Irrigation device and cell plug used therein

Abstract

An irrigation device comprising: a cell plug with an upward-facing opening and a holding section that is connected to the opening and is for holding a prescribed amount of a growth medium; a liquid-supplying part for supplying liquid to the growth medium in the cell plug; and a cell plug-raising / lowering part for lowering the cell plug if the weight of the cell plug increases due to liquid supplied by the liquid-supplying part and raising the cell plug if the weight of the cell plug decreases due to drying of the growth medium. The liquid-supplying part: comprises a contact end that intermittently contacts the growth medium as a result of the raising and lowering of the cell plug by the cell plug-raising / lowering part; and supplies liquid while the contact end is in contact with the growth medium and stops liquid supply when the contact end is separated from the growth medium.

Description

[Technical field]

[0001] The present invention relates to an irrigation system and a cell plug for use therein. [Background technology]

[0002] For example, Patent Document 1 discloses a seedling raising device that uses multiple cell plugs to raise multiple seedlings. The multiple cell plugs are separate containers, and each cell plug contains culture medium and one seedling (or a seed that will become a seedling) is planted in it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 047625 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to grow multiple seedlings uniformly, it is preferable to supply the culture medium with an appropriate amount of liquid (water or nutrient solution) according to the state of the culture medium for each cell plug. However, in order to supply the culture medium with an appropriate amount of liquid according to the state of the culture medium for each of the multiple cell plugs, a complex irrigation device is required, for example, which includes a soil moisture sensor that detects the moisture amount of the culture medium and a valve that controls the amount of liquid supplied based on the detection result of the sensor.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a simple structure that can supply an appropriate amount of liquid, neither too much nor too little, to the culture medium of a cell plug in which a seedling has been planted, according to the condition of the culture medium. [Means for solving the problem]

[0006] According to one aspect of the present invention, a cell plug having an upward opening and a container communicating with the opening for containing a predetermined amount of culture medium; A liquid supply unit that supplies liquid to the culture medium of the cell plug; a cell plug lifting unit that lowers the cell plug when the weight of the cell plug increases due to the liquid supplied by the liquid supply unit, and lifts the cell plug when the weight of the cell plug decreases due to drying of the culture medium, An irrigation device is provided in which the liquid supply unit has a contact end that intermittently contacts the culture medium by raising and lowering the cell plug by the cell plug lifting unit, and liquid is supplied while the contact end is in contact with the culture medium, and liquid supply is stopped when the contact end is away from the culture medium. Effect of the Invention

[0007] According to the present invention, with a simple configuration, it is possible to supply an appropriate amount of liquid, neither too much nor too little, depending on the condition of the culture medium of the cell plug in which the seedling is planted. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing an irrigation device according to a first embodiment of the present invention; [Diagram 2] FIG. 1 is an exploded perspective view of the irrigation device with the cell plugs removed. [Figure 3A] Cross-section of the irrigation system during liquid delivery [Figure 3B] Cross-section of irrigation system when liquid supply is interrupted [Figure 4] FIG. 3 is a cross-sectional view of an irrigation device according to a second embodiment of the present invention. [Diagram 5] FIG. 5 is a cross-sectional view of an irrigation device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an irrigation device according to an embodiment of the present invention will be described with reference to the drawings.

[0010] (Embodiment 1) FIG. 1 is a perspective view showing a schematic diagram of an irrigation device according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the irrigation device with a plurality of cell plugs removed. FIG. 3A is a cross-sectional view of the irrigation device during liquid supply. And FIG. 3B is a cross-sectional view of the irrigation device during interruption of liquid supply. Note that the XYZ coordinate system shown in the figures is for facilitating understanding of the present invention and does not limit the present invention. The Z-axis direction is the up-down direction, and the X-axis and Y-axis directions are horizontal directions perpendicular to the Z-axis direction.

[0011] The irrigation device 10 of this embodiment 1 has a plurality of cell plugs 12, a liquid supply unit 14 that supplies liquid F to each cell plug 12, and a cell plug lifting unit 16 that detachably holds each cell plug 12 and lifts and lowers it.

[0012] As shown in Fig. 3A, each of the cell plugs 12 is a cylindrical container with a bottom, which includes an opening 12a and a storage section 12b communicating with the opening 12a and storing a predetermined amount of culture medium S. A seedling W is planted in the culture medium S. The culture medium S may be natural soil, an artificial culture medium, a sponge, or the like.

