Cultivation device and cultivation method

Abstract

To use solar heat efficiently with an inexpensive structures in an agricultural facility.SOLUTION: A cultivation device of an embodiment includes: a housing arranged along a side face of a raised ridge provided in an agricultural facility for cultivating crops; a water supply mechanism for supplying water into the housing; a drainage mechanism for draining water from the housing; and a control unit for controlling the operation of at least one of the water supply mechanism and the drainage mechanism. The housing is filled with a thermal insulating material, and the control unit controls the supply or drainage of water to or from an area filled with the thermal insulating material to control a thermal conductivity within the housing.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cultivation device and a cultivation method for agricultural crops. [Background technology]

[0002] In recent years, there has been a call to reconsider agricultural systems that rely on fossil fuels. Heating agricultural facilities is a major source of carbon dioxide emissions due to fossil fuel consumption, and reducing this is important for realizing a decarbonized agricultural society. For example, strawberries are a winter crop, and room temperature is typically heated to ensure yields. However, in recent years, it has become clear that soil cultivation using raised beds can ensure workability while ensuring a certain yield without heating in winter. However, there are issues with yields being lower than when the room is heated, and with yields decreasing in cold winters. Therefore, there is a need for technology that can stabilize soil temperature without heating and enable stable crop cultivation.

[0003] Conventionally, there is known a technique for using rice husk as an insulating material in order to prevent the melting of snow mountains and utilize cold energy (see, for example, Non-Patent Document 1). Conventionally, there are also known techniques for changing the thermal conductivity by changing the crystal structure or by changing the moisture content of the insulating material (see, for example, Patent Document 1). Conventionally, there are also known techniques for storing heat during the day in water-filled tubes or heat-storage tanks and releasing it at night, as well as techniques for keeping the base of plants warm using insulating material and for storing heat during the day in cultivation beds made of stones with high specific heat (see, for example, Non-Patent Documents 2 and 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 60-109829 [Non-patent literature]

[0005] [Non-Patent Document 1] Yasushi Uemura et al., "Heat Transfer Process of Rice Husks as a Thermal Insulating Coating Material for Snow Storage, Part 1: Open-Air Snow Storage Experiments and Physical Property Measurements," Japanese Society of Snow and Ice, Journal of the Japanese Society of Snow and Ice, Vol. 70, No. 1, pp. 15-22, January 2008 [Non-patent document 2] Hiroki Kawashima et al., "The Effect of Using Multi-Layer Thermal Insulation Materials and Water Heat Storage on the Heating Load of a Pipe Greenhouse," Agricultural Facilities Society, Agricultural Facilities, Vol. 44, No. 2, pp. 23-32, June 2013 [Non-patent document 3] "Development of efficient thermal energy utilization technology in greenhouse agriculture," Ministry of Agriculture, Forestry and Fisheries, Agriculture, Forestry and Fisheries Research Council Secretariat, Project Research Results Series 576, pp.1-125, March 2017 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the conventional technology of changing thermal conductivity by altering the crystal structure described above is intended for small-scale applications such as cooling computer central processing units (CPUs), and application to large-scale facilities such as agricultural facilities can be extremely difficult from the standpoint of both cost and the manufacturing of insulation materials. Furthermore, conventional technologies that store heat during the day in tubes or tanks filled with water and release it at night, install heat-retaining materials around the base of plants, or store heat in stones with high specific heat capacities can be applied inexpensively in agricultural settings, but the control of heat storage and release is difficult, limiting their effectiveness. Therefore, there are cases where solar heat cannot be used efficiently.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide a cultivation device and a cultivation method in agricultural facilities that can efficiently utilize solar heat with a cheaper structure. [Means for solving the problem]

[0008] The cultivation device and cultivation method according to the present invention employ the following configuration. A first aspect of the present invention is a cultivation device comprising a housing arranged along the side of a raised ridge provided in an agricultural facility for cultivating crops, a water supply mechanism that supplies water into the housing, a drainage mechanism that drains water from the housing, and a control unit that controls the operation of at least one of the water supply mechanism and the drainage mechanism, wherein the housing is filled with insulating material, and the control unit controls the water supply or drainage to the area filled with the insulating material to control the thermal conductivity within the housing.

