JP2013202009A - Hydroponic culture apparatus and method of cultivating plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easy-to-handle hydroponic culture apparatus and a hydroponic culture method, allowing the control of a contained moisture amount corresponding to the cultivation of a plant sensitive to the contained moisture amount of soil, such as a tree.SOLUTION: By forming a region having a high moisture content by sufficiently supplying water below a root of a plant seeding and around the root with the root of the plant seeding as the center, and creating a state that the moisture content is reduced toward the root direction from the region, the root sensitive to moisture is protected from excessive moisture while sufficiently supplying moisture to a young root carrying the absorption of moisture and nourishment.

Description

  The present invention relates to a hydroponic cultivation apparatus and a hydroponic cultivation method for growing plant seedlings using a water-retaining medium, and in particular, hydroponic suitable for cultivation of plants that are sensitive to soil moisture such as trees, which has been difficult in the past. The present invention relates to a cultivation apparatus and a hydroponics method.

  In hydroponics, in addition to the narrow hydroponics that basically grows the roots in water, hydroponics that supplies water in a spray form, and a water-retaining medium commonly called hydroculture is used. Hydroponic cultivation is known.

  However, until now, most of these hydroponic cultivation targets are vegetables and foliage plants, and hydroponic cultivation that assumes trees such as fruit trees has been hardly known.

  On the other hand, in recent years, the invention about the hydroponic cultivation apparatus and cultivation system which assumed fruit tree cultivation has come to be disclosed for the purpose of efficiency improvement of fruit tree cultivation, reduction of cultivation cost, etc.

  Patent Document 1 discloses a technique for hydroponics cultivation of grapes. However, it is merely a description of a culture solution suitable for grape cultivation and a support shelf that supports the roots of grapes so that they do not touch the staying culture solution.

  Patent Document 2 discloses a simple fruit tree hydroponics system that is easy to move and disperse. However, the main focus is on facilitating movement, and the hydroponic mechanism itself has no great ingenuity.

  Patent Document 3 discloses a hydroponics method for cultivating fruit trees and components used therefor. However, although each component is novel, the cultivation method is within the range of general hydroponics.

  As described above, a general-purpose hydroponic cultivation apparatus for “fruit trees and trees” having a dedicated mechanism in accordance with characteristics of fruit trees and the like, in particular, suitability for soil moisture has not been known so far. In the proposed technique, when the fruit tree is actually hydroponically cultivated, it is easy to cause root rot and die.

JP-A-9-205911 JP 2002-369633 A Special table 2008-523811 gazette

  Generally, seedlings of trees such as fruit trees are sensitive to the moisture content of soil, unlike seedlings of vegetables and the like. In other words, for seedlings of fruit trees and the like, it is difficult to carry out hydroponics that can be easily carried out with vegetables, and cultivation is generally carried out in either a planting plant, a potted plant, or a planter that uses soil as a medium. It is.

  Since any method requires the use of soil, it is difficult to avoid the increase in weight, labor and dirt at the time of replanting, and the complexity of daily management such as fertilization. If fruit trees can be hydroponically cultivated like vegetables, these issues can be eliminated.

  Therefore, the present invention has been proposed in view of the above-described circumstances, and it is possible to control the moisture content corresponding to the cultivation of plants sensitive to the moisture content of soil, represented by fruit trees. An object of the present invention is to provide a hydroponic cultivation apparatus and a hydroponic cultivation method that are easy to handle.

  As already mentioned, tree seedlings are more sensitive to the water content of the soil or medium than vegetable seedlings. In particular, the so-called `` root '' part directly under the ground stem is (1) the epidermis is already old and the resistance to excess moisture is reduced, and (2) it is a part close to the stem, so it is somewhat close to the stem, excessive There is a situation that the tolerance to moisture does not reach the original “root”, and it is more sensitive to the excess moisture than the so-called “root” portion that extends into the ground (in the medium).

