WO2018168181A1 - Plant cultivation device and plant cultivation method - Google Patents

Abstract

A plant cultivation device wherein a plant is cultivated while soaking the roots of the plant in a liquid fertilizer. The plant cultivation device comprises a plant holding part, a cultivation tank and a bubble generating part. The plant holding part holds the plant. The cultivation tank comprises a bottom surface which receives the roots extending from the plant through the plant holding part and a side wall which surrounds the plant holding part, and the liquid fertilizer can be pooled therein. The bubble generating part, which is disposed above the cultivation tank, drops the liquid fertilizer so as to generate bubbles on the liquid surface of the liquid fertilizer pooled in the cultivation tank.

Description

Plant cultivation apparatus and plant cultivation method

The present disclosure relates to a plant cultivation apparatus and a plant cultivation method for cultivating a plant by immersing the root of the plant in liquid fertilizer.

As a plant cultivation device used in a plant factory that performs agriculture such as vegetable cultivation in an industrial form, a hydroponic plant cultivation device is known in which a plant is immersed in a liquid fertilizer housed in a cultivation tank. In this plant cultivation device, artificial light for photosynthesis is irradiated to a plant to be cultivated, and liquid fertilizer containing nutrients necessary for plant growth in the cultivation water is supplied around the roots of the plant. In such liquid fertilizer supply, not only nutrients but also dissolved oxygen dissolved in the liquid fertilizer may be absorbed by the roots. Therefore, a plant cultivation device having an oxygen supply function for increasing the oxygen content in the liquid fertilizer for cultivation has been proposed (see, for example, Patent Document 1).

In the prior art shown in Patent Document 1, an inverted T-shaped tube having an insertion cylinder for inserting a seedling pocket for planting a plant seedling on the upper side and a left and right cylinder serving as a passage for liquid fertilizer on the lower side is connected to each other. ing. Then, an outward connection pipe and a return connection pipe through which liquid fertilizer circulates and circulates are configured. A bubble generation pump chamber is provided on the most upstream side of the forward connection pipe, and oxygen is supplied to the liquid manure by generating bubbles in the liquid manure.

Moreover, in the conventional plant cultivation apparatus, the plant to be cultivated is irradiated with artificial light for photosynthesis, and liquid fertilizer containing nutrients necessary for plant growth in the cultivation water is supplied around the plant roots. . As a form of supplying such liquid fertilizer, there is known a system in which liquid fertilizer in a cultivation tank on which a plant is placed is circulated between a storage tank provided outside (see, for example, Patent Document 2).

In the prior art shown in Patent Document 2, a porous container planted with a plant is immersed in liquid fertilizer in a cultivation tank. A circulation method is adopted in which the liquid fertilizer discharged from the cultivation tank through the discharge port is stored in a storage tank, and the liquid fertilizer in the storage tank is supplied to the cultivation tank through the supply port. And supply and discharge | emission of liquid fertilizer are controlled by the system set beforehand.

Japanese Unexamined Patent Publication No. 2010-154822 Japanese Unexamined Patent Publication No. Sho 62-029924

The plant cultivation apparatus of the present disclosure cultivates a plant by immersing the root of the plant in liquid fertilizer.

The plant cultivation device has a plant holding unit, a cultivation tank, and a bubble generating unit.

The plant holding unit holds plants.

The cultivation tank has a bottom surface that receives roots extending from the plant through the plant holding part, and a side wall that surrounds the plant holding part, and can store liquid fertilizer.

The bubble generating unit is arranged above the cultivation tank, and generates bubbles on the liquid surface of the liquid fertilizer accumulated in the cultivation tank by dropping the liquid fertilizer.

The plant cultivation method of the present disclosure is a method using a plant cultivation apparatus that cultivates a plant by immersing the root of the plant in liquid fertilizer collected in a cultivation tank.

A plant cultivation apparatus used for a plant cultivation method includes a plant holding unit that holds a plant, a bottom surface that receives a root extending from the plant through the plant holding unit, and a cultivation tank that includes a side wall that surrounds the plant holding unit. Have.

