WO2018143450A1

WO2018143450A1 - Hydroponic device and hydroponic method

Info

Publication number: WO2018143450A1
Application number: PCT/JP2018/003774
Authority: WO
Inventors: 朗内山田; 剛平森田
Original assignee: 東洋紡株式会社
Priority date: 2017-02-06
Filing date: 2018-02-05
Publication date: 2018-08-09
Also published as: JP7192500B2; JPWO2018143450A1

Abstract

Provided are a hydroponic device and a hydroponic method, in which a culture solution is supplied and circulated to cultivate a plant, wherein fluctuations in ionic component balance in the culture solution are suppressed by means of a simple configuration, and the culture solution can be easily managed. This hydroponic device, in which a culture solution is supplied and circulated to cultivate a plant, has: a cultivating part in which the plant is cultivated; and a culture solution circulation path which starts from the cultivating part and reaches the cultivating part, wherein the culture solution circulation path has a culture solution separation means which, from a portion of the culture solution, discharges, to the outside of the culture solution circulation path, a component that makes up more than 50 mass% of a total of 100 mass% of components that remove water in the culture solution.

Description

Hydroponic cultivation apparatus and hydroponic cultivation method

The present invention relates to a hydroponic cultivation apparatus that cultivates a plant by supplying and circulating a culture solution, and a hydroponic cultivation method using the apparatus.

In recent years, plant factories, which are environmentally friendly production systems that aim to supply safe foods and supply foods throughout the year, have attracted attention. This plant factory is a system that systematically produces plants in a closed or semi-closed space where the internal environment is controlled. Specifically, the plants are arranged in a cultivation section such as a cultivation floor, and a culture solution is supplied. The plant is grown and harvested using natural or artificial light as a light source, using hydroponics that supplies nutrients by distributing it near the roots of the plant.

The culture solution in hydroponics is generally managed by adjusting the pH value and adjusting the electrical conductivity (hereinafter referred to as “EC”) as an index. In addition to adjusting the concentration of the culture solution based on the pH value or EC value, the culture solution is reused by, for example, filtering the effluent after the culture solution is supplied to the plant through a filtration membrane (for example, , See Patent Document 1 and Patent Document 2).

In addition, the effluent of the culture solution after being supplied to the plant is sterilized and reused (for example, Patent Documents 3 to 5), and the culture solution is purified and reused using activated carbon. (See, for example, Patent Document 6 and Patent Document 7).

Japanese Patent Laid-Open No. 9-107826 JP 2011-078332 A JP 2011-299116 A JP 63-29417 A JP 2001-346460 A Japanese Patent Laid-Open No. 50-18224 JP-A-9-313055

However, among the components that are beneficial to plant growth, there are components that are difficult to be absorbed by plants and components that are easily absorbed, so that components that are difficult to be absorbed by plants circulate when the culture solution is used for a long time. By consuming components that are accumulated in the system and are easily absorbed by plants, the ionic component balance in the culture solution tends to gradually collapse. In addition, in the conventional culture broth reuse technology, allelopathic substances (mainly organic acids) that are not beneficial to plant growth pass through the filtration membrane and accumulate in the broth, making it difficult to manage the broth There was a problem of becoming. As these countermeasures, for example, it is possible to perform analysis one by one using ion chromatography and control the culture solution components based on the analysis results, but the ion chromatography is expensive, and the culture solution components Since the management control of the system becomes complicated, it was not practical.

In plant factories, plants are cultivated in a state where the internal environment is controlled. Concentration control and pH control are performed for the culture solution using electrical conductivity. Since the plant will fall or the plant will be sick, it will be necessary to periodically replace the culture solution and clean the plant cultivation part, and this culture solution replacement will increase the waste and lose the cultivation period As a result, the cost and time are greatly lost.

The present invention has been made by paying attention to the above circumstances, and its purpose is to supply a culture solution and circulate it to cultivate a plant. An object of the present invention is to provide a hydroponic cultivation apparatus and a hydroponic cultivation method that can suppress and manage a culture solution easily.

