Hydroponic system, use of such system, and methods for seed germination and sprout, seedling and plant growth

Abstract

The invention relates to a hydroponic system for seed germination and growth into plants. The hydroponic system includes a container including an accommodation space. It further comprises a first wall element dividing the accommodation space into a lower portion arranged for accommodating a gas and an upper portion arranged for accommodating a liquid. The first wall element is provided with a first opening allowing gas-liquid communication between the lower portion and the upper portion. The system further comprises a connection arrangement arranged for connecting the gas pressure device to the lower portion. The system further comprises a support member arranged for holding the seed and the plant at a predetermined distance above the first wall element and substantially parallel to the first wall element. The support member includes a second opening for allowing humidification of the seeds and roots, and the roots grow through the second opening. The system further comprises a cover arrangement arranged for defining the hydroponic system on an upper side of the hydroponic system. A lid arrangement closes the support member together with the container. The invention also relates to the use of such a hydroponic system as well as to a method for the germination and growth of seeds into plants.

Description

Technical Field

[0001] The present invention relates to a hydroponic system for seed germination and the growth of sprouts, seedlings and plants. The present invention also relates to the use of such a system for the hydroponic germination of seeds and the growth of sprouts, seedlings and plants. The present invention also relates to a method for seed germination and the growth of sprouts, seedlings and plants. Background Art

[0002] Hydroponics is a type of horticulture that involves germinating or growing plants without soil by using water or a water-based mineral nutrient solution.

[0003] Today, there are various types of hydroponic systems. In all systems, overall plant growth is understood to consist of two different cycles: a germination cycle and a growth cycle. In the germination cycle, seeds are germinating and developing their first roots and stems (since the stems are not yet exposed to light, no chlorophyll is produced, and the stems are essentially colorless or very light in color). Then the sprouts develop into seedlings (seedlings, which are usually exposed to light and thus produce chlorophyll and are green (in the case of beetroot seedlings, f.i. red)). Seedlings are also referred to as microgreens. In the growth cycle, the sprouts develop into seedlings, and the seedlings develop into mature plants. Mature plants can be flowering and / or fruiting plants.

[0004] Most hydroponic systems require plants or at least sprouts during their growth cycle. Seeds are first germinated separately in different systems, namely so-called nurseries, and then transplanted into the actual hydroponic system where the plants or sprouts can grow.

[0005] An example in this regard is the Nutrient Film Technique (NFT). See, for example, GB1245581. After germination and full growth, the plants are placed in a nutrient-rich water channel, and a very shallow water flow containing dissolved nutrients (nutrient film) is recirculated through the exposed roots of the plants, thereby forming a thick root mat. Other examples are deep water culture, where the plant roots are continuously submerged in water containing nutrients, and ebb and flow systems, where the plant roots are only drenched in water a few times a day. Thus, these systems involve external inputs, such as manual labor or automatic environmental or setting changes, in order to transplant the sprouts or plants grown in another system into the hydroponic system.

[0006] Furthermore, in hydroponic systems, in addition to water, solid media can also be used. Rockwool is the most widely used medium in hydroponics. Other examples of the media used are wood fiber, wool, coir fiber, rice husk, perlite, vermiculite, pumice, sand and gravel. Therefore, these systems require materials that need to be exhausted, removed and disposed of or treated for recycling. The use, removal, disposal and / or recycling of solid media also involves additional manual or automatic operations.

[0007] To avoid plants growing in water that is prone to contamination, stagnation or reuse, an improvement to the foregoing example of a hydroponic system is to use bubbles to oxygenate the water to promote growth. See, for example, W02020100193. The main drawback of this improvement is that it also requires transplanting the plants or at least the sprouts from another system into the hydroponic system in which the initial seeds were germinated.

[0008] On the other hand, US4057930A describes an apparatus (claims 1, 7, and 11 of US’930) for germinating seeds to grow sprouts, namely a so-called nursery, comprising a seed support screen mounted at a predetermined distance above a reservoir, with an aerator grid immersed in the reservoir to provide a circulating flow of moist liquid droplets and moist air around and through the screen. Figure 5 、 8 and 11) for germinating seeds to grow sprouts, namely a so-called nursery, comprising a seed support screen mounted at a predetermined distance above a reservoir, with an aerator grid immersed in the reservoir to provide a circulating flow of moist liquid droplets and moist air around and through the screen.

[0009] In view of the foregoing, there is a great need for a new and further developed hydroponic system, the use of such a system, and a new method for germinating seeds and growing them into plants. In particular, there is a clear need in the art for a hydroponic system, the use of such a system, and a method for germinating seeds and growing them into plants that can be used for or applied to seed germination and the growth of seeds into plants. Summary of the Invention

[0010] A main object of the present invention is to provide an improved hydroponic system, the use of such a system, and a method for germinating seeds and growing them into plants to produce strong, green, nutritious and healthy sprouts, seedlings and plants.

[0011] Another object of the present invention is to provide a low-maintenance hydroponic system that is economical to use due to savings in maintenance, repair and replacement costs.

[0012] In a first aspect, the present invention relates to a hydroponic system for germinating seeds and growing them into plants. The hydroponic system comprises a container that includes an accommodation space. It also includes a first wall element that divides the accommodation space into a lower part arranged to accommodate gas and an upper part arranged to accommodate liquid. The first wall element is provided with a first opening to allow gas-liquid communication between the lower and upper parts. The system also includes a connection arrangement that is arranged to connect a gas pressure device to the lower section. The system also includes a support member that is arranged to hold the seeds and plants at a predetermined distance above the first wall element and substantially parallel to the first wall element. The support member includes a second opening for allowing humidification of the seeds and roots, and through which the roots grow. The system also includes a cover arrangement that is arranged to define the hydroponic system at the upper side of the hydroponic system. The cover arrangement encloses the support member together with the container.

