JP7268164B2 - Plant cultivation method and plant cultivation apparatus - Google Patents

Description

The present invention relates to a plant cultivation method and a plant cultivation apparatus for cultivating plants such as tomatoes.

Tomato cultivation methods range from soil culture in which seedlings are prepared in a hotbed and planted in the open field, to hydroponics in which production can be performed like a plant factory.

As this hydroponics method, in Patent Document 1, a cultivation tray having grooves formed in a substantially D-shaped horizontal cross section arranged in two rows in the longitudinal direction is filled with about 250 ml of culture medium ( (soil, coconut shells, rock wool, etc.) is put in and a nutrient solution for irrigation is supplied to each medium in which tomato seedlings are planted.

In the technique described in Patent Document 1, conventional media (soil, coconut shell, rock wool, etc.) have relatively good water retention, so the nutrient solution is watered 10 to 20% more than the amount of water required by the plant. Since the surplus liquid easily propagates bacteria, it has been generally disposed of as a waste liquid. In addition, since weakly acidic soil is said to be good for plant growth, the pH of the irrigation solution was adjusted to be slightly acidic.

Further, Patent Document 2 discloses a technique of using a gravel mixed medium composed of peridotite, coral sand and silica sand as a solid medium for cultivating plants with organic fertilizer without using soil. The gravel mixed medium in this technique has a mixing ratio of coral sand, peridotite, and silica sand of 1 to 3 peridotite and 1 to 9 silica sand to 3 coral sand.

JP 2007-306849 A Japanese Patent No. 4049370

However, in the technique described in Patent Document 1, the surplus of the irrigation nutrient solution is likely to propagate bacteria, so it is disposed of as a waste solution, which makes it difficult to reduce the cost of cultivating plants.

In addition, in the technique described in Patent Document 2, from the idea that it is better for the gravel mixed medium to be able to retain a certain amount of water, not only coral sand but also other two components are mixed for water retention. Since the other two components are relatively large, the mixing ratio of coral sand is 60% or less. It was difficult to reduce the cost of cultivating plants because it was easy for various bacteria to propagate and the liquid fertilizer had to be disposed of as waste liquid.

An object of the present invention is to provide a plant cultivation method and a plant cultivation apparatus capable of reducing the cost of plant cultivation.

The method for cultivating plants according to the first aspect of the present invention includes filling the inside of a container with a medium formed of coral gravel and components other than coral gravel, allowing plants to take root in the medium, and supplying liquid fertilizer to the medium. In the method for cultivating plants, the medium contains coral gravel at a rate of 70% or more.

Preferably, the method for cultivating plants according to claim 1 uses tomato as the plant.
In the method for cultivating plants according to the second aspect of the invention, a medium formed of coral gravel and components other than coral gravel is spread over a horizontally placed band-shaped gutter, and plants are allowed to take root in the medium at regular intervals. a irrigation tube is arranged above the culture medium, liquid fertilizer stored in a nutrient solution circulation tank is supplied to the culture medium through the irrigation tube, and the liquid fertilizer surplus from the supply is poured into the gutter. In the method for cultivating plants, the liquid fertilizer flowing through the drainage groove formed in the gutter is passed through the filter cloth attached to the inner surface, and the liquid fertilizer flowing in the drainage groove is returned from the gutter to the nutrient solution circulation tank. contains at a rate of 70% or more.

The method for cultivating plants according to the invention of claim 3 is characterized in that, in the method for cultivating plants according to claim 2, the nutrient solution is circulated according to a decrease in the amount of water indicated by a moisture meter installed in the culture medium or an instruction by a timer. The liquid fertilizer returned to the tank is reused by supplying it to the medium through the watering tube.

In the plant cultivation method of the invention according to claim 4, the liquid fertilizer returned to the nutrient solution circulation tank is supplied to the medium through the watering tube at a rate of a predetermined number of times or less per day. Reuse.