In the hydroponic cultivation apparatus for cultivating a plant by supplying a culture solution and circulating the plant while diligently studying to solve the above-mentioned problems, the inventors of the present invention are based on the sum of the components excluding the water content of the culture solution. Thus, it has been found that the separation means for discharging components exceeding a certain ratio out of the circulation route of the culture solution can suppress the fluctuation of the ionic component balance in the culture solution and can easily manage the culture solution. It came to be completed.

That is, the hydroponic cultivation apparatus of the present invention that has solved the above problems is a hydroponic cultivation apparatus that grows plants by supplying and circulating a culture solution, and a cultivation unit in which the plants are cultivated, A culture medium circulation path starting from the cultivation section and returning to the cultivation section, and the culture medium circulation path includes a component excluding moisture in the culture liquid for a part of the culture liquid. It has a feature in that it has separation means for discharging the component exceeding 50% by mass out of the culture medium circulation path with respect to 100% by mass in total.

By treating the culture broth and deliberately discharging a portion of the culture broth from the culture circulation path, the balance of the ionic components of the circulating broth is restored to be close to conditions suitable for plant growth. I am letting. It is preferable to discharge and supply the culture solution in small amounts, because discharging a large amount of the culture solution at a time and supplying a large amount of new culture solution involve a large production loss and economic loss. It is effective for maintaining the growth of plants to exchange the circulating culture solution and the newly supplied culture solution little by little.

In the hydroponic cultivation apparatus, the culture medium circulation path includes a first circulation tank located upstream of the cultivation unit, and a second circulation tank located downstream of the cultivation unit and upstream of the separating unit. Preferably it is.

In the hydroponic cultivation apparatus, the second circulation tank preferably has a microbubble generator that generates microbubbles.

In the hydroponic cultivation apparatus, the separation means preferably includes a reverse osmosis membrane and / or a nanofiltration membrane.

It is preferable that the hydroponic cultivation apparatus has a culture solution supply means for supplying a culture solution.

In the hydroponic cultivation apparatus, the culture medium circulation path preferably includes a thermometer, a pH meter, and an electrical conductivity meter.

In the hydroponic cultivation apparatus, it is preferable that a part of the cultivation part is shielded from light.

The hydroponic cultivation method using the hydroponic cultivation apparatus exceeds 50% by mass with respect to a total of 100% by mass of the components excluding water in the culture solution in a culture solution circulation path. It is preferable to include a first step in which the component is discharged out of the culture fluid circulation path and a second step in which a culture fluid is newly supplied to the culture fluid that has undergone the first step.

According to the hydroponic cultivation apparatus and hydroponic cultivation method of the present invention, it is possible to suppress the fluctuation of the ionic component balance in the culture solution and to easily manage the culture solution.

It is an example of the schematic block diagram of the hydroponic cultivation apparatus which concerns on embodiment of this invention. It is another example of the schematic block diagram of the hydroponic cultivation apparatus which concerns on embodiment of this invention. It is the schematic diagram which showed the history of the ionic component balance in the conventional culture solution. It is the schematic diagram which showed the history of the ionic component balance in the culture solution at the time of using the hydroponic cultivation apparatus which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited only to the following embodiments, and is implemented with modifications within a range that can meet the gist of the preceding and following descriptions. All of which are within the scope of the present invention. In the following description, the same parts are denoted by the same reference numerals.

FIG. 1 is an example of a schematic configuration diagram showing a hydroponic cultivation apparatus according to an embodiment of the present invention. As shown in FIG. 1, the hydroponic cultivation apparatus 1 supplies a culture solution 2 and circulates it to cultivate a plant 3, and starts from a cultivating unit 4 where the plant 3 is cultivated and a cultivating unit 4. And a culture medium circulation path 5 that returns to the cultivation unit 4. In addition, the culture medium circulation path 5 contains, for a part of the culture liquid 2, more than 50 mass% of the components with respect to 100 mass% of the total components excluding moisture in the culture liquid 2. 5 has separation means 6 for discharging outside.

