Elevated cultivation device

Abstract

To provide an elevated cultivation device capable of efficiently reducing the temperature of cultivation medium.SOLUTION: An elevated cultivation device 100 comprises: a cultivation tank 45 having water permeability which is formed of a water permeable sheet 40, and holds cultivation medium 90; a pan 60 which is positioned below the cultivation tank 45, and in which a recess 61 capable of storing water is formed; a wall surface part which extends from a side part 62 of the pan 60 toward a side part 46 of the cultivation tank 45, and partitions a space B under cultivation medium between the cultivation tank 45 and the pan 60; a cylindrical ventilation duct 70 which is arranged in the space B under cultivation medium, in which vent holes 74 for discharging air inside the duct in a direction of the cultivation tank 45 are formed and one end of which is closed; a sheet material 92 equipped with water absorption properties which is arranged between the cultivation tank 45 and ventilation duct 70; and blowing means 200 for blowing into the ventilation duct 70.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an elevated cultivation device provided with a cultivation tank. [Background technology]

[0002] Many of the strawberries produced in Japan are seasonal varieties such as "Amaou (registered trademark)," which are harvested and shipped in winter and spring. However, strawberries are used not only for eating fresh but also in confectionery, so there is a lot of demand for them outside of winter and spring. For this reason, summer-autumn cultivation is practiced, whereby strawberries are harvested and shipped in summer and autumn using evergreen strawberries, which can be cultivated outside of winter and spring, and methods are being adopted to extend the end of cultivation of seasonal strawberries from winter and spring to summer.

[0003] On the other hand, when strawberries are cultivated in seasons other than winter and spring, the temperature of the cultivation medium rises more than in winter and spring. Because strawberries are generally fruits that are suitable for cultivation in cool environments, there have been problems such as a decrease in yield and quality when the temperature of the cultivation medium rises, whether one-season strawberries or all-season strawberries are cultivated.

[0004] Nowadays, in order to lower the temperature of the cultivation medium, an elevated cultivation device as described in Non-Patent Document 1 has been proposed. This elevated cultivation device uses the blowing function of a heater to forcibly exhaust air from a vinyl duct with holes at equal intervals, and blows the wind onto the nonwoven fabric forming the cultivation tank. When the wind blows onto the nonwoven fabric, the water that has seeped out of the nonwoven fabric is evaporated, thereby lowering the surface temperature of the nonwoven fabric. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Takaaki Yamazaki and 2 others, "Effects of suppressing temperature rise of medium after planting and timing of fertilization on successive bud emergence in elevated cultivation of forced strawberry", Kinchu-Shi Agricultural Research Report, National Agriculture and Food Research Organization, March 11, 2008, No. 7, p.39-46 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the elevated cultivation device described in Non-Patent Document 1, even if the water that has seeped out from the nonwoven fabric is evaporated by the forced-out wind, the cooling effect due to the latent heat of evaporation is limited to only the surface part of the nonwoven fabric.

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an elevated cultivation device that can effectively lower the temperature of a cultivation medium. [Means for solving the problem]

[0008] In order to solve the above problems, the elevated cultivation device of the present invention is characterized in that it comprises a cultivation tank formed of a water-permeable sheet having water permeability and holding a cultivation medium, a tray located below the cultivation tank and having a recess capable of storing water, a wall portion extending from the side of the tray toward the side of the cultivation tank and dividing the space under the culture medium between the cultivation tank and the tray, a cylindrical ventilation duct located in the space under the culture medium and having an air vent formed therein for discharging internal air toward the cultivation tank and one end closed, a water-absorbent sheet material located between the cultivation tank and the ventilation duct, and an air blowing means for blowing air into the inside of the ventilation duct.

[0009] The above-mentioned elevated cultivation device may include a gutter member located between the cultivation tank and the sheet material for draining water dripping from the cultivation tank.

[0010] In addition, a discharge space for discharging air from the space below the culture medium may be formed between the side portion of the cultivation tank and the upper portion of the wall portion.

[0011] Furthermore, a water-retentive sheet having water-retentive properties may be provided on the inside of the wall portion.