The plant cultivation method is
A plant holding step of holding the plant by the plant holding unit;
A bubble generating step that is arranged above the cultivation tank and generates bubbles on the liquid surface of the liquid fertilizer accumulated in the cultivation tank by dropping the liquid fertilizer,
Have

FIG. 1 is a schematic cross-sectional view illustrating the configuration of the plant cultivation apparatus according to the first embodiment. FIG. 2 is a schematic plan view of the plant cultivation apparatus according to the first embodiment. FIG. 3 is an explanatory diagram of a fluid state of liquid fertilizer in the cultivation tank of the plant cultivation apparatus according to the first embodiment. FIG. 4 is an explanatory diagram illustrating a relationship between root growth and a liquid level of liquid fertilizer in the cultivation tank of the plant cultivation apparatus according to the first embodiment. FIG. 5 is an explanatory diagram illustrating the relationship between root growth and the level of liquid fertilizer in the cultivation tank of the plant cultivation apparatus according to the first embodiment. FIG. 6 is an explanatory diagram illustrating a relationship between root growth and liquid fertilizer water level in the cultivation tank of the plant cultivation apparatus according to the first embodiment. FIG. 7 is a schematic plan view of the plant cultivation apparatus according to the second embodiment.

In Patent Document 1, a bubble generation pump that supplies oxygen into liquid fertilizer is provided on the most upstream side of the forward connection pipe. The supply of oxygen to the plant seedlings is performed in a process in which liquid fertilizer sequentially flows through the forward connection pipe and the return connection pipe. Therefore, the dissolved oxygen concentration in the liquid fertilizer varies depending on the arrangement position of the seedling pockets where the plant seedlings are planted. As a result, the growth state of the seedlings to be cultivated varies. As described above, when the oxygen supply amount in the liquid fertilizer is increased in the conventional plant cultivation apparatus, it is difficult to make the dissolved oxygen concentration uniform, which may cause variations in the growth state.

Further, in Patent Document 2, it is difficult to uniformly replace the liquid fertilizer in the cultivation tank due to the arrangement of the supply port and the discharge port in the circulation path of the liquid fertilizer. In hydroponics where the nutrients and oxygen necessary for plant growth are supplied to the roots through liquid fertilization, even when the roots grow as the plant grows, the liquid fertilizer should be contacted as uniformly as possible to each part of the roots. Is desired.

However, in patent document 2, the supply port and discharge port of liquid fertilizer are unevenly distributed and provided in the cultivation tank. In such a case, the flow of liquid fertilizer is hardly induced at positions away from the supply port and the discharge port, and it is difficult to uniformly contact the liquid fertilizer over the entire root. For this reason, nutrients and oxygen are not uniformly supplied to the roots of the plant, and as a result, the growth state of the plant to be cultivated may vary. As described above, in conventional hydroponic cultivation devices, it is difficult to cause liquid fertilizer to flow evenly and uniformly in the entire root in the cultivation tank, which may cause variations in the growth state.

(Embodiment 1)
First, with reference to FIG. 1, the structure of the plant cultivation apparatus 1 is demonstrated. FIG. 1 is a schematic cross-sectional view illustrating the configuration of the plant cultivation apparatus 1 according to the first embodiment. The plant cultivation apparatus 1 has a function of industrially cultivating plants such as vegetables and foliage plants. In the present embodiment, a hydroponic method of cultivating a plant by immersing the root of the plant to be cultivated in liquid fertilizer is used. It has been adopted.

In FIG. 1, the plant 6 to be cultivated has its root held in a planting pot 5 containing a sponge or the like as a medium. The planting pot 5 is a plant holding unit that holds the plant 6. The planting pot 5 is mounted on a pot mounting portion 4 provided in a cultivation tank 2 having a concave cross section that can store liquid fertilizer 3 containing nutrients for cultivation in water. In addition, in this specification, the direction where the below-mentioned water supply pipe 14 is extended | stretched in the cultivation tank 2 is made into the 1st direction, and the direction orthogonal to a 1st direction is defined as a 2nd direction.

Below the cultivation tank 2, a storage tank 7 for storing liquid fertilizer 3 drained from the cultivation tank 2 is disposed. The storage tank 7 is a rectangular parallelepiped box-shaped container having a rectangular bottom 7a and side walls 7b erected from four sides of the bottom 7a. The cultivation tank 2 is held by a holding member (not shown) in a state where the upper part of the cultivation tank 2 is protruded from the upper surface of the storage tank 7 where the upper end of the side wall 7b is opened.

A space for storing the liquid fertilizer 3 is secured between the bottom surface 10 of the cultivation tank 2 and the bottom 7a of the storage tank 7. Thus, the whole height of the plant cultivation apparatus 1 can be made low by setting it as the structure which piles up the cultivation tank 2 on the storage tank 7. FIG. Therefore, a plurality of plant cultivation devices 1 can be arranged in a plurality of stages using a shelf or the like, and the plant cultivation device 1 excellent in area productivity is realized.