[0009] A second aspect of the cultivation device of the present invention further includes a first temperature sensor that detects the air temperature around the raised ridges and a second temperature sensor that detects the soil temperature of the raised ridges, and the control unit controls the supply or drainage of water to the area based on the temperature difference between the air temperature detected by the first temperature sensor and the soil temperature detected by the second temperature sensor.

[0010] The cultivation device of the third aspect of the present invention further includes a third temperature sensor that detects the temperature of the water in the housing, and the control unit controls the supply or drainage of water to the area based on the temperature of the water detected by the third temperature sensor.

[0011] In the cultivation device according to a fourth aspect of the present invention, the control unit further controls the supply or drainage of water to the area depending on the season and / or time of day.

[0012] In the cultivation device according to a fifth aspect of the present invention, the control unit further controls water supply or drainage to the area depending on the type of the crop or the type of soil in which the crop is cultivated.

[0013] In a sixth aspect of the present invention, the cultivation device further comprises the control unit controlling the water supply mechanism so that water drained by the drainage mechanism is supplied to soil in which the crops are cultivated.

[0014] A seventh aspect of the present invention is a cultivation method comprising a water supply mechanism that supplies water into a housing arranged along the side of a raised ridge provided in an agricultural facility for cultivating crops, a drainage mechanism that drains water from the housing, and controlling the operation of at least one of the water supply mechanism and the drainage mechanism, wherein the housing is filled with insulating material, and the supply of water to or drainage from the area filled with the insulating material is controlled to control the thermal conductivity within the housing. [Effects of the Invention]

[0015] According to aspects of the present invention, solar heat can be efficiently utilized in agricultural facilities with a cheaper structure. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a configuration diagram of a solar heat utilization system 1 that uses a cultivation device according to an embodiment. [Figure 2] 10A and 10B are diagrams for explaining an example of the arrangement of high ridge structures HS1 and HS2. [Figure 3] FIG. 2 is a diagram showing an example of the configuration of a cultivation device CE. [Figure 4] FIG. 1 is a diagram showing the relationship between the moisture state and thermal conductivity of rice husks. [Figure 5] FIG. 2 is a diagram illustrating an example of functions of a control device 100. [Figure 6] 4 is a flowchart illustrating an example of processing executed by the control device 100 of the embodiment. [Figure 7] This is a diagram showing an example in which water filled in the high ridge structure HS is supplied into the soil. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of a cultivation device and a cultivation method will be described with reference to the drawings. In the following, a heat utilization system in which a cultivation device installed in an agricultural facility uses heat from sunlight to adjust the temperature of the soil will be described.

[0018] [Schematic configuration] FIG. 1 is a configuration diagram of a solar heat utilization system 1 that uses a cultivation device of an embodiment. The solar heat utilization system 1 shown in FIG. 1 is provided with one or more cultivation devices CE1 to CEn in, for example, an agricultural greenhouse (an example of an agricultural facility) GH. Each of the cultivation devices CE1 to CEn cultivates agricultural products CR, such as strawberries, melons, watermelons, tomatoes, and sweet potatoes. The agricultural products CR may include various vegetables as well as fruit trees, mushrooms, grains, and the like. Hereinafter, the cultivation devices CE1 to CEn will be collectively referred to as "cultivation device CE" except when the cultivation devices CE1 to CEn are to be described separately.

[0019] In the embodiment, n cultivation devices are arranged at predetermined intervals in the Y-axis direction, for example. The cultivation device CE has raised ridges (raised beds) in which the soil ME for growing crops CR is raised a predetermined height above the ground surface RL, and structures (hereinafter referred to as "high ridge structures") HS1 and HS2 that support the high ridges are provided on the sides of the high ridges. The high ridge structures HS1 and HS2 are an example of a "casing." Figure 2 is a diagram for explaining an example arrangement of the high ridge structures HS1 and HS2. The high ridge structures HS1 and HS2 in the embodiment have a horizontally elongated structure that extends a predetermined distance in the X-axis direction in the figure along the soil ME of the high ridges.

