Water supply control system, water supply control method, and water supply control program

Abstract

To provide a water supply control system or the like that makes transpiration from leaves smooth, and can efficiently prepare a cultivation environment optimum for plants.SOLUTION: A water supply control system comprises: a leaf temperature sensor 1 which measures a leaf temperature; a leaf moisture sensor 2 which measures the water content of leaves L; an underground watering device 4 which waters into a solid medium 204 supporting plants PL; and a controller 7 which controls an operation of the underground watering device 4 on the basis of the measured values of the leaf temperature sensor 1 and the leaf moisture sensor 2, where the controller 7 activates the underground watering device 4 to start watering into the solid medium 204 when the measured value of the leaf temperature sensor 1 is a leaf temperature upper limit Tth or more and a rising speed of the measured value of the leaf temperature sensor 1 reaches an upper limit leaf temperature rising speed Vuth or more, and stops an operation of the underground watering device 4 to end watering into the solid medium 204 when the measured value of the leaf moisture sensor 2 exceeds a first leaf moisture lower limit Whth1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] 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 a plant. [Background technology]

[0002] Conventionally, when cultivating plants, particularly crops, in a greenhouse, environmental conditions such as the amount of irrigation water, environmental temperature and humidity, amount of solar radiation, and soil temperature have been controlled in order to keep the plants healthy and improve the quality of the harvested product and maximize the yield. In recent years, the condition of the plants themselves has been sensed, and the environmental conditions in the greenhouse have been controlled to keep the plants in an optimal condition based on the condition of the plants themselves.

[0003] Here, Patent Document 1 describes a technology that senses leaf temperature, which is one of the indicators of the plant's own condition, and controls the leaf temperature by adjusting the plant's growing environment based on the leaf temperature, thereby increasing the yield. If the leaf temperature is too high, the efficiency of photosynthesis decreases, so leaf temperature is extremely important as an indicator of the plant's own condition. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6886656 Summary of the Invention [Problem to be solved by the invention]

[0005] As described in Patent Document 1, the leaves of plants have stomata. Plants have the function of cooling the leaves by the heat of vaporization when releasing moisture from the stomata and keeping the leaf temperature as constant as possible, so that the leaf temperature does not usually rise too much. However, in a high-temperature environment such as midsummer, the leaves are irradiated with a lot of ultraviolet light, and the leaves tend to become hot, so the amount and speed of transpiration from the leaves increase. As a result, the supply of moisture to the leaves cannot keep up with the amount and speed of transpiration from the leaves, and there is a possibility that the leaves cannot be sufficiently cooled by the heat of vaporization of transpiration.

[0006] 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 create an optimal cultivation environment for plants. [Means for solving the problem]

[0007] A water supply control system according to one embodiment of the present invention is a water supply control system that controls water supply to a plant, and comprises a leaf temperature sensor that measures the leaf temperature of the plant, a leaf moisture sensor that measures the moisture content of the leaves of the plant, an underground irrigation device that irrigates a solid medium supporting the plant, and a control device that controls the operation of the underground irrigation device based on the measurement values ​​of the leaf temperature sensor and the leaf moisture sensor.The control device has an underground irrigation start command unit that operates the underground irrigation device to start irrigating the solid medium when the measurement value of the leaf temperature sensor is equal to or greater than a predetermined upper leaf temperature limit and the rate of increase of the measurement value of the leaf temperature sensor is equal to or greater than a predetermined upper limit leaf temperature increase rate, and an underground irrigation end command unit that stops the operation of the underground irrigation device and ends the irrigation of the solid medium when the measurement value of the leaf moisture sensor exceeds a predetermined first leaf moisture lower limit after operating the underground irrigation device.

[0008] The irrigation control system further includes a surface irrigation device that irrigates the surface of the solid medium, and the control device may further include a surface irrigation start command unit that operates the surface irrigation device to start irrigating the surface of the solid medium when, after operating the underground irrigation device, the measurement value of the leaf moisture sensor is below a predetermined start side second leaf moisture lower limit value and the rate of decrease in the measurement value of the leaf moisture sensor becomes equal to or above a predetermined first upper limit leaf moisture decrease rate, and a surface irrigation end command unit that stops operation of the surface irrigation device to end irrigation of the surface of the solid medium when, after operating the surface irrigation device, the measurement value of the leaf moisture sensor exceeds a predetermined end side second leaf moisture lower limit value.

[0009] In the above-mentioned irrigation control system, the surface irrigation device may irrigate a base of the plant in the vicinity of the plant.

[0010] In the above irrigation control system, the surface irrigation device may supply less water per unit time than the underground irrigation device.

