JPH0417606B2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a method for supplying a liquid suitable for the growth of plants when supplying a culture solution to grow plants, and an apparatus used therefor. It is something.

<Conventional examples and problems> In general, in order to grow plants by supplying a culture solution, it is necessary to consider the type of plant, the growth stage, the illumination, humidity, and temperature that the plant is receiving, and the medium in which the plant is planted. It is necessary to supply an appropriate amount of a material having a composition ratio appropriate to various factors such as the amount of evaporation.

In order to deal with these problems, it goes without saying that it is necessary to adjust the culture solution by inspecting the amount and concentration of the culture medium in which the culture solution is held, but it is also necessary to adjust the culture solution depending on the amount of illumination that the plants receive. Since the amount of culture solution absorbed by plants varies greatly, the culture solution must be supplied accordingly.

<Means for Solving the Problems> In view of the above-mentioned circumstances, the present invention has been proposed in order to achieve the following objects.

The illuminance of the culture solution supplied to the culture medium is detected at preset times and at times set outside of the preset time, and the solution is supplied to the culture medium according to the illuminance that the plants receive, adapting to the amount of culture solution absorbed by the plants. Add culture solution.

To detect the amount of liquid remaining in the culture medium after the plant absorbs the culture liquid, and to supply the liquid according to the amount of the liquid.

To prepare a culture solution to be supplied later by detecting the concentration and composition of the culture solution remaining in the medium.

etc.

The amount of culture solution absorbed by plants varies depending on the type of plant, and this can be done by setting the amount of solution supplied according to the type of plant, but the amount of absorbed solution can vary significantly depending on the illuminance that the plant receives. It is.

Therefore, it is difficult to expect healthy growth of plants unless a culture solution is supplied according to the illuminance that the plants receive.

Therefore, the present invention is capable of supplying a predetermined amount of liquid at a preset time, detecting the illuminance that the plant receives at other times, and supplying the culture liquid according to the illuminance. Based on this, when supplying the culture solution, the amount remaining in the culture medium can be detected and the amount of solution supplied can be changed accordingly, and the electrical conductivity in the culture medium to which the culture solution is supplied can be detected. This makes it possible to change the concentration and component composition ratio of the culture solution formed later.

In order to achieve the above object, the method for supplying a culture solution in hydroponic culture according to the first invention supplies the culture solution to the culture medium at a preset time, and at a set time different from the set time. In addition to detecting the illuminance and supplying the culture solution according to the detected illuminance, the system also controls the amount of culture solution contained in the culture medium at times other than the regular supply of culture solution according to each set time mentioned above. A method for supplying a culture solution in hydroponic cultivation according to a second invention is characterized in that the culture solution is supplied when the amount of the retained solution is less than a predetermined reference value. A culture solution is supplied to the culture medium at a preset time, and at a time different from the set time, the illuminance is detected and the culture solution is supplied according to the detected illuminance, and the amount of the culture solution to be supplied is adjusted from the culture medium. It is characterized in that it is controlled according to the amount of liquid discharged.

