CH718251A2 - Method and device for soilless culture. - Google Patents

Abstract

The present invention relates to an above-ground cultivation device comprising: at least one rail (2) arranged to be mounted above a nutrient basin (11); a plurality of rigid structures (3) sliding along said at least one rail (2) each structure (3) being equipped with several plant supports (31) arranged so that plants in said supports (31) can feeding in said basin (11); a plurality of floating elements arranged to cover said nutrient pool (11) to limit exposure of the nutrient pool (11) to a light source. The present invention also relates to a method of soilless cultivation, comprising the following steps: planting plants in plant supports (31) mounted on rigid structures (3) sliding along rails (2) above a nutrient pond (11) so that the plants can feed on nutrients in said pond (11); covering the surface of said nutrient pool (11) with a plurality of floating elements so as to limit direct exposure of the nutrient pool (11) to a light source; spacing said rigid supports (3) from each other when the plants grow.

Description

Technical area

The present invention relates to a method and a device for aboveground culture, in particular a method and a device for hydroculture.

State of the art

[0002] Traditional techniques for growing vegetables in the ground are limited in the management of production areas in that the space available for each plant is predetermined and can only be adapted as the plant grows at the cost of an individual movement of each plant. This process allows a densification of cultures, but is expensive and tedious, as well as potentially harmful for the plant because it induces a risk of deterioration during handling.

[0003] The same observation is valid for above-ground crops, particularly in hydroculture, where the adaptability of the production surfaces is only possible at the cost of manual and individual movement of each plant.

[0004] Some hydroculture systems are based on the use of a basin containing a nutrient solution. The crops are placed on the surface of the basin in plastic supports that do not allow the distances between the plants to be easily adapted.

Another obstacle to increasing productivity in this type of system lies in the exposure of the nutrient solution of the basins to a natural or artificial light source. Indeed, this exposure promotes on the one hand the proliferation of algae reducing the oxygen supply for the crops and on the other hand the evaporation of the nutrient solution itself. On areas of up to several hectares, these two problems can be extremely costly.

[0006] Document WO 2017/000046 A1 describes a hydroculture device in which plants are grown in a plurality of mobile gutters. A nutrient solution circulates in each gutter so as to feed the plants and the gutters can be moved along a guide so that the distance between two gutters can be adjusted. In addition, two types of gutters are arranged along the guide. The first type contains plant supports close to each other and intended to receive seedlings or small plants. The second type contains plant supports spaced further apart from each other and intended to accommodate larger plants.

This device requires manual transplantation of plants contained in the first type of gutter in the second type of gutter, which must be operated manually.

Brief summary of the invention

An object of the present invention is to provide an above-ground cultivation device to increase productivity, that is to say the number of plants grown per square meter.

Another object of the invention is to provide an above-ground cultivation device comprising a nutrient basin, making it possible to limit the spread of harmful algae in the basin, and to reduce the evaporation of the nutrient solution due to exposure to a light energy source such as the sun.

[0010] A third object of the invention is to provide an above-ground cultivation method comprising a step of adapting the cultivation surfaces so as to rationalize the production space.

[0011] Finally, a fourth object of the invention is to provide an above-ground culture method comprising a step for protecting the nutrient culture medium making it possible to limit or even eliminate the propagation of algae and to reduce evaporation. of the nutrient medium.

[0012] According to the invention, the first object is achieved by means of a mobile culture support making it possible to bring the rows of culture closer together, respectively away from them, depending on the space necessary for their optimal growth. Indeed, in the case of a lettuce, for example, the space required by the plant for its ideal development increases as it grows. In addition, once the harvest is done, a new cultivation cycle begins again with the introduction of young lettuce plants, which no longer require so much space. This mobile support device therefore makes it possible to develop the culture space as closely as possible to its needs while rationalizing it.

This culture medium comprises a plurality of rigid structures sliding horizontally on a system of rails fixed to the basin. These rigid structures comprise several plant supports themselves comprising a container intended to accommodate the plants and a tubular part which allows the plant to have direct access to the nutrient solution.

[0014] The second object is achieved thanks to the introduction of floating elements on the surface of the nutrient pool, making it possible to limit or even eliminate the direct exposure of the nutrient solution to a source of light energy such as the sun. or grow lights.

[0015] This dynamic system of floating elements can be constituted in one embodiment of plastic floating balls.

[0016] In another embodiment, the floating balls can be replaced by hexagonal elements provided with bevelled edges to obtain a "honeycomb" structure on the surface of the basin.