[0012] The lower end of the water retention sheet may extend to the recess. Effect of the Invention

[0013] According to the present invention, the temperature of the cultivation medium in an elevated cultivation device can be effectively lowered. [Brief description of the drawings]

[0014] [Figure 1] 1 is a perspective view showing an elevated cultivation device according to an embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view showing the II-II section of the elevated cultivation device of FIG. 1. [Diagram 3] FIG. 2 is a perspective view showing a schematic configuration of a ventilation duct. [Figure 4] 3 is an enlarged view showing a side portion of a cultivation tank in the elevated cultivation device of FIG. 2. [Diagram 5] FIG. 13 is an explanatory diagram for explaining the operation of the elevated cultivation device. [Figure 6] This figure shows the changes over time in the temperatures inside and outside the agricultural greenhouse and the soil temperature of the cultivation medium when the blower fan is turned on and off. [Figure 7] FIG. 11 is another explanatory diagram for explaining the operation of the elevated cultivation device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The elevated cultivation device according to the present invention will be described with reference to the drawings.

[0016] As shown in Figures 1 and 2, the elevated cultivation device 100 comprises an elevated bench 10, a water supply pipe 30 for watering (irrigation), a nonwoven fabric (permeable sheet) 40 that is permeable and holds a cultivation medium 90, a medium holding fitting 50 that holds the nonwoven fabric 40, a tray 60 with a recess 61 formed therein in which water (such as excess water described below) can be stored, a cylindrical ventilation duct 70 placed in the recess 61 of the tray 60, a wall portion 80 installed on the side of the elevated bench 10, a sheet material 92 arranged between the nonwoven fabric 40 and the ventilation duct 70, and a blower fan 200 that blows air into the ventilation duct 70.

[0017] The elevated bench 10 is constructed by combining a number of rod-shaped members. In detail, a pair of left and right legs (support columns) 11 (11a, 11b, 11c, ...), 12 (12a, 12b, 12c, ...) are aligned at equal intervals on the ground, and long vertical bars 13 (13a, 13b), 14 (14a, 14b) extending horizontally in the alignment direction are fixed to the upper and lower parts of the left and right legs 11, 12, respectively. The vertical bars fixed to the upper parts of the legs 11, 12 are called first vertical bars 13a, 13b, and the vertical bars fixed to the lower parts of the legs 11, 12 are called second vertical bars 14a, 14b.

[0018] In addition, short horizontal bars 15 (15a, 15b, 15c, ...), 16 (16a, 16b, 16c, ...) that maintain the distance between leg portion 11 and leg portion 12 are fixed to the upper and middle portions of legs 11, 12, respectively. The horizontal bars fixed to the upper portions of legs 11, 12 are called first horizontal bars 15 (15a, 15b, 15c, ...), and the horizontal bars fixed to the middle portions of legs 11, 12 are called second horizontal bars 16 (16a, 16b, 16c, ...). End horizontal bars 17 are attached to the ends of the left and right first vertical bars 13a, 13b. In addition, a plurality of LED support parts 18 (18a, 18b, 18c, 18d, . . . ) having a U-shaped cross section are provided on the upper surface side of the left and right first vertical bars 13a, 13b. LED lamps 19 are suspended from the plurality of LED support parts 18.

[0019] A culture medium holding fitting 50 bent into a W-shape is installed on the first vertical beams 13a and 13b. A central vertical beam 20 that supports the central portion of the culture medium holding fitting 50 from below is installed on the first horizontal beam 15 via a base portion 21. The nonwoven fabric 40 for holding the cultivation medium 90 is a rectangular long sheet, and is placed on the culture medium holding fitting 50 with its short portion bent to follow the bent shape (W-shape) of the culture medium holding fitting 50. The nonwoven fabric 40 may be bonded to the culture medium holding fitting 50 so that it does not slip or come off from the culture medium holding fitting 50. A cultivation tank 45 for strawberry cultivation is formed by the culture medium holding fitting 50 and the nonwoven fabric 40 placed thereon.

