JPH0965783A - Solution culture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reuse a culture solution (discharged solution), which is discharged from a culture medium, after its electric conductivity(EC)-value is adjusted. SOLUTION: The EC-value of a discharged solution recovered from a culture medium 2 is determined. Raw water is added to the discharged solution in an amount corresponding to the determined EC-value in a dilution tank 15 to prepare a dilution solution useful for obtaining a defined EC-value. While the EC-value is being determined, the prepared dilution solution is mixed with raw water or the discharged solution so as to adjust the EC-value at the objective value. Raw materials are added to the adjusted dilution solution in a liquid- supplying unit 24 to prepare a culture solution, and the culture solution is supplied to the culture medium 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for hydroponic cultivation in which a culture solution is supplied to a medium made of rock wool or the like to grow a crop.

[0002]

2. Description of the Related Art Well water or other raw water is added to at least one raw material selected from calcium nitrate, ammonium nitrate, potassium nitrate, potassium dihydrogen phosphate, potassium sulfate, etc. to prepare a culture solution, which is then made with rock wool or the like. The crops are grown by supplying the resulting medium. And
The culture solution (hereinafter referred to as "drainage") collected from the medium is
The supply amount reaches 10% to 15%, and when the raw water is added to the raw material, this waste liquid is mixed to save the raw material and the raw water (JP-A-7-53286).

[0003]

The fertilizer concentration of the culture broth is expressed as the conductivity (EC value) and is supplied to the medium within a certain range, but the effluent has a discharge amount and an EC value of 2 .0-1
Since it varies from 0.0, it is difficult to keep the EC value of the culture within a certain range (for example, 2.0 to 2.4 for "bulk").

[0004]

In order to solve the above problems, the present invention provides an EC for the drainage of a culture solution collected from a medium.
The value is detected, and the amount of raw water corresponding to the detected EC value is added to the effluent in the dilution tank 15 to create a diluted solution with a target EC value, and the EC value is detected in the completed diluted water. While adding raw water or drainage, the EC value is set to the target value, and the diluting solution stored in the target EC value is supplied to the liquid supply unit 2
In Example 4, the raw materials were added to prepare a culture solution, and this culture solution was supplied to the medium as a hydroponic cultivation method.

[0005]

According to the present invention, a crop is transplanted to a medium (or pellets thereon) made of rock wool or the like, and a culture solution is supplied to grow the crop. Since this culture solution is supplied in a slightly larger amount, 10% to 15% thereof is recovered as drainage. The EC value of the collected effluent is measured, and the amount of raw water (EC value of 0 to 0 is adjusted in the dilution tank 15 so as to lower the EC value to a constant value (target value).
0.1) is added. The effluent to which the raw water is added becomes a diluted solution, the EC value is measured again, and a small amount of the raw water or the effluent is added so that the value becomes the target value.

In this way, the diluted water having an EC value within a fixed range is sent to the liquid feeding unit 24, and the raw material is added in the liquid feeding unit 24 to have a constant fertilizer concentration (for example, an EC value of 2.0). ~ 2.4) culture solution is prepared and this culture solution is supplied to the above-mentioned medium.

[0007]

[Effect] According to the present invention, since the effluent which reaches 10 to 15% of the supplied amount is reused as the culture solution, not only the fertilizer (raw material) and the raw water are saved, but also this does not flow out, which causes environmental pollution. rare. Since this effluent is adjusted in advance to a predetermined EC value by adding required raw water according to the EC value, a culture solution having a stable EC value is promptly added by adding a predetermined raw material to the effluent. Can be obtained.

[0008]

An embodiment of the present invention will be described. As shown in FIG. 1, a medium 2 made of rockwool is provided in a house 1, on which a plurality of pellets 3, 3, ... Are placed side by side, and each pellet 3, 3 ,. , 4, ...
... is planted. The drippers 5, 5, ... are inserted into the respective pellets 3, 3, ..., and the culture fluid sent through the pipe 6 is pelleted by the respective drippers 5, 5, ... It is sent to the medium 2 and absorbs it to grow crops 4, 4, ....

The above culture solution is sent in excess of the amount absorbed by the crops 4, 4, ..., And 10% to 15% thereof is recovered as drainage. That is, the drainage received by the pan 7 under the medium 2 is collected in the drainage tank 10 via the EC sensor 8 and the flow meter 9 for measuring the fertilizer concentration by the electric conductivity (EC value). It has become. A raw water tank 11 containing well water and other raw water, an A tank 12 containing a mixed solution of calcium nitrate, ammonium nitrate and chelated iron (Fe330) in a fixed ratio, potassium nitrate, potassium dihydrogen phosphate, potassium nitrate, magnesium nitrate,
A B tank 13 containing a mixed solution of manganese sulfate, zinc sulfate, boric acid, copper sulfate, and sodium molybdate at a constant ratio, and an Acid tank 14 containing a solution for adjusting the PH value of the culture solution are arranged. There is.

A diluting tank 15 is provided, a valve 16,
When 17 is opened, the drainage collected in the drainage tank 10 and the raw water in the raw water tank 11 are supplied. In this dilution tank 15, a water level gauge 18 and a pump 19 are used to circulate the solution (diluted water) therein.
EC sensor 20 and PH sensor 2 for measuring C value and PH value
1 is provided. Diluent control unit (computer) 2
2 is provided, and the measured values of the EC sensor 23 for measuring the EC value of the drainage in the drainage tank 10, the water level gauge 18 and the EC sensor 20 are input, and the outputs thereof output the valves 16, 1.
7 is opened and closed as follows.

