JP7806779B2 - Hydroponic cultivation equipment - Google Patents

Description

The present invention relates to a hydroponic cultivation device.

In the agricultural industry, which faces various challenges, hydroponic cultivation using liquid fertilizer is attracting attention. However, hydroponic cultivation of root vegetables has yet to be put to practical use and has yet to be fully commercialized.

Patent Document 1 describes a hydroponic cultivation device applicable to root vegetables. This device includes a nutrient solution storage container and a lid member that is fixed to face the nutrient solution level in the nutrient solution storage container at a fixed distance.
Only the tip of the main root of the plant supported by the lid member is immersed in the nutrient solution in the nutrient solution storage container, which allows the roots of the root vegetable seedlings to grow and then thicken, so that root vegetables with long and thick roots can be grown even in hydroponics.

Patent No. 7276138

The hydroponic cultivation device described in Patent Document 1 was developed by the applicant and is extremely advantageous in that it can be applied to root vegetables.
The inventors have found improvements that are necessary for more efficient production of root vegetables in this hydroponic cultivation device, and have completed the present invention.

The objective of the present invention is to provide a highly productive hydroponic cultivation device that can be effectively used for root vegetables.

A first aspect of the present invention is a hydroponic cultivation device provided with a root extension unit for extending the roots of seedlings.
The root extension section has a plurality of nutrient solution tanks arranged in one direction with nutrient solution placed inside, and a support section whose upper surface supports a seedbed placed on the nutrient solution tanks.
The plurality of nutrient solution tanks are arranged at the highest position in one direction and are arranged so as to be successively lower toward the other, and the water level of the nutrient solution placed in each of the nutrient solution tanks is gradually lowered from one side toward the other in one direction in a stepped manner.
The distance between the surface of the nutrient solution placed in each nutrient solution tank and the upper surface of the support part gradually increases from one side to the other in one direction , and the nutrient solution layer in which the seedling roots are immersed can be changed by moving the seedbed relative to the nutrient solution tank .

The hydroponic cultivation device of the present invention is well suited to root vegetables and is highly productive.

1 is a block diagram of a hydroponic cultivation device according to an embodiment of the present invention. FIG. 2 is a perspective view showing a first unit of the hydroponic cultivation device. FIG. 2 is a schematic diagram showing the configuration of the first unit. FIG. 2 is a perspective view showing a second unit of the hydroponic cultivation device. FIG. 2 is a schematic diagram showing the configuration of the second unit. FIG. 10 shows a seedbed plate applied to the second unit. FIG. 10A is a diagram showing a sponge that constitutes a stopper of the seedbed, and FIG. 10B is a diagram showing the stopper. FIG. 10 is a schematic diagram showing a modified example of the second unit. FIG. 10 is a perspective view showing a modified example of the second unit.

A first embodiment of the present invention will be described below with reference to FIGS. 1 to 8. FIG.
FIG. 1 is a block diagram of a hydroponic cultivation device 1 according to this embodiment.
The hydroponic cultivation device 1 includes a first unit (root extension section) 100 for extending the roots of the seedlings to a sufficient length, and a second unit 200 for thickening the extended roots.

Figure 2 is a perspective view showing the first unit 100. The first unit 100 comprises a frame (supporting part) 110 and multiple nutrient solution tanks installed on the frame 110. Multiple seedbeds 10 are installed on top of the frame 110, and illumination light to promote growth is emitted from a light source (not shown). There are no particular restrictions on the specific configuration of the illumination, and a white light source or a combination of red and blue LEDs can be selected and used as appropriate.

3 is a schematic diagram showing the configuration of the first unit. The frame 110 is divided into multiple sections in one direction (the longitudinal direction in this embodiment), and nutrient solution tanks 111, 112, 113, 114, and 115 are arranged in each section, extending across the width of the frame. Each nutrient solution tank contains nutrient solution containing water and ingredients necessary for the growth of the root vegetables to be cultivated, and is open at the top. The nutrient solution can be obtained, for example, by diluting liquid fertilizer with water.
In this embodiment, the number of sections is five, but this is not essential and can be any desired number.