In the plant cultivation apparatus of the invention described in claim 5, a horizontally placed band-shaped gutter is covered with a medium formed of coral gravel and components other than coral gravel, and plants are rooted in the medium at regular intervals. a irrigation tube is arranged above the culture medium, liquid fertilizer stored in a nutrient solution circulation tank is supplied to the culture medium through the irrigation tube, and the liquid fertilizer surplus from the supply is poured into the gutter. A plant cultivating apparatus in which liquid fertilizer flows into a drainage groove formed in the gutter through a filter cloth attached to the inside, and the liquid fertilizer flowing in the drainage groove is returned from the end of the gutter to the nutrient solution circulation tank, wherein the A nutrient solution circulation tank, a liquid fertilizer adjustment tank, a first raw material liquid tank for storing the first raw material liquid, a second raw material liquid tank for storing the second raw material liquid, a liquid fertilizer mixer, a liquid fertilizer pump, A nutrient system comprising a liquid fertilizer transfer pump, a sprinkling pump, a level sensor for detecting the level of the liquid fertilizer in the nutrient solution circulation tank, and a solenoid valve, wherein the culture medium contains coral gravel at a concentration of 70% or more. When a certain amount of liquid fertilizer in the nutrient solution circulation tank is consumed, the nutrient solution device transfers the nutrient solution from the liquid fertilizer adjustment tank to the nutrient solution circulation tank by the liquid fertilizer transfer pump according to the instruction of the level sensor. When the water level of the liquid fertilizer adjustment tank is lowered, water is supplied to the liquid fertilizer adjustment tank to a predetermined position, and the liquid fertilizer pump and The liquid fertilizer mixer is used to mix the first raw material liquid and the second raw material liquid, and the nutrient solution control is performed so that the liquid fertilizer stored in the liquid fertilizer adjusting tank reaches an appropriate EC concentration.

According to a sixth aspect of the present invention, there is provided a plant cultivating apparatus according to the fourth aspect, further comprising a flow rate sensor for detecting a flow rate of the liquid fertilizer flowing through the irrigation tube, which is installed in the nutrient solution apparatus. The controller controls the nutrient solution, and displays the amount of liquid fertilizer supplied from the nutrient solution circulation tank to the culture medium based on the detection result of the flow rate sensor.

The plant cultivation method and the plant cultivation apparatus according to the present invention have made it possible to reduce the cost of plant cultivation.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the outline|summary of the cultivation method of the plant which concerns on the 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the coral gravel used for the cultivation method of the plant which concerns on the 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the gutter and filter cloth which are used for the cultivation method of the plant which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the whole facility using the cultivation apparatus of the plant which concerns on the 2nd Embodiment of this invention. It is a block diagram of a plant cultivation apparatus according to a second embodiment of the present invention. FIG. 4 is a plan view showing a nutrient solution device of the plant cultivation device according to the second embodiment of the present invention. It is the 1st side view which shows the nutrient solution apparatus of the plant cultivation apparatus which concerns on the 2nd Embodiment of this invention. It is the 2nd side view which shows the nutrient solution apparatus of the plant cultivation apparatus which concerns on the 2nd Embodiment of this invention. Fig. 10 is a first cross-sectional view showing a cultivation bed and an installation stand of the plant cultivation apparatus according to the second embodiment of the present invention; It is the 2nd sectional drawing which shows the cultivation bed and installation stand of the plant cultivation apparatus which concerns on the 2nd Embodiment of this invention.

<First embodiment>
FIG. 1 is an explanatory diagram showing the outline of the system according to the first embodiment of the present invention.
In FIG. 1, in the plant cultivation method according to the first embodiment of the present invention, a medium formed of coral gravel and components other than coral gravel inside a container (gutter 2) constituting a plant cultivation apparatus 1 3, the plant (tomato 10) is rooted in the medium 3, and the liquid fertilizer 4 is supplied to the medium 3, wherein the medium 3 contains coral gravel at a rate of 70% or more. is.

More specifically, the method for cultivating plants shown in FIG. Rooted at regular intervals, a watering tube 5 was placed above the culture medium 3, and the liquid fertilizer 4 stored in the nutrient solution circulation tank 6 was formed on the watering tube 5 at intervals of 5 cm through the watering tube 5. The culture medium 3 is supplied with liquid from the holes 5a, and the surplus liquid fertilizer 4 due to the supply of liquid is passed through the filter cloth 7 attached to the inside of the gutter 2 to the drainage groove 8 formed in the gutter 2. In the plant cultivation method in which the liquid manure 4 flowing into the drainage groove 8 is returned from the end of the gutter 2 to the nutrient solution circulation tank 6 via the drainage pipe 9, the culture medium 3 contains coral gravel in an amount of 70% or more. Contains in proportion.