The configuration of the cultivation tank 2 will be described with reference to FIGS. FIG. 2 is a schematic plan view of the plant cultivation apparatus 1 according to the first embodiment. The cultivation tank 2 is a container having a concave cross section in which side walls 11 are erected on four sides of a substantially square bottom 10. As shown in FIG. 1, a pot placement portion 4 for placing a planting pot 5 is provided at the center of the bottom surface 10. In the state where the planting pot 5 is placed on the pot placement unit 4, the planting pot 5 is surrounded from the periphery by the four side walls 11, and the bottom of the planting pot 5 is immersed in the liquid fertilizer 3. Become.

The cultivation tank 2 has a cover 12 that detachably covers an opening enclosed by these side walls 11. The cover 12 is provided with an opening 12 a corresponding to the placement position of the planting pot 5. In a state where the planting pot 5 in which the plant 6 is planted is placed in the cultivation tank 2, the stem portion of the plant 6 extends upward through the opening 12 a. By making the cover 12 detachable, it is possible to remove the cover 12 when necessary, and to efficiently check the supply state and drainage state of the liquid fertilizer 3 in the cultivation tank 2 and the internal cleaning.

An opening (not shown) communicating with the liquid fertilizer 3 in the cultivation tank 2 is provided at the bottom of the planting pot 5, and the bottom of the planting pot 5 extends from the root of the plant 6 during the growth of the plant 6. The bottom surface 10 of the cultivation tank 2 receives the roots 6a (see FIGS. 4, 5 and 6) in a prosperous state extending through the opening. And the root 6a is further extended | stretched toward the periphery along the upper surface of the bottom face 10 in the liquid fertilizer 3 in the cultivation tank 2. FIG. In the cultivation tank 2, the distance from the planting pot 5 to each side wall 11 is set to a distance that the root 6 a extending from the planting pot 5 can reach. The root 6 a reaches the surrounding side wall 11 as the plant 6 grows.

In each side wall 11, a plurality of drainage ports 13 for adjusting the water level are formed at a predetermined pitch in the horizontal direction, at a predetermined plurality of levels (here, three levels) from the upper surface of the bottom surface 10. Yes. That is, as shown in FIG. 1, a plurality of drainage ports 13 (lower drainage ports 13a, 13a, A middle drainage port 13b and an upper drainage port 13c) are formed.

The cultivation tank 2 is positioned above the liquid surface 3 a of the liquid fertilizer 3 accumulated in the cultivation tank 2, and a plurality of (here, two) water supply pipes 14 are arranged in an arrangement sandwiching the planting pot 5 in plan view. They are arranged in one direction (see FIG. 2). Here, the water supply pipe 14 is attached in the form of being laid between two opposing side walls 11. The height of the water supply pipe 14 is set to be higher than the height of the liquid surface 3a in a state where the liquid fertilizer 3 is accumulated in the cultivation tank 2 up to a water level higher than that of the uppermost upper drainage port 13c. Thus, by arranging the water supply pipe 14 above the liquid surface 3a of the liquid fertilizer 3, the liquid hole of the water supply pipe 14 is not clogged by the root 6a, and the supply of the liquid fertilizer 3 is stabilized. You can do it.

The water supply pipe 14 is connected to a connecting pipe 16 provided outside the cultivation tank 2, and the connecting pipe 16 is connected to a pump 17 disposed on the upper surface of the bottom 7 a of the storage tank 7. Furthermore, a plurality of liquid holes (not shown) are formed at a predetermined pitch on the lower surface of the water supply pipe 14 for discharging the liquid fertilizer 3 fed into the water supply pipe 14 in the form of a thin line-shaped discharge liquid 3b by the pressure of the pump 17. Has been. By operating the pump 17, the liquid fertilizer 3 stored in the storage tank 7 is fed to the water supply pipe 14 via the connection pipe 16 (arrow a in FIG. 1).

The liquid fertilizer 3 fed to the water supply pipe 14 falls as discharge liquid 3b from the liquid hole on the lower surface of the water supply pipe 14 toward the liquid surface 3a of the liquid fertilizer 3 accumulated in the cultivation tank 2 (arrow b in FIG. 1). ). Thereby, the liquid fertilizer 3 in the storage tank 7 is supplied to the cultivation tank 2. The pump 17, the connecting pipe 16, and the water supply pipe 14 serve as a liquid fertilizer supply unit that supplies the liquid fertilizer 3 to the cultivation tank 2. The liquid fertilizer 3 supplied to the cultivation tank 2 is dropped and returned to the storage tank 7 from the drain port 13 provided in the side wall 11, and the returned liquid fertilizer 3 is supplied to the cultivation tank 2 again. In this way, circulation supply of the liquid fertilizer 3 is repeatedly executed.