  Therefore, the present invention provides a hydroponic cultivation apparatus and a hydroponic cultivation method method for hydroponically cultivating such a plant based on the characteristics of plants sensitive to the moisture content of soil. Sufficient water is supplied to the so-called “root” while keeping the water content of the medium near the “root” low.

  Specifically, the hydroponic cultivation apparatus according to claim 1 includes a medium container provided with a hole through which water is passed while holding and holding a water-retaining medium in which the roots of plant seedlings are embedded; A water-resistant container that holds and holds a medium container in a state where a space is formed between the bottom surface and the bottom surface of the medium container, an external tank that stores water in which liquid fertilizer is dissolved, and water in which liquid fertilizer in the external tank is dissolved A water supply pipe for supplying directly into the inside, a drainage means for discharging the water in the water-resistant container outside the medium container to the outside of the water-resistant container, and a water level adjusting mechanism for adjusting the water level in the water-resistant container. By intermittently repeating the water supply from the tank to the medium and the discharge of excess water from the medium to the outside of the medium container from the water-resistant container, the water level in the water-resistant container is periodically raised and lowered from the water supply pipe. Water to be sent and medium container The water returning from the outside to the medium in the container, is characterized in that to supply water and nutrients to the medium.

  Moisture supplied from the external tank to the medium in the medium container through the water supply pipe reaches the inside of the water-resistant container from the inside of the medium container through the hole on the bottom surface of the medium container, and auxiliary water supply means to the medium It becomes.

  The hydroponic cultivation apparatus according to claim 2 is the hydroponic cultivation apparatus according to claim 1, wherein the tip of the water supply pipe is buried and arranged in the medium in the medium container. The water is supplied to a position away from the root of the plant seedling.

  The hydroponic cultivation apparatus according to claim 3 is the hydroponic cultivation apparatus according to claim 2, wherein the root periphery of the plant seedling in the medium is maintained in a dry state than the medium near the bottom of the medium container. In addition, a distribution is formed in which the water content of the medium decreases in the horizontal direction from the outer periphery toward the inner periphery, centering on the roots of the plant seedlings.

  The hydroponic cultivation apparatus according to claim 4 is the hydroponic cultivation apparatus according to any one of claims 1 to 3, wherein in the culture medium, excess moisture supplied beyond the water retention capacity of the culture medium is: It is characterized by the fact that it flows down downward and there is no horizontal and upward permeation diffusion.

  The hydroponic cultivation apparatus according to claim 5 is the hydroponic cultivation apparatus according to any one of claims 2 to 4, wherein the culture medium is made of a material having water retention capacity, In a position above the tip, a part of the culture medium is replaced with a material that does not absorb water or retain water.

  The hydroponic cultivation method according to claim 6, wherein a water-retaining medium is accommodated and held in a medium container provided with a hole through which water passes on the bottom, and the roots of plant seedlings are embedded in the medium. Hydroponics where the container is housed in a water-resistant container and maintained in a state where a space is formed between the bottom surface of the medium container and the bottom surface of the water-resistant container, and water in which liquid fertilizer is dissolved is supplied intermittently to the medium It is a cultivation method, and by adjusting the water supply position in the medium and adjusting the water permeation rate in the medium, excess water supplied beyond the water retention capacity of the medium is discharged downward from the bottom of the medium container, and moisture in the medium Is suppressed, and the distribution of the water content in the medium is maintained.

  The hydroponic cultivation method according to claim 7 is the hydroponic cultivation method according to claim 6, wherein the root periphery of the plant seedling in the medium is maintained in a dry state than the medium near the bottom of the medium container, A distribution in which the moisture content of the medium decreases in the horizontal direction from the outer periphery to the inner periphery, centering on the root of the plant seedling, is formed.

  In the hydroponic cultivation apparatus according to claim 1, when the water level in the water-resistant container is high, water is supplied to the medium by the water that enters the medium container from the bottom of the medium container. Further, as an auxiliary water supply, water is directly discharged from the water supply pipe to the medium.

