JP3474267B2 - Hydroponics method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an efficient method for hydroponics of plants such as vegetables and flowers.

[0002]

2. Description of the Related Art In conventional hydroponic culture, a plant in which a fertilizer or a trace amount of an element is dissolved in water is used as a culture solution and a plant is cultivated by a method called a solution type or a circulation type. The liquid phase method is a method in which a culture medium is aerated and aerated. The circulation type is a method of supplying oxygen in the process of circulating water, and can be divided into two types depending on the presence or absence of a tank. As for those without a tank, oxygen is supplied when the culture solution in the cultivation bed is pumped up and returned to the cultivation bed again; the culture solution in one of the two cultivation beds is pumped. For example, there is one that supplies oxygen by raising and lowering the water surface by repeatedly sucking it up, transferring it to the other cultivation bed, and returning it to the other bed when it is full. As for those having a tank, aeration is performed when the culture solution in the cultivation bed is dropped into the tank by utilizing the head and then the culture solution in the tank is pumped up and returned from the top of the cultivation bed. NF is one of the circulating hydroponics
There is a method called T plowing. In this method, a gently sloping bed is formed, and when the culture solution is made into a thin film with a depth of 1 to 2 cm to flow down, the upper part of the root of the plant is exposed to the air to directly absorb oxygen.

[0003]

Among the above-mentioned conventional hydroponic cultivation methods, in the aeration method of the liquid-tank type, the amount of roots of the plant is increased because the dissolution of oxygen in the solution by aeration is insufficient. If the amount increases, there is a drawback that oxygen becomes insufficient and the vent holes are clogged, resulting in uneven growth of the crop. NF
In the T-cultivation method, since the cultivation bed is inclined, the growth is good at the inlet of the culture solution, but there is a drawback that the flow is poor near the exit of the culture solution and uneven growth occurs. In addition, the liquid and circulation methods require the storage or circulation of a large amount of the culture solution at one time, which requires a robust and relatively large facility, and has the disadvantage of requiring a large amount of cost for the facility. is there. The object of the present invention is to solve these problems.

[0004]

[Means for Solving the Problems] As a result of extensive studies to solve the above problems, a hydroponic culture of plants comprising a water-soluble polymer aqueous solution containing bubbles; and a water-soluble polymer aqueous solution containing bubbles The inventors have found a culture solution for use in the present invention and completed the present invention. In the hydroponic cultivation method of the plant of the present invention, the water-soluble polymer aqueous solution used for the medium is foamed and the foaming is continued. By hydroponically cultivating the plant in the foamed culture solution, the amount of the culture solution used can be reduced, which allows the facility to be simplified and lightweight, and further, oxygen and the culture solution can be sufficiently supplied. for,
The plant will grow well.

The water-soluble polymer used in the present invention includes polyvinyl alcohol (hereinafter abbreviated as PVA), polyacrylamide, sodium polyacrylate, polyethylene oxide, ethylene oxide-propylene oxide copolymer, polyvinylpyrrolidone, Polyvinyl ether, isobutylene-maleic anhydride copolymer,
Polyallylamine, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, starch, sodium alginate, propylene glycol alginate, sodium starch glycolate, sodium starch phosphate ester, or modified products thereof, which are highly soluble in water It is a molecular compound. Among the above-mentioned water-soluble polymers, water-soluble polymers having a property of easily foaming after being dissolved in water and having a property of stably maintaining foaming are preferable. From this viewpoint, PVA having a saponification degree of 95 mol% or less, modified PVA having a hydrophobic group such as an alkyl group introduced therein, methyl cellulose, polyvinyl ether, and the above various water-soluble polymers modified with a hydrophobic group are more preferable. Among these water-soluble polymers, PVA is particularly preferable. The saponification degree of PVA is 5
0 to 93 mol% is preferable, 70 to 92 mol% is more preferable, and 80 to 90 mol% is more preferable. The viscosity average degree of polymerization of PVA (hereinafter abbreviated as the degree of polymerization) is 2
00-5000 are preferable and 500-4000 are more preferable.

The effective concentration of the water-soluble polymer dissolved in the culture medium is 0.0001 to 1.0%.
0.001-0.1% is more preferable. As a method for foaming the culture solution, a method by aeration, a method by stirring,
A method of circulating dropping is mentioned, but a method of ventilation is most effective. The culture solution may be foamed in the medium or may be foamed in advance and supplied to the medium. The temperature of the culture solution is preferably 5 to 40 ° C, more preferably 10 to 30 ° C. The average diameter of bubbles in the water-soluble polymer aqueous solution containing bubbles is 0.01 to
20 mm is preferable, 0.05-5 mm is more preferable, and 0.05-2 mm is even more preferable. The ratio of air bubbles to the water-soluble polymer aqueous solution in the medium is
10% or more is preferable, 50% or more is more preferable, and 7
0% or more is even more preferable, and it is particularly preferable that the entire medium is air bubbles. When air bubbles are partially generated in the water-soluble polymer aqueous solution, the air bubbles are present at the relatively upper part of the medium. The type of gas forming the bubbles is required to contain oxygen, and examples thereof include ordinary air and oxygen. In addition, depending on the plant to be cultivated, the culture solution contains Ca (NO ₃ ) ₂ .4H ₂ O, KNO ₃ , NH _{4
H 2 PO 4, MgSO 4 ·} 7H 2 O, other fertilizer components such as _{NH 4 NO 3, Fe-EDTA} , H 3 BO 3, MnCl
The ₂ · 4H ₂ trace elements O, or the like as appropriate formulation to be used. Suitable plants for the present invention include tomatoes, cucumbers, melons, strawberries, honeywort, leeks, perilla, vegetables such as lettuce,
Examples include flowers such as tulips, roses, gerberas, and carnations. Also, lilies, bouvargia, roses,
It can also be used for cut flowers such as carnations, and shrubs for rooftop greening such as shrimpbai, camellia and sasanqua. In addition, the method of the present invention may be used in combination with the method described in the section of the prior art, etc., within the range that does not impair the effects of the present invention.