[0013] In a second aspect, the invention relates to the use of a hydroponic system according to any one of the preceding claims for the hydroponic germination of seeds and the growth of seeds into plants.

[0014] In a third aspect, the invention relates to a method for germinating seeds and growing them into plants. The method comprises the step of providing a liquid to the upper part of the receiving space of the hydroponic system according to the first aspect. The method further comprises the step of providing a pressurized gas to the lower part via the connecting arrangement and the gas pressure device. The method further comprises the step of providing seeds, seedlings and / or plants to the support member. The method further comprises the step of holding the support member at a predetermined distance above the liquid. The support member includes a second opening for allowing roots to grow through the second opening and for allowing moisture-laden air to reach the seeds, seedlings and / or plants.

[0015] Any embodiment applicable to the first aspect of the invention is correspondingly applicable to the second and third aspects according to the invention.

[0016] At least one of the above objects is achieved by a hydroponic system according to the invention.

[0017] Without wishing to be bound by theory, the inventors believe that the method according to the invention causes the formation of bubbles in the liquid and the bubbles burst at the surface, providing moisture-laden air between the liquid and the support member holding the seeds, seedlings and / or plants, allowing the seeds and seedlings to be in a humid environment, and / or humidifying the seeds and / or roots, without the need for roots that can reach the water; this in turn allows the seeds to germinate and the first roots to grow. Depending on the distance between the support member and the liquid, the bubbles may first contact the support member before bursting. When the roots reach the liquid, since air passes through the liquid, the liquid is also well oxidized and the growth of the plant can take place within the same system. In addition, the bursting of the bubbles results in a good circulation of humid air, thus allowing an optimal flow of oxygen and nutrients to reach the seeds and / or roots. Other benefits of the system according to the invention are discussed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention is described below with reference to the drawings, in which embodiments of the invention are shown and in which the same reference numerals denote the same or similar elements.

[0019] Figure 1 An example of a hydroponic system for germinating seeds and growing them into plants according to the invention is shown in cross-sectional view, including a lid arrangement that allows the seeds to germinate continuously and germinate in a closed environment.

[0020] Figure 2A second example of a hydroponic system for germinating seeds and growing them into plants according to the present invention is shown in cross-sectional view after the lid arrangement has been removed to allow the plant to grow after germination and / or to allow the flowers and / or fruits to grow and to expose the plant to light.

[0021] Figure 3 A third example of a hydroponic system for germinating seeds and growing them into plants according to the present invention is shown in cross-sectional view, where the system accommodates seeds, sprouts, seedlings, and plants with flowers and fruits, indicating that the system can be used simultaneously for seeds and plants in various growth cycles and for growth in successive cycles over time.

[0022] Figures 4a) and b) show a fourth example of a hydroponic system for germinating seeds and growing them into plants according to the present invention, where the distance between the support member and the first wall element can be adjusted (from a) to b) and vice versa). This distance will be adjusted before the start of use of the system. However, those skilled in the art will understand that this distance can also be adjusted during the growth cycle.

[0023] Figure 5 A fifth example of a hydroponic system for germinating seeds and growing them into plants according to the present invention is shown in cross-sectional view, where there is a second wall element and a partial lid that provides a receiving space on the upper side even after the lid arrangement has been removed.

[0024] Figure 6 A second instance of a hydroponic system for germinating seeds and growing them into plants according to the present invention is shown in perspective view.

[0025] Figure 7 Three different microgreens are shown growing from top to bottom using a traditional ebb and flow hydroponic system with a jute mat solid medium, a coco mat solid medium, and a hydroponic system according to the present invention without using a solid medium.

[0026] Figure 8 a) and b) show root growth through the support member, where the seeds are grown using a traditional ebb and flow hydroponic system with a coco mat solid medium a) and using a hydroponic system according to the present invention without using a solid medium b).

[0027] Reference numerals:

[0028] 1. Container

[0029] 2. Receiving space

[0030] 3. First wall element

[0031] 4. Lower part

[0032] 5. Upper part

[0033] 6. First opening

[0034] 7. Connection arrangement

[0035] 8. Support member

[0036] 9. Second opening

[0037] 10. Cover arrangement

[0038] 11. Second wall element

[0039] 12. Rib

[0040] Detailed description of the drawings

[0041] Figure 1 A cross-sectional view of a container 1 including a receiving space 2 is shown, the receiving space having a first wall element 3 that divides the receiving space 2 into a lower part 4 and an upper part 5.

[0042] The lower part 4 contains a gas, such as air. The upper part 5 contains a liquid, such as water. This water can be rich in nutrients, such as minerals.

[0043] The first wall element 3 is provided with a first opening 6, thereby allowing gas to pass from the lower part 4 into the liquid in the upper part 5. This creates bubbles in the liquid. The openings 6 can be evenly distributed within the first wall element 3, thereby creating bubbles across the wall element 3. The first opening 6 is, for example, 0.1 - 1 mm. The size of the opening 6 affects the formation of bubbles in terms of the bubble formation rate and bubble size. The properties of the liquid, especially in terms of surface tension and viscosity, and the properties of the gas may also affect the characteristics of bubble formation.