Further, the culture solution supply device for hydroponic cultivation according to the third invention includes a stock solution tank that stores a concentrated stock solution before diluting the culture solution, and a storage tank in which the diluted culture solution to be supplied to the culture medium is prepared and stored. A tank, a water supply mechanism for supplying water to the liquid storage tank, a timer circuit, and a solenoid valve that is opened by a signal from the timer circuit, and for supplying the liquid from the liquid tank to the liquid storage tank. A undiluted solution supply mechanism, an illuminance sensor that detects the illuminance received by the plants, a culture solution supply mechanism that supplies the diluted culture solution from the solution storage tank to the culture medium, and a system that detects the concentration of the culture solution in the solution storage tank. , a first electrical conductivity sensor for closing the electromagnetic valve when the culture solution concentration reaches a predetermined concentration, a liquid level sensor for detecting the liquid level in the liquid storage tank, and the timer circuit. A culture solution supply mechanism is controlled by a signal from the liquid level sensor so that the culture solution is supplied to the culture medium at a set time, and the illuminance is detected by an illuminance sensor and the culture solution is supplied at a time different from the set time. a water supply control circuit for controlling a water supply mechanism that supplies water to the liquid storage tank based on a signal from a liquid level sensor in the liquid storage tank; If the detected value is below a predetermined reference value, a signal is output to open the solenoid valve of the stock solution control circuit, and the first electrical conductivity sensor indicates that the concentration of the culture solution in the liquid storage tank has reached a predetermined concentration. A second electrical conductivity sensor is provided to correct the concentration of the culture solution by supplying the stock solution until it detects A liquid volume sensor that detects the amount of culture solution contained in the culture medium during times other than the time when the solution is supplied, and outputs a signal to supply the culture solution if the amount of culture solution is less than a predetermined reference value. A culture solution supply device for hydroponic cultivation according to a fourth invention is characterized by comprising:
A stock solution tank containing a concentrated stock solution before diluting the culture solution, a liquid storage tank in which the diluted culture solution to be supplied to the culture medium is prepared and stored, a water supply mechanism for supplying water to the liquid storage tank, A timer circuit, a solenoid valve that is opened in response to a signal from the timer circuit, and a stock solution supply mechanism for supplying the stock solution from the stock tank to the storage tank, an illuminance sensor that detects the illuminance received by the plants, and a storage tank. A culture solution supply mechanism for supplying the prepared diluted culture solution from the solution tank to the culture medium, and an operation that detects the concentration of the culture solution in the solution storage tank and closes the electromagnetic valve when the concentration of the culture solution reaches a predetermined concentration. a first electrical conductivity sensor for detecting the liquid level in the liquid storage tank; a liquid level sensor for detecting the liquid level in the liquid storage tank; A control circuit controls a culture solution supply mechanism based on a signal from the liquid level sensor to detect the illuminance using an illuminance sensor and supply the culture solution at the time of A water supply control circuit for controlling the water supply mechanism that supplies water to the liquid tank, and a solenoid valve for the stock solution control circuit that detects the electrical conductivity of the culture solution in the culture medium, and if the detected value is less than a predetermined reference value. The device is configured to output a signal for an opening operation and to correct the concentration of the culture solution by supplying the stock solution until the first electrical conductivity sensor detects that the concentration of the culture solution in the liquid storage tank has reached a predetermined concentration. a second electrical conductivity sensor installed therein, a drain tank that collects the culture solution flowing out from the culture medium,
a liquid level sensor for detecting the amount of drained liquid in the drained liquid tank; a pump controlled by a signal from the liquid level sensor for detecting the amount of liquid in the drained liquid tank; a circuit for storing the amount of drained liquid; The present invention is characterized by comprising a liquid supply control circuit that controls the set supply amount of the culture solution to be supplied to the culture medium based on the output from the storage circuit for the amount of drained liquid.

<Example> Hereinafter, the present invention will be explained based on an example shown in the drawings.

FIG. 1 shows an embodiment of a culture solution supply device for hydroponic cultivation to which the present invention is applied.

1 is a liquid storage tank for preparing and storing a culture solution;
2 is a medium in which plants are planted; 3 and 4 are stock solution tanks for storing two types of culture solution; 5 and 6
9 is a valve, for example, a solenoid valve, which is installed in the stock solution supply pipes 7 and 8 for supplying the stock solution from the stock solution tank to the liquid storage tank 1 and can be controlled electrically; and 9 is a circulation valve for circulating the culture solution in the liquid storage tank 1. The pump 10 is a circulation pipe body.

The stock solution supply pipes 7 and 8 are connected to a mixer 10 for mixing the stock solution of the culture solution and sending it to the liquid storage tank 1.
It is connected to the circulation pipe 10 via a.

The stock solution supply mechanism includes the stock solution supply pipes 7 and 8, electromagnetic valves 5 and 6, a circulation pipe 10, a mixer 10a, and a circulation pump 9.

The water supply mechanism is composed of a water supply pump 11 for supplying water to the liquid storage tank 1, a liquid supply pipe 12 for water supply, and an electric valve 11a for controlling the amount of water supply when water cannot be supplied by water pressure such as well water. . In addition, if the water pressure for water supply, such as tap water, can be used in the liquid storage tank 1, the water supply pump 1
1 may be omitted.

