation device that irrigations the surface of the solid medium, and the control device is configured to control the water supply system so that the measured value of the leaf moisture sensor reaches a predetermined starting side after operating the underground irrigation device. When the leaf moisture is below the two leaf moisture lower limits and the rate of decrease in the measured value of the leaf moisture sensor is equal to or higher than the first predetermined upper limit rate of decrease in leaf moisture, the surface irrigation device is operated to a ground irrigation start command unit that starts irrigation to the ground irrigation device; and after operating the ground irrigation device, when the measured value of the leaf moisture sensor exceeds a predetermined end-side second leaf moisture lower limit value, the ground irrigation device It may further include a surface irrigation termination command unit that stops the operation of the solid culture medium and terminates irrigation to the surface of the solid culture medium.

In the above-mentioned irrigation control system, the above-mentioned surface irrigation device may perform irrigation to the base of a plant near the above-mentioned plant.

In the above-mentioned irrigation control system, the surface irrigation device may have a smaller water supply amount per unit time than the underground irrigation device.

The irrigation control system further includes a mist supply device that supplies mist-like moisture to the leaves of the plant, and the control device is configured such that after operating the surface irrigation device, the measurement value of the leaf moisture sensor is set to a predetermined value. is below the third lower limit of leaf moisture on the starting side, and when the rate of decrease in the measured value of the leaf moisture sensor is equal to or higher than the second upper limit rate of decrease in leaf moisture, which is greater than the first limit rate of decrease in leaf moisture, a mist supply start command unit that operates a mist supply device to start supplying mist to the leaves; and after operating the mist supply device, the measured value of the leaf moisture sensor is a predetermined end-side third leaf moisture lower limit. The apparatus may further include a mist supply termination command section that stops the operation of the mist supply device to terminate the mist supply to the leaves when the value exceeds the value.

The irrigation control system further includes a mist supply device that supplies mist-like moisture to the leaves of the plant, and the control device is configured such that after operating the underground irrigation device, the measurement value of the leaf moisture sensor is set to a predetermined value. is below the third leaf moisture lower limit on the starting side, and when the decreasing rate of the measured value of the leaf moisture sensor is equal to or higher than the upper limit leaf moisture decreasing rate, the mist supply device is operated to spray mist onto the leaves. a mist supply start command unit that starts supply; and an operation of the mist supply device when the measured value of the leaf moisture sensor exceeds a predetermined end-side third leaf moisture lower limit value after the mist supply device is operated. The apparatus may further include a mist supply termination command section that stops the mist supply to the leaves and terminates the mist supply to the leaves.

The above-mentioned irrigation control system further includes a medium moisture sensor that measures the moisture content of the solid medium, and the control device is configured such that the measured value of the leaf temperature sensor is equal to or higher than a predetermined leaf temperature lower limit value, and the leaf temperature When the rate of increase in the measured value of the sensor exceeds a predetermined reference leaf temperature increase rate, a predetermined medium moisture lower limit value, which is the lower limit value of the moisture content of the solid medium, is set before operating the underground irrigation device. The underground irrigation start command unit further includes a medium moisture change unit that increases the medium moisture content, and the underground irrigation start command unit controls the underground irrigation device when the measured value of the medium moisture sensor is equal to or lower than the medium moisture lower limit value after the increase. may be operated to start watering into the solid medium.

A water supply control method according to one aspect of the present invention is a water supply control method for controlling water supply to plants, in which a measured value of a leaf temperature sensor that measures leaf temperature of the plant is equal to or higher than a predetermined leaf temperature upper limit value. and an underground irrigation starting step of starting watering into the solid medium supporting the plant when the rate of increase in the measured value of the leaf temperature sensor exceeds a predetermined upper limit rate of increase in leaf temperature; Underground irrigation that terminates watering into the solid medium when the measured value of a leaf moisture sensor that measures the amount of water in the leaves of the plant exceeds a predetermined lower limit of leaf moisture after the start of watering into the solid medium. and a termination step.

A water supply control program according to one aspect of the present invention, in order to control water supply to plants, a computer is configured to perform a water supply control program when a measured value of a leaf temperature sensor that measures leaf temperature of the plant is equal to or higher than a predetermined leaf temperature upper limit; and an underground irrigation start means for starting watering into a solid medium supporting the plant when the rate of increase in the measured value of the leaf temperature sensor exceeds a predetermined upper limit rate of increase in leaf temperature, and the solid medium After the start of watering into the solid medium, when the measured value of a leaf moisture sensor that measures the water content of the leaves of the plant exceeds a predetermined lower limit of leaf water, the watering into the solid medium is ended. Function as a means.

According to the water supply control system and the like described above, it is possible to smooth transpiration from leaves and efficiently create an optimal cultivation environment for plants.