In supplying the liquid fertilizer 3 to the cultivation tank 2, bubbles 3c are generated on the liquid surface 3a of the liquid fertilizer 3 due to the drop of the discharge liquid 3b. That is, the water supply pipe 14 provided with a liquid hole for discharging and dropping the discharge liquid 3b is a bubble generating part that generates bubbles 3c on the liquid surface 3a. And the liquid fertilizer 3 of the storage tank 7 is sent to this bubble generating part by the pump 17.

Thus, by generating bubbles 3c on the liquid surface 3a of the liquid fertilizer 3 in the cultivation tank 2, the contact area between the liquid fertilizer 3 and the air in the bubbles 3c increases. Thereby, the oxygen supply amount in the liquid fertilizer 3 is increased, the oxygen uptake from the root 6a is increased, and the growth of the plant 6 can be promoted. That is, the oxygen supply amount in the liquid fertilizer 3 can be increased and the dissolved oxygen concentration can be made uniform to realize a good growth state.

As described above, in the bubble generating unit configured to drop the discharge liquid 3b from the water supply pipe 14 to generate bubbles on the liquid surface 3a, the water supply pipe 14 is installed between two opposing side walls 11 in the cultivation tank 2. Arranged in different forms. With this configuration, the discharge liquid 3b can be dropped from the water supply pipe 14 to a plurality of locations on the liquid surface 3a above the root 6a extending between the planting pot 5 and the side wall 11 as the plant 6 grows. Therefore, the bubbles 3c can be generated almost uniformly in the liquid fertilizer 3 around the root 6a extending toward the side wall 11, and the dissolved oxygen concentration in the liquid fertilizer 3 can be kept uniform.

Thus, by dropping the discharged liquid 3b from the water supply pipe 14 and supplying the liquid fertilizer 3 into the cultivation tank 2, the water level of the liquid fertilizer 3 in the cultivation tank 2 rises. As the water level rises, the liquid fertilizer 3 in the cultivation tank 2 is drained from the lower drainage port 13a, the middle drainage port 13b, and the upper drainage port 13c constituting the drainage port 13 and stored in the storage tank 7 below. At this time, the liquid fertilizer 3 is drained from the drainage port 13 at a height level corresponding to the water level of the liquid fertilizer 3 in the cultivation tank 2 among the lower drainage port 13a, the middle drainage port 13b, and the upper drainage port 13c. In FIG. 1, since the water level of the liquid fertilizer 3 in the cultivation tank 2 is low, the liquid fertilizer 3 is drained only from the lower drainage port 13a of the lowest height level (arrow c).

A water level limiting drain 15 is erected on the bottom surface 10 of the cultivation tank 2 at one corner. The water level limiting drain 15 is a hollow tube member having a drain inner hole 15 a, and the drain inner hole 15 a passes through the bottom surface 10 and communicates with the inside of the storage tank 7. The height of the upper end of the water level limiting drain 15 is set corresponding to the limiting water level in the cultivation tank 2. When the amount of liquid fertilizer 3 supplied into the cultivation tank 2 is larger than the amount of drainage drained through the drain port 13 and the water level in the cultivation tank 2 rises and exceeds the limit water level, excess liquid fertilizer 3 is discharged into the storage tank 7 through the drain hole 15a.

In the cultivation tank 2, a root-proof permeable sheet 18 is laid on the inner surface of the bottom surface 10 and the side wall 11 so as to cover the drainage port 13. The root-proof water-permeable sheet 18 is a water-permeable sheet-like member provided with openings of a prescribed mesh. The root-proof permeable sheet 18 has a shape that prevents the passage of the root 6 a while allowing the liquid fertilizer 3 to pass therethrough. By laying the root-proof permeable sheet 18 on the inner surface of the cultivation tank 2, the root 6 a can be prevented from entering the drain port 13 without hindering the function as the drain port 13. In other words, the cultivation tank 2 has a root-permeable water-permeable sheet 18 as a root-preventing means (root-protecting tool) for preventing the root 6a from entering the drain port 13.

Next, with reference to FIG. 3, the flow state of the liquid fertilizer 3 in the cultivation tank 2 will be described. FIG. 3 is a schematic top view of the cultivation tank 2 of the plant cultivation apparatus 1. As described above, the supply of the liquid fertilizer 3 into the cultivation tank 2 is performed by dropping the liquid fertilizer 3 from the water supply pipe 14 as the discharge liquid 3b. In supplying the liquid fertilizer 3, the water supply pipe 14 is arranged at the center inside the cultivation tank 2. Moreover, the drainage of the liquid fertilizer 3 from the cultivation tank 2 is performed through the drain port 13 formed in the side wall of the cultivation tank 2.

