JPH06319380A - Plant cultivation method and apparatus for producing plant cultivation water - Google Patents

Abstract

PURPOSE:To improve the quality and yield of a cultured plant and enable the culture of a plant in a high efficiency by using water having a high dissolved oxygen concentration higher than the saturated concentration in l atm air atmosphere by a specific amount at the culture temperature. CONSTITUTION:The water-preparation apparatus is provided with a membrane module 10 containing a gas-permeable and liquid-impermeable membrane, an oxygen-concentrating apparatus 16 to produce an oxygen enriched air having an oxygen concentration of >=40%, a pipe 23 for introducing stock water 11 and connected to a side of the membrane module 10 and a gas-inlet port 8 connected to the other side of the membrane and to a line for introducing an oxygen-enriched air produced by the oxygen concentrating apparatus 16. The dissolved oxygen concentration in the water prepared by the apparatus is >=1.2 times the saturated dissolved oxygen concentration under air of 1atm. The water having high dissolved oxygen content is introduced into the soil through a water-permeable pipe embedded in the soil. A plant having improved quality can be cultured in a high efficiency and an improved yield by this process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cultivating a plant using water in which a high concentration of oxygen is dissolved, and an apparatus for producing water for cultivating the plant.

[0002]

2. Description of the Related Art An example of using high oxygen water for cultivating a plant is Jikkou 5-13165, which can be used for cultivation in small containers such as planters and potted plants, but It is unsuitable for growing a large number of plants for commercial purposes. Further, there is no known apparatus for producing water for plant cultivation, which is a combination of a membrane module or a water pump and an oxygen concentrator for producing high oxygen water.

[0003]

In the case of multicellular plants, non-photosynthetic organs and tissues depend mainly on the supply of oxygen for cell respiration from outside the plant. The root system, which is a representative of non-photosynthetic organs, usually has no direct contact with the atmosphere and its oxygen acquisition efficiency depends on the surrounding atmosphere, so it is said that it always acquires a sufficient amount of oxygen. hard. For this reason, using conventional normal water, through the soil,
Alternatively, in the cultivation method in which the root system is immersed in the culture solution, the root system is often suffering from an oxygen-deficient state, and it is considered that the original growth potential of the plant is suppressed. Therefore, supplying a sufficient amount of oxygen to the root system of the plant may activate the root system, increase the absorption efficiency of water, nutrients and the like, promote healthy growth of the plant, and may lead to improvement in quality and increased yield.

[0004]

Means for Solving the Problems As a result of intensive studies on the method for supplying oxygen to the root system of the plant, the present inventors produced water having a dissolved oxygen concentration necessary and sufficient for the plant, and used this water for the plant. It was found that the use for cultivation is effective in improving quality and increasing yield, and further found an apparatus capable of efficiently producing water having a necessary and sufficient amount of dissolved oxygen concentration for plants, and completed the present invention. .

That is, according to the present invention, when the dissolved oxygen concentration is the use temperature, the saturated dissolved oxygen concentration of 1.
A method of cultivating a plant, characterized by using water that is more than twice as high (hereinafter referred to as high oxygen water), a membrane module incorporating a membrane that allows gas to permeate and liquid does not permeate, and oxygen concentration of 40% or more oxygen concentration. It is composed of an oxygen compression device that produces air.A water inlet pipe is connected to one side of the membrane of the membrane module, and an oxygen-concentrated air introduction pipe produced by the oxygen concentration device is connected to the other side of the membrane. A device for producing high-oxygen water for plant cultivation, comprising a water pump and the above oxygen concentrator, which is connected to the suction side of the water pump, and is connected to the raw water and oxygen-concentrated air by piping. The present invention relates to an apparatus for producing high-oxygen water for plant cultivation, which is characterized in that

[0006]

[Structure] The water for plant cultivation used in the present invention has a dissolved oxygen concentration of 1.2 times or more, preferably 1.3 times or more, and more preferably a saturated dissolved oxygen concentration under air of 1 atm at a use temperature. Is water which is 1.5 times or more, and the upper limit thereof is preferably 10 times or less, more preferably 5 times or less, the saturated dissolved oxygen concentration under air of 1 atm at the use temperature. If the dissolved oxygen concentration is less than this range, the effect is small, and if it exceeds this range, the amount of escape into the air increases, and the effect does not increase.However, high oxygen water produced within this range or at a higher concentration It is also possible to produce high-oxygen water in the above-mentioned dissolved oxygen concentration range by mixing with normal water. In this case, the dissolved oxygen concentration is 15 to 500 ppm by weight, preferably 25 to 200 ppm by weight is produced and mixed with air-saturated water or unsaturated water to obtain a dissolved oxygen concentration at the operating temperature. At 1.2 to 10 of oxygen saturation concentration under 1 atm of air
It is preferable to use twice as much cultivation water.