[0020] The nonwoven fabric 40 has air permeability and water permeability. When the water sprayed from the water supply pipe 30 reaches the bottom of the cultivation medium 90, the nonwoven fabric 40 causes the water to leak (permeate) into the sheet material 92 or the tray 60 as surplus water. In addition, the nonwoven fabric 40 has root prevention properties and prevents the roots of strawberries from spreading below the nonwoven fabric 40.

[0021] The water supply pipe 30 is placed on the cultivation medium 90 held by the cultivation tank 45. The water supply pipe 30 functions as a water supply unit such as a cooling water circulation device (chiller), and surplus water or well water pumped up by a pump (not shown) is sprayed onto the cultivation medium 90 through the spray holes of the water supply pipe 30. Note that the water supply pipe 30 may be installed above the cultivation medium 90 (for example, at the LED support portion 18) rather than being placed on the cultivation medium 90, and may be configured to irrigate the cultivation medium 90 from above.

[0022] The tray 60 has a long gutter shape extending in the alignment direction. The alignment direction ends of the tray 60 are supported by the shorter left and right legs 11z, 12z, and the main body is attached to the elevated bench 10 in a state of being spanned across a plurality of second horizontal bars 16 (16a, 16b, 16c, ...). The tray 60 is located below the cultivation tank 45 (nonwoven fabric 40 and culture medium holding fittings 50) and the sheet material 92, and is installed so that its recess 61 faces the underside of the sheet material 92. The tray 60 has a role of receiving excess water that leaks (permeates) from the nonwoven fabric 40.

[0023] The sheet material 92 is a rectangular long sheet formed of a nonwoven fabric (e.g., polyester) that is absorbent, quick-drying, and breathable. The sheet material 92 is installed on the first horizontal bars 15 (15a, 15b, 15c, ...) and is installed so as to face the bottom surface of the cultivation tank 45 from below. In addition, a gap S1 is formed between the short end of the sheet material 92 and the wall portion 80 to guide the air rising along the wall portion 80 to the side portion 46 of the cultivation tank 45.

[0024] As shown in FIG. 3, the ventilation duct 70 is a long cylindrical material (tube material) made of polyethylene stretched in the alignment direction, and one end 72 is closed. A plurality of ventilation holes 74 are provided on the upper surface of the ventilation duct 70 for discharging the air sent into the ventilation duct 70 by the blower fan 200 toward the cultivation tank 45 through the sheet material 92. In the ventilation duct 70 shown in FIG. 3, as an example, six ventilation holes 74 are formed in the width direction on the upper surface of the ventilation duct, and the six ventilation holes 74 are formed at equal intervals in the extension (long) direction of the ventilation duct. The ventilation duct 70 is disposed in the recess 61 of the tray 60, and the blower fan 200 is installed at the end of the tray 60 in the alignment direction. The other end 76 (the end where the opening is formed) of the ventilation duct 70 is connected to the blower fan 200.

[0025] The wall surface portion 80 is installed on the side of the elevated bench 10. As shown in Fig. 1, the wall surface portion 80 is composed of a panel having a width L corresponding to the distance between the legs 11, 12 and a height H corresponding to the height from the fixed position of the second horizontal rail 16 on the legs 11, 12 (the installation position of the tray 60) to the fixed position of the first vertical rails 13a, 13b. A plurality of S-shaped hooks 22 are suspended from the first vertical rails 13a, 13b at regular intervals, and a locking hole 80a is provided in the upper part of the wall surface portion 80 for inserting the tip of the S-shaped hook 22, as shown in Fig. 4.

[0026] By inserting the tip of the S-shaped hook 22 into the locking hole 80a, the wall surface portion 80 is hung and installed on the side of the elevated bench 10 as shown in Figs. 1 and 2. The wall surface portion 80 extends from the side portion 62 of the tray 60 toward the side portion 46 of the cultivation tank 45 between the left leg portions 11 and the right leg portions 12, and partitions the space B under the medium between the cultivation tank 45 and the tray 60. A part of the air discharged from the inside to the outside of the ventilation duct 70 due to the operation of the blower fan 200 hits the wall surface portion 80, passes through the gap S1, rises along the wall surface portion 80, and is guided to the side portion 46 of the cultivation tank 45. For convenience of explanation, the wall surface portion 80 is not shown in the range indicated by A in Fig. 1, but the wall surface portion 80 is actually installed therein.

