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 an apparatus and method for cultivating agricultural crops. [Background technology]

[0002] In recent years, there has been a demand to reconsider the agricultural system that relies on fossil fuels. Heating agricultural facilities is a major source of carbon dioxide emissions due to the consumption of fossil fuels, and reducing this is important for realizing a decarbonized society in the agricultural sector. For example, strawberries are a crop grown in winter, and it is common to heat the room temperature 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 in winter without heating, but there are issues with the yield being lower than when the room is heated and the yield decreasing in cold winter years. Therefore, there is a demand for technology that can stabilize the soil temperature without heating and cultivate agricultural crops stably.

[0003] Conventionally, there is known a technology that uses rice husks as a heat insulating material in order to suppress the melting of snowy mountains and utilize cold energy (see, for example, Non-Patent Document 1). Conventionally, there are also known technologies that change the thermal conductivity by changing the crystal structure, or that change the thermal conductivity by changing the moisture content of the heat insulating material (see, for example, Patent Document 1). Conventionally, there are also known technologies that store heat during the day in tubes filled with water or in heat storage tanks and release the heat at night, that use heat insulating materials to keep the base of plants warm, and that store heat during the day by making cultivation beds out 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 insulation covering material for snow storage. 1st report: Outdoor snow storage experiment and physical property measurement", Japan Society of Snow and Ice, Journal of the Japan 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 insulation covering 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 Technology Council Secretariat, Project Research Results Series 576, p.1-125, March 2017 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above-mentioned conventional technology of changing the thermal conductivity by changing the crystal structure is intended for small-scale use such as cooling a computer's CPU (Central Processing Unit), and application to large-scale facilities such as agricultural facilities can be very difficult in terms of cost and the manufacturing of insulation materials. In addition, conventional technologies of storing heat during the day in tubes or tanks filled with water and releasing it at night, installing insulation materials at the base of plants, and storing heat in stones with high specific heat can be applied inexpensively in agricultural fields, but it is difficult to control the heat storage and release, and the effect can be limited. 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 an agricultural facility that can efficiently utilize solar heat with a cheaper structure. [Means for solving the problem]

[0008] The cultivation apparatus and the 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 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, 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] The cultivation device of a second aspect of the present invention further includes a first temperature sensor for detecting the air temperature around the raised ridges and a second temperature sensor for detecting the soil temperature of the raised ridges, and the control unit controls water supply or drainage 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 a 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 water supply or drainage 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 cultivation device of the present invention, the control unit further controls the water supply mechanism so that water drained by the drainage mechanism is supplied to soil in which the crops are cultivated.

[0014] A cultivation method according to a seventh aspect of the present invention includes 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, and a drainage mechanism that drains water from the housing, and the operation of at least one of the water supply mechanism and the drainage mechanism is controlled, the housing is filled with insulating material, and the supply or drainage of water to or from an area filled with the insulating material is controlled to control the thermal conductivity within the housing. Effect of the Invention

[0015] According to an aspect of the present invention, solar heat can be efficiently utilized in an agricultural facility with a cheaper structure. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a configuration diagram of a solar heat utilization system 1 that utilizes a cultivation device according to an embodiment. [Diagram 2] 13 is a diagram for explaining an example of the arrangement of high ridge structures HS1 and HS2. FIG. [Diagram 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 husk. [Diagram 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 a process executed by the control device 100 of the embodiment. [Figure 7] This is a diagram showing an example in which water filled in a high ridge structure HS is supplied into the soil. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of a cultivation apparatus and a cultivation method will be described with reference to the drawings. In the following, a heat utilization system in which a cultivation apparatus installed in an agricultural facility uses heat from sunlight to adjust the temperature of 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. In the solar heat utilization system 1 shown in Fig. 1, one or more cultivation devices CE1 to CEn are provided in, for example, an agricultural house (an example of an agricultural facility) GH. In each of the cultivation devices CE1 to CEn, a crop CR, such as strawberries, melons, watermelons, tomatoes, sweet potatoes, etc., is cultivated. The crops CR may include fruit trees, mushrooms, grains, etc., in addition to various vegetables. 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. In the cultivation device CE, the soil ME for growing crops CR is a raised bed that is raised a predetermined height above the ground surface RL, and structures (hereinafter, "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 "housing." FIG. 2 is a diagram for explaining an example of the 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 equipment CE changes the thermal conductivity in the high ridge structures HS1 and HS2 by supplying water into the high ridge structures HS1 and HS2 according to predetermined conditions to fill them with water, or draining the water filled in the high ridge structures HS1 and HS2, thereby enabling the cultivation equipment CE to effectively utilize the 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 (for example, temperature) of crops CR, and controls water supply and drainage to high ridge structures HS1 and HS2. The functions of control device 100 will be described in detail later.

[0023] The temperature sensor 200 detects a temperature 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 ridge, and a second temperature sensor 200-2 that detects the temperature of the ground (soil ME). The temperature sensor 200 may also be provided with 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. In addition to the temperature sensor 200, the cultivation apparatus CE may also be provided with a sensor that detects the moisture state in the high ridge structures HS1 and HS2.

