JP7083465B2 - Cultivation equipment and cultivation method - Google Patents

Description

The present invention relates to a cultivation apparatus and a cultivation method.

For example, in reclaimed land along the coastline, the irrigation water that can be used for cultivating agricultural products may be water containing a relatively high concentration of salt, for example, brackish water containing seawater. When irrigation water containing salt is used, salt accumulates in the surface layer of the soil (the depth at which the crop takes root), and the salinity in the soil around the crop increases. If the salt concentration in the soil becomes too high, the crop growth will be hindered and the yield will decrease.

Therefore, when irrigation water containing salt is used, a work called leaching is performed in which irrigation water is sprinkled on the soil when the salinity in the soil rises to allow the salt in the surface layer of the soil to soak into the deep layer. Such leaching requires a large amount of irrigation water and is a laborious task.

On the other hand, in recent years, attempts have been made to industrialize agriculture, for example, by automatically controlling irrigation, fertilization, etc. to improve the yield and quality of agricultural products. When automating irrigation and fertilizer application, hydroponic cultivation using a cultivation solution in which fertilizer is mixed with irrigation water without using soil is suitable. Examples of the hydroponic cultivation include so-called hydroponics that does not use a solid medium, and solid medium cultivation that uses a restricted medium in which a medium such as sand, rock wool, or coconut shell is filled in a relatively small-capacity container. .. Compared to hydroponics, solid medium cultivation is easier to maintain the health of crops because it can supply air to the roots of the crops, and it is easier to maintain water quality due to microbial activity, so crops can be cultivated more efficiently. It is seen as promising if it can be done.

As an apparatus for such solid medium cultivation, a bottom water supply type cultivation apparatus has been proposed in which a cultivation liquid is supplied from a water tank arranged below to the bottom surface of a medium portion (restricted medium) by capillarity (for example, special feature). (See Kai 2016-27). In the cultivation apparatus described in the above publication, the amount of evaporation from the medium portion is small, and it is said that salt accumulation is unlikely to occur.

Japanese Unexamined Patent Publication No. 2016-27

In the cultivation apparatus described in the above publication, it is said that the salt concentration in the medium is difficult to increase due to the small amount of the medium, but this is premised on the use of irrigation water having a low salt concentration. That is, even in the cultivation apparatus described in the above publication, when irrigation water having a high salt concentration is used, the increase in the salt concentration in the medium cannot be sufficiently suppressed, and the growth of the crop can be inhibited. The salt concentration may increase.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a cultivation apparatus and a cultivation method capable of using irrigation water having a high salt concentration.

The cultivation apparatus according to one aspect of the present invention, which has been made to solve the above-mentioned problems, comprises a restriction medium for growing crops and a cultivation liquid which is arranged at a position lower than the restriction medium and is a mixture of irrigation water and fertilizer. In order to connect the storage tank for storage, the bottom of the restricted medium and the storage tank, and obtain a liquid feeding unit capable of supplying the cultivation liquid in the storage tank to the bottom of the restricted medium by the capillary phenomenon and the cultivation liquid. It has a mixing device that mixes fertilizer with irrigation water, and supplies the cultivation liquid to the restricted medium or storage tank so as to keep the liquid level height of the storage tank within a certain range, and the cultivation liquid supply unit. It is provided with an irrigation water sprinkling unit that sprinkles irrigation water as it is on the above-mentioned restriction medium.

Further, the cultivation method according to one aspect of the present invention includes a restriction medium for growing crops, a storage tank which is arranged at a position lower than the restriction medium and stores a cultivation liquid in which fertilizer is mixed with irrigation water, and the above. Using a cultivation device that connects the bottom of the restricted medium and the storage tank and has a liquid feeding unit capable of supplying the cultivation liquid in the storage tank to the bottom of the restricted medium by the capillary phenomenon, the liquid level height of the storage tank is high. A step of mixing fertilizer with the irrigation water and supplying the cultivation liquid obtained by this mixing to the restriction medium or the storage tank, and a step of sprinkling the irrigation water as it is into the restriction medium so as to keep the irrigation water within a certain range. And.

The cultivation apparatus according to one aspect of the present invention and the cultivation method according to another aspect of the present invention can use irrigation water having a high salt concentration.

It is a schematic sectional drawing which shows the cultivation apparatus which concerns on one Embodiment of this invention. It is a schematic cross-sectional view which shows the modification of the cultivation apparatus of FIG.