Regarding the concentration of dissolved gas other than oxygen dissolved in high-oxygen water, its kind and concentration are arbitrary, but the concentration of dissolved gas other than oxygen is the saturated concentration under air of 1 atm at the operating temperature. The following is preferable in order not to increase the escape rate of dissolved oxygen. By the way, the oxygen concentration contained in the air-saturated water at 25 ° C. at 1 atm is 8.1 ppm by weight and 9.7 ppm by weight at 17 ° C. (according to the Chemical Handbook). Then, plants are hardly affected by solutes such as salts and nutrients.

The concentration of oxygen dissolved in water is determined by the Ostwald method, the mass spectrum method, the gas chromatography, the galvanic cell type, the polarography type, and other simple electric dissolved oxygen concentration meters, colorimetric analysis methods, etc. Can be measured at. However, when the oxygen concentration of high-oxygen water is measured using an electric dissolved oxygen concentration meter, air bubbles may be generated in the sensor section, and accurate measurement may not be possible. In such a case, it is possible to adopt a method in which the water to be measured is diluted with water whose oxygen concentration is known, and the concentration is calculated.

High oxygen water can be used for plants in the same manner as normal water, and can be used at any time during sowing, planting, or during the cultivation period such as growing plants without any restrictions. Similar to the irrigation, it may be appropriately performed depending on the condition of plant growth and soil dryness and humidity, or may be performed regularly.

When irrigating high oxygen water, spray in air,
Any method such as watering the surface of the earth or irrigating the soil can be used, but in order to prevent dissolved oxygen from being released into the atmosphere as much as possible, high oxygen water is used especially for the root system of plants. Since it is preferable to irrigate the soil, irrigation to the soil is most preferable, and irrigation to the ground surface is second most preferable.

A method of irrigating soil with high oxygen water is a method of burying a water-permeable pipe or the like, for example, a porous rubber pipe or a PVC pipe with a large number of holes or a water-permeable unglazed pipe material in the soil. The irrigation depth and the amount of irrigation water can be arbitrarily set according to the growth stage of the plant and the development status of the root system.

Although it is possible to directly feed gaseous oxygen to soil as a means for supplying oxygen to the root system, its efficiency is lower than that of highly oxygenated water, and most of the applied gas diffuses to the atmosphere. . However, high-oxygen water is preferable in that dissolved oxygen diffuses slowly into the atmosphere as compared with gaseous oxygen, and the high-oxygen state near the root system of a plant can be maintained for a long time. Examples of plants used in the present invention include horticultural crops,
Especially, fruits and vegetables with a long harvest period are most suitable.

The high oxygen water used in the present invention is, for example, a membrane-type gas dissolving device for supplying raw water to one side of a membrane which is permeable to gas and impermeable to liquid and which is to be dissolved on the other side. The apparatus can be manufactured by using any type of apparatus such as a pressure dissolving apparatus for contacting pressurized water and pressurized gas in a pressure resistant container, a bubbling apparatus, an apparatus for supplying gas to the suction side of a water pump, and the like. Among these, the membrane-type gas dissolution apparatus has a small size, is easy to handle, and can easily produce highly concentrated oxygen supersaturated water.
Even when pure oxygen or high-concentration oxygen is used as the supply gas, it is preferable in that the amount discharged in vain is small, and the membrane is a hollow fiber membrane, and the inner diameter of the hollow fiber membrane is 250 μm or less. Therefore, the apparatus can be made compact, which is preferable. In addition, a heterogeneous membrane is suitable as a membrane because it has a high gas permeation rate and there is no risk of water leakage.
4-Methylpentene-1 is hydrophobic, has a high gas permeation rate and strength, and is suitable as a membrane material. It is also preferable to use a hydrophilic membrane having a water-side surface of the membrane because the amount of bubbles generated in water can be reduced. Next to the membrane gas dissolving device, a water pump device is preferable because it can be made smaller and lighter.