[0020] For example, as shown in Figures 1 and 2, the cultivation device CE changes the thermal conductivity within the high ridge structures HS1 and HS2 by supplying water into the high ridge structures HS1 and HS2 to fill them with water or draining the water filled within the high ridge structures HS1 and HS2 according to predetermined conditions. This allows the cultivation device CE to effectively utilize heat obtained from sunlight to control the temperature of the soil ME.

[0021] 3 is a diagram showing an example of the configuration of the cultivation device CE. The cultivation device CE includes, for example, a control device 100, a temperature sensor 200, a water supply mechanism 300, and a drainage mechanism 400. The control device 100 is an example of a "control unit."

[0022] Control device 100 controls the entire cultivation apparatus CE. Control device 100 acquires, for example, the surrounding conditions (e.g., temperature) of crops CR and controls the water supply and drainage to raised ridge structures HS1 and HS2. The functions of control device 100 will be described in detail later.

[0023] The temperature sensor 200 detects temperatures related to the cultivation apparatus CE. The temperature sensor 200 includes, for example, a first temperature sensor 200-1 that detects the air temperature (outside air temperature) around the high ridges, and a second temperature sensor 200-2 that detects the temperature of the ground (soil ME). The temperature sensor 200 may also include a third temperature sensor 200-3 that detects the temperature (water temperature) of the water filled in the high ridge structures HS1 and HS2. In the example of FIG. 3, the third temperature sensor 200-3 is provided only in the high ridge structure HS2, but it may also be provided in the high ridge structure HS1. The cultivation apparatus CE may also be provided with, in addition to the temperature sensor 200, a sensor that detects the moisture status in the high ridge structures HS1 and HS2, for example.

[0024] The water supply mechanism 300 supplies water to the high ridge structures HS1 and HS2. For example, the water supply mechanism 300 has a water supply valve, a water supply pump, etc., and opens the water supply valve or operates the water supply pump under the control of the control device 100 to supply water flowing through pipes, culverts, etc. to the high ridge structures HS1 and HS2. Also, under the control of the control device 100, the water supply mechanism 300 closes the water supply valve or stops the operation of the water supply pump to end the water supply.

[0025] The drainage mechanism 400 drains the water filled in the high ridge structures HS1 and HS2. For example, the drainage mechanism 400 has a drainage valve, and opens the drainage valve under the control of the control device 100 to drain the water in the high ridge structures HS1 and HS2 into pipes, culverts, or soil ME. The drainage mechanism 400 also closes the drainage valve under the control of the control device 100 to complete the drainage. Note that the water supply mechanism 300 and drainage mechanism 400 described above are merely examples, and other water supply and drainage mechanisms (devices) may be used to supply and drain water to the high ridge structures HS1 and HS2. In the example of FIG. 3, the water supply mechanism 300 and drainage mechanism 400 supply and drain water to both the high ridge structures HS1 and HS2, but a water supply mechanism 300 and drainage mechanism 400 may be provided for each of the high ridge structures HS1 and HS2, and different water supply and drainage may be performed for the high ridge structures HS1 and HS2.

[0026] Here, the high ridge structures HS1 and HS2 of the embodiment have plate-shaped walls B1 and B2 around their periphery. The walls B1 and B2 may be flat, wavy, or have other shapes. The high ridge structures HS1 and HS2 may be provided with a frame or the like to support the walls B1 and B2, and may be provided with a vinyl sheet or the like to cover the outer periphery of the walls B1 and B2 for water protection. The bottoms of the high ridge structures HS1 and HS2 are provided with a mechanism for filling and draining water by opening and closing a drain valve. The tops of the high ridge structures HS1 and HS2 are provided with openings to allow water to be supplied to the interior from the water supply mechanism 300.