1 is an overall schematic diagram of a water supply control system according to an embodiment of the present invention. Note that for convenience of explanation, the cultivation bed is shown in a longitudinal cross-sectional view. . It is a hardware block diagram of the control device in the above-mentioned water supply control system. It is a functional block diagram of a control device in the above-mentioned water supply control system. It is a flow chart which shows the control flow in the above-mentioned water supply control system.

(overall structure)
As shown in FIG. 1, the water supply control system 100 is a device that controls water supply to plants PL. In the present embodiment, the water supply control system 100 controls a cultivation bed 201, a water retention mat 202 provided at the bottom of the cultivation bed 201, a plurality of cultivation containers 203 placed on the water retention mat 202, and each cultivation container 203. The cultivation device 200 is provided with a solid culture medium 204 (which may be "soil", hereinafter simply referred to as a culture medium) contained therein. The cultivation device 200 is installed in a place where the cultivation environment can be adjusted, such as in a greenhouse or a plant factory. In addition, the cultivation apparatus 200 mentioned above is an example, Comprising: The structure can be changed suitably.

A bottom hole 203a is provided at the bottom of each cultivation container 203, and moisture (water and nutrient solution) from the water retention mat 202 is supplied to the culture medium 204 through the roots R extending from the inside of the cultivation container 203 to the outside through the bottom hole 203a. It is now possible to do so. That is, in this embodiment, water is applied into the culture medium 204 from the bottom surface 204b of the culture medium 204 by the underground irrigation device 4 of the water supply control system 100, which will be described in detail later.

(Water supply control system)
Next, the water supply control system 100 will be explained.
The water supply control system 100 includes a leaf temperature sensor 1 that measures the temperature of the leaf surface of a leaf L of a plant PL (hereinafter referred to as leaf temperature), and a leaf moisture sensor 2 that measures the water content of the leaf L (hereinafter referred to as leaf water content). , a medium moisture sensor 3 that measures the moisture content of the medium 204 (hereinafter referred to as medium moisture content), an underground irrigation device 4 that sprinkles water into the culture medium 204, and a surface irrigation device that sprinkles water on the surface (upper surface) 204a of the culture medium 204. 5, a mist supply device 6 that supplies (sprays) mist to the leaves L, and operations of the underground irrigation device 4, surface irrigation device 5, and mist supply device 6 based on the measured values of each sensor 1, 2, and 3. A control device 7 is provided.

The water supply control system 100 further includes a pump 8, which supplies water to the underground irrigation system 4, the surface irrigation system 5, and the mist supply system 6 from a water supply source (not shown).

(sensor)
Although the leaf temperature sensor 1 is not particularly limited, for example, a sensor device such as a radiation temperature sensor that senses infrared rays or a thermistor temperature sensor is preferably used. The leaf temperature sensor 1 is configured to take measurements at all times (for example, every 30 seconds to 1 minute). Leaf temperature sensor 1 is provided for each cultivation container 203.

Although the leaf moisture sensor 2 is not particularly limited, for example, an irradiation type sensor device that irradiates the leaf L with near infrared rays and calculates the leaf moisture content from the amount of reflection is preferably used. Further, the leaf moisture sensor 2 may be a sensor device that determines the wilting state of the leaf L from an image of the leaf and calculates the leaf water content based on the determined wilting state. The leaf moisture sensor 2 is configured to perform measurements at all times (for example, every 30 seconds to 1 minute). Leaf moisture sensor 2 is provided for each cultivation container 203. The leaf moisture sensor 2 is preferably installed near the growth point of the plant PL.

Although the medium moisture sensor 3 is not particularly limited, a sensor device that is inserted into the medium 204 from the surface 204a and is capable of calculating the moisture content of the medium 204 from the resistance value, dielectric constant, etc. of the medium 204 is preferably used. . The culture medium moisture sensor 3 is configured to perform measurements at all times (for example, every 30 seconds to 1 minute). The culture medium moisture sensor 3 is provided for each cultivation container 203.

(underground irrigation system)
The underground irrigation device 4 is a device that supplies water to the water retention mat 202 to irrigate the inside of the culture medium 204 from the bottom surface 204b of the culture medium 204 via the water retention mat 202 as described above. Specifically, the underground irrigation system 4 includes a water supply port 4a connected to the pump 8, and an electromagnetic valve 4b provided between the pump 8 and the water supply port 4a.

(Surface irrigation equipment)
The ground irrigation device 5 is a device that irrigations the surface (upper surface) 204a of the culture medium 204. The ground watering device 5 performs watering to the plant base near the plant PL, that is, to a region where many roots (capillary roots) R of the plant PL exist. Specifically, the ground irrigation device 5 includes a water supply nozzle 5a that supplies water to the plant by drip, and an electromagnetic valve 5b provided between the water supply nozzle 5a and the pump 8. ing.