The culture solution 2 is a liquid containing a component added as a fertilizer for growing the plant 3, and specifically, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, chlorine, etc. as ions as a large amount of component. include. Moreover, iron, manganese, zinc, copper, molybdenum, sodium, boron, etc. are contained as an ion as a trace component. For each plant to be cultivated and cultivated, a culture solution composition suitable for the state of raw water and the stage of plant growth has been devised.In the practice of the present invention, for example, it contains moderately nitrogenous nitrogen and is suitable for fruit vegetables from autumn to spring. As a corresponding culture medium formulation, OAT House No. 1, OAT House No. 2, OAT House No. 8 (all manufactured by OAT Agrio Co., Ltd.) and the like can be used.

The plant 3 that can be cultivated by the hydroponic cultivation apparatus 1 of the present invention can cultivate various fruit vegetables, leaf vegetables, and flowers according to the formulation of the culture solution 2. For example, OAT Agrio Co., Ltd. can be used as a culture solution formulation. Lettuce can be cultivated when OAT House No. 1, OAT House No. 2, and OAT House No. 8 are used.

The cultivation unit 4 is a place where plants are grown by hydroponics. For example, a material called a hydroponic cultivation board having a structure that has buoyancy on the culture solution 2 and can hold seedlings can be used. Specifically, seedlings are set in a hole formed in a hydroponics growth board and planted, and sunlight or artificial light on a bath filled with the culture solution 2, sometimes at room temperature, carbon dioxide in the air Cultivate by growing for several days to several tens of days in an environment where the gas concentration is adjusted.

The culture medium circulation path 5 is a path through which the culture medium 2 that starts from the cultivation section 4 where the plant 3 is grown and returns to the cultivation section 4 circulates. If the cultivation part 4 which is the start point and the cultivation part 4 which is the end point coincide with each other, the route in the middle is not particularly limited. For example, the first circulation which is a buffer for controlling EC and pH in the middle of the route. You may make it provide the tank 7a and distribute | circulate a culture solution toward the cultivation part 4 from the said 1st circulation tank 7a. Further, in the middle of the route from the cultivation unit 4 to the first circulation tank 7a, two routes may be provided: a route that passes through the separating unit 6 and a route that does not pass through the separating unit 6. With this configuration, the operation of the separating unit 6 can be freely controlled. In addition, as a material of the culture solution circulation path 5, for example, a stainless steel pipe can be used, and one having improved durability and corrosivity is used.

The separating means 6 will be described in detail below.
In the hydroponic cultivation apparatus 1 of the present invention, in order to suppress the fluctuation of the ionic component balance in the culture solution 2, attention was paid to changing the ionic component in the culture solution 2 as close to the initial value as possible. Specifically, in the hydroponic cultivation apparatus 1 of the present invention, in the culture solution circulation path 5, the total amount of components excluding moisture in the culture solution 2 is 100% by mass with respect to a part of the culture solution 2. The separation unit 6 is configured to discharge the component exceeding 50 mass% out of the culture medium circulation path 5. Conventionally, the culture fluid 2 has been returned to the culture fluid circulation path 5 as it is, but in the present invention, contrary to the conventional technology, a part of the components excluding moisture in the culture fluid 2 is discarded. (Exhaust) is characterized in that the fluctuation of the ionic component balance in the culture solution 2 is suppressed.

As described above, various ionic components in the culture medium exist and are mixed in a complicated manner. Therefore, here, main ionic components (nitrogen, phosphoric acid, potassium) are taken as an example based on FIG. 3 and FIG. This will be described below.

FIG. 3 schematically shows the history of the balance of ionic components in the culture medium by conventional EC value measurement. As shown in FIG. 3 (a), the ionic component balance in the culture solution is in the initial state, and the constituent values of nitrogen, phosphoric acid, and potassium in this state are nitrogen: phosphate: potassium = 1: 1: Assume that 1.

