Hydroponic cultivation sheets and hydroponic cultivation systems

Abstract

To hygienically and effectively reduce the effects of stopping a culture solution delivery pump in the NFT system.SOLUTION: A hydroponic system includes a culture solution channel R in which a culture solution flows down naturally, and a cultivation tray 40 that is provided above the culture solution channel R and holds plants. To the hydroponic system, a liquid-impermeable hydroponic sheet 50 is attached, which blocks a part of the culture solution flowing down the culture solution channel R.SELECTED DRAWING: Figure 1

Description

Technical Field

[0004]

[0001] The present invention relates to a sheet for hydroponics and a hydroponic cultivation system including the same.

Background Art

[0002] In hydroponics, there are multiple methods for supplying a culture solution to the roots of plants. However, the methods used for cultivating leafy vegetables such as spinach and lettuce can be broadly classified into two types: DFT (Deep Flow Technique) and NFT (Nutrient Film Technique). Both methods have a culture solution tank and a culture solution water pump, and the culture solution is supplied and circulated by pumping it into a water tank where the plants are located.

[0003] The DFT method is a hydroponic cultivation method in which the roots of plants are immersed in a water tank filled with a culture solution having a depth of about 10 cm. In the DFT method, even if the water pump stops, since there is enough culture solution in the water tank, there will be no inconveniences such as the death of cultivated products or growth delays due to drying. However, when performing multi-stage cultivation with multiple layers using artificial light sources as in a plant factory, the weight becomes heavy and a high-strength cultivation shelf is required, resulting in an increase in initial costs. On the other hand, the NFT method is a hydroponic cultivation method in which a small amount of culture solution is allowed to flow down on a flat surface having a gentle slope of about 1% and the culture solution is allowed to flow in a film shape of about 5 mm. In the NFT method, the amount of circulating culture solution is small, and even when performing multi-stage cultivation, a high-strength cultivation shelf is not required, and since the initial cost can be suppressed, it is adopted by many plant factories. However, when a failure or trouble occurs in the water pump and the water pump stops, the culture solution in the water tank will run out, and inconveniences such as the death of cultivated products or growth delays due to drying will occur within a few hours. The stop of the water pump in the NFT method affects all cultivated products, and there is only a few hours' grace period from the detection of the water pump stop to recovery. Therefore, multiple measures such as installing a backup pump or an automatic detection device for detecting failures may be implemented, leading to an increase in equipment costs and maintenance management costs.

[0004] For example, as shown in Patent Document 1, if a water-retaining sheet is laid in the culture medium flow path within the tank, the culture medium will be retained by the water-retaining sheet even if the water supply pump stops, thus extending the time before the culture medium is depleted. Furthermore, since only a water-retaining sheet needs to be prepared, the cost increase can be kept down compared to adding a backup pump or installing an automatic detection device. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-71824 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the method of laying water-retaining sheets in the culture medium channels has problems, such as the fact that the sheets remain in place throughout the cultivation period, leading to the proliferation of bacteria and other microorganisms within the sheets, making it unsanitary. Furthermore, especially when cultivating plants that require a lot of water, the water-retaining capacity of the sheets may not be sufficient to prolong the time before the culture medium is depleted.

[0007] This invention has been made in view of the above problems, and aims to hygienically and effectively reduce the impact of stopping the culture medium water supply pump in the NFT system. [Means for solving the problem]

[0010] Claim 1 The invention relating to this is An impermeable sheet that, when attached to a hydroponic cultivation system comprising a culture medium channel through which the culture medium flows naturally, and a cultivation tray provided above the culture medium channel to hold plants, dams up a portion of the culture medium flowing down the culture medium channel. A fixing part is inserted between the planting hole provided in the cultivation tray and the growing medium that fits into the planting hole, The device is characterized by comprising a main body that hangs down from the cultivation tray and is installed in a convex curve toward the downstream side of the culture medium channel, thereby damming a portion of the culture medium flowing down the culture medium channel.