[0027] The area (space) enclosed by the walls B1 and B2 is filled with insulating material HI. The insulating material HI is an organic material such as rice husk. The thermal conductivity of rice husk varies significantly depending on its moisture content. Figure 4 shows the relationship between the moisture content and thermal conductivity of rice husk. As an example, Figure 4 shows the relationship between the moisture content (water retention [pF]) and thermal conductivity [W / mk] using four types of rice husk samples. In the example shown in Figure 4, all samples have a high thermal conductivity of approximately 0.8 to 1.0 [W / mk] when saturated (0 [pF]). However, when drained to approximately 1 [pF], the thermal conductivity decreases to approximately 0.2 [W / mk] or less. Furthermore, rice husk has excellent drainage properties, allowing water to be quickly introduced into and removed from the insulating material HI. Furthermore, rice husk is relatively easy and inexpensive to obtain in paddy fields. Therefore, using rice husk can produce a more affordable insulating material HI. In the embodiment, coconut husks or peat moss used in hydroponic cultivation may be used instead of (or in addition to) rice husks.

[0028] [Control device] Next, a specific description will be given of the function of the control device 100. The control device 100 controls the water supply and drainage to one or more of the cultivation devices CE1 to CEn installed in the agricultural greenhouse GH. Therefore, one or more control devices 100 may be installed in the solar heat utilization system 1 of the embodiment.

[0029] FIG. 5 is a diagram illustrating an example of the functions of the control device 100. The control device 100 according to the embodiment includes, for example, an acquisition unit 110, a temperature control unit 120, and a storage unit 130. The acquisition unit 110 and the temperature control unit 120 are implemented by, for example, a hardware processor such as a central processing unit (CPU) executing a program (software). Some or all of these components may be implemented by hardware (including circuitry) such as a large-scale integration (LSI), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a graphics processing unit (GPU), or may be implemented by a combination of software and hardware. The program may be stored in advance in a storage device (a storage device having a non-transitory storage medium) such as a hard disk drive (HDD) or flash memory, or may be stored in a removable storage medium (a non-transitory storage medium) such as a DVD or CD-ROM, and installed in the storage device of the control device 100 by inserting the storage medium into a drive or the like.

[0030] The storage unit 130 may be realized by the various storage devices mentioned above, or an EEPROM (Electrically Erasable Programmable Read Only Memory), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The storage unit 130 stores, for example, information acquired by the acquisition unit 110, adjustment information 132 for controlling water supply and drainage, programs, and various other information. The adjustment information stores various conditions (parameters) such as thresholds for determining whether to supply or drain water.

[0031] The acquiring unit 110 acquires, for example, the ambient air temperature around the cultivation apparatus CE detected by the first temperature sensor 200-1 and the temperature in the soil ME detected by the second temperature sensor 200-2. Furthermore, when the temperature sensor 200 includes a third temperature sensor 200-3 that detects the water temperature in the high ridge structures HS1 and HS2, the acquiring unit 110 may acquire the water temperature. Furthermore, when the acquiring unit 110 includes a sensor that detects the moisture status in the high ridge structures HS1 and HS2, the acquiring unit 110 may acquire the moisture status in the high ridge structures HS1 and HS2 from the sensor. This information is acquired repeatedly at a predetermined period or at a predetermined timing.

[0032] The temperature control unit 120 controls at least one of the water supply control by the water supply mechanism 300 and the drainage control by the drainage mechanism 400 based on information input by the acquisition unit 110. The temperature control unit 120 includes, for example, a determination unit 122 and a water supply / drainage control unit 124. The determination unit 122 determines whether to perform water supply / drainage based on information acquired by the acquisition unit 110. The water supply / drainage control unit 124 controls at least one of the water supply control by the water supply mechanism 300 and the drainage control by the drainage mechanism 400 based on the determination result by the determination unit 122, thereby controlling the thermal conductivity of the high ridge structures HS1 and HS2. For example, the water supply / drainage control unit 124 controls the water supply / drainage to the high ridge structures HS1 and HS2 so that the temperature of the soil ME is within a predetermined temperature range. The predetermined temperature range may be a fixed range, a variable value depending on the type of soil ME or the type of crop CR, or variably set by a user (administrator), etc. Information about the predetermined temperature range is stored in the storage unit 130 as adjustment information 132, for example.

