JP2018139568A - Hydroponic system and hydroponic method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently increase a predetermined mineral component without causing physiological disorder.SOLUTION: A hydroponic system comprises: a cultivation unit on which a plant to be cultivated is arranged; and a nutritious liquid feeder which feeds nutritious liquid to the cultivation unit, and cultivates a plant arranged on the cultivation unit in nutritious liquid having low mineral component content for a predetermined period of time in a plant growth period.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydroponic cultivation system and a hydroponic cultivation method for cultivating a plant with a nutrient solution using a cultivation unit in which a plant to be cultivated is arranged.

Hydroponics means a method of cultivating a plant using water and nutrient solution (liquid fertilizer) without using soil or a soil substitute base material. In general, hydroponics is a cultivation form suitable for so-called plant factories and house cultivation, and is widely realized including leafy vegetables. The nutrient solution used for hydroponics mainly contains large elements (NO ₃ -N, NH ₄ -N, P, K, Ca and Mg) and trace elements (Fe, Mn, B, Cu, Zn and Mo). )It is included.

  Patent Literature 1 (JP-A-2006-86734) discloses a hydroponic cultivation system in which a cultivation panel in which seedlings to be cultivated are transplanted is arranged vertically. In this hydroponics system, nutrient solution is supplied to the cultivation panel via a liquid fertilizer supply pipe installed above the cultivation panel. Moreover, patent document 2 (patent 4792533) forms the independent 2 circulation flow path which circulates the nutrient solution from which a composition differs according to the growth of a plant to a hydroponic cultivation shelf unit, The said 2 circulation flow path is formed. The hydroponic cultivation apparatus which cultivates a plant by circulating the nutrient solution of a different component composition by switching and using is disclosed.

  Furthermore, in patent document 3 (Unexamined-Japanese-Patent No. 2015-136298), when the growth state of the plant grown simultaneously differs, the hydroponics apparatus which supplies the nutrient solution of a different composition according to the growth of each plant is provided. It is disclosed. Specifically, a nutrient solution suitable for the vegetative growth period and a nutrient solution suitable for the tuber induction period are prepared, and based on the judgment whether the plant is in the vegetative growth period or the tuber induction period, It is a switching device.

  As disclosed in Patent Documents 2 and 3, in the conventional hydroponic cultivation apparatus, it is possible to switch and use a plurality of types of nutrient solutions in conjunction with the growth of the plant, and to adjust the components contained in the plant, Or cultivation suitable for growth of a desired plant can be performed.

  By the way, about the mineral component among the various components contained in a plant, if the content can be increased / decreased, it can be characterized as a high mineral content plant or a low mineral content plant. For example, in Patent Document 4 (Japanese Patent Publication No. 3-4168), although the method is based on soil cultivation, the fasting root (water and fertilization are cut off until it begins to wither, and then a small amount of water and fertilization is repeated. ), A method of cultivating a high mineral content plant by performing fertilization including minerals is disclosed.

  Non-Patent Document 1 discloses that, just before harvesting, switching from a general nutrient solution to a high concentration single nutrient solution of an Fe compound (application of iron ammonium citrate) and absorbing Fe from the roots in a short period of time makes the ground for leafy vegetables. A method for increasing the iron content in leaves is disclosed.

JP, 2006-86734, A Japanese Patent No. 4792533 JP2015-136298A Japanese Patent Publication No. 3-4168

"Production of leafy vegetables with high iron content using hydroponics", Japanese Journal of Soil Liquid Fertilization, Vol. 65, No. 4, p, 436-440 (1994)

  However, the method disclosed in Patent Document 4 is a method by soil cultivation and is not applicable to hydroponics. Further, the method disclosed in Non-Patent Document 1 has a problem that the iron content cannot be sufficiently increased without causing physiological disorder.

  Then, an object of this invention is to provide the hydroponic cultivation system and hydroponic cultivation method which can fully raise a predetermined | prescribed mineral component, without producing a physiological disorder in view of the situation mentioned above.

  As a result of intensive studies by the present inventors in order to achieve the above-described object, cultivation is carried out in a nutrient solution having a low available mineral content in a predetermined period of plant growth in a hydroponic cultivation. Thus, the present inventors have found that the mineral content can be remarkably improved without causing physiological disorder, and the present invention has been completed.