Here, as for the combination of coral gravel and components other than coral gravel, the combination of coral gravel and unavoidable components is optimal, and components other than coral gravel are unnecessary. For example, the medium 3 may contain about 30% of components other than coral gravel so as not to have an adverse effect.

The irrigation pump 11 supplies the liquid fertilizer 4 returned to the nutrient solution circulation tank 6 to the culture medium 3 via the irrigation tube 5 according to the instruction from the timer 12 to reuse the liquid fertilizer 4 .

In the first embodiment of the present invention, when the air temperature is about 28° C., the maximum number of times of water supply by the watering pump 11 is seven times a day. Set the daily amount per share to 500ml. However, the frequency and amount of water supply by the watering pump 11 can be variously adjusted depending on the variety of the tomato 10 and the target sugar content.

Therefore, in the first embodiment of the present invention, the liquid fertilizer returned to the nutrient solution circulation tank 6 is supplied to the culture medium through the watering tube 5 at a rate equal to or less than a predetermined number of times per day. will be reused.
Moreover, the upper side of the culture medium 3 and the irrigation tube 5 is covered with a light shielding sheet (light shielding sheet 76 in FIG. 9) having a hole through which the stem of the tomato 10 passes.

FIG. 2 is a perspective view showing coral gravel used in the plant cultivation method according to the first embodiment of the present invention. FIG. ) shows the second type of coral gravel grains, and FIG. 2(c) shows the third type of coral gravel grains.

Grains 111 of the first type of coral gravel shown in FIG. 2(a) are crushed porous coral with relatively large pores, and have a columnar shape with a large number of relatively large pores 112 formed on the surface. It is The diameter of the grain 111 is D1, and the length of the grain 111 is L1.

The first type of coral gravel grains 121 shown in FIG. 2(b) is obtained by crushing porous coral with fine pores, and has a columnar shape with a large number of fine pores 122 formed on the surface. there is The diameter of the grain 121 is D2, and the length of the grain 121 is L2.

The first type of coral gravel grains 131 shown in FIG. 2(c) is obtained by crushing porous coral with fine pores on the surface and cavities in the center, and has a columnar shape with many fine particles on the surface. A hole 132 is formed and a cavity 133 is formed in the axial direction. The diameter of the grain 131 is D3, and the length of the grain 131 is L3.

Coral gravel grain diameters D1, D2, and D3 are applicable in the range of 0.5 to 10 mm, ideally 1 to 3 mm.
Coral gravel particle lengths L1, L2, and L3 are applicable in the range of 1 to 50 mm, and ideally 2 to 10 mm.

If the grains of coral sand and gravel are fine, they become too alkaline and their water holding capacity becomes too high. If they are coarse, their water holding capacity becomes too low.

Therefore, the grains of coral gravel are not made too fine like powder, but are made long enough to break a branch.

FIG. 3 is a perspective view showing a partially cutaway gutter and filter cloth used in the plant cultivation method according to the first embodiment of the present invention.
In FIG. 3, the gutter 2 is formed by molding styrene foam into the shape of a belt-like container with an open top.

The filter cloth 7 attached to the inside of the gutter 2 is formed by laminating a hydroponic black polyplastic sheet 21, a nonwoven fabric 22, a plastic net 23 and a nonwoven fabric 24 in order from the bottom. The hydroponic black polyplastic sheet 21 , nonwoven fabric 22 and nonwoven fabric 24 are formed to cover the entire upper side of the gutter 2 . The plastic net 23 is formed in the same size as the inner bottom surface of the gutter 2.

Here, rockwool, which is commonly used as a conventional medium, needs to be replaced every year, which costs money as industrial waste.
Coconut husk medium, which has become popular as a medium in recent years, needs to be replaced every 1-2 years because it is organic and changes over time.

