JPH02273129A - Manuring control method in nutriculture - Google Patents

Abstract

PURPOSE:To carry out manuring practice adapted to conditions of a plant body and root by controlling feed liquid amount and nurturing liquid concentration of nutriculture according to change of transpiration amount of culture crop and change of oxygen consumption amount. CONSTITUTION:Feed liquid amount necessary for plant culture or fertilizer concentration of nurturing liquid or the feed liquid amount and fertilizer concentration are controlled using a manuring control computer system provided with a barometer for detecting state of weather, weather display switch operated by receiving signals from the barometer, etc., according to the change of environmental conditions of light amount, rearing stage, dissolved oxygen amount, etc., by time or regardless of time and then the controlled nurturing liquid is fed to a culture bed.

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention tracks the amount of liquid supplied and the concentration of the nutrient solution in hydroponic cultivation, that is, hydroponic cultivation, in accordance with changes in the amount of transpiration and changes in the amount of oxygen consumed by cultivated crops. This invention relates to a control method for fertilizer management that adjusts and controls fertilizers.

(Prior Art) In hydroponic cultivation, in general, when the light becomes stronger, the water temperature also rises as the temperature rises. At this time, root respiration gradually increases and the demand for oxygen becomes stronger. Therefore, on a sunny day, the amount of photosynthesis and transpiration will increase, whereas on a cloudy and rainy day, the amount of photosynthesis and transpiration will decrease.

For this reason, on cloudy and rainy days, the products of photosynthesis (a)
The supply of nutrients to the roots is suppressed, the absorption of nutrients by the roots is reduced, and the amount of nutrients sent to the leaves, which are the aboveground parts, is reduced. It is a well-known fact that as a result, photosynthesis is further suppressed, and a vicious cycle repeats.

During photosynthesis, sugar is synthesized in one leaf, and the sugar descends to the roots and is used as an energy source, promoting rooting and development.At the growing point, the synthesis of the plant hormone auxin is promoted; It promotes rooting and development similar to the effect.

In this way, root activity and activation are supported by the supply of photosynthetic products from the leaves and the supply of hormones from the growing point.

However, as mentioned above, although photosynthesis is affected by changes in weather, conventional fertilizer management for hydroponic crops is carried out using the same control system for both sunny weather and cloudy/rainy weather. There is.

This conventional control system performs control to change the amount of liquid supplied based on the hypothesis that the amount of solar radiation per day is equal to the amount of transpiration from the leaf surface of the crop.

In addition, this control system is used in fertilizer management with an emphasis on maintaining plant homeostasis by using it in conjunction with the recently developed complex control liquid supply management.

(Problem to be solved by the invention) However, in reality, as mentioned above, there is a fact that the amount of photosynthesis and transpiration is high in clear weather conditions, but less on days with heavy rain; The amount of photosynthesis in the mouth is extremely low, the plant body is weak, and the absorption of nutrients and water from the roots is reduced. Also, although the roots are renewing, they are not always in a healthy state, and fertilization management needs to be tailored to the situation. In this case, if control is performed using the above-mentioned control system based on the hypothesis that the amount of solar radiation per day is equal to the amount of transpiration, the management will be inconsistent with the state of the roots, resulting in a problem.

The inventor conducted repeated experiments and research on this problem, and found that the relationship between the amount of dissolved oxygen consumed by roots and light is as follows.
As shown in Figure 2, the amount of oxygen consumed during cultivation under constant light on a rainy day shows almost no change depending on the time of day (
The amount of oxygen consumed during cultivation under high illuminance under clear weather conditions changes depending on the time of day (A in the same figure), and a curve similar to the curve of light ebb and flow (dashed line in A in the same figure) is drawn. The consumption amount also increased and decreased, and it was found that the roots were activated at that time.

In addition, even in cultivation under constant light on a rainy day, it was observed that if a low concentration nutrient solution was used, the oxygen consumption would follow a curve (C in the same figure).