In addition, if it is necessary to adjust the water quality to dilute the stock solution of the culture solution, a water treatment device 11b may be provided, or a filter 11c may be provided to remove impurities.
It is preferable to provide

13 is an electrical conductivity sensor for detecting the concentration of the culture solution disposed in the liquid storage tank 1;
4 is the height of the liquid level in the liquid storage tank 1, for example 1 cm.
This is a liquid level sensor that can measure in units. This liquid level sensor 14 has two functions: detecting the amount of liquid to be supplied and detecting the upper and lower limits of the liquid level in the liquid storage tank 1. Instead of this liquid level sensor 14, a flow meter is used to detect the amount of liquid to be supplied. and a liquid level sensor 28, which will be described later.
A liquid level sensor (not shown) for detecting upper and lower limits similar to the above may be used, and in this specification, the liquid level sensor 14
When referring to the liquid level sensor 14, it refers to both the liquid level sensor 14 and a flow meter and/or a liquid level sensor for detecting the upper and lower limits of the liquid level in its place.

The culture solution supply mechanism includes a solution supply pump 15 for supplying the culture solution from the solution storage tank 1 to the culture medium 2, and a supply pipe 16 for supplying the solution.

17 is a strainer disposed at the tip of the supply pipe 16 in the liquid storage tank 1; 18 and 19 are a pressure gauge and a flow meter respectively disposed at appropriate positions on the supply pipe 16; and 20 is connected to the supply pipe 16. A liquid supply adjustment pipe 21 is arranged to return a part of the culture liquid fed by the liquid supply pump 15 to the liquid storage tank 1.
is a control valve for controlling the flow rate in the liquid supply control pipe 20.

22 is a control box, which controls the operation of each of the above-mentioned mechanisms, such as a control circuit for controlling the supply amount of culture solution, a timer circuit, a water supply control circuit for controlling the water supply mechanism, and a control circuit for controlling stock solution supply. Contains electrical circuits for this purpose.

Reference numeral 23 indicates a liquid amount sensor for detecting the amount of culture solution held in the medium 2, and 24 indicates an electrical conductivity sensor for detecting the electrical conductivity of the culture solution within the culture medium 2 to measure the concentration.

When detecting the electrical conductivity of the culture solution in the medium 2, a more accurate detection value can be obtained by removing the culture solution remaining in the culture medium 2 and detecting the electrical conductivity of the removed culture solution. It is preferable to obtain it.

25 is an illuminance sensor that detects the illuminance received by the plants planted in the medium 2; 26 is a drainage tank that collects the surplus of the culture solution supplied to the medium 2; and 27 is a liquid drained from the medium 2 and placed in the drainage tank 26. This is a drain pipe for sending liquid.

A liquid level sensor 28 is disposed in the drain tank 26 to detect the level of the culture liquid to be collected.

Reference numeral 29 denotes a liquid supply pipe for returning the culture solution collected in the drain tank 26 to the liquid storage tank 1 or for draining the liquid, and forcibly transfers the culture solution collected to the inner end of the drain tank 26. A pump 30 is provided to send liquid to.

Next, according to the timing chart shown in Figure 2,
The operation of preparing a culture solution to be stored in the liquid storage tank 1 will be explained.

This culture solution adjustment is started when the liquid supply at a preset time and the liquid supply by detecting the illuminance at a time different from the set time are completed.

In addition, if the culture solution stored in the liquid storage tank 1 runs out even during the above-mentioned liquid supply, the culture medium 2
The culture solution is also prepared when the supply of liquid is stopped due to the detection of a signal that the amount of liquid in the culture medium is less than the minimum standard value.