[Explanation of Embodiment of the present invention]
The cultivation apparatus according to one aspect of the present invention includes a restriction medium for growing crops, a storage tank which is arranged at a position lower than the restriction medium and stores a cultivation liquid in which fertilizer is mixed with irrigation water, and the restriction medium. A liquid feeder that connects the bottom of the tank and the storage tank and can supply the cultivation liquid in the storage tank to the bottom of the restricted medium by the capillary phenomenon, and a mixture in which fertilizer is mixed with irrigation water to obtain the cultivation liquid. A cultivation liquid supply unit that has an apparatus and supplies the cultivation liquid to the restriction medium or the storage tank so as to keep the liquid level height of the storage tank within a certain range, and water the irrigation water to the restriction medium as it is. It is equipped with an irrigation water sprinkler section.

Since the cultivation device grows crops on a restricted medium capable of supplying the cultivation liquid from the storage tank to the bottom via the liquid feeding unit, the amount of water evaporation from the medium is small and the salt concentration in the medium increases. Can be suppressed. Further, the cultivation device has a mixing device for mixing fertilizer with irrigation water in order to obtain the cultivation solution, and the cultivation solution is used as a limiting medium so as to keep the liquid level height of the storage tank within a certain range. Alternatively, in addition to the cultivation liquid supply section that supplies the storage tank, an irrigation water sprinkling section that sprinkles the irrigation water as it is on the limiting medium is provided. Can be drained into the storage tank with irrigation water. In this way, the cultivation device can keep the salt concentration in the restricted medium within a certain range even if the irrigation water having a high salt concentration is used. Therefore, the crop is grown using the irrigation water having a high salt concentration. Can be cultivated.

In the cultivation apparatus, the volume of the limiting medium is preferably 30 L or less per crop strain. As described above, when the capacity of the restriction medium is not more than the above upper limit, the amount of irrigation water required for sprinkling water from the irrigation water sprinkling portion and discharging the salt content in the restriction medium can be reduced.

In the cultivation apparatus, the horizontal distance between the center of the watering position of the irrigation water from the irrigation water sprinkling section to the restriction medium and the center of the restriction medium is preferably 0.3 times or less the minor axis of the restriction medium. .. As described above, when the horizontal distance between the center of the watering position of the irrigation water from the irrigation water sprinkling portion to the restriction medium and the center of the restriction medium is not more than the upper limit, the irrigation water is spread over the entire restriction medium. It can be infiltrated and efficiently discharged salt.

In the cultivation apparatus, the vertical distance between the center of the watering position of the irrigation water from the irrigation water sprinkling portion to the restriction medium and the surface of the restriction medium is preferably 5 cm or more. As described above, when the vertical distance between the center of the watering position of the irrigation water from the irrigation water sprinkling portion to the restriction medium and the surface of the restriction medium is at least the lower limit, the irrigation water is spread over the entire restriction medium. It can be infiltrated and the salt can be discharged more efficiently.

In the cultivation device, the irrigation water sprinkler unit may fountain the irrigation water in a shower shape. In this way, the irrigation water sprinkling unit can infiltrate the irrigation water into the entire restriction medium and discharge the salt more efficiently by injecting the irrigation water in a shower shape.

The cultivation device may further include a recovery unit for recovering the irrigation water discharged into the storage tank. As described above, by further providing a recovery unit for recovering the irrigation water discharged to the storage tank, the cultivation apparatus can reuse the irrigation water and reduce the amount of water used.

Further, the cultivation method according to another aspect of the present invention includes a restriction medium for growing crops, a storage tank which is arranged at a position lower than the restriction medium and stores a cultivation liquid in which fertilizer is mixed with irrigation water. Using a cultivation device that connects the bottom of the restricted medium and the storage tank and has a liquid feeding unit capable of supplying the cultivation liquid in the storage tank to the bottom of the restricted medium by the capillary phenomenon, the liquid level of the storage tank is used. A step of mixing fertilizer with the irrigation water and supplying the cultivation liquid obtained by this mixing to the restriction medium or the storage tank so as to keep the height within a certain range, and sprinkling the irrigation water as it is on the restriction medium. It has a process.

Since the cultivation method uses a cultivation device provided with the restricted medium, a storage tank, and a liquid feeding unit, the amount of water evaporation from the medium is small, and an increase in salt concentration in the medium can be suppressed. Further, in the cultivation method, fertilizer is mixed with the irrigation water so that the liquid level height of the storage tank is kept within a certain range, and the cultivation liquid obtained by this mixing is supplied to the restricted medium or the storage tank. Since the step and the step of sprinkling the irrigation water as it is on the restricted medium are provided, even if the salt concentration in the restricted medium increases in the supply step, the salt content in the restricted medium is increased by the sprinkling of the irrigation water in the sprinkling step. Can be discharged to the storage tank. As described above, in the cultivation method, the salt concentration in the restricted medium can be kept within a certain range even if the irrigation water having a high salt concentration is used. Therefore, the crop is grown using the irrigation water having a high salt concentration. Can be cultivated.

