JP2011050293A - Method and device for supplying carbon dioxide microbubble-containing water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for supplying carbon dioxide microbubble-containing water by which sufficient carbon dioxide is efficiently supplied to the vicinity of the leaves of a cultivated plant, and to provide a device for supplying carbon dioxide microbubble-containing water with which sufficient carbon dioxide is efficiently supplied to the vicinity of the leaves of cultivated plants. <P>SOLUTION: The method for supplying carbon dioxide microbubble-containing water includes introducing carbon dioxide and water to a microbubble generation device 2 to generate carbon dioxide microbubble-containing water, and discharging the carbon dioxide microbubble-containing water as minute water droplets to a local portion of the cultivation plant x with a spray nozzle 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an apparatus and a method for supplying carbon dioxide to the local part of a cultivated plant.

Carbon dioxide (CO ₂ ) is a substrate for photosynthesis. In agricultural production, carbon dioxide gas (including CO ₂ -rich air and CO ₂ -dissolved water <carbonated water>) is applied to cultivated plants to keep the cultivation environment CO ₂ concentration high and increase the amount of photosynthesis It is called application of carbon dioxide (CO ₂ ) to achieve yield increase and quality improvement by promoting growth. In general, carbon dioxide gas is supplied through an air duct that extends throughout the cultivation facility.

CO ₂ application is a technology that has been put into practical use in a glass greenhouse with a long period of time when the cultivation facilities are closed and managed in a relatively cool and unradiant region of Europe. A large-scale tomato production plant factory in Japan has also introduced equipment for CO ₂ application. For example, air with a high CO ₂ concentration generated when LPG is burned (CO ₂ concentration is about 1500 ppm) is supplied by air ducts installed throughout the plant factory. This CO ₂ supply duct is installed in parallel with the gutter directly under the gutter where the tomato is grown, and is applied from a small hole having a diameter of about 1 mm on the duct surface.

Patent Document 1 also proposes a CO ₂ application method by spraying carbonated water onto a plant body. According to the summary, a carbonated water production process for producing carbonated water by supplying carbon dioxide gas and water to an in-line mixer interposed in a water supply pipe, and the carbonated water produced in the carbonated water production process are housed. The method of supplying carbon dioxide to the plant is constituted by the spraying process of carbonated water sprayed to the plant in the house or the house. Here, the carbonated water is produced by a bubbling device under high pressure.

JP 2008-199920 A

The biggest challenge of CO ₂ application in large-scale tomato production plant factories in Japan is the establishment of an efficient CO ₂ application method in the summer when ventilation is necessary. Compared to Europe where CO ₂ application technology has been put to practical use in Europe, where the heat is relatively cool and the sun is not strong, the summer in Japan is hot, intense, and humid. It is necessary to ventilate so that it is not too much. The purpose of this is to discharge the excessive heat to the outside of the plant factory by sending the gas that has become hot to the outside of the plant factory and taking in cool outside air. In such conditions, even if the CO ₂ application, CO _2, which is applied to the plant factory will be diffused and discharged quickly to the outside plant factory. Indeed, the timing of performing actively ventilate the summer, also the CO ₂ application system capable of 200 kgCO ₂ ha ^-1 h ^-1 by full capacity, CO ₂ concentration in the plant factory only to about 600~700ppm It is known not to rise.

Assuming that ventilation is performed in summer (current technology cannot maintain no ventilation during summer daytime), CO ₂ gas (or air with high CO ₂ concentration) is introduced into the plant factory by air ducts. ), The applied CO ₂ preferentially passes through spaces where leaves are sparse, such as work passages, and escapes outside the plant factory. As long as such CO ₂ application is continued, it is difficult to raise the cost-effectiveness of CO ₂ application, and the agricultural production form that releases CO ₂ , a greenhouse gas, into the atmosphere is sustainable in the future. It is not desirable for agricultural production.

On the other hand, the invention described in Patent Document 1 creates carbonated water by bubbling CO ₂ gas, sprays this from the top of the created community, sends water droplets with a fan, and efficiently attaches water droplets to plant leaves. I will try to let you. However, when the inventors tried such a method, it was found that the carbon dioxide concentration in the vicinity of the plant leaf could not be sufficiently improved. This is because, when carbon dioxide is suddenly released from the prepared carbonated water and water droplets adhere to the plant body, a considerable amount of carbon dioxide contained in the water droplets disappears.