The ground irrigation device 5 is capable of performing irrigation at intervals of minutes, such as by dripping every second. Moreover, the surface irrigation device 5 has a smaller water supply amount per unit time than the underground irrigation device 4, and performs irrigation with a discharge amount of about 20 [ml/min]. The irrigation time and amount of irrigation by the surface irrigation device 5 may be controlled by a control device 7, which will be described in detail later, or by a control device (not shown) provided separately from the control device 7.

(Mist supply device)
The mist supply device 6 is a device that sprays and supplies mist-like moisture toward the leaves L. Specifically, the mist supply device 6 includes a spray nozzle 6a that sprays water, and an electromagnetic valve 6b provided between the spray nozzle 6a and the pump 8, and is provided for each cultivation container 203.

The particle size of the mist sprayed from the mist supply device 6 is preferably as small as possible, and the particle size is preferably 10 [μm] to 100 [μm], preferably 70 [μm] or less. The spraying time is determined based on the measurement results of a sensor (not shown) that detects the wetness of the leaves L.The spraying time is determined based on the measurement results of a sensor (not shown) that detects the wetness of the leaves L. After spraying, the operation of the mist supply device 6 is controlled so as to stop spraying until the water on the surface of the leaves L evaporates. That is, the mist supply device 6 is designed to operate intermittently (for example, with a spraying time of about 10 seconds to 20 seconds) like the surface irrigation device 5. The spray time and spray amount by the mist supply device 6 may be controlled by a control device 7, which will be described in detail later, or by a control device (not shown) provided separately from the control device 7. Note that intermittent operation control may be performed to perform mist spraying when the atmospheric humidity near the plant PL falls below a predetermined value, or to stop mist spraying when the leaf temperature falls below a predetermined value. Intermittent operation control may also be performed.

(Control device)
As shown in FIG. 2, the control device 7 has a computer 70, and the computer 70 includes a CPU (Central Processing Unit) 700, a memory 710 such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and an HDD ( The device includes a nonvolatile storage device 720 such as a hard disk drive (hard disk drive) or a solid state drive (SSD), a power supply device 730, an input interface 740, an output interface 750, and a bus wiring 760 that connects these. The CPU 700 is a central processing unit and executes a water supply control program to be described later. The memory 710 is used as a work area and storage area for the CPU 700, and the storage device 720 stores an operating system, programs, etc. executed by the CPU 700.

As shown in FIG. 3, the computer 70 of the control device 7 includes a leaf temperature determination section 71, a leaf temperature increase rate determination section 72, a medium moisture content lower limit adjustment section 73, an adjusted medium moisture content determination section 74, Underground irrigation start command unit 75, first leaf water content determination unit 76, underground irrigation end command unit 77, first leaf water content reduction rate determination unit 78, and second leaf water content determination unit on the starting side 79 , a surface irrigation start command section 80, a second leaf moisture content determination section 81 on the end side, a surface irrigation end command section 82, a second leaf moisture reduction rate determination section 83, and a third leaf moisture content determination section on the start side. 84 , a mist supply start command section 85 , an end-side third leaf moisture content determination section 86 , and a mist supply end command section 87 .

The leaf temperature determination unit 71 determines whether the measured value of the leaf temperature sensor 1 is equal to or higher than a predetermined leaf temperature upper limit value T _th [° C.]. The leaf temperature upper limit T _th is a numerical value that is appropriately set depending on the type of plant, etc. For example, if the plant PL is a tomato, the upper limit value is 13 [°C] at which it is considered that the leaves L will not wilt. is set to

The leaf temperature increase rate determining unit 72 determines whether the rate of increase in the measured value of the leaf temperature sensor 1 is equal to or higher than a predetermined upper limit leaf temperature increase rate V _uth [° C./sec].

The medium moisture content lower limit adjustment section 73 adjusts a predetermined medium moisture lower limit value W _mth that is the lower limit value of the culture medium moisture content. That is, the medium moisture content lower limit adjustment unit 73 increases or decreases the medium moisture lower limit value W _mth under predetermined conditions as per the control flow described below.

The adjusted culture medium moisture content determination unit 74 determines whether the measured value of the culture medium moisture sensor 3 is equal to or less than the culture medium moisture lower limit value W _mth after being increased by the culture medium moisture content lower limit adjustment unit 73.

The underground irrigation start command unit 75 determines that the measured value of the leaf temperature sensor 1 is equal to or higher than the leaf temperature upper limit value T _th and the rate of increase in the measured value of the leaf temperature sensor 1 is equal to or higher than the upper limit leaf temperature increase rate V _th . At this time, by opening the solenoid valve 4b of the underground irrigation system 4, the underground irrigation system 4 is operated to supply water to the water retention mat 202, and water is supplied from the bottom surface 204b of the culture medium 204 into the culture medium 204 through the water retention mat 202. Start watering.