Therefore, this preparation should be started immediately if the culture solution is not being supplied to the culture medium 2, or if the amount of liquid in the liquid storage tank 1 is insufficient for the amount supplied to the culture medium 2 during the supply of the culture solution. If this is detected, the liquid supply is temporarily stopped and the remaining liquid supply amount is determined by the RAM circuit 38 shown in Fig. 3.
First, the water supply pump 11 and/or the electric valve 11a are operated to supply water to the liquid storage tank 1 via the water supply pipe 12. Next, when water is supplied until the liquid level in the liquid storage tank 1 reaches a preset level, the water supply pump 11 is stopped and/or the electric valve 11a is closed to stop the water supply, and then the circulation pump 9 is stopped. The system is operated to circulate the culture solution in the liquid storage tank 1 through the circulation pipe 10, and sufficiently stir and mix the supplied water and the remaining culture solution.

After a predetermined period of time has elapsed, a signal is output from a timer circuit consisting of a comparator circuit 32, a clock 36, etc. to indicate that, for example, one minute has elapsed, and the solenoid valves 5, 6
Open both or one of them to supply the stock solution stored in the stock solution tanks 3 and 4 to the liquid storage tank 1.

At this time, the circulation pump 9 is still operating, and the culture solution in the liquid storage tank 1 after being replenished with the stock solution is mixed and stirred so that it has a uniform concentration.

Then, the stock solution is supplied until the concentration of the stirred culture solution reaches the set concentration, and when the electric conductivity sensor 13 detects that the set concentration has been reached, the solenoid valves 5 and 6 are activated. Close it to stop supplying the stock solution.

The timer circuit outputs that a time period of, for example, one minute has elapsed since the supply of the stock solution is stopped until the concentration becomes uniform, and the circulation pump 9 is stopped, thereby completing the culture solution preparation process.

Next, the operation of supplying the culture solution of a predetermined concentration, prepared in this way and stored in the liquid storage tank 1, to the culture medium 2 will be explained.

The supply of the culture solution to the culture medium 2 is carried out by arbitrarily predetermining a predetermined time with one day being one cycle, and supplying a set amount of the solution at each time in principle. As an example of the time, 08:00 is set in the RAM circuit 38.
Set the time, such as 10:00 o'clock, 12:00 o'clock, 14:00 o'clock, 16:00 o'clock. In addition, the liquid supply time by detecting the illuminance can be set at 09:00, 11:00, 13:00, and 15:00.
Set it like 00 o'clock. Then, the liquid is supplied when the measured illuminance exceeds a preset reference illuminance. These set times can be changed as appropriate depending on the type of plant to be grown, the stage of growth, the season, etc.

When the set time arrives, the liquid supply pump 15 is activated by a signal from the timer circuit, and the culture liquid stored in the liquid storage tank 1 is passed through the strainer 17 and the supply pipe 16. and supply it to medium 2. In addition, in order to keep the pressure of the distribution pipe body 33 constant depending on the scale of the culture medium area, the control valve 21 is opened and a part of the culture solution is returned to the liquid storage tank 1 via the liquid supply adjustment pipe 20. In addition, when the pressure gauge 18 detects abnormal pressure during liquid supply, the control valve 21 is automatically opened and part or all of the culture medium is returned to the liquid storage tank 1 via the liquid supply adjustment pipe 20. It is also good as something to do.

The liquid supply to the medium 2 is performed in advance by the RAM circuit 38.
The liquid level sensor 1 indicates that the amount has reached the preset level.
When detected by 4, the liquid supply pump 15 is stopped,
The supply of culture medium is stopped.

On the other hand, even if the liquid volume sensor 23 detects that the amount of culture liquid contained in the medium 2 is less than the set minimum standard value during the period when the above-mentioned regular culture liquid supply is not performed, The culture solution may be supplied as needed. In this case, the liquid supply pump 15 is activated by the signal from the liquid level sensor 23 to supply the culture medium.

This occasional supply of culture fluid ends with supplying a specific amount of fluid that is smaller than the set amount by periodic fluid supply.

This type of liquid supply method is used as an auxiliary aid in emergencies, such as sudden weather changes such as rainy to sunny weather, or physical obstacles such as not being able to supply liquid to the culture medium at a fixed time or by illuminance detection. Used as a liquid supply means.