Next, as shown in FIG. 3 (b), in the state where the plant was cultivated to some extent by the hydroponic cultivation apparatus, the EC value of the whole culture solution was initially 3 as measured by the EC meter. Perceived to have decreased. Since the EC value of each component in the culture solution cannot be measured by the EC meter, the constituent values of nitrogen, phosphoric acid, and potassium in this state are as follows: nitrogen: phosphate: potassium = 0.7: 0. 7: 0.7.

Here, since the ratio of each ionic component consumed for the growth of the plant is different, the ionic component balance in the actual culture solution is as shown in FIG. It is assumed that nitrogen: phosphate: potassium = 1: 0.7: 0.4.

Next, as shown in FIG. 3 (d), based on the value detected by the EC meter, replenishment of the culture solution as supplementary fertilizer to replenish the reduced fertilizer component (3-2.1 = 0.9) (Nitrogen: phosphoric acid: potassium = 0.3: 0.3: 0.3) is performed.

Furthermore, as shown in FIG. 3 (e), the state of FIG. 3 (d) is supplemented to the state of FIG. 3 (c), so that nitrogen: phosphate: potassium = 1.3: 1: 0.7. In this state, the excess component nitrogen becomes excessive from the initial state, and the insufficient component potassium becomes insufficient from the initial state.

FIG. 4 schematically shows the history of ionic component balance in the culture solution when the hydroponic cultivation apparatus of the present invention is used. As shown in FIGS. 4 (a) and 4 (b), the initial state and the state in which the ionic components in the culture solution are consumed are the same as in FIGS. 3 (a) and 3 (c).

Next, as shown in FIG. 4 (c), in a state where the ionic components in the culture solution shown in FIG. 4 (b) are consumed, half of the total 100% by mass of the components excluding moisture in the culture solution. (Nitrogen: phosphate: potassium = 0.5: 0.35: 0.2) are discharged out of the culture medium circulation path.

Next, as shown in FIG. 4 (d), the culture solution is used as a supplementary fertilizer to replenish the fertilizer component (3-1.05 = 1.95) reduced by the discharge of the culture solution shown in FIG. 4 (c). (Nitrogen: Phosphoric acid: Potassium = 0.65: 0.65: 0.65) is performed.

Furthermore, as shown in FIG. 4 (e), the state of FIG. 4 (d) is supplemented to the state of FIG. 4 (c), so that nitrogen: phosphate: potassium = 1.15: 1: 0.85. Thus, it is possible to improve the balance of the ionic component in the culture broth produced in FIG. 4B. In addition, by repeating a series of flows from FIG. 4B to FIG. 4E, the ionic component balance in the culture solution can be brought close to the initial state as much as possible.

In addition, although the ratio discharged | emitted out of a culture solution path | route should just exceed 50 mass% with respect to a total of 100 mass% of the components except the water | moisture content of a culture solution, the operating time of a hydroponic cultivation apparatus, a culture solution In view of the balance between the discharge amount and the replenishing amount, it is preferably 60% by mass, more preferably 75% by mass, further preferably 90% by mass, and most preferably 99% by mass. By treating even part of the culture solution periodically, an environment that is gradually improved can be provided, which is advantageous for plant growth.

Here, the components other than the water in the culture solution include, for example, nitrogen, phosphate ions, iron ions, tin ions, zinc ions, boron ions, sodium ions, calcium ions, magnesium ions, etc., which are the culture components of the culture solution. That is.