[0011] Claim 2 The invention according to An impermeable sheet that, when attached to a hydroponic cultivation system comprising a culture medium channel through which the culture medium flows naturally, and a cultivation tray provided above the culture medium channel to hold plants, dams up a portion of the culture medium flowing down the culture medium channel. is characterized in that a slit is provided to follow the inner surface shape of the trough forming the culture solution flow path.

[0012] Claim 3 The invention according to An impermeable sheet that, when attached to a hydroponic cultivation system comprising a culture medium channel through which the culture medium flows naturally, and a cultivation tray provided above the culture medium channel to hold plants, dams up a portion of the culture medium flowing down the culture medium channel. the The overflow port is provided for adjusting the amount of the culture solution blocked by the baffle of the - gate.

[0013] The invention according to claim 4 is, In a hydroponic sheet according to any one of claims 1 to 3, It is characterized by being detachably fixed to the aforementioned hydroponic cultivation system. Claim 5 …… The invention according to A hydroponic cultivation system comprising a culture solution flow path through which the culture solution flows naturally, a cultivation tray provided above the culture solution flow path for holding plants, As described in any one of claims 1 to 3 a hydroponic cultivation sheet of, and is characterized by comprising.

Effect of the Invention

[0014] According to the present invention, in the NFT method, the influence caused by the stop of the culture solution water supply pump can be hygienically and effectively reduced.

Brief Description of the Drawings

[0015] [Figure 1] It is a diagram schematically showing the configuration of a hydroponic cultivation system according to an embodiment of the present invention. [Figure 2] It is a plan view showing the configuration of a hydroponic cultivation system according to an embodiment of the present invention. [Figure 3] It is a diagram showing the relationship between the trough, the cultivation tray, and the hydroponic cultivation sheet. [Figure 4] It is a diagram showing the main part of the hydroponic cultivation sheet in a state fixed to the cultivation tray. [Figure 5] It is a diagram showing the main part of the hydroponic cultivation sheet in a state fixed to the cultivation tray. [Figure 6] It is a diagram showing the main part of the hydroponic cultivation sheet in a state fixed to the cultivation tray. [Figure 7] It is a diagram showing a modified example of the hydroponic cultivation sheet. [Figure 8] It is a diagram showing a modified example of the hydroponic cultivation system.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the technical scope of the present invention is not limited to those exemplified in the following embodiments and drawings.

[0017] <Hydroponic cultivation system> FIG. 1 is a diagram schematically showing the configuration of the hydroponic cultivation system 1 according to the present embodiment. FIG. 2 is a plan view showing the configuration of the hydroponic cultivation system 1 according to the present embodiment. In FIG. 2, for the sake of convenience, the illustration of the water supply pipe 31, the culture medium 42, the cultivated products, etc. is omitted. The hydroponic cultivation system 1 is a hydroponic cultivation system of the NFT (Nutrient Film Technique) method, and is configured to include a plurality of troughs (garts) 10, a culture solution tank 20, a culture solution water supply pump 30, a plurality of cultivation trays (cultivation plates) 40, and a plurality of hydroponic cultivation sheets 50. The plants (cultivated products) targeted for production by the hydroponic cultivation system 1 are, for example, leafy vegetables with large root elongation such as spinach, turnip greens, lettuce, arugula, komatsuna, and mizuna.

[0018] Multiple troughs 10 are arranged side by side in the width direction (left-right direction) of the trough 10. Each trough 10 is a tank that forms a culture medium channel R through which the culture medium flows, and is installed with a slope of about 1% (1 / 100) downward from the upstream side (rear side) to the downstream side (front side). A drain outlet 11 is formed at the downstream side of the bottom of each trough 10, and a drain pipe 11a is attached to this drain outlet 11.

[0019] The culture medium tank 20 contains the culture medium. The culture medium supply pump 30 pumps the culture medium from the culture medium tank 20 and supplies it to the trough 10 via the supply pipe 31. The culture medium supplied to the trough 10 flows naturally from upstream to downstream through the culture medium flow path R (inside the trough 10), and returns to the culture medium tank 20 via the drain pipe 11a from the drain port 11 located on the downstream side of the culture medium flow path R. In other words, the culture medium tank 20 and the culture medium water pump 30 constitute a culture medium circulation supply means that circulates and supplies the culture medium to the trough 10.