[0033] [Processing flow] FIG. 6 is a flowchart illustrating an example of processing executed by the control device 100 according to the embodiment. The processing of FIG. 6 may be repeatedly executed at a predetermined interval or at a predetermined timing. In the example of FIG. 6, the acquisition unit 110 acquires the outside air temperature using the first temperature sensor 200-1 (step S110) and then acquires the soil temperature using the second temperature sensor 200-2 (step S120). The processing of steps S110 and S120 may be executed in reverse order. Next, the determination unit 122 determines whether the temperature difference between the outside air temperature and the soil temperature is equal to or greater than a threshold value (step S130). The threshold value may be a fixed value, a variable value depending on the components of the soil ME, a variable value depending on the type of crop CR, or the like, or may be variably set by a user (administrator), etc. The threshold value is stored in advance in the storage unit 130 as adjustment information 132.

[0034] If it is determined in the processing of step S130 that the temperature difference is greater than or equal to the threshold value, the water supply and drainage control unit 124 performs water supply and drainage control for the high ridge structures HS1 and HS2 (step S140). Note that the water supply and drainage control unit 124 may perform water supply and drainage control for both the high ridge structures HS1 and HS2, or may perform water supply and drainage control for either one of them. This ends the processing of this flowchart. Also, if it is determined in the processing of step S130 that the temperature difference is not greater than or equal to the threshold value, the processing of this flowchart ends.

[0035] Next, the processing of step S140 described above will be explained in detail. The following will explain an example in which the season (time) is winter. For example, the temperature control unit 120 controls the water supply and drainage into the high ridge structures HS1 and HS2 so that the soil temperature is within a predetermined temperature range. For example, when the temperature difference between the outside air temperature and the soil temperature is equal to or greater than a threshold value and the outside air temperature is higher than the soil temperature, the water supply and drainage control unit 124 controls the water supply mechanism 300 to supply water to the high ridge structures HS1 and HS2. This water supply fills the area (space) filled with the insulating material HI within the high ridge structures HS1 and HS2 with water, improving the thermal conductivity within the high ridge structures HS1 and HS2. This makes it easier for heat from the outside air temperature to be supplied to the soil ME, thereby warming the soil ME. The temperature of the water filled within the high ridge structures HS1 and HS2 can also be increased.

[0036] Furthermore, if it is determined that the temperature difference is equal to or greater than the threshold value and the soil temperature is greater than the outside air temperature, the water supply and drainage control unit 124 executes drainage control to drain the water filled in the area (space) of the heat insulating material HI in the high ridge structures HS1 and HS2 using the drainage mechanism 400. This reduces the thermal conductivity in the high ridge structures HS1 and HS2, making it difficult for heat in the soil ME to radiate to the outside, thereby improving the heat retention effect in the soil ME.

[0037] Instead of (or in addition to) the control shown in FIG. 6, the water supply and drainage control unit 124 may perform water supply and drainage control when it determines that either the outside air temperature or the soil temperature is equal to or higher than a predetermined temperature. For example, when the soil temperature exceeds an upper limit, or when it is determined that the soil temperature is likely to exceed the upper limit in the near future based on the rate of temperature increase over a predetermined period of time, the water supply control unit 124 may control the water supply to the high ridge structures HS1 and HS2 to fill them with water, thereby releasing heat from the soil ME to the outside and lowering the soil temperature to within a predetermined temperature range. The upper limit may be a fixed value, a variable value depending on the type of crop CE or the type of soil ME, or may be set by the user. Information on the upper limit is stored in the storage unit 130, for example, as adjustment information 132.