[0044] There is an opening in the lower part 4, which is a connection arrangement 7, and the connection arrangement is arranged for connecting a pneumatic device (not shown) to the lower part 4. The gas pressurizing device (not shown) is used to add pressurized gas to the lower part 4. When gas is added to the lower part 4, the gas can flow through the first opening 6 to form bubbles in the liquid held in the upper part 5. The gas pressure held in the lower part 4 prevents the liquid from entering the lower part 4 through the first opening 6. The diameter of the first opening 6 is preferably selected such that due to the surface tension of the liquid, the liquid cannot flow through the first opening 6. In this case, a two-phase flow in which the liquid and air expand through each other in opposite directions does not occur. The gas pressure in the lower part 4 affects the rate and uniformity of bubble formation.

[0045] There is a support member 8, which is arranged for holding seeds and plants at a predetermined distance above the first wall element 3 and substantially parallel to the first wall element 3.

[0046] The bubbles burst when they reach the surface of the liquid to generate micro - droplets in the space between the liquid and the support member 8. In one embodiment, the bubbles can also reach a certain size that allows them to first contact the support member 8 before bursting. This space accommodates gas, such as ambient air. The bursting of the bubbles on the liquid surface creates a flow in the air above it, keeping the humidified air in continuous motion. The amount of humidification and the generated air flow depend on the size of the bubbles and the rate of bubble bursting.

[0047] The support member 8 includes a second opening 9 for allowing humidification of the seeds and roots, and the roots grow through the second opening 9. For example, the support member 8 can be a mesh tray. The size of the second opening 9 should be at least large enough for the humid air to reach the seeds, but not so large that the seeds fall through the opening 9. The roots of the seeds should be able to grow through the opening 9. The distance between the liquid surface and the support member 8 affects the humidification level and the amount of moisture reaching the seeds and roots in the form of micro - droplets. This distance should be large enough to allow bubble formation and bubble bursting. The expected distance between the liquid surface and the support member 8 is between 0.1 - 7 cm, for example between 0.2 and 5 cm, or more specifically between 0.5 and 2 cm.

[0048] The liquid level may also affect the coalescence of the bubbles before they reach the liquid surface. The coalescence of the bubbles will result in larger bubbles forming and bursting on the liquid surface. The liquid level is also a factor affecting the degree of liquid movement, which in turn affects the accuracy of the location of bubble formation, coalescence, and / or bursting.

[0049] There is also a lid arrangement 10 which defines the hydroponic system on the upper side and encloses the support member 8 together with the container 1. Figure 1 The shown lid arrangement 10 is a lid. It creates a sealed environment, keeping the humidified gas (air) within the system. Another function of the lid arrangement 10 can be to provide a dark covering that limits the space above the seeds, and / or to provide a downward force and thus a resistance pushing the seeds backward, helping the seeds shed their seed coats and promoting stronger stem growth, mimicking the presence of soil on the seeds. The lid arrangement 10 can be removed to allow the user to access the system. Another reason for removing the lid arrangement 10 is to allow space for the plants to grow after germination and to expose the sprouts, seedlings, and / or plants to light.

[0050] Figure 2 Another example of a hydroponic system according to the present invention is shown. This system is very similar to the Figure 1 system, and the description provided for the Figure 1 accompanying drawings can be correspondingly applied to the Figure 2 system, except as follows. Figure 2 Compared with the Figure 1The difference is that the lid arrangement 10 is not depicted. The removal of the lid arrangement 10 allows space for the sprouts, seedlings and / or plants to grow after germination, for the plants to grow flowers and / or fruits and allows the plants to receive light.

[0051] Figure 3 Fig. 4 shows another example of a hydroponic system according to the present invention. This system is very similar to Figure 2 the system of Figure 2 and the description of the accompanying drawings provided for Figure 3 can be correspondingly applied to Figure 3 with the following exceptions. Figure 2 The difference from

[0052] Figs. 4A and B show another example of a hydroponic system according to the present invention. This system is very similar to Figures 1 - 3 the system of Figures 1 - 3 and the description of the accompanying drawings provided for Figures 1 - 3 can be correspondingly applied to Figs. 4A and B with the following exceptions. Figs. 4A and B differ from

[0053] Figure 5 Fig. 5 shows another example of a hydroponic system according to the present invention. This system is very similar to Figure 1 the system of Figure 1 and the description of the accompanying drawings provided for Figure 5 can be correspondingly applied to Figure 5 with the following exceptions. Figure 1 The difference from Figure 5 is that the upper part 5 includes a second wall element 11 which is at a predefined distance from and substantially parallel to the first wall element 3 for receiving the support member 8. As can be seen from Figure 1 in this example, the support member 8 is smaller in size than the width of the container 1 at its upper side. The second wall element 11 together with the lid arrangement 10 covers the receiving space 2 of the container 1 at the upper side. The presence of the second wall element 11 provides a partial cover of the receiving space 2 at the upper side even when the lid arrangement 10 is removed. The second wall element 11 and the support member 8 can be connected to each other. They can be removed from the container 1. Figure 1 In Figure 5In it, the cover arrangement 10 is supported by the second wall element 11 and only provides coverage for the support member 8.