The first leaf moisture determination unit 76 determines whether the measured value of the leaf moisture sensor 2 is equal to or less than a predetermined first lower limit value W _hth1 of leaf moisture.

When the measured value of the leaf moisture sensor 2 exceeds the first leaf moisture lower limit W _hth1 , the underground irrigation end command unit 77 closes the solenoid valve 4b of the underground irrigation device 4 and stops the operation of the underground irrigation device 4. is stopped to complete watering into the culture medium 204.

The first leaf water content decreasing rate determination unit 78 determines whether the decreasing rate of the measured value of the leaf moisture sensor 2 is equal to or higher than a predetermined first upper limit leaf moisture decreasing rate V _dth1 [° C./sec].

The start-side second leaf moisture content determination unit 79 determines whether the measured value of the leaf moisture sensor 2 is less than or equal to a predetermined start-side second leaf moisture lower limit value W _hth2s .

After operating the underground irrigation device 4, the surface irrigation start command unit 80 determines that the measured value of the leaf moisture sensor 2 is equal to or lower than the start-side second leaf moisture lower limit value W _hth2s , and that the measured value of the leaf moisture sensor 2 is When the rate of decrease becomes equal to or higher than the first upper limit leaf moisture decrease rate V _dth1 , the solenoid valve 5b of the surface irrigation device 5 is opened to operate the surface irrigation device 5 and start watering the surface 204a of the culture medium 204. let

The end-side second leaf moisture content determining unit 81 determines whether the measured value of the leaf moisture sensor 2 is equal to or less than a predetermined end-side second leaf moisture lower limit value W _hth2e after operating the ground irrigation device 5. judge.

When the measured value of the leaf moisture sensor 2 exceeds the end-side second leaf moisture lower limit W _hth2e after operating the ground irrigation device 5, the ground irrigation termination command unit 82 activates the solenoid valve 5b of the ground irrigation device 5. By blocking it, the operation of the surface irrigation device 5 is stopped and the irrigation to the surface 204a of the culture medium 204 is completed.

The second leaf water content reduction rate determination unit 83 determines whether the reduction rate of the measured value of the leaf moisture sensor 2 is equal to or higher than the second upper limit leaf water content reduction rate V _dth2 , which is greater than the first upper limit leaf moisture reduction rate V _dth1 . Determine whether

The starting side third leaf moisture content determination unit 84 determines whether the measured value of the leaf moisture sensor 2 is equal to or less than a predetermined starting side third leaf moisture lower limit value W _hth3s .

After operating the ground irrigation device 5, the mist supply start command unit 85 determines that the measured value of the leaf moisture sensor 2 is equal to or lower than the third leaf moisture lower limit W _hth3s on the start side, and that the measured value of the leaf moisture sensor 2 is When the reduction rate becomes equal to or higher than the second upper limit leaf moisture reduction rate V _dth2 , the solenoid valve 6b of the mist supply device 6 is opened to operate the mist supply device 6 and start supplying mist to the leaves L.

After operating the mist supply device 6, the end-side third leaf moisture determination unit 86 determines whether the measured value of the leaf moisture sensor 2 is equal to or less than a predetermined end-side third leaf moisture lower limit W _hth3e . judge.

The mist supply end command unit 87 controls the solenoid valve 6b of the mist supply device 6 when the measured value of the leaf moisture sensor 2 exceeds the end-side third leaf moisture lower limit W _hth3e after operating the mist supply device 6. By blocking the mist supply device 6, the operation of the mist supply device 6 is stopped and the mist supply to the leaves L is ended.

Next, with reference to FIG. 4, the flow of the water supply control program (water supply control method) will be described.
In the following explanation, "leaf temperature", "leaf moisture content", and "medium moisture content" all indicate the measured values of sensors 1, 2, and 3. Further, the following control flow is executed in parallel for each cultivation container 203.
First, step S1 is executed to determine whether the leaf temperature is equal to or higher than the leaf temperature upper limit value _Tth . If the leaf temperature is equal to or higher than the leaf temperature upper limit value _Tth , the determination is "YES" and the process proceeds to step S2. On the other hand, if the leaf temperature is less than the leaf temperature upper limit _Tth , the determination is "NO" and the process returns to step S1.
Note that if the determination in step S1 is "NO", the state is "normal". During this "normal time", the underground irrigation system 4 is operated as appropriate, and the measured value of the culture medium moisture sensor 3 and the discharge amount from the pump 8 are constantly monitored by a sensor (not shown) to maintain the moisture content of the culture medium in an optimal state. I try to keep it that way. On the other hand, if the determination in step S1 is "YES", it is an "emergency" and the control proceeds according to the flow below.

