JPH0533008B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a plant cultivation nutrient solution control device used in hydroponic cultivation and the like, and particularly relates to optimization of the supply amount of plant nutrient solution.

[Conventional technology]

In contrast to conventional soil cultivation, which uses soil to cultivate plants, plants are planted in an artificial culture medium such as fibrous materials, and nutrients such as fertilizers necessary for growth are dissolved in water. There is a culture medium cultivation method in which cultivation is carried out by supplying a nutrient solution. Compared to soil cultivation, this type of culture medium cultivation has excellent characteristics such as being more hygienic, allowing the optimal growth conditions to be set for each cultivated plant, and being easier to manage cultivation. It is extremely important to manage the supply time, supply amount, etc. of the nutrient solution. FIG. 4 shows an overview of a general hydroponic method for growing plants. In this hydroponic cultivation method, a nutrient solution is added to the nutrient solution mixing and diluting device 2 along with dilution water Wr such as agricultural water.
A highly concentrated nutrient solution (hereinafter referred to as undiluted solution M) containing dissolved fertilizer, etc. as the basis of Wm is supplied from the undiluted solution tank 4, and this undiluted solution M is mixed with dilution water Wr.
By diluting the concentration of , a nutrient solution Wm with a fertilizer concentration suitable for plant cultivation is obtained. Then, this nutrient solution Wm is sent to the cultivation area 10 via a nutrient solution supply device 6 consisting of a pressure pump, a filter, etc., and a supply pipe line 8. In the cultivation area 10, a plurality of branch pipes 12 attached to the supply pipe line 8 are arranged in the vicinity of the bed 16 in which the plants 14 are planted, and a drip nozzle 18 as a supply nozzle is connected to each branch pipe 12 for each plant. will be established. Therefore, the nutrient solution Wm pumped through the supply pipe 8 is
From the drip nozzle 18 to the plant 1 via the branch pipe 12
It is dripped and supplied in the vicinity of 4.

[Problems to be solved by the invention]

In such a hydroponic cultivation method, it is necessary to control the nutrient solution Wm by setting the optimal supply time and supply amount for the plants 14, and the supply time and supply amount differ for each plant 14. Moreover, since they vary greatly depending on the growth state and weather conditions such as solar radiation, it is necessary to set the supply time and amount while referring to growth data and weather data each time. Conventionally, the supply control of the nutrient solution Wm has been carried out by, for example, providing a valve in the supply pipe and opening the valve at regular time intervals to send the nutrient solution Wm to the cultivation area. In this method, even if the amount of nutrient solution Wm required by plants changes due to changes in the amount of sunlight, etc., the amount of nutrient solution Wm supplied remains constant, and the amount of nutrient solution is designed to prevent plants from dying due to insufficient supply. The maximum supply amount (supply amount during clear weather) is set. For this reason,
On cloudy or rainy days, the amount of nutrient solution Wm supplied is greater than the optimum supply amount, which is wasted, and the amount of water exceeds the optimum amount, which may have an adverse effect on plants. In addition, there is a risk that the supply of the nutrient solution Wm will be insufficient due to a shortage of dilution water Wr or a malfunction of the pressure pump, etc., which requires the administrator to monitor the supply status of the nutrient solution Wm. Therefore, an object of the present invention is to provide a plant cultivation nutrient solution control device that controls and optimizes the amount of nutrient solution supplied in accordance with weather conditions.

[Means to solve the problem]