  Therefore, in this hydroponic cultivation apparatus, the water supply can be kept at a height that does not reach the root portion close to the stem that is inferior in resistance to excess water. This is important for the growth of tree seedlings. However, there is a possibility that only the medium near the bottom of the medium container can receive the water supply only by replenishing the water from the water-resistant container. In this case, the water supply to the “root” other than the root is insufficient. However, in this hydroponic cultivation apparatus, the water for the “root” other than the root is supplemented by the water discharge directly from the water supply pipe to the medium.

  In the hydroponic cultivation apparatus of Claim 2, the front-end | tip part of the water | moisture-content supply piping is embed | buried and arrange | positioned in the culture medium in a culture medium container, and a water | moisture content is located in the culture medium in the position away from the root of a plant seedling. Supply.

  Therefore, in this hydroponic cultivation device, (1) excessive moisture is not supplied to the root, and (2) moisture is not supplied to the surface of the medium where transpiration of water is intense, so that concentration of salt in the moisture hardly occurs, and concentration of salt It has the effect of avoiding the negative effects caused by.

  In the hydroponic cultivation apparatus according to claim 3, the root periphery of the plant seedling in the culture medium is maintained in a dry state than the culture medium near the bottom of the culture medium container, and the outer periphery around the root of the plant seedling A distribution is formed in which the water content of the culture medium decreases in the horizontal direction from the center to the inner periphery. That is, this distribution is based on the direction of the root by providing an area with sufficient water supply and a high water content around the root of the plant seedling, at the lower side (the bottom of the medium container) and around the root. In this state, the water content decreases toward the surface. Thereby, it is possible to protect moisture-sensitive roots from excess moisture while supplying sufficient moisture to the young roots responsible for absorption of moisture and nutrients.

  In the hydroponic cultivation apparatus according to claim 4, in the culture medium, excess moisture supplied beyond the water retention capacity of the culture medium flows downward, and there is no osmotic diffusion in the horizontal direction and upward. In other words, by using a medium with fast water permeation, the time for excess water to remain in the medium is shortened as much as possible, and the permeation and diffusion of excess water in the lateral and upward directions is almost eliminated.

  Here, a medium with fast water permeation often has a weak water retention ability, and there is a concern that sufficient moisture cannot be supplied to the roots.In the present invention, such a concern is considered as a fluctuation cycle of the water level in the water-resistant container. It is possible to take measures by adjusting (that is, shortening the cycle of the water level and frequently supplying water).

  In addition, although the present invention intends to eliminate osmotic diffusion of “excess water”, since the medium is supplied unevenly, the region having a high water content is changed to a region having a low water content. Since the exudation of the contained water slowly exists, a small amount of water supply toward the root can be generated.

  In the hydroponic cultivation apparatus according to claim 5, the culture medium is made of a material having water retention, and at a position above the tip of the water supply pipe, a part of the culture medium has water absorption and It is replaced by a material that does not have water retention.

  In many plants, the roots extend downward or laterally and rarely grow upward. That is, it is considered that the root does not extend upward from the water supply position and extends downward from the water supply position. If so, it is not always necessary to fill the upper side of the water supply position with the culture medium. Rather, in terms of suppressing moisture transpiration, it is preferable that moisture does not penetrate above the water supply position. Therefore, in this hydroponic cultivation apparatus, at least a part of the medium located above the tip of the moisture supply pipe is replaced with a material that does not absorb water and retain water, thereby suppressing the upward penetration of moisture.

  In the hydroponic cultivation method according to claim 6, excess water supplied beyond the water retention capacity of the medium is adjusted downward from the bottom surface of the medium container by adjusting the water supply position in the medium and adjusting the water permeation rate in the medium. Drain, suppress the diffusion of water in the medium, and maintain the distribution of water content in the medium.