Furthermore, the conventional CO ₂ application does not consider which part of the plant body wants what amount of CO ₂ and gives CO ₂ to the whole plant community. In this case, the amount of CO ₂ applied becomes too small (loss of CO ₂ fixing opportunity) or excessively (wasted CO ₂ application cost). Therefore, based on the SPA (Speaking plant approach) concept, we evaluate the CO ₂ requirement of plant bodies using various plant biological information measurement technologies (the required CO ₂ amount differs between the upper and lower layers of the tomato community), and It is preferable that an appropriate amount of CO ₂ can be applied to an appropriate part of the plant body at an appropriate timing using environmental information measured in real time.

An object of this invention is to provide the carbon dioxide microbubble containing water supply method and carbon dioxide microbubble containing water supply apparatus which can supply sufficient carbon dioxide efficiently to the vicinity of the leaf of a cultivated plant.

In order to solve the above-described object, the carbon dioxide microbubble-containing water supply method of the present invention generates carbon dioxide microbubble-containing water by introducing carbon dioxide and water into a microbubble generator. It is characterized by discharging the contained water as fine water droplets to the local area of the cultivated plant with a spray nozzle. The size of the carbon dioxide microbubbles is preferably less than 30 μm, and the size of the minute water droplets is preferably 30 μm or more. Furthermore, applying the SPA principle, the plant body is irradiated with light at night, the chlorophyll fluorescence intensity data d (t) from the plant body is measured at different measurement times t, and the chlorophyll fluorescence intensity data d (t) is The maximum fluorescence intensity P = data d (t) at the point P that is the maximum value when arranged in the series is obtained, and the average fluorescence intensity ave () between the minimum point S that appears after the point P and the maximum point M that appears after that point P is obtained. S: M), and the ratio P / ave (S: M) of the maximum fluorescence intensity P and the average fluorescence intensity ave (S: M) is determined. Based on the obtained P / ave (S: M), carbon dioxide is obtained. By controlling the supply of water containing carbon microbubbles, carbon dioxide can be supplied according to the photosynthetic activity of the cultivated plant.

The carbon dioxide microbubble-containing water supply device of the present invention includes a microbubble generator, a carbon oxide supply source that supplies carbon dioxide to the microbubble generator, and carbon dioxide microbubble-containing water generated by the microbubble generator. It has the spray nozzle discharged as a fine water droplet with respect to the local of a cultivated plant, It is characterized by the above-mentioned.

The carbon dioxide microbubble-containing water supply method and the carbon dioxide microbubble-containing water supply device of the present invention can efficiently supply carbon dioxide to the leaves of a plant body. The required amount of carbon dioxide can be supplied according to the amount of carbon dioxide required by the plant.

It is a conceptual diagram which shows the outline | summary of a carbon dioxide microbubble containing water supply apparatus. It is a graph which shows the time change of the density | concentration of a carbon dioxide. It is a graph which shows the relationship between the water content of a carbon dioxide microbubble containing water, and a carbon dioxide discharge amount. It is a graph which shows the time change of the carbon dioxide microbubble containing water spray and the density | concentration of a carbon dioxide. It is a schematic diagram which shows the example of a photosynthetic activity evaluation apparatus. It is a graph which shows the emission spectrum of a LED panel light source, and the transmission spectrum of the long bass filter with which the CCD camera was mounted | worn. It is a graph which shows the irradiation light intensity distribution of the LED panel light source measured using the photon sensor. It is a schematic diagram which shows the example of the display screen of a chlorophyll fluorescence image analysis program. It is a top view which shows typically arrangement | positioning of the measurement object individual | organism | solid in a plant factory. It is a graph which shows the induction curve measured targeting the tomato individual in a plant factory. It is a graph which shows the example of a measurement of the induction curve measured targeting a plurality of tomato individuals in a plant factory. It is a graph which shows the relationship between Chl a / b ratio and P / ave (S: M).

The form for implementing this invention is demonstrated. FIG. 1 is a conceptual diagram showing an outline of a water supply device containing carbon dioxide microbubbles.

The carbon dioxide microbubble-containing water supply device 1 includes a microbubble generator 2, a carbon dioxide supply source 3 that supplies carbon dioxide to the microbubble generator 2, and carbon dioxide microbubbles generated by the microbubble generator 2. And a spray nozzle 4 for discharging water as fine water droplets to the local area of the cultivated plant x. A commercially available product can be used as the microbubble generator 2, and here, a high concentration microbubble generator (Win Corporation, B-02) is used. The carbon dioxide supply source 3 also used a normal carbon dioxide cylinder.