[0011] The irrigation control system further includes a mist supplying device that supplies mist-like moisture to the leaves of the plant, and the control device may further include a mist supply start command unit that operates the mist supplying device to start supplying mist to the leaves when, after operating the surface irrigation device, the measurement value of the leaf moisture sensor is below a predetermined start-side third leaf moisture lower limit value and the rate of decrease in the measurement value of the leaf moisture sensor becomes equal to or greater than a second upper limit leaf moisture decrease rate that is greater than the first upper limit leaf moisture decrease rate, and a mist supply end command unit that stops the operation of the mist supplying device and ends the supply of mist to the leaves when, after operating the mist supplying device, the measurement value of the leaf moisture sensor exceeds a predetermined end-side third leaf moisture lower limit value.

[0012] The irrigation control system further includes a mist supplying device that supplies mist-like moisture to the leaves of the plant, and the control device may further include a mist supply start command unit that operates the mist supplying device to start supplying mist to the leaves when, after operating the underground irrigation device, the measurement value of the leaf moisture sensor is below a predetermined start side third leaf moisture lower limit value and the rate of decrease in the measurement value of the leaf moisture sensor becomes equal to or above an upper limit leaf moisture decrease rate, and a mist supply end command unit that stops the operation of the mist supplying device and ends the supply of mist to the leaves when, after operating the mist supplying device, the measurement value of the leaf moisture sensor exceeds a predetermined end side third leaf moisture lower limit value.

[0013] The irrigation control system further includes a medium moisture sensor that measures the moisture content of the solid medium, and the control device further includes a medium moisture changing unit that increases a predetermined medium moisture lower limit, which is the lower limit of the moisture content of the solid medium, before operating the sub-surface irrigation device when the measurement value of the leaf temperature sensor is equal to or higher than a predetermined leaf temperature lower limit and the rate of increase of the measurement value of the leaf temperature sensor is equal to or higher than a predetermined standard leaf temperature increase rate, and the sub-surface irrigation command unit may operate the sub-surface irrigation device to start irrigating the solid medium when the measurement value of the medium moisture sensor is equal to or lower than the increased medium moisture lower limit.

[0014] A water supply control method according to one embodiment of the present invention is a water supply control method for controlling water supply to a plant, and includes an underground irrigation starting step of starting irrigation into a solid medium supporting the plant when a measurement value of a leaf temperature sensor that measures the leaf temperature of the plant is equal to or higher than a predetermined upper leaf temperature limit value and the rate of increase of the measurement value of the leaf temperature sensor is equal to or higher than a predetermined upper limit leaf temperature increase rate, and an underground irrigation ending step of ending irrigation into the solid medium when, after the start of irrigation into the solid medium, a measurement value of a leaf moisture sensor that measures the moisture content of the leaves of the plant exceeds a predetermined leaf moisture lower limit value.

[0015] A water supply control program according to one embodiment of the present invention controls water supply to a plant by causing a computer to function as an underground irrigation starting means for starting watering into a solid medium supporting the plant when a measurement value of a leaf temperature sensor that measures the leaf temperature of the plant is equal to or higher than a predetermined upper leaf temperature limit and the rate of increase of the measurement value of the leaf temperature sensor is equal to or higher than a predetermined upper limit leaf temperature increase rate, and an underground irrigation ending means for ending watering into the solid medium when, after the start of watering into the solid medium, a measurement value of a leaf moisture sensor that measures the moisture content of the leaves of the plant exceeds a predetermined leaf moisture lower limit. Effect of the Invention

[0016] The above-described water supply control system and the like can facilitate smooth transpiration from the leaves, and efficiently create an optimal cultivation environment for plants. [Brief description of the drawings]

[0017] [Figure 1] 1 is an overall schematic diagram of a water supply control system according to an embodiment of the present invention, in which a cultivation bed is shown in vertical cross section for ease of explanation. [Diagram 2] 2 is a hardware configuration diagram of a control device in the above-mentioned water supply control system. [Diagram 3] 3 is a functional block diagram of a control device in the water supply control system. FIG. [Figure 4] 4 is a flowchart showing a control flow in the water supply control system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] (Overall composition) As shown in FIG. 1, the water supply control system 100 is a device that controls water supply to a plant PL. In this embodiment, the water supply control system 100 is provided in a cultivation device 200 that includes 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 a solid medium 204 (which may be "soil"; hereinafter, simply referred to as a medium) contained in each cultivation container 203. 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. Note that the above-described cultivation device 200 is merely an example, and the configuration can be changed as appropriate.

[0019] A bottom hole 203a is provided in the bottom of each cultivation container 203, and moisture (water or nutrient solution) from the water retention mat 202 is supplied to the culture medium 204 through the roots R extending from inside to outside of the cultivation container 203 through the bottom hole 203a. That is, in this embodiment, water is irrigated into the culture medium 204 from a 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.