In this embodiment, the five nutrient solution tanks are roughly the same size and contain roughly the same amount of nutrient solution, but are installed at different heights. More specifically, the nutrient solution tank 111 located at one end of the direction in which the five sections are arranged is installed at the highest position, and the installation positions gradually decrease toward the nutrient solution tank 115 located at the other end, with the nutrient solution tank 115 being installed at the lowest position. As a result, the water level of the nutrient solution stored in each nutrient solution tank is highest in the nutrient solution tank 111 and gradually decreases toward the nutrient solution tank 115 in a stepped manner.
Each nutrient solution tank is connected to a different nutrient solution tank 121, 122, 123, 124, 125, and the nutrient solution is circulated by a pump P. New nutrient solution is periodically supplied to each nutrient solution tank, so that the nutrient solution in the nutrient solution tanks 111, 112, 113, 114, 115 is constantly renewed with almost no change in the water surface position, and a predetermined amount of the components necessary for crop growth is always maintained.

The seedbed 10 has planar dimensions that allow it to be placed within one section. In this embodiment, the planar shape of the seedbed 10 is a rectangle whose long sides are approximately the same length as the width of the frame 110 and whose short sides are approximately the same length as the dimensions of each section in the longitudinal direction of the frame 110.

The process of cultivating root vegetables using the hydroponic cultivation device 1 up to the first unit 100 will be described.
First, root vegetable seedlings are initially grown until they can be placed in the seedbed 10. There are no particular restrictions on the method of cultivation, but for example, seeds are sown on sponges cut to a specified size, floated on water to germinate, and the roots are allowed to grow to a length that allows them to be placed in the first unit (for example, 50 mm or more). At this time, if the floating water contains a lot of nutrients, the roots tend to branch out. For this reason, using water that does not contain nutrients is preferable, as it allows the roots to grow easily as a single root.

When the roots of the seedlings reach a desired length, the seedlings are placed in a seedbed 10, and the seedbed 10 is placed on a frame 110 positioned above a nutrient solution tank 111 where the water level of the nutrient solution is at the highest position.
The distance between the seedlings placed in the seedbed 10 and the nutrient solution tank 111 is set so that only a few centimeters from the tip of the seedling's roots are immersed in the nutrient solution.
In this state, seedlings are grown in the first section S1, which is equipped with the nutrient solution tank 111. Since only the tips of the roots of the seedlings are immersed in the nutrient solution, the roots do not branch out but only grow in length.

When the seedling roots reach a predetermined length, the seedbed 10 is moved to the top of the nutrient solution tank 112 adjacent to the nutrient solution tank 111. When moving, the seedbed 10 may be slid directly on the frame, or the seedbed 10 may be pulled up to avoid interference between the roots and the wall of the nutrient solution tank 111. At the same time, a new seedbed 10 may be installed in the vacant first section S1.
In this state, the seedlings continue to grow in the second section S2 where the nutrient solution tank 112 is installed. Because the water level in the nutrient solution tank 112 is lower than the water level in the nutrient solution tank 111, even in the second section S2, only the tips of the seedlings' roots remain immersed in the nutrient solution. Therefore, the roots do not branch out, but only grow in length.

In this way, by moving the seedling bed 10 to an adjacent section where the nutrient solution level is lower after each specified period of cultivation, seedlings with only one root that has grown long enough to be placed in the second unit 200 can be easily cultivated. By sequentially placing new seedling beds 10 in the vacant sections, it is possible to continuously and efficiently cultivate seedlings to be placed in the second unit 200.

In the first unit 100, the composition and concentration of nutrients in the nutrient solution may differ for each section. Furthermore, if nutrient solution of the same composition is used in multiple sections, one nutrient solution tank may be connected to two or more nutrient solution tanks. In other words, the nutrient solution tanks do not necessarily have to be provided in a one-to-one relationship.