[0038] The water supply and drainage control unit 124 may also control the amount of water supplied and drained and the time for supplying and draining the water. In this case, the water supply and drainage control unit 124 may control the amount of water supplied and drained according to the magnitude of the temperature difference between the outside air temperature and the soil temperature, or according to the type of thermal insulation material HI. By controlling the amount of water filled into the high ridge structures HS1 and HS2 according to the magnitude of the temperature difference, the thermal conductivity within the high ridge structures HS1 and HS2 can be more appropriately adjusted, thereby adjusting the soil temperature to an appropriate value and adjusting the degree of temperature change. Furthermore, since the relationship between the moisture state and the thermal conductivity may differ depending on the thermal insulation material HI, more appropriate temperature adjustment can be achieved by controlling the amount and time of water supply and drainage according to the type of thermal insulation material HI. Furthermore, the water supply and drainage control unit 124 may control the water supply and drainage so that the moisture state within the high ridge structures HS1 and HS2 acquired by the acquisition unit 110 is maintained at a predetermined state.

[0039] Furthermore, the water supply and drainage control unit 124 may control the water supply or drainage into the high ridge structures HS1 and HS2 according to the season (time of year) and / or time of day. This allows the temperature in the soil ME to be adjusted to an appropriate level simply based on the season (dates corresponding to summer and winter) and time of day (daytime, nighttime), etc., even in a configuration without a temperature sensor 200.

[0040] 6, the water supply and drainage control unit 124 may control the supply or drainage of water to the high ridge structures HS1 and HS2 based on the water temperature detected by the third temperature sensor 200-3. For example, if the water temperature is above a predetermined temperature, the water supply and drainage control unit 124 may determine that the soil temperature is too high, drain the stored water, and then supply new cold water, thereby dissipating heat from the soil ME. This allows the temperature of the soil ME to be more appropriately adjusted.

[0041] In addition, when draining water filled in the high ridge structures HS1 and HS2, the cultivation apparatus CE may supply the water into the soil ME sandwiched between the high ridge structures HS1 and HS2. FIG. 7 is a diagram showing an example in which water filled in the high ridge structure HS is supplied into the soil. For ease of explanation, the following example mainly describes the high ridge structure HS2, but a similar configuration may be provided on the high ridge structure HS1 side. The example in FIG. 7 shows the water supply valve 310 and water supply pump 320 provided in the water supply mechanism 300, and the drain valve 410 provided in the drainage mechanism 400. When the drainage valve 410 opens to drain the water filled in the high ridge structure HS2, the water supply mechanism 300 operates the water supply pump 320 under the control of the control device 100, moving the water discharged from the high ridge structure HS2 to the top of the soil ME and spraying it onto the soil ME from above. This allows for effective use of the water filled in the high ridge structure HS2. Furthermore, by providing water heated within the high ridge structure HS2 to the soil ME, the soil temperature can be increased more efficiently.

[0042] The thickness W1 of the space in the high ridge structures HS1 and HS2 where the insulating material HI is filled and the height H1 of the high ridge portion (height from the ground FL) may be changed as appropriate depending on the type of agricultural crop. The control device 100 can adjust the heat dissipation and heat retention by the high ridge structure HS by changing the thickness W1 and height H1.

[0043] According to the embodiment described above, the cultivation device comprises a high ridge structure HS (an example of a housing) arranged along the side of a high ridge provided in an agricultural facility for cultivating crops, a water supply mechanism 300 that supplies water into the high ridge structure HS, a drainage mechanism 400 that drains water from the high ridge structure HS, and a control device (an example of a control unit) 100 that controls the operation of at least one of the water supply mechanism 300 and the drainage mechanism 400.The high ridge structure HS is filled with insulating material HI, and the control device 100 controls the water supply or drainage to the area filled with the insulating material HI to control the thermal conductivity within the high ridge structure HS, thereby enabling solar heat to be used efficiently in the agricultural facility with a cheaper structure.