The above-mentioned occasional supply of the culture solution may be carried out throughout the 24 hours, but it may also be carried out only during a specific time period, for example, during the daytime when the temperature is high and the amount of culture solution consumed is large. These are RAM circuit 38
This can be done by making it an optional setting element in .

When correcting the concentration of the culture solution, the liquid retaining member 4
This may be carried out based on the electrical conductivity detected by the electrical conductivity sensor 24 disposed within the liquid retaining member 40, but since the culture solution may not be uniformly present within the liquid retaining member 40, A portion of the culture solution remaining in the liquid retaining member 40 is forcibly sucked and collected to detect electrical conductivity. In this way, accurate measurements can be detected, so
The concentration of the culture solution can be corrected more accurately.

Correction of the concentration and composition of the culture solution is performed by sending a signal to open both or one of the solenoid valves 5 and 6 when the detected value detected by the electrical conductivity sensor 24 is below a predetermined reference value. The liquid level sensor 1 installed in the liquid storage tank 1
4 sets the upper limit of water supply, and after supplying water, the undiluted solution is supplied until the culture solution reaches a predetermined concentration and composition ratio using the electrical conductivity sensor 13. That is, the upper limit of the liquid level of the diluent is set, and the water supply pump 11 is operated and/or operated until the liquid level reaches the upper limit set by the liquid level sensor 14.
Alternatively, the solenoid valve 11a is opened, and then, based on the electrical conductivity in the culture medium 2 of the culture solution by the electrical conductivity sensor 13, until the concentration and composition ratio are corrected by the program in the ROM circuit 31. Based on the signal from the electrical conductivity sensor 24, the electromagnetic valves 5 and 6 are opened to supply the stock solution.

Further, the amount of culture fluid supplied is corrected based on the amount of fluid collected in the drain tank 26. For example, the liquid level sensor 2 disposed inside the drain tank 26
8 detects the upper and lower limits of the liquid level, and controls the pump 30 to operate when the upper limit is reached and stop when the lower limit is reached, and the pump 30 is recovered based on the upper limit and the number of times the pump is activated in a day. Measure the amount of liquid.

This detection number is compared with a preset number of times, and if the difference is greater than the set number of times, it indicates that the amount of liquid supplied was excessive, so reduce the set amount of liquid supplied the next day, and reverse the detection. If the number of times is small, it indicates that the supply amount was insufficient, so increase the set supply amount for the next day.

When the culture medium to be supplied with the culture liquid is distributed over a wide area and the culture liquid is supplied in parts, the motor-operated valve 47 for switching the liquid supply first supplies a part of the medium 2. After the liquid is supplied to the medium 2 of the other portion, it is arranged so that it can be switched so that the liquid supply to the former medium is finished and the liquid is supplied to the latter medium.

This switching operation is performed, for example, when a culture solution is supplied to a part of the culture medium 2 and a preset amount of liquid is reached.
It is configured to control the electric valve 47.

At the time of starting the operation of the apparatus configured in this way, the input keyboard 50 is used to input the amount of liquid to be supplied to the culture medium 2, the amount of supply at any time, the time to start liquid supply, the time to end liquid supply, the regular liquid supply time, and the detection of illuminance. By setting and inputting the liquid supply time, standard concentration in the liquid storage tank, standard concentration in the medium, minimum amount of liquid retained in the medium, standard amount of culture liquid collected in the drainage tank, etc., you can increase the absorption rate by the plants. This can be carried out while automatically adjusting the concentration and supply amount of the culture solution depending on the amount of culture solution to be used and the difference in the transpiration effect of the plant depending on the illuminance.

FIG. 4 shows an example of medium 2.

40 is a liquid-retaining member formed in a rectangular parallelepiped shape and capable of being infiltrated with a culture solution, which includes liquid-absorbing rock wool or glass wool as an inorganic fiber material, a fiber-based material as an organic fiber material, liquid-absorbing urethane foam as a foamable synthetic resin, and A pine-shaped material made of charcoal, sand, etc., or other block-shaped material shall be used.

Reference numeral 41 denotes a liquid-permeable member, which is disposed on the lower and side surfaces of the liquid-retaining member 40 and is composed of a non-woven sheet made of non-woven fibers such as polyvinyl alcohol, polyester, polypropylene, nylon, etc.
Diameter that has liquid absorbing properties and can prevent plant roots from advancing
It shall have pores of 50 μm or less.