[0020] Multiple cultivation trays 40 are arranged in a line along the longitudinal direction (front-to-back direction) of the trough 10, with the longitudinal direction of each cultivation tray 40 aligned with the short direction (left-to-right direction) of the trough 10, so as to cover the upper opening of the trough 10. The cultivation tray 40 has multiple planting holes 41. Each planting hole 41 is fitted with a growing medium 42 for holding the plant and a hydroponic sheet 50 for blocking the flow of the nutrient solution through the nutrient solution channel R.

[0021] <Hydroponic cultivation sheet> Figure 3 shows the relationship between the trough 10 and cultivation tray 40 of the hydroponic cultivation system 1 and the hydroponic cultivation sheet 50. Figures 4 to 6 show the main parts of the hydroponic cultivation sheet 50 when fixed to the cultivation tray 40. The hydroponic sheet 50 is an impermeable sheet and consists of a fixing part 51 for fixing the hydroponic sheet 50 to the cultivation tray 40 and a rectangular main body part 52. In this embodiment, a lightweight and transparent polypropylene sheet is used as the hydroponic sheet 50, but it is not limited to this, and the hydroponic sheet 50 can be appropriately changed as long as it is an impermeable sheet.

[0022] As shown in Figure 4, for example, the hydroponic sheet 50 is detachably fixed to the cultivation tray 40 by inserting a fixing part 51 between the planting holes 41 of the cultivation tray 40 and the growing medium 42 that fits into the planting holes 41 from the top side of the cultivation tray 40. Furthermore, the hydroponic sheet 50 is installed with its main body 52 bent so that the tip of the main body 52 faces upstream (rear), as shown in Figure 5, for example. A portion of the nutrient solution flowing from upstream is blocked by the hydroponic sheet 50, while the remainder flows downstream through the gap between the hydroponic sheet 50 and the trough 10.

[0023] For example, as shown in Figure 3, a first fold 50a is provided at the boundary between the fixing part 51 and the main body part 52. In addition, the main body part 52 is provided with two folds 50b and 50c parallel to the first fold 50a. Hereinafter, the portion of the main body 52 from the first fold 50a to the second fold 50b will be referred to as the "first portion 52a", the portion from the second fold 50b to the third fold 50c will be referred to as the "second portion 52b", and the portion from the third fold 50c to the tip of the main body 52 will be referred to as the "third portion 52c".

[0024] The first portion 52a is provided along the upper surface of the cultivation tray 40, for example, as shown in Figure 5. That is, the length L1 of the first portion 52a is set to match the length from the planting hole 41 to the end of the cultivation tray 40 (the downstream end). The second part 52b hangs down from the top surface of the cultivation tray 40 to the bottom of the cultivation tray 40 (inside the trough 10), as shown in Figures 4 and 5, for example. The length L2 of the second part 52b is set to match the length from the top surface of the cultivation tray 40 to the bottom top surface of the trough 10, as shown in Figure 3, for example. The third section 52c is a part that dams up and retains (stores) the culture medium flowing through the culture medium channel R (inside the trough 10), as shown in Figure 5, for example. The length L3 of the third section 52c is set to a length that can dam up and retain (store) the culture medium flowing through the culture medium channel R, and is specifically set to, for example, 5 cm or more.

[0025] For example, as shown in Figure 3, two slits (cuts) S1 and S2 are provided at both ends (left end and right end) of the third portion 52c. As a result, two strip portions T1 and T2 are formed at both ends of the main body portion 52. The inner slit S1 of the two slits S1 and S2 extends from the tip of the third portion 52c to the third fold 50c. The outer slit S2 of the two slits S1 and S2 extends from the tip of the third portion 52c to a position beyond the third fold 50c. In other words, the outer slit S2 reaches the second portion 52b. Hereinafter, the portion of the third part 52c between one inner slit S1 and the other inner slit S1 will be referred to as the "main body of the third part 52c".