Specific examples of the separation means of the present invention include a membrane separation method in which separation is performed using a membrane. Membrane separation methods are classified into microfiltration method, ultrafiltration method, ion permeation method, nanofiltration method, reverse osmosis method, and gas separation method in the order of the size of the substance to be separated. Filtration membranes, ultrafiltration membranes, ion permeable membranes, nanofiltration membranes, reverse osmosis membranes, and gas separation membranes. Among the above separation membranes, in the practice of the present invention, it is preferable to use a separation membrane having a pore size of 10 nm or less, more preferably 5 nm or less, and even more preferably 2 nm. The following are preferable, and still more preferable is 1 nm or less. More specifically, it is preferable to use a nanofiltration membrane that allows moisture, sodium ions, and chloride ions to pass through and blocks the passage of macromolecules such as amino acids and proteins smaller than 2 nm, and more preferably allows only water to pass through. It is preferable to use a reverse osmosis membrane (Reverse Osmosis Membrane, hereinafter referred to as RO membrane) that does not allow components other than water such as ions and salts to pass through. Further, a nanofiltration membrane and an RO membrane may be used in combination.

In order to maintain the filtered water volume and the recovery rate, there is a method of heating the raw water to keep the raw water temperature constant and the permeated water quantity constant, but in this case, the equipment for heating the raw water and large energy are required. I need. In particular, this type of filtration membrane device requires a certain amount of concentrated drainage, and the energy used for heating the concentrated drainage is discarded without being effectively used. Further, in this method of heating raw water, there is a problem that it is impossible to eliminate the decrease in the amount of permeated water due to the clogging of the filtration membrane.

There is a method of controlling the discharge amount and pressure of the filtered water supply pump in order to keep the supply water amount and supply water pressure constant. Specifically, there are a method for controlling the number of revolutions of the raw water supply pump and a method for controlling the discharge amount by providing a control valve on the outlet side of the raw water supply pump.

In the practice of the present invention, the amount of the liquid supplied to the filtration membrane of the separation means is made constant, and the amount of the concentrated liquid generated at the time of filtration is made constant, so that the filtrate is not affected by the temperature fluctuation of the culture solution. You may use the apparatus which can make quantity and a recovery rate constant. Specifically, in a hydroponic cultivation apparatus that supplies a culture solution and circulates to grow a plant, a culture solution supply pump is provided in the culture solution circulation path leading to the separation means, and a flow rate is supplied to the filtrate path of the separation means. A filtrate flow rate control means for providing a transmitter, controlling the number of rotations of the culture solution supply pump based on a flow rate signal transmitted from the flow rate transmitter, and making the filtrate flow rate constant, and a concentrate of the separation means A concentrated liquid constant flow valve for making the flow rate of the concentrated liquid constant is provided in the path, interposed between the separation means and the concentrated liquid constant flow valve, and a pressure reducing valve for reducing the pressure of the concentrated liquid, the pressure reducing valve, and the above You may make it the structure provided with the pressure indicator interposed between concentrated liquid constant flow valves.

The treatment of the culture solution by the separation means may be performed continuously during the growth of the plant, but is preferably performed intermittently in order to reduce production loss and economic loss. Specifically, for example, a periodic operation such as operating the separation means may be performed once or more, more preferably twice or more, and even more preferably three times or more per week of the plant growth period.

By configuring the hydroponic cultivation apparatus 1 of the present invention as described above, it is possible to suppress the fluctuation of the ionic component balance in the culture solution and easily manage the culture solution.

The culture medium circulation path 5 includes a first circulation tank 7 a located upstream of the cultivation unit 4 and a second circulation tank 7 b located downstream of the cultivation unit 4 and upstream of the separating unit 6. It is preferable. That is, the culture medium circulation path 5 preferably includes a first circulation tank 7a that is a buffer for controlling EC and pH, and a second circulation tank 7b that is a buffer for partially treating the culture liquid. Since the culture solution circulation path 5 includes the first circulation tank 7a and the second circulation tank 7b, the operation of the separation means 6 can be freely controlled.

FIG. 2 is another example of a schematic configuration diagram showing the hydroponic cultivation apparatus according to the embodiment of the present invention. As shown in FIG. 2, the culture solution circulation path 5 has two routes: a route through which the culture solution 2 discharged from the cultivation unit 4 passes through the second circulation tank 7 b and a route through which the second circulation tank 7 b does not pass. May be provided. By configuring the culture medium circulation path 5 in this way, the operation of the separating means 6 can be freely controlled.