The present invention includes the following.
(1) A cultivation unit in which a plant to be cultivated is arranged, and a nutrient solution supply device that supplies nutrient solution to the cultivation unit, and a mineral component content in an available state for a predetermined period of the plant growth period. Hydroponic cultivation system characterized by cultivating plants arranged in the cultivation unit with a low nutrient solution.
(2) The nutrient solution supply apparatus is characterized in that the nutrient solution having a low mineral content in the available state and the nutrient solution having a high mineral component content in the available state are switched and supplied to the cultivation unit ( 1) Hydroponic cultivation system as described.
(3) The hydroponic cultivation system according to (1), wherein the nutrient solution contains an organic acid state of a mineral component.
(4) The hydroponic cultivation system according to (1), further comprising a control device that controls supply of the nutrient solution to the cultivation unit by the nutrient solution supply device.
(5) The cultivation unit includes a plant support jig that supports a plant and is supplied with a nutrient solution from the nutrient solution supply device. The plant support jig is provided for growing a plant to be cultivated. The hydroponic system according to (1), wherein nutrient solutions having different mineral component contents are supplied accordingly.
(6) The cultivation unit includes a support unit that supports plants, and a plurality of nutrient tanks and / or nutrient solution storage units to which the support unit is attached and the nutrient solution is supplied from the nutrient solution supply apparatus. The hydroponic cultivation system according to (1), wherein the plurality of nutrient solution tanks and / or nutrient solution storage units are respectively supplied with nutrient solutions having different mineral component contents in an available state.
(7) The hydroponic system according to (1), wherein the mineral component is at least one element selected from the group consisting of iron, zinc, and calcium.
(8) In the hydroponic cultivation method of cultivating the plant with a nutrient solution using the cultivation unit in which the plant to be cultivated is arranged, the nutrient component having a low available mineral component content in a predetermined period of the plant growth period A hydroponics method for cultivating a plant arranged in the cultivation unit with a liquid.
(9) Hydroponic cultivation according to (8), wherein a nutrient solution having a low available mineral content and a nutrient solution having a high mineral content are switched and supplied to the cultivation unit. Method.
(10) The hydroponic cultivation method according to (8), wherein the nutrient solution contains an organic acid state of a mineral component.
(11) The hydroponics method according to (8), wherein the supply of nutrient solution to the cultivation unit is controlled by a control device.
(12) The cultivation unit includes a plant support jig that supports a plant and is supplied with a nutrient solution, and the plant support jig has a different mineral content depending on the growth of the plant to be cultivated. The hydroponics method according to (8), wherein a nutrient solution is supplied.
(13) The cultivation unit includes a support unit that supports a plant, and a plurality of nutrient tanks and / or nutrient solution storage units to which the support unit is attached and the nutrient solution is supplied. Hydroponic culture according to (8), wherein the liquid tank and / or nutrient solution storage unit is supplied with nutrient solutions having different mineral content in each available state according to the growth of the plant to be cultivated. Cultivation method.
(14) The hydroponic cultivation method according to (8), wherein the mineral component is at least one element selected from the group consisting of iron, zinc, and calcium.
(15) The hydroponic cultivation according to (8), wherein the plant to be cultivated is cultivated with a nutrient solution having a low content of available mineral components and then cultivated with a nutrient solution having a high availability of mineral components Method.
(16) The water culture according to (8), wherein the plant to be cultivated is cultivated with a nutrient solution containing an organic acid state of a mineral component, and then cultured with a nutrient solution having a high available mineral component. Cultivation method.
(17) The water culture according to (8), wherein the plant to be cultivated is cultivated with a nutrient solution containing an organic acid state of a mineral component, and then cultured with a nutrient solution having a low available mineral component. Cultivation method.

  According to the hydroponic cultivation system and hydroponic cultivation method according to the present invention, it is possible to cultivate a high mineral content plant without causing physiological disorder.

1 is a schematic configuration diagram of a hydroponic cultivation system according to the present invention. It is a schematic block diagram which shows an example of the hydroponic cultivation system provided with the movable plant support jig | tool (cultivation panel). It is a schematic structure figure showing an example of a hydroponic cultivation system provided with a plurality of cultivation tanks. It is a schematic diagram of the characteristic which shows the relationship between the cultivation days of Example 2, and the iron concentration melt | dissolved in a nutrient solution. It is a schematic diagram of the characteristic which shows the relationship between the cultivation days of Example 9, and the iron concentration melt | dissolved in a nutrient solution. It is a schematic diagram of the characteristic which shows the relationship between the cultivation days of Example 10 and the concentration of iron melt | dissolved in a nutrient solution.

  Hereinafter, the hydroponics system and hydroponics method concerning the present invention are explained in detail with reference to drawings.

  The hydroponic cultivation system and hydroponic cultivation method according to the present invention provide a nutrient solution having a low content as a supply state for a predetermined mineral during a predetermined period of plant growth of a plant to be cultivated (a mineral component content in a supply state) Is cultivated with low nutrient solution). According to the hydroponic cultivation system and hydroponic cultivation method according to the present invention, the content of the mineral in the cultivated plant can be greatly improved. Here, the available state means a form that is easily absorbed by plants and easy to use for growth. Therefore, the nutrient solution having a low mineral component content in the available state only needs to have a low concentration as the available state with respect to the predetermined mineral component, and includes, for example, a nutrient solution containing the mineral component in a high concentration as the unavailable state Meaning. Here, the non-suppliable state means a compound that is difficult to be absorbed by plants. For example, although the details will be described later, it means an organic acid form or an inorganic acid form of a mineral component.