  In other words, a drain hole is provided on the bottom surface so that excess moisture can quickly fall out of the medium container, and the medium is supplied to a specific position in the medium container and intentionally used with a medium that allows quick permeation of water. Excess water that could not be absorbed is quickly discharged out of the medium container to suppress the diffusion of excess water, and a predetermined distribution is constantly generated in the water content of the medium.

  Here, “swiftly discharge excess moisture out of the medium container” means that the excess moisture flows down with a “slap” sound, and then the water drops to the extent of “potapota”. ing. In contrast, many common soil and hydroponic culture media are thought to allow water to permeate slowly, and the water to reach the entire medium during that time. Excess water is discharged over time. According to the method of claim 6, it is possible to supply sufficient moisture to the root while protecting the root of the plant seedling from excess moisture.

  In the hydroponics method according to claim 7, while maintaining the root periphery of the plant seedling in the culture medium in a dry state than the culture medium in the vicinity of the bottom of the culture medium container, with the root of the plant seedling as the center, from the outer periphery A distribution is formed in which the water content of the medium decreases in the horizontal direction toward the inner periphery.

  That is, the medium around the root of the plant seedling is always maintained in a state where the water content is lower than the medium at the bottom of the medium container, and the distribution of the moisture content of the medium around the root of the plant seedling is also horizontal in the container. Yes, when viewed at the horizontal position of the tip of the moisture supply pipe buried in the medium, the spatial distribution that the moisture content of the medium decreases from the outer periphery to the inside centered on the root of the plant seedling is steadily maintain.

  There is a small amount of water supply at the root due to the exudation of moisture from the surroundings, and it does not dry completely, so there is no problem with growth. On the other hand, moisture necessary for growth can be supplied to surrounding roots.

It is a side view explaining the composition of the hydroponic cultivation apparatus concerning the present invention. It is a side view explaining the structure of another hydroponic cultivation apparatus which concerns on this invention.

  Embodiments of the present invention will be described with reference to the drawings.

[First embodiment of hydroponic cultivation apparatus]
FIG. 1 is a side view illustrating a configuration of a hydroponic cultivation apparatus according to the present invention.

  In the hydroponic cultivation apparatus according to the present invention, a water-retaining medium 5 is accommodated and held in a medium container 3 provided with a hole 4 through which water passes, and the roots of plant seedlings 8 are embedded in the medium 5. Then, the medium container 3 is accommodated in the water-resistant container 1 and is maintained in a state where a space is formed between the bottom surface of the medium container 3 and the bottom surface of the water-resistant container 1. It is an apparatus for carrying out a hydroponics method for supplying intermittently.

  As shown in FIG. 1, this hydroponic cultivation apparatus accommodates and holds a water-retaining medium 5 and has a medium container 3 provided with a hole through which water passes and a bottom surface between the bottom surface and the bottom surface of the medium container. And a water-resistant container 1 that holds and holds the medium container 3 in a state where a space is formed in the container.

  A stand 2 is placed in the water-resistant container 1, and a medium container 3 containing a medium 5 is placed thereon. The gantry 2 is for providing a space between the water-resistant container 1 and the medium container 3. The entire bottom surface of the medium container 3 is provided with a hole 4 having a size that prevents the medium 5 from spilling out. A plant seedling 8 is contained in the center of the medium container 3.

  The hydroponic cultivation apparatus includes an external tank 13 that stores water in which liquid fertilizer is dissolved, a water supply pipe 6 that directly supplies water in which liquid fertilizer in the external tank 13 is dissolved, and a medium container 3 on the outside. A water recovery pipe 18 serving as a drainage means for discharging the water in the water resistant container 1 to the outside of the water resistant container 1 is provided. The moisture recovery pipe 18 is a pipe that recovers the water in the water-resistant container 1 to the external tank 13. In this hydroponic cultivation apparatus, water supply from the external tank 13 to the culture medium and recovery of excess water flowing from the culture medium 5 to the outside of the culture medium container 3 to the external tank 13 are repeated intermittently, and the water level in the water-resistant container 1 Is moved up and down periodically. The medium 5 is supplied with moisture and nutrients by the water returning from the outside of the medium container 3 into the medium container 3.