When the culture solution circulation path 5 has the first circulation tank 7a and the second circulation tank 7b, the separation means 6 processed the culture solution 2 stored in the second circulation tank 7b, and was obtained by the separation means 6. It is preferable to supply water to the culture solution circulation path 5 and store the culture solution 2 in the first circulation tank 7a. Since the culture solution circulation path 5 is configured in this way, the amount of drainage discharged from the hydroponic cultivation apparatus 1 can be reduced.

The water obtained by the separation means 6 is preferably supplied to the culture medium circulation path 5 and stored in the first circulation tank 7a. Specifically, as shown in FIG. 2 may be stored in the first circulation tank 7a after being returned to the circulation tank 7b. As shown in FIG. 2, the culture solution 2 is supplied to the path from the second circulation tank 7b to the first circulation tank 7a. You may store in the 1st circulation tank 7a.

The second circulation tank 7b preferably has a microbubble generator 11 that generates microbubbles. Since the second circulation tank 7b has the microbubble generating device 11, the allelopathic substance (details will be described later) released from the plant 3 to the culture solution 2 during the growth of the plant 3 in the cultivation unit 4 is microbubbled. The growth of the plant 3 can be prevented from being hindered by the accumulation of allelopathic substances in the culture solution 2 due to the circulation of the culture solution 2.

«Microbubbles refer to fine bubbles with a bubble diameter of 100 µm or less. It is considered that the allelopathic substance is erased by microbubbles because radicals are generated when the microbubbles are crushed and the allelopathic substances are decomposed by the radicals.

The type of microbubble generator is a swirling flow type that generates microbubbles by generating a swirling flow by sending pressure water with a pump into the device, and an ejector type that generates microbubbles by ejecting liquid from a nozzle at high speed However, in order to reduce the size of the microbubble generator, a rotary type that generates microbubbles by rotating the screw at high speed is preferable.

If microbubbles remain in the culture solution, the roots of the plant may be damaged, and the growth of the plant may be hindered or the plant may wither. Therefore, it is preferable not to circulate the culture solution in the second circulation tank in the culture solution circulation path during the operation of the microbubble generator so that the culture solution containing microbubbles is not supplied to the cultivation unit. Referring to FIG. 1 as an example, when the microbubble generator 11 in the second circulation tank 7b is operated to generate microbubbles in the culture solution 2 in the second circulation tank 7b, the second It is preferable to stop the pump 10 between the circulation tank 7b and the first circulation tank 7a so that the culture solution 2 in the second circulation tank 7b is not supplied into the first circulation tank 7a.

Also, in order to prevent the adverse effects of microbubbles on plants, not only during the operation of the microbubble generator, but also after a certain period of time has passed since the microbubble generator has been stopped until all the generated microbubbles have disappeared Even so, it is more preferable not to circulate the culture solution in the second circulation tank in the culture solution circulation path. That is, the pump 10 between the second circulation tank 7b and the first circulation tank 7a is stopped during a certain period of time after the operation of the microbubble generator 11 in the second circulation tank 7b and after the operation is stopped. More preferably, the culture solution 2 in the second circulation tank 7b is not supplied to the first circulation tank 7a. By circulating the culture solution through the culture solution circulation path in this way, it is possible to remove allelopathic substances in the culture solution, reduce the possibility that the microbubbles will adversely affect the plant, and increase the yield of the plant. In addition, by operating the pump between the 1st circulation tank 7a and the cultivation part 4 during the action | operation of the microbubble generator 11, it is possible to supply the culture solution 2 which does not contain a microbubble to the cultivation part 4. Thus, the plant 3 can be sufficiently grown.

In addition, from the viewpoint of periodically and quantitatively supplying the culture solution, the hydroponic cultivation apparatus 1 of the present invention may have a culture solution supply means 8 for supplying the culture solution as shown in FIG. preferable. Specifically, a culture medium storage tank 9 adjusted to a desired culture medium component is provided before being supplied to the cultivation unit, and the culture medium is quantitatively supplied from the storage tank by the pump 10. good.