  As a hydroponic cultivation system, for example, as shown in FIG. 1, a cultivation unit 1 in which a plant to be cultivated is arranged, and a nutrient solution having a low mineral component content available for the cultivation unit 1 (hereinafter simply referred to as a nutrient solution). And a nutrient solution supply apparatus 2a for supplying a nutrient solution having a low mineral component content). In addition, as shown in FIG. 1, the hydroponics system is a nutrient solution (hereinafter simply referred to as a mineral component content) that has a higher mineral component content in the available state as compared to the nutrient solution supplied by the nutrient solution supply device 2 a. You may provide the nutrient solution supply apparatus 2b which supplies (it may call a high nutrient solution). Furthermore, although not shown, the hydroponic cultivation system may include a thermometer, a temperature control device, a hygrometer, a humidity control device, and other various devices related to plant cultivation.

  Here, the mineral is not particularly limited, and means an inorganic substance composed of elements other than carbon, hydrogen, nitrogen and oxygen constituting the organic substance and an inorganic substance containing the element. Specifically, examples of the mineral include zinc, potassium, calcium, chromium, selenium, iron, copper, sodium, magnesium, manganese, molybdenum, iodine and phosphorus. In the hydroponic cultivation system and hydroponic cultivation method according to the present invention, it is preferable that the mineral is applied to at least one element selected from the group consisting of iron, zinc, and calcium. In particular, in the hydroponic cultivation system and hydroponic cultivation method according to the present invention, it is more preferable to apply to iron as a mineral.

  Here, the plant to be cultivated is not particularly limited. Including meaning. Especially, in the hydroponic cultivation system and hydroponic cultivation method which concern on this invention, it is preferable to make leaf lettuce or a komatsuna into the plant of cultivation object.

  More specifically, as a hydroponics system, it is preferable that a nutrient solution having a low mineral component content and a nutrient solution having a high mineral component content can be switched and supplied to the cultivation unit 1. As such a form, a plant support jig provided with a mechanism for supplying nutrient solution while supporting a plant is provided. For example, as shown in FIG. 2, a plurality of plants in which plants to be cultivated are arranged. The hydroponics system which has the cultivation unit 1 provided with the cultivation panel 3a, 3b which is a jig | tool for plant support of this, and the panel support member 4 which supports cultivation panel 3a, 3b so that a movement is possible is mentioned. In addition, about the hydroponics system shown in FIG. 2, the system disclosed by Unexamined-Japanese-Patent No. 2006-086734, for example, and the system disclosed by Unexamined-Japanese-Patent No. 5-076252 can be diverted suitably.

  In the hydroponic cultivation system shown in FIG. 2, the cultivation panel 3a and the cultivation panel 3b are attached to the panel support member 4 so as to be movable in the direction indicated by the arrows in the figure. For the sake of explanation, in the hydroponics system, the position of the cultivation panel 3a shown in FIG. 2 is referred to as a first position, and the position of the cultivation panel 3b shown in FIG. 2 is referred to as a second position.

  The hydroponic cultivation system shown in FIG. 2 includes a nutrient solution supply pipe 5a disposed above the first position and a nutrient solution supply pipe 5b disposed above the second position. . That is, in the state of FIG. 2, the nutrient solution supply pipe 5a is disposed above the cultivation panel 3a, and the nutrient solution supply pipe 5b is disposed above the cultivation panel 3b. Although not shown, these nutrient solution supply pipes 5a and 5b are connected to a nutrient solution supply device 2a for supplying a nutrient solution having a low mineral component content and a nutrient solution supply device 2b for supplying a nutrient solution having a high mineral component content, respectively. Has been.

  Although not shown in FIG. 2, the hydroponic cultivation system can be provided below the cultivation panels 3 a and 3 b and can include a nutrient solution tank (collection tank) for collecting the supplied nutrient solution. . In this case, the nutrient solution collected in the collection tank can be circulated and reused in the nutrient solution supply devices 2a and 2b.

  The cultivation panels 3a and 3b have a plurality of planting holes for holding seedlings of the plant to be cultivated. These planting holes are arranged at an appropriate interval in consideration of the size of the harvesting period of the plant to be cultivated, and are drilled at a certain angle with respect to the panel surface.

  Although not shown in particular, in order to transplant seedlings into a cultivation panel, for example, seedlings can be grown on a sponge-like medium cut into small pieces, and the medium can be held in the planting hole.

  In the cultivation panels 3a and 3b, one panel surface is a cultivation surface and the other panel surface is a nutrient solution supply surface. In order to transplant seedlings to the cultivation panel, the nutrient solution is transplanted so that its roots grow along the nutrient solution supply surface, and the nutrient solution supplied via the nutrient solution supply pipes 5a and 5b is the nutrient solution supply surface. To reach the roots of the transplanted seedlings.

  Although not shown, the nutrient solution supply pipes 5a and 5b are formed with a plurality of small holes so that the nutrient solution flowing inside the nutrient solution supply tubes 5a and 5b flows down toward the nutrient solution supply surfaces of the cultivation panels 3a and 3b. And while the nutrient solution supply apparatus 2a and 2b adjusts the flow volume and flow rate of nutrient solution suitably, the nutrient solution of cultivation panels 3a and 3b by arrangement | positioning and opening area of the small hole formed in the nutrient solution supply pipes 5a and 5b The nutrient solution can be uniformly supplied to the supply surface.