In this embodiment, once the seedlings have been grown for a predetermined period in the fifth section S5, which has the lowest nutrient solution water surface position, the seedlings are ready to be placed in the second unit 200, and the growth in the first unit 100 is completed.
Next, the second unit 200 will be described.

Fig. 4 is a perspective view showing the second unit 200. Fig. 5 is a schematic diagram showing the configuration of the second unit 200.
As shown in FIGS. 4 and 5 , the second unit 200 includes a nutrient solution tank 210 extending in one direction and a support rail 220 disposed above the nutrient solution tank 210 .

The nutrient solution tank 210 is a half-pipe-shaped component capable of storing nutrient solution inside. A rain gutter for general construction can also be used as long as it meets these conditions. The stored nutrient solution can be supplied manually, but it can also be connected to a nutrient solution tank by piping, as with the first unit 100, and automatically circulated using a pump, filter, etc.

The support rails 220 in this embodiment are a pair of rails that extend approximately parallel to the nutrient solution tank 210. A number of rollers 221 are arranged on the upper side of the support rails 220.

4 and 5, the seedling bed 20 is placed on the support rail 220. The seedling bed 20 has a pair of plates 21 and a stopper 25 placed on the plates 21.
The plate 21 is made of metal or the like and has enough rigidity to maintain a generally flat state even when fully grown target crops are supported while hung across the support rails 220. As shown in Fig. 6, the plate 21 of this embodiment is made up of a first plate 21a and a second plate 21b of the same shape and size, and when the recesses 22 formed on the periphery are brought close together so that they butt against each other, the recesses 22 form a desired number of holes penetrating the plate 21 in the thickness direction.

The stopper 25 according to this embodiment is configured using two sponges 26 each having an uneven surface, as shown in Fig. 7(a). The sponge 26 is square in plan view, and has a first notch 27a extending from one side of the periphery to the center in plan view, and multiple second notches 27b extending from the center in plan view but not reaching the periphery.
The stopper 25 is completed when the two sponges 26 are stacked so that the uneven surfaces face each other, the first recesses 27a extend in different directions, and the centers of the sponges are substantially aligned in a plan view.

The process of cultivating root vegetables using the hydroponic cultivation device 1, which is related to the second unit 200, will be described.
Once the seedlings have grown in the first unit 100 and have grown sufficiently long roots, they are removed from the seedbed 10 and placed in the seedbed 20.
When installing, the boundary between the root and stem is passed through the first recess 27a of one sponge 26, and the seedling is positioned near the center of the sponge in a plan view. Then, the boundary between the root and stem is passed through the first recess 27a of another sponge 26 and adjusted so that the two sponges form stopper 25, and stopper 25 is attached to the seedling.
The seedlings are placed in the seedbed 20 by placing the stopper 25 on the plate 21 while passing the roots of the seedlings through the holes formed in the plate 21.

When an operator places seedbeds 20 across the support rails 220, only the tips of the seedlings' roots (for example, several centimeters from the tip) are immersed in the nutrient solution in the nutrient solution tank 210. Furthermore, when installing seedbeds 20, the operator can push the already installed seedbed 20 with the plate 21 to be installed, causing the seedbed 20 to slide and move on the rollers 221, allowing the operator to easily install multiple seedbeds 20 on the support rails 220 without making large movements.
The timing for placing the seedlings in the seedbed can be set as appropriate. That is, as described above, the seedlings may be placed before the seedbed 20 is placed on the support rail 220, or after only the plate 21 is placed on the support rail 220.

After the seedbed 20 is set up, light for growth is irradiated from a light or the like (not shown) and the seedlings are grown for a predetermined period of time (for example, about 40 to 50 days in the case of radishes). When the root vegetable to be grown is a radish or the like, the roots can be prevented from turning green by blocking out light by covering the space between the support rail 220 and the nutrient solution tank 210 with a blackout curtain or the like. During growth, there is no need to move the seedbed 20 except when a new seedbed 20 is added, for example.
During growth in the second unit 200, the seedlings increase in thickness without significantly increasing the length of their roots. When the roots reach a sufficient thickness, the worker removes the grown crop from the seedbed 20 and harvests it. Even if the diameter of the grown roots becomes larger than the inner diameter of the holes formed in the plate 21, the roots can be easily removed by separating the first plate 21a and the second plate 21b.