Reference numeral 42 designates a breathable member, which is an air-enclosed sheet formed by superimposing flexible films and partially enclosing and sealing air, which is disposed on the lower surface of the liquid-permeable member 41, and whose both ends are connected to the liquid-permeable member 41. is welded to. This breathable member 42 may be a plate-like material formed into a corrugated plate shape, a slightly thick mesh board, a material having cylindrical or prismatic protrusions or hair-like bodies formed upright on at least the upper surface, or a board. It consists of a body that is combined to form a plurality of void chambers, a porous plate made of a breathable material, etc.

43 is a plant, and 44 is a liquid-retaining medium that was used when growing the plants, and is placed on the liquid-retaining member 40.

45 is a liquid-tight covering member, and the liquid-retaining medium 4
The medium 2 is covered except for the part where the medium 4 is placed.
The lower part of the covering member 45 serves as a receptacle for the culture solution, and the upper part supports the liquid-retaining medium 44 and is insulated to alleviate changes in temperature of the culture solution due to solar heat, etc., or to prevent generation of chlorella due to light irradiation. It is best to use a material made of a material with good light shielding properties.

Reference numeral 46 denotes a distribution pipe, which is connected to the supply pipe 16 and is a porous pipe made of a liquid-permeable material, or a pipe made of metal or synthetic resin such as vinyl chloride, and at least the liquid retaining member 40. Adopt one that has multiple small holes for dispersion in the part that comes in contact with.

In this embodiment, the liquid retaining amount sensor 23 disposed in the liquid retaining member 40 includes a heater and a temperature sensor in a tubular body within the liquid retaining member 40, and a sensor having high electrical insulation and thermal conductivity and the above-mentioned. It is assumed that a filler that can hold a heater and a temperature sensor is built in, and that the amount of liquid retained can be measured by sensing the temperature increase due to heat from the heater.

In the culture medium 2 configured in this way, the culture solution passes through the supply pipe 16 and the dispensing pipe body 46, and the necessary amount of the culture solution is absorbed and retained in the liquid retaining member 40, and the excess culture solution is covered with water. flowing through the bottom of member 45;
The liquid is collected in the drain tank 26 through the drain pipe 27.

Therefore, even if the supply of culture solution from the dispensing tube 46 is stopped, the necessary amount of culture solution is retained in the liquid retaining member 40, so there is no need to constantly supply the culture solution, and this eliminates the need for power outages, etc. We can respond to liquid supply problems caused by

Further, as the plant grows, roots extend, protrude from the liquid-retaining medium 44, and enter the liquid-retaining member 40.
Since this is provided, the advancement of the roots is prevented here, and there is no possibility that the roots of the plant will enter into the culture solution collected on the liquid-tight covering member 45.

Therefore, the roots of the plants are not directly immersed in the culture solution, and no harm is caused by excessive nutrition. Also,
A liquid permeable member 41 with an air permeable member 42 interposed therebetween.
Since the atmosphere is designed to enter the lower part of the liquid retaining member 40 from the lower surface of the liquid retaining member 40, the liquid permeable member 40 grows.
Since the roots in the liquid retaining member 40 that have reached the vicinity of 1 can absorb sufficient oxygen, no adverse effects due to lack of oxygen occur.

The operation of the present invention is controlled by a control panel (not shown) housed in the control box 22 of the apparatus shown in FIG. 1, and this control will be explained with reference to the block diagram shown in FIG. do.

Signals from the liquid level sensor 23 in the culture medium 2, the electrical conductivity sensor 24, the electrical conductivity sensor 13 and the illuminance sensor 25 in the liquid storage tank 1 are transmitted via the A/D converter 34 and the import 35, and also to the liquid storage tank. Signals from the liquid level sensor 14 in the drain tank 1, the liquid level sensor 28 disposed in the drain tank 26, and the clock 36 are respectively input to the CPU 37 of the comparison calculation circuit 32 via the import 35.