In conventional high-sugar tomato cultivation, liquid fertilizer (water) is used as little as possible to reduce the amount of water absorbed by the fruit and increase the sugar content, resulting in less fruit production.
In order to solve these problems, the medium 3 formed of coral gravel and components other than coral gravel used in the first embodiment of the present invention is alkaline and does not change over time, and has characteristics that make it difficult for bacteria to propagate. there is no need to replace.

In addition, in the medium 3 formed of coral gravel and components other than coral gravel, due to the characteristic that various bacteria are difficult to propagate, there is no need to perform extreme watering restrictions in high sugar content tomato cultivation, so productivity can be improved. I can.

In addition, the plant cultivation method according to the first embodiment is a closed system that recycles the waste liquid of the liquid fertilizer 4, and due to the characteristic that various bacteria in the medium 3 are difficult to propagate, a facility for sterilizing the waste liquid is installed. I don't need it.

In the first embodiment of the present invention, the components other than the coral gravel in the medium 3 are components such as sand that are not intended to retain water. Therefore, in the first embodiment of the present invention, the amount of water that cannot be retained in the medium 3 is close to 90%, and the propagation of bacteria in the medium 3 can be suppressed. As a result, it becomes a conventional hydroponics method, and the need to discard the medium medium 3 is eliminated.

In the first embodiment of the present invention, the medium 3 contains coral gravel at a rate of 70% or more, so that the amount of water that the medium 3 cannot hold becomes nearly 90%, and the liquid fertilizer 4 needs to be circulated. We now have.

In the conventional hydroponics method (other ordinary hydroponics), etc., the alkaline nature of the liquid fertilizer was low, so the propagation of various bacteria in the liquid fertilizer was a problem, but in the first embodiment of the present invention, the culture medium The coral gravel in 3 increases the alkalinity of the liquid fertilizer 4, so it is possible to suppress the growth of various bacteria in the liquid fertilizer.

In addition, the medium 3 formed of coral gravel and components other than coral gravel used in the first embodiment of the present invention abundantly contains many types (70 types) of essential minerals such as calcium and magnesium. Therefore, it is absorbed by tomatoes as a trace element during growth and produces tomatoes with a very high sugar content (8 to 12 degrees sugar content).

Therefore, according to the method for cultivating plants according to the first embodiment of the present invention, it is possible to reduce the cost of cultivating plants (tomatoes).

<Second embodiment>
4 to 10 relate to the second embodiment of the present invention, FIG. 4 is an explanatory diagram showing the entire facility using a plant cultivation apparatus, FIG. 5 is a block diagram of the plant cultivation apparatus, and FIG. 7 is a first side view showing the nutrient solution device, FIG. 8 is a second side view showing the nutrient solution device, and FIG. 9 is a gutter and surroundings of the plant cultivation device. FIG. 10 is a second cross-sectional view showing the gutter and peripheral parts of the plant cultivation apparatus.

Here, the second embodiment differs from the first embodiment in that moisture meters (detection sensors 71, 72, 5), the liquid fertilizer 4 (see FIG. 5) returned to the nutrient solution circulation tank 6 (see FIG. 5) is transferred to the culture medium 3 (see FIG. 5) through the watering tube 5 (see FIG. 5). 9).

In FIG. 4, a tomato cultivation facility (plant) 30 has first to third cultivation buildings 31, 32, and 33 arranged in three rows.

The first cultivation building 31 is composed of one plant cultivation device 34 . The plant cultivation device 34 is composed of one nutrient solution device 41 and a plurality of gutter 2, culture medium 3, watering tube 5, filter cloth 7 and drainage pipe 9 shown in FIG.

In FIG. 4, the second cultivation building 32 is composed of one plant cultivation device 35 and a collection/shipment chamber 36 . The plant cultivation device 35 is composed of one nutrient solution device 41 and a plurality of gutter 2, culture medium 3, watering tube 5, filter cloth 7 and drainage pipe 9 shown in FIG.

In FIG. 4, the third cultivation building 33 is composed of one plant cultivation device 37 . The plant cultivation device 37 is composed of one nutrient solution device 41 and a plurality of gutter 2, culture medium 3, watering tube 5, filter cloth 7 and drainage pipe 9 shown in FIG.