[0027] 2 and 4, the upper end 82 of the wall portion 80 is inclined toward the outside of the left and right legs 11, 12 with respect to the height position where the locking hole 80a is provided, and is extended to the vicinity of the side portion 46 of the cultivation tank 45. As a result, a discharge space S2 for discharging air from the space B below the culture medium is formed between the side portion 46 of the cultivation tank 45 and the upper end 82 of the wall portion 80.

[0028] The wall portion 80 is formed of a waterproof and non-breathable material such as vinyl, plastic, polystyrene foam, etc. By providing the wall portion 80, the humidity and temperature conditions inside the elevated cultivation device 100 (sub-culture medium space B) are less susceptible to the effects of the humidity and temperature conditions outside.

[0029] An inner wall sheet 81 made of a material with excellent water retention and water absorption properties, such as nonwoven fabric or polyester, is attached to the inner surface of the wall portion 80. However, the lower end of the inner wall sheet 81 is not attached to the inner surface of the wall portion 80, but extends to the recess 61 of the tray 60 and is guided into the recess 61. By guiding the lower end of the inner wall sheet 81 to the tray 60 in this manner, it is possible to close the gap between the tray 60 and the wall portion 80 with the inner wall sheet 81, and it is possible for the inner wall sheet 81 to absorb surplus water (water) of the cultivation tank 45 stored in the tray 60 and guide it to the wall portion 80.

[0030] 5 is an explanatory diagram for explaining the operation of the elevated cultivation apparatus 100 in which strawberries are planted in the cultivation medium 90. In the elevated cultivation apparatus 100, the strawberries are watered (supplied with water, irrigated) by the water supply pipe 30, and the water spreads over the entire cultivation medium 90. Excess water that reaches the bottom of the cultivation tank 45 permeates the nonwoven fabric 40 and drips onto the sheet material 92, and the excess water that cannot be absorbed by the sheet material 92 drips into the tray 60. The excess water stored in the tray 60 is absorbed by the inner wall sheet 81 and guided to the wall surface portion 80.

[0031] When the blower fan 200 blows air, the air is discharged (exhausted) from the inside to the outside through the ventilation holes 74 of the ventilation duct 70. The sheet material 92 and the inner wall sheet 81 of the wall surface portion 80 contain excess water in the cultivation tank 45, so that when the air discharged (exhausted) from the ventilation duct 70 hits them, the water contained in the sheet material 92 and the inner wall sheet 81 absorbs heat from the surroundings and is vaporized. Therefore, the cool air with a lowered temperature fills the sub-culture medium space B, lowering the internal temperature of the elevated cultivation device 100, making it possible to lower the temperature of the cultivation tank 45.

[0032] In particular, the sheet material 92 has excellent water absorption, quick drying and breathability, and the interior wall sheet 81 has excellent water retention and absorption properties, so the absorbed water spreads out over the surface. When air is exhausted (discharged) from the ventilation duct 70, each sheet receives the air over its entire surface, and the water that spreads over the surface loses heat efficiently and quickly and is evaporated.

[0033] Furthermore, since the sheet material 92 has high breathability, the air directed from the ventilation duct 70 to the bottom surface of the sheet material 92 is evaporatively cooled by the sheet material 92, passes through the upper surface side of the sheet material 92, and is directed to the surface (lower surface) of the cultivation tank 45 (nonwoven fabric 40). In addition, since a gap S1 is formed between the end of the sheet material 92 and the wall surface portion 80, the air evaporatively cooled by the sheet material 92 and the air evaporatively cooled by the inner wall sheet 81 are guided to the surface (lower surface) of the cultivation tank 45 (nonwoven fabric 40) through the gap S1. By guiding the cooled air to the surface (lower surface) of the cultivation tank 45 (nonwoven fabric 40), heat is taken from the cultivation medium 90, and the temperature of the cultivation tank 45 can be more effectively lowered.