[0054] Figure 6 A perspective view shows an example of a hydroponic system according to the present invention. The system is very similar to the Figures 1 - 5 system, and the description provided for the Figures 1 - 5 accompanying drawings can be correspondingly applied to the Figure 6 system, except as follows. The perspective view of the hydroponic system according to the present invention reveals ribs 12, which can be used to strengthen the lower part 4 so that it does not deform under pressure, for example. The bottom of the container 1 is connected to the first wall element 3 using ribs. Those skilled in the art will understand that various materials can be used for such ribs 12, such as fiberglass or plastic.

[0055] Figure 7 Three different microgreens are shown growing from top to bottom using a traditional ebb and flow hydroponic system with a solid medium of hemp mat, a solid medium of coco mat, and a hydroponic system according to the present invention without using a solid medium.

[0056] Figure 8 A and B show root growth through the support member, where seeds are grown using a traditional ebb and flow hydroponic system with a solid medium of coco mat (A), and a hydroponic system according to the present invention without using a solid medium (B). Detailed Description

[0057] As described above, the present invention in a first aspect relates to a hydroponic system for seed germination, seedling, and plant growth. In other words, the system is suitable for all growth cycles of plants. This includes seed germination to produce sprouts, the development of sprouts into seedlings (microgreens), the development of seedlings into plants, and the growth of plants until they reach maturity, for example until they flower or bear fruit, and / or are ready for harvest.

[0058] An object of the present invention is to provide a hydroponic system in which the seeds to be germinated and the growing seedlings and / or plants are suspended at a predetermined distance above a liquid, whereby a humid environment is created above the liquid by the formation of bubbles and by the bursting of the bubbles at the liquid surface through the supply of gas to the liquid. The bursting bubbles disperse minute water droplets, allowing the seeds as well as the seedlings and / or plants (their roots) to obtain the water and nutrients required for germination and growth, such that the hydroponic system can be used for the germination of seeds and the growth of seeds into plants without the need to pre-germinate the seeds in a separate nursery.

[0059] In an embodiment of the first aspect of the present invention, the first openings 6 are evenly distributed across the surface of the first wall element 3. The diameter of the first openings 6 is preferably chosen such that due to the surface tension of the liquid, the liquid cannot flow through the first openings 6. In this case, a two-phase flow in which the liquid and air can expand through each other in opposite directions does not occur. Furthermore, the gas pressure maintained in the lower part 4 prevents the liquid from entering the lower part 4 through the first openings 6.

[0060] Those skilled in the art will understand that the distance between the first openings 6 can vary and that this affects the bubble size and whether the bubbles coalesce. The inventors have found that if the distance between the first holes allows the bubbles to reach a certain size without coalescing and thus allows the bubbles to reach the support member 8 before bursting, this will result in the highest germination rate. Those skilled in the art will understand that foaming also allows the oxygenation of the liquid, which is beneficial for germination, healthy roots and increased nutrient uptake.

[0061] Another advantage of the system comprising the receiving space 2 divided by the first wall element 3 into a lower part 4 and an upper part 5 is that the first wall element 3 can be cleaned and maintained, wherein the lower part 4 is arranged to receive gas and the upper part 5 is arranged to receive liquid, and wherein the first wall element 3 is provided with the first openings 6 to allow gas-liquid communication between the lower part 4 and the upper part 5. For example, algae, bacteria and lime deposits can be easily removed, especially from the first openings 6. In a specific embodiment, the predefined distance between the first wall element 3 and the support member 8 is between 1.1 and 7 cm. In a more specific embodiment, this predefined distance is between 1.1 and 5 cm. In an even more specific embodiment, this predefined distance is between 1.5 and 3 cm.

[0062] In another embodiment of the first aspect, the second openings 9 are evenly distributed across the surface of the support member 8. In a specific embodiment, the support member 8 is a mesh tray.

[0063] The above arrangement allows for the uniform formation and distribution of bubbles and the optimal use of the available surface of the first wall element 3 and thus the available surface of the liquid for foaming, which results in a high yield and successful germination of germinated seeds, growing seedlings and / or plants. The effective humidification achieved by the above arrangement also results in a reduction in the need for liquid. Thus, the above arrangement allows for the economical use of (scarce) water, nutrients and other components of the liquid. The above arrangement further allows for the germination of seeds and the growth of seedlings and plants without the need for a solid medium.

[0064] In another embodiment of the first aspect, the lid arrangement 10 is movable to allow access to the support member 8 in a first position of the movable lid arrangement 10 and to block access to the support member 8 in a second position of the movable lid arrangement 10. "Access" herein refers to access by the system user. The lid arrangement 10 can be in the second position to form a closed system. This allows moisture to accumulate and remain within the system. Another function of the lid arrangement 10 can be to provide a dark covering, limit the space above the seeds, and / or provide a downward force, thereby providing resistance for the seeds to push backward, helping the seeds shed their seed coats and promoting stronger stem growth, mimicking the presence of soil on the seeds. The lid arrangement 10 can be placed in the first position to provide access to the system to the user. Another reason can be to provide more growing space for the sprouts, seedlings, and / or plants after germination and enable the sprouts, seedlings, and / or plants to receive light.

[0065] Accordingly, the movable lid arrangement 10 allows for further optimization of the combination of seed germination and plant and seedling growth within a system, allows for continuous seed germination in a closed environment, and allows for the growth of seedlings and plants in an open environment.

[0066] In another embodiment, the upper part 5 includes a second wall element 11 that is spaced a predetermined distance from and substantially parallel to the first wall element 3 for receiving the support member 8.