Plant cultivation apparatuses 34, 35, and 37 are formed of coral gravel and components other than coral gravel in horizontally placed belt-shaped gutters 2, and culture medium 3 containing coral gravel at a rate of 70% or more (Fig. 9). See) is spread, plants are rooted in the medium 3 at regular intervals, an irrigation tube 5 (see FIG. 5) is placed on the top of the medium 3, and liquid fertilizer stored in a nutrient circulation tank 51 (see FIG. 5) 4 (see FIG. 5) is supplied to the culture medium 3 through the watering tube 5, and the surplus liquid fertilizer 4 due to the supply is filtered through the filter cloth 7 (see FIG. 9) attached to the inside of the gutter 2. ) into the drainage groove 8 (see FIG. 9) formed in the gutter 2, and the liquid fertilizer 4 flowing into the drainage groove 8 is transferred from the end of the gutter 2 to the nutrient solution circulation tank 51 (see FIG. 5). Send it back.

The plant cultivation device 34 will be described in detail below.
In FIG. 5, the cultivation beds 42 and 43 of the plant cultivation apparatus 34 are a combination of the gutter 2 and filter cloth 7 shown in FIG.

5, the nutrient solution device 41 includes a nutrient solution circulation tank 51, a liquid fertilizer adjustment tank 52, an A solution tank (first raw material solution tank) 53 for storing A solution (first raw material solution), and a B solution. Liquid B tank (second raw material liquid tank) 54 for storing (second raw material liquid), liquid fertilizer mixer 55, liquid fertilizer pump 56, liquid fertilizer transfer pump 57, agitating pump 58, and sprinkling pumps 59, 60 , a drainage pump 61, a level sensor 62 for detecting the level of the liquid fertilizer 4 in the nutrient solution circulation tank 51, a level sensor 63 for detecting the level of the liquid fertilizer 4 in the liquid fertilizer adjustment tank 52, an EC sensor (fertilizer concentration sensor) 64, flow rate sensors 65 and 66 for detecting the flow rate of the liquid fertilizer 4 flowing through the irrigation tube 5, display devices 67 and 68 for displaying the detection results of the flow rate sensors 65 and 66, respectively, and an electromagnetic valve 69. , and a control panel 70 .

This C sensor (fertilizer concentration sensor) 64 measures the concentration in the liquid fertilizer adjusting tank 52 .
Furthermore, it is preferable to measure the flow rate from the liquid fertilizer adjustment tank 52 to the liquid fertilizer circulation tank 51 to measure the consumption. This is because it becomes possible to measure consumption and the like.

The cultivation beds 42 and 43 are provided with detection sensors 71 and 72 for detecting the water content of the culture medium 3, respectively.

As shown in FIG. 6, in the nutrient solution apparatus 41, the nutrient solution circulation tank 51, the liquid fertilizer adjustment tank 52, the A liquid tank 53, and the B liquid tank 54 are divided into one rectangular frame 50. is provided. A diaphragm pump 73 of a liquid fertilizer mixer 55 is provided between the A liquid tank 53 and the B liquid tank 54 .

FIG. 7 shows the nutrient solution apparatus viewed from direction C in FIG.
As shown in FIG. 7, the control panel 70 is attached above the nutrient solution circulation tank 51 .

FIG. 8 shows the nutrient solution apparatus viewed from direction D in FIG.
As shown in FIG. 8, the irrigation tube 5 is provided with a 40-mesh disk filter 74 and a 120-mesh disk filter 75 .
In FIG. 5, when a certain amount of the liquid fertilizer 4 in the nutrient solution circulation tank 51 is consumed, the nutrient solution device 41 is operated by the liquid fertilizer transfer pump 57 from the liquid fertilizer adjustment tank 52 according to the instruction of the level sensor 62. An appropriate amount of fertilizer is supplied to the nutrient solution circulation tank 51, and when the water level of the liquid fertilizer adjustment tank 52 is lowered, water is supplied to the liquid fertilizer adjustment tank 52 up to a predetermined position, and the liquid fertilizer 4 in the liquid fertilizer adjustment tank 52 is properly adjusted. In order to achieve the EC concentration, the liquid fertilizer pump 56 and the liquid fertilizer mixer 55 are used to mix the liquid A (first raw material liquid) and the liquid B (second raw material liquid), and the liquid fertilizer adjustment tank 52 The liquid fertilizer 4 stored in is supplied until it reaches an appropriate EC concentration.

