NL2022594B1 - An assembly for hydroculture of plants - Google Patents

Abstract

The present invention relates to an assembly for hydroculture of plants, wherein the assembly is comprised of a panel-shaped buoyant carrier for floating on water wherein the carrier comprises a multitude of apertures for receiving and holding a plant to be cultivated. The present invention further relates to a method for the cultivation of plants by hydroculture using the assembly of present invention, more specifically by Deep Flow Technology (DFT) cultivation.

Description

AN ASSEMBLY FOR HYDROCULTURE OF PLANTS Description The present invention relates to an assembly for hydroculture of plants, wherein the assembly is comprised of a panel-shaped buoyant carrier for floating on water wherein the carrier comprises a multitude of apertures for receiving and holding a plant to be cultivated. The present invention further relates to a method for the cultivation of plants by hydroculture using the assembly of present invention, more specifically by Deep Flow Technology (DFT) cultivation.

Deep Flow Technology is a technology in which the crop is grown on a large pond.

The plant's roots are allowed to dangle in the nutrient solution which is in a container or pond. From the pond the plants can absorb the nutrients. In a Deep flow technique (DFT) hydroponic system, plants are suspended on board systems or floats that floated on the surface of the nutrient solution (e.g. water comprising nutrients) that circulates around the roots via a pump and/or gravity drain.

In DFT systems, most float systems are comprised of extruded polystyrene (EPS) foam, also known as Styrofoam and are composed of 98% air, making it lightweight and buoyant. The float comprises multiple apertures wherein plants are placed such that the plant is positioned above the water, but with the roots of the plant in contact with the water underneath the float. Different floats are available for different young plant species and varieties and due the amount of plant apertures on a float, the density of the crop may be varied.

Growing crops on extruded polystyrene foam plates has the disadvantage that microbes develop into the pores of the material increasing the chance of infection and crop disease over. Furthermore, floats of styrofoam are difficult to clean and disinfect without destroying the plate structure. The float technology is applied for the production of short cultivation period vegetables, such as lettuce, endive, and spinach. Studies have shown that crop cultivation on soilless culture showed increased yield and plant growth in comparison to the related values in plants grown in the soil.

A drawback of a closed-loop soilless culture systems, such as the DFT hydroponic system, is that these systems are prone to nutrient imbalance and accumulation of compounds within the systems (such as microbial metabolites, ballast ions and root exudates) in the recirculating nutrient solution. It is difficult to maintain a proper water climate. Furthermore, the floats block interaction of the water surface and air around the plant that is cultivated in the float, Le. Oy / COs interaction between water and air for optimal growing conditions. The roots of the plant use the nutrients for growth and during the process salts are excreted from the roots. This leads to changes in the pH level of the nutrient solution surrounding the roots, and may eventually lead to inability to absorb nutrients properly leading to malnutrition of the plant. This problem iscurrently solved by taking out the plants from the floats and/or the nutrient solution, and rinsing the roots with clean water regularly. However, this step is costly and labour intensive.

Considering the above, there is a need in the art for a hydroculture system that is less prone to nutrient imbalance and accumulation of compounds within the cultivation system. In addition there is a need is the art for a method providing optimal growing conditions, reducing the pollution of the water climate during hydro cultivation, preventing the development of plant diseases and reducing the chance of malnutrition during hydroculture.

It is an object of the present invention, amongst other objects, to address the above need in the art. The object of present invention, amongst other objects, is met by the present invention as outlined in the appended claims.

Specifically, the above object, amongst other objects, is met, according 10 a first aspect, by the present invention by an assembly for hydroculture of plants, wherein the assembly is comprised of a panel-shaped buoyant carrier (10) for floating on water (12), wherein the carrier (10) comprises a multitude of apertures (16), each aperture (16) for receiving and holding a plant (13) to be cultivated, wherein the plant (13) is arranged in said aperture (16) such that only the roots (14) of the plant (13) are partially submerged in water (12) and the remaining part of the roots (14) is surrounded by air present in between the surface facing the water (12) of said carrier (10) and the water surface when said carrier (10) is floating on water (12) and is holding plants in said apertures (16), characterized in that at the circumference of each aperture (10) at least one recess (11) is present for providing a gas-communication (15) between air present at the upper surface of said carrier {10) and the air surrounding the roots (14) of the plant (13).