[0034] FIG. 6 shows the change over time in the soil temperature of each elevated bench 10 and the temperatures inside and outside the agricultural greenhouse over three sunny days, when the area inside the agricultural greenhouse is divided into two sections, an "evaporative cooling section" and a "non-evaporative cooling section," and two elevated cultivation devices 100 installed in the "evaporative cooling section" operate the blower fan 200 while supplying water from the water supply pipe 30, while two elevated cultivation devices 100 installed in the "non-evaporative cooling section" supply water from the water supply pipe 30 while stopping the blower fan 200.

[0035] The temperatures shown in Figure 6 are the average values ​​of the soil temperatures in the cultivation tank 45 measured at three longitudinal points in two elevated cultivation devices 100. "Soil temperature with evaporative cooling" in Figure 6 is a graph showing the change in the average soil temperature in the cultivation tank 45 when the blower fan 200 is operated, and "Soil temperature without evaporative cooling" is a graph showing the change in the average soil temperature in the cultivation tank 45 when the blower fan 200 is stopped. The "inside greenhouse" graph in Figure 6 shows the temperature change inside the agricultural greenhouse, and the "outside greenhouse" graph shows the temperature change outside the agricultural greenhouse.

[0036] As can be seen from FIG. 6, the temperatures inside and outside the agricultural greenhouse tended to be higher in the afternoon of each day, and the soil temperatures tended to be higher around 3:00 to 4:00 p.m. each day. Comparing "soil temperature with evaporative cooling" and "soil temperature without evaporative cooling" between 3:00 and 4:00 p.m., the soil temperature with evaporative cooling is lower by about 1° C. on average than the soil temperature without evaporative cooling. For this reason, by operating blower fan 200 to perform evaporative cooling, it is possible to lower the temperature of cultivation tank 45 more than when evaporative cooling is not performed.

[0037] In addition, the higher the temperature inside the greenhouse, the wider the difference in soil temperature between "soil temperature with evaporative cooling" and "soil temperature without evaporative cooling". Therefore, when the temperature inside the greenhouse is high, the temperature of the cultivation tank 45 can be lowered more effectively by operating the blower fan 200 to perform evaporative cooling. Furthermore, when the temperature difference between the temperature inside the agricultural greenhouse and "soil temperature with evaporative cooling" or "soil temperature without evaporative cooling" was examined, the temperature difference between the temperature inside the agricultural greenhouse and "soil temperature with evaporative cooling" tended to be wider than the temperature difference between the temperature inside the agricultural greenhouse and "soil temperature without evaporative cooling". In this way, by operating the blower fan 200 and cultivating strawberries in a state of "soil temperature with evaporative cooling", it is possible to lower the temperature of the cultivation tank 45 more effectively than before.

[0038] Furthermore, a discharge space S2 for discharging air from the space B below the culture medium is formed between the side portion 46 of the cultivation tank 45 and the upper portion of the wall portion 80, so that the cold air inside the elevated cultivation device 100 (space B below the culture medium) can be discharged and guided to the upper side of the cultivation tank 45 through the discharge space S2. In particular, when strawberries grow, the fruits and leaves tend to grow up to the vicinity of the outlet of the discharge space S2, as shown in Figures 2 and 4. Therefore, the cold air discharged and guided through the discharge space S2 is more likely to hit the fruits and leaves, making it possible to effectively lower the temperature of the fruits, etc.

[0039] Although the embodiment of the present invention has been described above, the embodiment of the present invention is not limited to the above, and may be appropriately modified without departing from the spirit of the invention.

[0040] In the above-described embodiment, the nonwoven fabric 40 is bent into a W-shape using a W-shaped medium-holding metal fitting 50, but the shape of the medium-holding metal fitting 50 may be a shape other than a W-shape. For example, by using a U-shaped medium-holding metal fitting, the nonwoven fabric 40 may be bent into a U-shape, and the bottom shape of the cultivation tank 45 may be an inverted arch shape. In addition, the nonwoven fabric 40 may be bent so that the number of peaks and valleys is greater than that of a W-shape, forming the bottom of the cultivation tank 45. By forming the bottom of the cultivation tank 45 in this manner, the surface area of ​​the nonwoven fabric 40 can be made larger, and the temperature of the cultivation tank 45 can be effectively lowered.