  In this hydroponic cultivation apparatus, water in which liquid manure is dissolved is supplied to the medium 5 through the water supply pipe 6, and water and nutrients are directly supplied to the medium 5. The tip of the water supply pipe 6 is configured in a ring shape, is buried in the medium 5 in the medium container 3, and is located around the plant seedling 8. Holes 7 are formed at substantially equal intervals at the tip of the water supply pipe 6, and water is directly supplied to the culture medium 5 from the holes 7 when water is supplied. From the moisture supply pipe 6, moisture is supplied in the medium 5 to a position away from the root of the plant seedling 8.

  From the external tank 13, the water in which the liquid fertilizer is dissolved is moved between the external tank 13 and the water-resistant container 1. That is, the water in the external tank 13 is supplied to the culture medium 5 from the tip of the water supply pipe 6 by the pump 10 through the water supply pipe 6. In addition, the water in the water-resistant container 1 is collected in the external tank 13 by the pump 11 through the moisture collection pipe 18. When the water level is high, the water surface 15 in the water-resistant container 1 rises from the bottom of the medium container 3 and is supplied to the medium 5 on the bottom side in the medium container 3. In the medium 5, excess water supplied beyond the water retention capacity of the medium 5 flows down from the holes 4 to the water resistant container 1.

  The pumps 10 and 11 are periodically operated by a timer in the control box 12 serving as a water level adjusting mechanism. After holding the water level 14 detected by the low water level sensor 9 at the low water level for a predetermined time, the water level is moved to the water level 15 detected at the high water level sensor 17 for a predetermined time. Move again to the low water level and repeat the operation. The low water level liquid level sensor 9 is disposed below the bottom of the medium container 3. The high water level sensor 17 is disposed above the bottom of the medium container 3.

  That is, in this hydroponic cultivation apparatus, the medium 5 is directly supplied with water, and excess moisture flows down and accumulates in the water-resistant container 1. If the water supply is further continued, the amount of water in the water-resistant container 1 increases and reaches the bottom of the medium container 3. Then, the water accumulated in the water-resistant container 1 returns to the medium container 3 and water is supplied to the medium 5. In this way, the water and nutrients are supplied to the culture medium 5 by the water sent from the water supply pipe 6 and the water returning from the outside of the culture medium container 3 into the culture medium container 3.

  In addition, FIG. 1 has shown the state at the time of a low water level. When the upper surface of the water-resistant container 1 is wide open, the transpiration of water is severe, and therefore a lid 16 that closes the upper surface of the water-resistant container 1 is provided.

  In this hydroponic cultivation apparatus, the vicinity of the root of the plant seedling 8 in the culture medium 5 is maintained in a dry state than the culture medium 5 near the bottom of the culture medium container 3. In addition, a distribution is formed in which the water content of the medium decreases in the horizontal direction from the outer periphery toward the inner periphery, with the root of the plant seedling 8 as the center. In the culture medium 5, excess water supplied beyond the water retention capacity of the culture medium 5 flows down, and there is no osmotic diffusion in the horizontal direction and upward.

  Excess water is discharged downward from the bottom surface of the medium container 3 to suppress the diffusion of water in the medium 5 and maintain the distribution of the water content in the medium 5 by adjusting the water supply position in the medium 5 and the medium 5. By adjusting the moisture permeation rate.

  Further, by adjusting the water supply position in the culture medium 5 and adjusting the moisture permeation rate in the culture medium 5, the root periphery of the plant seedling 8 in the culture medium 5 is maintained in a more dry state than the culture medium 5 near the bottom of the culture medium container 3. At the same time, a distribution is formed in which the water content of the medium decreases in the horizontal direction from the outer periphery toward the inner periphery, centering on the root of the plant seedling 8.