Thereby, in the process of continuously supplying the liquid fertilizer 3 into the cultivation tank 2, as shown in FIG. 3, the liquid fertilizer 3 in the direction from the center of the cultivation tank 2 to each side wall 11 is provided inside the cultivation tank 2. Is induced (arrow d). In the flow of the liquid fertilizer 3, a plurality of drain holes 13 are formed at predetermined positions at substantially equal intervals on the four side walls 11 of the cultivation tank 2. From this, a substantially uniform flow state can be realized in the entire range in the cultivation tank 2.

Therefore, even when the root 6a of the plant 6 extends from the planting pot 5 toward the peripheral side wall 11 in the cultivation tank 2 and thrives on the entire bottom surface 10, the flowing liquid fertilizer 3 is almost uniformly distributed over the entire root 6a. Can touch. Thereby, a nutrient and oxygen can be supplied uniformly to the whole root 6a, and the dispersion | variation in the growth state of the plant 6 can be prevented.

Next, with reference to FIG. 4, FIG. 5, FIG. 6, the relationship between the water level of the liquid fertilizer 3 in the cultivation tank 2 and the growth of the root 6a of the plant 6 will be described. 4, 5, and 6 are explanatory diagrams illustrating the relationship between the growth of the root 6 a and the water level of the liquid fertilizer 3 in the cultivation tank 2 of the plant cultivation apparatus 1 of the first embodiment. FIG. 4 shows a state in which the growth of the plant 6 is in an initial state, the root 6a has not yet grown sufficiently, and has not reached the vicinity of the side wall 11 in the cultivation tank 2. In this state, the drainage 3d (arrow e) from the lower drainage port 13a at the lowest stage is not obstructed by the root 6a at all, and the drainage amount from the lower drainage port 13a is defined by the water level on the bottom surface 10 of the cultivation tank 2. Is done.

That is, in this case, the water level in the cultivation tank 2 is such that the supply amount of the liquid fertilizer 3 supplied to the cultivation tank 2 in the form of the discharge liquid 3b from the water supply pipe 14 is balanced with the drainage amount from the lower drainage port 13a. It converges to level L1. At this time, the supply amount of the liquid fertilizer 3 from the water supply pipe 14 is set in advance so that the water level L1 is higher than the lower drainage port 13a and lower than the middle drainage port 13b.

Next, FIG. 5 shows a state where the growth of the plant 6 has progressed from the state of FIG. That is, the root 6a grows and proliferates, and the lower drainage port 13a at the lowest stage is almost blocked. In this state, the amount of the drainage 3d from the lower drainage port 13a decreases. As a result, the water level in the cultivation tank 2 rises and the discharge of the drainage 3e (arrow f) from the middle middle drainage port 13b is started.

At this time, the water level in the cultivation tank 2 converges to a water level L2 in which the amount of liquid fertilizer 3 supplied from the water supply pipe 14 is balanced with the amount of drainage from the lower drainage port 13a and the middle drainage port 13b. Although this water level L2 is higher than the middle drainage port 13b, it is at a height close to the root 6a that is prosperous on the bottom surface 10 of the cultivation tank 2. Thereby, the bubbles 3c generated below the liquid surface 3a by the discharge liquid 3b can reach the periphery of the root 6a.

In FIG. 6, the plant 6 grows further and grows until the root 6a is almost in a state of blocking the middle drainage port 13b. In this state, the drainage 3e from the middle drainage port 13b is inhibited and the water level in the cultivation tank 2 further rises. At this time, the discharge of the drainage 3f (arrow g) from the upper drainage port 13c at the uppermost stage is started, whereby the supply amount of the liquid fertilizer 3 from the water supply pipe 14, the lower drainage port 13a, the middle drainage port 13b, the upper stage The water level in the cultivation tank 2 is stabilized at the water level L3 that balances the amount of drainage from the drain port 13c. This water level L3 is at a position higher than the upper drainage port 13c, but is at a height close to the prosperous root 6a. Thereby, the bubble 3c generated below the liquid surface 3a can reach the periphery of the root 6a.

In addition, when clogging of the lower drainage port 13a, the middle drainage port 13b, and the upper drainage port 13c occurs for some reason, the water level in the cultivation tank 2 rises beyond the height of the upper drainage port 13c. . In such a case, when the water level reaches the height of the upper end surface of the water level limiting drain port 15, the water level overflows from the drain inner hole 15 a and flows down into the storage tank 7. Thereby, the overflow of the liquid fertilizer 3 from the cultivation tank 2 is prevented.

