JPH07102051B2 - 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 a hydroponic cultivation method for hydroponically growing vegetables using a hydroponic fertilizer solution.

[0002]

2. Description of the Related Art Generally, when cultivating a plant, the three major components such as nitrogen (nitrogen), phosphorus, and potassium, among the components necessary for growing the plant, tend to be particularly deficient, so that they must be provided as fertilizers sufficiently. Moreover, plants obtain chisso among these three major elements from chisso compounds (chisso source) such as inorganic compounds such as nitrates and ammonium salts. This chisso is a constituent element of organic compounds such as proteins, nucleic acids, and chlorophyll that play important roles in the living body of plants, and is the most important fertilizer for plant growth.

That is, a nitrogen compound is absorbed from a root of a plant to become an amino group, and this amino group reacts with a carbohydrate produced by photosynthesis in leaves or the like to form an amino acid, and the root, stem,
It is used for growing leaves.

On the other hand, in soil cultivation of vegetables, for example, continuous cropping failure occurs, root elongation is suppressed due to soil hardness, the growth of the whole vegetables is delayed, yield deterioration due to soil deterioration, etc. There's a problem. In recent years, a hydroponic cultivation method has attracted attention as a cultivation method for solving such a problem, and various devices have been developed.

In this hydroponic cultivation, an aqueous solution containing the above-mentioned three major elements and inorganic salts of other elements is used as a hydroponic fertilizer solution. Then, while making the hydroponic fertilizer solution containing oxygen flow in the cultivation container (hydroponic cultivation bed),
The roots of vegetables are dipped in the hydroponic fertilizer solution so that the vegetables absorb the components necessary for growth.

[0006]

By the way, compared with soil-cultivated vegetables, hydroponic vegetables have a significantly higher nitrate content. This nitrate has become a big problem not only as a bitter ingredient of vegetables but also as a carcinogen in the living body of animals.

Among vegetables cultivated by the hydroponic culture, leaf vegetables such as spinach have a high content of nitrates. The reason why the leaf vegetables have a large amount of nitrate is that they are due to the components of the hydroponic fertilizer solution, and the hydroponic fertilizer solution has a large ratio of nitrogen nitrate to ammonia nitrogen as compared to the soil fertilizer.

Therefore, according to the present invention, it is possible to supply a sufficient amount of nitrate necessary for growth during the growth of vegetables and
No matter which time it is harvested, it will be
It is an object of the present invention to provide a hydroponic cultivation method capable of sufficiently reducing nitrate taken up in a vegetable body .

[0009]

In order to achieve this object, the present invention is to hydroponically cultivate vegetables with a hydroponic fertilizer solution containing nitrate nitrogen, to grow the vegetables to some extent, and then to add the vegetables. For a certain period of time before harvesting, by hydroponically growing the vegetables with a hydroponic fertilizer solution having little or no nitrate nitrogen content, the nitrate nitrogen remaining inside the vegetables is consumed to produce It is characterized in that it is an cultivating method for growing vegetables.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, 1 is a slanted bed for hydroponic cultivation, 2 is a drainage pipe provided at the lower end of the bed 1, and 3 is disposed and supported on the bed 1 at intervals. A plant support such as a urethane mat and 4 are vegetables such as spinach (leaf vegetables) planted in the plant support 3.

Further, 5 is a solution tank disposed below the drainage pipe 2, 6 is a hydroponic fertilizer solution stored in the solution tank 5, and 7 is both ends in the solution tank 5 and in the upper end portion of the bed 1. Is a pipe for supplying a solution, and 8 is a pump for supplying a solution which is inserted in the middle of the pipe 7.

In such a structure, the hydroponic fertilizer solution 6 in the solution tank 5 is supplied into the upper end portion of the bed 1 through the pipe 7 by operating the pump 8, and the inside of the bed 1 is inclined. And then flow downward, and then flow through the drain pipe 2 and the solution tank 5 in that order to be refluxed. At this time, the vegetables 4 held on the plant support 3 absorb the nutrients in the hydroponic fertilizer solution 8 from their roots 4a, while undergoing photosynthesis by being exposed to light from a light source (not shown) or the like. Become.

Then, for example, the first solution of (1) is used as the hydroponic fertilizer solution 6 during the growth period (early period of growth), and the solution is grown for a certain period before harvest (for example, 2 weeks before harvest). Within the period (up to the time), for example, the second solution of (2) is used once or more as the hydroponic fertilizer solution 6 for a total of one day or more.
During this fixed period of time, the second solution of (2) can be used every day, or every other day or every few days. Further, the fixed period does not necessarily have to be two weeks, and may be longer or shorter than two weeks depending on the type of vegetables.