  In the present embodiment, a commercially available unglazed ceramic sphere (trade name: Hydroton) is used as the medium 5. This is necessary for the present invention (1) has the characteristics of “fast permeation of water”, and (2) in order to improve the drainage of water from the hole 4 at the bottom of the medium container, the hole diameter should be as large as possible and provided over the entire surface. This is because it satisfies the following two factors: a large medium that does not spill from the pores.

  When unglazed ceramic spheres are used as the medium 5, those having a large particle size with a particle size of 1 cm or more are particularly suitable for the present invention. The large particle size not only increases the permeability of excess moisture that has not been absorbed by the medium, but also has the effect of reducing the contact area between the grains and suppressing moisture diffusion between the grains. It is particularly effective. However, the high water permeability is conversely accompanied by the danger that water will flow down before the medium absorbs sufficient water during water supply. Therefore, in the present invention, water supply from the bottom surface in which the culture medium is immersed in water and sufficiently absorbs water is mainly used, and water supply by running water from the water supply pipe 6 is used as auxiliary water supply means.

  About the water supply from the bottom face of the culture medium container 3, as shown also from the installation position of the high water level liquid level sensor 17 in FIG. 1, the distance from the root of the plant seedling 8 and the deep position where the tip of the root reaches You must stop. This position depends on the plant species and the size of the seedlings, but when transplanting seedlings planted in No. 5 pots (pot diameter: about 15 centimeters), which are usually well marketed, to the device, the surface of the medium 10 to 12 centimeters is a standard for the high water level position.

  However, in hydroponic cultivation using a normal medium, water penetrates quickly into the medium, so even if water supply is stopped at this position, the water easily reaches the roots of the plant seedlings, causing a load on the seedlings. I will give it. In this invention, the subject that water cannot be supplied with respect to the culture medium of the area | region (The area | region where a root grows around the root of the root | base originally) above a high water level position remains. Therefore, as an auxiliary water supply means, a water supply pipe 6 is installed around the base, and water is supplied directly to an area that does not reach the water supply from the bottom surface.

  Although it is possible to supply water in a shower form from the upper surface of the medium 5 without burying the water supply pipe 6 in the medium, the water supply from the surface of the medium 5 causes a lot of transpiration of water to the atmosphere. It is desirable to bury the water supply pipe when supplying water directly to the culture medium because there is a harmful effect that it is necessary to increase the amount of water supply, and (2) the dissolved salt is easily concentrated near the surface of the culture medium. .

  Further, as will be described later, the medium 5 does not necessarily have to be above the water supply pipe 6, so that no particular advantage is observed in exposing the water supply pipe 6 on the medium 5. As the installation position of the water supply pipe 6, if it is a place of transplantation from potted plants, the area around the inside of the pot is a standard. The roots from which the soil has been loosened and spread are spread on the medium 5, and the water supply pipe 6 is placed directly or thinly on the medium 5, and the medium 5 is placed on the entire surface. If the moisture supply pipe 6 is installed deeply, the area where the roots above the moisture supply pipe 6 cannot be used increases. Therefore, the medium 5 may be thinly placed on the moisture supply pipe 6.

  In this hydroponics apparatus, since the water | moisture content is not supplied excessively to the root of the plant seedling 8, the cultivation method which was not able to be performed by the conventional hydroponics becomes possible. That is, when transferring plant seedlings cultivated in soil to hydroponics, the soil near the roots can be transferred to hydroponics without losing the surrounding roots and dropping the soil.

  In the case of the No. 5 pot seedling mentioned above, the roots are usually loosened from the roots to around 7-8 centimeters, and the soil is dropped and transplanted, so there is 3-5 between the remaining soil and the high water level position. About a centimeter is empty, and this space is occupied by the medium and roots. Also in the horizontal direction, it is preferable to provide a water supply pipe with a space of at least about 2 centimeters between the root soil left without dropping. For the soil at the root part away from the water supply position, there is only a slight water supply due to exudation from the surrounding medium, so it is not actually a “hydroponic environment” and the soil remains defective. Does not occur.