Therefore, the present invention was devised to solve the problems of the above-mentioned conventional technology based on new findings obtained from the above-mentioned experiments and research. The purpose of the present invention is to provide a novel fertilizer management method in hydroponic cultivation that can perform appropriate fertilizer management that is immediately responsive to the cultivation of plants.

(Means for Solving the Problems) In order to achieve the above object, the present invention firstly provides fertilizer management for hydroponic plants, in which the amount of nutrient solution necessary for cultivating plants is reduced by 1. The method is characterized in that the amount of light necessary for photosynthesis and the amount of dissolved oxygen consumed by root respiration are adjusted and supplied to the cultivation bed depending on the time of day or regardless of the time of day. Fertilization management is the process of adjusting the concentration of fertilizer in the nutrient solution required for plant cultivation at any given time or at any time, depending on changes in environmental conditions such as the amount of light, the growth stage, and the amount of dissolved oxygen. The third aspect is the fertilization management of hydroponic plants, in which the amount of nutrient solution and the concentration of nutrient solution necessary for cultivating plants are controlled at one time or at different times. Regardless, the nutrient solution is adjusted according to changes in environmental conditions such as the amount of light, growth stage, amount of dissolved oxygen, etc., and the nutrient solution is supplied to the cultivation bed.

(Function) According to the first configuration means, when the amount of photosynthesis and transpiration is small, such as on a rainy day, a constant amount of liquid can be supplied regardless of the time of day, and the clear weather port When the amount of photosynthesis and transpiration are large, as in the example above, the amount of liquid supplied can be changed depending on the time of day.

According to the second configuration means, when root activity and activation are slow, such as on a rainy day or on a sunny day the next day, the nutrient solution is adjusted to a constant low concentration regardless of the time of day. In addition, when root activity and activation are active, such as during sunny days, a nutrient solution with varying concentrations depending on the time of day is adjusted and supplied, and as mentioned above, root activity and activation are increased. When it is slow, it is possible to adjust and supply a nutrient solution with a low concentration that changes depending on the time of day.

According to the third configuration means, the amount of the nutrient solution supplied and the concentration of the nutrient solution are combined, and the nutrient solution is adjusted and supplied immediately in response to actual cultivation that reflects weather conditions and plant conditions, thereby achieving the ideal solution. Fertilization management can be performed.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram illustrating an overview of a method for implementing the method for controlling fertilization in hydroponic cultivation of the present invention.

As shown in the figure, the cultivation control system l of this embodiment is as follows:
Barometer to detect weather conditions 2. A weather display switch 3 that operates in response to a signal from the barometer 2, a computer 4 that determines the amount and concentration of nutrient solution to be supplied based on the signal from the weather display switch 3, and issues instructions; A pump 5 operated by a liquid signal, connected to this pump 5 to introduce liquid supply, and the computer 4
a supply liquid tank 7 comprising means 6 for sending a concentration signal of the supply liquid to;
A fertilizer tank 10 connected to the liquid supply tank 7 by a pipe 9 equipped with a solenoid valve 8, a pipe 11 connected to introduce raw water, a cultivation bellow (12) to which the liquid is supplied by the pump 5, and this cultivation A liquid level sensor 1 that collects drained liquid from the bed 12 via a pipe 14 equipped with a flow meter 13
5 and a nutrient solution recovery tank 16.

In this embodiment, the amount of liquid supplied by the computer 4 to the pump 5 is set for 100% clear skies, 50% cloudy skies, and 30% rainy/snowy skies. The amount of drained liquid detected by the liquid level sensor 15 (
Recovery amount/liquid supply amount x 100) is 20% or more, 20-5%
, each adjustment method in the case of 5% or less is as follows.

That is.