The microbubble generator 2 is connected to a water tank 7 by a water supply pipe 5 and a drain pipe 6. The microbubble generator 2 is housed in the sealed container 8. Here, a transparent plastic bag was used as the sealed container 8. An outlet of a carbon dioxide supply tube 9 attached to the carbon dioxide supply source 3 is inserted into the sealed container 8.

Carbon dioxide gas sent from the carbon dioxide supply source 3 to the carbon dioxide supply tube 9 enters the sealed container 8 and is taken into the microbubble generator 2 through the carbon dioxide intake 10. The water in the water tank 7 is taken into the microbubble generator 2 by the water supply pipe 5. The microbubble generator 2 generates carbon dioxide microbubbles having a diameter of 30 μm or less, generates water containing carbon dioxide microbubbles, and sends the water to the water tank 7 through the drain pipe 6. Water circulates through the water supply pipe 5 and the drain pipe 6, and carbon dioxide microbubbles are created in the water tank 7. According to the apparatus of this example, the microbubble generator 2 is continuously operated for about 10 minutes while supplying 100% carbon dioxide gas, so that 10 liters or more of carbon dioxide micro is generated using tap water (pH 7.2). Bubble-containing water can be produced. At this time, the pH of the carbon dioxide microbubble-containing water was 4.9, which was weakly acidic. Considering that the pH of commercially available carbonated water for beverages is about 4.4, it can be seen that a large amount of carbonate is produced in the water containing carbon dioxide microbubbles. Moreover, since carbonic acid in water containing carbon dioxide microbubbles is considered to be saturated, it is considered that a large amount of carbon dioxide is also dissolved. By covering the microbubble generator 2 with the sealed container 8 and circulating the water through the water supply pipe 5 and the drain pipe 6, water loss can be minimized and carbon dioxide microbubble-containing water can be produced efficiently.

The water tank 7 is connected to the spray nozzle 4 by a water distribution pipe 11. The water distribution pipe 11 is provided with a power pump 13 and sends the water containing carbon dioxide microbubbles in the water tank 7 to the spray nozzle 4. The spray nozzle 4 discharges fine water droplets, and for example, a nozzle commercially available for fine fog cooling can be used. Further, a solenoid valve 14 may be provided in the water distribution pipe 11.

The carbon dioxide microbubble-containing water supply device 1 is provided with a controller 15 for controlling the spraying of carbon dioxide microbubble-containing water. The controller 15 is connected to the microbubble generator 2, the power pump 13, and the electromagnetic valve 14. Further, a measuring instrument for observing the state of the plant such as a leaf thermometer (thermography), and a measuring instrument for observing the environment such as a thermometer, a hygrometer, and a solar radiation sensor are arranged in the vicinity, and these are also connected to the controller 15. be able to. Furthermore, as described in the examples, a photosynthetic activity evaluation apparatus can also be provided. Alternatively, the power pump 13 and the spray nozzle 4 may be mounted on a carriage and configured as a movable device.

FIG. 2 is a graph showing the change over time in the concentration of carbon dioxide. Using the chamber for measuring the amount of carbon dioxide generated, the time-dependent change in the carbon dioxide concentration in the chamber due to the release of carbon dioxide from the carbon dioxide microbubble-containing water is measured. From this, it can be confirmed that a large amount of carbon dioxide is released from the carbon dioxide microbubble-containing water, and the concentration of carbon dioxide in the chamber is increased. It is also shown that the carbon dioxide concentration in the chamber air is maintained high for a long time.

FIG. 3 is a graph showing the relationship between the amount of water containing carbon dioxide microbubbles and the amount of carbon dioxide released. Here, the total amount released for 3.5 minutes is displayed. The amount of carbon dioxide released increases almost in proportion to the amount of water containing carbon dioxide microbubbles.

FIG. 4 is a graph showing the time variation of the carbon dioxide microbubble-containing water spray and the concentration of carbon dioxide. A relatively large water droplet of 30 μm or more is discharged by the spray nozzle 4 and sprayed directly on the leaf surface of the cultivated plant. At this time, the change in the carbon dioxide concentration around the leaves was measured. Three types of spraying are performed: spraying for 30 seconds at intervals of 2 minutes, continuous spraying for 5 minutes, and spraying for 30 seconds at intervals of 5 minutes. In any case, an increase in the carbon dioxide concentration around the leaves can be confirmed. .

