JP2007244242A - Method and system for controlling temperature of culture media in hydroponics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a system each for controlling temperature of culture media easily controlling the temperature of culture media without causing reduction in utilization efficiency of fertilizer. <P>SOLUTION: The system for controlling temperature of culture media in hydroponics 1 is structured as follows: cultivation containers 2 each comprises an outer container provided with a drainage port at a prescribed height and an inner container supported by the outer container and provided with a storing part for culture media, and has slits each making the inside of the outer container communicate with the inside of the storing part at the storing part of the inner container so that culture solution and water supplied to the inner container can be stored in the outer container within the water level up to the position of the drainage port; and a control device 8 alternately supplies the culture solution and the water having prescribed temperature to the cultivation containers 2 respectively via open/close control of a first and second open/close valves 9, 10 to control the temperature of the culture media. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method and system for controlling the temperature of a medium in which plants are planted when hydroponically cultivating plants such as roses and tomatoes.

  In the hydroponic cultivation of plants, there is known a flow-through method in which nutrient solution or water is supplied to a medium such as rock wool planted with plants from a supply pipe or the like serving as a supply means, and the excess is discharged ( For example, see Patent Document 1). In addition, a circulation system in which the supplied nutrient solution is collected in a tank and returned to the supply pipe with a pump to supply the nutrient solution again is often used (see, for example, Patent Document 2).

JP 2002-306000 A JP-A-9-107827

In such hydroponics, it is important to manage the medium temperature in winter and summer because it leads to improvement in quality and yield. In the case of the former flow-through type, using a temperature control device such as a heater leads to an increase in cost. Therefore, it is conceivable to perform temperature control by supplying a large amount of liquid supply or irrigation. However, the amount discharged as a surplus is increased and the use efficiency of the fertilizer is deteriorated, and there is a risk of root rot due to the high humidity of the medium.
On the other hand, in the case of the latter circulation method, the use efficiency of fertilizer is not reduced even if a large amount of liquid supply or brine is used, but there is a problem that infection spreads when pathogenic bacteria enter the circulation liquid.

  Accordingly, an object of the present invention is to provide a medium temperature control method and system that can reduce the risk of infection with pathogens without reducing the fertilizer utilization efficiency, and that enables simpler temperature control of the medium. It is a thing.

In order to achieve the above-mentioned object, the invention according to claim 1 is a method for controlling a culture medium temperature, as a cultivation container for accommodating a culture medium in which a plant is planted, an outer container having an outlet at a predetermined height, A nutrient solution that is supported in the outer container and has an inner container provided with a medium container, and the inner container container has a communication part that communicates the inside of the outer container and the container, and is supplied to the inner container And the temperature of the culture medium is controlled by alternately supplying the nutrient solution and water at a predetermined temperature to the cultivation container at a predetermined interval, using water that can be stored in the outer container at the water level up to the discharge port position. It is characterized by that.
In addition to the object of claim 1, the invention described in claim 2 is a drainage tank that collects nutrient solution or the like that has flowed out from the outlet of the cultivation container, and the water level in the drainage tank reaches a predetermined amount. In addition to drainage means for draining nutrient solution etc. in the drainage tank, in order to supply appropriate nutrient solution etc. according to the weather, according to the number of drainage by the drainage means The supply amount of nutrient solution and water to the cultivation container is changed.

In order to achieve the above-mentioned object, the invention according to claim 3 is a culture medium supported by a culture container, an outer container having a discharge port at a predetermined height, and a culture medium as a medium temperature control system. The inner container is provided with a communication part that communicates the inside of the outer container with the inside of the container, and the nutrient solution and water supplied to the inner container are disposed up to the discharge port position. The control means for controlling the supply means can supply the nutrient solution and water at a predetermined temperature alternately to the cultivation container at predetermined intervals by the supply means, so that the temperature of the medium can be stored. It is characterized by controlling.
In addition to the object of claim 3, the invention described in claim 4 is a drainage tank that collects nutrient solution or the like flowing out from the outlet of the cultivation container, and when the water level in the drainage tank reaches a predetermined amount. And a drainage means for draining the nutrient solution etc. of the drainage tank, in order to supply an appropriate nutrient solution according to the weather, according to the number of times of drainage by the drainage means The supply amount of nutrient solution and water to the cultivation container is changed.