In the oxygen dissolution, the supply gas may be pure oxygen or a mixed gas such as air. Further, the supply gas may be pressurized or normal pressure. The higher the oxygen partial pressure of the supply gas, the higher the dissolved oxygen concentration can be. Therefore, when pure oxygen or high-concentration oxygen is used as the supply gas, high-oxygen water having a sufficient oxygen concentration can be obtained even if the gas pressure is normal pressure. On the other hand, when the supply gas is air, it is necessary to pressurize the supply gas to obtain high oxygen water. The supply air pressure is 0.3 to 10 kgf / cm ² G
Is preferable, and 0.7 to 7 kgf / cm ² G is more preferable. When pure oxygen or high-concentration oxygen is used as the supply gas, an oxygen cylinder, liquefied oxygen, PSA method (adsorption method) oxygen-enriched air, membrane separation method oxygen-enriched air, or the like can be used.

The pressure of water may be under pressure or normal pressure, but is preferably under pressure. In the case of the membrane gas dissolution method, it is preferable to operate under the condition that the pressure of the raw water is higher than the total pressure of the gas because the amount of bubbles generated in the water can be reduced.

The raw water used in the present invention is not particularly limited, and any of tap water, well water, spring water, river water, lake water and treated water thereof can be used. It may be water from which dissolved gas has been removed or reduced, which is suitable for producing high oxygen water in which the concentration of dissolved gas other than oxygen is equal to or lower than the saturation concentration under air of 1 atm at the working temperature. is there.

The raw water and / or high-oxygen water used in the present invention may contain salts, pH adjusters, fertilizers, insecticides, antibacterial agents, etc., which are irrigated or cultivated in hydroponic culture. May be used for.

The plant cultivation water production apparatus according to the present invention will be described with reference to the structural diagram of the module shown in FIG. 1 and the configuration diagrams shown in FIGS. 2 and 3. A first example of an apparatus for producing water for plant cultivation according to the present invention comprises a membrane module 10 incorporating a membrane 1 (a hollow fiber membrane in this example) which is permeable to gas and impermeable to liquid, and an oxygen concentrator 16. An inlet pipe for oxygen-enriched air produced by the oxygen concentrator 16 is connected to one side of the membrane of the membrane module 10 and a connection port or inflow pipe 23 for flowing water to the other side of the membrane.
Is a water device for plant cultivation.

The structure of the membrane 1 which is permeable to gas and impermeable to liquid is not particularly limited, and a homogeneous membrane or a heterogeneous membrane made of a gas permeable material, and a dense layer made of a gas permeable material. Any composite membrane, hydrophobic porous membrane or the like can be used, and as the membrane form, a flat membrane, a hollow fiber membrane or the like can be used. Among these, the hollow fiber membrane is preferable from the viewpoint that the device can be downsized, and the inner diameter of the hollow fiber membrane is 250.
More preferably, it is less than or equal to μm. In addition, a heterogeneous membrane is preferable because it has a high gas permeation rate and there is no risk of water leakage. As a membrane material, poly-4-methylpentene-1 is hydrophobic and has a high gas permeation rate and high strength. Therefore, it is suitable as a membrane material. It is also preferable to use a hydrophilic membrane having a water-side surface of the membrane because the amount of bubbles generated in water can be reduced.

The shape of the module 10 is not particularly limited, and any type such as a laminated type or a spiral type in the case of a flat membrane, an internal perfusion type or an external perfusion type in the case of a hollow fiber membrane or a tubular membrane is used. it can. Among these, the internal perfusion type using a hollow fiber membrane is preferable because it has a simple structure and can be manufactured at low cost. In either case, a liquid inlet and a liquid outlet are provided on the water side of the membrane module, and a gas inlet is provided on the gas side. It is preferable to provide a gas outlet on the gas side so that the surplus gas can be discharged, because fluctuations in the dissolved oxygen concentration can be reduced even during long-term use.

The oxygen concentrator 16 is capable of concentrating oxygen in the air to continuously produce oxygen-enriched air having an oxygen concentration of 40% or more, preferably 80% or more. For example, PSA
There are formulas (adsorption type) and membrane types. The PSA type includes an oxygen adsorption type and a nitrogen adsorption type, but the nitrogen adsorption type is preferable because high-pressure oxygen can be taken out without adding a compressor.

The gas side of the membrane module 10 is piped to introduce the oxygen-enriched air produced by the oxygen concentrator 16. If necessary, a flow rate adjusting valve, a pressure adjusting valve, or the like (for example, 17) can be provided in this pipe. Further, a pressure control valve or a flow rate control valve (for example, 18) can be connected to the gas outlet 9 of the membrane module provided as necessary.