[0017] According to the invention, the third object is achieved by means of a step of reconfiguring the culture support by distancing, respectively bringing together, the rows of culture between them, as well as by adding and deleting rows of culture. In particular, during this stage, plants are placed on several rigid supports sliding along a system of rails, which allows them to be moved away from each other as they grow.

The fourth object of this invention is achieved thanks to a step of covering the culture basin with floating elements intended to limit the exposure of the nutrient solution to a source of light energy such as the sun or lamps. culture in order to limit the proliferation of algae in the nutrient basin and to limit the evaporation of the nutrient solution.

[0019] This solution has the particular advantage over the prior art of solving the problem of the spacing between the crops without having to handle the plants themselves, which represents not only a considerable time saving but also a reduced stress for each plant and therefore better growth.

[0020] This solution also has the advantage of limiting the need for cleaning the nutrient basin, given that the quantity of algae is significantly reduced.

Another advantage of this solution lies in a minimization of the nutrient solution intake due to the limitation of its evaporation.

Brief description of figures

[0022] Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which: FIG. 1 illustrates a longitudinal section of an embodiment of the aforementioned hydroculture device. • Figure 1 illustrates a cross section of an embodiment of the aforementioned hydroculture device. • Figure 3 illustrates two top views (3a and 3b) of two possible arrangements of rigid structures arranged on two rails. • Figure 4 illustrates a top view of an embodiment of a floating element in the form of a hexagon with bevelled edges. • Figure 5 illustrates a side view of a device for moving rigid structures.

Example(s) of embodiment of the invention

The present invention relates to an above-ground cultivation device comprising at least one rail arranged to be mounted above a nutrient basin, a plurality of rigid structures sliding along said at least one rail, each structure being equipped several plant supports arranged so that plants in said supports can feed in said basin. The present invention also comprises a plurality of floating elements arranged so as to cover said nutrient basin to limit the exposure of the nutrient basin to a light source.

In one embodiment of the invention illustrated in Figure 1, the aboveground culture device comprises a hydroculture nutrient basin 11 having a width of approximately between 1 m and 20 m wide and a length of between between 5 m and 200 m, which is filled with a nutrient solution 12. The depth of the basin is between 20 cm and 100 cm. In a preferred variant, the basin 11 has a depth of approximately 40 cm so as to be filled to a height of approximately 30 cm with nutrient solution 12 and to provide an emerged space of approximately 10 cm.

The rail

According to the invention, at least one rail is arranged above a nutrient basin. In one embodiment illustrated in Figures 1 and 2, two parallel rails 2 are supported by vertical tubes 21 anchored in concrete pads 22 placed at the bottom of the nutrient basin 11.

In the embodiment illustrated in Figure 1, the rails 2 are fixed in a first part of the basin 11 so as to be flush with the surface of the nutrient solution 12 filling the basin. This first part, on the left in FIG. 1, corresponds for the plant grown to the seedling and/or young shoots stage. Young plants with short roots thus have guaranteed access to the nutrient solution 12. In a second part of the basin, the rails 2 are fixed so as to form an angle with the surface of the basin so that they move away from the nutrient solution 12. Finally, in a third part of the basin, the two rails 2 are fixed so as to be parallel to the surface of the basin 11 at a distance from the nutrient solution 12 making it possible to maximize the supply of oxygen for the roots plants at a later stage of growth.

[0027] More generally, an unlimited number of rails can be installed on larger basins in order to guarantee adequate support for the rigid structures carrying the plant supports. The rails can be fixed at any height deemed useful by those skilled in the art.

For the purpose of simplifying the description, it will be assumed below that the device described comprises two parallel rails as illustrated in FIG. 2, although the invention may comprise an arbitrary number of rails depending on requirements.

Rigid structures

According to the invention, a plurality of rigid structures is arranged on the rail system described above. In one embodiment shown in Figure 2, each rigid structure 3 extends perpendicular to the rails 2 over a portion of the width of the pool 11. Preferably, each rigid structure 3 extends over the entire width of the pool to maximize crop density. The rigid structures 3 are fixed to the rails 2 so as to be able to slide along them over a portion of the length of the basin 11, preferably over the entire length of the basin to allow easy access to the plants during the steps planting and/or harvesting.

Each rigid structure 3 comprises several plant supports 31, each plant support 31 being intended to receive at least one plant.

In one embodiment shown in Figures 1 and 2, each plant support 31 comprises container 311 on the upper surface of the rigid structure 3 intended to receive a plant and a tubular part 312 extending vertically from the surface bottom of the rigid structure 3 so as to allow access to the nutrient solution 12 for the roots of a plant. The tubular part 312 also makes it possible to protect the roots during a displacement of the rigid structure 3 on the surface of the pool 11.