According to invention of Claim 1 and 3, it becomes possible to control a culture medium temperature appropriately by the water of the predetermined temperature supplied alternately with a nutrient solution, the quality of a plant improves, and it leads to the increase in a yield. In addition, since only a certain amount of nutrient solution or the like is secured in the cultivation container due to its structure, the fertilizer is used efficiently, and the medium does not become overhumid and does not cause root rot. In addition, since the fertilizer component of the drainage is reduced, the environmental load can be reduced even if it is a flow-through type. Furthermore, since it is not necessary to circulate the nutrient solution, it is possible to suitably prevent infection with pathogenic bacteria, and it can be expected to be realized at low cost by eliminating the need for additional devices such as a filtration device and a sterilization device.
According to the second and fourth aspects of the invention, in addition to the effects of the first and third aspects, the supply amount of nutrient solution and water is changed according to the number of times of drainage, so that the drainage can be performed in rainy weather. When the amount is large, supply nutrient solution and water is reduced to prevent overhumidity, and when the amount of drainage is low during drying, etc., increase nutrient solution and water supply to prevent deficiency of fertilizer and water. It is possible to respond to the weather.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram illustrating an example of a culture medium temperature control system according to the present invention. The control system 1 includes a plurality of cultivation containers 2, 2. 3 is connected to each cultivation container 2 via branch pipes 5, 5,... And a drainage tank 7 is provided on the downstream side. The drainage pipe 6 and a control device 8 as a control means for controlling the operation of the entire control system 1 are provided. The supply pipe 4 is connected to the drainage pipe 6 on the downstream side, and on the upstream side, the first on-off valve 9 for opening and closing the water supply path from the water supply side, and the nutrient solution from the nutrient solution tank 3 side A second on-off valve 10 for opening and closing the supply path is provided. On the other hand, the drainage tank 7 is provided with a pump 11 as drainage means for discharging the accumulated nutrient solution and water (hereinafter referred to as “nutrient solution”) to the outside. In addition, what is necessary is just to provide the drainage tank 7 for every group of the predetermined number of cultivation containers 2 (for example, about one place per 10a). Moreover, the well-known thing which mixed inorganic components, such as nitrogen, phosphorus, potassium, calcium, and magnesium required for plant growth, with water by predetermined concentration is used for a nutrient solution.

As shown in FIG. 2, the cultivation container 2 has a double structure composed of an outer container 12 and an inner container 13, and the outer container 12 has a deep rectangular shape with an open top surface, and has one longitudinal direction. In the center of the side surface, a discharge port 14 to which the branch pipe 5 is connected is formed slightly below the center of the vertical height, and a circular recess 15 is formed in the center of the bottom.
On the other hand, the inner container 13 has an upper plate 16 whose outer shape is locked to the opening of the outer container 12 and a rectangular box-like shape that bulges downward from the central portion of the upper plate 16 to form a medium containing portion. The upper plate 16 has a mesh shape in which a large number of slits 18 are formed. Further, in the deep bottom portion 17, a cylindrical projection 19 whose tip is fitted to the concave portion 15 of the outer container 12 protrudes from the center of the bottom surface, and the inside and outside of the deep bottom portion 17 communicate with the periphery of the projection 19. The vertical slits 20, 20... As communication portions are formed at equal intervals in the circumferential direction. In addition, a pair of slits 21 and 21 that are communicating portions in the vertical direction are formed symmetrically on the longitudinal side surface of the deep bottom portion 17.

  By housing the inner container 13 so as to cover the outer container 12 from above, the upper plate 16 of the inner container 13 is locked to the opening of the outer container 12 to close the outer container 12, and the deep bottom portion 17 is The protrusion 19 protrudes into the container 12 and fits into the recess 15 and is supported in a stable state. The deep bottom portion 17 of the inner container 13 is filled with a medium such as rock wool, and a predetermined number of plants such as roses are planted.