  In addition, the nutrient solution supply surface of the cultivation panels 3a and 3b is provided with an uneven shape so that the nutrient solution can be efficiently distributed to the roots of the transplanted seedlings, or a nutrient solution pool in which the nutrient solution stays in the vicinity of the roots. Although it can also form, the specific form of a nutrient solution supply surface is not specifically limited.

  According to the hydroponic cultivation system shown in FIG. 2 configured as described above, for example, a nutrient solution having a low mineral component content via the nutrient solution supply pipe 5a with respect to the cultivation panel 3a in the first position. Can be supplied to the cultivation panel 3b in the second position via the nutrient solution supply pipe 5b. Therefore, in the hydroponic cultivation system shown in FIG. 2, a plant can be cultivated with a nutrient solution having a low mineral component content for a predetermined period of the plant growth period by arranging the plant to be cultivated on the cultivation panel 3a. Moreover, after the said period passes, a plant can be cultivated by the nutrient solution with a high mineral component content after the progress of the said period by moving the cultivation panel 3a to the 2nd position.

  Although not shown, when the cultivation panel 3a is moved from the first position to the second position, that is, before starting cultivation at the second position, the roots of the plants arranged on the cultivation panel 3a are washed. Also good. The hydroponic cultivation system may include, for example, a cleaning device for cleaning the roots of plants arranged on the cultivation panel 3a between the first position and the second position.

  In the hydroponics system shown in FIG. 2, the cultivation panels 3a and 3b are moved in the direction of the arrow, and the nutrient solution having a low mineral component content and the nutrient solution having a high mineral component content are switched for cultivation. However, in the hydroponics system shown in FIG. 2, the culture panel 3a in the first position is not moved, and a nutrient solution having a low mineral content is supplied from the nutrient solution supply pipe 5a for a predetermined period of the plant growth period. Then, a nutrient solution having a high mineral content may be supplied from the nutrient solution supply pipe 5a. In this case, the nutrient solution supply pipe 5a is connected to a nutrient solution supply device 2a for supplying a nutrient solution having a low mineral component content and a nutrient solution supply device 2b for supplying a nutrient solution having a high mineral component content. Either nutrient solution will be passed.

  On the other hand, the hydroponics system that can switch between a nutrient solution having a low mineral component content and a nutrient solution having a high mineral component content to supply to the cultivation unit 1 is not limited to the form shown in FIG. As shown in Fig. 4, a hydroponic cultivation system having a cultivation unit 1 including a plurality of nutrient solution tanks (cultivation tanks) 6a, 6b and 6c in which plants to be cultivated are arranged. In addition, about the hydroponics system shown in FIG. 3, the system disclosed by Unexamined-Japanese-Patent No. 2015-136298 can be diverted suitably, for example.

  The hydroponic cultivation system shown in FIG. 3 includes cultivation tanks 6a, 6b and 6c, a plurality of nutrient solution storage units 7a and 7b connected to the cultivation tanks 6a, 6b and 6c, a nutrient solution storage unit 7a and a cultivation tank. 1st piping 8 which connects 6a, 6b and 6c, and 2nd piping 9 which connects nutrient solution storage part 7b and cultivation tanks 6a, 6b and 6c are provided. Moreover, the hydroponics system has the drain pipe 10 connected to the cultivation tanks 6a, 6b, and 6c.

  Each of the cultivation tanks 6a, 6b, and 6c includes a support base 11 that supports a plant, and a container portion 12 that is attached with the support base 11 and holds a nutrient solution therein.

  Further, the hydroponic cultivation system has a first pump 13 at the start end of the first pipe 8 in the nutrient solution storage unit 7a and a start unit at the start of the second pipe 9 in the nutrient solution storage unit 7b. 2 pumps 14. The first pipe 8 and the second pipe 9 are provided with a plurality of valves 15 and 16, respectively.

  Furthermore, in the hydroponic cultivation system shown in FIG. 3, a nutrient solution having a low mineral component content is stored in the nutrient solution storage unit 7a, and a nutrient solution having a high mineral component content is stored in the nutrient solution storage unit 7b. Yes.

  In the hydroponic cultivation system configured as described above, for example, when the plant arranged in the cultivation tank 6a is in a predetermined period of the plant growth period, a nutrient solution having a low mineral component content is supplied from the nutrient solution storage unit 7a. To 6a. Specifically, the first pump 13 in the nutrient solution storage unit 7a is driven, the nutrient solution having a low mineral component content is passed through the first pipe 8, and the valve 15 of the first pipe 8 is controlled. Thus, a nutrient solution having a low mineral component content can be supplied to the cultivation tank 6a. And after a predetermined period passes, supply of the nutrient solution with a low mineral component content with respect to the cultivation tank 6a is stopped, and a nutrient solution with a high mineral component content is supplied to the cultivation part 6a from the nutrient solution storage part 7b. Thus, in the hydroponic cultivation system shown in FIG. 3, a plant is cultivated with a nutrient solution having a low mineral component content for a predetermined period of the plant growth period by switching the nutrient solution from the nutrient solution storage units 7a and 7b. be able to.