[0013] In the case of the first embodiment, as shown in Fig. 2, the cell plug 12 includes a square flange portion 12c which is an edge of the opening 12a, and a bottomed cylindrical main body portion 12d which extends from the flange portion 12c and defines the storage portion 12b therein. The main body portion 12d is composed of a rectangular parallelepiped cylindrical portion 12e which extends from the flange portion 12c in the opening direction of the opening 12a (Z-axis direction) and an inverted square truncated pyramid-shaped bottom portion 12f connected to the cylindrical portion. The reason for making the cell plug 12 into such a shape, which will be described in detail later, is to make the cell plug 12 float in liquid in a substantially constant position with the opening 12a facing upward so that liquid does not enter the storage portion 12b, just as a fishing float floats in a substantially constant position.

[0014] In addition, although details will be described later, in the case of this embodiment 1, the cell plug 12 contains a predetermined amount of culture medium S and is made of a material, such as a resin material, that floats on water when the entire culture medium S is moist (water-retaining state).

[0015] As shown in FIG. 1, the irrigation device 10 of this embodiment 1 has three cell plugs 12, but the number of cell plugs 12 in the irrigation device may be one or two, or four or more.

[0016] As shown in Figure 1, in this embodiment 1, the liquid supply section 14 of the irrigation device 10 includes a liquid storage section 18 and a plurality of liquid transport members 20 that supply the liquid in the liquid storage section 18 to the culture medium S of each of the plurality of cell plugs 12.

[0017] The liquid storage unit 18 of the liquid supply unit 14 is a tank that stores the liquid F, such as water or a nutrient solution, necessary for growing the seedlings W. In the case of the present embodiment 1, the liquid storage unit 18 is shared by a plurality of cell plugs 12. The liquid storage unit 18 may be a gutter through which the liquid F flows.

[0018] 3A and 3B, in the present embodiment 1, the multiple liquid transport members 20 of the liquid supply unit 14 are members that transport the liquid F from the liquid storage unit 18 to the culture medium S in the corresponding cell plug 12 by capillary action. The liquid transport members 20 are, for example, nonwoven fabric. Instead of nonwoven fabric, the liquid transport members 20 may be strings, sponges, nets, etc.

[0019] 3A and 3B, the liquid transport member 20 is a strip-shaped member having one end 20a that is immersed in the liquid F in the liquid storage section 18 and the other end 20b that is a contact end that comes into contact with the culture medium S in the cell plug 12. The liquid transport member 20 absorbs the liquid F in the liquid storage section 18 at its one end 20a, and transports the absorbed liquid F to the other end 20b by capillary action. The liquid F transported to the other end 20b is absorbed by the culture medium S when the other end 20b is in contact with the culture medium S in the cell plug 12. The liquid F then spreads throughout the entire culture medium S, as shown in FIG. 3B.

[0020] In the case of the first embodiment, a water retention member 22 such as a nonwoven fabric or a sponge is placed on the culture medium S in the cell plug 12, and the other end 20b of the liquid transport member 20 comes into contact with the water retention member 22. In this way, the liquid transport member 20 supplies the liquid F to the culture medium S via the water retention member 22. The water retention member 22 is a member for preventing the other end 20b of the liquid transport member 20 from coming into direct contact with the culture medium S and becoming dirty. Instead of using the water retention member 22, the liquid transport member 20 may be periodically replaced or washed.

[0021] In the first embodiment, the liquid supply unit 14 includes a support 24 that supports the liquid transport member 20 so that the other end (contact end) 20b of the liquid transport member 20 is located on the culture medium S (the water retention member 22 in the first embodiment) in the cell plug 12 and so that the other end 20b is located at the same level as or higher than the one end 20a. This prevents a large amount of liquid F from moving from the one end 20a to the other end 20b. As a result, when the liquid transport member 20 is separated from the water retention member 22 of the cell plug 12 (described in detail later), the liquid F is prevented from dripping from the other end 20b toward the cell plug 12, and an excessive supply of liquid F to the culture medium S in the cell plug 12 is prevented.

[0022] The cell plug lifting unit 16 of the irrigation device 10 is configured to lower the cell plug 12 as shown in Fig. 3B when the weight of the cell plug 12 increases due to the liquid F supplied by the liquid supply unit 14. The cell plug lifting unit 16 is also configured to lift the cell plug 12 as shown in Fig. 3A when the weight of the cell plug 12 decreases due to drying of the culture medium.

[0023] In the present embodiment 1, as shown in Figures 1 and 2, the cell plug lifting section 16 includes a working fluid storage section 26 and a working fluid WF stored in the working fluid storage section 26. In the present embodiment 1, as shown in Figures 3A and 3B, the cell plug lifting section 16 lifts and lowers the cell plug 12 by buoyancy acting on a part of the cell plug 12 immersed in the working fluid WF.