[0067] In another embodiment of the first aspect, the upper part 5 includes a second wall element 11 that is spaced a predetermined distance from and substantially parallel to the first wall element 3 for receiving the support member 8. In an embodiment, the predetermined distance between the first wall element 3 and the second wall element 11 is between 1 and 7 cm. The second wall element 11 allows for more control of the environment within the upper part 5 and thus allows for optimization of the humidification of the seeds, seedlings, and / or plants.

[0068] In another embodiment of the first aspect, the system includes an adjusting device for adapting the predetermined distance between the support member 8 and the first wall element 3 and / or between the second wall element 11 and the first wall element 3. The adjusting device for adapting the predetermined distance between the seeds, seedlings, and / or plants and the liquid allows for optimization of the humidification of the seeds.

[0069] In another embodiment of the first aspect, the hydroponic system further includes a gas pressure device arranged to generate pressurized gas, wherein the gas pressure device is communicatively coupled to the connection arrangement 7 for providing the pressurized gas to the lower part 4 via the connection arrangement 7. The gas pressure device can be anything that allows pressurized gas to enter the lower part 4.

[0070] Those skilled in the art will understand that embodiments of the first aspect of the hydroponic system of the present invention may be made of an opaque material to block light. As is well known, certain types of seeds prefer or even require darkness to germinate, while other types of seeds require or prefer light. In addition, the advantage of using an opaque material is that the blocking of light prevents the formation of algae.

[0071] As described above, in a second aspect, the present invention relates to the use of a hydroponic system according to any one of the preceding claims for the hydroponic germination of seeds and the growth of seeds into plants.

[0072] As described above, in a third aspect, the present invention relates to a method for the germination of seeds and the growth of seeds into plants.

[0073] In an embodiment of the third aspect, the method further comprises the steps of defining the receiving space 2 at the upper side of the receiving space 2 by means of the cover arrangement 10 and enclosing the support member 8 together with the container 1.

[0074] In another embodiment of the third aspect, the method further comprises the step of adjusting the predetermined distance between the support member 8 and the liquid by means of an adjusting device. Before germination and growth, the predetermined distance between the support member 8 and the liquid can be adjusted to optimize the system for a specific type of seed, sprout, seedling, and / or plant.

[0075] In another embodiment of the third aspect, the liquid is water or contains water. The liquid may contain nutrients (organic or inorganic), such as essential, variable, and non-essential macronutrients and micronutrients, such as nitrogen, potassium, phosphorus, calcium, magnesium, cobalt, and minerals. In a specific embodiment, the liquid is water containing nutrients. In addition, the pH value of the liquid can be changed to achieve an optimal setting for a specific type of seed, sprout, seedling, and / or plant.

[0076] In another embodiment of the third aspect, the distance between the surface of the liquid and the support member 8 is between 0.1 - 7 cm, preferably between 0.2 and 5 cm, more preferably between 0.5 and 2 cm. The optimal distance depends on the size of the bubbles at rupture and the required amount of humidification.

[0077] In another embodiment of the third aspect, a pressurized air flow through the first opening 6 provides a supply of single and / or coalesced bubbles that break on the surface of the liquid. Coalescence produces larger bubbles that break on the surface of the liquid, resulting in different amounts and rates of humidification. For some applications, it may be desirable to have little or no coalescence. For other applications, coalescence of the bubbles before rupture may be preferred. The amount of coalescence is affected, for example, by the diameter of the first opening 6 or the liquid level and properties present in the upper part 5 of the container 1. Those skilled in the art will understand that the humidification rate depends at least in part on the rate of bubble generation, which in turn depends at least in part on the gas pressure.

[0078] In another embodiment of the third aspect, for a pressurized air flow through 90 - 100% of the first opening 6, pressure accumulation in the lower part 4 is achieved. In one embodiment, the difference between the size (perforation diameter) of the first opening 6 and the volume of the lower part 4 of the container 1 allows for a static accumulation of pressure within the lower part 4 to provide a uniform gas distribution through said opening.

[0079] Compared with the system of US4057930A, the hydroponic system according to the present invention allows for effective humidification of seeds, resulting in a higher germination rate and higher yields. In addition, only a reduced amount of water is required. Moreover, the system has low maintenance costs and is easy to clean.

[0080] The hydroponic equipment disclosed in US4057930A is intended to be used as a nursery, which is evident from the fact that the system includes a water heater to generally maintain the temperature in the range of 68°F to 92°F (20 to 33°C), which in the case of using the system results in excessive growth of bacteria and fungi beyond the cultivation of sprouts. The system described in US4057930A includes an aerator grid arranged in the upper layer of water, and the aerator grid includes tubular members. The use of tubular members results in a non-uniform and sub-optimal distribution of perforations, only along a partial surface area of the water, thus resulting in non-uniform and sub-optimal humidification of germinating seeds. In addition, the tubes impose resistance to the air flow within the tubes, causing friction and turbulence, which in turn results in a pressure drop along the tubes, leading to non-uniform and sub-optimal humidification of germinating seeds. Moreover, since the aerator grid is placed in the upper layer of water, only due to the use of the aerator grid, the system requires substantially more water compared to other systems. In addition, due to this placement of the aerator grid in the upper layer of water, the lower layer of water remains undisturbed. The drawback is that it stimulates the growth of algae and bacteria in the stagnant layer of water. These algae and bacteria do not remain in a layer of water below the aerator grid but will quickly migrate to the upper layer. In addition, the water may have to be changed more frequently. Moreover, such an aerator grid requires regular cleaning, maintenance, and occasional repair or even replacement.