  Each of the hydroponic cultivation systems shown in FIGS. 2 and 3 can supply a nutrient solution having a low mineral content to the cultivation unit 1 by manual control by an operator, but supply the nutrient solution to the cultivation unit 1. A control device for controlling can also be provided. For example, in the hydroponics system shown in FIG. 2, the cultivation panels 3a and 3b are moved, the nutrient solution having a low mineral component content and the nutrient solution having a high mineral component content are switched, and the supply amount and timing of the nutrient solution are controlled. It can be controlled by the device. Further, in the hydroponic cultivation system shown in FIG. 3, the nutrient solution can be switched from the nutrient solution storage units 7 a and 7 b, the amount of liquid supplied, the timing, and the like can be controlled by the control device.

  Although not shown, the hydroponics system is a measuring device that measures the ion concentration of a specific mineral component contained in the nutrient solution supplied to the cultivation tanks 6a, 6b, and 6c, and the ion concentration measured by the measuring device. And a nutrient solution controller for controlling the nutrient solution supplied to the cultivation tanks 6a, 6b and 6c. Here, with the nutrient solution controller, the ion concentration of the mineral component contained in the nutrient solution supplied to the cultivation tanks 6a, 6b and 6c using a plurality of nutrient solutions set to different mineral component contents is within a predetermined range. It can be set as the means which supplies the liquid mixture which mixed the said some nutrient solution by the predetermined | prescribed ratio so that it may become to the cultivation tanks 6a, 6b, and 6c. The nutrient solution controller is not limited to the above-mentioned means, and ions of mineral components contained in the nutrient solution supplied to the cultivation tanks 6a, 6b and 6c using a plurality of nutrient solutions set to different mineral component contents. The plurality of nutrient solutions may be selectively supplied to the cultivation tanks 6a, 6b, and 6c so that the concentration is in a predetermined range. In particular, the nutrient solution controller is not limited to the above-mentioned means, and includes any means that can adjust the ion concentration of the mineral component contained in the nutrient solution supplied to the cultivation tanks 6a, 6b, and 6c to a predetermined range. .

  In the hydroponic cultivation system and hydroponic cultivation method according to the present invention, the plant cultivated by cultivating the plant arranged in the cultivation unit with a nutrient solution having a low mineral component content for a predetermined period of the plant growth period. The said mineral amount contained will improve significantly.

  Here, the plant growth period means a period after the seedling raising period and before harvesting. The seedling raising period varies depending on the plant to be cultivated, but is a period from 20 days to 40 days after seeding on a sponge-like medium. For example, in the case of leaf lettuce, there is a seedling growing period of 25 to 33 days after sowing, and then the plant growth period is approximately 15 to 30 days.

  The predetermined period of the plant growth period depends on the mineral content contained in the nutrient solution, for example, 6 to 20 days in the plant growth period, preferably 8 to 15 days, more preferably 10 to 12 days. means.

  Moreover, in the hydroponic cultivation system and hydroponic cultivation method according to the present invention, as a nutrient solution having a low mineral component content, a nutrient solution in which the concentration of the supply state of a specific mineral component is reduced compared to a normal nutrient solution And a nutrient solution containing a specific mineral component as a non-supplyable state (organic acid state or inorganic acid state).

  For example, in a normal nutrient solution, iron is contained in the available state in an amount of about 1 to 6 ppm, zinc is about 0.5 to 2 ppm, and calcium is about 50 to 250 ppm. Therefore, the nutrient solution in which the concentration of the specific mineral component is reduced as compared with the normal nutrient solution is, for example, 50% or less, preferably 10% or less, more preferably 5% with respect to the lower limit of these concentrations. It can be set as the nutrient solution containing a mineral component with the density | concentration of% or less. Furthermore, as a nutrient solution which reduced the density | concentration of the specific mineral component compared with the normal nutrient solution, it can also be set as the nutrient solution which the said mineral component is below a detection limit.

  In addition, the nutrient solution which reduced the density | concentration of the said specific mineral component compared with a normal nutrient solution may add the chelating agent which has the effect | action complexing a mineral component to a normal nutrient solution. Examples of chelating agents include organic acids such as EDTA, DTPA, TTHA, NTA, HEDP, citric acid, malic acid, gluconic acid, fulvic acid, humic acid, and ascorbic acid. Further, the nutrient solution having a low mineral component content in the available state may be one having a low mineral component content in the available state already at the time of supplying the nutrient solution to the plant. It is good also as a nutrient solution in which the mineral component content of a state becomes low.