As described above, in the second unit 200, the process of thickening the roots of a large number of seedlings can be easily carried out from setting the seedlings to harvesting.
Furthermore, since the nutrient solution tank 210 is in the form of a half pipe extending in one direction, a large number of seedlings can be grown with a relatively small amount of nutrient solution.

The stopper 25 of the applied seedbed 20 is constructed using two sponges 26, so that the seedlings can be easily passed through the first insert 27a, and after the seedlings have been passed through the stopper 25, the two first inserts 27a extend in different directions, which effectively prevents the seedlings from falling out.
Furthermore, the provision of the second notch 27b prevents the second notch 27b from widening and interfering with the growth of roots. In addition, the two sponges 26 are stacked with their concave and convex portions facing each other, which effectively prevents the two sponges constituting the stopper from misaligning in the planar direction.

The following modifications may also be made to the second unit 200 and the seedbed 20. These modifications may be made alone or in combination of two or more.
The nutrient solution tank 210 may be divided into multiple sections, and nutrient solutions with different nutrient compositions and amounts may be placed in each section.
A circulator may be installed to constantly mix the air in the space between the support rail 220 and the nutrient solution tank 210. This will prevent mold spores from settling on the surface of the growing roots.
The seedbed stopper may be formed from a material other than sponge (for example, a sheet made of rubber or elastomer).
The seedbed plates may be provided with a lock that keeps the first plate 21 a and the second plate 21 b in a state where they cannot be separated. This has the advantage of making it easier to place the seedbed with seedlings on the support rails and preventing the first plate 21 a and the second plate 21 b from separating as the roots grow.

As described above, the hydroponic cultivation apparatus 1 according to this embodiment makes it possible to efficiently cultivate and harvest large quantities of root vegetables by utilizing the various effects of the first unit 100 and the second unit 200. The hydroponic cultivation apparatus 1 can greatly contribute to the practical application of hydroponic cultivation of root vegetables, which is currently in the process of being put into practical use, in a manner that is sufficiently profitable.
Since the effects of the first unit 100 and the effects of the second unit 200 are not all closely related, a hydroponic cultivation device equipped with only one of the first unit 100 and the second unit 200 can also be expected to contribute significantly to the practical application of hydroponic cultivation of root vegetables.

Normally, when cultivating root vegetables, the roots are buried in the soil, making it difficult to monitor their growth status. However, when cultivating using the hydroponic cultivation device 1, there is no soil around the growing roots, so the growth status can be monitored at any time and the crops can be harvested at the appropriate time.

As another method, as shown in Figure 8, if a load cell 230 is attached to the underside of the seedbed 20 and positioned between it and the support rail 220, the weight of the crops can be monitored more accurately by subtracting the weight of the seedbed 20, etc. from the output value of the load cell 230. Furthermore, by periodically photographing the roots and leaves of the crops with a camera installed in the second unit 200 and preliminarily determining the relationship between the root dimensions calculated based on the images and the weight obtained by the load cell 230, it becomes possible to grasp the growth status of the crops with a certain degree of accuracy using only the images of the roots and leaves. By combining these methods, it is possible to reduce personnel involvement in crop production using the hydroponic cultivation device 1 and enable more efficient production.