[0081] By studying the drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement other variations of the disclosed embodiments when practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously. Any reference signs in the claims should not be construed as limiting their scope.

[0082] The scope of the present invention is defined by the appended claims. One or more objects of the present invention are achieved by the appended claims.

[0083] Example

[0084] The present invention is further illustrated based on the following examples, which are illustrative only and are not considered to be a limitation of the present invention.

[0085] Example 1

[0086] Materials and Methods

[0087] Parameter Settings

[0088] Internal experiments were carried out using the hydroponic system according to the present invention (hereinafter referred to as "HS"). This system has the following parameters:

[0089] - Distance between the bottom of the container (1) and the first wall element (3): 9 mm

[0090] - Distance between the first wall element (3) and the second wall element (11): 36 mm

[0091] - Distance between the first wall element (3) and the support member (8): 19 mm

[0092] - Support member (8); Dimensions of the second opening (9), unless otherwise specified: 1.5 mm × 1.5 mm

[0093] - Liquid level: 18 mm

[0094] - First wall element (3); Diameter of the first opening (6): 0.6 mm

[0095] - Air pressure: 2.3 PSI

[0096] - Distance between the support member (8) and the lid arrangement (10): 40 mm

[0097] Growth Space

[0098] During the duration of the germination and growth cycle, the HS system was placed in a closed growth space.

[0099] The air temperature and humidity in the growth space were monitored daily using an SHT31-D temperature and humidity sensor. Inside the growth space, the monitored air humidity was kept constant at about 85%, while the measured temperature was kept constant at 22 °C. For lighting purposes, a single full-spectrum 24W Barrina T8 grow light was placed 30 cm above the system and turned on starting from the 4th day during the transition from the germination cycle to the growth cycle.

[0100] Light Green

[0101] Radish (Raphanus sativus) "Sango" was used throughout the experiment.

[0102] Irrigation

[0103] According to the present invention, irrigation is achieved by the bursting of air bubbles at the liquid surface placed in the upper part (5) of the accommodation space (2). Air is introduced into the system for 20 minutes, causing the bursting of air bubbles, and then stopped for 40 minutes. This is repeated throughout the experiment; from the sown seeds to the moment of harvest (and thus for the germination and growth cycles).

[0104] For the first 3 days, tap water was used for irrigation. The measured average pH value was 7.8, while the water hardness concentration was measured at 230 ppm.

[0105] Fertilization

[0106] On the 4th day after sowing, the necessary micro - macro nutrients were introduced into the existing water in the system. The nutrient solution contained the necessary micro and macro nutrient components: TerraAquatica TriPart Original FloraGro 3 - 1 - 6. The fertilizer solution was obtained by mixing 1 mL of FloraGro per 1 L of water. The measured fertilizer solution had: 560 ppm (700 scale) and pH 6.

[0107] During the transition between the germination cycle and the growth cycle in the hydroponic system (HS) according to the present invention: the lid arrangement (10) is removed, thus providing light and space for the germinated seedlings for further growth.

[0108] Calculation of germination rate

[0109] On the 8th day, the germination rate was calculated as follows:

[0110]

[0111] Seed density = 1 m 2 of sown seeds (g) in

[0112] The micro - greens from different positions of the tray (8) were measured with a ruler from the base of the seedling stem to the top. Additionally, the micro - greens including their roots were measured with a ruler from the top of the seedling (micro - greens) to the root tip. Finally, the length of the first leaf (cotyledon) of the micro - greens was measured, which was achieved by taking the largest cotyledon between two given micro - greens and measuring longitudinally.

[0113] Calculation of fresh weight yield

[0114] Then the micro - greens were harvested by cutting the seedlings at the base of the seedling stem (hypocotyl part). Then the micro - greens harvested in each cultivation cycle were weighed to determine their fresh weight yield.

[0115] Results

[0116] Humidification as a function of parameters

[0117] Ha: Distance between the liquid level and the support member (8)

[0118] Hw: Liquid level height

[0119] d: Diameter of the first opening (6)

[0120] LP: Low pressure maintained in the lower part (4): 0.8 PSI

[0121] HP: High pressure maintained in the lower part (4): 1.8 PSI

[0122] Initial (starting) humidity 55%

[0123] Temperature inside the system 20.8 °C

[0124] Humidity is measured above the support member (8)

[0125] Table 1: Humidity (%) reached within 5 minutes and time (s) to reach 85% humidity under different parameters

[0126]

[0127]

[0128] The results show that, among other findings, compared to the low pressure, when a high pressure is introduced into the lower part (4), generally a higher humidity is reached within 5 minutes.

[0129] For both low and high pressures, the highest humidity reached within 5 minutes is when the diameter of the first opening (6) is 0.6 mm, the liquid level is 50 mm, and the distance between the liquid level and the support member (8) is 10 mm.

[0130] Regarding the time taken to reach 85% humidity (from the initial 55%), it can be noted that for both low and high pressures in the lower part (4), for a first opening (6) with a diameter of 0.6 mm, the shortest time recorded to reach this humidity is when the liquid level (Hw) is 50 mm.

[0131] For a first opening (6) with a diameter of 1 mm, the shortest times to reach 85% humidity are recorded for liquid levels (Hw) of 10 mm and 50 mm.