In the cultivation method, the amount of irrigation water sprinkled in the watering step is preferably 1.0 times or more and 3.0 times or less the capacity of the restricted medium. As described above, when the amount of irrigation water sprinkled in the above sprinkling step is within the above range, the salt concentration in the restricted medium can be surely reduced, and the amount of irrigation water used can be suppressed to reduce the amount of irrigation water used per crop yield. The amount of irrigation water used can be reduced.

In the cultivation method, the watering step may be performed when the salt concentration of the limiting medium is 1 g / L or more and 20 g / L or less. As described above, by performing the watering step when the salt concentration of the limiting medium is within the above range, it is possible to prevent salt damage and maintain the health condition of the crop while suppressing the amount of irrigation water used. ..

The “restricted medium” means a medium contained in a container, that is, a spatially restricted medium.

[Details of Embodiments of the present invention]
Hereinafter, the cultivation apparatus and cultivation method according to the embodiment of the present invention will be described with reference to the drawings as appropriate.

[First Embodiment]
The cultivation apparatus according to the embodiment of the present invention shown in FIG. 1 includes an irrigation water tank 1 for storing irrigation water, one or more fertilizer tanks 2 for storing fertilizer, a restricted medium 3 for growing crops, and the like. A storage tank 4 that is placed at a lower position than the restricted medium 3 and stores a cultivation liquid in which fertilizer is mixed with irrigation water is connected to the bottom of the restriction medium 3 and the storage tank 4, and the cultivation liquid in the storage tank 4 is connected. A liquid feeding unit 5 capable of supplying the bottom of the limiting medium 3 by the capillary phenomenon, and a cultivation liquid supply unit 6 for supplying the cultivation liquid to the storage tank 4 so as to keep the liquid level height of the storage tank 4 within a certain range. The irrigation water sprinkling unit 7 for sprinkling the irrigation water supplied from the irrigation water tank 1 directly onto the limiting medium 3 from above is provided.

In the cultivation apparatus, it is preferable that the storage tank 4 and the liquid feeding unit 5 are covered with a cover having a steam sealing property (not shown) in order to prevent water from evaporating from the storage tank 4 and the liquid feeding unit 5.

(Irrigation water tank)
The irrigation water tank 1 stores irrigation water. As the irrigation water stored in the irrigation water tank 1, brackish water (water in which fresh water and seawater are mixed) containing a relatively high concentration of salt can be used.

The upper limit of the salt concentration of irrigation water depends on the type of crop to be cultivated, but is preferably 1.0% by mass in terms of sodium chloride (converted to the mass of sodium chloride having the same molar concentration), and 0.3% by mass is preferable. More preferably, 0.1% by mass is further preferable. If the salinity of the irrigation water exceeds the above upper limit, high-frequency leaching is required, which may make it difficult to grow crops economically.

The capacity of the irrigation water tank 1 is selected in consideration of the required amount of irrigation water, the frequency of water supply to the irrigation water tank 1, and the like. For example, if irrigation water can be constantly supplied from a river, a well, or the like, the irrigation water tank 1 may be omitted.

(Fertilizer tank)
The fertilizer tank 2 stores fertilizer necessary for growing crops. As the fertilizer stored in the fertilizer tank 2, it is preferable to use a liquid fertilizer that can be easily mixed with irrigation water. Further, the cultivation apparatus may include a plurality of fertilizer tanks 2 and use a cultivation liquid in which a plurality of types of fertilizers are mixed with irrigation water.

The capacity of the fertilizer tank 2 can be selected in consideration of the required volume of fertilizer, the expected frequency of supplying fertilizer to the fertilizer tank 2, and the like. Further, the packaging container at the time of distribution of commercially available fertilizer may be used as it is as the fertilizer tank 2.

(Restricted medium)
The limiting medium 3 has a container 8 and a particulate solid medium 9 filled in the container 8.

Further, the limiting medium 3 may be arranged on the pedestal 10 in order to be arranged above the storage tank 4 described later.