The plant cultivation device 34 controls the nutrient solution by a control device (control panel 70) installed in the nutrient solution device 41, and the liquid fertilizer 4 supplied from the nutrient solution circulation tank 51 to the culture medium 3. is displayed based on the detection results of the flow rate sensors 65 and 66.

As shown in FIG. 9 , the cultivation bed 42 of the plant cultivation device 34 is placed on a mounting table 80 .
The installation table 80 includes a plate-like top plate 81 and a plurality of legs 82 and 83 that support the top plate 81 .

Legs 82 and 83 are extendable. In the state where the legs 82 and 83 shown in FIG. , and the top plate 81 and the cultivation bed 42 are at their lowest.

As shown in FIG. 10, when the legs 82 and 83 are at their longest (maximum bed height), the width of the region S surrounded by the top plate 81, the legs 82 and 83, and the ground is larger than the diameter of the hot air duct 90. Maintaining a slightly long state, the height of the region S is about 1.5 times the diameter of the hot air duct 90, the width of the region S is kept slightly longer than the diameter of the hot air duct 90, and the top plate 81 and the cultivation bed 42 is the highest state.

By adjusting the region S in this manner, the temperature of the cultivation bed 42 can be optimized.
The cultivating device 35 of the second cultivating building 32 is similar to the cultivating device 34 of the first cultivating building 31 except for the sizes of the cultivating bed 42 and its peripheral portion.
The cultivation device 37 of the third cultivation building 33 is similar to the cultivation device 34 of the cultivation building 31 .

According to the plant cultivation apparatuses 34, 35, and 37 according to the second embodiment of the present invention, the medium 3 is formed of coral gravel and components other than coral gravel and contains coral gravel at a rate of 70% or more. By using it, the same effects as in the first embodiment can be obtained, and the cost for cultivating plants (tomatoes) can be reduced.

It is sufficient that the medium contains mainly coral at a rate of 70% or more. At present, however, we believe that a larger number of corals is more suitable.
Other ingredients may include sand, pumice, gravel, and the like.
Other components are more preferably alkaline.
Other ingredients may be shells (such as scallops). In some cases, it may be only shells. Furthermore, we believe that it is possible to make the liquid fertilizer 4 chemically alkaline.

Although the liquid manure 4 flowing through the gutter 2 is drawn out from the end of the gutter 2 in the embodiment, it is also possible to provide a discharge port for discharging sequentially from the middle and discharge. In that case, there is an advantage that it does not need to be inclined, and the inclination can be gentle. This is particularly effective when the gutter 2 is long.
Also, it is preferable to observe the flow rate of the watering pumps 59 and 60 and measure how much water is used.
Similarly, it is preferable to monitor the flow rate of the liquid manure transfer pump 57 .

The structure, system, program, material, connection of each member, chemical substance, etc. of the present invention can be variously changed without changing the gist of the present invention.
The material can also be freely selected from metal, plastic, FRP, wood, concrete, and the like.

For example, two or more members can be combined into one, or conversely, one member can be configured from two or more different members and connected.

Moreover, the above-described first and second embodiments are merely two of the current best or nearly so.
Also, the control and the like may be controlled by a higher-level control section or by a more terminal control section.
Also, the order of control and the like can be changed as appropriate as long as it has a predetermined effect.

<Definition, etc.>
Plants to be cultivated in the present invention can be applied not only tomato but also to various vegetables and fruits such as mango, banana, melon, paprika, eggplant, cucumber and strawberry. In addition to cherry tomatoes, fruit ruby, Sicilian rouge, Momotaro, etc. are also applicable as varieties of tomatoes. In addition to vegetables and fruits, it can also be applied to plants such as cereals, which preferably have a high sugar content.