The plant cultivation nutrient solution control device of the present invention has a dilution water supply line (supply pipe line 2) to which dilution water (Wr) is supplied.
2) and a nutrient solution supply path (supply path 34) that is to supply nutrient solution (Wm) to the culture medium (cultivation area 10), receives dilution water from the dilution water supply path, and receives dilution water from the dilution water supply path. A nutrient solution mixing and diluting means ( A nutrient solution mixing diluter 26, a mixing and diluting tank 27), and a first stock solution tank 28 for storing the first stock solution to be supplied to the nutrient solution mixing and diluting means.
A, a second stock solution tank 28B that stores the second stock solution to be supplied to the nutrient solution mixing and diluting means, and installed in a stock solution supply path between the first stock solution tank and the nutrient solution mixing and diluting means. installed in a stock solution supply path between a first quantitative discharger 30A that supplies the first stock solution to the nutrient solution mixing and diluting means, and the second stock solution tank and the nutrient solution mixing and diluting means. a second supplying the second stock solution to the nutrient solution mixing and diluting means;
a fixed-quantity dispenser 30B, and a flow rate sensor 2 installed in the dilution water supply path to detect the flow rate of the dilution water.
4, a pressure feeding means (pressure pump 36) which is installed in the nutrient solution supply path and pumps the nutrient solution of the nutrient solution mixing and diluting means to the culture medium side; A pressure sensor 40 detects the pressure of the nutrient solution in the channel, a solar radiation sensor 42 detects the solar radiation on the medium, flow rate data from the flow rate sensor, and concentration data set in advance according to the cultivation conditions. The supply amount of the first or second stock solution to be supplied to the nutrient solution mixing and diluting means is calculated, and the amount of the first or second stock solution is calculated according to the calculation result.
The metering dispenser is operated, and the first amount of the supplied amount is
or a nutrient solution mixing control unit 32 that supplies a second stock solution or both stock solutions to the nutrient solution mixing and diluting means, and a nutrient solution supply data set according to the cultivation conditions of the plants to be cultivated to the solar radiation data from the solar radiation sensor. A weather condition correction calculation unit 241 is installed, and the corrected supply amount obtained by this weather condition correction calculation unit is compared with the flow rate data from the flow rate sensor, and the flow rate data to be supplied to the medium side is compared. A comparison calculation unit 242 is installed to calculate the supply time of the nutrient solution, and drives the pressure feeding means based on the supply time obtained by the comparison calculation unit, and also uses the flow rate data and pressure data from the pressure sensor. The present invention is characterized by comprising a nutrient solution supply control section (a nutrient solution supply control device 20) in which a supply abnormality detection section 47 for detecting an abnormality in the supply of the nutrient solution to the culture medium is installed.

[Effect]

According to this cultivation nutrient solution control device, the supply time t and supply amount Wmq of the nutrient solution Wm are set according to the plant 14, and the supply amount Wmq of the nutrient solution Wm is controlled according to the amount of solar radiation S. 14 and the amount of solar radiation S, the supply amount Wmq of the nutrient solution Wm is optimized. Since abnormalities are detected by detecting the nutrient solution pressure Pwm and the supply amount Wmq of the nutrient solution Wm supplied to the cultivation area 10, insufficient supply of the nutrient solution Wm to the cultivation area 10 can be prevented. . By the way, the weather condition correction calculation unit is means for calculating the supply amount Wmq according to the solar radiation amount S based on the supply amount setting value Xmq per unit solar radiation amount and the measured solar radiation amount S. Here, the supply amount setting value Xmq is
It is not a fixed value, but is set based on the degree of plant growth and high/low supply. Further, the comparison calculation unit calculates the supply time Ts by performing a comparison calculation based on the supply amount Wmr from the weather condition correction calculation unit and the flow rate signal Vwr from the flow rate sensor. Then, through the comparison calculations of the weather condition correction calculation section and the comparison calculation section, the supply amount Wmq is calculated from the supply amount setting value Xmq per unit solar radiation considered at a certain time and the solar radiation amount S, and based on this, The pump supply time Ts can be calculated from the flow rate signal Vmr from the flow rate sensor, and the pump is driven during that time.