  This means that for plant seedlings, the load due to transplantation ((1) load to drop soil, (2) load to change from soil to hydroponics) is greatly reduced. In fact, when a tree seedling is transplanted to the hydroponic cultivation apparatus of the present embodiment, no signs of weakening of the seedling are observed even immediately after transplanting, and the tree can be transferred to hydroponics very smoothly.

  The unglazed ceramic sphere culture medium used in the present embodiment tends to have insufficient water retaining ability in terms of material and also because it has a large particle size and thus has many voids. Therefore, the lack of water retention capacity is compensated by increasing the water supply frequency. According to the past results, it is possible to grow without water shortage by supplying water with a cycle of 6 to 8 hours in winter and a cycle of 2 to 3 hours in summer.

[Second embodiment of hydroponic cultivation apparatus]
FIG. 2 is a side view illustrating the configuration of another hydroponic cultivation apparatus according to the present invention.

  In this embodiment, as shown in FIG. 2, the culture medium 25 is made of a material having water retention, but at a position above the tip of the moisture supply pipe 26, a part of the culture medium 25 is The non-water-absorbing material 38 having no water absorption and water retention is substituted. That is, although the basic configuration is the same as that of the previous embodiment, the difference from the previous embodiment is that the non-water-absorbing material 38 is placed on the moisture supply pipe 26 and the rainproof cover 39 is on it. .

  Hereinafter, it demonstrates in detail focusing on the difference with previous embodiment. In addition, about the member same as previous embodiment, the code | symbol becomes what added "20" to the code | symbol in previous embodiment.

  In the present embodiment, instead of burying the water supply pipe 26 in the culture medium 25, the upper side of the water supply pipe 26 is covered with a non-water-absorbing material 38. This is because (1) the nature of the roots of the plant “nearly grows upward”, (2) the water supply does not reach above the water supply pipe 26, so the roots grow in the first place. Therefore, it is reasonable to replace it with a cheaper material without using an expensive medium. In order to suppress transpiration of water from the surface of the culture medium 25, it is desirable not to suck up moisture even during water supply, and it is preferable to select a non-water-absorbing material 38 having no water absorption.

  In the previous embodiment and the description so far, it is assumed that the apparatus is installed indoors or in a place that is hardly exposed to rain, such as a veranda. However, the hydroponic cultivation apparatus according to the present invention can be easily installed outdoors if it protects against rain to some extent. The rainproof cover 39 is a part necessary for such outdoor installation. That is, the rainproof cover 39 prevents the vicinity of the root of the plant seedling from getting wet by rain when the apparatus is installed outdoors. That is, since the rainproof cover 39 does not transmit rain, the rain falling on the rainproof cover 39 only reaches the outside of the rainproof cover and does not affect the root portion of the seedling under the rainproof cover.

  On the other hand, the rain that has fallen outside the rainproof cover 39 is bounced off by the non-water absorbent material 38 and stays outside the apparatus, or passes through the non-water absorbent material 38 and reaches the culture medium to be absorbed. run down. In any case, the root of the plant seedling 28 is hardly affected.

  Of course, it is satisfactory if a rain protection cover is installed so as to cover the entire upper surface of the apparatus (water resistant container 21 and medium container 23) excluding the plant seedling 28. However, in the case of the apparatus according to the present invention, it is sufficient to have the rainproof cover 39 after the rain protection to a certain extent so that the rainwater collected in the water resistant container 21 does not increase so much.