■When the liquid discharge volume is 20% or more, the liquid supply amount for 100% on clear and sunny days is changed to the liquid supply amount for 50% on cloudy days.
Or 100% liquid supply amount on clear and sunny days, 30% on rainy or snowy days.
Adjust the liquid supply amount by changing the amount of liquid supplied, respectively. ■When the drain amount is 20% to 5%, the amount of liquid supplied on clear and sunny days is 100%. The amount of liquid supplied on cloudy days is 50%. The amount of liquid supplied on rainy and snowy days is 30%. Supply liquid while maintaining the same amount of liquid, and when it is less than 0.5%.

In case of an emergency, regardless of the liquid supply time, continue to supply liquid in the same way as in (2) above. This is the method for adjusting the amount of nutrient solution supplied.

On the other hand, as a means for adjusting the concentration of the nutrient solution, a PH sensor 17 is used.
and an EC sensor 18 are provided in the liquid supply tank 7, and these transmit the level of the concentration of the supplied liquid to the computer 4, and the computer 4, which judges the suitability of the concentration level, sends the raw water pump 19.
The rotation speed of the fertilizer pipe 9 or the throttle of the solenoid valve 8 of the fertilizer pipe 9 is adjusted.

The EC sensor 18 detects the concentration of the salts as a whole, and the pH sensor 17 detects the concentration of each individual component.

In this embodiment, automatic variation of EC settings is performed as follows.

That is, when the computer 4 instructs the pump 5 to supply 100% of the liquid in a clear day.

Automatic variation of EC setting is ±0.1 When commanding 50% fluid supply amount on cloudy days, automatic fluctuation of EC setting is ±0.1, commanding 30% fluid supply amount on rainy or snowy days. At that time, that E
The automatic variation of C settings is ±0.2. In this case, + means winter time and - means summer time.

Next, the operation of the embodiment configured as described above will be explained.

If the weather is clear and sunny on a certain day for the plants that are being hydroponically cultivated in the cultivation bed, this will be automatically detected by the barometer 2, and the detection signal will turn on the clear and sunny switch 3a. This is input to the computer 4. The computer 4 that received the input signal to that effect has a clear sky/clear sky of 100.
The pump 5 is instructed to supply a liquid amount of % to the cultivation bellow 12, and the pump 5, which operates based on the command, supplies the liquid from the supply tank 7 to the cultivation bellow 12.

The plants growing in the cultivation bed 12 perform photosynthesis (carbon assimilation), which uses light to synthesize sugar using water taken in from the roots and carbon dioxide taken in from the leaves. The more active the water, the more water will be taken in through the roots and the more water will evaporate from the air vents. At this time, the amount of waste liquid collected from the cultivation het 12 into the nutrient solution recovery tank 16 is 20 to 5%, and the amount of liquid supplied to the cultivation bellow 12 is maintained and supplied as it is. Ru.

Photosynthesis takes place during the day, and becomes more active as the light gets stronger.
As the temperature and water temperature rise, root respiration gradually increases and oxygen consumption increases.

The relationship between dissolved oxygen consumption by roots and light during this period (under high illuminance) is as shown in Figure 2 (A), where the oxygen consumption increases and decreases in a curve similar to the curve of light decay (dashed line). The roots are revitalized.

On the other hand, in the case of clear skies and clear skies, the amount of photosynthetic acid and transpiration is low before the light intensity reaches its peak or at a weak point after it reaches its peak, and therefore the nutrient solution supplied to the cultivation vera) 12 is The amount of liquid drained into the recovery tank 16 is also 20% or more. In this case, the flow meter 13 or liquid level sensor 15 acts to notify the computer 4 of this, and the computer 4 instructs the computer 4 to change the liquid supply amount to 50%, which corresponds to cloudy days, or 30%, which corresponds to rainy or snowy days. Then, adjust the amount of liquid supplied to a smaller amount.

In addition, if the weather on a certain day is cloudy, rainy, or snowy from the beginning, the barometer 2 detects this and turns on the corresponding cloudy weather switch 3b or rainy/snowy weather switch 3c, which is transmitted to the computer 4. The computer 4 instructs the pump 5 to supply 50% of the corresponding liquid supply amount on cloudy days or 30% of the liquid supply amount on rainy/snowy days, and the pump 5 accordingly supplies the corresponding liquid supply amount to the cultivation bella). Supply to 12.