[0020] (Water supply control system) Next, the water supply control system 100 will be described. The water supply control system 100 includes a leaf temperature sensor 1 that measures the temperature of the leaf surface of the leaves L of the plant PL (hereinafter referred to as leaf temperature), a leaf moisture sensor 2 that measures the moisture content of the leaves L (hereinafter referred to as leaf moisture content), a medium moisture sensor 3 that measures the moisture content of the culture medium 204 (hereinafter referred to as culture medium moisture content), an underground irrigation device 4 that irrigates the culture medium 204, a surface irrigation device 5 that irrigates the surface (upper surface) 204a of the culture medium 204, a mist supply device 6 that supplies (sprays) mist to the leaves L, and a control device 7 that controls the operation of the underground irrigation device 4, the surface irrigation device 5, and the mist supply device 6 based on the measurement values ​​of each of the sensors 1, 2, and 3.

[0021] The water supply control system 100 further includes a pump 8, which supplies water from a water source (not shown) to the underground irrigation device 4, the surface irrigation device 5, and the mist supply device 6.

[0022] (Sensor) The leaf temperature sensor 1 is not particularly limited, but a sensor device such as a radiation temperature sensor that detects infrared rays or a thermistor temperature sensor is preferably used. The leaf temperature sensor 1 is configured to perform measurement constantly (for example, every 30 seconds to 1 minute). The leaf temperature sensor 1 is provided for each cultivation container 203.

[0023] The leaf moisture sensor 2 is not particularly limited, but an irradiation-type sensor device that irradiates near-infrared rays onto the leaves L and calculates the leaf moisture content from the amount of reflection is preferably used. The leaf moisture sensor 2 may also be a sensor device that determines the wilting state of the leaves L from an image of the leaves and calculates the leaf moisture content based on the determined wilting state. The leaf moisture sensor 2 is configured to perform measurements constantly (for example, every 30 seconds to 1 minute). The leaf moisture sensor 2 is provided for each cultivation container 203. It is preferable that the leaf moisture sensor 2 is installed near the growing point of the plants PL.

[0024] The medium moisture sensor 3 is not particularly limited, but a sensor device that is inserted into the medium 204 from the surface 204a and can calculate the moisture content of the medium 204 from the resistance value, dielectric constant, etc. of the medium 204 is preferably used. The medium moisture sensor 3 is designed to perform measurements constantly (for example, every 30 seconds to 1 minute). The medium moisture sensor 3 is provided for each cultivation container 203.

[0025] (Underground irrigation device) The sub-ground irrigation device 4 is a device that supplies water to the water retention mat 202, thereby irrigating the medium 204 from the bottom surface 204b of the medium 204 through the water retention mat 202 as described above. Specifically, the sub-ground irrigation device 4 has 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.

[0026] (Surface irrigation device) The surface irrigation device 5 is a device that irrigates the surface (upper surface) 204a of the culture medium 204. The surface irrigation device 5 irrigates the base of the plant near the plant PL, that is, the area where many roots (capillary roots) R of the plant PL are present. Specifically, the surface irrigation device 5 has a water supply nozzle 5a that supplies water by drip to the base of the plant, and an electromagnetic valve 5b provided between the water supply nozzle 5a and the pump 8, and is provided for each cultivation container 203.

[0027] The surface irrigation device 5 is capable of irrigating at intervals of minutes, for example, like drip irrigation in seconds. The surface irrigation device 5 supplies less water per unit time than the underground irrigation device 4, and irrigates at a discharge rate of about 20 ml / min. The irrigation time and amount by the surface irrigation device 5 may be controlled by the control device 7, which will be described in detail later, or by a control device (not shown) provided separately from the control device 7.

[0028] (Mist supply device) The mist supplying device 6 is a device that sprays and supplies mist-like moisture toward the leaves L. Specifically, the mist supplying device 6 has a spray nozzle 6a that sprays moisture and an electromagnetic valve 6b provided between the spray nozzle 6a and the pump 8, and is provided for each cultivation container 203.

[0029] The mist sprayed from the mist supplying device 6 is preferably as small as possible, and the particle size is 10 μm to 100 μm, preferably 70 μm or less. The mist supplying device 6 is controlled so that the spraying time is controlled based on the measurement result of a sensor (not shown) that detects the wetness of the leaves L, and the amount of water sprayed is stopped until the water on the surface of the leaves L evaporates after the amount of water sprayed is enough to keep the water on the surface of the leaves L without running off from the surface of the leaves L. That is, the mist supplying device 6 is designed to operate intermittently (for example, with a spraying time of about 10 to 20 seconds) like the surface irrigation device 5. The spraying time and amount of sprayed by the mist supplying device 6 may be controlled by the control device 7 described in detail later, or by a control device (not shown) provided separately from the control device 7. The intermittent operation control may be performed so that mist spraying is started when the humidity of the atmosphere near the plant PL becomes equal to or lower than a predetermined value, or the intermittent operation control may be performed so that mist spraying is stopped when the leaf temperature becomes equal to or lower than a predetermined value.