The apertures (16) in the assembly of present invention are preferably positioned in close proximity to the plant, such that the gas exchange (air comprising O; and CO,) is optimized between the gas present below the float surrounding the roots of the plant, and the air present at the upper surface near the plant (13), creating a small microclimate that surrounds the plant (13) and roots (14) and provides optimum growth conditions.

Oxygen drives root growth daring plant cultivation, and uptake of oxygen (O2) absorbed by the root also results in the production of carbon dioxide (CO,). The roots of most plants depend on the supply of O, and the discharge of the produced CO,. This aeration process is normally distorted in hydroculture using large floats fully covering the water surface and separating the roots from the plant leaves. This will lead to the accumulation of CO, at the root of the plant, negatively affecting plant growth. In the float of present invention the aeration process can take place through apertures (16) providing a gas exchange between the atmosphere above the float and the air present below the float and in between water surface and the bottom of the float.

Therefore, oxygen transport takes place from the atmosphere present on the upper surface of the float towards the roots (14) through the apertures (16) present in the float, whereas for carbondioxide this transport is reversed. As a result, harmful gases can evaporate from the water (12), the water (12) is less prone to nutrient imbalance and accumulation of compounds within the systems such as microbial metabolites, ballast ions and root exudates is reduced. The quality of the water (12) climate can be kept up to standard and the aeration at the roots (14) is improved during hydroculture, resulting in improved plant growth.

According to a preferred embodiment, the present invention relates to the assembly, wherein at the circamference of each aperture { 16) the carrier (10) is not in direct contact with the water (12) providing a gas chamber (18) between the surface facing the water (12) of said carrier (10) and the water surface when said carrier (10) is floating on water (12) and is holding a plant (13) in said aperture (16), wherein the gas chamber (18) has a radius of at least 100%, preferably at least 120%, more preferably at least 150% of the radius of the aperture (16). The gas chamber (18) has a radius that is larger than the aperture (16) itself, to ensure that the gases can flow from the plant (13) towards the water surface and vice versa. Furthermore, during plant (13) growth, also the root structure will increase and may take up partially space of the gas chamber (18), which need to be taken into account to avoid the gas chamber (18) being blocked.

According to another preferred embodiment, the present invention relates to the assembly, wherein said at least one recess (11) has a surface area of between 15 to 35 mm’, preferably 20 to 30 mm’, more preferably 22 to 27 mm’. These recesses (11) are positioned in close proximity to the plant (13) and provide a gas connection between the air comprising CO, produced by the roots (14) of the plant (13) present below the float in the gas chamber (18), and the plant leaves that take up the CO; for their growth. The surface area (size of the recess (11)) of the at feast one recess (11) in the carrier (10) is important for the gas exchange between air located in the gas chamber (18) below the carrier (10) {or float), and the air present at the top surface of the carrier (10) where the stem and leaves of the plant (13) are located. The at least one recess (11) needs to be large enough as to ensure a proper air flow. On the other hand, there are a number of adverse consequences when the recesses (11) are too large (i.e. more than 35 mm?2 of surface area), because larger recesses (11) will result in an increase in light on the root area of the plant (13) that is provided in the float, and causing these roots (14) to dry out more quickly. In addition, an increase of light incidence on the water surface with result in an increase in algae growth. Such increase in algae growth on the water surface can be detrimental to the growth and health of the plant (13) and will also affect the gas exchange between the plant (13) and the water surface.