The container 8 is made of a material having root resistance and sufficient strength to hold the solid medium 9, and has at least a water permeable bottom surface. Specifically, the container 8 may have a tubular body or a frame-shaped body formed of, for example, a resin or the like, and a water-permeable sheet for sealing the bottom surface of the tubular body or the frame-shaped body. .. Further, the container 8 may have an opening at the bottom surface, and the opening at the bottom surface may be sealed by a liquid feeding unit 5, which will be described later.

The material of the solid medium 9 may be a sandy substance, for example, silica sand such as sea sand, fine pumice stone such as Pamis sand, crushed particles of porous volcanic rock, granular rock wool, coral sand, coconut shell, etc. Examples include charcoal. The size of the sandy substance is preferably less than 10% by volume for particles smaller than 0.15 mm mesh, and more preferably 50% or more for particles having a size of 0.3 mm mesh or more.

Although it depends on the type of crop and the like, the lower limit of the volume of the limiting medium 3 per crop (internal volume per strain of the container 8) is preferably 0.2 L, more preferably 0.3 L. On the other hand, as the upper limit of the volume of the limiting medium 3 per crop strain, 30 L is preferable, and 10 L is more preferable. If the volume of the limiting medium 3 per crop is less than the above lower limit, the crop may not be sufficiently rooted. On the contrary, when the volume of the limiting medium 3 per crop exceeds the above upper limit, the amount of irrigation water required for leaching may increase unnecessarily.

(Reservoir)
The storage tank 4 is formed on the side of the pedestal 10 and is arranged at a position lower than that of the limiting medium 3. The storage tank 4 may be integrally formed with the pedestal 10. Further, the limiting medium 3 may be arranged above the storage tank 4 by providing the pedestal 10 in the storage tank 4.

The storage tank 4 preferably has a level sensor 11 for detecting the liquid level height of the cultivated liquid to be stored.

As the level sensor 11, a sensor having a movable portion floating on the liquid surface of the cultivation liquid may be adopted, but from the viewpoint of durability, it is preferable to adopt a sensor having no movable portion. Examples of the sensor having no such movable portion include contact type sensors such as electrode type sensors, capacitance type sensors, and optical sensors that come into contact with the cultivation liquid, such as capacitance type sensors, radio wave type sensors, and ultrasonic waves. A non-contact type sensor or the like that does not come into contact with the cultivation liquid such as a type sensor can be adopted. Among these, as the level sensor 11, it is preferable to use a capacitance type sensor from the viewpoint of good maintainability and low cost. In this case, the level sensor 11 is installed on the outer wall or the inner wall of the storage tank 4 to detect the presence or absence of the liquid level of the cultivation liquid at the installation height, and detects the increase or decrease of the cultivation liquid based on the presence or absence of the liquid level. Can be configured to.

The storage tank 4 may be formed of a solid material such as resin or metal, or may be formed by arranging a waterproof sheet along the inner surface of the recess of the member having the recess.

As the capacity of the storage tank 4, the amount of the cultivated liquid to be stored can be kept constant in consideration of the amount of water evaporating from the limiting medium 3 and the crop to be cultivated, the capacity of the cultivated liquid supply unit 6 described later, and the like. It is preferable to use the minimum capacity that can be used.

(Liquid feeder)
The liquid feeding unit 5 pumps the cultivation liquid stored in the storage tank 4 by capillarity and supplies it to the limiting medium 3. The liquid feeding unit 5 increases the supply amount of the cultivation liquid from the storage tank 4 to the limiting medium 3 as the amount of water in the limiting medium 3 becomes smaller. Since the height difference between the bottom surface of the limiting medium 3 and the liquid level of the storage tank 4 becomes the supply resistance of the cultivation liquid by the liquid feeding unit 5, the water content at the bottom of the limiting medium 3 depends on the liquid level of the storage tank 4. Can be adjusted.

The liquid feeding unit 5 can be formed by using a water-absorbent sheet such as paper, woven fabric, or non-woven fabric. Of these, woven fabrics are preferable from the viewpoint of easily obtaining those having excellent water absorption rate, pumping power and durability.

(Cultivation liquid supply department)
The cultivation liquid supply unit 6 is configured to supply the cultivation liquid to the storage tank 4 so as to keep the liquid level height of the cultivation liquid stored in the storage tank 4 within a certain range according to the output of the level sensor 11. To. Specifically, the supply of the cultivation liquid is started when the liquid level height of the storage tank 4 is below the predetermined lower limit, and the cultivation is started when the liquid level height of the storage tank 4 is above the predetermined upper limit. It can be configured to stop the supply of liquid.