The data inputted from each sensor and the clock 36 are compared and calculated in the CPU 37 with setting values previously input and stored in the RAM circuit 38 according to the operation program from the ROM circuit 31, and the resulting control signal is sent to the out port 39. Solenoid valves 5 and 6 for controlling the stock solution, and electric valve 11 for controlling the diluted solution.
a and water supply pump 11, circulation pump 9, culture medium 2
A liquid supply pump 15 for supplying culture liquid to the culture medium 2, a pump 30 for feeding or discharging the culture liquid discharged from the culture medium 2 and collected in the drain tank 26 to the liquid storage tank 1, and a pump 30 for discharging the culture liquid discharged from the medium 2 The culture solution suction pump 24a is used when detecting electrical conductivity by forcibly sucking the culture solution inside, and when supplying the culture solution in parts when the culture medium 2 is distributed over a wide area. , are output to the electric valve 47 that switches the liquid supply, and these operations are controlled.

Note that these controls may be performed using a microcomputer or other control means.

<Effects> The present invention has the above configuration and has the following effects.

Since the structure is such that the liquid is supplied even in accordance with the illuminance, which affects the amount of culture liquid absorbed by the plants, it is possible to supply the culture liquid suitable for the growth of the plants.

The concentration of the culture solution is adjusted by detecting the electrical conductivity of the solution remaining in the culture medium.
It is possible to grasp the amount of nutrients absorbed by plants and the balance of nutrients, and also to adjust the culture solution according to changes in the quality of the culture solution due to components eluted from the medium, making it possible to supply a culture solution suitable for plant growth.

When setting the amount of culture solution supplied, by detecting the amount of liquid discharged from the culture medium,
It is possible to grasp the amount of culture solution absorbed by plants, and supply culture solution according to the amount absorbed by plants.
The waste of liquid supply can be eliminated and efficient liquid supply can be performed.

When supplying culture medium, if the amount of liquid in the liquid storage tank is insufficient, the culture medium is adjusted to compensate for this, so even if the liquid storage tank is small, the culture medium can be placed over a wide area. It is possible to supply a sufficient amount of liquid over a wide range of conditions, and can be used in a wide range of applications regardless of the size of the culture medium.It is possible to reduce the space required to install the liquid storage tank and reduce equipment costs. .

By replenishing the culture solution in the liquid storage tank as described above, fresh water and stock solution are additionally stirred, so that the culture solution can be constantly activated and kept fresh.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a culture solution supply device showing one embodiment of the present invention, Fig. 2 is a timing chart showing the operating order of each pump and electric valve, and Fig. 3 is a block diagram showing an embodiment of the control circuit. FIG. 4 is a cross-sectional view of the culture medium. 1... Liquid storage tank, 2... Culture medium, 3, 4... Stock solution tank, 5, 6, 11a... Electric valve, 7, 8...
... Raw solution supply pipe, 9 ... Circulation pump, 10 ... Circulation pipe body, 11 ... Water supply pump, 12 ... Liquid supply pipe,
13... Electric conductivity sensor, 14, 28... Liquid level sensor, 15... Liquid supply pump, 16... Supply pipe,
22...control box, 24...electric conductivity sensor, 25...illuminance sensor, 26...drainage tank.

Claims (1)