[0026] In this embodiment, the gutter 10 is provided with two stepped sections 12 and 13 on both the inner surface on one side in the width direction (left inner surface) and the inner surface on the other side in the width direction (right inner surface), as shown in Figure 3, for example. Specifically, it is provided with a first stepped section 12 that is one step higher than the bottom of the gutter 10, and a second stepped section 13 that is one step higher than the first stepped section 12. The slits S1 and S2 are provided to allow the hydroponic sheet 50 to deform to conform to the shape inside the trough 10. That is, for example, as shown in Figure 3, the distance between one inner slit S1 and the other inner slit S1 (width of the third part 52c body) is set to be approximately the same as the width of the bottom upper surface of the trough 10. Also, the distance between the inner slit S1 and the outer slit S2 (width of the inner strip T1) is set to be approximately the same as the width of the upper surface of the first stage 12. Furthermore, the distance between the outer slit S2 and the side edges (left and right edges) of the hydroponic sheet 50 (width of the outer strip T2) is set to be slightly shorter than the width of the upper surface of the second stage 13.

[0027] Therefore, as shown in Figures 5 and 6, for example, the hydroponic sheet 50 is positioned such that the third part 52c rests on the bottom upper surface of the trough 10, and the side ends (left and right ends) of the third part 52c are in contact with the rising portion of the first stage 12, the inner strip T1 of the two strips T1 and T2 rests on the first stage 12, and the outer end of the inner strip T1 is in contact with the rising portion of the second stage 13, and the outer strip T2 of the two strips T1 and T2 rests on the second stage 13. In Figure 5, for convenience, the stepped portions 12 and 13 provided on the left inner surface of the gutter 10 and the strip portions T1 and T2 formed on the left end of the hydroponic cultivation sheet 50 are omitted from the illustration.

[0028] <Example 1> Furthermore, as shown in Figure 7, for example, the hydroponic sheet 50 may have an overflow port 53 through which the nutrient solution can pass. Specifically, for example, the overflow port 53 may be provided in the second part 52b of the main body 52. ​​The further the overflow port 53 is from the third part 52c, the greater the amount of nutrient solution dammed (water storage capacity) by the hydroponic sheet 50, and the closer the overflow port 53 is to the third part 52c, the greater the amount of nutrient solution dammed by the hydroponic sheet 50.

[0029] <Modification 2> Furthermore, in the above embodiment, hydroponic cultivation sheets 50 are provided in all planting holes 41 of the hydroponic cultivation system 1, but the invention is not limited to this. Specifically, for example, in the above embodiment, hydroponic sheets 50 were attached to all of the multiple cultivation trays 40 provided in the hydroponic cultivation system 1. However, as shown in Figure 8(a), for example, the cultivation trays 40 to which the hydroponic sheets 50 are attached may be only a portion of the multiple cultivation trays 40. Furthermore, in the above embodiment, the cultivation tray 40 was a tray having one row of planting holes 41, but as shown in Figure 8(b), for example, the cultivation tray 40 may be a tray having multiple rows of planting holes 41. In this case, as shown in Figure 8(b), for example, the hydroponic cultivation sheet 50 will be provided in the downstream row of the multiple rows of the cultivation tray 40.

[0030] <Effects> According to the hydroponic cultivation sheet 50 in the above embodiment (including modified versions), it is attached to a hydroponic cultivation system 1 that includes a nutrient solution channel R through which the nutrient solution flows naturally, and a cultivation tray 40 provided above the nutrient solution channel R to hold plants (cultivated products), and can dam up a portion of the nutrient solution flowing down the nutrient solution channel R. Therefore, the hydroponic cultivation sheet 50 can hold (dam up) a larger amount of nutrient solution than the amount that the water retention sheet can hold, thus effectively reducing the impact of the nutrient solution supply pump 30 stopping. Furthermore, the hydroponic sheet 50 is an impermeable sheet, and since bacteria and other microorganisms are less likely to grow on it compared to a water-retaining sheet, the impact of the nutrient solution supply pump 30 stopping can be hygienically reduced.