In step S2, if the determination is YES in step S1, it is determined whether the rate of increase in leaf temperature is equal to or higher than the upper limit rate of increase in leaf temperature V _uth . If the rate of increase in leaf temperature is equal to or higher than the upper limit rate of increase in leaf temperature V _uth , the determination is "YES" and the process proceeds to step S3. On the other hand, if the rate of increase in leaf temperature is less than the upper limit rate of increase in leaf temperature V _uth , the determination is "NO" and the process returns to step S1.

In step S3, when the determination is "YES" in step S2, the medium moisture lower limit value W _mth is increased. For example, if the volumetric water content (VWC) of the culture medium 204 is 48 in normal times when the water supply control program of this embodiment is not operating, the volumetric water content (VWC) is increased to, for example, about 49 to 50 in step S3. . That is, in step S3, the volumetric water content (VWC) is increased, for example, by about 1 to 3 compared to the normal value.

After that, step S4 is executed. In step S4, it is determined whether the culture medium moisture content is equal to or less than the lower limit W _mth of culture medium moisture after being increased in step S3. If the medium water content is equal to or less than the lower limit W _mth of medium water content after the increase, the determination is "YES" and the process proceeds to step S5. On the other hand, if the medium moisture content exceeds the increased medium moisture lower limit value W _mth , the determination is "NO" and the process returns to step S1. In addition, in step S4 of this embodiment, when the culture medium moisture content of at least one cultivation container 203 among the plurality of cultivation containers 203 is equal to or less than the culture medium moisture lower limit value W _mth , the determination is made as "YES". It has become.

In step S5, when the determination is "YES" in step S4, the underground irrigation device 4 is operated to start underground irrigation.

Next, step S6 is executed. In step S6, it is determined whether the leaf water content is less than or equal to the first leaf water lower limit W _hth1 . If the leaf water content is less than or equal to the first leaf water lower limit W _hth1 , the determination is "YES" and the process proceeds to step S7. On the other hand, if the leaf moisture content exceeds the first leaf moisture lower limit W _hth1 , the determination is "NO" and the process proceeds to step S61. In addition, in step S6 of this embodiment, when the leaf moisture content of the plants PL in all the cultivation containers 203 exceeds the first leaf moisture lower limit value W _hth1 , the determination is "NO". .

In step S61, when the determination in step S6 is "NO", the operation of the underground irrigation device 4 is stopped to end the underground irrigation. Thereafter, the process proceeds to step S62, where the medium moisture lower limit value W _mth is decreased to return to a normal value (for example, volumetric water content (VWC) is 48).

In step S7, it is determined whether the rate of decrease in leaf water content is equal to or higher than the first upper limit rate of decrease in leaf moisture _Vdth1 . If the rate of decrease in leaf water content is equal to or higher than the first upper limit rate of decrease in leaf moisture V _dth1 , the determination is "YES" and the process proceeds to step S8. On the other hand, if the rate of decrease in leaf water content is less than the first upper limit rate of decrease in leaf moisture _Vdth1 , the determination is "NO" and the process returns to step S6.

In step S8, it is determined whether the leaf water content is less than or equal to the starting second leaf water lower limit W _hth2s . If the leaf water content is less than or equal to the starting second leaf water lower limit value W _hth2s , the determination is "YES" and the process proceeds to step S9. On the other hand, if the leaf moisture content exceeds the starting second leaf moisture lower limit value W _hth2s , the determination is "NO" and the process returns to step S6. Here, the second leaf moisture lower limit value W _hth2s on the starting side may be the same value as the first leaf moisture lower limit value W _hth1 , or may be a value smaller than the first leaf moisture lower limit value W _hth1 .

In step S9, if the determination in step S8 is "YES", the ground irrigation device 5 is operated to start ground irrigation.

After that, step S10 is executed. In step S10, it is determined whether the leaf moisture content is equal to or less than the end-side second leaf moisture lower limit W _hth2e . If the leaf water content is less than or equal to the end-side second leaf water lower limit value W _hth2e , the determination is "YES" and the process proceeds to step S11. On the other hand, if the leaf moisture content exceeds the end-side second leaf moisture lower limit W _hth2e , the determination is "NO" and the process proceeds to step S101. Here, the end-side second leaf moisture lower limit value W _hth2e may be the same value as the start-side second leaf moisture lower limit value W _hth2s , or may be larger than the start-side second leaf moisture lower limit value W _hth2s to avoid chattering. May be used as a value.

In step S101, if the determination in step S10 is "NO", the operation of the ground irrigation device 5 is stopped to end the ground irrigation, and then the process returns to step S6.