On the other hand, carbon dioxide microbubble-containing water was sprayed above the community of cultivated plants. However, spraying was performed at intervals of 5 to 10 minutes for 30 seconds to 2 minutes, but no increase in carbon dioxide concentration around the leaves was observed. Therefore, it can be confirmed that it is effective to spray the plant body directly. In addition, by supplying the carbon dioxide microbubble-containing water locally in this way, carbon dioxide can be supplied to a specific part of a specific individual even in a large greenhouse, and selectively effective control is possible. Easy to do. Also, it can be applied to outdoor planting other than greenhouses.

Embodiments of the present invention will be described. This is an example in which a photosynthetic activity evaluation apparatus is additionally provided. FIG. 5 is a schematic diagram showing an example of a photosynthetic activity evaluation apparatus. This photosynthetic activity evaluation apparatus 21 includes a computer 22, a surface light source 23 that irradiates light to a plant, and a long-pass filter (not shown) that allows only chlorophyll fluorescence components to pass from light (reflected light and chlorophyll fluorescence) emitted from the plant. And a CCD camera 24 having sensitivity in the infrared region as a photographing device for photographing a chlorophyll fluorescent image of a plant through a long pass filter. Further, a moving carriage 25 is provided on which a computer 22, a surface light source 23, a long pass filter, and a CCD camera 24 having sensitivity in the infrared region are mounted.

The computer 22 is not particularly limited, and a commercially available personal computer or the like can be used. A computer of the controller 15 may be used, or a separate computer may be provided and connected to the controller 15. The computer 22 is installed with a photosynthetic activity evaluation program. In this photosynthetic activity evaluation program, a large amount of information processing is not required, so a small computer is sufficient, and a type called a notebook PC or mobile is convenient for movement.

A 65 cm × 65 cm LED panel light source (Senecom Corp., M5510A) was used as the surface light source 23 for exciting the chlorophyll fluorescence of the plant. In this example, a chlorophyll fluorescence image is picked up using a CCD camera 24 (Allied Vision Technologies GmbH, Stingray F145B ASG) having sensitivity in the infrared region to which a long pass filter (Fuji Film Co., Ltd., SC 70) is attached. FIG. 6 shows the emission spectrum of the LED panel light source (surface light source 23) and the transmission spectrum of the long bass filter. The reflected light component of the surface light source 23 is blocked by the long bass filter, and only the long wavelength chlorophyll fluorescence component is detected by the CCD camera 24 having sensitivity in the infrared region through the long bass filter.

FIG. 7 shows the irradiation light intensity distribution of the surface light source 23 measured using a photon sensor (LI-COR, LI-250A). It was confirmed that the irradiation was relatively uniform (± 11%) regardless of the distance from the light source. The surface light source 23 can project uniform light over a wide range from a short distance.

The CCD camera 24 is connected to the computer 22 by an IEEE 1394b cable. Image data photographed by the CCD camera 24 is transmitted to the computer 22 via an IEEE 1394b cable.

Here, the photosynthetic activity evaluation program will be described. This photosynthetic activity evaluation program is installed in the computer 22, and causes the computer 22 and the CCD camera 24 to act as a photosynthetic activity evaluation apparatus.

According to the photosynthetic activity evaluation program, the computer 22 instructs the CCD camera 24 to take images at predetermined time intervals and transmit the image data to the computer 22.

The pixel data constituting the image can be used as data for obtaining an induction curve, but in this example, one fluorescence intensity data is extracted from one image data. For this purpose, a plant body region is extracted for each image data. What is in a region other than the plant body only reflects light having the same wavelength as the irradiated light, so that the intensity is almost zero on the image taken through the long pass filter. Therefore, the plant body region and other regions can be easily identified with a relatively low threshold. The luminance value of each pixel is compared with a threshold value, and the pixels whose luminance value exceeds the threshold value are counted as pixels in the plant body region, and the luminance values of the pixels are also integrated. By dividing the integrated luminance value by the number of pixels in the plant region, the average fluorescence intensity in the image can be calculated.