According to the cultivation container 2, the nutrient solution or the like supplied to the medium in the inner container 13 flows into the outer container 12 through the slit 20 or the slit 21 of the protrusion 19 of the deep bottom portion 17 and is stored in the outer container 12. To do. When the amount of liquid reaches the position of the discharge port 14, it overflows from the discharge port 14 and is discharged to the drain pipe 6 through the branch pipe 5, so that the amount of liquid in the outer container 12 is kept constant. Accordingly, the amount of the nutrient solution or the like is similarly maintained constant in the deep bottom portion 17 that communicates with the outer container 12 through the slit 20, and there is no possibility that the medium is excessively immersed in the nutrient solution or the like. On the contrary, even a small amount of nutrient solution or the like can be reabsorbed to the inner container 13 side through the slit 20.
In addition, supply of nutrient solution etc. to each cultivation container 2 from the supply pipe 4 uses the ejection by a nozzle, or uses the capillary phenomenon by the nonwoven fabric which hang | suspended one end in the supply pipe 4 and the other end to the culture medium side, respectively. It is done.

  The control device 8 includes a known CPU, memory, timer, input unit, display unit, and the like, and alternately performs open / close control of the first and second open / close valves 9 and 10 according to the timer set in the input unit. In addition, when the water level obtained by a water level detection means (not shown) using a float and a contact provided in the drain tank 7 reaches a predetermined value, drain control for operating the pump 11 is executed. Further, as will be described later, the control device 8 controls the supply time of the nutrient solution (hereinafter referred to as “liquid supply time”) and the water supply time (hereinafter referred to as “watering time”) according to the number of times of drainage in the drainage tank 7. The medium temperature control (control method) for changing the temperature can be executed. The temperature and interval of the brine are set so that the temperature of the medium can be reduced in the high temperature period such as summer and the temperature of the medium can be prevented in the low temperature period such as winter. In this case, the interval may be changed between nighttime and daytime.

The culture medium temperature control of the control system 1 configured as described above will be described based on the flowcharts of FIGS. First, on the fertilizer supply side shown in FIG. 3, when the set time set by the timer in S1 is reached, the number of times b of drainage performed in the drainage tank 7 is read in S2. Next, in S3, the pump 11 is operated to drain the nutrient solution or the like from the drainage tank 7. When the drainage is completed, the drainage count is reset to 0 in S4.
And in S5, the 2nd on-off valve 10 is opened, a nutrient solution is poured to the supply pipe 4, and a nutrient solution is supplied to each cultivation container 2. FIG. However, here, it is performed in a time obtained by multiplying a reference time (z seconds) by a value obtained by multiplying a ratio of a preset number of drains a and the number of drains b read in S2 by a correction coefficient c. . Therefore, when the number of times of liquid discharge b is large, the liquid supply time is short (the amount of liquid supply is small), and when the number of times of liquid discharge b is small, the liquid supply time is long (the amount of liquid supply is large). When the calculated liquid supply time has elapsed, the second on-off valve 10 is closed and the supply of the nutrient solution is terminated.

  When the nutrient solution is supplied to the culture medium in this way, in each cultivation container 2, the nutrient solution that has passed through the culture medium is stored together with water at the bottom of the outer container 12 through the inner container 13, and branches when reaching a predetermined fluid amount. It is sent to the drainage tank 7 through the pipe 5 and the drainage pipe 6. When the water level in the drainage tank 7 reaches a predetermined value, the pump 11 is operated and the drainage is performed as described above. This drainage count b is counted in S6, and when the set time is reached, the processing from S1 is performed again. Is repeated.