In the above-described configuration, the drain port 13 formed in the side wall 11 functions as a water level adjusting unit (water level adjusting means) that adjusts the water level of the liquid fertilizer 3 in the cultivation tank 2. In the present embodiment, the water level adjusting portion is configured by a plurality of drainage ports 13 (three in this case, the lower drainage port 13a, the middle drainage port 13b, and the upper drainage port 13c) formed in the height direction of the side wall 11. Like to do.

With such a configuration, regardless of the inclination of the cultivation tank 2 in the installed state or the fluctuation of the water level of the liquid fertilizer 3 in the cultivation tank 2, the drainage port 13 at any stage is always located below the liquid level 3 a. Thereby, the liquid fertilizer 3 supplied from the water supply pipe 14 is discharged | emitted outside the cultivation tank 2 without staying, and the dissolved oxygen concentration of the liquid fertilizer 3 in the cultivation tank 2 can be kept substantially uniform. That is, the liquid fertilizer 3 can be made to flow in the cultivation tank 2 so as to contact the entire root 6a evenly and uniformly, thereby realizing a good growth state.

Furthermore, by this structure, as shown in FIG.4, FIG.5, FIG.6, in the plant cultivation apparatus 1 of the structure which supplies the liquid fertilizer 3 continuously from the water supply pipe 14 in the cultivation tank 2, of the root 6a of the plant 6 The water level of the liquid fertilizer 3 in the cultivation tank 2 can be increased sequentially according to the growth. That is, in the conventional hydroponics, in order to keep the root 6a that grows thick with the growth of the plant 6 and is properly immersed in the liquid fertilizer 3, the liquid fertilizer 3 from the water supply pipe 14 is maintained. It was necessary to always adjust the water level of the liquid fertilizer 3 in the cultivation tank 2 by adjusting the amount of water supply. On the other hand, in the plant cultivation apparatus 1 shown in this Embodiment, the water level of the liquid fertilizer 3 in the cultivation tank 2 is always set by a simple configuration in which a plurality of drain ports 13 formed in the height direction are provided in the side wall 11. It can be held properly.

(Embodiment 2)
In Embodiment 1, the cultivation tank 2 in the plant cultivation apparatus 1 showed the example which is a cross-sectional concave shape which has a substantially square planar shape. However, as shown in FIG. 7, the present invention can also be applied to a plant cultivation apparatus 1A in which the cultivation tank 2A has a rectangular planar shape that is long in one direction. FIG. 7 is a schematic plan view of the plant cultivation apparatus 1A according to the second embodiment.

That is, the cultivation tank 2A in the plant cultivation apparatus 1A of Embodiment 2 has a rectangular planar shape in which the side wall 11a extending in the first direction is longer than the side wall 11b extending in the second direction. A plurality (three in this case) of planting pots 5 are placed in the cultivation tank 2A along the first direction which is the longitudinal direction. The cultivation tank 2A has a cover 12 that detachably covers an opening enclosed by the side wall 11a and the side wall 11b. The cover 12 corresponds to the placement position of the planting pot 5 according to the first embodiment. An opening 12a having the same function as the above is provided.

In the cultivation tank 2A, two water supply pipes 14 having the same functions as those of the water supply pipe 14 in the first embodiment are arranged in the first direction in an arrangement that sandwiches the planting pot 5 in a plan view. Here, the water supply pipe 14 is attached in the form of being installed between two opposing side walls 11b. Further, on the two opposite side walls 11a, the drainage port 13 composed of the lower drainage port 13a, the middle drainage port 13b, and the upper drainage port 13c having the same configuration as the drainage port 13 shown in the first embodiment is provided on the entire length of the side wall 11a. Formed at a constant pitch.

Below the cultivation tank 2A, a storage tank 7A having a rectangular planar shape whose first direction is longer than the second direction is arranged. The storage tank 7 </ b> A has a function of storing the liquid fertilizer 3 drained from the drain port 13 of the cultivation tank 2 </ b> A, similarly to the storage tank 7 in the first embodiment. A pump 17 is disposed at one end of the storage tank 7 </ b> A in the first direction, and the pump 17 is connected to the water supply pipe 14 via a connecting pipe 16.

By operating the pump 17, as in the first embodiment, the liquid fertilizer 3 stored in the storage tank 7A is fed to the water supply pipe 14 via the connecting pipe 16, and the liquid of the liquid fertilizer 3 stored in the cultivation tank 2A. The discharged liquid 3b falls from the lower surface of the water supply pipe 14 toward the surface 3a. Then, the liquid fertilizer 3 collected in the cultivation tank 2A is drained from the drain port 13 and stored in a storage tank 7A located below.