[0132] Relationship between germination rate and fresh weight yield and liquid level

[0133] Table 2: Germination rate (%) and fresh weight yield (g / m 2 )

[0134] Liquid level Hw (mm) Germination rate (%) <![CDATA[Fresh weight yield (g / m 2 )]]> 5 67.3 849.29 10 79.3 923.84 15 92.3 1293.04 20 92.6 1333.45 25 90.7 1193.53 30 87.2 1176.28

[0135] Sowing seed density: 160 g / m 2

[0136] The results show that the optimal liquid level points for the selected system parameters are 15 mm and 20 mm. The inventors noted that in the systems used in these examples, at liquid levels of 10 mm and lower, there was not enough water, and thus not enough time for bubble formation and coalescence. Only very small bubbles burst, and the tiny droplets did not seem to reach the seeds and did not seem to produce water-saturated air. In contrast, at liquid levels of 25 mm and higher, more efficient bubble formation and coalescence led to turbulence within the liquid, as well as coalescence and bursting of bubbles at unexpected locations, such that some seeds, although initially sown evenly on top of the support member (8), did not enter the ideal environment (irrigation) evenly.

[0137] Example 2

[0138] Effect of seed density on fresh weight yield

[0139] Three HS devices were prepared and processed according to Example 1, except that a total of 6 different seed densities were sown and tested. The average values of the resulting results are shown below.

[0140] Results

[0141] Table 3: Effect of seed density (g / m 2 ) on fresh weight yield (g / m 2 ) grown in HS

[0142] <![CDATA[Seed density (g / m 2 )]]> <![CDATA[Fresh weight yield (g / m 2 )]]> 82.36 631.32 109.81 862.09 137.27 1051.89 164.72 1289.22 256.74 1910.48 342.32 2750.88

[0143] The results show that the trend of change in seed density with fresh weight yield is almost linearly increasing. Thus, for the tested seed densities, higher seed densities (including 342.32 g / m 2 ) led to higher harvested fresh weight yields.

[0144] The tested samples had no fungal disease infections, and no root rot was still observed for a sowing seed density of 342.32 g / m 2 . The inventors believe that the results are partly related to the fact that no solid medium was used, which would have contained (stagnant) water allowing the formation of such diseases. The lack of a solid medium also allowed more space for the sown seeds to germinate and grow, as well as allowing increased movement of air, which was further enhanced by the continuous movement of water-saturated air through the bursting of bubbles.

[0145] Example 3

[0146] Comparative experiment with a serpentine pipe system

[0147] The HS device was prepared and processed according to Example 1. The embodiments of the present invention were compared with a similar system, except that a serpentine duct (hereinafter referred to as "ST") was used instead of the lower part (4) to supply air in order to generate bubbles in and on the liquid surface and to oxygenate the liquid. Thus, in this system (ST) of the comparative example, there is no first wall (3). The serpentine duct used for the comparative example has the following parameters:

[0148] - Outer diameter: 9 mm

[0149] - Inner diameter: 6 mm

[0150] - Material: vinyl

[0151] As found in HS, the perforations along the duct have the same diameter and the relevant distance between them.

[0152] In ST, as in HS, air was introduced into the system for 20 minutes, bubble rupture occurred, and then it was stopped for 40 minutes. This was repeated throughout the experiment; from the sown seeds to the moment of harvest (thus for the germination and growth cycle).

[0153] Results

[0154] Table 4: Germination rate (%) and fresh weight yield (g / m 2 )

[0155]

[0156] The results showed that, for any seed density tested, the system according to the present invention (HS) gave significantly higher germination rates and fresh weight yields than the system with the serpentine duct (ST).

[0157] Throughout the experiment, it could be observed that, for the serpentine duct (ST), the further the perforations in the duct were from the source of the introduced pressurized air, the fewer (less effective) the bubbles obtained. Thus, the efficiency over the entire surface area of the accommodation space was not met as in HS.

[0158] Example 4

[0159] Comparative experiment on hydroponic techniques (and culture media)

[0160] The HS device was prepared and processed according to Example 1. For comparison purposes, a traditional hydroponic technique, namely the ebb and flow hydroponic system, was established. This is a technique in which the growing trays are placed above the reservoir. Two different culture media were used for this technique: coco coir mats and hemp mats (hereinafter denoted as "CM" and "HM" respectively). The seeds were sown directly on these culture media.

[0161] CM and HM (ebb and flow systems) are placed in the nursery during their germination cycle and in a closed growth space during their growth cycle.

[0162] For the hydroponic system, during the germination cycle, before changing in the nursery, the trays are irrigated twice a day from the top of the trays using a pressure sprayer. During the growth cycle, the trays are placed inside a closed growth space. According to traditional ebb and flow irrigation, the pump fills the upper trays with water (nutrient solution), and afterwards the solution drains back to the reservoir. This is repeated 6 times within 24 h. This enables the medium, coco mats and jute mats, to be rinsed regularly with water and air.

[0163] As for the HS setup, irrigation is carried out using tap water for the first 3 days. The measured pH value averages 7.8, while the water hardness concentration is measured at 230 ppm.

[0164] On the 4th day after sowing, the necessary micro-macro nutrients are introduced into the existing water in the ebb and flow system. The fertilizer solution is obtained by mixing 1 mL of FloraGro per 1 L of water. The measured fertilizer solution has: 560 ppm (700 scale) and pH 6.

[0165] For CM and HM, the mesh trays used have similar dimensions to HS: 34 cm x 25 cm x 3 cm. However, while no medium is placed on top of those trays for HS, coco mats with a thickness of 10 mm and jute mats with a thickness of 10 mm are placed on top of the trays of the ebb and flow systems (CM and HM respectively).