[0030] (Control device) 2, the control device 7 has a computer 70, which has a CPU (Central Processing Unit) 700, a memory 710 such as a ROM (Read Only Memory) or a RAM (Random Access Memory), a non-volatile storage device 720 such as a HDD (Hard Disk Drive) or an SSD (Solid State Drive), a power supply device 730, an input interface 740, an output interface 750, and a bus wiring 760 connecting these. The CPU 700 is a central processing unit and executes a water supply control program described later. The memory 710 is used as a working area and a storage area for the CPU 700, and the storage device 720 stores an operating system, programs, etc. executed by the CPU 700.

[0031] As shown in Figure 3, the computer 70 of the control device 7 has a leaf temperature determination unit 71, a leaf temperature rise rate determination unit 72, a medium moisture content lower limit adjustment unit 73, an adjusted medium moisture content determination unit 74, an underground irrigation start command unit 75, a first leaf moisture content determination unit 76, an underground irrigation end command unit 77, a first leaf moisture content decrease rate determination unit 78, a start side second leaf moisture content determination unit 79, a surface irrigation start command unit 80, an end side second leaf moisture content determination unit 81, a surface irrigation end command unit 82, a second leaf moisture content decrease rate determination unit 83, a start side third leaf moisture content determination unit 84, a mist supply start command unit 85, an end side third leaf moisture content determination unit 86, and a mist supply end command unit 87.

[0032] The leaf temperature determination unit 71 determines whether the measurement value of the leaf temperature sensor 1 is equal to or lower than a predetermined leaf temperature upper limit value T th Determine whether the leaf temperature is above [℃]. th is a value that is set appropriately depending on the type of plant, etc. For example, if the plant PL is a tomato, it is set to 13 [° C.], which is the upper limit at which the leaves L are thought not to wilt.

[0033] The leaf temperature rise rate determination unit 72 is configured to determine whether the rate of rise in the measurement value of the leaf temperature sensor 1 is equal to or lower than a predetermined upper limit leaf temperature rise rate V uth It is determined whether the temperature is above [°C / sec].

[0034] The medium moisture content lower limit adjustment unit 73 adjusts the medium moisture content lower limit W mth That is, the medium moisture content lower limit adjusting unit 73 adjusts the medium moisture content lower limit W under predetermined conditions according to the control flow described later. mth Increase or decrease.

[0035] The adjusted medium moisture content determination unit 74 determines the medium moisture lower limit value W after the measurement value of the medium moisture sensor 3 is increased by the medium moisture content lower limit adjustment unit 73. mth Determine whether the following is true:

[0036] The underground irrigation start command unit 75 is configured to start the underground irrigation when the measurement value of the leaf temperature sensor 1 reaches the 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 Vuth When this is the case, the solenoid valve 4b of the underground irrigation device 4 is opened to operate the underground irrigation device 4 and supply water toward the water retention mat 202, thereby starting watering the medium 204 from the bottom surface 204b of the medium 204 through the water retention mat 202.

[0037] The first leaf moisture content determination unit 76 determines whether the measurement value of the leaf moisture sensor 2 is equal to or lower than a predetermined first leaf moisture lower limit value W hth1 Determine whether the following is true:

[0038] The underground irrigation end command unit 77 is configured to stop the underground irrigation when the measurement value of the leaf moisture sensor 2 reaches the first leaf moisture lower limit value W hth1 When the pressure exceeds the limit, the solenoid valve 4b of the sub-surface irrigation device 4 is closed to stop the operation of the sub-surface irrigation device 4, thereby terminating the irrigation of the medium 204.

[0039] The first leaf moisture content reduction rate determination unit 78 is configured to determine whether the reduction rate of the measurement value of the leaf moisture sensor 2 is a predetermined first upper limit leaf moisture reduction rate V dth1 It is determined whether the temperature is above [°C / sec].

[0040] The start-side second leaf moisture content determination unit 79 is configured to determine whether the measurement value of the leaf moisture sensor 2 is a predetermined start-side second leaf moisture lower limit value W hth2s Determine whether the following is true:

[0041] After the surface irrigation start command unit 80 operates the underground irrigation device 4, the measurement value of the leaf moisture sensor 2 is set to the start side second leaf moisture lower limit value W hth2s The rate of decrease in the measurement value of the leaf moisture sensor 2 is equal to or lower than the first upper limit leaf moisture decrease rate V dth1 When the above is true, the solenoid valve 5b of the surface irrigation device 5 is opened to operate the surface irrigation device 5 and start irrigating the surface 204a of the culture medium 204.

[0042] The end-side second leaf moisture content determination unit 81 is configured to determine whether or not the measurement value of the leaf moisture sensor 2 is equal to or lower than the predetermined end-side second leaf moisture lower limit value W after the surface irrigation device 5 is operated. hth2e Determine whether the following is true:

[0043] After the surface irrigation device 5 is operated, the surface irrigation end command unit 82 determines whether the measurement value of the leaf moisture sensor 2 reaches the end side second leaf moisture lower limit value W hth2e When the pressure exceeds the limit, the solenoid valve 5b of the surface irrigation device 5 is closed to stop the operation of the surface irrigation device 5, thereby ending the irrigation of the surface 204a of the culture medium 204.