[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. The water supply mechanism 300 also closes the water supply valve or stops the operation of the water supply pump under the control of the control device 100 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 a pipe, a culvert, or the 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 the drainage mechanism 400 described above are only examples, and water supply and drainage to the high ridge structures HS1 and HS2 may be performed by other water supply and drainage mechanisms (devices). In the example of FIG. 3, the water supply mechanism 300 and the drainage mechanism 400 perform water supply and drainage for both the high ridge structures HS1 and HS2, but a water supply mechanism 300 and a 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 them. The walls B1 and B2 may be flat or wavy, or may have other shapes. The high ridge structures HS1 and HS2 may be provided with a frame or the like that supports the walls B1 and B2, and may be provided with a vinyl sheet or the like that covers the outer periphery of the walls B1 and B2 for water blocking. The bottoms of the high ridge structures HS1 and HS2 are provided with a mechanism that fills the high ridge structures HS1 and HS2 with water by opening and closing a drain valve, or that fills and drains the water. The upper parts of the high ridge structures HS1 and HS2 are provided with an opening so that water can be supplied to the inside from the water supply mechanism 300.

[0027] The region (space) surrounded by the walls B1 and B2 is filled with the heat insulating material HI. The heat insulating material HI is, for example, an organic material such as rice husk. The heat conductivity of rice husk varies greatly depending on the moisture state. FIG. 4 is a diagram showing the relationship between the moisture state and the heat conductivity of rice husk. In FIG. 4, the relationship between the moisture state (water retention [pF]) and the heat conductivity [W / mk] is shown using four types of samples (rice husk) as an example. In the example of FIG. 4, the heat conductivity of each sample is high at about 0.8 to 1.0 [W / mk] in the saturated state (0 [pF]), but when the heat conductivity is drained to about 1 [pF], it decreases to about 0.2 [W / mk] or less. In addition, rice husk has extremely high drainage properties, and water can be quickly introduced and discharged into the heat insulating material HI. In addition, rice husk is relatively easy and inexpensive to obtain in paddy fields. Therefore, by using rice husk, a cheaper heat insulating material HI can be formed. In addition, in the embodiment, coconut shells, peat moss, etc. 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 provided in the agricultural house GH. Therefore, one or more control devices 100 may be provided in the solar heat utilization system 1 of the embodiment.

[0029] FIG. 5 is a diagram showing an example of the functions of the control device 100. The control device 100 of 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 realized by, for example, a hardware processor such as a CPU (Central Processing Unit) executing a program (software). In addition, some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by cooperation between software and hardware. The program may be stored in advance in a storage device such as an HDD (Hard Disk Drive) or a flash memory (a storage device having a non-transient storage medium), or may be stored in a removable storage medium such as a DVD or a CD-ROM (a non-transient storage medium), and the storage medium may be installed in the storage device of the control device 100 by mounting the storage medium in a drive device or the like.

[0030] The storage unit 130 may be realized by the above-mentioned various storage devices, 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 outside 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 state in the high ridge structures HS1 and HS2, the acquiring unit 110 may acquire the moisture state in the high ridge structures HS1 and HS2 from the sensor. These pieces of information are 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 the 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 or not to perform water supply / drainage based on the 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 to control the thermal conductivity in 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 according to the type of soil ME or the type of agricultural crop CR, or may be variably set by a user (administrator) or the like. Information on 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 showing an example of a process executed by the control device 100 of the embodiment. The process of FIG. 6 may be repeatedly executed at a predetermined cycle or at a predetermined timing. In the example of FIG. 6, the acquisition unit 110 acquires the outside air temperature by the first temperature sensor 200-1 (step S110), and further acquires the soil temperature by the second temperature sensor 200-2 (step S120). The processes of steps S110 and S120 may be executed in the reverse order. Next, the determination unit 122 determines whether or not 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 according to the components of the soil ME, a variable value according to the type of agricultural crop CR, or the like, or may be variably set by a user (administrator) or the like. The threshold value is stored in advance as adjustment information 132 in the storage unit 130.

[0034] If it is determined in the processing of step S130 that the temperature difference is equal to or greater than 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). 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 only 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 equal to or greater than the threshold value, the processing of this flowchart ends.

[0035] Next, the process of step S140 described above will be specifically described. In the following, an example in which the season (time) is winter will be described as an example. For example, the temperature control unit 120 controls the supply and drainage of water 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 causes the water supply mechanism 300 to execute water supply control for the high ridge structures HS1 and HS2. By supplying water, the area (space) filled with the heat insulating material HI in the high ridge structures HS1 and HS2 is filled with water, and the thermal conductivity in the high ridge structures HS1 and HS2 is improved, so that the heat of the outside air temperature can be easily supplied to the soil ME, and the soil ME can be warmed. In addition, the temperature of the water filled in the high ridge structures HS1 and HS2 can also be increased.

[0036] Furthermore, when 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 thermal insulation material HI in the high ridge structures HS1 and HS2 by 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 be released to the outside, thereby improving the heat retention effect in the soil ME.