At this time, since the amount of liquid drained from the cultivated pet 12 to the nutrient solution recovery tank 16 is 20% to 5%, the liquid supply is continued in that state from beginning to end.

In addition, when supplying any amount of liquid, the amount of drained liquid is 5%.
In the following cases, as an emergency, the current state will be maintained and liquid supply will continue regardless of the liquid supply time.

As mentioned above, when cultivating under constant light on a rainy day, the amount of water supplied is not changed because the amount of photosynthesis and the amount of transpiration are small, as shown in Figure 2 (B).
), there is almost no change in the amount of oxygen consumed.The reason is that the amount of waste water collected in the nutrient solution recovery tank 16 is
% or more. In other words, roots are not as active under constant light cultivation as they are under high light cultivation.

However, even under constant illuminance, a curve of oxygen consumption appears when the nutrient solution is at a low concentration, as shown in Figure 2 (C).

This concentration control adjustment is performed by the EC sensor 18 and the pH sensor 1.
7 detects the overall salt concentration and individual concentrations, thereby performing complementary and balanced concentration adjustment.

In other words, depending on the time of day or at any time, the salts contained in the supplied liquid will be adjusted depending on the external conditions such as temperature and light dose, and the internal conditions such as the type of plant, physiological state, and growth stage. An EC sensor detects the overall concentration, and a pH sensor detects excess or deficiency of physiologically acidic fertilizer.

According to the above embodiment, fertilizer management for actual cultivation is automatically performed in close contact with plant growth factors.

(Effects of the Invention) In summary, according to the present invention, external conditions such as temperature and light dose that govern plant growth and 1. This fertilizer control method adjusts the supply amount and concentration of nutrient solution depending on the time of day or at any time in response to both the growth stage of the plant and its internal conditions such as physiological status. Fertilization management can be carried out in response to the condition of the plant's body and roots, and unlike conventional fertilizer control based on theoretical hypotheses, fertilizer management control for actual cultivation has been established that is closely related to external and internal conditions. It is. Therefore, the effect is that healthy plants can grow.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an overview of a system for carrying out the method for controlling fertilization in hydroponic cultivation of the present invention, and FIG. 2 is a chart comparing the respiration of roots of plants in hydroponic cultivation according to weather conditions. l... Fertilization management system, 2... Barometer, 3...
Weather display system. 6... Means for sending a concentration signal 27... Liquid supply tank, 8
...Solenoid valve, 9...Fertilizer pipe, 10...Fertilizer tank, 12...Cultivation bed, 13...Flow meter 215
...Liquid level sensor, 16...Recovery tank, 17...
pH sensor, 18...EC sensor,

Claims (3)

[Claims] (1) Fertilization management for hydroponic plants, in which the amount of nutrient solution necessary for plant cultivation is adjusted depending on the time of day or regardless of the time of day, and the amount of light necessary for photosynthesis and the dissolved oxygen consumed by root respiration. A method for controlling fertilizer in hydroponic cultivation, which is characterized by adjusting the amount according to the growth and development and supplying it to a cultivation bed. (2) Fertilization management for hydroponic plants, in which the concentration of fertilizer in the nutrient solution required for plant cultivation is adjusted depending on or regardless of the time of day, depending on changes in environmental conditions such as light dose, growth stage, amount of dissolved oxygen, etc. A method for controlling fertilizers in hydroponic cultivation, characterized by adjusting the nutrient solution accordingly and supplying the nutrient solution to a cultivation bed. (3) Fertilization management of hydroponic plants, which includes controlling the amount of nutrient solution and fertilizer concentration necessary for plant cultivation, depending on or regardless of the time of day, the amount of light, the growth stage, the amount of dissolved oxygen, etc. A fertilizer control method in hydroponic cultivation, characterized by adjusting the nutrient solution according to changes in environmental conditions and supplying the nutrient solution to a cultivation bed.