[0024] 3A and 3B, the working fluid containing section 26 of the cell plug lifting section 16 is a tank containing the working fluid WF in which a portion of each of the multiple cell plugs 12 is immersed to provide buoyancy to the cell plugs 12. In the case of the first embodiment, the working fluid containing section 26 is shared by the multiple cell plugs 12. The working fluid containing section 26 may be a gutter through which the working fluid WF flows.

[0025] The working fluid WF of the cell plug lifting unit 16 is, for example, water, and is a member that lifts and lowers the cell plug 12 by buoyancy. For example, as shown in Fig. 3B, the working fluid WF is a fluid that has a density such that the medium S in the cell plug 12 retains liquid F throughout and the cell plug 12 does not sink as a whole when the seedling in the cell plug 12 is at its maximum size. Note that the "maximum size" of the seedling refers to the maximum size of the seedling that can be handled by the irrigation device 10, and refers to the size at which the seedling needs to be transferred from the irrigation device 10 to another location (for example, soil).

[0026] The temperature of the medium S in the cell plug 12 may be adjusted by adjusting the temperature of the working fluid WF. For example, the medium S in the cell plug 12 can be kept constant by using a sensor (not shown) that detects the temperature of the working fluid WF and a heater (not shown) that heats the working fluid WF to maintain the temperature detected by the sensor at a predetermined temperature.

[0027] In addition, in the case of this embodiment 1, the cell plug lifting section 16 includes a guide member 28 that guides each of the multiple cell plugs 12 so that they preferably move in the vertical direction (Z-axis direction) by the buoyancy of the working fluid WF, as shown in FIG.

[0028] As shown in Figs. 1 and 22, the guide member 28 is plate-shaped and is disposed in a state of being submerged in the working fluid WF in the working fluid storage section 26. As shown in Fig. 2, the guide member 28 has a plurality of guide holes 28a in the form of through holes through which the main body 12d of the cell plug 12 can pass. The inner peripheral surface 28b of the guide hole 28a guides the outer peripheral surface of the cylindrical portion 12e of the main body 12d of the cell plug 12. The guide member 28 as described above more reliably maintains the cell plug 12 floating in the working fluid WF in a position in which the opening 12a faces upward. The guide member 28 may be configured to be detachable from the irrigation device 10. This allows the guide member 28 to be used as a tray for transporting a plurality of cell plugs 12 together.

[0029] Up to this point, a description has been given of the configuration of the irrigation device 10 of the present embodiment 1. From now on, the operation of the irrigation device 10 will be described with reference to Figures 3A and 3B.

[0030] First, the cell plug 12 when the entire medium S is dry as shown in Fig. 3A is lighter than the cell plug 12 when the entire medium S is wet (liquid F is retained throughout) as shown in Fig. 3B. Therefore, due to the buoyancy of the working fluid WF, the cell plug 12 when the entire medium S is dry is positioned at a higher level than the cell plug 12 when the entire medium S is wet.

[0031] 3A, when the cell plug 12 is located at a relatively high level in a state where the entire culture medium S is dried due to the buoyancy of the working fluid WF, the other end (contact end) 20b of the liquid transport member 20 of the liquid supply unit 14 contacts the water retention member 22 on the culture medium S. As a result, the liquid F in the liquid storage unit 18 of the liquid supply unit 14 is supplied to the dry culture medium S in the cell plug 12 via the liquid transport member 20 and the water retention member 22. As a result, the culture medium S begins to get wet.

[0032] As the area in the culture medium S that is permeated with the liquid F expands, the weight of the cell plug 12 increases accordingly. As a result, the cell plug 12 sinks (descends) into the working fluid WF. When the liquid F has finally permeated almost the entire culture medium S, the cell plug 12 reaches a relatively low level, as shown in Fig. 3B, and the other end (contact end) 20b of the liquid transport member 20 separates from the water retention member 22. As a result, the supply of liquid to the culture medium S by the liquid supply unit 14 is interrupted.

[0033] After the liquid supply is interrupted, the liquid F held by the culture medium S is consumed by the seedlings W and evaporates, decreasing the amount of the liquid F, causing the weight of the cell plugs 12 to decrease. As a result, the cell plugs 12 float (rise) in the working fluid WF. When the culture medium S finally dries over almost the entirety, the cell plugs 12 reach a relatively high level, as shown in Fig. 3A, and the other end (contact end) 20b of the liquid transport member 20 comes into contact with the water retention member 22 again. As a result, the liquid supply to the culture medium S by the liquid supply unit 14 is resumed.