[0031] Furthermore, by installing the hydroponic cultivation sheet 50, it becomes possible to suppress the entanglement of plant (cultivated) roots. Furthermore, the inventors have confirmed that by damming the nutrient solution with the hydroponic sheet 50, the root mass of the plant (cultivated product) increases compared to the root mass in a typical NFT (Nutrient Film Technique) method. This is thought to be because, by damming the nutrient solution with the hydroponic sheet 50, for example as shown in Figure 1, the water level in the nutrient solution channel R becomes higher than the water level in a typical NFT method (e.g., 5 mm), resulting in a state where the plant roots are immersed in the nutrient solution, similar to a DFT (Deep Fibre Technique) method. The increased water retention capacity of the roots increases due to the capillary effect caused by the increased root mass, and the synergistic effect between the hydroponic sheet 50 and the increased root mass results in an even greater water retention (water storage) effect compared to the case of the hydroponic sheet 50 alone. In addition, the increased root mass can be expected to promote the growth of the plant (cultivated product).

[0032] Furthermore, since the hydroponic sheet 50 is detachably fixed to the hydroponic system 1, the workability when cleaning the hydroponic system 1 is improved. In other words, since the hydroponic sheet 50 can be removed from the hydroponic system 1, it is possible to clean the hydroponic sheet 50 separately (separately from the cultivation tray 40, etc.). Therefore, it is easy to maintain a clean state without much effort, making it hygienic.

[0033] Furthermore, since the hydroponic sheet 50 can be detachably fixed to the hydroponic system, it can be retrofitted to an existing hydroponic system. In other words, simply by attaching the hydroponic sheet 50 to an existing hydroponic system, a hygienic and effective water retention function (water storage function) can be added to the existing hydroponic system. For example, in the hydroponic cultivation system 1 of the above embodiment (including modified versions), the components other than the hydroponic cultivation sheet 50 (multiple troughs 10, nutrient solution tanks 20, nutrient solution water pumps 30, and multiple cultivation trays 40) can be used as they are from existing hydroponic cultivation systems.

[0034] Furthermore, the hydroponic cultivation sheet 50 includes a fixing part 51 that is inserted between the planting holes 41 provided in the cultivation tray 40 and the culture medium 42 that fits into the planting holes 41, and a main body part 52 that hangs down from the cultivation tray 40 and is installed in a convex shape toward the downstream side (downstream side) of the culture medium channel R, thereby blocking a portion of the culture medium flowing down the culture medium channel R. Therefore, the hydroponic sheet 50 can be fixed to the hydroponic system simply by inserting the fixing part 51 between the planting hole 41 and the growing medium 42, making it easy to use. Furthermore, the main body 52 is curved in a convex shape toward the downstream side (downstream side) of the culture medium channel R, that is, it is installed in a state that makes it easy to receive the culture medium flowing from the upstream side, so that the culture medium can be efficiently dammed up.

[0035] Furthermore, the hydroponic sheet 50 is provided with slits S1 and S2 that conform to the inner surface shape of the trough 10 that forms the culture solution channel R, so that the culture solution flowing through the culture solution channel R can be efficiently blocked. The number of slits and their orientation can be changed as appropriate. If there are too many slits, the culture medium may flow down through the gaps between the slits, making it difficult to efficiently dam the culture medium (resulting in a reduced amount of dammed-up medium). Therefore, it is preferable to have the minimum number of slits that conform to the inner surface shape of the trough 10.

[0036] Furthermore, it is not necessary to provide slits S1 and S2 in the hydroponic sheet 50. Specifically, for example, the width of the hydroponic sheet 50 can be set to be approximately the same as the width of the bottom top surface of the trough 10. The inventors have confirmed that the amount of nutrient solution dammed by the hydroponic sheet 50 increases when slits S1 and S2 are provided compared to when slits S1 and S2 are not provided. This is thought to be because, for example, as shown in Figure 5, providing slits S1 and S2 allows the nutrient solution to accumulate not only on the bottom of the trough 10 but also on the first stage 12, and providing slits S1 and S2 reduces the gap between the hydroponic sheet 50 and the trough 10 compared to when slits S1 and S2 are not provided.