[0166] For all trays, 9.25 g of seeds / tray are sown by hand on the surface of each tray - unless otherwise stated. This corresponds to a seed density of 158.15 g / m 2 of.

[0167] The small greenery is harvested by cutting the seedlings at the base of their stems. Radish (Raphanus sativus) "Sango" is used throughout the experiment.

[0168] Results

[0169] Table 5: Germination rate (%), fresh weight yield (g / m 2 ), average shoot height (mm) and average leaf length (mm) of different hydroponic systems / media

[0170]

[0171] These results show that, compared with the traditional ebb and flow setups with different media: CM and HM, the germination rate, fresh weight yield, average shoot height and average leaf length in the HS setup increase.

[0172] Example 5

[0173] Comparative experiment of hydroponic techniques (and culture media) with different seed densities

[0174] Three HS settings, three CM settings, and three HM settings were prepared and processed according to Examples 1 and 4, except that for each setting (HS, CM, and HM), a total of 6 different seed densities were tested. The average values obtained are shown below.

[0175] Results

[0176] Table 6: Germination rate (%) and fresh weight yield (g / m 2 ) for different hydroponic systems / media, relative to different seed densities (g / m 2 )

[0177]

[0178] The results show that with the increase in seed density, the germination rate of HS is constant, while the germination rates of CM and HM decrease with the increase in seed density.

[0179] Again, here, the inventors believe that such results are due to the good retention and ideal settings in which the sown seeds can germinate successfully in the hydroponic system according to the present invention: a large humidity level and a constant movement of humid air from the bursting of air bubbles.

[0180] The results show that for the embodiment of the present invention (HS), compared with CM and HM, the increase in fresh weight yield (g / m 2 ) for increasing the seed density (g / m 2 ) is steeper, and it becomes steeper from a seed density of 256.74 g / m 2 .

Claims

1. A hydroponic system for seed germination and growth into plants, the hydroponic system comprising: Container (1), including an accommodation space (2); A first wall element (3) that divides the accommodation space (2) into a lower part (4) arranged to accommodate gas and an upper part (5) arranged to accommodate liquid, and wherein the first wall element (3) is provided with a first opening (6) to allow gas-liquid communication between the lower part (4) and the upper part (5); A connection arrangement (7) arranged to connect a gas pressure device to the lower part (4); A support member (8) arranged to hold the seeds and plants at a predetermined distance above the first wall element (3) and substantially parallel to the first wall element (3), wherein the support member (8) includes a second opening (9) for allowing humidification of the seeds and roots and for the roots to grow through the second opening (9); A lid arrangement (10) arranged to define the hydroponic system at the upper side of the hydroponic system and to enclose the support member (8) together with the container (1).

2. The hydroponic system according to claim 1, wherein the first openings (6) are evenly distributed across the first wall element (3).

3. The hydroponic system according to any one of claims 1 and 2, wherein the second openings (9) are evenly distributed across the surface of the support member (8), preferably, wherein the support member (8) is a mesh tray.

4. The hydroponic system according to any one of the preceding claims, wherein the cover arrangement (10) is movable to allow access to the support member (8) in a first position of the movable cover arrangement (10) and to block access to the support member (8) in a second position of the movable cover arrangement (10).

5. The hydroponic system according to any one of the preceding claims, wherein the upper part (5) comprises a second wall element (11) spaced a predetermined distance from and substantially parallel to the first wall element (3) for receiving the support member (8).

6. The hydroponic system according to any one of the preceding claims, wherein the system comprises adjustment means for adjusting the predetermined distance between the support member (8) and the first wall element (3) and / or between the second wall element (11) and the first wall element (3).

7. The hydroponic system according to any one of the preceding claims, wherein the hydroponic system further comprises: The gas pressure device, which is arranged to generate pressurized gas, wherein the gas pressure device is communicatively coupled to the connection arrangement (7) for supplying the pressurized gas to the lower part (4) via the connection arrangement (7).

8. Use of the hydroponic system according to any one of the preceding claims for seed germination and growth of seeds into plants.

9. A method for seed germination and growth into plants, the method comprising the steps of: Supplying liquid to the upper part (5) of the accommodation space (2) of the hydroponic system according to claims 1-7; Supplying pressurized gas to the lower part (4) through the connection arrangement (7) and the gas pressurizing device; Supplying seeds, seedlings and / or plants to the support member (8); Holding the support member (8) at a predetermined distance above the liquid, wherein the support member (8) includes a second opening (9) for allowing gas-liquid communication and for the roots to grow through the second opening (9).

10. The method according to claim 9, wherein the method further comprises the steps of: Defining the accommodation space (2) at the upper side of the accommodation space (2) through the lid arrangement (10) and enclosing the support member (8) together with the container (1).

11. The method according to any one of claims 9 and 10, wherein the method further comprises the following steps: Adjusting the predetermined distance between the support member (8) and the liquid through the adjustment arrangement.

12. The method according to any one of claims 9-11, wherein the liquid is water or contains water.

13. The method according to any one of claims 9-12, wherein the distance between the surface of the liquid and the support member (8) is between 0.1 and 7 cm, preferably between 0.2 and 5 cm, more preferably between 0.5 and 2 cm.

14. The method according to any one of claims 9-13, wherein the pressurized air flow through the first opening (6) provides a supply of single and / or coalesced bubbles that break on the surface of the liquid.

15. The method according to any one of claims 9-14, wherein pressure accumulation is achieved for the pressurized air flow through 90-100% of the first opening (6).

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