[0044] The second leaf moisture content reduction rate determination unit 83 is configured to determine whether the reduction rate of the measurement value of the leaf moisture sensor 2 is a first upper limit leaf moisture reduction rate V dth1 The second upper limit of leaf water loss rate V dth2 It is determined whether or not the value is equal to or greater than this value.

[0045] The start-side third leaf moisture content determination unit 84 is configured to determine whether the measurement value of the leaf moisture sensor 2 is equal to or lower than a predetermined start-side third leaf moisture lower limit value W hth3s Determine whether the following is true:

[0046] After the surface irrigation device 5 is operated, the mist supply start command unit 85 starts the mist supply start command when the measurement value of the leaf moisture sensor 2 reaches the start side third leaf moisture lower limit value W hth3s The rate of decrease in the measurement value of the leaf moisture sensor 2 is equal to or lower than the second upper limit leaf moisture decrease rate V dth2 When this is the case, the solenoid valve 6b of the mist supplying device 6 is opened to operate the mist supplying device 6 and start supplying mist to the leaves L.

[0047] The end-side third leaf moisture content determination unit 86 is configured to determine whether or not the measurement value of the leaf moisture sensor 2 is equal to or greater than the predetermined end-side third leaf moisture lower limit value W after the mist supply device 6 is operated. hth3e Determine whether the following is true:

[0048] After the mist supply device 6 is operated, the mist supply end command unit 87 is configured to stop the mist supply when the measurement value of the leaf moisture sensor 2 reaches the end side third leaf moisture lower limit value W hth3e When the amount of mist exceeds the limit, the solenoid valve 6b of the mist supply device 6 is closed to stop the operation of the mist supply device 6 and terminate the supply of mist to the leaves L.

[0049] Next, with reference to FIG. 4, the flow of the water-supply control program (water-supply control method) will be described. In the following description, "leaf temperature," "leaf moisture content," and "culture medium moisture content" all indicate the measured values ​​of sensors 1, 2, and 3. The following control flow is executed in parallel for each cultivation container 203. First, step S1 is executed, and the leaf temperature is set to the upper limit T th It is judged whether the leaf temperature is equal to or higher than the upper limit T th If the leaf temperature is equal to or higher than the upper limit T th If it is less than the limit, the determination is "NO" and the process returns to step S1. If the answer in step S1 is "NO", the system is in "normal" state. In this "normal" state, the underground irrigation device 4 is operated appropriately, and the measurement value of the culture medium moisture sensor 3 and the discharge rate from the pump 8 are constantly monitored by a sensor (not shown) to keep the culture medium moisture at an optimum level. On the other hand, if the answer in step S1 is "YES", the system is in "emergency" state, and control proceeds according to the following flow.

[0050] In step S2, if the answer to step S1 is "YES", the rate of increase in the leaf temperature is determined to be the upper limit of the leaf temperature increase rate V uth It is judged whether the rate of increase in leaf temperature is equal to or higher than the upper limit of the leaf temperature increase rate V uth If the leaf temperature increase rate is equal to or higher than the upper limit leaf temperature increase rate V uth If it is less than the limit, the determination is "NO" and the process returns to step S1.

[0051] In step S3, if the determination in step S2 is "YES", the lower limit of the medium moisture W mth For example, if the volumetric water content (VWC) of the culture medium 204 is 48 during normal times when the water supply control program of this embodiment is not running, 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 by, for example, about 1 to 3 compared to the normal value.

[0052] Then, step S4 is executed. In step S4, the lower limit W mth Determine whether the medium moisture content is below the lower limit W mth If it is equal to or less than the lower limit W of the medium moisture content after the increase, the determination is "YES" and the process proceeds to step S5. mth If the moisture content of at least one of the cultivation containers 203 exceeds the lower limit W of the cultivation container 203, the result is determined as "NO" and the process returns to step S1. mth If the following is true, the answer is determined to be "YES."

[0053] In step S5, if the determination in step S4 is "YES", the sub-surface irrigation device 4 is operated to start sub-surface irrigation.

[0054] Next, step S6 is executed. In step S6, the leaf moisture content is set to the first leaf moisture lower limit W hth1 It is judged whether the leaf moisture content is below the first leaf moisture lower limit W hth1 If the leaf moisture content is equal to or less than the first leaf moisture lower limit W hth1 If the leaf moisture content of the plants PL in all the cultivation containers 203 exceeds the first leaf moisture lower limit W hth1 If the value exceeds the threshold, the result will be “NO.”