[0034] In this manner, the supply of liquid F by the liquid supply unit 14 to the culture medium S in the cell plug 12 is performed intermittently depending on the state of the culture medium S, specifically, depending on the water retention capacity of the culture medium S. As a result, an appropriate amount of liquid F can be supplied to the culture medium S, neither too much nor too little.

[0035] Such intermittent supply of liquid F prevents problems that may occur due to the culture medium S retaining an excessive amount of liquid F, such as the proliferation of bacteria in the culture medium S and rotting of the roots of the seedlings W. It also prevents problems that may occur due to the culture medium S drying out excessively, such as the withering of the seedlings W.

[0036] According to this embodiment 1, the irrigation device 10 has a simple configuration without using any power-consuming devices such as sensors or valves, and can supply an appropriate amount of liquid F, neither too much nor too little, to the culture medium S of the cell plug 12 in which the seedling W is planted, depending on the condition of the culture medium.

[0037] Furthermore, by adjusting the amount of working fluid WF accommodated in working fluid accommodation portion 26 of cell plug lifting portion 16, i.e., by adjusting the liquid level of working fluid WF, it is possible to adjust the amount of liquid F supplied to culture medium S in a plurality of cell plugs 12 at once. Specifically, by adjusting the liquid level of working fluid WF, it is possible to adjust the contact time between the other end (contact end) 20b of liquid transport member 20 of liquid supply portion 14 and culture medium S (water retention member 22 thereon) in cell plug 12, and as a result, it is possible to adjust the supply time of liquid F to culture medium S.

[0038] Furthermore, the liquid F can be intermittently supplied to the culture medium S in the cell plug 12 by the liquid transport member 20 of the liquid supply unit 14 without using a pump, a valve, or the like.

[0039] (Embodiment 2) The present embodiment 2 is an improved version of the above-mentioned embodiment 1. Therefore, the irrigation device according to the present embodiment 2 will be described focusing on the differences from the above-mentioned embodiment 1. Note that the same reference numerals are used to designate components that are substantially the same as those in the above-mentioned embodiment 1.

[0040] FIG. 4 is a cross-sectional view of an irrigation device according to the second embodiment of the present invention.

[0041] In the irrigation device 110 according to the second embodiment shown in FIG. 4, the cell plug 12 is raised and lowered in the working fluid WF without coming into contact with the working fluid WF. To this end, the cell plug lifting unit 116 includes a cup-shaped holder 130 that detachably houses and holds the cell plug 12. The holder 130 is raised and lowered as a portion of the holder 130 is immersed in the working fluid WF and receives buoyancy. As a result, the cell plug 12 is raised and lowered in the working fluid WF without coming into contact with the working fluid WF. As a result, for example, there is no need to wipe the cell plug 12 when transporting it from the irrigation device 110 to another device.

[0042] In this second embodiment, as in the first embodiment described above, the irrigation device 110 has a simple configuration without using sensors, valves, etc., and can supply an appropriate amount of liquid F, neither too much nor too little, to the culture medium S of the cell plug 12 in which the seedling W is planted, depending on the condition of the culture medium.

[0043] (Embodiment 3) In this third embodiment, the configuration of the cell plug lifting unit that lifts and lowers the cell plugs is different from that of the first embodiment. Therefore, the irrigation device according to the third embodiment will be described focusing on the cell plug lifting unit that is different from that of the first embodiment. Note that the same reference numerals are used to designate components that are substantially the same as those of the first embodiment.

[0044] FIG. 5 is a cross-sectional view of an irrigation device according to a third embodiment of the present invention.

[0045] In the irrigation device 210 according to the third embodiment, the cell plug lifting section 216 includes a holder 230 that detachably holds the cell plug 12, and an elastic member 232 that supports the holder 230 so that it can be lifted and lowered. The elastic member 232 is, for example, a coil spring, an air spring, a cushion, rubber, a sponge, or the like. That is, the elastic member 232 is a member that elastically deforms in response to changes in the weight of the cell plug 12. In the case of the third embodiment, the elastic member 232 supports the holder 230 from below, and expands and contracts in the vertical direction (Z-axis direction) in response to changes in the weight of the cell plug 12 in the holder 230.

[0046] According to the cell plug lifting / lowering section 216, unlike the cell plug lifting / lowering section 16 of the above-mentioned first embodiment, the cell plug 12 can be lifted / lowered without using the working fluid WF.