[0041] In the above embodiment, a case has been described in which excess water sprayed (irrigated) by the water supply pipe 30 is absorbed by the sheet material 92 or stored in the tray 60. However, when managing the amount of water sprayed (irrigated) so as to prevent excess water from being produced, a water supply means for supplying water to the sheet material 92 or the tray 60 may be provided separately from the water supply pipe 30.

[0042] Furthermore, in the above-mentioned embodiment, the case where the excess water in the cultivation tank 45 is absorbed by the sheet material 92 has been described, but when there is a large amount of excess water, the sheet material 92 alone may not be able to absorb it sufficiently. For this reason, when it is possible to secure a space between the lower surface of the cultivation tank 45 and the sheet material 92 for air to pass (for air to escape), a gutter member 96 may be installed in this space as shown in Fig. 7. By providing the gutter member 96 to store and discharge the excess water in the cultivation tank 45, even if the excess water leaks (permeates) to an extent that the sheet material 92 cannot absorb, the water absorption state of the sheet material 92 can be optimized, and the temperature of the cultivation tank 45 can be more effectively lowered.

[0043] In the above embodiment, the case of cultivating strawberries in the cultivation tank 45 has been described, but the plants cultivated in the elevated cultivation device according to the present invention are not limited to strawberries. Plants other than strawberries can also be cultivated as long as they are suitable for elevated cultivation in a low-temperature environment. [Explanation of symbols]

[0044] 10 Elevated bench 11,11a,11b,11c,11z,12,12a,12b,12c,12z Legs 13, 13a, 13b First vertical crosspiece 14, 14a, 14b Second vertical bar 15, 15a, 15b, 15c First horizontal bar 16, 16a, 16b, 16c Second horizontal bar 17 End crosspiece 18,18a,18b,18c,18d LED support part 19 LED Light 20 Center crosspiece 21 Base 22 S-hook 30 Water Supply Pipe 40 Nonwoven fabric (permeable sheet) 45 Cultivation tank 46 (Cultivation tank) side 50 Culture medium holding fittings 60 Saucer 61 (of a saucer) 62 (Saucer) Side 70 Ventilation Duct 72 (of a ventilation duct) 74 Ventilation holes 76 (the other end of the ventilation duct) 80 Wall 80a (wall part) locking hole 81 Inner wall sheet (water-retaining sheet) 90 Cultivation medium 92 Sheet material 96 Gutter parts 100 Elevated cultivation equipment 200 Blower fan (blower means) B Space under the medium S1 Gap S2 discharge space

Claims

1. A cultivation tank formed of a water-permeable sheet having water permeability and holding a cultivation medium; A tray located below the cultivation tank and having a recess capable of storing water; A wall portion extending from a side portion of the tray toward a side portion of the cultivation tank and partitioning a space under the culture medium between the cultivation tank and the tray; A cylindrical ventilation duct arranged in the space under the culture medium, having a vent hole for discharging internal air toward the cultivation tank and one end closed; A water-absorbent sheet material disposed between the cultivation tank and the ventilation duct; A blowing means for blowing air into the inside of the ventilation duct; An elevated cultivation device comprising:

2. 2. The elevated cultivation device according to claim 1, further comprising a gutter member positioned between the cultivation tank and the sheet material for draining water dripping from the cultivation tank.

3. 2. The elevated cultivation device according to claim 1, wherein an exhaust space for exhausting air from the space under the culture medium is formed between the side of the cultivation tank and the upper part of the wall portion.

4. 2. The elevated cultivation device according to claim 1, wherein a water-retentive sheet having water retention properties is provided on the inner side of the wall portion.

5. 5. The elevated cultivation device according to claim 4, wherein a lower end of the water retaining sheet extends to the recess.

Images