As illustrated in Figure 3, the plant supports 31 can be staggered on two successive rigid structures 3 so as to increase the density of plants per square meter. Indeed, such an arrangement allows a configuration in which the rigid structures 3 are closer to each other, especially when the plants are still at an early stage of development.

The distance between two successive rigid structures 3 depends on the growth stage of the plants supported. In a preferred embodiment of the invention illustrated in Figure 1, lettuces are introduced at the stage of young plants in plant supports 31 on a rigid structure 3, itself arranged on two rails 2. At the end of the basin 11 in which the young lettuce shoots are located, corresponding to the left end in FIG. 1, the rails 2 are fixed so as to be flush with the surface of a nutrient solution 12 filling the basin 11, so that young lettuce shoots have easy access to the nutrient solution. After a certain time, the rigid structure is moved along the rails 2 by sliding and a new rigid structure is placed at the end of the basin in order to be able to receive new young plants. As the lettuces grow, the space provided between the rigid structures 3 during sliding also increases to allow optimal growth. Moreover, when the lettuce roots are long enough, the rails 2 supporting the rigid structures 3 gradually move away from the surface of the nutrient solution 12 in order to optimize the oxygen supply for the lettuce roots. The rigid structures 3 thus travel the entire length of the basin 11 by sliding. Finally, the lettuces lying on a rigid structure at the other end of the basin, corresponding to the right end in FIG. 1, are harvested.

Figure 3 illustrates two different configurations of rigid structures 3 on two rails 2 depending on the stage of growth of the plants supported. On the left end of FIG. 3a, six rigid structures each comprising five or six plant supports accommodate young shoots requiring no spacing between the rigid structures. In an intermediate part, six new rigid structures accommodate plants in an intermediate stage of growth requiring greater spacing between the rigid structures. Finally, a third portion of the two rails 2 is occupied by six rigid structures spaced apart from each other so as to provide sufficient space for the plants that have reached a stage close to harvesting.

In Figure 3b, another configuration of rigid structures is shown. This configuration is obtained by starting from the configuration represented in FIG. 3a and by applying the following steps: harvesting the plants on the two rigid structures at the right end in FIG. 3a; remove the two now empty rigid structures at the right end in Figure 3a; slide all the other rigid structures to the right, adapting the spacing to the development stage of the plants. As two rigid structures have been removed in the operation, there is more room to space the remaining rigid structures.

Floating elements

According to the invention, a plurality of opaque floating elements is arranged on the surface of the nutrient basin to limit the exposure of the nutrient basin to a light and/or thermal source. Exposure to sunlight or artificial light in a greenhouse promotes the growth of algae in the nutrient pool as well as the evaporation of the nutrient solution. This plurality of floating elements makes it possible to cover the nutrient basin dynamically, that is to say to limit the exposure of the nutrient solution to a source of light energy by covering it, while allowing sliding of the structures rigid without having to intervene manually at the level of the elements covering the nutrient solution.

[0037] The presence of algae in the nutrient basin is harmful for the development of the plants because part of the oxygen necessary for the roots of the plants is monopolized by the algae, thus slowing down the development of the crops. Limiting, or even eliminating, the light exposure of the nutrient solution with the aid of the aforementioned floating elements makes it possible to fight effectively against the proliferation of these algae.

The natural evaporation of the nutrient solution linked to its exposure to a source of light energy such as the sun outdoors or grow lamps inside greenhouses can reach several centimeters per day in summer. The floating elements described above make it possible to limit this evaporation.

In one embodiment shown in Figures 1 and 2, the floating elements consist of balls 4 of opaque plastic forming a floating mat on the surface of the nutrient basin 11. Their diameter can vary between about 5 mm and about 50 mm for a density per square meter varying between around 11,500 beads/m<2> for beads 10 mm in diameter and around 459 beads/m<2> for beads 50 mm in diameter.

[0040] The opacity of the floating elements makes it possible to prevent the proliferation of algae as well as the natural evaporation of the nutrient solution. Indeed, the appearance of algae is mainly due to the joint presence of water and light. Thus, the opacity of the floating elements drastically limits, or even eliminates, the supply of direct light to the nutrient solution. Similarly, evaporation is due to the interface between the solution and air, preferably dry. The floating mat formed by the floating elements significantly limits this interface and therefore evaporation. The balls 4 of smaller diameters fill a greater percentage of the surface of the basin 11 but are also more expensive per square meter. A combination of balls 4 having different diameters is also possible to combine the advantages.