[0007]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Commercially available liquid fertilizer for hydroponics (manufactured by Otsuka Chemical Co., Ltd., trade name:
Otsuka House fertilizer) is dissolved in water to 0.2%, and various water-soluble polymers shown in Table 1 are dissolved in water to 0.001% to be used in a medium (temperature 25 ° C). After the culture solution was prepared, the Arls-Seine melon seedlings, which had been sown for 3 weeks after sowing, were attached to the medium and continuously blown into the medium to foam and grow the medium. Good foaming was observed in the system containing water-soluble polymer,
Even when the amount of liquid fertilizer decreased, the liquid fertilizer could be sufficiently supplied to the root without drying the root of the melon. After that, by continuing hydroponics for two months,
After flowering, the melon fruit matured in 4 months by mating. On the other hand, when the water-soluble polymer was not used and when the air was not blown in, the melon growth was insufficient as compared with the inventive examples, as shown in the comparative example.
The results are shown in Table 1.

[0009]

[Table 1]

(*) The generation status of bubbles is indicated by the following symbols. ⊚: Bubbles having an average diameter of 0.1 to 1 mm are present in 100% of the medium. O: Bubbles having an average diameter of 0.5 to 2 mm are present in 70% of the medium. Δ: Bubbles having an average diameter of 1 to 5 mm are 50% of the medium. Present in ▲: bubbles having an average diameter of 10 to 20 mm are present in 5% of the culture medium ×: no bubbles are present

Example 2 The same commercially available liquid fertilizer for hydroponics as in Example 1 was used in an amount of 0.1% with respect to water, and the concentration of PVA shown in Table 2 (polymerization degree: 1750, saponification degree: 88 mol%) with respect to water. After adjusting the culture solution to be used as a medium by changing and dissolving the cucumber seedlings, the seedlings of the cucumber that have been raised for 3 weeks after seeding are added to the medium (temperature: 25 ° C).
The medium was foamed and grown by continuously blowing air into the medium. In the system containing PVA, good foaming was observed, and it was possible to sufficiently supply the liquid fertilizer to the root without drying the root of the cucumber even when the amount of the liquid fertilizer was small. After that, by continuously performing hydroponics for one and a half months, it bloomed and matured in 50 days. 5
The weight of each plant after 0 days was measured to evaluate the growth effect by using PVA. On the other hand, when the water-soluble polymer was not used or when air was not blown in, the growth of cucumber was insufficient as compared with the examples of the present invention, as shown in the comparative example. The results are shown in Table 2.

[0012]

[Table 2]

(*) Same as footnote in Table 1.

Example 3 The same commercially available liquid fertilizer for hydroponics as in Example 1 was used in an amount of 0.1% with respect to water, and the PVA shown in Table 3 (polymerization degree: 2000, saponification degree: 80 mol%) was added to water. After dissolving and adjusting the culture solution to be used in the medium (temperature 25 ° C.) so as to be 0.002%, the medium is foamed by continuously blowing air, and the medium having a length of 50 cm Hydroponics of rose seedlings was performed. After that, when hydroponics was continued for 6 months, a rather large beautiful flower bloomed. On the other hand, when the water-soluble polymer was not used or when air was not blown in, only flowers smaller than those of the present invention bloomed, as shown in Comparative Examples. In addition, no flowers bloomed when sodium dodecylbenzene sulfonate was used.
The results are shown in Table 3.

[0015]

[Table 3]

(*) Same as footnote in Table 1.

[0017]

According to the hydroponic cultivation method of the present invention, since the amount of the culture solution to be constantly fed can be reduced, the weight and cost of the apparatus can be reduced and the growth of plants can be improved.

Claims (2)

(57) [Claims] 1. A saponification degree of 80 to 90 mol containing bubbles.
A hydroponic cultivation method for plants, which comprises using an aqueous solution containing 0.001% to 1% of polyvinyl alcohol as a medium. 2. A saponification degree of 80 to 90 mol containing bubbles.
A culture solution for hydroponics of a plant, which comprises an aqueous solution containing 0.001% to 1% of polyvinyl alcohol .