【Example】

FIG. 1 shows an embodiment of the plant cultivation nutrient solution control device of the present invention. For example, agricultural water such as groundwater or rainwater is used as the dilution water Wr for obtaining the nutrient solution Wm of a specific concentration. This dilution water Wr is continuously supplied from a tank (not shown) through the supply pipe 22, but at some point along the supply pipe 22, there is a
Flow rate sensor 2 is used as a flow rate detection means to detect wr.
4 is installed, and the flow rate wr of the dilution water Wr is electrically detected by this flow rate sensor 24. Vwr indicates a flow rate signal representing the flow rate wr of dilution water Wr. The dilution water Wr is supplied to a nutrient solution mixing diluter 26 installed as a nutrient solution mixing and nutrient solution diluting means for mixing with the stock solution M. First and second stock solution tanks 28A and 28B are installed as stock solution storage means for storing first and second stock solutions Ma and Mb to be supplied to the nutrient solution mixing diluter 26, and these stock solution tanks 28A, The stock solutions Ma and Mb of 28B are
The nutrient solution is supplied to the nutrient solution mixing diluter 26 via first and second quantitative dischargers 30A and 30B, which serve as electrically controlled stock solution supply means. Stock solution Ma, Mb
For example, the necessary amount of the stock solution is supplied to the nutrient solution mixing diluter 26 through the metering dispensers 30A and 30B.
Ma or Mb is set to drip by gravity or a certain pressure. Then, the flow rate signal obtained by the flow rate sensor 24
Vwr is applied to a nutrient solution blending control section 32 installed as a nutrient solution blending control means. This nutrient solution preparation control unit 32 uses the flow rate data obtained from the ever-changing flow rate signal Vwr and the concentration data representing the concentration Xn set as necessary to obtain the concentration Xn. The stock solution amount mn is calculated, and the stock solution supply drive signals Va and Vb necessary to supply the stock solution amount mn are outputted to each metering dispenser 30A, 30.
Add to B. The operation time of the fixed quantity dispensers 30A, 30B is controlled, and the fixed quantity dispensers 30A, 30B
From the nutrient solution mixing diluter 26, an amount of the stock solution Ma or stock solution Mb, or both, necessary to obtain the set concentration Xn for the flow rate wr of the dilution water Wr is supplied to the nutrient solution mixing diluter 26. The supplied stock solutions Ma and Mb are stirred in the nutrient solution mixing diluter 26 according to the flow of the dilution water Wr to obtain the nutrient solution Wm of the required concentration, which is then used as a nutrient solution supply path on the cultivation field side. It is supplied through supply line 34. In that case, the nutrient solution Wm is pumped by a pressure pump 36 as a pressure feeding means, but the nutrient solution Wm is filtered by a filter 38 and a pressure sensor 40 installed as a pressure detection means. The nutrient solution pressure is detected electrically.
Vpw is a pressure signal representing the pressure for pumping the nutrient solution Wm. The pressure pump 36 is controlled to open and close by the nutrient solution supply control device 20 serving as a nutrient solution supply control section, and is controlled at the supply time t of the nutrient solution Wm and its supply amount.
Control Wmq according to weather conditions to optimize the supply amount Wmq of nutrient solution Wm. That is, the weather condition correction calculation unit 241 adds the set value Xmq of the supply amount of the nutrient solution Wm, and also calculates the amount of solar radiation S from the solar radiation sensor 42 installed as a solar radiation detection means for detecting the amount of solar radiation S to the plants 14. A solar radiation signal Vs is added. Weather condition correction calculation unit 24
1 corrects the set value Xmq according to the amount of solar radiation S,
Find the supply amount Wmq according to the amount of solar radiation S. The required nutrient solution Y for the amount of solar radiation The nutrient solution Wm is stored in section 241.
Correct the supply amount Wmq. The comparison calculation unit 242 compares and calculates the supply amount Wmq from the weather condition correction calculation unit 241 and the flow rate data represented by the flow rate signal Vwr from the flow rate sensor 24, and calculates the amount of the nutrient solution Wm determined by the dilution water Wr. The unit supply time Ts is corrected to set the unit supply time Ts according to the amount of solar radiation S. In this case, since the flow rate of the dilution water Wr can be detected, the supply amount of the nutrient solution Wm according to the amount of solar radiation S can be determined by setting the supply time Ts.