The cultivation liquid supply unit 6 has a mixing device 12 that mixes the fertilizer supplied from the fertilizer tank 2 with the irrigation water supplied from the irrigation water tank 1 in order to obtain the cultivation liquid to be supplied to the storage tank 4. As the mixing device 12, it is preferable to use a quantitative mixing device capable of mixing fertilizer with irrigation water at a constant ratio.

(Irrigation water sprinkler)
The irrigation water sprinkling unit 7 has a shower nozzle 13 arranged above the limiting medium 3, and by injecting irrigation water in a shower shape from the shower nozzle 13, the irrigation water becomes the solid medium 9 of the limiting medium 3. It is preferable to sprinkle water. By injecting the irrigation water in a shower shape in this way, the surface of the solid medium 9 of the restriction medium 3 can be widely sprinkled, and water can be evenly passed through the solid medium 9.

The upper limit of the horizontal distance between the center of the watering position of the irrigation water from the irrigation water sprinkling section 7 to the limiting medium 3, that is, the center of the water discharge surface of the shower nozzle 13 and the center of the solid medium 9 existence region of the limiting medium 3 is limited. The minor axis of the region where the solid medium 9 is present on the surface of the medium 3 is preferably 0.3 times, more preferably 0.2 times. If the horizontal distance between the center of the irrigation water sprinkling position from the irrigation water sprinkling section 7 to the limiting medium 3 and the center of the limiting medium 3 exceeds the above upper limit, water cannot be evenly passed through the solid medium 9 and the salt content Discharge may be inefficient.

The lower limit of the vertical distance between the center of the watering position of the irrigation water from the irrigation water sprinkling portion 7 to the limiting medium 3 and the surface of the solid medium 9 of the limiting medium 3 is preferably 5 cm, more preferably 8 cm. On the other hand, the upper limit of the vertical distance between the center of the watering position of the irrigation water from the irrigation water sprinkling portion 7 to the limiting medium 3 and the surface of the solid medium 9 of the limiting medium 3 is preferably 50 cm, more preferably 30 cm. When the vertical distance between the center of the watering position of the irrigation water from the irrigation water sprinkling section 7 to the limiting medium 3 and the surface of the solid medium 9 of the limiting medium 3 does not meet the above lower limit, water should be evenly passed through the solid medium 9. There is a risk that irrigation will not be possible and salt discharge will be inefficient. On the contrary, when the vertical distance between the center of the watering position of the irrigation water from the irrigation water sprinkling section 7 to the restriction medium 3 and the surface of the solid medium 9 of the restriction medium 3 exceeds the above upper limit, the irrigation water is outside the restriction medium 3. There is a risk that water may not be evenly passed through the solid medium 9 due to the risk of irrigation and the increase in the shade of the crop.

[Cultivation method]
In the cultivation method according to another embodiment of the present invention, fertilizer is mixed with irrigation water so as to keep the liquid level height of the storage tank 4 within a certain range by using the cultivation apparatus of FIG. It is provided with a step of supplying the cultivated liquid to the storage tank 4 (supply step) and a step of watering the irrigation water directly onto the limiting medium 3 from above (watering step).

The supply process is carried out continuously except during the watering process. In addition, continuous means that the liquid level height of the storage tank 4 is monitored continuously or at regular intervals and the cultivation liquid is supplied as needed, and the cultivation liquid is continuously supplied. It does not require that.

The watering step is performed when the salt concentration in the limiting medium 3 has risen to a certain concentration. This watering step is a so-called leaching step in which the salt content in the limiting medium 3 is discharged to the storage tank 4 together with the irrigation water by the irrigation water to be sprinkled.

Although it depends on the type of crop to be cultivated, for example, in the case of tomato, it is as follows. The lower limit of the salt concentration of the limiting medium 3 for which the watering step is performed is preferably 1 g / L, more preferably 5 g / L. On the other hand, the upper limit of the salt concentration of the limiting medium 3 for which the watering step is performed is preferably 20 g / L, more preferably 10 g / L. If the salt concentration of the restriction medium 3 for which the watering step is performed does not reach the above lower limit, the amount of irrigation water used may increase unnecessarily. On the contrary, when the salt concentration of the restriction medium 3 for which the watering step is performed exceeds the above upper limit, the growth of crops may be hindered by salt damage.

The salt concentration in the limiting medium 3 may be detected, for example, by arranging a salt concentration sensor in the limiting medium 3, but it is estimated by a simple salt balance model based on the supply amount of the cultivation liquid in the supply step. You may. As a result, it is possible to set the upper and lower limits of the preferable salt concentration for each type of crop, and it becomes possible to carry out good cultivation.