On the other hand, in the watering side shown in FIG. 4, when the set time is reached in the determination of S11, first, in S12, it is determined whether or not a standby time (w seconds) has elapsed since the immediately preceding liquid supply made in S5 of FIG. The If the time has elapsed, the number of times of drainage b is read in S13 as in the nutrient solution side, and then the nutrient solution and the like are drained from the drainage tank 7 in S14, and the drainage count is counted in S15. Is reset to zero. The reason for waiting for the elapse of the waiting time from the immediately preceding liquid supply is to effectively use the fertilizer supplied to the culture medium without flowing out in a short time.
In step S16, the first on-off valve 9 is opened to perform watering. This irrigation is also performed in a time obtained by multiplying a value obtained by multiplying a ratio of the preset number of drains a and the number of drains b read in S13 by a correction coefficient c by a reference time (y seconds). . Therefore, when the number of times of draining b is large, the watering time is short (the amount of water is small), and when the number of times of draining b is small, the watering time is long (the amount of water is large). When the calculated watering time elapses, the first on-off valve 9 is closed to end watering.

  In addition, even when irrigation is performed, in each cultivation container 2, the water that has passed through the culture medium is stored together with the nutrient solution at the bottom of the outer container 12 through the inner container 13, and reaches a predetermined liquid amount. 5 and the drainage pipe 6 to the drainage tank 7. When the water level in the drainage tank 7 reaches a predetermined value, the pump 11 is operated and drainage is performed. This drainage count b is counted in S17, and the processing from S11 is repeated again at the set time.

  Thus, according to the control system 1 of the said form, it consists of the outer container 12 provided with the discharge port 14, and the inner container 13 provided with the deep bottom part 17 supported in the outer container 12 as the cultivation container 2. The deep bottom portion 17 has slits 20 and 21 that allow the inside of the outer container 12 and the inside of the deep bottom portion 17 to communicate with each other, and the nutrient solution and water supplied to the inner vessel 13 are at the water level up to the position of the discharge port 14. In this case, the nutrient solution and water at a predetermined temperature are alternately supplied to the cultivation container 2 at a predetermined interval, so that the culture medium is supplied with the water at a predetermined temperature supplied alternately with the nutrient solution. Temperature can be properly controlled, plant quality is improved, and yield is increased. In addition, since only a certain amount of nutrient solution or the like is secured in the cultivation container 2 due to its structure, the fertilizer is efficiently used, and the medium does not become overhumid and does not cause root rot. In addition, since the fertilizer component of the drainage is reduced, the environmental load can be reduced even if it is a flow-through type. Furthermore, since it is not necessary to circulate the nutrient solution, it is possible to suitably prevent infection with pathogenic bacteria, and it can be expected to be realized at low cost by eliminating the need for additional devices such as a filtration device and a sterilization device.

  In particular, since the supply amount of the nutrient solution and water to the cultivation container 2 is changed according to the number of times of drainage in the drainage tank 7 from the immediately preceding liquid supply or irrigation water, it is drained in rainy weather etc. Reduce supply of nutrient solution and water to prevent overhumidity when the amount of liquid is large, and increase supply of nutrient solution and water to reduce deficiency of fertilizer and water when the amount of drainage is low during drying. It is possible to respond to the weather such as prevention.

FIG. 5 is a graph showing changes in medium temperature due to irrigation, where a is the water temperature, b is the medium temperature, and c is the medium temperature when no irrigation is performed. In addition, irrigation was performed at 250 ml / min per one cultivation container, and the medium temperature was measured at a depth of 10 cm from the surface of the medium.
As is apparent from this graph, the medium temperature also changes in a manner that follows the change in the irrigation temperature (about 15 ° C. to 23 ° C.), and it can be understood that the medium temperature can be controlled by irrigation.

In the above form, nutrient solution or the like is temporarily stored in the drainage tank and drained at a predetermined water level, but if the liquid supply and irrigation time are not corrected according to the number of drains, The drain tank and pump can be omitted.
In addition, if the supply of water is once stored in a tank like a nutrient solution and then supplied as hot water or cold water at a predetermined temperature by a heating means such as a heater or a hot water supply device or a cooling means, Temperature control can be performed more effectively. Of course, the water is not limited to the water supply, and groundwater can also be used.
Furthermore, the control means is not limited to the control device of the above embodiment, and it may be further simplified, for example, the culture medium temperature control may be executed by a combination of a timer and a pump that is turned on when the timer expires.