  That is, the rainwater that is excessive moisture quickly flows down from the bottom of the culture medium container 23 through the culture medium 25 and accumulates in the water-resistant container 21, but the rise of the water level due to this does not reach the bottom surface of the culture medium container 23. For example, it is only collected in the external tank 33 by adjusting the water level in the next water supply cycle. The apparatus functions as long as the water level rise due to rainwater can be prevented from reaching the bottom surface of the medium container 23. The amount of water in the external tank 33 increases as a result of rainwater, and the liquid fertilizer components are somewhat diluted, but this is a slight change compared to the total amount of water stored in this apparatus including the water-resistant container 21, and the effect is very small. .

  The present invention is applied to a hydroponic cultivation apparatus and a hydroponic cultivation method for growing plant seedlings using a water-retaining medium.

1,21 Water resistant container 2,22 Base 3,23 Medium container 4,24 hole 5,25 Medium 6,26 Water supply pipe 7,27 Water supply pipe hole 8,28 Plant seedling 9,29 Low water level sensor 10, 30 Pump 11, 31 Pump 12, 32 Control box 13, 33 External tank 14, 34 Water level at low water level 15, 35 Water level at high water level 16, 36 Lid 17, 37 High water level sensor 18, 38 Moisture Recovery piping 38 Non-water-absorbing material 39 Rainproof cover

Claims (7)

While containing and holding a water-retaining medium in which the roots of plant seedlings are embedded, a medium container provided with a hole through which water passes on the bottom surface;
In a state where a space is formed between the bottom surface and the bottom surface of the medium container, a water-resistant container that stores and holds the medium container,
An external tank for storing water in which liquid fertilizer is dissolved,
A water supply pipe for directly supplying water into which the liquid fertilizer in the external tank is dissolved;
Drainage means for discharging water in the water-resistant container outside the medium container to the outside of the water-resistant container;
A water level adjusting mechanism for adjusting the water level in the water resistant container,
Water supply from the external tank to the medium and discharge of excess water flowing from the medium to the outside of the medium container are repeated intermittently, and the water level in the water resistant container is periodically raised and lowered. Thus, water and nutrients are supplied to the culture medium by water sent from the moisture supply pipe and water returning from the outside of the culture medium container to the culture medium container. The tip of the moisture supply pipe is arranged buried in the medium in the medium container,
The hydroponic cultivation apparatus according to claim 1, wherein moisture is supplied to a position away from a root of the plant seedling in the medium. While the root periphery of the plant seedling in the medium is maintained in a dry state than the medium near the bottom of the medium container,
The hydroponic cultivation apparatus according to claim 2, wherein a distribution in which the water content of the medium decreases in a horizontal direction from the outer periphery toward the inner periphery with the root of the plant seedling as a center is formed. The excess water supplied beyond the water retention capacity of the culture medium flows down in the culture medium, and does not permeate and diffuse in the horizontal direction and in the upward direction. The hydroponic cultivation apparatus described. The medium is made of a material having water retention, and a part of the medium is replaced with a material having no water absorption and water retention at a position above the tip of the moisture supply pipe. The hydroponic cultivation apparatus according to any one of claims 2 to 4, wherein the hydroponic cultivation apparatus is characterized. A water-retaining medium is accommodated and held in a medium container provided with a hole through which water passes on the bottom, the roots of plant seedlings are embedded in the medium, and the medium container is accommodated in a water-resistant container, A hydroponics method for supplying water in which liquid fertilizer is dissolved intermittently to the medium, with a space formed between the bottom surface of the medium container and the bottom surface of the water resistant container,
By adjusting the water supply position in the medium and adjusting the water permeation rate in the medium, excess water supplied exceeding the water retention capacity of the medium is discharged downward from the bottom surface of the medium container, and the moisture content in the medium is reduced. Hydroponic cultivation method characterized by suppressing diffusion and maintaining the distribution of water content in the medium. While maintaining the root periphery of the plant seedling in the medium in a dry state than the medium near the bottom of the medium container,
The hydroponic cultivation method according to claim 6, wherein a distribution in which the water content of the medium decreases in a horizontal direction from the outer periphery toward the inner periphery with the root of the plant seedling as a center is formed.