[0055] In step S61, if the result of the determination in step S6 is "NO", the operation of the subsurface irrigation device 4 is stopped to end the subsurface irrigation. Then, the process proceeds to step S62, where the medium moisture lower limit value W mth to return it to a normal value (e.g., volumetric water content (VWC) of 48).

[0056] In step S7, the rate of decrease in leaf water content is determined to be equal to or lower than the first upper limit leaf water decrease rate V dth1It is judged whether the rate of decrease in leaf water content is equal to or greater than the first upper limit of the leaf water decrease rate V dth1 If the leaf water content is greater than or equal to the first upper limit leaf water content reduction rate V dth1 If it is less than the limit, the determination is "NO" and the process returns to step S6.

[0057] In step S8, the leaf moisture content is set to the second leaf moisture lower limit value W hth2s It is judged whether the leaf water content is equal to or less than the second leaf water content lower limit W hth2s If the leaf moisture content is equal to or less than the second leaf moisture lower limit W hth2s If it exceeds the lower limit W hth2s is the first leaf moisture limit W hth1 It may be equal to the first leaf moisture lower limit W hth1 It may be a value smaller than

[0058] In step S9, if the determination in step S8 is "YES", the surface irrigation device 5 is operated to start surface irrigation.

[0059] Then, step S10 is executed. In step S10, the leaf moisture content is adjusted to the end side second leaf moisture lower limit value W hth2e It is judged whether the leaf moisture content is equal to or less than the second end side leaf moisture lower limit W hth2e If the leaf moisture content is equal to or less than the second end-side leaf moisture lower limit W hth2e If it exceeds the lower limit W hth2e is the lower limit of the second leaf moisture on the starting side W hth2s To avoid chattering, the lower limit of moisture in the second leaf on the starting side W hth2s It may be a value larger than

[0060] In step S101, if the determination in step S10 is "NO", the operation of the surface irrigation device 5 is stopped to end the surface irrigation, and then the process returns to step S6.

[0061] In step S11, the rate of decrease in leaf water content is determined to be equal to or lower than the second upper limit leaf water decrease rate V dth2 It is judged whether the rate of decrease in leaf water content is equal to or greater than the second upper limit of the leaf water decrease rate V dth2 If the leaf water content is greater than or equal to the second upper limit leaf water content reduction rate V dth2 If it is less than the limit, the determination is "NO" and the process returns to step S10.

[0062] In step S12, if the determination in step S11 is "YES", the leaf water content is set to the start side third leaf water lower limit W hth3s It is judged whether the leaf water content is equal to or less than the third leaf water content lower limit W hth3s If the leaf moisture content is equal to or less than the start side third leaf moisture lower limit W hth3s If it exceeds the lower limit W hth3s is the lower limit of the second leaf moisture on the starting side W hth2s It may be equal to the lower limit of moisture in the second leaf on the starting side W hth2s It may be a value smaller than

[0063] In step S13, if the determination in step S12 is "YES", the mist supply device 6 is operated to start supplying (spraying) mist.

[0064] Then, step S14 is executed. In step S14, the leaf moisture content is set to the end side third leaf moisture lower limit value W hth3e It is judged whether the leaf moisture content is equal to or less than the third leaf moisture lower limit W hth3e If the leaf moisture content is equal to or less than the end-side third leaf moisture lower limit W hth3eIf it exceeds the lower limit W hth3e is the lower limit of the moisture content of the third leaf on the starting side W hth3s To avoid chattering, the lower limit of moisture in the third leaf on the starting side W hth3s It may be a value larger than

[0065] In step S15, if the determination in step S14 is "NO", the operation of the mist supply device 6 is stopped to end the mist supply (spray), and then the process returns to step S10.

[0066] (Action and effect) According to the water supply control system 100 of the present embodiment described above, the leaf temperature is set to the upper limit value T th When the transpiration from the leaf L is high, the rate of increase in the leaf temperature reaches the upper limit V uth When the above conditions are met, it is considered that the supply of water to the leaves L is delayed relative to the amount and speed of transpiration from the leaves L, causing a shortage of leaf water content, and an emergency occurs. In this case, in this embodiment, the underground irrigation device 4 can be operated, so that the medium water content can be increased in an emergency, and sufficient water can be supplied to the leaves L. This makes it possible to facilitate transpiration from the leaves L and keep the leaf temperature constant, thereby efficiently creating an optimal cultivation environment for plants.

[0067] In this embodiment, before the underground irrigation device 4 is operated, a lower limit value W mth By increasing the amount of water in the medium, the water stress on the plant PL can be alleviated in an emergency compared to normal times. Therefore, the amount of water in the medium can be kept higher than normal, sufficient water is supplied to the leaves L, and transpiration from the leaves L can be promoted.