According to yet another preferred embodiment, the present invention relates to the assembly wherein at most 50% of the roots (14) of the plant (13) are submerged in water (12), preferably at most 60%, more preferably at most 75%, most preferably at most 90 %. In the assembly of present invention, the plants are placed in a carrier (10) which floats on in the water (12) of the hydroculture system. The plants are positioned in apertures (16) for receiving the plant

(13), such that the roots (14) of the plants are only partially located into the water (12). The carrier (10) can also be equipped with special plant modules (17) or plant holders (17) in which the plants hang above the water (12) and wherein the roots { 14) are partially located into the water (12) and maintaining the recesses (11) for gas-communication.

According to yet another preferred embodiment, the present invention relates to the assembly wherein the assembly is comprised of polyethylene. The assembly are made of whole blown plastic, namely polyethylene, a plastic that is very easy to clean and resistant to high pressure and temperature. This plastic can be cleaned very well, reducing the chance on disease and bacterial infections during cultivation. The assembly is firm and not susceptible to breaking.

This makes the assembly an improvement compared to the known styrofoam (EPS) floats.

According to yet another preferred embodiment, the present invention relates to the assembly wherein the assembly is further comprised of a multitude of plant modules (17) provided in said apertures (16) for receiving and holding the plants, and wherein said at least one recess (11) is located between said plant module (17) and said carrier (10). The plant modules (17) in the float {5 are interchangeable, This ensures that different crops in different sizes can be grown on the float while the basic flotation remains the same, e.g. adjusted to different young plant forms, making the system applicable for many different plant species. In addition, due the flexible amount of plant modules (17) and apertures (16) on a carrier (10), the density of the crop can also be varied. The distance between plant (13) and water (12) under the float can also be varied by exchanging the plant modale (17).

According to another preferred embodiment, the present invention relates to the assembly wherein at the circumference of each aperture (16) at least one rib (20) is present for engaging with the plant modules (17) and for maintaining the plant modules in a fixed position, The rib present in the aperture maintains the plant holder in place and prevents rotation or other movement of the plant or plant holder in respect to the assembly. The plant holder is kept in a fixed position by the one or more ribs.

According to yet another preferred embodiment, the present invention relates to the assembly wherein said at least one recess are two recesses, preferably four recesses, more preferably eight recesses.

The present invention, according to a second aspect, relates to a method for the cultivation of plants by hydroculture, wherein the method comprises the steps of, a) providing a water supply and an assembly of present invention floating on the water supply, b) providing at least one plant (13) in each aperture (16) of the assembly for receiving and holding a plant (13) to be cultivated, wherein the roots (14) of said plant (13) are placed in the gas chamber (18) between the surfacefacing the water (12) of the assembly and the water surface, such that at most 50% of the roots (14) of the plant (13) are submerged in water (12), preferably at most 60%. more preferably at most 75%, most preferably at most 90 %, and wherein a gas-communication (15) is provided between air 5 present at the upper surface (top surface) of said assembly and the gas chamber (18) surrounding the roots (14) of the plant (13).

According to yet another preferred embodiment, the present invention relates to the method wherein hydroculture is a Deep Flow Technology (DFT) cultivation system.

The present invention will be further detailed in the following examples and figures wherein: Figure 1: Figure 1A and 1B show an assembly for hydroculture of plants of present invention comprised of a panel-shaped buoyant carrier (10) having a multitude of apertures (16) for receiving and holding a plant (13) to be cultivated. Figure 1B shows a blow up figure of an aperture (16) for receiving and holding a plant (13) to be cultivated, wherein at the circumference of the aperture (16) at least one recess (11) is present for providing a gas channel for gas-communication between air present at the upper surface of the carrier (10) and the air surrounding the roots of the plant (13).