By accumulating the obtained fluorescence intensity data d in the order of time, d1, d2, d3,... Dn,. If the imaging interval is Δt, dn is fluorescence intensity data d (t) at time t = n · Δt.

When a series of photographing is completed, fluorescence intensity data d (t) for determining an induction curve of the photographing target plant body is obtained. From this series of fluorescence intensity data d (t), the maximum fluorescence intensity P = data d (t) at the point P that is the maximum value is obtained. Further, the average fluorescence intensity ave (S: M) between the minimum point S appearing after the point P and the maximum point M appearing thereafter is obtained. Then, a ratio P / ave (S: M) between the maximum fluorescence intensity P and the average fluorescence intensity ave (S: M) is obtained. This value is a value for evaluating the photosynthetic activity of the plant body that is the subject of photographing.

Here, as a method for obtaining the average fluorescence intensity ave (S: M), searching for the minimum value S and the maximum value M can be considered. However, the shape of the induction curve is not always constant, and sometimes there is no clear maximum or minimum. Therefore, the following simple and highly practical algorithm was used here.

An induction curve in a plant to be measured and a cultivation environment is measured in advance. Then, it can be seen that the maximum value P, the minimum value S, and the maximum value M appear at substantially the same time in a common plant / cultivation environment. Therefore, these values are stored in the vicinity of the time when the local minimum value S appears as a start time ts in a predetermined time range and the time near the time when the local maximum value M appears as an end time te. Then, the average value of the fluorescence intensity data d (t) corresponding to the time between the start time ts and the end time te is obtained as the average fluorescence intensity ave (S: M).

On the other hand, since the maximum value P often appears relatively clearly, the maximum value of a series of fluorescence intensity data d (t) may be adopted as P. Alternatively, a time P at which a point P having the maximum value appears from an induction curve measured in advance may be determined, and the fluorescence intensity data d (P) at this time P may be used as the maximum fluorescence intensity P.

This embodiment will be described more specifically. The fluorescence image measurement was performed under dark conditions after 1 hour or more after sunset. After manually adjusting the position of the CCD camera 24 so that the growth point of the individual to be measured fits in the image, the LED panel light source (surface light source 23) is operated, and excitation light is irradiated for 30 seconds. Was recorded on the internal hard disk of the notebook PC. The distance between the growth point and the CCD camera was about 60 cm, the shutter speed of the camera was 0.06 seconds, and the frame rate was 15 frames / second.

The recorded chlorophyll fluorescence image was analyzed using an image analysis program created with Visual Basic 6.0. FIG. 8 is a schematic diagram showing an example of a display screen of the image analysis program. The image analysis program automatically extracts the plant body region and calculates the average fluorescence intensity for each image, and outputs an induction curve for each individual.

The LED panel light source, CCD camera and notebook PC are mounted on a manual cart, and the chlorophyll fluorescence image measurement is performed while moving the work passage in the plant factory, and the photosynthetic function diagnosis for the whole community is performed. The measurement was started on December 17, 2008 for a tomato (Salarum lycopersicum L., variety: Momotaro Fight) community cultivated at a solar-powered intelligent plant factory in the Faculty of Agriculture, Ehime University. Chl fluorescence image measurement target individuals were selected so that 60 individuals were uniformly distributed in the plant factory. FIG. 9 is a plan view schematically showing the arrangement of measurement target individuals in the plant factory.

In order to confirm the validity of the diagnostic value obtained by the present invention, the concentration of the chlorophyll (hereinafter referred to as Chl) and the Chl a / b ratio of the plant to be measured were measured. Chl concentration and Chl a / b ratio were measured for 18 individuals (individual circles in FIG. 9) among individuals targeted for Chl fluorescence image measurement. Cut out leaves of 1.15cm in diameter with a cork borer from three leaves collected from each individual, put them in a test tube, and dispense the Chl extract obtained by soaking in DMF for 24 hours in a cool and dark place. , The absorbance A _646.8 , A _663.8 , A ₇₅₀ at _646.8 nm, 663.8 nm, 750.0 nm was measured using a spectrophotometer (Hitachi, Ltd., U-1100), and the equation of Porra et al. (1989) was calculated. Used to calculate Chl a and b concentrations. This equation is as follows.
Chl a amount (μg ml- ¹ ) = 12.00 × (A _663.8 − A ₇₅₀ ) − 3.11 × (A _646.8 − A ₇₅₀ )
Chl b amount (μg ml ^-1 ) = 20.78 × (A _646.8 − A ₇₅₀ ) − 4.88 × (A _663.8 − A ₇₅₀ )