Also, from the viewpoint of improving the accuracy of management of the culture solution, the culture solution circulation path of the hydroponic cultivation apparatus of the present invention preferably includes a thermometer, a pH meter, and an electrical conductivity meter. More preferably, the temperature, pH, and electrical conductivity of the culture solution can be measured before and after supplying the cultivation part.

Furthermore, it is preferable that a part of the cultivation section of the hydroponic cultivation apparatus of the present invention is shielded from light. Specifically, the cultivation unit has a hydroponics growth board having a fixed planting hole for growing seedlings, and the board has a first layer (upper part) and a second layer (lower part). It is preferable that the first layer has a higher brightness than the second layer. By adopting such a configuration, the growth of the crop is promoted by increasing the light necessary for the photosynthesis of the crop using the reflected light from the above-mentioned hydroponics growth board. It can suppress that algae generate | occur | produces on the surface which contacts the culture solution of the cultivation board for hydroponics by reducing the transmitted light from.

In the cultivation department, leaves of plants that are growing may break or roots may break. If this leaf or root fragment is left untreated, allelopathic substances are released from the leaf or root fragment, or the leaf or root fragment is clogged by a separation device that is a culture medium circulation route or a culture solution separation means. May occur. In order to prevent the occurrence of these problems, it is preferable that the cultivation section has a foreign matter removing means for removing foreign matters such as plant leaves and root fragments. Examples of the foreign matter removing means include a rake-like object in which teeth are arranged in a rough comb shape in the cultivation part, and a mesh-like substance is arranged at a discharge port for discharging the culture solution in the cultivation part to the culture medium circulation path. .

Next, a hydroponic cultivation method using the hydroponic cultivation apparatus of the present invention will be described.

In order to hydroponically cultivate a plant using the hydroponic cultivation apparatus of the present invention, first, in the culture liquid circulation path of the hydroponic cultivation apparatus, a component excluding moisture in the culture liquid with respect to a part of the culture liquid The component exceeding 50% by mass is discharged out of the culture medium circulation path with respect to the total of 100% by mass (first step). Specifically, for example, as a component excluding moisture in the culture solution, components such as nitrogen, phosphate ion, iron ion, tin ion, zinc ion, boron ion, sodium ion, calcium ion, magnesium ion, etc., which are culture components It is preferable to discharge 99% by mass of the component out of the culture medium circulation path with respect to the total of 100% by mass. By doing in this way, the component of the major part of the ionic component in a culture solution will be discharged | emitted out of a culture solution circulation path | route.

Furthermore, a new culture solution is supplied to the moisture of the culture solution that has undergone the first step (second step). Specifically, for example, the culture solution is newly supplied in a state where the component concentration in the culture solution in the first step is lowered, and the ionic component that is deficient in the culture solution is replenished, and the culture solution The ionic component balance in the medium can be regenerated.

It is more preferable that the first step and the second step are repeated a plurality of times. By carrying out in this way, the collapse of the ionic component balance in the culture solution can be further improved. Moreover, you may add water further with respect to the water | moisture content of the culture solution which passed through the 1st step. By doing in this way, a culture solution can be made into the state of substantially fresh water, and the reproduction | regeneration of the ionic component balance in a culture solution by supply of the culture solution in a 2nd step can be promoted more.

Hydroponics, unlike soil cultivation, is a method of cultivating without using soil as a culture medium, giving it as a liquid fertilizer (culture solution) in which fertilizer is dissolved in water, with respect to the nutrient moisture necessary for plant growth, It is classified into a jet type, a thin film flow type (Nutrient Film Technique, hereinafter referred to as NFT) and a irrigation type (Deep Flow Technique, hereinafter referred to as DFT) depending on the configuration of circulating the culture solution. In the spraying type, a mist-like or water-drop-like culture solution is sprayed or dripped onto the roots of plants. Moreover, NFT is what flows a culture solution at a shallow water depth, DFT stores a culture solution in a bathtub and can immerse in deeper water depth. In many plant factories, DFT is adopted because of ease of plant production management. In the hydroponic cultivation apparatus and hydroponic cultivation method of the present invention, any of the above-described spraying type, NFT, and DFT methods is used. It is possible to use.