  On the other hand, the non-supplyable mineral component is not particularly limited, but iron citrate, sodium ferrous citrate, ammonium iron citrate, iron (II) fumarate, iron (II) oxalate, iron gluconate (II ), Iron (III) nitrate, organic acid iron such as fulvic acid complex and humic acid complex, ferrous sulfate, ferric sulfate, ferrous chloride, ferric chloride and other inorganic acid iron, zinc gluconate, etc. Organic acid zinc, inorganic acid zinc such as zinc chloride and zinc nitrate, calcium citrate, calcium stearate, calcium gluconate, calcium acetate, calcium benzoate and calcium lactate, organic acid calcium, and calcium carbonate, calcium bicarbonate, Calcium sulfate, calcium sulfite, calcium silicate, calcium phosphate, calcium pyrophosphate, calcium hypochlorite, calcium chlorate, excess Periodate, calcium bromate, calcium iodate, calcium chromate, calcium inorganic acids such as calcium tungstate and calcium molybdate and may hydrates thereof. In particular, a nutrient solution containing a specific mineral component as an organic acid state is preferable. These mineral components are preferably precipitated gradually in the nutrient solution. In particular, iron citrate, iron nitrate (III), and ferrous sulfate are preferable.

  In the hydroponic cultivation system and the hydroponic cultivation method according to the present invention, after cultivating a plant with a nutrient solution having a low mineral component content for a predetermined period of plant growth, the nutrient solution having a high mineral component content (ordinary nutrient solution) It is preferable to continue plant cultivation using Thereby, a plant with a high content of mineral components can be harvested. In addition, you may add the chelating agent which has the effect | action which complex | complexes a mineral component to the said nutrient solution (normal nutrient solution) with high mineral component content. Examples thereof include organic acids such as EDTA, DTPA, TTHA, NTA, HEDP, citric acid, malic acid, gluconic acid, fulvic acid, humic acid, and ascorbic acid.

  Further, in the hydroponic cultivation system and hydroponic cultivation method according to the present invention, after cultivating a plant using a nutrient solution containing a specific mineral component as an organic acid state for a predetermined period of plant growth, the mineral component It is preferable to continue plant cultivation using a nutrient solution with a reduced concentration compared to a normal nutrient solution and then harvest. Thereby, a plant with a high content of mineral components can be harvested.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, the technical scope of this invention is not limited to a following example.

[Example 1]
In this example, leaf lettuce (frilled ice, manufactured by Snow Brand Seed Seed Co., Ltd.) is used as a plant to be cultivated. At the same time, the yield and appearance of the edible portion were evaluated.

Cultivation conditions:
Nutrient environment / cultivation method: Soil cultivation, with aeration / Nutrient solution supply method: With additional fertilization (Nutrient solution components excluding target iron components)
・ Nutrient pH: pH 4-7
・ Nutrient solution adjustment: Ion exchange water or tap water from which chlorine has been removed ・ Number of planted plants: 10 to 3 strains per 8L liquid fertilizer, or 6 to 3 strains per 2.5L fertilizer:
"Fertilizer 1" is a trade name (product number): M-type hydroponic MK1 (OAT0162-3), M-type hydroponic M2 (OAT0008-5), M-type hydroponic M5 (OAT0163-4) (M-type) “Fertilizer 2” in Tables 1-1 and 1-2 are trade names: M-plus 1 and M-plus 2 (manufactured by Toago Material Technology Co., Ltd.). These “fertilizer 1” and “fertilizer 2” contain EDTA-iron as an iron component. “Fertilizer 3” was formulated with a Yamazaki prescription (target crop lettuce) so that the composition was nitrogen 6me / L, phosphorus 1.5me / L, potassium 4me / L, calcium 2me / L, magnesium 1me / L. Furthermore, as a trace element, boron 0.5 ppm, manganese 0.5 ppm, zinc 0.05 ppm, copper 0.02 ppm, molybdenum 0.01 ppm were adjusted, and a single fertilizer blended fertilizer was blended. Fertilizer 3 does not contain iron. Furthermore, “fertilizer 3 + iron citrate” and “fertilizer 3 + EDTA-iron” are fertilizers obtained by adding fertilizer 3 with iron citrate or EDTA-iron.
・ Fertilizer blending method:
"Fertilizer 1": Prepare two tanks, put 7.5kg of MK1 and 500g of M5 on one side, and 5kg of M2 on the other side, dissolve in 50L of tap water each to make a fertilizer stock solution. Ninety liters of tap water was stored in the cultivation tank, and 500 mL each of two types of fertilizer stock solutions were added and mixed to make fertilizer 1. If necessary, the electrical conductivity of the liquid fertilizer was adjusted by changing the added amount of the fertilizer stock solution concentration.
"Fertilizer 2": Prepare two tanks, put 7.5kg of M-plus 1 on one side and 5kg of M-plus 2 on the other side and dissolve each with 50L of tap water to make a fertilizer stock solution. 8 L of pure water was added to the cultivation tank, and 20 mL of each of the two types of fertilizer stock solutions was added to and mixed with this to make fertilizer 2. If necessary, the electrical conductivity of the liquid fertilizer was adjusted by changing the added amount of the fertilizer stock solution concentration.
“Fertilizer 3”: For large elements, prepare 2 containers, put KNO ₃ : 40.4 g, MgSO ₄ · 7H ₂ O: 12.3 g, NH ₄ H ₂ PO ₄ : 5.7 g on one side was dissolved in water, Ca to the other _{(NO 3) 2 · 4H 2} O: put 23.6 g, was dissolved in pure water 1L, to prepare a 100 times solution. For trace elements, H ₃ BO ₃ : 8.6 g, MnSO ₄ · 5H ₂ O: 6.3 g, ZnSO ₄ · 7H ₂ O: 0.67 g, CuSO ₄ · 5H ₂ O: 0.23 g, Na ₂ MoO ₄ · 2H ₂ O: 0.067 g was added and dissolved in 1 L of pure water to prepare a 3000-fold solution. 8 L of pure water was added to the cultivation tank, and 15 mL of each of the two types of fertilizer stock solutions and 2.7 mL of the trace amount of fertilizer stock solution were added and mixed to prepare fertilizer 3. If necessary, the electrical conductivity of the liquid fertilizer was adjusted by changing the added amount of the fertilizer stock solution concentration.
In addition, as a method for adding iron citrate, 100 ml of pure water containing 0.5 g of trade name: iron (III) citrate (n hydrate) (first grade, (Fe: 16 to 20%), manufactured by Kishida Chemical) And an iron citrate solution was prepared.
In addition, as a method for adding EDTA-iron, a trade name: Fe (III) -EDTA (manufactured by Dojin Chemical Co., Ltd.) was dissolved to a concentration of 1000 ppm to prepare an EDTA-iron solution.