[0044] Specifically, according to an embodiment, an insulating layer (high ridge structure) made of rice husk or the like is formed on the sides of the high ridges of a raised bed or the like. When the soil temperature is higher than the surrounding environment (e.g., air temperature), the insulating layer is drained to reduce the thermal conductivity of the insulating layer, allowing solar heat to be efficiently retained with a cheaper structure. Furthermore, according to an embodiment, when the soil temperature is lower than the surrounding temperature, water is added to the high ridge structure to saturate the insulating layer, increasing the thermal conductivity of the insulating layer and allowing surrounding heat to be absorbed into the soil. For example, an agricultural greenhouse GH is cool at night but can become hot during the day, especially on sunny days. Therefore, soil temperature can be appropriately controlled by repeatedly adding water to the high ridge structure during the day to increase its thermal conductivity and absorb the heat during the day, and then draining the water at night to reduce the thermal conductivity of the high ridge structure and maintain heat. Furthermore, according to an embodiment, soil temperature can be raised more efficiently by irrigating the soil with high-temperature water drained from the high ridge structure.

[0045] The method described in this embodiment can be deployed on a large scale at a lower cost and can be widely applied in agricultural fields with large-scale facilities, such as farms. Furthermore, large-scale deployment offers even greater cost advantages. Currently, most heat use in the field of indoor agriculture relies on fossil resources, and the global trend toward decarbonization calls for the reduction of greenhouse gas emissions across all industries in Japan. Because this embodiment is a system that maximizes the use of solar heat, a natural energy source, it can contribute to the decarbonization of agricultural facilities and can be a key technology for net-zero energy greenhouses (ZEGs). Furthermore, the method described in this embodiment may be applied to porous materials other than soil.

[0046] The above describes the form for carrying out the present invention using an embodiment, but the present invention is not limited to such an embodiment, and various modifications and substitutions can be made within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0047] 1...Solar heat utilization system, 100...Control device, 110...Acquisition unit, 120...Temperature control unit, 130...Memory unit, 200...Temperature sensor, 300...Water supply mechanism, 400...Drainage mechanism, HG...Agricultural greenhouse, CE...Cultivation device, HS1, HS2...High ridge structure

Claims

1. a housing disposed along a side of a raised ridge provided in an agricultural facility for cultivating crops; a water supply mechanism for supplying water into the housing; a drainage mechanism for draining water from the housing; a control unit that controls the operation of at least one of the water supply mechanism and the drainage mechanism, The housing is filled with a heat insulating material, the control unit controls the supply or drainage of water to or from the region filled with the heat insulating material to control the thermal conductivity within the housing. Cultivation equipment.

2. a first temperature sensor for detecting the temperature around the raised ridge; a second temperature sensor for detecting the soil temperature of the raised ridges; the control unit controls the supply or drainage of water to the area based on a temperature difference between the air temperature detected by the first temperature sensor and the soil temperature detected by the second temperature sensor. The cultivation device according to claim 1.

3. a third temperature sensor for detecting the temperature of the water in the housing; The control unit controls the supply or drainage of water to the area based on the temperature of the water detected by the third temperature sensor. The cultivation device according to claim 1.

4. The control unit controls the supply or drainage of water to the area depending on the season and / or time of day. The cultivation device according to claim 1.

5. the control unit controls water supply or drainage to the area depending on the type of the crop or the type of soil in which the crop is grown. The cultivation device according to claim 1.

6. the control unit controls the water supply mechanism so that the water drained by the drainage mechanism is supplied to the soil in which the crops are grown. The cultivation device according to claim 1.

7. a water supply mechanism that supplies water into a housing arranged along the side of a raised ridge provided in an agricultural facility for cultivating agricultural crops; a drainage mechanism that drains water from the housing; and controlling the operation of at least one of the water supply mechanism and the drainage mechanism; The housing is filled with a heat insulating material, controlling the supply or drainage of water to or from the region filled with the heat insulating material to control the thermal conductivity within the housing; Cultivation method.

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