Figure 2: Figure 2A and 2B show the plant (13) positioned in the aperture of the carrier floating on water (12). Recesses (11) are located at the circumference of the aperture, providing a gas channel (15) for gas communication between air present at the upper surface of the carrier (10) and the air surrounding the roots (14) of the plant (13). The plant (13) is arranged in the aperture such that only the roots (14) of the plant (13) are partially submerged in water {12) and the remaining part of the roots (14) is surrounded by air that is present in between the surface facing the water (12) of the carrier and the water surface. Figure 2B shows a blow up figure of the recesses (11) present at the circamference of the aperture, when the carrier (10) is holding a plant (13) in the aperture. A gas-communication (15) is provided between air present at the upper surface (top surface) of the assembly and the gas chamber (18) surrounding the roots (14) of the plant (13).

Figure 3: Figure 3A and 3B show an embodiment of present invention, wherein the assembly further comprises a multitude of plant holders (17) that can be provided in the apertures (16) for receiving and holding the plant (13). At the circumference of the aperture (16) at least one rib (20) is present for engaging with the plant modules (17) and for maintaining the plant modules in a fixed position, preventing rotationor other movement of the plant or plant holder in respect to the assembly. Figure 3C shows a blow up figure wherein the plant holder (17) that holds a plant (13) is positioned in the aperture (16) of the carrier (10). The recesses (11) are located at the circumference of the aperture (16), between the plant holder (17) and the carrier (10), again providing a gas connection (15) between air present at the upper surface of the carrier (10) and the air surrounding the roots (14) of the plant (13) in the gas chamber (18). Figure 4: Figure 4A and B show another embodiment of present invention, wherein the assembly further comprises a multitude of plant holders (17) that can be provided in the apertures (16) for receiving and holding the plant (13). Figure 4C shows a blow up figure wherein the plant holder (17) is positioned in the aperture (16) of the carrier (10). The recesses (11) are located at the circumference of the aperture (16), between the plant holder (17) and the carrier (10), providing a gas connection (15).

Clauses 1 An assembly for hydroculture of plants, wherein the assembly is comprised of a panel- shaped buoyant carrier (10) for floating on water (12), wherein the carrier (10) comprises a multitude of apertures (16), each aperture (16) for receiving and holding a plant (13) to be cultivated, wherein the plant (13) is arranged in said aperture (16) such that only the roots (14) of the plant (13) are partially submerged in water (12) and the remaining part of the roots (14) is surrounded by air that is present in between the surface facing the water (12) of said carrier (10) and the water surface when said carrier (10) is floating on water (12) and is holding plants in said apertures (16), characterized in that at the circumference of each aperture (16) at least one recess (11) is present for providing a gas channel (15) for gas-communication between air present at the upper surface of said carrier (10) and the air surrounding the roots (14) of the plant (13).

2. The assembly according to clause 1, wherein at the circumference of each aperture (16) the carrier (10) is not in direct contact with the water (12) providing an gas chamber (18) between the surface facing the water (12) of said carrier (10) and the water surface, when said carrier (10) is floating on water {12) and is holding a plant (13) in said aperture (16), wherein the gas chamber (18) has a radius of at least 100%, preferably at least 120%. more preferably at least 150% of the radius of the aperture (16).

3. The assembly according to clause 1 or 2, wherein said at least one recess (11) has a surface area of between 15 to 35 mm’, preferably 20 to 30 mm’, more preferably 22 to 27 mm”.

4. The assembly according to any of the clauses 1 to 3, wherein at most 50% of the roots (14) of the plant (13) are submerged in water (12), preferably at most 60%, more preferably at most 75%, most preferably at most 90 %.

5. The assembly according to any of the clauses 1 to 4, wherein the assembly is comprised of polyethylene.

6. The assembly according to any of the clauses 1 to 5, wherein the assembly is further comprised of a multitude of plant modules (17) provided in said apertures (16) for receiving and holding plants, and wherein said at least one recess (11) is located between said plant module (17) and said carrier (10).

7. The assembly according to clause to 6, wherein at the circumference of each aperture (16) at least one rib (20) is present for engaging with the plant module (17) and for maintaining the plant module in a fixed position.