FIG. 10 shows an induction curve measured for a tomato individual in a plant factory. In order to numerically evaluate the change in the shape of the induction curve, the ratio of the Chl fluorescence intensity of P to the average value of the Chl fluorescence intensity between S and M was calculated, and this was expressed as P / ave (S: M). Defined. In order to investigate the time taken from the start of excitation light irradiation to the appearance of S and M, an induction curve was measured for 20 individuals. S was about 13.5 seconds after the start of excitation light irradiation (start time ts), and M was It was found to appear after about 20.7 seconds (end time te). FIG. 11 is a graph showing a measurement example of the induction curve. Based on this result, ave (S: M) was defined as the average value of the Chl fluorescence intensity from 13.5 seconds to 20.7 seconds after the start of excitation light irradiation.

FIG. 12 is a graph showing the relationship between the Chl a / b ratio and P / ave (S: M). A significant correlation (R = 0.82, p <0.05) was confirmed between the two. That is, it was confirmed that the value P / ave (S: M) obtained in the present invention can serve as an index for evaluating the photosynthetic activity of plants. Since the relationship between the composition ratio of Chl a and Chl b and the photosynthetic function is common to other plants that perform photosynthesis, this photosynthesis activity evaluation method was shown to be applicable to various types of cultivated plants.

Based on the evaluation obtained by this photosynthetic activity evaluation method, carbon dioxide can be supplied in accordance with the photosynthetic activity of the plant by controlling the supply of water containing carbon dioxide microbubbles. For example, water containing carbon dioxide microbubbles can be preferentially supplied to a region having a high P / ave (S: M) value or an individual plant. Further, more water containing carbon dioxide microbubbles may be supplied at a time when the value of P / ave (S: M) is high.

This embodiment is an example of carbon dioxide supply based on the SPA principle. In addition, the leaf temperature can be measured by, for example, thermography, and when the leaf temperature exceeds a predetermined value, water containing carbon dioxide microbubbles can be sprayed. As a result, the leaves can be cooled to reduce heat stress, and more carbon dioxide can be supplied when receiving more light, thereby effectively promoting photosynthesis. Further, based on the value of the solar radiation sensor, it can be controlled to spray more carbon dioxide microbubble-containing water when the solar radiation is stronger.

1. 1. Carbon dioxide microbubble-containing water supply device 2. Microbubble generator 3. Carbon dioxide source 4. 4. Spray nozzle 5. Water supply pipe 6. Drain pipe Aquarium 8. 8. Airtight container Carbon dioxide supply tube 10. Carbon dioxide intake port 11. Water pipe 13. Power pump 14. Solenoid valve 15. Controller 21. Photosynthesis activity evaluation device 22. Computer 23. Surface light source (LED panel light source)

Claims (4)

Carbon dioxide microbubbles that introduce carbon dioxide and water into a microbubble generator to produce water containing carbon dioxide microbubbles, and discharge the carbon dioxide microbubble-containing water as fine water droplets to the local area of cultivated plants with a spray nozzle Containing water supply method. The carbon dioxide microbubble-containing water supply method according to claim 1, wherein the carbon dioxide microbubble size is less than 30 μm and the minute water droplet size is 30 μm or more. Point that becomes the maximum value when the plant body is irradiated with light at night, the fluorescence intensity data d (t) from the plant body is measured at different measurement times t, and the fluorescence intensity data d (t) is arranged in time series The maximum fluorescence intensity P at P = data d (t) is obtained, and the average fluorescence intensity ave (S: M) between the minimum point S appearing after the point P and the maximum point M appearing thereafter is obtained, and the maximum fluorescence intensity P The ratio P / ave (S: M) of the average fluorescence intensity ave (S: M) is calculated, and the supply of carbon dioxide microbubble-containing water is controlled based on the obtained P / ave (S: M) The water supply method containing carbon dioxide microbubbles according to claim 1 or 2. A microbubble generator, a carbon dioxide supply source that supplies carbon dioxide to the microbubble generator, and a spray that discharges water containing carbon dioxide generated by the microbubble generator as fine water droplets to the local area of the cultivated plant A water supply device containing carbon dioxide microbubbles having a nozzle.

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