Wmq is uniquely determined. The supply time signal _VTS representing the supply time Ts calculated by the comparison calculation unit 242 in this way is applied to the drive time control unit 243, and in the time signal Vt applied from the clock unit 44, the supply time signal VTS representing the supply time Ts calculated by the comparison calculation unit 242 is applied to the drive time control unit 243. At Ts, the driving time control unit 243:
Drive control signal for driving the pressure pump 36
Output Vt _T. In this case, the clock section 44 outputs a time signal Vt according to the set time Xt. and,
The drive circuit 46 generates a drive output signal Vp according to the drive control signal Vt _T and applies it to the pressure pump 36, and the pressure pump 36 is driven during the period of time to pump the required supply amount Wmq. In addition, the pressure signal Vpw of the pressure feed sensor 40 and the flow rate signal Vwr of the dilution water Wr are applied to the supply abnormality detection unit 47, and
Detects whether there is an abnormality in the supply of nutrient solution Wm from the flow rate. If an abnormality occurs, the nutrient solution Wm supply abnormality signal
_VX is output from the supply abnormality detection section 47 and drives the abnormality alarm 48 to notify the abnormality. The abnormality alarm 48 can be configured with optical means such as a lamp, sound generating means such as a buzzer, and the like. Therefore, according to such nutrient solution control, it is possible to correct and set the necessary supply amount Wmq of the nutrient solution Wm with respect to the amount of solar radiation S, and the supply amount Wm of the nutrient solution Wm
In addition to being able to optimize Wmq, it is also possible to know through a warning that there is a shortage in the supply of the nutrient solution Wm due to an abnormality in the supply of dilution water Wr, a failure in the pressure pump 36, a clogging of the filter 38, or the like. Further, the nutrient solution supply control device 20 of the embodiment is configured with an arithmetic processing device such as a microcomputer,
Supply control of the nutrient solution Wm can be realized. Next, FIG. 3 shows an example of a nutrient solution control device according to the present invention. Assuming that the nutrient solution control is started at time t ₀ on the first day of control, until 0:00 on that day, only the solar radiation amount S is detected and the solar radiation amount correction is not performed, and the necessary supply time t ₁₁ , t ₁₂ Drive the pressure pump 36 for a unit supply time T representing a constant supply amount Wmq from ......
Supply the nutrient solution Wm to the cultivation area 10. Then, solar radiation correction is performed from 0:00 on the next day, and from time t ₂₁ to t ₂₃ , the nutrient solution is adjusted according to the unit supply time T.
Wm is supplied, and at t ₂₄ and t ₂₅ , the supply time Ts becomes shorter as T ₁ and T ₂ according to the amount of solar radiation S, and the supply amount Wmq is optimized. In this case, in Figure 3, A ₁ is from 9 on the first day
Accumulated solar radiation at 11 o'clock [unit: cal/cm ² = ly or MJ/
The same applies below m ² (megajoule/m ² ). ], A ₂ is the cumulative solar radiation from 11 to 13:00 on the first day, A ₃ is the cumulative solar radiation from 13:00 to 15:00 on the first day, A ₄ is the cumulative solar radiation from 15:00 to 21:00 on the first day, A ₅ is the cumulative solar radiation from 11:00 to 21:00 on the first day. B 0 is the cumulative solar radiation of the previous day (first day), B ₁ is the cumulative solar radiation from 9 to 11 on the second day, B ₂ is the cumulative solar radiation from 9 to 11 on the second day, B ₂ is the cumulative solar radiation from 11 to 13 on the second day. _B3 is the cumulative solar radiation from 13:00 to 15:00 on the second day, _B4 is the cumulative solar radiation from 15:00 to 21:00 on the first day, _B5 is the cumulative solar radiation from 21:00 to 0:00 on the second day. represents. Each solar radiation level represents clear skies, cloudy skies, and rainy days, and the cumulative time is different. Since the solar radiation S varies greatly at different times of the day, the detection time is set based on the average cumulative solar radiation. This is to set the supply time t and supply time T of the nutrient solution Wm accordingly. In addition, T ₁ is T × cloudy day supply amount (%) / 100, T ₂
represents T×supply amount during rain (%)/100. In addition,
In the graph of Figure 3, the supply amount per unit solar radiation is
Based on Wmq, the supply amount Wmq is determined by the amount of solar radiation S.
is calculated, but the supply amount Wmq in Figure 3
The value obtained by multiplying the amount of solar radiation by the maximum amount of solar radiation at that time is calculated in advance, and the amount of solar radiation (%) is calculated by comparing the measured amount of solar radiation S at that time with the maximum amount of solar radiation.