In step S11, it is determined whether the rate of decrease in leaf water content is equal to or higher than the second upper limit rate of decrease in leaf moisture _Vdth2 . If the rate of decrease in leaf water content is equal to or higher than the second upper limit rate of decrease in leaf moisture V _dth2 , the determination is "YES" and the process proceeds to step S12. On the other hand, if the rate of decrease in leaf water content is less than the second upper limit rate of decrease in leaf moisture _Vdth2 , the determination is "NO" and the process returns to step S10.

In step S12, when it is determined as "YES" in step S11, it is determined whether or not the leaf water content is equal to or lower than the starting third leaf moisture lower limit W _hth3s . If the leaf water content is less than or equal to the starting third leaf water lower limit W _hth3s , the determination is "YES" and the process proceeds to step S13. On the other hand, if the leaf moisture content exceeds the starting third leaf moisture lower limit W _hth3s , the determination is "NO" and the process returns to step S10. Here, the starting side third leaf moisture lower limit value W _hth3s may be the same value as the starting side second leaf moisture lower limit value W _hth2s , or may be a value smaller than the starting side second leaf moisture lower limit value W _hth2s . .

In step S13, when the determination is "YES" in step S12, the mist supply device 6 is operated to start mist supply (spraying).

After that, step S14 is executed. In step S14, it is determined whether the leaf water content is equal to or less than the end-side third leaf water lower limit W _hth3e . If the leaf water content is equal to or less than the end-side third leaf water lower limit W _hth3e , the determination is "YES" and step S14 is repeated. On the other hand, if the leaf moisture content exceeds the end-side third leaf moisture lower limit value W _hth3e , the determination is "NO" and the process proceeds to step S15. Here, the end side third leaf moisture lower limit value W _hth3e may be the same value as the start side third leaf moisture lower limit value W _hth3s , or may be larger than the start side third leaf moisture lower limit value W _hth3s to avoid chattering. May be used as a value.

In step S15, when the determination is "NO" in step S14, the operation of the mist supply device 6 is stopped to end the mist supply (spraying), and then the process returns to step S10.

(effect)
According to the water supply control system 100 of the present embodiment described above, in a state where the leaf temperature is equal to or higher than the leaf temperature upper limit value T _th and transpiration from the leaves L is large, the leaf temperature increase rate is the upper limit leaf temperature increase rate V When the amount exceeds _uth , it is considered that the water supply to the leaves L is delayed with respect to the amount of transpiration and the transpiration speed from the leaves L, and the amount of water in the leaves is insufficient, resulting in an emergency situation. At this time, in the present embodiment, the underground irrigation device 4 can be operated, so that the moisture content of the medium can be increased in an emergency, and the leaves L can be sufficiently supplied with moisture. Therefore, transpiration from the leaves L can be facilitated to keep the leaf temperature constant, and it is possible to efficiently create an optimal cultivation environment for the plants.

In addition, in this embodiment, before operating the underground irrigation device 4, by increasing the lower limit value W _mth of culture medium moisture, which is the lower limit value of the culture medium moisture content, water stress on the plants PL is reduced in emergency compared to normal times. It can be alleviated. Therefore, the moisture content of the medium can be maintained at a higher level than normal, and moisture can be sufficiently supplied to the leaves L to promote transpiration from the leaves L.

In addition, after operating the underground irrigation system 4, the leaf water content is still in a low state below the starting side second leaf water lower limit value W _hth2s , and the leaf water content is in a large state where the leaf water content is higher than the first upper limit leaf water water reduction rate V _dth1 . If it is decreasing at a decreasing rate, underground irrigation alone is not enough to supply moisture to the leaves L, that is, there is a time lag between the recovery of the medium moisture content and the recovery of the leaf moisture content. In this case, by operating the surface watering device 5 to irrigate the surface 204a of the culture medium 204, water absorption from the roots R can be promoted to increase the leaf water content at an early stage, and the above-mentioned time lag can be reduced. The transpiration from L can be further smoothed. In this embodiment, the speed of water absorption from the roots can be further increased by watering the ground surface to the base of the plant, which is a region where a large number of capillary roots are present.

Furthermore, since the surface irrigation device 5 performs irrigation in a drip-like manner, the amount of water supplied per unit time is smaller than that of the underground irrigation device. Therefore, the time lag between the recovery of the medium moisture content and the recovery of the leaf moisture content can be reduced while avoiding the medium moisture content from becoming excessive.