The lower limit of the amount of irrigation water sprinkled in the watering step is preferably 1.0 times, more preferably 1.5 times the volume of the limiting medium 3. On the other hand, the upper limit of the amount of irrigation water sprinkled in the watering step is preferably 3.0 times, more preferably 2.5 times the volume of the limiting medium 3. If the amount of irrigation water sprinkled in the sprinkling step does not reach the above lower limit, the salt concentration in the limiting medium 3 may not be sufficiently reduced. On the contrary, if the amount of irrigated water sprinkled in the watering process exceeds the above upper limit, the irrigated water may be consumed unnecessarily.

<Advantage>
Since the cultivation device and the cultivation method supply the cultivation liquid from the storage tank 4 to the bottom of the restricted medium 3 having a relatively small volume via the liquid feeding unit 5, the amount of water evaporation is small and the salt content in the solid medium 9 is high. The increase in concentration can be suppressed. Further, in the cultivation device and the cultivation method, since the irrigation water sprinkling unit 7 sprinkles the irrigation water directly on the limiting medium 3 from above, the salt content in the limiting medium 3 can be discharged to the storage tank 4 with the irrigation water. .. Therefore, since the cultivation device and the cultivation method can keep the salt concentration in the limiting medium 3 within a certain range even if the irrigation water having a high salt concentration is used, the irrigation water having a high salt concentration is used. Can grow crops.

[Second Embodiment]
The cultivation apparatus according to another embodiment of the present invention shown in FIG. 2 includes an irrigation water tank 1 for storing irrigation water, one or a plurality of fertilizer tanks 2 for storing fertilizer, and a restricted medium 3a for growing crops. , A storage tank 4a that is placed at a position lower than this restricted medium 3a and stores a cultivation liquid in which fertilizer is mixed with irrigation water, and a bottom of the restricted medium 3a and a storage tank 4a are connected to cultivate in the storage tank 4a. A liquid feeding unit 5 capable of supplying the liquid to the bottom of the limiting medium 3a by the capillary phenomenon, and a growing liquid supply to supply the cultivation liquid to the surface of the limiting medium 3a so as to keep the liquid level height of the storage tank 4a within a certain range. A unit 6a and an irrigation water sprinkling unit 7a that directly sprinkles the irrigation water supplied from the irrigation water tank 1 onto the surface of the limiting medium 3a are provided. Further, the cultivation apparatus further includes a recovery unit 14 for recovering the irrigation water discharged from the restriction medium 3a in the storage tank 4a.

The configuration of the irrigation water tank 1, the fertilizer tank 2 and the liquid feeding section 5 in the cultivation device of FIG. 2 may be the same as the configuration of the irrigation water tank 1, the fertilizer tank 2 and the liquid feeding section 5 in the cultivation device of FIG. can. Therefore, with respect to the cultivation device of FIG. 2, the same components as those of the cultivation device of FIG. 1 are designated by the same reference numerals, and duplicate description will be omitted.

(Restricted medium)
In the cultivation apparatus of FIG. 2, the limiting medium 3 is arranged inside the storage tank 4a. Specifically, a pedestal 10a having a height smaller than the peripheral wall of the storage tank 4 is arranged inside the storage tank 4a, and the limiting medium 3 is housed in a space above the pedestal 10a in the storage tank 4a. ing.

The limiting medium 3a has a container 8a formed from a permeable sheet and a particulate solid medium 9 filled in the container 8a. The solid medium 9 in the cultivation device of FIG. 2 can be the same as the solid medium 9 in the cultivation device of FIG.

The bottom surface of the container 8a is placed on the pedestal 10a via the liquid feeding unit 5, and the upper portion is held in the storage tank 4a to hold the container shape for accommodating the solid medium 9.

(Reservoir)
The storage tank 4a stores the cultivation liquid in the space around the pedestal 10a. The storage tank 4a may be integrally formed with the pedestal 10a, or the pedestal 10a may be hollow.

The storage tank 4a preferably has a level sensor 11 for detecting the liquid level height of the stored cultivation liquid. The configuration of the level sensor 11 in the cultivation device of FIG. 2 can be the same as the configuration of the level sensor 11 in the cultivation device of FIG.

(Cultivation liquid supply department)
The cultivation liquid supply unit 6a limits the cultivation liquid so as to keep the liquid level height of the cultivation liquid stored in the storage tank 4a within a certain range according to the output of the level sensor 11. The surface of the solid medium 9 of the culture medium 3a. Is configured to supply to.