DESCRIPTION OF SYMBOLS 1... Plant cultivation apparatus 2... Gutter 3... Culture medium 4... Liquid fertilizer 5... Irrigation tube 6... Nutrient solution circulation tank 7... Filter cloth 10... Tomato

Claims (5)

A medium formed of coral gravel and components other than coral gravel is spread over a horizontally placed belt-shaped gutter, plants are rooted in the medium at regular intervals, an irrigation tube is placed on the top of the medium, and a nutrient solution is applied. The liquid fertilizer stored in the circulation tank is supplied to the culture medium through the watering tube, and the liquid fertilizer surplus from the supply is discharged through the filter cloth attached to the inside of the gutter to the drainage formed in the gutter. In the plant cultivation method in which the liquid fertilizer flowing in the liquid groove is returned from the gutter to the nutrient solution circulation tank, the medium contains coral gravel at a rate of 70% or more,
The filter cloth is formed by stacking at least a nonwoven fabric, a plastic net, and a nonwoven fabric in this order from the gutter side ,
The diameter of the coral gravel is in the range of 0.5 to 10 mm,
The length of the coral gravel ranges from 1 to 50 mm.
A plant cultivation method characterized by: The liquid fertilizer returned to the nutrient solution circulation tank is reused by supplying the liquid fertilizer to the culture medium through the watering tube when the water content indicated by the moisture meter installed in the culture medium decreases or when instructed by a timer. Item 1. A method for cultivating the plant according to item 1. The method for cultivating plants according to claim 2, wherein the liquid fertilizer returned to the nutrient solution circulation tank is reused by feeding it to the culture medium through the watering tube at a rate equal to or less than a predetermined number of times per day. A medium formed of coral gravel and components other than coral gravel is spread over a horizontally placed belt-shaped gutter, plants are rooted in the medium at regular intervals, an irrigation tube is placed on the top of the medium, and a nutrient solution is applied. The liquid fertilizer stored in the circulation tank is supplied to the culture medium through the watering tube, and the liquid fertilizer surplus from the supply is discharged through the filter cloth attached to the inside of the gutter to the drainage formed in the gutter. A plant cultivating apparatus that flows into a liquid groove and returns the liquid fertilizer flowing in the drainage groove from the end of the gutter to the nutrient solution circulation tank,
The filter cloth is formed by stacking at least a nonwoven fabric, a plastic net, and a nonwoven fabric in this order from the gutter side,
The nutrient solution circulation tank, the liquid fertilizer adjustment tank, the first raw material liquid tank for storing the first raw material liquid, the second raw material liquid tank for storing the second raw material liquid, the liquid fertilizer mixer, and the liquid fertilizer pump. , a nutrient solution device composed of a liquid fertilizer transfer pump, a sprinkling pump, a level sensor for detecting the level of the liquid fertilizer in the nutrient solution circulation tank, and an electromagnetic valve;
The medium contains coral gravel at a rate of 70% or more,
When a certain amount of liquid fertilizer in the nutrient solution circulation tank is consumed, the nutrient solution device properly supplies the nutrient solution to the nutrient solution circulation tank by the liquid fertilizer transfer pump from the liquid fertilizer adjustment tank according to the instruction of the level sensor. When the water level of the liquid fertilizer adjusting tank is lowered, water is supplied to the liquid fertilizer adjusting tank to a predetermined position, and the liquid fertilizer pump and the liquid fertilizer mixer are operated to make the liquid fertilizer in the liquid fertilizer adjusting tank have an appropriate EC concentration. to mix the first raw material liquid and the second raw material liquid using the
The diameter of the coral gravel is in the range of 0.5 to 10 mm,
The length of the coral gravel ranges from 1 to 50 mm.
plant cultivation equipment. Further comprising a flow rate sensor for detecting the flow rate of the liquid fertilizer flowing through the irrigation tube, the nutrient solution is controlled by a control device installed in the nutrient solution device, and the nutrient solution is supplied from the nutrient solution circulation tank to the culture medium. The plant cultivation device according to claim 4, wherein the amount of liquid fertilizer supplied is displayed based on the detection result of the flow rate sensor.

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