[Scope of Claims] 1. Supplying a culture solution to a culture medium at a preset time, detecting illuminance at a set time different from the set time, and supplying the culture solution according to the detected illuminance; The amount of culture fluid contained in the culture medium is detected during times other than the regular supply of culture fluid according to each set time, and if the amount of fluid retained is less than a predetermined reference value, A method for supplying a culture solution in hydroponic cultivation, characterized in that the culture solution is supplied. 2 Supplying the culture solution to the culture medium at a preset time, detecting the illuminance at a set time different from the set time, supplying the culture solution according to the detected illuminance, and controlling the supply amount of the culture solution. A method for supplying a culture solution in hydroponic cultivation, characterized in that control is performed according to the amount of solution discharged from a culture medium. 3. A stock solution tank that stores a concentrated stock solution before diluting the culture solution, a solution storage tank in which the diluted culture solution to be supplied to the culture medium is prepared and stored, and a water supply mechanism that supplies water to the solution storage tank. , a timer circuit, a stock solution supply mechanism that has a solenoid valve that is opened by a signal from the timer circuit and supplies the stock solution from the stock tank to the storage tank, and an illuminance sensor that detects the illuminance received by the plants; A culture solution supply mechanism for supplying the prepared diluted culture solution from the solution storage tank to the culture medium; and a culture solution supply mechanism that detects the concentration of the culture solution in the solution storage tank and closes the electromagnetic valve when the culture solution concentration reaches a predetermined concentration. A first electrical conductivity sensor for operation, a liquid level sensor for detecting the liquid level in the liquid storage tank, supply of culture medium to the culture medium at a time preset by the timer circuit, and the set time. A control circuit that controls a culture solution supply mechanism based on a signal from the liquid level sensor in order to detect illuminance with an illuminance sensor at different times and supply the culture solution, and a control circuit that controls a culture solution supply mechanism based on a signal from the liquid level sensor in order to supply the culture solution by detecting the illuminance at a different time. A water supply control circuit for controlling a water supply mechanism that supplies water to a liquid storage tank, and a solenoid valve for a stock solution control circuit that detects the electrical conductivity of the culture solution in the culture medium, and if the detected value is less than a predetermined reference value. In order to correct the concentration of the culture solution by outputting a signal to open the cell and supplying the stock solution until the first electrical conductivity sensor detects that the concentration of the culture solution in the liquid storage tank has reached a predetermined concentration. A second electrical conductivity sensor is provided, and the culture solution contained in the culture medium is retained in the culture medium at times other than the periodic supply of culture solution performed according to each of the above-mentioned set times. A culture fluid supply device for hydroponic cultivation, comprising: a fluid amount sensor that detects the amount of retained fluid and outputs a signal for supplying the culture fluid when the amount of retained fluid is less than a predetermined reference value. 4. A stock solution tank that stores a concentrated stock solution before diluting the culture solution, a solution storage tank in which the diluted culture solution to be supplied to the culture medium is prepared and stored, and a water supply mechanism that supplies water to the solution storage tank. , a timer circuit, a stock solution supply mechanism that has a solenoid valve that is opened by a signal from the timer circuit and supplies the stock solution from the stock tank to the storage tank, and an illuminance sensor that detects the illuminance received by the plants; A culture solution supply mechanism for supplying the prepared diluted culture solution from the solution storage tank to the culture medium; and a culture solution supply mechanism that detects the concentration of the culture solution in the solution storage tank and closes the electromagnetic valve when the culture solution concentration reaches a predetermined concentration. A first electrical conductivity sensor for operation, a liquid level sensor for detecting the liquid level in the liquid storage tank, supply of culture medium to the culture medium at a time preset by the timer circuit, and the set time. A control circuit that controls a culture solution supply mechanism based on a signal from the liquid level sensor in order to detect illuminance with an illuminance sensor at different times and supply the culture solution, and a control circuit that controls a culture solution supply mechanism based on a signal from the liquid level sensor in order to supply the culture solution by detecting the illuminance at a different time. A water supply control circuit for controlling a water supply mechanism that supplies water to a liquid storage tank, and a solenoid valve for a stock solution control circuit that detects the electrical conductivity of the culture solution in the culture medium, and if the detected value is less than a predetermined reference value. In order to correct the concentration of the culture solution by outputting a signal to open the cell and supplying the stock solution until the first electrical conductivity sensor detects that the concentration of the culture solution in the liquid storage tank has reached a predetermined concentration. a second electrical conductivity sensor disposed; a drain tank for collecting the culture liquid flowing out from the culture medium; a liquid level sensor for detecting the amount of drain liquid in the drain tank; A pump controlled by a signal from a liquid level sensor for detecting liquid volume, a circuit for storing the volume of drained liquid, and an output from the memory circuit for the volume of drained liquid to control the set supply amount of culture medium to be supplied to the culture medium. A culture solution supply device for hydroponic cultivation, comprising a solution supply control circuit;