Air-conditioning environment and temperature: Air-conditioner cooling 21 ° C setting (indoor), humidity 30% or more · CO ₂ : 400 ppm in the atmosphere

Light environment / light source: LED (Red / Blue ratio of LED chip = 12: 3, manufactured by Otomo Seisakusho, AGR900-PCN4D, power consumption 43.5W)
・ Distance from the light source of the cultivation surface 243mm, photosynthetic photon flux density 168 (μmolm ^-2 s ^-1 )
・ Irradiation time 12hr / day

  In this example, first, leaf lettuce to be cultivated was sown in a medium, and cultivated by sowing and greening with tap water for about one week. Further, for about 3 to 4 weeks, cultivation at the seedling stage is performed with the fertilizer 1, and then, cultivation is performed under the conditions shown in Tables 1-1 and 1-2. did.

  In Table 1-1 and Table 1-2, (iron addition) is obtained by adding the above-mentioned iron citrate solution or EDTA-iron solution to fertilizer 2 or fertilizer 3. “(Iron addition: iron citrate)” adds ferrous fertilizer 3 in an amount of 1/200 of the iron citrate solution, and “(iron addition: EDTA-iron)” is 1/100 of fertilizer 2 or fertilizer 3. An amount of ~ 1/200 EDTA-iron solution was added. Moreover, in Table 1-2, about Examples 1-9, it describes about the liquid fertilizer (it describes with immersion liquid here) containing iron used after growing with the nutrient solution which lacked iron.

Conditions for measuring iron content:
・ Leaf was the target site.
・ Pretreatment: Dry ashing method (samples were washed with ion-exchanged water, dried and then ashed in an electric furnace heated to 520 ° C. Then, pyrolysis and filtration with hydrochloric acid were performed, and the liquid after filtration was measured. A sample was used.)
-The measurement sample was measured with an apparatus: ICPE-9000 (manufactured by Shimadzu Corporation).

  Moreover, as shown to Table 1-1 and 1-2, the comparative example 1 uses iron-containing fertilizer (fertilizer 2) as a nutrient solution in all the growth periods like the normal nutrient solution culture conditions. This corresponds to the comparative example. Moreover, the comparative example 2 is corresponded to the comparative example which used the iron containing fertilizer (fertilizer which added iron citrate to fertilizer 3) as a nutrient solution in all the growth periods.

  Moreover, as shown to Table 1-1 and 1-2, Examples 1-8 use the nutrient solution which does not contain iron in the predetermined period of the growth period, and used the nutrient solution containing iron after that. It is. In Example 9, a nutrient solution containing iron citrate (an organic acid state of iron) was used as a nutrient solution not containing iron to be used in a predetermined period of growth, and then a nutrient solution containing iron was used. It is an example. In addition, the nutrient solution containing iron citrate has the property that iron precipitates with time and the iron content decreases. Furthermore, Examples 10-12 use the nutrient solution containing iron citrate (the organic acid state of iron) as the nutrient solution not containing iron used in the predetermined period of the growth period, and then does not contain iron. It is an example using a nutrient solution.

  Here, in the cultivation conditions of Example 2, the relationship between the cultivation days and the iron concentration dissolved in the nutrient solution is shown in FIG. Also in the cultivation conditions of Example 1, 3-8, the iron concentration in a nutrient solution is fluctuate | varied similarly to FIG.

  Moreover, in the cultivation conditions of Example 9, the relationship between the cultivation days and the iron concentration dissolved in the nutrient solution is shown in FIG. Also in the cultivation conditions of Example 9, the iron concentration in the nutrient solution varies as in FIG.

  Furthermore, in the cultivation conditions of Example 10, the relationship between the cultivation days and the iron concentration dissolved in the nutrient solution is shown in FIG. Also in the cultivation conditions of Examples 11 and 12, the iron concentration in the nutrient solution varies as in FIG.