On the other hand, in the cultivation container, a plurality of outlets and branch pipes may be provided in each cultivation container, and the position and shape of the slit of the inner container can be changed as appropriate. Of course, the size and shape of the container itself can be changed.
In addition to rock wool, a phenol foam resin can also be used as the medium. Phenolic foamed resin is a medium produced by adding an organic acid and a non-fluorocarbon foaming agent to phenolic resin. The liquid phase ratio at maximum water capacity is about 51%, which is smaller than 85% of rock wool. The gas phase rate is about 44%, and conversely, it has large characteristics compared with 10% of rock wool. Therefore, the oxygen concentration can be suitably maintained, it is difficult to become excessively humid, and root rot can be more effectively prevented. In particular, the combination with the cultivation container having the above-described form having a space between the culture medium and the water storage part is more advantageous for preventing excessive moisture.
In addition, the specific configuration of the control system itself can be changed as appropriate without departing from the spirit of the present invention, such as separately providing pipes for supplying nutrient solution and water, or connecting the supply pipe directly to the cultivation container. It is.

It is the schematic which shows an example of a control system. It is a disassembled perspective view of a cultivation container. It is a flowchart of the liquid supply control of a fertilizer. It is a flowchart of irrigation control. It is a graph which shows the change of the culture medium temperature by irrigation.

Explanation of symbols

1 .... Control system 2 .... Cultivation vessel 3 .... Nutrient tank 4 .... Supply pipe 5 .... Branch pipe 6 .... Drain pipe 7 ... Drain tank 8 ... Control device , 9 .. First on-off valve, 10 .. Second on-off valve, 11 .. Pump, 12 .. Outer container, 13 .. Inner container, 14 .. Discharge port, 16 .. Upper plate, 17. Bottom, 19 ... projection.

Claims (4)

In the nutrient solution culture in which the nutrient solution and water are supplied by a predetermined supply means to the cultivation container that contains the medium in which the plant is planted, the temperature of the medium is controlled,
The cultivation container includes an outer container having a discharge port at a predetermined height, and an inner container that is supported in the outer container and includes a storage part for the culture medium. The outer container is provided in the storage part of the inner container. It has a communication part that communicates the inside and the inside of the accommodating part, and uses the nutrient solution and water supplied to the inner container that can be stored in the outer container at the water level up to the discharge port position,
A method for controlling a medium temperature in hydroponics, wherein the temperature of the medium is controlled by alternately supplying a nutrient solution and water at a predetermined temperature to the cultivation container at predetermined intervals.   A drainage tank that collects nutrient solution etc. flowing out from the outlet of the cultivation container, and a drainage means that drains the nutrient solution etc. in the drainage tank when the water level in the drainage tank reaches a predetermined amount The medium temperature in hydroponics according to claim 1, wherein the supply amount of the nutrient solution and water to the cultivation container is changed according to the number of times of drainage by the drainage means. Control method. Controlling the temperature of the culture medium in hydroponics comprising a cultivation container that contains a culture medium in which plants are planted, a supply means that supplies nutrient solution and water to the cultivation container, and a control means that controls the supply means A system that
The cultivation container is composed of an outer container having a discharge port at a predetermined height and an inner container supported in the outer container and having an accommodating part for the culture medium. The outer container is provided in the accommodating part of the inner container. It has a communication part that allows communication between the inside and the storage part, and the nutrient solution and water supplied to the inner container can be stored in the outer container at the water level up to the discharge port position,
Medium temperature in hydroponics, wherein the control means controls the temperature of the culture medium by alternately supplying nutrient solution and water at a predetermined temperature at predetermined intervals to the cultivation container by the supply means. Control system. A drainage tank that collects nutrient solution etc. flowing out from the outlet of the cultivation container, and a drainage means that drains the nutrient solution etc. in the drainage tank when the water level in the drainage tank reaches a predetermined amount The medium temperature in hydroponics according to claim 3, wherein the supply amount of the nutrient solution and water to the cultivation container is changed according to the number of times of drainage by the drainage means. Control system.

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