Raw water 11 is introduced into the liquid inlet 6 of the membrane module 10 and high oxygen water 15 is taken out from the liquid outlet 7. A pipe connected to the liquid inlet 6 and / or a pipe connected to the liquid outlet 7 includes a pressure control valve, a flow control valve, a flow switch, etc. (for example, 13,
It is also possible to provide 14). It is also possible to connect a water-permeable pipe to the pipe connected to the liquid outlet 7 and directly irrigate the produced high oxygen water into the soil. The first example of this plant cultivation water producing device has a raw water pressure of 1 k.
When it is gf / cm ² G or more, it is particularly effective when tap water is used as raw water. When the water pressure of raw water is insufficient, it is possible to incorporate a water pump into this device.

The second example of the plant cultivation water producing apparatus of the present invention is composed of a water pump 22 and an oxygen concentrating device 20, and is configured to inhale oxygen-enriched air together with raw water into the suction side of the water pump 22. It is a water production device for plant cultivation.

The type of the water pump 22 is not particularly limited, but a turbo type water pump is preferable, and as the turbo type water pump, a centrifugal pump, a mixed flow pump, an axial flow pump, an electric power source, etc. Any power source such as a one-stage type, another-stage type, etc. can be used. The discharge side pressure of the water pump is preferably 0.2 to 10 kgf / cm ² G.
The turbo type water pump has a particularly high gas dissolving efficiency because water and air are sufficiently stirred in the pump. It is also possible to connect the water pumps in multiple stages in series, and in this case, it is also preferable to supply oxygen-saturated air to the suction side of the water pump of the second and subsequent stages. It is also preferable to use a multi-stage water pump of a type capable of supplying gas to the suction ports of the second and subsequent stages.

The suction side of the water pump 22 is the raw water 11
The high oxygen water 15 is taken out from the discharge side. On the suction side of the water pump 22, there is also provided an oxygen concentrating device 20 which is connected by piping to supply oxygen enriched air together with the raw water 11. A pipe connected to the suction side and / or the discharge side of the water pump 22 has a pressure control valve, a flow rate control valve, etc. (for example, 1
It is also possible to provide 3). Further, it is possible to connect a water-permeable pipe to the pipe 12 connected to the discharge side and directly irrigate the produced high oxygen water into the soil. Also,
Leak valve 1 for excess air that did not dissolve in water on the discharge side
4 is preferably provided.

The maximum supply pressure of the oxygen concentrator 20 is:
Oxygen-enriched air can be sent to the suction side of the starter pump 22.
Any pressure will do. That is, inhalation of the water pump 22
When the side pressure is almost atmospheric pressure, for example, raw water is stored in a water tank, etc.
If it is supplied from the
The applied pressure is 0.001-0.3kgf / cm ²
G is acceptable, but the suction side of the water pump 22 is
If connected to a pressurized water source, pressure above that pressure
You need power. The oxygen concentrator 20 is an oxygen adsorption type P
Except that SA type and membrane type can also be preferably used,
Oxygen concentrator used in a plant water production device
This is the same as in the case of 16. On the discharge side of the oxygen concentrator 20
Provide a flow control valve 21 and a water backflow prevention valve.
Is also possible. The apparatus for producing water for plant cultivation of the second example is
Water pressure is 1kgf / cm²Especially effective when G or less
It is fruitful.

Since the membrane-type and water-pump-type water producing apparatus for plant cultivation used in the present invention has excellent features such as being extremely easy to handle and being small and lightweight,
There is an advantage that the burden on workers in the field is small.

[0029]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

[Example 1] (Water production device for plant cultivation) Outer diameter 263 μm, inner diameter 207
A cylindrical module having a diameter of 11 cm and a length of 60 cm filled with 50,000 hollow fiber heterogeneous membranes made of poly-4-methylpentene-1 was prepared. That is, the hollow fiber membranes 1 bundled substantially in parallel are loaded into a cylindrical module housing 2, both ends of the hollow fiber membranes are sealed with resin 3 (also referred to as potting), and the end face 4 of the sealing portion is hollow. The inside of the thread film 1 is open. The module includes a liquid inlet 6 connected from one end of the hollow fiber membrane to the inside of the hollow fiber membrane, a liquid outlet 7 connected from the other end of the hollow fiber membrane to the inside of the hollow fiber membrane, and a gas connected to a space in contact with the outside of the hollow fiber. An inlet 8 and a gas outlet 9 are provided.