The hydroponic cultivation device 1 according to this embodiment has the advantage that it can not only efficiently produce root vegetables, but also contribute to elucidating the growth mechanisms of leafy vegetables, root vegetables, and the like.
For example, the hydroponic cultivation device 1 can easily obtain a wide variety of information that is extremely difficult to obtain through outdoor cultivation, such as the relationship between the intensity or wavelength profile of light irradiated on crops and growth patterns (growth amount, growth rate, etc.), the relationship between components contained in the nutrient solution and growth patterns, and the relationship between temperature, humidity, and growth patterns. Knowledge obtained based on this information can be used to optimize various settings in the hydroponic cultivation device, which can be expected to further improve production efficiency and adjust shipping timing.
This advantage becomes even more pronounced when the system is equipped with a weight detection device, such as the load cell, and a crop image acquisition device, such as a camera. Studies conducted by the inventors using a load cell and a camera have revealed that radishes grow more rapidly during periods when light is not irradiated, a previously unknown finding. Based on this finding, optimizing the allocation and placement of light-irradiated and non-irradiated periods without being bound by the natural state of approximately a 24-hour cycle may potentially increase production efficiency to a level not achievable with open-field cultivation.

One embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and modifications and combinations of configurations that do not deviate from the gist of the present invention are also included.

For example, in the first unit, the nutrient solution tanks themselves do not necessarily have to be arranged in a stepped manner as long as the water levels of the nutrient solution in the multiple nutrient solution tanks are stepped. However, arranging the nutrient solution tanks in a stepped manner has many advantages, such as the bottom surfaces of the nutrient solution tanks also being arranged in a stepped manner, which reduces the amount of nutrient solution used by the entire unit and also reduces the amount of interference between the roots and the nutrient solution tank when the seedbed is moved to the next unit. Therefore, it is preferable to arrange the nutrient solution tanks in a stepped manner so that the water level of the nutrient solution is stepped.
In the first unit, the above-mentioned effect can be achieved if the distance between the seedbed and the nutrient solution surface is shortest in the section where the seedbed 10 is first installed, and the distance gradually increases as the section moves to the adjacent section. Therefore, in addition to the aspects shown in the embodiment, the following configurations are also possible.
The height of the nutrient solution surface is the same in all nutrient solution tanks, but the upper surface of the frame 110 supporting the seedbed becomes higher in a stepped manner. The upper surface of the frame 110 becomes higher in a stepped manner, and the height of the nutrient solution surface becomes lower in a stepped manner. The height of the nutrient solution surface and the upper surface of the frame 110 both become higher in a stepped manner, but the increase in the height of the upper surface of the frame 110 exceeds the increase in the height of the nutrient solution surface. The height of the nutrient solution surface and the upper surface of the frame 110 both become lower in a stepped manner, but the decrease in the height of the nutrient solution surface exceeds the decrease in the height of the upper surface of the frame 110.

Furthermore, in the hydroponic cultivation device of the present invention, multiple second units 200 may be stacked vertically, as shown in Figure 9. This allows for increased crop yield per unit floor area, even reaching a level not possible with open-field cultivation. Of course, multiple first units 100 can also be stacked vertically, allowing for more efficient production of seedlings to be supplied to the second units 200.

The application of the hydroponic cultivation device 1 is not limited to the radish mentioned above, but can also be applied to other root vegetables such as turnip, burdock, carrot, and ginseng.

1 Hydroponic cultivation device 10 Seedbed 20 Seedbed 100 First unit (root elongation section)
110 Frame (support part)
111, 112, 113, 114, 115 Nutrient solution tank 200 Second unit 210 Nutrient solution tank 220 Support rail

Claims (1)

A hydroponic cultivation device having a root extension unit for extending the roots of seedlings,
The root extension portion is
a plurality of nutrient solution tanks arranged in one direction with nutrient solution therein;
a support portion that supports a seedbed placed on the nutrient solution tank from above ,
The plurality of nutrient solution tanks are arranged so that they are located at the highest position in one direction and are sequentially lowered toward the other direction,
The water level of the nutrient solution disposed in each of the nutrient solution tanks is stepped so as to gradually decrease from one side to the other side in the one direction,
the distance between the water surface of the nutrient solution disposed in each of the nutrient solution tanks and the upper surface gradually increases from one side to the other side in the one direction,
The seedbed is configured to be able to change the nutrient solution layer in which the roots of the seedlings are immersed by moving the seedbed relative to the nutrient solution tank.
Hydroponic cultivation equipment.