[0037] Furthermore, the hydroponic sheet 50 can be provided with an overflow port 53 to adjust the amount of damming of the nutrient solution by the hydroponic sheet 50 (see Figure 7). By providing the overflow port 53, it is possible to set the amount of damming of the nutrient solution by the hydroponic sheet 50 to a desired amount. In other words, by providing the overflow port 53, it is possible to set the water level of the nutrient solution in the nutrient solution channel R to a desired height. For example, if the amount of nutrient solution dammed by the hydroponic sheet 50 is too large, problems may occur such as the nutrient solution not reaching the downstream side, or the water level of the nutrient solution dammed by the hydroponic sheet 50 upstream rising too high and overflowing. In contrast, by providing an overflow port 53 and limiting the amount of nutrient solution dammed by the hydroponic sheet 50, it is possible to avoid such problems.

[0038] Furthermore, according to the hydroponic cultivation system 1 in the above embodiment (including modified versions), the system includes a nutrient solution channel R through which the nutrient solution flows naturally, a cultivation tray 40 provided above the nutrient solution channel R for holding plants, and an impermeable hydroponic cultivation sheet 50 that dams up a portion of the nutrient solution flowing down the nutrient solution channel R. Therefore, the hydroponic cultivation sheet 50 can hold (dam up) a larger amount of nutrient solution than the amount that the water-retaining sheet can hold, thereby effectively reducing the impact of the nutrient solution supply pump 30 stopping. Furthermore, the hydroponic sheet 50 is an impermeable sheet, and since bacteria and other microorganisms are less likely to grow on it compared to a water-retaining sheet, the impact of the nutrient solution supply pump 30 stopping can be hygienically reduced. [Explanation of Symbols]

[0039] 1. Hydroponic cultivation system 10 Gutters 40 cultivation trays 41 Planting hole 42 Culture medium 50 Hydroponic Sheets 51 Fixed part 52 body part 53. Cross-flow outlet R Culture medium flow path S1,S2 スリット

Claims

1. An impermeable sheet that, when attached to a hydroponic cultivation system comprising a culture medium channel through which the culture medium flows naturally, and a cultivation tray provided above the culture medium channel for holding plants, dams up a portion of the culture medium flowing down the culture medium channel. A fixing part is inserted between the planting hole provided in the cultivation tray and the growing medium that fits into the planting hole, A hydroponic sheet characterized by comprising: a main body that hangs down from the cultivation tray and is installed in a convex curve toward the downstream side of the culture solution channel, thereby damming a portion of the culture solution flowing down the culture solution channel.

2. An impermeable sheet that, when attached to a hydroponic cultivation system comprising a culture medium channel through which the culture medium flows naturally, and a cultivation tray provided above the culture medium channel for holding plants, dams up a portion of the culture medium flowing down the culture medium channel. A sheet for hydroponics, characterized in that it is provided with slits that conform to the inner surface shape of the trough that forms the culture medium channel.

3. An impermeable sheet that, when attached to a hydroponic cultivation system comprising a culture medium channel through which the culture medium flows naturally, and a cultivation tray provided above the culture medium channel for holding plants, dams up a portion of the culture medium flowing down the culture medium channel. A hydroponic sheet characterized by having an overflow port for adjusting the amount of the culture solution blocked by the sheet.

4. In the hydroponic sheet according to any one of claims 1 to 3, A hydroponic sheet characterized by being detachably fixed to the aforementioned hydroponic system.

5. A culture medium channel through which the culture medium flows naturally, A cultivation tray for holding plants is provided above the culture medium channel, A hydroponic cultivation system characterized by comprising a hydroponic cultivation sheet according to any one of claims 1 to 3.

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