In one embodiment, the plastic balls 4 are made of polypropylene or high density polyethylene both having a density less than 1, so that they float on water. This low density allows the use of solid balls, which are less expensive to produce than hollow balls obtained by blow molding. An additive can be added to the plastic so as to reduce its density and reduce the submerged part of the beads. In order to maximize resistance to UV radiation, the plastic material may be a UV blocking polymer.

The balls 4 are arranged on the surface of the nutrient solution filling the basin so as to form an opaque floating mat. This carpet arrangement makes it possible to slide the rigid structures 3 along the rails without hindrance. Indeed, the balls 4 deviate naturally as they pass the submerged tubular parts 312 of each plant support 31 and close naturally afterwards so that the floating mat regains a homogeneous shape on the surface after displacement of a rigid structure 3.

In another embodiment, the floating elements consist of opaque hexagons 5, illustrated in Figure 4, polymer such as for example polypropylene, high density polypropylene or other type of suitable polymers. These hexagons have a diameter of between approximately 20 mm and approximately 100 mm, preferably a diameter approximately equal to 35 mm. The thickness of the hexagons is between approximately 5 mm and approximately 50 mm, preferably approximately equal to 35 mm. Arranged on the surface of the basin, the hexagons 5 form a "honeycomb" structure covering the entire nutrient basin 11.

To improve buoyancy, the hexagons 5 may contain a core filled with a mixture of polymer and blowing agent. This technique allows a supply of air bubbles within the material and therefore an improvement in the buoyancy of the hexagons via the reduction in the total density. In a preferred embodiment, the density of the polymer is such that the honeycomb structure formed by the hexagons emerges at the surface of the basin. However, it is possible for the honeycomb structure to be slightly submerged if the density of the polymer is slightly lower.

Each hexagon 5 has several edges 51 extending radially on each of its two surfaces. These edges 51 are bevelled so as to be higher in the center of the hexagon and lower on its perimeter. This configuration allows the hexagons 5 to regain their honeycomb structure after passing through a rigid structure. Indeed, when a rigid structure 3 is moved, the submerged tubular part 312 of a plant support 31 moves the hexagons on top of each other. The bevelled edges 51 allow a hexagon that has been pushed onto another hexagon to slide along these edges to regain its place on the surface of the nutrient basin 11, thus reconstituting the honeycomb structure.

Robotization

The rigid structures 3 can be moved by a robot.

In a particular embodiment illustrated in Figure 5, such a robot comprises a traveling crane arranged above the nutrient basin 11, in the axis of the length of the basin, to which is fixed an arm 65 intended to drive the rigid structures 3 along the rail 2. More specifically, the end of the arm used to slide the rigid structures comprises a displacement module 6 comprising a base 61 parallel to the surface of the pool placed slightly above the plants on which are fixed two cylinders 62 movable vertically on either side of the base 61. By moving vertically in the direction of the ground, these cylinders 62 are temporarily fixed on a movable shuttle 63 located below the rigid structures 3 in order to allow a movement of the shuttle 63 parallel to the rails. This shuttle 63 is provided on its upper surface with a stop 64 which drives a rigid structure 3 when the mobile shuttle is moved by the cylinders 62, themselves driven by the base 61 fixed to the arm 65.

The stop 64 is configured such that it can pass under the rigid structures 3 when it is moved in one direction and that it catches the structures when it is moved in the opposite direction. Such a configuration can be obtained for example by a stop 64 fixed to the shuttle 63 by a pivot allowing it to pivot by 90°, i.e. to lie down, when it comes into contact with a rigid structure 3 so as to pass under the structure when the shuttle 63 is moved in one direction, and on the contrary to remain in a vertical position when it comes into contact with a rigid structure 3 when the shuttle 63 is moved in the opposite direction.

In order to simplify the explanation of a mode of use of the robot, it will be agreed that the end of the basin corresponding to the stage of harvesting is the right end of the basin while the end corresponding to the stage of planting of the plants will be the left end of the basin as shown in Figure 1. The layout can be reversed.

In an example of using the robot to move the rigid structures 3, the arm 65 is arranged, at the start of the maneuver, above the first rigid structure located at the right end of the basin, the cylinders 62 being in the raised position on the base 61, that is to say in a position allowing the arm 65 driven by the overhead crane to circulate freely above the basin 11. The shuttle 63 is located below this first rigid structure, the abutment 64 being located on the left side of this rigid structure. In order to move the rigid structure to the right, the left cylinder 62 is lowered until it is fixed in the shuttle 63 and the right cylinder 62 is maintained in its raised position. The arm 65 is then moved by the overhead crane to the right, carrying with it the rigid structure 3 pushed by the stop 64 of the shuttle 63. Once the structure has been moved to the desired location, the overhead crane sets off again towards the left so as to place the shuttle between the first and the second structure. The left cylinder is then raised so as to be able to pass over the second structure and the right cylinder lowered to drive the shuttle to the left and place it under the second structure with the stop on the left side. Finally, the left cylinder is lowered and the arm moved to the right so as to drive the second structure to the right. This operation is then repeated as many times as necessary to move all or part of the structures to the right. When all the structures have been moved, the shuttle is lifted by the robotic arm and brought back to the right end of the pool so that a movement cycle can be started again.