[0047] In this third embodiment, as in the first embodiment described above, the irrigation device 210 has a simple configuration without using sensors or the like, and can supply an appropriate amount of liquid F, neither too much nor too little, to the culture medium S of the cell plug 12 in which the seedling W is planted, depending on the condition of the culture medium.

[0048] Although the present invention has been described above with reference to the first to third embodiments, the present invention is not limited to these embodiments.

[0049] For example, in the case of the above-mentioned embodiment 1, when viewed in the opening direction of the opening 12a (Z-axis direction) of the cell plug 12, the body portion 12d has a rectangular cross section as shown in Fig. 2. However, the embodiment of the present invention is not limited thereto. For example, the body portion of the cell plug may have a circular cross section.

[0050] In the above-mentioned first to third embodiments, the liquid supply unit 14 supplies the liquid F to the culture medium S in the cell plug 12 using a liquid transport member 20, such as a nonwoven fabric, that generates capillary action. However, the present invention is not limited to this embodiment. For example, the liquid supply unit may use a mechanical valve equipped with a valve body (contact end) that contacts the culture medium. This mechanical valve is configured to open when the culture medium retracts the valve body due to the rise of the cell plug, and close when the cell plug descends by returning the valve body to its original position due to a spring or the like.

[0051] The above-mentioned embodiments have been described as examples of the technology of the present invention, and the accompanying drawings and detailed description have been provided for that purpose.

[0052] Therefore, among the components described in the attached drawings and the detailed description, not only are there components essential for solving the problem, but there may also be components that are not essential for solving the problem in order to illustrate the technology. Therefore, the fact that those non-essential components are described in the attached drawings or the detailed description should not be interpreted as immediately being essential.

[0053] Furthermore, since the above-described embodiment is intended to illustrate the technology of the present invention, various modifications, substitutions, additions, omissions, and the like can be made within the scope of the claims or their equivalents. [Industrial Applicability]

[0054] The present invention can be applied to any irrigation device that provides liquid to seedlings, regardless of the type of seedlings or the type of liquid provided to the seedlings.

Claims

1. a cell plug having an upward opening and a container communicating with the opening for containing a predetermined amount of culture medium; A liquid supply unit that supplies liquid to the culture medium of the cell plug; a cell plug lifting unit that lowers the cell plug when the weight of the cell plug increases due to the liquid supplied by the liquid supply unit, and lifts the cell plug when the weight of the cell plug decreases due to drying of the culture medium, The liquid supply unit has a contact end that intermittently contacts the culture medium by raising and lowering the cell plug by the cell plug lifting unit, and liquid is supplied while the contact end is in contact with the culture medium, and liquid supply is stopped when the contact end is away from the culture medium.

2. The irrigation device according to claim 1 , wherein the cell plug lifting section includes a working fluid containing section, and a working fluid contained in the working fluid containing section, in which a portion of the cell plug is immersed, to provide buoyancy to the cell plug.

3. The irrigation device according to claim 2 , wherein the cell plug lifting section includes a guide member that guides the cell plug so that the cell plug moves in an up-down direction.

4. The irrigation device according to claim 1 , wherein the cell plug lifting section includes a holder that holds the cell plug, and an elastic member that supports the holder so that it can be lifted and lowered.

5. The irrigation device according to claim 1 , wherein the cell plug is detachable from the cell plug lifting section.

6. An irrigation device as described in any one of claims 1 to 5, wherein the liquid supply section includes a liquid storage section, one end immersed in the liquid in the liquid storage section and the other end being the contact end, and a liquid transport member that transports liquid from the one end to the other end by capillary action.

7. 7. The irrigation device according to claim 6, wherein the liquid supply portion includes a support portion that supports the liquid transport member so that the other end of the liquid transport member is positioned at the same or higher level than the one end of the liquid transport member.

8. The irrigation device according to claim 6 or 7, wherein the liquid transport member is a nonwoven fabric.

9. 9. The irrigation device according to claim 6, further comprising a water retention member provided on the culture medium in the cell plug, the water retention member being in contact with the other end of the liquid transport member.

10. The container has an opening and a body portion defining a storage portion communicating with the opening and storing a predetermined amount of culture medium; The main body portion includes a cylindrical portion extending from an edge of the opening in an opening direction of the opening, and an inverted cone-shaped or inverted frustum-shaped bottom portion connected to the cylindrical portion, Made from a material that floats in liquid, When the cell plug is immersed in liquid with a culture medium contained in the container, the cell plug floats alone in the liquid with the opening facing upward.

11. A cell plug as described in claim 10, wherein the tubular portion is tubular in the opening direction and longer in the opening direction than in other directions perpendicular to the opening direction.

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