【Effect of the invention】

As explained above, according to the present invention, the amount of stock solution required for the flow rate of dilution water is calculated according to the concentration setting of the nutrient solution, and the amount of stock solution is controlled based on the calculation result. The amount of the stock solution can be controlled immediately in response to fluctuations in the flow rate of the nutrient solution, and the nutrient solution mixing diluter installed between the dilution water supply route and the nutrient solution supply route allows the first or second stock solution or both to be mixed with the dilution water. The nutrient solution can be continuously prepared by mixing, and the concentration of the nutrient solution can be freely set to achieve a predetermined concentration.
In hydroponic cultivation, plants can be grown by stably supplying a nutrient solution with an appropriate concentration, and the amount of nutrient solution supplied can be adjusted depending on weather conditions.
Optimization of the nutrient solution for plants can be realized, and the plants can be grown efficiently.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the plant cultivation nutrient solution control device of the present invention, Fig. 2 is a diagram showing the necessary amount of nutrient solution depending on the amount of solar radiation, and Fig. 3 is a diagram showing the amount of solar radiation and the supply status of the nutrient solution. FIG. 4 is a block diagram showing an outline of a general hydroponic cultivation apparatus for plants. Wr... dilution water, Wm... nutrient solution, Ma... first stock solution, Mb... second stock solution, 10... cultivation area (medium), 20... nutrient solution supply control device (nutrient solution supply control part), 22... supply pipe line, (dilution water supply), 24...
...Flow rate sensor, 26... Nutrient solution mixing diluter (nutrient solution mixing and diluting means), 27... Mixing dilution tank (nutrient solution mixing and diluting means), 28A... First stock solution tank,
28B... Second stock solution tank, 30A... First fixed amount dispenser, 30B... Second fixed amount dispenser, 32
... Nutrient solution preparation control unit, 34 ... Supply pipe (nutrient solution supply path), 36 ... Pressure pump (pressure feeding means), 40 ...
... Pressure sensor, 42 ... Solar radiation sensor, 47 ... Supply abnormality detection unit, 48 ... Abnormality alarm, 241 ...
Weather condition correction calculation unit, 242... Comparison calculation unit.

Claims (1)

[Scope of Claims] 1. A dilution water supply channel that is inserted between a dilution water supply channel to which dilution water is supplied and a nutrient solution supply channel that is to supply nutrient solution to the culture medium to receive the dilution water from the dilution water supply channel; A nutrient solution mixing and diluting means for diluting the first or second stock solution or both stock solutions with the dilution water to form a nutrient solution, and supplying the nutrient solution to the culture medium according to the water pressure of the dilution water; a first stock solution tank for storing the first stock solution to be supplied to the nutrient solution mixing and diluting means; a second stock solution tank for storing the second stock solution to be supplied to the nutrient solution mixing and diluting means; a first quantitative discharger installed in a stock solution supply path between the stock solution tank and the nutrient solution mixing and diluting means to supply the first stock solution to the nutrient solution mixing and diluting means; and the second stock solution tank. and the nutrient solution mixing and diluting means, a second quantitative discharge device installed in the nutrient solution mixing and diluting means to supply the second nutrient solution to the nutrient solution mixing and diluting means; a flow rate sensor for detecting the flow rate of the dilution water; a pumping means installed in the nutrient solution supply path and pumping the nutrient solution of the nutrient solution mixing and diluting means to the medium side; and a pumping output side of the nutrient solution mixing and diluting means. a pressure sensor that detects the pressure of the nutrient solution in the nutrient solution supply path; a solar radiation sensor that detects solar radiation on the culture medium; flow rate data from the flow rate sensor; and concentration data that is set in advance according to cultivation conditions. The supply amount of the first or second stock solution to be supplied to the nutrient solution mixing and diluting means is calculated from the above, and the first or second metering dispenser is operated according to the calculation result, and the supply amount is a nutrient solution mixing control unit that supplies the first or second undiluted solution or both undiluted solutions to the nutrient solution mixing and diluting means; A weather condition correction calculation unit is installed to correct the weather condition correction calculation unit using solar radiation data, and the corrected supply amount obtained by the weather condition correction calculation unit is compared with the flow rate data from the flow rate sensor, and the flow rate data for supplying the medium to the medium side is compared. A comparison calculation unit is installed to calculate the supply time of the nutrient solution, and the pressure feeding means is driven based on the supply time obtained by the comparison calculation unit, and the flow rate data and the pressure data from the pressure sensor are A nutrient solution control device for cultivating plants, comprising: a nutrient solution supply control section in which a supply abnormality detection section is installed to detect an abnormality in the supply of the nutrient solution to the culture medium. 2. Claim 1, characterized in that when the supply abnormality detection unit of the nutrient solution supply control unit detects an abnormality in the supply of the nutrient solution to the culture medium, it operates an alarm to notify of the supply abnormality. A nutrient solution control device for cultivating plants as described in 2.