[0068] In addition, after the underground irrigation device 4 is operated, the leaf moisture content is still below the second leaf moisture lower limit W hth2s The leaf water content is in a low state below the first upper limit of the leaf water loss rate V dth1When the water content is decreasing at such a large rate, the supply of water to the leaves L is not enough by underground irrigation alone, that is, there is a time lag between the recovery of the medium water content and the recovery of the leaf water content. In this case, by operating the surface irrigation device 5 to irrigate the surface 204a of the medium 204, water absorption from the roots R can be promoted and the leaf water content can be increased early, the time lag can be reduced, and transpiration from the leaves L can be further facilitated. In this embodiment, the rate of water absorption from the roots can be further increased by performing surface irrigation at the base of the plant, which is an area where many capillary roots are present.

[0069] Furthermore, the surface irrigation device 5 irrigates in a drip-like manner, so the amount of water supplied per unit time is smaller than that of an underground irrigation device. This makes it possible to prevent the medium from becoming too moist and to reduce the time lag between the recovery of the medium moisture and the recovery of the leaf moisture.

[0070] In this embodiment, even after the surface irrigation device 5 is operated, the leaf moisture content is still below the third leaf moisture lower limit W hth3s The leaf water content is in a low state below the second upper limit of the leaf water loss rate V dth2 When the rate of decrease is as large as the above, it means that underground irrigation and surface irrigation alone are not enough to supply moisture to the leaves L in time. In this case, operating the mist supplying device 6 to spray mist onto the leaves L can promote moisture absorption from the leaves L and further facilitate transpiration from the leaves L. Also, spraying mist directly onto the leaves L can lower the leaf temperature.

[0071] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the configurations and their combinations in the above-mentioned embodiments are merely examples, and addition, omission, substitution, and other modifications of the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments, but is limited only by the claims.

[0072] For example, after the underground irrigation device 4 is operated, the mist supplying device 6 may be operated instead of the surface irrigation device 5, or the operations may be performed in the order of the underground irrigation device 4 → the mist supplying device 6 → the surface irrigation device 5. Furthermore, after the underground irrigation device 4 is operated, the mist supplying device 6 and the surface irrigation device 5 may be operated simultaneously.

[0073] A temperature regulator may also be provided to keep the temperature of the culture medium 204 constant. Furthermore, the leaf temperature exceeds the upper limit T th When this occurs, the light incident on the plant PL may be blocked by a light-shielding curtain.

[0074] Furthermore, each of the above-mentioned predetermined values ​​that serve as criteria for judgment when the water supply control program is executed may be able to be preset (preselected) in the control device 7 as appropriate according to the type of plant PL.

[0075] Furthermore, although the underground irrigation device 4 of the above-described embodiment is configured to irrigate the culture medium 204 from the bottom surface 204b of the culture medium 204, the device is not particularly limited to irrigation from the bottom surface 204b, and may be any device that irrigates the culture medium 204 from at least a position other than the surface 204a of the culture medium 204.

[0076] Further, the underground irrigation device 4 may be provided for each of the plurality of cultivation containers 203. That is, for example, the water supply port 4a may be provided near each cultivation container 203. In this case, it is possible to determine the moisture content of the medium for each cultivation container 203 in parallel also in step S4 of the above control flow. [Industrial Applicability]

[0077] According to the water supply control system of the present invention, it is possible to facilitate transpiration from the leaves and efficiently create an optimal cultivation environment for plants. [Explanation of symbols]

[0078] 1...Leaf temperature sensor 2. Leaf moisture sensor 3. Culture medium moisture sensor 4…Underground irrigation device 5…Surface irrigation device 6…Mist supply device 7...Control device 70...Calculator 71...Leaf temperature determination section 72…Leaf temperature rise rate determination section 73...Medium moisture lower limit adjustment unit 74…Adjusted medium moisture content determination section 75…Underground irrigation start command center 76...First leaf water content determination section 77…Underground irrigation end command center 78…First leaf water content reduction rate determination unit 79...Starting side second leaf moisture content determination section 80…Surface irrigation start command unit 81...End side second leaf water content determination unit 82…Surface irrigation end command center 83…Second leaf water content reduction rate determination unit 84…Starting side third leaf water content determination section 85…Mist supply start command unit 86…End side third leaf moisture content judgment part 87…Mist supply termination command center 100...Water supply control system 204...Solid medium L…leaf PL…Plant R…root T th …Leaf temperature upper limit V dth1 …First upper limit leaf water reduction rate V dth2 …Second upper limit leaf water reduction rate V uth …Upper limit leaf temperature rise rate W hth1 …First leaf moisture limit W hth2s …Start side second leaf moisture limit W hth2e …Lower limit of moisture in second leaf on end side W hth3s …Lower limit of moisture in the third leaf on the starting side W hth3e …Lower limit of moisture in the third leaf on the end side W mth…Lower limit of medium moisture

Claims

1. A water supply control system for controlling water supply to a plant, comprising: A leaf temperature sensor that measures the leaf temperature of the plant; A leaf moisture sensor that measures the moisture content of the leaves of the plant; An underground irrigation device for irrigating a solid medium supporting the plant; A control device that controls the operation of the underground irrigation device based on the measurement values ​​of the leaf temperature sensor and the leaf moisture sensor; Equipped with The control device includes: an underground irrigation start command unit that operates the underground irrigation device to start irrigating the solid medium when the measurement 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 measurement value of the leaf temperature sensor is equal to or higher than a predetermined upper limit of leaf temperature increase rate; An underground irrigation end command unit that stops the operation of the underground irrigation device and ends irrigation into the solid medium when the measurement value of the leaf moisture sensor exceeds a predetermined first leaf moisture lower limit value after the underground irrigation device is operated; A water supply control system having the above structure.