Further, in this embodiment, after operating the ground irrigation device 5, the leaf water content is still in a low state below the starting side third leaf water lower limit W _hth3s , and the leaf water content is lower than the second upper limit leaf water reduction rate V _dth2. If the amount is decreasing at such a large rate, it means that the water supply to the leaves L is not enough with underground irrigation and surface irrigation alone. In this case, by operating the mist supply device 6 to spray mist onto the leaves L, water absorption from the leaves L can be promoted and transpiration from the leaves L can be further facilitated. Moreover, by spraying mist directly toward the leaves L, the leaf temperature can also be lowered.

The embodiments of the present invention have been described above in detail with reference to the drawings, but each configuration and combination thereof in the above embodiments are merely examples, and additions and omissions of configurations may be made without departing from the spirit of the present invention. , substitutions, and other changes are possible. Furthermore, the present invention is not limited by the embodiments, but only by the claims.

For example, after operating the underground irrigation device 4, the mist supply device 6 may be operated instead of the surface irrigation device 5, and the order of operation is the underground irrigation device 4 → the mist supply device 6 → the surface irrigation device 5. You can. Furthermore, after operating the underground irrigation device 4, the mist supply device 6 and the surface irrigation device 5 may be operated simultaneously.

Further, a temperature control device may be provided to keep the temperature of the culture medium 204 constant.
Furthermore, when the leaf temperature becomes equal to or higher than the leaf temperature upper limit value T _th , a light shielding curtain may be used to block the light incident on the plant PL.

Further, each of the above-mentioned predetermined values, which serve as a criterion when executing the water supply control program, may be set in advance (pre-selected) in the control device 7 as appropriate depending on the type of plant PL.

In addition, although the underground irrigation device 4 of the above-described embodiment performs irrigation into the culture medium 204 from the bottom surface 204b of the culture medium 204, it is not particularly limited to irrigation from the bottom surface 204b, and at least other than the surface 204a of the culture medium 204. Any device that can irrigate the culture medium 204 from the position shown in FIG.

Further, the underground irrigation device 4 may be provided individually for each of the plurality of cultivation containers 203. That is, for example, a water supply port 4a may be provided near each cultivation container 203. In this case, also in step S4 of the control flow described above, it is possible to determine the moisture content of the culture medium in parallel for each cultivation container 203.

According to the water supply control system and the like of the present invention, it is possible to smooth transpiration from leaves and efficiently create an optimal cultivation environment for plants.

1...Leaf temperature sensor 2...Leaf moisture sensor 3...Medium moisture sensor 4...Underground irrigation device 5...Surface irrigation device 6...Mist supply device 7...Control device 70...Computer 71...Leaf temperature determination section 72...Leaf temperature rise rate Determination unit 73...Medium moisture content lower limit adjustment unit 74...Adjusted medium moisture content determination unit 75...Underground irrigation start command unit 76...First leaf moisture content determination unit 77...Underground irrigation end command unit 78...First leaf moisture Volume reduction speed determining unit 79...Starting side second leaf water content determining unit 80...Ground surface irrigation start command unit 81...Ending side second leaf water content determining unit 82...Ground irrigation end command unit 83...Second leaf water content decreasing speed Determination unit 84...Starting side third leaf moisture content determination unit 85...Mist supply start commanding unit 86...Ending side third leaf moisture content determination unit 87...Mist supply end commanding unit 100...Water supply control system 204...Solid medium L...Leaf PL...Plant R...Root T _th ...Upper limit of leaf temperature V _dth1 ...First upper limit rate of decrease in leaf moisture V _dth2 ...Second upper limit rate of decrease in leaf moisture V _uth ...Upper limit rate of increase in leaf temperature W _hth1 ...Lowest limit of leaf moisture W _hth2s ... Lower limit of second leaf moisture on the starting side W _hth2e ... Lower limit of second leaf moisture on the ending side W _hth3s ... Lower limit of third leaf moisture on the starting side W _hth3e ... Lower limit of third leaf moisture on the ending side W _mth ... Lower limit of medium moisture value

Claims (9)