Also in Embodiment 2 shown in FIG. 7, in the cultivation tank 2A, the liquid fertilizer 3 supplied from the water supply pipe 14 located in the vicinity of the center portion in the second direction is first toward the drain port 13 of the side wall 11a which is the long side. Flows in two directions. Here, since the plurality of drain outlets 13 in the side wall 11a are arranged at a constant pitch along the first direction which is the longitudinal direction, the flow state of the liquid fertilizer 3 in the second direction in the cultivation tank 2A is about the first direction. It becomes uniform and the same effect as in the first embodiment is obtained.

As described above, the first and second embodiments relate to the plant cultivation apparatuses 1 and 1A for cultivating the plant 6 by immersing the root 6a of the plant 6 in the liquid fertilizer 3.

The plant cultivation apparatus 1, 1 </ b> A has a planting pot 5, a cultivation tank 2, and a water supply pipe 14.

The planting pot 5 is a plant holding unit that holds the plant 6.

The cultivation tank 2 has a concave cross section capable of storing the liquid fertilizer 3, and has a bottom surface 10 that receives the root 6 a extending from the plant 6 and a side wall 11 that surrounds the planting pot 5.

The water supply pipe 14 is a bubble generating unit that is arranged above the liquid level 3a of the liquid manure 3 accumulated in the cultivation tank 2 and generates bubbles 3c on the liquid level 3a by dropping the liquid fertilizer 3 toward the liquid level 3a. .

As a result, the contact area between the liquid fertilizer 3 and the air in the bubbles 3c is increased, the amount of oxygen supplied in the liquid fertilizer 3 is increased to increase oxygen uptake from the root 6a, and the dissolved oxygen concentration in the liquid fertilizer 3 is increased. A uniform growth state of the plant 6 can be realized by making it uniform.

Moreover, the plant cultivation apparatuses 1 and 1A according to the first and second embodiments include a planting pot 5, a cultivation tank 2, a water supply pipe 14, a pump 17, and a water level adjusting unit.

The planting pot 5 is a plant holding unit that holds the plant 6.

The cultivation tank 2 has a concave cross section capable of storing the liquid fertilizer 3, and has a bottom surface 10 that receives the root 6 a extending from the plant 6 and a side wall 11 that surrounds the planting pot 5.

The pump 17, the connecting pipe 16, and the water supply pipe 14 are liquid fertilizer supply units that supply the liquid fertilizer 3 to the cultivation tank 2.

The water level adjustment unit adjusts the water level of the liquid fertilizer 3 in the cultivation tank 2. The water level adjuster is composed of a lower drainage port 13a, an intermediate drainage port 13b, and an upper drainage port 13c formed at a plurality of positions in the height direction of the side wall 11.

Moreover, the plant cultivation apparatuses 1 and 1A in the first and second embodiments realize that the liquid fertilizer 3 flows in the cultivation tank 2 so that the liquid fertilizer 3 uniformly contacts the entire root 6a to achieve a good growth state. One purpose. By this structure, the liquid fertilizer 3 can be made to flow in the cultivation tank 2 so that it may uniformly contact the whole root 6a, and the favorable growth state of the plant 6 can be realized.

Embodiments 1 and 2 are as described above, but the present invention may be implemented with appropriate design changes without departing from the scope of the invention. For example, although the drain port 13 is formed only on the side wall 11 of the cultivation tank 2 in the first embodiment, it may be formed on both the side wall 11 and the bottom surface 10.

In the first and second embodiments, a plurality of water supply pipes 14 are used. However, a water supply pipe formed by connecting the water supply pipes 14 into an annular shape may be used.

In the first and second embodiments, the storage tanks 7 and 7A are arranged directly below the cultivation tank 2. However, the storage tanks 7 and 7A may be arranged at positions separated in the horizontal direction, and the liquid fertilizer 3 discharged from the drain port 13 may be collected by the drainage duct and collected in the storage tanks 7 and 7A.

According to the present disclosure, a good growth state can be realized.

The plant cultivation apparatus and the plant cultivation method of the present disclosure have an effect that the oxygen supply amount in liquid fertilizer is increased and the dissolved oxygen concentration is made uniform to realize a good growth state. Therefore, it is useful in the hydroponics field where plants are cultivated by immersing plant roots in liquid fertilizer.