The cultivation liquid supply unit 6a has a mixing device 12 that mixes the fertilizer supplied from the fertilizer tank 2 with the irrigation water supplied from the irrigation water tank 1 in order to obtain the cultivation liquid to be supplied to the storage tank 4a. The mixing device 12 in the cultivation device of FIG. 2 can be the same as the mixing device 12 in the cultivation device of FIG.

Further, the cultivation liquid supply unit 6a can be configured to have a sprinkling tube 15 which is placed on the surface of the solid medium 9 of the restriction medium 3a at the end thereof and has a plurality of outflow holes from which the cultivation liquid flows out. By using such a watering tube 15, the cultivation liquid can be dispersed and supplied to the entire solid medium 9.

(Irrigation water sprinkler)
The irrigation water sprinkling section 7a is configured to sprinkle irrigation water on the surface of the solid medium 9 of the restriction medium 3a. The irrigation water sprinkling unit 7a can be configured to share the watering tube 15 with the cultivation liquid supply unit 6a. By sharing the sprinkling tube 15 between the cultivation liquid supply unit 6a and the irrigation water sprinkling unit 7, the cultivation liquid supply unit 6a and the irrigation water sprinkling unit 7 do not interfere with each other, and both the cultivation liquid and the irrigation water are solid media. It becomes easy to design so that water can pass through the whole of 9.

(Recovery department)
When the recovery unit 14 sprinkles irrigation water from the irrigation water sprinkling unit 7a onto the restricted medium 3a, the recovery unit 14 discharges the irrigation water (which may contain fertilizer and the like) discharged from the restricted medium 3a to the storage tank 4a from the storage tank 4a. It is a mechanism to collect in a water tank (not shown). By providing such a recovery unit 14, the cultivation apparatus can recover and reuse the irrigation water used for leaching, so that the amount of irrigation water used can be suppressed.

As a specific configuration of the collection unit 14, a drain pipe as shown in the figure can be adopted, or for example, an overflow flow path, a drainage pump, or the like can be used.

[Cultivation method]
In the cultivation method according to still another embodiment of the present invention, fertilizer is mixed with irrigation water so as to keep the liquid level height of the storage tank 4a within a certain range by using the cultivation apparatus of FIG. The present invention includes a step of supplying the obtained cultivation liquid to the limiting medium 3a from the surface (supplying step) and a step of watering the irrigation water directly onto the limiting medium 3a from above (watering step).

The timing of the supply step and the watering step and the amount of watering in the watering step in the cultivation method using the cultivation device of FIG. Can be similar to.

<Advantage>
In the cultivation device and the cultivation method, since the irrigation water sprinkling unit 7a sprinkles the irrigation water as it is on the limiting medium 3a, the salt content in the limiting medium 3a can be discharged to the storage tank 4a. Therefore, since the cultivation device and the cultivation method can keep the salt concentration in the restricted medium 3a within a certain range even if the irrigation water having a high salt concentration is used, the irrigation water having a high salt concentration is used. Can grow crops.

[Other embodiments]
It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is not limited to the configuration of the above embodiment, but is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims. To.

For example, the shower nozzle 13 of the cultivation device of FIG. 1 and the watering tube 15 of the cultivation device of FIG. 2 are interchangeable. Further, in the cultivation apparatus of FIG. 1, the cultivation liquid supply unit 6 may supply the cultivation liquid to the limiting medium 3, and in the cultivation equipment of FIG. 2, the cultivation liquid supply unit 6a supplies the cultivation liquid to the storage tank 4a. You may do so.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

<Cultivation example 1>
As a cultivation example 1, a tomato "Momotaro York" having leaf mold disease resistance Cf9 was cultivated using a cultivation device according to FIG. 1 installed in a vinyl house. The volume of the limiting medium was 0.5 L, and Tottori Sand Dunes sand was used as the solid medium. As the irrigation water, a 1000 mass ppm sodium chloride aqueous solution was used. In the water supply step, the cultivation liquid was supplied so that the liquid level height of the storage tank was −7 cm with respect to the bottom surface of the limiting medium. The watering step was performed when the salt concentration in the limiting medium estimated by the simple salt balance model became 10 g / L or more. In each watering step, the same amount of irrigation water as the volume of the limiting medium was sprinkled.

<Cultivation example 2>
Cultivation example 2 was the same as that of cultivation example 1 except that the liquid level height of the storage tank was -4 cm.