The EC value of the drainage varies widely from 2.0 to 10.0, but the EC sensor 23 measures the actual EC value of the drainage collected in the drainage tank 10. Then, the diluted liquid is input to the diluted liquid control unit 22. The diluted liquid control unit 22
The valve 16 is opened to supply the drainage into the dilution tank 15, and when the water level gauge 18 reaches a predetermined amount, the valve 16 is opened.
Close. Next, open the valve 17 and add the raw water to the drainage to make diluted water. If the target EC value of this diluted water is set to 0.5, for example, the amount of drainage measured by the water level gauge 18 will be measured. With the EC value measured by the EC sensor 23, the amount of raw water to be added is determined by a simple calculation. The valve 17 closes when the calculated amount of raw water is supplied to the dilution tank 15.

After that, the EC sensor 20 measures the actual EC value of the diluted solution formed by mixing the drainage liquid and the raw water, and if it is higher than the set target value, the valve 17 is opened to add the raw water, and the value is low. Then, the valve 16 is opened to add drainage, and if necessary, this is repeated until the EC value of the diluent in the dilution tank 15 falls within the target value range. A liquid supply unit (mixer) 24 is provided to supply the diluted solution in the diluted tank 15, the solution (raw material for fertilizer) in the A tank 12 and the B tank 13, and the solution in the Acid tank 14. The respective liquids are mixed in the liquid supply unit 24 to become a culture liquid, and flow into the pipe 6 via the pump 25, the flow meter 26 and the valve 27. A liquid supply control unit (computer) 28 is provided, the measured values of the EC sensor 8, the flow meter 9 and the flow meter 26 are input, and valves 29, 3 are provided.
0, 31 and the pump 25 and the valve 27 are output. That is, when the supply time of the culture solution comes, the valves 29 and 30 are opened to supply the raw materials in the A tank 12 and the B tank 13 to the liquid supply unit 24 at a constant ratio, the pump 25 is operated, and the valve 27 is opened. The culture solution opened and supplied in the liquid supply unit 24 is supplied to the medium 2. Then, the EC value of the discharged liquid is measured by the EC sensor 8, and when the value is high, the opening degree of the valve 27 is increased to increase the supply amount of the culture liquid. Then, the supply amount of the diluting solution increases and the EC value of the culture solution decreases. On the contrary, when the EC value measured by the EC sensor 8 is low, the opening degree of the valve 27 is decreased to decrease the supply amount of the culture solution. Then, the supply amount of the diluting solution decreases and the EC value of the culture solution increases.

A pH sensor is provided in the liquid supply unit 24, and the valve 31 is opened / closed according to the measured value to adjust the PH value of the culture solution to 5.5. Further, in the above, when adjusting the EC value of the culture solution, the EC value of the drainage measured by the EC sensor 8 was used. However, an EC sensor is provided in the liquid supply unit 24, and the valves 30, 31 and By opening / closing the valve between the dilution tank 15 and the liquid supply unit 24, the EC value of the culture liquid can be adjusted to 2.0 (2-2.4).

FIG. 2 shows another embodiment. That is, the C tank 32 is added, and the solution therein is supplied to the liquid supply unit 24 via the valve 33. Then, the ratio of calcium nitrate and potassium nitrate in the A tank 12 and the B tank 13 is set to, for example, 2
The mixed solution thus lowered is placed in the C tank 24. Here, the effluent contains a large amount of components containing Ca, No3 and K, and if these are repeatedly reused, there is a risk that the plants will be adversely affected. Here, when the EC value of the drainage is high and the flow rate thereof is high as measured by the EC sensor 8 and the flow meter 9, the liquid supply controller 28
With the output of, the valve 33 throttles the flow path from the C tank 32,
Reduce the inflow of the solution. On the contrary, E of drainage
When the C value is low and the flow rate is low, the flow path is opened and the flow rate of the solution in the C tank 32 is increased. At other times, the flow rate is set to the intermediate value. Then, the component of the fertilizer when using the drainage can be brought closer to the target value.

FIG. 3 shows another embodiment. That is, in addition to the one shown in FIG. 1, the raw water tank 11 and the liquid supply unit 24 are connected by a flow path provided with a valve 34. Then, the diluted solution in the diluted tank 15, the raw water in the raw water tank 11 and the A
The solutions in the tank 12, the B tank 13, and the Acid tank 14 are supplied to the liquid supply unit 24, and these are mixed to make a culture solution.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a block diagram of another embodiment.

FIG. 3 is a block diagram of another embodiment.

[Explanation of symbols]

 2 Medium 15 Dilution tank 24 Liquid supply unit

Claims (1)

[Claims] 1. EC of the drainage of the culture solution recovered from the culture medium 2.
The value is detected, and the amount of raw water corresponding to the detected EC value is added to the effluent in the dilution tank 15 to create a diluted solution with a target EC value, and the EC value is detected in the completed diluted water. While adding raw water or drainage, the EC value is set to the target value, and the diluting solution stored in the target EC value is supplied to the liquid supply unit 2
The raw materials are added in 4 to make a culture solution, and this culture solution is used as the medium 2
Method of supplying hydroponics to.