A water supply control system that controls water supply to plants,
a leaf temperature sensor that measures the leaf temperature of the plant;
a leaf moisture sensor that measures the moisture content of leaves of the plant;
an underground irrigation device for irrigating into a solid medium that supports the plants;
a control device that controls the operation of the underground irrigation system based on the measured values of the leaf temperature sensor and the leaf moisture sensor;
Equipped with
The control device includes:
When the measured value of the leaf temperature sensor is equal to or higher than a predetermined leaf temperature upper limit value, and the rate of increase in the measured value of the leaf temperature sensor is equal to or higher than the predetermined upper limit leaf temperature increase rate, the underground irrigation device is operated. an underground irrigation start command unit that operates to start irrigation into the solid medium;
After operating the underground irrigation device, when the measured value of the leaf moisture sensor exceeds a predetermined first lower limit of leaf moisture, the operation of the underground irrigation device is stopped and water is irrigated into the solid medium. an underground irrigation termination command unit that terminates the
Water supply control system with. Further comprising a surface irrigation device for irrigation on the surface of the solid medium,
The control device includes:
After operating the underground irrigation system, the measured value of the leaf moisture sensor is equal to or lower than the predetermined second leaf moisture lower limit on the starting side, and the rate of decrease of the measured value of the leaf moisture sensor is equal to or lower than the predetermined first lower limit value. a surface irrigation start command unit that operates the surface irrigation device to start irrigation to the surface of the solid medium when the upper limit leaf moisture reduction rate is exceeded;
After operating the ground irrigation device, when the measured value of the leaf moisture sensor exceeds a predetermined end-side second leaf moisture lower limit, the operation of the ground irrigation device is stopped and water is applied to the surface of the solid medium. a surface irrigation termination command unit that terminates irrigation;
The water supply control system according to claim 1, further comprising: 3. The water supply control system according to claim 2, wherein the ground irrigation device irrigations a plant base near the plant. The water supply control system according to claim 2 or 3, wherein the surface irrigation device has a smaller water supply amount per unit time than the underground irrigation device. further comprising a mist supply device that supplies mist-like moisture to the leaves of the plant,
The control device includes:
After operating the ground irrigation device, the measured value of the leaf moisture sensor is equal to or lower than the predetermined starting third leaf moisture lower limit, and the rate of decrease of the measured value of the leaf moisture sensor is equal to or lower than the first upper limit leaf moisture. a mist supply start command unit that operates the mist supply device to start supplying mist to the leaves when the moisture decrease rate reaches a second upper limit, which is higher than the moisture decrease rate;
After operating the mist supply device, when the measured value of the leaf moisture sensor exceeds a predetermined end-side third leaf moisture lower limit value, the operation of the mist supply device is stopped and the mist supply to the leaves is stopped. a mist supply termination command unit to terminate the mist supply;
The water supply control system according to claim 2, further comprising: further comprising a mist supply device that supplies mist-like moisture to the leaves of the plant,
The control device includes:
After operating the underground irrigation device, the measured value of the leaf moisture sensor is equal to or lower than the predetermined starting third leaf moisture lower limit, and the rate of decrease of the measured value of the leaf moisture sensor is the upper limit leaf moisture reduction. a mist supply start command unit that operates the mist supply device to start supplying mist to the leaves when the speed exceeds the speed;
After operating the mist supply device, when the measured value of the leaf moisture sensor exceeds a predetermined end-side third leaf moisture lower limit value, the operation of the mist supply device is stopped and the mist supply to the leaves is stopped. a mist supply termination command unit to terminate the mist supply;
The water supply control system according to claim 1, further comprising: Further comprising a medium moisture sensor that measures the moisture content of the solid medium,
When the measured value of the leaf temperature sensor is equal to or higher than a predetermined leaf temperature lower limit value, and the rate of increase in the measured value of the leaf temperature sensor is equal to or higher than a predetermined reference leaf temperature increase rate, the control device The method further includes a medium moisture changing unit that increases a predetermined medium moisture lower limit value, which is a lower limit value of the moisture content of the solid medium, before operating the underground irrigation system;
The underground irrigation start command unit operates the underground irrigation device to irrigate the solid culture medium when the measured value of the culture medium moisture sensor is equal to or less than the increased medium moisture lower limit value. The water supply control system according to any one of claims 1, 2, 5, and 6, wherein the water supply control system starts the water supply control system. A water supply control method for controlling water supply to plants, the method comprising:
When the measured value of the leaf temperature sensor that measures the leaf temperature of the plant is equal to or higher than a predetermined leaf temperature upper limit, and the rate of increase in the measured value of the leaf temperature sensor is equal to or higher than the predetermined upper limit leaf temperature increase rate. , a subsurface irrigation initiation step of initiating irrigation into a solid medium supporting the plants;
After the start of watering into the solid medium, when the measured value of a leaf moisture sensor that measures the amount of water in the leaves of the plant exceeds a predetermined lower limit of leaf moisture, the watering into the solid medium is stopped. medium irrigation end step;
water supply control methods including; In order to control water supply to plants, a computer is used to determine whether the measured value of a leaf temperature sensor that measures the leaf temperature of the plant is equal to or higher than a predetermined leaf temperature upper limit, and the rate of increase in the measured value of the leaf temperature sensor is underground irrigation starting means for starting watering into a solid medium that supports the plant when the rate of increase in leaf temperature reaches a predetermined upper limit; underground irrigation termination means for terminating irrigation into the solid medium when a measured value of a leaf moisture sensor that measures moisture content exceeds a predetermined lower limit of leaf moisture;
A water supply control program to function as a water supply control program.

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