In an alternative embodiment, not shown, of the robotic system for moving rigid structures, the shuttle is driven by a belt inside the rail. There is then no longer any need for an overhead crane or an arm.

The system described above driving the rigid structures along the rail can be provided with a spray boom for watering and/or treating the plants. A floating element cleaning system can also be fitted to the robotic arm.

Reference numbers used in the figures

[0053] 1 Above-ground culture device 11 Nutrient basin 12 Nutrient solution 2 Rail 21 Vertical tube 22 Concrete pad 3 Rigid structure 31 Plant support 311 Plant container 312 Tubular part 4 Opaque floating ball 5 Opaque floating hexagon 51 Bevelled edge 6 Movement module 61 Base 62 Cylinder 63 Mobile shuttle 64 Stopper 65 Arm

Claims (14)

1. Above-ground culture device (1) comprising: at least one rail (2) arranged to be mounted above a nutrient basin (11); a plurality of rigid structures (3) sliding along said at least one rail (2), each structure (3) being equipped with several plant supports (31) arranged so that plants in said supports can feed in said basin (11); a plurality of floating elements arranged to cover said nutrient pool (11) to limit exposure of the nutrient pool to a light source. 2. Device according to claim 1, wherein each said plant support (31) comprises: a container (311) intended to receive a plant, a tubular part (312), fixed by one of its ends below said container (311), the other end being intended to be immersed in the basin (11), so as to allow direct vertical access between said container and said nutrient basin. 3. Device according to one of the preceding claims, wherein the plurality of floating elements consists of opaque balls (4) of diameters between about 5 mm and about 50 mm. 4. Device according to claim 3, wherein said opaque balls (4) are made of polypropylene or high density polyethylene. 5. Device according to one of the preceding claims, in which the plurality of floating elements consists of opaque hexagons (5) comprising bevelled edges (51), of diameters between approximately 20 mm and approximately 100 mm and of thickness between about 5 mm and about 50 mm. 6. Device according to one of the preceding claims, in which the arrangement of the plant supports (31) of a rigid structure (3) with respect to the plant supports of the adjacent rigid structures is staggered so as to be able to reduce the spacing between rigid structures. 7. Device according to one of the preceding claims, wherein said at least one rail (2) is arranged so as to provide several levels for the rigid structures (3) so as to be able to adapt the height of the rigid structures relative to the surface of said nutrient basin (11) according to the growth stages of the plants. 8. Device according to one of the preceding claims, wherein the plurality of rigid structures (3) can be moved automatically by a robotic system. 9. Device according to the preceding claim, wherein said robotic system comprises a traveling crane parallel to at least one rail (2) supporting a robotic arm (65) configured to cause said rigid structures (3) to slide along said at least one rail. 10. Device according to the preceding claim, wherein said robotic system comprises a shuttle (63) fixed to said robotic arm (65) and sliding parallel to said at least one rail (2), under said rigid structures (3), said shuttle (63 ) comprising on an upper face a stop (64) configured to drive a rigid structure (3) when the shuttle is moved in one direction and to pass under a rigid structure when it is moved in the other direction. 11. Device according to the preceding claim, wherein said shuttle (63) is temporarily fixed to the robotic arm (65) by two jacks (63) movable perpendicularly to a plane containing the rigid structures (3), said jacks (62) being configured to be able to rise and lower so that the shuttle (63) is always driven by at least one cylinder. 12. Above-ground culture method, comprising the following steps: planting seedlings in seedling supports (31) mounted on rigid structures (3) sliding along at least one rail (2) above a nutrient basin (11), so that the seedlings can feed on nutrients in said pond; covering the surface of said nutrient pool (11) with a plurality of floating elements so as to limit direct exposure of the nutrient pool to a light source; spacing said rigid structures (3) from each other when the plants grow. 13. Method of above-ground culture according to the preceding claim, in which said plants are planted at different times according to the rigid structure (3), so that at each moment certain rigid structures close to each other carry young plants while other rigid structures more spaced from each other on the same basin (11) carry older plants. 14. Method according to one of claims 12 to 13, wherein the step of spacing said rigid structures (3) is automated.