(1) First Solution (for Plant Growth, Early Growth) Calcium Nitrate [Ca (NO3) 4H2O] 830 mg / l Potassium Nitrate [KNO3] 600 mg / l Ammonium Phosphate [NH4H2PO4] 150 mg / l Magnesium Sulfate [MgSO4]・ 7H2O] 370mg / l Iron [Fe] 2ppm Boron [B] 0.2ppm Manganese [Mn] 0.2ppm (2) Second solution (for reducing nitrate content in plants, late growth stage) Nitrate nitrogen (10mg / L) or less Chelate iron (10 mg / l) or more In this way, at the latter stage of growth in hydroponics of vegetables 4, the fertilizer solution formulation of hydroponic fertilizer solution 6 is changed, that is, nitric acid in hydroponic fertilizer solution 6 is changed. Very low content of crystalline nitrogen. As a result, in the latter stage of growth, the vegetables 4 make amino acids based on the nitrate nitrogen taken into the body in the earlier stage of growth and utilize them for the growth of roots, stems, leaves and the like. That is, it grows while consuming the nitrate nitrogen in the vegetables, and consumes most of the nitrate nitrogen in the body when the vegetables are harvested. In this way, even if the content of nitrate nitrogen is made small in the latter stage of growth, the nitrate in the vegetable body can be remarkably reduced without causing physiological damage to the vegetable 4.

For example, spinach is used as the vegetable 4 and is grown in the first solution (1) (ordinary hydroponic fertilizer solution) of (1) in the early growth period (for 20 days or more after sowing), and then in the second harvest period. If grown in the second solution of (2) for a week,
(b) The results as shown after the treatment were obtained. In addition, (a) of (3)
Before the treatment, the case where only the first solution of (1) is grown is shown.

(3) Nutrient content in spinach body Analysis item (a) Before treatment (b) After treatment Nitrate content 145 mg / 100 g (1 mg / 100 g) or less Raw weight 11 g 20 g Plant height 20 cm 20 cm Water content 92 % 92% Carbohydrate 2.9% 3.2% Vitamin C 21 mg / 100 g 41 mg / 100 g As can be seen from this (3), the content of nitrate nitrogen in the spinach can be determined by cultivating by the method of the present invention. Although it could be reduced to less than one-hundredth of that of the conventional one, there was no deterioration in quality such as length, increase in water content, decrease in sugars and vitamins, but rather increase in sugars and vitamin C. The quality has improved.

In the embodiments described above, the example of applying the hydroponic cultivation method of the present invention to spinach, which is a leafy vegetable, is shown, but the invention is not necessarily limited to spinach and can be applied to other vegetables and the like. .

[0018]

[Effect] As described above, the present invention is a vegetable and hydroponics by hydroponic fertilizer solution contains nitrate nitrogen, since so as to some extent growing the vegetables, vegetable
When growing, it is possible to supply enough nitrate necessary for growth.
Moreover, by hydroponically cultivating the vegetables with a hydroponic fertilizer solution having little or no nitrate nitrogen content for a certain period before harvesting the vegetables, the nitrate nitrogen remaining inside the vegetables is removed. Since the vegetables are grown so as to be consumed , no matter whether the vegetables are harvested at any point during the growth process,
Nitrate taken up in the vegetables during the growing process at harvest
Can be sufficiently reduced. This makes the vegetables
Even if this vegetable is harvested during growth,
There is no bitterness, and the growth of vegetables is done in this way.
By immediately stopping, the water content in the vegetables decreases
However, the content of sugar and vitamin C is increased.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a hydroponic cultivation apparatus for explaining a hydroponic cultivation method according to the present invention.

[Explanation of symbols]

 1 ... Bed 3 ... Plant support 4 ... Vegetables 6 ... Hydroponic fertilizer solution

Claims (1)

[Claims] 1. After the vegetables are hydroponically cultivated with a hydroponic fertilizer solution containing nitrate nitrogen and the vegetables are grown to some extent, there is almost no nitrate nitrogen content for a certain period before the harvest of the vegetables. A hydroponic cultivation method comprising hydroponically cultivating the vegetable with a hydroponic fertilizer solution that does not exist or at all, thereby consuming the nitrate nitrogen remaining inside the vegetable to grow the vegetable.