8. The assembly according to any of the clauses 1 to 7, wherein said at least one recess are two recesses, preferably four recesses, more preferably eight recesses.

9. A method for the cultivation of plants by hydroculture, wherein the method comprises the steps of, a) providing a water supply and an assembly according to any of the clauses 1 to 8 floating on said water supply, b) providing at least one plant (13) in each aperture (16) of the assembly for receiving and holding a plant (13) to be cultivated, wherein the roots (14) of said plant (13) are placed in the gas chamber (18) between the surface facing the water (12) of said carrier (10) and the water surface when said carrier (10) is floating on water (12), such that at most 50% of the roots (14) of the plant (13) are submerged in water (12), preferably at most 60%, more preferably at most 75%, most preferably at most 90 %, and wherein a gas-communication (15) is provided between air present at the upper surface of said assembly and the gas chamber (18) surrounding the roots (14) of the plant (13).

10. The method according to clause 9, wherein hydroculture is a Deep Flow Technology (DFT) cultivation system,

Claims (10)

Conclusions A plant hydroponic assembly, the assembly comprising a panel-shaped floating support (10) for floating on water (12), the support (10) comprising a plurality of openings (16), each opening (16) is suitable for receiving and holding a plant (13) to be grown, the plant (13) being arranged in the opening (16) such that only the roots (14) of the plant (13) are partially submerged in water ( 12) and the remaining part of the roots (14) is surrounded by air that is present between the surface of the support (10) facing the water (12) and the water surface when the support (10) is floating on water (12) and planting in said openings (16), characterized in that in the periphery of each opening (16) there is at least one recess (11) for providing a gas channel (15) for gas communication between air present at the top surface of the said carrier (10) and the air entering the roots (14) of surrounds the plant (13). An assembly according to claim 1, wherein at the periphery of each opening (16) the carrier (10) is not in direct contact with the water (12) providing a gas chamber (18) between the water-facing surface (12). of said support (10) and the water surface, when said support (10) floats on water (12) and holds a plant (13) in said opening (16), the gas chamber (18) having a radius of at least 100% , preferably at least 120%, more preferably at least 150% of the radius of the opening (16). Assembly according to claim 1 or 2, wherein the at least one recess (11) comprises a surface area of bags 15 and 35 mm, preferably 20 to 30 mm ", more preferably 22 to 27 mm". Assembly according to any one of claims 1 to 3, wherein at most 50% of the roots (14) of the plant (13) are submerged in water (12), preferably at most 60%, more preferably at least highest 75%. %, most preferably at most 90%. Assembly according to any of claims 1 to 4, wherein the assembly comprises polyethylene. An assembly according to any of claims 1 to 5, wherein the assembly further comprises a plurality of plant modules (17) provided in said openings (16) for receiving and holding plants, and wherein said at least one recess (11) is located between the planting module (17) and the carrier (10). An assembly according to claim 6, wherein at least one rib (20) is present in the circumference of each opening (16) to engage the plant module (17) and hold the plant module in a fixed position. Assembly according to any one of claims 1 to 7, wherein said at least one recess are two recesses, preferably four recesses, more preferably eight 10 recesses. A method of growing plants by hydroponics, the method comprising the steps of, a) providing a water supply and an assembly according to any of the claims | to 8 floating on said water supply, b) providing at least one plant (13) in each opening (16) of the assembly for receiving and holding a plant (13) to be grown, the roots (14) ) of the plant (13) are placed in the gas chamber (18) between the surface of the support (10) facing the water (12) and the water surface when the support (10) is floating on water (12), such that at least at most 50% of the roots (14) of the plant (13) are immersed in water (12), preferably at most 60%, more preferably at most 75%, most preferably at most 90%, and wherein a gas communication (15) is provided between the top surface of the assembly and the gas chamber (18) surrounding the roots (14) of the plant (13). The method of claim 9, wherein hydroponics is a Deep Flow Technology (DFT) cultivation system.