<Cultivation example 3>
Cultivation Example 3 was the same as Cultivation Example 2 except that the amount of water sprinkled in each watering step was twice the volume of the limiting medium.

<Cultivation example 4>
Cultivation Example 4 was the same as Cultivation Example 3 except that Aomori sand "Lunasand H" manufactured by Lunasand Co., Ltd. was used as the solid medium.

<Cultivation example 5>
As cultivation example 5, the same tomatoes as cultivation examples 1 to 4 were cultivated by soil cultivation in the same vinyl house as cultivation examples 1 to 4. As the soil, Tottori sand dunes are used, and a moisture sensor "WD3-WET-5TE" manufactured by Graftech is installed on the surface of the soil to maintain the electrical conductivity at 0.19V (11% by volume in terms of moisture content). Irrigation water was irrigated from one drip tube per strain.

The following table shows the yield of fruits and the average sugar content of fruits in the above cultivation examples 1 to 5. In cultivation examples 1 to 4, each of the watering steps was performed 9 times.

As described above, in the cultivation examples 1 to 4 using the cultivation apparatus according to the embodiment of the present invention, the yield is significantly increased and the sugar content is also increased as compared with the cultivation example 5 by soil cultivation. From this, the cultivation apparatus according to the embodiment of the present invention grows high-quality crops by efficiently discharging the salt in the medium and preventing salt damage even if irrigation water having a high salt concentration is used. It was confirmed that the irrigation was possible and the yield was sufficiently obtained.

The cultivation apparatus and cultivation method of the present invention can also be used when fresh water is used as irrigation water, but are particularly preferably used in agriculture using irrigation water having a high salinity.

1 Irrigation water tank 2 Fertilizer tank 3, 3a Restricted medium 4, 4a Storage tank 5 Liquid feeding part 6, 6a Cultivation liquid supply part 7, 7a Irrigation water sprinkling part 8, 8a Container 9 Solid medium 10, 10a Pedestal 11 Level sensor 12 Mixing device 13 Shower nozzle 14 Recovery unit 15 Sprinkler tube

Claims (9)

A limiting medium for growing crops and
A storage tank that is located lower than the above-mentioned restriction medium and stores the cultivation liquid in which fertilizer is mixed with irrigation water.
A liquid feeding unit that connects the bottom of the restricted medium and the storage tank and can supply the cultivation liquid in the storage tank to the bottom of the restricted medium by capillarity.
Cultivation that has a mixing device that mixes fertilizer with irrigation water in order to obtain the cultivation liquid, and supplies the cultivation liquid to the restricted medium or the storage tank so as to keep the liquid level height of the storage tank within a certain range. Liquid supply unit and
A cultivation device provided with an irrigation water sprinkling unit that either sprinkles the irrigation water as it is on the restricted medium, or switches the irrigated water from the state of supplying the cultivation liquid and sprinkles the irrigation water on the restricted medium. The cultivation apparatus according to claim 1, wherein the volume of the restriction medium is 30 L or less per crop strain. 1. The cultivation apparatus according to 2. The cultivation apparatus according to claim 1, claim 2 or claim 3, wherein the vertical distance between the center of the watering position of the irrigation water from the irrigation water sprinkling section to the restricted medium and the surface of the restricted medium is 5 cm or more. The cultivation device according to claim 4, wherein the irrigation water sprinkling unit sprays irrigation water in a shower shape. The cultivation apparatus according to any one of claims 1 to 5, further comprising a recovery unit for recovering the irrigation water discharged to the storage tank. A restriction medium for growing crops, a storage tank placed at a position lower than the restriction medium and storing a cultivation solution in which fertilizer is mixed with irrigation water, and a bottom of the restriction medium and the storage tank are connected to each other. Using a cultivation device equipped with a liquid feeding unit capable of supplying the cultivation liquid in the storage tank to the bottom of the restriction medium by the capillary phenomenon, the cultivation device was used.
A step of mixing fertilizer with the irrigation water and supplying the cultivation liquid obtained by this mixing to the restricted medium or the storage tank so as to keep the liquid level height of the storage tank within a certain range.
A cultivation method comprising a step of sprinkling the irrigation water as it is on the restricted medium , or switching the irrigated water from the state of supplying the cultivation liquid and sprinkling the irrigation water on the restricted medium. The cultivation method according to claim 7, wherein the amount of irrigation water sprinkled in the watering step is 1.0 times or more and 3.0 times or less the capacity of the restricted medium. The cultivation method according to claim 7 or 8, wherein the watering step is performed when the salt concentration of the restriction medium is 1 g / L or more and 20 g / L or less.

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