DESCRIPTION OF SYMBOLS 1,1A Plant cultivation device 2,2A Cultivation tank 3 Liquid fertilizer 3a Liquid surface 3c Bubble 3d Drainage 3e Drainage 3f Drainage 4 Pot placement part 5 Planting pot 6 Plant 6a Root 7, 7A Storage tank 7a Bottom part 7b Side wall 10 Bottom face 11 11a, 11b Side wall 12 Cover 12a Opening 13 Drainage port 13a Lower drainage port 13b Middle drainage port 13c Upper drainage port 14 Water supply pipe 15 Water level restriction drainage port 15a Drainage inner hole 16 Connection pipe 17 Pump 18 Root-proof water-permeable sheet

Claims (20)

A plant cultivation apparatus for cultivating a plant by immersing the root of the plant in liquid fertilizer,
A plant holding unit for holding the plant;
A bottom surface that receives roots extending from the plant through the plant holding unit, a side wall that surrounds the plant holding unit, and a cultivation tank capable of storing the liquid fertilizer;
A bubble generating unit that is arranged above the cultivation tank and generates bubbles on the liquid surface of the liquid fertilizer accumulated in the cultivation tank by dropping the liquid fertilizer,
With
Plant cultivation equipment. The bubble generating unit drops the liquid manure on the liquid surface above the root of the plant extending between the side walls from the plant holding unit,
The plant cultivation apparatus according to claim 1. The bubble generating unit drops the liquid fertilizer at a plurality of locations on the liquid surface,
The plant cultivation apparatus according to claim 2. A storage tank for storing the liquid fertilizer drained from the cultivation tank;
A pump for sending the liquid fertilizer of the storage tank to the bubble generating unit;
Further equipped with,
The plant cultivation apparatus according to claim 1. The storage tank is disposed below the cultivation tank,
The plant cultivation apparatus according to claim 4. A water level adjustment unit for adjusting the level of the liquid fertilizer in the cultivation tank;
The plant cultivation apparatus according to claim 1. The water level adjuster is a plurality of drains formed in the height direction of the cultivation tank,
The plant cultivation apparatus according to claim 6. A liquid fertilizer supply section for supplying the liquid fertilizer to the cultivation tank;
A water level adjusting unit for adjusting the water level of the liquid fertilizer in the cultivation tank;
Further comprising
The water level adjuster is a plurality of drains formed in the height direction of the side wall.
The plant cultivation apparatus according to claim 1. The distance from the plant holding part to the side wall is a distance that the root extending from the plant holding part can reach,
The plant cultivation apparatus according to claim 8. The cultivation tank has a root preventer that prevents the root from entering the drain.
The plant cultivation apparatus according to claim 9. A storage tank for storing the liquid fertilizer drained from the drain;
The liquid fertilizer supply unit supplies the liquid fertilizer of the storage tank to the cultivation tank.
The plant cultivation apparatus according to claim 8. A plant cultivation method by a plant cultivation apparatus for cultivating a plant by immersing plant roots in liquid fertilizer accumulated in a cultivation tank, wherein the plant cultivation apparatus passes through a plant holding unit for holding the plant and the plant holding unit. And having a bottom receiving the roots extending from the plant, and a cultivation tank having a side wall surrounding the plant holding part,
The plant cultivation method is:
A plant holding step of holding the plant by the plant holding unit;
A bubble generating step that is arranged above the cultivation tank and generates bubbles on the liquid surface of the liquid fertilizer accumulated in the cultivation tank by dropping the liquid fertilizer,
Comprising
Plant cultivation method. In the bubble generation step, the liquid fertilizer is dropped onto the liquid surface above the root of the plant extending between the side walls from the plant holding part,
The plant cultivation method according to claim 12. In the bubble generation step, liquid fertilizer is dropped at a plurality of locations on the liquid surface,
The plant cultivation method according to claim 13. A water level adjustment step of adjusting the level of liquid fertilizer in the cultivation tank,
The plant cultivation method according to claim 12. In the water level adjustment step, the water level is increased according to the growth of the roots.
The plant cultivation method according to claim 15. The plant cultivation method is:
Liquid fertilizer supply step of supplying liquid fertilizer to the cultivation tank;
A water level adjustment step of adjusting the level of liquid fertilizer in the cultivation tank by a plurality of drains formed in the height direction of the side wall of the cultivation tank;
Further comprising
The plant cultivation method according to claim 12. The distance from the plant holding part to the side wall is a distance that the root extending from the plant holding part can reach,
The plant cultivation method according to claim 17. The cultivation tank has a root preventer that prevents the root from entering the drain.
The plant cultivation method according to claim 18. The plant cultivation device has a storage tank for storing the liquid fertilizer drained from the drain port,
In the liquid fertilizer supply unit step, the liquid fertilizer of the storage tank is supplied to the cultivation tank.
The plant cultivation method according to claim 17.

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