As the oxygen concentrator 16, a PSA oxygen concentration
Compressor (nitrogen adsorption type, generated oxygen concentration 90%, generated amount 2 l
/ Min) via the pressure adjusting valve 17 at 3 Kgf /
cm ²To supply the oxygen enriched air of G to the module 10.
Connected A branch pipe 12 is attached to the liquid outflow 7 of the membrane module.
Connect and connect the flow control valve 13 of high oxygen water to one of them
And connect the leak valve 14 to the other
An apparatus for producing water for product cultivation was produced.

(Production of High Oxygenated Water) 25 ° C. water is introduced as raw water 11 into the liquid inlet 6 of the membrane module 10 of this plant cultivation water producing apparatus, and the flow control valve 13 connected to the liquid outlet 7 is introduced. The flow rate was adjusted to 10 l / min.
On the other hand, air having an oxygen concentration of 90% was introduced into the gas inlet 6 by the oxygen concentrator 16, and excess air was leaked as the leak gas 19 from the leak valve 18 connected to the gas outlet 9. At this time, the dissolved oxygen concentration of the raw water flowing into the module was 7.9 ppm by weight. The dissolved oxygen concentration of water flowing out from the liquid outlet was 57.0 ppm by weight (7.0 times the saturated oxygen concentration).

[Example 2] (Water production device for plant cultivation) A water pump 22 was a spiral pump having a maximum pressure of 3 kgf / cm2G and a discharge rate of 50 l / min, and the oxygen concentrator 20 was a PSA oxygen concentrator (nitrogen adsorption type). , Generated oxygen concentration 90%, generated amount 2
1 / min) was used. The discharge side of the oxygen concentrator 20 is connected to one of the branch pipes 24 immediately before the suction port of the water pump 22 via the flow rate control valve 21, and the raw water introducing pipe 23 is connected to the other port of the branch pipe 24. did. A branch pipe 12 is connected to the discharge side of the water pump 22, one side of which is a flow rate control valve 13, and the other side is a leak gas discharge leak valve 1.
4 connected.

(Production of high oxygen water) Water of 25 ° C. is introduced by connecting the raw water introduction pipe 23 of the water pump 22 suction port of this plant cultivation water production device to the water tank, and connected to the water pump 22 discharge port. Flow control valve 13
The flow rate was adjusted to 10 l / min. The leak valve 14 connected to the discharge port of the water pump 22 was adjusted so that the outflow rate of water discharged together with the surplus air not dissolved in water was 0.3 l / min or less. On the other hand, the oxygen concentrator 20 supplied air having an oxygen concentration of 90% to the water pump inlet.

At this time, the dissolved oxygen concentration of raw water was 8.0 ppm by weight, which was a value close to the saturated oxygen concentration (8.1 ppm). The dissolved oxygen concentration of water flowing out from the liquid outlet was 32.0 weight ppm (4.0 times the saturated oxygen concentration).

Example 3 Cucumber Cultivation Method Cucumber cultivar Sharp 1 was used and seeded on the nursery. One planted in a glass greenhouse one month after sowing, 25 m in length and 1.2 m in width, with 40 cm between plants and 2 lines vertically (interval 60 cm), 44 trees per growth bed (1 line 2).
2 plants were planted from the nursery. Porous rubber tubes (trade name: Leaky Pipe (registered trademark); manufactured by Nippon Oxygen Co., Ltd.) were pre-installed in the growth bed in the lengthwise direction, two per length, at intervals of 60 cm just below the cucumber. , Depth 15 cm
It was buried in the part. The two buried leaky pipes were connected in soil using vinyl chloride pipes. One end of the vinyl chloride pipe was brought to the ground by an L-shaped pipe so that water could be supplied. Water was supplied daily for 6 hours at a flow rate of 160 l / h. In the test section, one growth bed was set as one section, and as a high oxygen section, high oxygen water having a dissolved oxygen concentration of 12.5 weight ppm and a saturated oxygen concentration of 1.54 times was exposed to the aerial part through a flow meter. A section where the soil was irrigated from one end of the vinyl chloride pipe and a section where normal water was irrigated with the leaky pipe into the soil were provided as the normal water section. Fertilization management followed the practice.
Harvesting is carried out from 40 days to 75 days after planting, and the harvested products are examined for quality (bending etc.) and weight by observing the appearance. And The results are shown in Table 1.