In addition, when a culture solution is used for a long period of time in hydroponics, a substance that suppresses the growth of other plants by decaying the roots of seeds, seed shells, etc. in addition to disruption of the ionic component balance in the culture solution ( (Allelochemical) is released, and animals and microorganisms are attracted. These effects are collectively defined as allelopathy. In the culture medium of hydroponics, components that are harmful to plant growth accumulate due to elution of allelopathic substances (mainly organic acids) and propagation of pathogenic bacteria such as viruses and bacteria. According to the hydroponic cultivation apparatus and hydroponic cultivation method of the present invention, out of the culture solution containing the harmful components, more than half of the components excluding moisture are discharged out of the culture solution circulation path, and then newly cultured. Since the solution is replenished, allelopathic substances in the culture solution can also be removed.

As described above, the hydroponic cultivation apparatus and hydroponic cultivation method of the present invention provide 50% by mass with respect to a total of 100% by mass of the components excluding moisture in the culture solution, with respect to a part of the culture solution. By having separation means for discharging the excess components out of the culture medium circulation path, the fluctuation of the ionic component balance in the culture solution can be suppressed, the culture solution can be easily managed, and an automatic pH controller is provided. By adding, it enables free maintenance of culture solution management in hydroponics.

This application claims the benefit of priority based on Japanese Patent Application No. 2017-019906 filed on Feb. 6, 2017. The entire contents of Japanese Patent Application No. 2017-019906 filed on Feb. 6, 2017 are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1 Hydroponic cultivation apparatus 2 Culture solution 3 Plant 4 Cultivation part 5 Culture solution circulation path 6 Separation means 7a First circulation tank 7b Second circulation tank 8 Culture solution supply means 9 Culture solution storage tank 10 Pump 11 Microbubble generator

Claims

A hydroponic cultivation apparatus that supplies a culture solution and circulates to grow a plant,
A cultivation section where the plant is cultivated;
A culture medium circulation path starting from the cultivation section and returning to the cultivation section,
In the culture medium circulation path, with respect to a part of the culture liquid, the component exceeding 50% by mass out of the culture medium circulation path with respect to a total of 100% by mass of the components excluding moisture in the culture liquid. A hydroponic cultivation apparatus comprising separation means for discharging.
The culture medium circulation path is a first circulation tank located upstream of the cultivation unit,
The hydroponic cultivation apparatus according to claim 1, further comprising a second circulation tank located downstream of the cultivation unit and upstream of the separation unit.
The hydroponic cultivation apparatus according to claim 2, wherein the second circulation tank has a microbubble generator that generates microbubbles.
The hydroponic cultivation apparatus according to any one of claims 1 to 3, wherein the separation means includes a reverse osmosis membrane and / or a nanofiltration membrane.
The hydroponic cultivation apparatus according to any one of claims 1 to 4, further comprising a culture solution supply means for supplying the culture solution.
The hydroponic cultivation apparatus according to any one of claims 1 to 5, wherein the culture solution circulation path includes a thermometer, a pH meter, and an electric conductivity meter.
The hydroponic cultivation apparatus according to any one of claims 1 to 6, wherein a part of the cultivation section is shielded from light.
A hydroponic cultivation method using the hydroponic cultivation apparatus according to any one of claims 1 to 7,
In the culture medium circulation path, with respect to a part of the culture liquid, the component exceeding 50 mass% is discharged out of the culture liquid circulation path with respect to 100 mass% in total of the components excluding moisture in the culture liquid. A first step,
A hydroponics method comprising: a second step in which a culture solution is newly supplied to the culture solution that has undergone the first step.