2. Further comprising a surface irrigation device for irrigating the surface of the solid medium; The control device includes: a surface irrigation start command unit that operates the surface irrigation device to start irrigating the surface of the solid medium when the measurement value of the leaf moisture sensor is equal to or lower than a predetermined second leaf moisture lower limit value on the start side and the rate of decrease of the measurement value of the leaf moisture sensor is equal to or higher than a predetermined first upper limit leaf moisture decrease rate after the underground irrigation device is operated; A surface irrigation end command unit that stops the operation of the surface irrigation device and ends irrigation of the surface of the solid medium when the measurement value of the leaf moisture sensor exceeds a predetermined end side second leaf moisture lower limit value after the surface irrigation device is operated; The water supply control system further comprises:

3. The water supply control system according to claim 2 , wherein the surface irrigation device irrigates a base of the plant in the vicinity of the plant.

4. 4. The water supply control system according to claim 2, wherein the surface irrigation device supplies less water per unit time than the underground irrigation device.

5. The method further includes a mist supplying device that supplies water in the form of a mist to the leaves of the plant. The control device includes: a mist supply start command unit that operates the mist supply device to start supplying mist to the leaves when, after operating the surface irrigation device, the measurement value of the leaf moisture sensor is equal to or lower than a predetermined start side third leaf moisture lower limit value and the rate of decrease of the measurement value of the leaf moisture sensor is equal to or higher than a second upper limit leaf moisture decrease rate that is greater than the first upper limit leaf moisture decrease rate; A mist supply end command unit that stops the operation of the mist supply device and ends the mist supply to the leaves when the measurement 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 water supply control system according to claim 2 , further comprising:

6. The method further includes a mist supplying device that supplies water in the form of a mist to the leaves of the plant. The control device includes: a mist supply start command unit that operates the mist supply device to start supplying mist to the leaves when the measurement value of the leaf moisture sensor is equal to or lower than a predetermined start side third leaf moisture lower limit value and the rate of decrease of the measurement value of the leaf moisture sensor is equal to or higher than an upper limit leaf moisture decrease rate after the underground irrigation device is operated; A mist supply end command unit that stops the operation of the mist supply device and ends the mist supply to the leaves when the measurement 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 water supply control system of claim 1 further comprising:

7. Further comprising a medium moisture sensor for measuring the moisture content of the solid medium; The control device further includes a medium moisture change 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 device when the measurement value of the leaf temperature sensor is equal to or higher than a predetermined leaf temperature lower limit value and the rate of increase of the measurement value of the leaf temperature sensor is equal to or higher than a predetermined reference leaf temperature increase rate, A water supply control system as described in any one of claims 1, 2, 5, and 6, wherein the underground irrigation command unit operates the underground irrigation device to start irrigating the solid medium when the measurement value of the culture medium moisture sensor is below the increased culture medium moisture lower limit value.

8. A water supply control method for controlling water supply to a plant, comprising: an underground irrigation starting step of starting irrigation into a solid medium supporting the plant when a measurement value of a leaf temperature sensor that measures the leaf temperature of the plant is equal to or higher than a predetermined upper limit of the leaf temperature and the rate of increase of the measurement value of the leaf temperature sensor is equal to or higher than a predetermined upper limit of the leaf temperature increase rate; an underground irrigation termination step of terminating the irrigation into the solid medium when a measurement value of a leaf moisture sensor that measures the moisture content of the leaves of the plant exceeds a predetermined leaf moisture lower limit value after the start of irrigation into the solid medium; A water supply control method comprising:

9. A computer is used to control the water supply to the plants. an underground irrigation starting means for starting irrigation into a solid medium supporting the plant when a measurement value of a leaf temperature sensor for measuring the leaf temperature of the plant is equal to or higher than a predetermined upper limit of leaf temperature and the rate of increase of the measurement value of the leaf temperature sensor is equal to or higher than a predetermined upper limit of leaf temperature increase rate; a subsurface irrigation termination means for terminating irrigation into the solid medium when a measurement value of a leaf moisture sensor for measuring the moisture content of the leaves of the plant exceeds a predetermined leaf moisture lower limit value after irrigation into the solid medium is started; A water supply control program to function as a

Images