[0037]

[Table 1]

[Example 4] (Method of cultivating tomato) As tomato, cultivar Momotaro was used.
One month after seedling seeding, two rows (interval 100 cm) were planted in a glass greenhouse in a growth bed having a width of 1.2 m with a spacing of 40 cm. A leaky pipe was previously buried at a depth of 20 cm in the center of the growing bed, and an L-shaped pipe made of vinyl chloride was provided above the ground to allow water to be supplied. The irrigation is 160 l / day for 6 hours a day after the first fruit cluster enlargement period (75 days after seeding).
It was performed every 3 days at a flow rate of h. As a high-oxygen area, a section in which high-oxygen water having a dissolved oxygen concentration of 25 ppm by weight and a saturation oxygen concentration of 3.1 times is irrigated, and a normal water area in which normal water is irrigated with a leaky pipe are provided. It was Fertilization management followed the practice. The tomatoes were harvested from 90 days to 130 days after sowing. The survey was conducted with respect to the quality of appearance (whether cracked fruits, chak, hollow fruits, irregular fruits, etc.) and weight. The results are shown in Table 2.

[0039]

[Table 2]

From the above test results, as compared with the case of using normal water, the use of high oxygen water increased the total amount of harvest and the ratio of harvested fines.

[0041]

EFFECTS OF THE INVENTION The use of high oxygen water makes it possible to improve the quality and increase the yield as compared with the case of using normal water. In addition, high oxygen water can be efficiently produced by the plant cultivation water producing apparatus of the present invention.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a membrane module of the present invention.

FIG. 2 is a water production device for plant cultivation using the membrane module of the present invention.

FIG. 3 is a plant cultivation water production apparatus using the water pump of the present invention.

[Explanation of symbols]

 1 ... Hollow fiber membrane 2 ... Module housing 3 ... Resin sealing portion 4 ... End surface 5 ... Cap 6 ... Liquid inlet 7 ... Liquid outlet 8 ... Gas inlet 9 ... Gas outlet 10 ... Membrane module 11 ... Raw water 12 ... Branch pipe 13 ... Flow control valve 14 ... Leak valve 15 ... High oxygen water 16 ... Oxygen concentrator 17 ... Pressure control valve 18 ... Leak valve 19-Leak gas 20-Oxygen concentrator 21-Flow control valve 22-Water pump 23-Raw water inlet pipe 34- Branch pipe

Claims (8)

[Claims] 1. A method of cultivating a plant, which comprises using water having a dissolved oxygen concentration of 1.2 times or more of a saturated dissolved oxygen concentration under air of 1 atm at a use temperature. 2. Cultivation of a plant, wherein water having a dissolved oxygen concentration of 1.2 times or more of a saturated dissolved oxygen concentration under air of 1 atm at a use temperature is supplied to a root system of the plant. Method. 3. The method for cultivating a plant according to claim 2, wherein the irrigation is carried out into the soil through a water-permeable pipe embedded in the soil. 4. The water of which dissolved oxygen concentration is 1.2 times or more the saturated dissolved oxygen concentration under air of 1 atm at the use temperature is produced by the membrane gas dissolution method. 4. The method for cultivating the plant according to any one of 3 to 3. 5. The method for cultivating a plant according to claim 4, wherein the membrane used in the membrane gas dissolution method is a hollow fiber membrane. 6. The method for cultivating a plant according to claim 5, wherein the hollow fiber membrane is a heterogeneous membrane. 7. A membrane module incorporating a membrane that is permeable to gas and impermeable to liquid and an oxygen concentrator for producing oxygen-enriched air having an oxygen concentration of 40% or more, wherein water is provided on one side of the membrane of the membrane module. An inflow pipe connected to the other side of the membrane, and an oxygen-concentrated air introduction pipe manufactured by an oxygen concentrator connected to the other side of the membrane; An apparatus for producing water for plant cultivation, which has a saturated dissolved oxygen concentration of 1.2 times or more below. 8. A water pump and an oxygen concentration of 40%
It is composed of an oxygen concentrator for producing the above oxygen-enriched air, and is characterized in that the intake side of the water pump is connected to an inlet pipe for raw water and an oxygen-enriched air inlet pipe produced by the oxygen concentrator. An apparatus for producing water for plant cultivation, wherein the dissolved oxygen concentration is 1.2 times or more the saturated dissolved oxygen concentration under air of 1 atm at the use temperature.