[0037] In addition, 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 is determined 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 the upper limit value, or when it is determined based on the rate of temperature increase in a predetermined time that the soil temperature is likely to exceed the upper limit value in the near future, the water supply control to the high ridge structures HS1 and HS2 may be performed to fill the high ridge structures HS1 and HS2 with water to release heat in the soil ME to the outside, thereby lowering the soil temperature until it falls within a predetermined temperature range. In addition, the upper limit value may be a fixed value, or may be a variable value according to the type of agricultural crop CE or the type of soil ME, or may be set by the user. Information on the upper limit value is stored in the storage unit 130 as, for example, adjustment information 132.

[0038] The water supply and drainage control unit 124 may also control the amount of water to be 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 according to the magnitude of the temperature difference between the outside air temperature and the soil temperature, or according to the type of the heat insulating 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 in the high ridge structures HS1 and HS2 can be more appropriately adjusted, the soil temperature can be adjusted to an appropriate value, and the degree of temperature change can also be adjusted. Since the relationship between the moisture state and the thermal conductivity may differ depending on the heat insulating 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 the heat insulating material HI. The water supply and drainage control unit 124 may also control water supply and drainage so that the moisture state in the high ridge structures HS1 and HS2 acquired by the acquisition unit 110 becomes 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 in which the temperature sensor 200 is not provided.

[0040] 6, the water supply and drainage control unit 124 may control the water supply or drainage to the high ridge structures HS1 and HS2 based on the water temperature detected by the third temperature sensor 200-3. For example, when the water temperature is equal to or higher than a predetermined temperature, the water supply and drainage control unit 124 determines that the soil temperature is too high, drains the filled water, and then supplies 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 the 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 the water filled in the high ridge structure HS is supplied into the soil. In the following example, for convenience of explanation, the high ridge structure HS2 will be mainly described, but a similar configuration may be provided on the high ridge structure HS1 side. In the example of FIG. 7, the water supply valve 310 and the water supply pump 320 provided in the water supply mechanism 300 and the drainage valve 410 provided in the drainage mechanism 400 are shown. When the drainage valve 410 is opened 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, moves the water discharged from the high ridge structure HS2 to the top of the soil ME, and sprays it from the top onto the soil ME. This allows the water filled in the high ridge structure HS2 to be effectively used. 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 heat insulating material HI is filled and the height H1 of the high ridge portion (height from the ground FL) may be appropriately changed 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 the thickness W1 and the height H1.

[0043] According to the embodiment described above, the cultivation device comprises a high ridge structure HS (an example of a housing) that is 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, and 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 utilized efficiently in the agricultural facility with a cheaper structure.

[0044] Specifically, according to the embodiment, a heat insulating layer (high ridge structure) using rice husks or the like is formed on the side of the high ridges of a raised bed or the like, and when the temperature of the soil is higher than the surrounding environment (air temperature, etc.), the heat insulating layer is drained to reduce the thermal conductivity of the heat insulating layer, so that solar heat can be efficiently kept warm with a cheaper structure. Also, according to the embodiment, when the temperature of the soil is lower than the surrounding temperature, water is added to the high ridge structure to saturate the heat insulating layer, thereby increasing the thermal conductivity of the heat insulating layer, and the surrounding heat can be taken into the soil ME. For example, the inside of the agricultural greenhouse GH is cold at night, but becomes hot during the day, especially when the weather is good. Therefore, the soil temperature can be appropriately controlled by repeating the operation of adding water to the high ridge structure during the day to increase the thermal conductivity, working on the soil to keep the daytime heat warm, and draining the water at night to reduce the thermal conductivity of the high ridge structure to keep it warm. Also, according to the embodiment, the soil temperature can be raised more efficiently by irrigating the soil with high-temperature water drained from the high ridge structure.

[0045] The method shown in this embodiment can be deployed on a large scale at a lower cost, and can be widely applied to agricultural fields with large-scale facilities such as farming. In addition, by deploying it on a large scale, the cost advantage becomes higher. Currently, most heat use in the field of facility agriculture depends on fossil resources, so the global trend toward decarbonization requires reduction of greenhouse gas emissions in all industries in Japan as well. Since this embodiment is a system that makes maximum use of solar heat, which is a natural energy, it can contribute to the decarbonization of agricultural facilities and can become a component technology of net-zero energy greenhouses (ZEG). In addition, the method shown in this embodiment may be applied to porous bodies 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 arranged along a side of a raised ridge provided in an agricultural facility for cultivating agricultural crops; a water supply mechanism for supplying water into the housing; a drainage mechanism for draining water from within 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 insulating material to control the thermal conductivity within the housing. Cultivation equipment.

2. A first temperature sensor for detecting an air temperature around the raised ridge; A second temperature sensor for detecting a soil temperature of the high ridge; The control unit controls water supply or drainage 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 a 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 agricultural crops are grown. The cultivation device according to claim 1.

7. A water supply mechanism that supplies water into a housing that is arranged along a side of a raised ridge provided in an agricultural facility for cultivating agricultural crops, a drainage mechanism that drains water from within 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, The thermal conductivity inside the housing is controlled by controlling the supply or drainage of water to or from the region filled with the insulating material. Cultivation method.

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