  About Examples 1-12 and Comparative Examples 1-2, after harvesting, the iron content per 1 g of dry matter (ppm / dry matter 1 g) was measured. About Examples 1-3 and 5-9, before being immersed in the nutrient solution which does not contain iron, it harvested partly, and measured the iron content (ppm / dry matter 1g) per gram of dry matter. Moreover, about Examples 1-12 and Comparative Examples 1-2, while measuring the yield of an edible part after harvesting, the external appearance (the presence or absence of a physiological disorder or withering) was visually evaluated. These results are shown in Table 2.

  From Table 2, it became clear that the iron content was remarkably improved at the time of harvesting by cultivation using a nutrient solution that did not contain iron during a predetermined period in the growth period. In particular, for Examples 1 to 9, a nutrient solution that does not contain iron (fertilizer 3), or a nutrient solution that contains iron citrate, and in which iron citrate is sufficiently precipitated and becomes iron deficient is used. Then, it is thought that absorption of iron was promoted by using a nutrient solution containing iron. On the other hand, about Examples 10-12, it is a nutrient solution containing iron citrate and iron is absorbed in the root in a state where the iron is dissolved, and then it is absorbed into the root by growing in a nutrient solution not containing iron. It is thought that the iron moved to the leaves.

  In Table 2, iron deficiency means a nutrient solution that has become deficient in iron, that is, a nutrient solution in which the available iron content is low.

Claims (17)

A cultivation unit in which plants to be cultivated are arranged;
A nutrient solution supply device that supplies nutrient solution to the cultivation unit,
A hydroponic cultivation system characterized by cultivating a plant arranged in the cultivation unit with a nutrient solution having a low available mineral content for a predetermined period of plant growth.   The said nutrient solution supply apparatus switches the nutrient solution with a low mineral component content of an available state, and the nutrient solution with a high mineral component content of an available state, and supplies it to the said cultivation unit. Hydroponics system.   The hydroponic cultivation system according to claim 1, wherein the nutrient solution contains an organic acid state of a mineral component.   The hydroponic cultivation system according to claim 1, further comprising a control device that controls supply of the nutrient solution to the cultivation unit by the nutrient solution supply device. The cultivation unit includes a plant support jig that supports a plant and is supplied with a nutrient solution from the nutrient solution supply device.
The hydroponic cultivation system according to claim 1, wherein the plant supporting jig is supplied with a nutrient solution having different mineral component contents according to the growth of the plant to be cultivated. The cultivation unit includes a support unit that supports a plant, and a plurality of nutrient tanks and / or nutrient solution storage units to which the support unit is attached and the nutrient solution is supplied from the nutrient solution supply device,
The hydroponic cultivation system according to claim 1, wherein the plurality of nutrient solution tanks and / or nutrient solution storage units are supplied with nutrient solutions having different mineral content in an available state.   The hydroponic system according to claim 1, wherein the mineral component is at least one element selected from the group consisting of iron, zinc and calcium. In the hydroponics method of cultivating the plant with nutrient solution using the cultivation unit where the plant to be cultivated is arranged,
A hydroponic cultivation method characterized by cultivating a plant arranged in the cultivation unit with a nutrient solution having a low mineral content in an available state during a predetermined period of plant growth.   The hydroponic cultivation method according to claim 8, wherein a nutrient solution having a low available mineral component content and a nutrient solution having a high mineral component content are switched and supplied to the cultivation unit.   The hydroponic cultivation method according to claim 8, wherein the nutrient solution contains an organic acid state of a mineral component.   The hydroponic cultivation method according to claim 8, wherein supply of nutrient solution to the cultivation unit is controlled by a control device. The cultivation unit includes a plant support jig that supports a plant and is supplied with a nutrient solution.
The hydroponic cultivation method according to claim 8, wherein the plant supporting jig is supplied with a nutrient solution having different mineral component contents depending on the growth of the plant to be cultivated. The cultivation unit includes a support unit that supports a plant, and a plurality of nutrient tanks and / or nutrient solution storage units to which the support unit is attached and the nutrient solution is supplied.
The plurality of nutrient solution tanks and / or nutrient solution storage units are respectively supplied with nutrient solutions having different mineral contents in an available state according to the growth of the plant to be cultivated. The hydroponics method of description.   The hydroponic cultivation method according to claim 8, wherein the mineral component is at least one element selected from the group consisting of iron, zinc, and calcium.   9. The hydroponic cultivation method according to claim 8, wherein the plant to be cultivated is cultivated with a nutrient solution containing a low amount of available mineral components and then cultivated with a nutrient solution containing a high amount of available mineral components.   9. The hydroponic cultivation method according to claim 8, wherein the plant to be cultivated is cultivated with a nutrient solution containing an organic acid state of a mineral component, and then cultured with a nutrient solution having a high available mineral component.   9. The hydroponic cultivation method according to claim 8, wherein the plant to be cultivated is cultivated with a nutrient solution containing an organic acid state of a mineral component, and then cultured with a nutrient solution having a low available mineral component.

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